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.
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http://dx.doi.org/10.1016/j.prostaglandins.2021.106577 | DOI Listing |
Nat Metab
January 2025
CECAD Excellence Center, University of Cologne, Cologne, Germany.
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 PDFArch 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 PDFBackground: 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 PDFAm 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 PDFInt J Mol Sci
January 2025
School of Applied Sciences, College of Health, Science and Society, University of the West of England, Coldharbour Lane, Bristol BS16 1QY, UK.
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.
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