Signaling pathways regulating blood–tissue barriers — Lesson from the testis

摘要

Abstract Signaling pathways that regulate blood–tissue barriers are important for studying the biology of various blood–tissue barriers. This information, if deciphered and better understood, will provide better therapeutic management of diseases particularly in organs that are sealed by the corresponding blood–tissue barriers from systemic circulation, such as the brain and the testis. These barriers block the access of antibiotics and/or chemotherapeutical agents across the corresponding barriers. Studies in the last decade using the blood–testis barrier (BTB) in rats have demonstrated the presence of several signaling pathways that are crucial to modulate BTB function. Herein, we critically evaluate these findings and provide hypothetical models regarding the underlying mechanisms by which these signaling molecules/pathways modulate BTB dynamics. This information should be carefully evaluated to examine their applicability in other tissue barriers which shall benefit future functional studies in the field. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve. Highlights ? Signaling pathways recently shown to be involved in modulating BTB dynamics are critically reviewed. ? Both mTORC1 and mTORC2, and p-FAK-Tyr397 and –Tyr407 are involved in modulating BTB dynamics. ? mTORC1 and mTORC2 have antagonistic effects on BTB dynamics in which the former makes the BTB leaky and the latter tightens the BTB. ? p-FAK-Tyr397 and -Tyr407 have antagonistic effects on BTB dynamics in which the former makes the BTB leaky and the latter tightens the BTB. ? Combined effects of these modulators provide an effective mechanism to support germ cell transport across the BTB during spermatogenesis.