ri Combined inhibition of MDM2 and BCR-ABL1 tyrosine kinase targets chronic myeloid leukemia stem/progenitor cells in a murine model By www.haematologica.org Published On :: 2020-05-01T00:05:41-07:00 Although highly effective, BCR-ABL1 tyrosine kinase inhibitors do not target chronic myeloid leukemia (CML) stem cells. Most patients relapse upon tyrosine kinase inhibitor therapy cessation. We reported previously that combined BCR-ABL1 and BCL-2 inhibition synergistically targets CML stem/progenitor cells. p53 induces apoptosis mainly by modulating BCL-2 family proteins. Although infrequently mutated in CML, p53 is antagonized by MDM2, which is regulated by BCR-ABL1 signaling. We hypothesized that MDM2 inhibition could sensitize CML cells to tyrosine kinase inhibitors. Using an inducible transgenic Scl-tTa-BCR-ABL1 murine CML model, we found, by RT-PCR and CyTOF proteomics increased p53 signaling in CML bone marrow (BM) cells compared with controls in CD45+ and linage-SCA-1+C-KIT+ populations. CML BM cells were more sensitive to exogenous BH3 peptides than controls. Combined inhibition of BCR-ABL1 with imatinib and MDM2 with DS-5272 increased NOXA level, markedly reduced leukemic linage-SCA-1+C-KIT+ cells and hematopoiesis, decreased leukemia burden, significantly prolonged the survival of mice engrafted with BM cells from Scl-tTa-BCR-ABL1 mice, and significantly decreased CML stem cell frequency in secondary transplantations. Our results suggest that CML stem/progenitor cells have increased p53 signaling and a propensity for apoptosis. Combined MDM2 and BCR-ABL1 inhibition targets CML stem/progenitor cells and has the potential to improve cure rates for CML. Full Article
ri Oncogenic fusion protein BCR-FGFR1 requires the breakpoint cluster region-mediated oligomerization and chaperonin Hsp90 for activation By www.haematologica.org Published On :: 2020-05-01T00:05:41-07:00 Mutation and translocation of fibroblast growth factor receptors often lead to aberrant signaling and cancer. This work focuses on the t(8;22)(p11;q11) chromosomal translocation which creates the breakpoint cluster region (BCR) fibroblast growth factor receptor1 (FGFR1) (BCR-FGFR1) fusion protein. This fusion occurs in stem cell leukemia/lymphoma, which can progress to atypical chronic myeloid leukemia, acute myeloid leukemia, or B-cell lymphoma. This work focuses on the biochemical characterization of BCR-FGFR1 and identification of novel therapeutic targets. The tyrosine kinase activity of FGFR1 is required for biological activity as shown using transformation assays, interleukin-3 independent cell proliferation, and liquid chromatography/mass spectroscopy analyses. Furthermore, BCR contributes a coiled-coil oligomerization domain, also essential for oncogenic transformation by BCR-FGFR1. The importance of salt bridge formation within the coiled-coil domain is demonstrated, as disruption of three salt bridges abrogates cellular transforming ability. Lastly, BCR-FGFR1 acts as a client of the chaperonin heat shock protein 90 (Hsp90), suggesting that BCR-FGFR1 relies on Hsp90 complex to evade proteasomal degradation. Transformed cells expressing BCR-FGFR1 are sensitive to the Hsp90 inhibitor Ganetespib, and also respond to combined treatment with Ganetespib plus the FGFR inhibitor BGJ398. Collectively, these data suggest novel therapeutic approaches for future stem cell leukemia/lymphoma treatment: inhibition of BCR oligomerization by disruption of required salt bridges; and inhibition of the chaperonin Hsp90 complex. Full Article
ri Appropriation of GPIb{alpha} from platelet-derived extracellular vesicles supports monocyte recruitment in systemic inflammation By www.haematologica.org Published On :: 2020-05-01T00:05:41-07:00 Interactions between platelets, leukocytes and the vessel wall provide alternative pathological routes of thrombo-inflammatory leukocyte recruitment. We found that when platelets were activated by a range of agonists in whole blood, they shed platelet-derived extracellular vesicles which rapidly and preferentially bound to blood monocytes compared to other leukocytes. Platelet-derived extracellular vesicle binding to monocytes was initiated by P-selectin-dependent adhesion and was stabilised by binding of phosphatidylserine. These interactions resulted in the progressive transfer of the platelet adhesion receptor GPIbα to monocytes. GPIbα+-monocytes tethered and rolled on immobilised von Willebrand Factor or were recruited and activated on endothelial cells treated with TGF-β1 to induce the expression of von Willebrand Factor. In both models monocyte adhesion was ablated by a function-blocking antibody against GPIbα. Monocytes could also bind platelet-derived extracellular vesicle in mouse blood in vitro and in vivo. Intratracheal instillations of diesel nanoparticles, to model chronic pulmonary inflammation, induced accumulation of GPIbα on circulating monocytes. In intravital experiments, GPIbα+-monocytes adhered to the microcirculation of the TGF-β1-stimulated cremaster muscle, while in the ApoE–/– model of atherosclerosis, GPIbα+-monocytes adhered to the carotid arteries. In trauma patients, monocytes bore platelet markers within 1 hour of injury, the levels of which correlated with severity of trauma and resulted in monocyte clearance from the circulation. Thus, we have defined a novel thrombo-inflammatory pathway in which platelet-derived extracellular vesicles transfer a platelet adhesion receptor to monocytes, allowing their recruitment in large and small blood vessels, and which is likely to be pathogenic. Full Article
