Pathogenesis Of Type 2 Diabetes Mellitus Research Articles

Immune dysfunction in developmental programming of type 2 diabetes mellitus.

Intrauterine growth restriction (IUGR) is a common complication of pregnancy and increases the risk of the offspring developing type 2 diabetes mellitus (T2DM) later in life. Alterations in the immune system are implicated in the pathogenesis of IUGR-induced T2DM. The development of the fetal immune system is a delicate balance as it must remain tolerant of maternal antigens whilst also preparing for the post-birth environment. In addition, the fetal immune system is susceptible to an altered intrauterine milieu caused by maternal and placental inflammatory mediators or secondary to nutrient and oxygen deprivation. Pancreatic-resident macrophages populate the pancreas during fetal development, and their phenotype is dynamic through the neonatal period. Furthermore, macrophages in the islets are instrumental in islet development as they influence β-cell proliferation and islet neogenesis. In addition, cytokines, derived from β-cells and macrophages, are important to islet homeostasis in the fetus and adult and, when perturbed, can cause islet dysfunction. Several activated immune pathways have been identified in the islets of people who experienced IUGR, with alternations in the levels of IL-1β and IL-4 as well as changes in TGFβ signalling. Leptin levels are also altered. Immunomodulation has shown therapeutic benefit in T2DM and might be particularly useful in IUGR-induced T2DM.

Epigenetic Regulation of PDX-1 in Type 2 Diabetes Mellitus.

Type 2 diabetes mellitus (T2DM) is a metabolic disease characterized by hyperglycemia which is caused by insufficient insulin secretion or insulin resistance. Interaction of genetic, epigenetic and environmental factors plays a significant role in the development of T2DM. Several environmental factors including diet and lifestyle, as well as age have been associated with an increased risk for T2DM. It has been demonstrated that these environmental factors may affect global epigenetic status, and alter the expression of susceptible genes, thereby contributing to the pathogenesis of T2DM. In recent years, a growing body of molecular and genetic studies in diabetes have been focused on the ways to restore the numbers or function of β-cells in order to reverse a range of metabolic consequences of insulin deficiency. The pancreatic duodenal homeobox 1 (PDX-1) is a transcriptional factor that is essential for the development and function of islet cells. A number of studies have shown that there is a significant increase in the level of DNA methylation of PDX-1 resulting in reduced activity in T2DM islets. The decrease in PDX-1 activity may be a critical mediator causing dysregulation of pancreatic β cells in T2DM. This article reviews the epigenetic mechanisms of PDX-1 involved in T2DM, focusing on diabetes and DNA methylation, and discusses some potential strategies for the application of PDX-1 in the treatment of diabetes.

The Interplay Between Diet and the Epigenome in the Pathogenesis of Type-1 Diabetes.

The autoimmune disease, Type 1 Diabetes Mellitus (T1DM), results in the destruction of pancreatic β-cells, and the International Diabetes Federation reports that its incidence is increasing worldwide. T1DM is a complex disease due to the interaction between genetic and environmental factors. Certain dietary patterns and nutrients are known to cause epigenetic modifications in physiological conditions and diseases. However, the interplay between diet and epigenetics is not yet well-understood in the context of T1DM. Several studies have described epigenetic mechanisms involved in the autoimmune reactions that destroy the β-cells, but few explored diet components as potential triggers for epigenetic modifications. Clarifying the link between diet and epigenome can provide new insights into the pathogenesis of T1DM, potentially leading to new diagnostic and therapeutic approaches. In this mini review, we shed light on the influence of the diet-epigenome axis on the pathophysiology of T1DM.

MEAN SERUM FERRITIN LEVELS IN TYPE-2 DIABETES MELLITUS IN PAKISTANI POPULATION

Objective: To evaluate the mean serum ferritin in type-2 diabetic patients.
 Study Design: Cross-sectional study.
 Place and Duration of Study: Department of Medicine, Combined Military Hospital, Peshawar, from Sep 2014 to Feb 2015.
 Methodology: A total of one hundred patients with type-2 diabetes mellitus fulfilling inclusion criteria were selected. Blood sample was collected from all patients by the clean-catch technique after they received standardized verbal instructions. Blood samples were seen by classified pathologist in the laboratory.
 Results: Mean age of patients was 55.51 ± 5.40 years with 60% male gender predominating the overall sample of diabetics. Mean serum ferritin was 219 ± 70.67 ng/ml and mean HbA1c was 7.24 ± 0.61%. Stratification with regard to age and gender was also carried out.
 Conclusion: Serum ferritin levels were observed raised in type-2 diabetics, suggestive of possible role in the pathogenesis of type-2 diabetes mellitus. We recommend further research work over its pathogenesis so that the guidelines for its control may be formulated.

