An Experimental Study On The Effect Of 1,25(OH)2D3 On The Improvement Of High Glucose Load Damage In U-937 Cells

Background and Purpose:As a liposoluble vitamin, Vitamin D (VD) plays an important role in regulating calcium and phosphorous metabolism, bones metabolism and sclerotin formation. It is found in recent studies that VD involves in the pathophysiological processes, such as inflammatory reaction,immune adjustment and glucolipid metabolism, except for traditional calcium and phosphorous metabolism. The study shows that VD plays an important role in the development of2-type diabetes. The VD level in serum is negatively correlated to the incidence of2-type diabetes. Replenishment of VD may become a means of prevention and cure against diabetes. This project is to research high glucose loading U-937cell functions by vitamin D and discuss relevant biological mechanism to provide evidences on the application of Vitamin D.Methods:Adopt human's mononuclear cell line U-937and divide the cells into six groups. There are8parallel holes to intervene glucose with different concentrations of11mmol/L (Contrast Group),15mmol/L (high-glucose1Group),20mmol/L (high-glucose2Group),25mmol/L (high-glucose3Group),30mmol/L (high-glucose4Group) and45mmol/L (high glucose-5Group). Test the phagocytic function, interleukin-6(IL-6) and resistin secretion of monocytes in each group after24-hour intervention. Based on the above experiment results, establish the high glucose status of U-937cell with a glucose concentration of45mmol/L. Divide the cell lines into five groups. Each group has8parallel holes. Intervene on each group with glucose of45mmol/L concentration for24hours. The high glucose status will be established24hours later. With exception to Contrast Group, intervene each experiment group with1,25(OH)2D3in different concentrations of3.2*10-11mol/L(VD31Group),1.6*10-10mol/L(VD32Group),8*10-10mol/L (VD33Group) and4*10-9mol/L (VD34Group).Test the phagocytic function, interleukin-6(IL-6) and resistin secretion of monocytes in each group after24-hour intervention. The phagocytic function of monocytes is tested with flow cytometry while IL-6and resistin are tested with enzyme-linked immunosorbent assay (ELISA).Results:After24-hour intervention with glucose of different concentrations, the phagocytic function of monocytes in high-glucose4group(30mmol/L) and high-glucose5groups(45mmol/L) are respectively38.74and35.03, which are distinctly lower than46.66of Contrast Group. The resistin concentrations of high-glucose2Group(20mmol/L), high-glucose3group(25mmol/L), high-glucose4group and high-glucose5groups are respectively15.74ng/mL,15.54ng/mL,17.97ng/mL and28.04ng/mL, which are distinctly higher than11.63ng/mL of Contrast Group. The IL-6concentrations in high-glucose4group and high-glucose5groups are respectively20.9pg/mL and31.68pg/mL, which are distinctly higher than15.55pg/mL of Contrast Group. After the intervention on monocytes with different concentrations of l,25(OH)2D3'in high glucose, the fluorescene intensity of VD32Group(1.6*10-10mol/L) is41.2, which is obviously higher than34.86of Contrast Group. The concentrations of resistin and IL-6in each experiment group are remarkably lower than that of Contrast Group.Conclusion:High concentration glucose can restrain the phagocytic function of monocytes and promote the secretion of resistin and IL-6.1,25(OH)2D3may improve the effect of high glucose on the phagocytic function of monocytes and restrain the secretion of resistin and IL-6.