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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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2
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Bi J, Zhou W, Tang Z. Pathogenesis of diabetic complications: Exploring hypoxic niche formation and HIF-1α activation. Biomed Pharmacother 2024; 172:116202. [PMID: 38330707 DOI: 10.1016/j.biopha.2024.116202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 01/11/2024] [Accepted: 01/22/2024] [Indexed: 02/10/2024] Open
Abstract
Hypoxia is a common feature of diabetic tissues, which highly correlates to the progression of diabetes. The formation of hypoxic context is induced by disrupted oxygen homeostasis that is predominantly driven by vascular remodeling in diabetes. While different types of vascular impairments have been reported, the specific features and underlying mechanisms are yet to be fully understood. Under hypoxic condition, cells upregulate hypoxia-inducible factor-1α (HIF-1α), an oxygen sensor that coordinates oxygen concentration and cell metabolism under hypoxic conditions. However, diabetic context exploits this machinery for pathogenic functions. Although HIF-1α protects cells from diabetic insult in multiple tissues, it also jeopardizes cell function in the retina. To gain a deeper understanding of hypoxia in diabetic complications, we focus on the formation of tissue hypoxia and the outcomes of HIF-1α dysregulation under diabetic context. Hopefully, this review can provide a better understanding on hypoxia biology in diabetes.
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Affiliation(s)
- Jingjing Bi
- Basic Medicine Research Innovation Center for cardiometabolic diseases, Ministry of Education,Southwest Medical University, Ministry of Education, Southwest Medical University, Luzhou, China
| | - Wenhao Zhou
- Yucebio Technology Co., Ltd., Shenzhen, China
| | - Zonghao Tang
- Basic Medicine Research Innovation Center for cardiometabolic diseases, Ministry of Education,Southwest Medical University, Ministry of Education, Southwest Medical University, Luzhou, China; Baylor College of Medicine, Department of Molecular and Cellular Biology, Houston, TX, USA.
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3
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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: 13] [Impact Index Per Article: 6.5] [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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Wang Z, Wang Q, Cui N, Xiao L, Wei H, Kang J, Sheng X, Qi X, Xing K, Guo Y, Ni H, Wang X. Heat stress and hypoxia inhibit the secretion of androgens and induce epithelial-to-mesenchymal transition associated with activated TGF-β/Smad signalling in canine cryptorchidism. Reprod Domest Anim 2022; 57:1046-1055. [PMID: 35678492 DOI: 10.1111/rda.14174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 06/04/2022] [Indexed: 11/29/2022]
Abstract
Cryptorchidism, as a common congenital disease of canine testes, is mainly caused by factors leading to endocrine abnormalities in testes and infertility in a heat stress and hypoxia microenvironment. Moreover, heat stress and hypoxia, as critical microenvironmental factors, promote epithelial-mesenchymal transition (EMT), which occurs during adult tissue remodelling responses including carcinogenesis and fibrosis and is the main cause of testicular tumours. In this study, we found by haematoxylin-eosin staining that the canine cryptorchid tissue produced a lot of collagen fibres. Also, the quantitative PCR and Western blot results showed that the mRNA and protein levels of the heat stress makers HSP70 and HO-1 and the hypoxia maker HIF-1α are significant higher compared with normal testes. Moreover, we found the expression levels of TGF-βs and its two receptors TGF-βRI and TGF-βRII increased in case of cryptorchidism. From the study in vitro, we found both heat stress and COCl2 mimic hypoxia inhibited the secretion of testosterone (T) and androstenedione (A4) and promoted the expression of the EMT maker α-SMA and vimentin in Leydig cells, and also that heat stress and COCl2 stimulated with the TGF-β signalling promoted the expression of TGF-βs and its two type receptors and also the active phosphorylation of Smad2 and Smad3. The use of LY2109761, a receptor inhibitor of TGF-βs/Smad signalling pathway, was associated with heat stress and COCl2 suppression of androgens' secretion and stimulated EMT in Leydig cells. These findings characterized a novel pathogenesis of cryptorchidism and provided a new idea for therapeutics.
