scholarly journals Update on the synergistic effect of HSL and insulin in the treatment of metabolic disorders

2019 ◽  
Vol 10 ◽  
pp. 204201881987730 ◽  
Author(s):  
Yu-Long Lan ◽  
Jia-Cheng Lou ◽  
Wen Lyu ◽  
Bo Zhang
Keyword(s):  
Insulin Resistance ◽  
Fatty Liver ◽  
Energy Demand ◽  
Insulin Injection ◽  
Current Data ◽  
Hormone Sensitive Lipase ◽  
Future Research ◽  
Metabolic Complications ◽  
Mutual Regulation ◽  
Impaired Insulin Action

Hormone-sensitive lipase (HSL) is one of the three lipases in adipose tissue present during periods of energy demand. HSL is tightly controlled by insulin regulation via the central and peripheral systems. The suppressive effects of insulin on HSL are also associated with complex crosstalk with other pathways in the metabolic network. Because impaired insulin action is the driving force behind the pathogenesis of diabetes and other metabolic complications, elucidation of the intricate relationships between HSL and insulin may provide an in-depth understanding of these pandemic diseases and potentially identify strategies to inhibit disease development. Insulin not only differentially regulates HSL isoform transcription but also post-transcriptionally affects HSL phosphorylation by stimulating PKA and endothelin (ET-1), and controls its expression indirectly via regulating the activity of growth hormone (GH). In addition, a rapid elevation of HSL levels was detected after insulin injection in patients, which suggests that the inhibitory effects of insulin on HSL can be overridden by insulin-induced hypoglycemia. Conversely, individuals with hereditary HSL deficiency, and animals with experimental HSL deletion, showed major disruptions in mRNA/protein expression in insulin signaling pathways, ultimately leading to insulin resistance, diabetes, and fatty liver. Notably, HSL inactivation could cause insulin-independent fatty liver, while insulin resistance induced by HSL deficiency may further aggravate disease progression. The common beliefs that HSL is the overall rate-limiting enzyme in lipolysis and that insulin is an inhibitor of HSL have been challenged by recent discoveries; therefore, a renewed examination of their relationships is required. In this review, by analyzing current data related to the role of, and mutual regulation between, HSL and insulin and discussing unanswered questions and disparities in different lines of studies, the authors intend to shed light on our understanding of lipid metabolism and provide a rational basis for future research in drug development.

scholarly journals Lipodystrophies—Disorders of the Fatty Tissue

2020 ◽  
Vol 21 (22) ◽  
pp. 8778
Author(s):  
Birgit Knebel ◽  
Dirk Müller-Wieland ◽  
Jorg Kotzka
Keyword(s):  
Insulin Resistance ◽  
Fatty Liver ◽  
Molecular Mechanisms ◽  
Clinical Manifestations ◽  
Fat Distribution ◽  
Fat Cells ◽  
Fatty Tissue ◽  
Loss Of Function ◽  
Metabolic Complications ◽  
Crucial Difference

Lipodystrophies are a heterogeneous group of physiological changes characterized by a selective loss of fatty tissue. Here, no fat cells are present, either through lack of differentiation, loss of function or premature apoptosis. As a consequence, lipids can only be stored ectopically in non-adipocytes with the major health consequences as fatty liver and insulin resistance. This is a crucial difference to being slim where the fat cells are present and store lipids if needed. A simple clinical classification of lipodystrophies is based on congenital vs. acquired and generalized vs. partial disturbance of fat distribution. Complications in patients with lipodystrophy depend on the clinical manifestations. For example, in diabetes mellitus microangiopathic complications such as nephropathy, retinopathy and neuropathy may develop. In addition, due to ectopic lipid accumulation in the liver, fatty liver hepatitis may also develop, possibly with cirrhosis. The consequences of extreme hypertriglyceridemia are typically acute pancreatitis or eruptive xanthomas. The combination of severe hyperglycemia with dyslipidemia and signs of insulin resistance can lead to premature atherosclerosis with its associated complications of coronary heart disease, peripheral vascular disease and cerebrovascular changes. Overall, lipodystrophy is rare with an estimated incidence for congenital (<1/1.000.000) and acquired (1–9/100.000) forms. Due to the rarity of the syndrome and the phenotypic range of metabolic complications, only studies with limited patient numbers can be considered. Experimental animal models are therefore useful to understand the molecular mechanisms in lipodystrophy and to identify possible therapeutic approaches.

scholarly journals Defective FXR-SHP Regulation in Obesity Aberrantly Increases miR-802 Expression, Promoting Insulin Resistance and Fatty Liver

