Moreover, the pancreatic intrinsic nervous system (PINS) was damaged during HFD-STZ-induced T2DM as Fig. 2D. The expression of pan-neuronal marker protein gene product 9.5 (PGP9.5) in the pancreatic tissue of the model group was significantly lower than that in the control rats (Fig. 2E, G). This evidence concerns the gene UCHL1 and type 2 diabetes mellitus.