Dataset Information

Sphingomyelin synthase–related protein SMSr is a phosphatidylethanolamine phospholipase C protein that promotes nonalcoholic fatty liver disease

ABSTRACT: Sphingomyelin synthase (SMS)–related protein (SMSr) is a phosphatidylethanolamine phospholipase C (PE-PLC) molecule that is conserved and ubiquitous in mammals. However, its biological function is still not clear. We previously observed that SMS1 deficiency–mediated glucosylceramide accumulation caused nonalcoholic fatty liver diseases (NAFLD), including nonalcoholic steatohepatitis (NASH) and liver fibrosis. Here, first, we evaluated high-fat diet/fructose-induced NAFLD in Smsr knock out (KO) and WT mice. Second, we evaluated whether SMSr deficiency can reverse SMS1 deficiency-mediated NAFLD, using Sms1/Sms2 double and Sms1/Sms2/Smsr triple KO mice. We found that SMSr/PE-PLC deficiency attenuated high-fat diet/fructoseinduced fatty liver and NASH, and attenuated glucosylceramide accumulation-induced NASH, fibrosis, and tumor formation. Further, we found that SMSr/PE-PLC deficiency reduced the expression of many inflammatory cytokines and fibrosis-related factors, and PE supplementation in vitro or in vivo mimicked the condition of SMSr/PE-PLC deficiency. Furthermore, we demonstrated that SMSr/PEPLC deficiency or PE supplementation effectively prevented membrane-bound βcatenin transfer to the nucleus, thereby preventing tumor-related gene expression. Finally, we observed that patients with NASH had higher SMSr protein levels in the liver, lower plasma PE levels, and lower plasma PE/phosphatidylcholine (PC) ratios, and that human plasma PE levels are negatively associated with TNF-α and TGFβ1 levels. In conclusion, SMSr/PE-PLC deficiency causes PE accumulation, which can attenuate fatty liver, NASH, and fibrosis. These results suggest that SMSr/PE-PLC inhibition therapy may mitigate NAFLD.

ORGANISM(S): Mus musculus

PROVIDER: GSE241036 | GEO | 2023/08/17

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Objective: Nonalcoholic fatty liver disease (NAFLD) is linked to obesity and diabetes, suggesting an important role of adipose tissue in the pathogenesis of NAFLD. Here we aim to investigate the interaction between adipose tissue and liver in NAFLD, and identify potential early plasma markers that predict NASH. Research Design and Methods: C57Bl/6 mice were chronically fed a high fat diet to induce NAFLD and compared with mice fed low fat diet. Extensive histological and phenotypical analyses coupled with a time-course study of plasma proteins using multiplex assay was performed. Results: Mice exhibited pronounced heterogeneity in liver histological scoring, leading to classification into 4 subgroups: LF-low (LFL) responders displaying normal liver morphology, LF-high (LFH) responders showing benign hepatic steatosis, HF-low (HFL) responders displaying pre-NASH with macrovesicular lipid droplets, and HF-high (HFH) responders exhibiting overt NASH characterized by ballooning of hepatocytes, presence of Mallory bodies, and activated inflammatory cells. Compared to HFL responders, HFH mice gained weight more rapidly and exhibited adipose tissue dysfunction characterized by decreased final fat mass, enhanced macrophage infiltration and inflammation, and adipose tissue remodelling. Plasma haptoglobin, IL-1β, TIMP-1, adiponectin and leptin were significantly changed in HFH mice. Multivariate analysis indicated that in addition to leptin, plasma CRP, haptoglobin, eotaxin and MIP-1α early in the intervention were positively associated with liver triglycerides. Intermediate prognostic markers of liver triglycerides included IL-18, IL-1β, MIP-1γ and MIP-2, whereas insulin, TIMP-1, GCP-2 and MPO emerged as late markers. Conclusions: Our data support the existence of a tight relationship between adipose tissue dysfunction and NASH pathogenesis and point to several novel potential predictive biomarkers for NASH. Keywords: Expression profiling by array Male wildtype C57Bl/6 mice were fed LFD or HFD for 21 weeks. Mice were divided into 4 groups based on liver histology.

Project description:Nonalcoholic fatty liver disease (NAFLD) has become the most common cause of liver disease affecting 20-30% of the population in developed countries. NAFLD is strongly associated with abdominal obesity and is recognized as the hepatic manifestation of the metabolic syndrome. In a subgroup of patients with NAFLD inflammation and fibrosis develops, this so-called Non-Alcoholic Steatohepatitis (NASH) may progress to cirrhosis and hepatocellular carcinoma. A multi-hit hypothesis has been proposed in which during the first “hit” fat accumulation occurs in hepatocytes from excessive delivery of fatty acids from adipose tissue, in addition there is an imbalance in lipid synthesis and export. However, the reason why fat accumulation is subsequently followed by inflammation and fibrosis in some patients is poorly understood. We studied the role of inflammatory processes in visceral and subcutaneous fat at the transcriptional level using microarray in bariatric patients from whom the liver histology was available. Patients scheduled for bariatric surgery were recruited in two centers (Pretoria/South-Africa and Antwerpen/Belgium). At the time of the procedure, tissue samples of the visceral and subcutaneous fat were taken for molecular analysis as well as liver tissue for histology, also full biochemical data was collected. Patients were grouped according histology: group I (<5% steatosis), group II (NAFLD, 30-50% steatosis), group III (NASH) and group IV (NASH + fibrosis F2-F3). The following samples were used for microarray (number of 'patients' respectively for stages I-II-III-IV): visceral fat (9-7-7-5), subcutaneous fat (6-6-6-5). Microarrays were run in two batches (15xxx versus 17xxx CEL file samples; indicated in the description field). Samples from two patients (FN61; FN76) were put twice on array (15078+17881; 15064+17877) to verify and exclude batch effects. Please note that, due to technical repeats with two patient samples, the number of 'visceral fat samples' for stages I-II-III-IV is 10-7-8-5.

Dataset Information

Sphingomyelin synthase–related protein SMSr is a phosphatidylethanolamine phospholipase C protein that promotes nonalcoholic fatty liver disease

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure