In:
Cell Communication and Signaling, Springer Science and Business Media LLC, Vol. 18, No. 1 ( 2020-12)
Abstract:
Thrombospondin-1 (TSP-1), a Ca 2+ -binding trimeric glycoprotein secreted by multiple cell types, has been implicated in the pathophysiology of several clinical conditions. Signaling involving TSP-1, through its cognate receptor CD47, orchestrates a wide array of cellular functions including cytoskeletal organization, migration, cell-cell interaction, cell proliferation, autophagy, and apoptosis. In the present study, we investigated the impact of TSP-1/CD47 signaling on Ca 2+ dynamics, survival, and deformability of human red blood cells (RBCs). Methods Whole-cell patch-clamp was employed to examine transmembrane cation conductance. RBC intracellular Ca 2+ levels and multiple indices of RBC cell death were determined using cytofluorometry analysis. RBC morphology and microvesiculation were examined using imaging flow cytometry. RBC deformability was measured using laser-assisted optical rotational cell analyzer. Results Exposure of RBCs to recombinant human TSP-1 significantly increased RBC intracellular Ca 2+ levels. As judged by electrophysiology experiments, TSP-1 treatment elicited an amiloride-sensitive inward current alluding to a possible Ca 2+ influx via non-selective cation channels. Exogenous TSP-1 promoted microparticle shedding as well as enhancing Ca 2+ - and nitric oxide-mediated RBC cell death. Monoclonal (mouse IgG1) antibody-mediated CD47 ligation using 1F7 recapitulated the cell death-inducing effects of TSP-1. Furthermore, TSP-1 treatment altered RBC cell shape and stiffness (maximum elongation index). Conclusions Taken together, our data unravel a new role for TSP-1/CD47 signaling in mediating Ca 2+ influx into RBCs, a mechanism potentially contributing to their dysfunction in a variety of systemic diseases.
Type of Medium:
Online Resource
ISSN:
1478-811X
DOI:
10.1186/s12964-020-00651-5
DOI:
10.21203/rs.3.rs-106694/v1
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2020
detail.hit.zdb_id:
2126315-2
SSG:
12
