Polymorphisms in TIE2 and ANGPT-1 genes are associated with protection against diabetic retinopathy in a Brazilian population.

Objective: The objective of this study was to investigate the association between SNPs in the TIE2 and ANGPT-1 genes and diabetic retinopathy (DR). Subjects and methods: This study comprised 603 patients with type 2 diabetes mellitus (T2DM) and DR (cases) and 388 patients with T2DM for more than 10 years and without DR (controls). The TIE2 rs639225 (A/G) and rs638203 (A/G) SNPs and the ANGPT-1 rs4324901 (G/T) and rs2507800 (T/A) SNPs were genotyped by real-time PCR using TaqMan MGB probes. Results: The G/G genotype of the rs639225/TIE2, the G/G genotype of the rs638203/ TIE2 and the T allele of the rs4324901/ANGPT-1 SNPs were associated with protection against DR after adjustment for age, glycated hemoglobin, gender, and presence of hypertension (P = 0.042, P = 0.003, and P = 0.028, respectively). No association was found between the rs2507800/ANGPT-1 SNP and DR. Conclusion: We demonstrated, for the first time, the association of TIE2 rs638203 and rsrs939225 SNPs and ANGPT-1 rs4324901 SNP with protection against DR in a Brazilian population.

Polymorphisms in TIE2 and ANGPT-1 genes are associated with protection against diabetic retinopathy in a Brazilian population

ABSTRACT Objective: The objective of this study was to investigate the association between SNPs in the TIE2 and ANGPT-1 genes and diabetic retinopathy (DR). Subjects and methods: This study comprised 603 patients with type 2 diabetes mellitus (T2DM) and DR (cases) and 388 patients with T2DM for more than 10 years and without DR (controls). The TIE2 rs639225 (A/G) and rs638203 (A/G) SNPs and the ANGPT-1 rs4324901 (G/T) and rs2507800 (T/A) SNPs were genotyped by real-time PCR using TaqMan MGB probes. Results: The G/G genotype of the rs639225/TIE2, the G/G genotype of the rs638203/TIE2 and the T allele of the rs4324901/ANGPT-1 SNPs were associated with protection against DR after adjustment for age, glycated hemoglobin, gender, and presence of hypertension (P = 0.042, P = 0.003, and P = 0.028, respectively). No association was found between the rs2507800/ANGPT-1 SNP and DR. Conclusion: We demonstrated, for the first time, the association of TIE2 rs638203 and rsrs939225 SNPs and ANGPT-1 rs4324901 SNP with protection against DR in a Brazilian population.

Genetic polymorphisms associated with susceptibility to COVID-19 disease and severity: A systematic review and meta-analysis.

Although advanced age and presence of comorbidities significantly impact the variation observed in the clinical symptoms of COVID-19, it has been suggested that genetic variants may also be involved in the disease. Thus, the aim of this study was to perform a systematic review with meta-analysis of the literature to identify genetic polymorphisms that are likely to contribute to COVID-19 pathogenesis. Pubmed, Embase and GWAS Catalog repositories were systematically searched to retrieve articles that investigated associations between polymorphisms and COVID-19. For polymorphisms analyzed in 3 or more studies, pooled OR with 95% CI were calculated using random or fixed effect models in the Stata Software. Sixty-four eligible articles were included in this review. In total, 8 polymorphisms in 7 candidate genes and 74 alleles of the HLA loci were analyzed in 3 or more studies. The HLA-A*30 and CCR5 rs333Del alleles were associated with protection against COVID-19 infection, while the APOE rs429358C allele was associated with risk for this disease. Regarding COVID-19 severity, the HLA-A*33, ACE1 Ins, and TMPRSS2 rs12329760T alleles were associated with protection against severe forms, while the HLA-B*38, HLA-C*6, and ApoE rs429358C alleles were associated with risk for severe forms of COVID-19. In conclusion, polymorphisms in the ApoE, ACE1, TMPRSS2, CCR5, and HLA loci appear to be involved in the susceptibility to and/or severity of COVID-19.

Accuracy evaluation of 2021 Chronic Kidney Disease Epidemiology Collaboration, Full Age Spectrum and European Kidney Function Consortium equations for estimating glomerular filtration rate in type 2 diabetes mellitus and healthy adults.

