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Sahoo P, Sarkar D, Sharma S, Verma A, Naik SK, Prashar V, Parkash J, Singh SK. Knockdown of type 2 orexin receptor in adult mouse testis potentiates testosterone production and germ cell proliferation. Mol Cell Endocrinol 2024; 592:112312. [PMID: 38866320 DOI: 10.1016/j.mce.2024.112312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 06/06/2024] [Accepted: 06/08/2024] [Indexed: 06/14/2024]
Abstract
Orexins (OXs) are neuropeptides which regulate various physiological processes. OXs exist in two different forms, mainly orexin A (OXA) and orexin B (OXB) and their effects are mediated via OX1R and OX2R. Presence of OXB and OX2R in mouse testis is also reported. However, the role of OXB/OX2R in the male gonad remains unexplored. Herein we investigated the role of OXB/OX2R system in testicular physiology under in vivo and ex vivo conditions. Adult mice were given a single dose of bilateral intratesticular injection of siRNA targeting OX2R and were sacrificed 96 h post-injection. OX2R-knockdown potentiated serum and intratesticular testosterone levels with up-regulation in the expressions of major steroidogenic proteins. Germ cell proliferation also increased in siRNA-treated mice. Results of the ex vivo experiment also supported the findings of the in vivo study. In conclusion, OX2R may regulate testosterone production and thereby control the fine-tuning between steroidogenesis and germ cell dynamics.
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Affiliation(s)
- Pratikshya Sahoo
- Department of Zoology, School of Basic Sciences, Central University of Punjab, VPO-Ghudda, Bathinda, 151401, India
| | - Debarshi Sarkar
- Department of Zoology, School of Basic Sciences, Central University of Punjab, VPO-Ghudda, Bathinda, 151401, India.
| | - Shubhangi Sharma
- Department of Zoology, School of Basic Sciences, Central University of Punjab, VPO-Ghudda, Bathinda, 151401, India
| | - Arpit Verma
- Department of Zoology, School of Basic Sciences, Central University of Punjab, VPO-Ghudda, Bathinda, 151401, India
| | - Suraj Kumar Naik
- Department of Zoology, School of Basic Sciences, Central University of Punjab, VPO-Ghudda, Bathinda, 151401, India
| | - Vikash Prashar
- Department of Zoology, School of Basic Sciences, Central University of Punjab, VPO-Ghudda, Bathinda, 151401, India
| | - Jyoti Parkash
- Department of Zoology, School of Basic Sciences, Central University of Punjab, VPO-Ghudda, Bathinda, 151401, India
| | - Shio Kumar Singh
- Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi-221005, India
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Carpi M, Palagini L, Fernandes M, Calvello C, Geoffroy PA, Miniati M, Pini S, Gemignani A, Mercuri NB, Liguori C. Clinical usefulness of dual orexin receptor antagonism beyond insomnia: Neurological and psychiatric comorbidities. Neuropharmacology 2024; 245:109815. [PMID: 38114045 DOI: 10.1016/j.neuropharm.2023.109815] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 12/21/2023]
Abstract
Orexin is a neurotransmitter produced by a small group of hypothalamic neurons. Besides its well-known role in the regulation of the sleep-wake cycle, the orexin system was shown to be relevant in several physiological functions including cognition, mood and emotion modulation, and energy homeostasis. Indeed, the implication of orexin neurotransmission in neurological and psychiatric diseases has been hypothesized via a direct effect exerted by the projections of orexin neurons to several brain areas, and via an indirect effect through orexin-mediated modulation of sleep and wake. Along with the growing evidence concerning the use of dual orexin receptor antagonists (DORAs) in the treatment of insomnia, studies assessing their efficacy in insomnia comorbid with psychiatric and neurological diseases have been set in order to investigate the potential impact of DORAs on both sleep-related symptoms and disease-specific manifestations. This narrative review aimed at summarizing the current evidence on the use of DORAs in neurological and psychiatric conditions comorbid with insomnia, also discussing the possible implication of modulating the orexin system for improving the burden of symptoms and the pathological mechanisms of these disorders. Target searches were performed on PubMed/MEDLINE and Scopus databases and ongoing studies registered on Clinicaltrials.gov were reviewed. Despite some contradictory findings, preclinical studies seemingly support the possible beneficial role of orexin antagonism in the management of the most common neurological and psychiatric diseases with sleep-related comorbidities. However, clinical research is still limited and further studies are needed for corroborating these promising preliminary results.
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Affiliation(s)
- Matteo Carpi
- Sleep and Epilepsy Centre, Neurology Unit, University Hospital Tor Vergata, Rome, Italy.
| | - Laura Palagini
- Department of Clinical and Experimental Medicine, Unit of Psychiatry, Azienda Ospedaliero Universitaria Pisana AUOP, Pisa, Italy.
| | - Mariana Fernandes
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy.
| | - Carmen Calvello
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy.
| | - Pierre Alexis Geoffroy
- Département de Psychiatrie et D'addictologie, AP-HP, GHU Paris Nord, DMU Neurosciences, Hopital Bichat - Claude Bernard, F-75018, Paris, France; GHU Paris - Psychiatry & Neurosciences, Paris, France; Université de Paris, NeuroDiderot, Inserm, FHU I2-D2, F-75019, Paris, France.
| | - Mario Miniati
- Department of Clinical and Experimental Medicine, Unit of Psychiatry, Azienda Ospedaliero Universitaria Pisana AUOP, Pisa, Italy.
| | - Stefano Pini
- Department of Clinical and Experimental Medicine, Unit of Psychiatry, Azienda Ospedaliero Universitaria Pisana AUOP, Pisa, Italy.
| | - Angelo Gemignani
- Unit of Psychology, Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, Azienda Ospedaliero Universitaria Pisana AUOP, Pisa, Italy.
| | | | - Claudio Liguori
- Sleep and Epilepsy Centre, Neurology Unit, University Hospital Tor Vergata, Rome, Italy; Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy.
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Jászberényi M, Thurzó B, Bagosi Z, Vécsei L, Tanaka M. The Orexin/Hypocretin System, the Peptidergic Regulator of Vigilance, Orchestrates Adaptation to Stress. Biomedicines 2024; 12:448. [PMID: 38398050 PMCID: PMC10886661 DOI: 10.3390/biomedicines12020448] [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: 01/18/2024] [Revised: 02/10/2024] [Accepted: 02/15/2024] [Indexed: 02/25/2024] Open
Abstract
The orexin/hypocretin neuropeptide family has emerged as a focal point of neuroscientific research following the discovery that this family plays a crucial role in a variety of physiological and behavioral processes. These neuropeptides serve as powerful neuromodulators, intricately shaping autonomic, endocrine, and behavioral responses across species. Notably, they serve as master regulators of vigilance and stress responses; however, their roles in food intake, metabolism, and thermoregulation appear complementary and warrant further investigation. This narrative review provides a journey through the evolution of our understanding of the orexin system, from its initial discovery to the promising progress made in developing orexin derivatives. It goes beyond conventional boundaries, striving to synthesize the multifaceted activities of orexins. Special emphasis is placed on domains such as stress response, fear, anxiety, and learning, in which the authors have contributed to the literature with original publications. This paper also overviews the advancement of orexin pharmacology, which has already yielded some promising successes, particularly in the treatment of sleep disorders.
