Membrane trafficking and exocytosis are upregulated in port wine stain blood vessels

Rong Yin^1,2,9, Shawn J. Rice³, Jinwei Wang^1,8, Lin Gao⁵, Joseph Tsai¹, Radean T. Anvari¹, Fang Zhou^1,8, Xin Liu³, Gang Wang⁵, Yuxin Tang⁸, Martin C. Mihm Jr⁶, Chandra P. Belani^3,4, Dong-bao Chen¹⁰, J. Stuart Nelson^1,7 and Wenbin Tan<sup>1,2

1</sup>Department of Surgery, Beckman Laser Institute and Medical Clinic, University of California, Irvine, California, ²Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, South Carolina, ³Penn State Cancer Institute, ⁴Department of Medicine, Penn State College of Medicine, Hershey, USA, ⁵Department of Dermatology, Xijing Hospital, Xi'an, China, ⁶Department of Dermatology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, ⁷Department of Biomedical Engineering, University of California, Irvine, California, USA, ⁸Department of Urology, the Xiangya 3rd Hospital, Xiangya School of Medicine, Central South University, Changsha, Hunan, ⁹Department of Dermatology, the Second Hospital of Shanxi Medical University, Taiyuan, China and ¹⁰Department of Obstetrics and Gynecology, University of California, Irvine, California, USA

Offprint requests to: Wenbin Tan, Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, South Carolina 29209, USA; Department of Surgery, Beckman Laser Institute and Medical Clinic, University of California, Irvine, California 92617, USA. e-mail: wenbin.tan@uscmed.sc.edu or wenbint@uci.edu

Summary. Introduction. Port wine stain (PWS) is characterized as a progressive dilatation of immature venule-like vasculatures which result from differentiation-impaired endothelial cells. In this study, we aimed to identify the major biological pathways accounting for the pathogenesis of PWS. Methods. Sequential windowed acquisition of all theoretical fragment ion mass spectra (SWATH-MS) was used to identify differentially expressed proteins in PWS lesions, followed by confirmative studies with immunohistochemistry, immunoblot and transmission electron microscopy (TEM). Results. 107 out of 299 identified proteins showed differential expressions in PWS lesions as compared to normal skin, mainly involving the functions of biosynthesis, membrane trafficking, cytoskeleton and cell adhesion/migration. The confirmative studies showed that expressions of membrane trafficking/ exocytosis related proteins such as VAT1, IQGAP1, HSC70, clathrin, perlecan, spectrin α1 and GDIR1 were significantly increased in PWS blood vessels as compared to normal ones. Furthermore, TEM studies showed there is a significant upregulation of extracellular vesicle exocytosis from PWS blood vessels as compared to control. Conclusions. The biological process of membrane trafficking and exocytosis is enhanced in PWS blood vessels. Our results imply that the extracellular vesicles released by lesional endothelial cells may act as potential intercellular signaling mediators to contribute to the pathogenesis of PWS. Histol Histopathol 34, 479-490 (2019)

Key words: Port wine stain, Vascular malformations, Endothelial cells, Extracellular vesicle, Exocytosis, SWATH-MS

DOI: 10.14670/HH-18-051