ri Extensive multilineage analysis in patients with mixed chimerism after allogeneic transplantation for sickle cell disease: insight into hematopoiesis and engraftment thresholds for gene therapy By www.haematologica.org Published On :: 2020-05-01T00:05:41-07:00 Although studies of mixed chimerism following hematopoietic stem cell transplantation in patients with sickle cell disease (SCD) may provide insights into the engraftment needed to correct the disease and into immunological reconstitution, an extensive multilineage analysis is lacking. We analyzed chimerism simultaneously in peripheral erythroid and granulomonocytic precursors/progenitors, highly purified B and T lymphocytes, monocytes, granulocytes and red blood cells (RBC). Thirty-four patients with mixed chimerism and ≥12 months of follow-up were included. A selective advantage of donor RBC and their progenitors/precursors led to full chimerism in mature RBC (despite partial engraftment of other lineages), and resulted in the clinical control of the disease. Six patients with donor chimerism <50% had hemolysis (reticulocytosis) and higher HbS than their donor. Four of them had donor chimerism <30%, including a patient with AA donor (hemoglobin >10 g/dL) and three with AS donors (hemoglobin <10 g/dL). However, only one vaso-occlusive crisis occurred with 68.7% HbS. Except in the patients with the lowest chimerism, the donor engraftment was lower for T cells than for the other lineages. In a context of mixed chimerism after hematopoietic stem cell transplantation for SCD, myeloid (rather than T cell) engraftment was the key efficacy criterion. Results show that myeloid chimerism as low as 30% was sufficient to prevent a vaso-occlusive crisis in transplants from an AA donor but not constantly from an AS donor. However, the correction of hemolysis requires higher donor chimerism levels (i.e. ≥50%) in both AA and AS recipients. In the future, this group of patients may need a different therapeutic approach. Full Article
ri Long-term outcome of a randomized controlled study in patients with newly diagnosed severe aplastic anemia treated with antithymocyte globulin and cyclosporine, with or without granulocyte colony-stimulating factor: a Severe Aplastic Anemia Working Party By www.haematologica.org Published On :: 2020-05-01T00:05:41-07:00 This follow-up study of a randomized, prospective trial included 192 patients with newly diagnosed severe aplastic anemia receiving antithymoglobulin and cyclosporine, with or without granulocyte colony-stimulating factor (G-CSF). We aimed to evaluate the long-term effect of G-CSF on overall survival, event-free survival, probability of secondary myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML), clinical paroxysmal nocturnal hemoglobinuria, relapse, avascular osteonecrosis and chronic kidney disease. The median follow-up was 11.7 years (95% CI, 10.9-12.5). The overall survival rate at 15 years was 57±12% in the group given G-CSF and 63±12% in the group not given G-CSF (P=0.92); the corresponding event-free survival rates were 24±10% and 23±10%, respectively (P=0.36). In total, 9 patients developed MDS or AML, 10 only a clonal cytogenetic abnormality, 7 a solid cancer, 18 clinical paroxysmal nocturnal hemoglobinuria, 8 osteonecrosis, and 12 chronic kidney disease, without any difference between patients treated with or without G-CSF. The cumulative incidence of MDS, AML or isolated cytogenetic abnormality at 15 years was 8.5±3% for the G-CSF group and 8.2±3% for the non-G-CSF group (P=0.90). The cumulative incidence of any late event including myelodysplastic syndrome or acute myeloid leukemia, isolated cytogenetic abnormalities, solid cancer, clinical paroxysmal nocturnal hemoglobinuria, aseptic osteonecrosis, chronic kidney disease and relapse was 50±12% for the G-CSF group and 49±12% for the non-G-CSF group (P=0.65). Our results demonstrate that it is unlikely that G-CSF has an impact on the outcome of severe aplastic anemia; nevertheless, very late events are common and eventually affect the prognosis of these patients, irrespectively of their age at the time of immunosuppressive therapy (NCT01163942). Full Article
ri Prion protein deficiency impairs hematopoietic stem cell determination and sensitizes myeloid progenitors to irradiation By www.haematologica.org Published On :: 2020-05-01T00:05:41-07:00 Highly conserved among species and expressed in various types of cells, numerous roles have been attributed to the cellular prion protein (PrPC). In hematopoiesis, PrPC regulates hematopoietic stem cell self-renewal but the mechanisms involved in this regulation are unknown. Here we show that PrPC regulates hematopoietic stem cell number during aging and their determination towards myeloid progenitors. Furthermore, PrPC protects myeloid progenitors against the cytotoxic effects of total body irradiation. This radioprotective effect was associated with increased cellular prion mRNA level and with stimulation of the DNA repair activity of the Apurinic/pyrimidinic endonuclease 1, a key enzyme of the base excision repair pathway. Altogether, these results show a previously unappreciated role of PrPC in adult hematopoiesis, and indicate that PrPC-mediated stimulation of BER activity might protect hematopoietic progenitors from the cytotoxic effects of total body irradiation. Full Article
ri Early growth response 1 regulates hematopoietic support and proliferation in human primary bone marrow stromal cells By www.haematologica.org Published On :: 2020-05-01T00:05:41-07:00 Human bone marrow stromal cells (BMSC) are key elements of the hematopoietic environment and they play a central role in bone and bone marrow physiology. However, how key stromal cell functions are regulated is largely unknown. We analyzed the role of the immediate early response transcription factor EGR1 as key stromal cell regulator and found that EGR1 was highly expressed in prospectively-isolated primary BMSC, down-regulated upon culture, and low in non-colony-forming CD45neg stromal cells. Furthermore, EGR1 expression was lower in proliferative regenerating adult and fetal primary cells compared to adult steady-state BMSC. Overexpression of EGR1 in stromal cells induced potent hematopoietic stroma support as indicated by an increased production of transplantable CD34+CD90+ hematopoietic stem cells in expansion co-cultures. The improvement in bone marrow stroma support function was mediated by increased expression of hematopoietic supporting genes, such as VCAM1 and CCL28. Furthermore, EGR1 overexpression markedly decreased stromal cell proliferation whereas EGR1 knockdown caused the opposite effects. These findings thus show that EGR1 is a key stromal transcription factor with a dual role in regulating proliferation and hematopoietic stroma support function that is controlling a genetic program to co-ordinate the specific functions of BMSC in their different biological contexts. Full Article
ri Structured assessment of frailty in multiple myeloma as a paradigm of individualized treatment algorithms in cancer patients at advanced age By www.haematologica.org Published On :: 2020-05-01T00:05:41-07:00 Full Article
