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Braun A, Manavis J, Yamanaka A, Ootsuka Y, Blumbergs P, Bobrovskaya L. The role of orexin in Parkinson's disease. J Neurosci Res 2024; 102:e25322. [PMID: 38520160 DOI: 10.1002/jnr.25322] [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: 09/01/2023] [Revised: 02/28/2024] [Accepted: 03/09/2024] [Indexed: 03/25/2024]
Abstract
Emerging evidence has implicated the orexin system in non-motor pathogenesis of Parkinson's disease. It has also been suggested the orexin system is involved in the modulation of motor control, further implicating the orexin system in Parkinson's disease. Parkinson's disease is the second most common neurodegenerative disease with millions of people suffering worldwide with motor and non-motor symptoms, significantly affecting their quality of life. Treatments are based solely on symptomatic management and no cure currently exists. The orexin system has the potential to be a treatment target in Parkinson's disease, particularly in the non-motor stage. In this review, the most current evidence on the orexin system in Parkinson's disease and its potential role in motor and non-motor symptoms of the disease is summarized. This review begins with a brief overview of Parkinson's disease, animal models of the disease, and the orexin system. This leads into discussion of the possible roles of orexin neurons in Parkinson's disease and levels of orexin in the cerebral spinal fluid and plasma in Parkinson's disease and animal models of the disease. The role of orexin is then discussed in relation to symptoms of the disease including motor control, sleep, cognitive impairment, psychological behaviors, and the gastrointestinal system. The neuroprotective effects of orexin are also summarized in preclinical models of the disease.
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Affiliation(s)
- Alisha Braun
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Jim Manavis
- Discipline of Anatomy and Pathology, Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | | | - Youichirou Ootsuka
- College of Medicine and Public Health, Flinders Medical and Health Research Institute, Flinders University, Adelaide, South Australia, Australia
| | - Peter Blumbergs
- Discipline of Anatomy and Pathology, Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Larisa Bobrovskaya
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
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Ball HL, Said H, Chapman K, Fu R, Xiong Y, Burk JA, Rosenbaum D, Veneziano R, Cotten ML. Orexin A, an amphipathic α-helical neuropeptide involved in pleiotropic functions in the nervous and immune systems: Synthetic approach and biophysical studies of the membrane-bound state. Biophys Chem 2023; 297:107007. [PMID: 37037119 DOI: 10.1016/j.bpc.2023.107007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/11/2023] [Accepted: 03/12/2023] [Indexed: 03/16/2023]
Abstract
This research reports on the membrane interactions of orexin A (OXA), an α-helical and amphipathic neuropeptide that contains 33 residues and two disulfide bonds in the N-terminal region. OXA, which activates the orexins 1 and 2 receptors in neural and immune cell membranes, has essential pleiotropic physiological effects, including at the levels of arousal, sleep/wakefulness, energy balance, neuroprotection, lipid signaling, the inflammatory response, and pain. As a result, the orexin system has become a prominent target to treat diseases such as sleep disorders, drug addiction, and inflammation. While the high-resolution structure of OXA has been investigated in water and bound to micelles, there is a lack of information about its conformation bound to phospholipid membranes and its receptors. NMR is a powerful method to investigate peptide structures in a membrane environment. To facilitate the NMR structural studies of OXA exposed to membranes, we present a novel synthetic scheme, leading to the production of isotopically-labeled material at high purity. A receptor activation assay shows that the 15N-labeled peptide is biologically active. Biophysical studies are performed using surface plasmon resonance, circular dichroism, and NMR to investigate the interactions of OXA with phospholipid bilayers. The results demonstrate a strong interaction between the peptide and phospholipids, an increase in α-helical content upon membrane binding, and an in-plane orientation of the C-terminal region critical to function. This new knowledge about structure-activity relationships in OXA could inspire the design of novel therapeutics that leverage the anti-inflammatory and neuro-protective functions of OXA, and therefore could help address neuroinflammation, a major issue associated with neurological disorders such as Alzheimer's disease.
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Affiliation(s)
- Haydn L Ball
- Department of Chemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Hooda Said
- Department of Bioengineering, College of Engineering and Computing, George Mason University, Fairfax, VA 22030, USA
| | - Karen Chapman
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Riqiang Fu
- National High Magnetic Field Laboratory, Tallahassee, FL 32310, USA
| | - Yawei Xiong
- Department of Applied Science, William & Mary, Williamsburg, VA 23185, USA
| | - Joshua A Burk
- Department of Psychological Sciences, William & Mary, Williamsburg, VA 23185, USA
| | - Daniel Rosenbaum
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Remi Veneziano
- Department of Bioengineering, College of Engineering and Computing, George Mason University, Fairfax, VA 22030, USA
| | - Myriam L Cotten
- Department of Applied Science, William & Mary, Williamsburg, VA 23185, USA.
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Chatterjee O, Gopalakrishnan L, Pullimamidi D, Raj C, Yelamanchi S, Gangadharappa BS, Nair B, Mahadevan A, Raju R, Keshava Prasad TS. A molecular network map of orexin-orexin receptor signaling system. J Cell Commun Signal 2023; 17:217-227. [PMID: 36480100 PMCID: PMC10030760 DOI: 10.1007/s12079-022-00700-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 09/04/2022] [Accepted: 09/15/2022] [Indexed: 12/13/2022] Open
Abstract
Orexins are excitatory neuropeptides, which are predominantly associated with feeding behavior, sleep-wake cycle and energy homeostasis. The orexinergic system comprises of HCRTR1 and HCRTR2, G-protein-coupled receptors of rhodopsin family and the endogenous ligands processed from HCRT pro-hormone, Orexin A and Orexin B. These neuropeptides are biosynthesized by the orexin neurons present in the lateral hypothalamus area, with dense projections to other brain regions. The orexin-receptor signaling is implicated in various metabolic as well as neurological disorders, making it a promising target for pharmacological interventions. However, there is limited information available on the collective representation of the signal transduction pathways pertaining to the orexin-orexin receptor signaling system. Here, we depict a compendium of the Orexin A/B stimulated reactions in the form of a basic signaling pathway map. This map catalogs the reactions into five categories: molecular association, activation/inhibition, catalysis, transport, and gene regulation. A total of 318 downstream molecules were annotated adhering to the guidelines of NetPath curation. This pathway map can be utilized for further assessment of signaling events associated with orexin-mediated physiological functions and is freely available on WikiPathways, an open-source pathway database ( https://www.wikipathways.org/index.php/Pathway:WP5094 ).
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Affiliation(s)
- Oishi Chatterjee
- Institute of Bioinformatics, International Tech Park, 560 066, Bangalore, India
- Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, 690 525, Kollam, India
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), 575 018, Mangalore, India
| | - Lathika Gopalakrishnan
- Institute of Bioinformatics, International Tech Park, 560 066, Bangalore, India
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), 575 018, Mangalore, India
- Manipal Academy of Higher Education (MAHE), 576 104, Manipal, India
| | | | - Chinmayi Raj
- Institute of Bioinformatics, International Tech Park, 560 066, Bangalore, India
| | - Soujanya Yelamanchi
- Institute of Bioinformatics, International Tech Park, 560 066, Bangalore, India
| | | | - Bipin Nair
- Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, 690 525, Kollam, India
| | - Anita Mahadevan
- Human Brain Tissue Repository, Neurobiology Research Centre, National Institute of Mental Health and Neurosciences, 560 029, Bangalore, India
- Department of Neuropathology, Neurobiology Research Centre, National Institute of Mental Health and Neurosciences, 560 029, Bangalore, India
| | - Rajesh Raju
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), 575 018, Mangalore, India.
| | - T S Keshava Prasad
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), 575 018, Mangalore, India.
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RNAseq Analysis of FABP4 Knockout Mouse Hippocampal Transcriptome Suggests a Role for WNT/β-Catenin in Preventing Obesity-Induced Cognitive Impairment. Int J Mol Sci 2023; 24:ijms24043381. [PMID: 36834799 PMCID: PMC9961923 DOI: 10.3390/ijms24043381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/02/2023] [Accepted: 02/06/2023] [Indexed: 02/10/2023] Open
Abstract
Microglial fatty-acid binding protein 4 (FABP4) is a regulator of neuroinflammation. We hypothesized that the link between lipid metabolism and inflammation indicates a role for FABP4 in regulating high fat diet (HFD)-induced cognitive decline. We have previously shown that obese FABP4 knockout mice exhibit decreased neuroinflammation and cognitive decline. FABP4 knockout and wild type mice were fed 60% HFD for 12 weeks starting at 15 weeks old. Hippocampal tissue was dissected and RNA-seq was performed to measure differentially expressed transcripts. Reactome molecular pathway analysis was utilized to examine differentially expressed pathways. Results showed that HFD-fed FABP4 knockout mice have a hippocampal transcriptome consistent with neuroprotection, including associations with decreased proinflammatory signaling, ER stress, apoptosis, and cognitive decline. This is accompanied by an increase in transcripts upregulating neurogenesis, synaptic plasticity, long-term potentiation, and spatial working memory. Pathway analysis revealed that mice lacking FABP4 had changes in metabolic function that support reduction in oxidative stress and inflammation, and improved energy homeostasis and cognitive function. Analysis suggested a role for WNT/β-Catenin signaling in the protection against insulin resistance, alleviating neuroinflammation and cognitive decline. Collectively, our work shows that FABP4 represents a potential target in alleviating HFD-induced neuroinflammation and cognitive decline and suggests a role for WNT/β-Catenin in this protection.
