Abstract 1123: Critical Role Of Adipose Senescence In Insulin Resistance And Vascular Dysfunction

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Masayuki Orimo ◽  
Tohru Minamino ◽  
Hideyuki Miyauchi ◽  
Kaoru Tateno ◽  
Sho Okada ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Inflammatory Cytokines ◽  
Cellular Senescence ◽  
Vascular Dysfunction ◽  
Critical Role ◽  
Serum Levels ◽  
P53 Expression ◽  
Deficient Mice ◽  
Pro Inflammatory Cytokines

Cellular senescence is originally described as the finite replicative lifespan of human somatic cells in culture. As a consequence of semi-conservative DNA replication, the extreme terminals of the chromosomes are not duplicated completely, resulting in successive shortening of telomeres with each cell division. Telomerase is a ribonucleoprotein that adds telomeres to the ends of chromosomes. Critically short telomeres are thought to trigger DNA damage response, thereby inducing cellular senescence. Accumulating evidence has suggested that senescent cells promote aging phenotypes or age-related pathologies. Here we show that adipose senescence is critically involved in the regulation of insulin resistance that underlies age-associated cardiovascular disease. The later generation of telomerase-deficient mice with short telomeres exhibited insulin resistance and vascular dysfunction when fed on a high-calorie diet. Adipose tissue of these mice revealed senescence-like phenotypes such as an increase in neutral β galactosidase activity and upregulation of p53 and pro-inflammatory cytokines. Serum levels of pro-inflammatory cytokines were markedly elevated in telomerase-deficient mice and treatment of these mice with a neutralizing antibody against TNF-α significantly improved insulin and glucose intolerance. Removal of senescent adipose tissue reduced serum levels of pro-inflammatory cytokines and thereby improved insulin resistance in telomerase-deficient mice. Conversely, implantation of senescent adipose tissue to wild-type mice impaired insulin sensitivity and glucose tolerance in recipients. Introduction of telomere dysfunction to young adipose tissue markedly upregulated p53 expression and increased the production of pro-inflammatory cytokines. Inhibition of p53 activity significantly improved senescence-like phenotypes of adipose tissue, insulin resistance, and vascular dysfunction in telomerase-deficient mice. These results disclose a novel mechanism of insulin resistance and suggest that adipose senescence is a potential therapeutic target for the treatment of diabetes and diabetic vasculopathy.

scholarly journals Influence of Menopause on Inflammatory Cytokines during Murine and Human Bone Fracture Healing

2018 ◽  
Vol 19 (7) ◽  
pp. 2070 ◽  
Author(s):  
Verena Fischer ◽  
Miriam Kalbitz ◽  
Fabian Müller-Graf ◽  
Florian Gebhard ◽  
Anita Ignatius ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Osteogenic Differentiation ◽  
Inflammatory Cytokines ◽  
Serum Levels ◽  
Estrogen Deficiency ◽  
Negative Regulator ◽  
Human Mscs ◽  
Male And Female ◽  
Deficient Mice ◽  
Pro Inflammatory Cytokines

Postmenopausal females display a chronic inflammatory phenotype with higher levels of circulating pro-inflammatory cytokines. Furthermore, the inflammatory response to injury may be altered under estrogen-deficiency, because it was shown previously that estrogen-deficient mice displayed increased levels of the inflammatory cytokines Midkine (Mdk) and Interleukin-6 (IL-6) in the early fracture hematoma. Because a balanced immune response to fracture is required for successful bone regeneration, this might contribute to the delayed fracture healing frequently observed in osteoporotic, postmenopausal fracture patients. In this study, we aimed to investigate whether further cytokines in addition to Mdk and IL-6 might be affected by estrogen-deficiency after fracture in mice and whether these cytokines are also relevant during human fracture healing. Additionally, we aimed to investigate whether serum from male vs. female fracture patients affects osteogenic differentiation of human mesenchymal stem cells (MSCs). To address these questions, female mice were either sham-operated or ovariectomized (OVX) and subjected to standardized femur osteotomy. A broad panel of pro- and anti-inflammatory cytokines was determined systemically and locally in the fracture hematoma. In a translational approach, serum was collected from healthy controls and patients with an isolated fracture. Mdk and IL-6 serum levels were determined at day 0, day 14 and day 42 after fracture. Subgroup analysis was performed to investigate differences between male and female fracture patients after menopause. In an in vitro approach, human MSCs were cultured with the collected patient serum and osteogenic differentiation was assessed by qPCR and alkaline-phosphatase staining. Our results suggest an important role for the pro-inflammatory cytokines Mdk and IL-6 in the response to fracture in estrogen-deficient mice among all of the measured inflammatory mediators. Notably, both cytokines were also significantly increased in the serum of patients after fracture. However, only Mdk serum levels differed significantly between male and female fracture patients after menopause. MSCs cultivated with serum from female fracture patients displayed significantly reduced osteogenic differentiation, which was attenuated by Mdk-antibody treatment. In conclusion, our study demonstrated increased Mdk levels after fracture in OVX mice and female fracture patients after menopause. Because Mdk is a negative regulator of bone formation, this might contribute to impaired osteoporotic fracture healing.