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Affiliation(s)
- Zihui Wang
- Animal Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Qian Wang
- Animal Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Nan Cui
- Animal Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Longfei Xiao
- Animal Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Huawei Wei
- Beijing Detector Dog Developing Facility GACC, Beijing, China
| | - Jian Kang
- Guangdong Polytechnic of Science and Trade, Guangdong, China
| | - Xihui Sheng
- Animal Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Xiaolong Qi
- Animal Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Kai Xing
- Animal Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Yong Guo
- Animal Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Hemin Ni
- Animal Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Xiangguo Wang
- Animal Science and Technology College, Beijing University of Agriculture, Beijing, China
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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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Wang X, Zou Z, Yang Z, Jiang S, Lu Y, Wang D, Dong Z, Xu S, Zhu L. HIF 1 inhibits StAR transcription and testosterone synthesis in murine Leydig cells. J Mol Endocrinol 2018; 62:JME-18-0148.R2. [PMID: 30400066 DOI: 10.1530/jme-18-0148] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 10/18/2018] [Indexed: 12/12/2022]
Abstract
Hypoxia-inducible factor-1 (HIF1) is a critical transcription factor involved in cell response to hypoxia. Under physiological conditions, its a subunit is rapidly degraded in most tissues except testes. HIF1 is stably expressed in Leydig cells, which are the main source of testosterone for male, and might bind to the promoter region of steroidogenic acute regulatory protein (Star), which is necessary for the testosterone synthesis, according to software analysis. This study aims to identify the binding sites of HIF1 on Star promoter and its transcriptional regulation of Star to affect testosterone synthesis. Testosterone level and steroid synthesis-related proteins were determined in male Balb/C mice exposed to hypoxia (8% O2). While HIF1 was upregulated, the testosterone level was significantly decreased. This was further confirmed by in vitro experiments with rat primary Leydig cells or TM3 cells exposed to hypoxia (1% O2), CoCl2 or DFX to raise HIF1. The decline of testosterone was reversed by pregnenolone but not cAMP, indicating the cholesterol transport disorder as the main cause. In agreement, StAR expression level was decreased in response to HIF1, while 3b-hydroxysteroid dehydrogenase, 17b-hydroxysteroid dehydrogenase and p450scc did not exhibit significant changes. By ChIP, EMSA supershift and dual-luciferase reporter assays, HIF1 was found to bind to the Star promoter region and repress the expression of StAR. Mutation assays identified three HIF1-binding sites on mouse Star promoter. These findings indicate that HIF1 represses Star transcription through directly binding to the Star promoter at -2082/-2078, -2064/-2060 and -1910/-1906, leading to the negative regulation of testosterone synthesis.
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Affiliation(s)
- Xueting Wang
- X Wang, Biochemisty, Institute of Nautical Medicine, Nantong, China
| | - Zhiran Zou
- Z Zou, Biochemisty, Institute of Nautical Medicine, Nantong, China
| | - Zhihui Yang
- Z Yang, Biochemistry, Institute of Nautical Medicine, Nantong, China
| | - Shan Jiang
- S Jiang, Biochemisty, Institute of Nautical Medicine, Nantong, China
| | - Yapeng Lu
- Y Lu, Biochemisty, Institute of Nautical Medicine, Nantong, China
| | - Dan Wang
- D Wang, Biochemisty, Institute of Nautical Medicine, Nantong, China
| | - Zhangji Dong
- Z Dong, Molecular Biology, Key laboratory of neuroregeneration of Jiangsu and Ministry of Education, Nantong, China
| | - Sha Xu
- S Xu, physiology, Medical College of Soochow University, Suzhou, China
| | - Li Zhu
- L Zhu, Biochemisty, Institute of Nautical Medicine, Nantong, China
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Ma Y, Zhou Y, Zhu YC, Wang SQ, Ping P, Chen XF. Lipophagy Contributes to Testosterone Biosynthesis in Male Rat Leydig Cells. Endocrinology 2018; 159:1119-1129. [PMID: 29304246 DOI: 10.1210/en.2017-03020] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 12/22/2017] [Indexed: 12/21/2022]
Abstract
In recent years, autophagy was found to regulate lipid metabolism through a process termed lipophagy. Lipophagy modulates the degradation of cholesteryl esters to free cholesterol (FC), which is the substrate of testosterone biosynthesis. However, the role of lipophagy in testosterone production is unknown. To investigate this, primary rat Leydig cells and varicocele rat models were administered to inhibit or promote autophagy, and testosterone, lipid droplets (LDs), total cholesterol (TC), and FC were evaluated. The results demonstrated that inhibiting autophagy in primary rat Leydig cells reduced testosterone production. Further studies demonstrated that inhibiting autophagy increased the number and size of LDs and the level of TC, but decreased the level of FC. Furthermore, hypoxia promoted autophagy in Leydig cells. We found that short-term hypoxia stimulated testosterone secretion; however, the inhibition of autophagy abolished stimulated testosterone release. Hypoxia decreased the number and size of LDs in Leydig cells, but the changes could be largely rescued by blocking autophagy. In experimental varicocele rat models, the administration of autophagy inhibitors substantially reduced serum testosterone. These data demonstrate that autophagy contributes to testosterone biosynthesis at least partially through degrading intracellular LDs/TC. Our observations might reveal an autophagic regulatory mode regarding testosterone biosynthesis.
