Expression analysis of molecular chaperones associated with disaggregation complex in rotenone-induced Parkinsonian rat model

Abstract

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the aberrant aggregation and phosphorylation (ser129) of α-synuclein (α-syn, a presynaptic protein) which leads to the formation of pathogenic Lewy bodies. A critical factor in the pathogenesis of PD is the disruption of the cellular protein quality control system, where molecular chaperones and their co-chaperones are integral for mitigating proteotoxic stress. Although the role of molecular chaperones in PD and other protein aggregation diseases has been extensively investigated, the in vivo investigation of disaggregation chaperones, including HSP70, HSP105, and co-chaperone DNAJBs, remains relatively limited. The present study aims to elucidate the expression dynamics of the disaggregation molecular chaperones within the substantia nigra pars compacta of the rotenone-induced Parkinsonian rat model and its association with α-syn aggregation. The rotenone-treated rats exhibited significant behavioural symptoms, α-syn aggregation and degeneration of dopaminergic neurons, confirming the development of Parkinsonism. Significant upregulation of α-syn expression/phosphorylation and co-localization in TH+ve neurons in the SNpc of treated rats was observed. Further, the gene and protein analysis of HSP70, DNAJB6, and HSP105 were found to be upregulated and TH+ve neurons showed their co-localization with p-α-syn^ser129 expression. The total proteomic analysis of SNpc correlated the altered cellular processes with cellular homeostasis imbalance. The observations of the present study provide an in vivo analysis of disaggregation-associated molecular chaperones in Parkinsonian or α-syn related conditions. The study can be helpful for further manipulation in the expression or activity of disaggregation-related chaperones for advanced therapeutic strategies and mechanistic studies in protein aggregation-associated diseases.