The Effects Of Knock-down Chemerin On Wnt/β-catenin Signaling Pathway Throw3T3-L1Adipogenesis

As a novel adipokine, chemerin was reported to affect3T3-L1cell line adipogenesis at theearly time after cell adipogenesis induced, but the specific role of it has not been studied yet.Herein, in our study, loss-of-function was chosen to knock down the expression of chemerin withthe help of RNA interferance. At the same time, PPAR-γ was also been interposed with the aimof finding the interaction between chemerin and Wnt/β-catenin signaling pathway.In this experiment, the adenovirus shuttle plasmids with shRNA for chemerin and theadenovirus genome package plasmids were transfected into HEK293cells, and then with thehelp of Cre/LoxP system, we finally gained chemerin shRNA recombinant adenovirus. Later, therecombinant adenovirus was used for3T3-L1before induced, and then those cells were inducedin a normal way after this. What’s more, total RNA and protein were extracted at the3rd,7th and14thday after induced. At last, real time PCR and western blotting were used to identify the keymolecular involved in adipogenesis and Wnt/β-catenin signaling pathway. Further studies wereusing rosiglitazone to enhigh the function of PPAR-γ, and LiCl to rose the stability of β-catenin,which made us more clearly about the interaction between chemerin and β-catenin signalingpathway.Another experiment was also done in vivo to test the in vitro results we gained, and C57BL/6J wild type mice were used. Rosiglitazone and LiCl were used for intraperitoneal injection,later the epididymis white adipose tissue was extracted for histomorphology and westernblotting.When we saw the result of the experiment above, PPAR-γ (P<0.01), C/EBPα (P<0.01),C/EBP (P<0.05) and adiponectin (P<0.01) showed a decrease at the level of RNA expression tothe control group at the3rd,7th,14thday after cell adipogenesis, while the key protein β-cateninhave none significantly difference, however the level of Wnt10b(P<0.01) decrease. WB alsoshowed us the same result to RNA expression when we test the target gene of PPAR-γ (P<0.01),C/EBPβ (P<0.01), but the content of adiponectin showed an increase. What`s more the level ofβ-catenin showed increase at the same time. The expression of chemerin was saved by rosiglitazone, however, the content of PPAR-γand β-catenin showed a decrease to the same effects, by the way the level of adiponectin showedan increase. When we test the level of adipogenesis by Oil Red O, we find that rosiglitazone canalso save it. LiCl made the expression of chemerin increase.In vivo, we gained the same results to in vitro. The expression of β-catenin showed adecrease while chemerin increase with the effect of rosiglitazone, and LiCl made chemerin andβ-catenin increase at the same time.With all that showed above, as a novel adipokine, chemerin was expressed to control thefunction of β-catenin, as a result, it made the level of adipgenesis increase.