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Affiliation(s)
- Yi Ma
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200135, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai 200135, China
| | - Yan Zhou
- Department of Central Laboratory, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Yin-Ci Zhu
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200135, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai 200135, China
| | - Si-Qi Wang
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200135, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai 200135, China
| | - Ping Ping
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200135, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai 200135, China
| | - Xiang-Feng Chen
- Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200135, China
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai 200135, China
- Shanghai Human Sperm Bank, Department of Urology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200135, China
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Pinto CL, Markey K, Dix D, Browne P. Identification of candidate reference chemicals for in vitro steroidogenesis assays. Toxicol In Vitro 2017; 47:103-119. [PMID: 29146384 DOI: 10.1016/j.tiv.2017.11.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 10/19/2017] [Accepted: 11/11/2017] [Indexed: 11/15/2022]
Abstract
The Endocrine Disruptor Screening Program (EDSP) is transitioning from traditional testing methods to integrating ToxCast/Tox21 in vitro high-throughput screening assays for identifying chemicals with endocrine bioactivity. The ToxCast high-throughput H295R steroidogenesis assay may potentially replace the low-throughput assays currently used in the EDSP Tier 1 battery to detect chemicals that alter the synthesis of androgens and estrogens. Herein, we describe an approach for identifying in vitro candidate reference chemicals that affect the production of androgens and estrogens in models of steroidogenesis. Candidate reference chemicals were identified from a review of H295R and gonad-derived in vitro assays used in methods validation and published in the scientific literature. A total of 29 chemicals affecting androgen and estrogen levels satisfied all criteria for positive reference chemicals, while an additional set of 21 and 15 chemicals partially fulfilled criteria for positive reference chemicals for androgens and estrogens, respectively. The identified chemicals included pesticides, pharmaceuticals, industrial and naturally-occurring chemicals with the capability to increase or decrease the levels of the sex hormones in vitro. Additionally, 14 and 15 compounds were identified as potential negative reference chemicals for effects on androgens and estrogens, respectively. These candidate reference chemicals will be informative for performance-based validation of in vitro steroidogenesis models.
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Affiliation(s)
- Caroline Lucia Pinto
- U.S. EPA, Office of Science Coordination and Policy, Washington, D.C. 20004, United States; Oak Ridge Institute for Science and Education, Oak Ridge, TN 37831-0117, United States.
| | - Kristan Markey
- U.S. EPA, Office of Science Coordination and Policy, Washington, D.C. 20004, United States
| | - David Dix
- U.S. EPA, Office of Chemical Safety and Pollution Prevention, Washington, D.C. 20004, United States
| | - Patience Browne
- U.S. EPA, Office of Science Coordination and Policy, Washington, D.C. 20004, United States
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Hwang GS, Chen CC, Chou JC, Chang LL, Kan SF, Lai WH, Lieu FK, Hu S, Wang PS, Wang SW. Stimulatory Effect of Intermittent Hypoxia on the Production of Corticosterone by Zona Fasciculata-Reticularis Cells in Rats. Sci Rep 2017; 7:9035. [PMID: 28831034 PMCID: PMC5567345 DOI: 10.1038/s41598-017-07054-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 06/23/2017] [Indexed: 12/17/2022] Open
Abstract
Hypoxia or intermittent hypoxia (IH) have known to alter both synthesis and secretion of hormones. However, the effect of IH on the production of adrenal cortical steroid hormones is still unclear. The aim of present study was to explore the mechanism involved in the effect of IH on the production of corticosterone by rat ZFR cells. Male rats were exposed at 12% O2 and 88% N2 (8 hours per day) for 1, 2, or 4 days. The ZFR cells were incubated at 37 °C for 1 hour with or without ACTH, 8-Br-cAMP, calcium ion channel blockers, or steroidogenic precursors. The concentration of plasma corticosterone was increased time-dependently by administration of IH hypoxia. The basal levels of corticosterone production in cells were higher in the IH groups than in normoxic group. IH resulted in a time-dependent increase of corticosterone production in response to ACTH, 8-Br-cAMP, progesterone and deoxycorticosterone. The production of pregnenolone in response to 25-OH-C and that of progesterone in response to pregnenolone in ZFR cells were enhanced by 4-day IH. These results suggest that IH in rats increases the secretion of corticosterone via a mechanism at least in part associated with the activation of cAMP pathway and steroidogenic enzymes.
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Affiliation(s)
- Guey-Shyang Hwang
- Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan.,Department of Nursing, Chang Gung University of Science and Technology, Taoyuan, 33303, Taiwan.,Aesthetic Medical Center, Department of Dermatology, Chang Gung Memorial Hospital, Taoyuan, 33378, Taiwan
| | - Chih-Chieh Chen
- Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan
| | - Jou-Chun Chou
- Medical Center of Aging Research, China Medical University Hospital, Taichung, 40402, Taiwan.,Department of Life Sciences, National Chung Hsing University, Taichung, 40254, Taiwan
| | - Ling-Ling Chang
- Department of Chemical and Materials Engineering, Chinese Culture University, Taipei, 11114, Taiwan
| | - Shu-Fen Kan
- Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan
| | - Wei-Ho Lai
- Department of Rehabilitation, Cheng Hsin General Hospital, Taipei, 11212, Taiwan
| | - Fu-Kong Lieu
- Department of Rehabilitation, Cheng Hsin General Hospital, Taipei, 11212, Taiwan
| | - Sindy Hu
- Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, Taoyuan, 33302, Taiwan.,Department of Nursing, Chang Gung University of Science and Technology, Taoyuan, 33303, Taiwan.,Aesthetic Medical Center, Department of Dermatology, Chang Gung Memorial Hospital, Taoyuan, 33378, 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 Medical Research, Taipei Veterans General Hospital, Taipei, 11217, Taiwan.,Graduate Institute of Basic Medical Science,College of Medicine, China Medical University, Taichung, 40402, Taiwan.,Department of Biotechnology, College of Health Science, Asia University, Taichung, 41354, Taiwan, Republic of China
| | - Shyi-Wu Wang
- Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, Taoyuan, 33302, Taiwan. .,Aesthetic Medical Center, Department of Dermatology, Chang Gung Memorial Hospital, Taoyuan, 33378, Taiwan.
