HSPB8

HSPB8 Full Name

heat shock 22kDa protein 8

HSPB8 Introduction

HSPB8 (heat shock protein 22 kDa protein 8), also known as Hsp22, is a member of the small heat shock protein (sHSP) family that plays an essential role in maintaining cellular proteostasis under physiological and stress conditions. Small heat shock proteins act as ATP-independent molecular chaperones that stabilize misfolded or damaged proteins and prevent their toxic aggregation. HSPB8 is widely expressed in skeletal muscle, cardiac tissue, and the nervous system, where cells are particularly vulnerable to proteotoxic stress. In recent years, researchers have increasingly focused on HSPB8 because disruptions in protein quality control pathways are a major challenge in understanding neurodegenerative and neuromuscular diseases. As a result, HSPB8 has emerged as an important molecular target in studies aiming to understand how cells respond to protein misfolding and maintain intracellular protein balance.

Functionally, HSPB8 is a key regulator of protein quality control through a specialized pathway known as chaperone-assisted selective autophagy (CASA). In this process, HSPB8 cooperates with co-chaperones such as BAG3, HSC70, and the ubiquitin ligase CHIP to identify and eliminate misfolded or aggregation-prone proteins. This chaperone complex promotes the autophagic degradation of damaged proteins, thereby protecting cells from proteotoxic stress. Experimental studies have shown that HSPB8 can facilitate the clearance of pathogenic proteins such as mutant SOD1 and TDP-43, which are strongly associated with neurodegenerative disorders. By enhancing autophagy and maintaining protein homeostasis, HSPB8 plays a critical protective role in neurons and muscle cells, making it a promising molecular target for therapeutic strategies designed to mitigate diseases driven by protein aggregation.

Growing evidence also links HSPB8 to a wide spectrum of human diseases, particularly neuromuscular disorders and cancers. Genetic mutations in the HSPB8 gene have been associated with several inherited neuromuscular diseases, including distal hereditary motor neuropathy (dHMN) and Charcot–Marie–Tooth disease type 2L (CMT2L). Many pathogenic missense mutations occur in the N-terminal region or the conserved α-crystallin domain, often resulting in toxic gain-of-function effects that impair the CASA pathway and promote protein aggregation. Beyond neuromuscular disorders, HSPB8 has also been implicated in cancer biology. For example, elevated HSPB8 expression has been reported in bladder cancer and correlates with immune cell infiltration and poorer clinical outcomes, suggesting its value as a potential prognostic biomarker. In contrast, reduced HSPB8 expression in prostate cancer has been linked to enhanced tumor proliferation and migration, possibly through dysregulation of the PI3K–AKT signaling pathway. These findings highlight the context-dependent roles of HSPB8 in disease progression and underscore its growing importance as both a biomarker and a potential therapeutic target in precision medicine research.

Alternate Names for HSPB8

HSPB8; heat shock 22kDa protein 8; H11; HMN2; CMT2L; DHMN2; E2IG1; HMN2A; HSP22; heat shock protein beta-8; protein kinase H11; alpha-crystallin C chain; E2-induced gene 1 protein; heat shock 27kDa protein 8; small stress protein-like protein HSP22;

• 1.Rashed HR, et al.; The Spectrum of Small Heat Shock Protein B8 (HSPB8)-Associated Neuromuscular Disorders. Int J Mol Sci. 2025, 26(7):2905.
  2.Tan Z, et al.; HSPB8 is a Potential Prognostic Biomarker that Correlates With Immune Cell Infiltration in Bladder Cancer. Front Genet. 2022, 13:804858.