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Nigro E, D’Arco D, Moscatelli F, Pisani A, Amicone M, Riccio E, Capuano I, Argentino F, Monda M, Messina G, Daniele A, Polito R. Increased Expression of Orexin-A in Patients Affected by Polycystic Kidney Disease. Int J Mol Sci 2024; 25:6243. [PMID: 38892431 PMCID: PMC11172798 DOI: 10.3390/ijms25116243] [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: 04/08/2024] [Revised: 05/02/2024] [Accepted: 06/04/2024] [Indexed: 06/21/2024] Open
Abstract
Orexin-A is a neuropeptide product of the lateral hypothalamus that acts on two receptors, OX1R and OX2R. The orexinergic system is involved in feeding, sleep, and pressure regulation. Recently, orexin-A levels have been found to be negatively correlated with renal function. Here, we analyzed orexin-A levels as well as the incidence of SNPs in the hypocretin neuropeptide precursor (HCRT) and its receptors, HCRTR1 and HCRTR2, in 64 patients affected by autosomal dominant polycystic kidney disease (ADPKD) bearing truncating mutations in the PKD1 or PKD2 genes. Twenty-four healthy volunteers constituted the control group. Serum orexin-A was assessed by ELISA, while the SNPs were investigated through Sanger sequencing. Correlations with the main clinical features of PKD patients were assessed. PKD patients showed impaired renal function (mean eGFR 67.8 ± 34.53) and a statistically higher systolic blood pressure compared with the control group (p < 0.001). Additionally, orexin-A levels in PKD patients were statistically higher than those in healthy controls (477.07 ± 69.42 pg/mL vs. 321.49 ± 78.01 pg/mL; p < 0.001). Furthermore, orexin-A inversely correlated with blood pressure (p = 0.0085), while a direct correlation with eGFR in PKD patients was found. None of the analyzed SNPs showed any association with orexin-A levels in PKD. In conclusion, our data highlights the emerging role of orexin-A in renal physiology and its potential relevance to PKD. Further research is essential to elucidate the intricate mechanisms underlying orexin-A signaling in renal function and its therapeutic implications for PKD and associated cardiovascular complications.
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Affiliation(s)
- Ersilia Nigro
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche, Farmaceutiche, Università della Campania “Luigi Vanvitelli”, Via Vivaldi 43, 81100 Caserta, Italy;
- CEINGE-Biotecnologie Avanzate Scarl “Franco Salvatore”, Via G. Salvatore 486, 80145 Napoli, Italy; (D.D.); (F.A.)
| | - Daniela D’Arco
- CEINGE-Biotecnologie Avanzate Scarl “Franco Salvatore”, Via G. Salvatore 486, 80145 Napoli, Italy; (D.D.); (F.A.)
| | - Fiorenzo Moscatelli
- Department of Human Sciences, Telematic University Pegaso, 80100 Naples, Italy;
| | - Antonio Pisani
- Unità di Nefrologia, Dipartimento di Sanità Pubblica, Università di Napoli “Federico II”, Via Pansini 5, 80131 Napoli, Italy; (A.P.); (M.A.); (E.R.); (I.C.)
| | - Maria Amicone
- Unità di Nefrologia, Dipartimento di Sanità Pubblica, Università di Napoli “Federico II”, Via Pansini 5, 80131 Napoli, Italy; (A.P.); (M.A.); (E.R.); (I.C.)
| | - Eleonora Riccio
- Unità di Nefrologia, Dipartimento di Sanità Pubblica, Università di Napoli “Federico II”, Via Pansini 5, 80131 Napoli, Italy; (A.P.); (M.A.); (E.R.); (I.C.)
| | - Ivana Capuano
- Unità di Nefrologia, Dipartimento di Sanità Pubblica, Università di Napoli “Federico II”, Via Pansini 5, 80131 Napoli, Italy; (A.P.); (M.A.); (E.R.); (I.C.)
| | - Francesca Argentino
- CEINGE-Biotecnologie Avanzate Scarl “Franco Salvatore”, Via G. Salvatore 486, 80145 Napoli, Italy; (D.D.); (F.A.)
| | - Marcellino Monda
- Sezione di Fisiologia Umana e Unità di Dietetica e Medicina dello Sport, Dipartimento di Medicina Sperimentale, Università degli Studi della Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (M.M.); (G.M.)
| | - Giovanni Messina
- Sezione di Fisiologia Umana e Unità di Dietetica e Medicina dello Sport, Dipartimento di Medicina Sperimentale, Università degli Studi della Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (M.M.); (G.M.)
| | - Aurora Daniele
- CEINGE-Biotecnologie Avanzate Scarl “Franco Salvatore”, Via G. Salvatore 486, 80145 Napoli, Italy; (D.D.); (F.A.)