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Costello A, Linning-Duffy K, Vandenbrook C, Lonstein JS, Yan L. Effects of bright light therapy on neuroinflammatory and neuroplasticity markers in a diurnal rodent model of Seasonal Affective Disorder. Ann Med 2023; 55:2249015. [PMID: 37625385 PMCID: PMC10461522 DOI: 10.1080/07853890.2023.2249015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/09/2023] [Accepted: 08/14/2023] [Indexed: 08/27/2023] Open
Abstract
BACKGROUND Bright light therapy (BLT) is widely used for treating Seasonal Affective Disorder (SAD). However, the neural mechanisms underlying the therapeutic effects of BLT remain largely unexplored. The present study used a diurnal rodent (Nile grass rats; Arvicanthis niloticus) to test the hypothesis that the therapeutic effects of BLT could be, in part, due to reduced neuroinflammation and/or enhanced neuroplasticity. Our previous research has demonstrated that compared to grass rats housed in a summer-like daytime bright light condition (1000 lux), those housed in a winter-like daytime dim light condition (50 lux) showed increased depression- and anxiety-like behaviours, as well as impaired sociosexual behaviours and spatial memory, similar to what is observed in patients suffering from SAD. MATERIALS AND METHODS In the present study, male and female grass rats were housed under the winter-like dim daytime light condition (lights on 600-1800 hr, 50 lux). The experimental groups received daily 1-h early morning BLT from 0600-0700 using full-spectrum light (10,000 lux), while the control groups received narrowband red light (λmax, 780 nm). Following 4 weeks of treatment, the expression of several neuroinflammatory or plasticity markers was examined in the medial prefrontal cortex (mPFC), basolateral amygdala (BLA), and the CA1 of the dorsal hippocampus. RESULTS For the neuroinflammatory markers, BLT reduced TNF-α in the BLA of females, and upregulated CD11b in the mPFC and IL6 in the BLA in males. For the neuroplasticity markers, BLT downregulated BDNF in the CA1 and TrkB in all three brain regions in females but upregulated BDNF in the BLA and CA1 in males. CONCLUSIONS These results indicate that the therapeutic effects of BLT on sleep, mood, and cognition may be attributed in part to mechanisms involving neuroinflammation and neuroplasticity in corticolimbic brain regions. Moreover, these effects appear to vary between sexes.
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Affiliation(s)
| | | | | | - Joseph S. Lonstein
- Department of Psychology, MI State University, MI, USA
- Neuroscience Program, Michigan State University, MI, USA
| | - Lily Yan
- Department of Psychology, MI State University, MI, USA
- Neuroscience Program, Michigan State University, MI, USA
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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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Microglial FABP4-UCP2 Axis Modulates Neuroinflammation and Cognitive Decline in Obese Mice. Int J Mol Sci 2022; 23:ijms23084354. [PMID: 35457171 PMCID: PMC9032181 DOI: 10.3390/ijms23084354] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 04/07/2022] [Accepted: 04/11/2022] [Indexed: 01/22/2023] Open
Abstract
The microglial fatty-acid-binding protein 4-uncoupling protein 2 (FABP4-UCP2) axis is a key regulator of neuroinflammation in high-fat-diet (HFD)-fed animals, indicating a role for FABP4 in brain immune response. We hypothesized that the FABP4-UCP2 axis is involved in regulating diet-induced cognitive decline. We tested cognitive function in mice lacking microglial FABP4 (AKO mice). Fifteen-week-old male AKO and wild-type (WT) mice were maintained on 60% HFD or normal chow (NC) for 12 weeks. Body composition was measured using EchoMRI. Locomotor activity, working memory, and spatial memory were assessed using behavioral tests (open field, T-maze, and Barnes maze, respectively). Hippocampal microgliosis was assessed via immunohistochemical staining. An inflammatory cytokine panel was assayed using hippocampal tissue. Real-time RT-PCR was performed to measure microglial UCP2 mRNA expression. Our data support that loss of FABP4 prevents cognitive decline in vivo. HFD-fed WT mice exhibited impaired long- and short-term memory, in contrast with HFD-fed AKO mice. HFD-fed WT mice had an increase in hippocampal inflammatory cytokine expression (IFNγ, IL-1β, IL-5, IL-6, KC/GRO(CXCL1), IL-10, and TNFα) and microgliosis, and decreased microglial UCP2 expression. HFD-fed AKO mice had decreased hippocampal inflammatory cytokine expression and microgliosis and increased microglial UCP2 expression compared to HFD-fed WT mice. Collectively, our work supports the idea that the FABP4-UCP2 axis represents a potential therapeutic target in preventing diet-induced cognitive decline.
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Sunkaria A, Bhardwaj S. Sleep Disturbance and Alzheimer's Disease: The Glial Connection. Neurochem Res 2022; 47:1799-1815. [PMID: 35303225 DOI: 10.1007/s11064-022-03578-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 02/27/2022] [Accepted: 03/09/2022] [Indexed: 12/28/2022]
Abstract
Poor quality and quantity of sleep are very common in elderly people throughout the world. Growing evidence has suggested that sleep disturbances could accelerate the process of neurodegeneration. Recent reports have shown a positive correlation between sleep deprivation and amyloid-β (Aβ)/tau aggregation in the brain of Alzheimer's patients. Glial cells have long been implicated in the progression of Alzheimer's disease (AD) and recent findings have also suggested their role in regulating sleep homeostasis. However, how glial cells control the sleep-wake balance and exactly how disturbed sleep may act as a trigger for Alzheimer's or other neurological disorders have recently gotten attention. In an attempt to connect the dots, the present review has highlighted the role of glia-derived sleep regulatory molecules in AD pathogenesis. Role of glia in sleep disturbance and Alzheimer's progression.
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Affiliation(s)
- Aditya Sunkaria
- Department of Biotechnology, Guru Nanak Dev University, Amritsar, Punjab, 143005, India.
| | - Supriya Bhardwaj
- Department of Dermatology, Postgraduate Institute of Medical Education and Research, Chandigarh, 160012, India
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Ramser A, Dridi S. Avian Orexin: Feed Intake Regulator or Something Else? Vet Sci 2022; 9:vetsci9030112. [PMID: 35324840 PMCID: PMC8950792 DOI: 10.3390/vetsci9030112] [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] [Received: 01/17/2022] [Revised: 02/25/2022] [Accepted: 03/02/2022] [Indexed: 02/04/2023] Open
Abstract
Originally named for its expression in the posterior hypothalamus in rats and after the Greek word for “appetite”, hypocretin, or orexin, as it is known today, gained notoriety as a neuropeptide regulating feeding behavior, energy homeostasis, and sleep. Orexin has been proven to be involved in both central and peripheral control of neuroendocrine functions, energy balance, and metabolism. Since its discovery, its ability to increase appetite as well as regulate feeding behavior has been widely explored in mammalian food production animals such as cattle, pigs, and sheep. It is also linked to neurological disorders, leading to its intensive investigation in humans regarding narcolepsy, depression, and Alzheimer’s disease. However, in non-mammalian species, research is limited. In the case of avian species, orexin has been shown to have no central effect on feed-intake, however it was found to be involved in muscle energy metabolism and hepatic lipogenesis. This review provides current knowledge and summarizes orexin’s physiological roles in livestock and pinpoints the present lacuna to facilitate further investigations.
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Affiliation(s)
- Alison Ramser
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA;
- Cell and Molecular Biology Program, Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Sami Dridi
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA;
- Cell and Molecular Biology Program, Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
- Correspondence: ; Tel.: +1-(479)-575-2583; Fax: +1-(479)-575-7139
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Boushra AF, Mahmoud RH, Ayoub SE, Mohammed RA, Shamardl HA, El Amin Ali AM. The Potential Therapeutic Effect of Orexin-Treated versus Orexin-Untreated Adipose Tissue-Derived Mesenchymal Stem Cell Therapy on Insulin Resistance in Type 2 Diabetic Rats. J Diabetes Res 2022; 2022:9832212. [PMID: 35083338 PMCID: PMC8786498 DOI: 10.1155/2022/9832212] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 12/05/2021] [Accepted: 12/20/2021] [Indexed: 11/18/2022] Open
Abstract
Type 2 diabetes mellitus is a chronic metabolic disease characterized by resistance to peripheral insulin actions. Mesenchymal stem cells have been studied for years in T2DM therapy, including adipose tissue-derived mesenchymal stem cells (AD-MSCs). Orexin neuropeptides (A and B) are well-known regulators of appetite and physical activity. The aim of this work was to elucidate the possible therapeutic effect of AD-MSC preconditioning with orexin A (OXA) on insulin resistance in rats. Twenty-eight adult male albino rats were divided into 4 equal groups: a normal control group and 3 diabetic groups (a control T2DM group, diabetic rats treated by an AD-MSCs group, and diabetic rats treated by AD-MSCs preconditioned with OXA). We noticed that the treated groups showed a significant alleviation of insulin resistance parameters as shown in lowering the serum levels of glucose, insulin, total cholesterol, inflammatory markers, and HOMA-IR as compared to the control diabetic group with more significant reduction observed in the OXA-pretreated AD-MSCs-administrated group. More improvement was also noted in the glucose uptake and GLUT-4 gene expression in the skeletal muscle and adipose tissue in the OXA-pretreated AD-MSCs-administrated group compared to the untreated diabetic group. Conclusion. Preconditioning of AD-MSCs with OXA can significantly increase their potential to reduce the insulin resistance in the rat model of T2DM.
