Circulatory levels of lysophosphatidylcholine species in obese adolescents: Findings from cross-sectional and prospective lipidomics analyses.

BACKGROUND AND AIMS: Obesity has reached epidemic proportions, emphasizing the importance of reliable biomarkers for detecting early metabolic alterations and enabling early preventative interventions. However, our understanding of the molecular mechanisms and specific lipid species associated with childhood obesity remains limited. Therefore, the aim of this study was to investigate plasma lipidomic signatures as potential biomarkers for adolescent obesity. METHODS AND RESULTS: A total of 103 individuals comprising overweight/obese (n = 46) and normal weight (n = 57) were randomly chosen from the baseline ORANGE (Obesity Reduction and Noncommunicable Disease Awareness through Group Education) cohort, having been followed up for a median of 7.1 years. Plasma lipidomic profiling was performed using the UHPLC-HRMS method. We used three different models adjusted for clinical covariates to analyze the data. Clustering methods were used to define metabotypes, which allowed for the stratification of subjects into subgroups with similar clinical and metabolic profiles. We observed that lysophosphatidylcholine (LPC) species like LPC.16.0, LPC.18.3, LPC.18.1, and LPC.20.3 were significantly (p < 0.05) associated with baseline and follow-up BMI in adolescent obesity. The association of LPC species with BMI remained consistently significant even after adjusting for potential confounders. Moreover, applying metabotyping using hierarchical clustering provided insights into the metabolic heterogeneity within the normal and obese groups, distinguishing metabolically healthy individuals from those with unhealthy metabolic profiles. CONCLUSION: The specific LPC levels were found to be altered and increased in childhood obesity, particularly during the follow-up. These findings suggest that LPC species hold promise as potential biomarkers of obesity in adolescents, including healthy and unhealthy metabolic profiles.

Syzygium cumini ameliorates high fat diet induced glucose intolerance, insulin resistance, weight gain, hepatic injury and nephrotoxicity through modulation of PTP1B and PPARγ signaling.

Metabolic disorders are majorly associated with insulin resistance and an impaired glucose tolerance. Since, many of the currently available drugs exhibit adverse effects and are resistant to therapies, natural products are a promising alternate in the alleviation of complex metabolic disorders. In the current study, Syzygium cumini methanolic extract (SCE) was investigated for its anti-diabetic and anti-adipogenic potential using C57BL/6 mice fed on high fat diet (HFD). The HFD fed obese mice were treated with 200 mg/kg SCE and compared with positive controls Metformin, Pioglitazone and Sodium Orthovanadate. The biometabolites in SCE were characterized using Fourier transform infrared and gas chromatography and mass spectroscopy. A reduction in blood glucose levels with improved insulin sensitivity and glucose tolerance was observed in SCE-treated HFD obese mice. Histopathological and biochemical investigations showed a reduction in hepatic injury and nephrotoxicity in SCE-administered HFD mice. Results showed inhibition of PTP1B and an upregulation of IRS1 and PKB-mediated signaling in skeletal muscle. A significant decrease in lipid markers such as TC, TG, LDL-c and VLDL-c levels were observed with increased HDL-c in SCE-treated HFD mice. A significant decrease in weight and adiposity was observed in SCE-administered HFD mice in comparison to controls. This decrease could be due to the partial agonism of PPARγ and an increased expression of adiponectin, an insulin sensitizer. Hence, the dual-modulatory effect of SCE, partly due to the presence of 26% Pyrogallol, could be useful in the management of diabetes and its associated maladies.

Metformin Reduces the Progression of Atherogenesis by Regulating the Sestrin2-mTOR Pathway in Obese and Diabetic Rats.

Objective: In previous research, we found that Sestrin2 has a strong association with plasma atherogenicity and combats the progression of atherogenesis by regulating the AMPK-mTOR pathway. Metformin, an activator of AMPK, is widely used as a first-line therapy for diabetes, but its role in preventing atherosclerosis and cardiac outcomes is unclear. Hence, we aimed to assess the effect of metformin on preventing atherosclerosis and its regulatory role in the Sestrin2-AMPK -mTOR pathway in obese/diabetic rats. Methods: Animals were fed a high-fat diet to induce obesity, administered streptozotocin to induce diabetes, and then treated with metformin (150 mg/kg body weight) for 14 weeks. Aorta and heart tissues were analyzed for Sestrin2 status by western blotting and immunohistochemistry, AMPK and mTOR activities were investigated using western blotting, and atherogenicity-related events were evaluated using reverse transcription quantitative polymerase chain reaction and histology. Results: Obese and diabetic rats showed significant decrease in Sestrin2 levels and AMPK activity, accompanied by increased mTOR activity in the heart and aorta tissues. Metformin treatment significantly restored Sestrin2 and AMPK levels, reduced mTOR activity, and restored the altered expression of inflammatory markers and adhesion molecules in obese and diabetic rats to normal levels. A histological analysis of samples from obese and diabetic rats showed atherosclerotic lesions both in aorta and heart tissues. The metformin-treated rats showed a decrease in atherosclerotic lesions, cardiac hypertrophy, and cardiomyocyte degeneration. Conclusion: This study presents further insights into the beneficial effects of metformin and its protective role against atherosclerosis through regulation of the Sestrin2-AMPK-mTOR pathway.

