Department of Orthopedics, The First Affiliated Hospital of Chongqing Medical University, 1 Youyi Road, Yuanjiagang, Yuzhong District, Chongqing, 400016, China.
Department of Rehabilitation, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Osteoporos Int. 2017 Apr;28(4):1305-1311. doi: 10.1007/s00198-016-3873-3. Epub 2016 Dec 17.
Secreted frizzled-related protein 5 (sFRP5) level in bone marrow environment is inversely correlated with bone formation markers, suggesting that it decreases bone mass by inhibiting bone formation. Besides, it functions in a local fashion when regulating bone metabolism. sFRP5 may be a target when developing anti-osteoporotic agents.
The purpose of the study is to investigate the relationship between bone marrow sFRP5 level and bone turnover state.
Eighty-three total knee arthroplasty patients were enrolled in this study. Data were collected prospectively and reviewed retrospectively. Lumbar spine and femoral neck bone mineral density (BMD), marrow adipose tissue (MAT) sFRP5 messenger RNA (mRNA) expression level, sFRP5 concentrations in marrow fluid and serum, concentrations of bone formation and resorption markers were measured for each participant.
Marrow fluid sFRP5 concentration was positively correlated with both MAT sFRP5 expression (p = 0.040) and serum sFRP5 concentration (p = 0.043). Significantly positive correlation existed between MAT sFRP5 expression level and BMD (p < 0.05). Marrow fluid sFRP5 concentration had a moderate but not significant positive association with BMD. MAT sFRP5 was negatively related to serum bone formation markers including N-terminal propeptide of type 1 procollagen (P1NP) (p = 0.011), osteocalcin (OC), and alkaline phosphatase (ALP). Marrow fluid and serum sFRP5 concentrations also had mild negative correlations with bone formation markers but reached no significance. There was no significant correlation between bone resorption marker β-crosslaps (β-CTX) and sFRP5. The mRNA expression level of MAT sFRP5 was positively related with those of MAT leptin, peroxisome proliferator-activated receptor-γ (PPARγ), and adiponectin, and its correlation with leptin was statistically significant (p = 0.026).
Bone marrow sFRP5 level is closely correlated with BMD and bone formation markers. sFRP5 may be a potential negative regulator of bone mass by inhibiting bone formation. It may exert its effects on bone metabolism in a paracrine, rather than endocrine manner.
研究骨髓 sFRP5 水平与骨转换状态的关系。
前瞻性收集 83 例初次行全膝关节置换术患者的临床资料，回顾性分析。检测所有患者腰椎及股骨颈骨密度（BMD）、骨髓脂肪组织（MAT）中 sFRP5 信使 RNA（mRNA）表达水平、骨髓腔液及血清 sFRP5 浓度、骨形成和骨吸收标志物浓度。
骨髓腔液 sFRP5 浓度与 MAT sFRP5mRNA 表达（p=0.040）和血清 sFRP5 浓度（p=0.043）呈正相关。MAT sFRP5mRNA 表达水平与 BMD 呈显著正相关（p<0.05）。骨髓腔液 sFRP5 浓度与 BMD 呈中度正相关，但无统计学意义。MAT sFRP5 与血清骨形成标志物，包括Ⅰ型前胶原 N 端前肽（P1NP）（p=0.011）、骨钙素（OC）和碱性磷酸酶（ALP）均呈负相关。骨髓腔液和血清 sFRP5 浓度与骨形成标志物也有轻度负相关，但无统计学意义。骨吸收标志物β-胶原交联（β-CTX）与 sFRP5 无明显相关性。MAT sFRP5mRNA 表达水平与 MAT 瘦素、过氧化物酶体增殖物激活受体-γ（PPARγ）和脂联素呈正相关，与瘦素的相关性具有统计学意义（p=0.026）。
骨髓 sFRP5 水平与 BMD 和骨形成标志物密切相关。sFRP5 可能通过抑制骨形成而成为负向调节骨量的潜在因子，其在骨代谢中的作用可能为旁分泌而非内分泌方式。