Inhibition of Lipid Accumulation in Skeletal Muscle and Liver Cells: A Protective Mechanism of Bilirubin Against Diabetes Mellitus Type 2.

Ectopic lipid accumulation in skeletal muscle and liver drives the pathogenesis of diabetes mellitus type 2 (DMT2). Mild hyperbilirubinaemia has been repeatedly suggested to play a role in the prevention of DMT2 and is known for its capacity to shape an improved lipid phenotype in humans and in animals. To date, the effect of bilirubin on lipid accumulation in tissues that are prone to ectopic lipid deposition is unclear. Therefore, we analyzed the effect of bilirubin on lipid accumulation in skeletal muscle and liver cell lines. C2C12 skeletal mouse muscle and HepG2 human liver cells were treated with physiological concentrations of free fatty acids (FFA) (0.5 mM and 1 mM) and unconjugated bilirubin (UCB) (17.1 and 55 µM). The intracellular presence of UCB upon exogenous UCB administration was confirmed by HPLC and the lipid accumulation was assessed by using Nile red. Exposure of both cell lines to UCB significantly reduced lipid accumulation by up to 23% (p ≤ 0.001) in HepG2 and by up to 17% (p ≤ 0.01) in C2C12 cells at 0.5 and 5 h under hypoglycaemic conditions. Simultaneously, UCB slightly increased FFA uptake in HepG2 cells after 0.5 and 5 h and in C2C12 cells after 12 h as confirmed by gas chromatographic analyses of the remaining FFA content in the incubation media. The effects of UCB on lipid accumulation and uptake were abolished in the presence of higher glucose concentrations. Monitoring the uptake of a radiolabeled glucose analogue [18F]FDG: (2-deoxy-2-[18F]fluoro-D-glucose) into both cell types further indicated higher glucose consumption in the presence of UCB. In conclusion, our findings show that UCB considerably decreases lipid accumulation in skeletal muscle and liver cells within a short incubation time of max. 5 h which suggests that mildly elevated bilirubin levels could lower ectopic lipid deposition, a major key element in the pathogenesis of DMT2.

Yunpi Heluo decoction attenuates insulin resistance by regulating SIRT1-FoxO1 autophagy pathway in skeletal muscle of Zucker diabetic fatty rats

Ethnopharmacological relevanceDiabetes is a serious chronic metabolic disorder, and type 2 diabetes mellitus (T2DM) accounts for more than 90% of all diabetes cases. Insulin resistance (IR) is an early symptom, typical feature and main pathogenesis of T2DM due to the combined effects of genetic and environmental factors. Current evidence shows that IR is mainly caused by nutrient overload, systemic fatty acid excess, fatty tissue inflammation, endoplasmic reticulum stress, oxidative stress and abnormal autophagy. Autophagy plays an important role in the development of IR and decreased autophagy activity can cause IR through various ways. Aim of the studyYunpiheluo (YPHL) decoction is a Chinese herbal formula with unique advantages for the treatment of T2DM. The aim of the present study was to investigate the regulatory mechanism of YPHL on the autophagy pathway in the skeletal muscle of IR Zucker diabetic fatty (ZDF) rats. MethodsT2DM ZDF rats were treated with YPHL or transfected with SIRT1 adeno-associated virus. Serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), insulin resistance index (IRI) and skeletal muscle TG levels were detected in a T2DM ZDF rat model. The skeletal muscle morphology was observed by histological analysis and Oil Red O Staining. Autophagosomes were observed by transmission electron microscopy (TEM). The skeletal muscle morphology and fat deposition were observed by histological examination and Oil Red O Staining. A rat skeletal muscle IR cell model was established and transfected with SIRT1 overexpression plasmids. Cell apoptosis was observed by DAPI staining. SIRT1 levels in skeletal muscle tissues and cells were detected by qRT-PCR. The protein expressions of SIRT1, FOXo1, LC3B and P62 were detected by Western blotting. ResultsLarge numbers of lipid droplets and swollen mitochondria were observed in the skeletal muscle in both model group and negative control (NC) group receiving blank plasmid. Autophagosomes were seen in the skeletal muscle of YPHL and SIRT1 groups, with no significant structural abnormality. In addition, the protein expression of LC3B was decreased and the protein expression of p62 was increased significantly in the model group as compared with the NC group. After intervention with YPHL and SIRT1 overexpression, the protein expression of LC3B was significantly increased and p62 was significantly decreased. However, there was no significant difference in cell apoptosis between the two groups. ConclusionThe SIRT1-FoxO1 autophagy pathway may play a significant role in the pathogenesis of IR. YPHL could increase the autophagy level by regulating the SIRT1-FoxO1 signaling pathway in the skeletal muscle and improving the lipid metabolism, thereby attenuating IR.

