Data from: A short peptide exerts neuroprotective effects on cerebral ischemia-reperfusion injury by reducing inflammation via the miR-6328/IKKβ/NF-κB axis

Methods

A cDNA-encoding peptide was extracted and identified from RNA extracted from Rana limnocharis skin, and its neuroprotective properties were evaluated using a middle cerebral artery occlusion/reperfusion (MCAO/R) model in rats and an oxygen-glucose deprivation/reperfusion (OGD/R) model in neuron-like PC12 cells. The underlying molecular mechanisms were explored using microRNA (miRNA) sequencing, quantitative real-time polymerase chain reaction, dual-luciferase reporter gene assay, and western blotting.

Results A new peptide (NP1) with an amino acid sequence of ‘FLPAAICLVIKTC’ was identified. NP1 showed no obvious toxicities in vivo and in vitro. Intraperitoneal administration of NP1 (10 nmol/kg) effectively reduced the volume of cerebral infarction and relieved neurological dysfunction in MCAO/R model rats.

Moreover, NP1 significantly alleviated the decrease in viability of PC12 cells induced by OGD/R. NP1 effectively suppressed inflammation by reducing interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) levels in vitro and in vivo. Furthermore, NP1 up-regulated the expression of miRNA-6328, which targeted down-regulation of the inflammation-related factor inhibitor kappa B kinase β (IKKβ), thereby reducing nuclear factor-kappa B p65 (NF-κB p65) and inhibitor of NF-κB (I-κB) phosphorylation and inhibiting the NF-κB pathway.

Conclusions NP1 exerted neuroprotective effects by reducing inflammation via the miRNA-6328/IKKβ/NF-κB axis. This study highlights the importance of peptides in the development of new drugs, elucidation of pathological mechanisms, and discovery of new drug targets.