scholarly journals Depletion of Prmt1 in Adipocytes Impairs Glucose Homeostasis in Diet-Induced Obesity

2021 ◽  
Author(s):  
Seri Choi ◽  
Dahee Choi ◽  
Yun-Kyung Lee ◽  
Seung Hyun Ahn ◽  
Je Kyung Seong ◽  
...  
Keyword(s):  
Whole Body ◽  
Peripheral Tissues ◽  
Lipid Catabolism ◽  
Diet Induced Obesity ◽  
Insulin Tolerance ◽  
Impaired Insulin ◽  
Lipid Droplet Size ◽  
Mitochondrial Lipid

Protein arginine methyltransferase (PRMT) 1 is involved in the regulation of various metabolic pathways such as glucose metabolism in liver and atrophy in the skeletal muscle. However, the role of PRMT1 in the fat tissues under the disease state has not been elucidated to date. <p>Here, we delineate the function of this protein in adipocytes <i>in vivo</i>. PRMT1 expression was abundant in the white adipose tissues (WAT), which was induced upon high fat diet in mice as well as by obesity in humans. We found that adipocyte-specific depletion of <i>Prmt1</i> resulted in the decreased fat mass without overall changes in body weight in mice. Mechanistically, the depletion of <i>Prmt1</i> in WAT led to the activation of AMPK pathway, which was causal to the increased lipophagy, mitochondrial lipid catabolism and the resultant reduction in lipid droplet size in WAT <i>in vivo</i>. Interestingly, in spite of the increased energy expenditure, we observed a promotion of adipose tissue inflammation and an ectopic accumulation of triglycerides in the peripheral tissues in <i>Prmt1</i> adipocyte-specific knockout mice, which promoted the impaired insulin tolerance that is reminiscent of mouse models of lipodystrophy. These data collectively suggest that PRMT1 prevents WAT from excessive degradation of triglycerides by limiting AMPK-mediated lipid catabolism to control whole body metabolic homeostasis in diet-induced obesity conditions. </p>

scholarly journals Depletion of Prmt1 in Adipocytes Impairs Glucose Homeostasis in Diet-Induced Obesity

2021 ◽  
Author(s):  
Seri Choi ◽  
Dahee Choi ◽  
Yun-Kyung Lee ◽  
Seung Hyun Ahn ◽  
Je Kyung Seong ◽  
...  
Keyword(s):  
Whole Body ◽  
Peripheral Tissues ◽  
Lipid Catabolism ◽  
Diet Induced Obesity ◽  
Insulin Tolerance ◽  
Impaired Insulin ◽  
Lipid Droplet Size ◽  
Mitochondrial Lipid

Protein arginine methyltransferase (PRMT) 1 is involved in the regulation of various metabolic pathways such as glucose metabolism in liver and atrophy in the skeletal muscle. However, the role of PRMT1 in the fat tissues under the disease state has not been elucidated to date. <p>Here, we delineate the function of this protein in adipocytes <i>in vivo</i>. PRMT1 expression was abundant in the white adipose tissues (WAT), which was induced upon high fat diet in mice as well as by obesity in humans. We found that adipocyte-specific depletion of <i>Prmt1</i> resulted in the decreased fat mass without overall changes in body weight in mice. Mechanistically, the depletion of <i>Prmt1</i> in WAT led to the activation of AMPK pathway, which was causal to the increased lipophagy, mitochondrial lipid catabolism and the resultant reduction in lipid droplet size in WAT <i>in vivo</i>. Interestingly, in spite of the increased energy expenditure, we observed a promotion of adipose tissue inflammation and an ectopic accumulation of triglycerides in the peripheral tissues in <i>Prmt1</i> adipocyte-specific knockout mice, which promoted the impaired insulin tolerance that is reminiscent of mouse models of lipodystrophy. These data collectively suggest that PRMT1 prevents WAT from excessive degradation of triglycerides by limiting AMPK-mediated lipid catabolism to control whole body metabolic homeostasis in diet-induced obesity conditions. </p>

scholarly journals Role of 11β-hydroxysteroid dehydrogenase type 1 in the development of atopic dermatitis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Noo Ri Lee ◽  
Beom Jun Kim ◽  
Chung Hyeok Lee ◽  
Young Bin Lee ◽  
Solam Lee ◽  
...  
Keyword(s):  
Atopic Dermatitis ◽  
De Novo ◽  
Hydroxysteroid Dehydrogenase ◽  
Whole Body ◽  
Epidermal Keratinocytes ◽  
Human Epidermal Keratinocytes ◽  
Peripheral Tissues

