scholarly journals The role of inflammation and macrophage accumulation in the development of obesity-induced type 2 diabetes mellitus and the possible therapeutic effects of long-chainn-3 PUFA

2010 ◽  
Vol 69 (2) ◽  
pp. 232-243 ◽  
Author(s):  
Elizabeth Oliver ◽  
Fiona McGillicuddy ◽  
Catherine Phillips ◽  
Sinead Toomey ◽  
Helen M. Roche
Keyword(s):  
Diabetes Mellitus ◽  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Insulin Receptor ◽  
Insulin Signalling ◽  
Serine Phosphorylation ◽  
Therapeutic Effects ◽  
Low Grade

The WHO estimate that >1×106deaths in Europe annually can be attributed to diseases related to excess body weight, and with the rising global obesity levels this death rate is set to drastically increase. Obesity plays a central role in the metabolic syndrome, a state of insulin resistance that predisposes patients to the development of CVD and type 2 diabetes mellitus. Obesity is associated with low-grade chronic inflammation characterised by inflamed adipose tissue with increased macrophage infiltration. This inflammation is now widely believed to be the key link between obesity and development of insulin resistance. In recent years it has been established that activation of pro-inflammatory pathways can cross talk with insulin signalling pathways via a number of mechanisms including (a) down-regulation of insulin signalling pathway proteins (e.g. GLUT4 and insulin receptor substrate (IRS)-1), (b) serine phosphorylation of IRS-1 blocking its tyrosine phosphorylation in response to insulin and (c) induction of cytokine signalling molecules that sterically hinder insulin signalling by blocking coupling of the insulin receptor to IRS-1. Long-chain (LC)n-3 PUFA regulate gene expression (a) through transcription factors such as PPAR and NF-κB and (b) via eicosanoid production, reducing pro-inflammatory cytokine production from many different cells including the macrophage. LCn-3 PUFA may therefore offer a useful anti-inflammatory strategy to decrease obesity-induced insulin resistance, which will be examined in the present review.

Protein Tyrosine Phosphatase 1B Inhibitors: A Novel Therapeutic Strategy for the Management of type 2 Diabetes Mellitus

2019 ◽  
Vol 25 (23) ◽  
pp. 2526-2539 ◽  
Author(s):  
Pranav K. Prabhakar ◽  
Ponnurengam M. Sivakumar
Keyword(s):  
Diabetes Mellitus ◽  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Insulin Receptor ◽  
Therapeutic Strategy ◽  
Insulin Signalling ◽  
Tyrosine Phosphatase ◽  
Protein Tyrosine Phosphatase 1B

Diabetes is one of the most common endocrine non-communicable metabolic disorders which is mainly caused either due to insufficient insulin or inefficient insulin or both together and is characterized by hyperglycemia. Diabetes emerged as a serious health issue in the industrialized and developing country especially in the Asian pacific region. Out of the two major categories of diabetes mellitus, type 2 diabetes is more prevalent, almost 90 to 95% cases, and the main cause of this is insulin resistance. The main cause of the progression of type 2 diabetes mellitus has been found to be insulin resistance. The type 2 diabetes mellitus may be managed by the change in lifestyle, physical activities, dietary modifications and medications. The major currently available management strategies are sulfonylureas, biguanides, thiazolidinediones, α-glucosidase inhibitors, dipeptidyl peptidase-IV inhibitors, and glucagon-like peptide-1 (GLP-1) agonist. Binding of insulin on the extracellular unit of insulin receptor sparks tyrosine kinase of the insulin receptor which induces autophosphorylation. The phosphorylation of the tyrosine is regulated by insulin and leptin molecules. Protein tyrosine phosphatase-1B (PTP1B) works as a negative governor for the insulin signalling pathways, as it dephosphorylates the tyrosine of the insulin receptor and suppresses the insulin signalling cascade. The compounds or molecules which inhibit the negative regulation of PTP1B can have an inductive effect on the insulin pathway and finally help in the management of diabetes mellitus. PTP1B could be an emerging therapeutic strategy for diabetes management. There are a number of clinical and basic research results which suggest that induced expression of PTP1B reduces insulin resistance. In this review, we briefly elaborate and explain the place of PTP1B and its significance in diabetes as well as a recent development in the PTP1B inhibitors as an antidiabetic therapy.