Gut Microbiota and Type 1 Diabetes Mellitus: The Effect of Mediterranean Diet.

Type 1 diabetes mellitus (T1DM) is a chronic autoimmune disease resulting from a complex interplay between genetic susceptibility and environmental factors. Regarding the latter, gut microbiota has a pivotal role in the pathogenesis of T1DM, by affecting intestinal permeability, molecular mimicry, and modulating innate and adaptive immune system, as described in several previous studies. The composition of the gut microbiota is largely influenced by diet. Some observational studies have shown that a low fiber intake is associated with the development of many inflammatory and immune-mediated diseases. In this context, the Mediterranean diet (MD), which is based on high consumption of cereals (preferably as whole grains), legumes, nuts, vegetables, fruits, olive oil, and fish, could play a protective role. Many of the characteristic components of MD have functional characteristics with positive effects on health and well-being. Eating habits are the main significant determinants of the microbial multiplicity of the intestine and the food components influence both microbial populations and their metabolic activities from the early stages of life. Moreover, food metabolites influence the immune response. The intestine is considered the primary site where food metabolites mediate their effects, through epithelial integrity or mucosal immunity. The compromised epithelial integrity allows the translocation of bacteria and/or the diffusion of their products, such as food antigens and lipopolysaccharides, from the intestinal lumen to the tissues, which could enhance the stimulation of immune cells, contributing to the pathogenesis of autoimmune diseases, such as T1DM. The intake of a high amount of fiber and therefore of prebiotics with MD allows the microbiota to have a good microbial balance. Moreover, as more dietary fibers are ingested, a higher amount of short-chain fatty acids (SCFAs) is produced by anaerobic gut microbiota, promoting gut homeostasis, to which also contribute tryptophan metabolites and omega-3-fatty acids. Furthermore, the higher intake of polyunsaturated fatty acids and omega-3-fatty-acids contribute to a better metabolic control. In this review we report the relationship between gut microbiota and T1DM and we explore the effects of Mediterranean diet on microbiota as a potential therapeutic strategy, aimed at preventing or delaying progression of T1DM and its complications.

Assessment of serum adropin level in type 2 diabetic patients with or without nephropathy

