Role of SLMAP genetic variants in susceptibility of diabetes and diabetic retinopathy in Qatari population

Intraretinal Microvascular Abnormalities and Venous Beading Have Different Genetic Profiles in Caucasian Patients with Non-Proliferative Diabetic Retinopathy

Diabetic Retinopathy (DR) is a leading cause of preventable visual impairment in the working age population. Despite the increasing prevalence of DR, there remain gaps in our understanding of its pathophysiology. This is a prospective case-control study comparing the genetic profiles of patients with no DR vs. non-proliferative DR (NPDR) focusing on intraretinal microvascular abnormalities (IRMA) and venous beading (VB) in Caucasians. A total of 596 participants were recruited to the study; 199 with moderate/severe NPDR and 397 with diabetes for at least 5 years without DR. Sixty-four patients were excluded due to technical issues. In total, 532 were analysed; 181 and 351 were in the NPDR group and no DR group, respectively. Those with severe IRMA and VB had distinctly different genetic profiles from each other and from the no DR group, which further supports the theory that these two features of DR might have different etiologies. This also suggests that IRMA and VB are independent risk factors for the development of PDR and may have different pathophysiologies. If these findings are confirmed in larger studies, this could pave the way for personalised treatment options for those more at risk of developing different features of NPDR.

An association between the sarcolemmal membrane-associated protein gene and microvascular endothelial diabetic retinopathy in patients with type 2 diabetes mellitus: A preliminary case control study

BACKGROUND AND AIMS

Diabetic retinopathy (DR) is one of the most common microvascular diabetic complications. Sarcolemmal membrane-associated protein (SLMAP) has been implicated in playing a role in microvascular endothelial dysfunction. This study aimed to assess the significance of SLMAP rs17058639C > T gene polymorphism among patients with type 2 diabetes mellitus (T2DM) and its relevance to microvascular endothelial diabetic retinopathy.

METHODS

We conducted this case-control study on 100 individuals divided into 60 participants with T2DM and 40 healthy controls. Patients with T2D were stratified into two groups: 40 patients with DR and 20 patients with diabetic non-retinopathy (DNR). Patients with T2DM were compared with age- and sex-matched healthy controls. Fundus examinations were conducted to detect microvascular endothelial changes. The polymorphism of SLMAP rs17058639C > T gene was identified by real-time polymerase chain reaction (RT-PCR) TaqMan allelic discrimination.

RESULTS

Patients with DR have significantly increased glycated hemoglobin (HbA1c) compared to patients with DNR (P < 0.001). There was no statistically significant difference found between diabetic and control groups regarding the frequency of SLMAP rs17058639C > T genotypes. The homozygous CC genotype was the most common variant among patients with DR; however, the results did not reach statistical significance.

CONCLUSIONS

Diabetic retinopathy is correlated with poor glycemic control, and SLMAP rs17058639C > T polymorphism was associated with microvascular endothelial DR in patients with T2DM, although further studies with a large sample size are needed to confirm our findings.

The Promising Role of Microbiome Therapy on Biomarkers of Inflammation and Oxidative Stress in Type 2 Diabetes: A Systematic and Narrative Review

Background

One in 10 adults suffer from type 2 diabetes (T2D). The role of the gut microbiome, its homeostasis, and dysbiosis has been investigated with success in the pathogenesis as well as treatment of T2D. There is an increasing volume of literature reporting interventions of pro-, pre-, and synbiotics on T2D patients.

Methods

Studies investigating the effect of pro-, pre-, and synbiotics on biomarkers of inflammation and oxidative stress in T2D populations were extracted from databases such as PubMed, Scopus, Web of Science, Embase, and Cochrane from inception to January 2022.

Results

From an initial screening of 5,984 hits, 47 clinical studies were included. Both statistically significant and non-significant results have been compiled, analyzed, and discussed. We have found various promising pro-, pre-, and synbiotic formulations. Of these, multistrain/multispecies probiotics are found to be more effective than monostrain interventions. Additionally, our findings show resistant dextrin to be the most promising prebiotic, followed closely by inulin and oligosaccharides. Finally, we report that synbiotics have shown excellent effect on markers of oxidative stress and antioxidant enzymes. We further discuss the role of metabolites in the resulting effects in biomarkers and ultimately pathogenesis of T2D, bring attention toward the ability of such nutraceuticals to have significant role in COVID-19 therapy, and finally discuss few ongoing clinical trials and prospects.