Echinops Spp. Polysaccharide B Ameliorates Metabolic Abnormalities in a Rat Model of Type 2 Diabetes Mellitus

2020 ◽  
Vol 19 (1) ◽  
pp. 106-114
Author(s):  
Guang Hao ◽  
Xiaoyu Ma ◽  
Mengru Jiang ◽  
Zhenzhen Gao ◽  
Ying Yang
Keyword(s):  
Diabetes Mellitus ◽  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Insulin Secretion ◽  
Insulin Receptor ◽  
Skeletal Muscles ◽  
Insulin Receptor Substrate ◽  
Sprague Dawley

This study examined the in vivo effects of Echinops spp. polysaccharide B on type 2 diabetes mellitus in Sprague-Dawley rats. We constructed a type 2 diabetes mellitus Sprague-Dawley rat models by feeding a high-fat and high-sugar diet plus intraperitoneal injection of a small dose of streptozotocin. Using this diabetic rat model, different doses of Echinops polysaccharide B were administered orally for seven weeks. Groups receiving Xiaoke pill and metformin served as positive controls. The results showed that Echinops polysaccharide B treatment normalized the weight and blood sugar levels in the type 2 diabetes mellitus rats, increased muscle and liver glycogen content, improved glucose tolerance, increased insulin secretion, and reduced glucagon and insulin resistance indices. More importantly, Echinops polysaccharide B treatment upregulated the expression of insulin receptor in the liver, skeletal muscles, and pancreas, and significantly improved the expression levels of insulin receptor substrate-2 protein in the liver and pancreas, as well as it increased insulin receptor substrate-1 expression in skeletal muscles. These two proteins play crucial roles in increasing insulin secretion and in controlling type 2 diabetes mellitus. The findings of the present study suggest that Echinops polysaccharide B could improve the status of diabetes in type 2 diabetes mellitus rats, which may be achieved by improving insulin resistance. Our study provides a new insight into the development of a natural drug for the control of type 2 diabetes mellitus.

scholarly journals Physical exercise prevents the development of type 2 diabetes mellitus in Psammomys obesus

2002 ◽  
Vol 282 (2) ◽  
pp. E370-E375 ◽  
Author(s):  
Yuval Heled ◽  
Yair Shapiro ◽  
Yoav Shani ◽  
Dani S. Moran ◽  
Lea Langzam ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Exercise Training ◽  
Insulin Receptor ◽  
High Energy ◽  
Serine Phosphorylation ◽  
Psammomys Obesus ◽  
Group Protein

We hypothesized that exercise training might prevent diabetes mellitus in Psammomys obesus. Animals were assigned to three groups: high-energy diet (CH), high-energy diet and exercise (EH), and low-energy diet (CL). The EH group ran on a treadmill 5 days/wk, twice a day. After 4 wk, 93% of the CH group were diabetic compared with only 20% of the EH group. There was no difference in weight gain among the groups. Both EH and CH groups were hyperinsulinemic. Epididymal fat (% of body weight) was higher in the CH group than in either the EH and or the CL group. Protein kinase C (PKC)-δ activity and serine phosphorylation were higher in the EH group. No differences were found in tyrosine phosphorylation of the insulin receptor, insulin receptor substrate-1, and phosphatidylinositol 3-kinase among the groups. We demonstrate for the first time that exercise training effectively prevents the progression of diabetes mellitus type 2 in Psammomys obesus. PKC-δ may be involved in the adaptive effects of exercise in skeletal muscles that lead to the prevention of type 2 diabetes mellitus.

scholarly journals Influence of metabolic disorders on phenotypic modulation of vascular endothelium in type 2 diabetes mellitus

2017 ◽  
Vol 70 (11-12) ◽  
pp. 437-443
Author(s):  
Romana Mijovic ◽  
Branislava Ilincic ◽  
Suncica Kojic-Damjanov ◽  
Biljana Vuckovic ◽  
Radmila Zeravica ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Endothelial Dysfunction ◽  
Adhesion Molecules ◽  
Vascular Endothelium ◽  
Low Grade ◽  
Phenotypic Modulation

