[1α, 25(OH)(2) D(3) protects pancreatic β-cell line from cytokine-induced apoptosis and impaired insulin secretion].
OBJECTIVE
To explore the protective effects and potential mechanisms of 1α, 25(OH)(2) D(3) (VitD(3)) on pancreatic β-cells.


METHODS
The apoptosis of NIT-1 cells was induced by interleukin-1β (IL-1β) and interferon-γ (IFN-γ) in vitro. Then the apoptotic rate of NIT-1 cells was determined by Hoechest33342 staining and Annexin V-FITC/PI flow cytometry. The insulin secretion level of NIT-1 cells was measured by ELISA. The NIT-1 cells were treated with VitD(3) at the final concentrations of 10(-8) mol/L or underwent transient transfection with vitamin D receptor (VDR)-SiRNA.


RESULTS
After the treatment of VitD(3), the apoptotic rate of NIT-1 cells decreased to 39.7%. There were significant differences in apoptotic rate between the VitD(3) treatment and IL-1β/IFN-γ groups (68.4%) (P < 0.01). Similarly impaired glucose-stimulated insulin secretion (GSIS) of NIT-1 cells recovered ((7.34 ± 0.21) ng/ml) after the treatment of VitD(3) as compared with the IL-1β/IFN-γ group ((4.88 ± 0.32) ng/ml, P < 0.01). Moreover, most of the protective effects of VitD(3) on pancreatic β-cells could be blocked by the transfection of VDR-SiRNA.


CONCLUSIONS
VitD(3) may protect pancreatic β-cells from cytokine-induced apoptosis and impaired insulin secretion through its conjugation with VDR.
Diabetes Center, Second Xiangya Hospital & Institute of Metabolism and Endocrinology, Key Laboratory of Diabetes Immunology, Ministry of Education, Central South University, Changsha 410011, China.
An-ping
AP
Wang
Xia
X
Li
Chen
C
Chao
Gan
G
Huang
Bi-lian
BL
Liu
Jian
J
Peng
Zhi-guang
ZG
Zhou
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002117:Calcitriol / Q000494:pharmacology*; D002460:Cell Line; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000187:drug effects*; D007371:Interferon-gamma / Q000494:pharmacology; D053583:Interleukin-1beta / Q000494:pharmacology; D051379:Mice
D007328:Insulin; D053583:Interleukin-1beta; D007371:Interferon-gamma; D002117:Calcitriol