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Appiah CB, Gardner JJ, Farmer GE, Cunningham RL, Cunningham JT. Chronic intermittent hypoxia-induced hypertension: the impact of sex hormones. Am J Physiol Regul Integr Comp Physiol 2024; 326:R333-R345. [PMID: 38406843 DOI: 10.1152/ajpregu.00258.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 02/12/2024] [Accepted: 02/15/2024] [Indexed: 02/27/2024]
Abstract
Obstructive sleep apnea, a common form of sleep-disordered breathing, is characterized by intermittent cessations of breathing that reduce blood oxygen levels and contribute to the development of hypertension. Hypertension is a major complication of obstructive sleep apnea that elevates the risk of end-organ damage. Premenopausal women have a lower prevalence of obstructive sleep apnea and cardiovascular disease than men and postmenopausal women, suggesting that sex hormones play a role in the pathophysiology of sleep apnea-related hypertension. The lack of protection in men and postmenopausal women implicates estrogen and progesterone as protective agents but testosterone as a permissive agent in sleep apnea-induced hypertension. A better understanding of how sex hormones contribute to the pathophysiology of sleep apnea-induced hypertension is important for future research and possible hormone-based interventions. The effect of sex on the pathophysiology of sleep apnea and associated intermittent hypoxia-induced hypertension is of important consideration in the screening, diagnosis, and treatment of the disease and its cardiovascular complications. This review summarizes our current understanding of the impact of sex hormones on blood pressure regulation in sleep apnea with a focus on sex differences.
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Affiliation(s)
- Cephas B Appiah
- Department of Physiology and Anatomy, School of Biomedical Sciences, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas, United States
| | - Jennifer J Gardner
- Department of Physiology and Anatomy, School of Biomedical Sciences, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas, United States
| | - George E Farmer
- Department of Physiology and Anatomy, School of Biomedical Sciences, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas, United States
| | - Rebecca L Cunningham
- Department of Pharmaceutical Sciences, System College of Pharmacy, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas, United States
| | - J Thomas Cunningham
- Department of Physiology and Anatomy, School of Biomedical Sciences, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas, United States
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Mabry S, Bradshaw JL, Gardner JJ, Wilson EN, Cunningham RL. Sex-dependent effects of chronic intermittent hypoxia: implication for obstructive sleep apnea. Biol Sex Differ 2024; 15:38. [PMID: 38664845 PMCID: PMC11044342 DOI: 10.1186/s13293-024-00613-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 04/17/2024] [Indexed: 04/28/2024] Open
Abstract
BACKGROUND Obstructive sleep apnea (OSA) affects 10-26% of adults in the United States with known sex differences in prevalence and severity. OSA is characterized by elevated inflammation, oxidative stress (OS), and cognitive dysfunction. However, there is a paucity of data regarding the role of sex in the OSA phenotype. Prior findings suggest women exhibit different OSA phenotypes than men, which could result in under-reported OSA prevalence in women. To examine the relationship between OSA and sex, we used chronic intermittent hypoxia (CIH) to model OSA in rats. We hypothesized that CIH would produce sex-dependent phenotypes of inflammation, OS, and cognitive dysfunction, and these sex differences would be dependent on mitochondrial oxidative stress (mtOS). METHODS Adult male and female Sprague Dawley rats were exposed to CIH or normoxia for 14 days to examine the impact of sex on CIH-associated circulating inflammation (IL-1β, IL-6, IL-10, TNF-α), circulating steroid hormones, circulating OS, and behavior (recollective and spatial memory; gross and fine motor function; anxiety-like behaviors; and compulsive behaviors). Rats were implanted with osmotic minipumps containing either a mitochondria-targeting antioxidant (MitoTEMPOL) or saline vehicle 1 week prior to CIH initiation to examine how inhibiting mtOS would affect the CIH phenotype. RESULTS Sex-specific differences in CIH-induced inflammation, OS, motor function, and compulsive behavior were observed. In female rats, CIH increased inflammation (plasma IL-6 and IL-6/IL-10 ratio) and impaired fine motor function. Conversely, CIH elevated circulating OS and compulsivity in males. These sex-dependent effects of CIH were blocked by inhibiting mtOS. Interestingly, CIH impaired recollective memory in both sexes but these effects were not mediated by mtOS. No effects of CIH were observed on spatial memory, gross motor function, or anxiety-like behavior, regardless of sex. CONCLUSIONS Our results indicate that the impact of CIH is dependent on sex, such as an inflammatory response and OS response in females and males, respectively, that are mediated by mtOS. Interestingly, there was no effect of sex or mtOS in CIH-induced impairment of recollective memory. These results indicate that mtOS is involved in the sex differences observed in CIH, but a different mechanism underlies CIH-induced memory impairments.
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Affiliation(s)
- Steve Mabry
- Department of Pharmaceutical Sciences, System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107-2699, USA
| | - Jessica L Bradshaw
- Department of Pharmaceutical Sciences, System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107-2699, USA
| | - Jennifer J Gardner
- Department of Pharmaceutical Sciences, System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107-2699, USA
| | - E Nicole Wilson
- Department of Pharmaceutical Sciences, System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107-2699, USA
| | - Rebecca L Cunningham
- Department of Pharmaceutical Sciences, System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107-2699, USA.
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Mabry S, Wilson EN, Bradshaw JL, Gardner JJ, Fadeyibi O, Vera E, Osikoya O, Cushen SC, Karamichos D, Goulopoulou S, Cunningham RL. Sex and age differences in social and cognitive function in offspring exposed to late gestational hypoxia. Biol Sex Differ 2023; 14:81. [PMID: 37951901 PMCID: PMC10640736 DOI: 10.1186/s13293-023-00557-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 10/09/2023] [Indexed: 11/14/2023] Open
Abstract
BACKGROUND Gestational sleep apnea is a hypoxic sleep disorder that affects 8-26% of pregnancies and increases the risk for central nervous system dysfunction in offspring. Specifically, there are sex differences in the sensitivity of the fetal hippocampus to hypoxic insults, and hippocampal impairments are associated with social dysfunction, repetitive behaviors, anxiety, and cognitive impairment. Yet, it is unclear whether gestational sleep apnea impacts these hippocampal-associated functions and if sex and age modify these effects. To examine the relationship between gestational sleep apnea and hippocampal-associated behaviors, we used chronic intermittent hypoxia (CIH) to model late gestational sleep apnea in pregnant rats. We hypothesized that late gestational CIH would produce sex- and age-specific social, anxiety-like, repetitive, and cognitive impairments in offspring. METHODS Timed pregnant Long-Evans rats were exposed to CIH or room air normoxia from GD 15-19. Behavioral testing of offspring occurred during either puberty or young adulthood. To examine gestational hypoxia-induced behavioral phenotypes, we quantified hippocampal-associated behaviors (social function, repetitive behaviors, anxiety-like behaviors, and spatial memory and learning), hippocampal neuronal activity (glutamatergic NMDA receptors, dopamine transporter, monoamine oxidase-A, early growth response protein 1, and doublecortin), and circulating hormones in offspring. RESULTS Late gestational CIH induced sex- and age-specific differences in social, repetitive, and memory functions in offspring. In female pubertal offspring, CIH impaired social function, increased repetitive behaviors, and elevated circulating corticosterone levels but did not impact memory. In contrast, CIH transiently induced spatial memory dysfunction in pubertal male offspring but did not impact social or repetitive functions. Long-term effects of gestational CIH on social behaviors were only observed in female offspring, wherein CIH induced social disengagement and suppression of circulating corticosterone levels in young adulthood. No effects of gestational CIH were observed in anxiety-like behaviors, hippocampal neuronal activity, or circulating testosterone and estradiol levels, regardless of sex or age of offspring. CONCLUSIONS Our results indicate that hypoxia-associated pregnancy complications during late gestation can increase the risk for behavioral and physiological outcomes in offspring, such as social dysfunction, repetitive behaviors, and cognitive impairment, that are dependent on sex and age.