scholarly journals Beneficial effects of diacerein on adipokines and pro-inflammatory cytokines involved in diet-induced nonalcoholic steatohepatitis in rats

2017 ◽  
Vol 6 (4) ◽  
pp. 811 ◽  
Author(s):  
Omaima M. Abd Allah
Keyword(s):  
Insulin Resistance ◽  
Blood Glucose ◽  
Inflammatory Cytokines ◽  
Blood Lipids ◽  
Fasting Blood Glucose ◽  
Liver Weight ◽  
Serum Levels ◽  
Beneficial Effects ◽  
Tnf Α ◽  
Pro Inflammatory Cytokines

Background: Non-alcoholic steatohepatitis (NASH) is considered as a progressive liver disease, so effective therapies are needed to ameliorate hepatic steatosis, inflammation and fibrosis, and to prevent the progression to cirrhosis and hepatocellular carcinoma. Diacerein is an anti-inflammatory drug that inhibits the synthesis and activity of pro-inflammatory cytokines. The present study was designed to investigate the effect of diacerein on pro-inflammatory cytokines as well as adipokines involved in diet-induced NASH rat model.Methods: Thirty-two adult male rats were divided into four groups: control, diacerein-treated, NASH-untreated and NASH+diacerein-treated groups. NASH was induced by feeding rats with high-fat and high-cholesterol diet for 12 weeks. Body weight, liver weight, fasting blood glucose and insulin levels for estimation of insulin resistance, blood lipids, alanine transaminase, and aspartate aminotransferase were evaluated. Serum levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), adiponectin, visfatin and leptin were also detected. Histopathological examination of liver sections was performed.Results: Diacerein significantly reduced liver weight, fasting blood glucose, insulin level, transaminases and ameliorates insulin resistance with favourable effects on blood lipids. These results were accompanied with a significant reduction in serum levels of TNF-α, IL-1β, IL-6, and visfatin, while, adiponectin was significantly increased and leptin was insignificantly affected. Liver sections revealed that diacerein reduced steatosis and lobular inflammatory grades.Conclusions: These data suggest that diacerein administration may have a potential usefulness in the prevention of NASH as a possible result of inhibition of pro-inflammatory cytokines and the beneficial effects on adipokines especially adiponectin and visfatin.

scholarly journals CD11b regulates obesity-induced insulin resistance via limiting alternative activation and proliferation of adipose tissue macrophages

2015 ◽  
Vol 112 (52) ◽  
pp. E7239-E7248 ◽  
Author(s):  
Chunxing Zheng ◽  
Qian Yang ◽  
Chunliang Xu ◽  
Peishun Shou ◽  
Jianchang Cao ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
High Fat Diet ◽  
Critical Role ◽  
Alternative Activation ◽  
Wild Type ◽  
Adipose Tissue Macrophages ◽  
Monocytes And Macrophages ◽  
And Function ◽  
Deficient Mice

