API

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Relationship: 2010

Title

A descriptive phrase which clearly defines the two KEs being considered and the sequential relationship between them (i.e., which is upstream, and which is downstream). More help

Histone deacetylase inhibition leads to Spermatocyte depletion

Upstream event
The causing Key Event (KE) in a Key Event Relationship (KER). More help
Histone deacetylase inhibition
Downstream event
The responding Key Event (KE) in a Key Event Relationship (KER). More help
Spermatocyte depletion

Key Event Relationship Overview

The utility of AOPs for regulatory application is defined, to a large extent, by the confidence and precision with which they facilitate extrapolation of data measured at low levels of biological organisation to predicted outcomes at higher levels of organisation and the extent to which they can link biological effect measurements to their specific causes.Within the AOP framework, the predictive relationships that facilitate extrapolation are represented by the KERs. Consequently, the overall WoE for an AOP is a reflection in part, of the level of confidence in the underlying series of KERs it encompasses. Therefore, describing the KERs in an AOP involves assembling and organising the types of information and evidence that defines the scientific basis for inferring the probable change in, or state of, a downstream KE from the known or measured state of an upstream KE. More help

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

Taxonomic Applicability

Latin or common names of a species or broader taxonomic grouping (e.g., class, order, family) that help to define the biological applicability domain of the KER.In general, this will be dictated by the more restrictive of the two KEs being linked together by the KER.  More help
Term Scientific Term Evidence Link
rat Rattus norvegicus High NCBI

Sex Applicability

An indication of the the relevant sex for this KER. More help
Sex Evidence
Male High

Life Stage Applicability

An indication of the the relevant life stage(s) for this KER.  More help
Term Evidence
Adult, reproductively mature Moderate

Key Event Relationship Description

Provides a concise overview of the information given below as well as addressing details that aren’t inherent in the description of the KEs themselves. More help

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

Include a description of the approach for identification and assembly of the evidence base for the KER. For evidence identification, include, for example, a description of the sources and dates of information consulted including expert knowledge, databases searched and associated search terms/strings.  Include also a description of study screening criteria and methodology, study quality assessment considerations, the data extraction strategy and links to any repositories/databases of relevant references.Tabular summaries and links to relevant supporting documentation are encouraged, wherever possible. More help

Evidence Supporting this KER

Addresses the scientific evidence supporting KERs in an AOP setting the stage for overall assessment of the AOP. More help

MAA administration induces spermatocyte deaths, which has been revealed by section staining of the germ cell death [Wade et al., 2008].

Biological Plausibility
Addresses the biological rationale for a connection between KEupstream and KEdownstream.  This field can also incorporate additional mechanistic details that help inform the relationship between KEs, this is useful when it is not practical/pragmatic to represent these details as separate KEs due to the difficulty or relative infrequency with which it is likely to be measured.   More help

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
Addresses inconsistencies or uncertainties in the relationship including the identification of experimental details that may explain apparent deviations from the expected patterns of concordance. More help

Known modulating factors

This table captures specific information on the MF, its properties, how it affects the KER and respective references.1.) What is the modulating factor? Name the factor for which solid evidence exists that it influences this KER. Examples: age, sex, genotype, diet 2.) Details of this modulating factor. Specify which features of this MF are relevant for this KER. Examples: a specific age range or a specific biological age (defined by...); a specific gene mutation or variant, a specific nutrient (deficit or surplus); a sex-specific homone; a certain threshold value (e.g. serum levels of a chemical above...) 3.) Description of how this modulating factor affects this KER. Describe the provable modification of the KER (also quantitatively, if known). Examples: increase or decrease of the magnitude of effect (by a factor of...); change of the time-course of the effect (onset delay by...); alteration of the probability of the effect; increase or decrease of the sensitivity of the downstream effect (by a factor of...) 4.) Provision of supporting scientific evidence for an effect of this MF on this KER. Give a list of references.  More help
Response-response Relationship
Provides sources of data that define the response-response relationships between the KEs.  More help
Time-scale
Information regarding the approximate time-scale of the changes in KEdownstream relative to changes in KEupstream (i.e., do effects on KEdownstream lag those on KEupstream by seconds, minutes, hours, or days?). More help

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
Define whether there are known positive or negative feedback mechanisms involved and what is understood about their time-course and homeostatic limits. More help

Domain of Applicability

A free-text section of the KER description that the developers can use to explain their rationale for the taxonomic, life stage, or sex applicability structured terms. More help

・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].

References

List of the literature that was cited for this KER description. More help

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