Association of POC-based Measurement of Skin AGEs with Serum AGEs as well as AGE Biomarkers in Individuals with and without Glucose Intolerance.

Accumulation of advanced glycation end products (AGEs) occurs with aging and in various disease states. There are no reliable screening techniques to measure AGEs in clinical settings. In this study, a point-of-care (POC) device was used to validate skin AGE measurements with serum AGE levels and to assess its usefulness to identify individuals with abnormal glucose tolerance (AGT). MATERIALS AND METHODS: The study group comprised individuals with normal glucose tolerance (NGT: n = 47) and with AGT, that is, either diabetes or prediabetes (n = 68). Intrinsic AGE fluorescence was measured spectrofluorimetrically using multimode plate reader in the serum by exciting the samples at 370 nm and emission readouts at 440 nm. Skin AGEs were acquired using a CE-marked Scout DS commercial device. Serum levels of biomarkers carboxymethyl lysine (CML), carboxyethyl lysine (CEL), and pentosidine were analyzed by enzyme-linked immunosorbent assay (ELISA). RESULTS: In subjects with AGT, the skin AGEs [61.3 vs 53.7 arbitrary units (AU), p<0.0001] and serum AGEs (3.5 vs 2.8 AU, p<0.0001) were significantly higher than in individuals with NGT. The levels of CML, CEL, and pentosidine were also significantly higher in the subjects with AGT when compared with NGT (138 vs 89 pg/mL; 2.4 vs 1.4 nmol/mL, and 64 vs 48 pmol/mL, p<0.0001), respectively. Pearson correlation analysis showed a significant positive association of skin AGEs with serum AGEs (r = 0.344) (p<0.001), CML (r = 0.323) (p<0.001), CEL (r = 0.308) (p<0.001), and pentosidine (r = 0.251) (p<0.001). In addition, it also showed a positive correlation with fasting plasma glucose (FPG) (p<0.001), 2-hour post-glucose (p<0.001), glycated hemoglobin (HbA1c) (p<0.001), and body mass index (BMI) (p<0.05). Multiple logistic regression analysis using AGT as a dependent variable showed that skin AGE scores were significantly (p<0.001) associated with AGT (odds ratio: 1.133, confidence intervals: 1.067-1.203). CONCLUSION: This study shows that the measurement of skin AGEs using a POC device may be suitable for mass screening of AGT even in low-resource settings.

Correction: Blood-derived miRNA levels are not correlated with metabolic or anthropometric parameters in obese pre-diabetic subjects but with systemic inflammation.

[This corrects the article DOI: 10.1371/journal.pone.0263479.].

Blood-derived miRNA levels are not correlated with metabolic or anthropometric parameters in obese pre-diabetic subjects but with systemic inflammation.

