Increased osteoblast apoptosis in apert craniosynostosis -: Role of protein kinase c and interleukin-1
Increased osteoblast apoptosis in apert craniosynostosis -: Role of protein kinase c and interleukin-1
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DOI：
10.1016/s0002-9440(10)64139-9
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发表时间：
2001-05-01
影响因子：
6
通讯作者：
Marie, PJ
中科院分区：
文献类型：
--
作者：
Lemonnier, J;Hay, E;Marie, PJ
Apert综合征是一种常染色体显性遗传疾病，其特征是成纤维细胞生长因子受体-2（FGFR-2）激活突变导致的过早颅骨骨化。我们研究了S252 W FGFR-2 Apert突变对人突变成骨细胞凋亡的影响及其潜在机制。末端脱氧核苷酸转移酶介导的缺口末端标记的体内分析显示，与正常冠状缝相比，Apert缝中的成熟成骨细胞和骨细胞过早凋亡。在体外，突变成骨细胞表现出增加的凋亡，如末端脱氧核苷酸转移酶介导的缺口末端标记分析，台盼蓝染色，DNA片段化。突变成骨细胞还表现出caspase-8和效应器caspase活性增加这与蛋白激酶C激活有关，因为选择性蛋白激酶C抑制剂calphostin C抑制突变成骨细胞中的半胱天冬酶-8、效应物半胱天冬酶和凋亡。Apert成骨细胞还显示白细胞介素（IL）-1 α、IL-1 β、Fas和Bax的表达增加，降低Bcl-2水平。特异性中和抗IL-1抗体降低突变细胞中Fas水平、Bax表达、效应子半胱天冬酶活性和凋亡。因此，Apert S252 W FGFR-2突变通过蛋白激酶C的活化、IL-1和Fas的过表达、半胱天冬酶-8的活化和Bax/Bcl-2水平的增加促进人成骨细胞的凋亡，导致效应物半胱天冬酶和DNA片段化的增加。这鉴定了在人颅骨成骨细胞中由Apert S252 W FGFR-2突变诱导的过早凋亡中涉及的复杂FGFR-2信号传导途径。
Apert syndrome is an autosomal dominant disorder characterized premature cranial ossification resulting from fibroblast growth factor receptor-2 (FGFR-2)-activating mutations. We have studied the effects of the prominent S252W FGFR-2 Apert mutation on apoptosis and the underlying mechanisms in human mutant osteoblasts. In vivo analysis of terminal deoxynucleotidyl transferase-mediated nick-end labeling revealed premature apoptosis of mature osteoblasts and osteocytes in the Apert suture compared to normal coronal suture. In vitro, mutant osteoblasts showed increased apoptosis, as demonstrated by terminal deoxynucleotidyl transferase-mediated nick-end labeling analysis, trypan blue staining, and DNA fragmentation. Mutant osteoblasts also showed increased activity of caspase-8 and effector caspases (-3, -6, -7) constitutively, This was related to protein kinase C activation because the selective protein kinase C inhibitor calphostin C inhibited caspase-8, effector caspases, and apoptosis in mutant osteoblasts, Apert osteoblasts also showed increased expression of interleukin (IL)-1 alpha, IL-1 beta, Fas, and Bax, and decreased Bcl-2 levels. Specific neutralizing anti-IL-1 antibody reduced Fas levels, Bax expression, effector caspases activity, and apoptosis in mutant cells. Thus, the Apert S252W FGFR-2 mutation promotes apoptosis in human osteoblasts through activation of protein kinase C, overexpression of IL-1 and Fas, activation of caspase-8, and increased Bax/Bcl-2 levels, leading to increased effector caspases and DNA fragmentation. This identifies a complex FGFR-2 signaling pathway involved in the premature apoptosis induced by the Apert S252W FGFR-2 mutation in human calvaria osteoblasts.