ri Genetics of "high-risk" chronic lymphocytic leukemia in the times of chemoimmunotherapy By www.haematologica.org Published On :: 2020-05-01T00:05:41-07:00 Full Article
ri A post-stem cell transplant risk score for Philadelphia-negative acute lymphoblastic leukemia By www.haematologica.org Published On :: 2020-05-01T00:05:41-07:00 Full Article
ri 100-Year Old Haematologica Images: The Quarrel about the Origin of Platelets (I) By www.haematologica.org Published On :: 2020-05-01T00:05:41-07:00 Full Article
ri Characterization of response and corneal events with extended follow-up after belantamab mafodotin (GSK2857916) monotherapy for patients with relapsed multiple myeloma: a case series from the first-time-in-human clinical trial By www.haematologica.org Published On :: 2020-05-01T00:05:42-07:00 Full Article
ri Severe treatment-refractory T-cell-mediated immune skin toxicities observed with obinutuzumab/rituximab-atezo-pola in two patients with follicular lymphoma By www.haematologica.org Published On :: 2020-05-01T00:05:42-07:00 Full Article
ri Revisiting the link between platelets and depression through genetic epidemiology: new insights from platelet distribution width By www.haematologica.org Published On :: 2020-05-01T00:05:42-07:00 Full Article
ri CRISPR/Cas9-mediated gene deletion efficiently retards the progression of Philadelphia-positive acute lymphoblastic leukemia in a p210 BCR-ABL1T315I mutation mouse model By www.haematologica.org Published On :: 2020-05-01T00:05:42-07:00 Full Article
ri Disease progression in myeloproliferative neoplasms: comparing patients in accelerated phase with those in chronic phase with increased blasts (<10%) or with other types of disease progression By www.haematologica.org Published On :: 2020-05-01T00:05:42-07:00 Full Article
ri Suppressive effects of anagrelide on cell cycle progression and the maturation of megakaryocyte progenitor cell lines in human induced pluripotent stem cells By www.haematologica.org Published On :: 2020-05-01T00:05:42-07:00 Full Article
ri Functional assessment of glucocerebrosidase modulator efficacy in primary patient-derived macrophages is essential for drug development and patient stratification By www.haematologica.org Published On :: 2020-05-01T00:05:42-07:00 Full Article
ri A Mendelian Randomization Study Provides Evidence That Adiposity and Dyslipidemia Lead to Lower Urinary Albumin-to-Creatinine Ratio, a Marker of Microvascular Function By diabetes.diabetesjournals.org Published On :: 2020-04-20T12:00:34-07:00 Urinary albumin-to-creatinine ratio (ACR) is a marker of diabetic nephropathy and microvascular damage. Metabolic-related traits are observationally associated with ACR, but their causal role is uncertain. Here, we confirmed ACR as a marker of microvascular damage and tested whether metabolic-related traits have causal relationships with ACR. The association between ACR and microvascular function (responses to acetylcholine [ACH] and sodium nitroprusside) was tested in the SUMMIT study. Two-sample Mendelian randomization (MR) was used to infer the causal effects of 11 metabolic risk factors, including glycemic, lipid, and adiposity traits, on ACR. MR was performed in up to 440,000 UK Biobank and 54,451 CKDGen participants. ACR was robustly associated with microvascular function measures in SUMMIT. Using MR, we inferred that higher triglyceride (TG) and LDL cholesterol (LDL-C) levels caused elevated ACR. A 1 SD higher TG and LDL-C level caused a 0.062 (95% CI 0.040, 0.083) and a 0.026 (95% CI 0.008, 0.044) SD higher ACR, respectively. There was evidence that higher body fat and visceral body fat distribution caused elevated ACR, while a metabolically "favorable adiposity" phenotype lowered ACR. ACR is a valid marker for microvascular function. MR suggested that seven traits have causal effects on ACR, highlighting the role of adiposity-related traits in causing lower microvascular function. Full Article
ri Risk Factors for Diabetic Peripheral Neuropathy and Cardiovascular Autonomic Neuropathy in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) Study By diabetes.diabetesjournals.org Published On :: 2020-04-20T12:00:34-07:00 The Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study demonstrated that intensive glucose control reduced the risk of developing diabetic peripheral neuropathy (DPN) and cardiovascular autonomic neuropathy (CAN). We evaluated multiple risk factors and phenotypes associated with DPN and CAN in this large, well-characterized cohort of participants with type 1 diabetes, followed for >23 years. DPN was defined by symptoms, signs, and nerve conduction study abnormalities in ≥2 nerves; CAN was assessed using standardized cardiovascular reflex tests. Generalized estimating equation models assessed the association of DPN and CAN with individual risk factors measured repeatedly. During DCCT/EDIC, 33% of participants developed DPN and 44% CAN. Higher mean HbA1c was the most significant risk factor for DPN, followed by older age, longer duration, greater height, macroalbuminuria, higher mean pulse rate, β-blocker use, and sustained albuminuria. The most significant risk factor for CAN was older age, followed by higher mean HbA1c, sustained albuminuria, longer duration of type 1 diabetes, higher mean pulse rate, higher mean systolic blood pressure, β-blocker use, estimated glomerular filtration rate <60 mL/min/1.73 m2, higher most recent pulse rate, and cigarette smoking. These findings identify risk factors and phenotypes of participants with diabetic neuropathy that can be used in the design of new interventional trials and for personalized approaches to neuropathy prevention. Full Article
