scholarly journals Key Role of STAT4 Deficiency in the Hematopoietic Compartment in Insulin Resistance and Adipose Tissue Inflammation

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Anca D. Dobrian ◽  
Kaiwen Ma ◽  
Lindsey M. Glenn ◽  
Margaret A. Hatcher ◽  
Bronson A. Haynes ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Bone Marrow Cells ◽  
Cd8 Cells ◽  
Diet Induced Obesity ◽  
Hematopoietic Lineage ◽  
Islet Inflammation ◽  
Visceral Adipose

Visceral adipose tissue (AT) inflammation is linked to the complications of obesity, including insulin resistance (IR) and type 2 diabetes. Recent data from our lab showed that germline deficiency in STAT4 reduces inflammation and improves IR in obese mice. The objective of this study was to determine the contribution of selective STAT4 deficiency in subsets of hematopoietic cells to IR and AT inflammation. To determine the contribution of hematopoietic lineage, we sublethally irradiated Stat4−/−C57Bl6 mice and reconstituted them with bone marrow cells (BMC) from Stat4+/+C57Bl6 congenic donors. We also established the contribution of selective STAT4 deficiency in CD4+ or CD8+ T cells using adoptive transfer in Rag1−/− mice. All mice received a HFD for 15 weeks (n=7–12 mice/group). BMC that expressed STAT4 induced increases in glucose intolerance and IR compared to STAT4-deficient cells. Also, AT inflammation was increased and the numbers of CD8+ cells infiltrating AT were higher in mice with STAT4 expressing BMC. Studies in Rag1−/− mice further confirmed the prominent role of CD8+ cells expressing STAT4 in insulin resistance and AT and islet inflammation. Collectively our results show specific and dominant contribution of STAT4 in the hematopoietic compartment to metabolic health and inflammation in diet-induced obesity.

scholarly journals Collagen 24 α1 Is Increased in Insulin-Resistant Skeletal Muscle and Adipose Tissue

2020 ◽  
Vol 21 (16) ◽  
pp. 5738
Author(s):  
Xiong Weng ◽  
De Lin ◽  
Jeffrey T. J. Huang ◽  
Roland H. Stimson ◽  
David H. Wasserman ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Insulin Resistant ◽  
Global View ◽  
Novel Association ◽  
Visceral Adipose ◽  
Subcutaneous Adipose

Aberrant extracellular matrix (ECM) remodelling in muscle, liver and adipose tissue is a key characteristic of obesity and insulin resistance. Despite its emerging importance, the effective ECM targets remain largely undefined due to limitations of current approaches. Here, we developed a novel ECM-specific mass spectrometry-based proteomics technique to characterise the global view of the ECM changes in the skeletal muscle and liver of mice after high fat (HF) diet feeding. We identified distinct signatures of HF-induced protein changes between skeletal muscle and liver where the ECM remodelling was more prominent in the muscle than liver. In particular, most muscle collagen isoforms were increased by HF diet feeding whereas the liver collagens were differentially but moderately affected highlighting a different role of the ECM remodelling in different tissues of obesity. Moreover, we identified a novel association between collagen 24α1 and insulin resistance in the skeletal muscle. Using quantitative gene expression analysis, we extended this association to the white adipose tissue. Importantly, collagen 24α1 mRNA was increased in the visceral adipose tissue, but not the subcutaneous adipose tissue of obese diabetic subjects compared to lean controls, implying a potential pathogenic role of collagen 24α1 in obesity and type 2 diabetes.

scholarly journals Role of Muscle c-Jun NH2-Terminal Kinase 1 in Obesity-Induced Insulin Resistance

2009 ◽  
Vol 30 (1) ◽  
pp. 106-115 ◽  
Author(s):  
Guadalupe Sabio ◽  
Norman J. Kennedy ◽  
Julie Cavanagh-Kyros ◽  
Dae Young Jung ◽  
Hwi Jin Ko ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
High Fat Diet ◽  
Wild Type ◽  
High Fat ◽  
Akt Activation ◽  
Peripheral Insulin Resistance ◽  
Diet Induced Obesity

ABSTRACT Obesity caused by feeding of a high-fat diet (HFD) is associated with an increased activation of c-Jun NH2-terminal kinase 1 (JNK1). Activated JNK1 is implicated in the mechanism of obesity-induced insulin resistance and the development of metabolic syndrome and type 2 diabetes. Significantly, Jnk1 − / − mice are protected against HFD-induced obesity and insulin resistance. Here we show that an ablation of the Jnk1 gene in skeletal muscle does not influence HFD-induced obesity. However, muscle-specific JNK1-deficient (MKO) mice exhibit improved insulin sensitivity compared with control wild-type (MWT) mice. Thus, insulin-stimulated AKT activation is suppressed in muscle, liver, and adipose tissue of HFD-fed MWT mice but is suppressed only in the liver and adipose tissue of MKO mice. These data demonstrate that JNK1 in muscle contributes to peripheral insulin resistance in response to diet-induced obesity.

