The rs1800469 T/T and rs1800470 C/C genotypes of the TGFB1 gene confer protection against diabetic retinopathy in a Southern Brazilian population.

The transforming growth factor beta 1 (TGFB1) is a pro-inflammatory cytokine that plays a key role in the mechanisms of angiogenesis and breakdown of the blood-retina barrier, which are implicated in the pathogenesis of diabetic retinopathy (DR). Polymorphisms in the TGFB1 gene have been associated with DR; however, results are still contradictory. Therefore, the aim of this study was to investigate the potential association between two TGFB1 polymorphisms and DR. This study included 992 patients with diabetes mellitus (DM): 546 patients with DR (cases) and 446 patients without DR and with ≥10 years of DM (controls). The TGFB1 rs1800469 and rs1800470 polymorphisms were genotyped by real-time PCR. Frequency of rs1800469 T/T genotype was higher in controls compared to DR cases (18.3% vs. 12.7%, P= 0.022). This genotype remained associated with protection for DR, adjusting for covariables (OR= 0.604; 95% CI 0.395 - 0.923; P= 0.020, recessive model). The rs1800470 C/C genotype was observed in 25.4% of the controls and 18.0% of the cases (P= 0.015); thus, being associated with protection against DR under the recessive model (OR= 0.589; 95% CI 0.405 - 0.857; P= 0.006), adjusting for covariables. In conclusion, the TGFB1 rs1800469 and rs1800470 polymorphisms are associated with protection against DR in DM patients from Southern Brazil.

The lncRNA MALAT1 is upregulated in urine of type 1 diabetes mellitus patients with diabetic kidney disease.

Long non-coding RNAs (lncRNAs) are RNAs with >200 nucleotides that are unable to encode proteins and are involved in gene expression regulation. LncRNAs have a key role in many physiological and pathological processes and, consequently, they have been associated with several human diseases, including diabetes chronic complications, such as diabetes kidney disease (DKD). In this context, some studies have identified the dysregulation of the lncRNAs MALAT1 and TUG1 in patients with DKD; nevertheless, available data are still contradictory. Thus, the objective of this study was to compare MALAT1 and TUG1 expressions in urine of patients with type 1 diabetes mellitus (T1DM) categorized according to DKD presence. This study comprised 18 T1DM patients with DKD (cases) and 9 long-duration T1DM patients without DKD (controls). MALAT1 and TUG1 were analyzed using qPCR. Bioinformatics analyses were done to identify both lncRNA target genes and the signaling pathways under their regulation. The lncRNA MALAT1 was upregulated in urine of T1DM patients with DKD vs. T1DM controls (P = 0.007). The expression of lncRNA TUG1 did not differ between groups (P = 0.815). Bioinformatics analysis showed these two lncRNAs take part in metabolism-related pathways. The present study shows that the lncRNA MALAT1 is upregulated in T1DM patients presenting DKD.

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.

The rs3931283/PVT1 and rs7158663/MEG3 polymorphisms are associated with diabetic kidney disease and markers of renal function in patients with type 2 diabetes mellitus.

BACKGROUND: Long non-coding RNAs (lncRNAs) are key regulators of gene expression. Some studies have reported the association of polymorphisms in lncRNA genes with diabetes mellitus (DM) and its chronic complications, including diabetic kidney disease (DKD); however, the results are still inconclusive. Thus, we investigated the association of the rs3200401/MALAT1, rs1894720/MIAT, rs3931283/PVT1, rs11993333/PVT1, rs5749201/TUG1, and rs7158663/MEG3 polymorphisms with DKD in patients with type 2 DM (T2DM). METHODS AND RESULTS: This study comprised 902 patients with T2DM and DKD (cases) and 394 patients with T2DM without DKD (controls). The six polymorphisms of interest were genotyped by real-time PCR using TaqMan probes. Frequency of the rs3931283/PVT1 G/G genotype was 36.2% in cases and 31.9% in controls (P = 0.331). After adjustment for gender, glycated hemoglobin, HDL cholesterol, ethnicity, hypertension, and diabetic retinopathy, the G/G genotype was associated with risk for DKD (OR = 1.625, 95% CI 1.020-2.588; P = 0.041). The rs3931283/PVT1 G/G genotype was also associated with higher urinary albumin excretion levels compared to A allele carriers (P = 0.017). No difference was found in rs7158663/MEG3 genotype frequencies between T2DM controls and DKD patients (OR = 1.087, 95% CI 0.686-1.724; P = 0.722). However, the rs7158663/MEG3 G/G genotype was associated with protection against severe DKD (OR = 0.694, 95% CI 0.488-0.989; P = 0.043, for patients with severe DKD vs. T2DM controls). The rs7158663/MEG3 G/G genotype was also associated with lower creatinine levels (P = 0.007) and higher estimated glomerular filtration rate (P = 0.010) compared to A allele carriers. No association was found between the rs11993333/PVT1, rs3200401/MALAT1, rs1894720/MIAT, and rs5749201/TUG1 polymorphisms and DKD or its laboratory markers. CONCLUSION: The rs3931283/PVT1 G/G and rs7158663/MEG3 G/G are associated with DKD and markers of renal function in T2DM patients from 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.

