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.

Association of the UCP polymorphisms with susceptibility to obesity: case-control study and meta-analysis.

This paper describes a case-control study and a meta-analysis performed to evaluate if the following polymorphisms are associated with presence of obesity: -3826A/G (UCP1); -866G/A, Ala55Val and Ins/Del (UCP2) and -55C/T (UCP3). The case-control study enrolled 282 obese and 483 non-obese patients with type 2 diabetes. A literature search was made to identify all studies that evaluated associations between UCP1-3 polymorphisms and obesity. In the case-control study the distributions of the UCP variants did not differ between obese and non-obese groups (P > 0.05). Forty-seven studies were eligible for the meta-analysis and the results showed that the UCP2 -866G/A and UCP3 -55C/T polymorphisms were associated with protection to obesity in Europeans (OR = 0.89, 95% CI 0.82-0.97 and OR = 0.88, 95% CI 0.80-0.97, respectively). The UCP2 Ala55 val polymorphism was associated with obesity in Asians (OR = 1.61, 95% CI 1.13-2.30). The UCP2 Ins/Del polymorphism was associated with obesity mainly in Europeans (OR = 1.19, 95% CI 1.00-1.42). There was no significant association of the UCP1 -3826A/G polymorphism with obesity. In our case-control study we were not able to demonstrate any association between UCP polymorphisms and obesity in T2DM patients; however, in the meta-analysis we detected a significant association of UCP2 -866G/A, Ins/Del, Ala55Val and UCP3 -55C/T polymorphisms with obesity.

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.

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.

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.

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.

Association between rs7903146 and rs12255372 polymorphisms of transcription factor 7-like 2 gene and polycystic ovary syndrome: a systematic review and meta-analysis.

The present systematic review and meta-analysis of case-control studies examines the associations between rs7903146 and rs12255372 polymorphisms of the TCF7L2 gene and PCOS. A search of the literature published until August 2014 was carried out in PubMed, Cochrane Central Register of Controlled Trials, EMBASE, and LILACS. There were no other limits except for the end date. We included observational studies with women of any age diagnosed with PCOS and healthy controls that analyzed polymorphisms rs7903146 and rs12255372. We included case-control or cross-sectional studies analyzing polymorphism rs7903146 or rs12255372 in women with PCOS and healthy controls. Eighteen studies were identified after the primary literature search and seven articles were included in the meta-analysis. All employed Rotterdam criteria for the diagnosis of PCOS. The genotypic distributions in the control groups were in agreement with Hardy-Weinberg equilibrium in all studies. The pooled population included Asian descendents (Chinese, Korean), Caucasians from southern Brazil, Tunisian, and European populations (British/Irish, Northern Finns, Greeks, Czechs), including 1,892 women with PCOS and 2,695 controls. There were no significant associations between PCOS and TCF7L2 rs7903146 or rs12255372 polymorphisms, irrespective of whether allele contrast, additive, dominant, or recessive models of inheritance were used. Furthermore, no significant associations were found after stratification for ethnicity (Asian or non-Asian). There was no significant heterogeneity between studies and no publication bias. The present results suggest that rs7903146 T allele or rs12255372 is not associated with risk for PCOS in non-Asian or Asian women. This systematic review and meta-analysis are registered in PROSPERO under number CRD42013005930.

Toll-like receptor 3 (TLR3) and the development of type 1 diabetes mellitus.

Type 1 diabetes mellitus (T1DM) is a chronic, progressive autoimmune disease characterized by metabolic decompensation often leading to dehydration and ketoacidosis. Viral agents seem to play an important role in triggering the autoimmune destruction that leads to the development of T1DM. Among several viral strains investigated so far, the enterovirus family has been consistently associated with the onset of T1DM in humans. One of the mediators of viral damage is the double-stranded RNA (dsRNA) generated during replication and transcription of viral RNA and DNA. The Toll-like receptor 3 (TLR3) gene codes for an endoplasmic receptor of the pattern-recognition receptors (PRRs) family that recognizes dsRNA, plays an important role in the innate immune response triggered by viral infection. Binding of dsRNA to the TLR3 triggers the release of proinflammatory cytokines, such as interferons, which exhibit potent antiviral action; thus, protecting uninfected cells and inducing apoptosis of infected ones. Therefore, the TLR3 gene is a good candidate for the development of T1DM. Within this context, the objective of the present review was to address the role of the TLR3 gene in the development of T1DM.

Polymorphisms in the TLR3 gene are associated with risk for type 1 diabetes mellitus.

INTRODUCTION: Viral pathogens seem to play a role in triggering the autoimmune destruction that leads to the development of type 1 diabetes mellitus (T1DM). Toll-like receptor 3 (TLR3) has been shown to recognize double-stranded RNA, a molecular signature of most viruses. It is expressed at high levels in pancreatic ß-cells and immune cells, suggesting a role for it in the pathogenesis of T1DM. Therefore, the aim of this study was to investigate whether TLR3 polymorphisms are associated with T1DM. METHODS: Frequencies of the TLR3 rs11721827, rs13126816, rs5743313, rs7668666, and rs3775291 polymorphisms were analyzed in 449 T1DM patients and in 507 nondiabetic subjects. Haplotypes constructed from the combination of these polymorphisms were inferred using a Bayesian statistical method. RESULTS: The rs3775291 and rs13126816 polymorphisms were associated with T1DM, and the strongest association was observed for the additive model (odds ratio (OR)=2.3, 95% CI 1.3-4.2 and OR=2.1, 95% CI 1.3-3.1 respectively). In the same way, the frequency of T1DM was higher as more risk alleles of the five polymorphisms were present (P-trend=0.001). Moreover, in T1DM patients, the minor alleles of the rs5743313 and rs117221827 polymorphisms were associated with an early age at diagnosis and worse glycemic control. CONCLUSION: The TLR3 rs3775291 and rs13126816 polymorphisms are associated with risk for T1DM, while the rs5743313 and rs11721827 polymorphisms are associated with age at T1DM diagnosis and poor glycemic control. The number of risk alleles of the five TLR3 polymorphisms in the haplotypes seems to influence the risk for T1DM, suggesting that these polymorphisms might interact in the susceptibility for the disease.

