The cyclic GMP-AMP synthase (cGAS) protein is a pattern-recognition receptor of the mammalian innate immune system that is recognized as a main cytosolic sensor of pathogenic or damaged DNA. cGAS DNA binding initiates catalytic production of the second messenger, cyclic GMP-AMP, which activates the STING-TBK1-IRF3 signaling axis to induce cytokine expression. Post-translational modification (PTM) has started to be recognized as a critical component of cGAS regulation, yet the extent of these modifications remains unclear. Here, we report the identification and functional analysis of cGAS phosphorylations and acetylations in several cell types under basal and immune-stimulated conditions. cGAS was enriched by immunoaffinity purification from human primary fibroblasts prior to and after infection with herpes simplex virus type 1 (HSV-1), as well as from immune-stimulated STING-HEK293T cells. Six phosphorylations and eight acetylations were detected, of which eight PTMs were not previously documented. PTMs were validated by parallel reaction monitoring (PRM) mass spectrometry in fibroblasts, HEK293T cells, and THP-1 macrophage-like cells. Primary sequence and structural analysis of cGAS highlighted a subset of PTM sites with elevated surface accessibility and high evolutionary sequence conservation. To assess the functional relevance of each PTM, we generated a series of single-point cGAS mutations. Stable cell lines were constructed to express cGAS with amino acid substitutions that prevented phosphorylation (Ser-to-Ala) and acetylation (Lys-to-Arg) or that mimicked the modification state (Ser-to-Asp and Lys-to-Gln). cGAS-dependent apoptotic and immune signaling activities were then assessed for each mutation. Our results show that acetyl-mimic mutations at Lys384 and Lys414 inhibit the ability of cGAS to induce apoptosis. In contrast, the Lys198 acetyl-mimic mutation increased cGAS-dependent interferon signaling when compared to the unmodified charge-mimic. Moreover, targeted PRM quantification showed that Lys198 acetylation is decreased upon infections with two herpesviruses—HSV-1 and human cytomegalovirus (HCMV), highlighting this residue as a regulatory point during virus infection.

Invitation Only Research Event

Ceramides (Cers) with ultralong (~32-carbon) chains and -esterified linoleic acid, composing a subclass called omega-O-acylceramides (acylCers), are indispensable components of the skin barrier. Normal barriers typically contain acylCer concentrations of ~10 mol%; diminished concentrations, along with altered or missing long periodicity lamellar phase (LPP), and increased permeability accompany an array of skin disorders, including atopic dermatitis, psoriasis, and ichthyoses. We developed model membranes to investigate the effects of the acylCer structure and concentration on skin lipid organization and permeability. The model membrane systems contained six to nine Cer subclasses as well as fatty acids, cholesterol, and cholesterol sulfate; acylCer content—namely, acylCers containing sphingosine (Cer EOS), dihydrosphingosine (Cer EOdS), and phytosphingosine (Cer EOP) ranged from zero to 30 mol%. Systems with normal physiologic concentrations of acylCer mixture mimicked the permeability and nanostructure of human skin lipids (with regard to LPP, chain order, and lateral packing). The models also showed that the sphingoid base in acylCer significantly affects the membrane architecture and permeability and that Cer EOP, notably, is a weaker barrier component than Cer EOS and Cer EOdS. Membranes with diminished or missing acylCers displayed some of the hallmarks of diseased skin lipid barriers (i.e., lack of LPP, less ordered lipids, less orthorhombic chain packing, and increased permeability). These results could inform the rational design of new and improved strategies for the barrier-targeted treatment of skin diseases.