Obesity-associated inflammation is accompanied by the accumulation of adipose tissue macrophages (ATMs), which is believed to predispose obese individuals to insulin resistance. CD11b (integrin αM) is highly expressed on monocytes and macrophages and is critical for their migration and function. We found here that high-fat diet–induced insulin resistance was significantly reduced in CD11b-deficient mice. Interestingly, the recruitment of monocytes to adipose tissue is impaired when CD11b is deficient, although the cellularity of ATMs in CD11b-deficient mice is higher than that in wild-type mice. We further found that the increase in ATMs is caused mainly by their vigorous proliferation in the absence of CD11b. Moreover, the proliferation and alternative activation of ATMs are regulated by the IL-4/STAT6 axis, which is inhibited by CD11b through the activity of phosphatase SHP-1. Thus, CD11b plays a critical role in obesity-induced insulin resistance by limiting the proliferation and alternative activation of ATMs.

scholarly journals Depletion of adipocyte sphingosine kinase 1 leads to cell hypertrophy, impaired lipolysis, and nonalcoholic fatty liver disease

2020 ◽  
Vol 61 (10) ◽  
pp. 1328-1340 ◽  
Author(s):  
Andrea K. Anderson ◽  
Johana M. Lambert ◽  
David J. Montefusco ◽  
Bao Ngan Tran ◽  
Patrick Roddy ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Inflammatory Cytokines ◽  
Systemic Inflammation ◽  
Lipolytic Activity ◽  
Sphingosine Kinase ◽  
Sphingosine Kinase 1 ◽  
Nonalcoholic Fatty Liver ◽  
Triacylglycerol Accumulation ◽  
Pro Inflammatory Cytokines

Sphingolipids have become established participants in the pathogenesis of obesity and its associated maladies. Sphingosine kinase 1 (SPHK1), which generates S1P, has been shown to increase in liver and adipose of obese humans and mice and to regulate inflammation in hepatocytes and adipose tissue, insulin resistance, and systemic inflammation in mouse models of obesity. Previous studies by us and others have demonstrated that global sphingosine kinase 1 KO mice are protected from diet-induced obesity, insulin resistance, systemic inflammation, and NAFLD, suggesting that SPHK1 may mediate pathological outcomes of obesity. As adipose tissue dysfunction has gained recognition as a central instigator of obesity-induced metabolic disease, we hypothesized that SPHK1 intrinsic to adipocytes may contribute to HFD-induced metabolic pathology. To test this, we depleted Sphk1 from adipocytes in mice (SK1fatKO) and placed them on a HFD. In contrast to our initial hypothesis, SK1fatKO mice displayed greater weight gain on HFD and exacerbated impairment in glucose clearance. Pro-inflammatory cytokines and neutrophil content of adipose tissue were similar, as were levels of circulating leptin and adiponectin. However, SPHK1-null adipocytes were hypertrophied and had lower basal lipolytic activity. Interestingly, hepatocyte triacylglycerol accumulation and expression of pro-inflammatory cytokines and collagen 1a1 were exacerbated in SK1fatKO mice on a HFD, implicating a specific role for adipocyte SPHK1 in adipocyte function and inter-organ cross-talk that maintains overall metabolic homeostasis in obesity. Thus, SPHK1 serves a previously unidentified essential homeostatic role in adipocytes that protects from obesity-associated pathology. These findings may have implications for pharmacological targeting of the SPHK1/S1P signaling axis.

Acute Ischemic Stroke is Associated with Increased Serum Levels of Pro-inflammatory Cytokines

2020 ◽  
Author(s):  
Bhagirath Ramawat ◽  
Alvee Saluja ◽  
Jayashree Bhatacharjee ◽  
Anshuman Srivastava ◽  
Rajinder K. Dhamija
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Inflammatory Cytokines ◽  
Serum Levels ◽  
Pro Inflammatory Cytokines

scholarly journals Estrogens Protect against High-Fat Diet-Induced Insulin Resistance and Glucose Intolerance in Mice

Endocrinology ◽  
2009 ◽  
Vol 150 (5) ◽  
pp. 2109-2117 ◽  
Author(s):  
Elodie Riant ◽  
Aurélie Waget ◽  
Haude Cogo ◽  
Jean-François Arnal ◽  
Rémy Burcelin ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Glucose Intolerance ◽  
High Fat Diet ◽  
Chow Diet ◽  
High Fat ◽  
Normal Chow ◽  
Visceral Adipose ◽  
Deficient Mice ◽  
Normal Chow Diet