AbstractGlucocorticoids (GCs) are potent anti-inflammatory drugs, the secretion of which is mediated and controlled by the hypothalamic–pituitary–adrenal axis. However, they are also secreted de novo by peripheral tissues for local use. Several tissues express 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1), including the skin. The inactive GC cortisone is converted by 11β-HSD1 to active GC cortisol, which is responsible for delayed wound healing during a systemic excess of GC. However, the role of 11β-HSD1 in inflammation is unclear. We assessed whether 11β-HSD1 affects the development of atopic dermatitis (AD) in vitro and in vivo. The expression of 11β-HSD1 in the epidermis of AD lesions was higher than that in the epidermis of healthy controls. Knockdown of 11β-HSD1 in human epidermal keratinocytes increased the production of thymic stromal lymphopoietin. In an oxazolone-induced mouse model of AD, localized inhibition of 11β-HSD1 aggravated the development of AD and increased serum cytokine levels associated with AD. Mice with whole-body knockout (KO) of 11β-HSD1 developed significantly worse AD upon induction by oxazolone. We propose that 11β-HSD1 is a major factor affecting AD pathophysiology via suppression of atopic inflammation due to the modulation of active GC in the skin.

scholarly journals Paradoxical Glucose-Sensitizing yet Proinflammatory Effects of Acute ASP Administration in Mice

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Alexandre Fisette ◽  
Pegah Poursharifi ◽  
Katerina Oikonomopoulou ◽  
Mercedes N. Munkonda ◽  
Marc Lapointe ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Whole Body ◽  
Diet Induced Obesity ◽  
Insulin Tolerance ◽  
M1 Macrophage ◽  
Acylation Stimulating Protein ◽  
Inflammatory Processes

Acylation stimulating protein (ASP) is an adipokine derived from the immune complement system, which stimulates fat storage and is typically increased in obesity, type 2 diabetes, and cardiovascular disease. Using a diet-induced obesity (DIO) mouse model, the acute effects of ASP on energy metabolism and inflammatory processesin vivowere evaluated. We hypothesized that ASP would specifically exert proinflammatory effects. C57Bl/6 wild-type mice were put on a high-fat-high-sucrose diet for 12 weeks. Mice were then subjected to both glucose and insulin tolerance tests, each manipulation being preceded by recombinant ASP or vehicle (control) bolus injection. ASP supplementation increased whole-body glucose excursion, and this was accomplished with reduced concomitant insulin levels. However, ASP did not directly alter insulin sensitivity. ASP supplementation induced a proinflammatory phenotype, with higher levels of cytokines including IL-6 and TNF-αin plasma and in adipose tissue, liver, and skeletal muscle mRNA. Additionally, ASP increased M1 macrophage content of these tissues. ASP exerted a direct concentration-dependent role in the migration and M1 activation of cultured macrophages. Altogether, thein vivoandin vitroexperiments demonstrate that ASP plays a role in both energy metabolism and inflammation, with paradoxical whole-body glucose-sensitizing yet proinflammatory effects.

Abstract 1766: Diet-Induced Obesity Causes Inflammation by Activating Toll-Like Receptor 4 Signaling and Downregulates AMPK in Heart

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Hwi Jin Ko ◽  
Dae Young Jung ◽  
Zhexi Ma ◽  
Jason K Kim
Keyword(s):  
Glucose Metabolism ◽  
Whole Body ◽  
Chow Diet ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Myocardial Glucose Metabolism ◽  
Cardiac Inflammation ◽  
Protein Levels ◽  
Diet Induced Obesity

