Inhibition of phospholipase D1 ameliorates NAFLD by reducing PPARγ/CD36 pathway mediated lipid accumulation in hepatocytes
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA854629 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Objective：Phospholipase D1 (PLD1), a phosphatidylcholine-hydrolyzing enzyme, has been found to be involved in cellular lipid metabolism. However, how PLD1 involves in hepatocyte lipid metabolism and thus affects non-alcoholic fatty liver diseases (NAFLD) has not been explicitly explored. Method: NAFLD is induced in hepatocyte-specific Pld1 knockout (Pld1(H)-KO) mice or control (Pld1-Flox) mice with a high fat diet (HFD) for 20 weeks. Plasma glucose and lipid levels, liver lipid and function parameters and inflammation- and fibrogenesis-related gene expression levels were studied. Changes in lipid composition of liver were detected by lipidomic analyses. Changes in gene expression profile were detected by mRNA sequencing. In vitro, alpha mouse liver 12 (AML12) cells were incubated with sodium palmitate (SP) to explore the mechanisms of PLD1 on development of NAFLD. The protein levels of PLD1 and CD36 were detected in the liver tissues of NAFLD patients. Finally, the therapeutic effect of NAFLD by inhibiting PLD with 5-Fluoro-2-indolyl deschlorohalopemide (FIPI) was examined. Results: PLD1 expression levels were increased in the liver tissues of NAFLD patients and the hepatocytes of HFD-induced mice. Compared with Pld1-Flox mice, Pld1(H)-KO mice exhibited lower plasma glucose and lipids levels, and decreased lipid accumulation, inflammation and fibrosis related gene expression levels in the liver tissues after HFD feeding. Inhibition of hepatocyte PLD1 significantly altered lipid composition, especially phosphatidic acids (PA) and lyso-PAs (LPA) levels in the liver tissues after NAFLD. Transcriptomic analysis showed that hepatocyte specific deficiency of PLD1 mainly decreased CD36 expression levels in the NAFLD liver tissues, which was confirmed at the protein and gene expression levels. In vitro, inhibition of PLD1 markedly decreased CD36 expression and lipid accumulation in SP treated AML12 cells. Furthermore, PA, the downstream product catalyzed by PLD1, increased the expression levels of CD36 and lipid accumulation in vitro, which was reversed by PPARγ antagonist. These suggested that PPARγ played an important role in transcriptional regulation of CD36 expression after PA stimulation. Finally, PLD inhibitor FIPI had significant therapeutic effect on HFD-induced NAFLD. Conclusion: Hepatocyte-specific deficiency of PLD1 ameliorates lipid accumulation and NAFLD development by inhibiting PPARγ/CD36 pathway conducted by PA.
2023-08-01 | GSE207281 | GEO
Project description:With the improvement of people's living standards and lifestyle changes, nonalcoholic fatty liver disease (NAFLD) has become one of the most common chronic liver diseases worldwide. However, few drugs are available for NAFLD, partly due to an incomplete understanding of its pathogenic mechanisms. Here, using in vivo and in vitro gain- and loss-of function approaches, we identified DKK1 as a pivotal mediator of the progression of NAFLD and its accompanying metabolic disorders in dietary obese mice. Mechanistic study reveals that DKK1 enhances the capacity of hepatocytes to uptake fatty acids through ERK-PPARγ-CD36 pathway. Moreover, DKK1 increased insulin resistance by activating the JNK signaling pathway, which in turn exacerbates disorders of hepatic lipid metabolism. These results suggest that DKK1 is a regulator of fatty acid uptake in lipid metabolism and insulin signaling, and may be a potential therapeutic candidate for NAFLD
2022-11-19 | GSE197746 | GEO
Project description:A time course of the effect of overexpressing GPI-PLD on global gene expression in HepG2 cells was compared to control virus. Experiment Overall Design: This experiment compares the global gene expression in HepG2 cells that were either transduced with an adenovirus expressing GPI-phospholipase D or an adenovirus expressing beta galactosidase as a control. Treatment was for 6 or 12 hrs. Four replicates for each condition were used. 10 micrograms of total RNA was assayed per genechip using standard Affymetrix protocols. CONTEXT: Recent studies demonstrated that de novo lipogenesis is increased in patients with nonalcoholic fatty liver disease (NAFLD). Patients with NAFLD also have plasma lipid abnormalities. These lipid abnormalities may in part be related to insulin resistance, which is common in patients with NAFLD. Insulin resistance is associated with alterations in proteins involved in lipid metabolism including glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD), which is involved in triglyceride metabolism. OBJECTIVE: The objective of the study was to determine whether alterations in serum and hepatic levels of GPI-PLD occur in patients with NAFLD. DESIGN AND PATIENTS: We examined the following: 1) levels of serum GPI-PLD in nondiabetics with nonalcoholic steatohepatitis, compared with matched controls; 2) hepatic expression of GPI-PLD mRNA in patients with normal liver or NAFLD; and 3) effect of overexpressing GPI-PLD vs. beta-galactosidase (control) on global gene expression in a human hepatoma cell line. RESULTS: The serum levels of GPI-PLD were significantly higher in patients with nonalcoholic steatohepatitis than in matched controls (119 +/- 24 vs.105 +/- 15 microg/ml, P = 0.047). The hepatic expression of GPI-PLD mRNA was increased nearly 3-fold in NAFLD patients, compared with patients with normal liver (3.1 +/- 2.6 vs. 1.1 +/- 1.0 arbitrary units per microgram total RNA, P = 0.026). Finally, overexpressing GPI-PLD was associated with an increase in de novo lipogenesis genes. CONCLUSIONS: Patients with NAFLD have elevated serum levels and hepatic expression of GPI-PLD, and its overexpression in vitro is associated with increased expression of de novo lipogenesis genes. These results suggest that GPI-PLD may play a role in the pathogenesis of NAFLD and/or its metabolic features and warrants further investigation.