Background/aim Diabetes predisposes the affected individual to long-term macrovascular and microvascular complications. Renal complications represent a major turning point in the life of people with diabetes. Adropin is a peptide primarily secreted by the liver and brain. It is encoded by the Energy Homeostasis Associated gene (Enho). Adropin main function is to prevent insulin resistance, dyslipidemia, and impaired glucose tolerance. This study aimed to assess the serum adropin level in patients with type 2 diabetes mellitus (T2DM) and diabetic nephropathy (DN). Patients and methods This case–control study was conducted on 50 diabetic patients from Inpatient and Outpatient Clinics of Internal Medicine Department, Benha University Hospitals, Egypt, in addition to 25 apparently healthy controls. Upon their informed consent, and after complete history taking and full clinical examination, blood samples were taken for biochemical analysis and serum adropin level measurement. Adropin was measured using enzyme-linked immunosorbent assay technique. Fasting and 2-h postprandial blood glucose, glycated hemoglobin, blood urea, serum creatinine, and glomerular filtration rate were done. Results This study demonstrated that adropin shows significant reduction in the diabetic group when compared with the control group and also exhibits significant decline in the DN group when compared with the diabetic group. There was a significant negative correlation between adropin and T2DM duration as well as with glycated hemoglobin (r=−0.552 and −0.467, and P=0.001 and 0.001, respectively). Moreover, there was a significant positive correlation between adropin and estimated glomerular filtration rate (r=0.358 and P=0.002). Conclusion Adropin is significantly reduced in T2DM when compared with normal participants, and the reduction of adropin is correlated with the deterioration in kidney functions manifested by the reduction in estimated glomerular filtration rate. These findings suggested that the reduction of serum adropin may play a role in the pathogenesis of T2DM and DN.

Inhibition of the Keap1/Nrf2 Signaling Pathway Significantly Promotes the Progression of Type 1 Diabetes Mellitus.

Type 1 diabetes mellitus (T1DM) is an autoimmune disease characterized by insulin deficiency due to pancreatic β-cell damage and leads to hyperglycemia. The precise molecular mechanisms of the etiology of T1DM are not completely understood. Oxidative stress and the antioxidant status of pancreatic β-cells play a vital role in the pathogenesis and progression of T1DM. The Keap1/Nrf2 signaling pathway plays a critical role in cellular resistance to oxidative stress. This study is aimed at investigating the role of the Keap1/Nrf2 signaling pathway in the progression of T1DM. An alloxan- (ALX-) stimulated T1DM animal model in wild-type (WT) and Nrf2 knockout (Nrf2−/−) C57BL/6J mice and a mouse pancreatic β-cell line (MIN6) were established. Compared with the tolerant (ALX exposure, nondiabetic) WT mice, the sensitive (ALX exposure, diabetic) WT mice exhibited higher blood glucose levels and lower plasma insulin levels. The Keap1/Nrf2 signaling pathway was significantly inhibited in the sensitive WT mice, which was reflected by overexpression of Keap1 and low expression of Nrf2, accompanied by a marked decrease in the expression of the antioxidative enzymes. Compared with WT mice, the Nrf2−/− mice had an increased incidence of T1DM and exhibited more severe pancreatic β-cell damage. The results of in vitro experiments showed that ALX significantly inhibited the viability and proliferation and promoted the apoptosis of MIN6 cells. ALX also markedly increased intracellular ROS production and caused DNA damage in MIN6 cells. In addition, the Keap1/Nrf2 signaling pathway was significantly inhibited in the damaged MIN6 cells. Moreover, Nrf2 silencing by transfection with Nrf2 siRNA markedly exacerbated ALX-induced MIN6 cell injury. Conclusively, this study demonstrates that inhibition of the Keap1/Nrf2 signaling pathway could significantly promote the incidence of T1DM. This study indicates that activation of Keap1/Nrf2 signaling in pancreatic β-cells may be a useful pharmacological strategy for the clinical prevention and treatment of T1DM.

Prediction of type 2 diabetes mellitus based on nutrition data.

Numerous predictive models for the risk of type 2 diabetes mellitus (T2DM) exist, but a minority of them has implemented nutrition data so far, even though the significant effect of nutrition on the pathogenesis, prevention and management of T2DM has been established. Thus, in the present study, we aimed to build a predictive model for the risk of T2DM that incorporates nutrition data and calculates its predictive performance. We analysed cross-sectional data from 1591 individuals from the population-based Cooperative Health Research in the Region of Augsburg (KORA) FF4 study (2013-14) and used a bootstrap enhanced elastic net penalised multivariate regression method in order to build our predictive model and select among 193 food intake variables. After selecting the significant predictor variables, we built a logistic regression model with these variables as predictors and T2DM status as the outcome. The values of area under the receiver operating characteristic (ROC) curve, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of our predictive model were calculated. Eleven out of the 193 food intake variables were selected for inclusion in our model, which yielded a value of area under the ROC curve of 0⋅79 and a maximum PPV, NPV and accuracy of 0⋅37, 0⋅98 and 0⋅91, respectively. The present results suggest that nutrition data should be implemented in predictive models to predict the risk of T2DM, since they improve their performance and they are easy to assess.