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Affiliation(s)
- Steve Mabry
- Department of Pharmaceutical Sciences, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
| | - E Nicole Wilson
- Department of Pharmaceutical Sciences, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
| | - Jessica L Bradshaw
- Department of Pharmaceutical Sciences, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
| | - Jennifer J Gardner
- Department of Pharmaceutical Sciences, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA
| | - Oluwadarasimi Fadeyibi
- Department of Pharmaceutical Sciences, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
| | - Edward Vera
- Department of Pharmaceutical Sciences, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
- Texas College of Osteopathic Medicine, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA
| | - Oluwatobiloba Osikoya
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA
| | - Spencer C Cushen
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA
- Texas College of Osteopathic Medicine, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA
| | - Dimitrios Karamichos
- Department of Pharmaceutical Sciences, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3430 Camp Bowie Blvd, Fort Worth, TX, 76107, USA
- Department of Pharmacology and Neuroscience, University of North Texas Health Science, Fort Worth, TX, 76107, USA
| | - Styliani Goulopoulou
- Departments of Basic Sciences, Gynecology and Obstetrics, Lawrence D. Longo, MD Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA
| | - Rebecca L Cunningham
- Department of Pharmaceutical Sciences, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA.
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Phua TJ. Understanding human aging and the fundamental cell signaling link in age-related diseases: the middle-aging hypovascularity hypoxia hypothesis. FRONTIERS IN AGING 2023; 4:1196648. [PMID: 37384143 PMCID: PMC10293850 DOI: 10.3389/fragi.2023.1196648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/23/2023] [Indexed: 06/30/2023]
Abstract
Aging-related hypoxia, oxidative stress, and inflammation pathophysiology are closely associated with human age-related carcinogenesis and chronic diseases. However, the connection between hypoxia and hormonal cell signaling pathways is unclear, but such human age-related comorbid diseases do coincide with the middle-aging period of declining sex hormonal signaling. This scoping review evaluates the relevant interdisciplinary evidence to assess the systems biology of function, regulation, and homeostasis in order to discern and decipher the etiology of the connection between hypoxia and hormonal signaling in human age-related comorbid diseases. The hypothesis charts the accumulating evidence to support the development of a hypoxic milieu and oxidative stress-inflammation pathophysiology in middle-aged individuals, as well as the induction of amyloidosis, autophagy, and epithelial-to-mesenchymal transition in aging-related degeneration. Taken together, this new approach and strategy can provide the clarity of concepts and patterns to determine the causes of declining vascularity hemodynamics (blood flow) and physiological oxygenation perfusion (oxygen bioavailability) in relation to oxygen homeostasis and vascularity that cause hypoxia (hypovascularity hypoxia). The middle-aging hypovascularity hypoxia hypothesis could provide the mechanistic interface connecting the endocrine, nitric oxide, and oxygen homeostasis signaling that is closely linked to the progressive conditions of degenerative hypertrophy, atrophy, fibrosis, and neoplasm. An in-depth understanding of these intrinsic biological processes of the developing middle-aged hypoxia could provide potential new strategies for time-dependent therapies in maintaining healthspan for healthy lifestyle aging, medical cost savings, and health system sustainability.
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Affiliation(s)
- Teow J. Phua
- Molecular Medicine, NSW Health Pathology, John Hunter Hospital, Newcastle, NSW, Australia
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Mabry S, Wilson EN, Bradshaw JL, Gardner JJ, Fadeyibi O, Vera E, Osikoya O, Cushen SC, Karamichos D, Goulopoulou S, Cunningham RL. Sex and age differences in social and cognitive function in offspring exposed to late gestational hypoxia. RESEARCH SQUARE 2023:rs.3.rs-2507737. [PMID: 37333114 PMCID: PMC10275064 DOI: 10.21203/rs.3.rs-2507737/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Background Gestational sleep apnea affects 8-26% of pregnancies and can increase the risk for autism spectrum disorder (ASD) in offspring. ASD is a neurodevelopmental disorder associated with social dysfunction, repetitive behaviors, anxiety, and cognitive impairment. To examine the relationship between gestational sleep apnea and ASD-associated behaviors, we used a chronic intermittent hypoxia (CIH) protocol between gestational days (GD) 15-19 in pregnant rats to model late gestational sleep apnea. We hypothesized that late gestational CIH would produce sex- and age-specific social, mood, and cognitive impairments in offspring. Methods Timed pregnant Long-Evans rats were exposed to CIH or room air normoxia from GD 15-19. Behavioral testing of offspring occurred during either puberty or young adulthood. To examine ASD-associated phenotypes, we quantified ASD-associated behaviors (social function, repetitive behaviors, anxiety-like behaviors, and spatial memory and learning), hippocampal activity (glutamatergic NMDA receptors, dopamine transporter, monoamine oxidase-A, EGR-1, and doublecortin), and circulating hormones in offspring. Results Late gestational CIH induced sex- and age-specific differences in social, repetitive and memory functions in offspring. These effects were mostly transient and present during puberty. In female pubertal offspring, CIH impaired social function, increased repetitive behaviors, and increased circulating corticosterone levels, but did not impact memory. In contrast, CIH transiently induced spatial memory dysfunction in pubertal male offspring but did not impact social or repetitive functions. Long-term effects of gestational CIH were only observed in female offspring, wherein CIH induced social disengagement and suppression of circulating corticosterone levels in young adulthood. No effects of gestational CIH were observed on anxiety-like behaviors, hippocampal activity, circulating testosterone levels, or circulating estradiol levels, regardless of sex or age of offspring. Conclusions Our results indicate that hypoxia-associated pregnancy complications during late gestation can increase the risk for ASD-associated behavioral and physiological outcomes, such as pubertal social dysfunction, corticosterone dysregulation, and memory impairments.
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Affiliation(s)
- Steve Mabry
- UNTHSC: University of North Texas Health Science Center
| | | | | | | | | | - Edward Vera
- UNTHSC: University of North Texas Health Science Center
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Su L, Chen J, Qu H, Luo C, Wu J, Jiao Y. Association between snoring frequency and male serum testosterone: Findings from the 2015-2016 National Health and Nutrition Examination Survey. Sleep Med 2022; 100:1-5. [PMID: 35969946 DOI: 10.1016/j.sleep.2022.07.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/09/2022] [Accepted: 07/26/2022] [Indexed: 01/11/2023]
Abstract
BACKGROUND This study aimed to assess the association between snoring frequency and male serum testosterone levels. METHODS We analyzed data from the 2015 to 2016 National Health and Nutrition Examination Survey. Snoring frequency was relied on self-report, and was divided into never, rarely (1-2 nights a week), occasionally (3-4 nights a week), or frequently (5 or more nights a week) groups. Multivariable analysis controlling for age, race, waist circumference, total cholesterol, diabetes, and hypertension was used to evaluate the association between snoring frequency and male serum testosterone. Furthermore, we performed the subgroup analyses stratified by age and waist circumference. RESULTS Our analysis included 1900 participants. In the fully adjusted model, only frequent snoring was inversely associated with male serum testosterone (β -0.053, 95% CI -0.101 to -0.006, P = 0.028); According to the subgroup analysis stratified by age, only in 40-59 years group, frequent snoring was inversely associated with male serum testosterone in the fully adjusted model (β -0.113, 95% CI -0.196 to -0.031, P = 0.007). As for the subgroup analysis stratified by waist circumference, our results showed only in the waist circumference ≥102 cm group (abdominal obesity), frequent snoring was inversely associated with male serum testosterone (β -0.133, 95% CI -0.216 to -0.05, P = 0.002). CONCLUSIONS Frequent snoring (5 or more nights a week) is inversely associated with male serum testosterone levels, especially in those aged 40-59 years and those with abdominal obesity.
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Affiliation(s)
- Liang Su
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jianpu Chen
- The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hua Qu
- Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Chenglong Luo
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jie Wu
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China.
| | - Yongzheng Jiao
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China; Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China.