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi “Federico II”, Via Pansini 5, 80131 Napoli, Italy
| | - Rita Polito
- Department of Clinical and Experimental Medicine, University of Foggia, 71122 Foggia, Italy;
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Narai E, Yoshimura Y, Honaga T, Mizoguchi H, Yamanaka A, Hiyama TY, Watanabe T, Koba S. Orexinergic neurons contribute to autonomic cardiovascular regulation for locomotor exercise. J Physiol 2024. [PMID: 38380995 DOI: 10.1113/jp285791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 01/26/2024] [Indexed: 02/22/2024] Open
Abstract
While the hypothalamic orexinergic nervous system is established as having a pivotal role in the long-term regulation of various organismic functions, including wakefulness, metabolism and hypertensive states, whether this system contributes to the rapid autonomic cardiovascular regulation during physical activity remains elusive. This study aimed to elucidate the role of the orexinergic nervous system in transmitting volitional motor signals, i.e. central command, to drive somatomotor and sympathetic cardiovascular responses. We first found that this system is activated by voluntary locomotor exercise as evidenced by an increased expression of Fos, a marker of neural activation, in the orexinergic neurons of Sprague-Dawley rats engaged in spontaneous wheel running. Next, using transgenic Orexin-Cre rats for optogenetic manipulation of orexinergic neurons, we found that optogenetic excitation of orexinergic neurons caused sympathoexcitation on a subsecond timescale under anaesthesia. In freely moving conscious rats, this excitatory stimulation rapidly elicited exploration-like behaviours, predominantly locomotor activity, along with pressor and tachycardiac responses. Meanwhile, optogenetic inhibition of orexinergic neurons during spontaneous wheel running immediately suppressed locomotor activities and blood pressure elevation without affecting basal cardiovascular homeostasis. Taken together, these findings demonstrate the essential role of the orexinergic nervous system in the central circuitry that transmits central command signals for locomotor exercise. This study not only offers insights into the brain circuit mechanisms precisely regulating autonomic cardiovascular systems during voluntary exercise but also likely contributes to our understanding of brain mechanisms underlying abnormal cardiovascular adjustments to exercise in pathological conditions, such as hypertension. KEY POINTS: The hypothalamic orexinergic nervous system plays various roles in the long-term regulation of autonomic and endocrine functions, as well as motivated behaviours. We present a novel, rapid role of the orexinergic nervous system, revealing its significance as a crucial substrate in the brain circuit mechanisms that coordinate somatomotor and autonomic cardiovascular controls for locomotor exercise. Our data demonstrate that orexinergic neurons relay volitional motor signals, playing a necessary and sufficient role in the autonomic cardiovascular regulation required for locomotor exercise in rats. The findings contribute to our understanding of how the brain precisely regulates autonomic cardiovascular systems during voluntary exercise, providing insights into the central neural mechanisms that enhance physical performance moment-by-moment during exercise.
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Affiliation(s)
- Emi Narai
- Division of Integrative Physiology, Tottori University Faculty of Medicine, Yonago, Japan
| | - Yuki Yoshimura
- Division of Integrative Physiology, Tottori University Faculty of Medicine, Yonago, Japan
| | - Takaho Honaga
- Division of Integrative Physiology, Tottori University Faculty of Medicine, Yonago, Japan
| | - Hiroyuki Mizoguchi
- Department of Neuropsychopharmacology and Hospital Pharmacy, Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Akihiro Yamanaka
- Chinese Institute for Brain Research, Beijing (CIBR), Beijing, China
| | - Takeshi Y Hiyama
- Division of Integrative Physiology, Tottori University Faculty of Medicine, Yonago, Japan
| | - Tatsuo Watanabe
- Division of Integrative Physiology, Tottori University Faculty of Medicine, Yonago, Japan
| | - Satoshi Koba
- Division of Integrative Physiology, Tottori University Faculty of Medicine, Yonago, Japan
- Division of Veterinary Physiology, Tottori University Faculty of Agriculture, Tottori, Japan
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Bai F, Huang L, Deng J, Long Z, Hao X, Chen P, Wu G, Wen H, Deng Q, Bao X, Huang J, Yang M, Li D, Ren Y, Zhang M, Xiong Y, Li H. Prelimbic area to lateral hypothalamus circuit drives social aggression. iScience 2023; 26:107718. [PMID: 37810230 PMCID: PMC10551839 DOI: 10.1016/j.isci.2023.107718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 06/06/2023] [Accepted: 08/22/2023] [Indexed: 10/10/2023] Open
Abstract
Controlling aggression is a vital skill in social species such as rodents and humans and has been associated with the medial prefrontal cortex (mPFC). In this study, we showed that during aggressive behavior, the activity of GABAergic neurons in the prelimbic area (PL) of the mPFC was significantly suppressed. Specific activation of GABAergic PL neurons significantly curbed male-to-male aggression and inhibited conditioned place preference (CPP) for aggression-paired contexts, whereas specific inhibition of GABAergic PL neurons brought about the opposite effect. Moreover, GABAergic projections from PL neurons to the lateral hypothalamus (LH) orexinergic neurons mediated aggressive behavior. Finally, directly modulated LH-orexinergic neurons influence aggressive behavior. These results suggest that GABAergic PL-orexinergic LH projection is an important control circuit for intermale aggressive behavior, both of which could be targets for curbing aggression.
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Affiliation(s)
- Fuhai Bai
- Department of Anesthesiology, Xinqiao Hospital, Army Medical University, Chongqing 400037, China
| | - Lu Huang
- Department of Anesthesiology, Xinqiao Hospital, Army Medical University, Chongqing 400037, China
| | - Jiao Deng
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Air Force Medical University, Xi’an, Shaanxi 710032, China
| | - Zonghong Long
- Department of Anesthesiology, Xinqiao Hospital, Army Medical University, Chongqing 400037, China
| | - Xianglin Hao
- Department of Pathology, Xinqiao Hospital, Army Medical University, Chongqing 400037, P.R. China
| | - Penghui Chen
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Army Medical University, Chongqing 400038, China
| | - Guangyan Wu
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
| | - Huizhong Wen
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Army Medical University, Chongqing 400038, China
| | - Qiangting Deng
- Editorial Office of Journal of Army Medical University, Chongqing 400038, China
| | - Xiaohang Bao
- Department of Anesthesiology, Xinqiao Hospital, Army Medical University, Chongqing 400037, China
| | - Jing Huang
- Department of Anesthesiology, Xinqiao Hospital, Army Medical University, Chongqing 400037, China
| | - Ming Yang
- Department of Anesthesiology, Xinqiao Hospital, Army Medical University, Chongqing 400037, China
| | - Defeng Li
- Clinical Medical Research Center, Xinqiao Hospital, Army Medical University, Chongqing 400037, China
| | - Yukun Ren
- Department of Anesthesiology, Xinqiao Hospital, Army Medical University, Chongqing 400037, China
| | - Min Zhang
- Department of Anesthesiology, Xinqiao Hospital, Army Medical University, Chongqing 400037, China
| | - Ying Xiong
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Army Medical University, Chongqing 400038, China
| | - Hong Li
- Department of Anesthesiology, Xinqiao Hospital, Army Medical University, Chongqing 400037, China
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Lu J, Qin C, Wang C, Sun J, Mao H, Wei J, Shen X, Chen Y, Liu S, Qu X. Lateral hypothalamic orexin neurons mediate electroacupuncture-induced anxiolytic effects in a rat model of post-traumatic stress disorder. Brain Res Bull 2023; 201:110712. [PMID: 37481143 DOI: 10.1016/j.brainresbull.2023.110712] [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: 05/06/2023] [Revised: 07/13/2023] [Accepted: 07/18/2023] [Indexed: 07/24/2023]
Abstract
The lateral hypothalamus' orexinergic system has been associated with anxiety-related behaviors, and electroacupuncture (EA) modifies orexin neurons to control the anti-anxiety process. However, in a rat model of post-traumatic stress disorder (PTSD), the important role of LH orexin neurons (OXNs) in the anxiolytic effects induced by EA has not been explored. In this study, rats underwent modified single prolonged stress (MSPS) for seven days before developing EA. The rats were then subjected to elevated plus maze (EPM) and open field (OFT) tests, and western blot and c-Fos/orexin double labeling investigations were carried out to determine the functional activation of LH orexinergic neurons. Compared to MSPS model rats, it has been demonstrated that EA stimulation enhanced the amount of time spent in the central zone (TSCZ) in OFT and the amount of time spent in the open arm (TSOA) in EPM in MSPS model rats (P < 0.01). After behavioral testing, MSPS model rats had decreased activated c-Fos positive OXNs. Still, EA in SPS rats increased that number and elevated orexin type 1 receptors (OXR1) protein expression in the LH. Furthermore, after administering SB334867 (an OXR1 antagonist) to MSPS model rats, the effects of EA therapy on anxiety-like behaviors (ALBs) were significantly diminished. Additionally, when low-dose orexin-A (LORXA) was administered intracerebroventricularly together with EA stimulation in MSPS rats, the anxiolytic effects of the stimulation were substantially enhanced (P < 0.05). The results of this study reveal the mechanisms by which acupuncture may reduce PTSD and advance our understanding of the function of LH orexin signaling in EA's anxiolytic effects.
