[The effects of leptin on neuron apoptosis in mice with cerebral ischemia/reperfusion injury].

Objective: To study the effect of leptin on neuron apoptosis in mice with cerebral ischemia injury.

Methods: Seventy-five male Kuming mice were randomly divided into 3 groups:sham, model and leptin intervention group, respectively. Focal cerebral ischemia/reperfusion injury model in mice was established by middle cerebral artery occlusion. Leptin intervention group was injected with leptin (1g/g weight, I. P.) at 0 min of ischemic injury. Neuron apoptosis was detected by TUNEL staining. The mRNA expression of apoptosis relative gene bcl-2 and caspase-3 were detected by RT-PCR. The protein expression of bcl-2 and caspase-3 were detected by immunohistochemistry.

Results: In model group, most of the neurons in the central area of cerebral ischemia had necrosis obviously, and the amount of neuron apop-tosis was much higher than that in sham group (<0.01). Compared with sham group, both expression of pro-apoptosis gene caspase-3 and anti-apoptosis gene bcl-2 increased significantly in model group (<0.01). Compared with model group, the amount of neuron apoptosis and expression level of caspase-3 were decreased significantly (<0.01), whereas the mRNA and protein expression of bcl-2 were increased sig-nificantly in leptin intervention group (<0.01).

Conclusions: Leptin could reduce neuron apoptosis through down-regulation the expression of caspase-3 and up-regulation the expression of bcl-2. It suggests that leptin could play a neuroprotective role in cerebral ischemia injury.