Different Density Of FFA Effect On Adiponectin Receptors Of HepG2 Liver Cells

ObjectiveAdiponectin/Acrp30 is a hormone secreted by adipocytes, which acts as an antidiabetic and antiatheogenic adipokine. We reported previously that adipoRl and R2 serve ad receptors for adiponectin and mediate in creased fatty acid oxidation and glucose uptake by adiponecin. In the present study,we examined the expression levels and roles of AdipoR1/R2 in several physiolofical and patho-physiological states such as obesity, and insulin resistance. Insulin resistance is a major charateristic of Type 2 diabetes, and is also commonly associated with o-besity, hypertension and cardiovascular disease. It can be defined as a failure of target tissue to increase whole body glucose disposal in response to insulin. The elevated levels of plasma free fatty acids (FFA) noted in patients with Ttype2 diabetes and obesity may lead to insulin resistance. In this study,we demonstrated that saturated FFAs, such as palmitic acid markedly suppressed the HepG2 liver cell survival in a dose - dependent manner to show that the expression of AdipoR1/R2 .MethodsThe gene expression of AR1 or AR2 on HepG2 liver cells was confirmed by both RT - PCR and immunocytchemistry, HepG2 liver cells were isolated and incubated with graded various FFA concetrrations( 100,200,400umol/l) For 2. 6, 24h respetively. RNA was isolated with peqGOLD TriFast according to the manufacturer' instructions ,Total RNA treated with Rnase - free DNase. QuantitativePCR was perormed with SYBR Green I dye on a high - speed thermal cycler with an integrated mucrovoliume fluorometrer according to the instruction of the manufacturer. The following primers were obtained forom Invitrogen.ResultsARl and AR2 (esp. AR2) were expressed in HepG2 liver cells testified by RT-PCR. When incubated in DMEM meduim with FFA ( 200umol/l) for 6 h and 24h , The expression of ARl and AR2 both reduced, but the expression of AR2 reduced at a higher level . ( both p < 0.01) .ConclusionARl and AR2 ( predominant) are expressed on HepG2 liver cells. When HepG2 cells are incubated with high FFA concentration, the expression of ARl/ AR2 both reduced,but AR2 reduced more.