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Affiliation(s)
- Amy F. Boushra
- Department of Medical Physiology, Faculty of Medicine, Fayoum University, Egypt
| | - Rania H. Mahmoud
- Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Fayoum University, Egypt
| | - Shymaa E. Ayoub
- Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Fayoum University, Egypt
| | - Rehab A. Mohammed
- Department of Medical Physiology, Faculty of Medicine, Fayoum University, Egypt
| | - Hanan A. Shamardl
- Department of Medical Pharmacology Faculty of Medicine, Fayoum University, Egypt
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Orexin-A Regulates Follicular Growth, Proliferation, Cell Cycle and Apoptosis in Mouse Primary Granulosa Cells via the AKT/ERK Signaling Pathway. Molecules 2021; 26:molecules26185635. [PMID: 34577105 PMCID: PMC8467508 DOI: 10.3390/molecules26185635] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/08/2021] [Accepted: 09/12/2021] [Indexed: 11/16/2022] Open
Abstract
Granulosa cells (GCs) are essential for follicular growth, development, and atresia. The orexin-A (OXA) neuropeptide is widely involved in the regulation of various biological functions. OXA selectively binds to orexin receptor type 1 (OX1R) and mediates all its biological actions via OX1R. This study aimed to explore the expression of OXA and OX1R and their regulatory role in GCs proliferation, cell cycle progression, apoptosis, oocyte maturation, and underlying molecular mechanisms of these processes and elucidate its novel signaling pathway. Western blotting and RT-qPCR showed that OXA and OX1R were expressed during different developmental stages of GCs, and siRNA transfection successfully inhibited the expression of OX1R at the translational and transcriptional levels. Flow cytometry revealed that OX1R knockdown upregulated GCs apoptosis and triggered S-phase arrest in cell cycle progression. RT-qPCR and Western blotting showed significantly reduced expression of Bcl-2 and elevated expression of Bax, caspase-3, TNF-α, and P21 in OX1R-silenced GCs. Furthermore, the CCK-8 assay showed that knockdown of OX1R suppressed GCs proliferation by downregulating the expression of PCNA, a proliferation marker gene, at the translational and transcriptional levels. Western blotting revealed that knockdown of OX1R resulted in a considerable decrease of the phosphorylation level of the AKT and ERK1/2 proteins, indicating that the AKT/ERK1/2 pathway is involved in regulating GCs proliferation and apoptosis. In addition, OX1R silencing enhanced the mRNA expression of GDF9 and suppressed the mRNA expression of BMP15 in mouse GCs. Collectively, these results reveal a novel regulatory role of OXA in the development of GCs and folliculogenesis by regulating proliferation, apoptosis, and cell cycle progression. Therefore, OXA can be a promising therapeutic agent for female infertility.
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La Torre ME, Villano I, Monda M, Messina A, Cibelli G, Valenzano A, Pisanelli D, Panaro MA, Tartaglia N, Ambrosi A, Carotenuto M, Monda V, Messina G, Porro C. Role of Vitamin E and the Orexin System in Neuroprotection. Brain Sci 2021; 11:brainsci11081098. [PMID: 34439717 PMCID: PMC8394512 DOI: 10.3390/brainsci11081098] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/13/2021] [Accepted: 08/16/2021] [Indexed: 12/24/2022] Open
Abstract
Microglia are the first line of defense at the level of the central nervous system (CNS). Phenotypic change in microglia can be regulated by various factors, including the orexin system. Neuroinflammation is an inflammatory process mediated by cytokines, by the lack of interaction between neurotransmitters and their specific receptors, caused by systemic tissue damage or, more often, associated with direct damage to the CNS. Chronic activation of microglia could lead to long-term neurodegenerative diseases. This review aims to explore how tocopherol (vitamin E) and the orexin system may play a role in the prevention and treatment of microglia inflammation and, consequently, in neurodegenerative diseases thanks to its antioxidant properties. The results of animal and in vitro studies provide evidence to support the use of tocopherol for a reduction in microglia inflammation as well as a greater activation of the orexinergic system. Although there is much in vivo and in vitro evidence of vitamin E antioxidant and protective abilities, there are still conflicting results for its use as a treatment for neurodegenerative diseases that speculate that vitamin E, under certain conditions or genetic predispositions, can be pro-oxidant and harmful.
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Affiliation(s)
- Maria Ester La Torre
- Department of Clinical and Experimental Medicine, University of Foggia, 71122 Foggia, Italy; (M.E.L.T.); (G.C.); (A.V.); (D.P.); (C.P.)
| | - Ines Villano
- Department of Experimental Medicine, Section of Human Physiology and Unit of Dietetics and Sports Medicine, Università degli Studi della Campania “Luigi Vanvitelli”, 80100 Naples, Italy; (I.V.); (M.M.); (A.M.); (V.M.)
| | - Marcellino Monda
- Department of Experimental Medicine, Section of Human Physiology and Unit of Dietetics and Sports Medicine, Università degli Studi della Campania “Luigi Vanvitelli”, 80100 Naples, Italy; (I.V.); (M.M.); (A.M.); (V.M.)
| | - Antonietta Messina
- Department of Experimental Medicine, Section of Human Physiology and Unit of Dietetics and Sports Medicine, Università degli Studi della Campania “Luigi Vanvitelli”, 80100 Naples, Italy; (I.V.); (M.M.); (A.M.); (V.M.)
| | - Giuseppe Cibelli
- Department of Clinical and Experimental Medicine, University of Foggia, 71122 Foggia, Italy; (M.E.L.T.); (G.C.); (A.V.); (D.P.); (C.P.)
| | - Anna Valenzano
- Department of Clinical and Experimental Medicine, University of Foggia, 71122 Foggia, Italy; (M.E.L.T.); (G.C.); (A.V.); (D.P.); (C.P.)
| | - Daniela Pisanelli
- Department of Clinical and Experimental Medicine, University of Foggia, 71122 Foggia, Italy; (M.E.L.T.); (G.C.); (A.V.); (D.P.); (C.P.)
| | - Maria Antonietta Panaro
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, 70125 Bari, Italy;
| | - Nicola Tartaglia
- Department of Medical and Surgical Sciences, University of Foggia, Viale Pinto, 71122 Foggia, Italy; (N.T.); (A.A.)
| | - Antonio Ambrosi
- Department of Medical and Surgical Sciences, University of Foggia, Viale Pinto, 71122 Foggia, Italy; (N.T.); (A.A.)
| | - Marco Carotenuto
- Clinic of Child and Adolescent Neuropsychiatry, Department of Mental Health, Physical and Preventive Medicine, Università degli Studi della Campania “Luigi Vanvitelli”, 80100 Naples, Italy;
| | - Vincenzo Monda
- Department of Experimental Medicine, Section of Human Physiology and Unit of Dietetics and Sports Medicine, Università degli Studi della Campania “Luigi Vanvitelli”, 80100 Naples, Italy; (I.V.); (M.M.); (A.M.); (V.M.)
| | - Giovanni Messina
- Department of Clinical and Experimental Medicine, University of Foggia, 71122 Foggia, Italy; (M.E.L.T.); (G.C.); (A.V.); (D.P.); (C.P.)
- Correspondence: ; Tel.: +39-8815-88095
| | - Chiara Porro
- Department of Clinical and Experimental Medicine, University of Foggia, 71122 Foggia, Italy; (M.E.L.T.); (G.C.); (A.V.); (D.P.); (C.P.)
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13
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Zhu J, Tang S, Zhao D, Zeng Z, Mo H, Hu K. Orexin A improves the cognitive impairment induced by chronic intermittent hypoxia in mice. Brain Res Bull 2021; 173:203-210. [PMID: 34051297 DOI: 10.1016/j.brainresbull.2021.05.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 05/09/2021] [Accepted: 05/24/2021] [Indexed: 01/04/2023]
Abstract
The orexin neuron in lateral hypothalamus (LH) was involved in the regulation of sleep-wake cycle. However, the effect of orexin A (OXA) on cognitive impairment resulting from diverse diseases remains controversial. In this study, we investigated the effect of OXA on cognitive impairment induced by chronic intermittent hypoxia (CIH) in mice. Adult (10 weeks old) male C57BL/6 mice were randomly divided into the following four groups: normoxia control (NC)+normal saline (NS), NC + OXA, CIH + NS and CIH + OXA group. Following the CIH mice models establishment, OXA was injected into the right lateral ventricles of mice by a micro-injection system. Water maze test was used to assess spatial memory abilities of the mice. The expression of OXA and c-Fos in LH were analyzed by immunofluorescence staining. Apoptotic cell death and oxidative stress in hippocampus were evaluated using multiple methods including TUNEL, western blot and biochemical analysis. Behavioral tests revealed that CIH significantly increased the escape latency and time of arriving platform, of which were markedly decreased by OXA treatment. Similarly, the CIH + NS group was worse than NC + NS group in terms of the number of platform crossing and time in the target quadrant, of which were also significantly improved by OXA treatment. The number of OXA + neuron in LH was decreased, but the percentage of c-Fos+/OXA + neuron in LH was remarkably increased by CIH. Furthermore, we found that micro-injection of OXA attenuated CIH-induced apoptotic cell death and oxidative stress in the hippocampus. Our results suggested that OXA might improve cognitive impairment induced by CIH through inhibiting hippocampal apoptosis and oxidative stress.
