Background:

Higher trust in healthcare providers has been linked to better health outcomes and satisfaction. Lower trust has been associated with healthcare-based discrimination.

The pursuit of harnessing data for knowledge creation has been an enduring quest, with the advent of machine learning (ML) and artificial intelligence (AI) marking significant milestones in this journey. ML, a subset of AI, emerged as the practice of employing mathematical models to enable computers to learn and improve autonomously based on their experiences. In the pharmaceutical and biopharmaceutical sectors, a significant portion of manufacturing data remains untapped or insufficient for practical use. Recognizing the potential advantages of leveraging the available data for process design and optimization, manufacturers face the daunting challenge of data utilization. Diverse proprietary data formats and parallel data generation systems compound the complexity. The transition to Pharma 4.0 necessitates a paradigm shift in data capture, storage, and accessibility for manufacturing and process operations. This paper highlights the pivotal role of AI in converting process data into actionable knowledge to support critical functions throughout the whole product life cycle. Furthermore, it underscores the importance of maintaining compliance with data integrity guidelines, as mandated by regulatory bodies globally. Embracing AI-driven transformations is a crucial step toward shaping the future of the pharmaceutical industry, ensuring its competitiveness and resilience in an evolving landscape.

Visible particle is an important issue in the biopharmaceutical industry, and it may occur across all the stages in the life cycle of biologics. Upon the occurrence of visible particles, it is often necessary to conduct chemical identification and root cause analysis to safeguard the safety and efficacy of the biotherapeutic products. In this article, we present a number of typical particles and relevant root cause analysis in the categories of extrinsic, intrinsic, and inherent particles that are commonly encountered in the biopharma industry. In particular, the optical images of particles obtained both in situ and after isolation are provided, along with spectral and elemental information. The particle identification was carried out with multiple microscopic and microspectroscopic techniques, including stereo optical microscopy, Fourier-transform infrared microscopy, confocal Raman microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Both commercial and in-house spectral databases were used for comparison and identification. In addition to particle identification, we placed significant efforts on the root cause analysis of the addressed particles with the intention to provide a relatively whole picture of the particle-related issues and practical references to particle mitigation for our peers in the biopharmaceutical industry.

Obidoxime chloride is an antidote for nerve gas intoxication. As an emergency medicine, it is being stored by the Israel Defense Forces (IDF) scattered throughout Israel in depots without a controlled environment (field conditions), thus being exposed to high and fluctuating temperatures. These conditions do not meet the manufacturer’s requirements. In addition, due to possible supply shortages, the utilization of expired batches was suggested. The current work investigated these matters. Long-term (15 years) storage under different conditions was initiated. Chemical stability and toxicity in rats were assessed. No difference was found between field conditions vs the controlled environment. The obidoxime assay remained >95% for 5 years and >90% for 7 years. The pH remained above the lower specification limit for 7–8 years. The major degradation product, 4-pyridinealdoxime, surpassed the allowed limit at 5 years. The content of total unknown impurities reached its maximum allowed by the IDF limit at 4–5 years. Threefold higher than clinically utilized doses of valid-to-date Toxogonin batches administered to rats did not cause any abnormality. However, expired batches produced significant toxic effects. Although no difference was found between storage of obidoxime ampoules when adhering to manufacturer’s recommendations vs field conditions, accumulation of degradants over the limit allowed by the IDF at 4–5 years of storage and the toxicity of the expired batches observed in rats led the IDF to a decision to shorten the shelf-life of this product from 5 to 4 years when stored in an uncontrolled environment of the Mediterranean climate.

Caenorhabditis elegans is an important model organism for human health and disease, with foundational contributions to the understanding of gene expression and tissue patterning in animals. An invaluable tool in modern gene expression research is the presence of a high-resolution ribosome structure, though no such structure exists for C. elegans. Here, we present a high-resolution single-particle cryogenic electron microscopy (cryo-EM) reconstruction and molecular model of a C. elegans ribosome, revealing a significantly streamlined animal ribosome. Many facets of ribosome structure are conserved in C. elegans, including overall ribosomal architecture and the mechanism of cycloheximide, whereas other facets, such as expansion segments and eL28, are rapidly evolving. We identify uL5 and uL23 as two instances of tissue-specific ribosomal protein paralog expression conserved in Caenorhabditis, suggesting that C. elegans ribosomes vary across tissues. The C. elegans ribosome structure will provide a basis for future structural, biochemical, and genetic studies of translation in this important animal system.

End-to-end RNA-sequencing methods that capture 5'-sequence content without cumbersome library manipulations are of great interest, particularly for analysis of long RNAs. While template-switching methods have been developed for RNA sequencing by distributive short-read RTs, such as the MMLV RTs used in SMART-Seq methods, they have not been adapted to leverage the power of ultraprocessive RTs, such as those derived from group II introns. To facilitate this transition, we dissected the individual processes that guide the enzymatic specificity and efficiency of the multistep template-switching reaction carried out by RTs, in this case, by MarathonRT. Remarkably, this is the first study of its kind, for any RT. First, we characterized the nucleotide specificity of nontemplated addition (NTA) reaction that occurs when the RT extends past the RNA 5'-terminus. We then evaluated the binding specificity of specialized template-switching oligonucleotides, optimizing their sequences and chemical properties to guide efficient template-switching reaction. Having dissected and optimized these individual steps, we then unified them into a procedure for performing RNA sequencing with MarathonRT enzymes, using a well-characterized RNA reference set. The resulting reads span a six-log range in transcript concentration and accurately represent the input RNA identities in both length and composition. We also performed RNA-seq from total human RNA and poly(A)-enriched RNA, with short- and long-read sequencing demonstrating that MarathonRT enhances the discovery of unseen RNA molecules by conventional RT. Altogether, we have generated a new pipeline for rapid, accurate sequencing of complex RNA libraries containing mixtures of long RNA transcripts.

The noncoding RNA BC200 is elevated in human cancers and is implicated in translation regulation as well as cell survival and proliferation. Upon BC200 overexpression, we observed correlated expression of a second, smaller RNA species. This RNA is expressed endogenously and exhibits cell-type-dependent variability relative to BC200. Aptamer-tagged expression constructs confirmed that the RNA is a truncated form of BC200, and sequencing revealed a modal length of 120 nt; thus, we refer to the RNA fragment as BC120. We present a methodology for accurate and specific detection of BC120 and establish that BC120 is expressed in several normal human tissues and is also elevated in ovarian cancer. BC120 exhibits remarkable stability relative to BC200 and is resistant to knockdown strategies that target the 3' unique sequence of BC200. Combined knockdown of BC200 and BC120 exhibits greater phenotypic impacts than knockdown of BC200 alone, and overexpression of BC120 negatively impacts translation of a GFP reporter, providing insight into a potential translational regulatory role for this RNA. The presence of a novel, truncated, and stable form of BC200 adds complexity to the investigation of this noncoding RNA that must be considered in future studies of BC200 and other related Alu RNAs.

Vault RNAs (vtRNAs) are evolutionarily conserved small noncoding RNAs transcribed by RNA polymerase III. Vault RNAs were initially described as components of the vault particle, but have since been assigned multiple vault-independent functions, including regulation of PKR activity, apoptosis, autophagy, lysosome biogenesis, and viral particle trafficking. The full-length transcript has also been described as a noncanonical source of miRNAs, which are processed in a DICER-dependent manner. As central molecules in vault-dependent and independent processes, vtRNAs have been attributed numerous biological roles, including regulation of cell proliferation and survival, response to viral infections, drug resistance, and animal development. Yet, their impact to mammalian physiology remains largely unexplored. To study vault RNAs in vivo, we generated a mouse line with a conditional Vaultrc5 loss-of-function allele. Because Vaultrc5 is the sole murine vtRNA, this allele enables the characterization of the physiological requirements of this conserved class of small regulatory RNAs in mammals. Using this strain, we show that mice constitutively null for Vaultrc5 are viable and histologically normal but have a slight reduction in platelet counts, pointing to a potential role for vtRNAs in hematopoiesis. This work paves the way for further in vivo characterizations of this abundant but mysterious RNA molecule. Specifically, it enables the study of the biological consequences of constitutive or lineage-specific Vaultrc5 deletion and of the physiological requirements for an intact Vaultrc5 during normal hematopoiesis or in response to cellular stresses such as oncogene expression, viral infection, or drug treatment.

