Effects Of N-linked Oligosaccharide Chains On Proliferation, Expression Of β₁ Integrin And Cyclin D₁ In High Glucose-induced Glomerular Mesangial Cells

OBJECTIVE: Mesangial expansion is the pathological foundation ofdiabetic nephropathy which exact mechanisms have not been defined. Integrins are some N-glycosylated proteins which are located on the cell surface. Through binding to their receptors, they are involved in regulating gene expression, cell cycle progression, cell differentiation and apoptosis. The obeject of our experiment was to observe the effects of TM-the inhibitor of N-glycosylation of proteins on the expression of β₁ integrin and cyclin D₁ in high glucose-induced glomerular mesangial cells(GMC), in order to explore the effect of inhibitors of N-linked oligosacchande chains on the cell proliferation and discuss the interaction of β₁ integrin and cyclin D₁, attempt to find a new synteresis method of diabetic nephropathy.METHODS: Cultured HBZY-1 rat mesangial cells were divided into 5groups: control group, high glucose-treated group; mannitol- treated group; high glucose and TM-treated group, TM-treated group. The expression of β₁ integrin was measured by flow cytometry, and expression of cyclin D₁ wasmeasured by immunohistochemistry, and proliferation of GMCs was measured by MTT.RESULTS:1. Control group has the expression of Pi integrin and cyclin Dj.2. The expression of Pi integrin and cyclin Di was increased in high glucose-treated group. There is no significant difference in mannitol-treated group and proliferated ability was increased in high glucose-treated group.3.The expression of Pi integrin and cyclin Di was decreased notably in TM-treated group and TM-high glucose treated group, and proliferation of cell is decreased in TM and high glucose-TM treated group.CONCLUSIONS:1. The expression of Pi integrin and cyclin Di exists in normal glomerular mesangial cells.2. High glucose can stimulate significantly expression of Pi integrin and cyclin Di, and induce the GMCs proliferation.3. TM can decrease notably the expression of Pi integrin and cyclin Di, and inhibited cell proliferation.4. There is somewhat correlation between the expression of Pi integrin, cyclin Di and proliferation. Integrin P i maybe regulates cell proliferation through cyclin Dj.