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Affiliation(s)
- Jiaqi Lu
- School of Acupuncture-Moxibustion and Tuina, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Chuan Qin
- School of Acupuncture-Moxibustion and Tuina, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Can Wang
- School of Acupuncture-Moxibustion and Tuina, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jia Sun
- School of Acupuncture-Moxibustion and Tuina, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Huijuan Mao
- School of Acupuncture-Moxibustion and Tuina, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jianzi Wei
- School of Acupuncture-Moxibustion and Tuina, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xueyong Shen
- School of Acupuncture-Moxibustion and Tuina, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yang Chen
- College of Traditional Chinese Medicine, Xinjiang Medical University, Urumqi, China.
| | - Sheng Liu
- School of Acupuncture-Moxibustion and Tuina, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
| | - Xiaoyi Qu
- School of Acupuncture-Moxibustion and Tuina, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
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Soejima Y, Iwata N, Nishioka R, Honda M, Nakano Y, Yamamoto K, Suyama A, Otsuka F. Interaction of Orexin and Bone Morphogenetic Proteins in Steroidogenesis by Human Adrenocortical Cells. Int J Mol Sci 2023; 24:12559. [PMID: 37628739 PMCID: PMC10454954 DOI: 10.3390/ijms241612559] [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: 06/16/2023] [Revised: 07/31/2023] [Accepted: 08/04/2023] [Indexed: 08/27/2023] Open
Abstract
Orexins are neuropeptides that play important roles in sleep-wake regulation and food intake in the central nervous system, but their receptors are also expressed in peripheral tissues, including the endocrine system. In the present study, we investigated the functions of orexin in adrenal steroidogenesis using human adrenocortical H295R cells by focusing on its interaction with adrenocortical bone morphogenetic proteins (BMPs) that induce adrenocortical steroidogenesis. Treatment with orexin A increased the mRNA levels of steroidogenic enzymes including StAR, CYP11B2, CYP17, and HSD3B1, and these effects of orexin A were further enhanced in the presence of forskolin. Interestingly, orexin A treatment suppressed the BMP-receptor signaling detected by Smad1/5/9 phosphorylation and Id-1 expression through upregulation of inhibitory Smad7. Orexin A also suppressed endogenous BMP-6 expression but increased the expression of the type-II receptor of ActRII in H295R cells. Moreover, treatment with BMP-6 downregulated the mRNA level of OX1R, but not that of OX2R, expressed in H295R cells. In conclusion, the results indicate that both orexin and BMP-6 accelerate adrenocortical steroidogenesis in human adrenocortical cells; both pathways mutually inhibit each other, thereby leading to a fine-tuning of adrenocortical steroidogenesis.
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Affiliation(s)
| | | | | | | | | | | | | | - Fumio Otsuka
- Department of General Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kitaku, Okayama 700-8558, Japan (A.S.)
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He J, Fang J, Wang Y, Ge C, Liu S, Jiang Y. Discovery of Small-Molecule Antagonists of Orexin 1/2 Receptors from Traditional Chinese Medicinal Plants with a Hypnotic Effect. Pharmaceuticals (Basel) 2023; 16:ph16040542. [PMID: 37111298 PMCID: PMC10146837 DOI: 10.3390/ph16040542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/25/2023] [Accepted: 03/31/2023] [Indexed: 04/29/2023] Open
Abstract
Insomnia is an important public health problem. The currently available treatments for insomnia can cause some adverse effects. Orexin receptors 1 (OX1R) and 2 (OX2R) are burgeoning targets for insomnia treatment. It is an effective approach to screening OX1R and OX2R antagonists from traditional Chinese medicine, which contains abundant and diverse chemical components. This study established an in-home ligand library of small-molecule compounds from medicinal plants with a definite hypnotic effect, as described in the Chinese Pharmacopoeia. Molecular docking was applied to virtually screen potential orexin receptor antagonists using molecular operating environment software, and surface plasmon resonance (SPR) technology was used to detect the binding affinity between potential active compounds and orexin receptors. Finally, the results of virtual screening and SPR analysis were verified through in vitro assays. We successfully screened one potential lead compound (neferine) as an orexin receptor antagonist from the in-home ligand library, which contained more than 1000 compounds. The screened compound was validated as a potential agent for insomnia treatment through comprehensive biological assays. This research enabled the discovery of a potential small-molecule antagonist of orexin receptors for the treatment of insomnia, providing a novel screening approach for the detection of potential candidate compounds for corresponding targets.