Identification of glutathione-S-transferase gene polymorphisms in type 2 diabetes mellitus patients attending Abdullahi Wase Specialist Hospital, Kano State Nigeria

Glutathione-S-transferases (GSTs) are a family of antioxidant enzymes that include several classes with various polymorphisms. This work was aimed at investigating the association between the polymorphisms of the GSTT1 gene and type 2 diabetes mellitus (T2DM). The frequency of GSTT1 genotypes in T2DM patients and non-diabetic controls were studied. A total of 30 diagnosed cases of type 2 diabetes mellitus were selected from the diabetes clinic section of Abdullahi Wase Specialist Hospital, Kano Nigeria. A total of 30 non-diabetic individuals were also selected as control from the outpatient department (OPD) section of the hospital. All the subjects were assessed for fasting blood sugar (FBS), body mass index (BMI), Systolic and Diastolic Blood Pressures (SBP and DBP) and the genotypes of GSTT1 were determined using multiplex polymerase chain reaction (mPCR) techniques. FBS and BMI were significantly high (P<0.05) in diabetics (225.58±83.58mg/dL and 27.53±3.99kg/m2 respectively) as compared to the non-diabetic controls (90.85±14.87mg/dL and 21.46±4.36kg/m2 respectively). There were no significant differences (P<0.05) for SBP and DBP in the diabetics (125.73±20.72mmHg and 85.83±13.65mmHg respectively) as compared to the non-diabetic controls (117.33±3.04mmHg and 79.90±10.05mmHg respectively). This implies that the body weight of the diabetic patients is increased being a risk factor in diabetes mellitus. Furthermore, the GSST1 positive polymorphism was present in 95% of the samples analyzed (i.e. diabetics and controls). There was no presence of the deletion polymorphism in the two groups. This implies that there was no association of GSTT1 polymorphisms with T2DM in the studied population; Even though GSTT1 is associated with T2DM in other populations. Other polymorphisms of GST should be studied to ascertain their roles in the pathogenesis of T2DM in this population.

RISK ASSESSMENT OF NON-CONVENTIONAL CONTRIBUTORY FACTORS IN ONSET OF DIABETES MELLITUS TYPE II

The aim of current study is the risk assessment of biochemical variables of medical importance, vitamin D and calcium, in pathogenesis of Diabetes Mellitus Type II (T2DM) human beings and the risk assessment due to variation of these biochemical variables in diabetic patients. One hundred subjects (n=100) were recruited from different hospitals in Lahore (31.5204° N, 74.3587° E) after taken informed consents individually. This study was approved by the ethical committee of Institute of Molecular Biology and Biotechnology (IMBB), The University of Lahore, Lahore. Subjects were equally divide in two groups; diabetic (case group; n=50) and non-diabetic (control; n=50). Calcium and vitamin D levels were measured by the biochemical laboratory of Hospitals. Finally the data was statistically analyzed by using SPSS software (Version 16). A total of 52 % males and 48 % females were investigated for changes in serum calcium and vitamin D in relation to their biochemical importance in Diabetes Mellitus. Both calcium and vitamin D levels were significantly low in diabetic group (p=0.003 and p=0.001 respectively) as compare to control group. Persons correlation showed calcium and vitamin D were directly proportional to each other (R2= 0.577). Odds ratio showed that the low vitamin D and low Calcium levels were 3.47 and 3.17 time more prevalent in diabetic group as compare to the non- diabetic group. Diabetes Mellitus is an increasing health issue in world causing severe morbidity and mortality. So it is important to investigate the non-conventional risk factors of Diabetes Mellitus. Thus, the current study illuminates the risk assessment of altered levels of vitamin D and calcium, their possible pathogenesis in Diabetes Mellitus. It can be concluded from this study that supplementation of vitamin D and calcium till to the normal physiological limits can help not only lowering the risk of diabetes but may also prevent its progression.