GPR120 is implicated as a lipid receptor in the oro-sensory detection of dietary fatty acids. However, the effects of GPR120 activation on dietary fat intake or obesity are not clearly understood. We investigated to determine whether the binding of TUG891, a novel GPR120 agonist, to lingual GPR120 modulates fat preference in mice. We explored the effects of TUG891 on obesity-related hormones and conducted behavioral choice tests on mice to better understand the physiologic relevance of the action of TUG891. In cultured mouse and human taste bud cells (TBCs), TUG891 induced a rapid increase in Ca²⁺ by acting on GPR120. A long-chain dietary fatty acid, linoleic acid (LA), also recruited Ca²⁺ via GPR120 in human and mouse TBCs. Both TUG891 and LA induced ERK1/2 phosphorylation and enhanced in vitro release of glucagon-like peptide-1 from cultured human and mouse TBCs. In situ application of TUG891 onto the tongue of anesthetized mice triggered the secretion of pancreatobiliary juice, probably via the tongue-brain-gut axis. Furthermore, lingual application of TUG891 altered circulating concentrations of cholecystokinin and adipokines, associated with decreased circulating LDL, in conscious mice. In behavioral tests, mice exhibited a spontaneous preference for solutions containing either TUG891 or LA instead of a control. However, addition of TUG891 to a solution containing LA significantly curtailed fatty acid preference. Our study demonstrates that TUG891 binds to lingual GPR120 receptors, activates the tongue-brain-gut axis, and modulates fat preference. These findings may support the development of new fat taste analogs that can change the approach to obesity prevention and treatment.

Zinc metallopeptidase STE24 (ZMPSTE24) is essential for the conversion of farnesyl–prelamin A to mature lamin A, a key component of the nuclear lamina. In the absence of ZMPSTE24, farnesyl–prelamin A accumulates in the nucleus and exerts toxicity, causing a variety of disease phenotypes. By ~4 months of age, both male and female Zmpste24^–/– mice manifest a near-complete loss of adipose tissue, but it has never been clear whether this phenotype is a direct consequence of farnesyl–prelamin A toxicity in adipocytes. To address this question, we generated a conditional knockout Zmpste24 allele and used it to create adipocyte-specific Zmpste24–knockout mice. To boost farnesyl–prelamin A levels, we bred in the "prelamin A–only" Lmna allele. Gene expression, immunoblotting, and immunohistochemistry experiments revealed that adipose tissue in these mice had decreased Zmpste24 expression along with strikingly increased accumulation of prelamin A. In male mice, Zmpste24 deficiency in adipocytes was accompanied by modest changes in adipose stores (an 11% decrease in body weight, a 23% decrease in body fat mass, and significantly smaller gonadal and inguinal white adipose depots). No changes in adipose stores were detected in female mice, likely because prelamin A expression in adipose tissue is lower in female mice. Zmpste24 deficiency in adipocytes did not alter the number of macrophages in adipose tissue, nor did it alter plasma levels of glucose, triglycerides, or fatty acids. We conclude that ZMPSTE24 deficiency in adipocytes, and the accompanying accumulation of farnesyl–prelamin A, reduces adipose tissue stores, but only modestly and only in male mice.

apoB exists as apoB100 and apoB48, which are mainly found in hepatic VLDLs and intestinal chylomicrons, respectively. Elevated plasma levels of apoB-containing lipoproteins (Blps) contribute to coronary artery disease, diabetes, and other cardiometabolic conditions. Studying the mechanisms that drive the assembly, intracellular trafficking, secretion, and function of Blps remains challenging. Our understanding of the intracellular and intraorganism trafficking of Blps can be greatly enhanced, however, with the availability of fusion proteins that can help visualize Blp transport within cells and between tissues. We designed three plasmids expressing human apoB fluorescent fusion proteins: apoB48-GFP, apoB100-GFP, and apoB48-mCherry. In Cos-7 cells, transiently expressed fluorescent apoB proteins colocalized with calnexin and were only secreted if cells were cotransfected with microsomal triglyceride transfer protein. The secreted apoB-fusion proteins retained the fluorescent protein and were secreted as lipoproteins with flotation densities similar to plasma HDL and LDL. In a rat hepatoma McA-RH7777 cell line, the human apoB100 fusion protein was secreted as VLDL- and LDL-sized particles, and the apoB48 fusion proteins were secreted as LDL- and HDL-sized particles. To monitor lipoprotein trafficking in vivo, the apoB48-mCherry construct was transiently expressed in zebrafish larvae and was detected throughout the liver. These experiments show that the addition of fluorescent proteins to the C terminus of apoB does not disrupt their assembly, localization, secretion, or endocytosis. The availability of fluorescently labeled apoB proteins will facilitate the exploration of the assembly, degradation, and transport of Blps and help to identify novel compounds that interfere with these processes via high-throughput screening.

