ABSTRACT
BACKGROUND: Sexual dimorphism in biological responses is a critical knowledge for therapeutic proposals. However, gender differences in intestinal stem cell physiology have been poorly studied. Given the important role of the protease-activated receptor PAR2 in the control of colon epithelial primitive cells and cell cycle genes, we have performed a sex-based comparison of its expression and of the effects of PAR2 activation or knockout on cell proliferation and survival functions. METHODS: Epithelial primitive cells isolated from colons from male and female mice were cultured as colonoids, and their number and size were measured. PAR2 activation was triggered by the addition of SLIGRL agonist peptide in the culture medium. PAR2-deficient mice were used to study the impact of PAR2 expression on colon epithelial cell culture and gene expression. RESULTS: Colonoids from female mice were more abundant and larger compared to males, and these differences were further increased after PAR2 activation by specific PAR2 agonist peptide. The proliferation of male epithelial cells was lower compared to females but was specifically increased in PAR2 knockout male cells. PAR2 expression was higher in male colon cells compared to females and controlled the gene expression and activation of key negative signals of the primitive cell proliferation. This PAR2-dependent brake on the proliferation of male colon primitive cells was correlated with stress resistance. CONCLUSIONS: Altogether, these data demonstrate that there is a sexual dimorphism in the PAR2-dependent regulation of primitive cells of the colon crypt.
