MAPK8 and diabetes mellitus: The main findings of the current study are: 1) Overexpression of the proNGF mimics diabetes action resulting in retinal neurodegeneration in vivo and in vitro, 2) Inhibiting Rho kinase exerted neuroprotective effects by inhibiting p75NTR expression, inhibiting inflammation and activation of JNK/p38MAPK in response to proNGF or diabetes (Fig. 8).