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10
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Goda M, Oda K, Oda A, Kobayashi N, Otsuka M. Involvement of the Multidrug and Toxic Compound Extrusion Transporter in Testosterone Release from Cultured Pig Leydig Cells. Pharmacology 2017; 100:31-39. [DOI: 10.1159/000460822] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 02/09/2017] [Indexed: 11/19/2022]
Abstract
Testosterone is considered to be released from Leydig cells via passive diffusion because of its hydrophobicity; however, the exact mechanism underlying testosterone secretion and the transporter involved are both unknown. Multidrug and toxic compound extrusion (MATE) transporters are predominantly found in the kidneys and liver and are thought to function in the elimination of metabolic organic cations during the final step of excretion in the kidney. In contrast, mMATE2 has been shown to be predominantly expressed in testicular Leydig cells. Although the physiological function of mMATE2 in Leydig cells is unknown, we hypothesized that mMATE2 acts as a testosterone exporter and is responsible for the secretion of testosterone from Leydig cells. Therefore, in the present study, we investigated the involvement of the MATE transporter in testosterone secretion from pig Leydig cells. Immunohistochemical analysis with anti-pig MATE2 antiserum indicated that the MATE transporter is present in pig Leydig cells. Additionally, treatment with the MATE inhibitors cimetidine and pyrimethamine reduced the testosterone secretion from pig Leydig cells but increased the intracellular testosterone levels. Estradiol release and intracellular estradiol level induced by human chorionic gonadotropin (hCG) further increased with cimetidine treatment. These results indicated that testosterone produced by hCG treatment is secreted from Leydig cells via the MATE transporter; however, in the presence of cimetidine or pyrimethamine, this MATE transporter-mediated secretion was inhibited, resulting in increased intracellular testosterone levels and estradiol production in Leydig cells. Thus, the MATE transporter may be responsible for testosterone secretion from Leydig cells.
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11
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Variation of reproductive hormone profile in male patients with obstructive sleep apnea: a meta-analysis. Sleep Biol Rhythms 2015. [DOI: 10.1007/s41105-015-0041-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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12
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Sarin H. Pressuromodulation at the cell membrane as the basis for small molecule hormone and peptide regulation of cellular and nuclear function. J Transl Med 2015; 13:372. [PMID: 26610602 PMCID: PMC4660824 DOI: 10.1186/s12967-015-0707-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 10/21/2015] [Indexed: 12/15/2022] Open
Abstract
Building on recent knowledge that the specificity of the biological interactions of small molecule hydrophiles and lipophiles across microvascular and epithelial barriers, and with cells, can be predicted on the basis of their conserved biophysical properties, and the knowledge that biological peptides are cell membrane impermeant, it has been further discussed herein that cellular, and thus, nuclear function, are primarily regulated by small molecule hormone and peptide/factor interactions at the cell membrane (CM) receptors. The means of regulating cellular, and thus, nuclear function, are the various forms of CM Pressuromodulation that exist, which include Direct CM Receptor-Mediated Stabilizing Pressuromodulation, sub-classified as Direct CM Receptor-Mediated Stabilizing Shift Pressuromodulation (Single, Dual or Tri) or Direct CM Receptor-Mediated Stabilizing Shift Pressuromodulation (Single, Dual or Tri) cum External Cationomodulation (≥3+ → 1+); which are with respect to acute CM receptor-stabilizing effects of small biomolecule hormones, growth factors or cytokines, and also include Indirect CM- or CM Receptor-Mediated Pressuromodulation, sub-classified as Indirect 1ary CM-Mediated Shift Pressuromodulation (Perturbomodulation), Indirect 2ary CM Receptor-Mediated Shift Pressuromodulation (Tri or Quad Receptor Internal Pseudo-Cationomodulation: SS 1+), Indirect 3ary CM Receptor-Mediated Shift Pressuromodulation (Single or Dual Receptor Endocytic External Cationomodulation: 2+) or Indirect (Pseudo) 3ary CM Receptor-Mediated Shift Pressuromodulation (Receptor Endocytic Hydroxylocarbonyloetheroylomodulation: 0), which are with respect to sub-acute CM receptor-stabilizing effects of small biomolecules, growth factors or cytokines. As a generalization, all forms of CM pressuromodulation decrease CM and nuclear membrane (NM) compliance (whole cell compliance), due to pressuromodulation of the intracellular microtubule network and increases the exocytosis of pre-synthesized vesicular endogolgi peptides and small molecules as well as nuclear-to-rough endoplasmic reticulum membrane proteins to the CM, with the potential to simultaneously increase the NM-associated chromatin DNA transcription of higher molecular weight protein forms, secretory and CM-destined, mitochondrial and nuclear, including the highest molecular weight nuclear proteins, Ki67 (359 kDa) and Separase (230 kDa), with the latter leading to mitogenesis and cell division; while, in the case of growth factors or cytokines with external cationomodulation capability, CM Receptor External Cationomodulation of CM receptors (≥3+ → 1+) results in cationic extracellular interaction (≥3+) with extracellular matrix heparan sulfates (≥3+ → 1+) concomitant with lamellopodesis and cell migration. It can be surmised that the modulation of cellular, and nuclear, function is mostly a reactive process, governed, primarily, by small molecule hormone and peptide interactions at the cell membrane, with CM receptors and the CM itself. These insights taken together, provide valuable translationally applicable knowledge.