Increasing evidence implicates the role of inflammation in diabetes and complications. Macrophages are shown to infiltrate adipose tissue in obesity, and inflammatory cytokines alter glucose metabolism in peripheral organs. Male C57BL/6 mice were fed high-fat diet (HFD; 55% fat by calories) or chow diet for 6 weeks, and heart samples were taken for analysis (n = 5~7). Chronic HFD increased whole body fat mass, measured by 1 H-MRS, by 3-fold, and elevated plasma IL-6 and TNF-α levels by 40%. Diet-induced obesity caused inflammation in heart and increased macrophage-specific CD68 levels by 5-fold (Fig. 1) (* P < 0.05 vs Chow). Diet-induced cardiac inflammation was associated with significant increases in toll-like receptor 4 (TLR4) and MyD88 levels in heart (Fig. 2). HFD also increased cardiomyocyte SOCS3 levels by more than 3-fold (Fig. 3). Myocardial glucose metabolism was measured using intravenous injection of 2-[ 14 C]deoxyglucose in awake mice (n = 6). Chronic HFD reduced myocardial glucose uptake by 50%, and this was associated with significant reductions in total GLUT4 and GLUT1 protein levels. Further, Thr 172 phosphorylation of AMPK, a critical regulator of energy balance, was markedly reduced in heart following HFD (Fig. 4). These results demonstrate that diet-induced obesity causes macrophage infiltration and inflammation in heart by increasing TLR4 signaling in cardiomyocytes. Similar to the effects of inflammation on peripheral glucose metabolism, diet-induced cardiac inflammation reduced myocardial glucose metabolism by downregulating AMPK and GLUT protein levels. Thus, our findings underscore an important role of inflammation in diabetic heart.

scholarly journals Role of antennary structure of N-linked sugar chains in renal handling of recombinant human erythropoietin

Blood ◽  
1995 ◽  
Vol 86 (11) ◽  
pp. 4097-4104 ◽  
Author(s):  
T Misaizu ◽  
S Matsuki ◽  
TW Strickland ◽  
M Takeuchi ◽  
A Kobata ◽  
...  
Keyword(s):  
Whole Body ◽  
Renal Handling ◽  
Sugar Chain ◽  
Erythroid Progenitor ◽  
Human Erythropoietin ◽  
Sugar Chains ◽  
Effective Transfer ◽  
Branched Structure

To elucidate the role of the branched structure of sugar chains of human erythropoietin (EPO) in the expression of in vivo activity, the pharmacokinetic profile of a less active recombinant human EPO sample (EPO-bi) enriched with biantennary sugar chains was compared with that of a highly active control EPO sample enriched with tetraantennary sugar chains. After an intravenous injection in rats, 125I-EPO-bi disappeared from the plasma with 3.2 times greater total body clearance (Cltot) than control 125I-EPO. Whole-body autoradiography after 20 minutes of administration indicated that the overall distribution of radioactivity is similar, but 125I-EPO-bi showed a higher level of radioactivity in the kidneys than control 125I-EPO. Quantitative determination of radioactivity in the tissues also indicated that radioactivity of 125I-EPO-bi in the kidneys was two times higher than that of control 125I-EPO. The difference in plasma disappearance between 125I-EPO-bi and control 125I-EPO was not observed in bilaterally nephrectomized rats. The distribution of 125I-EPO-bi to bone marrow and spleen was similarly inhibited by simultaneous injection of excess amounts of either the nonlabeled EPO-bi or control EPO. These results indicate that the low in vivo biologic activity of EPO-bi results from rapid clearance from the systemic circulation by renal handling. Thus, the well-branched structure of the N-linked sugar chain of EPO is suggested to play an important role in maintaining its higher plasma level, which guarantees an effective transfer to target organs and stimulation of erythroid progenitor cells.

scholarly journals TLR4-interactor with leucine-rich repeats (TRIL) is involved in diet-induced hypothalamic inflammation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexandre Moura-Assis ◽  
Pedro A. S. Nogueira ◽  
Jose C. de-Lima-Junior ◽  
Fernando M. Simabuco ◽  
Joana M. Gaspar ◽  
...  
Keyword(s):  
Dietary Fats ◽  
Whole Body ◽  
Metabolic Dysfunction ◽  
Diet Induced Obesity ◽  
Hypothalamic Inflammation ◽  
Novel Target ◽  
Tlr4 Activation ◽  
Leucine Rich Repeats ◽  
Body Energy