Introduction. Endothelium is a dynamic, strategically positioned defensive regulator of vascular homeostasis. Physiology and Pathophysiology of Vascular Endothelium. Endothelial phenotypic modulation involves five basic characteristics: the expression of leukocyte adhesion molecules, the production of cytokines, change in the shape and the permeability of the endothelium, prothrombotic changes and upregulation of autoantigens. Obesity, Metabolic Inflammation and Vascular Endothelium One of the most important pathophysiological manifestations of adiposopathy may be the phenotypic conversion of vascular endothelium. Insulin Resistance and Vascular Endothelium. Under the conditions of insulin resistance and consequent hyperinsulinemia, there is imbalance between the production of endothelial vasoconstrictors and vasodilators, increased expression of adhesion molecules, and platelet hyperreactivity. Hyperglycemia and Vascular Endothelium. Hyperglycemia causes endothelial dysfunction by various mechanisms that involve activation of polyol pathway and production of sorbitol, increased formation of advanced glycation end products, activation of various isoforms of protein kinase C and activation of hexosamine pathway. Dyslipidemia and vascular endothelium. Dyslipidemia takes an important role in a cascade of pathophysiological processes that result in endothelial activation and chronic dysfunction. Conclusion. Hyperglycemia, hyperinsulinemia, insulin resistance, dyslipidemia, visceral obesity and low-grade inflammation are the main factors responsible for development of endothelial dysfunction in type 2 diabetes mellitus.

Molecular mechanism of insulin resistance in type 2 diabetes mellitus: role of the insulin receptor variant forms

2001 ◽  
Vol 17 (5) ◽  
pp. 363-373 ◽  
Author(s):  
Giorgio Sesti ◽  
Massimo Federici ◽  
Davide Lauro ◽  
Paolo Sbraccia ◽  
Renato Lauro
Keyword(s):  
Diabetes Mellitus ◽  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Insulin Receptor ◽  
Molecular Mechanism

Fatty acid-induced insulin resistance: role of insulin receptor substrate 1 serine phosphorylation in the retroregulation of insulin signalling

2003 ◽  
Vol 31 (6) ◽  
pp. 1152-1156 ◽  
Author(s):  
Y. Le Marchand-Brustel ◽  
P. Gual ◽  
T. Grémeaux ◽  
T. Gonzalez ◽  
R. Barrès ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Fatty Acid ◽  
Insulin Receptor ◽  
Tyrosine Phosphorylation ◽  
Glucose Transport ◽  
Insulin Signalling ◽  
Serine Phosphorylation ◽  
Insulin Receptor Substrate

Insulin resistance, when combined with impaired insulin secretion, contributes to the development of type 2 diabetes. Insulin resistance is characterized by a decrease in the insulin effect on glucose transport in muscle and adipose tissue. Tyrosine phosphorylation of IRS-1 (insulin receptor substrate 1) and its binding to PI 3-kinase (phosphoinositide 3-kinase) are critical events in the insulin signalling cascade leading to insulin-stimulated glucose transport. Various studies have implicated lipids as a cause of insulin resistance in muscle. Elevated plasma fatty acid concentrations are associated with reduced insulin-stimulated glucose transport activity as a consequence of altered insulin signalling through PI 3-kinase. Modification of IRS-1 by serine phosphorylation could be one of the mechanisms leading to a decrease in IRS-1 tyrosine phosphorylation, PI 3-kinase activity and glucose transport. Recent findings demonstrate that non-esterified fatty acids, as well as other factors such as tumour necrosis factor α, hyperinsulinaemia and cellular stress, increase the serine phosphorylation of IRS-1 and identified Ser307 as one of the phosphorylated sites. Moreover, several kinases able to phosphorylate this serine residue have been identified. These exciting results suggest that Ser307 phosphorylation is a possible hallmark of insulin resistance in biologically insulin-responsive cells or tissues. Identification of IRS-1 kinases could enable rational drug design in order to selectively inhibit the activity of the relevant enzymes and generate a novel class of therapeutic agents for type 2 diabetes.

scholarly journals Elevated Serum TNF-α Is Related to Obesity in Type 2 Diabetes Mellitus and Is Associated with Glycemic Control and Insulin Resistance

2020 ◽  
Vol 2020 ◽  
pp. 1-5 ◽  
Author(s):  
Hana Alzamil
Keyword(s):  
Diabetes Mellitus ◽  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Chronic Inflammation ◽  
Affinity Column ◽  
Diabetic Patients ◽  
Low Grade ◽  
Model Assessment

