未折叠蛋白反应在发育不良性髋臼软骨中作用机制研究  

Identification of unfolded protein response in normal and dysplastic acetabular cartilage

作　　者：倪晓燕 林伊凤[2] 裴新红 马瑞雪 Ni Xiaoyan;Lin Yifeng;Pei Xinhong;Ma Ruixue(Department of Orthopedics,Affiliated Children’s Hospital,Fudan University,Shanghai 201102,China;Institute of Pediatrics,Affiliated Children’s Hospital,Fudan University,Shanghai 201102,China)

机构地区：[1]复旦大学附属儿科医院骨科,上海201102 [2]复旦大学附属儿科医院儿科研究院,上海201102

出　　处：《中华小儿外科杂志》2019年第11期1036-1043,共8页Chinese Journal of Pediatric Surgery

基　　金：国家自然科学基金面上项目(81371914)。

摘　　要：目的 研究未折叠蛋白反应在正常和发育不良性髋臼软骨发育中的影响.方法 通过新生大鼠伸髋伸膝位模拟婴儿襁褓体位制作发育不良髋臼软骨模型,取对照组和模型组髋臼软骨标本,对不同时期(生后1周、2周、4周及8周)行HE染色观察组织形态学特点,测量髋臼软骨上缘生长板肥大区以及增殖区宽度,荧光定量PCR方法检测不同时期软骨细胞成熟分化Sox9、Col2a1、Acan和肥大化指标Runx2、Col10A1、Mmp13 mRNA表达的变化.同时利用荧光定量PCR检测两组髋臼软骨中Grp78 mRNA的表达情况,利用免疫组织化学染色法检测髋臼软骨上缘生长板ATF6、XBP1s、p-eIF2α的表达情况.结果 ①不同时期模型组髋臼上缘平直,生长板细胞排列紊乱,极性异常,生长板增殖区和肥大区宽度短缩,与对照组相比差异有统计学意义(P<0.05);②不同时期模型组软骨细胞分化指标Sox9、Col2A1、Acan及肥大化指标Runx2、Col10a1、Mmp13表达下降,2周、4周、8周与对照组相比,差异具统计学意义(P<0.05);③不同时期模型组髋臼软骨细胞中Grp78表达下降,2周、4周、8周与对照组相比,差异具统计学意义(P<0.05),不同时期模型组髋臼软骨上缘生长板中未折叠蛋白反应信号通路蛋白XBP1s、P50A T F6表达下降,2周、4周、8周与对照组相比差异具有统计学意义(P<0.01),不同时期模型组p-eIF2α表达下降,与对照组相比,差异具有统计学意义(P<0.05).结论 生理性未折叠蛋白反应通路参与了正常软骨细胞的成熟分化以及软骨内骨化,而发育不良性髋臼软骨中该通路受到抑制,干扰了软骨细胞正常的成熟分化以及软骨内骨化过程,可能参与了发育不良性髋臼软骨的病理过程.Objective To explore the role of unfolded protein response in normal and dysplastic acetabular cartilages .Methods The rat model of dysplastic acetabulum was established by maintaining hips in a swaddling position .Hematoxylin & eosin staining was utilized for observing the morphological characteristics of acetabular cartilage in normal and DDH models and the width of growth plate measured ,including hypertrophic zone (HZ) and proliferative zone (PZ) .The mRNA expressions of chondrocyte differentiating markers (Sox9 ,Col2a1 & Acan) and hypertrophic markers (Runx2 ,Col10a1 & Mmp13) were measured by quantitative polymerase chain reaction (qPCR) at different timepoints .The expressions of unfolded protein response genes of Grp78 ,P50ATF6 ,XBP1s and phosphorylated eIF2αwere detected by qPCR and immunohistochemistry respectively .Results a) As compared with control ,upper side of acetabulum became flatter with the progression of DDH .Cells in growth plate were disturbed with a loss of polarity .The width of hypertrophic zone (HZ) and proliferative zone (PZ) of growth plates became significantly shortened (P< 0 .05);b) The mRNA expressions of Sox9 ,Col2a1 and Acan and Runx2 ,Col10a1 and Mmp13 decreased significantly in a time-dependent manner(P<0 .05);c) The mRNA expressions of Grp78 were markedly inhibited in acetabular cartilages(P<0 .05) .The protein expressions of XBP1s ,P50ATF6 and p-eIF2αinvolved in unfolded protein response were significantly suppressed in growth plates (P< 0 .05) .Conclusions Chondrocyte differentiation and endochondral ossification require the participation of a physiological unfolded protein response whereas unfolded protein response is inhibited in DDH model ,interfering with normal chondrocyte maturation and endochondral ossification .Thus it may be somewhat involved in the pathological process of dysplastic acetabular cartilage .

关 键 词：髋臼 软骨 未折叠蛋白反应 髋脱位 发育性 软骨细胞分化 

分 类 号：R68[医药卫生—骨科学]