The ROS/GRK2/HIF-1α/NLRP3 Pathway Mediates Pyroptosis of Fibroblast-Like Synoviocytes and the Regulation of Monomer Derivatives of Paeoniflorin

Figure 4

Hypoxia induces fibroblast-like synoviocytes (FLS) pyroptosis by upregulating the expression of nucleotide-binding oligomerization segment-like receptor family 3 (NLRP3) inflammasome in FLS and the effect of monomeric derivatives of paeoniflorin (MDP). (a, b) shHIF-1α was transfected into FLS and exposed to hypoxia for 2 h. The expression of hypoxia-inducible factor (HIF)-1α, NLRP3, speck-like protein containing CARD (ASC), caspase-1, and cleaved-caspase-1 in FLS was detected by Western blot (). (c, d) NLRP3 short hairpin (shNLRP3) construct was transfected into FLS and exposed to hypoxia for 2 h. The expression of HIF-1α, NLRP3, and N-terminal domain of human gasdermin D (GSDMD-N) in FLS after exposure to hypoxia for 2 h was detected by Western blot (). (e, f) FLS were treated with or without MDP and exposed to hypoxia for 2 h. The expression of HIF-1α, NLRP3, ASC, caspase-1, cleaved-caspase-1, and GSDMD-N in FLS was detected by Western blot (). Data are expressed as . ^#, ^## vs. the control group; , vs. the hypoxia group. (g) Analysis of expression levels of HIF-1α in the nucleus. (h) Quantitative PCR analysis and quantification of the mRNA levels of NLRP3, ASC, and caspase-1. Data are expressed as mean SD. ^# vs. the control group; vs. the hypoxia group.

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