Z M Huang1, S H Du2, L G Huang3, J H Li4, L Xiao5, P Tong6. 1. Department of Orthopaedic Surgery, Xiaoshan Chinese Medical Hospital, China; Department of Orthopaedic Surgery, Affiliated Jiangnan Hospital of Zhejiang Chinese Medical University, China; Zhejiang Chinese Medical University, China; Institute of Orthopaedics and Traumatology of Zhejiang Province, China. 2. Department of Orthopedic Surgery, the Second Affiliated Hospital, School of Medicine, Zhejiang University, China. 3. Zhejiang Chinese Medical University, China. 4. Department of Orthopaedic Surgery, Xiaoshan Chinese Medical Hospital, China. 5. Zhejiang Chinese Medical University, China; Institute of Orthopaedics and Traumatology of Zhejiang Province, China; Department of Orthopaedic Surgery, the First Affiliated Hospital of Zhejiang Chinese Medical University, China. 6. Zhejiang Chinese Medical University, China; Institute of Orthopaedics and Traumatology of Zhejiang Province, China; Department of Orthopaedic Surgery, the First Affiliated Hospital of Zhejiang Chinese Medical University, China. Electronic address: pjtongzj@sina.com.
Abstract
OBJECTIVE: Leptin has been found highly expressed in human osteoarthritis. We aimed to explore the possible effects and mechanisms of leptin on the apoptosis and autophagy of chondrocytes during osteoarthritis pathogenesis. METHODS: Gene expression profile from osteoarthritis affected and preserved cartilage were downloaded from NCBI's Gene Expression Omnibus database (GSE57218). Lysyl oxidase-like 3 (LOXL3) mRNA expression in cartilage tissues and leptin concentration in joint synovial fluid (SF) was measured in samples from 45 osteoarthritis patients and 25 healthy donors by real-time PCR and radioimmunoassay, respectively. Rat osteoarthritis model was induced by anterior cruciate ligament transection (ACLT). The expression of apoptosis regulators and autophagy markers were detected by Western blot. Cell survival and cell apoptosis were identified by CCK-8 and flow cytometry, respectively. RESULTS: Re-analysis on GSE57218 indicated that LOXL3 mRNA was upregulated in osteoarthritis affected cartilage. LOXL3 mRNA was upregulated in osteoarthritis patients, which was positively correlated with SF leptin concentration. Similar results were obtained in rat osteoarthritis model. Moreover, ACLT surgery led to a significant increase in the protein levels of cleaved caspase 3, and a notable decrease in the protein levels of Bcl-2, LC3 II/LC3 I and Beclin1. Silencing of LOXL3 in ACLT and leptin treated primary chondrocytes significantly inhibited cell apoptosis, and promoted cell proliferation and autophagy. Moreover, overexpression of LOXL3 remarkably inhibited autophagy of chondrocytes via activating mTORC1. CONCLUSIONS: LOXL3, a downstream of leptin, stimulated the apoptosis, but inhibited the autophagy of chondrocytes. LOXL3 is a potential therapy target for osteoarthritis.
OBJECTIVE:Leptin has been found highly expressed in humanosteoarthritis. We aimed to explore the possible effects and mechanisms of leptin on the apoptosis and autophagy of chondrocytes during osteoarthritis pathogenesis. METHODS: Gene expression profile from osteoarthritis affected and preserved cartilage were downloaded from NCBI's Gene Expression Omnibus database (GSE57218). Lysyl oxidase-like 3 (LOXL3) mRNA expression in cartilage tissues and leptin concentration in joint synovial fluid (SF) was measured in samples from 45 osteoarthritispatients and 25 healthy donors by real-time PCR and radioimmunoassay, respectively. Ratosteoarthritis model was induced by anterior cruciate ligament transection (ACLT). The expression of apoptosis regulators and autophagy markers were detected by Western blot. Cell survival and cell apoptosis were identified by CCK-8 and flow cytometry, respectively. RESULTS: Re-analysis on GSE57218 indicated that LOXL3 mRNA was upregulated in osteoarthritis affected cartilage. LOXL3 mRNA was upregulated in osteoarthritispatients, which was positively correlated with SF leptin concentration. Similar results were obtained in ratosteoarthritis model. Moreover, ACLT surgery led to a significant increase in the protein levels of cleaved caspase 3, and a notable decrease in the protein levels of Bcl-2, LC3 II/LC3 I and Beclin1. Silencing of LOXL3 in ACLT and leptin treated primary chondrocytes significantly inhibited cell apoptosis, and promoted cell proliferation and autophagy. Moreover, overexpression of LOXL3 remarkably inhibited autophagy of chondrocytes via activating mTORC1. CONCLUSIONS:LOXL3, a downstream of leptin, stimulated the apoptosis, but inhibited the autophagy of chondrocytes. LOXL3 is a potential therapy target for osteoarthritis.
Authors: Alfonso Cordero-Barreal; María González-Rodríguez; Clara Ruiz-Fernández; Djedjiga Ait Eldjoudi; Yousof Ramadan Farrag AbdElHafez; Francisca Lago; Javier Conde; Rodolfo Gómez; Miguel Angel González-Gay; Ali Mobasheri; Jesus Pino; Oreste Gualillo Journal: Int J Mol Sci Date: 2021-02-27 Impact factor: 5.923