BACKGROUND AND AIMS: Estimated glomerular filtration rate (eGFR) equations accuracy has been questioned in diabetes mellitus (DM). We aimed to evaluate the performance of three equations - European Kidney Function Consortium (EKFC), Full Age Spectrum (FAS), and 2021 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) - in healthy and type 2 DM participants. MATERIAL AND METHODS: This cross-sectional studycompared eGFR equations withareference method: measured GFR (mGFR) by 51Cr-EDTA. The equations performance was assessed usingBland-Altman plot,concordance correlation coefficient (CCC), bias,P30 andP15 accuracy. RESULTS: In the 100 healthy adults included (aged 39 ± 15 years, 67% women, mean mGFR 107 ± 15, 2021 CKD-EPI 109 ± 14, FAS 107 ± 18 and EKFC 101 ± 12 mL/min/1.73 m2), all equations reached P30 accuracy above the desirable benchmark of 90%. In the 122 patients with type 2 DM (aged 61 ± 10 years, 55% women, mGFR97 ± 22, 2021 CKD-EPI 86 ± 20, FAS 83 ± 25 and EKFC 79 ± 18 mL/min/1.73 m2), the equations presented larger biases, worst agreement with mGFR and inferior accuracy, with 2021 CKD-EPI (83%) and EKFC (82%) presenting greater P30 than FAS (77%). CONCLUSION: In healthy Brazilian adults, 2021 CKD-EPI, FAS and EKFC are suitable to estimate GFR. However, all equations underperform in people with type 2 DM.

Polymorphisms in ACE1, TMPRSS2, IFIH1, IFNAR2, and TYK2 Genes Are Associated with Worse Clinical Outcomes in COVID-19.

Although advanced age, male sex, and some comorbidities impact the clinical course of COVID-19, these factors only partially explain the inter-individual variability in disease severity. Some studies have shown that genetic polymorphisms contribute to COVID-19 severity; however, the results are inconclusive. Thus, we investigated the association between polymorphisms in ACE1, ACE2, DPP9, IFIH1, IFNAR2, IFNL4, TLR3, TMPRSS2, and TYK2 and the clinical course of COVID-19. A total of 694 patients with COVID-19 were categorized as: (1) ward inpatients (moderate symptoms) or patients admitted at the intensive care unit (ICU; severe symptoms); and (2) survivors or non-survivors. In females, the rs1990760/IFIH1 T/T genotype was associated with risk of ICU admission and death. Moreover, the rs1799752/ACE1 Ins and rs12329760/TMPRSS2 T alleles were associated with risk of ICU admission. In non-white patients, the rs2236757/IFNAR2 A/A genotype was associated with risk of ICU admission, while the rs1799752/ACE1 Ins/Ins genotype, rs2236757/IFNAR2 A/A genotype, and rs12329760/TMPRSS2 T allele were associated with risk of death. Moreover, some of the analyzed polymorphisms interact in the risk of worse COVID-19 outcomes. In conclusion, this study shows an association of rs1799752/ACE1, rs1990760/IFIH1, rs2236757/IFNAR2, rs12329760/TMPRSS2, and rs2304256/TYK2 polymorphisms with worse COVID-19 outcomes, especially among female and non-white patients.

Glycated Hemoglobin and Blood Pressure Levels in Adults With Type 2 Diabetes: How Many Patients Are on Target?

OBJECTIVES: Achieving glycated hemoglobin (A1C) and blood pressure targets is an important strategy for preventing chronic vascular complications in diabetes. Our aim in this study was to determine the proportion of type 2 diabetes patients who meet the recommended A1C and arterial blood pressure targets and to identify the determinants of failure to do so. METHODS: A cross-sectional study was conducted in an outpatient endocrine clinic at a university hospital. The A1C goal was 7% in general and 8% for patients with advanced chronic complications. Regarding blood pressure, the overall expected target was 140/90 mmHg. RESULTS: A total of 602 type 2 diabetes patients were analyzed: 62% were female, 14% self-reported as black, mean age was 63±11 years, mean diabetes duration was 17±9 years and median A1C was 8.0% (interquartile range, 7.0% to 9.5%). Macrovascular disease was present in 33% of the patients, diabetic retinopathy in 47%, peripheral neuropathy in 43% and diabetic kidney disease in 56%. Regarding metabolic control, 403 (67%) patients were not at the adjusted target A1C level, and being female, black, young and an insulin user were the main determinants of poor glycemic control. Regarding blood pressure, 348 (58%) patients were not at the recommended targets, and a more advanced age was the main associated factor. CONCLUSIONS: Because more than half of type 2 diabetes outpatients do not meet the recommended A1C and blood pressure target values, there is a major call to overcome the therapeutic inertia and target treatment of patients on an individual basis.

