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. 2022 Apr 6;2022:1835900. doi: 10.1155/2022/1835900

Figure 5.

Figure 5

ERS signaling inhibitor 4-PBA reverses chondrocyte proliferation, apoptosis, and inflammation caused by USP7 knockdown under TNF-α-induced inflammation. (a) Relative BiP and CHOP mRNA expression in USP7 knockdown and its control groups under TNF-α-induced inflammation after 48 h chondrogenic induction, with and without 4-PBA. (b) p-eIF2α, eIF2α, ATF4, CHOP, p-p65, and p65 protein expression in USP7 knockdown and its control groups under TNF-α-induced inflammation after 48 h chondrogenic induction, with and without 4-PBA. (c) Quantitative measurement of (b). (d) Alcian blue and toluidine blue staining in USP7 knockdown and its control groups under TNF-α-induced inflammation after 48 h chondrogenic induction, with and without 4-PBA. Scale bars = 100 μm. (e) Growth curves in USP7 knockdown and its control groups under TNF-α-induced inflammation after 48 h chondrogenic induction, with and without 4-PBA, measured by CCK8-assay. (f) Relative Col2a1 and Sox9 mRNA expression in USP7 knockdown and its control groups under TNF-α-induced inflammation after 48 h chondrogenic induction, with and without 4-PBA. (g) Col2a1, Sox9, Cleaved Caspase-3, Bax, and Bcl-2 protein expression in USP7 knockdown and its control groups under TNF-α-induced inflammation after 48 h chondrogenic induction, with and without 4-PBA. (h) Quantitative measurement of (g). (i) Relative Caspase-3 activity in USP7 knockdown and its control groups under TNF-α-induced inflammation after 48 h chondrogenic induction, with and without 4-PBA. (j) TUNEL staining in USP7 knockdown and its control groups under TNF-α-induced inflammation after 48 h chondrogenic induction, with and without 4-PBA. White arrows indicate TUNEL-positive cells. Scale bars = 50 μm. (k) Quantitative measurement of (j). (l) Relative IL-6, COX, NOS2, and MMP13 mRNA expression of in USP7 knockdown and its control groups under TNF-α-induced inflammation after 48 h chondrogenic induction, with and without 4-PBA. (m) IL-6 expression in USP7 knockdown and its control group supernatant under TNF-α-induced inflammation after 48 h chondrogenic induction, with and without 4-PBA. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001, and ∗∗∗∗p < 0.0001.