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Journal articles
Desert Hedgehog-Driven Endothelium Integrity Is Enhanced by Gas1 (Growth Arrest-Specific 1) but Negatively Regulated by Cdon (Cell Adhesion Molecule-Related/Downregulated by Oncogenes)
Abstract : Objective: Evidences accumulated within the past decades identified hedgehog signaling as a new regulator of endothelium integrity. More specifically, we recently identified desert hedgehog (Dhh) as a downstream effector of Klf2 (Kruppel-like factor 2) in endothelial cells (ECs). The purpose of this study is to investigate whether hedgehog coreceptors Gas1 (growth arrest-specific 1) and Cdon (cell adhesion molecule-related/downregulated by oncogenes) may be used as therapeutic targets to modulate Dhh signaling in ECs. Approach and Results: We demonstrated that both Gas1 and Cdon are expressed in adult ECs and relied on either siRNAs- or EC-specific conditional knockout mice to investigate their role. We found that Gas1 deficiency mainly phenocopies Dhh deficiency especially by inducing VCAM (vascular cell adhesion molecule)-1 and ICAM (intercellular adhesion molecule)-1 overexpression while Cdon deficiency has opposite effects by promoting endothelial junction integrity. At a molecular level, Cdon prevents Dhh binding to Ptch1 (patched-1) and thus acts as a decoy receptor for Dhh, while Gas1 promotes Dhh binding to Smo (smoothened) and as a result potentiates Dhh effects. Since Cdon is upregulated in ECs treated by inflammatory cytokines, including TNF (tumor necrosis factor)-α and Il (interleukin)-1β, we then tested whether Cdon inhibition would promote endothelium integrity in acute inflammatory conditions and found that both fibrinogen and IgG extravasation were decreased in association with an increased Cdh5 (cadherin-5) expression in the brain cortex of EC-specific Cdon knockout mice administered locally with Il-1β.
Conclusions: Altogether, these results demonstrate that Gas1 is a positive regulator of Dhh in ECs while Cdon is a negative regulator. Interestingly, Cdon blocking molecules may then be used to promote endothelium integrity, at least in inflammatory conditions.
Cited literature [4 references]
https://www.hal.inserm.fr/inserm-02983021
Contributor : Christelle Boullé Connect in order to contact the contributor
Submitted on : Thursday, October 29, 2020 - 11:10:22 AM
Last modification on : Thursday, February 25, 2021 - 11:27:46 AM
Long-term archiving on: : Saturday, January 30, 2021 - 6:14:41 PM
Contributor : Christelle Boullé Connect in order to contact the contributor
Submitted on : Thursday, October 29, 2020 - 11:10:22 AM
Last modification on : Thursday, February 25, 2021 - 11:27:46 AM
Long-term archiving on: : Saturday, January 30, 2021 - 6:14:41 PM