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Affiliation(s)
- Miklós Jászberényi
- Department of Pathophysiology, University of Szeged, H-6701 Szeged, Hungary; (M.J.); (B.T.); (Z.B.)
| | - Balázs Thurzó
- Department of Pathophysiology, University of Szeged, H-6701 Szeged, Hungary; (M.J.); (B.T.); (Z.B.)
- Emergency Patient Care Unit, Albert Szent-Györgyi Health Centre, University of Szeged, H-6725 Szeged, Hungary
| | - Zsolt Bagosi
- Department of Pathophysiology, University of Szeged, H-6701 Szeged, Hungary; (M.J.); (B.T.); (Z.B.)
| | - László Vécsei
- Department of Neurology, Albert Szent-Györgyi Medical School, University of Szeged, H-6725 Szeged, Hungary;
- HUN-REN-SZTE Neuroscience Research Group, Hungarian Research Network, University of Szeged (HUN-REN-SZTE), Danube Neuroscience Research Laboratory, Tisza Lajos krt. 113, H-6725 Szeged, Hungary
| | - Masaru Tanaka
- HUN-REN-SZTE Neuroscience Research Group, Hungarian Research Network, University of Szeged (HUN-REN-SZTE), Danube Neuroscience Research Laboratory, Tisza Lajos krt. 113, H-6725 Szeged, Hungary
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Mavanji V, Georgopoulos AP, Kotz CM. Orexin enhances neuronal synchronization in adult rat hypothalamic culture: a model to study hypothalamic function. J Neurophysiol 2022; 127:1221-1229. [PMID: 35353632 PMCID: PMC9054260 DOI: 10.1152/jn.00041.2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 03/28/2022] [Indexed: 11/22/2022] Open
Abstract
The regulation of sleep/wake behavior and energy homeostasis is maintained in part by the hypothalamic neuropeptide orexin A (OXA, hypocretin). Reduction in orexin signaling is associated with sleep disorders and obesity, whereas higher lateral hypothalamic (LH) orexin signaling and sensitivity promotes obesity resistance. Similarly, dysregulation of hypothalamic neural networks is associated with onset of age-related diseases, including obesity and several neurological diseases. Despite the association of obesity and aging, and that adult populations are the target for the majority of pharmaceutical and obesity studies, conventional models for neuronal networks utilize embryonic neural cultures rather than adult neurons. Synchronous activity describes correlated changes in neuronal activity between neurons and is a feature of normal brain function, and is a measure of functional connectivity and final output from a given neural structure. Earlier studies show alterations in hypothalamic synchronicity following behavioral perturbations in embryonic neurons obtained from obesity-resistant rats and following application of orexin onto embryonic hypothalamic cultures. Synchronous network dynamics in adult hypothalamic neurons remain largely undescribed. To address this, we established an adult rat hypothalamic culture in multi-electrode-array (MEA) dishes and recorded the field potentials. Then we studied the effect of exogenous orexin on network synchronization of these adult hypothalamic cultures. In addition, we studied the wake promoting effects of orexin in vivo when directly injected into the lateral hypothalamus (LH). Our results showed that the adult hypothalamic cultures are viable for nearly 3 mo in vitro, good quality MEA recordings can be obtained from these cultures in vitro, and finally, that cultured adult hypothalamus is responsive to orexin. These results support that adult rat hypothalamic cultures could be used as a model to study the neural mechanisms underlying obesity. In addition, LH administration of OXA enhanced wakefulness in rats, indicating that OXA enhances wakefulness partly by promoting neural synchrony in the hypothalamus.NEW & NOTEWORTHY This study, for the first time, demonstrates that adult hypothalamic cultures are viable in vitro for a prolonged duration and are electrophysiologically active. In addition, the study shows that orexin enhances neural synchronization in adult hypothalamic cultures.
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Affiliation(s)
- Vijayakumar Mavanji
- Research Service, Veterans Affairs Health Care System, Minneapolis, Minnesota
| | - Apostolos P Georgopoulos
- Research Service, Veterans Affairs Health Care System, Minneapolis, Minnesota
- Brain Sciences Center, Veterans Affairs Health Care System, Minneapolis, Minnesota
- Department of Neuroscience, University of Minnesota Medical School, Minneapolis, Minnesota
- Department of Psychiatry, University of Minnesota Medical School, Minneapolis, Minnesota
- Center for Cognitive Sciences, University of Minnesota, Minneapolis, Minnesota
- Department of Neurology, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Catherine M Kotz
- Research Service, Veterans Affairs Health Care System, Minneapolis, Minnesota
- Minnesota Nutrition and Obesity Research Center, St. Paul, Minnesota
- Geriatric Research Education Clinical Center, Veterans Affairs Health Care System, Minneapolis, Minnesota
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, Minnesota
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Hypothalamic expression of huntingtin causes distinct metabolic changes in Huntington's disease mice. Mol Metab 2022; 57:101439. [PMID: 35007790 PMCID: PMC8814380 DOI: 10.1016/j.molmet.2022.101439] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 01/05/2022] [Indexed: 11/29/2022] Open
Abstract
Objective In Huntington's disease (HD), the disease-causing huntingtin (HTT) protein is ubiquitously expressed and causes both central and peripheral pathology. In clinical HD, a higher body mass index has been associated with slower disease progression, indicating the role of metabolic changes in disease pathogenesis. Underlying mechanisms of metabolic changes in HD remain poorly understood, but recent studies suggest the involvement of hypothalamic dysfunction. The present study aimed to investigate whether modulation of hypothalamic HTT levels would affect metabolic phenotype and disease features in HD using mouse models. Methods We used the R6/2 and BACHD mouse models that express different lengths of mutant HTT to develop lean- and obese phenotypes, respectively. We utilized adeno-associated viral vectors to overexpress either mutant or wild-type HTT in the hypothalamus of R6/2, BACHD, and their wild-type littermates. The metabolic phenotype was assessed by body weight measurements over time and body composition analysis using dual-energy x-ray absorptiometry at the endpoint. R6/2 mice were further characterized using behavioral analyses, including rotarod, nesting-, and hindlimb clasping tests during early- and late-time points of disease progression. Finally, gene expression analysis was performed in R6/2 mice and wild-type littermates in order to assess transcriptional changes in the hypothalamus and adipose tissue. Results Hypothalamic overexpression of mutant HTT induced significant gender-affected body weight gain in all models, including wild-type mice. In R6/2 females, early weight gain shifted to weight loss during the corresponding late stage of disease despite increased fat accumulation. Body weight changes were accompanied by behavioral alterations. During the period of early weight gain, R6/2 mice displayed a comparable locomotor capacity to wild-type mice. When assessing behavior just prior to weight loss onset in R6/2 mice, decreased locomotor performance was observed in R6/2 females with hypothalamic overexpression of mutant HTT. Transcriptional downregulation of beta-3 adrenergic receptor (B3AR), adipose triglyceride lipase (ATGL), and peroxisome proliferator-activated receptor-gamma (PPARγ) in gonadal white adipose tissue was accompanied by distinct alterations in hypothalamic gene expression profiles in R6/2 females after mutant HTT overexpression. No significant effect on metabolic phenotype in R6/2 was seen in response to wild-type HTT overexpression. Conclusions Taken together, our findings provide further support for the role of HTT in metabolic control via hypothalamic neurocircuits. Understanding the specific central neurocircuits and their peripheral link underlying metabolic imbalance in HD may open up avenues for novel therapeutic interventions. Overexpression of hypothalamic huntingtin affects weight in Huntington's disease mice. Hypothalamic huntingtin expression results in gene expression changes in white fat and the hypothalamus. Hypothalamic huntingtin cannot prevent late-stage weight loss in R6/2 mice.