2007-10-26 | E-GEOD-4731 | biostudies-arrayexpress
Project description:We generated hepatocyte-specific CD36 knockout (CD36LKO) mice to study in vivo effects of CD36 on de novo lipogenesis (DNL) under high fat diet (HFD). Lipid deposition and DNL were analyzed in primary hepatocytes isolated from CD36LKO mice or HepG2 cells with CD36 overexpression. RNA-sequence, co-immunoprecipitation and proximity ligation assay were carried out to determine its role in regulating DNL. Results: Hepatic CD36 expression was upregulated in NAFLD mice and patients, and CD36LKO mice exhibited attenuated HFD-induced hepatic steatosis and insulin resistance. We identified hepatocyte CD36 as a key regulator for DNL in the liver. Sterol regulatory element-binding protein 1 (SREBP1) and its downstream lipogenic enzymes such as FASN, ACCα and ACLY were significantly downregulated in the liver of HFD-fed CD36LKO mice, whereas overexpression CD36 stimulated insulin-mediated DNL and lipid droplet formation in vitro. Mechanistically, CD36 was activated by insulin and formed a complex with insulin induced gene-2 (INSIG2), that disrupts the interaction between SREBP cleavage-activating protein (SCAP) and INSIG2, thereby leading to the translocation of SREBP1 from ER to Golgi for processing. Furthermore, treatment with 25-hydroxycholesterol or betulin, molecules shown to enhance SCAP/INSIG interaction, reversed the effects of CD36 on SREBP1 cleavage.
2022-01-03 | GSE191059 | GEO
Project description:Nonalcoholic fatty liver disease (NAFLD) is the most common liver disorder with high morbidity and mortality. The current study aims to explore the role of Cullin-associated and neddylation-dissociated protein 1 (CAND1) in the development of NAFLD and the underlying mechanisms. CAND1 is reduced in the liver of NAFLD male patients and high fat diet (HFD)-fed male mice. CAND1 alleviates palmitate (PA) induced lipid accumulation in vitro. Hepatocyte-specific knockout of CAND1 exacerbates HFD-induced liver injury in HFD-fed male mice, while hepatocyte-specific knockin of CAND1 ameliorates these pathological changes. Mechanistically, deficiency of CAND1 enhances the assembly of Cullin1, F-box only protein 42 (FBXO42) and acetyl-CoA acyltransferase 2 (ACAA2) complexes, and thus promotes the ubiquitinated degradation of ACAA2. ACAA2 overexpression abolishes the exacerbated effects of CAND1 deficiency on NAFLD. Additionally, androgen receptor binds to the -187 to -2000 promoter region of CAND1. Collectively, CAND1 mitigates NAFLD by inhibiting Cullin1/FBXO42 mediated ACAA2 degradation
2023-10-24 | PXD043719 | Pride
Project description:Adipose-derived MSCs (AMSC) are currently utilized in clinical trials for various diseases including osteoarthritis, amyotrophic lateral sclerosis, and multiple system atrophy. Whilst AMSCs may be defined by the surface expression of classical markers including CD44, CD90, CD105, and absence of CD45, these cells may exhbit donor-to-donor differences in differentiation potential. In this study we evaluated the expression of CD36 amongst AMSCs and utilized magnetic cell sorting to enrich for CD36+ cells. Whole transcriptome RNA-sequencing was performed on unsorted, CD36+ enriched, and CD36+ depleted cells to determine gene expression difference between these populations of cells. CD36 sorted or unsorted cells were then plated and maintained in growth medium. Cells were expanded for 2 passages and passage 8 cells were plated for RNA-sequencing analysis. Trizol reagent was used to harvest cells when they were proliferating cells (~80%) or 100% confluent cells.
2021-11-28 | GSE189525 | GEO
Project description:Limb expression 1-like protein (LIX1L) plays important role in various liver disorders, but its role and underlying mechanism in nonalcoholic hepatitis (NASH) and HCC progression remains obscure. Here, we report that LIX1L functions as a key integrative regulator linking lipid metabolism and inflammation, adipose tissue dysfunction and hepatic microenvironment reprogramming which promotes NASH progression. LIX1L significantly upregulated in NAFLD/NASH patients, mouse models and palmitic acid-stimulated hepatocytes. Lix1l deletion inhibits lipid deposition, inflammatory response and fibrosis in liver as well as adipocyte differentiation by downregulation of fatty acid translocase CD36 expression, alleviating NASH and associated HCC progression. In contrast, adeno-associated virus (AAV)-mediated LIX1L overexpression exacerbates NASH progression in mice. Mechanistically, metabolic stress promotes PARP1 mediated poly-ADP-ribosylation (PARylation) of LIX1L, subsequently increasing the stability and RNA binding ability of LIX1L protein. LIX1L binds to AU-rich element (ARE) in the 3’ untranslated region (UTR) of CD36 mRNA, thus attenuating CD36 mRNA decay. In NASH and associated HCC mouse models, LIX1L deficiency-mediated downregulation of CD36 suppresses adipogenesis, hepatic lipid uptake, and reprograms the tumor-prone liver microenvironment with increased cytotoxic T lymphocytes (CTLs), reduced immunosuppressive cell proportions. These data indicate a systematic function of LIX1L in the pathogenesis of NASH and underscore the PARP1/LIX1L/CD36 axis as a potential target for treatment of NASH and associated HCC.
2024-04-25 | GSE264479 | GEO