As blood-derived miRNAs (c-miRNAs) are modulated by exercise and nutrition, we postulated that they might be used to monitor the effects of a lifestyle intervention (LI) to prevent diabetes development. To challenge this hypothesis, obese Asian Indian pre-diabetic patients were submitted to diet modifications and physical activity for 4 months (LI group) and compared to a control group which was given recommendations only. We have considered 2 periods of time to analyze the data, i.e.; a first one to study the response to the intervention (4 months), and a second one post-intervention (8 months). At basal, 4 months and 8 months post-intervention the levels of 17 c-miRNAs were quantified, selected either for their relevance to the pathology or because they are known to be modulated by physical activity or diet. Their variations were correlated with variations of 25 metabolic and anthropometric parameters and cytokines. As expected, fasting-glycaemia, insulin-sensitivity, levels of exercise- and obesity-induced cytokines were ameliorated after 4 months. In addition, the levels of 4 miRNAs (i.e.; miR-128-3p, miR-374a-5p, miR-221-3p, and miR-133a-3p) were changed only in the LI group and were correlated with metabolic improvement (insulin sensitivity, cytokine levels, waist circumference and systolic blood pressure). However, 8 months post-intervention almost all ameliorated metabolic parameters declined indicating that the volunteers did not continue the protocol on their own. Surprisingly, the LI positive effects on c-miRNA levels were still detected, and were even more pronounced 8 months post-intervention. In parallel, MCP-1, involved in tissue infiltration by immune cells, and Il-6, adiponectin and irisin, which have anti-inflammatory effects, continued to be significantly and positively modified, 8 months post-intervention. These data demonstrated for the first time, that c-miRNA correlations with metabolic parameters and insulin sensitivity are in fact only indirect and likely associated with the level systemic inflammation. More generally speaking, this important result explains the high variability between the previous studies designed to identify specific c-miRNAs associated with the severity of insulin-resistance. The results of all these studies should take into account the level of inflammation of the patients. In addition, this finding could also explain why, whatever the pathology considered (i.e.; cancers, diabetes, neurodegenerative disorders, inflammatory diseases) the same subset of miRNAs is always found altered in the blood of patients vs healthy subjects, as these pathologies are all associated with the development of inflammation.

Beneficial Primary Outcomes of Metabolic Surgery with Changes in Telomere Length and Mitochondrial DNA in Obese Asian Indians with Dysglycemia.

INTRODUCTION: Although metabolic surgery has been shown to offer beneficial primary outcome results in obese individuals / obese Type 2 diabetes mellitus (T2DM) patients, there is paucity of information on the underlying mechanisms. In the recent years, estimations of non-invasive molecular parameters viz., telomere length and mtDNA copy number (mtDNAcn) assume significance as robust biomarkers. However, there is lack of evidence about this especially, in the Indian context. To assess the changes in the telomere length and mtDNAcn levels after metabolic surgery in obese Asian Indians with dysglycemia along with routine measurements of anthropometry, glycemic/lipidimic parameters and inflammatory markers. METHODS: This study is a prospective one-year follow-up study of 16 obese individuals with dysglycemia who underwent metabolic surgery at a tertiary diabetes centre in South India. Telomere length, mtDNAcn, serum adiponectin, glycated haemoglobin and high- sensitivity C-reactive protein (hs-CRP) levels were analysed before surgery and at 6 and 12 months after surgery. RESULTS: There was a significant reduction in weight (p<0.001), BMI (p<0.001), waist circumference (p<0.001), fasting and postprandial glucose (p<0.05), HbA1c (p<0.001), triglycerides (p<0.05), hs CRP (p<0.05) and increase in serum adiponectin (p<0.05) at 6 and 12 months post-surgery compared to the preoperative status. There was a significant reduction in mtDNAcn (p<0.001) and a significant increase in telomere length (p<0.001) at 6 and 12 months post metabolic surgery. CONCLUSION: We report an increase in telomere length and decrease in circulatory mtDNA copy number levels at 6 and 12 months post metabolic surgery in obese individuals with T2DM in India.

Augmentation of RBP4/STRA6 signaling leads to insulin resistance and inflammation and the plausible therapeutic role of vildagliptin and metformin.

A role of Retinol Binding Protein-4 (RBP4) in insulin resistance is widely studied. However, there is paucity of information on its receptor viz., Stimulated by Retinoic Acid-6 (STRA6) with insulin resistance. To address this, we investigated the regulation of RBP4/STRA6 expression in 3T3-L1 adipocytes exposed to glucolipotoxicity (GLT) and in visceral adipose tissue (VAT) from high fat diet (HFD) fed insulin-resistant rats. 3T3-L1 adipocytes were subjected to GLT and other experimental maneuvers with and without vildagliptin or metformin. Real-time PCR and western-blot experiments were performed to analyze RBP4, STRA6, PPARγ gene and protein expression. Adipored staining and glucose uptake assay were performed to evaluate lipid and glucose metabolism. Oral glucose tolerance test (OGTT) and Insulin Tolerance Test (ITT) were performed to determine the extent of insulin resistance in HFD fed male Wistar rats. Total serum RBP4 was measured by quantitative sandwich enzyme-linked immunosorbent assay kit. Adipocytes under GLT exhibited significantly increased RBP4/STRA6 expressions and decreased insulin sensitivity/glucose uptake. Vildagliptin and metformin not only restored the above but also decreased the expression of IL-6, NFκB, SOCS-3 along with lipid accumulation. Furthermore, HFD fed rats exhibited significantly increased serum levels of RBP4 along with VAT expression of RBP4, STRA6, PPARγ, IL-6. These molecules were significantly altered by the vildagliptin/ metformin treatment. We conclude that RBP4/STRA6 pathway is primarily involved in mediating inflammation and insulin resistance in adipocytes and visceral adipose tissues under glucolipotoxicity and in insulin resistant rats.