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Farré R, Almendros I, Martínez-García MÁ, Gozal D. Experimental Models to Study End-Organ Morbidity in Sleep Apnea: Lessons Learned and Future Directions. Int J Mol Sci 2022; 23:ijms232214430. [PMID: 36430904 PMCID: PMC9696027 DOI: 10.3390/ijms232214430] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 11/17/2022] [Accepted: 11/18/2022] [Indexed: 11/22/2022] Open
Abstract
Sleep apnea (SA) is a very prevalent sleep breathing disorder mainly characterized by intermittent hypoxemia and sleep fragmentation, with ensuing systemic inflammation, oxidative stress, and immune deregulation. These perturbations promote the risk of end-organ morbidity, such that SA patients are at increased risk of cardiovascular, neurocognitive, metabolic and malignant disorders. Investigating the potential mechanisms underlying SA-induced end-organ dysfunction requires the use of comprehensive experimental models at the cell, animal and human levels. This review is primarily focused on the experimental models employed to date in the study of the consequences of SA and tackles 3 different approaches. First, cell culture systems whereby controlled patterns of intermittent hypoxia cycling fast enough to mimic the rates of episodic hypoxemia experienced by patients with SA. Second, animal models consisting of implementing realistic upper airway obstruction patterns, intermittent hypoxia, or sleep fragmentation such as to reproduce the noxious events characterizing SA. Finally, human SA models, which consist either in subjecting healthy volunteers to intermittent hypoxia or sleep fragmentation, or alternatively applying oxygen supplementation or temporary nasal pressure therapy withdrawal to SA patients. The advantages, limitations, and potential improvements of these models along with some of their pertinent findings are reviewed.
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Affiliation(s)
- Ramon Farré
- Unitat de Biofísica i Bioenginyeria, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
- CIBER de Enfermedades Respiratorias, 1964603 Madrid, Spain
- Institut Investigacions Biomediques August Pi Sunyer, 08036 Barcelona, Spain
- Correspondence: (R.F.); (D.G.)
| | - Isaac Almendros
- Unitat de Biofísica i Bioenginyeria, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
- CIBER de Enfermedades Respiratorias, 1964603 Madrid, Spain
- Institut Investigacions Biomediques August Pi Sunyer, 08036 Barcelona, Spain
| | - Miguel-Ángel Martínez-García
- CIBER de Enfermedades Respiratorias, 1964603 Madrid, Spain
- Pneumology Department, University and Polytechnic La Fe Hospital, 46026 Valencia, Spain
| | - David Gozal
- Department of Child Health and Child Health Research Institute, School of Medicine, The University of Missouri, Columbia, MO 65201, USA
- Correspondence: (R.F.); (D.G.)
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Wilson EN, Mabry S, Bradshaw JL, Gardner JJ, Rybalchenko N, Engelland R, Fadeyibi O, Osikoya O, Cushen SC, Goulopoulou S, Cunningham RL. Gestational hypoxia in late pregnancy differentially programs subcortical brain maturation in male and female rat offspring. Biol Sex Differ 2022; 13:54. [PMID: 36175941 PMCID: PMC9524087 DOI: 10.1186/s13293-022-00463-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 09/22/2022] [Indexed: 11/23/2022] Open
Abstract
Background Hypoxia is associated with pregnancy complications, such as preeclampsia, placental abruption, and gestational sleep apnea. Hypoxic insults during gestation can impact the brain maturation of cortical and subcortical pathways, such as the nigrostriatal pathway. However, the long-term effects of in utero hypoxic stress exposure on brain maturation in offspring are unclear, especially exposure during late gestation. The purpose of this study was to determine the impact of gestational hypoxia in late pregnancy on developmental programming of subcortical brain maturation by focusing on the nigrostriatal pathway. Methods Timed pregnant Long–Evans rats were exposed to chronic intermittent hypoxia or room air normoxia from gestational day (GD) 15–19 (term 22–23 days). Male and female offspring were assessed during two critical periods: puberty from postnatal day (PND) 40–45 or young adulthood (PND 60–65). Brain maturation was quantified by examining (1) the structural development of the nigrostriatal pathway via analysis of locomotor behaviors and the substantia nigra dopaminergic neuronal cell bodies and (2) the refinement of the nigrostriatal pathway by quantifying ultrasonic vocalizations (USVs). Results The major findings of this study are gestational hypoxia has age- and sex-dependent effects on subcortical brain maturation in offspring by adversely impacting the refinement of the nigrostriatal pathway in the absence of any effects on the structural development of the pathway. During puberty, female offspring were impacted more than male offspring, as evidenced by decreased USV call frequency, chirp USV call duration, and simple call frequency. In contrast, male offspring were impacted more than female offspring during young adulthood, as evidenced by increased latency to first USV, decreased simple USV call intensity, and increased harmonic USV call bandwidth. No effects of gestational hypoxia on the structural development of the nigrostriatal pathway were observed. Conclusions These novel findings demonstrate hypoxic insults during pregnancy mediate developmental programming of the cortical and subcortical pathways, in which male offspring exhibit long-term adverse effects compared to female offspring. Impairment of cortical and subcortical pathways maturation, such as the nigrostriatal pathway, may increase risk for neuropsychiatric disorders (e.g., mood disorders, cognitive dysfunction, brain connectivity dysfunction). Supplementary Information The online version contains supplementary material available at 10.1186/s13293-022-00463-x. Brain maturation of the nigrostriatal pathway is sex- and age- dependent. Exposure to hypoxia in late pregnancy impacts brain maturation of the nigrostriatal pathway that can be observed during puberty and young adulthood. Gestational hypoxia impacted female offspring during puberty more than males, whereas it impacted male offspring during young adulthood more than females. These novel findings demonstrate that hypoxic insults during pregnancy mediate developmental programming of the cortical and subcortical pathways, in which male offspring exhibit long-term adverse effects compared to female offspring. Long-term adverse effects of gestational hypoxia in offspring can occur in the absence of pregnancy complications, especially if they occur within critical embryological developmental periods.
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Affiliation(s)
- E Nicole Wilson
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
| | - Steve Mabry
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
| | - Jessica L Bradshaw
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
| | - Jennifer J Gardner
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA.,Department of Pharmaceutical Sciences, UNT System College of Pharmacy, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
| | - Nataliya Rybalchenko
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
| | - Rachel Engelland
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
| | - Oluwadarasimi Fadeyibi
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
| | - Oluwatobiloba Osikoya
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA
| | - Spencer C Cushen
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA.,Texas College of Osteopathic Medicine, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA
| | - Styliani Goulopoulou
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA.,Department of Basic Sciences, Lawrence D. Longo, MD Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA
| | - Rebecca L Cunningham
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, School of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA.
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Oyedokun PA, Akhigbe RE, Ajayi LO, Ajayi AF. Impact of hypoxia on male reproductive functions. Mol Cell Biochem 2022; 478:875-885. [PMID: 36107286 DOI: 10.1007/s11010-022-04559-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 09/02/2022] [Indexed: 11/30/2022]
Abstract
Male reproductive functions, which include testicular steroidogenesis, spermatogenesis, and sexual/erectile functions are key in male fertility, but may be adversely altered by several factors, including hypoxia. This review demonstrates the impact of hypoxia on male reproductive functions. Acute exposure to hypoxia promotes testosterone production via stimulation of autophagy and upregulation of steroidogenic enzymes and voltage-gated L-type calcium channel, nonetheless, chronic exposure to hypoxia impairs steroidogenesis via suppression of the hypothalamic-pituitary-testicular axis. Also, hypoxia distorts spermatogenesis and reduces sperm count, motility, and normal forms via upregulation of VEGF and oxidative stress-sensitive signaling. Furthermore, hypoxia induces sexual and erectile dysfunction via a testosterone-dependent downregulation of NO/cGMP signaling and upregulation of PGE1/TGFβ1-driven penile endothelial dysfunction. Notably, hypoxia programs male sexual function and spermatogenesis/sperm quality via feminization and demasculinization of males and oxidative stress-mediated alteration in sperm DNA methylation. Since oxidative stress plays a central role in hypoxia-induced male reproductive dysfunction, studies exploring the effects of antioxidants and upregulation of transcription of antioxidants on hypoxia-induced male reproductive dysfunction are recommended.
