Lisignoli Gina, Toneguzzi Stefania, Piacentini Anna, Cristino Sandra, Grassi Francesco, Cavallo Carola, Facchini Andrea
Laboratorio di Immunologia e Genetica, Istituti Ortopedici Rizzoli, Bologna, Italy.
J Cell Physiol. 2006 Jan;206(1):78-85. doi: 10.1002/jcp.20435.
To evaluate the role of CXC chemokines CXCL8 (IL8), CXCL10 (IP-10), CXCL12 (SDF-1), and CXCL13 (BCA-1) in bone remodeling, we analyzed their effects on osteoblasts (OBs) obtained from subchondral trabecular bone tissue of osteoarthritis (OA) and post-traumatic (PT) patients. The expression of CXC receptors/ligands (CXCR1/CXCL8, CXCR2/CXCL8, CXCR3/CXCL10, CXCR4/CXCL12, and CXCR5/CXCL13) was analyzed in cultured OBs by flow cytometry and immunocytochemistry. Functional assays on CXC chemokine-treated-OBs in the presence or absence of their specific inhibitors were performed to analyze cellular proliferation and the enzymatic response to chemokine activation. The expression of chemokine ligands/receptors was also confirmed in bone tissue samples by immunohistochemical analysis. Collagen type I and alkaline phosphatase mRNA expression were analyzed on CXCL12- and CXCL13-treated OBs by real-time PCR. OBs from both OA and PT patients expressed high levels of CXCR3 and CXCR5 and lower amounts of CXCR1 and CXCR4. CXCL12 and CXCL13, only in OBs from OA patients, induced a significant proliferation that was also confirmed by specific blocking experiments. Moreover, OBs from OA patients released a higher amount of CXCL13 than those of PT patients while no differences were found for CXCL12. In the remodeling area of bone tissue samples, immunohistochemical analysis confirmed that OBs expressed CXCL12/CXCR4 and CXCL13/CXCR5 both in OA and PT samples. CXCL12 and CXCL13 upregulated collagen type I mRNA expression in OBs from OA patients. These data suggest that CXCL12 and CXCL13 may directly modulate cellular proliferation and collagen type I in OA patients, so contributing to the remodeling process that occurs in the evolution of this disease.
为评估CXC趋化因子CXCL8（IL8）、CXCL10（IP - 10）、CXCL12（SDF - 1）和CXCL13（BCA - 1）在骨重塑中的作用，我们分析了它们对从骨关节炎（OA）和创伤后（PT）患者的软骨下小梁骨组织中获取的成骨细胞（OBs）的影响。通过流式细胞术和免疫细胞化学分析培养的成骨细胞中CXC受体/配体（CXCR1/CXCL8、CXCR2/CXCL8、CXCR3/CXCL10、CXCR4/CXCL12和CXCR5/CXCL13）的表达。在有或没有其特异性抑制剂的情况下，对CXC趋化因子处理的成骨细胞进行功能测定，以分析细胞增殖和对趋化因子激活的酶促反应。通过免疫组织化学分析也证实了骨组织样本中趋化因子配体/受体的表达。通过实时PCR分析CXCL12和CXCL13处理的成骨细胞中I型胶原和碱性磷酸酶mRNA的表达。OA和PT患者的成骨细胞均高表达CXCR3和CXCR5，而CXCR1和CXCR4表达量较低。仅在OA患者的成骨细胞中，CXCL12和CXCL13诱导了显著的增殖，特异性阻断实验也证实了这一点。此外，OA患者的成骨细胞释放的CXCL13比PT患者的多，而CXCL12没有差异。在骨组织样本的重塑区域，免疫组织化学分析证实，在OA和PT样本中，成骨细胞均表达CXCL12/CXCR4和CXCL13/CXCR5。CXCL12和CXCL13上调了OA患者成骨细胞中I型胶原mRNA的表达。这些数据表明，CXCL12和CXCL13可能直接调节OA患者的细胞增殖和I型胶原，从而促进该疾病发展过程中发生的重塑过程。