The rs705708 A allele of the ERBB3 gene is associated with lower prevalence of diabetic retinopathy and arterial hypertension and with improved renal function in type 1 diabetic patients.

INTRODUCTION: The Erb-b2 receptor tyrosine kinase 3 (ERBB3) is involved in autoimmune processes related to type 1 diabetes mellitus (T1DM) pathogenesis. Accordingly, some studies have suggested that single nucleotide polymorphisms (SNPs) in the ERBB3 gene confer risk for T1DM. Proliferation-associated protein 2G4 (PA2G4) is another candidate gene for this disease because it regulates cell proliferation and adaptive immunity. Moreover, PA2G4 regulates ERBB3. To date, no study has evaluated the association of PA2G4 SNPs and T1DM. AIM: To evaluate the association of ERBB3 rs705708 (G/A) and PA2G4 rs773120 (C/T) SNPs with T1DM and its clinical and laboratory characteristics. METHODS: This case-control study included 976 white subjects from Southern Brazil, categorized into 501 cases with T1DM and 475 non-diabetic controls. The ERBB3 and PA2G4 SNPs were genotyped by allelic discrimination-real-time PCR. RESULTS: ERBB3 rs705708 and PA2G4 rs773120 SNPs were not associated with T1DM considering different inheritance models and also when controlling for covariables. However, T1DM patients carrying the ERBB3 rs705708 A allele developed T1DM at an earlier age vs. G/G patients. Interestingly, in the T1DM group, the rs705708 A allele was associated with lower prevalence of diabetic retinopathy and arterial hypertension as well as with improved renal function (higher estimated glomerular filtration rate and lower urinary albumin excretion levels) compared to G/G patients. CONCLUSIONS: Although no association was observed between the ERBB3 rs705708 and PA2G4 rs773120 SNPs and T1DM, the rs705708 A allele was associated, for the first time in literature, with lower prevalence of diabetic retinopathy and arterial hypertension. Additionally, this SNP was associated with improved renal function.

The A allele of the rs759853 single nucleotide polymorphism in the AKR1B1 gene confers risk for diabetic kidney disease in patients with type 2 diabetes from a Brazilian population

ABSTRACT Objective: The AKR1B1 gene encodes an enzyme that catalyzes the reduction of glucose into sorbitol. Chronic hyperglycemia in patients with diabetes mellitus (DM) leads to increased AKR1B1 affinity for glucose and, consequently, sorbitol accumulation. Elevated sorbitol increases oxidative stress, which is one of the main pathways related to chronic complications of diabetes, including diabetic kidney disease (DKD). Accordingly, some studies have suggested the rs759853 polymorphism in the AKR1B1 gene is associated with DKD; however, findings are still contradictory. The aim was to investigate the association of the rs759853 polymorphism in the AKR1B1 gene and DKD. Materials and methods: The sample comprised 695 patients with type 2 DM (T2DM) and DKD (cases) and 310 patients with T2DM of more than 10 years' duration, but no DKD (controls). The polymorphism was genotyped by real-time PCR. Results: Allelic and genotype frequencies of this polymorphism did not differ significantly between groups. However, the A/A genotype was associated with risk for DKD after adjustment for gender, triglycerides, BMI, presence of hypertension and diabetic retinopathy, and duration of DM, under both recessive (P = 0.048) and additive (P = 0.037) inheritance models. Conclusion: Our data suggest an association between the AKR1B1 rs759853A/A genotype and risk for DKD in Brazilians T2DM patients.

