Abstract:

Abstract： Objective To investigate the effects of 1,25-dihydroxyvitamin D3[1,25 (OH)2D3] on cell proliferation in hu⁃
man glomerular mesangial cells and it′s effects on the regulation of mTOR/p70s6K signaling pathway in this cell line. Meth⁃
ods The cultured human mesangial cells at passage 3-7 were divided into four groups: control group， VD group (addition of
10-8 mol/L of 1,25-dihydroxyvitamin D3 )， R group (addition of 5 mg/L of rapamycin) and R+VD group（addition of 5 mg/L ra⁃
pamycin combined with 10-8 mol/L of 1,25-dihydroxyvitamin D3） . Drug incubation last 48 h. The effect of mesangial cell pro⁃
liferation was measured by CCK-8 colorimetric assay. The cell cycles were measured by flow cytometry. The expression of
mTOR and p70s6K were detected by immunofluorescence. Results (1) The absorbance of A450 was higher in control group
than that in VD group than that in R group than that in R+VD group. But the inhibition rate (IR) was lower in control group
than that in VD group than that in R group than that in R+VD group. All comparisons were of statistic significance. (2) Cells
in G1 phase were higher while cells in G2/M and S phases as well as proliferation rate (PI) were lower in control group than
those in VD group than those in R group than those in R+VD group. All comparisons were of statistic significance except in⁃
dexes between group R and group VD. (3) mTOR and p30s6K expressions in mesangial cells were higher in control group
than those in VD group than those in R group than those in R+VD group. All comparisons were of statistic significance ex⁃
cept indexes between group R and group VD. Conclusion 1,25-dihydroxyvitamin D3 might inhibit mesangial cell prolifera⁃
tion significantly through mTOR/p70s6K signaling pathways.

Key words: Key words：mesangial cells, cell proliferation, cell cycle, ribosomal protein S6 kinases, 70-kDa, 1,25 (OH)2D3, mTOR/p70s6K signaling pathway