ri Claudin-5 Redistribution Induced by Inflammation Leads to Anti-VEGF-Resistant Diabetic Macular Edema By diabetes.diabetesjournals.org Published On :: 2020-04-20T12:00:34-07:00 Approximately 40% of patients with diabetic macular edema (DME) are resistant to anti–vascular endothelial growth factor (VEGF) therapy (rDME). Here, we demonstrate that significant correlations between inflammatory cytokines and VEGF, as observed in naive DME, are lost in patients with rDME. VEGF overexpression in the mouse retina caused delayed inflammatory cytokine upregulation, monocyte/macrophage infiltration (CD11b+ Ly6C+ CCR2+ cells), macrophage/microglia activation (CD11b+ CD80+ cells), and blood-retinal barrier disruption due to claudin-5 redistribution, which did not recover with VEGF blockade alone. Phosphorylated protein analysis of VEGF-overexpressed retinas revealed rho-associated coiled-coil–containing protein kinase (ROCK) activation. Administration of ripasudil, a selective ROCK inhibitor, attenuated retinal inflammation and claudin-5 redistribution. Ripasudil also contributed to the stability of claudin-5 expression by both transcriptional enhancement and degradation suppression in inflammatory cytokine–stimulated endothelium. Notably, the anti-VEGF agent and the ROCK inhibitor were synergic in suppressing cytokine upregulation, monocyte/macrophage infiltration, macrophage/microglia activation, and claudin-5 redistribution. Furthermore, in vitro analysis confirmed that claudin-5 redistribution depends on ROCK2 but not on ROCK1. This synergistic effect was also confirmed in human rDME cases. Our results suggest that ROCK-mediated claudin-5 redistribution by inflammation is a key mechanism in the anti-VEGF resistance of DME. Full Article
ri Microencapsulated G3C Hybridoma Cell Graft Delays the Onset of Spontaneous Diabetes in NOD Mice by an Expansion of Gitr+ Treg Cells By diabetes.diabetesjournals.org Published On :: 2020-04-20T12:00:34-07:00 As an alternative to lifelong insulin supplementation, potentiation of immune tolerance in patients with type 1 diabetes could prevent the autoimmune destruction of pancreatic islet β-cells. This study was aimed to assess whether the G3c monoclonal antibody (mAb), which triggers the glucocorticoid-induced TNFR-related (Gitr) costimulatory receptor, promotes the expansion of regulatory T cells (Tregs) in SV129 (wild-type) and diabetic-prone NOD mice. The delivery of the G3c mAb via G3C hybridoma cells enveloped in alginate-based microcapsules (G3C/cps) for 3 weeks induced Foxp3+ Treg-cell expansion in the spleen of wild-type mice but not in Gitr–/– mice. G3C/cps also induced the expansion of nonconventional Cd4+Cd25–/lowFoxp3lowGitrint/high (GITR single-positive [sp]) Tregs. Both Cd4+Cd25+GitrhighFoxp3+ and GITRsp Tregs (including also antigen-specific cells) were expanded in the spleen and pancreas of G3C/cps-treated NOD mice, and the number of intact islets was higher in G3C/cps-treated than in empty cps-treated and untreated animals. Consequently, all but two G3C/cps-treated mice did not develop diabetes and all but one survived until the end of the 24-week study. In conclusion, long-term Gitr triggering induces Treg expansion, thereby delaying/preventing diabetes development in NOD mice. This therapeutic approach may have promising clinical potential for the treatment of inflammatory and autoimmune diseases. Full Article
ri Interindividual Heterogeneity of SGLT2 Expression and Function in Human Pancreatic Islets By diabetes.diabetesjournals.org Published On :: 2020-04-20T12:00:34-07:00 Studies implicating sodium–glucose cotransporter 2 (SGLT2) inhibitors in glucagon secretion by pancreatic α-cells reported controversial results. We hypothesized that interindividual heterogeneity in SGLT2 expression and regulation may affect glucagon secretion by human α-cells in response to SGLT2 inhibitors. An unbiased RNA-sequencing analysis of 207 donors revealed an unprecedented level of heterogeneity of SLC5A2 expression. To determine heterogeneity of SGLT2 expression at the protein level, the anti-SGLT2 antibody was first rigorously evaluated for specificity, followed by Western blot and immunofluorescence analysis on islets from 10 and 12 donors, respectively. The results revealed a high interdonor variability of SGLT2 protein expression. Quantitative analysis of 665 human islets showed a significant SGLT2 protein colocalization with glucagon but not with insulin or somatostatin. Moreover, glucagon secretion by islets from 31 donors at low glucose (1 mmol/L) was also heterogeneous and correlated with dapagliflozin-induced glucagon secretion at 6 mmol/L glucose. Intriguingly, islets from three donors did not secrete glucagon in response to either 1 mmol/L glucose or dapagliflozin, indicating a functional impairment of the islets of these donors to glucose sensing and SGLT2 inhibition. Collectively, these data suggest that heterogeneous expression of SGLT2 protein and variability in glucagon secretory responses contribute to interindividual differences in response to SGLT2 inhibitors. Full Article
ri Inorganic Nitrate Promotes Glucose Uptake and Oxidative Catabolism in White Adipose Tissue Through the XOR-Catalyzed Nitric Oxide Pathway By diabetes.diabetesjournals.org Published On :: 2020-04-20T12:00:34-07:00 An aging global population combined with sedentary lifestyles and unhealthy diets has contributed to an increasing incidence of obesity and type 2 diabetes. These metabolic disorders are associated with perturbations to nitric oxide (NO) signaling and impaired glucose metabolism. Dietary inorganic nitrate, found in high concentration in green leafy vegetables, can be converted to NO in vivo and demonstrates antidiabetic and antiobesity properties in rodents. Alongside tissues including skeletal muscle and liver, white adipose tissue is also an important physiological site of glucose disposal. However, the distinct molecular mechanisms governing the effect of nitrate on adipose tissue glucose metabolism and the contribution of this tissue to the glucose-tolerant phenotype remain to be determined. Using a metabolomic and stable-isotope labeling approach, combined with transcriptional analysis, we found that nitrate increases glucose uptake and oxidative catabolism in primary adipocytes and white adipose tissue of nitrate-treated rats. Mechanistically, we determined that nitrate induces these phenotypic changes in primary adipocytes through the xanthine oxidoreductase–catalyzed reduction of nitrate to NO and independently of peroxisome proliferator–activated receptor-α. The nitrate-mediated enhancement of glucose uptake and catabolism in white adipose tissue may be a key contributor to the antidiabetic effects of this anion. Full Article
