Research Article Details
| Article ID: | A48908 |
| PMID: | 24814604 |
| Source: | Am J Pathol |
| Title: | Adverse signaling of scavenger receptor class B1 and PGC1s in alcoholic hepatosteatosis and steatohepatitis and protection by betaine in rat. |
| Abstract: | Because scavenger receptor class B type 1 is the cholesterol uptake liver receptor, whereas peroxisome proliferator-activated receptor γ coactivator-1β (PGC-1β) and PGC-1α are critical for lipid synthesis and degradation, we investigated the roles of these signaling molecules in the actions of ethanol-polyunsaturated fatty acids and betaine on hepatosteatosis and steatohepatitis. Ethanol-polyunsaturated fatty acid treatment caused the following: i) hepatosteatosis, as evidenced by increased liver cholesterol and triglycerides, lipid score, and decreased serum adiponectin; ii) marked inhibition of scavenger receptor class B type 1 glycosylation, its plasma membrane localization, and its hepatic cholesterol uptake function; and iii) moderate steatohepatitis, as evidenced by histopathological characteristics, increased liver tumor necrosis factor α and IL-6, decreased glutathione, and elevated serum alanine aminotransferase. These actions of ethanol involved up-regulated PGC-1β, sterol regulatory element-binding proteins 1c and 2, acetyl-CoA carboxylase, and HMG-CoA reductase mRNAs/proteins and inactive non-phosphorylated AMP kinase; and down-regulated silence regulator gene 1 and PGC-1α mRNA/proteins and hepatic fatty acid oxidation. Betaine markedly blunted all these actions of ethanol on hepatosteatosis and steatohepatitis. Therefore, we conclude that ethanol-mediated impaired post-translational modification, trafficking, and function of scavenger receptor class B type 1 may account for alcoholic hyperlipidemia. Up-regulation of PGC-1β and lipid synthetic genes and down-regulation of silence regulator gene 1, PGC-1α, adiponectin, and lipid degradation genes account for alcoholic hepatosteatosis. Induction of proinflammatory cytokines and depletion of endogenous antioxidant, glutathione, account for alcoholic steatohepatitis. We suggest betaine as a potential therapeutic agent because it effectively protects against adverse actions of ethanol. |
| DOI: | 10.1016/j.ajpath.2014.03.005 |
| Strategy ID | Therapy Strategy | Synonyms | Therapy Targets | Therapy Drugs | |
|---|---|---|---|---|---|
| S05 | Anti-inflammatory | inflammatory | Bile acid; TNF-a inhibitor; Dual PPAR-α and -δ agonists; Toll-Like Receptor; (TLR)-4 antagonist; Caspase inhibitor; ASK-1 inhibitor | Ursodeoxycholic Acid; Pentoxifylline; Elafibranor; JKB-121; Emricasan; Selonsertib; | Details |
| Target ID | Target Name | GENE | Action | Class | UniProtKB ID | Entry Name | |
|---|---|---|---|---|---|---|---|
| T08 | Tumor necrosis factor | TNF | inhibitor | Cytokine | P01375 | TNFA_HUMAN | Details |
| T18 | Acetyl-CoA carboxylase 1 | ACACA | inhibitor | Enzyme | Q13085 | ACACA_HUMAN | Details |
| T05 | Peroxisome proliferator-activated receptor gamma | PPARG | agonist | Nuclear hormone receptor | P37231 | PPARG_HUMAN | Details |
| T15 | 3-hydroxy-3-methylglutaryl-coenzyme A reductase | HMGCR | inhibitor | Enzyme | P04035 | HMDH_HUMAN | Details |
| Diseases ID | DO ID | Disease Name | Definition | Class |
|---|
| Drug ID | Drug Name | Type | DrugBank ID | Targets | Category | Latest Progress | |
|---|---|---|---|---|---|---|---|
| D032 | Betaine | Chemical drug | DB06756 | DNMTs stimulant | Improve insulin resistance | Under clinical trials | Details |
| D579 | Emfilermin | Miscellany | -- | adipocytes | Enhance lipid metabolism | Under investigation | Details |
| D581 | sobetirome | Chemical drug | -- | Thyroid hormone receptor beta agonists | Enhance lipid metabolism | Under investigation | Details |
| D199 | L-alanine | Chemical drug | DB00160 | KYNU | -- | Failed in clinical trials | Details |
| D328 | Serine | Chemical drug | DB00133 | SRR | Improve insulin resistance | Under clinical trials | Details |
| D504 | Polyunsaturated Fatty Acids | Supplement | -- | -- | -- | Under clinical trials | Details |
| D083 | CLA | Chemical drug | DB01211 | KCNH2; SLCO1B1; SLCO1B3 | -- | Under clinical trials | Details |
| D248 | Obeticholic Acid | Chemical drug | DB05990 | NR1H4 activator; NR1H4 agonist; FXR agonist | Enhance lipid metabolism | Approval rejected | Details |
| D316 | S-adenosyl-L-methionine | Chemical drug | DB00118 | GNMT cofactor | Antiviral | Under clinical trials | Details |
| D158 | Glutathione | Chemical drug | DB00143 | MGST3; HPGDS; GSTM2; GSTM5; GPX7 cofactor; MGST2; GSS; GSTM1; GSTK1; GSTM3; GSTM4; GPX1 cofactor; GPX2 cofactor; GPX3 cofactor | -- | Under clinical trials | Details |