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Spatio‐temporal Dynamics of Sphingosine‐1‐Phosphate Receptor 1 Activity in Endothelial Cells During Lung Injury and Resolution
Author(s) -
Akhter Md. Zahid,
Mehta Dolly
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.595.6
Subject(s) - s1pr1 , microbiology and biotechnology , green fluorescent protein , biology , chemistry , vascular endothelial growth factor a , cancer research , vascular endothelial growth factor , biochemistry , gene , vegf receptors
Sphingosine‐1‐phosphate receptor 1 (S1PR1) signaling has been implicated in regulation of vascular permeability, lymphocyte trafficking, inflammation, and cardiac function. In endothelial cells (ECs), S1PR1 stimulates Gi‐dependent intracellular signaling cascades, which enhances barrier function. ECs regulate primary host defense mechanism. In this study, we used S1PR1‐GFP signaling reporter mice to determine dynamics of S1PR1 activity in the lung in response to endotoximia during injury and resolution. These mice, having S1pr1 knockin vector crossed with histone‐GFP reporter (H2B‐GFP) mice. Activation of S1PR1 induces β‐arrestin‐tobacco etch virus (TEV) protease binding to the activated receptor and subsequent release of tetracycline transcriptional activator (tTA) leading to translocation of tTA to nucleus to drive transcription of the histone‐GFP reporter. LPS in a time dependent manner increased GFP expressing cells in the lung. Flow cytometry of GFP gated cells revealed significantly increase in ECs (CD45 − CD31 + GFP + ) in the lungs of S1PR1 GFP signaling mice, compared to that in control H2B‐GFP mice. Whereas, LPS increased apoptosis of non‐GFP + cells at 16 h, S1PR1 activated ECs remain viable. Immuno‐histological detection of GFP + nuclei in lung tissue section revealed localized activation of S1PR1 during injury and repair. Studies are underway to characterize the endothelial cells (ECs) showing S1PR1 activity versus control ECs to assess if S1PR1 activity in ECs is a potential determinant of EC‐regeneration.