Cadmium-induced Sertoli Cell Injury Through p38-MAPK and Related Signaling Proteins—A Study by RNA Sequencing

Abstract

Environmental toxicants, such as cadmium, found in foods, water and consumer products are known to induce male reproductive dysfunction. However, the underlying molecular mechanism(s) by which cadmium-induced Sertoli cell injury as manifested by a disruption of the blood-testis barrier remains unknown. Interestingly, one of the primary targets of cadmium toxicity in the testis is the cytoskeletons of the Sertoli cells, which, in turn, impedes cell junctions in the seminiferous epithelium. In order to expand these earlier observations and to provide a roadmap for future studies, we embarked a study using RNA-Seq to identify the pertinent genes involved in cadmium-induced Sertoli cell injury. Using bioinformatics analyses, multiple gene sets that regulated actin and microtubule (MT) cytoskeletons were identified along with components of the MAPK (mitogen activated protein kinase) signaling protein and several signaling pathways. More important, we have also discovered that while the gene expression of p38-MAPK (also JNK or c-Jun) was considerably up- or down-regulated during cadmium-induced Sertoli cell injury, the activated (phosphorylated) form was up-regulated. Importantly, doramapimod (BIRB 796), a specific p38-MARK inhibitor, that was shown to selectively block cadmium-induced p-p38 MAPK activation via phosphorylation in Sertoli cells, was indeed capable of blocking cadmium-induced Sertoli cell injury including disruption of the Sertoli cell-permeability barrier function, disruptive distribution of BTB-associated proteins, and disruptive organization of the actin and MT cytoskeletons. These data provide a helpful source of information for investigators to probe the role of signaling proteins and/or cascades, besides MAPKs, that likely utilized by cadmium to induce reproductive dysfunction.

Deoxynivalenol Induces Blood–Testis Barrier Dysfunction through Disrupting p38 Signaling Pathway-Mediated Tight Junction Protein Expression and Distribution in Mice

“…p38, an essential member of the MAPK family, is implicated in exogenous toxin-induced BTB injury. , The p38 signaling pathway is activated in the intestinal epithelial barrier, gastric mucosal barrier, and blood–brain barrier in a DON-induced TJ model of injury. ,, However, whether the damage caused by DON to TJ proteins expression and localization in the BTB is via the p38 signaling pathway is still unclear. In this study, we focused on the action of the p38 signaling pathway and its downstream components in DON-induced injury in testicular TJs.…”

Map-1a regulates Sertoli cell BTB dynamics through the cytoskeletal organization of microtubule and F-actin

“…Sertoli cells were isolated from the testes of 20-day-old male pups for primary cultures as earlier described [ 25 ] and detailed elsewhere in our laboratory [ 26 ]. Freshly isolated Sertoli cells were seeded on Matrigel (BD Biosciences, San Jose, CA)-coated culture dishes (either 6-, 12-, or 24-well dishes), coverslips (to be placed in 12-well dishes), and bicameral units (Millipore, Burlington, MA; to be placed in 24-well dishes).…”

“…Sertoli cells cultured for 3 days were treated with 0.9% NaCl (control) versus CdCl 2 at 1 µM for 6 h for IF or at 3 µM for 24 h for IB, qPCR, and RNA-Seq for transcriptome profiling. The selection of these concentrations and treatment times for specific experiments reported herein was based on the results of a series of pilot experiments, and published in earlier reports [ 25 , 30 – 32 ], to obtain the notable phenotypes without impeding cell viability. For in vivo experiments, adult rats were treated with CdCl 2 at 3 mg/kg b.w.…”

“…Sertoli cell BTB integrity in vitro was further assessed by the ability of a functional BTB to block the passage of a small membrane-impermeable biotin, EZ-LinkSulfo-NHS-LC-Biotin (Mr 556.59; Thermo Fisher Scientific, Waltham, MA) as described [ 25 , 36 ] and detailed elsewhere [ 37 ]. In brief, freshly isolated Sertoli cells were plated on Matrigel-coated round coverslips (placed in 12-well dishes) at a density of 0.03 ~ 0.04 × 10 6 cells/cm 2 so the cell–cell interface in the epithelium can be distinctively visible by fluorescence microscopy.…”

Inhibition of p38MAPK signalling pathway alleviates radiation‐induced testicular damage through improving spermatogenesis

“…translocation of germ cells (Siu et al, 2009;Wong et al, 2004). Some studies have suggested that the abnormal reproductive function caused by the environmental poison cadmium can be treated by targeting the p38MAPK pathway (Wang et al, 2023;Yu et al, 2008).…”