Bacterial regulatory RNAs (sRNAs) are important players to control gene expression. In Staphylococcus aureus, SprC is an antivirulent trans-acting sRNA known to base-pair with the major autolysin atl mRNA, preventing its translation. Using MS2-affinity purification coupled with RNA sequencing, we looked for its sRNA-RNA interactome and identified 14 novel mRNA targets. In vitro biochemical investigations revealed that SprC binds two of them, czrB and deoD, and uses a single accessible region to regulate its targets, including Atl translation. Unlike Atl regulation, the characterization of the SprC-czrB interaction pinpointed a destabilization of the czrAB cotranscript, leading to a decrease of the mRNA level that impaired CzrB zinc efflux pump expression. On a physiological standpoint, we showed that SprC expression is detrimental to combat against zinc toxicity. In addition, phagocyctosis assays revealed a significant, but moderate, increase of czrB mRNA levels in a sprC-deleted mutant, indicating a functional link between SprC and czrB upon internalization in macrophages, and suggesting a role in resistance to both oxidative and zinc bursts. Altogether, our data uncover a novel pathway in which SprC is implicated, highlighting the multiple strategies used by S. aureus to balance virulence using an RNA regulator.

The SARS-CoV-2 frameshifting element (FSE) has been intensely studied and explored as a therapeutic target for coronavirus diseases, including COVID-19. Besides the intriguing virology, this small RNA is known to adopt many length-dependent conformations, as verified by multiple experimental and computational approaches. However, the role these alternative conformations play in the frameshifting mechanism and how to quantify this structural abundance has been an ongoing challenge. Here, we show by DMS and dual-luciferase functional assays that previously predicted FSE mutants (using the RAG graph theory approach) suppress structural transitions and abolish frameshifting. Furthermore, correlated mutation analysis of DMS data by three programs (DREEM, DRACO, and DANCE-MaP) reveals important differences in their estimation of specific RNA conformations, suggesting caution in the interpretation of such complex conformational landscapes. Overall, the abolished frameshifting in three different mutants confirms that all alternative conformations play a role in the pathways of ribosomal transition.

SEquence Evaluation through k-mer Representation (SEEKR) is a method of sequence comparison that uses sequence substrings called k-mers to quantify the nonlinear similarity between nucleic acid species. We describe the development of new functions within SEEKR that enable end-users to estimate P-values that ascribe statistical significance to SEEKR-derived similarities, as well as visualize different aspects of k-mer similarity. We apply the new functions to identify chromatin-enriched lncRNAs that contain XIST-like sequence features, and we demonstrate the utility of applying SEEKR on lncRNA fragments to identify potential RNA-protein interaction domains. We also highlight ways in which SEEKR can be applied to augment studies of lncRNA conservation, and we outline the best practice of visualizing RNA-seq read density to evaluate support for lncRNA annotations before their in-depth study in cell types of interest.

Non-invasive ventilation (NIV) is the mainstay to treat patients who need augmentation of ventilation for acute and chronic forms of respiratory failure. The last several decades have witnessed an extension of the indications for NIV to a variety of acute and chronic lung diseases. Evolving advancements in technology and personalised approaches to patient care make it feasible to prioritise patient-centred care models that deliver home-based management using telemonitoring and telemedicine systems support. These trends may improve patient outcomes, reduce healthcare costs and improve the quality of life for patients who suffer from chronic diseases that precipitate respiratory failure.

Background

Halm's clinical stability criteria have long guided antibiotic treatment and hospital discharge decisions for patients hospitalised with community-acquired pneumonia (CAP). Originally introduced in 1998, these criteria were established based on a relatively small and select patient population. Consequently, our study aims to reassess their applicability in the management of CAP in a contemporary real-world setting.

Organic anion transporting polypeptide (OATP) 1B1 and OATP1B3 are important hepatic transporters. We previously identified OATP1B3 being critically implicated in the disposition of abiraterone. We aimed to further investigate the effects of abiraterone on the activities of OATP1B1 and OATP1B3 utilizing a validated endogenous biomarker coproporphyrin I (CP-I). We used OATP1B-transfected cells to characterize the inhibitory potential of abiraterone against OATP1B-mediated uptake of CP-I. Inhibition constant (K_i) was incorporated into our physiologically based pharmacokinetic (PBPK) modeling to simulate the systemic exposures of CP-I among cancer populations receiving either our model-informed 500 mg or clinically approved 1000 mg abiraterone acetate (AA) dosage. Simulated data were compared with clinical CP-I concentrations determined among our nine metastatic prostate cancer patients receiving 500 mg AA treatment. Abiraterone inhibited OATP1B3-mediated, but not OATP1B1-mediated, uptake of CP-I in vitro, with an estimated K_i of 3.93 μM. Baseline CP-I concentrations were simulated to be 0.81 ± 0.26 ng/ml and determined to be 0.72 ± 0.16 ng/ml among metastatic prostate cancer patients, both of which were higher than those observed for healthy subjects. PBPK simulations revealed an absence of OATP1B3-mediated interaction between abiraterone and CP-I. Our clinical observations confirmed that CP-I concentrations remained comparable to baseline levels up to 12 weeks post 500 mg AA treatment. Using CP-I as an endogenous biomarker, we identified the inhibition of abiraterone on OATP1B3 but not OATP1B1 in vitro, which was predicted and observed to be clinically insignificant. We concluded that the interaction risk between AA and substrates of OATP1Bs is low.

Hepatocyte nuclear factor 4 alpha antisense 1 (HNF4A-AS1) is a long noncoding RNA (lncRNA) gene physically located next to the transcription factor HNF4A gene in the human genome. Its transcription products have been reported to inhibit the progression of hepatocellular carcinoma (HCC) and negatively regulate the expression of cytochrome P450s (CYPs), including CYP1A2, 2B6, 2C9, 2C19, 2E1, and 3A4. By altering CYP expression, lncRNA HNF4A-AS1 also contributes to the susceptibility of drug-induced liver injury. Thus, HNF4A-AS1 lncRNA is a promising target for controlling HCC and modulating drug metabolism. However, HNF4A-AS1 has four annotated alternative transcripts in the human genome browsers, and it is unclear which transcripts the small interfering RNAs or small hairpin RNAs used in the previous studies are silenced and which transcripts should be used as the target. In this study, four annotated and two newly identified transcripts were confirmed. These six transcripts showed different expression levels in different liver disease conditions, including metabolic dysfunction-associated steatotic liver disease, alcohol-associated liver disease, and obesity. The expression patterns of all HNF4A-AS1 transcripts were further investigated in liver cell growth from human embryonic stem cells to matured hepatocyte-like cells, HepaRG differentiation, and exposure to rifampicin treatment. Several HNF4A-AS1 transcripts highly displayed correlations with these situations. In addition, some of the HNF4A-AS1 transcripts also showed a strong correlation with CYP3A4 during HepaRG maturation and rifampicin exposure. Our findings provide valuable insights into the specific roles of HNF4A-AS1 transcripts, paving the way for more targeted therapeutic strategies for liver diseases and drug metabolism.