Mitochondrial ND1 T4216C and ND2 C5178A mutations are associated with maternally transmitted diabetes mellitus

Mutations in mitochondrial DNA (mtDNA) are important causes for type 2 diabetes mellitus (T2DM). To investigate the association between mtDNA mutations/variants and diabetes, we reported here clinical, genetic and biochemical characterization of a Chinese pedigree with maternally transmitted T2DM. Using PCR and direct sequencing analysis of mitochondrial genomes from the matrilineal relatives, we identified two potential pathogenic mutations, m.T4216C (p.Y304H) and m.C5178A (p.L237M) in the ND1 and ND2 genes, respectively, together with a set of genetic polymorphisms belonging to the human mitochondrial haplogroup D4b. Moreover, by isolating and analyzing polymononuclear leukocytes generated from the T2DM patients and controls, we identified lower levels of mitochondrial membrane potential and ATP production in T2DM patients than in the controls, in contrast, a significantly higher level of reactive oxygen species was observed in the T2DM patients carrying both of the m.T4216C and m.C5178A mutations (p < 0.05 for all). In addition, the plasma levels of malondialdehyde and 8-hydroxydeoxyguanosine in the T2DM patients markedly increased, while the level of superoxide dismutase decreased (p < 0.05 for all). Taken together, our data indicated that the ND1 T4216C and ND2 C5178A mutations may lead to oxidative stress and impair the mitochondrial function, and this, in turn, might have been involved in the pathogenesis and progression of T2DM in this pedigree. Thus, our study provides novel insight into the pathophysiology of T2DM that is manifested by mitochondrial dysfunction.

Fetuin-A gene polymorphism and its serum level association with atherosclerotic vascular disease in type 2 diabetes patients with early diabetic kidney disease

Background: The incidence of type 2 diabetes mellitus (T2DM) is increasing over the past years. Early identification and management of its complications, especially diabetic kidney disease (DKD), is of great importance. Multiple factors play a role in the pathogenesis of T2DM and DKD. We aimed to study Fetuin-A gene polymorphisms and Fetuin-A serum levels in T2DM patients with early DKD.&#x0D; Methods: The present work was conducted on 120 patients with T2DM (60 patients with microalbuminuria and 60 without albuminuria), and 30 healthy subjects (as a control group). Serum Fetuin-A levels were measured with ELISA. Fetuin-A, Thr256Ser and Thr248Met polymorphisms were determined by PCR-RFLP.&#x0D; Results: Patients with T2DM had a significantly higher mean serum Fetuin-A compared to controls (p &lt; 0.001), while no difference was observed when comparing mean serum Fetuin-A in patients with microalbuminuria and patients without albuminuria (p = 0.916). Multivariate regression analysis demonstrated that carotid intima-media thickness (CIMT) and insulin resistance had positive correlations with serum Fetuin-A (p &lt; 0.001 and p &lt; 0.001, respectively). Ankle-brachial pressure index (ABPI) had a negative correlation with serum Fetuin-A (p=0.046), while Fetuin-A levels neither affected eGFR nor albuminuria. The distribution of the alleles of both polymorphisms showed increased frequency of TT (rs248) and GG (rs256) in patients without albuminuria compared to patients with microalbuminuria.&#x0D; Conclusion: Increased serum Fetuin-A is associated with insulin resistance and increased risk of atherosclerosis in patients with T2DM, but is not associated with the development of DKD. TT (rs248) and GG (rs256) polymorphisms may be associated with lower risk of DKD.

Gut microbiota transplantation from db/db mice induces diabetes-like phenotypes and alterations in Hippo signaling in pseudo germ-free mice.

Type 2 diabetes mellitus (T2DM) is an age-related metabolic disease that is of increasing concern. Gut microbiota might have a critical role in the pathogenesis of T2DM. Additionally, Hippo signaling has been associated strongly with the progression of T2DM and the aging process. We adopted db/db male mice as a T2DM model, and the gut microbiota of db/db and m/m mice were transplanted successfully into pseudo germ-free mice. Furthermore, Hippo signaling, including mammalian sterile 20-like protein kinases 1 (MST1), large tumor suppressors 1 (LATS1), Yes-associated protein (YAP), and phosphorylation of YAP (p-YAP) in peripheral tissues were significantly altered and highly correlated with blood glucose in db/db mice. Interestingly, the host after gut microbiota transplantation from db/db mice showed decreased MST1 and LATS1 levels, and p-YAP/YAP ratio in the heart, liver, and kidney compared to those from m/m mice. Negative correlations between fasting blood glucose and Hippo signaling levels in selected peripheral tissues also were identified. These findings suggest that alterations in Hippo signaling in selected peripheral tissues may contribute to the development of T2DM, and that therapeutic interventions improving Hippo signaling by gut microbiota transplantation might be beneficial for the treatment of T2DM and other age-related metabolic diseases.