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.

The role of the uncoupling protein 1 (UCP1) on the development of obesity and type 2 diabetes mellitus.

It is well established that genetic factors play an important role in the development of both type 2 diabetes mellitus (DM2) and obesity, and that genetically susceptible subjects can develop these metabolic diseases after being exposed to environmental risk factors. Therefore, great efforts have been made to identify genes associated with DM2 and/or obesity. Uncoupling protein 1 (UCP1) is mainly expressed in brown adipose tissue, and acts in thermogenesis, regulation of energy expenditure, and protection against oxidative stress. All these mechanisms are associated with the pathogenesis of DM2 and obesity. Hence, UCP1 is a candidate gene for the development of these disorders. Indeed, several studies have reported that polymorphisms -3826A/G, -1766A/G and -112A/C in the promoter region, Ala64Thr in exon 2 and Met299Leu in exon 5 of UCP1 gene are possibly associated with obesity and/or DM2. However, results are still controversial in different populations. Thus, the aim of this study was to review the role of UCP1 in the development of these metabolic diseases.

Toll-like receptor 3 (TLR3) and the development of type 1 diabetes mellitus

Type 1 diabetes mellitus (T1DM) is a chronic, progressive autoimmune disease characterized by metabolic decompensation often leading to dehydration and ketoacidosis. Viral agents seem to play an important role in triggering the autoimmune destruction that leads to the development of T1DM. Among several viral strains investigated so far, the enterovirus family has been consistently associated with the onset of T1DM in humans. One of the mediators of viral damage is the double-stranded RNA (dsRNA) generated during replication and transcription of viral RNA and DNA. The Toll-like receptor 3 (TLR3) gene codes for an endoplasmic receptor of the pattern-recognition receptors (PRRs) family that recognizes dsRNA, plays an important role in the innate immune response triggered by viral infection. Binding of dsRNA to the TLR3 triggers the release of proinflammatory cytokines, such as interferons, which exhibit potent antiviral action; thus, protecting uninfected cells and inducing apoptosis of infected ones. Therefore, the TLR3 gene is a good candidate for the development of T1DM. Within this context, the objective of the present review was to address the role of the TLR3 gene in the development of T1DM. Arch Endocrinol Metab. 2015;59(1):4-12.

The role of the uncoupling protein 1 (UCP1) on the development of obesity and type 2 diabetes mellitus / Papel da proteína desacopladora 1 (UCP1) no desenvolvimento da obesidade e do diabetes melito tipo 2

It is well established that genetic factors play an important role in the development of both type 2 diabetes mellitus (DM2) and obesity, and that genetically susceptible subjects can develop these metabolic diseases after being exposed to environmental risk factors. Therefore, great efforts have been made to identify genes associated with DM2 and/or obesity. Uncoupling protein 1 (UCP1) is mainly expressed in brown adipose tissue, and acts in thermogenesis, regulation of energy expenditure, and protection against oxidative stress. All these mechanisms are associated with the pathogenesis of DM2 and obesity. Hence, UCP1 is a candidate gene for the development of these disorders. Indeed, several studies have reported that polymorphisms -3826A/G, -1766A/G and -112A/C in the promoter region, Ala64Thr in exon 2 and Met299Leu in exon 5 of UCP1 gene are possibly associated with obesity and/or DM2. However, results are still controversial in different populations. Thus, the aim of this study was to review the role of UCP1 in the development of these metabolic diseases.

Está bem estabelecido que fatores genéticos têm papel importante no desenvolvimento do diabetes melito tipo 2 (DM2) e obesidade e que indivíduos suscetíveis geneticamente podem desenvolver essas doenças metabólicas após exposição a fatores de risco ambientais. Assim, grandes esforços têm sido feitos para a identificação de genes associados ao DM2 e/ou à obesidade. A proteína desacopladora 1 (UCP1) é principalmente expressa no tecido adiposo marrom e atua na termogênese, regulação do gasto energético e proteção contra o estresse oxidativo, mecanismos associados tanto à patogênese do DM2 como à obesidade. Portanto, UCP1 é um gene candidato para o desenvolvimento dessas doenças. De fato, diversos estudos relataram que os polimorfismos -3826A/G, -1766A/G e -112A/C na região promotora, Ala64Thr no éxon 2 e Met299Leu no éxon 5 do gene UCP1 estão possivelmente associados à obesidade e/ou ao DM2. Entretanto, os resultados são ainda controversos em diferentes populações. Então, o objetivo deste estudo foi revisar o papel da UCP1 no desenvolvimento dessas doenças metabólicas.