Effects of methotrexate exposure on medaka (<i>Oryzias latipes</i>) testes

Abstract

For the purpose of clarifying the histopathological effects of methotrexate (MTX) on medaka testes, wild-type and homogenic p53-deficient male medaka at 4 to 6 months post-hatching were exposed to 0.25 mg/ml of MTX for 96 h with histopathological examination of testes at 24, 48, 72 and 96 h. At 72 and 96 h after the start of MTX exposure, numerous apoptotic cells were observed in the spermatogonia and spermatocytes, and the pyknotic cell rate and the TUNEL-positive and cleaved caspase-3-positive rates in the spermatogonia and spermatocytes of MTX-treated wild type medaka were higher compared with those in the control wild-type medaka. Starting at 48 h, the phospho-histone H3-positive rate in the spermatogonia and spermatocytes of was significantly lower in MTX-treated wild-type medaka than in control wild-type medaka. In homogenic p53-deficient medaka, apoptosis was not induced in the spermatogonia and spermatocytes by exposure to MTX. Starting at 48 h, the phospho-histone H3-positive rate in spermatogonia and spermatocytes of MTX-treated homogenic p53-deficient medaka was lower than in control homogenic p53-deficient medaka. Throughout the entire experimental period, there were no significant differences in phospho-histone H3-positive rates in the spermatogonia and spermatocytes between the MTX-treated homogenic p53-deficient medaka group and the MTX-treated wild-type medaka group. In the present study, spermatogonia and spermatocytes of medaka testes were sensitive to MTX at 0.25 mg/ml in the culture water, and MTX-induced apoptosis in the testes was dependent on p53 expression; however, inhibition of MTX-induced cell proliferation was independent of p53 expression.

Selenium mitigates methotrexate‐induced testicular injury: Insights from male NMRI mice model

“…Bcl‐2 helps in the regulation of antioxidant pathways and cell defenses against lipid oxidation without affecting the intracellular ROS levels, which demonstrate its powerful antioxidant effects indirectly. Previous research also has indicated that MTX causes oxidative stress and induces testicular tissue damage, including degeneration of the seminiferous tubules and germ‐cell apoptosis, as well as activating the p53 ‐signaling pathway, which is associated with the mitochondrial cell death cascade (Hirako et al, 2017; Sheikhbahaei et al, 2016; Sherif et al, 2020). The antiapoptotic activity of Se has been reported in numerous studies, confirming that it inhibits apoptosis by affecting apoptotic pathways such as Bax, p53 , and caspase‐3 (Chen et al, 2013; Chen et al, 2014; Rahbardar et al, 2021; Yeo & Kang, 2007).…”

Paternal methotrexate exposure affects sperm small RNA content and causes craniofacial defects in the offspring

“…Despite the drug's contraindication for pregnant women due to the risk of miscarriage and birth abnormalities, the paternal influence of MTX on their offspring was largely unknown. In addition to this, the vast majority of studies in fish models such as medaka and zebrafish has been performed during embryological stages [57][58][59][60] , while few have evaluated the effect on adults 61 and the consequences on their offspring.…”