Antifolates are important for chemotherapy in non–small cell lung cancer (NSCLC). They mainly rely on reduced folate carrier (RFC) and proton-coupled folate transporter (PCFT) to enter cells. PCFT is supposed to be the dominant transporter of the two in tumors, as it operates optimally at acidic pH and has limited transport activity at physiological pH, whereas RFC operates optimally at neutral pH. In this study, we found RFC showed a slightly pH-dependent uptake of antifolates, with similar affinity values at pH 7.4 and 6.5. PCFT showed a highly pH-dependent uptake of antifolates, with an optimum pH of 6.0 for pemetrexed and 5.5 for methotrexate. The Michaelis-Menten constant (K_m) value of PCFT for pemetrexed at pH 7.4 was more than 10 times higher than that at pH 6.5. Interestingly, we found that antifolate accumulations mediated by PCFT at acidic pH were significantly affected by the efflux transporter, breast cancer resistance protein (BCRP). The highest pemetrexed concentration was observed at pH 7.0–7.4 after a 60-minute accumulation in PCFT-expressing cells, which was further evidenced by the cytotoxicity of pemetrexed, with the IC₅₀ value of pemetrexed at pH 7.4 being one-third of that at pH 6.5. In addition, the in vivo study indicated that increasing PCFT and RFC expression significantly enhanced the antitumor efficacy of pemetrexed despite the high expression of BCRP. These results suggest that both RFC and PCFT are important for antifolates accumulation in NSCLC, although there is an acidic microenvironment and high BCRP expression in tumors.

Human organic anion transporting polypeptide (OATP) 1B1 and 1B3 are two highly homologous liver-specific uptake transporters. However, 2’,7’-dichlorofluorescein (DCF) is preferably transported by OATP1B1. In the present study, the molecular mechanisms for the selective transport of DCF by OATP1B1 were investigated by constructing and characterizing an array of OATP1B1/1B3 chimeras and site-directed mutagenesis. Our results show that transmembrane domain (TM) 10 is crucial for the surface expression and function of OATP1B1, in which Q541 and L545 play the most important roles in DCF transport. Replacement of TM10 in OATP1B1 with its OATP1B3 counterpart led to OATP1B1’s complete intracellular retention. Q541 and L545 may interact with DCF directly via hydrogen bonding and hydrophobic interactions. The decrease of DCF uptake by Q541A and L545S was due to their reduced binding affinity for DCF as compared with OATP1B1. In addition, Q541 and L545 are also crucial for the transport of estradiol-17β-glucuronide (E17βG) but not for the transport of estrone-3-sulfate (E3S), indicating different interaction modes between DCF/E17βG and E3S in OATP1B1. Taken together, Q541 and L545 in TM10 are critical for OATP1B1-mediated DCF uptake, but their effect is substrate-dependent.

Exogenous substances, including drugs and chemicals, can transfer into human seminal fluid and influence male fertility and reproduction. In addition, substances relevant in the context of sports drug testing programs, can be transferred into the urine of a female athlete (after unprotected sexual intercourse) and trigger a so-called adverse analytical finding. Here, the question arises as to whether it is possible to distinguish analytically between intentional doping offenses and unintentional contamination of urine by seminal fluid. To this end, 480 seminal fluids from nonathletes were analyzed to identify concentration ranges and metabolite profiles of therapeutic drugs that are also classified as doping agents. Therefore, a screening procedure was developed using liquid chromatography connected to a triple quadrupole mass spectrometer, and suspect samples (i.e., samples indicating the presence of relevant compounds) were further subjected to liquid chromatography-high-resolution accurate mass (tandem) mass spectrometry. The screening method yielded 90 findings (including aromatase inhibitors, selective estrogen receptor modulators, diuretics, stimulants, glucocorticoids, beta-blockers, antidepressants, and the nonapproved proliferator-activated receptor delta agonist GW1516) in a total of 81 samples, with 91% of these suspected cases being verified by the confirmation method. In addition to the intact drug, phase-I and -II metabolites were also occasionally observed in the seminal fluid. This study demonstrated that various drugs including those categorized as doping agents partition into seminal fluid. Monitoring substances and metabolites may contribute to a better understanding of the distribution and metabolism of exogenous substances in seminal fluid that may be responsible for the impairment of male fertility.

Compound probiotics have been widely used and commonly coadministered with other drugs for treating various chronic illnesses, yet their effects on drug pharmacokinetics remain underexplored. This study elucidated the impact of VSL#3 on the metabolism of probe drugs for cytochrome P450 enzymes (P450s), specifically omeprazole, tolbutamide, midazolam, metoprolol, phenacetin, and chlorzoxazone. Male Wistar rats were administered drinking water containing VSL#3 or not for 14 days and then intragastrically administered a P450 probe cocktail; this was done to investigate the host P450’s metabolic phenotype. Stool, liver/jejunum, and serum samples were collected for 16S ribosomal RNA sequencing, RNA sequencing, and bile acid profiling. The results indicated significant differences in both α and β diversity of intestinal microbial composition between the probiotic and vehicle groups in rats. In the probiotic group, the bioavailability of omeprazole increased by 269.9%, whereas those of tolbutamide and chlorpropamide decreased by 28.1% and 27.4%, respectively. The liver and jejunum exhibited 1417 and 4004 differentially expressed genes, respectively, between the two groups. In the probiotic group, most of P450 genes were upregulated in the liver but downregulated in the jejunum. The expression of genes encoding metabolic enzymes and drug transporters also changed. The serum-conjugated bile acids in the probiotic group were significantly reduced. Shorter duodenal villi and longer ileal villi were found in the probiotic group. In summary, VSL#3 administration altered the gut microbiota, host drug–processing gene expression, and intestinal structure in rats, which could be reasons for pharmacokinetic changes.

Solute carrier family 6 member 19 (SLC6A19) inhibitors are being studied as therapeutic agents for phenylketonuria. In this work, a potent SLC6A19 inhibitor (RA836) elevated rat kidney uremic toxin indoxyl sulfate (IDS) levels by intensity (arbitrary unit) of 13.7 ± 7.7 compared with vehicle 0.3 ± 0.1 (P = 0.01) as determined by tissue mass spectrometry imaging analysis. We hypothesized that increased plasma and kidney levels of IDS could be caused by the simultaneous inhibition of both Slc6a19 and a kidney IDS transporter responsible for excretion of IDS into urine. To test this, we first confirmed the formation of IDS through tryptophan metabolism by feeding rats a Trp-free diet. Inhibiting Slc6a19 with RA836 led to increased IDS in these rats. Next, RA836 and its key metabolites were evaluated in vitro for inhibiting kidney transporters such as organic anion transporter (OAT)1, OAT3, and breast cancer resistance protein (BCRP). RA836 inhibits BCRP with an IC₅₀ of 0.045 μM but shows no significant inhibition of OAT1 or OAT3. Finally, RA836 analogs with either potent or no inhibition of SLC6A19 and/or BCRP were synthesized and administered to rats fed a normal diet. Plasma and kidney samples were collected to quantify IDS using liquid chromatography–mass spectrometry. Neither a SLC6A19 inactive but potent BCRP inhibitor nor a SLC6A19 active but weak BCRP inhibitor raised IDS levels, whereas compounds inhibiting both transporters caused IDS accumulation in rat plasma and kidney, supporting the hypothesis that rat Bcrp contributes to the excretion of IDS. In summary, we identified that inhibiting Slc6a19 increases IDS formation, while simultaneously inhibiting Bcrp results in IDS accumulation in the kidney and plasma.

Exercise significantly alters human physiological functions, such as increasing cardiac output and muscle blood flow and decreasing glomerular filtration rate (GFR) and liver blood flow, thereby altering the absorption, distribution, metabolism, and excretion of drugs. In this study, we aimed to establish a database of human physiological parameters during exercise and to construct equations for the relationship between changes in each physiological parameter and exercise intensity, including cardiac output, organ blood flow (e.g., muscle blood flow and kidney blood flow), oxygen uptake, plasma pH and GFR, etc. The polynomial equation P = a_iHRⁱ was used for illustrating the relationship between the physiological parameters (P) and heart rate (HR), which served as an index of exercise intensity. The pharmacokinetics of midazolam, quinidine, digoxin, and lidocaine during exercise were predicted by a whole-body physiologically based pharmacokinetic (WB-PBPK) model and the developed database of physiological parameters following administration to 100 virtual subjects. The WB-PBPK model simulation results showed that most of the observed plasma drug concentrations fell within the 5^th–95^th percentiles of the simulations, and the estimated peak concentrations (C_max) and area under the curve (AUC) of drugs were also within 0.5–2.0 folds of observations. Sensitivity analysis showed that exercise intensity, exercise duration, medication time, and alterations in physiological parameters significantly affected drug pharmacokinetics and the net effect depending on drug characteristics and exercise conditions. In conclusion, the pharmacokinetics of drugs during exercise could be quantitatively predicted using the developed WB-PBPK model and database of physiological parameters.