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Affiliation(s)
- P A Oyedokun
- Anchor Reproductive Physiology and Bioinformatics Research Unit, Department of Physiology, Ladoke Akintola University of Technology, Ogbomoso, Oyo, Nigeria
| | - R E Akhigbe
- Anchor Reproductive Physiology and Bioinformatics Research Unit, Department of Physiology, Ladoke Akintola University of Technology, Ogbomoso, Oyo, Nigeria.
- Reproductive Biology and Toxicology Research Laboratory, Oasis of Grace Hospital, Osogbo, Osun, Nigeria.
| | - L O Ajayi
- Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Oyo, Nigeria
| | - A F Ajayi
- Anchor Reproductive Physiology and Bioinformatics Research Unit, Department of Physiology, Ladoke Akintola University of Technology, Ogbomoso, Oyo, Nigeria
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Farré R, Martínez-García MA, Gozal D. Systematic reviews and meta-analyses in animal model research: as necessary, and with similar pros and cons, as in patient research. Eur Respir J 2022; 59:59/3/2102438. [PMID: 35301241 DOI: 10.1183/13993003.02438-2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 09/18/2021] [Indexed: 12/22/2022]
Affiliation(s)
- Ramon Farré
- Unitat de Biofísica i Bioenginyeria, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain .,CIBER de Enfermedades Respiratorias, Madrid, Spain.,Institut Investigacions Biomediques August Pi Sunyer, Barcelona, Spain
| | - Miguel A Martínez-García
- CIBER de Enfermedades Respiratorias, Madrid, Spain.,Pneumology Dept, University and Polytechnic la Fe Hospital, Valencia, Spain
| | - David Gozal
- Dept of Child Health, The University of Missouri School of Medicine, Columbia, MO, USA
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11
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Snyder B, Wu HK, Tillman B, Floyd TF. Aged Mouse Hippocampus Exhibits Signs of Chronic Hypoxia and an Impaired HIF-Controlled Response to Acute Hypoxic Exposures. Cells 2022; 11:cells11030423. [PMID: 35159233 PMCID: PMC8833982 DOI: 10.3390/cells11030423] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/15/2022] [Accepted: 01/21/2022] [Indexed: 02/01/2023] Open
Abstract
Altered hypoxia-inducible factor-alpha (HIF-α) activity may have significant consequences in the hippocampus, which mediates declarative memory, has limited vascularization, and is vulnerable to hypoxic insults. Previous studies have reported that neurovascular coupling is reduced in aged brains and that diseases which cause hypoxia increase with age, which may render the hippocampus susceptible to acute hypoxia. Most studies have investigated the actions of HIF-α in aging cortical structures, but few have focused on the role of HIF-α within aged hippocampus. This study tests the hypothesis that aging is associated with impaired hippocampal HIF-α activity. Dorsal hippocampal sections from mice aged 3, 9, 18, and 24 months were probed for the presence of HIF-α isoforms or their associated gene products using immunohistochemistry and fluorescent in situ hybridization (fISH). A subset of each age was exposed to acute hypoxia (8% oxygen) for 3 h to investigate changes in the responsiveness of HIF-α to hypoxia. Basal mean intensity of fluorescently labeled HIF-1α protein increases with age in the hippocampus, whereas HIF-2α intensity only increases in the 24-month group. Acute hypoxic elevation of HIF-1α is lost with aging and is reversed in the 24-month group. fISH reveals that glycolytic genes induced by HIF-1α (lactose dehydrogenase-a, phosphoglycerate kinase 1, and pyruvate dehydrogenase kinase 1) are lower in aged hippocampus than in 3-month hippocampus, and mRNA for monocarboxylate transporter 1, a lactose transporter, increases. These results indicate that lactate, used in neurotransmission, may be limited in aged hippocampus, concurrent with impaired HIF-α response to hypoxic events. Therefore, impaired HIF-α may contribute to age-associated cognitive decline during hypoxic events.
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Affiliation(s)
- Brina Snyder
- Department of Anesthesiology and Pain Management, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; (B.S.); (H.-K.W.); (B.T.)
| | - Hua-Kang Wu
- Department of Anesthesiology and Pain Management, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; (B.S.); (H.-K.W.); (B.T.)
| | - Brianna Tillman
- Department of Anesthesiology and Pain Management, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; (B.S.); (H.-K.W.); (B.T.)
| | - Thomas F. Floyd
- Department of Anesthesiology and Pain Management, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; (B.S.); (H.-K.W.); (B.T.)
- Department of Cardiothoracic Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Correspondence:
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12
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Karamichos D, Escandon P, Vasini B, Nicholas SE, Van L, Dang DH, Cunningham RL, Riaz KM. Anterior pituitary, sex hormones, and keratoconus: Beyond traditional targets. Prog Retin Eye Res 2021; 88:101016. [PMID: 34740824 PMCID: PMC9058044 DOI: 10.1016/j.preteyeres.2021.101016] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 10/15/2021] [Accepted: 10/18/2021] [Indexed: 12/13/2022]
Abstract
"The Diseases of the Horny-coat of The Eye", known today as keratoconus, is a progressive, multifactorial, non-inflammatory ectatic corneal disorder that is characterized by steepening (bulging) and thinning of the cornea, irregular astigmatism, myopia, and scarring that can cause devastating vision loss. The significant socioeconomic impact of the disease is immeasurable, as patients with keratoconus can have difficulties securing certain jobs or even joining the military. Despite the introduction of corneal crosslinking and improvements in scleral contact lens designs, corneal transplants remain the main surgical intervention for treating keratoconus refractory to medical therapy and visual rehabilitation. To-date, the etiology and pathogenesis of keratoconus remains unclear. Research studies have increased exponentially over the years, highlighting the clinical significance and international interest in this disease. Hormonal imbalances have been linked to keratoconus, both clinically and experimentally, with both sexes affected. However, it is unclear how (molecular/cellular signaling) or when (age/disease stage(s)) those hormones affect the keratoconic cornea. Previous studies have categorized the human cornea as an extragonadal tissue, showing modulation of the gonadotropins, specifically luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Studies herein provide new data (both in vitro and in vivo) to further delineate the role of hormones/gonadotropins in the keratoconus pathobiology, and propose the existence of a new axis named the Hypothalamic-Pituitary-Adrenal-Corneal (HPAC) axis.
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Affiliation(s)
- Dimitrios Karamichos
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3430 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA.
| | - Paulina Escandon
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3430 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA
| | - Brenda Vasini
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3430 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA
| | - Sarah E Nicholas
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3430 Camp Bowie Blvd, Fort Worth, TX, 76107, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA
| | - Lyly Van
- University of Oklahoma Health Sciences Center, 940 Stanton L Young, Oklahoma City, OK, USA; Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Deanna H Dang
- College of Medicine, University of Oklahoma Health Sciences Center, 940 Stanton L Young, Oklahoma City, OK, USA
| | - Rebecca L Cunningham
- Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA
| | - Kamran M Riaz
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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13
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Tančić-Gajić M, Vukčević M, Ivović M, Marina LV, Arizanović Z, Soldatović I, Stojanović M, Đogo A, Kendereški A, Vujović S. Obstructive Sleep Apnea Is Associated With Low Testosterone Levels in Severely Obese Men. Front Endocrinol (Lausanne) 2021; 12:622496. [PMID: 34381420 PMCID: PMC8350060 DOI: 10.3389/fendo.2021.622496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 06/16/2021] [Indexed: 11/16/2022] Open
Abstract
Background Disrupted sleep affects cardio-metabolic and reproductive health. Obstructive sleep apnea syndrome represents a major complication of obesity and has been associated with gonadal axis activity changes and lower serum testosterone concentration in men. However, there is no consistent opinion on the effect of obstructive sleep apnea on testosterone levels in men. Objective The aim of this study was to determine the influence of obstructive sleep apnea on total and free testosterone levels in severely obese men. Materials and methods The study included 104 severely obese (Body Mass Index (BMI) ≥ 35 kg/m2) men, aged 20 to 60, who underwent anthropometric, blood pressure, fasting plasma glucose, lipid profile, and sex hormone measurements. All participants were subjected to polysomnography. According to apnea-hypopnea index (AHI) patients were divided into 3 groups: <15 (n = 20), 15 - 29.9 (n = 17) and ≥ 30 (n = 67). Results There was a significant difference between AHI groups in age (29.1 ± 7.2, 43.2 ± 13.2, 45.2 ± 10.2 years; p < 0.001), BMI (42.8 ± 5.9, 43.2 ± 5.9, 47.1 ± 7.8 kg/m2; p = 0.023), the prevalence of metabolic syndrome (MetS) (55%, 82.4%, 83.6%, p = 0.017), continuous metabolic syndrome score (siMS) (4.01 ± 1.21, 3.42 ± 0.80, 3.94 ± 1.81, 4.20 ± 1.07; p = 0.038), total testosterone (TT) (16.6 ± 6.1, 15.2 ± 5.3, 11.3 ± 4.44 nmol/l; p < 0.001) and free testosterone (FT) levels (440.4 ± 160.8, 389.6 ± 162.5, 294.5 ± 107.0 pmol/l; p < 0.001). TT level was in a significant negative correlation with AHI, oxygen desaturation index (ODI), BMI, MetS and siMS. Also, FT was in a significant negative correlation with AHI, ODI, BMI, age, MetS and siMS. The multiple regression analysis revealed that both AHI and ODI were in significant correlation with TT and FT after adjustment for age, BMI, siMS score and MetS components. Conclusion Obstructive sleep apnea is associated with low TT and FT levels in severely obese men.