Trans-ethnic gut microbiota signatures of type 2 diabetes in Denmark and India.

BACKGROUND: Type 2 diabetes (T2D), a multifactorial disease influenced by host genetics and environmental factors, is the most common endocrine disease. Several studies have shown that the gut microbiota as a close-up environmental mediator influences host physiology including metabolism. The aim of the present study is to examine the compositional and functional potential of the gut microbiota across individuals from Denmark and South India with a focus on T2D. Many earlier studies have investigated the microbiome aspects of T2D, and it has also been anticipated that such microbial associations would be dependent on diet and ethnic origin. However, there has been no large scale trans-ethnic microbiome study earlier in this direction aimed at evaluating any "universal" microbiome signature of T2D. METHODS: 16S ribosomal RNA gene amplicon sequencing was performed on stool samples from 279 Danish and 294 Indian study participants. Any differences between the gut microbiota of both populations were explored using diversity measures and negative binomial Wald tests. Study samples were stratified to discover global and country-specific microbial signatures for T2D and treatment with the anti-hyperglycemic drug, metformin. To identify taxonomical and functional signatures of the gut microbiota for T2D and metformin treatment, we used alpha and beta diversity measures and differential abundances analysis, comparing metformin-naive T2D patients, metformin-treated T2D patients, and normoglycemic individuals. RESULTS: Overall, the gut microbial communities of Danes and Indians are compositionally very different. By analyzing the combined study materials, we identify microbial taxonomic and functional signatures for T2D and metformin treatment. T2D patients have an increased relative abundance of two operational taxonomic units (OTUs) from the Lachnospiraceae family, and a decreased abundance of Subdoligranulum and Butyricicoccus. Studying each population per se, we identified T2D-related microbial changes at the taxonomic level within the Danish population only. Alpha diversity indices show that there is no significant difference between normoglycemic individuals and metformin-naive T2D patients, whereas microbial richness is significantly decreased in metformin-treated T2D patients compared to metformin-naive T2D patients and normoglycemic individuals. Enrichment of two OTUs from Bacteroides and depletion of Faecalibacterium constitute a trans-ethnic signature of metformin treatment. CONCLUSIONS: We demonstrate major compositional differences of the gut microbiota between Danish and South Indian individuals, some of which may relate to differences in ethnicity, lifestyle, and demography. By comparing metformin-naive T2D patients and normoglycemic individuals, we identify T2D-related microbiota changes in the Danish and Indian study samples. In the present trans-ethnic study, we confirm that metformin changes the taxonomic profile and functional potential of the gut microbiota.

Trans-ethnic gut microbial signatures of prediabetic subjects from India and Denmark.

BACKGROUND: Recent studies have indicated an association of gut microbiota and microbial metabolites with type 2 diabetes mellitus (T2D). However, large-scale investigation of the gut microbiota of "prediabetic" (PD) subjects has not been reported. Identifying robust gut microbiome signatures of prediabetes and characterizing early prediabetic stages is important for the understanding of disease development and could be crucial in early diagnosis and prevention. METHODS: The current study performed amplification and sequencing on the variable regions (V1-V5) of the 16S rRNA genes to profile and compare gut microbiota of prediabetic individuals (N = 262) with normoglycemic individuals (N = 275) from two cohorts in India and Denmark. Similarly, fasting serum inflammatory biomarkers were profiled from the study participants. RESULTS: After correcting for strong country-specific cohort effect, 16 operational taxonomic units (OTUs) including members from the genera Prevotella9, Phascolarctobacterium, Barnesiella, Flavonifractor, Tyzzerella_4, Bacteroides, Faecalibacterium, and Agathobacter were identified as enriched in normoglycaemic subjects with respect to the subjects with prediabetes using a negative binomial Wald test. We also identified 144 OTUs enriched in the prediabetic subjects, which included members from the genera Megasphaera, Streptococcus, Prevotella9, Alistipes, Mitsuokella, Escherichia/Shigella, Prevotella2, Vibrio, Lactobacillus, Alloprevotella, Rhodococcus, and Klebsiella. Comparative analyses of relative abundance of bacterial taxa revealed that the Streptococcus, Escherichia/Shigella, Prevotella2, Vibrio, and Alloprevotella OTUs exhibited more than fourfold enrichment in the gut microbiota of prediabetic subjects. When considering subjects from the two geographies separately, we were able to identify additional gut microbiome signatures of prediabetes. The study reports a probable association of Megasphaera OTU(s) with impaired glucose tolerance, which is significantly pronounced in Indian subjects. While the overall results confirm a state of proinflammation as early as in prediabetes, the Indian cohort exhibited a characteristic pattern of abundance of inflammatory markers indicating low-grade intestinal inflammation at an overall population level, irrespective of glycemic status. CONCLUSIONS: The results present trans-ethnic gut microbiome and inflammation signatures associated with prediabetes, in Indian and Danish populations. The identified associations may be explored further as potential early indicators for individuals at risk of dysglycemia.