In this study, the nonclinical pharmacokinetics of OLX702A-075-16, an RNA interference therapeutic currently in development, were investigated. OLX702A-075-16 is a novel N-acetylgalactosamine conjugated asymmetric small-interfering RNA (GalNAc-asiRNA) used for the treatment of an undisclosed liver disease. Its unique 16/21-mer asymmetric structure reduces nonspecific off-target effects without compromising efficacy. We investigated the plasma concentration, tissue distribution, metabolism, and renal excretion of OLX702A-075-16 following a subcutaneous administration in mice and rats. For bioanalysis, high-performance liquid chromatography with fluorescence detection was used. The results showed rapid clearance from plasma (0.5 to 1.5 hours of half-life) and predominant distribution to the liver and/or kidney. Less than 1% of the liver concentration of OLX702A-075-16 was detected in the other tissues. Metabolite profiling using liquid chromatography coupled with high-resolution mass spectrometry revealed that the intact duplex OLX702A-075-16 was the major compound in plasma. The GalNAc moiety was predominantly metabolized from the sense strand in the liver, with the unconjugated sense strand of OLX702A-075-16 accounting for more than 95% of the total exposure in the rat liver. Meanwhile, the antisense strand was metabolized by the sequential loss of nucleotides from the 3'-terminus by exonuclease, with the rat liver samples yielding the most diverse truncated forms of metabolites. Urinary excretion over 96 hours was less than 1% of the administered dose in rats. High plasma protein binding of OLX702A-075-16 likely inhibited its clearance through renal filtration.

The organic cation transporter (OCT)-1 mediates hepatic uptake of cationic endogenous compounds and xenobiotics. To date, limited information exists on how Oct1/OCT1 functionally develops with age in rat and human livers and how this would affect the pharmacokinetics of OCT substrates in children or juvenile animals. The functional ontogeny of rOct/hOCT was profiled in suspended rat (2–57 days old) and human hepatocytes (pediatric liver tissue donors: age 2–12 months) by determining uptake clearance of 4-[4-(dimethylamino)styryl]-N-methylpyridinium iodide (ASP+) as a known rOct/hOCT probe substrate. mRNA expression was determined in rat liver tissue corresponding to rat ages used in the functional studies, while hOCT1 mRNA expressions were determined in the same hepatocyte batches as those used for uptake studies. Maturation of rOct/hOCT activity and expression were evaluated by comparing values obtained at the various ages to the adult values. Relative to adult values (at 8 weeks), ASP⁺ uptake clearance in suspended rat hepatocytes aged 0, 1, 2, 3, 4, 5, and 6 weeks reached 26%, 29%, 33%, 37%, 72%, 63%, and 71%, respectively. Hepatic Oct1 mRNA expression was consistent with Oct activity (correlation coefficient of 0.92). In human hepatocytes, OCT1 activity was age dependent and also correlated with mRNA levels (correlation coefficient of 0.88). These data show that Oct1/OCT1 activities and expression mature gradually in rat/human liver, thereby mirroring the expression pattern of organic anion transporting polypeptide in rat. These high-resolution transporter ontogeny profiles will allow for more accurate prediction of the pharmacokinetics of OCT1/Oct1 substrates in pediatric populations and juvenile animals.

Organic anion transporting polypeptides (OATP, gene symbol SLCO) are well-recognized key determinants for the absorption, distribution, and excretion of a wide spectrum of endogenous and exogenous compounds including many antineoplastic agents. It was therefore proposed as a potential drug target for cancer therapy. In our previous study, it was found that low-dose X-ray and carbon ion irradiation both upregulated the expression of OATP family member OATP1A2 and in turn, led to a more dramatic killing effect when cancer cells were cotreated with antitumor drugs such as methotrexate. In the present study, the underlying mechanism of the phenomenon was explored in breast cancer cell line MCF-7. It was found that the nonreceptor tyrosine kinase v-YES-1 Yamaguchi sarcoma viral oncogene homolog 1 (YES-1) was temporally coordinated with the change of OATP1A2 after irradiation. The overexpression of YES-1 significantly increased OATP1A2 both at the mRNA and protein level. The signal transducer and activator of transcription 3 (STAT3) pathway is likely the downstream target of YES-1 because phosphorylation and nuclear accumulation of STAT3 were both enhanced after overexpressing YES-1 in MCF-7 cells. Further investigation revealed that there are two possible binding sites of STAT3 localized at the upstream sequence of SLCO1A2, the encoding gene of OATP1A2. Electrophoretic mobility shift assay and chromatin immunoprecipitation analysis suggested that these two sites bound to STAT3 specifically and the overexpression of YES-1 significantly increased the association of the transcription factor with the putative binding sites. Finally, inhibition or knockdown of YES-1 attenuated the induction effect of radiation on the expression of OATP1A2.

Sterol 12α-hydroxylase (CYP8B1) is the unique P450 enzyme with sterol 12-oxidation activity, playing an exclusive role in 12α-hydroxylating intermediates along the bile acid (BA) synthesis pathway. Despite the long history of BA metabolism studies, it is unclear whether CYP8B1 catalyzes 12α-hydroxylation of C₂₇ BAs, the key intermediates shuttling between mitochondria and peroxisomes. This work provides robust in vitro evidence that both microsomal and recombinant CYP8B1 enzymes catalyze the 12α-hydroxylation of dihydroxycoprostanic acid (DHCA) into trihydroxycoprostanic acid (THCA). On the one hand, DHCA 12α-hydroxylation reactivity is conservatively detected in liver microsomes of both human and preclinical animals. The reactivity of human tissue fractions conforms well with the selectivity of CYP8B1 mRNA expression, while the contribution of P450 enzymes other than CYP8B1 is excluded by reaction phenotyping in commercial recombinant enzymes. On the other hand, we prepared functional recombinant human CYP8B1 proteins according to a recently published protocol. Titration of the purified CYP8B1 proteins with either C4 (7α-hydroxy-4-cholesten-3-one) or DHCA yields expected blue shifts of the heme Soret peak (type I binding). The recombinant CYP8B1 proteins efficiently catalyze 12α-hydroxylation of both DHCA and C4, with substrate concentration occupying half of the binding sites of 3.0 and 1.9 μM and k_cat of 3.2 and 2.6 minutes^–1, respectively. In summary, the confirmed role of CYP8B1 in 12α-hydroxylation of C₂₇ BAs has furnished the forgotten passageway in the BA synthesis pathway. The present finding might have opened a new window to consider the biology of CYP8B1 in glucolipid metabolism and to evaluate CYP8B1 inhibition as a therapeutic approach of crucial interest for metabolic diseases.

The CYP3A7 enzyme accounts for ~50% of the total cytochrome P450 (P450) content in fetal and neonatal livers and is the predominant P450 involved in neonatal xenobiotic metabolism. Additionally, it is a key player in healthy birth outcomes through the oxidation of dehydroepiandrosterone (DHEA) and DHEA-sulfate. The amount of the other hepatic CYP3A isoforms, CYP3A4 and CYP3A5, expressed in neonates is low but highly variable, and therefore the activity of individual CYP3A isoforms is difficult to differentiate due to their functional similarities. Consequently, a better understanding of the contribution of CYP3A7 to drug metabolism is essential to identify the risk that drugs may pose to neonates and developing infants. To distinguish CYP3A7 activity from CYP3A4/5, we sought to further characterize the selectivity of the specific CYP3A inhibitors CYP3cide, clobetasol, and azamulin. We used three substrate probes, dibenzylfluorescein, luciferin-PPXE, and midazolam, to determine the IC₅₀ and metabolism-dependent inhibition (MDI) properties of the CYP3A inhibitors. Probe selection had a significant effect on the IC₅₀ values and P450 inactivation across all inhibitory compounds and enzymes. CYP3cide and azamulin were both identified as MDIs and were most specific for CYP3A4. Contrary to previous reports, we found that clobetasol propionate (CP) was not an MDI of CYP3A5 but was more selective for CYP3A5 over CYP3A4/7. We further investigated CYP3cide and CP’s ability to differentiate CYP3A7 activity in an equal mixture of recombinant CYP3A4, CYP3A5, and CYP3A7, and our results provide confidence of CYP3cide’s and CP’s ability to distinguish CYP3A7 activity in the presence of the other CYP3A isoforms.