Background. Diabetes and obesity are very common associated metabolic disorders that are linked to chronic inflammation. Leptin is one of the important adipokines released from adipocytes, and its level increases with increasing body mass index (BMI). Tumor necrosis factor alpha (TNF-α) is a cytokine that is released by adipocytes and inflammatory cells in response to chronic inflammation. Type 2 diabetes mellitus (T2DM) is believed to be associated with low-grade chronic inflammation. The current study aims to investigate the involvement of leptin and TNF-α in T2DM associated with obesity. Methodology. This is a cross-sectional study involving 63 healthy volunteers and 65 patients with T2DM. Body composition was measured, and fasting venous blood samples were analyzed for blood glucose, glycosylated hemoglobin (HbA1c), basal insulin, leptin, and TNF-α. HbA1c was measured by the affinity column method. Insulin, leptin, and TNF-α immunoassays were performed by the ELISA technique. Insulin resistance and beta-cell function were assessed using the homeostasis model assessment (HOMA-IR and HOMA-B). Results. Our study showed a significantly higher level of TNF-α in T2DM patients compared to controls (7.51 ± 2.48 and 6.19 ± 3.01, respectively; p=0.008). In obese diabetic patients, the serum level of TNF-α was significantly higher in comparison with nonobese diabetic patients (p<0.018) and obese nondiabetic group (p<0.001). TNF-α correlated positively with HbA1c (r = 0.361, p=0.003) and HOMA-IR (r = 0.296, p=0.017) in patients with T2DM. Conclusion. TNF-α is associated with concurrent obesity and T2DM and correlates with HbA1c. This suggests that TNF-α needs further investigation to explore if it has a role in monitoring the effectiveness of management in individuals with obesity and T2DM.

scholarly journals DR3 stimulation of adipose resident ILC2s ameliorates type 2 diabetes mellitus

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Pedram Shafiei-Jahani ◽  
Benjamin P. Hurrell ◽  
Lauriane Galle-Treger ◽  
Doumet Georges Helou ◽  
Emily Howard ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Adipose Tissue ◽  
Death Receptor ◽  
Lymphoid Cells ◽  
Low Grade ◽  
Group 2

Abstract Disturbances in glucose homeostasis and low-grade chronic inflammation culminate into metabolic syndrome that increase the risk for the development of type 2 diabetes mellitus (T2DM). The recently discovered group 2 innate lymphoid cells (ILC2s) are capable of secreting copious amounts of type 2 cytokines to modulate metabolic homeostasis in adipose tissue. In this study, we have established that expression of Death Receptor 3 (DR3), a member of the TNF superfamily, on visceral adipose tissue (VAT)-derived murine and peripheral blood human ILC2s is inducible by IL-33. We demonstrate that DR3 engages the canonical and/or non-canonical NF-κB pathways, and thus stimulates naïve and co-stimulates IL-33-activated ILC2s. Importantly, DR3 engagement on ILC2s significantly ameliorates glucose tolerance, protects against insulin-resistance onset and remarkably reverses already established insulin-resistance. Taken together, these results convey the potent role of DR3 as an ILC2 regulator and introduce DR3 agonistic treatment as a novel therapeutic avenue for treating T2DM.

scholarly journals Impaired Function of Regulatory T Cells in Type 2 Diabetes Mellitus

2020 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Rona Kartika ◽  
Heri Wibowo
Keyword(s):  
Diabetes Mellitus ◽  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
T Cells ◽  
Type 2 Diabetes Mellitus ◽  
Regulatory T Cells ◽  
Inflammatory Response ◽  
Treg Cells ◽  
Low Grade

Pathogenesis of type 2 Diabetes Mellitus (DM) is often associated with chronic low-grade inflammation. This kind of inflammation is characterized by an increased level of pro-inflammatory cytokines such as tumor necrosis factor α (TNF-α), interleukin (IL)-6 and IL-1β. From an immunological point of view, an inflammatory response is always followed by an anti-inflammatory response as negative feedback to avoid excessive tissue damages. Regulatory T cells are a subset of cluster of differentiation (CD)4+ T cells that have the function to maintain peripheral tolerance and suppress immune response. This review would discuss the impaired function of regulatory T cells in type 2 DM. DM is a group of metabolic diseases characterized by hyperglycemia due to a defect of insulin secretion or a combination of insulin resistance and relative insulin deficiency. Chronic low-grade inflammation has been known as a key factor in the development of insulin resistance. Regulatory T cells (Treg cells) action through contact and non-contact inhibition could suppress inflammatory response in innate and adaptive immune systems. In type 2 DM, the proportion and function of CD4+CD25+Foxp3+ and CD4+CD25+ regulatory T cell decreases due to the reduced number of Treg cells and the Treg cells depletion contributes to metabolic conditions such as insulin resistance. Moreover, Treg cells are more susceptible to apoptosis, the ability of Treg cells to produce anti-inflammatory cytokines such as transforming growth factor β (TGF-β) and IL-10 decreases, and there is an imbalance between the proportion of Th1/Th17 cells and Treg cells. This inadequate anti-inflammatory response gives rise to the chronic low-grade inflammatory condition in type 2 DM.Keywords: type 2 diabetes mellitus, inflammation, regulatory T cell

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