New bone formation enhanced by ADSCs overexpressing hRunx2 during mandibular distraction osteogenesis in osteoporotic rabbits

Promoting new bone formation during distraction osteogenesis (DO) in elderly patients with osteoporosis is still a challenge. In this study, we investigated the effect of gene therapy using local Runt‐related gene 2 on new bone formation during osteoporotic mandibular DO in rabbits. First, we successfully established a mandibular osteoporotic animal model by ovariectomizing rabbits. Second, the right mandibles of the osteoporotic rabbits were distracted after corticotomy. The distraction gap of the rabbits in Group A2 and B2 were injected with Adv‐hRunx2‐GFP‐transfected adipose‐derived stromal cells (ADSCs) and Adv‐GFP‐transfected ADSCs, respectively. Rabbits in Groups C2 (ovariectomized control) and D2 (sham surgery control) were injected with physiologic saline. New‐generation bone tissue in the distraction gap was analyzed via plain radiographic examinations, micro‐computed tomography, histological examinations, and biomechanical testing at weeks 3, 6, and 9 of the consolidation period. Results of above examinations showed that no ideal new bone formation was observed in Groups B2 and C2, but obvious ideal new bone formation was observed in Group A2 and D2. The results suggested that gene therapy using rhRunx2‐modified ADSCs promoted new bone formation during osteoporotic mandibular DO and effectively compensated for the detrimental effects of systemic osteoporosis on new bone formation. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:709–720, 2014.     

Ⅱ型糖尿病肾病大鼠肾动脉与肾内小动脉钙化及BMP2和Runx2的表达

【摘要】 目的 观察Ⅱ型糖尿病肾病（DN）大鼠肾动脉与肾内小动脉钙化以及骨形态发生蛋白2（BMP2）和成骨特异性转录因子2(Runx2)的表达。方法 将24只大鼠随机分为对照组（N组）和Ⅱ型糖尿病肾病组（DN组, STZ加高脂高糖饮食诱导的Ⅱ型DN大鼠模型）,分别于12周,16周处死大鼠。全自动生化分析仪检测大鼠血糖、尿素氮（BUN）、肌酐（Scr）、胱抑素C（CysC)及24 h尿蛋白水平。CVon Kossa染色观察肾动脉及肾内小动脉钙盐沉积情况,免疫组化检测肾动脉及肾内小动脉BMP2及Runx2蛋白表达。结果 DN组大鼠各时间点血糖、尿素氮、胱抑素C、肌酐及24小时尿蛋白水平均较N组明显升高(均P＜005)。 Von Kossa染色可见N组大鼠肾动脉及肾内小动脉各时间点均无明显钙盐沉积,而DN组大鼠肾动脉第12周时即有黑色颗粒沉积,16周时黑色钙盐沉积进一步增多,但各时间点肾内小动脉均无明显黑色颗粒沉积。DN组大鼠肾动脉上可见BMP2及Runx2的较多表达,较N组明显升高（P＜005）;肾内小动脉也可见BMP2及Runx2少量表达,但与N组相比差异无统计学意义（P＞005）。结论 Ⅱ型糖尿病肾病模型大鼠早期肾动脉即可出现血管钙化,但肾内小动脉无明显钙化,提示糖尿病血管钙化较多发生在大血管,而不易发生在脏器内小动脉。     

Deletions of the RUNX2 gene are present in about 10% of individuals with cleidocranial dysplasia

Cleidocranial Dysplasia (CCD) is an autosomal dominant skeletal disorder characterized by hypoplastic or absent clavicles, increased head circumference, large fontanels, dental anomalies, and short stature. Hand malformations are also common. Mutations in RUNX2 cause CCD, but are not identified in all CCD patients. In this study we screened 135 unrelated patients with the clinical diagnosis of CCD for RUNX2 mutations by sequencing analysis and demonstrated 82 mutations 48 of which were novel. By quantitative PCR we screened the remaining 53 unrelated patients for copy number variations in the RUNX2 gene. Heterozygous deletions of different size were identified in 13 patients, and a duplication of the exons 1 to 4 of the RUNX2 gene in one patient. Thus, heterozygous deletions or duplications affecting the RUNX2 gene may be present in about 10% of all patients with a clinical diagnosis of CCD which corresponds to 26% of individuals with normal results on sequencing analysis. We therefore suggest that screening for intragenic deletions and duplications by qPCR or MLPA should be considered for patients with CCD phenotype in whom DNA sequencing does not reveal a causative RUNX2 mutation. © 2010 Wiley‐Liss, Inc.