Gene Expression Profile of Isolated Dermal Vascular Endothelial Cells in Keloids

Noriko M Matsumoto; Masayo Aoki; Yuri Okubo; Kosuke Kuwahara; Shigeyoshi Eura; Teruyuki Dohi; Satoshi Akaishi; Rei Ogawa

doi:10.3389/fcell.2020.00658

Gene Expression Profile of Isolated Dermal Vascular Endothelial Cells in Keloids

Front Cell Dev Biol. 2020 Jul 29:8:658. doi: 10.3389/fcell.2020.00658. eCollection 2020.

Authors

Noriko M Matsumoto¹, Masayo Aoki^{1

2}, Yuri Okubo¹, Kosuke Kuwahara¹, Shigeyoshi Eura¹, Teruyuki Dohi¹, Satoshi Akaishi³, Rei Ogawa¹

Affiliations

¹ Department of Plastic, Reconstructive and Aesthetic Surgery, Nippon Medical School, Tokyo, Japan.
² Department of Biochemistry and Molecular Biology, Nippon Medical School, Tokyo, Japan.
³ Department of Plastic Surgery, Nippon Medical School Musashi Kosugi Hospital, Kawasaki, Japan.

Abstract

Wound healing is a complex biological process, and imbalances of various substances in the wound environment may prolong healing and lead to excessive scarring. Keloid is abnormal proliferation of scar tissue beyond the original wound margins with excessive deposition of extracellular matrix (ECM) and chronic inflammation. Despite numerous previous research efforts, the pathogenesis of keloid remains unknown. Vascular endothelial cells (VECs) are a major type of inductive cell in inflammation and fibrosis. Despite several studies on vascular morphology in keloid formation, there has been no functional analysis of the role of VECs. In the present study, we isolated living VECs from keloid tissues and investigated gene expression patterns using microarray analysis. We obtained 5 keloid tissue samples and 6 normal skin samples from patients without keloid. Immediately after excision, tissue samples were gently minced and living cells were isolated. Magnetic-activated cell sorting of VECs was performed by negative selection of fibroblasts and CD45⁺ cells and by positive selection of CD31⁺cells. After RNA extraction, gene expression analysis was performed to compare VECs isolated from keloid tissue (KVECs) with VECs from normal skin (NVECs). After cell isolation, the percentage of CD31⁺ cells as measured by flow cytometry ranged from 81.8%-98.6%. Principal component analysis was used to identify distinct molecular phenotypes in KVECs versus NVECs and these were divided into two subgroups. In total, 15 genes were upregulated, and 3 genes were downregulated in KVECs compared with NVECs using the t-test (< 0.05). Quantitative RT-PCR and immunohistochemistry showed 16-fold and 11-fold overexpression of SERPINA3 and LAMC2, respectively. SERPINA3 encodes the serine protease inhibitor, α1-antichymotripsin. Laminin γ2-Chain (LAMC2) is a subunit of laminin-5 that induces retraction of vascular endothelial cells and enhances vascular permeability. This is the first report of VEC isolation and gene expression analysis in keloid tissue. Our data suggest that SERPINA3 and LAMC2 upregulation in KVECs may contribute to the development of fibrosis and prolonged inflammation in keloid. Further functional investigation of these genes will help clarify the mechanisms of abnormal scar tissue proliferation.

Keywords: LAMC2; SERPINA3; keloid; vascular endothelial cells; wound healing.