A comparative study on the cellular stressors in mesenchymal stem cells (MSCs) and pancreatic ß-cells under hyperglycemic milieu.

ß-cell dysfunction is a critical determinant for both type 1 diabetes and type 2 diabetes and ß-cells are shown to be highly susceptible to cellular stressors. Mesenchymal stem cells (MSCs) on the other hand are known to have immunomodulatory potential and preferred in clinical applications. However, there is paucity of a comparative study on these cells in relation to several cellular stressors in response to hyperglycemia and this forms the rationale for the present study. INS1 ß-cells and MSCs were subjected to high-glucose treatment without and with Metformin, Lactoferrin, or TUDCA and assessed for stress signaling alterations using gene expression, protein expression, as well as functional read-outs. Compared to the untreated control cells, INS1 ß-cells or MSCs treated with high glucose showed significant increase in mRNA expressions of ER stress, senescence, and proinflammation. This was accompanied by increased miR146a target genes and decreased levels of SIRT1, NRF2, and miR146a in both the cell types. Consistent with the mRNA results, protein expression levels do reflect the same alterations. Notably, the alterations are relatively less extent in MSCs compared to INS1 ß-cells. Interestingly, three different agents, viz., Metformin, Lactoferrin, or TUDCA, were found to overcome the high glucose-induced cellular stresses in a concerted and inter-linked way and restored the proliferation and migration capacity in MSCs as well as normalized the glucose-stimulated insulin secretion in INS1 ß-cells. While our study gives a directionality for potential supplementation of metformin/lactoferrin/TUDCA in optimization protocols of MSCs, we suggest that in vitro preconditioning of MSCs with such factors should be further explored with in-depth investigations to harness and enhance the therapeutic capacity/potential of MSCs.

Asymmetric dimethylarginine (ADMA) accelerates renal cell fibrosis under high glucose condition through NOX4/ROS/ERK signaling pathway.

We previously reported that the circulatory level of Asymmetric dimethylarginine (ADMA), an endogenous competitive inhibitor of nitric oxide synthase, was increased in diabetic kidney disease patients. However, the mechanism and the role of ADMA in diabetic kidney injury remain unclear. Hence, our principal aim is to investigate the causal role of ADMA in the progression of renal cell fibrosis under high glucose (HG) treatment and to delineate its signaling alterations in kidney cell injury. High Glucose/ADMA significantly increased fibrotic events including cell migration, invasion and proliferation along with fibrotic markers in the renal cells; whereas ADMA inhibition reversed the renal cell fibrosis. To delineate the central role of ADMA induced fibrotic signaling pathway and its downstream signaling, we analysed the expression levels of fibrotic markers, NOX4, ROS and ERK activity by using specific inhibitors and genetic manipulation techniques. ADMA stimulated the ROS generation along with a significant increase in NOX4 and ERK activity. Further, we observed that ADMA activated NOX-4 and ERK are involved in the extracellular matrix proteins accumulation. Also, we observed that ADMA induced ERK1/2 phosphorylation was decreased after NOX4 silencing. Our study mechanistically demonstrates that ADMA is involved in the progression of kidney cell injury under high glucose condition by targeting coordinated complex mechanisms involving the NOX4- ROS-ERK pathway.

Outcomes of metabolic surgery in obese patients with type 2 diabetes with respect to impact on beta cell function, insulin sensitivity and diabetes remission - A study from south India.

