Department of Orthopaedic Surgery, Chang Gung Memorial Hospital, Linkou, Taiwan; Department of Nursing, Chang Gung University of Science and Technology, Taoyuan, Taiwan.
Department of Orthopaedic Surgery, E-Da Hospital, I-Shou University.
Osteoarthritis Cartilage. 2019 Sep;27(9):1372-1381. doi: 10.1016/j.joca.2019.05.011. Epub 2019 May 27.
MicroRNA (miRNA)107 expression is downregulated but high mobility group box 1 (HMGB-1), Toll-like receptors (TLRs), and receptor for advanced glycation end products (RAGE) are upregulated in osteoarthritic (OA) cartilage. We investigated mir-107/HMGB-1 signaling in OA after hyperbaric oxygen (HBO) treatment.
MiR-107 mimic was transfected and the HMGB-1 was analyzed in OA chondrocytes. MiRNA targets were identified using bioinformatics and a luciferase reporter assay. After HBO treatment, the mRNA or protein levels of HMGB-1, RAGE, TLR2, TLR4, and inducible nitric oxide (NO) synthase (iNOS) and phosphorylation of mitogen-activated protein kinase (MAPK) were evaluated. The secreted HMGB-1 and matrix metalloproteases (MMPs) levels were quantified. Finally, we detected the HMGB-1 and iNOS expression in rabbit cartilage defects.
Overexpression of miR-107 suppressed HMGB-1 expression in OA chondrocytes. The 3'UTR of HMGB-1 mRNA contained a 'seed-matched-sequence' for miR-107. MiR-107 was induced by HBO and a marked suppression of HMGB-1 was observed simultaneously in OA chondrocytes. Knockdown of miR-107 upregulated HMGB-1 expression in hyperoxic cells. HBO downregulated the mRNA and protein expression of HMGB-1, RAGE, TLR2, TLR4, and iNOS, and the secretion of HMGB-1. HBO decreased the nuclear translocation of nuclear factor (NF)-κB, downregulated the phosphorylation of MAPK, and significantly decreased the secretion of MMPs. Morphological and immunohistochemical observation demonstrated that HBO markedly enhanced cartilage repair and the area stained positive for HMGB-1 and iNOS tended to be lower in the HBO group.
HBO inhibits HMGB-1/RAGE signaling related pathways by upregulating miR-107 expression in human OA chondrocytes.
微小 RNA（miRNA）107 的表达下调，但高迁移率族蛋白 B1（HMGB-1）、 Toll 样受体（TLRs）和晚期糖基化终产物受体（RAGE）在骨关节炎（OA）软骨中上调。我们研究了高压氧（HBO）治疗后 OA 中的 mir-107/HMGB-1 信号。
转染 miR-107 模拟物并分析 OA 软骨细胞中的 HMGB-1。使用生物信息学和荧光素酶报告基因检测鉴定 miRNA 靶标。HBO 治疗后，评估 HMGB-1、RAGE、TLR2、TLR4 和诱导型一氧化氮合酶（iNOS）的 mRNA 或蛋白水平以及丝裂原活化蛋白激酶（MAPK）的磷酸化。定量测定分泌的 HMGB-1 和基质金属蛋白酶（MMPs）水平。最后，我们检测了兔软骨缺损中 HMGB-1 和 iNOS 的表达。
miR-107 的过表达抑制了 OA 软骨细胞中 HMGB-1 的表达。HMGB-1 mRNA 的 3'UTR 包含 miR-107 的“种子匹配序列”。HBO 诱导 miR-107，同时 OA 软骨细胞中 HMGB-1 的表达明显受到抑制。缺氧细胞中 miR-107 的敲低上调了 HMGB-1 的表达。HBO 下调了 HMGB-1、RAGE、TLR2、TLR4 和 iNOS 的 mRNA 和蛋白表达，以及 HMGB-1 的分泌。HBO 减少了核因子（NF）-κB 的核转位，下调了 MAPK 的磷酸化，并显著减少了 MMPs 的分泌。形态学和免疫组织化学观察表明，HBO 明显促进了软骨修复，HBO 组中 HMGB-1 和 iNOS 染色阳性的区域趋于较低。
HBO 通过上调人 OA 软骨细胞中 miR-107 的表达抑制了 HMGB-1/RAGE 信号通路。