Lower serum 25-hydroxyvitamin D levels are associated with impaired glomerular filtration rate in type 2 diabetes patients.

BACKGROUND: 25-Hydroxyvitamin D [25(OH)D] deficiency has been implicated as a possible risk factor for the onset and progression of diabetes kidney disease (DKD). The aim of this study was to evaluate the interaction between levels of 25(OH)D and DKD in type 2 diabetes mellitus (DM) patients. METHODS: Cross-sectional design, outpatient type 2 DM. Glomerular filtration rate (GFR) was measured by 51Cr-EDTA and estimated by Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), urinary albumin excretion (UAE) by immunoturbidimetry, and 25(OH)D by chemiluminescence. Receiver operating characteristic (ROC) curve analysis and generalized linear model (Poisson robust regression estimator) were used to assess the interaction between 25(OH)D levels and renal function. RESULTS: A total of 114 type 2 DM patients aged 60 ± 10 years, 49 males (43%), DM duration 22 ± 10 years, with GFR > 60 ml/min/1.73 m2 were evaluated. Patients with GFRs 60-90 (n = 50) had significantly lower 25(OH)D levels than individuals with GFRs > 90 ml/min/1.73 m2 (n = 64), respectively 40 ± 20 versus 48 ± 20 nmol/l, p = 0.027. This difference was more pronounced for older individuals (39 ± 20 versus 54 ± 23 nmol/l, respectively), and Poisson robust regression disclosed that lower 25(OH)D [Poisson regression (PR) = 0.989, confidence interval (CI): 0.978-0.999, p = 0.034], and advanced age (PR = 1.050, CI: 1.007-1.096, p = 0.023) were significantly associated with the lower GFR category, adjusted for seasons. ROC curve analysis showed that the cutoff point of 25(OH)D of 41 nmol/l was associated with lower GFR [area under the curve (AUC) = 0.694, p = 0.009]. CKD-EPI estimated GFR (eGFR) was not associated with 25(OH)D in any analysis. There was no difference in 25(OH)D levels between patients with elevated UAE as compared with normoalbuminuric ones (44 ± 21 versus 46 ± 19 nmol/l, p = 0.587). CONCLUSION: Lower levels of 25(OH)D are associated with decreased GFR in patients with type 2 DM, especially in older patients, with no evidence of interaction with UAE levels.

Urinary peptidomics and bioinformatics for the detection of diabetic kidney disease.

The aim of this study was to establish a peptidomic profile based on LC-MS/MS and random forest (RF) algorithm to distinguish the urinary peptidomic scenario of type 2 diabetes mellitus (T2DM) patients with different stages of diabetic kidney disease (DKD). Urine from 60 T2DM patients was collected: 22 normal (stage A1), 18 moderately increased (stage A2) and 20 severely increased (stage A3) albuminuria. A total of 1080 naturally occurring peptides were detected, which resulted in the identification of a total of 100 proteins, irrespective of the patients' renal status. The classification accuracy showed that the most severe DKD (A3) presented a distinct urinary peptidomic pattern. Estimates for peptide importance assessed during RF model training included multiple fragments of collagen and alpha-1 antitrypsin, previously associated to DKD. Proteasix tool predicted 48 proteases potentially involved in the generation of the 60 most important peptides identified in the urine of DM patients, including metallopeptidases, cathepsins, and calpains. Collectively, our study lightened some biomarkers possibly involved in the pathogenic mechanisms of DKD, suggesting that peptidomics is a valuable tool for identifying the molecular mechanisms underpinning the disease and thus novel therapeutic targets.

The G Allele of the rs12050217 Polymorphism in the BDKRB1 Gene Is Associated with Protection for Diabetic Retinopathy.