BACKGROUND AND AIMS: Metabolic surgery is gaining popularity as a procedure for the treatment of morbid obesity among patients with type 2 diabetes (T2DM). The aim of the study was to evaluate the effects of metabolic surgery on beta cell function, insulin sensitivity and glycemic status in obese Asian Indian patients. METHODS: This is a prospective study of 26 patients with T2DM who underwent metabolic surgery. Complete diabetes remission was defined as FPG<100 mg/dl and HbA1c < 6%, without antidiabetic medications one-year post surgery. Anthropometry, HOMA-IR (insulin resistance), HOMA-insulin sensitivity, beta cell function and antidiabetic drug usage were measured at baseline, 6 months and 12 months post-surgery. RESULTS: The overall duration of diabetes was 10.3 ± 5.4 years. At one year, 7 (27%) of 26 T2DM patients, achieved diabetes remission while the other 19 had improvement in diabetes status. ROC curves showed that those who had diabetes duration <8.5 years achieved remission. There was a significant decrease in HOMA-IR [3.7 ± 1.8 vs 1.4 ± 0.9 vs1.2 ± 0.6, p < 0.001] and improvement in HOMA-Insulin sensitivity [34 ± 17 vs 93 ± 50 vs 112 ± 62, p < 0.001] from baseline to 6 and 12 months post-surgery respectively. There was a significant (p < 0.001) reduction in the usage of anti-diabetes medications post-surgery. The limitations of this study are small sample size and limited follow up period of 1 year. CONCLUSIONS: Among T2DM patients, metabolic surgery resulted in significant improvement in beta cell function and insulin sensitivity along with reduction in anti-diabetes medication. Diabetes remission was mainly seen in those who had duration of diabetes <8.5 years.

Acceptability and Utilization of Newer Technologies and Effects on Glycemic Control in Type 2 Diabetes: Lessons Learned from Lockdown.

Aim: To evaluate the effects of a prolonged lockdown due to Coronavirus (COVID-19) on the adoption of newer technologies and changes in glycemic control on patients with type 2 diabetes (T2D) in India. Methods: The study population included a random list of 3000 individuals with T2D derived from 30,748 individuals who had visited a large tertiary diabetes center during the past year. The survey was carried out through a telephonic interview. A structured questionnaire was used to collect information on changes in lifestyle, access and challenges to diabetes care and use of technologies such as telemedicine facilities and use of self-monitoring of blood glucose (SMBG), etc. Results: Of the 2510 individuals successfully interviewed (83.7% response rate), 382 (15.2%) reported having attempted to consult their health care providers during the lockdown, of whom only 30.6% utilized the telemedicine facility. However, 96 (82%) of those who utilized the telemedicine facility (n = 117) were happy with their experience and 68 (58.1%) were willing to continue to use the facility in the future. Only 11.4% of participants utilized online support for management of diabetes. Use of SMBG increased significantly from 15.5% to 51.3% during the lockdown. There was an improvement in glycemic control during the lockdown (HbA1c:before vs. during lockdown: 8.2% ± 1.9% vs. 7.7% ± 1.7%, P < 0.001) in a nonrandomly selected subset of subjects (n = 205). Conclusions: Acceptance of telemedicine facilities remains suboptimal in this Asian Indian population, in spite of high levels of satisfaction among those who utilized it. The COVID-19 pandemic and the subsequent lockdown have not adversely affected metabolic control in our patients, and indeed there appears to be an improvement in HbA1c levels. Greater accessibility and acceptance of technology could help individuals with diabetes to maintain better contact with their physicians and ensure better metabolic control in the future.

Altered circulatory levels of miR-128, BDNF, cortisol and shortened telomeres in patients with type 2 diabetes and depression.

AIMS: Several studies have reported the role of biomarkers either in diabetes or depression. The present study is aimed at profiling the circulating levels of miR-128, brain-derived neurotrophic factor (BDNF), cortisol and telomere length in patients with type 2 diabetes with and without depression compared to individuals with normal glucose tolerance. METHODS: Study subjects (n = 160) were recruited from an ongoing epidemiological study in southern India. Non-diabetic and diabetic individuals were diagnosed as per the World Health Organization criteria. Depression score was derived using PHQ-12 questionnaire. Real-time quantitative PCR and ELISA methodologies were used to quantify the biomarkers. RESULTS: Circulatory levels of miR-128 and cortisol were significantly (p < 0.05) increased with decreased BDNF levels and shortened telomeres in T2DM patients with or without depression compared to NGT individuals. T2DM patients with depression had the highest levels of miR-128 and cortisol and lowest levels of BDNF and telomere length compared to other groups. Pearson correlation analysis showed miR-128 levels were negatively associated with BDNF, telomere length and HDL cholesterol and positively correlated with cortisol, depression score, poor glycemic control and insulin resistance. Regression analysis confirmed that miR-128 was significantly associated with depression score even after adjusted for several confounding factors. However, this association was lost when adjusted for cortisol or telomere length. CONCLUSIONS: Patients with type 2 diabetes and depression exhibited increased circulatory levels of miR-128 and serum cortisol and decreased levels of BDNF and shortened telomeres. These neuroendocrine signatures were more markedly altered in those with combined diabetes and depression.