Conclusion

Current literature of pro-, pre- and synbiotic administration for T2D therapy is promising and shows many significant results with respect to most markers of inflammation and oxidative stress.

Statins are associated with new onset type 2 diabetes mellitus (T2DM) in Medicare patients ≥65 years

BACKGROUND

To evaluate the association of statins and co-morbidities with new onset type 2 diabetes mellitus (T2DM) in patients 65 years and older.

METHODS

This retrospective study used de-identified administrative healthcare claims and enrolment data from a Medicare Advantage Prescription Drug (MAPD) health plan offered by a large multistate healthcare company. The plan covered >2.4 million individuals, of whom >1.7 million individuals were ≥65 years. Of these, 265 554 individuals had continuous MAPD enrolment January 2008 to December 2015. The unadjusted model assessed demographic, pharmacy and T2DM co-morbidities as covariates. Significant variables (P < .05) in the unadjusted model were then included in the adjusted model. The adjusted model used Cox proportional hazards to evaluate covariate effects. Matched propensity score analysis was used to analyse the association of statins and T2DM onset.

RESULTS

The cumulative rate of diagnosed T2DM onset in the study cohort was 4.82% (4314/89 390). Annualised incidence of T2DM diagnosis was 0.82%, 0.88%, 1.04% and 2.09% in 2012, 2013, 2014 and 2015, respectively. T2DM onset was associated with male sex, non-white (African American or Hispanic ethnicity), statin use, hypertension, hyperlipidaemia, heart failure, lower limb ulceration, atherosclerosis, other retinopathy, angina pectoris, poor vision and blindness and absence ischaemic heart disease (IHD). Matched propensity score analysis showed that statin use was significantly associated with T2DM onset (Odds Ratio = 1.26, 95% Confidence Interval: 1.12-1.41, P < .0001) in the adjusted model.

CONCLUSIONS

Analyses indicated that statin usage was associated with new onset T2DM after adjusting for covariates.

Identifying Genetic Risk Factors for Diabetic Macular Edema and the Response to Treatment

Diabetic retinopathy (DR) is the most common microvascular complication of diabetes mellitus (DM). DR is complex and the term encompasses several clinical subtypes of diabetic eye disease, including diabetic macular edema (DME), the most frequent cause of central vision loss in DR patients. Both genetic and environmental factors contribute to the pathophysiology of DR and its subtypes. While numerous studies have identified several susceptibility genes for DR, few have investigated the impact of genetics on DME susceptibility. This review will focus on the current literature surrounding genetic risk factors associated with DME. We will also highlight the small number of studies investigating the genetics of response to antivascular endothelial growth factor (anti-VEGF) injection, which is used to treat DME.

Qatari Genotype May Contribute to Complications in Type 2 Diabetes

OBJECTIVE

There is increasing evidence of a strong genetic component in type 2 diabetes (T2DM) that may contribute to diabetes complications. Given the high prevalence of diabetes with its associated complications in the Middle East, we sought to determine if the genotype within a Middle East population may be contributory. Therefore, three genotype-based Qatari ancestral groups, Q1 Arab Bedouin, Q2 Asian/Persian, and Q3 sub-Saharan African, with a fourth admixed group were correlated with T2DM prevalence and its complications to determine if they differed between the 4 Qatari ancestries, particularly for the SLMAP allele-associated diabetic retinopathy.

METHODS

In this cross-sectional study, 398 Qatari subjects, 220 with and 178 without T2DM, were genotyped by Affymetrix 500k SNP arrays. Ancestry was correlated with diabetes complications.

RESULTS

398 subjects were included, the mean age was 49.8 years, and 56.8% were male. The genotype-based ancestry and T2DM prevalence were as follows: 164 (41.2%) with ancestry Q1, 60.4% with T2DM; 149 (37.4%) with ancestry Q2, 49.7% with T2DM; 31 (7.8%) with ancestry Q3, 61.3% with T2DM; and 54 (13.6%) with "admixed" ancestry, 51.9% with T2DM. For patients with diabetes, hypertension (p < 0.035) and retinopathy (p < 0.016) were greater in the Q3 ancestry.