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Du D, Zhang Y, Zhu C, Chen H, Sun J. Metabolic Regulation of Hypoxia-Inducible Factors in Hypothalamus. Front Endocrinol (Lausanne) 2021; 12:650284. [PMID: 33763034 PMCID: PMC7984363 DOI: 10.3389/fendo.2021.650284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 01/29/2021] [Indexed: 12/30/2022] Open
Abstract
The earliest hypoxia-inducible factor (HIF) function was to respond to hypoxia or hypoxic conditions as a transcription factor. Recent studies have expanded our understanding of HIF, and a large amount of evidence indicates that HIF has an essential effect on central regulation of metabolism. The central nervous system's response to glucose, inflammation, and hormones' main influence on systemic metabolism are all regulated by HIF to varying degrees. In the hypothalamus, HIF mostly plays a role in inhibiting energy uptake and promoting energy expenditure, which depends not only on the single effect of HIF or a single part of the hypothalamus. In this paper, we summarize the recent progress in the central regulation of metabolism, describe in detail the role of HIF in various functions of the hypothalamus and related molecular mechanisms, and reveal that HIF is deeply involved in hypothalamic-mediated metabolic regulation.
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Affiliation(s)
- Dan Du
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Yugang Zhang
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Canjun Zhu
- Guangdong Province Key Laboratory of Animal Nutritional Regulation, College of Animal Science, South China Agricultural University, Guangzhou, China
- *Correspondence: Jia Sun, ; Hong Chen, ; Canjun Zhu,
| | - Hong Chen
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- *Correspondence: Jia Sun, ; Hong Chen, ; Canjun Zhu,
| | - Jia Sun
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- *Correspondence: Jia Sun, ; Hong Chen, ; Canjun Zhu,
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Liang J, Jia Y, Yan H, Shen Q, Bian W, Zhao D, Xu Y, Jin Y, Yang M. Prdm16-Mediated Browning is Involved in Resistance to Diet-Induced and Monosodium Glutamate-Induced Obesity. Diabetes Metab Syndr Obes 2021; 14:4351-4360. [PMID: 34737591 PMCID: PMC8558318 DOI: 10.2147/dmso.s335526] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/14/2021] [Indexed: 11/23/2022] Open
Abstract
PURPOSE To investigate resistance to diet-induced obesity (DIO) and monosodium glutamate (MSG)-induced obesity as well as the underlying mechanisms. METHODS Newborn mice were used to construct DIO and MSG-induced obesity models. Obesity indices, such as body weight, body length, Lee index, body temperature, food intake, fat weight, and leptin level, were examined. Mice that did not exhibit obesity were defined as the obesity-resistant group. The morphological changes of white adipose tissue were observed by hematoxylin and eosin staining, and expression levels of PR domain containing 16 (Prdm16) and uncoupling protein-1 (Ucp-1) in white adipose tissue were measured by Western blot. RESULTS Obesity-resistant mice fed a high-fat diet showed resistance beginning at week 5 along with lower weights and lengths than those in the obesity group from weeks 5 to 12. MSG-induced obesity-resistant mice showed features consistent with resistance to obesity from week 1 along with higher body lengths relative to the obesity group; however, the weight difference was not significant until week 10, when body weights decreased significantly in obesity-resistant mice. The Lee index was lower in obesity-resistant mice than in the obesity group and the normal group, further suggesting obesity resistance. Additionally, obesity-resistant mice showed higher levels of leptin, whereas obese mice induced by a high-fat diet showed leptin resistance. Furthermore, Prdm16 and Ucp-1 levels were both downregulated in the obesity group and upregulated in obesity-resistant mice, showing that white fat browning was highest in obesity-resistant mice. CONCLUSION The phenotypes of mice with DIO and MSG-induced obesity differed. Obesity resistance might be related to Prdm16 and Ucp-1-mediated white adipocyte browning.