Early detection of drug-drug interactions (DDIs) can facilitate timely drug development decisions, prevent unnecessary restrictions on patient enrollment, resulting in clinical study populations that are not representative of the indicated study population, and allow for appropriate dose adjustments to ensure safety in clinical trials. All of these factors contribute to a streamlined drug approval process and enhanced patient safety. Here we describe a new approach for early prediction of the magnitude of change in exposure for cytochrome P450 (P450) CYP3A4-related DDIs of small-molecule anticancer drugs based on the model-based extrapolation of human-CYP3A4-transgenic mice pharmacokinetics to humans. Victim drugs brigatinib and lorlatinib were evaluated with the new approach in combination with the perpetrator drugs itraconazole and rifampicin. Predictions of the magnitude of change in exposure deviated at most 0.99- to 1.31-fold from clinical trial results for inhibition with itraconazole, whereas exposure predictions for the induction with rifampicin were less accurate, with deviations of 0.22- to 0.48-fold. Results for the early prediction of DDIs and their clinical impact appear promising for CYP3A4 inhibition, but validation with more victim and perpetrator drugs is essential to evaluate the performance of the new method.

Pregnane X receptor (PXR) belongs to the nuclear receptor superfamily that plays a crucial role in hepatic physiologic and pathologic conditions. Phase separation is a process in which biomacromolecules aggregate and condense into a dense phase as liquid condensates and coexist with a dilute phase, contributing to various cellular and biologic functions. Until now, whether PXR could undergo phase separation remains unclear. This study aimed to investigate whether PXR undergoes phase separation. Analysis of the intrinsically disordered regions (IDRs) using algorithm tools indicated a low propensity of PXR to undergo phase separation. Experimental assays such as hyperosmotic stress, agonist treatment, and optoDroplets assay demonstrated the absence of phase separation for PXR. OptoDroplets assay revealed the inability of the fusion protein of Cry2 with PXR to form condensates upon blue light stimulation. Moreover, phase separation of PXR did not occur even though the mRNA and protein expression levels of PXR target, cytochrome P450 3A4, changed after sorbitol treatment. In conclusion, for the first time, these findings suggested that exogenous PXR does not undergo phase separation following activation or under hyperosmotic stress in nucleus of cells.

The -aminobutyric acid type A (GABA_A) receptor is modulated by a number of neuroactive steroids. Sulfated steroids and 3β-hydroxy steroids inhibit, while 3α-hydroxy steroids typically potentiate the receptor. Here, we have investigated inhibition of the α1β32L GABA_A receptor by the endogenous neurosteroid 3α-hydroxy-5β-pregnan-20-one (3α5βP) and the synthetic neuroactive steroid 3α-hydroxy-5α-androstane-17β-carbonitrile (ACN). The receptors were expressed in Xenopus oocytes. All experiments were done using two-electrode voltage-clamp electrophysiology. In the presence of low concentrations of GABA, 3α5βP and ACN potentiate the GABA_A receptor. To reveal inhibition, we conducted the experiments on receptors activated by the combination of a saturating concentration of GABA and propofol to fully activate the receptors and mask potentiation, or on mutant receptors in which potentiation is ablated. Under these conditions, both steroids inhibited the receptor with IC₅₀s of ~13 μM and maximal inhibitory effects of 70–90%. Receptor inhibition by 3α5βP was sensitive to substitution of the α1 transmembrane domain (TM) 2-2' residue, previously shown to ablate inhibition by pregnenolone sulfate. However, results of coapplication studies and the apparent lack of state dependence suggest that pregnenolone sulfate and 3α5βP inhibit the GABA_A receptor independently and through distinct mechanisms. Mutations to the neurosteroid binding sites in the α1 and β3 subunits statistically significantly, albeit weakly and incompletely, reduced inhibition by 3α5βP and ACN.

The orexigenic gut peptide ghrelin is an endogenous ligand for the growth hormone secretagogue receptor type 1a (GHSR1a). Systemic ghrelin administration has previously been shown to increase gastric motility and emptying. While these effects are known to be mediated by the vagus nerve, the cellular mechanism underlying these effects remains unclear. Therefore, the purpose of the present study was to investigate the signaling mechanism by which GHSR1a inhibits voltage-gated Ca²⁺ channels in isolated rat gastric vagal afferent neurons using whole-cell patch-clamp electrophysiology. The ghrelin pharmacological profile indicated that Ca²⁺ currents were inhibited with a log (Ic₅₀) = –2.10 ± 0.44 and a maximal inhibition of 42.8 ± 5.0%. Exposure to the GHSR1a receptor antagonist (D-Lys3)-GHRP-6 reduced ghrelin-mediated Ca²⁺ channel inhibition (29.4 ± 16.7% vs. 1.9 ± 2.5%, n = 6, P = 0.0064). Interestingly, we observed that activation of GHSR1a inhibited Ca²⁺ currents through both voltage-dependent and voltage-independent pathways. We also treated the gastric neurons with either pertussis toxin (PTX) or YM-254890 to examine whether the Ca²⁺ current inhibition was mediated by the Gα_i/o or Gα_q/11 family of subunits. Treatment with both PTX (Ca²⁺ current inhibition = 15.7 ± 10.6%, n = 8, P = 0.0327) and YM-254890 (15.2 ± 11.9%, n = 8, P = 0.0269) blocked ghrelin’s effects on Ca²⁺ currents, as compared with control neurons (34.3 ± 18.9%, n = 8). These results indicate GHSR1a can couple to both Gα_i/o and Gα_q/11 in gastric vagal afferent neurons. Overall, our findings suggest GHSR1a-mediated inhibition of Ca²⁺ currents occurs through two distinct pathways, offering necessary insights into the cellular mechanisms underlying ghrelin’s regulation of gastric vagal afferents.

Ketamine is a glutamate receptor antagonist that was developed over 50 years ago as an anesthetic agent. At subanesthetic doses, ketamine and some metabolites are analgesics and fast-acting antidepressants, presumably through targets other than glutamate receptors. We tested ketamine and its metabolites for activity as allosteric modulators of opioid receptors expressed as recombinant receptors in heterologous systems and with native receptors in rodent brain; signaling was examined by measuring GTP binding, β-arrestin recruitment, MAPK activation, and neurotransmitter release. Although micromolar concentrations of ketamine alone had weak agonist activity at μ opioid receptors, the combination of submicromolar concentrations of ketamine with endogenous opioid peptides produced robust synergistic responses with statistically significant increases in efficacies. All three opioid receptors (μ, , and ) showed synergism with submicromolar concentrations of ketamine and either methionine-enkephalin (Met-enk), leucine-enkephalin (Leu-enk), and/or dynorphin A17 (Dyn A17), albeit the extent of synergy was variable between receptors and peptides. S-ketamine exhibited higher modulatory effects compared with R-ketamine or racemic ketamine, with ~100% increase in efficacy. Importantly, the ketamine metabolite 6-hydroxynorketamine showed robust allosteric modulatory activity at μ opioid receptors; this metabolite is known to have analgesic and antidepressant activity but does not bind to glutamate receptors. Ketamine enhanced potency and efficacy of Met-enkephalin signaling both in mouse midbrain membranes and in rat ventral tegmental area neurons as determined by electrophysiology recordings in brain slices. Taken together, these findings support the hypothesis that some of the therapeutic effects of ketamine and its metabolites are mediated by directly engaging the endogenous opioid system.

