Loss of lysophosphatidic acid receptor 1 in hepatocytes reduces steatosis via down-regulation of CD36.

Prostaglandins Other Lipid Mediat

The Southern California Research Center for ALPD and Cirrhosis, Department of Pathology, Keck School of Medicine, University of Southern California, CA, 90033, United States. Electronic address:

Published: October 2021

Nonalcoholic steatohepatitis is a major public health concern and is characterized by the accumulation of triglyceride in hepatocytes and inflammation in the liver. Steatosis is caused by dysregulation of the influx and efflux of lipids, lipogenesis, and mitochondrial β-oxidation. Extracellular lysophosphatidic acid (LPA) regulates a broad range of cellular processes in development, tissue injury, and cancer. In the present study, we examined the roles of LPA in steatohepatitis induced by a methionine-choline-deficient (MCD) diet in mice. Hepatocytes express LPA receptor (Lpar) 1-3 mRNAs. Steatosis developed in mice fed the MCD diet was reduced by treatment with inhibitors for pan-LPAR or LPAR1. Hepatocyte-specific deletion of the Lpar1 gene also reduced the steatosis in the MCD model. Deletion of the Lpar1 gene in hepatocytes reduced expression of Cd36, a gene encoding a fatty acid transporter. Although LPA/LPAR1 signaling induces expression of Srebp1 mRNA in hepatocytes, LPA does not fully induce expression of SREBP1-target genes involved in lipogenesis. Human hepatocytes repopulated in chimeric mice are known to develop steatosis and treatment with an LPAR1 inhibitor reduces expression of CD36 mRNA and steatosis. Our data indicate that antagonism of LPAR1 reduces steatosis in mouse and human hepatocytes by down-regulation of Cd36.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8490298PMC
http://dx.doi.org/10.1016/j.prostaglandins.2021.106577DOI Listing

Publication Analysis

Top Keywords

lysophosphatidic acid
8
reduces steatosis
8
down-regulation cd36
8
mcd diet
8
deletion lpar1
8
lpar1 gene
8
expression cd36
8
human hepatocytes
8
hepatocytes
7
steatosis
7

Similar Publications

Dysfunctions in autophagy, a cellular mechanism for breaking down components within lysosomes, often lead to neurodegeneration. The specific mechanisms underlying neuronal vulnerability due to autophagy dysfunction remain elusive. Here we show that autophagy contributes to cerebellar Purkinje cell (PC) survival by safeguarding their glycolytic activity.

View Article and Find Full Text PDF

NHERF2 regulatory function in signal transduction pathways and control of gene expression: Implications for cellular homeostasis and breast cancer.

Arch Med Res

January 2025

Programa de Investigación de Cancer de Mama, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico; Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico. Electronic address:

Na⁺/H⁺ exchanger regulatory factor 2 (NHERF2) is a nucleocytoplasmic protein initially identified as a regulator of membrane-bound sodium-hydrogen exchanger 3 (NHE3). In the cytoplasm, NHERF2 regulates the activity of G protein-coupled receptors (GPCRs), including beta-2 adrenergic receptor (2β-AR), lysophosphatidic acid receptor 2, and parathyroid hormone type 1 receptor. In the nucleus, NHERF2 acts as a coregulator of transcription factors such as sex-determining region Y protein (SRY), involved in male sex determination, and estrogen receptor alpha (ERα).

View Article and Find Full Text PDF

Background: Systemic sclerosis (SSc) is a rare connective tissue disease, frequently affecting the skin, lungs, and pulmonary vasculature. Approximately 30-50% of SSc patients develop interstitial lung disease (SSc-ILD), with 30-35% of related deaths attributed to it. Even though men are less likely to develop systemic sclerosis, they have a higher incidence of SSc-ILD than women, and they tend to develop it at a younger age with a higher mortality rate.

View Article and Find Full Text PDF

Effect of cardiomyocyte-specific lipid phosphate phosphatase 3 overexpression on high-fat diet-induced cardiometabolic dysfunction in mice.

Am J Physiol Heart Circ Physiol

January 2025

Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, 355 Campus Ring Road, Saint John, New Brunswick, E2L 4L5, Canada.

Lipid phosphate phosphatase 3 (LPP3) is a membrane-bound enzyme that hydrolyzes lipid phosphates including the bioactive lipid, lysophosphatidic acid (LPA). Elevated circulating LPA production and cellular LPA signaling are implicated in obesity-induced metabolic and cardiac dysfunction. Deletion of LPP3 in the cardiomyocyte increases circulating LPA levels and causes heart failure and mitochondrial dysfunction in mice.

View Article and Find Full Text PDF

The active metabolite of vitamin D3, calcitriol (1,25D), is widely recognised for its direct anti-proliferative and pro-differentiation effects. However, 1,25D is calcaemic, which restricts its clinical use for cancer treatment. Non-calcaemic agonists of the vitamin D receptor (VDR) could be better candidates for cancer treatment.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!