Cell Junction Dynamics in the Testis: Sertoli-Germ Cell Interactions and Male Contraceptive Development

Abstract

Spermatogenesis is an intriguing but complicated biological process. However, many studies since the 1960s have focused either on the hormonal events of the hypothalamus-pituitary-testicular axis or morphological events that take place in the seminiferous epithelium. Recent advances in biochemistry, cell biology, and molecular biology have shifted attention to understanding some of the key events that regulate spermatogenesis, such as germ cell apoptosis, cell cycle regulation, Sertoli-germ cell communication, and junction dynamics. In this review, we discuss the physiology and biology of junction dynamics in the testis, in particular how these events affect interactions of Sertoli and germ cells in the seminiferous epithelium behind the blood-testis barrier. We also discuss how these events regulate the opening and closing of the blood-testis barrier to permit the timely passage of preleptotene and leptotene spermatocytes across the blood-testis barrier. This is physiologically important since developing germ cells must translocate across the blood-testis barrier as well as traverse the seminiferous epithelium during their development. We also discuss several available in vitro and in vivo models that can be used to study Sertoli-germ cell anchoring junctions and Sertoli-Sertoli tight junctions. An in-depth survey in this subject has also identified several potential targets to be tackled to perturb spermatogenesis, which will likely lead to the development of novel male contraceptives.

The effect of zinc oxide nanoparticles on mouse spermatogenesis

“…Sertoli cells secrete hormonal and nutritive factors into the adluminal compartment which creates a specialized microenvironment for development and viability of germ cells. In addition, Sertoli cells provide efficient paracrine signaling mechanisms between these cells as well as physical support to developing germ cells [3]. The intricate regulation and cellular interactions that occur in the testis provide multiple distinct targets by which toxicants can disrupt spermatogenesis [2].…”

Effect of beta-carotene on titanium oxide nanoparticles-induced testicular toxicity in mice

“…Sertoli cells secrete hormonal and nutritive factors into the adluminal compartment which creates a specialized microenvironment for development and viability of germ cells. In addition, Sertoli cells provide efficient paracrine signaling mechanisms between these cells as well as physical support to developing germ cells [3]. Leydig cells synthesis and release testosterone.…”

Intercellular adhesion molecule-1 is a regulator of blood–testis barrier function

“…These events allow germ cells to traverse the seminiferous epithelium while developing into elongated spermatids that are eventually released into the tubule lumen at late stage VIII of the seminiferous epithelial cycle during spermiation (Cheng and Mruk, 2002;de Kretser and Kerr, 1988;Mruk and Cheng, 2004;O'Donnell et al, 2011). For example, many different junction types are known to constitute the function of the blood-testis barrier (BTB, also known as the Sertoli cell barrier).…”