Impaired collagen fibril assembly in keloids with enhanced expression of lumican and collagen V.
Impaired collagen fibril assembly in keloids with enhanced expression of lumican and collagen V.
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DOI：
10.1016/j.abb.2020.108676
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发表时间：
2020-11
影响因子：
3.9
通讯作者：
Bo Zhou;T. Tu;Zhen Gao;Xiaoli Wu;Wenbo Wang;Wei Liu
中科院分区：
文献类型：
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作者：
Bo Zhou;T. Tu;Zhen Gao;Xiaoli Wu;Wenbo Wang;Wei Liu
疤痕疙瘩的特征是成纤维细胞活化和细胞外基质（ECM）结构改变。在疤痕疙瘩中观察到 ECM 分子的过度沉积和胶原纤维的不规则组织。然而，胶原蛋白超微结构的改变尚未得到充分研究。本研究利用组织学、透射电子显微镜（TEM）、qPCR、Western blot、免疫组化和生物信息学等手段探讨瘢痕疙瘩及其病灶外皮肤（ELS）在组织结构、胶原超微结构、基质成分、力学性能和胶原组装分子方面的差异。组织学评估显示，瘢痕疙瘩中的纤维更细，III 型胶原和蛋白聚糖含量增加，这得到了 TEM 发现的支持，即与 ELS 相比，瘢痕疙瘩中胶原纤维更细，D 带周期性更不发达 (p< 0.05)。此外，与 ELS 相比，疤痕疙瘩中的总胶原蛋白和水含量显着增加 (p< 0.05)，并且产生更丰富的蛋白聚糖，这也导致与 ELS 相比，疤痕疙瘩的硬度增加并降低了最大负荷。机制研究表明，与基质组装相关的多个分子在疤痕疙瘩中显着上调（p<0.05）。特别是，lumican 和胶原蛋白 V 在共表达分析中表现出高度的共表达分析，并且从微阵列数据中揭示了它们的上调水平，这也在疤痕疙瘩中的基因和蛋白质水平上得到了验证 (p<0.05)。然而，Lumican的siRNA敲低未能影响体外胶原组装，但导致胶原V表达上调，同时上调粘着斑激酶、TGF-β1、TGF-β3和PDGF，其中一些已知能够增强胶原V表达。总之，这项研究表明胶原蛋白组装受损，同时 lumican 和胶原蛋白 V 的表达增强，这两种蛋白都会干扰胶原纤维组装。
Keloids are characterized by fibroblast activation and altered architecture of extracellular matrix (ECM). Excessive deposition of ECM molecules and irregular organization of collagen fibers have been observed in keloids. However, the ultrastructural alteration of collagen has not been fully investigated. In this study, the differences in tissue structure, collagen ultrastructure, matrix components, mechanical properties and collagen assembling molecules between keloids and their extra-lesional skins (ELSs) were explored using histology, transmission electron microscope (TEM), qPCR, Western blot, immunohistochemistry and bioinformatics. Histological evaluation showed thinner fibers in keloids with increased contents of collagen III and proteoglycans, which were supported by TEM findings of thinner collagen fibrils and less developed D-band periodicity in keloids than in ELSs (p< 0.05). In addition, total collagen and water contents were significantly increased (p< 0.05) along with richer proteoglycan production in keloids vs ELSs, which also led to increased stiffness and decreased maximal load in keloids compared with ELSs. Mechanism study showed that multiple molecules related to matrix assembly were significantly upregulated in keloids (p< 0.05). In particular, lumican and collagen V showed high degrees in co-expression analysis and their upregulation levels were revealed from microarray data, which were also verified in keloids at both gene and protein levels (p< 0.05). Nevertheless, siRNA knockdown of lumican failed to affectin vitrocollagen assembly, but caused upregulated collagen V expression along with the upregulation of focal adhesion kinase,TGF-β1,TGF-β3andPDGF, among which some are known for capable of enhancing collagen V expression. In conclusion, this study demonstrates impaired collagen assembly along with enhanced expression of lumican and collagen V, both are known for interfering with collagen fibril assembly.