ri The Limited Role of Glucagon for Ketogenesis During Fasting or in Response to SGLT2 Inhibition By diabetes.diabetesjournals.org Published On :: 2020-04-20T12:00:34-07:00 Glucagon is classically described as a counterregulatory hormone that plays an essential role in the protection against hypoglycemia. In addition to its role in the regulation of glucose metabolism, glucagon has been described to promote ketosis in the fasted state. Sodium–glucose cotransporter 2 inhibitors (SGLT2i) are a new class of glucose-lowering drugs that act primarily in the kidney, but some reports have described direct effects of SGLT2i on α-cells to stimulate glucagon secretion. Interestingly, SGLT2 inhibition also results in increased endogenous glucose production and ketone production, features common to glucagon action. Here, we directly test the ketogenic role of glucagon in mice, demonstrating that neither fasting- nor SGLT2i-induced ketosis is altered by interruption of glucagon signaling. Moreover, any effect of glucagon to stimulate ketogenesis is severely limited by its insulinotropic actions. Collectively, our data suggest that fasting-associated ketosis and the ketogenic effects of SGLT2 inhibitors occur almost entirely independent of glucagon. Full Article
ri A Variation on the Theme: SGLT2 Inhibition and Glucagon Secretion in Human Islets By diabetes.diabetesjournals.org Published On :: 2020-04-20T12:00:34-07:00 Full Article
ri The Use of Mendelian Randomization to Determine the Role of Metabolic Traits on Urinary Albumin-to-Creatinine Ratio By diabetes.diabetesjournals.org Published On :: 2020-04-20T12:00:34-07:00 Full Article
ri Apolipoprotein M and Sphingosine-1-Phosphate: A Potentially Antidiabetic Tandem Carried by HDL By diabetes.diabetesjournals.org Published On :: 2020-04-20T12:00:34-07:00 Full Article
ri The Peripheral Peril: Injected Insulin Induces Insulin Insensitivity in Type 1 Diabetes By diabetes.diabetesjournals.org Published On :: 2020-04-20T12:00:34-07:00 Insulin resistance is an underappreciated facet of type 1 diabetes that occurs with remarkable consistency and considerable magnitude. Although therapeutic innovations are continuing to normalize dysglycemia, a sizable body of data suggests a second metabolic abnormality—iatrogenic hyperinsulinemia—principally drives insulin resistance and its consequences in this population and has not been addressed. We review this evidence to show that injecting insulin into the peripheral circulation bypasses first-pass hepatic insulin clearance, which leads to the unintended metabolic consequence of whole-body insulin resistance. We propose restructuring insulin therapy to restore the physiological insulin balance between the hepatic portal and peripheral circulations and thereby avoid the complications of life-long insulin resistance. As technology rapidly advances and our ability to ensure euglycemia improves, iatrogenic insulin resistance will become the final barrier to overcome to restore normal physiology, health, and life in type 1 diabetes. Full Article
ri Pervasive Small RNAs in Cardiometabolic Research: Great Potential Accompanied by Biological and Technical Barriers By diabetes.diabetesjournals.org Published On :: 2020-04-20T12:00:34-07:00 Advances in small RNA sequencing have revealed the enormous diversity of small noncoding RNA (sRNA) classes in mammalian cells. At this point, most investigators in diabetes are aware of the success of microRNA (miRNA) research and appreciate the importance of posttranscriptional gene regulation in glycemic control. Nevertheless, miRNAs are just one of multiple classes of sRNAs and likely represent only a minor fraction of sRNA sequences in a given cell. Despite the widespread appreciation of sRNAs, very little research into non-miRNA sRNA function has been completed, likely due to some major barriers that present unique challenges for study. To emphasize the importance of sRNA research in cardiometabolic diseases, we highlight the success of miRNAs and competitive endogenous RNAs in cholesterol and glucose metabolism. Moreover, we argue that sequencing studies have demonstrated that miRNAs are just the tip of the iceberg for sRNAs. We are likely standing at the precipice of immense discovery for novel sRNA-mediated gene regulation in cardiometabolic diseases. To realize this potential, we must first address critical barriers with an open mind and refrain from viewing non-miRNA sRNA function through the lens of miRNAs, as they likely have their own set of distinct regulatory factors and functional mechanisms. Full Article
ri Evolutionary insights in Amazonian turtles (Testudines, Podocnemididae): co-location of 5S rDNA and U2 snRNA and wide distribution of Tc1/Mariner [RESEARCH ARTICLE] By bio.biologists.org Published On :: 2020-04-28T06:57:17-07:00 Manoella Gemaque Cavalcante, Cleusa Yoshiko Nagamachi, Julio Cesar Pieczarka, and Renata Coelho Rodrigues Noronha Eukaryotic genomes exhibit substantial accumulation of repetitive DNA sequences. These sequences can participate in chromosomal reorganization events and undergo molecular cooption to interfere with the function and evolution of genomes. In turtles, repetitive DNA sequences appear to be accumulated at probable break points and may participate in events such as non-homologous recombination and chromosomal rearrangements. In this study, repeated sequences of 5S rDNA, U2 snRNA and Tc1/Mariner transposons were amplified from the genomes of the turtles, Podocnemis expansa and Podocnemis unifilis, and mapped by fluorescence in situ hybridization. Our data confirm the 2n=28 chromosomes for these species (the second lowest 2n in the order Testudines). We observe high conservation of the co-located 5S rDNA and U2 snRNA genes on a small chromosome pair (pair 13), and surmise that this represents the ancestral condition. Our analysis reveals a wide distribution of the Tc1/Mariner transposons and we discuss how the mobility of these transposons can act on karyotypic reorganization events (contributing to the 2n decrease of those species). Our data add new information for the order Testudines and provide important insights into the dynamics and organization of these sequences in the chelonian genomes. Full Article
