Potential role of Peroxisome Proliferator Activated Receptor gamma analogues in regulation of endothelial progenitor cells in diabetes mellitus: An overview

IGF1 and PPARG polymorphisms are associated with reduced estimated glomerular filtration rate in a cohort of children and adolescents with type 1 diabetes

INTRODUCTION

Several genetic loci have been associated with diabetic nephropathy; however, the underlying genetic mechanisms are still poorly understood, with no robust candidate genes identified yet.

AIM

We aimed to determine whether two polymorphisms, previously associated with renal decline, influence kidney impairment evaluating their association with markers of renal function in a pediatric population with type 1 diabetes (T1D).

MATERIAL AND METHODS

Renal function was evaluated by glomerular filtration rate (eGFR) and albumin-to-creatinine ratio (ACR) in a cohort of pediatric subjects with T1D (n = 278). Risk factors for diabetes complications (diabetes duration, blood pressure, HbA1c) were assessed. The IGF1 rs35767 and PPARG rs1801282 SNPs were genotyped by TaqMan RT-PCR system. An additive genetic interaction was calculated. Association analysis between markers of renal function and both SNPs or their additive interaction were performed.

RESULTS

Both SNPs showed a significant association with eGFR: the A allele of rs35767 or the C allele of rs1801282 were associated to reduced eGFR compared to G alleles. Multivariate regression analysis adjusted for age, sex, z-BMI, T1D duration, blood pressure and Hba1c values showed that the additive genetic interaction was independently associated with lower eGFR (β = -3.59 [-6.52 to -0.66], p = 0.017). No associations were detected between SNPs, their additive interaction and ACR.

CONCLUSIONS

These results provide new insight into the genetic predisposition to renal dysfunction, showing that two polymorphisms in IGF1 and PPARG genes can lead to a reduction in renal filtration rate leading these patients to be exposed to a higher risk of early renal complications.

Co-Delivery of Therapeutics and Bioactive Gas Using a Novel Liposomal Platform for Enhanced Treatment of Acute Arterial Injury

Atherosclerosis is a complex, multi-stage disease characterized by pathological changes across the vascular wall. Endothelial dysfunction, inflammation, hypoxia, and vascular smooth muscle cell proliferation contribute to its progression. An effective strategy capable of delivering pleiotropic treatment to the vascular wall is essential to limit neointimal formation. Echogenic liposomes (ELIP), which can encapsulate bioactive gases and therapeutic agents, have the potential to deliver enhanced penetration and treatment efficacy for atherosclerosis. In this study, liposomes loaded with nitric oxide (NO) and rosiglitazone, a peroxisome proliferator-activated receptor agonist, were prepared using hydration, sonication, freeze-thawing, and pressurization. The efficacy of this delivery system was evaluated in a rabbit model of acute arterial injury induced by balloon injury to the common carotid artery. Intra-arterial administration of rosiglitazone/NO co-encapsulated liposomes (R/NO-ELIP) immediately following injury resulted in reduced intimal thickening after 14 days. The anti-inflammatory and anti-proliferative effects of the co-delivery system were investigated. These liposomes were echogenic, enabling ultrasound imaging to assess their distribution and delivery. R/NO-ELIP delivery exhibited a greater attenuation (88 ± 15%) of intimal proliferation when compared to NO-ELIP (75 ± 13%) or R-ELIP (51 ± 6%) delivery alone. The study demonstrates the potential of echogenic liposomes as a promising platform for ultrasound imaging and therapeutic delivery.

Potential Therapeutic Benefits of Metformin Alone and in Combination with Sitagliptin in the Management of Type 2 Diabetes Patients with COVID-19

