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Miller L, Bodemeier Loayza Careaga M, Handa RJ, Wu TJ. The Effects of Chronic Variable Stress and Photoperiod Alteration on the Hypothalamic-Pituitary-Adrenal Axis Response and Behavior of Mice. Neuroscience 2022; 496:105-118. [PMID: 35700818 DOI: 10.1016/j.neuroscience.2022.06.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 06/06/2022] [Accepted: 06/07/2022] [Indexed: 11/30/2022]
Abstract
The hypothalamic-pituitary-adrenal (HPA) axis mediates the physiological response to stressors and also synchronizes different physiological systems to environmental cues. Changes in day length (i.e., photoperiod) as well as chronic exposure to stressors are known to impact the HPA axis activity regulating the levels of glucocorticoid hormones. Over-exposure to inappropriate levels of glucocorticoids has been implicated in increased disease risk. In the present study, we examined the impact of chronic stress, using a chronic variable stress (CVS) paradigm, in combination with changes in photoperiod on physiological and behavioral measures, as well as on the reactivity and regulation of the HPA axis, in male and female mice. Six weeks of CVS, regardless of the photoperiod condition, decreased the body weight and attenuated the HPA axis reactivity to an acute stressor in both sexes. The attenuated HPA axis reactivity observed in stressed animals was related to reduced Pro-opiomelanocortin (POMC) mRNA levels in the pituitary of females. The gene expression analyses of key regulators of the HPA axis also indicated a sex-dependent effect with opposite patterns in the pituitary and adrenal glands. CVS effects on behavior were limited and related to an anxiety-like phenotype in both sexes, regardless of photoperiod condition. Our findings highlight sex-specific differences in the HPA axis and also sex-dependent effects of CVS on physiological parameters.
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Affiliation(s)
- Lauren Miller
- Department of Gynecologic Surgery and Obstetrics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States; Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Mariella Bodemeier Loayza Careaga
- Department of Gynecologic Surgery and Obstetrics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States; Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Robert J Handa
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO, United States
| | - T John Wu
- Department of Gynecologic Surgery and Obstetrics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States; Program in Neuroscience, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.
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Russell AL, Miller L, Yi H, Keil R, Handa RJ, Wu TJ. Knockout of the circadian gene, Per2, disrupts corticosterone secretion and results in depressive-like behaviors and deficits in startle responses. BMC Neurosci 2021; 22:5. [PMID: 33509094 PMCID: PMC7841886 DOI: 10.1186/s12868-020-00607-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 12/30/2020] [Indexed: 12/13/2022] Open
Abstract
Background The Period Circadian Regulator 2 (Per2) gene is important for the modulation of circadian rhythms that influence biological processes. Circadian control of the hypothalamus-pituitary-adrenal (HPA) axis is critical for regulation of hormones involved in the stress response. Dysregulation of the HPA axis is associated with neuropsychiatric disorders. Therefore, it is important to understand how disruption of the circadian rhythm alters the HPA axis. One way to address this question is to delete a gene involved in regulating a central circadian gene such as Per2 in an animal model and to determine how this deletion may affect the HPA axis and behaviors that are altered when the HPA axis is dysregulated. To study this, corticosterone (CORT) levels were measured through the transition from light (inactive phase) to dark (active phase). Additionally, CORT levels as well as pituitary and adrenal mRNA expression were measured following a mild restraint stress. Mice were tested for depressive-like behaviors (forced swim test (FST)), acoustic startle response (ASR), and pre-pulse inhibition (PPI). Results The present results showed that Per2 knockout impacted CORT levels, mRNA expression, depressive-like behaviors, ASR and PPI. Unlike wild-type (WT) mice, Per2 knockout (Per2) mice showed no diurnal rise in CORT levels at the onset of the dark cycle. Per2−/− mice had enhanced CORT levels and adrenal melanocortin receptor 2 (Mc2R) mRNA expression following restraint. There were no changes in expression of any other pituitary or adrenal gene. In the FST, Per2−/− mice spent more time floating (less time struggling) than WT mice, suggesting increased depressive-like behaviors. Per2−/− mice had deficits in ASR and PPI startle responses compared to WT mice. Conclusions In summary, these findings showed that disruption of the circadian system via Per2 gene deletion dysregulated the HPA stress axis and is subsequently correlated with increased depressive-like behaviors and deficits in startle response.
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Affiliation(s)
- Ashley L Russell
- Program in Neuroscience, Uniformed Services University of the Health Sciences, Bethesda, MD, USA.,Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Lauren Miller
- Department of Obstetrics and Gynecology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA
| | - Hannah Yi
- Department of Obstetrics and Gynecology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA
| | - Rita Keil
- Department of Obstetrics and Gynecology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA
| | - Robert J Handa
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - T John Wu
- Program in Neuroscience, Uniformed Services University of the Health Sciences, Bethesda, MD, USA. .,Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA. .,Department of Obstetrics and Gynecology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA.
