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Acute Ozone-Induced Transcriptional Changes in Markers of Oxidative Stress and Glucocorticoid Signaling in the Rat Hippocampus and Hypothalamus are Sex-Specific.
Citation:
Valdez, M., D. Freeborn, P. Vulimiri, J. Valdez, U. Kodavanti, AND P. Kodavanti. Acute Ozone-Induced Transcriptional Changes in Markers of Oxidative Stress and Glucocorticoid Signaling in the Rat Hippocampus and Hypothalamus are Sex-Specific. International Journal of Molecular Sciences. MDPI, Basel, Switzerland, 24(7):1, (2023). https://doi.org/10.3390/ijms24076404
Impact/Purpose:
This study highlights the importance of gender on the effects of Air pollutants. Current study was carried to identify some of the mechanistic aspects at genomic level in brain regions that are critical for observed neuronal effects of acute ozone exposure. Present results indicate that sex-specific responses to air pollution may, in part, be caused by difference in brain transcriptomic responses. This information may be useful for the regulatory community in determining the risk of air pollutants and influence of gender.
Description:
Exposure to a prototypic air pollutant ozone (O3) has been associated with the activation of neuroendocrine stress response along with neural changes in oxidative stress (OS), inflammation, and Alzheimer’s disease-like pathologies in susceptible animal models. We hypothesized that neural oxidative and transcriptional changes induced by O3 in stress responsive regions are sex-dependent. Male and female adult Long-Evans rats were exposed to filtered-air of O3 for 2 consecutive days (0.8 ppm, 4 hr/day) and brain regions were flash-frozen. Activities of cerebellar oxido-reductive (OS) and mitochondrial complex I, II, and IV enzymes, and protein carbonyls were assessed to confirm prior findings. We assessed transcriptional changes in hypothalamus (HYP) and hippocampus (HIP) for markers of OS, microglial activity and glucocorticoid signaling using qPCR. Although there were no O3 or sex-related differences in the cerebellar activities of OS and mitochondrial enzymes, the levels of protein carbonyls and complex II activities were higher in females regardless of O3. There were no statistical differences in baseline expression of genes related to OS (Cat, Dhcr24, Foxm1, Gpx1, Gss, Nfe2l2, Sod1) except for lower HYP Sod1 expression in air-exposed females than males and higher HIP Gss expression in O3-exposed females relative to matched-males. Microglial marker Aif1 expression was higher in O3-exposed females relative to males; O3 inhibited Itgam only in males. The expression of Bdnf in HIP and HYP was inhibited by O3 in both sexes. Genes related to glucocorticoid signaling (Fkbp4, Fkbp5, Hsp90aa1, Hspa4, nr3c1, nr3c2) showed sex-specific effects due to O3 exposure. Baseline expression of HIP Fkbp4 was higher in females relative to males. O3 inhibited Nr3c1 in female HIP and male HYP but Nr3c2 was inhibited in male HYP. Fkbp4 expression was higher in O3-exposed females when compared to matched-males, whereas Fkbp5, was expressed at higher levels in both brain regions of males and females. These results indicate that sex-specific brain region responses to O3 might, in part, be caused by OS and regulation of glucocorticoid signaling.
URLs/Downloads:
DOI: Acute Ozone-Induced Transcriptional Changes in Markers of Oxidative Stress and Glucocorticoid Signaling in the Rat Hippocampus and Hypothalamus are Sex-Specific.