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Affiliation(s)
- Jia Liang
- Department of Pharmacology, Binzhou Medical University, Yantai, People’s Republic of China
| | - Ying Jia
- Department of Pharmacology, Binzhou Medical University, Yantai, People’s Republic of China
| | - Haijing Yan
- Department of Pharmacology, Binzhou Medical University, Yantai, People’s Republic of China
| | - Qingyu Shen
- Department of Pharmacology, Binzhou Medical University, Yantai, People’s Republic of China
| | - Weihua Bian
- Department of Cell Biology, Binzhou Medical University, Yantai, People’s Republic of China
| | - Dongmei Zhao
- Department of Anatomy, Binzhou Medical University, Yantai, People’s Republic of China
| | - Yong Xu
- Department of Pharmacology, Binzhou Medical University, Yantai, People’s Republic of China
| | - Yongjun Jin
- Department of Endocrinology, Binzhou Medical University, Yantai, People’s Republic of China
| | - Meizi Yang
- Department of Pharmacology, Binzhou Medical University, Yantai, People’s Republic of China
- Correspondence: Meizi Yang; Yongjun Jin Department of Pharmacology, Binzhou Medical University, Yantai, 264003, People’s Republic of ChinaTel +86 535 691 9507Fax +86 535 691 3163 Email ;
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Methylation of Hypothalamic Tsc1-mTOR Signaling in Regulation of Obesity and Obesity Resistance. BIOMED RESEARCH INTERNATIONAL 2020; 2020:8723869. [PMID: 33532487 PMCID: PMC7836023 DOI: 10.1155/2020/8723869] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 11/10/2020] [Accepted: 12/20/2020] [Indexed: 02/05/2023]
Abstract
The Tsc1-mTOR signaling pathway is often related to obesity, and epigenetic modification may lead to expression changes of obesity-related gene. Therefore, we aim to investigate the methylation of the Tsc1-mTOR signaling pathway in regulation of obesity susceptibility. Wistar rats were fed a normal diet or a high-fat diet to develop animal models. Protein and mRNA expression levels of Tsc1-mTOR signaling in the hypothalamus were determined by Western blot and quantitative real-time PCR. Methylation of Tsc1 gene promoter was detected by bisulfite genomic sequence. Both mRNA and protein expression levels of Tsc1 in DIO group hypothalamus were lower; mTOR and its downstream targets S6K1, 4EBP1, and S6 protein expression levels were higher than those of the DIO-R group and the chow group. The Tsc1 gene promoter methylation rate in the hypothalamus was 92.05 ± 3.07% in the DIO group, 87.27 ± 1.91% in the DIO-R group, and 88.18% ± 3.20% in the chow group, respectively, with significantly higher levels in the DIO group. Both the expression levels of Tsc1 gene promoter methylation and Tsc1-mTOR signaling pathway in the hypothalamus of DIO rats and DIO-R rats are different. These findings may shed light on the potential mechanism for the differentiation of obesity susceptibility.
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Abstract
In this highly digitalized era, sleep disorders are becoming more common and are associated with an increased burden of chronic disease. Shift workers are at an increased risk for both sleep disorders and metabolic syndrome. In this article, the authors outline the connection between circadian discordance, hormonal imbalance, and the development of metabolic syndrome in shift workers. Based on a literature review of animal model studies, observational studies, and clinical trials conducted between August and October of 2018, the authors offer several clinical interventions, including work schedules, light therapy, medications, and dietary habits to improve the circadian synchronicity of shift workers and reduce their risk of morbidity and mortality. It is important for physicians to be familiar with the consequences of shift work and ways to mitigate the risks for this patient population.
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Wang P, Wang M, Zhang L, Zhong S, Jiang W, Wang Z, Sun C, Zhang S, Liu Z. Functional characterization of an orexin neuropeptide in amphioxus reveals an ancient origin of orexin/orexin receptor system in chordate. SCIENCE CHINA-LIFE SCIENCES 2019; 62:1655-1669. [PMID: 30945108 DOI: 10.1007/s11427-018-9421-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Accepted: 10/10/2018] [Indexed: 01/09/2023]
Abstract
Amphioxus belongs to the subphylum cephalochordata, an extant representative of the most basal chordates, whose regulation of endocrine system remains ambiguous. Here we clearly demonstrated the existence of a functional orexin neuropeptide in amphioxus, which is able to interact with orexin receptor, activate both PKC and PKA pathways, decrease leptin expression, and stimulate lipogenesis. We also showed the transcription level of amphioxus orexin was affected by fasting or temperature, indicating a role of this gene in the regulation of energy balance. In addition, the expression of the amphioxus orexin was detected at cerebral vesicle, which has been proposed to be a homolog of the vertebrate brain. These data collectively suggest that a functional orexin neuropeptide has already emerged in amphioxus, which provide insights into the evolutionary origin of orexin in chordate and the functional homology between the cerebral vesicle and vertebrate brain.
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Affiliation(s)
- Peng Wang
- Institute of Evolution & Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Meng Wang
- Institute of Evolution & Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Liping Zhang
- Institute of Evolution & Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Shenjie Zhong
- Institute of Evolution & Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Wanyue Jiang
- Institute of Evolution & Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Ziyue Wang
- Institute of Evolution & Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Chen Sun
- Institute of Evolution & Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Shicui Zhang
- Institute of Evolution & Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China.
| | - Zhenhui Liu
- Institute of Evolution & Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China.
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Couvineau A, Voisin T, Nicole P, Gratio V, Abad C, Tan YV. Orexins as Novel Therapeutic Targets in Inflammatory and Neurodegenerative Diseases. Front Endocrinol (Lausanne) 2019; 10:709. [PMID: 31695678 PMCID: PMC6817618 DOI: 10.3389/fendo.2019.00709] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 10/02/2019] [Indexed: 02/05/2023] Open
Abstract
Orexins [orexin-A (OXA) and orexin-B (OXB)] are two isoforms of neuropeptides produced by the hypothalamus. The main biological actions of orexins, focused on the central nervous system, are to control the sleep/wake process, appetite and feeding, energy homeostasis, drug addiction, and cognitive processes. These effects are mediated by two G protein-coupled receptor (GPCR) subtypes named OX1R and OX2R. In accordance with the synergic and dynamic relationship between the nervous and immune systems, orexins also have neuroprotective and immuno-regulatory (i.e., anti-inflammatory) properties. The present review gathers recent data demonstrating that orexins may have a therapeutic potential in several pathologies with an immune component including multiple sclerosis, Alzheimer's disease, narcolepsy, obesity, intestinal bowel diseases, septic shock, and cancers.
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Affiliation(s)
- Alain Couvineau
- INSERM UMR1149/Inflammation Research Center (CRI), Team “From Inflammation to Cancer in Digestive Diseases” Labeled by “la Ligue Nationale Contre le Cancer”, University of Paris, Paris, France
- *Correspondence: Alain Couvineau
| | - Thierry Voisin
- INSERM UMR1149/Inflammation Research Center (CRI), Team “From Inflammation to Cancer in Digestive Diseases” Labeled by “la Ligue Nationale Contre le Cancer”, University of Paris, Paris, France
| | - Pascal Nicole
- INSERM UMR1149/Inflammation Research Center (CRI), Team “From Inflammation to Cancer in Digestive Diseases” Labeled by “la Ligue Nationale Contre le Cancer”, University of Paris, Paris, France
| | - Valérie Gratio
- INSERM UMR1149/Inflammation Research Center (CRI), Team “From Inflammation to Cancer in Digestive Diseases” Labeled by “la Ligue Nationale Contre le Cancer”, University of Paris, Paris, France
| | - Catalina Abad
- University of Rouen Normandy, INSERM U1234 PANTHER, IRIB, Rouen, France
| | - Yossan-Var Tan
- University of Rouen Normandy, INSERM U1234 PANTHER, IRIB, Rouen, France
- Yossan-Var Tan
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Sengupta P, Dutta S, Tusimin M, Karkada I. Orexins and male reproduction. ASIAN PACIFIC JOURNAL OF REPRODUCTION 2019. [DOI: 10.4103/2305-0500.268145] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Microglial Immune Response to Low Concentrations of Combustion-Generated Nanoparticles: An In Vitro Model of Brain Health. NANOMATERIALS 2018; 8:nano8030155. [PMID: 29522448 PMCID: PMC5869646 DOI: 10.3390/nano8030155] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 03/03/2018] [Accepted: 03/08/2018] [Indexed: 11/16/2022]
Abstract
The brain is the central regulator for integration and control of responses to environmental cues. Previous studies suggest that air pollution may directly impact brain health by triggering the onset of chronic neuroinflammation. We hypothesize that nanoparticle components of combustion-generated air pollution may underlie these effects. To test this association, a microglial in vitro biological sensor model was used for testing neuroinflammatory response caused by low-dose nanoparticle exposure. The model was first validated using 20 nm silver nanoparticles (AgNP). Next, neuroinflammatory response was tested after exposure to size-selected 20 nm combustion-generated nanoparticles (CGNP) collected from a modern diesel engine. We show that low concentrations of CGNPs promote low-grade inflammatory response indicated by increased pro-inflammatory cytokine release (tumor necrosis factor-α), similar to that observed after AgNP exposure. We also demonstrate increased production of reactive oxygen species and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65 phosphorylation in microglia after CGNP stimulation. Finally, we show conditioned media from CGNP-stimulated microglia significantly reduced hypothalamic neuronal survival in vitro. To our knowledge, this data show for the first time that exposure to AgNP and CGNP elicits microglial neuroinflammatory response through the activation of NF-κB.