Bile acids (BAs) facilitate intestinal absorption of lipid-soluble nutrients and modulate various metabolic pathways through the farnesoid X receptor (FXR) and Takeda G-protein-coupled receptor 5. These receptors are targets for therapy in cholestatic and metabolic diseases. However, dissimilarities in BA metabolism between humans and mice complicate translation of preclinical data. Cytochrome P450 family 2 subfamily c polypeptide 70 (CYP2C70) was recently proposed to catalyze the formation of rodent-specific muricholic acids (MCAs). With CRISPR/Cas9-mediated somatic genome editing, we generated an acute hepatic Cyp2c70 knockout mouse model (Cyp2c70^ako) to clarify the role of CYP2C70 in BA metabolism in vivo and evaluate whether its activity modulates effects of pharmacologic FXR activation on cholesterol homeostasis. In Cyp2c70^ako mice, chenodeoxycholic acid (CDCA) increased at the expense of βMCA, resulting in a more hydrophobic human-like BA pool. Tracer studies demonstrated that, in vivo, CYP2C70 catalyzes the formation of βMCA primarily by sequential 6β-hydroxylation and C7-epimerization of CDCA, generating αMCA as an intermediate metabolite. Physiologically, the humanized BA composition in Cyp2c70^ako mice blunted the stimulation of fecal cholesterol disposal in response to FXR activation compared with WT mice, predominantly due to reduced stimulation of transintestinal cholesterol excretion. Thus, deletion of hepatic Cyp2c70 in adult mice translates into a human-like BA pool composition and impacts the response to pharmacologic FXR activation. This Cyp2c70^ako mouse model may be a useful tool for future studies of BA signaling and metabolism that informs human disease development and treatment.

The formation and properties of liquid-ordered (Lo) lipid domains (rafts) in the plasma membrane are still poorly understood. This limits our ability to manipulate ordered lipid domain-dependent biological functions. Giant plasma membrane vesicles (GPMVs) undergo large-scale phase separations into coexisting Lo and liquid-disordered lipid domains. However, large-scale phase separation in GPMVs detected by light microscopy is observed only at low temperatures. Comparing Förster resonance energy transfer-detected versus light microscopy-detected domain formation, we found that nanodomains, domains of nanometer size, persist at temperatures up to 20°C higher than large-scale phases, up to physiologic temperature. The persistence of nanodomains at higher temperatures is consistent with previously reported theoretical calculations. To investigate the sensitivity of nanodomains to lipid composition, GPMVs were prepared from mammalian cells in which sterol, phospholipid, or sphingolipid composition in the plasma membrane outer leaflet had been altered by cyclodextrin-catalyzed lipid exchange. Lipid substitutions that stabilize or destabilize ordered domain formation in artificial lipid vesicles had a similar effect on the thermal stability of nanodomains and large-scale phase separation in GPMVs, with nanodomains persisting at higher temperatures than large-scale phases for a wide range of lipid compositions. This indicates that it is likely that plasma membrane nanodomains can form under physiologic conditions more readily than large-scale phase separation. We also conclude that membrane lipid substitutions carried out in intact cells are able to modulate the propensity of plasma membranes to form ordered domains. This implies lipid substitutions can be used to alter biological processes dependent upon ordered domains.

The estimation results might be incorrect in PROC PANEL when the RANONE and NOINT options are specified in the MODEL statement.

When you run SAS Deployment Wizard to install or update SAS 9.4 software, the file system is examined. If any files that the wizard needs to delete are found to be locked, they are reported as unwritable f

If the following conditions are met in PROC QLIM: the SELECT option and DISCRETE option are specified in the same MODEL statement or ENDOGENOUS statement the same dependent variable with S

