scholarly journals Adiponectin as a Link Between Type 2 Diabetes and Vascular NADPH Oxidase Activity in the Human Arterial Wall: The Regulatory Role of Perivascular Adipose Tissue

Diabetes ◽  
2014 ◽  
Vol 64 (6) ◽  
pp. 2207-2219 ◽  
Author(s):  
Alexios S. Antonopoulos ◽  
Marios Margaritis ◽  
Patricia Coutinho ◽  
Cheerag Shirodaria ◽  
Costas Psarros ◽  
...  
Diabetes ◽  
2015 ◽  
Vol 64 (6) ◽  
pp. 1904-1906 ◽  
Author(s):  
Jaume Padilla ◽  
Victoria J. Vieira-Potter ◽  
Guanghong Jia ◽  
James R. Sowers

2009 ◽  
Vol 55 (5) ◽  
pp. 43-48 ◽  
Author(s):  
V Shvarts

This review deals with the role of adipose tissue inflammation (ATI) in the development of type 2 diabetes mellitus (DM2). ATI is regarded as a link between obesity and DM2. The review illustrates the involvement of main adipokines in pathogenesis of DM2 and provides a detailed description of such factors as impaired adiponectin and stimulation of cytokine production responsible for metabolic disorders, activation of lipolysis, in adipocytes, increased fatty acid and triglyceride levels, suppression of insulin activity at the receptor and intracellular levels. Adipokines, in the first place cytokines, act on the insulin signal pathway and affect the intracellular inflammatory kinase cascade. At the intercellular level, ATI stimulates JNK and IKK-beta/kB responsible for the development of insulin resistance via such mechanisms as activation of cytokine secretion in the adipose tissue, oxidative stress, and induction of endoplasmic reticulum enzymes. The key role of JNK and IKK-beta/kB in the inhibition of the insulin signal pathway is mediated through inactivation of insulin receptor substrate 1. Also, it is shown that ATI modulates B-cell function and promotes progressive reduction of insulin secretion.


Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 601
Author(s):  
Aditya Saxena ◽  
Nitin Wahi ◽  
Anshul Kumar ◽  
Sandeep Kumar Mathur

The pathogenic mechanisms causing type 2 diabetes (T2D) are still poorly understood; a greater awareness of its causation can lead to the development of newer and better antidiabetic drugs. In this study, we used a network-based approach to assess the cellular processes associated with protein–protein interaction subnetworks of glycemic traits—HOMA-β and HOMA-IR. Their subnetworks were further analyzed in terms of their overlap with the differentially expressed genes (DEGs) in pancreatic, muscle, and adipose tissue in diabetics. We found several DEGs in these tissues showing an overlap with the HOMA-β subnetwork, suggesting a role of these tissues in β-cell failure. Many genes in the HOMA-IR subnetwork too showed an overlap with the HOMA-β subnetwork. For understanding the functional theme of these subnetworks, a pathway-to-pathway complementary network analysis was done, which identified various adipose biology-related pathways, containing genes involved in both insulin secretion and action. In conclusion, network analysis of genes showing an association between T2D and its intermediate phenotypic traits suggests their potential role in beta cell failure. These genes enriched the adipo-centric pathways and were expressed in both pancreatic and adipose tissue and, therefore, might be one of the potential targets for future antidiabetic treatment.


2019 ◽  
Vol 8 (6) ◽  
pp. 854 ◽  
Author(s):  
Min-Woo Lee ◽  
Mihye Lee ◽  
Kyoung-Jin Oh

Obesity is one of the main risk factors for type 2 diabetes mellitus (T2DM). It is closely related to metabolic disturbances in the adipose tissue that primarily functions as a fat reservoir. For this reason, adipose tissue is considered as the primary site for initiation and aggravation of obesity and T2DM. As a key endocrine organ, the adipose tissue communicates with other organs, such as the brain, liver, muscle, and pancreas, for the maintenance of energy homeostasis. Two different types of adipose tissues—the white adipose tissue (WAT) and brown adipose tissue (BAT)—secrete bioactive peptides and proteins, known as “adipokines” and “batokines,” respectively. Some of them have beneficial anti-inflammatory effects, while others have harmful inflammatory effects. Recently, “exosomal microRNAs (miRNAs)” were identified as novel adipokines, as adipose tissue-derived exosomal miRNAs can affect other organs. In the present review, we discuss the role of adipose-derived secretory factors—adipokines, batokines, and exosomal miRNA—in obesity and T2DM. It will provide new insights into the pathophysiological mechanisms involved in disturbances of adipose-derived factors and will support the development of adipose-derived factors as potential therapeutic targets for obesity and T2DM.


