Neuroprotective effect of melatonin in cerebellums in Alzheimer's disease animal models via MAPK/ERK signaling pathway / 中国药理学通报

ABSTRACT

Aim: To investigate the effect of melatonin on neuroprotection in cerebellums of rats with Alzheimer' s disease via MAPK/ERK signaling pathway. Methods: Thirty-two male Sprague-Dawley rats were randomly divided into four groups control group, Aβ1-42 lateral ventricle injection group (AD), and melatonin intraperitoneal injection group (MT), and Aβ1-42 lateral ventricle injection combined with melatonin intraperitoneal injection group (AD + MT). The pathological changes of rat cerebellar cortex were detected by HE staining; the expression of NeuN (neuronal marker), Calbindin(Purkinje cell marker) and p-ERK protein in each group was detected by immunofluorescence; the expression of ERK and p-ERK in each group was determined by Western blot. Results: The HE staining showed that the expression of neurons decreased, followed with the disordered arrangement and morphological alteration of cells in AD. Melatonin could significantly alleviate the pathological damage in cerebellum. Immunofluorescence results showed that compared with AD group, the expression of NeuN (neuronal marker) increased, the number of Purkinje cells marked by Calbindin significantly was up-regulated(P < 0. 01), and the expression of p-ERK was down-regulated in AD + MT group. Western blot showed that the expression of p-ERK was down-regulated by melatonin. Conclusions: Melatonin may exert the neuroprotective effect and relieve the pathological changes by inhibiting the activation of MAPK/ERK signaling pathway.