2021 ◽  
Author(s):  
Sunmi Seok ◽  
Hao Sun ◽  
Young-Chae Kim ◽  
Byron Kemper ◽  
Jongsook Kim Kemper
Keyword(s):  
Insulin Resistance ◽  
Fatty Liver ◽  
Farnesoid X Receptor ◽  
Dependent Manner ◽  
Obese Mice ◽  
Metabolic Complications ◽  
Alcoholic Fatty Liver ◽  
Beneficial Effects ◽  
Elevated Expression ◽  
Glucose And Lipid Homeostasis

Aberrantly elevated expression in obesity of microRNAs (miRs), including miR-802, contributes to obesity-associated metabolic complications but the mechanisms underlying the elevated expression are unclear. Farnesoid-X-Receptor (FXR), a key regulator of hepatic energy metabolism, has great potential for treatment of obesity-related diseases. We examined whether a nuclear receptor cascade involving FXR and FXR-induced Small Heterodimer Partner (SHP) regulates expression of <i>miR-802</i> to maintain glucose and lipid homeostasis. Hepatic miR-802 levels are increased in FXR-knockout (KO) or SHP-KO mice and are decreased by activation of FXR in a SHP-dependent manner. Mechanistically, transactivation of <i>miR-802 </i>by<i> </i>Aromatic Hydrocarbon Receptor (AHR) is inhibited by SHP. In obese mice, activation of FXR by obeticholic acid treatment reduced miR-802 levels and improved insulin resistance and hepatosteatosis, but these beneficial effects were largely abolished by overexpression of miR-802. In non-alcoholic fatty liver disease patients and obese mice, occupancy of SHP is reduced and that of AHR is modestly increased at the <i>miR-802</i> promoter, consistent with elevated hepatic miR-802 expression. These results demonstrate that normal inhibition of <i>miR-802</i> by FXR-SHP is defective in obesity, resulting in increased <i>miR-802</i> levels, insulin resistance and fatty liver. This FXR-SHP-miR-802 pathway may present novel targets for treating type 2 diabetes and NAFLD.

scholarly journals Defective FXR-SHP Regulation in Obesity Aberrantly Increases miR-802 Expression, Promoting Insulin Resistance and Fatty Liver

2021 ◽  
Author(s):  
Sunmi Seok ◽  
Hao Sun ◽  
Young-Chae Kim ◽  
Byron Kemper ◽  
Jongsook Kim Kemper
Keyword(s):  
Insulin Resistance ◽  
Fatty Liver ◽  
Farnesoid X Receptor ◽  
Dependent Manner ◽  
Obese Mice ◽  
Metabolic Complications ◽  
Alcoholic Fatty Liver ◽  
Beneficial Effects ◽  
Elevated Expression ◽  
Glucose And Lipid Homeostasis

Aberrantly elevated expression in obesity of microRNAs (miRs), including miR-802, contributes to obesity-associated metabolic complications but the mechanisms underlying the elevated expression are unclear. Farnesoid-X-Receptor (FXR), a key regulator of hepatic energy metabolism, has great potential for treatment of obesity-related diseases. We examined whether a nuclear receptor cascade involving FXR and FXR-induced Small Heterodimer Partner (SHP) regulates expression of <i>miR-802</i> to maintain glucose and lipid homeostasis. Hepatic miR-802 levels are increased in FXR-knockout (KO) or SHP-KO mice and are decreased by activation of FXR in a SHP-dependent manner. Mechanistically, transactivation of <i>miR-802 </i>by<i> </i>Aromatic Hydrocarbon Receptor (AHR) is inhibited by SHP. In obese mice, activation of FXR by obeticholic acid treatment reduced miR-802 levels and improved insulin resistance and hepatosteatosis, but these beneficial effects were largely abolished by overexpression of miR-802. In non-alcoholic fatty liver disease patients and obese mice, occupancy of SHP is reduced and that of AHR is modestly increased at the <i>miR-802</i> promoter, consistent with elevated hepatic miR-802 expression. These results demonstrate that normal inhibition of <i>miR-802</i> by FXR-SHP is defective in obesity, resulting in increased <i>miR-802</i> levels, insulin resistance and fatty liver. This FXR-SHP-miR-802 pathway may present novel targets for treating type 2 diabetes and NAFLD.

scholarly journals WW domain-binding protein 2 overexpression prevents diet-induced liver steatosis and insulin resistance through AMPKβ1

2021 ◽  
Vol 12 (3) ◽  
Author(s):  
Zhe Zheng ◽  
Yue Li ◽  
Siyuan Fan ◽  
Jie An ◽  
Xi Luo ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Liver Disease ◽  
Fatty Liver ◽  
Binding Protein ◽  
Liver Steatosis ◽  
Fat Deposition ◽  
Liver Fat ◽  
Future Research ◽  
Ww Domain ◽  
Important Relationship