Role of Adiponectin and Tumor Necrosis Factor-Alpha in the Pathogenesis and Evolution of Type 1 Diabetes Mellitus in Children and Adolescents.

Type 1 diabetes mellitus (T1DM) is a complex condition caused by the destruction of pancreatic beta cells by autoimmune mechanisms. As a result, insulin deficiency and subsequent hyperglycemia occur. The aim of the present study is to investigate the role of adiponectin and tumor necrosis factor alpha (TNF-α) in the development of T1DM. The study is designed as an observational case-control study, involving 52 diabetic patients and 66 controls. Z scores for Body Mass Index (BMI), weight, height, and adiponectin and TNF-α serum levels were assessed in both groups. The T1DM group had significantly higher TNF-α levels and a significantly higher proportion of high-risk patients for inflammation based on TNF-α values as compared to the control group, while both groups had statistically similar adiponectin levels and a similar proportion of high/medium-risk patients based on adiponectin values. TNF-α plays a significant role in the pathogenesis and evolution of T1DM and it may represent an additional marker of disease progression, as well as a potential target of immunotherapeutic strategies. In the present study, no statistically significant differences were recorded in adiponectin levels neither in diabetic patients and controls, nor in high/medium severity risk diabetic patients.

Expression of Notch 2 and ABCC8 genes in patients with type 2 diabetes mellitus and their association with diabetic kidney disease

Background. The incidence of type 2 diabetes mellitus (T2DM) has increased over the past years and early identification and management of its complications especially diabetic kidney disease (DKD) is of great importance. T2DM and DKD are of multifactorial etiology with contribution of genetic and environmental factors. We aimed to study the expression of ABCC8 and Notch 2 genes in patients with T2DM and to find their association with DKD. Methods. The present work was carried on 80 patients with T2DM (40 with DKD and 40 without DKD) and 40 healthy subjects as a control group. Real time polymerase chain reaction was used to assess gene expression. Results. Altered expression of ABCC8 and Notch 2 genes were found in patients with T2DM compared to control group. ABCC8 expression had significant positive correlation with HbA1c while Notch 2 expression had significant positive correlation with fasting plasma glucose and HbA1c. Notch 2 expression was significantly higher in patients with DKD compared to those without DKD. Multivariate regression analysis showed that Notch 2 expression had independent relation with increased urinary albumin excretion and reduced estimated glomerular filtration rate. ABCC8 gene expression did not show significant difference between diabetic patients with DKD compared to those without DKD. Conclusion. Increased expression of ABCC8 and Notch 2 genes may play a role in pathogenesis of T2DM. Overexpression of Notch 2 gene may have a role in the development of albuminuria and DKD in patients with T2DM which may represent a possible diagnostic tool and a possible therapeutic target.

Role of mitochondria in pathogenesis of type 2 diabetes mellitus.

Type 2 diabetes mellitus (T2DM) is global health problem. An estimated 425 million people in the world had diabetes in 2017. It is a major cause of morbidity and mortality worldwide. Although, pathogenesis of T2DM and its complications have been focus of medical research for long, much remains to be learned. A better understanding of molecular pathogenesis is essential for more effective preventive and therapeutic interventions. Role of mitochondria in pathogenesis of metabolic problems such as obesity, metabolic syndrome, and T2DM is the focus of many recent research studies. Mitochondrial dysfunction contributes to the oxidative stress and systemic inflammation leading to insulin resistance (IR). Mitochondria are also essential for pancreatic beta cell insulin secretion. Hence, mitochondria are important players in the pathogenesis of T2DM. In this article, pathogenesis of T2DM is examined from a mitochondrial perspective.

