Open AccessA functional analysis of Wnt inducible signalling pathway protein −1 (WISP‐1/CCN4)
Author(s) -
Stephens Sarah,
Palmer Joanne,
Konstantinova Irena,
Pearce Andrew,
Jarai Gabor,
Day Elizabeth
Publication year - 2015
Publication title -
journal of cell communication and signaling
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.329
H-Index - 44
eISSN - 1873-961X
pISSN - 1873-9601
DOI - 10.1007/s12079-015-0267-9
Subject(s) - integrin , ctgf , microbiology and biotechnology , wnt signaling pathway , extracellular matrix , secretion , cyr61 , cell adhesion , integrin, beta 6 , receptor , signal transduction , biology , chemistry , growth factor , cell , biochemistry
Wnt‐1 inducible signalling pathway protein 1 (WISP‐1/CCN4) is an extracellular matrix protein that belongs to the Cyr61 (cysteine‐rich protein 61), CTGF (connective tissue growth factor) and NOV (CCN) family and plays a role in multiple cellular processes. No specific WISP‐1 receptors have been identified but emerging evidence suggests WISP‐1 mediates its downstream effects by binding to integrins. Here we describe a functional analysis of integrin receptor usage by WISP‐1. Truncated WISP‐1 proteins were produced using a baculovirus expression system. Full length WISP‐1 and truncated proteins were evaluated for their ability to induce adhesion in A549 epithelial cells and β‐catenin activation and CXCL3 secretion in fibroblasts (NRK49‐F cells). Subsequent inhibition of these responses by neutralising integrin antibodies was evaluated. A549 cells demonstrated adhesion to full‐length WISP‐1 whilst truncated proteins containing VWC, TSP or CT domains also induced adhesion, with highest activity observed with proteins containing the C‐terminal TSP and CT domains. Likewise the ability to induce β‐catenin activation and CXCL3 secretion was retained in truncations containing C‐terminal domains. Pre‐treatment of A549s with either integrin αVβ5, αVβ3 or β1 neutralising antibodies partially inhibited full length WISP‐1 induced adhesion whilst combining integrin αVβ5 and β1 antibodies increased the potency of this effect. Incubation of NRK49‐F cells with integrin neutralising antibodies failed to effect β‐catenin translocation or CXCL3 secretion. Analysis of natural WISP‐1 derived from human lung tissue showed the native protein is a high order oligomer. Our data suggest that WISP‐1 mediated adhesion of A549 cells is an integrin‐driven event regulated by the C‐terminal domains of the protein. Activation of β‐catenin signalling and CXCL3 secretion also resides within the C‐terminal domains of WISP‐1 but are not regulated by integrins. The oligomeric nature of native WISP‐1 may drive a high avidity interaction with these receptors in vivo.