[Effects of 1, 25(OH)(2);D(3); on parathyroid hormone induced transdifferentiation and TGF-β(1); expression in cultured human renal tubular epithelial cells].
OBJECTIVE
To explore the effects of 1, 25(OH)(2);D(3); on parathyroid hormone (PTH) induced transdifferentiation and TGF-β(1);  expression in cultured human renal tubular epithelial cells.


METHODS
HK-2 cells were cultured in DMEM/F12 medium supplemented with 50 mL/L FBS. Cells were divided into three groups. (1) CONTROL GROUP:  without PTH or 1, 25(OH)(2);D(3);;  (2) PTH group:  10(-10); mol/L PTH;  (3) PTH and 1, 25(OH)(2);D(3); group:  10(-10); mol/L PTH and different concentrations of 1, 25(OH)(2);D(3); (10(-10);,  10(-9);,  10(-8); and 10(-7); mol/L). The gene expressions of α-SMA and TGF-β(1); were detected by semi-quantitative RT-PCR. The protein expressions of α-SMA and TGF-β(1); were detected by Western blot. Immunocytochemisty (ICC) was used to measure the expression of α-SMA in HK-2. ELISA was used to assay the level of TGF-β(1); in the supernatant.


RESULTS
The gene expressions of α-SMA and TGF-β(1); in PTH group were significantly higher than those in control group (P<0.05). In contrast,  they were significantly lower in PTH and 1, 25(OH)(2);D(3); group than those in PTH group (P<0.05). Western blot results showed α-SMA could not be detected in normal HK-2 cells,  which could be detected in PTH group. TGF-β(1); protein expression in PTH group was higher than that in control group. In PTH and 1, 25(OH)(2);D(3); group,  α-SMA and TGF-β(1); protein expressions were significantly lower than those in PTH group (P<0.05). ICC results showed that α-SMA was hardly expressed in cells of control group. However,  positive expression of α-SMA could be seen in many cells in PTH group. In PTH and 1, 25(OH)(2);D(3); group,  the cells of α-SMA positive expressed were significantly less than those in PTH group (P<0.05). ELISA results showed that the level of TGF-β(1); in the supernatant of PTH group was higher than that in control group,  which was also higher than that in PTH and  1, 25(OH)(2);D(3); group (P<0.05).


CONCLUSIONS
1, 25(OH)(2);D(3); can  attenuate PTH-induced transdifferentiation and TGF-β(1); expression in cultured human renal tubular epithelial cells.
Department of Nephrology, Tangshan Worker's Hospital, Tangshan, China. lixiaodong628@yahoo.com.cn
Xiao-dong
XD
Li
Ying
Y
Li
Xin-guo
XG
Ding
Shan-lin
SL
Gao
Zhi-jun
ZJ
Guo
D000199:Actins / Q000235:genetics / Q000378:metabolism; D002117:Calcitriol / Q000494:pharmacology*; D002460:Cell Line; D054338:Cell Transdifferentiation / Q000187:drug effects*; D004847:Epithelial Cells / Q000166:cytology* / Q000187:drug effects*; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007687:Kidney Tubules, Proximal / Q000187:drug effects / Q000378:metabolism*; D010281:Parathyroid Hormone / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1 / Q000235:genetics / Q000378:metabolism*
C541116:ACTA2 protein, human; D000199:Actins; D010281:Parathyroid Hormone; D053773:Transforming Growth Factor beta1; D002117:Calcitriol