Research Article Details

Article ID: A21643
PMID: 25157160
Source: Proc Natl Acad Sci U S A
Title: Ghrelin promotes hepatic lipogenesis by activation of mTOR-PPARγ signaling pathway.
Abstract: Although ghrelin has been demonstrated to stimulate energy intake and storage through a central mechanism, its effect on hepatic lipid metabolism remains largely uncharacterized. Ghrelin receptor antagonism or gene deletion significantly decreased obesity-associated hepatic steatosis by suppression of de novo lipogenesis, whereas exogenous ghrelin stimulated lipogenesis, leading to hepatic lipid accumulation in mice. The effects of ghrelin were mediated by direct activation of its receptor on hepatocytes. Cultured hepatocytes responded to ghrelin with increased lipid content and expression of lipogenesis-related genes. Ghrelin increased phosphorylation of S6, the downstream target of mammalian target of rapamycin (mTOR) signaling in cultured hepatocytes, whereas ghrelin receptor antagonism reduced hepatic phosphorylation of S6 in db/db mice. Inhibition of mTOR signaling by rapamycin markedly attenuated ghrelin-induced up-regulation of lipogenesis in hepatocytes, whereas activation of hepatic mTOR signaling by deletion of TSC1 increased hepatic lipogenesis. By interacting with peroxisome proliferator-activated receptor-γ (PPARγ), mTOR mediates the ghrelin-induced up-regulation of lipogenesis in hepatocytes. The stimulatory effect of ghrelin on hepatic lipogenesis was significantly attenuated by PPARγ antagonism in cultured hepatocytes and in PPARγ gene-deficient mice. Our study indicates that ghrelin activates its receptor on hepatocytes to promote lipogenesis via a mechanism involving the mTOR-PPARγ signaling pathway.
DOI: 10.1073/pnas.1411571111

Strategy ID Therapy Strategy Synonyms Therapy Targets Therapy Drugs
S02 Enhance lipid metabolism triglyceride-lowering; lipid tolerance; lipid metabolism 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) inhibitor; Decreases intestinal cholesterol absorption; FXR agonist; ACC inhibitor; FAS inhibitor; DGAT2 inhibitor; SCD-1 inhibitor Atorvastatin; Ezetimibe; Obeticholic Acid; GS-9674; GS-0976; TVB-2640; IONIS-DGAT2rx; Aramchol; Details
S07 Anti-lipogenesis de novo lipogenesis; de novo lipogenesis; DNL; anti-lipogenic mechanisms; adipogenesis; anti-obesity stearoyl-CoA desaturase 1 (SCD-1); Acetyl-coenzyme carboxylase; acyl-CoA carboxylase inhibitor (ACC inhibitor); stearoyl Coenzyme A desaturase inhibitor (SCD inhibitor); THR-beta selective agonist; DGAT2 inhibitor; FASN inhibitor Aramchol; Firsocostat (GS-0976); VK-2809; ION 224 Details

Target ID Target Name GENE Action Class UniProtKB ID Entry Name
T10 Caspase-1 CASP1 inhibitor Enzyme P29466 CASP1_HUMAN Details
T18 Acetyl-CoA carboxylase 1 ACACA inhibitor Enzyme Q13085 ACACA_HUMAN Details

Diseases ID DO ID Disease Name Definition Class
I14 9970 Obesity An overnutrition that is characterized by excess body fat, traditionally defined as an elevated ratio of weight to height (specifically 30 kilograms per meter squared), has_material_basis_in a multifactorial etiology related to excess nutrition intake, decreased caloric utilization, and genetic susceptibility, and possibly medications and certain disorders of metabolism, endocrine function, and mental illness. https://en.wikipedia.org/wiki/Obesity disease of metabolism/acquired metabolic disease/ nutrition disease/overnutrition Details

Drug ID Drug Name Type DrugBank ID Targets Category Latest Progress
D160 Growth Hormone Biological drug DB00052 GHR ligand; PRLR ligand -- Under clinical trials Details
D579 Emfilermin Miscellany -- adipocytes Enhance lipid metabolism Under investigation Details
D612 Rapamycin Miscellany -- Immunosuppressants; Methylmalonyl CoA mutase stimulants; MTOR protein inhibitors; T lymphocyte inhibitors -- Under investigation Details
D328 Serine Chemical drug DB00133 SRR Improve insulin resistance Under clinical trials Details
D343 Somatropin Biological drug DB00052 GHR ligand; PRLR ligand Hormone replacement drug Under clinical trials Details