Type 2 diabetes mellitus (T2DM) is a potential risk factor for the development of COVID-19 and is associated with higher severity and mortality rates. T2DM patients are commonly treated with metformin monotherapy or metformin plus sitagliptin. In the present case-control, single-center cohort study, a total number of 112 T2DM patients suffering from COVID-19 and aged 44−62 years old were compared with 78 T2DM patients without COVID-19 and aged 42−56 years old. Both the patient group and the control group were allocated into four groups. Group A: T2DM patients with COVID-19 on metformin treatments plus standard therapy (n = 60); group B: T2DM patients with COVID-19 on metformin plus sitagliptin plus standard therapy (n = 52); group C: T2DM patients without COVID-19 on metformin treatments (n = 40); and group D: T2DM patients without COVID-19 on metformin plus sitagliptin (n = 38). The investigation duration was 2−3 weeks. Anthropometric measurements, serological and biochemical investigations, pulmonary radiological findings, and clinical outcomes were evaluated. Only 101 T2DM patients with COVID-19 continued the study, 71 (70.29%) with mild-moderate COVID-19 and 30 (29.7%) with severe COVID-19 were compared with 78 T2DM patients as a control. Inflammatory biomarkers (C reactive protein, ferritin, and procalcitonin), a lung injury biomarker (lactate dehydrogenase), and a coagulopathy biomarker (D-dimer) were elevated in severe COVID-19 patients compared with mild-moderate COVID-19 (p < 0.05) and T2DM patients (p < 0.05). However, metformin plus sitagliptin was more effective than metformin monotherapy in T2DM patients with COVID-19, as evidenced by the mitigation of oxidative stress, CT scan score, and clinical outcomes. The present study confirmed the protective effects of this combination against the development of COVID-19 severity, as most T2DM COVID-19 patients develop mild-moderate forms. Herein, the combination of metformin and sitagliptin may lead to more beneficial effects than metformin monotherapy.

microRNA-199a downregulation alleviates hyperuricemic nephropathy via the PPARγ/β-catenin axis

Hyperuricemia always develops into hyperuricemic nephropathy (HN). The role of microRNA (miR) in HN is less studied. We aimed to discuss the role of miR-199a in HN. The expression of miR-199a and PPARγ in renal tissues of HN rats was detected. The targeting relation between miR-199a and PPARγ was verified. The contents of SCr, UA, BUN, and mALB, renal injury-relevant biomarkers were detected, and the pathological changes of renal tissue and renal interstitial fibrosis were observed by histological staining. After miR-199a and PPARγ knockdown, the contents of SCr, BUN, and mALB and renal interstitial fibrosis were estimated. Collectively, overexpression of miR-199a aggravated the renal injury in HN rats. By contrast, inhibition of miR-199a weakened renal injury, as evidenced by decreased contents of SCr, UA, BUN, and mALB, and mitigated renal interstitial fibrosis. miR-199a targeted PPARγ. Silencing of PPARγ upregulated the levels of downstream genes of β-catenin and the contents of SCr, UA, BUN, and mALB and deteriorated renal interstitial fibrosis. Moreover, the silencing of PPARγ blocked the alleviative effects of miR-199a inhibitor on the renal injury. Overall, miR-199a targets PPARγ and activates the β-catenin pathway, thus aggravating HN, which might provide a future target for the treatment of HN.

rs10865710 polymorphism in PPARG promoter is associated with the severity of type 2 diabetes mellitus and coronary artery disease in a Chinese population

BACKGROUND

Relationship between polymorphisms in peroxisome proliferator-activated receptor gamma (PPARG) and progression of type 2 diabetes mellitus (T2DM) and coronary artery disease (CAD) remains to be clarified.

METHODS

635 subjects were divided into T2DM, CAD, T2DM complicated with CAD (T2DM/CAD) and control groups according to diagnostic criteria. The rs10865710 and rs3856806 polymorphisms were genotyped, and the severity of T2DM and CAD was evaluated for all subjects.

RESULTS

In patients with T2DM, G allele carriers of rs10865710 polymorphism had significantly higher levels of glucose, triglycerides, apolipoprotein B (ApoB) and lipoprotein (a) (Lp(a)) than non-carriers, T allele carriers of rs3856806 polymorphism had significantly higher levels of glucose, low-density lipoprotein cholesterol (LDL-C), ApoB and Lp(a) than non-carriers. In patients with CAD, G allele carriers of rs10865710 polymorphism had significantly higher levels of total cholesterol (TC), ApoB and Lp(a) than non-carriers, T allele carriers of rs3856806 polymorphism had significantly higher levels of body mass index, blood pressure, TC, LDL-C and ApoB than non-carriers. Patients with one or two G alleles of rs10865710 polymorphism had significantly higher levels of Gensini scores and more diseased coronary branches than those patients without CAD. The rs3856806 polymorphism was not associated with CAD severity, but it was found to be significantly associated with T2DM/CAD, T allele frequency was significantly higher in T2DM/CAD group than that in T2DM/CAD-free group.

CONCLUSIONS

The rs10865710 and rs3856806 polymorphisms in PPARG are significantly associated with glucose levels in patients with T2DM. The rs10865710 polymorphism is significantly associated with the severity of CAD, which is possibly mediated by hyperlipidaemia and hyperglycaemia.

