Ascofuranone stimulates expression of adiponectin and peroxisome proliferator activated receptor through the modulation of mitogen activated protein kinase family members in 3T3-L1, murine pre-adipocyte cell line.

ABSTRACT

Ascofuranone, an isoprenoid antibiotic, was originally isolated as a hypolipidemic substance from a culture broth of the phytopathogenic fungus, Ascochyta visiae. Adiponectin is mainly synthesized by adipocytes. It relieves insulin resistance by decreasing the plasma triglycerides and improving glucose uptake, and has anti-atherogenic properties. Here, we found that ascofuranone increases expression of adiponectin and PPARγ, a major transcription factor for adiponectin, in 3T3-L1, murine pre-adipocytes cell line, without promoting accumulation of lipid droplets. Ascofuranone induced expression of adiponectin, and increases the promoter activity of adiponectin and PPRE, PPAR response element, as comparably as a PPARγ agonist, rosiglitazone, that stimulates lipid accumulation in the preadipocyte cell line. Moreover, inhibitors for MEK and JNK, like ascofuranone, considerably increased the expression of adiponectin and PPARγ, while a p38 inhibitor significantly suppressed. Ascofuranone significantly suppressed ERK phosphorylation, while increasing p38 phosphorylation, during adipocyte differentiation program. These results suggest that ascofuranone regulates the expression of adiponectin and PPARγ through the modulation of MAP kinase family members.