This study aims to investigate the effects and the molecular mechanism of Huangdi Anxiao Capsules(HDAX)-containing serum in protecting the rat adrenal pheochromocytoma(PC12) cells from diabetes-associated cognitive dysfunction induced by high glucose and whether the mechanism is related to the regulation of NOD-like receptor thermal protein domain associated protein 3(NLRP3)-mediated pyroptosis. The PC12 cell model of diabetes-associated cognitive dysfunction induced by high glucose was established and mcc950 was used to inhibit NLRP3. PC12 cells were randomized into control, model, HDAX-containing serum, mcc950, and HDAX-containing serum+mcc950 groups. Methyl thiazolyl tetrazolium(MTT) assay was employed to determine the viability, and Hoechst 33258/PI staining to detect pyroptosis of PC12 cells. Enzyme-linked immunosorbent assay(ELISA) was employed to measure the levels of interleukin-1 beta(IL-1β) and IL-18. Western blot was employed to determine the protein levels of postsynaptic density protein 95(PSD-95), NLRP3, apoptosis-associated speck-like protein containing a CARD(ASC), gasdermin D(GSDMD), GSDMD-N, and cleaved cysteinyl aspartate specific proteinase-1(caspase-1), and RT-PCR to determine the mRNA levels of NLRP3, ASC, GSDMD, and caspase-1. The immunofluorescence assay was adopted to measure the levels and distribution of NLRP3 and GSDMD-N in PC12 cells. Compared with the control group, the model group showed decreased cell proliferation, increased PI positive rate, down-regulated protein level of PSD-95, up-regulated protein levels of NLRP3, ASC, GSDMD-N, GSDMD, and cleaved caspase-1, up-regulated mRNA levels of NLRP3, ASC, GSDMD, and caspase-1, and elevated levels of IL-1β and IL-18. Compared with the model group, HDAX-containing serum, mcc950, and the combination of them improved cell survival rate and morphology, decreased the PI positive rate, down-regulated the protein levels of NLRP3, ASC, GSDMD-N, GSDMD, and cleaved caspase-1 and the mRNA levels of NLRP3, ASC, GSDMD, and caspase-1, and promoted the secretion of IL-1β and IL-18. The findings demonstrated that HDAX-containing serum can inhibit the pyroptosis-mediated by NLRP3 and protect PC12 cells from the cognitive dysfunction induced by high glucose.
Keywords: Huangdi Anxiao Capsules-containing serum; NLRP3 inflammasome; PC12 cells; pyroptosis.