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Mavanji V, Butterick TA, Duffy CM, Nixon JP, Billington CJ, Kotz CM. Orexin/hypocretin treatment restores hippocampal-dependent memory in orexin-deficient mice. Neurobiol Learn Mem 2017; 146:21-30. [PMID: 29107703 DOI: 10.1016/j.nlm.2017.10.014] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/02/2017] [Accepted: 10/27/2017] [Indexed: 12/31/2022]
Abstract
Orexin A is produced in neurons of the lateral, perifornical and dorsomedial regions of the lateral hypothalamic area, which then project widely throughout the central nervous system to regulate arousal state, sleep-wake architecture, energy homeostasis and cognitive processes. Disruption of orexin signaling leads to sleep disturbances and increased body mass index, but recent studies also indicate that orexin neuron activation improves learning and memory. We hypothesized that hippocampal orexin receptor activation improves memory. To test this idea, we obtained orexin/ataxin-3 (O/A3) mice, which become deficient in orexin neurons by about 12 weeks of age. We first measured hippocampal orexin receptor 1 (OX1R) gene expression and protein levels, then tested acquisition and consolidation of two-way active avoidance (TWAA) memory, a hippocampal-dependent learning and memory task. Finally, we determined if exogenous intra-hippocampal OXA treatment could reverse cognitive impairment (as determined by TWAA) in OA/3 mice. We showed that OX1R mRNA expression and protein levels were significantly elevated in O/A3 mice, indicating the potential for preserved orexin responsiveness. The O/A3 mice were significantly impaired in TWAA memory vs. control mice, but OXA treatment (both acute and chronic) reversed these memory deficits. These results demonstrate that orexin plays an important role in hippocampal-dependent consolidation of two-way active avoidance memory, and orexin replacement can rescue the cognitive impairment.
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Affiliation(s)
- Vijayakumar Mavanji
- Research Service, Veterans Affairs Health Care System, Minneapolis, MN 55417 USA
| | - Tammy A Butterick
- Research Service, Veterans Affairs Health Care System, Minneapolis, MN 55417 USA; Department of Food Science and Nutrition, University of Minnesota, St Paul, MN 55108 USA; Minnesota Obesity Center, St Paul, MN 55108 USA
| | - Cayla M Duffy
- Research Service, Veterans Affairs Health Care System, Minneapolis, MN 55417 USA; Department of Food Science and Nutrition, University of Minnesota, St Paul, MN 55108 USA; Minnesota's Discovery, Research and Innovation Economy, Brain Conditions, University of Minnesota, Minneapolis, MN 55455
| | - Joshua P Nixon
- Research Service, Veterans Affairs Health Care System, Minneapolis, MN 55417 USA; Department of Food Science and Nutrition, University of Minnesota, St Paul, MN 55108 USA
| | - Charles J Billington
- Research Service, Veterans Affairs Health Care System, Minneapolis, MN 55417 USA; Minnesota Obesity Center, St Paul, MN 55108 USA; Department of Medicine, University of Minnesota, Minneapolis, MN 55455 USA
| | - Catherine M Kotz
- Research Service, Veterans Affairs Health Care System, Minneapolis, MN 55417 USA; Minnesota Obesity Center, St Paul, MN 55108 USA; Geriatric Research Education Clinical Center, Veterans Affairs Health Care System, Minneapolis, MN 55417 USA; Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN 55455 USA.
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15
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Wan X, Liu Y, Zhao Y, Sun X, Fan D, Guo L. Orexin A affects HepG2 human hepatocellular carcinoma cells glucose metabolism via HIF-1α-dependent and -independent mechanism. PLoS One 2017; 12:e0184213. [PMID: 28886081 PMCID: PMC5590901 DOI: 10.1371/journal.pone.0184213] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Accepted: 08/21/2017] [Indexed: 01/20/2023] Open
Abstract
Orexins are hypothalamic neuropeptides that regulate feeding, reward, wakefulness and energy homeostasis. The present study sought to characterize the involvement of orexin A in glucose metabolism in HepG2 human hepatocellular carcinoma cells, and investigated the role of hypoxia-inducible factor-1α (HIF-1α) in the response. HepG2 cells were exposed to different concentrations of orexin A (10−9 to 10−7 M) in vitro, without or with the orexin receptor 1 (OX1R) inhibitor (SB334867), HIF-1α inhibitor (YC-1) or a combination of both inhibitors. Subsequently, OX1R, HIF-1α expression and localization, glucose uptake, glucose transporter 1 (GLUT1) expression and ATP content were measured. We further investigated the intracellular fate of glucose by measuring the gene expression of pyruvate dehydrogenase kinase 1 (PDK1), lactate dehydrogenase (LDHA) and pyruvate dehydrogenase B (PDHB), as well as metabolite levels including lactate generation and mitochondrial pyruvate dehydrogenase (PDH) activity. The activity of phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway was also assessed. Our results showed that the expression of OX1R was predominantly located in the nucleus in HepG2 cells. Orexin A oxygen-independently promoted the mRNA and protein expression of HIF-1α as well as its nuclear accumulation in HepG2 cells and the elevated HIF-1α protein was associated, at least partly, with the activation of the PI3K/Akt/mTOR pathway. Orexin A stimulated GLUT1 expression, glucose uptake as well as ATP generation in HepG2 cells via OX1R acting through the HIF-1α pathway. Moreover, orexin A inhibited LDHA, PDK1 expression and lactate production, stimulated PDHB expression and PDH enzyme activity independent of HIF-1α. Our results indicated that orexin signaling facilitated the glucose flux into mitochondrial oxidative metabolism rather than glycolysis in HepG2 cells. These findings provide new insight into the regulation of glucose metabolism by orexin A in hepatocellular carcinoma cells.
