scholarly journals Hepatocyte-specific activity of TSC22D4 triggers progressive NAFLD by impairing mitochondrial function

2021 ◽  
Author(s):  
Gretchen Wolff ◽  
Minako Sakurai ◽  
Amit Mhamane ◽  
Adriano Maida ◽  
Ioannis K Deligiannis ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Liver Disease ◽  
Single Cell ◽  
Transforming Growth Factor Beta ◽  
Lipid Accumulation ◽  
Transforming Growth Factor ◽  
Specific Activity ◽  
Liver Lipid ◽  
Alcoholic Fatty Liver ◽  
Progressive Liver Disease

Objective: Fibrotic organ responses have recently been identified as long-term complication in diabetes. Indeed, insulin resistance and aberrant hepatic lipid accumulation represent driving features of progressive non-alcoholic fatty liver disease (NAFLD), ranging from simple steatosis and non-alcoholic steatohepatitis (NASH) to fibrosis. Effective pharmacological regimens to stop progressive liver disease are still lacking to-date. Methods: Based on our previous discovery of transforming growth factor beta-like stimulated clone (TSC)22D4 as a key driver of insulin resistance and glucose intolerance in obesity and type diabetes, we generated a TSC22D4-hepatocyte specific knockout line (TSC22D4-HepaKO) and exposed mice to control or NASH diet models. Mechanistic insights were generated by metabolic phenotyping and single cell liver sequencing. Results: Hepatic TSC22D4 expression was significantly correlated with markers of liver disease progression and fibrosis in both murine and human livers. Indeed, hepatic TSC22D4 levels were elevated in human NASH patients as well as in several murine NASH models. Specific genetic deletion of TSC22D4 in hepatocytes led to reduced liver lipid accumulation, improvements in steatosis and inflammation scores and decreased apoptosis in mice. Single cell RNA sequencing revealed a distinct gene signature identifying an upregulation of mitochondrial-related processes. An enrichment of genes involved in the TCA cycle, mitochondrial organization, and triglyceride metabolism underscored the hepatocyte-protective phenotype and overall decreased liver damage as seen in mouse models. Conclusions: Together, our data uncover a new connection between targeted depletion of TSC22D4 and intrinsic metabolic processes in progressive liver disease. Cell-specific reduction of TSC22D4 improves hepatic steatosis, inflammation and promotes hepatocyte survival thus paving the way for further preclinical therapy developments.

scholarly journals Physiological Disturbance in Fatty Liver Energy Metabolism Converges on IGFBP2 Abundance and Regulation in Mice and Men

2020 ◽  
Vol 21 (11) ◽  
pp. 4144 ◽  
Author(s):  
Pia Fahlbusch ◽  
Birgit Knebel ◽  
Tina Hörbelt ◽  
David Monteiro Barbosa ◽  
Aleksandra Nikolic ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Liver Disease ◽  
Energy Metabolism ◽  
Fatty Liver ◽  
Lipid Accumulation ◽  
Fatty Liver Disease ◽  
De Novo ◽  
De Novo Lipogenesis ◽  
Hepatic Insulin Resistance ◽  
Alcoholic Fatty Liver

Fatty liver occurs from simple steatosis with accumulated hepatic lipids and hepatic insulin resistance to severe steatohepatitis, with aggravated lipid accumulation and systemic insulin resistance, but this progression is still poorly understood. Analyses of hepatic gene expression patterns from alb-SREBP-1c mice with moderate, or aP2-SREBP-1c mice with aggravated, hepatic lipid accumulation revealed IGFBP2 as key nodal molecule differing between moderate and aggravated fatty liver. Reduced IGFBP2 expression in aggravated fatty liver was paralleled with promoter hypermethylation, reduced hepatic IGFBP2 secretion and IGFBP2 circulating in plasma. Physiologically, the decrease of IGFBP2 was accompanied with reduced fatty acid oxidation and increased de novo lipogenesis potentially mediated by IGF1 in primary hepatocytes. Furthermore, methyltransferase and sirtuin activities were enhanced. In humans, IGFBP2 serum concentration was lower in obese men with non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) compared to non-obese controls, and liver fat reduction by weight-loss intervention correlated with an increase of IGFBP2 serum levels. In conclusion, hepatic IGFBP2 abundance correlates to its circulating level and is related to hepatic energy metabolism and de novo lipogenesis. This designates IGFBP2 as non-invasive biomarker for fatty liver disease progression and might further provide an additional variable for risk prediction for pathogenesis of fatty liver in diabetes subtype clusters.