AbstractNonalcoholic fatty liver disease (NAFLD) is prevalent clinically and can lead to more serious chronic liver disease. However, the pathological mechanism is still unclear, and thus, there are no approved drugs on the market. Transcriptional coactivator WW domain-binding protein 2 (WBP2) is a newly discovered oncogene that has an important relationship with the occurrence and development of breast cancer and mediates the interaction between Wnt and various other signaling pathways. The expression level of WBP2 was decreased in NAFLD. Overexpression of WBP2 with AAV in vivo alleviated liver fat deposition and insulin resistance induced by a high-fat diet (HFD). Knockdown of WBP2 with AAV aggravated HFD-induced fatty liver and insulin resistance. In vitro experiments showed that in the human normal hepatocyte cell line LO2 and primary hepatocytes isolated from mice, overexpression of WBP2 reduced fat deposition, and knocking out or knocking down WBP2 aggravated PA-induced fat deposition. Through mass spectrometry, we found that WBP2 can bind to AMPKβ1, and by mutating AMPKβ1, we found that WBP2 can induce phosphorylation of AMPKβ1 at S108 and then activate the AMPK pathway to affect lipid metabolism. The effect of WBP2 on NAFLD provides a possible new direction for future research on NAFLD.

Therapeutic Effect of Metformin and Vitamin E Versus Prescriptive Diet in Obese Adolescents with Fatty Liver

2011 ◽  
Vol 81 (6) ◽  
pp. 398-406 ◽  
Author(s):  
Akcam ◽  
Boyaci ◽  
Pirgon ◽  
Kaya ◽  
Uysal ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Vitamin E ◽  
Fatty Liver ◽  
Liver Steatosis ◽  
Tnf Alpha ◽  
Dietary Advice ◽  
Model Assessment ◽  
Fasting Insulin ◽  
Alcoholic Fatty Liver ◽  
Obese Adolescents

Objective: The aim of the study was to determine whether metformin or vitamin E treatment for six months is effective in reducing body weight, blood pressure, and also ameliorating insulin resistance, adiponectin, and tumor necrosis factor (TNF)-alpha in obese adolescents with non-alcoholic fatty liver disease (NAFLD). Methods: Sixty-seven obese adolescents with liver steatosis (age range, 9 - 17 years) were included in the study. The metformin group received an 850-mg dose of metformin daily and the vitamin E group received 400 U vitamin E /daily, in capsule form for 6 months, plus an individually tailored diet, exercise, and behavioral therapy. Results: After 6 months later, there was a significant decline in body mass index, and fasting insulin and homeostatic model assessment (HOMA) values in all three groups. Moreover, in comparingson of changes in HOMA among the groups, the metformin- treated group showed significantly improved metabolic control and insulin sensitivity (HOMA) at the end of the study. There were no significant differences for changes of adiponectin, TNF-alpha, in all three groups after 6 months study. Conclusion: These data suggest that metformin treatment is more effective than dietary advice and vitamin E treatment in reducing insulin resistance, and also in ameliorating metabolic parameters such as fasting insulin and lipid levels, in obese adolescents having NAFLD.

Non-Alcoholic Fatty Liver Disease in Overweight Children and its Relationship with Retinol Serum Levels

2008 ◽  
Vol 78 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Suano de Souza ◽  
Silverio Amancio ◽  
Saccardo Sarni ◽  
Sacchi Pitta ◽  
Fernandes ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Liver Disease ◽  
Fatty Liver ◽  
Lipid Profile ◽  
Fatty Liver Disease ◽  
Thiobarbituric Acid ◽  
Serum Levels ◽  
Control Group ◽  
Alcoholic Fatty Liver ◽  
Alcoholic Fatty Liver Disease

Objectives: To evaluate the frequency of non-alcoholic fatty liver disease, the retinol serum levels, lipid profile, and insulin resistance in overweight/obese children. To relate these biochemical variables with the risk of this disease in the population studied. Methods: The study was cross-sectional and prospective, with 46 overweight/obese school children (28 female, 18 male; mean age 8.6 years). The control group consisted of 45 children, paired by age and gender. Hepatic steatosis, evaluated by ultrasound, was classified as normal, mild, moderate, or severe. Also evaluated were serum retinol levels; thiobarbituric acid reactive substances; lipid profile; and fasting glucose and serum insulin levels, used for the calculation of the Homeostasis Model Assessment. Results: Hepatic ultrasound alterations were found in 56.5% and 48,9% of the overweight/obese and control group children, respectively. Presence of obesity was associated with high levels of triglycerides (OR = 4.6; P = 0.002). In the studied children, the risk of steatosis was related to a trend to a higher percentage of retinol inadequacy (OR = 2.8; p = 0.051); there was no association with thiobarbituric acid reactive substances, lipid profile, or insulin resistance. Conclusions: The high frequency of non-alcoholic fatty liver disease in both groups, evaluated by hepatic ultrasound, in low-socioeconomic level children, independent of nutritional condition and without significant association with insulin resistance, emphasizes that especially in developing countries, other risk factors such as micronutrient deficiencies (e.g. vitamin A) are involved.

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