Association of glycaemic status and outcomes in diabetic foot problems: a retrospective evidence from South India

OBJECTIVES

Emerging shreds of evidence indicates that the risk of diabetic foot ulcer and associated morbidity can be reduced through the intensive glycemic control. There are very few studies which assessed the effects of glycemic control on diabetic foot problems among Indian patients. We aimed to assess the effect of glycemic control on the outcomes of diabetic foot problems among adult type 2 diabetes (T2DM) patients with foot ulcers.

METHODS

A cross sectional study was conducted among the T2DM patients from a tertiary care teaching hospital in South India. The demographic characters, risk factors, treatment characters, glycemic status were collected among the patients and analyzed against the outcomes of diabetic foot ulcers by reviewing their medical records. Descriptive statistics were used to present the data. The Chi-square test and ANOVA were used for was used for the categorical variables and continuous parameters to identify the factors affecting the outcomes, respectively. All analysis was performed in SPSS v21.

RESULTS

Out of the 100 participants included in the study, 70% were male. The majority (78%) were from an age group of 40 to 70 years, and the mean age was found to be 59.91 ± 10.6 years. The mean duration of diabetes was 9.66 years. Only ankle-brachial Index score (p=0.001) was significantly associated with the type of ulcers, whereas other factors not (p>0.05). A high level of average HbA_1c, BMI, ABI index and poor glycemic status was associated with a significant debridement strategy and longer duration of hospitalization; however, it was not substantial.

CONCLUSION

Our study inferred that poor glycemic status is associated with a significant debridement strategy and longer duration of hospitalization. However, these findings need to be strengthened with adequately powered prospective studies.

Efficacy and Safety of Commonly Used Insulin Analogues in the Treatment of Diabetic Ketoacidosis: A Bayesian Indirect Treatment Comparison

PURPOSE

Insulin analogues (IAs) are the mainstay for the management of diabetic ketoacidosis (DKA). However, the relative efficacy of newer IAs is uncertain. The aim of this study was to compare the relative efficacy and safety of IAs for the management of DKA using an indirect treatment comparison (ITC).

METHODS

PubMed, EMBASE, Scopus, the Cochrane Library, and ClinicalTrials.gov were searched for randomized controlled trials (RCTs) comparing short-, rapid-, and long-acting IAs in patients with DKA. The primary outcomes of interest were time taken to normalize DKA and time taken to normalize blood glucose levels. The secondary outcomes of interest were the amount of insulin needed to normalize DKA, the length of hospital stay, and the number of hypoglycemic events in the intervention and comparator groups. Bayesian ITC was performed by using the gemtc package in the R program. Continuous outcomes are reported as mean difference (MD), and binary outcomes are reported as odds ratios (ORs), with 95% credible intervals (CrIs). The Cochrane risk of bias tool was used to assess the risk of bias in the included RCTs.

FINDINGS

Ten RCTs randomizing 435 participants to treatment were included in this ITC. A total of 5 interventions (lispro, glargine with regular insulin [RI], glulisine, aspart, and regular insulin) were compared for both safety and efficacy outcomes in DKA. Glargine co-administered with regular insulin showed superiority for clinical outcomes compared with regular insulin: consuming less time (MD, -3.1 h; 95% CrI, -7.9 to 1.8), amount of insulin required (MD, -32 U; 95% CrI, 83.0 to 18.0), and the length of hospitalization (MD, -0.82 day; 95% CrI, -2.7 to 1.0) to normalize DKA. However, these results were not statistically significant. Insulin aspart had fewer reports of hypoglycemic events (OR, 1.7; 95% CrI, 0.34 to 9.3) than regular insulin.

IMPLICATIONS

Newer IAs were found to be equally effective and safe as regular insulin in the treatment of DKA. Thus, administering these IAs can be considered a safe and cost-effective alternative for DKA management in non-ICU settings. Cost-effective analysis of the newer IAs is needed because these agents are expensive compared with regular insulin.

Endothelial Dysfunction in Diabetic Retinopathy

Diabetic retinopathy (DR) is a diabetic complication which affects retinal function and results in severe loss of vision and relevant retinal diseases. Retinal vascular dysfunction caused by multifactors, such as advanced glycosylation end products and receptors, pro-inflammatory cytokines and chemokines, proliferator-activated receptor-γ disruption, growth factors, oxidative stress, and microRNA. These factors promote retinal endothelial dysfunction, which results in the development of DR. In this review, we summarize the contributors in the pathophysiology of DR for a better understanding of the molecular and cellular mechanism in the development of DR with a special emphasis on retinal endothelial dysfunction.