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

Abstract

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-Httex1-Q74 insolubility, and reduces the size and cytotoxicity of GFP-Httex1-Q74 aggregates in PC-12 cells. Conclusion This recombinant sHSPB5-Fc exhibits chaperone activity to protect cells against proteotoxicity.

Alpha B-Crystallin in Muscle Disease Prevention: The Role of Physical Activity

“…The most prominent and well-studied member of sHSPs family is HSPB5 (alpha B-crystallin, CRYAB), a protein playing a crucial role in several cellular processes related to survival and stress recovery [ 13 , 14 ]. HSPB5 is expressed constitutively in a variety of tissues including lens, skeletal muscle, heart, brain, lung, and kidney, as well as in extracellular fluids where it exhibits pleiotropic roles [ 14 , 15 , 16 , 17 , 18 ]. Moreover, scientific evidence highlights the importance of this protein in maintaining cellular functions; indeed, either HSPB5 overexpression or its deleterious mutations are found in a number of known disorders [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ].…”