scholarly journals MGL1 promotes adipose tissue inflammation and insulin resistance by regulating 7/4hi monocytes in obesity

2009 ◽  
Vol 206 (13) ◽  
pp. 3143-3156 ◽  
Author(s):  
Daniel J. Westcott ◽  
Jennifer B. DelProposto ◽  
Lynn M. Geletka ◽  
Tianyi Wang ◽  
Kanakadurga Singer ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Critical Role ◽  
Alternatively Activated Macrophages ◽  
Inflammatory Monocytes ◽  
Diet Induced Obesity ◽  
Adipose Tissue Macrophages ◽  
Visceral Adipose

Adipose tissue macrophages (ATMs) play a critical role in obesity-induced inflammation and insulin resistance. Distinct subtypes of ATMs have been identified that differentially express macrophage galactose-type C-type lectin 1 (MGL1/CD301), a marker of alternatively activated macrophages. To evaluate if MGL1 is required for the anti-inflammatory function of resident (type 2) MGL1+ ATMs, we examined the effects of diet-induced obesity (DIO) on inflammation and metabolism in Mgl1−/− mice. We found that Mgl1 is not required for the trafficking of type 2 ATMs to adipose tissue. Surprisingly, obese Mgl1−/− mice were protected from glucose intolerance, insulin resistance, and steatosis despite having more visceral fat. This protection was caused by a significant decrease in inflammatory (type 1) CD11c+ ATMs in the visceral adipose tissue of Mgl1−/− mice. MGL1 was expressed specifically in 7/4hi inflammatory monocytes in the blood and obese Mgl1−/− mice had lower levels of 7/4hi monocytes. Mgl1−/− monocytes had decreased half-life after adoptive transfer and demonstrated decreased adhesion to adipocytes indicating a role for MGL1 in the regulation of monocyte function. This study identifies MGL1 as a novel regulator of inflammatory monocyte trafficking to adipose tissue in response to DIO.

scholarly journals RGC32 deficiency protects against high-fat diet-induced obesity and insulin resistance in mice

2014 ◽  
Vol 224 (2) ◽  
pp. 127-137 ◽  
Author(s):  
Xiao-Bing Cui ◽  
Jun-Na Luan ◽  
Jianping Ye ◽  
Shi-You Chen
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Adipose Tissue ◽  
High Fat Diet ◽  
Tolerance Test ◽  
High Fat ◽  
Diet Induced Obesity

Obesity is an important independent risk factor for type 2 diabetes, cardiovascular diseases and many other chronic diseases. Adipose tissue inflammation is a critical link between obesity and insulin resistance and type 2 diabetes and a contributor to disease susceptibility and progression. The objective of this study was to determine the role of response gene to complement 32 (RGC32) in the development of obesity and insulin resistance. WT and RGC32 knockout (Rgc32−/− (Rgcc)) mice were fed normal chow or high-fat diet (HFD) for 12 weeks. Metabolic, biochemical, and histologic analyses were performed. 3T3-L1 preadipocytes were used to study the role of RGC32 in adipocytes in vitro. Rgc32−/− mice fed with HFD exhibited a lean phenotype with reduced epididymal fat weight compared with WT controls. Blood biochemical analysis and insulin tolerance test showed that RGC32 deficiency improved HFD-induced dyslipidemia and insulin resistance. Although it had no effect on adipocyte differentiation, RGC32 deficiency ameliorated adipose tissue and systemic inflammation. Moreover, Rgc32−/− induced browning of adipose tissues and increased energy expenditure. Our data indicated that RGC32 plays an important role in diet-induced obesity and insulin resistance, and thus it may serve as a potential novel drug target for developing therapeutics to treat obesity and metabolic disorders.

scholarly journals Adipose tissue inflammation and metabolic dysfunction: a clinical perspective

2013 ◽  
Vol 15 (1) ◽  
Author(s):  
Charmaine S. Tam ◽  
Leanne M. Redman
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Low Grade ◽  
Metabolic Dysfunction ◽  
Adipose Tissue Inflammation ◽  
Tissue Inflammation ◽  
Proinflammatory Mediators ◽  
Low Grade Inflammation