T-type (Cav3) Ca2+ channels are important regulators of excitability and rhythmic activity of excitable cells. Among other voltage-gated Ca2+ channels, Cav3 channels are uniquely sensitive to oxidation and zinc. Using recombinant protein expression in HEK293 cells, patch clamp electrophysiology, site-directed mutagenesis, and homology modeling, we report here that modulation of Cav3.2 by redox agents and zinc is mediated by a unique extracellular module containing a high-affinity metal-binding site formed by the extracellular IS1–IS2 and IS3–IS4 loops of domain I and a cluster of extracellular cysteines in the IS1–IS2 loop. Patch clamp recording of recombinant Cav3.2 currents revealed that two cysteine-modifying agents, sodium (2-sulfonatoethyl) methanethiosulfonate (MTSES) and N-ethylmaleimide, as well as a reactive oxygen species–producing neuropeptide, substance P (SP), inhibit Cav3.2 current to similar degrees and that this inhibition is reversed by a reducing agent and a zinc chelator. Pre-application of MTSES prevented further SP-mediated current inhibition. Substitution of the zinc-binding residue His191 in Cav3.2 reduced the channel's sensitivity to MTSES, and introduction of the corresponding histidine into Cav3.1 sensitized it to MTSES. Removal of extracellular cysteines from the IS1–IS2 loop of Cav3.2 reduced its sensitivity to MTSES and SP. We hypothesize that oxidative modification of IS1–IS2 loop cysteines induces allosteric changes in the zinc-binding site of Cav3.2 so that it becomes sensitive to ambient zinc.

Despite considerable progress, development of glucose-responsive insulins (GRI) still largely depends on empirical knowledge and tedious experimentation – especially on rodents. To assist the rational design and clinical translation of the therapeutic, we present a Pharmacokinetic Algorithm Mapping GRI Efficacies in Rodents and Humans (PAMERAH), built upon our previous human model. PAMERAH constitutes a framework for predicting the therapeutic efficacy of a GRI candidate from its user-specified mechanism of action, kinetics, and dosage, which we show is accurate when checked against data from experiments and literature. Results from simulated glucose clamps also agree quantitatively with recent GRI publications. We demonstrate that the model can be used to explore the vast number of permutations constituting the GRI parameter space, and thereby identify the optimal design ranges that yield desired performance. A design guide aside, PAMERAH more importantly can facilitate GRI’s clinical translation by connecting each candidate’s efficacies in rats, mice, and humans. The resultant mapping helps find GRIs which appear promising in rodents but underperform in humans (i.e. false-positives). Conversely, it also allows for the discovery of optimal human GRI dynamics not captured by experiments on a rodent population (false-negatives). We condense such information onto a translatability grid as a straightforward, visual guide for GRI development.

Hyperglycemia is a potent regulator of endogenous glucose production (EGP). Loss of this ‘glucose effectiveness’ is a major contributor to elevated plasma glucose concentrations in type 2 diabetes (T2D). ATP-sensitive potassium channels (K_ATP channels) in the central nervous system (CNS) have been shown to regulate EGP in humans and rodents. We examined the contribution of central K_ATP channels to glucose effectiveness. Under fixed hormonal conditions (‘pancreatic clamp’ studies), hyperglycemia suppressed EGP by ~50% in both non-diabetic humans and normal Sprague Dawley rats. By contrast, antagonism of K_ATP channels with glyburide significantly reduced the EGP-lowering effect of hyperglycemia in both humans and rats. Furthermore, the effects of glyburide on EGP and gluconeogenic enzymes in rats were abolished by intracerebroventricular (ICV) administration of the KATP channel agonist diazoxide. These findings indicate that about half of EGP suppression by hyperglycemia is mediated by central K_ATP channels. These central mechanisms may offer a novel therapeutic target for improving glycemic control in T2D.

Multidrug resistance (MDR) in cancer arises from cross-resistance to structurally- and functionally-divergent chemotherapeutic drugs. In particular, MDR is characterized by increased expression and activity of ATP-binding cassette (ABC) superfamily transporters. Sphingolipids are substrates of ABC proteins in cell signaling, membrane biosynthesis, and inflammation, for example, and their products can favor cancer progression. Glucosylceramide (GlcCer) is a ubiquitous glycosphingolipid (GSL) generated by glucosylceramide synthase, a key regulatory enzyme encoded by the UDP-glucose ceramide glucosyltransferase (UGCG) gene. Stressed cells increase de novo biosynthesis of ceramides, which return to sub-toxic levels after UGCG mediates incorporation into GlcCer. Given that cancer cells seem to mobilize UGCG and have increased GSL content for ceramide clearance, which ultimately contributes to chemotherapy failure, here we investigated how inhibition of GSL biosynthesis affects the MDR phenotype of chronic myeloid leukemias. We found that MDR is associated with higher UGCG expression and with a complex GSL profile. UGCG inhibition with the ceramide analog d-threo-1-(3,4,-ethylenedioxy)phenyl-2-palmitoylamino-3-pyrrolidino-1-propanol (EtDO-P4) greatly reduced GSL and monosialotetrahexosylganglioside levels, and co-treatment with standard chemotherapeutics sensitized cells to mitochondrial membrane potential loss and apoptosis. ABC subfamily B member 1 (ABCB1) expression was reduced, and ABCC-mediated efflux activity was modulated by competition with nonglycosylated ceramides. Consistently, inhibition of ABCC-mediated transport reduced the efflux of exogenous C6-ceramide. Overall, UGCG inhibition impaired the malignant glycophenotype of MDR leukemias, which typically overcomes drug resistance through distinct mechanisms. This work sheds light on the involvement of GSL in chemotherapy failure, and its findings suggest that targeted GSL modulation could help manage MDR leukemias.