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Affiliation(s)
- Milina Tančić-Gajić
- Department for Obesity, Reproductive and Metabolic Disorders, Clinic for Endocrinology, Diabetes and Metabolic Diseases, University Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Miodrag Vukčević
- Department of Pulmonology, Clinical Hospital Centre Zemun, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Miomira Ivović
- Department for Obesity, Reproductive and Metabolic Disorders, Clinic for Endocrinology, Diabetes and Metabolic Diseases, University Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Ljiljana V. Marina
- Department for Obesity, Reproductive and Metabolic Disorders, Clinic for Endocrinology, Diabetes and Metabolic Diseases, University Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Zorana Arizanović
- Department for Obesity, Reproductive and Metabolic Disorders, Clinic for Endocrinology, Diabetes and Metabolic Diseases, University Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Ivan Soldatović
- Institute of Medical Statistics and Informatics, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Miloš Stojanović
- Department for Obesity, Reproductive and Metabolic Disorders, Clinic for Endocrinology, Diabetes and Metabolic Diseases, University Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Aleksandar Đogo
- Department of Endocrinology, Clinical Center of Montenegro, Podgorica, Montenegro
| | - Aleksandra Kendereški
- Department for Obesity, Reproductive and Metabolic Disorders, Clinic for Endocrinology, Diabetes and Metabolic Diseases, University Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Svetlana Vujović
- Department for Obesity, Reproductive and Metabolic Disorders, Clinic for Endocrinology, Diabetes and Metabolic Diseases, University Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
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14
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Hypoxia, Acidification and Inflammation: Partners in Crime in Parkinson’s Disease Pathogenesis? IMMUNO 2021. [DOI: 10.3390/immuno1020006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Like in other neurodegenerative diseases, protein aggregation, mitochondrial dysfunction, oxidative stress and neuroinflammation are hallmarks of Parkinson’s disease (PD). Differentiating characteristics of PD include the central role of α-synuclein in the aggregation pathology, a distinct vulnerability of the striato-nigral system with the related motor symptoms, as well as specific mitochondrial deficits. Which molecular alterations cause neurodegeneration and drive PD pathogenesis is poorly understood. Here, we summarize evidence of the involvement of three interdependent factors in PD and suggest that their interplay is likely a trigger and/or aggravator of PD-related neurodegeneration: hypoxia, acidification and inflammation. We aim to integrate the existing knowledge on the well-established role of inflammation and immunity, the emerging interest in the contribution of hypoxic insults and the rather neglected effects of brain acidification in PD pathogenesis. Their tight association as an important aspect of the disease merits detailed investigation. Consequences of related injuries are discussed in the context of aging and the interaction of different brain cell types, in particular with regard to potential consequences on the vulnerability of dopaminergic neurons in the substantia nigra. A special focus is put on the identification of current knowledge gaps and we emphasize the importance of related insights from other research fields, such as cancer research and immunometabolism, for neurodegeneration research. The highlighted interplay of hypoxia, acidification and inflammation is likely also of relevance for other neurodegenerative diseases, despite disease-specific biochemical and metabolic alterations.
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15
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Exaggerated potassium current reduction by oxytocin in visceral sensory neurons following chronic intermittent hypoxia. Auton Neurosci 2020; 229:102735. [PMID: 33032244 DOI: 10.1016/j.autneu.2020.102735] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 08/18/2020] [Accepted: 09/21/2020] [Indexed: 11/22/2022]
Abstract
Oxytocin (OT) from the hypothalamus is increased in several cardiorespiratory nuclei and systemically in response to a variety of stimuli and stressors, including hypoxia. Within the nucleus tractus solitarii (nTS), the first integration site for cardiorespiratory reflexes, OT enhances synaptic transmission, action potential (AP) discharge, and cardiac baroreflex gain. The hypoxic stressor obstructive sleep apnea, and its CIH animal model, elevates blood pressure and alters heart rate variability. The nTS receives sensory input from baroafferent neurons that originate in the nodose ganglia. Nodose neurons express the OT receptor (OTR) whose activation elevates intracellular calcium. However, the influence of OT on other ion channels, especially potassium channels important for neuronal activity during CIH, is less known. This study sought to determine the mechanism (s) by which OT modulates sensory afferent-nTS mediated reflexes normally and after CIH. Nodose ganglia neurons from male Sprague-Dawley rats were examined after 10d CIH (6% O2 every 3 min) or their normoxic (21% O2) control. OTR mRNA and protein were identified in Norm and CIH ganglia and was similar between groups. To examine OTR function, APs and potassium currents (IK) were recorded in dissociated neurons. Compared to Norm, after CIH OT depolarized neurons and reduced current-induced AP discharge. After CIH OT also produced a greater reduction in IK that where tetraethylammonium-sensitive. These data demonstrate after CIH OT alters ionic currents in nodose ganglia cells to likely influence cardiorespiratory reflexes and overall function.
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16
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Duong P, Tenkorang MAA, Trieu J, McCuiston C, Rybalchenko N, Cunningham RL. Neuroprotective and neurotoxic outcomes of androgens and estrogens in an oxidative stress environment. Biol Sex Differ 2020; 11:12. [PMID: 32223745 PMCID: PMC7104511 DOI: 10.1186/s13293-020-0283-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 01/20/2020] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND The role of sex hormones on cellular function is unclear. Studies show androgens and estrogens are protective in the CNS, whereas other studies found no effects or damaging effects. Furthermore, sex differences have been observed in multiple oxidative stress-associated CNS disorders, such as Alzheimer's disease, depression, and Parkinson's disease. The goal of this study is to examine the relationship between sex hormones (i.e., androgens and estrogens) and oxidative stress on cell viability. METHODS N27 and PC12 neuronal and C6 glial phenotypic cell lines were used. N27 cells are female rat derived, whereas PC12 cells and C6 cells are male rat derived. These cells express estrogen receptors and the membrane-associated androgen receptor variant, AR45, but not the full-length androgen receptor. N27, PC12, and C6 cells were exposed to sex hormones either before or after an oxidative stressor to examine neuroprotective and neurotoxic properties, respectively. Estrogen receptor and androgen receptor inhibitors were used to determine the mechanisms mediating hormone-oxidative stress interactions on cell viability. Since the presence of AR45 in the human brain tissue was unknown, we examined the postmortem brain tissue from men and women for AR45 protein expression. RESULTS Neither androgens nor estrogens were protective against subsequent oxidative stress insults in glial cells. However, these hormones exhibited neuroprotective properties in neuronal N27 and PC12 cells via the estrogen receptor. Interestingly, a window of opportunity exists for sex hormone neuroprotection, wherein temporary hormone deprivation blocked neuroprotection by sex hormones. However, if sex hormones are applied following an oxidative stressor, they exacerbated oxidative stress-induced cell loss in neuronal and glial cells. CONCLUSIONS Sex hormone action on cell viability is dependent on the cellular environment. In healthy neuronal cells, sex hormones are protective against oxidative stress insults via the estrogen receptor, regardless of sex chromosome complement (XX, XY). However, in unhealthy (e.g., high oxidative stress) cells, sex hormones exacerbated oxidative stress-induced cell loss, regardless of cell type or sex chromosome complement. The non-genomic AR45 receptor, which is present in humans, mediated androgen's damaging effects, but it is unknown which receptor mediated estrogen's damaging effects. These differential effects of sex hormones that are dependent on the cellular environment, receptor profile, and cell type may mediate the observed sex differences in oxidative stress-associated CNS disorders.