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Affiliation(s)
- Hemant Sarin
- Freelance Investigator in Translational Science and Medicine, Charleston, WV, USA.
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Aubrecht TG, Jenkins R, Magalang UJ, Nelson RJ. Influence of gonadal hormones on the behavioral effects of intermittent hypoxia in mice. Am J Physiol Regul Integr Comp Physiol 2014; 308:R489-99. [PMID: 25552660 DOI: 10.1152/ajpregu.00379.2014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Obstructive sleep apnea (OSA) is characterized by repetitive upper airway obstruction resulting in cyclic intermittent hypoxia (IH) during sleep in affected individuals. OSA occurs more frequently in postmenopausal than premenopausal women and the severity of OSA increases after menopause. Gonadal hormones can influence brain and behavior; testosterone and estrogens in particular can enhance spatial learning and memory. We hypothesized that estrogens may protect mice from IH-induced hippocampal morphological and behavioral changes. To test this hypothesis we exposed intact or gonadectomized male and female mice to room air or IH [15 cycles/h, 8 h/day, fraction of inspired oxygen (FiO 2) nadir of 5%] for a total of 30 days. During the final 4 days of IH, mice were tested for anxiety- and depressive-like behaviors. After cessation of IH exposure mice were tested on the Barnes maze and passive avoidance tests to assess learning and memory. Ovariectomy paired with IH treatment, impaired spatial learning and memory compared to all other female groups. Intact male mice receiving IH treatment also had impaired learning and memory compared with intact or castrated male mice exposed to room air. Learning and memory changes were mirrored by changes in basilar dendritic length of the CA1 region of the hippocampus. These data suggest that estrogens provide protection against IH-induced deficits, whereas androgens partially exacerbate IH-induced deficits on learning and memory.
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Affiliation(s)
- Taryn G Aubrecht
- Department of Neuroscience and Neuroscience Research Institute, Wexner Medical Center, The Ohio State University, Columbus, Ohio; and
| | - Richelle Jenkins
- Department of Neuroscience and Neuroscience Research Institute, Wexner Medical Center, The Ohio State University, Columbus, Ohio; and
| | - Ulysses J Magalang
- Department of Neuroscience and Neuroscience Research Institute, Wexner Medical Center, The Ohio State University, Columbus, Ohio; and Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Wexner Medical Center, The Ohio State University, Columbus, Ohio
| | - Randy J Nelson
- Department of Neuroscience and Neuroscience Research Institute, Wexner Medical Center, The Ohio State University, Columbus, Ohio; and
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Torres M, Laguna-Barraza R, Dalmases M, Calle A, Pericuesta E, Montserrat JM, Navajas D, Gutierrez-Adan A, Farré R. Male fertility is reduced by chronic intermittent hypoxia mimicking sleep apnea in mice. Sleep 2014; 37:1757-65. [PMID: 25364071 DOI: 10.5665/sleep.4166] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
STUDY OBJECTIVES Obstructive sleep apnea (OSA) is characterized by intermittent hypoxia and oxidative stress. However, it is unknown whether intermittent hypoxia mimicking OSA modifies male fertility. We tested the hypothesis that male fertility is reduced by chronic intermittent hypoxia mimicking OSA in a mouse model. DESIGN Case-control comparison in a murine model. SETTING University research laboratory. PARTICIPANTS Eighteen F1 (C57BL/6xCBA) male mice. INTERVENTIONS Mice were subjected to a pattern of periodic hypoxia (20 sec at 5% O2 followed by 40 sec of room air) 6 h/day for 60 days or normoxia. After this period, mice performed a mating trial to determine effective fertility by assessing the number of pregnant females and fetuses. MEASUREMENTS AND RESULTS After euthanasia, oxidative stress in testes was assessed by measuring the expression of glutathione peroxidase 1 (Gpx1) and superoxide dismutase-1 (Sod1) by reverse-transcription polymerase chain reaction. Sperm motility was determined by Integrated Semen Analysis System (ISAS). Intermittent hypoxia significantly increased testicular oxidative stress, showing a reduction in the expression of Gpx1 and Sod1 by 38.9% and 34.4%, respectively, as compared with normoxia (P < 0.05). Progressive sperm motility was significantly reduced from 27.0 ± 6.4% in normoxia to 12.8 ± 1.8% in the intermittent hypoxia group (P = 0.04). The proportion of pregnant females and number of fetuses per mating was significantly lower in the intermittent hypoxia group (0.33 ± 0.10 and 2.45 ± 0.73, respectively) than in normoxic controls (0.72 ± 0.16 and 5.80 ± 1.24, respectively). CONCLUSIONS These results suggest that the intermittent hypoxia associated with obstructive sleep apnea (OSA) could induce fertility reduction in male patients with this sleep breathing disorder.