Although corroborating data indicate that estrogens influence glucose metabolism through the activation of the estrogen receptor α (ERα), it has not been established whether this pathway could represent an effective therapeutic target to fight against metabolic disturbances induced by a high-fat diet (HFD). To this end, we first evaluated the influence of chronic 17β-estradiol (E2) administration in wild-type ovariectomized mice submitted to either a normal chow diet or a HFD. Whereas only a modest effect was observed in normal chow diet-fed mice, E2 administration exerted a protective effect against HFD-induced glucose intolerance, and this beneficial action was abolished in ERα-deficient mice. Furthermore, E2 treatment reduced HFD-induced insulin resistance by 50% during hyperinsulinemic euglycemic clamp studies and improved insulin signaling (Akt phosphorylation) in insulin-stimulated skeletal muscles. Unexpectedly, we found that E2 treatment enhanced cytokine (IL-6, TNF-α) and plasminogen activator inhibitor-1 mRNA expression induced by HFD in the liver and visceral adipose tissue. Interestingly, although the proinflammatory effect of E2 was abolished in visceral adipose tissue from chimeric mice grafted with bone marrow cells from ERα-deficient mice, the beneficial effect of the hormone on glucose tolerance was not altered, suggesting that the metabolic and inflammatory effects of estrogens can be dissociated. Eventually comparison of sham-operated with ovariectomized HFD-fed mice demonstrated that endogenous estrogens levels are sufficient to exert a full protective effect against insulin resistance and glucose intolerance. In conclusion, the regulation of the ERα pathway could represent an effective strategy to reduce the impact of high-fat diet-induced type 2 diabetes.

Abstract 424: Phospholipid Transfer Protein Deficiency Promotes Inflammatory Factors' Expression via TLR4-TAK1-NFκB Pathway in Macrophage

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Yang Yu
Keyword(s):  
Inflammatory Cytokines ◽  
Inflammatory Factors ◽  
Phospholipid Transfer Protein ◽  
Wild Type ◽  
Transfer Protein ◽  
Phospholipid Transfer ◽  
Nfκb Pathway ◽  
Nuclear Levels ◽  
Deficient Mice ◽  
Pro Inflammatory Cytokines

Phospholipid transfer protein (PLTP) plays important roles in macrophage mediated inflammation. In the current study we observed that endogenous PLTP modulated pro-inflammatory pathways in macrophage. With the presence of LPS, peritoneal derived macrophage (PDM) or bone marrow derived macrophage (BMDM) from PLTP deficient mice (PLTP-/-) expressed significantly higher level of pro-inflammatory cytokines compared with PDM or BMDM from wild-type mice (WT), respectively. LPS induced TNFα expression in PLTP-/- BMDM or PLTP knockdown RAW264.7 were suppressed by (5Z)-7-Oxozeaenol, a TAK1 inhibitor, suggesting PLTP deficiency enhanced the expression of pro-inflammatory cytokines via TAK1-NFκB pathway in macrophage. Furthermore, abundance of TLR4 on the membrane was dramatically increased in BMDM from PLTP-/- compared with WT. In addition, inhibition of ABCA1 by chemical inhibitor, glyburide, did not reduce nuclear levels of active STAT3 of BMDM, which indicated that no autocrine PLTP triggered ABCA1-JAK2-STAT3 pathway in this study. In conclusion, PLTP deficiency or low expression may enhance LPS induced pro-inflammatory cytokines expression via TLR4-TAK1-NFκB pathway in macrophage.

Edible Red Seaweed Campylaephora Hypnaeoides J. Agardh Alleviates Obesity and Related Metabolic Disorders in Mice by Suppressing Oxidative Stress and Inflammatory Response

2021 ◽  
Author(s):  
Shigeru Murakami ◽  
Chihiro Hirazawa ◽  
Rina Yoshikawa ◽  
Toshiki Mizutani ◽  
Takuma Ohya ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Hepatic Steatosis ◽  
White Adipose Tissue ◽  
Metabolic Disorders ◽  
Public Health Problem ◽  
Serum Levels ◽  
Diet Group ◽  
Raw264.7 Cells ◽  
Edible Seaweed