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Affiliation(s)
- Phong Duong
- Department of Physiology and Anatomy, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA
| | - Mavis A A Tenkorang
- Department of Physiology and Anatomy, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA
| | - Jenny Trieu
- Texas College of Osteopathic Medicine, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA
| | - Clayton McCuiston
- Texas College of Osteopathic Medicine, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA
| | - Nataliya Rybalchenko
- Department of Physiology and Anatomy, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA
| | - Rebecca L Cunningham
- Department of Physiology and Anatomy, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA. .,Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, 3400 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA.
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17
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Smith C, Contreras-Garza J, Cunningham RL, Wong JM, Vann PH, Metzger D, Kasanga E, Oppong-Gyebi A, Sumien N, Schreihofer DA. Chronic Testosterone Deprivation Sensitizes the Middle-Aged Rat Brain to Damaging Effects of Testosterone Replacement. Neuroendocrinology 2020; 110:914-928. [PMID: 31671430 DOI: 10.1159/000504445] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 10/30/2019] [Indexed: 11/19/2022]
Abstract
INTRODUCTION An increasing number of middle-aged men are being screened for low testosterone levels and the number of prescriptions for various forms of testosterone replacement therapy (TRT) has increased dramatically over the last 10 years. However, the safety of TRT has come into question with some studies suggesting increased morbidity and mortality. OBJECTIVE Because the benefits of estrogen replacement in postmenopausal women and ovariectomized rodents are lost if there is an extended delay between estrogen loss and replacement, we hypothesized that TRT may also be sensitive to delayed replacement. METHODS We compared the effects of testosterone replacement after short-term (2 weeks) and long-term testosterone deprivation (LTTD; 10 weeks) in middle-aged male rats on cerebral ischemia, oxidative stress, and cognitive function. We hypothesized that LTTD would increase oxidative stress levels and abrogate the beneficial effects of TRT. RESULTS Hypogonadism itself and TRT after short-term castration did not affect stroke outcome compared to intact rats. However, after long-term hypogonadism in middle-aged male Fischer 344 rats, TRT exacerbated the detrimental behavioral effects of experimental focal cerebral ischemia, whereas this detrimental effect was prevented by administration of the free-radical scavenger tempol, suggesting that TRT exacerbates oxidative stress. In contrast, TRT improved cognitive performance in non-stroked rats regardless of the length of hypogonadism. In the Morris water maze, peripheral oxidative stress was highly associated with decreased cognitive ability. CONCLUSIONS Taken together, these data suggest that TRT after long-term hypogonadism can exacerbate functional recovery after focal cerebral ischemia, but in the absence of injury can enhance cognition. Both of these effects are modulated by oxidative stress levels.
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Affiliation(s)
- Charity Smith
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Jo Contreras-Garza
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Rebecca L Cunningham
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Jessica M Wong
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Philip H Vann
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Daniel Metzger
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Ella Kasanga
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Anthony Oppong-Gyebi
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Nathalie Sumien
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Derek A Schreihofer
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA,
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas, USA,
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Galhardo APM, Mukai MK, Mori M, Carvalho KC, Baracat MCP, Simões MDJ, Soares JM, Baracat EC. Influence of age and gender on sex steroid receptors in rat masticatory muscles. Sci Rep 2019; 9:18403. [PMID: 31804540 PMCID: PMC6895217 DOI: 10.1038/s41598-019-54774-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 11/12/2019] [Indexed: 12/11/2022] Open
Abstract
The temporomandibular muscle dysfunction is characterized by myofascial pain and is more prevalent in women of reproductive age. Sex steroid hormones are hypothetically involved in the dysfunction, but few are the studies of steroid receptors in masticatory and mastication-related muscles. Our aim was to determine estrogen and testosterone receptor expression in rat masticatory and mastication-related muscles within the context of age and gender. Twelve rats were equally divided into four groups: (a) 10-month-old females; (b) 10-month-old males; (c) 24-month-old females; and (d) 24-month-old males. Euthanasia of the females was performed in the proestrous phase (vaginal smears) and the masticatory and accessory muscles were removed for immunohistochemical analysis. Statistical analysis was performed with ANOVA and the Tukey test. Estrogen receptor expression was similarly low in all muscles and groups. Testosterone receptor expression in the Masseter muscle of the 24-month-old male rats was higher than that in the other groups and significantly superior to its expression in the Posterior Digastric muscle. In short, testosterone receptor expression was highest in old male rats. If we generalize to humans, this fact could indicate age- and sex-related hormonal influence on temporomandibular muscle dysfunction. Further studies, however, are necessary to strengthen this hypothesis.
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Affiliation(s)
- Alessandra Pucci Mantelli Galhardo
- Departamento de Obstetrícia e Ginecologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brasil.
| | - Márcio Katsuyoshi Mukai
- Departamento de Prótese da Faculdade de Odontologia da Universidade de São Paulo, São Paulo, Brasil
| | - Matsuyoshi Mori
- Departamento de Prótese da Faculdade de Odontologia da Universidade de São Paulo, São Paulo, Brasil
| | - Katia Candido Carvalho
- Departamento de Obstetrícia e Ginecologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brasil
| | - Maria Cândida Pinheiro Baracat
- Departamento de Obstetrícia e Ginecologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brasil
| | - Manuel de Jesus Simões
- Departamento de Morfologia e Genética da Universidade Federal de São Paulo, São Paulo, Brasil
| | - José Maria Soares
- Departamento de Obstetrícia e Ginecologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brasil
| | - Edmund Chada Baracat
- Departamento de Obstetrícia e Ginecologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brasil
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Liu PY. A Clinical Perspective of Sleep and Andrological Health: Assessment, Treatment Considerations, and Future Research. J Clin Endocrinol Metab 2019; 104:4398-4417. [PMID: 31042277 PMCID: PMC6735730 DOI: 10.1210/jc.2019-00683] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 04/25/2019] [Indexed: 12/29/2022]
Abstract
CONTEXT Sleep that is insufficient, misaligned, or disrupted causes hypersomnolence and neuropsychological deficits, adversely affects cardiometabolic health, and is increasingly recognized to impair other biological processes that lead to conditions important to men, such as hypogonadism, erectile dysfunction, and infertility. EVIDENCE ACQUISITION Literature review from 1970 to December 2018. EVIDENCE SYNTHESIS High-quality and complementary epidemiological and interventional studies establish that abnormal sleep is associated with increased mortality, hypertension, and other cardiometabolic disorders (insufficient, disrupted, and misaligned sleep), as well as reduced fecundity and total sperm count (insufficient sleep), erectile dysfunction (disrupted sleep), and low testosterone (both). Circadian misalignment shifts the peak of testosterone's diurnal rhythm to occur soon after waking up, irrespective of the biological clock time, but it does not change the mean concentration. Preliminary studies show that extending sleep in individuals who are chronically sleep deprived may become a strategy to reduce insulin resistance and hypertension. Continuous positive airway pressure therapy can improve erectile function, and possibly systemic testosterone exposure, but only when used adherently by men with obstructive sleep apnea. Both high-dose and replacement-dose testosterone therapies modestly worsen sleep-disordered breathing, but they also improve cardiometabolic function and sexual desire. Persistence of either the adverse or beneficial outcomes over the longer term requires further investigation. CONCLUSIONS Sleep is increasingly recognized to be essential for healthy living. Establishing the effect of abnormal sleep, and of improving sleep, on andrological issues of prime interest to men will promote prioritization of sleep, and may thereby improve overall long-term health outcomes.