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Affiliation(s)
- Jia He
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute for Rational and Safe Medication Practices, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Jing Fang
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute for Rational and Safe Medication Practices, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Yuxin Wang
- College of Pharmacy, Dali University, Dali 671000, China
| | - Chengyu Ge
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute for Rational and Safe Medication Practices, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Shao Liu
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute for Rational and Safe Medication Practices, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Yueping Jiang
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute for Rational and Safe Medication Practices, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
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Muacevic A, Adler JR. Physiological Role of Orexin/Hypocretin in the Human Body in Motivated Behavior: A Comprehensive Review. Cureus 2023; 15:e34009. [PMID: 36814741 PMCID: PMC9939734 DOI: 10.7759/cureus.34009] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 01/20/2023] [Indexed: 01/22/2023] Open
Abstract
Neurohormones are neurosecretory materials released by neurosecretory cells that serve both as neuromodulators in the brain and spinal cord and as circulating regulatory hormones. They serve a wide range of functions, including homeostasis, development, and modulation of neuronal and muscle activity. In the hypothalamus, neurohormones called hypocretins are created that were discovered in the late nineties. Orexin receptors (OXRs) have been shown to enhance synaptic signaling in the central nervous system at the cellular level. The orexins improve stimulated neural activity in the hippocampus, which, in turn, aids with spatial memory, learning, and mood. They present themselves as mediators for the hypothalamic functions. They have been shown to regulate sleep-wake cycles, arousal mechanisms, addiction, sympathetic nerve activity (SNA), blood pressure, and thermogenesis. Its role in storing brown adipose tissue has implications for thermal homeostasis. The significant role of orexins is seen in tumorigenesis when orexin A (OrxA) and orexin B (OrxB) induce apoptosis in fast-growing tumor cells. Orexin-null subjects show clinical narcolepsy, indicating that orexins were responsible for keeping them awake. Orexin microinjections in mice brains stimulated increased physical activity, thus possibly countering diet-induced obesity. Physical activity significantly increased plasma orexin-A levels, which facilitated the process of energy homeostasis. The amount of adrenocorticotropic hormone (ACTH) increases in stress conditions, which further facilitates the release of the stress hormone cortisol. No increase in the ACTH hormone is seen in stressed mice administered with orexin receptor 2 (OX2R) antagonists thus showing orexin's role in stress reaction. As a result of linking hypocretin/orexin to various physiological procedures, increased research into the medicinal potential of drugs targeting these receptors is emerging. We summed up in this review the recent advances in our understanding of how orexin and its receptor system play an essential role in clinical and pathological functions. This research summarizes a new area for research in human medicine, providing the possibility of controlling a vast array of physiological functions through intra-cerebroventricular injections of a single neuropeptide.
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Bigalke JA, Shan Z, Carter JR. Orexin, Sleep, Sympathetic Neural Activity, and Cardiovascular Function. Hypertension 2022; 79:2643-2655. [PMID: 36148653 PMCID: PMC9649879 DOI: 10.1161/hypertensionaha.122.19796] [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] [Indexed: 11/04/2022]
Abstract
Inadequate sleep duration and quality are associated with reduced cardiovascular health and increased mortality. Experimental evidence points to the sympathetic nervous system as a key mediator in the observed relationship between poor sleep and cardiovascular dysfunction. However, brain mechanisms underpinning the impaired sympathetic function associated with poor sleep remain unclear. Recent evidence suggests the central orexin system, particularly orexins A and B and their receptors, have a key regulatory role for sleep in animal and human models. While orexin system activity has been observed to significantly impact sympathetic regulation in animals, the extension of these findings to humans has been difficult due to an inability to directly assess orexin system activity in humans. However, direct measures of sympathetic activity in populations with narcolepsy and chronic insomnia, 2 sleep disorders associated with deficient and excessive orexin neural activity, have allowed indirect assessment of the relationships between orexin, sleep, and sympathetic regulation. Further, the recent pharmaceutical development of dual orexin receptor antagonists for use in clinical insomnia populations offers an unprecedented opportunity to examine the mechanistic role of orexin in sleep and cardiovascular health in humans. The current review assesses the role of orexin in both sleep and sympathetic regulation from a translational perspective, spanning animal and human studies. The review concludes with future research directions necessary to fully elucidate the mechanistic role for orexin in sleep and sympathetic regulation in humans.
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Affiliation(s)
- Jeremy A. Bigalke
- Department of Health and Human Development, Montana State University, Bozeman, Montana
- Department of Psychology, Montana State University, Bozeman, Montana
| | - Zhiying Shan
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan
| | - Jason R. Carter
- Department of Health and Human Development, Montana State University, Bozeman, Montana
- Department of Psychology, Montana State University, Bozeman, Montana
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Meusel M, Voß J, Krapalis A, Machleidt F, Vonthein R, Hallschmid M, Sayk F. Intranasal orexin A modulates sympathetic vascular tone - a pilot study in healthy male humans. J Neurophysiol 2022; 127:548-558. [PMID: 35044844 DOI: 10.1152/jn.00452.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION Previous research suggests that the neuropeptide orexin A contributes to sympathetic blood pressure (BP) control inasmuch as hypothalamic injection of orexin A increases sympathetic vasomotor tone and arterial BP in rodents. In humans with narcolepsy, a disorder associated with loss of orexin-producing neurons, vasoconstrictive muscle sympathetic nerve activity (MSNA) is reduced. Since intranasally administered oligopeptides like orexin are known to modulate brain function, we investigated the effect of intranasal orexin A on vascular sympathetic baroreflex function in healthy humans. METHODS In a balanced, double-blind cross-over study, orexin A (500 nmol) and placebo, respectively, were intranasally administered to 10 lean healthy males (age, 25.8±4.6 years). MSNA was assessed microneurographically before and 30-45 minutes after either substance administration. Additionally, baroreflex was challenged via graded infusions of vasoactive drugs before and after substance administration. Baroreflex function was defined as the correlation of BP with MSNA and heart rate. RESULTS Intranasal orexin A compared to placebo induced a significant increase in resting MSNA from prior to post administration (Δ-burst rate, orexin A vs. placebo: +5.8±0.8 vs. +2.1±0.6; p=0.007; total activity (169±11.5% vs. 115±5.0%; p=0.002). BP, heart rate and sympathovagal balance to the heart, as represented by HRV, as well as baroreflex sensitivity during the vasoactive challenge were not altered. CONCLUSION Intranasally administered orexin A acutely induced vasoconstrictory sympathoactivation in healthy male humans. This result suggests that orexin A mediates upward resetting of the vascular baroreflex setpoint at centers superordinate to the mere baroreflex-feedback-loop.
