Fig. 4.
β-Cell compensation to diet-induced obesity in TIMP-2 KO mice. A, β-Cell mass was increased in male TIMP-2 KO, but not WT, HFD-fed mice (genotype, P = 0.003; diet, P = 0.004). B, β-Cell proliferation was unaltered in chow-fed TIMP-2 KO mice but increased in HFD-fed TIMP-2 KO mice to a greater extent than HFD-fed WT mice (diet, P < 0.0001; genotype, P = 0.0001). C, Male TIMP-2 KO islets in vivo displayed decreased Pdx1 expression. D, Both insulin and GLUT2 expression were decreased in TIMP-2 KO islets in vivo. E, Western blot analysis of isolated islets confirmed decreased Pdx1 and GLUT2 expression observed in vivo. F, HFD had no effect on TIMP-2 expression in isolated islets (Western blotting) or islets in vivo (immunofluorescence). Scale bars, 50 μm. n = 4; *, P < 0.05; #, P < 0.001; ##, P < 0.0001.