Integrin pattern and effect on contraction in cultured testicular peritubular myoid cells

PROBLEM: Neither the integrin pattern nor the biological functions of integrins have been extensively documented in human cultured testicular peritubular myoid cells (TPMC). The integrin pattern and the presence of some proteins of the immunoglobulin superfamily on human TPMC as well as the role of integrins in TPMC contraction were examined. METHOD OF STUDY: Integrin expression was evaluated bq immunofluorescence and FACS analysis. To assess the role of integrin in TPMC contraction, human and rat cells were added to a collagen gel system and exposed to contractile stimuli. RESULTS: The immunofluorescence and cytofluorimetric analysis showed that human cultured TPMC express alpha (1), alpha (2), alpha (3), alpha (5), alpha (6), alpha (v), beta (1), beta (3), and beta (4) integrin subunits, and significant amounts of intercellular adhesion molecule-1 (ICAM-1), whereas they do not present alpha (4), beta (2), beta (7) subunits, nor intercellular adhesion molecule-2 (ICAM-2) and neural cell adhesion molecule (NCAM). The preincubation of human cells with an anti-beta (1) mAb and of rat cells with a polyclonal anti-beta (1) antibody inhibited TPMC contraction induced by different contractile stimuli. CONCLUSION: Our investigation documented a broad integrin pattern on human cultured TPMC as well as a role for integrins in human and rat TPMC contraction.