Purpose: The plasma kallikrein-kinin system is activated during vascular injury caused by diabetic retinopathy (DR), being involved in hyperpermeability and inflammation. Bradykinin B1 receptor (B1R) is expressed in human retina, and its levels are increased in murine models of diabetes. Experimental studies reveal that B1R antagonists ameliorate retinal injury caused by diabetes in rodents. Thus, the aim of this study was to investigate the association between the rs12050217A/G polymorphism in the BDKRB1 gene, the gene that codifies B1R, and DR in type 2 diabetes mellitus (T2DM) patients. Methods: We analyzed 636 T2DM patients and 443 non-diabetic subjects. T2DM patients were categorized by the presence of non-proliferative DR (NPDR, n = 267), proliferative DR (PDR, n = 197), and absence of DR (n = 172). The BDKRB1 rs12050217A/G polymorphism was genotyped by real-time PCR using TaqMan MGB probes. Results: The genotype frequencies of the BDKRB1 rs12050217A/G polymorphism are in Hardy-Weinberg equilibrium and did not differ between T2DM patients and non-diabetic subjects (P > 0.05). The presence of the genotypes containing the rs12050217 G allele was less frequent in patients with PDR when compared to patients with NPDR and without DR (32.0%, 41.9%, and 43.0%, P = 0.045, respectively). Interestingly, the presence of G allele was associated with ~40% protection for PDR, which was confirmed after correction for the presence of hypertension, ethnicity, age, HDL, and gender (odds ratio = 0.616, 95% confidence interval 0.385-0.986, P = 0.043). Conclusion: For the first time, we showed that BDKRB1 rs12050217 G allele is associated with protection for the advanced stage of DR in T2DM patients; however, further studies are needed to confirm this finding.

Renal effects of exendin-4 in an animal model of brain death.

Organ transplantation is the gold standard therapy for the majority of patients with terminal organ failure. However, it is still a limited treatment especially due to the low number of brain death (BD) donors in relation to the number of waiting list recipients. Strategies to increase the quantity and quality of donor organs have been studied, and the administration of exendin-4 (Ex-4) to the donor may be a promising approach. Male Wistar rats were randomized into 3 groups: (1) control, without central nervous system injury; (2) BD induced experimentally, and (3) BD induced experimentally + Ex-4 administered immediately after BD induction. After BD induction, animals were monitored for 6 h before blood collection and kidney biopsy. Kidney function was assessed by biochemical quantification of plasma kidney markers. Gene and protein expressions of inflammation- and stress-related genes were evaluated by RT-qPCR and immunoblot analysis. Animals treated with Ex-4 had lower creatinine and urea levels compared with controls. BD induced oxidative stress in kidney tissue through increased expression of Ucp2, Sod2 and Inos, and Ex-4 administration reduced the expression of these genes. Ex-4 also induced increased expression of the anti-apoptotic Bcl2 gene. Nlrp3 and Tnf expressions were up-regulated in the BD group compared with controls, but Ex-4 treatment had no effect on these genes. Our findings suggest that Ex-4 administration in BD rats reduces BD-induced kidney damage by decreasing the expression of oxidative stress genes and increasing the expression of Bcl2.

Quantification of peripheral blood CD34+ cells prior to stem cell harvesting by leukapheresis: a single center experience

ABSTRACT Background: Due to laboratory logistic issues, our center has traditionally scheduled peripheral blood stem cell harvests based on timing from the start of mobilization. This has proved to be useful in some cases, but also resulted in many fruitless harvests due to poor mobilization. In order to improve the efficiency of collections and compare the effectiveness of peripheral blood CD34+ cells as a predictor with data from other reports, this study analyzed the implementation of this routine. Methods: Peripheral blood and leukapheresis samples were quantified by flow cytometry and the association between these parameters was assessed. Results: Sixty-six consecutive leukapheresis samples were collected from 34 patients after the collection of peripheral blood samples for CD34+ quantification. A moderate positive correlation was observed between peripheral blood CD34+ cell count and total CD34+ cell count/kg (r = 0.596; p-value < 0.001). A multivariable regression model also confirmed this association and allowed the estimation that for every increase in five CD34+ cells/µL in the peripheral blood, a mean increase of 0.38 × 106 CD34+ cells/kg could be predicted. Demographic characteristics, baseline comorbidities and mobilization regimen did not influence final CD34+ cell count in this sample. Conclusions: As observed in other centers, quantification of peripheral blood CD34+ progenitor cells is a strong predictor of effectiveness to guide stem cell harvesting. Due to the results of this study, a modification in the peripheral blood stem cell harvesting logistics was implemented at our center in order to incorporate this routine.