Abstract Background: The obesity epidemic has become a serious public health problem in many countries worldwide. Seaweed has few calories and is rich in active nutritional components necessary for health promotion and disease prevention. The aim of this study was to investigate the effects of the Campylaephora hypnaeoides J. Agardh (C. hypnaeoides), an edible seaweed traditionally eaten in Japan, on high-fat (HF) diet-induced obesity and related metabolic diseases in mice.Methods: Male C57BL/6J mice were randomly divided into the following groups: normal diet group, HF diet group, HF diet supplemented with 2% C. hypnaeoides, and HF diet supplemented with 6% C. hypnaeoides. After 13 weeks of treatment, the weight of the white adipose tissue and liver, and the serum levels of glucose, insulin, adipokines, and lipids were measured. Hepatic levels of adipokines, oxidant markers, and antioxidant markers were also determined. Insulin resistance was assessed by a glucose tolerance test. Polysaccharides of C. hypnaeoides were purified and their molecular weight was determined by high-performance seize exclusion chromatography. The anti-inflammatory effects of purified polysaccharides were evaluated in RAW264.7 cells. Results: Treatment of HF diet-induced obese mice with C. hypnaeoides for 13 weeks suppressed the increase in body weight and white adipose tissue weight. It also ameliorated insulin resistance, diabetes, hepatic steatosis, and hypercholesterolemia. The ingestion of an HF diet increased serum levels of malondialdehyde (MDA), tumor necrosis factor a (TNF-a), and monocyte chemoattractant protein-1 (MCP-1), while it decreased serum adiponectin levels. In the liver, an HF diet markedly increased the MDA, TNF-a, and interleukin-6 (IL-6) levels, while it decreased glutathione (GSH) and superoxide dismutase (SOD). These metabolic changes induced by HF diet feeding were ameliorated by dietary C. hypnaeoides. Purified polysaccharides and ethanol extract from C. hypnaeoides inhibited the lipopolysaccharide-induced overproduction of nitric oxide and TNF-a in macrophage RAW264.7 cells. Conclusions: The present results indicated that C. hypnaeoides was able to alleviate HF diet-induced metabolic disorders, including obesity, diabetes, hepatic steatosis, and hypercholesterolemia by attenuating inflammation and improving the antioxidant capacity in mice. Polysaccharides and polyphenols may be involved in these beneficial effects of C. hypnaeoides.

scholarly journals My D88-Dependent Interplay Between Myeloid and Endothelial Cells in the Initiation and Progression of Obesity-Associated Inflammatory Diseases

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. SCI-44-SCI-44
Author(s):  
Xiaoxia Li
Keyword(s):  
Insulin Resistance ◽  
Endothelial Cells ◽  
Adipose Tissue ◽  
Systemic Inflammation ◽  
Conflicts Of Interest ◽  
Ex Vivo ◽  
Inflammatory Diseases ◽  
Critical Role ◽  
Low Grade

Abstract Low-grade systemic inflammation is often associated with metabolic syndrome, which plays a critical role in the development of the obesity-associated inflammatory diseases, including insulin resistance and atherosclerosis. Here, we investigate how Toll-like receptor-MyD88 signaling in myeloid and endothelial cells coordinately participates in the initiation and progression of high fat diet-induced systemic inflammation and metabolic inflammatory diseases. MyD88 deficiency in myeloid cells inhibits macrophage recruitment to adipose tissue and their switch to an M1-like phenotype. This is accompanied by substantially reduced diet-induced systemic inflammation, insulin resistance, and atherosclerosis. MyD88 deficiency in endothelial cells results in a moderate reduction in diet-induced adipose macrophage infiltration and M1 polarization, selective insulin sensitivity in adipose tissue, and amelioration of spontaneous atherosclerosis. Both in vivo and ex vivo studies suggest that MyD88-dependent GM-CSF production from the endothelial cells might play a critical role in the initiation of obesity-associated inflammation and development of atherosclerosis by priming the monocytes in the adipose and arterial tissues to differentiate into M1-like inflammatory macrophages. Collectively, these results implicate a critical MyD88-dependent interplay between myeloid and endothelial cells in the initiation and progression of obesity-associated inflammatory diseases. Disclosures No relevant conflicts of interest to declare.

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