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Affiliation(s)
- Marta Torres
- CIBER Enfermedades Respiratorias, Bunyola, Spain ; Laboratori de la Son, Servei de Pneumologia, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Ricardo Laguna-Barraza
- INIA, Departamento de Reproducción Animal y Conservación de Recursos Zoogenéticos, Madrid
| | - Mireia Dalmases
- CIBER Enfermedades Respiratorias, Bunyola, Spain ; Laboratori de la Son, Servei de Pneumologia, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Alexandra Calle
- INIA, Departamento de Reproducción Animal y Conservación de Recursos Zoogenéticos, Madrid
| | - Eva Pericuesta
- INIA, Departamento de Reproducción Animal y Conservación de Recursos Zoogenéticos, Madrid
| | - Josep M Montserrat
- CIBER Enfermedades Respiratorias, Bunyola, Spain ; Laboratori de la Son, Servei de Pneumologia, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain ; Institut Investigacions Biomèdiques August Pi Sunyer, Barcelona, Spain
| | - Daniel Navajas
- CIBER Enfermedades Respiratorias, Bunyola, Spain ; Unitat Biofísica i Bioenginyeria, Facultat de Medicina, Universitat de Barcelona, Spain ; Institut Bioenginyeria Catalunya, Barcelona, Spain
| | - Alfonso Gutierrez-Adan
- INIA, Departamento de Reproducción Animal y Conservación de Recursos Zoogenéticos, Madrid
| | - Ramon Farré
- CIBER Enfermedades Respiratorias, Bunyola, Spain ; Institut Investigacions Biomèdiques August Pi Sunyer, Barcelona, Spain ; Unitat Biofísica i Bioenginyeria, Facultat de Medicina, Universitat de Barcelona, Spain
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Gonzales GF, Chaupis D. Higher androgen bioactivity is associated with excessive erythrocytosis and chronic mountain sickness in Andean Highlanders: a review. Andrologia 2014; 47:729-43. [PMID: 25277225 DOI: 10.1111/and.12359] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/12/2014] [Indexed: 01/12/2023] Open
Abstract
Populations living at high altitudes (HA), particularly in the Peruvian Central Andes, are characterised by presenting subjects with erythrocytosis and others with excessive erythrocytosis (EE)(Hb>21 g dl(-1) ). EE is associated with chronic mountain sickness (CMS), or lack of adaptation to HA. Testosterone is an erythropoietic hormone and it may play a role on EE at HA. The objective of the present review was to summarise findings on role of serum T levels on adaptation at HA and genes acting on this process. Men at HA without EE have higher androstenedione levels and low ratio androstenedione/testosterone than men with EE, suggesting low activity of 17beta-hydroxysteroid dehydrogenase (17beta-HSD), and this could be a mechanism of adaptation to HA. Higher conversion of dehydroepiandrosterone to testosterone in men with EE suggests nigher 17beta-HSD activity. Men with CMS at Peruvian Central Andes have two genes SENP1, and ANP32D with higher transcriptional response to hypoxia relative to those without. SUMO-specific protease 1 (SENP1) is an erythropoiesis regulator, which is essential for the stability and activity of hypoxia-inducible factor 1 (HIF-1α) under hypoxia. SENP1 reverses the hormone-augmented SUMOylation of androgen receptor (AR) increasing the transcription activity of AR.In conclusion, increased androgen activity is related with CMS.
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Affiliation(s)
- G F Gonzales
- Laboratory of Endocrinology and Reproduction, High Altitude Research Institute and Department of Biological and Physiological Sciences, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - D Chaupis
- Laboratory of Endocrinology and Reproduction, High Altitude Research Institute and Department of Biological and Physiological Sciences, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima, Peru
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Fournier S, Gulemetova R, Joseph V, Kinkead R. Testosterone potentiates the hypoxic ventilatory response of adult male rats subjected to neonatal stress. Exp Physiol 2014; 99:824-34. [DOI: 10.1113/expphysiol.2013.077073] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Sébastien Fournier
- Department of Pediatrics; Centre de Recherche du CHU de Québec; Université Laval; Québec QC Canada
| | - Roumiana Gulemetova
- Department of Pediatrics; Centre de Recherche du CHU de Québec; Université Laval; Québec QC Canada
| | - Vincent Joseph
- Department of Pediatrics; Centre de Recherche du CHU de Québec; Université Laval; Québec QC Canada
| | - Richard Kinkead
- Department of Pediatrics; Centre de Recherche du CHU de Québec; Université Laval; Québec QC Canada
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17
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Zhang GL, Dai DZ, Zhang C, Dai Y. Apocynin and raisanberine alleviate intermittent hypoxia induced abnormal StAR and 3β-HSD and low testosterone by suppressing endoplasmic reticulum stress and activated p66Shc in rat testes. Reprod Toxicol 2013; 36:60-70. [DOI: 10.1016/j.reprotox.2012.12.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 12/04/2012] [Accepted: 12/11/2012] [Indexed: 01/22/2023]
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18
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Gonzales GF. Serum testosterone levels and excessive erythrocytosis during the process of adaptation to high altitudes. Asian J Androl 2013; 15:368-74. [PMID: 23524530 DOI: 10.1038/aja.2012.170] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Populations living at high altitudes (HAs), particularly in the Peruvian Andes, are characterized by a mixture of subjects with erythrocytosis (16 g dl(-1)<haemoglobin (Hb)≤21 g dl(-1)) and others with excessive erythrocytosis (EE) (Hb>21 g dl(-1)). Elevated haemoglobin values (EE) are associated with chronic mountain sickness, a condition reflecting the lack of adaptation to HA. According to current data, native men from regions of HA are not adequately adapted to live at such altitudes if they have elevated serum testosterone levels. This seems to be due to an increased conversion of dehydroepiandrosterone sulphate (DHEAS) to testosterone. Men with erythrocytosis at HAs show higher serum androstenedione levels and a lower testosterone/androstenedione ratio than men with EE, suggesting reduced 17beta-hydroxysteroid dehydrogenase (17beta-HSD) activity. Lower 17beta-HSD activity via Δ4-steroid production in men with erythrocytosis at HA may protect against elevated serum testosterone levels, thus preventing EE. The higher conversion of DHEAS to testosterone in subjects with EE indicates increased 17beta-HSD activity via the Δ5-pathway. Currently, there are various situations in which people live (human biodiversity) with low or high haemoglobin levels at HA. Antiquity could be an important adaptation component for life at HA, and testosterone seems to participate in this process.
