Sex-specific role of CYP4A isoforms in ischemic stroke: a target for male-specific neuroprotection

Background and hypothesis: Sex differences in ischemic stroke outcomes have been widely observed, with males exhibiting greater engagement of programmed necrosis pathways. However, the molecular mechanisms underlying this disparity remain poorly understood. We identified that cytochrome P450 (CYP4A) isoforms are selectively expressed and upregulated in male neurons following ischemic injury. This study explores the role of CYP4A isoforms in ischemic stroke and their potential as a sex-specific therapeutic target. Methods: 3-month-old Sprague-Dawley rats underwent middle cerebral artery occlusion with interventions including castration (CAST), CAST with androgen replacement, or ovariectomy. Rats were treated with HET0016 (1 mg/kg intraperitoneally) or vehicle prior to reperfusion and at 3 hours post-reperfusion. Quantitative RT-PCR analysis was performed on ipsilateral cerebral hemispheres to assess CYP4A isoform expression (4A1, 4A2, 4A3, 4A8) at 6 hours post-reperfusion. Turning preference on the corner test and infarct volume measured with 2,3,5-triphenyltetrazolium chloride staining was assessed at 3 days post-reperfusion. Results: CYP4A8 was uniquely expressed in male brains and induced following ischemic injury across all male groups (sham, CAST, CAST with androgen replacement). No significant changes in CYP4A2 or CYP4A3 expression were observed in either sex. HET0016 treatment significantly reduced infarct volume and improved neurobehavioral outcomes (corner test) in males but not in females. CAST males treated with HET0016 showed trends toward reduced infarct volume and improved behavior, indicating that CYP4A8-mediated effects are sex-dependent rather than strictly androgen-dependent. Conclusion: CYP4A8 exhibits a sex-dependent expression pattern and may mediate male-specific vulnerability to ischemic injury in rats. Inhibition of CYP4A activity with HET0016 provides neuroprotection in males, as demonstrated by reduced infarct volume and improved neurobehavioral performance, but has no significant effect in females. These findings highlight CYP4A8 as a promising therapeutic target for addressing ischemic brain injury in male patients. This work is supported by the JHU Anesthesiology StARR program. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.