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Affiliation(s)
- Xing Wan
- Department of Medical Oncology, First Affiliated Hospital, China Medical University, Shenyang, Liaoning, P.R. China
| | - Yuanyuan Liu
- Department of Endocrinology, First Affiliated Hospital, China Medical University, Shenyang, Liaoning, P.R. China
| | - Yuyan Zhao
- Department of Endocrinology, First Affiliated Hospital, China Medical University, Shenyang, Liaoning, P.R. China
- * E-mail: (LG); (YZ)
| | - Xiaoqi Sun
- Department of Endocrinology, First Affiliated Hospital, China Medical University, Shenyang, Liaoning, P.R. China
| | - Dongxiao Fan
- Department of Orthopedic Surgery, First Affiliated Hospital, China Medical University, Shenyang, Liaoning, P.R. China
| | - Lei Guo
- Department of Orthopedic Surgery, First Affiliated Hospital, China Medical University, Shenyang, Liaoning, P.R. China
- * E-mail: (LG); (YZ)
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16
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Di Bonaventura MVM, Lutz TA, Romano A, Pucci M, Geary N, Asarian L, Cifani C. Estrogenic suppression of binge-like eating elicited by cyclic food restriction and frustrative-nonreward stress in female rats. Int J Eat Disord 2017; 50:624-635. [PMID: 28230907 PMCID: PMC5500915 DOI: 10.1002/eat.22687] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 01/02/2017] [Accepted: 01/11/2017] [Indexed: 01/18/2023]
Abstract
Because binge eating and emotional eating vary through the menstrual cycle in human females, we investigated cyclic changes in binge-like eating in female rats and their control by estrogens. Binge-like eating was elicited by three cycles of 4 days of food restriction and 4 days of free feeding followed by a single frustrative nonreward-stress episode (15 min visual and olfactory exposure to a familiar palatable food) immediately before presentation of the palatable food. Intact rats showed binge-like eating during the diestrous and proestrous phases of the ovarian cycle, but not during the estrous (periovulatory) phase. Ovariectomized (OVX) rats not treated with estradiol (E2) displayed binge-like eating, whereas E2-treated OVX rats did not. The procedure did not increase signs of anxiety in an open-field test. OVX rats not treated with E2 that were subjected to food restriction and sacrificed immediately after frustrative nonreward had increased numbers of cells expressing phosphorylated extracellular signal-regulated kinases (ERK) in the central nucleus of the amygdala (CeA), paraventricular nucleus of hypothalamus (PVN), and dorsal and ventral bed nuclei of the stria terminalis (BNST) compared with nonrestricted or E2-treated rats. These data suggest that this female rat model is appropriate for mechanistic studies of some aspects of menstrual-cycle effects on emotional and binge eating in human females, that anxiety is not a sufficient cause of binge-like eating, and that the PVN, CeA, and BNST may contribute to information processing underlying binge-like eating.
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Affiliation(s)
| | - Thomas A. Lutz
- Institute of Veterinary Physiology and Center for Integrative Human Physiology, University of Zurich, 8057 Zurich, Switzerland
| | - Adele Romano
- Department of Physiology and Pharmacology, Sapienza University of Rome, 00185 Rome, Italy
| | - Mariangela Pucci
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, 64100 Teramo, Italy
| | - Nori Geary
- Department of Psychiatry (Retired), Weill Medical College of Cornell University, New York, NY 10065, USA
| | - Lori Asarian
- Institute of Veterinary Physiology and Center for Integrative Human Physiology, University of Zurich, 8057 Zurich, Switzerland
| | - Carlo Cifani
- School of Pharmacy, Pharmacology Unit, University of Camerino, 62032 Camerino, Italy
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Duffy CM, Nixon JP, Butterick TA. Orexin A attenuates palmitic acid-induced hypothalamic cell death. Mol Cell Neurosci 2016; 75:93-100. [PMID: 27449757 DOI: 10.1016/j.mcn.2016.07.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 07/15/2016] [Accepted: 07/19/2016] [Indexed: 10/21/2022] Open
Abstract
Palmitic acid (PA), an abundant dietary saturated fatty acid, contributes to obesity and hypothalamic dysregulation in part through increase in oxidative stress, insulin resistance, and neuroinflammation. Increased production of reactive oxygen species (ROS) as a result of PA exposure contributes to the onset of neuronal apoptosis. Additionally, high fat diets lead to changes in hypothalamic gene expression profiles including suppression of the anti-apoptotic protein B cell lymphoma 2 (Bcl-2) and upregulation of the pro-apoptotic protein B cell lymphoma 2 associated X protein (Bax). Orexin A (OXA), a hypothalamic peptide important in obesity resistance, also contributes to neuroprotection. Prior studies have demonstrated that OXA attenuates oxidative stress induced cell death. We hypothesized that OXA would be neuroprotective against PA induced cell death. To test this, we treated an immortalized hypothalamic cell line (designated mHypoA-1/2) with OXA and PA. We demonstrate that OXA attenuates PA-induced hypothalamic cell death via reduced caspase-3/7 apoptosis, stabilization of Bcl-2 gene expression, and reduced Bax/Bcl-2 gene expression ratio. We also found that OXA inhibits ROS production after PA exposure. Finally, we show that PA exposure in mHypoA-1/2 cells significantly reduces basal respiration, maximum respiration, ATP production, and reserve capacity. However, OXA treatment reverses PA-induced changes in intracellular metabolism, increasing basal respiration, maximum respiration, ATP production, and reserve capacity. Collectively, these results support that OXA protects against PA-induced hypothalamic dysregulation, and may represent one mechanism through which OXA can ameliorate effects of obesogenic diet on brain health.
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Affiliation(s)
- Cayla M Duffy
- Minneapolis Veterans Affairs Health Care System, Research 151, One Veterans Dr, Minneapolis, MN 55417, USA; Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave, St. Paul, MN 55108, USA
| | - Joshua P Nixon
- Minneapolis Veterans Affairs Health Care System, Research 151, One Veterans Dr, Minneapolis, MN 55417, USA; Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave, St. Paul, MN 55108, USA
| | - Tammy A Butterick
- Minneapolis Veterans Affairs Health Care System, Research 151, One Veterans Dr, Minneapolis, MN 55417, USA; Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave, St. Paul, MN 55108, USA; Minnesota Obesity Center, University of Minnesota, 1334 Eckles Ave, St. Paul, MN 55108, USA.