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Affiliation(s)
- Moritz Meusel
- Department of Internal Medicine II, University Heart Center Lübeck, University Hospital Schleswig-Holstein, Lübeck, Germany
| | - Jacqueline Voß
- Dept. of Internal Medicine I, University Hospital of Schleswig-Holstein, Luebeck, Germany
| | - Alexander Krapalis
- Dept. of Internal Medicine I, University Hospital of Schleswig-Holstein, Luebeck, Germany
| | - Felix Machleidt
- Department of Infectious Diseases and Respiratory Medicine, Charité, Universitätsmedizin Berlin, Berlin, Germany
| | - Reinhard Vonthein
- Institute for Medical Biometry and Statistics, University of Lübeck, Lübeck, Germany
| | - Manfred Hallschmid
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany.,Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University Tübingen, Tübingen, Germany
| | - Friedhelm Sayk
- Dept. of Internal Medicine I, University Hospital of Schleswig-Holstein, Luebeck, Germany
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Abstract
Brain PCO2 is sensed primarily via changes in [H+]. Small pH changes are detected in the medulla oblongata and trigger breathing adjustments that help maintain arterial PCO2 constant. Larger perturbations of brain CO2/H+, possibly also sensed elsewhere in the CNS, elicit arousal, dyspnea, and stress, and cause additional breathing modifications. The retrotrapezoid nucleus (RTN), a rostral medullary cluster of glutamatergic neurons identified by coexpression of Phoxb and Nmb transcripts, is the lynchpin of the central respiratory chemoreflex. RTN regulates breathing frequency, inspiratory amplitude, and active expiration. It is exquisitely responsive to acidosis in vivo and maintains breathing autorhythmicity during quiet waking, slow-wave sleep, and anesthesia. The RTN response to [H+] is partly an intrinsic neuronal property mediated by proton sensors TASK-2 and GPR4 and partly a paracrine effect mediated by astrocytes and the vasculature. The RTN also receives myriad excitatory or inhibitory synaptic inputs including from [H+]-responsive neurons (e.g., serotonergic). RTN is silenced by moderate hypoxia. RTN inactivity (periodic or sustained) contributes to periodic breathing and, likely, to central sleep apnea. RTN development relies on transcription factors Egr2, Phox2b, Lbx1, and Atoh1. PHOX2B mutations cause congenital central hypoventilation syndrome; they impair RTN development and consequently the central respiratory chemoreflex.
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Affiliation(s)
- Patrice G Guyenet
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States.
| | - Douglas A Bayliss
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States
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11
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Li S, Zhang R, Hu S, Lai J. Plasma Orexin-A Levels in Patients With Schizophrenia: A Systematic Review and Meta-Analysis. Front Psychiatry 2022; 13:879414. [PMID: 35693955 PMCID: PMC9174516 DOI: 10.3389/fpsyt.2022.879414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 04/29/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Orexins are polypeptides regulating appetite, sleep-wake cycle, and cognition functions, which are commonly disrupted in patients with schizophrenia. Patients with schizophrenia show a decreased connectivity between the prefrontal cortex and midline-anterior thalamus, and orexin can directly activate the axon terminal of cells within the prefrontal cortex and selectively depolarize neurons in the midline intralaminar nuclei of the thalamus. To address the relationship between orexin and schizophrenia, this study performed a meta-analysis on the alteration of plasma orexin-A levels in patients with schizophrenia. METHOD We searched eligible studies in PubMed, Embase, Cochrane, and China National Knowledge Infrastructure (CNKI) from 1998 to September 3, 2021. A total of 8 case-control studies were included in the meta-analyses, providing data on 597 patients with schizophrenia and 370 healthy controls. The Stata version 16.0 software was used to calculate the Hedges's adjusted g with 95% confidence intervals (CI). RESULTS The plasma orexin-A levels were not altered in subjects with schizophrenia (n = 597) when compared to healthy controls (n = 370). Subgroup analyses of gender (male and female vs. only male), country (China vs. other countries), medication (medication vs. non-medication), and the measurement of plasma orexin-A (Enzyme-linked immunosorbent assay vs. radioimmunoassay) revealed heterogeneity ranging from 30.15 to 98.15%, but none showed a significant alteration of plasma orexin-A levels in patients with schizophrenia. Heterogeneity was lower in the other countries and radioimmunoassay subgroup, while other subgroups remained to be highly heterogeneous. No significant evidence of publication bias was found either in Begg's test or the Egger's test. CONCLUSION The present meta-analysis indicated that patients with schizophrenia did not show abnormal plasma levels of orexin-A. SYSTEMATIC REVIEW REGISTRATION https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021283455, identifier: CRD42021283455.