CONCLUSION

These data suggest that the genotype may contribute to complication risk, as exemplified by the increase in hypertension and retinopathy in the Q3 ancestry, though the SLMAP allele was not implicated; however, diabetes prevalence did not differ between the four Qatari ancestries.

Targeting SLMAP-ALK-a novel gene fusion in lung adenocarcinoma

Assessment of ALK gene rearrangements is strongly recommended by the Molecular Testing Guideline for Selection of Lung Cancer Patients proposed by IASLC, AMP, and CAP at the time of diagnosis for patients with advanced stage disease. Non-small-cell lung cancer (NSCLC) with ALK gene rearrangements or the resulting fusion proteins have been, for the most part, successfully targeted with ALK tyrosine kinase inhibitors (TKIs). The most frequent rearrangement, the EML4-ALK oncogenic fusion, has more than 10 distinct variants, each with a discrete breakpoint in EML4. Recent studies have suggested that EML4-ALK variants may have differential responses to TKIs. Additionally, non-EML4-ALK fusions that result from ALK rearrangements with diverse 5′ partners could possibly have varied biologic and clinical implications in their therapeutic responses and outcomes of patients with NSCLC. Existing literature documents at least 20 non-EML4 fusion partners for ALK, and the clinical responsiveness to crizotinib ranges from increased sensitivity to resistance. This underscores the importance of identifying the precise 5′ fusion partner to ALK before initiation of therapy. Herein we report the identification of a novel SLMAP-ALK fusion in a patient with NSCLC.

Genetic polymorphisms associated with type 2 diabetes in the Arab world: A systematic review and meta-analysis

AIMS

T2DM reach epidemic levels in the Arab countries. In this study, we aimed to perform a systematic review and meta-analysis to underline the susceptibility genetic profile of Arab patients with T2DM that result from SNPs.

METHODS

We searched four literature databases (PubMed, Scopus, Science Direct and Web of Science) through January 2019. We included all SNPs in candidate genes with an OR > 1 that were associated with T2DM among Arab patients with T2DM. Statistical programs such as software Review Manager (Version 5.02) and STATA (Version 15.1) were used. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated with a random effects model or a fixed effect model depending on the heterogeneity among studies. I² statistics and Egger's tests were performed to assess heterogeneity and publication bias.

RESULTS

Out of 2245 studies, 47 were used for meta-analysis. We captured 31,307 cases and 26,464 controls in which we collected 71 SNPs in 32 genes. A pooled meta-analysis demonstrated 24-69% increase in T2DM risk. Among the 57 SNPs (in 32 genes) that were not included in the meta-analysis, the OR for diabetes ranged from 1.02 to 5.10, with a median of 1.38 (interquartile range 1.33-2.09). Ten studies examined the association between the TCF7L2 polymorphism rs7903146 and T2DM, leading to an aggregated OR of 1.34 (95%CI 1.27-1.41).

CONCLUSION

The genetic profile that confer susceptibility to T2DM in Arab patients is diverse. This study may serve as a platform for designing a gene panel for testing the susceptibility to T2DM.

Type 2 Diabetes Mellitus (T2DM) "Remission" in Non-bariatric Patients 65 Years and Older

Objective: To analyze the factors associated with type 2 diabetes mellitus (T2DM) “remission” in non-bariatric Medicare patients 65 years and older.

Research Design and Methods: A retrospective cohort analysis of a Medicare Advantage health plan was conducted using administrative data. An individual was identified as T2DM if the individual had: ≥ 2 medical claims for T2DM coded 250.xx excluding type 1 diabetes; or ≥ 2 pharmacy claims related to T2DM; or ≥ 2 combined medical claims, pharmacy claims for T2DM in 12 months. A T2DM individual was in “remission” if they had no T2DM related claims for more than 12 months continuously. This is different from the standard American Diabetes Association (ADA) definition of remission which includes HbA1c values and hence is represented in quotation (as “remission”). 10,059 T2DM individuals were evaluated over a period of 8 years from 2008 to 2015. Cox proportional hazards was used to identify significant variables associated with T2DM “remission.”

Results: 4.97% of patients studied met the definition of T2DM “remission” in the study cohort. After adjusting for covariates this study found a number of variables associated with T2DM “remission” that were not previously reported: no statin use; low diabetes complications severity index score; no hypertension; no neuropathy; no retinopathy; race (non-white and non-African American); presence of other chronic ischemic heart disease (IHD) and females (p < 0.05).