Histone Deacetylase 3 Aggravates Type 1 Diabetes Mellitus by Inhibiting Lymphocyte Apoptosis Through the microRNA-296-5p/Bcl-xl Axis.

Type 1 diabetes mellitus (T1DM) is a chronic autoimmune disease characterized by immune-mediated destruction of pancreatic beta-cells. Multiple microRNAs (miRNAs) have been implicated in T1DM pathogenesis. Although histone deacetylase 3 (HDAC3) has been reported to be involved in T1DM, the underlying mechanisms remain to be further elucidated. This study was designed to investigate the potential regulatory role of Hdac3 on T1DM progression. The expression of miR-296-5p and B-cell leukemia-XL (BCL-XL) was determined using RT-qPCR and Western blot assay in peripheral blood mononuclear cells (PBMCs) of patients with T1DM, tumor necrosis factor-α (TNF-α)- and cycloheximide (CHX)-induced cell model, and streptozotocin (STZ)-induced rat model. The binding affinity between miR-296-5p and Bcl-xl was verified by using dual-luciferase reporter gene assay, and the binding between Hdac3 and the promoter region of miR-296-5p was validated using chromatin immunoprecipitation assay. Western blot analysis and flow cytometry were conducted to assess the apoptotic events of lymphocytes. miR-296-5p expression was downregulated while BCL-XL expression was upregulated in PBMCs of patients with T1DM. An adverse correlation was identified between miR-296-5p and Bcl-xl in mouse TE15 B lymphocytes. Bcl-xl was further validated to be targeted and negatively regulated by miR-296-5p in 293 T cells. Hdac3 inhibited miR-296-5p expression by binding to its promoter region. The effects of overexpressed Hdac3 on lymphocyte apoptosis was counterweighed via downregulation of Bcl-xl or upregulation of miR-296-5p, the mechanism of which was further validated in a rat model of DM. Taken together, the Hdac3-mediated upregulation of Bcl-xl via inhibiting miR-296-5p promoter activity enhanced the anti-apoptotic capacity of lymphocytes to accelerate the occurrence of T1DM.

Low serum levels of meteorin-like/subfatin: an indicator of diabetes mellitus and insulin resistance?

Meteorin-like (Metrnl), also known as subfatin, is a recently discovered adipokine with a favourable effect on insulin sensitivity. Studies have shown lower Metrnl levels in obese patients. However, data on its circulating levels in type 2 diabetes mellitus (T2DM) patients are contradictory. This study aims to evaluate serum Metrnl levels in T2DM patients and determine the relationship between serum Metrnl levels and insulin resistance in these patients. This cross-sectional study was conducted among 150 participants. The study was carried out between June 2019 and December 2019 at the internal medicine outpatient clinic of a tertiary university hospital. The participants were divided into three groups: group 1 (control group, n = 50), group 2 (newly diagnosed T2DM, n = 50), and group 3 (long-standing diagnosed T2DM, n = 50). An enzyme-linked immunosorbent assay (ELISA) was used to measure the serum levels of Subfatin (Metrnl), and the correlations of Metrnl level with anthropometric parameters, HOMA index, and biochemical measurements were assessed. There was no statistically significant difference between the gender (p = 0.468) and age (p = 0.067) characteristics of the three groups. The Metrnl (subfatin) levels of the participants were as follows: control group - 20.05 (1.56-103.78); newly diagnosed T2DM group - 2.62 (1.25-103.78); and long-standing diagnosed T2DM group - 2.01 (0.80-19.84) pg/mL. The Metrnl (subfatin) levels of the participants in the control group were higher than in the participants in the newly diagnosed T2DM and long-standing diagnosed T2DM groups (p < 0.001). Subfatin demonstrated a negative correlation with insulin and HOMA-IR in the control group and long-standing diagnosed T2DM group. The subfatin level was found to be higher in the healthy control group than in both diabetic patient groups. Subfatin level showed negative correlation with both insulin level and HOMA index. There was a relationship between subfatin and insulin resistance. Low levels of subfatin in the diabetic patient groups may play a role in the pathogenesis of T2DM by increasing insulin resistance.