Calreticulin Binds to Fas Ligand and Inhibits Neuronal Cell Apoptosis Induced by Ischemia-Reperfusion Injury

Abstract EN

Background.

Calreticulin (CRT) can bind to Fas ligand (FasL) and inhibit Fas/FasL-mediated apoptosis of Jurkat T cells.

However, its effect on neuronal cell apoptosis has not been investigated.

Purpose.

We aimed to evaluate the neuroprotective effect of CRT following ischemia-reperfusion injury (IRI).

Methods.

Mice underwent middle cerebral artery occlusion (MCAO) and SH-SY5Y cells subjected to oxygen glucose deprivation (OGD) were used as models for IRI.

The CRT protein level was detected by Western blotting, and mRNA expression of CRT, caspase-3, and caspase-8 was measured by real-time PCR.

Immunofluorescence was used to assess the localization of CRT and FasL.

The interaction of CRT with FasL was verified by coimmunoprecipitation.

SH-SY5Y cell viability was determined by MTT assay, and cell apoptosis was assessed by flow cytometry.

The measurement of caspase-8 and caspase-3 activity was carried out using caspase activity assay kits.

Results.

After IRI, CRT was upregulated on the neuron surface and bound to FasL, leading to increased viability of OGD-exposed SH-SY5Y cells and decreased activity of caspase-8 and caspase-3.

Conclusions.

This study for the first time revealed that increased CRT inhibited Fas/FasL-mediated neuronal cell apoptosis during the early stage of ischemic stroke, suggesting it to be a potential protector activated soon after IRI.