The heat shock response (HSR) is responsible for the maintenance of proteome integrity within cells. HSR is induced under conditions of proteotoxic stress such as the presence of aggregates or aberrantly-folded proteins, as observed in Huntington´s disease (HD). The master regulator of the HSR is HSF1, which regulates the transcriptional activation of the heat shock genes. The pharmacological induction of HSR is a promising therapeutic strategy in HD. Previously our group has shown that HSR pharmacological induction reduces aggregation and improves survival in HD mouse models. However, these effects were transient as the ability to induce HSR became impaired with disease progression.Aims
To study the mechanisms involved in HSR impairment in HD and how this progressive impairment could be improved or restored by increasing HSF1 activity.Methods
C57BL/6J mice were dosed with the HSP90 inhibitor NVP-HSP990, which releases HSF1 from its HSP90 inhibitory complex. To quantify heat shock protein (HSP) gene expression, we have established a novel Quantigene multiplex assay (ThermoFisher Scientific) to measure the concomitant expression of 11 HSPs and their regulators. Quantitative RT-PCR (qPCR) was used to validate the expression of a subset of these genes.Results
Our results have identified a set of HSP genes that are induced by NVP-HSP990 in mouse brain and muscle. The multiplex HSP Quantigene assay produces comparable data to qPCR, whilst its simple workflow on tissues homogenates allows the analysis of many more HSP genes that is practical by qPCR. We have used these tools to define the kinetics of the pharmacological HSR induction.Conclusions
The establishment of the multiplex HSP Quantigene assay, together with NVP-HSP990 provides the tools with which to investigate approaches to restore the HSR impairment in HD.Conclusions
This work is supported by the CHDI Foundation.