Andrew S. Kimball
Sep 1, 2017; 66:2459-2471
Immunology and Transplantation

Maria Sörhede Winzell
Dec 1, 2004; 53:S215-S219
Section V: The Incretin Pathway

Anne Jörns
Apr 1, 2020; 69:624-633
Islet Studies

Jens Juul Holst
Dec 1, 2004; 53:S197-S204
Section V: The Incretin Pathway

VOLUME 295 (2020) PAGES 3285–3300An incorrect graph was used in Fig. 5C. This error has now been corrected. Additionally, some of the statistics reported in the legend and text referring to Fig. 5C were incorrect. The F statistics for Fig. 5C should state Fken(3,16) = 7.454, p < 0.01; FCCCP(1,16) = 102.9, p < 0.0001; Finteraction(3,16) = 7.480, p < 0.01. This correction does not affect the results or conclusions of this work.jbc;295/17/5835/F5F1F5Figure 5C.

VOLUME 295 (2020) PAGES 1898–1914Yichen Zhong's name was misspelled. The correct spelling is shown above.

Invitation Only Research Event

AS ARTISTES and musicians try to manage the situation brought on by COVID-19’s stranglehold on the world and its economy, in the interim, many have resorted to hosting live-stream events. But that only succeeds to a point. Performers retain their...

Approximately 10% of patients with type 2 diabetes suffer from latent autoimmune diabetes in adults (LADA). This study provides a systematic assessment of the pathology of the endocrine pancreas of patients with LADA and for comparison in a first rat model mimicking the characteristics of patients with LADA. Islets in human and rat pancreases were analyzed by immunohistochemistry for immune cell infiltrate composition, by in situ RT-PCR and quantitative real-time PCR of laser microdissected islets for gene expression of proinflammatory cytokines, the proliferation marker proliferating cell nuclear antigen (PCNA), the anti-inflammatory cytokine interleukin (IL) 10, and the apoptosis markers caspase 3 and TUNEL as well as insulin. Human and rat LADA pancreases showed differences in areas of the pancreas with respect to immune cell infiltration and a changed ratio between the number of macrophages and CD8 T cells toward macrophages in the islet infiltrate. Gene expression analyses revealed a changed ratio due to an increase of IL-1β and a decrease of tumor necrosis factor-α. IL-10, PCNA, and insulin expression were increased in the LADA situation, whereas caspase 3 gene expression was reduced. The analyses into the underlying pathology in human as well as rat LADA pancreases provided identical results, allowing the conclusion that LADA is a milder form of autoimmune diabetes in patients of an advanced age.

Mendelian randomisation - it’s a technique that uses the chance distribution of genes in a population, combined with big data sets, to investigate causative relationships. But there are a lot of questions we have in The BMJ about how the technique works - the association between genes and apparently non-biologically mediated behaviours, how much...

For the next few months Talk Evidence is going to focus on the new corona virus pandemic. There is an enormous amount of uncertainty about the disease, what the symptoms are, fatality rate, treatment options, things we shouldn't be doing. We're going to try to get away from the headlines and talk about what we need to know - to hopefully give...

