Zhou Lu, Yoon Sun Jung, Jang Kyu Yun, Moon Young Jae, Wagle Sajeev, Lee Kwang Bok, Park Byung-Hyun, Kim Jung Ryul
Departments of Orthopedic Surgery, Chonbuk National University Medical School, Research Institute for Endocrine Sciences and Research Institute of Clinical Medicine, Jeonju, Republic of Korea; Department of Sports Medicine, Taishan Medical University, Shandong, China.
Departments of Orthopedic Surgery, Chonbuk National University Medical School, Research Institute for Endocrine Sciences and Research Institute of Clinical Medicine, Jeonju, Republic of Korea.
PLoS One. 2014 Oct 17;9(10):e110593. doi: 10.1371/journal.pone.0110593. eCollection 2014.
Angiogenesis is considered essential for proper bone regeneration. The purpose of this investigation was to determine if a combined therapy of bone morphogenetic protein-2 (BMP-2) and cartilage oligomeric matrix protein angiopoietin-1 (COMP-Ang1) can potentiate the therapeutic effect of BMP-2 in a rat model of ischemic necrosis of the femoral head (INFH). INFH was surgically induced in the femoral head of rats, and the animals were divided into the following groups: 1) a sham-operated group (sham group), 2) a bovine serum albumin-injected group (BSA group), 3) a BMP-2-injected group (BMP-2 group), and 4) a COMP-Ang1 and BMP-2-injected group (COMP-Ang1 + BMP-2 group) (n = 20/group). Radiologic, histologic, and histomorphometric assessments were performed to assess femoral head morphology, vascular density, and bone resorption activity. Western blots and immunohistochemical staining were performed to evaluate production of BMP-related signaling proteins in C3H10T1/2 cells and tissues. Real-time RT-PCR was performed to investigate expression of the target integrin gene, and the effect of integrin on C3H10T1/2 cells was determined using a cell adhesion assay. Radiographs obtained six weeks after injection revealed better preservation of the architecture of the femoral head in the COMP-Ang1 + BMP-2 group compared with the BSA and BMP-2 groups. Histological findings indicated increased trabecular bone and vascularity and decreased osteoclast bone resorption activity in the COMP-Ang1 + BMP-2 group compared with those in the BSA and BMP-2 groups. The combination of COMP-Ang1 and BMP-2 increased phosphorylation of Smad1/3/5, p38, and Akt. Increased integrin α3 and β1 mRNA expression in the COMP-Ang1 + BMP-2 group promoted cell adhesion. These results suggest that COMP-Ang1 preserved the necrotic femoral head through the potentiation of BMP-2 signaling pathways and angiogenesis. Combination treatment with COMP-Ang1 and BMP-2 may be a clinically useful therapeutic application in INFH.
血管生成被认为是正常骨再生所必需的。本研究的目的是确定骨形态发生蛋白-2（BMP-2）与软骨寡聚基质蛋白血管生成素-1（COMP-Ang1）的联合疗法是否能增强BMP-2在大鼠股骨头缺血性坏死（INFH）模型中的治疗效果。通过手术诱导大鼠股骨头发生INFH，并将动物分为以下几组：1）假手术组（假手术组），2）注射牛血清白蛋白组（BSA组），3）注射BMP-2组（BMP-2组），4）注射COMP-Ang1和BMP-2组（COMP-Ang1 + BMP-2组）（每组n = 20）。进行放射学、组织学和组织形态计量学评估以评估股骨头形态、血管密度和骨吸收活性。进行蛋白质免疫印迹和免疫组织化学染色以评估C3H10T1/2细胞和组织中BMP相关信号蛋白的产生。进行实时RT-PCR以研究靶整合素基因的表达，并使用细胞黏附试验确定整合素对C3H10T1/2细胞的作用。注射六周后获得的X线片显示，与BSA组和BMP-2组相比，COMP-Ang1 + BMP-2组股骨头结构的保存更好。组织学结果表明，与BSA组和BMP-2组相比，COMP-Ang1 + BMP-2组小梁骨和血管增多，破骨细胞骨吸收活性降低。COMP-Ang1和BMP-2的联合增加了Smad1/3/5、p38和Akt的磷酸化。COMP-Ang1 + BMP-2组整合素α3和β1 mRNA表达增加促进了细胞黏附。这些结果表明，COMP-Ang1通过增强BMP-2信号通路和血管生成来保护坏死的股骨头。COMP-Ang1和BMP-2联合治疗可能是INFH临床上有用的治疗方法。
