The engineered expression of secreted HSPB5-Fc in CHO cells exhibits cytoprotection in vitro

BACKGROUND: HSPB5 is an ATP-independent molecular chaperone that is induced by heat shock or other proteotoxic stresses. HSPB5 is cytoprotective against stress both intracellularly and extracellularly. It acts as a potential therapeutic candidate in ischemia-reperfusion and neurodegenerative diseases. RESULTS: In this paper, we constructed a recombinant plasmid that expresses and extracellularly secrets a HSPB5-Fc fusion protein (sHSPB5-Fc) at 0.42 μg/ml in CHO-K1 cells. This sHSPB5-Fc protein contains a Fc-tag at the C-terminal extension of HSPB5, facilitating protein-affinity purification. Our study shows that sHSPB5-Fc inhibits heat-induced aggregation of citrate synthase in a time and dose dependent manner in vitro. Administration of sHSPB5-Fc protects lens epithelial cells against cisplatin- or UVB-induced cell apoptosis. It also decreases GFP-Htt(ex1)-Q74 insolubility, and reduces the size and cytotoxicity of GFP-Htt(ex1)-Q74 aggregates in PC-12 cells. CONCLUSION: This recombinant sHSPB5-Fc exhibits chaperone activity to protect cells against proteotoxicity. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12896-021-00700-y.