Quantification of peripheral blood CD34+ cells prior to stem cell harvesting by leukapheresis: a single center experience.

BACKGROUND: Due to laboratory logistic issues, our center has traditionally scheduled peripheral blood stem cell harvests based on timing from the start of mobilization. This has proved to be useful in some cases, but also resulted in many fruitless harvests due to poor mobilization. In order to improve the efficiency of collections and compare the effectiveness of peripheral blood CD34+ cells as a predictor with data from other reports, this study analyzed the implementation of this routine. METHODS: Peripheral blood and leukapheresis samples were quantified by flow cytometry and the association between these parameters was assessed. RESULTS: Sixty-six consecutive leukapheresis samples were collected from 34 patients after the collection of peripheral blood samples for CD34+ quantification. A moderate positive correlation was observed between peripheral blood CD34+ cell count and total CD34+ cell count/kg (r = 0.596; p-value < 0.001). A multivariable regression model also confirmed this association and allowed the estimation that for every increase in five CD34+ cells/µL in the peripheral blood, a mean increase of 0.38 × 106 CD34+ cells/kg could be predicted. Demographic characteristics, baseline comorbidities and mobilization regimen did not influence final CD34+ cell count in this sample. CONCLUSIONS: As observed in other centers, quantification of peripheral blood CD34+ progenitor cells is a strong predictor of effectiveness to guide stem cell harvesting. Due to the results of this study, a modification in the peripheral blood stem cell harvesting logistics was implemented at our center in order to incorporate this routine.

Update in diagnosis and management of primary aldosteronism.

Primary aldosteronism (PA) is a group of disorders in which aldosterone is excessively produced. These disorders can lead to hypertension, hypokalemia, hypervolemia and metabolic alkalosis. The prevalence of PA ranges from 5% to 12% around the globe, and the most common causes are adrenal adenoma and adrenal hyperplasia. The importance of PA recognition arises from the fact that it can have a remarkably adverse cardiovascular and renal impact, which can even result in death. The aldosterone-to-renin ratio (ARR) is the election test for screening PA, and one of the confirmatory tests, such as oral sodium loading (OSL) or saline infusion test (SIT), is in general necessary to confirm the diagnosis. The distinction between adrenal hyperplasia (AH) or aldosterone-producing adenoma (APA) is essential to select the appropriate treatment. Therefore, in order to identify the subtype of PA, imaging exams such as computed tomography or magnetic ressonance imaging, and/or invasive investigation such as adrenal catheterization must be performed. According to the subtype of PA, optimal treatment - surgical for APA or pharmacological for AH, with drugs like spironolactone and amiloride - must be offered.

Use of additives, scaffolds and extracellular matrix components for improvement of human pancreatic islet outcomes in vitro: A systematic review.

Pancreatic islet transplantation is an established treatment to restore insulin independence in type 1 diabetic patients. Its success rates have increased lately based on improvements in immunosuppressive therapies and on islet isolation and culture. It is known that the quality and quantity of viable transplanted islets are crucial for the achievement of insulin independence and some studies have shown that a significant number of islets are lost during culture time. Thus, in an effort to improve islet yield during culture period, researchers have tested a variety of additives in culture media as well as alternative culture devices, such as scaffolds. However, due to the use of different categories of additives or devices, it is difficult to draw a conclusion on the benefits of these strategies. Therefore, the aim of this systematic review was to summarize the results of studies that described the use of medium additives, scaffolds or extracellular matrix (ECM) components during human pancreatic islets culture. PubMed and Embase repositories were searched. Of 5083 articles retrieved, a total of 37 articles fulfilled the eligibility criteria and were included in the review. After data extraction, articles were grouped as follows: 1) "antiapoptotic/anti-inflammatory/antioxidant," 2) "hormone," 3) "sulphonylureas," 4) "serum supplements," and 5) "scaffolds or ECM components." The effects of the reviewed additives, ECM or scaffolds on islet viability, apoptosis and function (glucose-stimulated insulin secretion - GSIS) were heterogeneous, making any major conclusion hard to sustain. Overall, some "antiapoptotic/anti-inflammatory/antioxidant" additives decreased apoptosis and improved GSIS. Moreover, islet culture with ECM components or scaffolds increased GSIS. More studies are needed to define the real impact of these strategies in improving islet transplantation outcomes.

