Parvalbumin is a calcium-binding albumin protein that is involved in neuronal maturation, differentiation, axonal transport, and neurotransmitter release. Parvalbumin protects neuron from cell death through reduction of intracellular Ca²⁺ concentrations. In this study, we investigated parvalbumin expression after neuronal cell injury. Middle cerebral artery occlusions (MCAO) were surgically performed in a rat model to induce focal cerebral ischemic injury. Adult male rats were used and brain tissues were collected 24 h after MCAO. MCAO increases infarct damages and apoptotic cell death in cerebral cortex. A proteomic approach revealed a decrease of parvalbumin expression in MCAO-operated animals. RT-PCR and Western blot analyses showed that MCAO induces a reduction in parvalbumin transcript and protein levels, respectively. The numbers of parvalbumin-positive cells were also decreased in the cerebral cortices of MCAO-operated animals. Moreover, glutamate exposure significantly increased intracellular Ca²⁺ concentrations and induced a reduction of parvalbumin expression in a hippocampal-derived cell line. These results suggest that the reduction in parvalbumin levels after ischemic brain injury can modulate neuronal cell death.
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