AbstractObesity and high-fat diet (HFD) consumption result in hypothalamic inflammation and metabolic dysfunction. While the TLR4 activation by dietary fats is a well-characterized pathway involved in the neuronal and glial inflammation, the role of its accessory proteins in diet-induced hypothalamic inflammation remains unknown. Here, we demonstrate that the knockdown of TLR4-interactor with leucine-rich repeats (Tril), a functional component of TLR4, resulted in reduced hypothalamic inflammation, increased whole-body energy expenditure, improved the systemic glucose tolerance and protection from diet-induced obesity. The POMC-specific knockdown of Tril resulted in decreased body fat, decreased white adipose tissue inflammation and a trend toward increased leptin signaling in POMC neurons. Thus, Tril was identified as a new component of the complex mechanisms that promote hypothalamic dysfunction in experimental obesity and its inhibition in the hypothalamus may represent a novel target for obesity treatment.

scholarly journals Regulation of dendritic cell migration and adaptive immune response by leukotriene B4 receptors: a role for LTB4 in up-regulation of CCR7 expression and function

Blood ◽  
2006 ◽  
Vol 109 (2) ◽  
pp. 626-631 ◽  
Author(s):  
Annalisa Del Prete ◽  
Wen-Hai Shao ◽  
Stefania Mitola ◽  
Giuseppe Santoro ◽  
Silvano Sozzani ◽  
...  
Keyword(s):  
Gene Array ◽  
Adaptive Immune Response ◽  
Leukotriene B4 ◽  
Contact Hypersensitivity ◽  
Mrna Levels ◽  
Peripheral Tissues ◽  
Ccr7 Expression ◽  
Adaptive Immune

Abstract Trafficking of dendritic cells (DCs) to peripheral tissues and to secondary lymphoid organs depends on chemokines and lipid mediators. Here, we show that bone marrow–derived DCs (BM-DCs) express functional leukotriene B4 (LTB4) receptors as observed in dose-dependent chemotaxis and calcium mobilization responses. LTB4, at low concentrations, promoted the migration of immature and mature DCs to CCL19 and CCL21, which was associated with a rapid (30-minute) increase of CCR7 expression at the membrane level. At longer incubation times (6 hours), gene array analysis revealed a promoting role of LTB4, showing a significant increase of CCR7 and CCL19 mRNA levels. BM-DCs cultured from BLT1−/− or BLT1/2−/− mice showed a normal phenotype, but in vivo BLT1/2−/−DCs showed dramatic decrease in migration to the draining lymph nodes relative to wild-type (WT) DCs. Consistent with these observations, BLT1/2−/− mice showed a reduced response in a model of 2,4-dinitro-fluorobenzene (DNFB)–induced contact hypersensitivity. Adoptive transfer of 2,4-dinitrobenzene sulfonic acid (DNBS)–pulsed DCs directly implicated the defect in DC migration to lymph node with the defect in contact hypersensitivity. These results provide strong evidence for a role of LTB4 in regulating DC migration and the induction of adaptive immune responses.

Impaired insulin action but normal insulin receptor activity in diabetic rat liver: effect of vanadate

1990 ◽  
Vol 258 (3) ◽  
pp. E459-E467 ◽  
Author(s):  
O. Blondel ◽  
J. Simon ◽  
B. Chevalier ◽  
B. Portha
Keyword(s):  
Insulin Receptor ◽  
Insulin Action ◽  
Diabetic Rats ◽  
Receptor Kinase ◽  
Peripheral Tissues ◽  
Impaired Insulin ◽  
Insulin Dependent ◽  
Insulin Receptor Kinase ◽  
Impaired Insulin Action

In vivo insulin resistance is a characteristic of the liver and peripheral tissues in 10-wk-old female rats with non-insulin-dependent diabetes induced by streptozotocin given on day 5 after birth. Oral administration of vanadate (0.2 mg/ml) for 20 days in the diabetic rats lowered their plasma glucose levels to normal values without affecting their basal plasma insulin levels. In the basal state as well as after submaximal or maximal hyperinsulinemia (euglycemic clamp studies), peripheral glucose utilization and hepatic glucose production in vivo were normalized in the diabetic rats after the vanadate treatment. In wheat germ agglutinin purified receptors, 125I-labeled porcine insulin binding, basal and insulin-stimulated insulin receptor kinase activities for both the autophosphorylation of the beta-subunit and the phosphorylation of the artificial substrate poly (Glu-Tyr) 4:1, were found identical in diabetic and control rats, treated or not with vanadate. Liver phosphoenolpyruvate carboxykinase activity was significantly enhanced in untreated diabetic rats (P less than 0.01) as compared with control rats and returned to normal values after the 20-day vanadate treatment. Thus, in that model of non-insulin-dependent diabetes, 1) oral vanadate exerts a corrective insulin-like effect on impaired insulin action both at the level of liver and peripheral tissues, 2) impaired insulin action with no alteration of the insulin receptor tyrosine kinase is observed in the liver of untreated rats, and 3) corrective effect of vanadate on liver glucose metabolism is probably distal to the insulin receptor kinase activity.

