S Li1, G Niu2, Y Wu3, G Du4, C Huang5, X Yin6, Z Liu7, C Song8, H Leng9. 1. Department of Orthopaedics, Peking University Third Hospital, Beijing 100191, China. Electronic address: 986454119@qq.com. 2. Beijing Key Lab of Spine Diseases, Beijing 100191, China. Electronic address: tiankun23@163.com. 3. 2nd Dental Center, Peking University School and Hospital of Stomatology, Beijing 100101, China. Electronic address: yuweiwu@bjmu.edu.cn. 4. Department of Orthopaedics, Peking University Third Hospital, Beijing 100191, China. Electronic address: duguohong1@126.com. 5. Medical Central Lab, Peking University Third Hospital, Beijing 100191, China. Electronic address: candyhuang719@hotmail.com. 6. Beijing Key Lab of Spine Diseases, Beijing 100191, China. Electronic address: luckyemail2008@sina.com. 7. Department of Orthopaedics, Peking University Third Hospital, Beijing 100191, China. Electronic address: liuzj@med.mail.com.cn. 8. Beijing Key Lab of Spine Diseases, Beijing 100191, China. Electronic address: schl@bjmu.edu.cn. 9. Department of Orthopaedics, Peking University Third Hospital, Beijing 100191, China. Electronic address: lenghj@bjmu.edu.cn.
Abstract
OBJECTIVE: To explore the effect of vitamin D on turnover of articular cartilage with ovariectomy (OVX) induced OA, and to investigate transforming growth factor-β1 (TGF-β1) as a possible underlying mechanism mediated by 1α,25(OH)2D3. DESIGN: Sixty-six rats were randomly allocated into seven groups: sham plus control diet (SHAM+CTL), OVX+CTL diet, sham plus vitamin D-deficient (VDD) diet, OVX+VDD diet, and three groups of ovariectomized rats treated with different doses of 1α,25(OH)2D3. The cartilage erosion and the levels of serum 17β-estradiol, 1α,25(OH)2D3 and C-telopeptide of type II collagen (CTX-II) were measured. TGF-β1, type II Collagen (CII), matrix metalloproteinases (MMP)-9,-13 in articular cartilage were assessed by immunohistochemistry. TGF-β1 and CTX-II expression were measured in articular cartilage chondrocytes treated with/without tumor necrosis factor (TNF-α), 1α,25(OH)2D3, and TGF-β receptor inhibitor (SB505124) in vitro. RESULTS: Cartilage erosion due to OVX was significantly reduced in a dose-dependent manner by 1α,25(OH)2D3 supplementation, and exacerbated by VDD. The expressions of TGF-β1 and CII in articular cartilage were suppressed by OVX and VDD, and rescued by 1α,25(OH)2D3 supplementation. The expression of MMP-9,-13 in articular cartilage increased with OVX and VDD, and decreased with 1α,25(OH)2D3 supplementation. In vitro experiments showed that 1α,25(OH)2D3 increased the TGF-β1 expression of TNF-α stimulated chondrocytes in a dose-dependent manner. 1α,25(OH)2D3 significantly counteracted the increased CTX-II release due to TNF-α stimulation, and this effect was significantly suppressed by SB505124. CONCLUSION: VDD aggravated cartilage erosion, and 1α,25(OH)2D3 supplementation showed protective effects in OVX-induced OA partly through the TGF-β1 pathway.
OBJECTIVE: To explore the effect of vitamin D on turnover of articular cartilage with ovariectomy (OVX) induced OA, and to investigate transforming growth factor-β1 (TGF-β1) as a possible underlying mechanism mediated by 1α,25(OH)2D3. DESIGN: Sixty-six rats were randomly allocated into seven groups: sham plus control diet (SHAM+CTL), OVX+CTL diet, sham plus vitamin D-deficient (VDD) diet, OVX+VDD diet, and three groups of ovariectomized rats treated with different doses of 1α,25(OH)2D3. The cartilage erosion and the levels of serum 17β-estradiol, 1α,25(OH)2D3 and C-telopeptide of type II collagen (CTX-II) were measured. TGF-β1, type II Collagen (CII), matrix metalloproteinases (MMP)-9,-13 in articular cartilage were assessed by immunohistochemistry. TGF-β1 and CTX-II expression were measured in articular cartilage chondrocytes treated with/without tumor necrosis factor (TNF-α), 1α,25(OH)2D3, and TGF-β receptor inhibitor (SB505124) in vitro. RESULTS:Cartilage erosion due to OVX was significantly reduced in a dose-dependent manner by 1α,25(OH)2D3 supplementation, and exacerbated by VDD. The expressions of TGF-β1 and CII in articular cartilage were suppressed by OVX and VDD, and rescued by 1α,25(OH)2D3 supplementation. The expression of MMP-9,-13 in articular cartilage increased with OVX and VDD, and decreased with 1α,25(OH)2D3 supplementation. In vitro experiments showed that 1α,25(OH)2D3 increased the TGF-β1 expression of TNF-α stimulated chondrocytes in a dose-dependent manner. 1α,25(OH)2D3 significantly counteracted the increased CTX-II release due to TNF-α stimulation, and this effect was significantly suppressed by SB505124. CONCLUSION:VDD aggravated cartilage erosion, and 1α,25(OH)2D3 supplementation showed protective effects in OVX-induced OA partly through the TGF-β1 pathway.