Figure 3: The effect of DPP4 inhibition on collagen IV expression DPP4 inhibition with linagliptin (30 nM) did not reduce high glucose induced collagen IV expression. HK2 cells were treated with high glucose (30 mM) and linagliptin (30 nM) for 24 h. Cell lysate was collected and collagen IV was quantitated using western blot. N=3, *p<0.05 vs. ctrl.