Conclusion: T2DM “remission” in Medicare patients 65 years and older is observed in a community setting in a small proportion of non-bariatric patients.

Diabetic macular oedema: under-represented in the genetic analysis of diabetic retinopathy

Diabetic retinopathy, a complication of both type 1 and type 2 diabetes, is a complex disease and is one of the leading causes of blindness in adults worldwide. It can be divided into distinct subclasses, one of which is diabetic macular oedema. Diabetic macular oedema can occur at any time in diabetic retinopathy and is the most common cause of vision loss in patients with type 2 diabetes. The purpose of this review is to summarize the large number of genetic association studies that have been performed in cohorts of patients with type 2 diabetes and published in English-language journals up to February 2017. Many of these studies have produced positive associations with gene polymorphisms and diabetic retinopathy. However, this review highlights that within this large body of work, studies specifically addressing a genetic association with diabetic macular oedema, although present, are vastly under-represented. We also highlight that many of the studies have small patient numbers and that meta-analyses often inappropriately combine patient data sets. We conclude that there will continue to be conflicting results and no meaningful findings will be achieved if the historical approach of combining all diabetic retinopathy disease states within patient cohorts continues in future studies. This review also identifies several genes that would be interesting to analyse in large, well-defined cohorts of patients with diabetic macular oedema in future candidate gene association studies.

Weighted Gene Co-expression Network Analysis Identifies FKBP11 as a Key Regulator in Acute Aortic Dissection through a NF-kB Dependent Pathway

Acute aortic dissection (AAD) is a life-threatening disease. Despite the higher risk of mortality, currently there are no effective therapies that can ameliorate AAD development or progression. Identification of meaningful clusters of co-expressed genes or representative biomarkers for AAD may help to identify new pathomechanisms and foster development of new therapies. To this end, we performed a weighted gene co-expression network analysis (WGCNA) and calculated module-trait correlations based on a public microarray dataset (GSE 52093) and discovered 9 modules were found to be related to AAD. The module which has the strongest positive correlation with AAD was further analyzed and the top 10 hub genes SLC20A1, GINS2, CNN1, FAM198B, MAD2L2, UBE2T, FKBP11, SLMAP, CCDC34, and GALK1 were identified. Furthermore, we validated the data by qRT-PCR in an independent sample set originated from our study center. Overall, the qRT-PCR results were consistent with the results of the microarray analysis. Intriguingly, the highest change was found for FKBP11, a protein belongs to the FKBP family of peptidyl-prolyl cis/trans isomerases, which catalyze the folding of proline-containing polypeptides. In congruent with the gene expression analysis, FKBP11 expression was induced in cultured endothelial cells by angiotensin II treatment and endothelium of the dissected aorta. More importantly we show that FKBP11 provokes inflammation in endothelial cells by interacting with NF-kB p65 subunit, resulting in pro-inflammatory cytokines production. Accordingly, siRNA mediated knockdown of FKBP11 in cultured endothelial cells suppressed angiotensin II induced monocyte transmigration through the endothelial monolayer. Based on these data, we hypothesize that pro-inflammatory cytokines elicited by FKBP11 overexpression in the endothelium under AAD condition could facilitate transendothelial migration of the circulating monocytes into the aorta, where they differentiate into active macrophages and secrete MMPs and other extracellular matrix (ECM) degrading proteins, contributing to sustained inflammation and AAD. Taken together, our data identify important role of FKBP11 which can serve as biomarker and/or therapeutic target for AAD.

Update on genetics and diabetic retinopathy

Clinical risk factors for diabetic retinopathy (DR), such as duration of disease and degree of glucose control, do not adequately predict disease progression in individual patients, suggesting the presence of a genetic component. Multiple smaller studies have investigated genotype–phenotype correlations in genes encoding vascular endothelial growth factor, aldose reductase, the receptor for advanced glycation end products, and many others. In general, reported results have been conflicting, due to factors including small sample sizes, variations in study design, differences in clinical end points, and underlying genetic differences between study groups. At this time, there is no confirmed association with any risk allele reported. As we continue to collect data from additional studies, the role of genetics in DR may become more apparent.