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Affiliation(s)
- Jing Zhu
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, Hubei, China; Department of Respiratory and Critical Care Medicine, the People's Hospital of China Three Gorges University, Yichang, Hubei, China
| | - Si Tang
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Dong Zhao
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Zhaofu Zeng
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Huaheng Mo
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Ke Hu
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Wuhan, Hubei, China.
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14
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Erichsen JM, Calva CB, Reagan LP, Fadel JR. Intranasal insulin and orexins to treat age-related cognitive decline. Physiol Behav 2021; 234:113370. [PMID: 33621561 PMCID: PMC8053680 DOI: 10.1016/j.physbeh.2021.113370] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 02/19/2021] [Indexed: 02/06/2023]
Abstract
The intranasal (IN) administration of neuropeptides, such as insulin and orexins, has been suggested as a treatment strategy for age-related cognitive decline (ARCD). Because dysfunctional neuropeptide signaling is an observed characteristic of ARCD, it has been suggested that IN delivery of insulin and/or orexins may restore endogenous peptide signaling and thereby preserve cognition. IN administration is particularly alluring as it is a relatively non-invasive method that directly targets peptides to the brain. Several laboratories have examined the behavioral effects of IN insulin in young, aged, and cognitively impaired rodents and humans. These studies demonstrated improved performance on various cognitive tasks following IN insulin administration. Fewer laboratories have assessed the effects of IN orexins; however, this peptide also holds promise as an effective treatment for ARCD through the activation of the cholinergic system and/or the reduction of neuroinflammation. Here, we provide a brief overview of the advantages of IN administration and the delivery pathway, then summarize the current literature on IN insulin and orexins. Additional preclinical studies will be useful to ultimately uncover the mechanisms underlying the pro-cognitive effects of IN insulin and orexins, whereas future clinical studies will aid in the determination of the most efficacious dose and dosing paradigm. Eventually, IN insulin and/or orexin administration may be a widely used treatment strategy in the clinic for ARCD.
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Affiliation(s)
- Jennifer M Erichsen
- University of South Carolina School of Medicine, Department of Pharmacology, Physiology, and Neuroscience, Columbia, SC 29208, United States.
| | - Coleman B Calva
- University of South Carolina School of Medicine, Department of Pharmacology, Physiology, and Neuroscience, Columbia, SC 29208, United States
| | - Lawrence P Reagan
- University of South Carolina School of Medicine, Department of Pharmacology, Physiology, and Neuroscience, Columbia, SC 29208, United States; Columbia VA Health Care System, Columbia, SC, 29208, United States
| | - Jim R Fadel
- University of South Carolina School of Medicine, Department of Pharmacology, Physiology, and Neuroscience, Columbia, SC 29208, United States
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15
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Abstract
Twenty-two years after their discovery, the hypocretins (Hcrts), also known as orexins, are two of the most studied peptidergic systems, involved in myriad physiological systems that range from sleep, arousal, motivation, homeostatic regulation, fear, anxiety and learning. A causal relationship between activity of Hcrt and arousal stability was established shortly after their discovery and have led to the development of a new class of drugs to treat insomnia. In this review we discuss the many faces of the Hcrt system and examine recent findings that implicate decreased Hcrt function in the pathogenesis of a number of neuropsychiatric conditions. We also discuss future therapeutic strategies to replace or enhance Hcrt function as a treatment option for these neuropsychiatric conditions.
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Affiliation(s)
- Erica Seigneur
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA
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16
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Greene ES, Zampiga M, Sirri F, Ohkubo T, Dridi S. Orexin system is expressed in avian liver and regulates hepatic lipogenesis via ERK1/2 activation. Sci Rep 2020; 10:19191. [PMID: 33154530 PMCID: PMC7645691 DOI: 10.1038/s41598-020-76329-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 10/22/2020] [Indexed: 12/01/2022] Open
Abstract
Orexins are originally characterized as orexigenic hypothalamic neuropeptides in mammals. Subsequent studies found orexin to be expressed and perform pleiotropic functions in multiple tissues in mammals. In avian (non-mammalian) species, however, orexin seemed to not affect feeding behavior and its physiological roles are poorly understood. Here, we provide evidence that orexin and its related receptors are expressed in chicken hepatocytes. Double immunofluorescence staining showed that orexin is localized in the ER, Golgi, and in the lysosomes in LMH cells. Brefeldin A treatment reduced orexin levels in the culture media, but increased it in the cell lysates. Administration of recombinant orexins upregulated the expression of orexin system in the liver of 9-day old chicks, but did not affect feed intake. Recombinant orexins increased fatty acid synthase (FASN) protein levels in chicken liver, activated acetyl-CoA carboxylase (ACCα), and increased FASN, ATP citrate lyase(ACLY), and malic enzyme (ME) protein expression in LMH cells. Blockade ERK1/2 activation by PD98059 attenuated these stimulating effects of orexin on lipogenic factors. Overexpression of ERK1/2 increased the expression of lipogenic genes, and orexin treatment induced the phosphorylated levels of ERK1/2Thr202/Tyr204, but not that of p38 Thr180/Tyr182 or JNK1/2 Thr183/Tyr185 in chicken liver and LMH cells. Taken together, this is the first report evidencing that orexin is expressed and secreted from chicken hepatocytes, and that orexin induced hepatic lipogenesis via activation of ERK1/2 signaling pathway.
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Affiliation(s)
- E S Greene
- Center of Excellence for Poultry Science, University of Arkansas, 1260 W. Maple Street, Fayetteville, AR, 72701, USA
| | - M Zampiga
- Dipartimento Di Scienze E Tecnologie Agro-Alimentari, Alma Mater Studiorum-Università Di Bologna, Bologna, Italy
| | - F Sirri
- Dipartimento Di Scienze E Tecnologie Agro-Alimentari, Alma Mater Studiorum-Università Di Bologna, Bologna, Italy
| | - T Ohkubo
- College of Agriculture, Ibaraki University, Ibaraki, 300-0393, Japan
| | - Sami Dridi
- Center of Excellence for Poultry Science, University of Arkansas, 1260 W. Maple Street, Fayetteville, AR, 72701, USA.
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17
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Role of 2-Arachidonoyl-Glycerol and CB1 Receptors in Orexin-A-Mediated Prevention of Oxygen-Glucose Deprivation-Induced Neuronal Injury. Cells 2020; 9:cells9061507. [PMID: 32575773 PMCID: PMC7349736 DOI: 10.3390/cells9061507] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/17/2020] [Accepted: 06/18/2020] [Indexed: 11/16/2022] Open
Abstract
Orexin-A (OX-A) protects the brain against oxidative stress-mediated ischemic injury. Since the endocannabinoid 2-arachidonoylglycerol (2-AG) and cannabinoid type-1 (CB1) receptors were previously shown to mediate some of the effects of OX-A exerted through the orexin-1 receptor (OX-1R), we investigated the involvement of 2-AG in OX-A-induced neuroprotection following oxygen and glucose deprivation (OGD) in mouse cortical neurons. OGD-induced reactive oxygen species (ROS) accumulation and neuronal death were prevented by both OX-A and arachidonyl-2′-chloroethylamide (ACEA), a synthetic CB1 receptor agonist, in a manner sensitive to OX-1R and CB1 receptor antagonists, SB334867 and AM251. OX-A stimulated 2-AG biosynthesis in cortical neurons. In neurons isolated from monoacylglycerol lipase (MAGL, a 2-AG hydrolyzing enzyme) null mice, 10-fold higher 2-AG concentrations were found and OGD failed to induce ROS production and cell death, whereas AM251 restored these noxious effects. OX-A-induced neuroprotection was mediated by the phosphoinositide-3-kinase/Akt (PI3K/Akt) survival pathway since both OX-A and ACEA induced phosphorylation of Akt and prevented OGD-induced cytochrome c release from the mitochondria, in a manner counteracted by SB334867 or AM251. Administration of OX-A reduced infarct volume and elevated brain 2-AG levels in a mouse model of transient ischemia. These results suggest that 2-AG and CB1 receptor mediate OX-A prevention of ischemia-induced neuronal apoptosis.
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18
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Liu C, Xue Y, Liu MF, Wang Y, Chen L. Orexin and Parkinson's disease: A protective neuropeptide with therapeutic potential. Neurochem Int 2020; 138:104754. [PMID: 32422324 DOI: 10.1016/j.neuint.2020.104754] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 05/06/2020] [Accepted: 05/11/2020] [Indexed: 02/06/2023]
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disease caused by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta. PD is characterized by motor dysfunctions as well as non-motor disorders. Orexin (also known as hypocretin) is a kind of neuropeptide involved in the regulation of motor control, the sleep/wake cycle, learning and memory, gastric motility and respiratory function. Several lines of evidence suggest that the orexinergic system is involved in the manifestations of PD, especially the non-motor disorders. Recent studies have revealed the protective actions and potential therapeutic applications of orexin in both cellular and animal models of PD. Here we present a brief overview of the involvement of the orexinergic system in PD, including the pathological changes in the lateral hypothalamus, the loss of orexinergic neurons and the fluctuation of orexin levels in CSF. Furthermore, we also review the neuroprotective effects of orexin in cellular and animal models of PD.