UCP2 Expression Is Increased in Pancreas From Brain-Dead Donors and Involved in Cytokine-Induced ß Cells Apoptosis.

BACKGROUND: Systemic inflammation associated with brain death (BD) decreases islet yield and quality, negatively affecting outcomes of human islet transplantation. A recent study from our group showed an increased expression of uncoupling protein-2 (UCP2) in pancreas from rats with BD as compared with controls. UCP2 is located in the mitochondrial inner membrane and regulates production of reactive oxygen species and glucose-stimulated insulin secretion. It has been suggested that UCP2 also plays a role in ß cell apoptosis, but these findings remain controversial. METHODS: We have presently performed a case-control study to assess UCP2 expression in pancreas from BD donors (cases) and subjects who underwent pancreatectomy (controls). We next investigated the role of Ucp2 in cytokine-induced apoptosis of rat insulin-producing INS-1E cells. RESULTS: UCP2 gene expression was higher in pancreas from BD donors compared with controls (1.73 ± 0.93 vs 0.75 ± 0.66; fold change, P < 0.05). Ucp2 knockdown (80% at the protein and messenger RNA levels) reduced by 30% cytokine-induced apoptosis and nitric oxide production in INS-1E cells. This protection was associated with decreased expression of cleaved (activated) caspases 9 and 3, suggesting that Ucp2 knockdown interferes with cytokine triggering of the intrinsic apoptotic pathway. Moreover, both messenger RNA and protein concentrations of the antiapoptotic protein Bcl-2 were increased after Ucp2 knockdown in INS-1E cells. CONCLUSIONS: These data suggest that UCP2 has an apoptotic effect in ß cells via regulation of the intrinsic pathway of apoptosis.

Polymorphisms in genes encoding miR-155 and miR-146a are associated with protection to type 1 diabetes mellitus.

AIMS: Type 1 diabetes mellitus (T1DM) is characterized by severe autoimmune destruction of pancreatic beta-cells. The triggering of autoimmunity against beta-cells is probably caused by a combination of environmental and genetic risk factors. Even though much is known about the genetic of T1DM, more information is needed to completely unravel this tangled disease. MicroRNAs (miRNAs) are a class of small noncoding RNAs molecules that negatively regulate gene expression by inducing target mRNA cleavage or by inhibiting protein translation. Abnormal miRNA expressions have been described in autoimmune diseases and T1DM. Polymorphisms in genes codifying miRNAs may alter the expression of the corresponding miRNA and, thus, confer susceptibility for a given disease. Therefore, the aim of this study was to investigate whether polymorphisms in genes encoding miR-155, miR-146a, and miR-375 are associated with T1DM. METHODS: Frequencies of the miRNA-146a rs2910164, miRNA-155 rs767649 and miRNA-375 rs6715345 polymorphisms were analyzed in 490 T1DM patients and in 469 nondiabetic subjects. RESULTS: The miR-146a rs2910164 and miR-155 rs767649 polymorphisms were associated with protection for T1DM, and the strongest association was observed for the dominant model [odds ratio (OR) = 0.557 95% CI 0.355-0.874 and OR = 0.508, 95% CI 0.265-0.973, respectively, after adjustment for age, ethnicity, and risk HLA loci]. However, miR-375 rs6715345 frequencies did not differ between cases and controls. CONCLUSION: MiR-146a rs2910164 and miR-155 rs767649 polymorphisms were associated with protection for T1DM.

Neuron-enriched RNA-binding Proteins Regulate Pancreatic Beta Cell Function and Survival.