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Affiliation(s)
- Gustavo F Gonzales
- High Altitude Research Institute and Department of Biological and Physiological Sciences, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima 31, Peru.
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Nielsen GD, Larsen ST, Wolkoff P. Recent trend in risk assessment of formaldehyde exposures from indoor air. Arch Toxicol 2013; 87:73-98. [PMID: 23179754 PMCID: PMC3618407 DOI: 10.1007/s00204-012-0975-3] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 10/31/2012] [Indexed: 01/09/2023]
Abstract
Studies about formaldehyde (FA) published since the guideline of 0.1 mg/m(3) by the World Health Organization (WHO) in 2010 have been evaluated; critical effects were eye and nasal (portal-of-entry) irritation. Also, it was considered to prevent long-term effects, including all types of cancer. The majority of the recent toxicokinetic studies showed no exposure-dependent FA-DNA adducts outside the portal-of-entry area and FA-DNA adducts at distant sites were due to endogenously generated FA. The no-observed-adverse-effect level for sensory irritation was 0.5 ppm and recently reconfirmed in hypo- and hypersensitive individuals. Investigation of the relationship between FA exposure and asthma or other airway effects in children showed no convincing association. In rats, repeated exposures showed no point mutation in the p53 and K-Ras genes at ≤15 ppm neither increased cell proliferation, histopathological changes and changes in gene expression at 0.7 ppm. Repeated controlled exposures (0.5 ppm with peaks at 1 ppm) did not increase micronucleus formation in human buccal cells or nasal tissue (0.7 ppm) or in vivo genotoxicity in peripheral blood lymphocytes (0.7 ppm), but higher occupational exposures were associated with genotoxicity in buccal cells and cultivated peripheral blood lymphocytes. It is still valid that exposures not inducing nasal squamous cell carcinoma in rats will not induce nasopharyngeal cancer or lymphohematopoietic malignancies in humans. Reproductive and developmental toxicity are not considered relevant in the absence of sensory irritation. In conclusion, the WHO guideline has been strengthened.
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Affiliation(s)
- Gunnar Damgård Nielsen
- National Research Centre for the Working Environment, Lersø Parkallé 105, 2100 Copenhagen, Denmark.
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20
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Guven A, Ickin M, Uzun O, Bakar C, Gulec Balbay E, Balbay O. Erdosteine protects rat testis tissue from hypoxic injury by reducing apoptotic cell death. Andrologia 2012; 46:50-58. [DOI: 10.1111/and.12041] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/18/2012] [Indexed: 11/28/2022] Open
Affiliation(s)
- A. Guven
- Department of Histology and Embryology; School of Medicine; Canakkale Onsekiz Mart University; Canakkale Turkey
| | - M. Ickin
- Department of Histology and Embryology; School of Medicine; Canakkale Onsekiz Mart University; Canakkale Turkey
| | - O. Uzun
- Department of Pharmacology; Faculty of Medicine; University of Abant Izzet Baysal; Bolu Turkey
| | - C. Bakar
- Department of Public Health; Faculty of Medicine; Canakkale Onsekiz Mart University; Canakkale Turkey
| | - E. Gulec Balbay
- Department of Pulmonary Medicine, Faculty of Medicine; University of Duzce; Duzce Turkey
| | - O. Balbay
- Department of Pulmonary Medicine; Faculty of Medicine; University of Duzce; Duzce Turkey
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21
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The hypoxic testicle: physiology and pathophysiology. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2012; 2012:929285. [PMID: 23056665 PMCID: PMC3465913 DOI: 10.1155/2012/929285] [Citation(s) in RCA: 135] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2012] [Revised: 08/07/2012] [Accepted: 08/09/2012] [Indexed: 12/15/2022]
Abstract
Mammalian spermatogenesis is a complex biological process occurring in the seminiferous tubules in the testis. This process represents a delicate balance between cell proliferation, differentiation, and apoptosis. In most mammals, the testicles are kept in the scrotum 2 to 7°C below body core temperature, and the spermatogenic process proceeds with a blood and oxygen supply that is fairly independent of changes in other vascular beds in the body. Despite this apparently well-controlled local environment, pathologies such as varicocele or testicular torsion and environmental exposure to low oxygen (hypoxia) can result in changes in blood flow, nutrients, and oxygen supply along with an increased local temperature that may induce adverse effects on Leydig cell function and spermatogenesis. These conditions may lead to male subfertility or infertility. Our literature analyses and our own results suggest that conditions such as germ cell apoptosis and DNA damage are common features in hypoxia and varicocele and testicular torsion. Furthermore, oxidative damage seems to be present in these conditions during the initiation stages of germ cell damage and apoptosis. Other mechanisms like membrane-bound metalloproteinases and phospholipase A2 activation could also be part of the pathophysiological consequences of testicular hypoxia.