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Affiliation(s)
- Shaoli Li
- Department of Psychiatry, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Medical Oncology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Ruili Zhang
- Department of Psychiatry, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Shaohua Hu
- Department of Psychiatry, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,The Key Laboratory of Mental Disorders' Management in Zhejiang Province, Hangzhou, China.,Brain Research Institute of Zhejiang University, Hangzhou, China.,Zhejiang Engineering Center for Mathematical Mental Health, Hangzhou, China.,Department of Neurobiology, NHC and CAMS Key Laboratory of Medical Neurobiology, School of Brain Science and Brian Medicine, and MOE Frontier Science Center for Brain Science and Brain-Machine Integration, Zhejiang University School of Medicine, Hangzhou, China
| | - Jianbo Lai
- Department of Psychiatry, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,The Key Laboratory of Mental Disorders' Management in Zhejiang Province, Hangzhou, China.,Brain Research Institute of Zhejiang University, Hangzhou, China.,Zhejiang Engineering Center for Mathematical Mental Health, Hangzhou, China.,Department of Neurobiology, NHC and CAMS Key Laboratory of Medical Neurobiology, School of Brain Science and Brian Medicine, and MOE Frontier Science Center for Brain Science and Brain-Machine Integration, Zhejiang University School of Medicine, Hangzhou, China
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12
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Pittman QJ. Vasopressin and central control of the cardiovascular system: A 40-year retrospective. J Neuroendocrinol 2021; 33:e13011. [PMID: 34235812 DOI: 10.1111/jne.13011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 06/25/2021] [Indexed: 01/24/2023]
Abstract
In the 40 years since vasopressin (AVP) was reported to have a central action with respect to raising blood pressure, the finding has been repeatedly replicated using a variety of complimentary approaches. The role of AVP as a central neurotransmitter involved in control of the cardiovascular system is now textbook material. However, it is evident that brain AVP plays, at best, a minor role in regulation of normal blood pressure. However, it appears to be an important player in a several cardiovascular-associated pathologies, ranging from hypertension to neural changes associated with heart failure. There are many interventions that have been shown to affect neural function, many of which are associated with alterations in behaviour. Possible alterations in neuronal AVP actions relevant to cardiovascular control in the setting of chronic inflammatory disease, early-life stress and inflammation are suggested areas for future research.
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Affiliation(s)
- Quentin J Pittman
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
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13
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Parekh RU, White A, Leffler KE, Biancardi VC, Eells JB, Abdel-Rahman AA, Sriramula S. Hypothalamic kinin B1 receptor mediates orexin system hyperactivity in neurogenic hypertension. Sci Rep 2021; 11:21050. [PMID: 34702886 PMCID: PMC8548389 DOI: 10.1038/s41598-021-00522-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 10/13/2021] [Indexed: 12/05/2022] Open
Abstract
Brain orexin system hyperactivity contributes to neurogenic hypertension. We previously reported upregulated neuronal kinin B1 receptor (B1R) expression in hypertension. However, the role of central B1R activation on the orexin system in neurogenic hypertension has not been examined. We hypothesized that kinin B1R contributes to hypertension via upregulation of brain orexin-arginine vasopressin signaling. We utilized deoxycorticosterone acetate (DOCA)-salt hypertension model in wild-type (WT) and B1R knockout (B1RKO) mice. In WT mice, DOCA-salt-treatment increased gene and protein expression of orexin A, orexin receptor 1, and orexin receptor 2 in the hypothalamic paraventricular nucleus and these effects were attenuated in B1RKO mice. Furthermore, DOCA-salt- treatment increased plasma arginine vasopressin levels in WT mice, but not in B1RKO mice. Cultured primary hypothalamic neurons expressed orexin A and orexin receptor 1. B1R specific agonist (LDABK) stimulation of primary neurons increased B1R protein expression, which was abrogated by B1R selective antagonist R715 but not by the dual orexin receptor antagonist, ACT 462206, suggesting that B1R is upstream of the orexin system. These data provide novel evidence that B1R blockade blunts orexin hyperactivity and constitutes a potential therapeutic target for the treatment of salt-sensitive hypertension.
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Affiliation(s)
- Rohan Umesh Parekh
- Department of Pharmacology and Toxicology, Brody School of Medicine at East Carolina University, 600 Moye Blvd, Greenville, NC, 27834, USA
| | - Acacia White
- Department of Pharmacology and Toxicology, Brody School of Medicine at East Carolina University, 600 Moye Blvd, Greenville, NC, 27834, USA
| | - Korin E Leffler
- Department of Pharmacology and Toxicology, Brody School of Medicine at East Carolina University, 600 Moye Blvd, Greenville, NC, 27834, USA
| | - Vinicia C Biancardi
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA
- Center for Neuroscience Initiative, Auburn University, Auburn, AL, USA
| | - Jeffrey B Eells
- 4Department of Anatomy and Cell Biology, Brody School of Medicine at East, Carolina University, Greenville, NC, 27834, USA
| | - Abdel A Abdel-Rahman
- Department of Pharmacology and Toxicology, Brody School of Medicine at East Carolina University, 600 Moye Blvd, Greenville, NC, 27834, USA
| | - Srinivas Sriramula
- Department of Pharmacology and Toxicology, Brody School of Medicine at East Carolina University, 600 Moye Blvd, Greenville, NC, 27834, USA.
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14
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Azeez IA, Igado OO, Olopade JO. An overview of the orexinergic system in different animal species. Metab Brain Dis 2021; 36:1419-1444. [PMID: 34224065 DOI: 10.1007/s11011-021-00761-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 06/06/2021] [Indexed: 01/13/2023]
Abstract
Orexin (hypocretin), is a neuropeptide produced by a subset of neurons in the lateral hypothalamus. From the lateral hypothalamus, the orexin-containing neurons project their fibres extensively to other brain structures, and the spinal cord constituting the central orexinergic system. Generally, the term ''orexinergic system'' usually refers to the orexin peptides and their receptors, as well as to the orexin neurons and their projections to different parts of the central nervous system. The extensive networks of orexin axonal fibres and their terminals allow these neuropeptidergic neurons to exert great influence on their target regions. The hypothalamic neurons containing the orexin neuropeptides have been implicated in diverse functions, especially related to the control of a variety of homeostatic functions including feeding behaviour, arousal, wakefulness stability and energy expenditure. The broad range of functions regulated by the orexinergic system has led to its description as ''physiological integrator''. In the last two decades, the orexinergic system has been a topic of great interest to the scientific community with many reports in the public domain. From the documentations, variations exist in the neuroanatomical profile of the orexinergic neuron soma, fibres and their receptors from animal to animal. Hence, this review highlights the distinct variabilities in the morphophysiological aspects of the orexinergic system in the vertebrate animals, mammals and non-mammals, its presence in other brain-related structures, including its involvement in ageing and neurodegenerative diseases. The presence of the neuropeptide in the cerebrospinal fluid and peripheral tissues, as well as its alteration in different animal models and conditions are also reviewed.