Pancreatic beta cell failure is the central event leading to diabetes. Beta cells share many phenotypic traits with neurons, and proper beta cell function relies on the activation of several neuron-like transcription programs. Regulation of gene expression by alternative splicing plays a pivotal role in brain, where it affects neuronal development, function, and disease. The role of alternative splicing in beta cells remains unclear, but recent data indicate that splicing alterations modulated by both inflammation and susceptibility genes for diabetes contribute to beta cell dysfunction and death. Here we used RNA sequencing to compare the expression of splicing-regulatory RNA-binding proteins in human islets, brain, and other human tissues, and we identified a cluster of splicing regulators that are expressed in both beta cells and brain. Four of them, namely Elavl4, Nova2, Rbox1, and Rbfox2, were selected for subsequent functional studies in insulin-producing rat INS-1E, human EndoC-ßH1 cells, and in primary rat beta cells. Silencing of Elavl4 and Nova2 increased beta cell apoptosis, whereas silencing of Rbfox1 and Rbfox2 increased insulin content and secretion. Interestingly, Rbfox1 silencing modulates the splicing of the actin-remodeling protein gelsolin, increasing gelsolin expression and leading to faster glucose-induced actin depolymerization and increased insulin release. Taken together, these findings indicate that beta cells share common splicing regulators and programs with neurons. These splicing regulators play key roles in insulin release and beta cell survival, and their dysfunction may contribute to the loss of functional beta cell mass in diabetes.

Nitric oxide levels in patients with diabetes mellitus: A systematic review and meta-analysis.

BACKGROUND: Altered serum nitric oxide (NO) levels in patients with diabetes mellitus (DM) have been reported by different studies; however, results are still controversial. Until this date, no meta-analysis evaluated the association of NO levels with DM. Thus, this paper describes a meta-analysis conducted to evaluate if there is a relationship between NO levels and type 1 DM (T1DM) or type 2 DM (T2DM). METHODS: A literature search was done to identify all studies that investigated NO levels between T1DM or T2DM patients (cases) and non-diabetic subjects (controls). Measurement of nitrate and nitrite (NOx - the stable NO products) were used to estimate NO concentrations because they closely reflect NO bioavailability. Weighted mean differences (WMD) of NOx levels between case and control samples were calculated for T1DM and T2DM groups. RESULTS: Thirty studies were eligible for inclusion in the meta-analysis (8 in T1DM samples and 22 in T2DM samples). NOx levels were increased in European T1DM patients compared with controls [random effect model (REM) WMD = 8.55, 95% CI 2.88 - 14.21]. No other ethnicity was evaluated in T1DM studies. NOx levels were also increased in both European (REM WMD = 18.76, 95% CI 1.67 - 35.85) and Asian (REM WMD = 18.41, 95% CI 8.01 - 28.81) T2DM patients, but not in Latin American patients compared with controls. CONCLUSIONS: This meta-analysis detected a significant increase in NOx levels in European T1DM patients as well as European and Asian T2DM patients. Further studies in other ethnicities are necessary to confirm these data.

Exendin-4 attenuates brain death-induced liver damage in the rat.

The majority of liver grafts destined for transplantation originate from brain dead donors. However, significantly better posttransplantation outcomes are achieved when organs from living donors are used, suggesting that brain death (BD) causes irreversible damage to the liver tissue. Recently, glucagon-like peptide-1 (GLP1) analogues were shown to possess interesting hepatic protection effects in different liver disease models. We hypothesized that donor treatment with the GLP1 analogue exendin-4 (Ex-4) could alleviate BD-induced liver damage. A rat model of BD was employed in order to estimate BD-induced liver damage and Ex-4's potential protective effects. Liver damage was assessed by biochemical determination of circulating hepatic markers. Apoptosis in the hepatic tissue was assessed by immunoblot and immunohistochemistry using an antibody that only recognizes the active form of caspase-3. Gene expression changes in inflammation and stress response genes were monitored by quantitative real-time polymerase chain reaction. Here, we show that Ex-4 administration to the brain dead liver donors significantly reduces levels of circulating aspartate aminotransferase and lactate dehydrogenase. This was accompanied by a remarkable reduction in hepatocyte apoptosis. In this model, BD caused up-regulation of tumor necrosis factor and stress-related genes, confirming previous findings in clinical and animal studies. In conclusion, treatment of brain dead rats with Ex-4 reduced BD-induced liver damage. Further investigation is needed to determine the molecular basis of the observed liver protection. After testing in a randomized clinical trial, the inclusion of GLP1 analogues in organ donor management might help to improve organ quality, maximize organ donation, and possibly increase liver transplantation success rates.