IRAK1 and Hyperglycemia: Sildenafil, a phosphodiesterase type 5 inhibitor, improved DSP by enhancing miRNA-146a expression and decreasing the levels of IL-1 receptor-activated kinase (IRAK1) and TNF receptor-associated factor (TRAF) 6 levels in DRG neurons since blockage of miR-146a diminished the effects sildenafil on the expression of IRAK1 and TRAF6 and lost the protection of DRG neurons during hyperglycemia [210].