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Affiliation(s)
- Cui Liu
- Department of Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Yan Xue
- Department of Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Mei-Fang Liu
- Department of Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Ying Wang
- Department of Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Lei Chen
- Department of Physiology, School of Basic Medicine, Qingdao University, Qingdao, China.
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19
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Orexins role in neurodegenerative diseases: From pathogenesis to treatment. Pharmacol Biochem Behav 2020; 194:172929. [PMID: 32315694 DOI: 10.1016/j.pbb.2020.172929] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 04/07/2020] [Accepted: 04/08/2020] [Indexed: 12/12/2022]
Abstract
Orexin is a neurotransmitter that mainly regulates sleep/wake cycle. In addition to its sleep cycle regulatory role, it is involved in regulation of attention, energy homeostasis, neurogenesis and cognition. Several evidences has shown the involvement of orexin in narcolepsy, but there are also growing evidences that shows the disturbance in orexin system in neurodegenerative diseases including Alzheimer's, Parkinson's, Epilepsy, Huntington's diseases and Amyotrophic lateral sclerosis. Pathogenesis and clinical symptoms of these disorders can be partly attributed from orexin system imbalance. However, there are controversial reports on the exact relationship between orexin and these neurodegenerative diseases. Therefore, the aim of this review is to summarize the current evidences regarding the role of orexin in these neurodegenerative diseases.
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20
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Han X, Zhou J, Peng W. Orexins Facilitates Osteogenic Differentiation of MC3T3-E1 Cells. IUBMB Life 2019; 70:633-641. [PMID: 29999239 DOI: 10.1002/iub.1757] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Accepted: 03/12/2018] [Indexed: 12/14/2022]
Abstract
Dysfunction of osteoblastic bone formation and matrix mineralization plays a key role in the pathological development of osteoporosis. The orexin peptide orexin-A, a highly excitatory neuropeptide hormone, possesses various biological functions by activating its specific G protein-coupled receptors, orexin-1 receptor (OX1R) and orexin-2 receptor (OX2R). Here, we report that OX1R but not OX2R was expressed in MC3T3-E1 cells. Importantly, we found that orexin-A accelerated osteoblast differentiation and matrix mineralization in MC3T3-E1 cells, as manifested by elevation of physiological markers of osteoblastic differentiation [alkaline phosphatase (ALP) and osteogenic genes] and Alizarin Red staining, respectively. Importantly, our findings indicated that orexin-A significantly increased the expression of runt-related transcription factor 2 (Runx-2), which is the central transcriptional factor. Orexin-A treatment phosphorylated the kinase p38 mitogen-activated protein kinase (MAPK) in a dose- and time-dependent manner. Also, orexin-induced increase in gene expression (Runx-2, ALP, osteocalcin, and osterix) and matrix mineralization were prevented by the p38 MAPK specific inhibitor SB203580. Additionally, we also revealed that protein kinase D (PKD) is involved in the effects of Orexin-A on p38 MAPK activation and Runx-2 expression. Finally, we found that Orexin-A-induced osteoblastic formation and matrix mineralization and the activation of the PKD/p38 MAPK pathway are mediated by OX1R. Based on these findings, we concluded that activation of OX1R by orexin-A might possess a therapeutic strategy for bone disease. © 2018 IUBMB Life, 70(7):633-641, 2018.
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Affiliation(s)
- Xuesong Han
- New Medical Department of Orthopedics, Daqing People's Hospital, Daqing, Heilongjiang, China
| | - Jicheng Zhou
- Department of Orthopeadic Surgery, Daqing People's Hospital, Daqing, Heilongjiang, China
| | - Wei Peng
- Department of Orthopeadic Surgery, Daqing People's Hospital, Daqing, Heilongjiang, China
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21
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Niknia S, Kaeidi A, Hajizadeh MR, Mirzaei MR, Khoshdel A, Hajializadeh Z, Fahmidehkar MA, Mahmoodi M. Neuroprotective and antihyperalgesic effects of orexin-A in rats with painful diabetic neuropathy. Neuropeptides 2019; 73:34-40. [PMID: 30447858 DOI: 10.1016/j.npep.2018.11.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 11/06/2018] [Accepted: 11/06/2018] [Indexed: 01/19/2023]
Abstract
AIM OF STUDY Diabetes mellitus is related to the development of neuronal tissue injury in different peripheral and central nervous system regions. A common complication of diabetes is painful diabetic peripheral neuropathy (PDN). We have studied the neuroprotective and anti-nociceptive properties of neuropeptide orexin-A in an animal experimental model of diabetic neuropathy. METHODS All experiments were carried out on male Wistar rats (220-250 g). Diabetes was induced by a single intraperitoneal injection of 55 mg/kg (i.p.) streptozotocin (STZ). Orexin-A was chronically administrated into the implanted intrathecal catheter (0.6, 2.5 and 5 nM/L, daily, 4 weeks). The tail-flick and rotarod treadmill tests were used to evaluate the nociceptive threshold and motor coordination of these diabetic rats, respectively. Cleaved caspase-3, Bax, Bcl2 and the Bax/Bcl-2 ratio, as the biochemical indicators of apoptosis, were investigated in the dorsal half of the lumbar spinal cord tissue by western blotting method. RESULTS Treatment of the diabetic rats with orexin-A (5 nM/L) significantly attenuated the hyperalgesia and motor deficit in diabetic animals. Furthermore, orexin-A (5 nM/L) administration suppressed pro-apoptotic cleaved caspase-3 and Bax proteins. Also, orexin-A (5 nM/L) reduced the expression of Bax/Bcl-2 ratio in spinal cord dorsal half of rats with PDN. CONCLUSIONS Altogether our data suggest that the orexin-A has anti-hyperalgesic and neuroprotective effects in rats with PDN. Cellular mechanisms underlying the observed effects may, at least partially, be related to reducing the neuronal apoptosis.
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Affiliation(s)
- Seddigheh Niknia
- Department of Clinical Biochemistry, Faculty of Medicine, Rafsanjan University of Medical Sciences, Rafsanjan, Iran; Molecular Medicine Research Center, Research Institute of Basic Medical Sciences, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Ayat Kaeidi
- Physiology-Pharmacology Research Center, Research Institute of Basic Medical Sciences, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Mohammad Reza Hajizadeh
- Department of Clinical Biochemistry, Faculty of Medicine, Rafsanjan University of Medical Sciences, Rafsanjan, Iran; Molecular Medicine Research Center, Research Institute of Basic Medical Sciences, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Mohammad Reza Mirzaei
- Department of Clinical Biochemistry, Faculty of Medicine, Rafsanjan University of Medical Sciences, Rafsanjan, Iran; Molecular Medicine Research Center, Research Institute of Basic Medical Sciences, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Alireza Khoshdel
- Department of Clinical Biochemistry, Faculty of Medicine, Rafsanjan University of Medical Sciences, Rafsanjan, Iran; Pistachio Safety Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Zahra Hajializadeh
- Endocrinology and Metabolism Research Center, Institute of Basic and Clinical Physiology Sciences, Kerman University of Medical Sciences, Kerman, Iran
| | - Mohammad Ali Fahmidehkar
- Department of Clinical Biochemistry, Faculty of Medicine, Rafsanjan University of Medical Sciences, Rafsanjan, Iran; Department of Laboratory Science, School of Paramedical Sciences, Torbat Heydariyeh University of Medical Sciences, Torbat Heydariyeh, Iran
| | - Mehdi Mahmoodi
- Department of Clinical Biochemistry, Faculty of Medicine, Rafsanjan University of Medical Sciences, Rafsanjan, Iran; Molecular Medicine Research Center, Research Institute of Basic Medical Sciences, Rafsanjan University of Medical Sciences, Rafsanjan, Iran; Department of Clinical Biochemistry, Afzalipoor Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran.
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22
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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: 41] [Impact Index Per Article: 8.2] [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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23
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Duffy CM, Hofmeister JJ, Nixon JP, Butterick TA. High fat diet increases cognitive decline and neuroinflammation in a model of orexin loss. Neurobiol Learn Mem 2018; 157:41-47. [PMID: 30471346 DOI: 10.1016/j.nlm.2018.11.008] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 10/26/2018] [Accepted: 11/16/2018] [Indexed: 12/23/2022]
Abstract
Midlife obesity is a risk factor for cognitive decline and is associated with the earlier onset of Alzheimer's disease (AD). Diets high in saturated fat potentiate the onset of obesity, microglial activation, and neuroinflammation. Signaling deficiencies in the hypothalamic peptide orexin and/or orexin fiber loss are linked to neurodegeneration, cognitive impairment, and neuroinflammation. Prior studies show that orexin is neuroprotective, suppresses neuroinflammation, and that treatment with orexin improves cognitive processes in orexin/ataxin-3 (O/A3) mice, a transgenic mouse model of orexin neurodegeneration. Our overall hypothesis is that loss of orexin contributes to high fat diet (HFD)-induced hippocampal neuroinflammation and cognitive decline. To examine this, we tested male O/A3 mice (7-8 mo. of age) in a two-way active avoidance (TWAA) hippocampus-dependent memory task. We tested whether (1) orexin loss impaired cognitive function; (2) HFD worsened cognitive impairment; and (3) HFD increased microglial activation and neuroinflammation. O/A3 mice showed significant impairments in TWAA task learning vs. wild type (WT) mice (increased escapes p < 0.05, reduced avoidances p < 0.0001). Mice were then placed on HFD (45% total fat, 31.4% saturated fat) or remained on normal chow (NC; 4% total fat and 1% saturated fat), and TWAA was retested at 2 and 4 weeks. Learning impairment was evident at both 2 and 4 weeks in O/A3 mice fed HFD for following diet exposure vs. WT mice on normal chow or HFD (increased escapes, reduced avoidances p < 0.05). Additionally, O/A3 mice had increased gene expression of the microglial activation marker Iba-1 (measured via qRT-PCR, p < 0.001). Further characterization of the microglial immune response genes in hippocampal tissue revealed a significant increase in CX3 chemokine receptor 1 (CX3CR1), tumor necrosis factor-alpha (TNF-α) and the mitochondria-associated enzyme immune responsive gene-1 (Irg1). Collectively, our results indicate that orexin loss impairs memory, and that HFD accelerates hippocampus-dependent learning deficits and the onset of neuroinflammation.