ri Loss of cerebellar function selectively affects intrinsic rhythmicity of eupneic breathing [RESEARCH ARTICLE] By bio.biologists.org Published On :: 2020-04-13T03:41:34-07:00 Yu Liu, Shuhua Qi, Fridtjof Thomas, Brittany L. Correia, Angela P. Taylor, Roy V. Sillitoe, and Detlef H. Heck Respiration is controlled by central pattern generating circuits in the brain stem, whose activity can be modulated by inputs from other brain areas to adapt respiration to autonomic and behavioral demands. The cerebellum is known to be part of the neuronal circuitry activated during respiratory challenges, such as hunger for air, but has not been found to be involved in the control of spontaneous, unobstructed breathing (eupnea). Here we applied a measure of intrinsic rhythmicity, the CV2, which evaluates the similarity of subsequent intervals and is thus sensitive to changes in rhythmicity at the temporal resolution of individual respiratory intervals. The variability of intrinsic respiratory rhythmicity was reduced in a mouse model of cerebellar ataxia compared to their healthy littermates. Irrespective of that difference, the average respiratory rate and the average coefficient of variation (CV) were comparable between healthy and ataxic mice. We argue that these findings are consistent with a proposed role of the cerebellum in modulating the duration of individual respiratory intervals, which could serve the purpose of coordinating respiration with other rhythmic orofacial movements, such as fluid licking and swallowing. Full Article
ri A topological analysis of difference topology experiments of condensin with topoisomerase II [RESEARCH ARTICLE] By bio.biologists.org Published On :: 2020-04-03T02:47:42-07:00 Soojeong Kim and Isabel K. Darcy An experimental technique called difference topology combined with the mathematics of tangle analysis has been used to unveil the structure of DNA bound by the Mu transpososome. However, difference topology experiments can be difficult and time consuming. We discuss a modification that greatly simplifies this experimental technique. This simple experiment involves using a topoisomerase to trap DNA crossings bound by a protein complex and then running a gel to determine the crossing number of the knotted product(s). We develop the mathematics needed to analyze the results and apply these results to model the topology of DNA bound by 13S condensin and by the condensin MukB. Full Article
ri Nucleolar stress in Drosophila neuroblasts, a model for human ribosomopathies [RESEARCH ARTICLE] By bio.biologists.org Published On :: 2020-04-13T03:41:34-07:00 Sonu Shrestha Baral, Molly E. Lieux, and Patrick J. DiMario Different stem cells or progenitor cells display variable threshold requirements for functional ribosomes. This is particularly true for several human ribosomopathies in which select embryonic neural crest cells or adult bone marrow stem cells, but not others, show lethality due to failures in ribosome biogenesis or function (now known as nucleolar stress). To determine if various Drosophila neuroblasts display differential sensitivities to nucleolar stress, we used CRISPR-Cas9 to disrupt the Nopp140 gene that encodes two splice variant ribosome biogenesis factors (RBFs). Disruption of Nopp140 induced nucleolar stress that arrested larvae in the second instar stage. While the majority of larval neuroblasts arrested development, the mushroom body (MB) neuroblasts continued to proliferate as shown by their maintenance of deadpan, a neuroblast-specific transcription factor, and by their continued EdU incorporation. MB neuroblasts in wild-type larvae appeared to contain more fibrillarin and Nopp140 in their nucleoli as compared to other neuroblasts, indicating that MB neuroblasts stockpile RBFs as they proliferate in late embryogenesis while other neuroblasts normally enter quiescence. A greater abundance of Nopp140 encoded by maternal transcripts in Nopp140-/- MB neuroblasts of 1–2-day-old larvae likely rendered these cells more resilient to nucleolar stress. This article has an associated First Person interview with the first author of the paper. Full Article
ri Improving mental health in autistic young adults: a qualitative study exploring help-seeking barriers in UK primary care By bjgp.org Published On :: 2020-04-30T16:04:41-07:00 BackgroundAutistic people are at increased risk of developing mental health problems. To reduce the negative impact of living with autism in a non-autistic world, efforts to improve take-up and access to care, and support in early years, which will typically start with a GP appointment, must be grounded in the accounts of autistic young adults.AimTo explore how autistic young adults understand and manage mental health problems; and to consider help seeking as a focus.Design and settingA cross-sectional, qualitative study. Autistic participants were purposively selected to represent a range of mental health conditions including anxiety and depression. A subsample were recruited from a population cohort screened for autism in childhood. The study concerns access to primary care.MethodNineteen autistic young adults without learning disabilities, aged 23 or 24 years, were recruited. In-depth, semi-structured interviews explored how they understood and managed mental health problems. Data were analysed thematically.ResultsYoung adults preferred self-management strategies. Multiple factors contributed to a focus on self-management, including: beliefs about the aetiology of mental health difficulties and increased vulnerability with the context of a diagnosis of autism, knowledge of self-management, and a view that formal support was unavailable or inadequate. Families had limited awareness of professional support.ConclusionYoung autistic adults without learning disabilities, and their families, may hold erroneous beliefs about autism and mental health. This may affect help seeking and contribute to an exacerbation of symptoms. GPs need to be alert to the fact that autistic young adults in their care may be experiencing mental health difficulties but may not recognise them as such. Full Article