High molecular weight adiponectin reduces glucolipotoxicity-induced inflammation and improves lipid metabolism and insulin sensitivity via APPL1-AMPK-GLUT4 regulation in 3T3-L1 adipocytes.

BACKGROUND AND AIMS: Although the importance of adipokines in modulating the disease process of type 2 diabetes is well recognized, there is dearth of data on the specific role of high molecular weight adiponectin (HMW Ad) on insulin resistance and obesity. Therefore, we tested the effects of HMW Ad on glucolipotoxcity-induced inflammation and insulin resistance in 3T3-L1 adipocytes. METHODS: 3T3-L1 adipocytes were subject to glucolipotoxicity with and without HMW Ad treatment. Real-time PCR and Western-blot experiments were performed to analyse gene and protein expressions, respectively. Lipolysis, adipored staining, and glucose uptake assay were performed to evaluate alterations in lipid and glucose metabolism. RESULTS: Adipocytes subject to glucolipotoxicity showed significantly (p < 0.05) decreased mRNA expression of adiponectin, AdipoR2, GLUT4, and increased inflammation, lipid accumulation as well as lipolysis. Treatment with HMW Ad beneficially modulated lipid metabolism, reduced inflammation and improved glucose uptake in adipocytes. HMW Ad also beneficially regulated APPL1 and AMPK signaling in adipocytes. Silencing of APPL1 gene in adipocytes significantly reduced the effects of HMW Ad on pAMPK protein expression, indicating that HMW Ad plays an important role in regulating AMPK phosphorylation via APPL1 in 3T3-L1 adipocytes. CONCLUSIONS: HMW Ad treatment improved glucose homeostasis and resulted in reduced lipolysis, inflammation and insulin resistance in adipocytes subject to glucolipotoxicity. The beneficial modulation and regulation of APPL1 and AMPK signals by HMW Ad observed in this study represent a novel mechanism. Raising endogenous HMW Ad levels either by pharmacological or lifestyle modification could have a therapeutic value.

Bisphenol A exposure under metabolic stress induces accelerated cellular senescence in vivo in a p53 independent manner.

Senescence is an irreversible process that is a characteristic of age-associated disease like Type 2 diabetes (T2D). Bisphenol-A (BPA), one of the most common endocrine disruptor chemicals, received special attention in the development of insulin resistance and T2D. To understand the role played by BPA in cellular senescence under metabolic stress, zebrafish embryos were exposed to BPA in the absence and presence of hyperglycaemia. Transcriptional levels of the senescence markers p15, p53, Rb1 and ß-galactosidase were increased when BPA was combined with metabolic stress. In addition, zebrafish embryos that were exposed to combination of hyperglycaemia and BPA exhibited increased levels of apoptosis. However, cellular senescence remained induced by a combination of hyperglycaemia and BPA exposure even in the absence of a translated p53 protein suggesting that senescence is primarily independent of it but dependent on the p15-Rb1 pathway under our experimental conditions. To confirm that our results hold true in adult mammalian tissues, we validated our embryonic experiments in an adult mammalian metabolic model of skeletal muscle cells. Our work reveals a novel and unique converging role of senescence and apoptosis axis contributing to glucose dyshomeostasis. Thus, we conclude that BPA exposure can exacerbate existing metabolic stress to increase cellular senescence that leads to aggravation of disease phenotype in age-associated diseases like type 2 diabetes.

Novel insights of elevated systemic levels of bisphenol-A (BPA) linked to poor glycemic control, accelerated cellular senescence and insulin resistance in patients with type 2 diabetes.

There is a striking interaction of genes and environment in the etiology of type 2 diabetes mellitus (T2DM). While endocrine disrupting chemicals (EDCs) like bisphenol-A (BPA) have received special attention for their mechanistic role in metabolic disruption, there is a lack of clinically relevant data on BPA levels in Asian Indians, a population which is more susceptible to type 2 diabetes mellitus (T2DM) and cardiovascular diseases. Therefore, we measured systemic levels of BPA in patients with T2DM compared to individuals with normal glucose tolerance (n = 30 each). Serum BPA levels were estimated using ELISA kit, and biochemical determinations were done by standard protocols. Peripheral blood mononuclear cells (PBMCs) were used to profile the gene expression alterations with special reference to inflammation, estrogen receptors, and cellular senescence in these subjects. Serum levels of BPA were significantly higher in patients with T2DM compared to control individuals and positively correlated to poor glycemic control and insulin resistance. Patients with T2DM exhibited significantly elevated mRNA levels of senescence (GLB1, p16, p21, and p53) and inflammatory (IL6 and TNF-α) markers, shortened telomeres as well as elevated levels of estrogen-related receptor gamma (ERRγ), a recently identified receptor for BPA. BPA levels were positively correlated to senescence indicators, inflammatory markers and ERRγ and negatively correlated to telomere length. Our study is the first data in the clinical diabetes setting to demonstrate an association of increased BPA levels with cellular senescence, proinflammation, poor glycemic control, insulin resistance, and shortened telomeres in patients with T2DM.

