Exercise intensity impacts the improvement of metabolic dysfunction-associated steatotic liver disease via variations of monoacylglycerol O-acyltransferase 1 expression.

BACKGROUND: The involvement of monoacylglycerol O-acyltransferase 1 (MOGAT1) in the pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD) has been recognized. While exercise is recommended for the improvement of obesity and MASLD, the impact of exercise intensity remains unclear. This study aimed to examine the influence of exercise intensity on MOGAT1 expression in high-fat diet (HFD)-induced obese mice with MASLD. METHOD: Male C57BL/6 mice aged 6 weeks were subjected to either a regular or HFD with 60 % fat content for 8 weeks. The mice were categorized into 5 groups based on their diet and exercise intensity: normal diet group (ND), HFD group, low-intensity exercise with HFD group (HFD+LIE), moderate-intensity exercise with HFD group (HFD+MIE), and high-intensity exercise (HIE) with HFD group (HFD+HIE). The duration of running was adjusted to ensure uniform exercise load across groups (total distance = 900 m): HFD+LIE at 12 m/min for 75 min, HFD+MIE at 15 m/min for 60 min, and HFD+HIE at 18 m/min for 50 min. RESULTS: Lipid droplet size and MASLD activity score were significantly lower in the HFD+HIE group compared to other exercise-intensity groups (p < 0.05). Among the 3 intensity exercise groups, the lowest MOGAT1 protein expression was found in the HFD+HIE group (p < 0.05). CONCLUSION: This study reveals that high-intensity exercise has the potential to mitigate MASLD development, partly attributed to the downregulation of MOGAT1 expression.

Aerobic exercise reduces hepatic lipid deposition in non-alcoholic fatty liver disease / 中华物理医学与康复杂志

Objective:To observe any effect of aerobic exercise on lipid deposition in the liver and monoacylglycerol O-acyltransferase 1 (MGAT1) signaling in non-alcoholic fatty liver disease (NAFLD).Methods:Male Sprague-Dawley rats were fed a 45% diet fat for 6 weeks, after which they were confirmed to have NAFLD. The rats were then randomly divided into an exercise group, a sedentary group and a diet adjustment group. The exercise and sedentary groups remained on the high-fat diet, but the exercise group underwent 8 weeks of aerobic exercise, while the diet adjustment group returned to a normal diet without any exercise. After the intervention, lipid accumulation in liver tissues was detected by hematoxylin-eosin staining and hepatic steatosis indices were calculated. Liver MGAT1 and the expression of peroxisome proliferator activated receptor γ (PPARγ) protein were detected using western blotting.Results:Liver steatosis indices in the exercise and the diet adjustment groups had decreased significantly after the eight weeks. The expression of MGAT1 protein had decreased significantly in the exercise group and the expression of PPARγ protein had increased significantly. Compared with the sedentary group, no significant changes were observed in the expression of MGAT1 protein in the livers of the diet adjustment group, though their average PPARγ protein expression had increased significantly. Compared with the diet adjustment group, the average liver steatosis index had increased significantly in the exercise group, but the expression of MGAT1 protein had decreased significantly.Conclusions:Aerobic exercise can significantly improve liver lipid deposition in NAFLD, at least in rats. The mechanism may be related to inhibition of the MGAT1 signal pathway. Aerobic exercise may be a rehabilitation intervention for NAFLD patients.

Regular moderate aerobic exercise improves high-fat diet-induced nonalcoholic fatty liver disease via monoacylglycerol O-acyltransferase 1 pathway suppression.

PURPOSE: Monoacylglycerol O-acyltransferase 1 (MGAT1) is reported to play a key role in the development of diet-induced nonalcoholic fatty liver disease (NAFLD). Thus, this study investigated the effect of exercise on suppression of the MGAT1 pathway in NAFLD tissue of high-fat diet (HFD)-induced obese rats. METHODS: Male Sprague-Dawley rats were fed an HFD containing 45% fat for 6 weeks. Upon confirmation that NAFLD had been induced in the obese animals, they were divided into HFD-fed groups provided with exercise (HFD + EXE) or without exercise (HFD) and a group given dietary adjustment (DA) only, for a further 6 weeks of intervention treatment. The 6-week regular moderate aerobic exercise consisted of an accommodation phase with increasing exercise. Lipid accumulation in the liver tissue was determined by Oil Red O staining. The MGAT1 and liver lipogenic gene mRNA levels were measured by qPCR, and their protein levels by western blot assay. RESULTS: Oil Red O staining showed that NAFLD was successfully induced by HFD-fed. The gene expression of MGAT1 was significantly lower in HFD + EXE than HFD. However, there was no significant difference between HFD + EXE and DA. The protein expression of MGAT1 was significantly lower in HFD + EXE than both HFD and DA. Messenger RNA and protein expression of other lipogenic genes were not different among groups. These data indicate that exercise suppresses MGAT1 pathway regardless of HFD feeding; in part, this effect could be greater than DA. CONCLUSION: Our data suggest that exercise can improve NAFLD, which is probably due to suppression of MGAT1 pathway.

Dataset of the human homologues and orthologues of lipid-metabolic genes identified as DAF-16 targets their roles in lipid and energy metabolism.

The data presented in this article are related to the review article entitled 'Unravelling the role of fatty acid metabolism in cancer through the FOXO3-FOXM1 axis' (Saavedra-Garcia et al., 2017) [24]. Here, we have matched the DAF-16/FOXO3 downstream genes with their respective human orthologues and reviewed the roles of these targeted genes in FA metabolism. The list of genes listed in this article are precisely selected from literature reviews based on their functions in mammalian FA metabolism. The nematode Caenorhabditis elegans gene orthologues of the genes are obtained from WormBase, the online biological database of C. elegans. This dataset has not been uploaded to a public repository yet.

Mogat1 deletion does not ameliorate hepatic steatosis in lipodystrophic (Agpat2-/-) or obese (ob/ob) mice.

Reducing triacylglycerol (TAG) in the liver continues to pose a challenge in states of nonalcoholic hepatic steatosis. MonoacylglycerolO-acyltransferase (MOGAT) enzymes convert monoacylglycerol (MAG) to diacylglycerol, a precursor for TAG synthesis, and are involved in a major pathway of TAG synthesis in selected tissues, such as small intestine. MOGAT1 possesses MGAT activity in in vitro assays, but its physiological function in TAG metabolism is unknown. Recent studies suggest a role for MOGAT1 in hepatic steatosis in lipodystrophic [1-acylglycerol-3-phosphateO-acyltransferase (Agpat)2(-/-)] and obese (ob/ob) mice. To test this, we deletedMogat1in theAgpat2(-/-)andob/obgenetic background to generateMogat1(-/-);Agpat2(-/-)andMogat1(-/-);ob/obdouble knockout (DKO) mice. Here we report that, despite the absence ofMogat1in either DKO mouse model, we did not find any decrease in liver TAG by 16 weeks of age. Additionally, there were no measureable changes in plasma glucose (diabetes) and insulin resistance. Our data indicate a minimal role, if any, of MOGAT1 in liver TAG synthesis, and that TAG synthesis in steatosis associated with lipodystrophy and obesity is independent of MOGAT1. Our findings suggest that MOGAT1 likely has an alternative function in vivo.