N‐acetylcysteine prevents MAA induced male germ cell apoptosis: role of glutathione and cytochrome c

Abstract

Exposure to methoxyacetic acid (MAA), a major byproduct of the paint industry, causes testicular atrophy in multiple species. This study demonstrates DNA breakdown in rat germ cells after exposure to MAA in vivo within 12 h, leading to 40% germ cell death by 24 h. Within 4 h of treatment, cytochrome c is released from the mitochondria into the cytosol without the involvement of mitochondrial potential loss, reactive oxygen species generation or lipid peroxidation events. Peak activation of caspase-9 and caspase-3 is detectable post treatment at 4 and 8 h respectively. There is a decrease in germ cell glutathione levels within 2 h of MAA treatment. Replenishment of glutathione by pretreatment of the animals with the antioxidant N-acetylcysteine prior to MAA treatment could prevent the release of cytochrome c, DNA fragmentation and cell death. ß

Interactions of methoxyacetic acid with androgen receptor

“…The full significance of the potentiation of nuclear receptor activity by MAA is uncertain. The proximal cause of MAAinduced spermatocyte apoptosis appears to be a fall in the level of reduced glutathione as compared to oxidized glutathione, insofar as spermatocyte apoptosis is substantially reduced when cellular glutathione levels are restored by treatment with N-acetyl cysteine, an antioxidant (Rao and Shaha, 2002). In our study, treatment of cells with N-acetyl cysteine had no impact on MAA-induced potentiation of AR activity, indicating that the enhancement of AR transcriptional activity is not a consequence of changes in cellular glutathione levels.…”

“…MAA decreases the ratio of reduced glutathione to oxidized glutathione in germ cells, triggering apoptosis; restoration of glutathione levels by treatment with N-acetyl cysteine prevents germ cell death (Rao and Shaha, 2002). Several intracellular signaling pathways, including tyrosine kinase signaling, are modulated by the intracellular redox state (Kamata and Hirata, 1999), suggesting that the effects of MAA on tyrosine kinase signaling and AR potentiation could involve changes in redox state.…”

Diethylstilbestrol Induces Rat Spermatogenic Cell Apoptosis in Vivo through Increased Expression of Spermatogenic Cell Fas/FasL System

“…Detection of DNA fragmentation by TUNEL staining was carried out as described previously (19,23) using a TUNEL assay kit according to instructions from the manufacturer. Briefly, deparaffinized tissue sections were treated with equilibration buffer (200 mM potassium cacodylate, 25 mM Tris-HCl, pH 8.0, 0.2 mM DTT, 0.25 mg/ml BSA, 2.5 mM cobalt chloride) for 10 min at room temperature followed by incubation with TdT buffer containing nucleotide mix (50 M dUTP-biotin, 100 M dATP, 10 mM Tris-HCl, pH 8.0, 1 mM EDTA, pH 7.6) for 1 h at 37°C.…”

“…Western Blot and DNA Analysis-Electrophoresis on 12% polyacrylamide gels, Western blots, and DNA extractions were carried out as described previously (19,23).…”

Ethylene glycol and propylene glycol ethers – Reproductive and developmental toxicity

“…Dimeryzacja Bak i Bax ułatwia uwalnianie z mitochondriów cytochromu c, co skutkuje aktywacją prokaspazy 9 do kaspazy 9, a następnie aktywacją kaspazy 3 i apoptozą [37]. Świadczy to o tym, że apoptoza indukowana przez MAA przebiega na szlaku mitochondrialnym [26,37].…”