Effect Of Calcium Ion On GHS Rat Renal Tubular Epithelial Cells Cbfα1and Osterix Expression

Objectives To investigate the effect of calcium ion on GHS rats renal tubular epithelial cells cbfal and osterix transcription factor expression and whether there is similar to molecular mechanisms of vascular calcification.Methods Primary culture renal tubular epithelial cells and transfer into culture plate, then incubation12,24and48hours with different concentrations of calcium solution together. There are five groups in this experiment:Negative control group (+PBS); group Ⅰ (+0.5mmol/LCa2+); group Ⅱ (+1.0mmol/L Ca2+); group Ⅲ (+1.5mmol/L Ca2+); group Ⅳ (+2.0mmol/L Ca2+). Cbfal and osterix mRNA expression were detected by RT-PCR, and cbfal and osterix protein expression levels were determined via western blotting.Results RT-PCR results:Cbfα1gene mRNA relative expression levels of groupⅠ-Ⅳ vs negative control group were1.25times,1.58times,1.92times, and1.82times at24hours respectively. GroupⅡ-Ⅳ vs negative control group (P<0.05); groupⅢ vs groupⅠ、Ⅱ、Ⅳ (P <0.05). The osterix mRNA relative expression of groupⅠ-Ⅳ vs control group were1.41times,1.60times,2.13times, and1.85times respectively. GroupⅠ-Ⅳ vs negative control group (P<0.05); groupⅢ vs groupⅠ、Ⅱ、Ⅳ (P<0.05). Western blotting results:24hours cbfal protein results:groupⅠ-Ⅳ relative expression were0.98±0.11,1.15±016,1.38±0.27, and1.24±0.21respectively. While the negative control group was0.81±0.11. Group Ⅱ-Ⅳ vs negative control group (P<0.05); groupⅢ vs groupⅠ、Ⅱ、Ⅳ(P<0.05). The osterix protein relative expression of groupⅠ-Ⅳ were1.40±0.25,1.58±0.33,1.92±0.43, and1.73±0.38respectively. While the negative control group was1.20±0.20.GroupⅡ-Ⅳ vs negative control group (P<0.05); groupⅢ vs groupⅠ、Ⅱ、Ⅳ (P<0.05). The cbfal and osterix mRNA and protein relative expression levels of experimental group(GroupⅢ) at the time of0-24h are gradually increases,24h to spike(P<0.05) and24-48h are gradually reduces, while the control group has no obvious change in the whole experiment process (P>0.05).Conclusions Calcium ion increases the expression of cbfal and osterix, suggests it could be up and regulating BMP2-Cbfal-Osterix signaling pathway in GHS rat renal tubular epithelial cells. Similar vascular ectopic calcification mechanisms may be involved in the GHS rat renal interstitial calcification.