The A allele of the rs759853 single nucleotide polymorphism in the AKR1B1 gene confers risk for diabetic kidney disease in patients with type 2 diabetes from a Brazilian population.

OBJECTIVE: The AKR1B1 gene encodes an enzyme that catalyzes the reduction of glucose into sorbitol. Chronic hyperglycemia in patients with diabetes mellitus (DM) leads to increased AKR1B1 affinity for glucose and, consequently, sorbitol accumulation. Elevated sorbitol increases oxidative stress, which is one of the main pathways related to chronic complications of diabetes, including diabetic kidney disease (DKD). Accordingly, some studies have suggested the rs759853 polymorphism in the AKR1B1 gene is associated with DKD; however, findings are still contradictory. The aim was to investigate the association of the rs759853 polymorphism in the AKR1B1 gene and DKD. METHODS: The sample comprised 695 patients with type 2 DM (T2DM) and DKD (cases) and 310 patients with T2DM of more than 10 years' duration, but no DKD (controls). The polymorphism was genotyped by real-time PCR. RESULTS: Allelic and genotype frequencies of this polymorphism did not differ significantly between groups. However, the A/A genotype was associated with risk for DKD after adjustment for gender, triglycerides, BMI, presence of hypertension and diabetic retinopathy, and duration of DM, under both recessive (P = 0.048) and additive (P = 0.037) inheritance models. CONCLUSION: Our data suggest an association between the AKR1B1 rs759853A/A genotype and risk for DKD in Brazilians T2DM patients.

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.

The rs2442598 polymorphism in the ANGPT-2 gene is associated with risk for diabetic retinopathy in patients with type 1 diabetes mellitus in a Brazilian population

ABSTRACT Objective: As studies have reported the involvement of angiopoietin-2 (ANGPT-2) in the pathogenesis of diabetic retinopathy (DR), the aim of this study was to investigate the association between the ANGPT-2 rs2442598 polymorphism and DR. Materials and methods: This case-control study comprised 107 patients with type 1 diabetes mellitus (T1DM) and DR (cases) and 129 patients with T1DM without DR (controls) and with ≥ 10 years of DM. The ANGPT-2 rs2442598 (G/A) polymorphism was genotyped by real-time PCR using TaqMan MGB probes. Results: Genotype distributions of this polymorphism were consistent with the Hardy-Weinberg equilibrium. The frequency of the rs2442598 A allele was higher in cases compared to controls (p = 0.011). Moreover, the A/A genotype was more frequent in cases than in controls (p = 0.017) and was associated with risk for DR after adjustments for duration of DM, HbA1c, triglycerides, estimated glomerular filtration rate, and hypertension (odds ratio [OR] = 5.19, 95% confidence interval [CI] 1.21-22.27). This association was maintained under recessive (OR = 4.78, 95% CI 1.14-19.99) and additive (OR = 6.861, 95% CI 1.45-32.38) inheritance models. Conclusion: Our data demonstrated, for the first time, an association between the ANGPT-2 rs2442598 A allele and risk for DR in T1DM patients from southern Brazil. Additional studies are necessary to replicate this association in other populations.

The rs2442598 polymorphism in the ANGPT-2 gene is associated with risk for diabetic retinopathy in patients with type 1 diabetes mellitus in a Brazilian population.

OBJECTIVE: As studies have reported the involvement of angiopoietin-2 (ANGPT-2) in the pathogenesis of diabetic retinopathy (DR), the aim of this study was to investigate the association between the ANGPT-2 rs2442598 polymorphism and DR. METHODS: This case-control study comprised 107 patients with type 1 diabetes mellitus (T1DM) and DR (cases) and 129 patients with T1DM without DR (controls) and with ≥ 10 years of DM. The ANGPT-2 rs2442598 (G/A) polymorphism was genotyped by real-time PCR using TaqMan MGB probes. RESULTS: Genotype distributions of this polymorphism were consistent with the Hardy-Weinberg equilibrium. The frequency of the rs2442598 A allele was higher in cases compared to controls (p = 0.011). Moreover, the A/A genotype was more frequent in cases than in controls (p = 0.017) and was associated with risk for DR after adjustments for duration of DM, HbA1c, triglycerides, estimated glomerular filtration rate, and hypertension (odds ratio [OR] = 5.19, 95% confidence interval [CI] 1.21-22.27). This association was maintained under recessive (OR = 4.78, 95% CI 1.14-19.99) and additive (OR = 6.861, 95% CI 1.45-32.38) inheritance models. CONCLUSION: Our data demonstrated, for the first time, an association between the ANGPT-2 rs2442598 A allele and risk for DR in T1DM patients from southern Brazil. Additional studies are necessary to replicate this association in other populations.

