title: Inhibition of claudin-11 and occludin expression in rat Sertoli cells by mono-(2-ethylhexyl) phthalate through p44/42 mitogen-activated protein kinase pathway.
abstract: Our objectives were to evaluate the effects of mono(2-ethylhexyl) phthalate  (MEHP) on tight junctions (TJ) in cultured rat Sertoli cells (SC) and to  investigate changes in the signal transduction pathways in SCs following MEHP  treatment. SCs were isolated and purified from the testes of 18-day-old  Sprague Dawley rats and incubated at 34°C for 3 days. After treatment of  SCs with either the vehicle or MEHP for 0.5, 1, 3, 6 and 24 hours, whole cell  lysates were isolated from each replicate to prepare RNA and protein.  Expression levels of claudin-11, occludin, and zonula occludens-1 (ZO-1) mRNA  were evaluated by quantitative real-time reverse  transcription-polymerase chain reaction and changes in signal  transduction pathways possibly induced by MEHP treatment were assessed by  Western blot analyses. MEHP treatment led to significant decreases in the  expression of claudin-11 and occludin mRNA, but not that of ZO-1, in rat SCs.  Exposure of rat SCs to MEHP resulted in the marked induction of phosphorylated  p44/42 mitogen-activated protein kinase (MAPK), whereas other pathways  examined in this study were not activated by MEHP. Furthermore, treatment of  rat SCs with a specific inhibitor of p44/42 MAPK prevented the MEHP-induced  down-regulation of claudin-11 and occludin. These findings demonstrate that  MEHP exposure inhibited the expression of claudin-11 and occludin mRNA in rat  SCs through the p44/42 MAPK pathway, suggesting the possible involvement of  MEHP in spermatogenic function by regulating major components of TJs in  SCs.
authors.affiliation: Division of Urology, Department of Surgery Related, Faculty of Medicine, Kobe University Graduate School of Medicine, Kobe, Japan. kchiba@med.kobe-u.ac.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Chiba
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kondo
authors.forename: Kohei
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Hideaki
authors.initials: H
authors.lastname: Miyake
authors.forename: Masato
authors.initials: M
authors.lastname: Fujisawa
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D057167:Claudins / Q000037:antagonists & inhibitors*; D004051:Diethylhexyl Phthalate / Q000031:analogs & derivatives* / Q000633:toxicity; D008297:Male; D008565:Membrane Proteins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D062793:Occludin; D010750:Phosphoproteins / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012708:Sertoli Cells / Q000187:drug effects* / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013091:Spermatogenesis / Q000187:drug effects*; D019108:Tight Junctions / Q000187:drug effects / Q000378:metabolism; D062826:Zonula Occludens-1 Protein
chemical_list: D057167:Claudins; C492353:Cldn11 protein, rat; D008565:Membrane Proteins; D062793:Occludin; C568987:Ocln protein, rat; D010750:Phosphoproteins; C569044:Tjp1 protein, rat; D062826:Zonula Occludens-1 Protein; D004051:Diethylhexyl Phthalate; D048052:Mitogen-Activated Protein Kinase 3; C016599:mono-(2-ethylhexyl)phthalate