ri Brief interventions for obesity when patients are asked to pay for weight loss treatment: an observational study in primary care with an embedded randomised trial By bjgp.org Published On :: 2020-04-30T16:04:41-07:00 BackgroundA brief intervention whereby GPs opportunistically facilitate an NHS-funded referral to a weight loss programme is clinically and cost-effective.AimTo test the acceptability of a brief intervention and attendance at a weight loss programme when GPs facilitate a referral that requires patients to pay for the service.Design and settingAn observational study of the effect of a GP encouraging attendance at a weight loss programme requiring self-payment in the West Midlands from 16 October 2018 to 30 November 2018, to compare with a previous trial in England in which the service was NHS-funded.MethodSixty patients with obesity who consecutively attended primary care appointments received an opportunistic brief intervention by a GP to endorse and offer a referral to a weight loss programme at the patient’s own expense. Participants were randomised to GPs who either stated the weekly monetary cost of the programme (basic cost) or who compared the weekly cost to an everyday discretionary item (cost comparison). Participants were subsequently asked to report whether they had attended a weight loss programme.ResultsOverall, 47% of participants (n = 28) accepted the referral; 50% (n = 15) in the basic cost group and 43% (n = 13) in the cost comparison group. This was significantly less than in a previous study when the programme was NHS-funded (77%, n = 722/940; P<0.0001). Most participants reported the intervention to be helpful/very helpful and appropriate/very appropriate (78%, n = 46/59 and 85%, n = 50/59, respectively) but scores were significantly lower than when the programme was NHS-funded (92% n = 851/922 and 88% n = 813/922, respectively; P = 0.004). One person (2%) attended the weight loss programme, which is significantly lower than the 40% of participants who attended when the programme was NHS-funded (P<0.0001).ConclusionGP referral to a weight loss programme that requires patients to pay rather than offering an NHS-funded programme is acceptable; however, it results in almost no attendance. Full Article
ri Shared decision making about blood tests: secondary analysis of video-recorded primary care consultations By bjgp.org Published On :: 2020-04-30T16:04:41-07:00 BackgroundAwareness of the importance of shared decision making (SDM) is widespread; however, little research has focused on discussions surrounding investigations, despite increasing laboratory testing in primary care.AimTo explore the discussion of blood tests in routine primary care consultations.Design and settingA secondary analysis of 50 video-recorded routine primary care consultations, linked surveys, and records data (all from the One in a Million [OiaM] archive). The consultations were taken by 22 GPs across 12 practices.MethodA coding scheme was developed, using qualitative content analysis, to explore discussion of blood tests in transcripts of recorded consultations. Codes focused on instigating testing, the extent of SDM, and how results were explained. Survey data were used to compare patients’ pre-visit expectations with consultation content. Medical records were reviewed to compare tests discussed with those ordered.ResultsIn 36 out of 50 consultations that discussed ordering blood tests, 11 patients (31%) hinted that they wanted a blood test; however, none asked explicitly. Only four patients (11%) were offered alternative options. In 29 cases (81%) the GP gave some explanation of the indication, but only in six cases (17%) were the limitations of testing explained. Only 10 out of 31 patients (32%) were informed about all blood tests ordered. Of the 23 out of 50 consultations in which results were conveyed, the GP gave no explanation of the results in six cases (26%). Thirteen patients (57%) were only informed of an assessment of the results (for example, ‘normal’), rather than the actual results.ConclusionA lack of information dissemination and SDM exists around ordering tests and conveying results. Promoting SDM could reduce unnecessary testing and improve patient-centred care. Full Article
ri Optimising management of UTIs in primary care: a qualitative study of patient and GP perspectives to inform the development of an evidence-based, shared decision-making resource By bjgp.org Published On :: 2020-04-30T16:04:41-07:00 BackgroundUrinary tract infections (UTIs) are one of the most common bacterial infections managed in general practice. Many women with symptoms of uncomplicated UTI may not benefit meaningfully from antibiotic treatment, but the evidence base is complex and there is no suitable shared decision-making resource to guide antibiotic treatment and symptomatic care for use in general practice consultations.AimTo develop an evidence-based, shared decision-making intervention leaflet to optimise management of uncomplicated UTI for women aged <65 years in the primary care setting.Design and settingQualitative telephone interviews with GPs and patient focus group interviews.MethodIn-depth interviews were conducted to explore how consultation discussions around diagnosis, antibiotic use, self-care, safety netting, and prevention of UTI could be improved. Interview schedules were based on the Theoretical Domains Framework.ResultsBarriers to an effective joint consultation and appropriate prescribing included: lack of GP time, misunderstanding of depth of knowledge and miscommunication between the patient and the GP, nature of the consults (such as telephone consultations), and a history of previous antibiotic therapy.ConclusionConsultation time pressures combined with late symptom presentation are a challenge for even the most experienced of GPs: however, it is clear that enhanced patient–clinician shared decision making is urgently required when it comes to UTIs. This communication should incorporate the provision of self-care, safety netting, and preventive advice to help guide patients when to consult. A shared decision-making information leaflet was iteratively co-produced with patients, clinicians, and researchers at Public Health England using study data. Full Article