The rs2304256 Polymorphism in TYK2 Gene Is Associated with Protection for Type 1 Diabetes Mellitus.

BACKGROUND: Tyrosine kinase 2 (TYK2) is a candidate gene for type 1 diabetes mellitus (T1DM) since it plays an important role in regulating apoptotic and pro-inflammatory pathways in pancreatic ß-cells through modulation of the type I interferon signaling pathway. The rs2304256 single nucleotide polymorphism (SNP) in TYK2 gene has been associated with protection for different autoimmune diseases. However, to date, only two studies have evaluated the association between this SNP and T1DM, with discordant results. This study thus aimed to investigate the association between the TYK2 rs2304256 SNP and T1DM in a Southern Brazilian population. METHODS: This case-control study comprised 478 patients with T1DM and 518 non-diabetic subjects. The rs2304256 (C/A) SNP was genotyped by real-time polymerase chain reaction technique using TaqMan minor groove binder (MGB) probes. RESULTS: Genotype and allele frequencies of the rs2304256 SNP differed between T1DM patients and non-diabetic subjects (P<0.0001 and P=0.001, respectively). Furthermore, the A allele was associated with protection against T1DM under recessive (odds ratio [OR], 0.482; 95% confidence interval [CI], 0.288 to 0.806) and additive (OR, 0.470; 95% CI, 0.278 to 0.794) inheritance models, adjusting for human leukocyte antigen (HLA) DR/DQ genotypes, gender, and ethnicity. CONCLUSION: The A/A genotype of TYK2 rs2304256 SNP is associated with protection against T1DM in a Southern Brazilian population.

Association of TYK2 polymorphisms with autoimmune diseases: A comprehensive and updated systematic review with meta-analysis.

Autoimmune diseases are characterized by the loss of self-tolerance, leading to immune-mediated tissue destruction and chronic inflammation. Tyrosine kinase 2 (TYK2) protein plays a key role in immunity and apoptosis pathways. Studies have reported associations between single nucleotide polymorphisms (SNPs) in the TYK2 gene and autoimmune diseases; however, results are still inconclusive. Thus, we conducted a systematic review followed by meta-analysis. A literature search was performed to find studies that investigated associations between TYK2 SNPs and autoimmune diseases (multiple sclerosis, systemic lupus erythematosus, Crohn's disease, ulcerative colitis, psoriasis, rheumatoid arthritis, type 1 diabetes, and inflammatory bowel disease). Pooled odds ratios (OR) with 95 % CI were calculated using random (REM) or fixed (FEM) effects models in the Stata 11.0 Software. Thirty-four articles were eligible for inclusion in the meta-analyses, comprising 9 different SNPs: rs280496, rs280500, rs280523, rs280519, rs2304256, rs12720270, rs12720356, rs34536443, and rs35018800. Meta-analysis results showed the minor alleles of rs2304256, rs12720270, rs12720356, rs34536443, and rs35018800 SNPs were associated with protection against autoimmune diseases. Moreover, the A allele of the rs280519 SNP was associated with risk for systemic lupus erythematosus. Our meta-analyses demonstrated that the rs2304256, rs12720270, rs12720356, rs34536443, rs35018800, and rs280519 SNPs in the TYK2 gene are associated with different autoimmune diseases.

The Impact of lncRNAs in Diabetes Mellitus: A Systematic Review and In Silico Analyses.

Long non-coding RNAs (lncRNAs) are non-coding transcripts that have emerged as one of the largest and diverse RNA families that regulate gene expression. Accumulating evidence has suggested a number of lncRNAs are involved in diabetes mellitus (DM) pathogenesis. However, results about lncRNA expressions in DM patients are still inconclusive. Thus, we performed a systematic review of the literature on the subject followed by bioinformatics analyses to better understand which lncRNAs are dysregulated in DM and in which pathways they act. Pubmed, Embase, and Gene Expression Omnibus (GEO) repositories were searched to identify studies that investigated lncRNA expression in cases with DM and non-diabetic controls. LncRNAs consistently dysregulated in DM patients were submitted to bioinformatics analysis to retrieve their target genes and identify potentially affected signaling pathways under their regulation. Fifty-three eligible articles were included in this review after the application of the inclusion and exclusion criteria. Six hundred and thirty-eight lncRNAs were differentially expressed between cases and controls in at least one study. Among them, six lncRNAs were consistently dysregulated in patients with DM (Anril, Hotair, Malat1, Miat, Kcnq1ot1, and Meg3) compared to controls. Moreover, these six lncRNAs participate in several metabolism-related pathways, evidencing their importance in DM. This systematic review suggests six lncRNAs are dysregulated in DM, constituting potential biomarkers of this disease.

