Anti-HSPB2 monoclonal antibody, clone BG6F6

Anesthetic preconditioning occurs when cells previously exposed to inhaled anesthetics are protected against subsequent injury. We hypothesize that inhaled anesthetics may cause slight protein misfolding that involves site-specific dehydration, stimulating cytoprotective mechanisms. Human neuroblastoma cells were exposed to ethanol (as the dehydration agent) followed by quantitative analysis of the expression of five heat shock genes: DNAJC5G, CRYAA, HSPB2, HSF4 and HSF2. There was an ethanol-induced upregulation of all genes except HSF4, similar to previous observations using iso-flurane. CRYAA (the gene for alphaA-crystallin) exhibited a 23.19 and 17.15-fold increase at 24 and 48 h post ethanol exposure, respectively. Additionally, we exposed glyceraldehyde 3-phosphate dehydrogenase to ethanol, which altered oligomeric subspecies and caused protein aggregation in a concentration-dependent manner. Ethanol-mediated dehydration-induced protein aggregation was prevented by incubation with alpha-crystallin. These data indicate that ethanol mimics the effects of isoflurane presumably through a cellular preconditioning mechanism that involves dehydration-induced protein aggregation.

The small heat shock protein family (sHsp) comprises molecular chaperones able to interact with incorrectly folded proteins. Alzheimer's disease (AD) is characterized by pathological lesions such as senile plaques (SPs), cerebral amyloid angiopathy (CAA) and neurofibrillary tangles (NFTs), predominantly consisting of the incorrectly folded proteins amyloid-beta (A beta) and tau respectively. The aim of this study was to investigate the association of the chaperones Hsp20, HspB2, alpha B-crystallin and Hsp27 with the pathological lesions of AD brains. For this purpose, a panel of well-characterized antibodies directed against these sHsps was used in immunohistochemistry and immunoblotting. We observed extracellular expression of Hsp20, Hsp27 and HspB2 in classic SPs, and Hsp20 expression in diffuse SPs. In addition, extracellular expression of HspB2 was observed in CAA. Both Hsp27 and alpha B-crystallin were also observed in astrocytes associated with both SPs and CAA. Furthermore, none of the sHsps were observed in NFTs in AD brains. We conclude that specific sHsp species may be involved in the pathogenesis of either SPs or CAA in AD.