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Affiliation(s)
- Peter Y Liu
- Division of Endocrinology, Metabolism, and Nutrition, Department of Medicine, Harbor-UCLA Medical Center and Los Angeles Biomedical Research Institute, Torrance, California
- David Geffen School of Medicine at UCLA, Los Angeles, California
- Correspondence and Reprint Requests: Peter Y. Liu, PhD, Division of Endocrinology and Metabolism, Department of Medicine, Harbor UCLA Medical Center and Los Angeles Biomedical Research Institute, 1124 West Carson Street, Box 446, Torrance, California 90502. E-mail:
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Cho YM, Chou JC, Fang CM, Hu S, Wang KL, Wang SW, Wang PS. Chronic intermittent hypoxia stimulates testosterone production in rat Leydig cells. Life Sci 2019; 233:116694. [PMID: 31351970 DOI: 10.1016/j.lfs.2019.116694] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Revised: 07/17/2019] [Accepted: 07/24/2019] [Indexed: 12/27/2022]
Abstract
AIMS The hypoxia-stimulated response of the endocrine system depends on the kind and duration of hypoxia. Hypoxia has been reported to stimulate testosterone (T) production in rats, but the mechanisms remain to be investigated. MATERIALS AND METHODS Male rats were divided into two groups. The rats exposed to chronic intermittent hypoxia (CIH) at 8 h/day were housed in a hypoxic chamber (12% O2) for 14 days. Normoxic rats were used as control animals. T was measured after challenging the rat Leydig cells (LCs) with different stimulators, including hCG (0.01 IU/ml), forskolin (10-5 M), 8-bromo-cAMP (10-4 M), A23187 (10-5 M), cyclopiazonic acid (10-4 M), and androstenedione (10-8 M). Meanwhile, the LCs were incubated with trilostane (10-5 M) and/or 25-OH-hydroxycholesterol (10-5 M); thereafter the media were collected for pregnenolone assay. KEY FINDINGS In the CIH group, plasma T levels were increased, but the serum luteinizing hormone (LH) was decreased. Furthermore, at several time intervals after hCG injection, plasma T levels were higher in the CIH group. The evoked-release of T and pregnenolone were significantly increased in the CIH group. Compared with the normoxic group, the CIH group had higher mRNA and protein expression levels of the LH receptor and CYP11A1 but not StAR. The plasma and testicular microvasculature VEGF levels were increased in the CIH group. The testicular vessel distribution was more obvious in CIH rats. SIGNIFICANCE CIH-induced T secretion might be partially mediated by mechanisms involving the induction of LH receptor expression, testicular angiogenesis, CYP11A1 activity, 17β-HSD activity, and calcium-related pathway.
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Affiliation(s)
- Yu-Min Cho
- Department of Physiology, School of Medicine, National Yang-Ming University, Taipei 11221, Taiwan; Center for East West Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, 90024, USA
| | - Jou-Chun Chou
- Department of Life Science, National Chung Hsing University, Taichung 40254, Taiwan
| | - Chia-Mei Fang
- Department of Physiology, School of Medicine, National Yang-Ming University, Taipei 11221, Taiwan
| | - Sindy Hu
- Anesthetic Medical Center, Department of Dermatology, Chang Gung Memorial Hospital, Taoyuan 33378, Taiwan; Department of Medicine, College of Medicine Chang Gung University, Taoyuan 33302, Taiwan
| | - Kai-Lee Wang
- Department of Physiology, School of Medicine, National Yang-Ming University, Taipei 11221, Taiwan; Department of Nursing, Ching Kuo Institute of Management and Health, Keelung City 20301, Taiwan.
| | - Shyi-Wu Wang
- Anesthetic Medical Center, Department of Dermatology, Chang Gung Memorial Hospital, Taoyuan 33378, Taiwan; Department of Physiology and Pharmacology, Chang Gung University, Taoyuan 33302, Taiwan.
| | - Paulus S Wang
- Department of Physiology, School of Medicine, National Yang-Ming University, Taipei 11221, Taiwan; Medical Center of Aging Research, China Medical University Hospital, Taichung 40402, Taiwan; Department of Biotechnology, College of Health Science, Asia University, Taichung 41354, Taiwan; Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan.
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21
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Wang X, Jin L, Jiang S, Wang D, Lu Y, Zhu L. Transcription regulation of NRF1 on StAR reduces testosterone synthesis in hypoxemic murine. J Steroid Biochem Mol Biol 2019; 191:105370. [PMID: 31028793 DOI: 10.1016/j.jsbmb.2019.04.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 04/17/2019] [Accepted: 04/22/2019] [Indexed: 12/14/2022]
Abstract
Male chronic obstructive pulmonary disease (COPD) and sleep apnea patients are associated with serum testosterone level decline because of hypoxemia, resulting in male sexual dysfunction and lower reproductive capacity. Although testosterone replacement therapy used in clinic achieves good results, the side effects indicates that understanding the mechanism followed with targeted treatments are more meaningful. The known mechanism of Hypoxia-inducible factor-1 (HIF-1) mediated steroidogenic acute regulatory protein (StAR) repression did not well explain the reason of hypoxia induced testosterone decline. Our primary results indicated Nuclear respiratory factor 1(NRF1) might be participate in StAR transcription regulation. The study aims to identify the mechanism of the regulation of StAR by NRF1, providing an explanation for the decrease of testosterone induced by hypoxemia. Testosterone level and StAR were determined in COPD model rats, sleep apnea model mice and hypoxia rats (10%O2). Results indicated NRF1, StAR and testosterone decreased in testis and ovary and increased in adrenal. Regulation of NRF1 expression under normoxia or hypoxia induced synchronous changes of both StAR and testosterone, indicating the decrease of NRF1 induced StAR repression in hypoxemia were the main cause of serum testosterone decline. The results were confirmed by dual-luciferase reporter assays, regulation of NRF1 synchronously altered the transcriptional activity of StAR. By ChIP, EMSA supershift, NRF1 was found to bind to the Star promoter region. Mutation assays identified two NRF1-binding sites on mouse Star promoter. These findings indicated that NRF1 positivly regulated Star transcription through directly binding to the Star promoter at -1445/-1422 and -44/-19.
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Affiliation(s)
- Xueting Wang
- Institute of Special Environmental Medicine, Nantong University, China; Co-innovation Center of Neuroregeneration, Nantong University, China
| | - Liuhan Jin
- Institute of Special Environmental Medicine, Nantong University, China; Co-innovation Center of Neuroregeneration, Nantong University, China
| | - Shan Jiang
- Institute of Special Environmental Medicine, Nantong University, China; Co-innovation Center of Neuroregeneration, Nantong University, China
| | - Dan Wang
- Institute of Special Environmental Medicine, Nantong University, China; Co-innovation Center of Neuroregeneration, Nantong University, China
| | - Yapeng Lu
- Institute of Special Environmental Medicine, Nantong University, China; Co-innovation Center of Neuroregeneration, Nantong University, China
| | - Li Zhu
- Institute of Special Environmental Medicine, Nantong University, China; Co-innovation Center of Neuroregeneration, Nantong University, China.