Sestrin2 regulates monocyte activation through AMPK-mTOR nexus under high-glucose and dyslipidemic conditions.

The vicious cycle between hyperinsulinemia and insulin resistance results in the progression of atherosclerosis in the vessel wall. The complex interaction between hyperglycemia and lipoprotein abnormalities promotes the development of atherogenesis. In the early phase of atherosclerosis, macrophage-derived foam cells play an important role in vascular remodeling. Mechanistic target of rapamycin (mTOR) signaling pathway has been identified to play an essential role in the initiation, progression, and complication of atherosclerosis. Recently sestrin2, an antioxidant, was shown to modulate TOR activity and thereby regulating glucose and lipid metabolism. But the role of sestrin2 in monocyte activation is still not clearly understood. Hence, this study is focussed on investigating the role of sestrin2 in monocyte activation under hyperglycemic and dyslipidemic conditions. High-glucose and oxidized low-density lipoprotein (LDL) treatments mediated proinflammatory cytokine production (M1) with a concomitant decrease in the anti-inflammatory cytokine (M2) levels in human monocytic THP1 cells. Both glucose and oxidized LDL (OxLDL) in a dose and time-dependent manner increased the mTOR activation with a marked reduction in the levels of pAMPK and sestrin2 expression. Both high-glucose and OxLDL treatment increased foam cell formation and adhesion of THP1 cells to endothelial cells. Experiments employing activator or inhibitor of adenosine monophosphate kinase (AMPK) as well as overexpression or silencing of sestrin2 indicated that high-glucose mediated monocyte polarization and adhesion of monocytes to the endothelial cells were appeared to be programmed via sestrin2-AMPK-mTOR nexus. Our results evidently suggest that sestrin2 plays a major role in regulating monocyte activation via the AMPK-mTOR-pathway under diabetic and dyslipidemic conditions and also AMPK regulates sestrin2 in a feedback mechanism.

Body mass index is negatively associated with telomere length: a collaborative cross-sectional meta-analysis of 87 observational studies.

Background: Even before the onset of age-related diseases, obesity might be a contributing factor to the cumulative burden of oxidative stress and chronic inflammation throughout the life course. Obesity may therefore contribute to accelerated shortening of telomeres. Consequently, obese persons are more likely to have shorter telomeres, but the association between body mass index (BMI) and leukocyte telomere length (TL) might differ across the life span and between ethnicities and sexes. Objective: A collaborative cross-sectional meta-analysis of observational studies was conducted to investigate the associations between BMI and TL across the life span. Design: Eighty-seven distinct study samples were included in the meta-analysis capturing data from 146,114 individuals. Study-specific age- and sex-adjusted regression coefficients were combined by using a random-effects model in which absolute [base pairs (bp)] and relative telomere to single-copy gene ratio (T/S ratio) TLs were regressed against BMI. Stratified analysis was performed by 3 age categories ("young": 18-60 y; "middle": 61-75 y; and "old": >75 y), sex, and ethnicity. Results: Each unit increase in BMI corresponded to a -3.99 bp (95% CI: -5.17, -2.81 bp) difference in TL in the total pooled sample; among young adults, each unit increase in BMI corresponded to a -7.67 bp (95% CI: -10.03, -5.31 bp) difference. Each unit increase in BMI corresponded to a -1.58 × 10(-3) unit T/S ratio (0.16% decrease; 95% CI: -2.14 × 10(-3), -1.01 × 10(-3)) difference in age- and sex-adjusted relative TL in the total pooled sample; among young adults, each unit increase in BMI corresponded to a -2.58 × 10(-3) unit T/S ratio (0.26% decrease; 95% CI: -3.92 × 10(-3), -1.25 × 10(-3)). The associations were predominantly for the white pooled population. No sex differences were observed. Conclusions: A higher BMI is associated with shorter telomeres, especially in younger individuals. The presently observed difference is not negligible. Meta-analyses of longitudinal studies evaluating change in body weight alongside change in TL are warranted.