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Affiliation(s)
- Idris A Azeez
- Department of Veterinary Anatomy, University of Jos, Jos, Nigeria
| | - Olumayowa O Igado
- Department of Veterinary Anatomy, University of Ibadan, Ibadan, Nigeria
| | - James O Olopade
- Department of Veterinary Anatomy, University of Ibadan, Ibadan, Nigeria.
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15
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Kowalewski S, Czarzasta K, Puchalska L, Szczepańska-Sadowska E, Wsol A, Cudnoch-Jędrzejewska A. Interaction of Orexin A and Vasopressin in the Brain Plays a Role in Blood Pressure Regulation in WKY and SHR Rats. Med Sci Monit 2020; 26:e926825. [PMID: 33048914 PMCID: PMC7568440 DOI: 10.12659/msm.926825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Background Orexin A (OXA) and vasopressin (AVP) exert a central hypertensive effect due to an increase in sympathetic nerve activity. To date, little is known about the interaction of these 2 neuropeptides in the central regulation of blood pressure. The present study compared the consequences of infusion into the left cerebral ventricle (ICV) of OXA on mean arterial blood pressure (MABP) in normotensive (WKY) and spontaneously hypertensive (SHR) rats, and explored whether the central pressor action of OXA in these 2 strains depends on activation of brain AVP V1a receptors (V1aR). Material/Methods Ten groups of experiments were performed on 12-week-old WKY and SHR rats implanted with ICV cannulas for infusion of OXA (3 nmol) and V1aR antagonist (V1aRANT, 500 ng), administered separately and together. Levels of V1aR and OXR in the medulla oblongata of WKY and SHR rats were compared in separate series. Results We found that: 1) OXA significantly increased MABP only in WKY rats, 2) V1aRANT prevented an increase in MABP induced by OXA in WKY rats and decreased MABP in SHR rats, 3) OXA abolished the hypotensive action of V1aRANT in SHR rats, and 4) SHR rats had significantly higher levels of OX1R and V1aR proteins and OX1R mRNA in the brain medulla. Conclusions The present study shows that OXA and AVP can interact in the brain to affect blood pressure regulation, and that this interaction differs in normotension and hypertension.
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Affiliation(s)
- Stanisław Kowalewski
- Department of Experimental and Clinical Physiology, Laboratory of the Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
| | - Katarzyna Czarzasta
- Department of Experimental and Clinical Physiology, Laboratory of the Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
| | - Liana Puchalska
- Department of Experimental and Clinical Physiology, Laboratory of the Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
| | - Ewa Szczepańska-Sadowska
- Department of Experimental and Clinical Physiology, Laboratory of the Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
| | - Agnieszka Wsol
- Department of Experimental and Clinical Physiology, Laboratory of the Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
| | - Agnieszka Cudnoch-Jędrzejewska
- Department of Experimental and Clinical Physiology, Laboratory of the Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
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16
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Guyenet PG, Stornetta RL, Souza GMPR, Abbott SBG, Brooks VL. Neuronal Networks in Hypertension: Recent Advances. Hypertension 2020; 76:300-311. [PMID: 32594802 DOI: 10.1161/hypertensionaha.120.14521] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Neurogenic hypertension is associated with excessive sympathetic nerve activity to the kidneys and portions of the cardiovascular system. Here we examine the brain regions that cause heightened sympathetic nerve activity in animal models of neurogenic hypertension, and we discuss the triggers responsible for the changes in neuronal activity within these regions. We highlight the limitations of the evidence and, whenever possible, we briefly address the pertinence of the findings to human hypertension. The arterial baroreflex reduces arterial blood pressure variability and contributes to the arterial blood pressure set point. This set point can also be elevated by a newly described cerebral blood flow-dependent and astrocyte-mediated sympathetic reflex. Both reflexes converge on the presympathetic neurons of the rostral medulla oblongata, and both are plausible causes of neurogenic hypertension. Sensory afferent dysfunction (reduced baroreceptor activity, increased renal, or carotid body afferent) contributes to many forms of neurogenic hypertension. Neurogenic hypertension can also result from activation of brain nuclei or sensory afferents by excess circulating hormones (leptin, insulin, Ang II [angiotensin II]) or sodium. Leptin raises blood vessel sympathetic nerve activity by activating the carotid bodies and subsets of arcuate neurons. Ang II works in the lamina terminalis and probably throughout the brain stem and hypothalamus. Sodium is sensed primarily in the lamina terminalis. Regardless of its cause, the excess sympathetic nerve activity is mediated to some extent by activation of presympathetic neurons located in the rostral ventrolateral medulla or the paraventricular nucleus of the hypothalamus. Increased activity of the orexinergic neurons also contributes to hypertension in selected models.
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Affiliation(s)
- Patrice G Guyenet
- From the Department of Pharmacology, University of Virginia, Charlottesville (P.G.G., R.L.S., G.M.P.R.S., S.B.G.A.)
| | - Ruth L Stornetta
- From the Department of Pharmacology, University of Virginia, Charlottesville (P.G.G., R.L.S., G.M.P.R.S., S.B.G.A.)
| | - George M P R Souza
- From the Department of Pharmacology, University of Virginia, Charlottesville (P.G.G., R.L.S., G.M.P.R.S., S.B.G.A.)
| | - Stephen B G Abbott
- From the Department of Pharmacology, University of Virginia, Charlottesville (P.G.G., R.L.S., G.M.P.R.S., S.B.G.A.)
| | - Virginia L Brooks
- Department of Chemical Physiology and Biochemistry, Oregon Health & Sciences University, Portland (V.L.B.)
