Wang Yao, Hess Maria Elena, Tan Yan, Esser Philipp R, Nyström Alexander, Boerries Melanie, Sayar Saliha Beyza, Has Cristina
Department of Dermatology, Medical Center - University of Freiburg, Freiburg, Germany.
Institute of Medical Bioinformatics and Systems Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany; Faculty of Biology, University of Freiburg, Freiburg, Germany.
Matrix Biol. 2025 Feb;135:12-23. doi: 10.1016/j.matbio.2024.11.005. Epub 2024 Nov 28.
Integrin α6β4 subunits and type XVII collagen are critical transmembrane proteins involved in cell-matrix adhesion in skin, while laminin 332 serves as their ligand in the basement membrane zone (BMZ). Those proteins contribute to the composition of hemidesmosomes (HDs) and pathogenic variants in their corresponding genes cause junctional epidermolysis bullosa (JEB). Although the genotype-phenotype relationships in JEB have been extensively studied, the pathogenetic changes of extracellular matrix (ECM) and cell-matrix adhesion resulting from gene mutations remain unclear. We conducted a global unbiased transcriptome analysis using bulk RNA sequencing (RNA-seq) on selected JEB donor-derived cell lines lacking integrin β4 subunit (ITGB4-), type XVII collagen (COL17-) and laminin β3 chain (LAMB3-), respectively. Additional JEB cell lines and JEB donor skin samples were used for validation of relevant findings. Collectively, the results revealed similar dysregulation patterns of ECM and focal adhesion (FAs) associated genes in ITGB4- and COL17- cell lines, while LAMB3- cells displayed a relatively opposite tendency. Importantly, key nodes in the dysregulated network were associated with ECM proteins involved in wound healing processes. Additionally, a group of inflammatory-associated genes was disclosed to be up-regulated in JEB keratinocytes and could not be normalized by the adhesion rescue. The functional assay further revealed the hierarchy of stable adhesion among mutant cell lines COL17->ITGB4->LAMB3-, which correlates with the severity of their clinical manifestations. Our results indicated a wound healing associated ECM and inflammatory microenvironment established by JEB keratinocytes.
整合素α6β4亚基和XVII型胶原蛋白是参与皮肤细胞与基质黏附的关键跨膜蛋白，而层粘连蛋白332在基底膜带（BMZ）中作为它们的配体。这些蛋白质有助于半桥粒（HDs）的组成，其相应基因的致病性变异会导致交界性大疱性表皮松解症（JEB）。尽管已经对JEB中的基因型-表型关系进行了广泛研究，但基因突变导致的细胞外基质（ECM）和细胞-基质黏附的致病变化仍不清楚。我们分别对缺乏整合素β4亚基（ITGB4-）、XVII型胶原蛋白（COL17-）和层粘连蛋白β3链（LAMB3-）的选定JEB供体来源的细胞系进行了基于大量RNA测序（RNA-seq）的全基因组无偏转录组分析。另外的JEB细胞系和JEB供体皮肤样本用于验证相关发现。总体而言，结果显示ITGB4-和COL17-细胞系中ECM和黏着斑（FAs）相关基因存在相似的失调模式，而LAMB3-细胞系则呈现出相对相反的趋势。重要的是，失调网络中的关键节点与参与伤口愈合过程的ECM蛋白相关。此外，一组炎症相关基因在JEB角质形成细胞中被发现上调，并且不能通过黏附挽救使其正常化。功能测定进一步揭示了突变细胞系COL17->ITGB4->LAMB3-之间稳定黏附的层次结构，这与其临床表现的严重程度相关。我们的结果表明JEB角质形成细胞建立了与伤口愈合相关的ECM和炎症微环境。