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Affiliation(s)
- C M Duffy
- Minneapolis Veterans Affairs Health Care System, Minneapolis, MN, United States; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, United States
| | - J J Hofmeister
- Minneapolis Veterans Affairs Health Care System, Minneapolis, MN, United States; Minneapolis Center for Veterans Research and Education, Minneapolis, MN, United States
| | - J P Nixon
- Minneapolis Veterans Affairs Health Care System, Minneapolis, MN, United States; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, United States; Minneapolis Center for Veterans Research and Education, Minneapolis, MN, United States
| | - T A Butterick
- Minneapolis Veterans Affairs Health Care System, Minneapolis, MN, United States; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, United States; Minneapolis Center for Veterans Research and Education, Minneapolis, MN, United States.
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Orexin A may suppress inflammatory response in fibroblast-like synoviocytes. Biomed Pharmacother 2018; 107:763-768. [DOI: 10.1016/j.biopha.2018.07.159] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 07/18/2018] [Accepted: 07/31/2018] [Indexed: 12/28/2022] Open
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Kooshki R, Abbasnejad M, Esmaeili Mahani S, Raoof M, Moeini Aghtaei MM, Dabiri S. Orexin-A inhibits capsaicin-induced changes in cyclooxygenase-2 and brain-derived neurotrophic factor expression in trigeminal nucleus caudalis of rats. Korean J Pain 2018; 31:174-182. [PMID: 30013731 PMCID: PMC6037813 DOI: 10.3344/kjp.2018.31.3.174] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 06/03/2018] [Accepted: 06/12/2018] [Indexed: 12/26/2022] Open
Abstract
Background The trigeminal nucleus caudalis (Vc) is a primary central site for trigeminal transmitting. Noxious stimulation of the trigeminal nociceptors alters the central synaptic releases and neural expression of some inflammatory and trophic agents. Orexin-A and the orexin 1 receptor (OX1R) are expressed in pain pathways including trigeminal pain transmission. However, the the mechanism(s) underling orexin-A effects on trigeminal pain modulation have not been fully clarified. Methods Trigeminal pain was induced by subcutaneous injection of capsaicin in the upper lip in rats. The effect of trigeminal pain on cyclooxygenase-2 (COX-2) and brain-derived neurotrophic factor (BDNF) expression in the Vc of animals was determined by immunofluorescence. Subsequently, OX1R agonist (orexin-A) and antagonist (SB-334867-A) was administrated in the Vc to investigate the possible roles of the Vc OX1R on changes in COX-2 and BDNF levels following pain induction. Results The data indicated an increase in COX-2 and decrease in BDNF immuno-reactivity in the Vc of capsaicin, and capsaicin- pretreated with SB-334867-A (80 nM), groups of rat. However, the effect of capsaicin on COX-2 and BDNF expressions was reversed by a Vc microinjection of orexin-A (100 pM). Conclusions Overall, the present data reveals that orexin-A can attenuate capsaicin-induced trigeminal pain through the modulation of pain effects on COX-2 and BDNF expressions in the Vc of rats.
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Affiliation(s)
- Razieh Kooshki
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Mehdi Abbasnejad
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Saeed Esmaeili Mahani
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Maryam Raoof
- Endodontology Research Center, Kerman University of Medical Sciences, Kerman, Iran.,Laboratory of Molecular Neuroscience, Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Mohammad Mehdi Moeini Aghtaei
- Pathology and Stem Cell Research Center, Department of Pathology, Afzalipour Kerman University of Medical Science, Kerman, Iran
| | - Shahriar Dabiri
- Pathology and Stem Cell Research Center, Department of Pathology, Afzalipour Kerman University of Medical Science, Kerman, Iran
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Ferroni P, Barbanti P, Della-Morte D, Palmirotta R, Jirillo E, Guadagni F. Redox Mechanisms in Migraine: Novel Therapeutics and Dietary Interventions. Antioxid Redox Signal 2018; 28:1144-1183. [PMID: 28990418 DOI: 10.1089/ars.2017.7260] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
SIGNIFICANCE Migraine represents the third most prevalent and the seventh most disabling human disorder. Approximately 30% of migraine patients experience transient, fully reversible, focal neurological symptoms (aura) preceding the attack. Recent Advances: Awareness of the hypothesis that migraine actually embodies a spectrum of illnesses-ranging from episodic to chronic forms-is progressively increasing and poses novel challenges for clarifying the underlying pathophysiological mechanisms of migraine as well as for the development of novel therapeutic interventions. Several theories have evolved to the current concept that a combination of genetic, epigenetic, and environmental factors may play a role in migraine pathogenesis, although their relative importance is still being debated. CRITICAL ISSUES One critical issue that deserves a particular attention is the role of oxidative stress in migraine. Indeed, potentially harmful oxidative events occur during the migraine attack and long-lasting or frequent migraine episodes may increase brain exposure to oxidative events that can lead to chronic transformation. Moreover, a wide variety of dietary, environmental, physiological, behavioral, and pharmacological migraine triggers may act through oxidative stress, with clear implications for migraine treatment and prophylaxis. Interestingly, almost all current prophylactic migraine agents exert antioxidant effects. FUTURE DIRECTIONS Increasing awareness of the role of oxidative stress and/or decreased antioxidant defenses in migraine pathogenesis and progression to a chronic condition lays the foundations for the design of novel prophylactic approaches, which, by reducing brain oxidative phenomena, could favorably modify the clinical course of migraine. Antioxid. Redox Signal. 28, 1144-1183.
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Affiliation(s)
- Patrizia Ferroni
- 1 Department of Human Sciences and Quality of Life Promotion, San Raffaele Roma Open University , Rome, Italy .,2 IRCCS San Raffaele Pisana , Rome, Italy
| | - Piero Barbanti
- 3 Headache and Pain Unit, Department of Neurological, Motor and Sensorial Sciences, IRCCS San Raffaele Pisana , Rome, Italy
| | - David Della-Morte
- 1 Department of Human Sciences and Quality of Life Promotion, San Raffaele Roma Open University , Rome, Italy .,2 IRCCS San Raffaele Pisana , Rome, Italy .,4 Department of Systems Medicine, University of Rome "Tor Vergata ," Rome, Italy
| | - Raffaele Palmirotta
- 5 Department of Biomedical Sciences and Human Oncology, "A. Moro" University , Bari, Italy
| | - Emilio Jirillo
- 6 Department of Basic Medical Sciences, Neuroscience and Sensory Organs, "A. Moro" University , Bari, Italy
| | - Fiorella Guadagni
- 1 Department of Human Sciences and Quality of Life Promotion, San Raffaele Roma Open University , Rome, Italy .,2 IRCCS San Raffaele Pisana , Rome, Italy
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Liguori G, Squillacioti C, Assisi L, Pelagalli A, Vittoria A, Costagliola A, Mirabella N. Potential role of orexin A binding the receptor 1 for orexins in normal and cryptorchid dogs. BMC Vet Res 2018; 14:55. [PMID: 29482574 PMCID: PMC5828418 DOI: 10.1186/s12917-018-1375-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 02/15/2018] [Indexed: 01/17/2023] Open
Abstract
Background Cryptorchidism is one of the most common birth disorders of the male reproductive system identified in dogs and other mammals. This condition is characterised by the absence of one (unilateral) or both (bilateral) gonads from the scrotum. The peptides orexin A (OxA) and B (OxB) were obtained by post-transcriptional proteolytic cleavage of a precursor molecule, called prepro-orexin. These substances bind two types of G-coupled receptors called receptor 1 (OX1R) and 2 (OX2R) for orexins. OX1R is specific to OxA while OX2R binds the two peptides with equal affinity. Orexins modulate a great variety of body functions, such as the reproductive mechanism. The purpose of the present research was to study the presence of OxA and its receptor 1 and their possible involvement in the canine testis under healthy and pathological conditions. Methods This study was performed using adult male normal dogs and male dogs affected by unilateral cryptorchidism. Tissue samples were collected from testes and were divided into three groups: normal, contralateral and cryptic. The samples were used for immunohistochemistry, Western blot and in vitro tests for testosterone evaluation in normal and pathological conditions. Results OxA-immunoreactivity (IR) was described in interstitial Leydig cells of the normal gonad, and Leydig, Sertoli cells and gonocytes in the cryptic gonad. In the normal testis, OX1R-IR was described in Leydig cells, in pachytene and second spermatocytes and in immature and mature spermatids throughout the stages of the germ developing cycle of the male gonad. In the cryptic testis OX1R-IR was distributed in Leydig and Sertoli cells. The presence of prepro-orexin and OX1R was demonstrated by Western blot analysis. The incubation of fresh testis slices with OxA caused the stimulation of testosterone synthesis in the normal and cryptic gonad while the steroidogenic OxA-induced effect was cancelled by adding the selective OX1R antagonist SB-408124. Conclusions These results led us to hypothesise that OxA binding OX1R might be involved in the modulation of spermatogenesis and steroidogenesis in canine testis in healthy and pathological conditions.