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Abstract
Nicotinic acid adenine dinucleotide phosphate (NAADP) is a potent intracellular Ca(2+)-mobilising messenger. Much evidence indicates that NAADP targets novel Ca(2+) channels located on acidic organelles but the identity of these channels has remained obscure. Recent studies have converged on a novel class of ion channels, the two-pore channels (TPCs) as likely molecular targets. The location of these channels to the endo-lysosomal system and their sensitivity to NAADP match closely those of endogenous NAADP-sensitive channels in both mammalian cells and sea urchin eggs, where the effects of NAADP were discovered. Moreover, the functional coupling of TPCs to archetypal endoplasmic reticulum (ER) Ca(2+) channels is also matched. Biophysical analysis in conjunction with site-directed mutagenesis demonstrates that TPCs are pore-forming subunits of NAADP-gated ion channels. TPCs have a unique two-repeat structure, are regulated by N-linked glycosylation and harbor an endo-lysosomal targeting motif in their N-terminus. Knockdown studies have shown TPCs to regulate smooth muscle contraction, differentiation and endothelial cell activation consistent with previous studies implicating NAADP in these processes. Thus multiple lines of evidence indicate that TPCs are the likely long sought targets for NAADP.
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Affiliation(s)
- Robert Hooper
- Department of Cell and Developmental Biology, University College London, UK.
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23
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Andersen ML, Alvarenga TF, Mazaro-Costa R, Hachul HC, Tufik S. The association of testosterone, sleep, and sexual function in men and women. Brain Res 2011; 1416:80-104. [PMID: 21890115 DOI: 10.1016/j.brainres.2011.07.060] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 07/29/2011] [Accepted: 07/30/2011] [Indexed: 11/29/2022]
Abstract
Testosterone has been the focus of several investigations and review studies in males, but few have addressed its effects on sleep and sexual function, despite evidence of its androgenic effects on circadian activity in both sexes. Studies have been conducted to understand how sleeping increases (and how waking decreases) testosterone levels and how this rhythm can be related to sexual function. This review addresses the inter-relationships among testosterone, sexual function and sleep, including sleep-disordered breathing in both sexes, specifically its effects related to sleep deprivation. In addition, hormonal changes in testosterone that occur in the gonadal and adrenal axis with obstructive sleep apnea and other conditions of chronic sleep deprivation, and which consequently affect sexual life, have also been explored. Nevertheless, hormone-associated sleep disruptions occur across a lifetime, particularly in women. The association between endogenous testosterone and sex, sleep and sleep disturbances is discussed, including the results of clinical trials as well as animal model studies. Evidence of possible pathophysiological mechanisms underlying this relationship is also described. Unraveling the associations of sex steroid hormone concentrations with sleep and sexual function may have clinical implications, as sleep loss reduces testosterone levels in males, and low sex steroid hormone concentrations have been associated with sexual dysfunction.
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Affiliation(s)
- Monica L Andersen
- Departmento de Psicobiologia, Universidade Federal de São Paulo, Brazil.
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NAADP as an intracellular messenger regulating lysosomal calcium-release channels. Biochem Soc Trans 2011; 38:1424-31. [PMID: 21118101 DOI: 10.1042/bst0381424] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Recent studies into the mechanisms of action of the Ca(2+)-mobilizing messenger NAADP (nicotinic acid-adenine dinucleotide phosphate) have demonstrated that a novel family of intracellular Ca(2+)-release channels termed TPCs (two-pore channels) are components of the NAADP receptor. TPCs appear to be exclusively localized to the endolysosomal system. These findings confirm previous pharmacological and biochemical studies suggesting that NAADP targets acidic Ca(2+) stores rather than the endoplasmic reticulum, the major site of action of the other two principal Ca(2+)-mobilizing messengers, InsP(3) and cADPR (cADP-ribose). Studies of the messenger roles of NAADP and the function of TPCs highlight the novel role of lysosomes and other organelles of the endocytic pathway as messenger-regulated Ca(2+) stores which also affects the regulation of the endolysosomal system.
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Gonzales GF, Tapia V, Gasco M, Gonzales-Castañeda C. Serum testosterone levels and score of chronic mountain sickness in Peruvian men natives at 4340 m. Andrologia 2011; 43:189-95. [DOI: 10.1111/j.1439-0272.2010.01046.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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