[Effect of parathyroid hormone and 1,25-(OH)2-D3 on the expression of the mRNA of calbindin D9k in Caco-2 cells].
OBJECTIVE
To study the effect of parathyroid hormone (PTH) on the expression of the mRNA of calbindin D9k(CaBP-D9k) in Caco-2 Cells and whether PTH influences the effect of 1,25-(OH)2-D3 on the expression of calbindin mRNA in Caco-2 Cells.


METHODS
Caco-2 cells were used as the model of human small intestinal enterocytes. Caco-2 cells were treated 5, 10, 20, 40 and 80 min at the dose of 10(-8), 10(-9) and 10(-12) mol/L PTH, another groups of Caco-2 cells were treated for 2, 4, 8, 16 and 24h at the dose of 10(-8) mol/L 1,25-(OH)2-D3 alone. The other groups of Caco-2 cells were treated for 2, 4, 8, 16 and 24h at the dose of 10(-8) mol/L 1,25-(OH)2-D3 plus at the dose of 10(-8), 10(-9) and 10(-12) mol/L of PTH respectively. 0.1% ethanol solutions were used as the vehicle for the later two groups. The expression of calbindin D9k mRNA was determined by RT-PCR (the level of GAPDH was taken as internal control).


RESULTS
The expressions of calbindin D9k mRNA were more higher than those of blank controls when Caco-2 cells were treated at the dose of 10(-8) mol/L 1,25-(OH)2-D3 for 2, 4, 8, 16 and 24h, the expressions of CaBP-D9k mRNA were higher than those of vehicle. The increases of CaBP-D9k mRNA levels caused by 10(-8) mol/L 1,25-(OH)2-D3 plus PTH were more lower than those caused by 1,25-(OH)2-D3 alone.


CONCLUSIONS
10(-8) and 10(-12) mol/L PTH probably caused increase on the expression of CaBP-D9k mRNA in short period (1 - 20min). 10(-8) mol/L 1,25-(OH)2-D3 increases CaBP-D9k mRNA levels in Caco-2 cells. PTH may inhibit or counteract the increase in CaBP-D9k mRNA caused by 1,25-(OH)2-D3 in Caco-2 cells.
Mao
Xuedan
X
Institute of Nutrition and Food Safety, China Center for Disease Control and Prevention, Beijing 100021, China.
Mao
Zebin
Z
Huo
Zhuoping
Z
D018938:Caco-2 Cells; D064026:Calbindins; D002117:Calcitriol / Q000494:pharmacology*; D006801:Humans; D010281:Parathyroid Hormone / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D064030:S100 Calcium Binding Protein G / Q000235:genetics / Q000378:metabolism*
D064026:Calbindins; D010281:Parathyroid Hormone; D012333:RNA, Messenger; D064030:S100 Calcium Binding Protein G; C576506:S100G protein, human; D002117:Calcitriol