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Affiliation(s)
- Giovanna Liguori
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Via Delpino 1, 80137, Naples, Italy.
| | - Caterina Squillacioti
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Via Delpino 1, 80137, Naples, Italy
| | - Loredana Assisi
- Department of Biology, University of Naples "Federico II", Via Mezzocannone 6, 80134, Naples, Italy
| | - Alessandra Pelagalli
- Department of Advanced Biomedical Sciences, University of Naples "Federico II", Via Pansini 5, 80131, Naples, Italy.,Institute of Biostructures and Bioimages, National Research Council, Via De Amicis 95, 80131, Naples, Italy
| | - Alfredo Vittoria
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Via Delpino 1, 80137, Naples, Italy
| | - Anna Costagliola
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Via Delpino 1, 80137, Naples, Italy
| | - Nicola Mirabella
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Via Delpino 1, 80137, Naples, Italy
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Suo L, Chang X, Zhao Y. The Orexin-A-Regulated Akt/mTOR Pathway Promotes Cell Proliferation Through Inhibiting Apoptosis in Pancreatic Cancer Cells. Front Endocrinol (Lausanne) 2018; 9:647. [PMID: 30429828 PMCID: PMC6220114 DOI: 10.3389/fendo.2018.00647] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 10/15/2018] [Indexed: 12/12/2022] Open
Abstract
The orexin-A and its receptors are associated with many physiological processes in peripheral organs and the central nervous system and play important roles in a series of human diseases, including narcolepsy, obesity, and drug addiction. Increasing evidence has indicated high expression of orexin-A and OX1 receptor (OX1R) in malignant tumors, suggesting that the stimulation of OX1R might be essential for tumorigenesis. Here, we attempted to clarify the correlation between orexin-A expression and malignancy in pancreatic cancer. Our results indicated that the stimulation of OX1R promotes cell proliferation in pancreatic cancer PANC1 cells. Additionally, orexin-A treatment can protect PANC1 cells from apoptosis, whereas inhibition of the stimulation of OX1R results in apoptosis through regulating pancreatic cancer cell expression levels of Bcl-2, caspase-9, and c-myc, which are key apoptotic factors. Further investigation revealed that orexin-A treatment activates theAkt/mTOR signaling pathway to promote cell proliferation byinhibiting Bcl-2/caspase-9/c-myc-mediated apoptosis in pancreatic cancer cells. Our findings revealed that the stimulation of OX1R might be important for tumorigenesis in pancreatic cancer and is a potential target for the treatment of patients with pancreatic cancer.
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Affiliation(s)
- Linna Suo
- Department of Endocrinology, The First Affiliated Hospital, China Medical University, Shenyang, China
- Department of Endocrinology and Metabolism, The Fourth Affiliated Hospital, China Medical University, Shenyang, China
| | - Xiaocen Chang
- Department of Endocrinology, The First Affiliated Hospital, China Medical University, Shenyang, China
- Department of Endocrinology and Metabolism, The Fourth Affiliated Hospital, China Medical University, Shenyang, China
| | - Yuyan Zhao
- Department of Endocrinology, The First Affiliated Hospital, China Medical University, Shenyang, China
- *Correspondence: Yuyan Zhao
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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: 52] [Impact Index Per Article: 7.4] [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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Hadadianpour Z, Fatehi F, Ayoobi F, Kaeidi A, Shamsizadeh A, Fatemi I. The effect of orexin-A on motor and cognitive functions in a rat model of Parkinson’s disease. Neurol Res 2017; 39:845-851. [DOI: 10.1080/01616412.2017.1352185] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Zahra Hadadianpour
- Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Farangis Fatehi
- Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Fateme Ayoobi
- Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Ayat Kaeidi
- Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
- Department of Physiology and Pharmacology, School of Medicine, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Ali Shamsizadeh
- Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
- Department of Physiology and Pharmacology, School of Medicine, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Iman Fatemi
- Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
- Department of Physiology and Pharmacology, School of Medicine, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
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Kooshki R, Abbasnejad M, Esmaeili-Mahani S, Raoof M. The Modulatory Role of Orexin 1 Receptor in CA1 on Orofacial Pain-induced Learning and Memory Deficits in Rats. Basic Clin Neurosci 2017; 8:213-222. [PMID: 28781729 PMCID: PMC5535327 DOI: 10.18869/nirp.bcn.8.3.213] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Introduction: Cognitive impairment is commonly associated with pain. The modulatory role of orexin 1 receptor (OX1R) in pain pathways as well as learning and memory processes is reported in several studies. The current study was designed to investigate the possible role of CA1-hippocampal OX1R on spatial learning and memory of rats following capsaicin-induced orofacial pain. Methods: Orofacial pain was induced by subcutaneous intra lip injection of capsaicin (100 μg). CA1 administration of orexin A and its selective antagonist (SB-334867-A) were performed 20 minutes prior to capsaicin injection. Learning and spatial memory performances were assessed by Morris Water Maze (MWM) task. Results: Capsaicin treated rats showed impairment in spatial learning and memory. In addition, pretreatment with orexin A (20 and 40 nM/rat) significantly attenuated learning and memory impairment in capsaicin-treated rats. Conversely, blockage of OX1R via SB-334867-A (40 and 80 nM/rat) significantly exaggerated learning and memory loss in capsaicin-treated rats. Conclusion: The obtained results indicated that CA1 OX1R may be involved in modulation of capsaicin –induced spatial learning and memory impairment.
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Affiliation(s)
- Razieh Kooshki
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Mehdi Abbasnejad
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Saeed Esmaeili-Mahani
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Maryam Raoof
- Laboratory of Molecular Neuroscience, Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran.,Department of Endodontics, School of Dentistry, Kerman University of Medical Sciences, Kerman, Iran
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Pasban-Aliabadi H, Esmaeili-Mahani S, Abbasnejad M. Orexin-A Protects Human Neuroblastoma SH-SY5Y Cells Against 6-Hydroxydopamine-Induced Neurotoxicity: Involvement of PKC and PI3K Signaling Pathways. Rejuvenation Res 2017; 20:125-133. [PMID: 27814668 DOI: 10.1089/rej.2016.1836] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Parkinson's disease (PD) is a common neurodegenerative disorder that is characterized by progressive and selective death of dopaminergic neurons. Multifunctional neuropeptide orexin-A is involved in many biological events of the body. It has been shown that orexin-A has protective effects in neurodegenerative disease such as PD. However, its cellular mechanisms have not yet been fully clarified. Here, we investigated the intracellular signaling pathway of orexin-A neuroprotection in 6-hydroxydopamine (6-OHDA)-induced SH-SY5H cells damage as an in vitro model of PD. The cells were incubated with 150 μM 6-OHDA, and the viability was examined by 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2-tetrazolium bromide (MTT) assay. Mitochondrial membrane potential and intracellular calcium were measured by fluorescent probes. Western blotting was also used to determine cyclooxygenase type 2 (COX-2), nuclear factor erythroid 2 related factor 2 (Nrf2), and HSP70 protein levels. The data showed that 6-OHDA has decreasing effects on cell viability, Nrf2, and HSP70 protein expression and increases the level of mitochondrial membrane potential, intracellular calcium, and COX-2 protein. Orexin-A (500 pM) significantly attenuated the 6-OHDA-induced cell damage. Furthermore, Orexin-A significantly prevented the mentioned effects of 6-OHDA on SH-SY5Y cells. Orexin 1 receptor antagonist (SB3344867), PKC, and PI3-kinase (PI3K) inhibitors (chelerythrin and LY294002, respectively) could suppress the orexin-A neuroprotective effect. In contrast, blockage of PKA by a selective inhibitor (KT5720) had no effects on the orexin protection. The results suggest that orexin-A protective effects against 6-OHDA-induced neurotoxicity are performed via its receptors, PKC and PI3K signaling pathways.