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Tenkorang MAA, Duong P, Cunningham RL. NADPH Oxidase Mediates Membrane Androgen Receptor-Induced Neurodegeneration. Endocrinology 2019; 160:947-963. [PMID: 30811529 PMCID: PMC6435014 DOI: 10.1210/en.2018-01079] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 02/22/2019] [Indexed: 12/21/2022]
Abstract
Oxidative stress (OS) is a common characteristic of several neurodegenerative disorders, including Parkinson disease (PD). PD is more prevalent in men than in women, indicating the possible involvement of androgens. Androgens can have either neuroprotective or neurodamaging effects, depending on the presence of OS. Specifically, in an OS environment, androgens via a membrane-associated androgen receptor (mAR) exacerbate OS-induced damage. To investigate the role of androgens on OS signaling and neurodegeneration, the effects of testosterone and androgen receptor activation on the major OS signaling cascades, the reduced form of NAD phosphate (NADPH) oxidase (NOX)1 and NOX2 and the Gαq/inositol trisphosphate receptor (InsP3R), were examined. To create an OS environment, an immortalized neuronal cell line was exposed to H2O2 prior to cell-permeable/cell-impermeable androgens. Different inhibitors were used to examine the role of G proteins, mAR, InsP3R, and NOX1/2 on OS generation and cell viability. Both testosterone and DHT/3-O-carboxymethyloxime (DHT)-BSA increased H2O2-induced OS and cell death, indicating the involvement of an mAR. Furthermore, classical AR antagonists did not block testosterone's negative effects in an OS environment. Because there are no known antagonists specific for mARs, an AR protein degrader, ASC-J9, was used to block mAR action. ASC-J9 blocked testosterone's negative effects. To determine OS-related signaling mediated by mAR, this study examined NOX1, NOX2, Gαq. NOX1, NOX2, and the Gαq complex with mAR. Only NOX inhibition blocked testosterone-induced cell loss and OS. No effects of blocking either Gαq or G protein activation were observed on testosterone's negative effects. These results indicate that androgen-induced OS is via the mAR-NOX complex and not the mAR-Gαq complex.
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Affiliation(s)
- Mavis A A Tenkorang
- Department of Physiology and Anatomy, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas
| | - Phong Duong
- Department of Physiology and Anatomy, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas
| | - Rebecca L Cunningham
- Department of Physiology and Anatomy, Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, Texas
- Correspondence: Rebecca L. Cunningham, PhD, Department of Physiology and Anatomy, University of North Texas Health Science Center, 3400 Camp Bowie Boulevard, Fort Worth, Texas 76107. E-mail:
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Snyder B, Duong P, Tenkorang M, Wilson EN, Cunningham RL. Rat Strain and Housing Conditions Alter Oxidative Stress and Hormone Responses to Chronic Intermittent Hypoxia. Front Physiol 2018; 9:1554. [PMID: 30459637 PMCID: PMC6232418 DOI: 10.3389/fphys.2018.01554] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Accepted: 10/17/2018] [Indexed: 12/15/2022] Open
Abstract
Sleep apnea has been associated with elevated risk for metabolic, cognitive, and cardiovascular disorders. Further, the role of hypothalamic–pituitary–adrenal (HPA) activation in sleep apnea has been controversial in human studies. Chronic intermittent hypoxia (CIH) is a rodent model, which mimics the hypoxemia experienced by patients with sleep apnea. Most studies of CIH in rats have been conducted in the Sprague Dawley rat strain. Previously published literature suggests different strains of rats exhibit various responses to disease models, and these effects can be further modulated by the housing conditions experienced by each strain. This variability in response is similar to what has been observed in clinical populations, especially with respect to the HPA system. To investigate if strain or housing (individual or pair-housed) can affect the results of CIH (AHI 8 or 10) treatment, we exposed individual and pair-housed Sprague Dawley and Long-Evans male rats to 7 days of CIH treatment. This was followed by biochemical analysis of circulating hormones, oxidative stress, and neurodegenerative markers. Both strain and housing conditions altered oxidative stress generation, hyperphosphorylated tau protein (tau tangles), circulating corticosterone and adrenocorticotropic hormone (ACTH), and weight metrics. Specifically, pair-housed Long-Evans rats were the most sensitive to CIH, which showed a significant association between oxidative stress generation and HPA activation under conditions of AHI of 8. These results suggest both strain and housing conditions can affect the outcomes of CIH.
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Affiliation(s)
- Brina Snyder
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Phong Duong
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Mavis Tenkorang
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - E Nicole Wilson
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Rebecca L Cunningham
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, United States
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Snyder B, Duong P, Trieu J, Cunningham RL. Androgens modulate chronic intermittent hypoxia effects on brain and behavior. Horm Behav 2018; 106:62-73. [PMID: 30268884 PMCID: PMC6486829 DOI: 10.1016/j.yhbeh.2018.09.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 09/19/2018] [Accepted: 09/25/2018] [Indexed: 12/31/2022]
Abstract
Sleep apnea is associated with testosterone dysregulation as well as increased risk of developing neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD). A rodent model of the hypoxemic events of sleep apnea, chronic intermittent hypoxia (CIH), has been previously documented to impair cognitive function and elevate oxidative stress in male rats, while simultaneously decreasing testosterone. Therefore, androgens may modulate neuronal function under CIH. To investigate the role of androgens during CIH, male rats were assigned to one of four hormone groups: 1) gonadally intact, 2) gonadectomized (GDX), 3) GDX + testosterone (T) supplemented, or 4) GDX + dihydrotestosterone (DHT) supplemented. Each group was exposed to either normal room air or CIH exposure for one week, followed by memory and motor task assessments. Brain regions associated with AD and PD (entorhinal cortex, dorsal hippocampus, and substantia nigra) were examined for oxidative stress and inflammatory markers, key characteristics of AD and PD. Gonadally intact rats exhibited elevated oxidative stress due to CIH, but no significant memory and motor impairments. GDX increased memory impairments, regardless of CIH exposure. T preserved memory function and prevented detrimental CIH-induced changes. In contrast, DHT was not protective, as evidenced by exacerbated oxidative stress under CIH. Further, CIH induced significant spatial memory impairment in rats administered DHT. These results indicate androgens can have both neuroprotective and detrimental effects under CIH, which may have clinical relevance for men with untreated sleep apnea.
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Affiliation(s)
- Brina Snyder
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, United States of America
| | - Phong Duong
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, United States of America
| | - Jenny Trieu
- Texas College of Osteopathic Medicine, University of North Texas Health Science Center, Fort Worth, TX, United States of America
| | - Rebecca L Cunningham
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, United States of America.
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Mourot L. Limitation of Maximal Heart Rate in Hypoxia: Mechanisms and Clinical Importance. Front Physiol 2018; 9:972. [PMID: 30083108 PMCID: PMC6064954 DOI: 10.3389/fphys.2018.00972] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 07/02/2018] [Indexed: 12/17/2022] Open
Abstract
The use of exercise intervention in hypoxia has grown in popularity amongst patients, with encouraging results compared to similar intervention in normoxia. The prescription of exercise for patients largely rely on heart rate recordings (percentage of maximal heart rate (HRmax) or heart rate reserve). It is known that HRmax decreases with high altitude and the duration of the stay (acclimatization). At an altitude typically chosen for training (2,000-3,500 m) conflicting results have been found. Whether or not this decrease exists or not is of importance since the results of previous studies assessing hypoxic training based on HR may be biased due to improper intensity. By pooling the results of 86 studies, this literature review emphasizes that HRmax decreases progressively with increasing hypoxia. The dose–response is roughly linear and starts at a low altitude, but with large inter-study variabilities. Sex or age does not seem to be a major contributor in the HRmax decline with altitude. Rather, it seems that the greater the reduction in arterial oxygen saturation, the greater the reduction in HRmax, due to an over activity of the parasympathetic nervous system. Only a few studies reported HRmax at sea/low level and altitude with patients. Altogether, due to very different experimental design, it is difficult to draw firm conclusions in these different clinical categories of people. Hence, forthcoming studies in specific groups of patients are required to properly evaluate (1) the HRmax change during acute hypoxia and the contributing factors, and (2) the physiological and clinical effects of exercise training in hypoxia with adequate prescription of exercise training intensity if based on heart rate.
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Affiliation(s)
- Laurent Mourot
- EA 3920 Prognostic Markers and Regulatory Factors of Cardiovascular Diseases and Exercise Performance, Health, Innovation Platform, University of Franche-Comté, Besançon, France.,Tomsk Polytechnic University, Tomsk, Russia
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