Involvement of miR-126 rs4636297 and miR-146a rs2910164 polymorphisms in the susceptibility for diabetic retinopathy: a case-control study in a type 1 diabetes population.

BACKGROUND AND PURPOSE: MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression. MiRNA-126 and miRNA-146a have been described as having abnormal expressions in diabetic retinopathy (DR) patients. Polymorphisms in genes codifying miRNAs (miRSNPs) may alter the expression of the corresponding miRNA and, thus, interfere with susceptibility to DR. Therefore, miRSNPs in miR-126 and miR-146a genes could be associated with DR susceptibility. The purpose of this study was to investigate the association between miR-126 rs4636297 (G/A) and miR-146a rs2910164 (G/C) miRSNPs and DR. METHODS: This case-control study included 195 type 1 diabetes mellitus (T1DM) patients with DR (cases) and 215 patients without DR and with ≥10 years of T1DM (controls). MiRSNPs were genotyped by real-time PCR. RESULTS: Genotype distributions of two analysed miRSNPs were in Hardy-Weinberg equilibrium in controls (p > 0.050). Frequencies of the miR-126 rs4636297 miRSNP were not significantly different between case and control groups (p = 0.169). However, after adjustment for age, glycated haemoglobin, triglycerides, estimated glomerular filtration rate and ethnicity, the A allele of this miRSNP was associated with protection for DR under additive [OR: 0.444 (95% CI: 0.211-0.936), p = 0.033] and dominant [OR: 0.512 (95% CI: 0.303-0.865), p = 0.012] inheritance models. Genotype and allele frequencies of miR-146a rs2910164 miRSNP did not differ between groups (p = 0.368 and p = 0.957), and this polymorphism was not associated with DR when assuming different inheritance models. CONCLUSION: Our results suggest an association between the A allele of miR-126 rs4636297 miRSNP and protection for DR in a Southern Brazilian population.

Comparison of two techniques for assessing pancreatic islet viability: flow cytometry and fluorescein diacetate/propidium iodine staining

Introduction: The success of islet transplantation for patients with unstable type 1 diabetes mellitus depends, in part, on the number of isolated islets and their quality, which is assessed by functional and viability tests. The test currently employed to evaluate islet viability, used by the Collaborative Islet Transplant Registry to release products for transplantation, is fluorescein diacetate/propidium iodide (FDA/PI) staining. However, the efficacy of this method relies on researcher experience; in this context, a quantitative method may be useful. The aim of this study was to compare islet viability as assessed by flow cytometry and the FDA/PI assay. Methods: Viability was analyzed in islets isolated from 10 male Wistar rats. Upon FDA/PI staining, 50 islets from each animal were analyzed under fluorescence microscopy by two well-trained researchers. For flow cytometry, islets were dispersed and 100 000 single cells were incubated with the 7-amino-actinomycin D (7AAD) fluorophore (dyes necrotic and late apoptotic cells) and the Annexin V-APC antibody (marks early apoptotic cells). Results: A moderate correlation was found between techniques (r = 0.6; p = 0.047). The mean islet viability measured by flow cytometry was higher than that estimated using FDA/PI staining (95.5 ± 1.4% vs 89.5 ± 5.0%; p = 0.002). Conclusions: Although flow cytometry is more expensive and time-consuming than FDA/PI staining, it is a quantitative technique with greater reproducibility that is less subject to inter-observer variability than FDA/PI. Therefore, flow cytometry appears to be the technique of choice when aiming for a more precise determination of islet viability. (AU)

The rs11755527 polymorphism in the BACH2 gene and type 1 diabetes mellitus: case control study in a Brazilian population.

