Role of CypD-mediated mPTP in melatonin improving cognitive impairment induced by repeated exposure to sevoflurane / 中国药理学通报

ABSTRACT

Aim To investigate the involvement of cy-clophilin D ( CypD ) -mediated mitochondrial permeability transition pore ( mPTP) in the neuroprotective effects of melatonin on cognitive impairment induced by repeated exposure to sevoflurane in newborn animals. Methods Mice were randomly assigned into control group, sevoflurane ( Sevo) group, and melatonin pre-treatment + sevoflurane ( Sevo + Mel) group. JC-1 kit was used to assess the mitochondrial membrane potential ( MMP) ; Western blot analysis was used to evaluate the protein expressions of CypD, postsynaptic density protein 95 ( PSD95 ), and Synapsin-1; and behavioral test were employed to measure cognitive function. Results The MMP level in the Sevo group was significantly reduced compared to the control group (P < 0. 01 ), the expression of CypD increased (P <0. 05), whereas the expression of PSD95 and Synapsin-1 decreased ( P < 0. 01) . Furthermore, the new object recognition index and spatial memory ability both exhibited a significant decline (P < 0. 01, P < 0. 05). However, when compared to the Sevo group, Sevo + Mel group could raise the MMP level (P <0. 01), increase the expression of synaptic proteins ( P < 0. 05 ), decrease the expression of CypD (P <0. 01) and elevate the new object recognition index and the spatial memory capacity ( P < 0. 01 ). Conclusions Melatonin could ameliorate cognitive impairment induced by repeated exposure to sevoflurane in newborn mice, and the underlying mechanism may be attributed to the inhibition of mPTP mediated by CypD and the promotion of synaptic protein synthesis.