Inhibition of HSP90 protects cultured neurons from oxygen-glucose deprivation induced necroptosis by decreasing RIP3 expression

Heat shock protein 90 (HSP90) maintains cell stabilization and regulates cell death, respectively. Recent studies have shown that HSP90 is involved in receptor interacting protein 3 (RIP3)-mediated necroptosis in HT29 cells. It is known that oxygen and glucose deprivation (OGD) can induce necroptosis, which is regulated by RIP3 in neurons. However, it is still unclear whether HSP90 participates in the process of OGD-induced necroptosis in cultured neurons via the regulation of RIP3. Our study found that necroptosis occurs in primary cultured cortical neurons and PC-12 cells following exposure to OGD insult. Additionally, the expression of RIP3/p-RIP3, MLKL/p-MLKL, and the RIP1/RIP3 complex (necrosome) significantly increased following OGD, as measured through immunofluorescence (IF) staining, Western blotting (WB), and immunoprecipitation (IP) assay. Additionally, data from computer simulations and IP assays showed that HSP90 interacts with RIP3. In addition, HSP90 was overexpressed following OGD in cultured neurons, as measured through WB and IF staining. Inhibition of HSP90 in cultured neurons, using the specific inhibitor, geldanamycin (GA), and siRNA/shRNA of HSP90, protected cultured neurons from necrosis. Our study showed that the inhibitor of HSP90, GA, rescued cultured neurons not only by decreasing the expression of total RIP3/MLKL, but also by decreasing the expression of p-RIP3/p-MLKL and the RIP1/RIP3 necrosome. In this study, we reveal that inhibition of HSP90 protects primary cultured cortical neurons and PC-12 cells from OGD-induced necroptosis through the modulation of RIP3 expression.