Isolation and Characterisation of Lymphatic Endothelial Cells from Lung Tissues Affected by Lymphangioleiomyomatosis

Abstract

Lymphangioleiomyomatosis (LAM) is a rare pulmonary disease characterised by the proliferation of smooth muscle-like cells (LAM cells), and an abundance of lymphatic vessels in LAM lesions. Studies reported that vascular endothelial growth factor-D (VEGF-D) secreted by LAM cells contributes to LAM-associated lymphangiogenesis, however, the precise mechanisms of lymphangiogenesis and characteristics of lymphatic endothelial cells (LECs) in LAM lesions have not yet been elucidated. In this study, human primary-cultured LECs were obtained both from LAM-affected lung tissues (LAM-LECs) and normal lung tissues (control LECs) using fluorescence-activated cell sorting (FACS). We found that LAM-LECs had significantly higher ability of proliferation and migration compared to control LECs. VEGF-D significantly promoted migration of LECs but not proliferation of LECs in vitro. cDNA microarray and FACS analysis revealed the expression of vascular endothelial growth factor receptor (VEGFR)-3 and integrin α9 were elevated in LAM-LECs. Inhibition of VEGFR-3 suppressed proliferation and migration of LECs, and blockade of integrin α9 reduced VEGF-D-induced migration of LECs. Our data uncovered the distinct features of LAM-associated LECs, increased proliferation and migration, which may be due to higher expression of VEGFR-3 and integrin α9. Furthermore, we also found VEGF-D/VEGFR-3 and VEGF-D/ integrin α9 signaling play an important role in LAM-associated lymphangiogenesis.

Sorafenib inhibits invasion of multicellular organoids that mimic Lymphangioleiomyomatosis nodules

“…The copyright holder for this preprint this version posted June 12, 2023. ; https://doi.org/10.1101/2023.06.12.544372 doi: bioRxiv preprint JCI possibility that LEC-secreted chemokines and Sorafenib may compete to bind to the same receptors on the surface of LAM-cells. Alternatively, juxtacrine receptor saturation involves the presence of integrins expressed on the surface of LAM and LEC cells (66,67), particularly α9β1integrin on LAM organoids as previously shown (68). Given that VEGF-D can bind to both VEGFR3 and α9β1 integrin, a wedging and dual stimulation of both cell types may occur, leading to the anchoring of LECs in LAM nodules and abrogating the efficacy of Sorafenib treatment.…”