Research Article Details

Article ID: A46117
PMID: 20967760
Source: Hepatology
Title: Disruption of the 12/15-lipoxygenase gene (Alox15) protects hyperlipidemic mice from nonalcoholic fatty liver disease.
Abstract: UNLABELLED: We have shown that Alox15, the gene encoding for 12/15-lipoxygenase (12/15-LO), is markedly up-regulated in livers from apolipoprotein E-deficient (ApoE(-/-)) mice, which spontaneously develop nonalcoholic fatty liver disease secondary to hyperlipidemia. In the current study, we used ApoE(-/-) mice with a targeted disruption of the Alox15 gene to assess the role of 12/15-LO in the development and progression of hepatic steatosis and inflammation. Compared with ApoE(-/-) mice, which exhibited extensive hepatic lipid accumulation and exacerbated inflammatory injury, ApoE/12/15-LO double-knockout (ApoE(-/-)/12/15-LO(-/-)) mice showed reduced serum alanine aminotransferase levels; decreased hepatic steatosis, inflammation, and macrophage infiltration; and decreased fatty acid synthase, tumor necrosis factor α (TNFα), monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)-18, and IL-6 expression. Remarkably, disruption of Alox15 attenuated glucose intolerance and high-fat diet-induced insulin resistance, up-regulated insulin receptor substrate-2, and exerted opposite effects on hepatic c-Jun amino-terminal kinase and adenosine monophosphate-activated protein kinase phosphorylation, known negative and positive regulators of insulin signaling, respectively. In adipose tissue, the absence of Alox15 induced significant reductions in the expression of the proinflammatory and insulin-resistant adipokines MCP-1, TNFα, and resistin while increasing the expression of glucose transporter-4. Interestingly, compared with ApoE(-/-) mice, which exhibited increased hepatic caspase-3 staining, ApoE(-/-)/12/15-LO(-/-) mice showed attenuated hepatocellular injury. Consistent with this finding, hepatocytes isolated from ApoE(-/-) mice were more vulnerable to TNFα-induced programmed cell death, an effect that was not observed in hepatocytes carrying a targeted disruption of the Alox15 gene. CONCLUSION: Collectively, our data suggest a potentially relevant mechanism linking 12/15-LO to the promotion of hepatic steatosis, insulin resistance, and inflammation in experimental liver disease of metabolic origin.
DOI: 10.1002/hep.23928

Strategy ID Therapy Strategy Synonyms Therapy Targets Therapy Drugs
S01 Improve insulin resistance insulin sensitizer; insulin resistance; glucose tolerance Biguanide: increases 5-AMP activated protein kinase signaling; SGLT-2 inhibitor; Thiazalidinedione: selective PPAR-γ agonists; GLP-1 agonist Metformin; Empagliflozin; Canagliflozin; Rosiglitazone; Pioglitazone; Liraglutide Details
S13 Anti-apoptosis hepatocyte apoptosis; hepatic autophagy; apoptosis Pan-caspase inhibitor Emricasan Details
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
T10 Caspase-1 CASP1 inhibitor Enzyme P29466 CASP1_HUMAN Details
T11 Caspase-3 CASP3 inhibitor Enzyme P42574 CASP3_HUMAN Details
T45 Arachidonate 12-lipoxygenase ALOX12 inhibitor Enzyme P18054 LOX12_HUMAN Details
T18 Acetyl-CoA carboxylase 1 ACACA inhibitor Enzyme Q13085 ACACA_HUMAN Details
T20 Fatty acid synthase FASN inhibitor Enzyme P49327 FAS_HUMAN Details

Diseases ID DO ID Disease Name Definition Class
I05 9352 Type 2 diabetes mellitus A diabetes that is characterized by chronic hyperglycaemia with disturbances of carbohydrate, fat and protein metabolism resulting from defects in insulin secretion, insulin action, or both. A diabetes mellitus that is characterized by high blood sugar, insulin resistance, and relative lack of insulin. http://en.wikipedia.org/wiki/Diabetes, http://en.wikipedia.org/wiki/Diabetes_mellitus_type_2 disease of metabolism/inherited metabolic disorder/ carbohydrate metabolic disorder/glucose metabolism disease/diabetes/ diabetes mellitus Details

Drug ID Drug Name Type DrugBank ID Targets Category Latest Progress
D328 Serine Chemical drug DB00133 SRR Improve insulin resistance Under clinical trials Details
D316 S-adenosyl-L-methionine Chemical drug DB00118 GNMT cofactor Antiviral Under clinical trials Details
D182 Insulin Biological drug DB00030 INSR agonist; CPE modulator&product of -- Under clinical trials Details
D199 L-alanine Chemical drug DB00160 KYNU -- Failed in clinical trials Details