The antitumor effect of cardiotonic steroids (CTS) has stimulated the search for new methods to evaluate both kinetic and thermodynamic aspects of their binding to Na⁺/K⁺-ATPase (IUBMB Enzyme Nomenclature). We propose a real-time assay based on a chromogenic substrate for phosphatase activity (pNPPase activity), using only two concentrations with an inhibitory progression curve, to obtain the association rate (k_on), dissociation rate (k_off), and equilibrium (K_i) constants of CTS for the structure-kinetics relationship in drug screening. We show that changing conditions (from ATPase to pNPPase activity) resulted in an increase of K_i of the cardenolides digitoxigenin, essentially due to a reduction of k_on. In contrast, the K_i of the structurally related bufadienolide bufalin increased much less due to the reduction of its k_off partially compensating the decrease of its k_on. When evaluating the kinetics of 15 natural and semisynthetic CTS, we observed that both k_on and k_off correlated with K_i (Spearman test), suggesting that differences in potency depend on variations of both k_on and k_off. A rhamnose in C3 of the steroidal nucleus enhanced the inhibitory potency by a reduction of k_off rather than an increase of k_on. Raising the temperature did not alter the k_off of digitoxin, generating a H (k_off) of –10.4 ± 4.3 kJ/mol, suggesting a complex dissociation mechanism. Based on a simple and inexpensive methodology, we determined the values of k_on, k_off, and K_i of the CTS and provided original kinetics and thermodynamics differences between CTS that could help the design of new compounds.

Aberrant type 2 inflammatory responses are the underlying cause of the pathophysiology of allergic asthma, allergic rhinitis, and other atopic diseases, with an alarming prevalence in relevant parts of the Western world. A bulk of evidence points out the important role of the DP2 receptor in these inflammation processes. A screening of different polyunsaturated fatty acids at a fluorescence resonance energy transfer–based DP2 receptor conformation sensor expressed in human embryonic kidney (HEK) cells revealed an agonistic effect of the prostaglandin (PG)-D₂ precursor arachidonic acid on DP2 receptor activity of about 80% of the effect induced by PGD₂. In a combination of experiments at the conformation sensor and using a bioluminescence resonance energy transfer–based G protein activation sensor expressed together with DP2 receptor wild type in HEK cells, we found that arachidonic acid acts as a direct activator of the DP2 receptor, but not the DP1 receptor, in a concentration range considered physiologically relevant. Pharmacological inhibition of cyclooxygenases and lipoxygenases as well as cytochrome P450 did not lead to a diminished arachidonic acid response on the DP2 receptor, confirming a direct action of arachidonic acid on the receptor.

ABSTRACTIntroduction:Postpartum hemorrhage (PPH) remains the leading cause of maternal mortality. A new clinical intervention (E-MOTIVE) holds the potential to improve early PPH detection and management. We aimed to develop and pilot implementation strategies to support uptake of this intervention in Kenya, Nigeria, South Africa, and Tanzania.Methods:Implementation strategy development: We triangulated findings from qualitative interviews, surveys and a qualitative evidence synthesis to identify current PPH care practices and influences on future intervention implementation. We mapped influences using implementation science frameworks to identify candidate implementation strategies before presenting these at stakeholder consultation and design workshops to discuss feasibility, acceptability, and local adaptations. Piloting: The intervention and implementation strategies were piloted in 12 health facilities (3 per country) over 3 months. Interviews (n=58), case report forms (n=1,269), and direct observations (18 vaginal births, 7 PPHs) were used to assess feasibility, acceptability, and fidelity.Results:Implementation strategy development: Key influences included shortages of drugs, supplies, and staff, limited in-service training, and perceived benefits of the intervention (e.g., more accurate PPH detection and reduced PPH mortality). Proposed implementation strategies included a PPH trolley, on-site simulation-based training, champions, and audit and feedback. Country-specific adaptations included merging the E-MOTIVE intervention with national maternal health trainings, adapting local PPH protocols, and PPH trollies depending on staff needs. Piloting: Intervention and implementation strategy fidelity differed within and across countries. Calibrated drapes resulted in earlier and more accurate PPH detection but were not consistently used at the start. Implementation strategies were feasible to deliver; however, some instances of limited use were observed (e.g., PPH trolley and skills practice after training).Conclusion:Systematic intervention development, piloting, and process evaluation helped identify initial challenges related to intervention fidelity, which were addressed ahead of a larger-scale effectiveness evaluation. This has helped maximize the internal validity of the trial.

The development of transforming growth factor βreceptor inhibitors (TGFβRi) as new medicines has been affected by cardiac valvulopathy and arteriopathy toxicity findings in nonclinical toxicology studies. PF-06952229 (MDV6058) selected using rational drug design is a potent and selective TGFβRI inhibitor with a relatively clean off-target selectivity profile and good pharmacokinetic properties across species. PF-06952229 inhibited clinically translatable phospho-SMAD2 biomarker (≥60%) in human and cynomolgus monkey peripheral blood mononuclear cells, as well as in mouse and rat splenocytes. Using an optimized, intermittent dosing schedule (7-day on/7-day off/cycle; 5 cycles), PF-06952229 demonstrated efficacy in a 63-day syngeneic MC38 colon carcinoma mouse model. In the pivotal repeat-dose toxicity studies (rat and cynomolgus monkey), PF-06952229 on an intermittent dosing schedule (5-day on/5-day off cycle; 5 cycles, 28 doses) showed no cardiac-related adverse findings. However, new toxicity findings related to PF-06952229 included reversible hepatocellular (hepatocyte necrosis with corresponding clinically monitorable transaminase increases) and lung (hemorrhage with mixed cell inflammation) findings at ≥ targeted projected clinical efficacious exposures. Furthermore, partially reversible cartilage hypertrophy (trachea and femur in rat; femur in monkey) and partially to fully reversible, clinically monitorable decreases in serum phosphorus and urinary phosphate at ≥ projected clinically efficacious exposures were observed. Given the integral role of TGFβ in endochondral bone formation, cartilage findings in toxicity studies have been observed with other TGFβRi classes of compounds. The favorable cumulative profile of PF-06952229 in biochemical, pharmacodynamic, pharmacokinetic, and nonclinical studies allowed for its evaluation in cancer patients using the intermittent dosing schedule (7-day on/7-day off) and careful protocol-defined monitoring.

The diagnostic work-up of patients with fever of unknown origin (FUO) begins with a thorough history and physical examination, complete blood count with differential, chest x-ray, urinalysis and culture, electrolyte panel, liver enzymes, erythrocyte sedimentation rate, and C-reactive protein level. Additional imaging procedures, including nuclear medicine tests, are generally used as second-line procedures, with ¹⁸F-FDG PET and PET/CT assuming increasingly important roles in the diagnostic work-up. The Society of Nuclear Medicine and Molecular Imaging, the Infectious Diseases Society of America, and the American College of Nuclear Medicine convened an autonomous expert work group to comprehensively review the published literature for nuclear imaging in adults and children with FUO and establish appropriate use criteria (AUC). This process was performed in accordance with the Protecting Access to Medicare Act of 2014, which requires that all referring physicians consult AUC by using a clinical decision support mechanism before ordering advanced diagnostic imaging services. The complete findings and discussions of the work group were published on January 8, 2023, and are available at https://www.snmmi.org/ClinicalPractice/content.aspx?ItemNumber=15666. The AUC in the final document are intended to assist referring health care providers in appropriate use of nuclear medicine imaging procedures in patients with FUO. The work group noted limitations in the current literature on nuclear medicine imaging for FUO, with the need for well-designed prospective multicenter investigations. Consensus findings from published data and expert opinions were used to create recommendations in common clinical scenarios for adults and children. Included in the complete document is a discussion of inflammation of unknown origin (IUO), a recently described entity. In view of the fact that the criteria for FUO and IUO are similar (except for fever > 38.3°C [100.9°F]) and that the most common etiologies of these 2 entities are similar, it is the expert opinion of the work group that the recommendations for nuclear medicine imaging of FUO are also applicable to IUO. These recommendations are included in the full guidance document. This summary reviews rationale, methodology, and main findings and refers the reader to the complete AUC document.