scholarly journals High-fat diet leads to key hepatic miRNAs modulation that may drive lipid accumulation in liver that preceds insulin resistance in male mice

2018 ◽  
Author(s):  
Carolina Panzarin ◽  
Adriana Souza Torsoni ◽  
Laís A. de P. Simino ◽  
Mariana C. S. Mancini ◽  
Marina F. Fontana ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Liver Disease ◽  
Lipid Accumulation ◽  
High Fat Diet ◽  
Fatty Liver Disease ◽  
Male Mice ◽  
High Fat ◽  
Alcoholic Fatty Liver ◽  
Prevalence Of Obesity ◽  
Alcoholic Fatty Liver Disease

High-fat diet (HFD) consumption can lead to Non-Alcoholic Fatty Liver Disease (NAFLD), which is characterized by hepatic triglycerides accumulation and is directly associated with the prevalence of obesity in worldwide. Insulin resistance underlies the genesis of both obesity and NAFLD. These mecanisms can be regulated by microRNAs, such as miR-122 and Let-7 in the liver. Therefore, the aim of the present study was to investigate a possible connection between insulin resistance, obesity, NAFLD development and alterations in miR-122 and Let-7 expression in mice fed a HFD.

scholarly journals Lack of ClC-2 Alleviates High Fat Diet-Induced Insulin Resistance and Non-Alcoholic Fatty Liver Disease

2018 ◽  
Vol 45 (6) ◽  
pp. 2187-2198 ◽  
Author(s):  
Dongxia Fu ◽  
Haibin Cui ◽  
Yunna Zhang
Keyword(s):  
Insulin Resistance ◽  
Fatty Acid ◽  
Liver Disease ◽  
Fatty Liver ◽  
Lipid Accumulation ◽  
High Fat Diet ◽  
Fatty Liver Disease ◽  
High Fat ◽  
Alcoholic Fatty Liver ◽  
Alcoholic Fatty Liver Disease

Background/Aims: Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease. This study aims to investigate whether chloride channel 2 (ClC-2) is involved in high fat diet (HFD)-induced NAFLD and possible molecular mechanisms. Methods: ClC-2 expression was liver-specifically downregulated using adeno-associated virus in C57BL/6 mice treated with a chow diet or HFD for 12 weeks. Peripheral blood and liver tissues were collected for biochemical and pathological estimation respectively. Western blotting was applied to detect the protein expressions of lipid synthesis-related enzymes and the phosphorylated level of IRS-1, Akt and mTOR. Results: ClC-2 mRNA level was significantly increased in patients with non-alcoholic steatohepatitis, which positively correlated with the plasma levels of alanine transaminase (ALT), aspartate transaminase (AST) and insulin. Knockdown of ClC-2 in liver attenuated HFD-induced weight gain, obesity, hepatocellular ballooning, and liver lipid accumulation and fibrosis, accompanied by reduced plasma free fatty acid (FFA), triglyceride (TG), total cholesterol (TC), ALT, AST, glucose and insulin levels and homeostasis model of insulin resistance (HOMA-IR) value. Moreover, HFD-treated mice lacking ClC-2 showed inhibited hepatic lipid accumulation via regulating lipid metabolism through decreasing sterol regulatory element binding protein (SREBP)-1c expression and its downstream targeting enzymes such as fatty acid synthase (FAS), HMG-CoA reductase (HMGCR) and acetyl-Coenzyme A carboxylase (ACCα). In addition, in vivo and in vitro results demonstrated that ClC-2 downregulation in HFD-treated mice or HepG2 cells increased the sensitivity to insulin via activation of IRS-1/Akt/mTOR signaling pathway. Conclusion: Our present study reveals a critical role of ClC-2 in regulating metabolic diseases. Mice lacking ClC-2 are associated with a remarkably beneficial metabolic phenotype, suggesting that decreasing ClC-2 may be an attractive therapeutic strategy for the treatment of 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.

Non-alcoholic fatty liver disease and its association with insulin resistance in an obese population

2018 ◽  
Author(s):  
Frederique Van de Velde ◽  
Marlies Bekaert ◽  
Anne Hoorens ◽  
Marleen Praet ◽  
Arsene-Helene Batens ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Liver Disease ◽  
Fatty Liver ◽  
Fatty Liver Disease ◽  
Alcoholic Fatty Liver ◽  
Obese Population ◽  
Alcoholic Fatty Liver Disease
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