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18
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Han C, Rice MW, Cai D. Neuroinflammatory and autonomic mechanisms in diabetes and hypertension. Am J Physiol Endocrinol Metab 2016; 311:E32-41. [PMID: 27166279 PMCID: PMC4967151 DOI: 10.1152/ajpendo.00012.2016] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 05/03/2016] [Indexed: 02/07/2023]
Abstract
Interdisciplinary studies in the research fields of endocrinology and immunology show that obesity-associated overnutrition leads to neuroinflammatory molecular changes, in particular in the hypothalamus, chronically causing various disorders known as elements of metabolic syndrome. In this process, neural or hypothalamic inflammation impairs the neuroendocrine and autonomic regulation of the brain over blood pressure and glucose homeostasis as well as insulin secretion, and elevated sympathetic activation has been appreciated as a critical mediator. This review describes the involved physiology and mechanisms, with a focus on glucose and blood pressure balance, and suggests that neuroinflammation employs the autonomic nervous system to mediate the development of diabetes and hypertension.
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Affiliation(s)
- Cheng Han
- Department of Molecular Pharmacology, Diabetes Research Center, Institute of Aging, Albert Einstein College of Medicine, Bronx, New York
| | - Matthew W Rice
- Department of Molecular Pharmacology, Diabetes Research Center, Institute of Aging, Albert Einstein College of Medicine, Bronx, New York
| | - Dongsheng Cai
- Department of Molecular Pharmacology, Diabetes Research Center, Institute of Aging, Albert Einstein College of Medicine, Bronx, New York
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19
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Sá FGDSD, Lima-Leopoldo AP, Jacobsen BB, Ferron AJT, Estevam WM, Campos DHS, Castardeli E, Cunha MRHD, Cicogna AC, Leopoldo AS. Obesity Resistance Promotes Mild Contractile Dysfunction Associated with Intracellular Ca2+ Handling. Arq Bras Cardiol 2015; 105:588-96. [PMID: 26761369 PMCID: PMC4693663 DOI: 10.5935/abc.20150134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 07/28/2015] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Diet-induced obesity is frequently used to demonstrate cardiac dysfunction. However, some rats, like humans, are susceptible to developing an obesity phenotype, whereas others are resistant to that. OBJECTIVE To evaluate the association between obesity resistance and cardiac function, and the impact of obesity resistance on calcium handling. METHODS Thirty-day-old male Wistar rats were distributed into two groups, each with 54 animals: control (C; standard diet) and obese (four palatable high-fat diets) for 15 weeks. After the experimental protocol, rats consuming the high-fat diets were classified according to the adiposity index and subdivided into obesity-prone (OP) and obesity-resistant (OR). Nutritional profile, comorbidities, and cardiac remodeling were evaluated. Cardiac function was assessed by papillary muscle evaluation at baseline and after inotropic maneuvers. RESULTS The high-fat diets promoted increase in body fat and adiposity index in OP rats compared with C and OR rats. Glucose, lipid, and blood pressure profiles remained unchanged in OR rats. In addition, the total heart weight and the weight of the left and right ventricles in OR rats were lower than those in OP rats, but similar to those in C rats. Baseline cardiac muscle data were similar in all rats, but myocardial responsiveness to a post-rest contraction stimulus was compromised in OP and OR rats compared with C rats. CONCLUSION Obesity resistance promoted specific changes in the contraction phase without changes in the relaxation phase. This mild abnormality may be related to intracellular Ca2+ handling.
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Affiliation(s)
| | - Ana Paula Lima-Leopoldo
- Departamento de Desportos, Centro de Educação Física e Desportos, Universidade Federal do Espírito Santo, Vitória, ES, Brazil
| | - Bruno Barcellos Jacobsen
- Departamento de Desportos, Centro de Educação Física e Desportos, Universidade Federal do Espírito Santo, Vitória, ES, Brazil
| | - Artur Junio Togneri Ferron
- Departamento de Desportos, Centro de Educação Física e Desportos, Universidade Federal do Espírito Santo, Vitória, ES, Brazil
| | - Wagner Muller Estevam
- Departamento de Desportos, Centro de Educação Física e Desportos, Universidade Federal do Espírito Santo, Vitória, ES, Brazil
| | - Dijon Henrique Salomé Campos
- Departamento de Clínica Médica, Faculdade de Medicina, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Edson Castardeli
- Departamento de Desportos, Centro de Educação Física e Desportos, Universidade Federal do Espírito Santo, Vitória, ES, Brazil
| | - Márcia Regina Holanda da Cunha
- Departamento de Desportos, Centro de Educação Física e Desportos, Universidade Federal do Espírito Santo, Vitória, ES, Brazil
| | - Antonio Carlos Cicogna
- Departamento de Clínica Médica, Faculdade de Medicina, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - André Soares Leopoldo
- Departamento de Desportos, Centro de Educação Física e Desportos, Universidade Federal do Espírito Santo, Vitória, ES, Brazil
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20
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Duffy CM, Yuan C, Wisdorf LE, Billington CJ, Kotz CM, Nixon JP, Butterick TA. Role of orexin A signaling in dietary palmitic acid-activated microglial cells. Neurosci Lett 2015; 606:140-4. [PMID: 26306651 DOI: 10.1016/j.neulet.2015.08.033] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 08/05/2015] [Accepted: 08/19/2015] [Indexed: 12/23/2022]
Abstract
Excess dietary saturated fatty acids such as palmitic acid (PA) induce peripheral and hypothalamic inflammation. Hypothalamic inflammation, mediated in part by microglial activation, contributes to metabolic dysregulation. In rodents, high fat diet-induced microglial activation results in nuclear translocation of nuclear factor-kappa B (NFκB), and increased central pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6). The hypothalamic neuropeptide orexin A (OXA, hypocretin 1) is neuroprotective in brain. In cortex, OXA can also reduce inflammation and neurodegeneration through a microglial-mediated pathway. Whether hypothalamic orexin neuroprotection mechanisms depend upon microglia is unknown. To address this issue, we evaluated effects of OXA and PA on inflammatory response in immortalized murine microglial and hypothalamic neuronal cell lines. We demonstrate for the first time in microglial cells that exposure to PA increases gene expression of orexin-1 receptor but not orexin-2 receptor. Pro-inflammatory markers IL-6, TNF-α, and inducible nitric oxide synthase in microglial cells are increased following PA exposure, but are reduced by pretreatment with OXA. The anti-inflammatory marker arginase-1 is increased by OXA. Finally, we show hypothalamic neurons exposed to conditioned media from PA-challenged microglia have increased cell survival only when microglia were pretreated with OXA. These data support the concept that OXA may act as an immunomodulatory regulator of microglia, reducing pro-inflammatory cytokines and increasing anti-inflammatory factors to promote a favorable neuronal microenvironment.