2012 ◽  
Vol 302 (1) ◽  
pp. C122-C130 ◽  
Author(s):  
David D. New ◽  
Karen Block ◽  
Basant Bhandhari ◽  
Yves Gorin ◽  
Hanna E. Abboud

Extracellular matrix accumulation contributes to the progression of chronic kidney disease. Many growth factors including insulin-like growth factor-I (IGF-I) enhance matrix protein accumulation. Proximal tubular epithelial cells (PTCs) synthesize matrix proteins. NADPH oxidases are major sources of reactive oxygen species (ROS), important signaling molecules that mediate biological responses in a variety of cells and tissue. We investigated the mechanism by which IGF-I regulates fibronectin accumulation in PTCs and the role of a potential redox-dependent signaling pathway. IGF-I induces an increase in NADPH-dependent superoxide generation, enhances the release of hydrogen peroxide, and increases the expression of NADPH oxidase 4 (Nox4) in PTCs. IGF-I also stimulates phosphorylation of Akt, and inhibition of Akt or its upstream activator phosphatidylinositol 3-kinase attenuates IGF-I-induced fibronectin accumulation. Expression of dominant negative Akt also inhibits IGF-I-induced expression of fibronectin, indicating a role for this kinase in fibronectin accumulation. Expression of dominant negative adenovirus Nox4 inhibits IGF-I-induced NADPH oxidase activity, Akt phosphorylation, and fibronectin protein expression. Moreover, transfection of small interfering RNA targeting Nox4 decreases Nox4 protein expression and blocks IGF-I-induced Akt phosphorylation and the increase in fibronectin, placing Nox4 and ROS upstream of Akt signaling pathway. To confirm the role of Nox4, PTCs were infected with adenovirus construct expressing wild-type Nox4. Ad-Nox4, but not control Ad-green fluorescent protein, upregulated Nox4 expression and increased NADPH oxidase activity as well as fibronectin expression. Taken together, these results provide the first evidence for a role of Nox4 in IGF-I-induced Akt phosphorylation and fibronectin expression in tubular epithelial cells.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
S Saxton ◽  
R J Potter ◽  
S B Withers ◽  
R Grencis ◽  
A M Heagerty

Abstract Background/Purpose Perivascular adipose tissue (PVAT) is essential in the modulation of vascular tone. Recently we have shown that resident eosinophils play a vital role in regulating PVAT function. In obesity, eosinophil numbers are reduced and PVAT anticontractile function is lost, resulting in increased vascular tone, which will contribute to development of hypertension and type-2 diabetes. Evidence suggests that eosinophilia resulting from parasitic infection may be useful in improving glucose tolerance; therefore, we investigated the effects of eosinophilia on PVAT function in health and obesity. Methods Control mice and a high fat fed mouse model of obesity were administered intraperitoneal injections of interleukin-33 (IL-33, 0.1μg) over a five day period. Blood pressure, blood glucose and plasma insulin were measured and compared with un-injected control and obese mice. Wire myography was used to assess the vascular contractility of mesenteric arteries (<250μm, +/− PVAT) from both injected and un-injected control and obese mice in response to noradrenaline. ELISAs and immunohistochemistry were used to examine eosinophil numbers. Results High fat feeding induced significant elevations in blood pressure, blood glucose and plasma insulin, which were reduced using IL-33 injections. Eosinophilia was confirmed in blood plasma using an eosinophil cationic protein ELISA. Using wire myography, mesenteric arteries from control mice PVAT exerted an anticontractile effect on the vessels, which was enhanced in control mice injected with IL-33. In obese mice, the PVAT anticontractile effect was lost, but was restored in IL-33 injected obese mice. Using immunohistochemistry, we confirm that eosinophils numbers in PVAT were reduced in obesity and increased in IL-33 treated PVAT. Conclusions IL-33 injections induced eosinophilia in both control and obese mice. IL-33 treatment restored PVAT function in obesity, and enhanced the anticontractile function of PVAT in healthy animals. In addition, only five consecutive injections of IL-33 reversed development of hypertension and type-2 diabetes in obese mice. These data suggest that IL-33 induced eosinophilia presents a novel approach to treatment of hypertension and type-2 diabetes in obesity. Acknowledgement/Funding British Heart Foundation


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