Session: MON 338-354-Physiological Impacts of Endocrine Disrupting Chemicals
Poster Board MON-344
Sertoli cells were isolated from 20-day-old male rats and cultured for 5 days. Cells were exposed to MEHP (200 µM) alone or MEHP plus N-Acetyl-cysteine (NAC - 1mM) during the last 24 h of culture. The localization and expression of adherens (N-cadherin, α, ß and p120-catenins), tight (occludin, claudin-11, zonula occludens-1(ZO-1)), and gap (connexin 43 (Cx-43)) junction proteins were evaluated by immunofluorescence (IF) and Western blot (Wb) (2). Intracellular GSH level and G-S-T activity were determined by spectrophotometry (2). Alternatively, SC were treated only the last hour, and LPO levels were quantified by the FOX2 method (3). Results were expressed as percentage of control value, ANOVA and Tukey’s test.
As an indicative of oxidative stress, LPO concentrations (161±17%, P<0.005 vs control) were higher in MEHP treated SC. Exposure to MEHP reduced GSH levels to 19±4% (P<0.001 vs control). NAC treatment increased GSH levels in comparison to control (185±12%, P<0.001). The addition of MEHP plus NAC reduced GSH levels to 150±12% (P<0.01 vs NAC). These results indicate that NAC helped to partially prevent MEHP effects. A concomitant increase in G-S-T activity was observed under MEHP treatment (162±26%, P<0.01 vs control), indicating that GSH could conjugate MEHP to detoxify the exposed SC. MEHP induced a delocalization of the IF signal from SC membrane to the cytoplasm for N-cadherin, α-catenin and ZO-1 proteins. By Wb analysis, MEHP significant increased N-cadherin, α and ß-catenin and ZO-1 and reduced Cx-43 expression levels. No changes in p-120 catenin, claudin-11 and occludin were found. Also, we observed a down regulation of N-cadherin and α-catenin expression in SC treated with MEHP plus NAC, similar to control SC. Our data suggest that disruption of intercellular junctions induced by MEHP in Sertoli cell may be mediated through oxidative stress signaling.
Nothing to Disclose: HFS, CMS, RN, LL, BD
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