Night shift work, behavioral rhythms, and the common MTNR1B risk single nucleotide polymorphism (SNP), rs10830963, associate with type 2 diabetes; however, whether they exert joint effects to exacerbate type 2 diabetes risk is unknown. Among employed participants of European ancestry in the UK Biobank (N = 189,488), we aimed to test the cross-sectional independent associations and joint interaction effects of these risk factors on odds of type 2 diabetes (n = 5,042 cases) and HbA_1c levels (n = 175,156). Current shift work, definite morning or evening preference, and MTNR1B rs10830963 risk allele associated with type 2 diabetes and HbA_1c levels. The effect of rs10830963 was not modified by shift work schedules. While marginal evidence of interaction between self-reported morningness-eveningness preference and rs10830963 on risk of type 2 diabetes was seen, this interaction did not persist when analysis was expanded to include all participants regardless of employment status and when accelerometer-derived sleep midpoint was used as an objective measure of morningness-eveningness preference. Our findings suggest that MTNR1B risk allele carriers who carry out shift work or have more extreme morningness-eveningness preference may not have enhanced risk of type 2 diabetes.

This study aims to model genetic, immunologic, metabolomics, and proteomic biomarkers for development of islet autoimmunity (IA) and progression to type 1 diabetes in a prospective high-risk cohort. We studied 67 children: 42 who developed IA (20 of 42 progressed to diabetes) and 25 control subjects matched for sex and age. Biomarkers were assessed at four time points: earliest available sample, just prior to IA, just after IA, and just prior to diabetes onset. Predictors of IA and progression to diabetes were identified across disparate sources using an integrative machine learning algorithm and optimization-based feature selection. Our integrative approach was predictive of IA (area under the receiver operating characteristic curve [AUC] 0.91) and progression to diabetes (AUC 0.92) based on standard cross-validation (CV). Among the strongest predictors of IA were change in serum ascorbate, 3-methyl-oxobutyrate, and the PTPN22 (rs2476601) polymorphism. Serum glucose, ADP fibrinogen, and mannose were among the strongest predictors of progression to diabetes. This proof-of-principle analysis is the first study to integrate large, diverse biomarker data sets into a limited number of features, highlighting differences in pathways leading to IA from those predicting progression to diabetes. Integrated models, if validated in independent populations, could provide novel clues concerning the pathways leading to IA and type 1 diabetes.

Obesity-associated type 2 diabetes mellitus (T2DM) entails insulin resistance and loss of β-cell mass. Adipose tissue mitochondrial dysfunction is emerging as a key component in the etiology of T2DM. Identifying approaches to preserve mitochondrial function, adipose tissue integrity, and β-cell mass during obesity is a major challenge. Mitochondrial ferritin (FtMT) is a mitochondrial matrix protein that chelates iron. We sought to determine whether perturbation of adipocyte mitochondria influences energy metabolism during obesity. We used an adipocyte-specific doxycycline-inducible mouse model of FtMT overexpression (FtMT-Adip mice). During a dietary challenge, FtMT-Adip mice are leaner but exhibit glucose intolerance, low adiponectin levels, increased reactive oxygen species damage, and elevated GDF15 and FGF21 levels, indicating metabolically dysfunctional fat. Paradoxically, despite harboring highly dysfunctional fat, transgenic mice display massive β-cell hyperplasia, reflecting a beneficial mitochondria-induced fat-to-pancreas interorgan signaling axis. This identifies the unique and critical impact that adipocyte mitochondrial dysfunction has on increasing β-cell mass during obesity-related insulin resistance.

Type 2 diabetes accounts for 90% of the population with diabetes, and these patients are generally obese and hyperlipidemic. In addition to hyperglycemia, hyperlipidemia is also closely related with diabetic retinopathy. The aim was to investigate retinopathy in a model closely mimicking the normal progression and metabolic features of the population with type 2 diabetes and elucidate the molecular mechanism. Retinopathy was evaluated in rats fed a 45% kcal as fat diet for 8 weeks before administering streptozotocin, 30 mg/kg body weight (T2D), and compared with age- and duration-matched type 1 diabetic rats (T1D) (60 mg/kg streptozotocin). The role of epigenetic modifications in mitochondrial damage was evaluated in retinal microvasculature. T2D rats were obese and severely hyperlipidemic, with impaired glucose and insulin tolerance compared with age-matched T1D rats. While at 4 months of diabetes, T1D rats had no detectable retinopathy, T2D rats had significant retinopathy, their mitochondrial copy numbers were lower, and mtDNA and Rac1 promoter DNA methylation was exacerbated. At 6 months, retinopathy was comparable in T2D and T1D rats, suggesting that obesity exaggerates hyperglycemia-induced epigenetic modifications, accelerating mitochondrial damage and diabetic retinopathy. Thus, maintenance of good lifestyle and BMI could be beneficial in regulating epigenetic modifications and preventing/retarding retinopathy in patients with diabetes.