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Oyola MG, Johnson RC, Bauman BM, Frey KG, Russell AL, Cho‐Clark M, Buban KN, Bishop‐Lilly KA, Merrell DS, Handa RJ, Wu TJ. Gut microbiota and metabolic marker alteration following dietary isoflavone-photoperiod interaction. Endocrinol Diabetes Metab 2021; 4:e00190. [PMID: 33532621 PMCID: PMC7831223 DOI: 10.1002/edm2.190] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/09/2020] [Accepted: 09/12/2020] [Indexed: 11/06/2022] Open
Abstract
Introduction The interaction between isoflavones and the gut microbiota has been highlighted as a potential regulator of obesity and diabetes. In this study, we examined the interaction between isoflavones and a shortened activity photoperiod on the gut microbiome. Methods Male mice were exposed to a diet containing no isoflavones (NIF) or a regular diet (RD) containing the usual isoflavones level found in a standard vivarium chow. These groups were further divided into regular (12L:12D) or short active (16L:8D) photoperiod, which mimics seasonal changes observed at high latitudes. White adipose tissue and genes involved in lipid metabolism and adipogenesis processes were analysed. Bacterial genomic DNA was isolated from fecal boli, and 16S ribosomal RNA sequencing was performed. Results NIF diet increased body weight and adipocyte size when compared to mice on RD. The lack of isoflavones and photoperiod alteration also caused dysregulation of lipoprotein lipase (Lpl), glucose transporter type 4 (Glut-4) and peroxisome proliferator-activated receptor gamma (Pparg) genes. Using 16S ribosomal RNA sequencing, we found that mice fed the NIF diet had a greater proportion of Firmicutes than Bacteroidetes when compared to animals on the RD. These alterations were accompanied by changes in the endocrine profile, with lower thyroid-stimulating hormone levels in the NIF group compared to the RD. Interestingly, the NIF group displayed increased locomotion as compared to the RD group. Conclusion Together, these data show an interaction between the gut bacterial communities, photoperiod length and isoflavone compounds, which may be essential for understanding and improving metabolic health.
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Affiliation(s)
- Mario G. Oyola
- Department of Obstetrics and GynecologyUniformed Services University of the Health SciencesBethesdaMDUSA
- Center for Neuroscience and Regenerative MedicineUniformed Services University of the Health SciencesBethesdaMDUSA
- Henry M. Jackson Foundation for the Advancement of Military MedicineBethesdaMDUSA
| | - Ryan C. Johnson
- Henry M. Jackson Foundation for the Advancement of Military MedicineBethesdaMDUSA
| | - Bradly M. Bauman
- Department of Obstetrics and GynecologyUniformed Services University of the Health SciencesBethesdaMDUSA
| | - Kenneth G. Frey
- Genomics and Bioinformatics DepartmentBiological Defense Research DirectorateNaval Medical Research Center – FrederickFort DetrickMDUSA
| | - Ashley L. Russell
- Department of Obstetrics and GynecologyUniformed Services University of the Health SciencesBethesdaMDUSA
- Center for Neuroscience and Regenerative MedicineUniformed Services University of the Health SciencesBethesdaMDUSA
| | - Madelaine Cho‐Clark
- Department of Obstetrics and GynecologyUniformed Services University of the Health SciencesBethesdaMDUSA
| | - Katelyn N. Buban
- Department of Obstetrics and GynecologyUniformed Services University of the Health SciencesBethesdaMDUSA
- Henry M. Jackson Foundation for the Advancement of Military MedicineBethesdaMDUSA
| | - Kimberly A. Bishop‐Lilly
- Genomics and Bioinformatics DepartmentBiological Defense Research DirectorateNaval Medical Research Center – FrederickFort DetrickMDUSA
- Program in Emerging Infectious DiseasesUniformed Services University of the Health SciencesBethesdaMDUSA
| | - D. Scott Merrell
- Program in Emerging Infectious DiseasesUniformed Services University of the Health SciencesBethesdaMDUSA
- Department of Microbiology and ImmunologyUniformed Services University of the Health SciencesBethesdaMDUSA
| | - Robert J. Handa
- Department of Biomedical SciencesColorado State UniversityFort CollinsCOUSA
| | - T. John Wu
- Department of Obstetrics and GynecologyUniformed Services University of the Health SciencesBethesdaMDUSA
- Center for Neuroscience and Regenerative MedicineUniformed Services University of the Health SciencesBethesdaMDUSA
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