AbstractObesity is characterized by a state of chronic low-grade inflammation due to increased immune cells, specifically infiltrated macrophages into adipose tissue, which in turn secrete a range of proinflammatory mediators. This nonselective low-grade inflammation of adipose tissue is systemic in nature and can impair insulin signaling pathways, thus, increasing the risk of developing insulin resistance and type 2 diabetes. The aim of this review is to provide an update on clinical studies examining the role of adipose tissue in the development of obesity-associated complications in humans. We will discuss adipose tissue inflammation during different scenarios of energy imbalance and metabolic dysfunction including obesity and overfeeding, weight loss by calorie restriction or bariatric surgery, and conditions of insulin resistance (diabetes, polycystic ovarian syndrome).

scholarly journals Protocatechuic acids protects against high glucose- induced insulin resistance in human visceral adipose tissue

2016 ◽  
Vol 62 (5) ◽  
pp. 45-46
Author(s):  
Paulina Ormazabal ◽  
Beatrice Scazzocchio ◽  
Rosaria Varì ◽  
Annunziata Iacovelli ◽  
Roberta Masella
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Visceral Adipose Tissue ◽  
High Glucose ◽  
Protective Role ◽  
Insulin Sensitizer ◽  
20 Nm ◽  
Visceral Adipose

Adipocytes exposed to high glucose concentrations exhibit impaired insulin signaling. Binding of insulin to its membrane receptor activates insulin metabolic pathway leading to IRS-1 and AKT phosphorylations. The accumulation of visceral adipose tissue (VAT) correlates with insulin resistance and metabolic syndrome. Anthocyanins (ACN) are bioactive food compounds of great nutritional interest. We have shown that protocatechuic acid (PCA), a major metabolite of ACN, might exert insulin-sensitizer activities in human visceral adipose tissue. The aim of this work was to define the protective role of PCA against insulin-resistance induced by high glucose in VAT.Methodology: VAT obtained from control subject (BMI≤25) were separated in four experimental groups: i) PCA: samples treated for 24 h with 100 μM PCA, ii) GLU: VAT treated with 30 mM glucose for 24 h, iii) PCA+GLU: 1 hour incubation with 100 μM PCA before adding glucose (30 mM, 24 h), iv) CTR: vehicle. After treatment, VAT groups were (or not) acutely stimulated with insulin (20 nM, 20 min). Tyr-IRS-1 and Ser-Akt phosphorylations were assessed by Western blotting (WB) in basal or insulin stimulated tissues in all experimental groups. Samples were assessed for IRS-1, IR, Akt and GLUT4 protein content by WB. Results: No differences in protein contents between experimental groups were found. GLU tissues showed a lower increment in insulin-stimulated phosphorylation of IRS-1 and Akt compared to CTR and PCA samples. This impaired activation was completely reversed by the pretreatment with PCA.Conclusion: An in-vitro insulin-resistance condition induced by high glucose was established in biopsies of VAT. PCA restores the ability of GLU-tissues to fully respond to insulin by increasing IRS-1 and Akt phosphorylations. These results confirm the insulin-sensitizer effect of PCA on VAT previously reported by our group. An anthocyanin rich diet might help to protect against insulin-resistance in VAT.

scholarly journals Effects of food pattern change and physical exercise on cafeteria diet-induced obesity in female rats

2012 ◽  
Vol 108 (8) ◽  
pp. 1511-1518 ◽  
Author(s):  
Jéferson F. Goularte ◽  
Maria B. C. Ferreira ◽  
Gilberto L. Sanvitto
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
Physical Exercise ◽  
Energy Intake ◽  
Liver Weight ◽  
Cafeteria Diet ◽  
Chow Diet ◽  
Diet Induced Obesity ◽  
Visceral Adipose

Obesity affects a large number of people around the world and appears to be the result of changes in food intake, eating habits and physical activity levels. Changes in dietary patterns and physical exercise are therefore strongly recommended to treat obesity and its complications. The present study tested the hypothesis that obesity and metabolic changes produced by a cafeteria diet can be prevented with dietary changes and/or physical exercise. A total of fifty-six female Wistar rats underwent one of five treatments: chow diet; cafeteria diet; cafeteria diet followed by a chow diet; cafeteria diet plus exercise; cafeteria diet followed by a chow diet plus exercise. The duration of the experiment was 34 weeks. The cafeteria diet resulted in higher energy intake, weight gain, increased visceral adipose tissue and liver weight, and insulin resistance. The cafeteria diet followed by the chow diet resulted in energy intake, body weight, visceral adipose tissue and liver weight and insulin sensitivity equal to that of the controls. Exercise increased total energy intake at week 34, but produced no changes in the animals' body weight or adipose tissue mass. However, insulin sensitivity in animals subjected to exercise and the diet was similar to that of the controls. The present study found that exposure to palatable food caused obesity and insulin resistance and a diet change was sufficient to prevent cafeteria diet-induced obesity and to maintain insulin sensitivity at normal levels. In addition, exercise resulted in normal insulin sensitivity in obese rats. These results may help to develop new approaches for the treatment of obesity and type 2 diabetes mellitus.

