The Study Of Endoplasmic Reticulum Stress Might Mediate The Effect Of Monosodium Urates Crystals On The Proliferation And Differentiation Of 3T3-E1 Cells

Objective: To identify the effect of different dose of monosodium urate(MSU)crystals on the proliferation、differentiation and secretion of 3T3-E1 cells,and explore the relationship to the endoplasmic reticulum stress.Methods: We assigned urate crystals with uric acid.We cultured 3T3-E1 cells and induced differentiation to mature osteoblast.During this process,we treated with different dose of MSU crystals.We used MTT assay to observe the cell viability with the concentration of MSU(0.02、0.06、0.10、0.30、0.50mg/ml)after 48 h cultured.ALP and Alizarin Red S staining observe the situation of mineralization after 7 days cultured with the concentration of MSU(0.02、0.10、0.30mg/ml).RT-PCR show the expression of runt related transcription factor 2(Runx2),Osterix,Osteocalcin and Collal1 with the concentration of monosodium urate crystals(0.02、0.10mg/ml)after 3 days,7days and 14 days cultured.We induced 3T3-E1 cells differentiate to mature osteoblast with the concentration of MSU(0.02、0.04、0.06,0.08,0.10mg/ml)after 7 days.RT-PCR to detect the expression of HSP90,Bip,CHOP,ATF4,e IF2α,and Western-blot toob serve the expression of GAPDH,Bip,CHOP,ATF4,e IF2αthat relationship to the endoplasmic reticulum stress.Results: MSU can inhibit osteoblast precursor cells 3T3-E1 proliferation,and the higher concentrations of the more obvious inhibitory effect.Alkaline phosphatase and Alizarin Red Sstaining showed that with the concentration of MSU increased,the dyeing is more shallow.RT-PCR show the expression of runt related transcription factor 2(Runx2),Osterix,Osteocalcin and Collal1 isreducedwith the concentration of monosodium urate crystals(0.02、0.10mg/ml)after 3 days,7days and 14 days.RT-PCR show the expression of Bip,CHOP is increased and the expression of ATF4 induced with theconcentration of monosodium urate crystals(0.02,0.04,0.06,0.08,0.10mg/ml)after 7days cultured.Western-blot show with the concentration of MSU increased,the protein expression of Bip,CHOP is increased,and the expression of ATF4 and p-e IF2αis induced.Conclusions: Monosodium urate crystals(MSU)can inhibit osteoblast precursor cells(3T3-E1)proliferation,and can inhibit the process of differentiation and the secretory function of Osteocalcin and Collal I,the process might relate to endoplasmic reticulum stress.