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17
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Guyenet PG, Stornetta RL, Holloway BB, Souza GMPR, Abbott SBG. Rostral Ventrolateral Medulla and Hypertension. Hypertension 2019; 72:559-566. [PMID: 30354763 DOI: 10.1161/hypertensionaha.118.10921] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Patrice G Guyenet
- From the Department of Pharmacology, University of Virginia, Charlottesville
| | - Ruth L Stornetta
- From the Department of Pharmacology, University of Virginia, Charlottesville
| | - Benjamin B Holloway
- From the Department of Pharmacology, University of Virginia, Charlottesville
| | - George M P R Souza
- From the Department of Pharmacology, University of Virginia, Charlottesville
| | - Stephen B G Abbott
- From the Department of Pharmacology, University of Virginia, Charlottesville
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18
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Tan YY, Fang L, Yao FR, Cao DY, Zhang Q. Orexin Receptor-1 in the Rostral Ventrolateral Medulla Mediates the Antihypertensive Effects of Electroacupuncture. Front Neurosci 2019; 13:282. [PMID: 30971886 PMCID: PMC6443850 DOI: 10.3389/fnins.2019.00282] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 03/11/2019] [Indexed: 12/15/2022] Open
Abstract
Electroacupuncture (EA) has been used to treat numerous diseases, including hypertension. This study aimed to investigate the long-term effect and underlying mechanisms of EA stimulation at the LI11 point on the hypertension and sympathetic nerve activity in two-kidney, one-clip (2K1C) hypertensive rats. EA (0.1–0.4 mA, 2 and 15 Hz) was applied to the acupoints LI11 overlying the deep radial nerve once a day for 6 weeks. The mean arterial pressure (MAP) and heart rate (HR) were determined by radiotelemetry, and the sympathetic nerve activity was evaluated by telemetric analyses of the low-frequency component of blood pressure (BP) and by plasma epinephrine and norepinephrine levels. The results showed 6 weeks of EA significantly lowered the increased BP effectively, inhibited the enhanced sympathetic nerve activities and attenuated cardiac hypertrophy in 2K1C hypertensive rats. The level of orexin receptor-1 (OX1R) in the rostral ventrolateral medulla (RVLM) after EA treatment was markedly reduced in 2K1C rats, while there was no difference in the RVLM expression of orexin receptor-2 (OX2R) in 2K1C and 2K1C+EA rats. Moreover, the increased pressor and depressor responses to microinjection of orexin A or OX1R antagonist SB408124 into the RVLM of 2K1C rats were significantly blunted by the EA treatment. These findings suggest that BP-lowering effect of EA on renovascular hypertension may be through inhibition of central sympathetic activities and modulation of functional orexin receptors in the RVLM.
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Affiliation(s)
- Ying-Ying Tan
- Shaanxi Key Laboratory of Chinese Medicine Encephalopathy, Shaanxi University of Chinese Medicine, Xianyang, China
| | - Ling Fang
- Shaanxi Key Laboratory of Chinese Medicine Encephalopathy, Shaanxi University of Chinese Medicine, Xianyang, China
| | - Fan-Rong Yao
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC, United States
| | - Dong-Yuan Cao
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, Research Center of Stomatology, Xi'an Jiaotong University College of Stomatology, Xi'an, China
| | - Qi Zhang
- Shaanxi Key Laboratory of Chinese Medicine Encephalopathy, Shaanxi University of Chinese Medicine, Xianyang, China
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19
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Huber MJ, Fan Y, Jiang E, Zhu F, Larson RA, Yan J, Li N, Chen QH, Shan Z. Increased activity of the orexin system in the paraventricular nucleus contributes to salt-sensitive hypertension. Am J Physiol Heart Circ Physiol 2017; 313:H1075-H1086. [PMID: 28667055 DOI: 10.1152/ajpheart.00822.2016] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 05/08/2017] [Accepted: 06/22/2017] [Indexed: 01/29/2023]
Abstract
The orexin system is involved in arginine vasopressin (AVP) regulation, and its overactivation has been implicated in hypertension. However, its role in salt-sensitive hypertension (SSHTN) is unknown. Here, we tested the hypothesis that hyperactivity of the orexin system in the paraventricular nucleus (PVN) contributes to SSHTN via enhancing AVP signaling. Eight-week-old male Dahl salt-sensitive (Dahl S) and age- and sex-matched Sprague-Dawley (SD) rats were placed on a high-salt (HS; 8% NaCl) or normal-salt (NS; 0.4% NaCl) diet for 4 wk. HS intake did not alter mean arterial pressure (MAP), PVN mRNA levels of orexin receptor 1 (OX1R), or OX2R but slightly increased PVN AVP mRNA expression in SD rats. HS diet induced significant increases in MAP and PVN mRNA levels of OX1R, OX2R, and AVP in Dahl S rats. Intracerebroventricular infusion of orexin A (0.2 nmol) dramatically increased AVP mRNA levels and immunoreactivity in the PVN of SD rats. Incubation of cultured hypothalamus neurons from newborn SD rats with orexin A increased AVP mRNA expression, which was attenuated by OX1R blockade. In addition, increased cerebrospinal fluid Na+ concentration through intracerebroventricular infusion of NaCl solution (4 µmol) increased PVN OX1R and AVP mRNA levels and immunoreactivity in SD rats. Furthermore, bilateral PVN microinjection of the OX1R antagonist SB-408124 resulted in a greater reduction in MAP in HS intake (-16 ± 5 mmHg) compared with NS-fed (-4 ± 4 mmHg) anesthetized Dahl S rats. These results suggest that elevated PVN OX1R activation may contribute to SSHTN by enhancing AVP signaling.NEW & NOTEWORTHY To our best knowledge, this study is the first to investigate the involvement of the orexin system in salt-sensitive hypertension. Our results suggest that the orexin system may contribute to the Dahl model of salt-sensitive hypertension by enhancing vasopressin signaling in the hypothalamic paraventricular nucleus.
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Affiliation(s)
- Michael J Huber
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan
| | - Yuanyuan Fan
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan.,Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi, China
| | - Enshe Jiang
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan.,Institute for Nursing and Health Research, Henan University, Kaifeng, China
| | - Fengli Zhu
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan
| | - Robert A Larson
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan
| | - Jianqun Yan
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi, China
| | - Ningjun Li
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia; and
| | - Qing-Hui Chen
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan.,Biotech Research Center, Michigan Technological University, Houghton, Michigan
| | - Zhiying Shan
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan; .,Biotech Research Center, Michigan Technological University, Houghton, Michigan
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