scholarly journals Progression from High Insulin Resistance to Type 2 Diabetes Does Not Entail Additional Visceral Adipose Tissue Inflammation

PLoS ONE ◽  
2012 ◽  
Vol 7 (10) ◽  
pp. e48155 ◽  
Author(s):  
Nuria Barbarroja ◽  
Chary Lopez-Pedrera ◽  
Lourdes Garrido-Sanchez ◽  
Maria Dolores Mayas ◽  
Wilfredo Oliva-Olivera ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Adipose Tissue ◽  
Visceral Adipose Tissue ◽  
Adipose Tissue Inflammation ◽  
Tissue Inflammation ◽  
High Insulin ◽  
Visceral Adipose

scholarly journals Important role of fat tissue hormones in development of comorbid chronic pancreatitis and obesity

2017 ◽  
Vol 37 (3) ◽  
pp. 30-35
Author(s):  
T. N. Hristich
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Adipose Tissue ◽  
Chronic Pancreatitis ◽  
Pancreatic Disease ◽  
Pancreatic Tissue ◽  
Visceral Adipose

Aim of this paper is to consider the role of hormones of the adipose tissue in mechanisms of obesity, metabolic syndrome, type 2 diabetes mellitus upon chronic pancreatitis. Materials and methods. The literature review indicates the value of visceral fat in the development of insulin resistance, dyslipidemia, including atherogenic one, taking into account the possible infiltration of pancreatic tissue by adipocytes. Participation of some adipocytokines of adipose tissue in the development of obesity upon chronic pancreatitis is highlighted. It is shown that in some cases the hormones of visceral adipose tissue, penetrating through the portal vein to the liver and then to the pancreas, aggravated the course of systemic chronic inflammation of the inherent chronic pancreatitis, promote steatosis and development of fatty pancreatic disease. Conclusion. Literary sources indicate the leading role of visceral adipose tissue and its hormones in the formation of obesity in chronic pancreatitis. Due to the infiltration of the pancreatic tissue by adipocytes, lipoidosis and steatosis develop. With the progression of the process type 2 diabetes mellitus, fatty liver or pancreatic disease, or cancer of these orhans. Consequently, there is a need for serious differentiated preventive and curative measures aimed at promoting a healthy lifestyle to improve the quality of life of patients suffering from chronic pancreatitis.

scholarly journals Significant role of fat tissue hormones in development of comorbid chronic pancreatitis and obesity

2018 ◽  
Vol 39 (1) ◽  
pp. 4-9
Author(s):  
T. N. Hristich
Keyword(s):  
Type 2 Diabetes ◽  
Adipose Tissue ◽  
Chronic Pancreatitis ◽  
Visceral Adipose Tissue ◽  
Healthy Lifestyle ◽  
Pancreatic Disease ◽  
Pancreatic Tissue ◽  
Visceral Adipose

Aim is to consider the role of hormones in the adipose tissue of obesity mechanisms of metabolic syndrome, type 2 diabetes mellitus in chronic pancreatitis. Materials and methods. Literature review indicates the value of visceral fat in the development of insulin resistance, dyslipidemia, including atherogenic one, taking into account the possible infiltration of pancreatic tissue by adipocytes. Participation of some adipocytokines of adipose tissue in the development of obesity in chronic pancreatitis is highlighted. It is shown that in some cases the hormones of visceral adipose tissue, penetrating through the portal vein to the liver and then to the pancreas, aggravated the course of systemic chronic inflammation typical for the inherent chronic pancreatitis, formed steatosis and promoted development of fatty disease of the pancreas. Conclusion. Literary sources show the leading role of visceral adipose tissue and its hormones in the formation of obesity in chronic pancreatitis. Lipoidosis or steatosis develop due to the infiltration of the liver and pancreatic tissue by adipocytes. Upon the progression of the type 2 diabetes, fatty liver or pancreatic disease, or cancer of these organs may develop. Consequently, there is a strong need for a serious differentiated preventive and curative measures aimed at promoting a healthy lifestyle to improve the quality of life of patients suffering from chronic pancreatitis.

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