Invitation Only Research Event

2 September 2015

This paper explores the potential of using public procurement policy to promote the uptake of sustainable food products in order to reduce imports of agricultural products associated with deforestation.

28 January 2016

Private-sector commitments and government policies, a loss of support for biofuels, and health concerns over the consumption of palm oil and beef, are factors that may help to restrict the further expansion of agricultural land into forest areas.

Inflammation contributes to ventricular remodeling after myocardial ischemia, but its role in nonischemic heart failure is poorly understood. Local tissue inflammation is difficult to assess serially during pathogenesis. Although ¹⁸F-FDG accumulates in inflammatory leukocytes and thus may identify inflammation in the myocardial microenvironment, it remains unclear whether this imaging technique can isolate diffuse leukocytes in pressure-overload heart failure. We aimed to evaluate whether inflammation with ¹⁸F-FDG can be serially imaged in the early stages of pressure-overload–induced heart failure and to compare the time course with functional impairment assessed by cardiac MRI. Methods: C57Bl6/N mice underwent transverse aortic constriction (TAC) (n = 22), sham surgery (n = 12), or coronary ligation as an inflammation-positive control (n = 5). MRI assessed ventricular geometry and contractile function at 2 and 8 d after TAC. Immunostaining identified the extent of inflammatory leukocyte infiltration early in pressure overload. ¹⁸F-FDG PET scans were acquired at 3 and 7 d after TAC, under ketamine-xylazine anesthesia to suppress cardiomyocyte glucose uptake. Results: Pressure overload evoked rapid left ventricular dilation compared with sham (end-systolic volume, day 2: 40.6 ± 10.2 μL vs. 23.8 ± 1.7 μL, P < 0.001). Contractile function was similarly impaired (ejection fraction, day 2: 40.9% ± 9.7% vs. 59.2% ± 4.4%, P < 0.001). The severity of contractile impairment was proportional to histology-defined myocardial macrophage density on day 8 (r = –0.669, P = 0.010). PET imaging identified significantly higher left ventricular ¹⁸F-FDG accumulation in TAC mice than in sham mice on day 3 (10.5 ± 4.1 percentage injected dose [%ID]/g vs. 3.8 ± 0.9 %ID/g, P < 0.001) and on day 7 (7.8 ± 3.7 %ID/g vs. 3.0 ± 0.8 %ID/g, P = 0.006), though the efficiency of cardiomyocyte suppression was variable among TAC mice. The ¹⁸F-FDG signal correlated with ejection fraction (r = –0.75, P = 0.01) and ventricular volume (r = 0.75, P < 0.01). Western immunoblotting demonstrated a 60% elevation of myocardial glucose transporter 4 expression in the left ventricle at 8 d after TAC, indicating altered glucose metabolism. Conclusion: TAC induces rapid changes in left ventricular geometry and contractile function, with a parallel modest infiltration of inflammatory macrophages. Metabolic remodeling overshadows inflammatory leukocyte signal using ¹⁸F-FDG PET imaging. More selective inflammatory tracers are requisite to identify the diffuse local inflammation in pressure overload.