ri Women’s experiences of diagnosis and management of polycystic ovary syndrome: a mixed-methods study in general practice By bjgp.org Published On :: 2020-04-30T16:04:41-07:00 BackgroundPolycystic ovary syndrome (PCOS) is a common lifelong metabolic condition with serious associated comorbidities. Evidence points to a delay in diagnosis and inconsistency in the information provided to women with PCOS.AimTo capture women’s experiences of how PCOS is diagnosed and managed in UK general practice.Design and settingThis was a mixed-methods study with an online questionnaire survey and semi-structured telephone interviews with a subset of responders.MethodAn online survey to elicit women’s experiences of general practice PCOS care was promoted by charities and BBC Radio Leicester. The survey was accessible online between January 2018 and November 2018. A subset of responders undertook a semi-structured telephone interview to provide more in-depth data.ResultsA total of 323 women completed the survey (average age 35.4 years) and semi-structured interviews were conducted with 11 women. There were five key themes identified through the survey responses. Participants described a variable lag time from presentation to PCOS diagnosis, with a median of 6–12 months. Many had experienced mental health problems associated with their PCOS symptoms, but had not discussed these with the GP. Many were unable to recall any discussion about associated comorbidities with the GP. Some differences were identified between the experiences of women from white British backgrounds and those from other ethnic backgrounds.ConclusionFrom the experiences of the women in this study, it appears that PCOS in general practice is not viewed as a long-term condition with an increased risk of comorbidities including mental health problems. Further research should explore GPs’ awareness of comorbidities and the differences in PCOS care experienced by women from different ethnic backgrounds. Full Article
ri Infection in older adults: a qualitative study of patient experience By bjgp.org Published On :: 2020-04-30T16:04:41-07:00 BackgroundInfection is common in older adults. Serious infection has a high mortality rate and is associated with unplanned hospital admissions. Little is known about the factors that prompt older patients to seek medical advice when they may have an infection.AimTo explore the symptoms of infection from the perspective of older adults, and when and why older patients seek healthcare advice for a possible infection.Design and settingA qualitative interview study among adults aged ≥70 years with a clinical diagnosis of infection recruited from ambulatory care units in Oxford, UK.MethodInterviews were semi-structured and based on a flexible topic guide. Participants were given the option to be interviewed with their carer. Thematic analysis was facilitated using NVivo (version 11).ResultsA total of 28 participants (22 patients and six carers) took part. Patients (aged 70–92 years) had experienced a range of different infections. Several early non-specific symptoms were described (fever, feeling unwell, lethargy, vomiting, pain, and confusion/delirium). Internally minimising symptoms was common and participants with historical experience of infection tended to be better able to interpret their symptoms. Factors influencing seeking healthcare advice included prompts from family, specific or intolerable symptoms, symptom duration, and being unable to manage with self-care. For some, not wanting to be a burden affected their desire to seek help.ConclusionTailored advice to older adults highlighting early symptoms of infection may be beneficial. Knowing whether patients have had previous experience of infection may help healthcare professionals in assessing older patients with possible infection. Full Article
ri Understanding how patients establish strategies for living with asthma: a qualitative study in UK primary care as part of IMP2ART By bjgp.org Published On :: 2020-04-30T16:04:41-07:00 BackgroundIn the context of a variable condition such as asthma, patient recognition of deteriorating control and knowing what prompt action to take is crucial. Yet, implementation of recommended self-management strategies remains poor.AimTo explore how patients with asthma and parents/carers of children with asthma develop and establish recommended self-management strategies for living with asthma, and how clinicians can best support the process.Design and settingA qualitative study in UK primary care.MethodPatients with asthma and parents/carers of children with asthma from 10 general practices were purposively sampled (using age, sex, and duration of asthma) to participate in focus groups or interviews between May 2016 and August 2016. Participants’ experiences of health care, management of asthma, and views on supported self-management were explored. Interviews and focus group sessions were audio-recorded and transcribed verbatim. Iterative thematic analysis was conducted, guided by the research questions and drawing on habit theory in discussion with a multidisciplinary research team.ResultsA total of 49 participants (45 patients; 4 parents/carers) took part in 32 interviews and five focus groups. Of these, 11 reported using an action plan. Patients learnt how to self-manage over time, building knowledge from personal experience and other sources, such as the internet. Some regular actions, for example, taking medication, became habitual. Dealing with new or unexpected scenarios required reflective abilities, which may be supported by a tailored action plan.ConclusionPatients reported learning intuitively how to self-manage. Some regular actions became habitual; dealing with the unexpected required more reflective cognitive skills. In order to support implementation of optimal asthma self- management, clinicians should consider both these aspects of self-management and support, and educate patients proactively. Full Article
ri It could happen to anyone: vulnerability and boundaries By bjgp.org Published On :: 2020-04-30T16:04:41-07:00 Full Article
ri Yonder: Oncogeriatrics, binge eating in black women, dissection, and podcasts By bjgp.org Published On :: 2020-04-30T16:04:41-07:00 Full Article
ri Borderlands: the difficulty of the liminal in primary care By bjgp.org Published On :: 2020-04-30T16:04:41-07:00 Full Article
ri Viewpoint: The COVID-19 and climate crises By bjgp.org Published On :: 2020-04-30T16:04:41-07:00 Full Article
ri Managing patients with COVID-19 infections: a first-hand experience from the Wuhan Mobile Cabin Hospital By bjgp.org Published On :: 2020-04-30T16:04:41-07:00 Full Article
ri Video consultations in UK primary care in response to the COVID-19 pandemic By bjgp.org Published On :: 2020-04-30T16:04:41-07:00 Full Article
ri Delivering long-term cancer care in primary care By bjgp.org Published On :: 2020-04-30T16:04:41-07:00 Full Article
ri How accurate are GPs at integrating evidence into prescribing decisions? By bjgp.org Published On :: 2020-04-30T16:04:41-07:00 Full Article