Studies of the antibody-dependent killing of schistosomula of Schistosoma mansoni employing haptenic target antigens. Analysis of mechanisms responsible for the rejection of parasites in vivo

Parasitology ◽  
1981 ◽  
Vol 83 (3) ◽  
pp. 543-558
Author(s):  
Gina Moser ◽  
F. von Lichtenberg ◽  
A. Sher
Keyword(s):  
Schistosoma Mansoni ◽  
Passive Immunization ◽  
Early Response ◽  
Challenge Infection ◽  
Delayed Hypersensitivity ◽  
Whole Body ◽  
Hypersensitivity Response ◽  
Time Points

SUMMARYSchistosomula, surface labelled with trinitrophenyl (TNP) target antigens were tested for their susceptibility to killing by humoral- or cell-mediated anti-TNP effector mechanisms in vivo. It was found that mice passively immunized with anti-TNP serum effectively rejected an intravenous (i.v.) challenge infection with TNP-labelled schistosomula. In contrast, mice which demonstrated a strong TNP-specific, delayed hypersensitivity response to the haptenated larvae as evidenced by ear swelling, were unable to eliminate the same challenge infection. Significant passive immunization against TNP-labelled schistosomula was shown to require microlitre quantities of anti-TNP serum and could be conferred with an IgG fraction purified from the serum. The role of cells in the antibody-dependent rejection of TNP-labelled schistosomula was investigated using histopathological methods. In passively immunized mice, haptenated larvae elicited neutrophil-enriched focal reactions in the lungs and showed evidence of degeneration as early as 2 h after injection. These cellular reactions were not observed in recipients which had received prior whole-body irradiation. Nevertheless, by 24 h TNP-labelled larvae were found to have been killed in the lungs of the irradiated mice despite the absence of significant cellular attack. The above observations suggest that the antibody-dependent destruction of haptenated schistosomula results from two overlapping responses, an early response mediated by radio-sensitive cells and a second, radio-resistant response manifesting its effects at later time points. Since mice genetically deficient in the fifth component of complement fail to develop the later response, it probably reflects the effect of the lytic pathway of complement on the parasite.

Copper transport in rats involving a new plasma protein

1985 ◽  
Vol 249 (1) ◽  
pp. E77-E88 ◽  
Author(s):  
K. C. Weiss ◽  
M. C. Linder
Keyword(s):  
Time Course ◽  
Specific Activity ◽  
High Specific Activity ◽  
Apparent Molecular Weight ◽  
Female Rats ◽  
Whole Body ◽  
Peripheral Tissues ◽  
Chelex 100

The time course of distribution of high-specific activity 67CuCl2 to tissues and plasma components was followed in adult, female rats. Immediately after intubation or injection, tracer 67Cu associated with two components of the blood plasma separable on columns of Sephadex G-150: albumin and another (larger) component, which was not ceruloplasmin. The latter, tentatively named transcuprein, had an apparent molecular weight of 270,000 and a high affinity for Cu2+, as judged by processing through Chelex-100, dilution, and exchange with albumin copper, in vitro and in vivo. It was capable of donating copper to tumor cells in serum-free medium. Analysis of "cold" plasma by furnace atomic absorption confirmed the presence of 10-15% of plasma copper in this peak. Plots of percent dose and 67Cu specific activity against time showed that copper followed a very specific pathway after binding to albumin and transcuprein, entering mainly the liver, then reappearing in the plasma on ceruloplasmin, and then achieving peak distribution in peripheral tissues (muscles, brain, etc.). 67Cu disappeared from liver and kidney with an apparent half-life of 4.5 days, the same exponential rate found for whole body turnover. Apparent turnover of ceruloplasmin copper was more rapid. Even after 7-12 days, tracer copper in plasma was still found exclusively with ceruloplasmin. The results indicate that copper follows a carefully prescribed path, on entering the blood and binding to a new transport protein.

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