The role of gastrin-releasing peptide receptor (GRPR) in various diseases, including cancer, has been extensively studied and has emerged as a promising therapeutic target. In this study, we successfully achieved the use of [²¹²Pb]Pb-DOTAM-GRPR1, comprising the α-particle generator, ²¹²Pb, combined with a GRPR-targeting peptide, GRPR1, in a prostate cancer model. Methods: Pharmacokinetics, toxicity, radiation dosimetry, and efficacy were assessed in GRPR-positive prostate tumor–bearing mice after intravenous administration of [²¹²Pb]Pb-DOTAM-GRPR1 (where DOTAM is 1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraazacyclododecane). Results: Preclinical studies have shown tumor targeting of up to 5 percent injected dose per gram over 24 h, and optimization of the drug formulation and quantity has led to minimized oxidation and off-target binding, respectively. Particularly, an increase in peptide amount from 28 to 280 ng was shown to reduce off-target uptake, especially at the level of the pancreas, by about 30%. Furthermore, dosimetry studies confirmed the kidney as the dose-limiting organ, and toxicity studies revealed that a nontoxic dose of up to 1,665 kBq could be injected into mice. Efficacy studies indicated a median survival time of 9 wk in the control group, which received only a buffer solution, compared with 19 wk in the group that received 4 injections of 370 kBq at 3-wk intervals. Conclusion: Taken together, these combined data demonstrate the safety, tolerability, and efficacy of [²¹²Pb]Pb-DOTAM-GRPR1, thus warranting further exploration in clinical trials.

²²⁶Ac (t_1/2 = 29.37 h) has been proposed as a theranostic radioisotope leveraging both its diagnostic -emissions and therapeutic α-emissions. ²²⁶Ac emits 158 and 230 keV -photons ideal for quantitative SPECT imaging and acts as an in vivo generator of 4 high-energy α-particles. Because of these nuclear decay properties, ²²⁶Ac has potential to act as a standalone theranostic isotope. In this proof-of-concept study, we evaluated a preclinical ²²⁶Ac-radiopharmaceutical for its theranostic efficacy and present the first ²²⁶Ac-targeted α-therapy study. Methods: ²²⁶Ac was produced at TRIUMF and labeled with the chelator-peptide bioconjugate crown-TATE. [²²⁶Ac]Ac-crown-TATE was selected to target neuroendocrine tumors in male NRG mice bearing AR42J tumor xenografts for SPECT imaging, biodistribution, and therapy studies. A preclinical SPECT/CT scanner acquired quantitative images reconstructed from both the 158 and the 230 keV emissions. Mice in the biodistribution study were euthanized at 1, 3, 5, 24, and 48 h after injection, and internal radiation dosimetry was derived for the tumor and organs of interest to establish appropriate therapeutic activity levels. Mice in the therapy study were administered 125, 250, or 375 kBq treatments and were monitored for tumor size and body condition. Results: We present quantitative SPECT images of the in vivo biodistribution of [²²⁶Ac]Ac-crown-TATE, which showed agreement with ex vivo measurements. Biodistribution studies demonstrated high uptake (>30%IA/g at 5 h after injection) and retention in the tumor, with an estimated mean absorbed dose coefficient of 222 mGy/kBq. [²²⁶Ac]Ac-crown-TATE treatments significantly extended the median survival from 7 d in the control groups to 16, 24, and 27 d in the 125, 250, and 375 kBq treatment groups, respectively. Survival was prolonged by slowing tumor growth, and no weight loss or toxicities were observed. Conclusion: This study highlights the theranostic potential of ²²⁶Ac as a standalone therapeutic isotope in addition to its demonstrated diagnostic capabilities to assess dosimetry in matched ²²⁵Ac-radiopharmaceuticals. Future studies will investigate maximum dose and toxicity to further explore the therapeutic potential of ²²⁶Ac-radiopharmaceuticals.

This single-center, single-arm, phase II trial (ChiCTR2100050057) investigated the ability of ¹⁸F-labeled fibroblast activation protein inhibitor ([¹⁸F]AlF-NOTA-FAPI-04, denoted as ¹⁸F-FAPI) PET/CT to predict the response to neoadjuvant camrelizumab plus chemotherapy (nCC) in locally advanced esophageal squamous cell carcinoma (LA-ESCC). Methods: This study included 32 newly diagnosed LA-ESCC participants who underwent ¹⁸F-FAPI PET/CT at baseline, of whom 23 also underwent scanning after 2 cycles of nCC. The participants underwent surgery after 2 cycles of nCC. Recorded PET parameters included maximum, peak, and mean SUVs and tumor-to-background ratios (TBRs), metabolic tumor volume, and total lesion FAP expression. PET parameters were compared between patient groups with good and poor pathologic responses, and the predictive performance for treatment response was analyzed. Results: The good and poor response groups each included 16 participants (16/32, 50.0%). On ¹⁸F-FAPI PET/CT, the posttreatment SUVs were significantly lower in good responders than in poor responders, whereas the changes in SUVs with treatment were significantly higher (all P < 0.05). SUV_max (area under the curve [AUC], 0.87; P = 0.0026), SUV_peak (AUC, 0.89; P = 0.0017), SUV_mean (AUC, 0.88; P = 0.0021), TBR_max (AUC, 0.86; P = 0.0031), and TBR_mean (AUC, 0.88; P = 0.0021) after nCC were significant predictors of pathologic response to nCC, with sensitivities of 63.64%–81.82% and specificities of 83.33%–100%. Changes in SUV_max (AUC, 0.81; P = 0.0116), SUV_peak (AUC, 0.82; P = 0.0097), SUV_mean (AUC, 0.81; P = 0.0116), and TBR_mean (AUC, 0.74; P = 0.0489) also were significant predictors of the pathologic response to nCC, with sensitivities and specificities in similar ranges. Conclusion: ¹⁸F-FAPI PET/CT parameters after treatment and their changes from baseline can predict the pathologic response to nCC in LA-ESCC participants.

The clinical impact of 16α-¹⁸F-fluoro-17β-estradiol (¹⁸F-FES) PET/CT on patient management has not been well investigated. The aim of this study was to assess the clinical impact of ¹⁸F-FES PET/CT on the management of patients with recurrent or metastatic breast cancer. Methods: Study subjects were identified retrospectively from a database of a prospective trial for postmarketing surveillance of ¹⁸F-FES between 2021 and 2023. Patients who were suspected or known to have recurrent or metastatic estrogen receptor–positive breast cancer based on a routine standard workup were included. Planned management before and actual management after ¹⁸F-FES PET/CT were assessed by 2 experienced medical oncologists via medical chart review. A 5-point questionnaire was provided to evaluate the value of ¹⁸F-FES PET/CT for management planning. The rate of intention-to-treat and interdisciplinary changes, and the impact of ¹⁸F-FES PET/CT according to PET/CT result or clinical indication, were examined. Results: Of the 344 included patients, 120 (35%) experienced a change in management after ¹⁸F-FES PET/CT. In 139 (40%) patients,¹⁸F-FES PET/CT supported the existing management decision without a change in management. Intention-to-treat and interdisciplinary changes accounted for 64% (77/120) and 68% (82/120) of all changes, respectively. A higher rate of change was observed when lesions were ¹⁸F-FES–negative (44% [36/81]) than ¹⁸F-FES–positive (30% [51/172]) or mixed ¹⁸F-FES–positive/negative (36% [33/91]). Regarding clinical indications, the highest rate of change was shown when evaluating the origins of metastasis of double primary cancers (64% [9/14]). Conclusion: ¹⁸F-FES PET/CT modified the management of recurrent or metastatic breast cancer, serving as an impactful imaging modality in clinical practice.

gp130 functions as a shared signal-transducing subunit not only for interleukin (IL)-6 but also for eight other human cytokine receptor complexes. The IL-6 signaling pathway mediated through gp130 encompasses classical, trans, or cluster signaling, intricately regulated by a diverse array of modulators affecting IL-6, its receptor, and gp130. Currently, only a limited number of small molecule antagonists and agonists for gp130 are known. This review aims to comprehensively examine the current knowledge of these modulators and provide insights into their pharmacological properties, particularly in the context of cancer and other diseases. Notably, the prominent gp130 modulators SC144, bazedoxifene, and raloxifene are discussed in detail, with a specific focus on the discovery of SC144’s iron-chelating properties. This adds a new dimension to the understanding of its pharmacological effects and therapeutic potential in conditions where iron homeostasis is significant. Our bioinformatic analysis of gp130 and genes related to iron homeostasis reveals insightful correlations, implicating the role of iron in the gp130 signaling pathway. Overall, this review contributes to the evolving understanding of gp130 modulation and its potential therapeutic applications in various disease contexts.

