Integrin expression in cells of the intervertebral disc.
In this study, we investigated the profile of integrin expression in human and porcine intervertebral disc tissue. Differences in extracellular matrix composition between anulus fibrosus (AF) and nucleus pulposus (NP) regions of the disc, as well as differences in cellular responses to environmental stimuli, suggest a role for integrins in presenting matrix signals that may mediate these responses. Human disc tissue and porcine AF and NP tissue were stained with antibodies to alpha integrin subunits 1-6, V and IIb, and beta integrin subunits 1-6 and graded for evidence of positive staining on a scale from 0 (no staining) to 3 (high incidence of staining). Human tissue expressed alpha and beta integrin subunits shown to be present in articular cartilage, including alpha(1), alpha(5) and alpha(V). Porcine AF tissue expressed similar integrin subunits to human disc, with both expressing alpha(1), alpha(5), beta(1), beta(3) and beta(5) subunits, whereas porcine NP tissue expressed higher levels of alpha(6), beta(1) and beta(4) than AF tissue. The expressed subunits are known to interact with proteins including collagens, fibronectin and laminin; however, additional studies will be required to characterize the interactions of the integrin subunits with specific matrix constituents, as well as their specific involvement in regulating environmental stimuli.
Nettles
Dana L
DL
Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA.
Richardson
William J
WJ
Setton
Lori A
LA
D000818:Animals; D005109:Extracellular Matrix / Q000737:chemistry; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D039423:Integrin alpha1 / Q000032:analysis; D039482:Integrin alpha5 / Q000032:analysis; D039503:Integrin alpha6 / Q000032:analysis; D039564:Integrin alphaV / Q000032:analysis; D039641:Integrin beta Chains / Q000032:analysis; D019012:Integrin beta1 / Q000032:analysis; D039661:Integrin beta3 / Q000032:analysis; D039663:Integrin beta4 / Q000032:analysis; D016023:Integrins / Q000032:analysis*; D007403:Intervertebral Disc / Q000737:chemistry* / Q000166:cytology; D040201:Platelet Membrane Glycoprotein IIb / Q000032:analysis; D013045:Species Specificity; D013552:Swine / Q000378:metabolism*
D039423:Integrin alpha1; D039482:Integrin alpha5; D039503:Integrin alpha6; D039564:Integrin alphaV; D039641:Integrin beta Chains; D019012:Integrin beta1; D039661:Integrin beta3; D039663:Integrin beta4; D016023:Integrins; D040201:Platelet Membrane Glycoprotein IIb; C084344:integrin beta5