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Affiliation(s)
- Cayla M Duffy
- Veterans Administration Medical Center, Minneapolis, MN, USA; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, USA
| | - Ce Yuan
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, USA
| | - Lauren E Wisdorf
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, USA
| | - Charles J Billington
- Veterans Administration Medical Center, Minneapolis, MN, USA; Department of Medicine, University of Minnesota, Minneapolis, MN, USA; Minnesota Obesity Center, St Paul, MN USA
| | - Catherine M Kotz
- Veterans Administration Medical Center, Minneapolis, MN, USA; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, USA; Minnesota Obesity Center, St Paul, MN USA
| | - Joshua P Nixon
- Veterans Administration Medical Center, Minneapolis, MN, USA; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, USA
| | - Tammy A Butterick
- Veterans Administration Medical Center, Minneapolis, MN, USA; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, USA.
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21
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Nixon JP, Mavanji V, Butterick TA, Billington CJ, Kotz CM, Teske JA. Sleep disorders, obesity, and aging: the role of orexin. Ageing Res Rev 2015; 20:63-73. [PMID: 25462194 DOI: 10.1016/j.arr.2014.11.001] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 09/19/2014] [Accepted: 11/14/2014] [Indexed: 02/03/2023]
Abstract
The hypothalamic neuropeptides orexin A and B (hypocretin 1 and 2) are important homeostatic mediators of central control of energy metabolism and maintenance of sleep/wake states. Dysregulation or loss of orexin signaling has been linked to narcolepsy, obesity, and age-related disorders. In this review, we present an overview of our current understanding of orexin function, focusing on sleep disorders, energy balance, and aging, in both rodents and humans. We first discuss animal models used in studies of obesity and sleep, including loss of function using transgenic or viral-mediated approaches, gain of function models using exogenous delivery of orexin receptor agonist, and naturally-occurring models in which orexin responsiveness varies by individual. We next explore rodent models of orexin in aging, presenting evidence that orexin loss contributes to age-related changes in sleep and energy balance. In the next section, we focus on clinical importance of orexin in human obesity, sleep, and aging. We include discussion of orexin loss in narcolepsy and potential importance of orexin in insomnia, correlations between animal and human studies of age-related decline, and evidence for orexin involvement in age-related changes in cognitive performance. Finally, we present a summary of recent studies of orexin in neurodegenerative disease. We conclude that orexin acts as an integrative homeostatic signal influencing numerous brain regions, and that this pivotal role results in potential dysregulation of multiple physiological processes when orexin signaling is disrupted or lost.
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22
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Feng Y, Liu T, Li XQ, Liu Y, Zhu XY, Jankovic J, Pan TH, Wu YC. Neuroprotection by Orexin-A via HIF-1α induction in a cellular model of Parkinson's disease. Neurosci Lett 2014; 579:35-40. [PMID: 25038418 DOI: 10.1016/j.neulet.2014.07.014] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 07/01/2014] [Accepted: 07/08/2014] [Indexed: 01/20/2023]
Abstract
Orexin-A, a neuropeptide secreted by hypothalamic neurons, may be neuroprotective in many neurological conditions such as cerebral ischaemia. One mechanism postulated to be involved in the neuroprotection by Orexin-A is the induction of hypoxia inducible factor 1 alpha (HIF-1α). Parkinson's disease (PD) is a progressive neurodegenerative disorder and mitochondrial dysfunction has been demonstrated to play a role in its pathogenesis. Mitochondrial dysfunction may cause reduction of O2 consumption and subsequently activate prolyl hydroxylase, which leads to decreased level of HIF-1α. In this study, we used MPP(+)-treated SH-SY5Y cells as an in vitro cellular model of PD to test the role of Orexin-A as an inducer of HIF-1α. Our results showed that Orexin-A not only induced HIF-1α but also activated downstream targets of HIF-1α, such as vascular endothelial growth factor and erythropoietin. Thus, Orexin-A treatment attenuated MPP(+)-induced cell injury and this effect was blocked when HIF-1α was suppressed. Hence, we conclude that induction of HIF-1α is one of the mechanisms involved in the neuroprotection by Orexin-A.
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Affiliation(s)
- Ya Feng
- Department of Neurology, Shanghai First People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, PR China
| | - Te Liu
- Shanghai Geriatric Institute of Chinese Medicine, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200031, PR China
| | - Xin-Qun Li
- Department of Experimental Therapeutics, M.D. Anderson Cancer Center, Houston, TX 77030, USA
| | - Ye Liu
- Department of Neurology, Shanghai First People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, PR China
| | - Xiao-Ying Zhu
- Department of Neurology, Shanghai First People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, PR China
| | - Joseph Jankovic
- Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Tian-Hong Pan
- Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Yun-Cheng Wu
- Department of Neurology, Shanghai First People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, PR China.
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23
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Kistner A, Lhommée E, Krack P. Mechanisms of body weight fluctuations in Parkinson's disease. Front Neurol 2014; 5:84. [PMID: 24917848 PMCID: PMC4040467 DOI: 10.3389/fneur.2014.00084] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 05/16/2014] [Indexed: 11/13/2022] Open
Abstract
Typical body weight changes are known to occur in Parkinson’s disease (PD). Weight loss has been reported in early stages as well as in advanced disease and malnutrition may worsen the clinical state of the patient. On the other hand, an increasing number of patients show weight gain under dopamine replacement therapy or after surgery. These weight changes are multifactorial and involve changes in energy expenditure, perturbation of homeostatic control, and eating behavior modulated by dopaminergic treatment. Comprehension of the different mechanisms contributing to body weight is a prerequisite for the management of body weight and nutritional state of an individual PD patient. This review summarizes the present knowledge and highlights the necessity of evaluation of body weight and related factors, as eating behavior, energy intake, and expenditure in PD.
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Affiliation(s)
- Andrea Kistner
- Movement Disorder Unit, Department of Psychiatry and Neurology, University Hospital Grenoble , Grenoble , France ; Unité 836, Équipe 11, INSERM, Grenoble Institut des Neurosciences , Grenoble , France
| | - Eugénie Lhommée
- Movement Disorder Unit, Department of Psychiatry and Neurology, University Hospital Grenoble , Grenoble , France ; Unité 836, Équipe 11, INSERM, Grenoble Institut des Neurosciences , Grenoble , France
| | - Paul Krack
- Movement Disorder Unit, Department of Psychiatry and Neurology, University Hospital Grenoble , Grenoble , France ; Unité 836, Équipe 11, INSERM, Grenoble Institut des Neurosciences , Grenoble , France ; Joseph Fourier University , Grenoble , France
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