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Champroux, A.

Publications and source records attributed to Champroux, A..

3 recordsLinked to original sources

Exposure of Men to PTSD-Promoting Trauma Elevates Levels of Sperm miRNAs with Anxiety and Depression-Inducing Activities

Chronically stressing male rodents can induce stress-specific epigenetic changes in sperm that contribute to altered offspring phenotypes. Whether similar phenomena occur in men is unclear. This study addresses this knowledge gap by analyzing sperm microRNAs (miRNAs) from 51 men exposed to various levels of adult trauma including crime, disaster, and physical or sexual violence, quantified by the Trauma History Questionnaire (THQ), a measure of risk for Post-Traumatic Stress Disorder (PTSD). Four sperm miRNAs, miR-532-3p, 491-5p, 375-3p and 361-3p correlated positively with mens THQ scores, showing 4X to 130X over expression in sperm from the most highly traumatized men. These changes were independent of mens adverse childhood experiences (ACEs), which we previously linked to decreased miR-34/449 in their sperm; and sperm miR-34/449 levels were not associated with THQ scores. Injecting these 4 miRNAs into fertilized mouse oocytes at levels comparable to those found in men reporting high THQ scores yielded offspring with elevated anxiety-and depression-like phenotypes. This finding differs from the stress related phenotypes we observed in offspring of mice fertilized by sperm with reduced levels of miR-34/449. Consistent with only a small subset of men with high THQ scores developing PTSD, we observed no statistically significant increase in overall anxiety or depression among this highly traumatized group, however there were indications of increased sleeplessness, appetite and concentration difficulties and negative self-concept among this group. Nevertheless, almost all men reporting high THQ scores had elevated levels of all 4 of these miRNAs in their sperm, suggesting these trauma-induced epigenetic changes may raise mental health risks in the offspring of men with only subtle mental health problems. Since [~]20 % of men report either THQ or ACE scores in the ranges linked here and in our earlier study to changes in sperm miRNAs that in mice lead to elevated levels of stress-related behaviors, a large human population with an elevated risk of transmitting stress-related traits to their offspring likely exists.

genetics↗

Astrocyte-Derived Exosomes Regulate Sperm miR-34c Levels to Mediate the Transgenerational Effects of Paternal Chronic Social Instability Stress

The effects of chronically stressing male mice can be transmitted across generations by stress-specific changes in their sperm miRNA content that induce stress-specific phenotypes in their offspring. But how each stress paradigm alters the levels of distinct sets of sperm miRNAs is not understood. Here we describe evidence for astrocyte-derived exosomes (A-Exos) containing miR-34c mediating how chronic social instability (CSI) stress suppesses levels of miR-34c in sperm, which we showed previously contributes to how this stress protocol leads to both elevated anxiety and defective sociability in their female offspring and reduced sperm miR-34c in their male offspring. In particular, we found that CSI stress decreases content of miR-34c in A-Exos isolated from the prefrontal cortex and amygdala, as well as in blood of CSI-stressed males. Strikingly, miR-34c content is also reduced in A-Exos isolated from these tissues of their F1 male offspring, who also display reduced sperm miR-34c levels despite never being directly exposed to stress and transmit these stress related traits to their offspring. In addition, restoring A-Exos miR-34c content in the blood of CSI-stressed males by IV injection of miR-34c-containing A-Exos restores miR-34c levels in their sperm. These findings reveal a surprising role for A-Exos in maintaining sperm miR-34c levels by a process that when suppressed by CSI stress mediates this example of transgenerational epigenetic inheritance.

genetics↗

Preimplantation Embryos Amplify Sperm-Derived miRNA Levels to Mediate Transgenerational Epigenetic Inheritance

The effects of chronically stressing male mice can be transmitted across generations by stress-specific changes in their sperm miRNA content that induce stress-specific phenotypes in their offspring. But how each stress paradigm alters the levels of distinct sets of sperm miRNAs is not known. We showed previously that exposure of male mice to chronic social instability (CSI) stress results in elevated anxiety and reduced sociability specifically in their female offspring across multiple generations because it reduces miR-34c levels in sperm of stressed males and their unstressed male offspring. Here we describe evidence that astrocyte-derived exosomes (A-Exos) carrying miR-34c mediate how CSI stress has this transgenerational effect on sperm. We found that CSI stress decreases miR-34c carried by A-Exos in the prefrontal cortex and amygdala, as well as in the blood of males. Importantly, miR-34c A-Exos levels are also reduced in these tissues in their F1 male offspring, who despite not being exposed to stress exhibit reduced sperm miR-34c levels and transmit the same stress-associated traits to their male and female offspring. Furthermore, restoring A-Exos miR-34c content in the blood of CSI-stressed males by intravenous injection of miR-34c-containing A-Exos restores miR-34c levels in their sperm. These findings reveal an unexpected role for A-Exos in maintaining sperm miR-34c levels by a process that when suppressed by CSI stress mediates this example of transgenerational epigenetic inheritance.

genetics↗