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Histone deacetylase inhibition leads to Spermatocyte depletion
Key Event Relationship Overview
AOPs Referencing Relationship
|AOP Name||Adjacency||Weight of Evidence||Quantitative Understanding||Point of Contact||Author Status||OECD Status|
|Histone deacetylase inhibition leading to testicular atrophy||non-adjacent||Moderate||Moderate||Brendan Ferreri-Hanberry (send email)||Open for citation & comment||WPHA/WNT Endorsed|
Life Stage Applicability
|Adult, reproductively mature||Moderate|
Key Event Relationship Description
Histone deacetylase inhibition triggered by histone deacetylase inhibitors such as methoxyacetic acid (MAA) leads to spermatocyte death causing spermatocyte depletion [Wade et al., 2008]. Histone deacetylase inhibition leads to an increase in histone acetylation, leading to spermatocyte apoptosis.
Evidence Collection Strategy
Evidence Supporting this KER
MAA administration induces spermatocyte deaths, which has been revealed by section staining of the germ cell death [Wade et al., 2008].
Histone deacetylase inhibition causes histone acetylation, which increases the gene expression of cell-cyle-related proteins, followed by spermatocyte apoptosis in testis.
Uncertainties and Inconsistencies
Known modulating factors
TUNEL-positive germ cells were increased after 8, 12, and 24 hrs of MAA exposure (650 mg/kg i.p.) in the rats [Wade et al., 2008]. TUNEL-positive zygotene spermatocytes have emerged after 12 hrs of MAA exposure in the rats, which was confirmed by the section staining [Wade et al., 2008].
Known Feedforward/Feedback loops influencing this KER
Domain of Applicability
・Histone deacetylase inhibition by histone deacetylase inhibitors caused spermatocyte death in rats. MAA treatment induced spermatocyte death in Sprague-Dawley rats (Rattus norvegicus) [Wade et al., 2008].
・VPA exposure caused a decrease in sperm count in humans (Homo sapiens) [Yerby and McCoy, 1999; Kose-Ozlece et al., 2015].
Kose-Ozlece, H. et al. (2015), "Alterations in semen parameters in men wıth epilepsy treated with valproate", Iran J Neurol 14:164-167
Wade, M.G. et al. (2008), "Methoxyacetic acid-induced spermatocyte death is associated with histone hyperacetylation in rats", Biol Reprod 78:822-831
Yerby, M.S. and McCoy, G.B. (1999), "Male infertility: Possible association with valproate exposure", Epilepsia 40:520-521