Objective Type 1 diabetes mellitus (T1DM) is an autoimmune disorder caused by a complex interaction between environmental and genetic risk factors. BTB domain and CNC homolog 2 (BACH2) gene encodes a transcription factor that acts on the differentiation and formation of B and T lymphocytes. BACH2 is also involved in the suppression of apoptosis and inflammation in pancreatic beta-cells, indicating a role for it in the development of T1DM. Therefore, the aim of this study was to evaluate the association of the BACH2 rs11755527 single nucleotide polymorphism (SNP) with T1DM. Subjects and methods This case-control study comprised 475 patients with T1DM and 598 nondiabetic individuals. The BACH2 rs11755527 (C/G) SNP was genotyped using real-time PCR with TaqMan MGB probes. Results Genotype distributions of rs11755527 SNP were in accordance with frequencies predicted by the Hardy-Weinberg equilibrium in case and control groups and were similar between groups (P = 0.729). The minor allele frequency was 43.6% in cases and 42.5% in controls (P = 0.604). Moreover, the G allele frequency did not differ between groups when considering different inheritance models and adjusting for age, gender, body mass index, and HLA DR/DQ genotypes of high-risk for T1DM. Although, well-known high-risk T1DM HLA DR/DQ genotypes were associated with T1DM in our population [OR= 7.42 (95% CI 3.34 - 17.0)], this association was not influenced by the rs11755527 SNP. Conclusion The BACH2 rs11755527 SNP seems not to be associated with T1DM in a Brazilian population.

The rs11755527 polymorphism in the BACH2 gene and type 1 diabetes mellitus: case control study in a Brazilian population

ABSTRACT Objective Type 1 diabetes mellitus (T1DM) is an autoimmune disorder caused by a complex interaction between environmental and genetic risk factors. BTB domain and CNC homolog 2 (BACH2) gene encodes a transcription factor that acts on the differentiation and formation of B and T lymphocytes. BACH2 is also involved in the suppression of apoptosis and inflammation in pancreatic beta-cells, indicating a role for it in the development of T1DM. Therefore, the aim of this study was to evaluate the association of the BACH2 rs11755527 single nucleotide polymorphism (SNP) with T1DM. Subjects and methods This case-control study comprised 475 patients with T1DM and 598 nondiabetic individuals. The BACH2 rs11755527 (C/G) SNP was genotyped using real-time PCR with TaqMan MGB probes. Results Genotype distributions of rs11755527 SNP were in accordance with frequencies predicted by the Hardy-Weinberg equilibrium in case and control groups and were similar between groups (P = 0.729). The minor allele frequency was 43.6% in cases and 42.5% in controls (P = 0.604). Moreover, the G allele frequency did not differ between groups when considering different inheritance models and adjusting for age, gender, body mass index, and HLA DR/DQ genotypes of high-risk for T1DM. Although, well-known high-risk T1DM HLA DR/DQ genotypes were associated with T1DM in our population [OR= 7.42 (95% CI 3.34 - 17.0)], this association was not influenced by the rs11755527 SNP. Conclusion The BACH2 rs11755527 SNP seems not to be associated with T1DM in a Brazilian population.

Association of long non-coding RNA and leukemia: A systematic review.

INTRODUCTION: Long non-coding RNAs (lncRNAs) are RNA molecules that structurally resemble mRNA but do not encode proteins. Studies have been associated this class of non-coding RNA with the development of several disease, among them the different types of leukemia. However, the results are contradictory. Thus, we performed a systematic review of the literature available in order to better understand the involvement of lncRNAs in the development of leukemia. MATERIALS AND METHODS: Pubmed and Embase databases were used to identify all studies that evaluated the expression of one or more lncRNA between human samples (peripheral blood, bone marrow) with leukemia (cases) and without leukemia (controls). RESULTS: A total of 3675 articles were found in the databases, and after exclusion of articles that did not meet the eligibility criteria, 86 articles were included in this systematic review. In the 86 included studies, 3927 lncRNAs were differentially expressed between cases and controls. Among these, 110 lncRNAs were reported as being altered in samples from at least 2 studies and only 16 of them in ≥3 studies, which were selected for further evaluation. Of these, 12 lncRNAs were consistently dysregulated between cases and controls (CCAT1, CCDC26, CRNDE, HOTAIR, KCNQ5IT1, LINC00265, MALAT1, PVT1, SNHG5, TUG1: increased in cases, MEG3 and NEAT1: decreased in cases) in human samples of patients with some type of leukemia. CONCLUSION: Our data demonstrate that 12 lncRNAs are dysregulated in leukemia.