Fibroblast activation protein (FAP), which promotes tumor growth and progression, is overexpressed in cancer-associated fibroblasts of many human epithelial cancers. Because of its low expression in normal organs, FAP is an excellent target for theranostics. In this study, we used radionuclides with relatively long half-lives, ⁶⁴Cu (half-life, 12.7 h) and ²²⁵Ac (half-life, 10 d), to label FAP inhibitors (FAPIs) in mice with human pancreatic cancer xenografts. Methods: Male nude mice (body weight, 22.5 ± 1.2 g) were subcutaneously injected with human pancreatic cancer cells (PANC-1, n = 12; MIA PaCa-2, n = 8). Tumor xenograft mice were investigated after the intravenous injection of ⁶⁴Cu-FAPI-04 (7.21 ± 0.46 MBq) by dynamic and delayed PET scans (2.5 h after injection). Static scans 1 h after the injection of ⁶⁸Ga-FAPI-04 (3.6 ± 1.4 MBq) were also acquired for comparisons using the same cohort of mice (n = 8). Immunohistochemical staining was performed to confirm FAP expression in tumor xenografts using an FAP-α-antibody. For radioligand therapy, ²²⁵Ac-FAPI-04 (34 kBq) was injected into PANC-1 xenograft mice (n = 6). Tumor size was monitored and compared with that of control mice (n = 6). Results: Dynamic imaging of ⁶⁴Cu-FAPI-04 showed rapid clearance through the kidneys and slow washout from tumors. Delayed PET imaging of ⁶⁴Cu-FAPI-04 showed mild uptake in tumors and relatively high uptake in the liver and intestine. Accumulation levels in the tumor or normal organs were significantly higher for ⁶⁴Cu-FAPI-04 than for ⁶⁸Ga-FAPI-04, except in the heart, and excretion in the urine was higher for ⁶⁸Ga-FAPI-04 than for ⁶⁴Cu-FAPI-04. Immunohistochemical staining revealed abundant FAP expression in the stroma of xenografts. ²²⁵Ac-FAPI-04 injection showed significant tumor growth suppression in the PANC-1 xenograft mice, compared with the control mice, without a significant change in body weight. Conclusion: This proof-of-concept study showed that ⁶⁴Cu-FAPI-04 and ²²⁵Ac-FAPI-04 could be used in theranostics for the treatment of FAP-expressing pancreatic cancer. α-therapy targeting FAP in the cancer stroma is effective and will contribute to the development of a new treatment strategy.

Optimal immune-based therapies for type 1 diabetes (T1D) should restore self-tolerance without inducing chronic immunosuppression. CD4⁺Foxp3⁺ regulatory T cells (T_regs) are a key cell population capable of facilitating durable immune tolerance. However, clinical trials with expanded T_regs in T1D and solid-organ transplant recipients are limited by poor T_reg engraftment without host manipulation. We showed that T_reg engraftment and therapeutic benefit in nonautoimmune models required ablative host conditioning. Here, we evaluated T_reg engraftment and therapeutic efficacy in the nonobese diabetic (NOD) mouse model of autoimmune diabetes using nonablative, combinatorial regimens involving the anti-CD3 (αCD3), cyclophosphamide (CyP), and IAC (IL-2/JES6–1) antibody complex. We demonstrate that αCD3 alone induced substantial T-cell depletion, impacting both conventional T cells (T_conv) and T_regs, subsequently followed by more rapid rebound of T_regs. Despite robust depletion of host T_conv and host T_regs, donor T_regs failed to engraft even with interleukin-2 (IL-2) support. A single dose of CyP after αCD3 depleted rebounding host T_regs and resulted in a 43-fold increase in donor T_reg engraftment, yet polyclonal donor T_regs failed to reverse diabetes. However, infusion of autoantigen-specific T_regs after αCD3 alone resulted in robust T_reg engraftment within the islets and induced remission in all mice. This novel combinatorial therapy promotes engraftment of autoantigen-specific donor T_regs and controls islet autoimmunity without long-term immunosuppression.

OBJECTIVE

Previous randomized trials found that treating periodontitis improved glycemic control in patients with type 2 diabetes (T2D), thus lowering the risks of developing T2D-related microvascular diseases and cardiovascular disease (CVD). Some payers in the U.S. have started covering nonsurgical periodontal treatment for those with chronic conditions, such as diabetes. We sought to identify the cost-effectiveness of expanding periodontal treatment coverage among patients with T2D.

Mary M Tai
Feb 1, 1994; 17:152-154
Short Report

Steven M Haffner
Oct 1, 1996; 19:1138-1141
Short Report

At least two people died and more than a dozen were hurt Friday when a moderate earthquake struck in Iran's northern city of Damavand, near Tehran.

Boeing was awarded a $128.5 million modification to its Ground-based Midcourse Defense development and sustainment contract Thursday, according to the Pentagon.