title: Disruption effects of monophthalate exposures on inter-Sertoli tight junction in a two-compartment culture model.
abstract: Phthalates are suspect environmental endocrine disruptors that may affect male reproduction and development by disturbing androgen synthesis and cell-cell interactions in the seminiferous epithelium. The in vivo metabolites, monophthalates, are thought to be the active agents, and toxicant effects including testicular damage and decreased sperm motility have been described previously. In this study, the aim was to investigate the effect of monophthalates on Sertoli cells using a two-compartment cell culture model, asking whether tight junction protein structures are affected, compromising the blood-testis barrier and contributing to male-mediated toxicity. Sertoli cells were isolated from Sprague Dawley rat testes and seeded onto the filters of two-compartment wells. A Sertoli cell monolayer was allowed to form, whereupon the cultures were treated with 0, 10, 30, 150, and 600 micromol/L monobutyl phthalate (MBP) or mono-2-ethylhexyl phthalate (MEHP) for 24 h. Effects on the tight junctions between adjacent Sertoli cells were studied by light and transmission electron microscopy, the transepithelial electrical resistance (TEER) assay, and immunofluorescence localization. Results showed that exposures to monophthalates destroyed tight junctional structure in Sertoli cell monolayers in a dose-depended manner, as evidenced by a loss of single-cell layer organization in the cultures, decline of TEER value, and decreased expression of proteins associated with tight junctions such as zonula occludens-1 (ZO-1), F-actin, and Occludin. The changes were observed at doses of 150 and 600 micromol/L, which is 10-100 times higher relative to estimated human exposures from the environment. These results are consistent with monophthalate-induced damage to tight junctions between adjacent Sertoli cells, suggesting that damage to Sertoli cell tight junctions induced by monophthalates may be an underlying mechanism of their male-mediated reproductive toxicity.
authors.affiliation: Department of Environmental Health, School of Public Health, Fudan University, Shanghai 200032, People's Republic of China.
authors.forename: Yun-Hui
authors.initials: YH
authors.lastname: Zhang
authors.forename: Ling
authors.initials: L
authors.lastname: Lin
authors.forename: Zhi-Wei
authors.initials: ZW
authors.lastname: Liu
authors.forename: Xue-Zhi
authors.initials: XZ
authors.lastname: Jiang
authors.forename: Bing-Heng
authors.initials: BH
authors.lastname: Chen
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D002463:Cell Membrane Permeability / Q000187:drug effects; D002478:Cells, Cultured; D004051:Diethylhexyl Phthalate / Q000031:analogs & derivatives* / Q000633:toxicity; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D008954:Models, Biological; D062793:Occludin; D010750:Phosphoproteins / Q000378:metabolism; D010795:Phthalic Acids / Q000633:toxicity*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012708:Sertoli Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D019108:Tight Junctions / Q000187:drug effects*; D062826:Zonula Occludens-1 Protein
chemical_list: D000199:Actins; D008565:Membrane Proteins; C568985:OCLN protein, human; D062793:Occludin; C568987:Ocln protein, rat; D010750:Phosphoproteins; D010795:Phthalic Acids; D012333:RNA, Messenger; C569042:TJP1 protein, human; C569044:Tjp1 protein, rat; D062826:Zonula Occludens-1 Protein; D004051:Diethylhexyl Phthalate; C016599:mono-(2-ethylhexyl)phthalate; C028577:monobutyl phthalate