Historically, the intestinal lymphatics were considered passive conduits for fluids, immune cells, dietary lipids, lipid soluble vitamins, and lipophilic drugs. Studies of intestinal lymphatic drug delivery in the late 20th century focused primarily on the drugs’ physicochemical properties, especially high lipophilicity, that resulted in intestinal lymphatic transport. More recent discoveries have changed our traditional view by demonstrating that the lymphatics are active, plastic, and tissue-specific players in a range of biological and pathological processes, including within the intestine. These findings have, in turn, inspired exploration of lymph-specific therapies for a range of diseases, as well as the development of more sophisticated strategies to actively deliver drugs or vaccines to the intestinal lymph, including a range of nanotechnologies, lipid prodrugs, and lipid-conjugated materials that "hitchhike" onto lymphatic transport pathways. With the increasing development of novel therapeutics such as biologics, there has been interest in whether these therapeutics are absorbed and transported through intestinal lymph after oral administration. Here we review the current state of understanding of the anatomy and physiology of the gastrointestinal lymphatic system in health and disease, with a focus on aspects relevant to drug delivery. We summarize the current state-of-the-art approaches to deliver drugs and quantify their uptake into the intestinal lymphatic system. Finally, and excitingly, we discuss recent examples of significant pharmacokinetic and therapeutic benefits achieved via intestinal lymphatic drug delivery. We also propose approaches to advance the development and clinical application of intestinal lymphatic delivery strategies in the future.

Over 4 decades of research support the link between Alzheimer disease (AD) and somatostatin [somatotropin-releasing inhibitory factor (SRIF)]. SRIF and SRIF-expressing neurons play an essential role in brain function, modulating hippocampal activity and memory formation. Loss of SRIF and SRIF-expressing neurons in the brain rests at the center of a series of interdependent pathological events driven by amyloid-β peptide (Aβ), culminating in cognitive decline and dementia. The connection between the SRIF and AD further extends to the neuropsychiatric symptoms, seizure activity, and inflammation, whereas preclinical AD investigations show SRIF or SRIF receptor agonist administration capable of enhancing cognition. SRIF receptor subtype-4 activation in particular presents unique attributes, with the potential to mitigate learning and memory decline, reduce comorbid symptoms, and enhance enzymatic degradation of Aβ in the brain. Here, we review the links between SRIF and AD along with the therapeutic implications.

α-Synuclein (α-Syn) aggregation in Lewy bodies and Lewy neurites has emerged as a key pathogenetic feature in Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. Various factors, including posttranslational modifications (PTMs), can influence the propensity of α-Syn to misfold and aggregate. PTMs are biochemical modifications of a protein that occur during or after translation and are typically mediated by enzymes. PTMs modulate several characteristics of proteins including their structure, activity, localization, and stability. α-Syn undergoes various posttranslational modifications, including phosphorylation, ubiquitination, SUMOylation, acetylation, glycation, O-GlcNAcylation, nitration, oxidation, polyamination, arginylation, and truncation. Different PTMs of a protein can physically interact with one another or work together to influence a particular physiological or pathological feature in a process known as PTMs crosstalk. The development of detection techniques for the cooccurrence of PTMs in recent years has uncovered previously unappreciated mechanisms of their crosstalk. This has led to the emergence of evidence supporting an association between α-Syn PTMs crosstalk and synucleinopathies. In this review, we provide a comprehensive evaluation of α-Syn PTMs, their impact on misfolding and pathogenicity, the pharmacological means of targeting them, and their potential as biomarkers of disease. We also highlight the importance of the crosstalk between these PTMs in α-Syn function and aggregation. Insight into these PTMS and the complexities of their crosstalk can improve our understanding of the pathogenesis of synucleinopathies and identify novel targets of therapeutic potential.

Bile acids are the end products of cholesterol catabolism. Hepatic bile acid synthesis accounts for a major fraction of daily cholesterol turnover in humans. Biliary secretion of bile acids generates bile flow and facilitates biliary secretion of lipids, endogenous metabolites, and xenobiotics. In intestine, bile acids facilitate the digestion and absorption of dietary lipids and fat-soluble vitamins. Through activation of nuclear receptors and G protein-coupled receptors and interaction with gut microbiome, bile acids critically regulate host metabolism and innate and adaptive immunity and are involved in the pathogenesis of cholestasis, metabolic dysfunction-associated steatotic liver disease, alcohol-associated liver disease, type-2 diabetes, and inflammatory bowel diseases. Bile acids and their derivatives have been developed as potential therapeutic agents for treating chronic metabolic and inflammatory liver diseases and gastrointestinal disorders.

This review explores the concept of synergy in pharmacology, emphasizing its importance in optimizing treatment outcomes through the combination of drugs with different mechanisms of action. Synergy, defined as an effect greater than the expected additive effect elicited by individual agents according to specific predictive models, offers a promising approach to enhance therapeutic efficacy while minimizing adverse events. The historical evolution of synergy research, from ancient civilizations to modern pharmacology, highlights the ongoing quest to understand and harness synergistic interactions. Key concepts, such as concentration-response curves, additive effects, and predictive models, are discussed in detail, emphasizing the need for accurate assessment methods throughout translational drug development. Although various mathematical models exist for synergy analysis, selecting the appropriate model and software tools remains a challenge, necessitating careful consideration of experimental design and data interpretation. Furthermore, this review addresses practical considerations in synergy assessment, including preclinical and clinical approaches, mechanism of action, and statistical analysis. Optimizing synergy requires attention to concentration/dose ratios, target site localization, and timing of drug administration, ensuring that the benefits of combination therapy detected bench-side are translatable into clinical practice. Overall, the review advocates for a systematic approach to synergy assessment, incorporating robust statistical analysis, effective and simplified predictive models, and collaborative efforts across pivotal sectors, such as academic institutions, pharmaceutical companies, and regulatory agencies. By overcoming critical challenges and maximizing therapeutic potential, effective synergy assessment in drug development holds promise for advancing patient care.

Multiple sclerosis (MS) is a chronic inflammatory demyelinating and neurodegenerative disease of the central nervous system (CNS), with a putative autoimmune origin and complex pathogenesis. Modification of the natural history of MS by reducing relapses and slowing disability accumulation was first attained in the 1990 s with the development of the first-generation disease-modifying therapies. Glatiramer acetate (GA), a copolymer of L-alanine, L-lysine, L-glutamic acid, and L-tyrosine, was discovered due to its ability to suppress the animal model of MS, experimental autoimmune encephalomyelitis. Extensive clinical trials and long-term assessments established the efficacy and the safety of GA. Furthermore, studies of the therapeutic processes induced by GA in animal models and in MS patients indicate that GA affects various levels of the innate and the adaptive immune response, generating deviation from proinflammatory to anti-inflammatory pathways. This includes competition for binding to antigen presenting cells; driving dendritic cells, monocytes, and B-cells toward anti-inflammatory responses; and stimulating T-helper 2 and T-regulatory cells. The immune cells stimulated by GA reach the CNS and secrete in situ anti-inflammatory cytokines alleviating the pathological processes. Furthermore, cumulative findings reveal that in addition to its immunomodulatory effect, GA promotes neuroprotective repair processes such as neurotrophic factors secretion, remyelination, and neurogenesis. This review aims to provide an overview of MS pathology diagnosis and treatment as well as the diverse mechanism of action of GA.