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Affiliation(s)
- Hamzeh Pasban-Aliabadi
- 1 Department of Biology, Faculty of Sciences, ShahidBahonar University of Kerman , Kerman, Iran
| | - Saeed Esmaeili-Mahani
- 1 Department of Biology, Faculty of Sciences, ShahidBahonar University of Kerman , Kerman, Iran .,2 Laboratory of Molecular Neuroscience, Kerman Neuroscience Research Center (KNRC), Kerman University of Medical Sciences , Kerman, Iran
| | - Mehdi Abbasnejad
- 1 Department of Biology, Faculty of Sciences, ShahidBahonar University of Kerman , Kerman, Iran
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Identification of a fatty acid binding protein4-UCP2 axis regulating microglial mediated neuroinflammation. Mol Cell Neurosci 2017; 80:52-57. [PMID: 28214555 DOI: 10.1016/j.mcn.2017.02.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 02/07/2017] [Accepted: 02/13/2017] [Indexed: 12/22/2022] Open
Abstract
Hypothalamic inflammation contributes to metabolic dysregulation and the onset of obesity. Dietary saturated fats activate microglia via a nuclear factor-kappa B (NFκB) mediated pathway to release pro-inflammatory cytokines resulting in dysfunction or death of surrounding neurons. Fatty acid binding proteins (FABPs) are lipid chaperones regulating metabolic and inflammatory pathways in response to fatty acids. Loss of FABP4 in peripheral macrophages via either molecular or pharmacologic mechanisms results in reduced obesity-induced inflammation via a UCP2-redox based mechanism. Despite the widespread appreciation for the role of FABP4 in mediating peripheral inflammation, the expression of FABP4 and a potential FABP4-UCP2 axis regulating microglial inflammatory capacity is largely uncharacterized. To that end, we hypothesized that microglial cells express FABP4 and that inhibition would upregulate UCP2 and attenuate palmitic acid (PA)-induced pro-inflammatory response. Gene expression confirmed expression of FABP4 in brain tissue lysate from C57Bl/6J mice and BV2 microglia. Treatment of microglial cells with an FABP inhibitor (HTS01037) increased expression of Ucp2 and arginase in the presence or absence of PA. Moreover, cells exposed to HTS01037 exhibited attenuated expression of inducible nitric oxide synthase (iNOS) compared to PA alone indicating reduced NFκB signaling. Hypothalamic tissue from mice lacking FABP4 exhibit increased UCP2 expression and reduced iNOS, tumor necrosis factor-alpha (TNF-α), and ionized calcium-binding adapter molecule 1 (Iba1; microglial activation marker) expression compared to wild type mice. Further, this effect is negated in microglia lacking UCP2, indicating the FABP4-UCP2 axis is pivotal in obesity induced neuroinflammation. To our knowledge, this is the first report demonstrating a FABP4-UCP2 axis with the potential to modulate the microglial inflammatory response.
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Pace M, Adamantidis A, Facchin L, Bassetti C. Role of REM Sleep, Melanin Concentrating Hormone and Orexin/Hypocretin Systems in the Sleep Deprivation Pre-Ischemia. PLoS One 2017; 12:e0168430. [PMID: 28061506 PMCID: PMC5218733 DOI: 10.1371/journal.pone.0168430] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 12/01/2016] [Indexed: 12/19/2022] Open
Abstract
STUDY OBJECTIVES Sleep reduction after stroke is linked to poor recovery in patients. Conversely, a neuroprotective effect is observed in animals subjected to acute sleep deprivation (SD) before ischemia. This neuroprotection is associated with an increase of the sleep, melanin concentrating hormone (MCH) and orexin/hypocretin (OX) systems. This study aims to 1) assess the relationship between sleep and recovery; 2) test the association between MCH and OX systems with the pathological mechanisms of stroke. METHODS Sprague-Dawley rats were assigned to four experimental groups: (i) SD_IS: SD performed before ischemia; (ii) IS: ischemia; (iii) SD_Sham: SD performed before sham surgery; (iv) Sham: sham surgery. EEG and EMG were recorded. The time-course of the MCH and OX gene expression was measured at 4, 12, 24 hours and 3, 4, 7 days following ischemic surgery by qRT-PCR. RESULTS A reduction of infarct volume was observed in the SD_IS group, which correlated with an increase of REM sleep observed during the acute phase of stroke. Conversely, the IS group showed a reduction of REM sleep. Furthermore, ischemia induces an increase of MCH and OX systems during the acute phase of stroke, although, both systems were still increased for a long period of time only in the SD_IS group. CONCLUSIONS Our data indicates that REM sleep may be involved in the neuroprotective effect of SD pre-ischemia, and that both MCH and OX systems were increased during the acute phase of stroke. Future studies should assess the role of REM sleep as a prognostic marker, and test MCH and OXA agonists as new treatment options in the acute phase of stroke.
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Affiliation(s)
- Marta Pace
- Center for Experimental Neurology (ZEN), Department of Neurology, Bern University Hospital, Bern, Switzerland
- Department of Neuroscience and Brain Technologies, Italian Institute of Technology (IIT), Genova, Italy
- * E-mail:
| | - Antoine Adamantidis
- Center for Experimental Neurology (ZEN), Department of Neurology, Bern University Hospital, Bern, Switzerland
| | - Laura Facchin
- Center for Experimental Neurology (ZEN), Department of Neurology, Bern University Hospital, Bern, Switzerland
| | - Claudio Bassetti
- Center for Experimental Neurology (ZEN), Department of Neurology, Bern University Hospital, Bern, Switzerland
- Sleep-Wake-Epilepsy-Center, Department of Neurology, Bern University Hospital, Bern, Switzerland
- Division of Cognitive and Restorative Neurology, Department of Neurology, Bern University Hospital, Bern, Switzerland
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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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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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Song J, Kim E, Kim CH, Song HT, Lee JE. The role of orexin in post-stroke inflammation, cognitive decline, and depression. Mol Brain 2015; 8:16. [PMID: 25884812 PMCID: PMC4357085 DOI: 10.1186/s13041-015-0106-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 02/23/2015] [Indexed: 01/02/2023] Open
Abstract
Ischemic stroke results in diverse pathophysiologies, including cerebral inflammation, neuronal loss, cognitive dysfunction, and depression. Studies aimed at identifying therapeutic solutions to alleviate these outcomes are important due to the increase in the number of stroke patients annually. Recently, many studies have reported that orexin, commonly known as a neuropeptide regulator of sleep/wakefulness and appetite, is associated with neuronal cell apoptosis, memory function, and depressive symptoms. Here, we briefly summarize recent studies regarding the role and future perspectives of orexin in post-ischemic stroke. This review advances our understanding of the role of orexin in post-stroke pathologies, focusing on its possible function as a therapeutic regulator in the post-ischemic brain. Ultimately, we suggest the clinical potential of orexin to regulate post-stroke pathologies.
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Affiliation(s)
- Juhyun Song
- Department of Anatomy, Yonsei University College of Medicine, Seoul, 120-752, South Korea.
| | - Eosu Kim
- Department of Pharmacology, Yonsei University College of Medicine, 120-752, Seoul, South Korea.
| | - Chul-Hoon Kim
- Department of Psychiatry, Yonsei University College of Medicine, 120-752, Seoul, South Korea.
| | - Ho-Taek Song
- Department of Diagnostic Radiology, Yonsei University College of Medicine, 120-752, Seoul, South Korea.
| | - Jong Eun Lee
- Department of Anatomy, Yonsei University College of Medicine, Seoul, 120-752, South Korea. .,BK21 Plus Project for Medical Sciences, and Brain Research Institute, Yonsei University, College of Medicine, Seoul, 120-752, South Korea.
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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: 79] [Impact Index Per Article: 8.8] [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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Gemici B, Tan R, Birsen İ, İzgüt Uysal VN. Gastroprotective effect of orexin-A and heme oxygenase system. J Surg Res 2015; 193:626-33. [DOI: 10.1016/j.jss.2014.08.048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 07/25/2014] [Accepted: 08/27/2014] [Indexed: 12/24/2022]
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Liu Y, Zhao Y, Ju S, Guo L. Orexin A upregulates the protein expression of OX1R and enhances the proliferation of SGC-7901 gastric cancer cells through the ERK signaling pathway. Int J Mol Med 2014; 35:539-45. [PMID: 25515760 DOI: 10.3892/ijmm.2014.2038] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Accepted: 11/25/2014] [Indexed: 11/06/2022] Open
Abstract
Orexins are hypothalamic peptides that regulate food intake, wakefulness, the reward system and energy metabolism. Recent studies have demonstrated the ability of orexins to promote a robust apoptosis and subsequent inhibition of cell growth in various types of cancer cells. The present study was conducted to investigate the effects of orexin A on the survival of human gastric cancer cells, SGC‑7901, and the possible mechanisms. SGC‑7901 cells were exposed to various concentrations of orexin A in vitro in the presence or absence of the orexin receptor 1 (OX1R) antagonist (SB334867), extracellular signal‑regulated kinases 1 and 2 (ERK1/2) antagonist (U0126) or a combination of the two antagonists. The amount of cell proliferation, viability and apoptosis, caspase‑8 and caspases‑9 activities, OX1R protein expression and ERK1/2 protein levels were determined. The expression of OX1R in SGC‑7901 cells was observed. Orexin A (10-10 to 10-6 M) stimulated SGC‑7901 cell proliferation and viability, reduced the pro‑apoptotic activity of caspase‑9 and protected the cells from apoptosis in a dose‑dependent manner. Additionally, ERK1/2 phosphorylation was stimulated by orexin A (10-10 to 10-6 M). However, the OX1R antagonist SB334867 (10-6 M), ERK1/2 antagonist U0126 (30 µM) or the combination of antagonists blocked the effects of orexin A to a certain extent. These results suggest that stimulation of OX1R induces the growth of SGC‑7901 gastric cancer cells through activation of ERK1/2 signaling pathway. These findings add a new dimension to the biological activities of orexin, which may have important implications in health and disease, in particular gastric cancer.
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Affiliation(s)
- Yuanyuan Liu
- Department of Endocrinology, First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Yuyan Zhao
- Department of Endocrinology, First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Shujing Ju
- Department of Endocrinology, First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Lei Guo
- Department of Orthopedic Surgery, First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
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Lassiter K, Greene E, Piekarski A, Faulkner OB, Hargis BM, Bottje W, Dridi S. Orexin system is expressed in avian muscle cells and regulates mitochondrial dynamics. Am J Physiol Regul Integr Comp Physiol 2014; 308:R173-87. [PMID: 25502749 DOI: 10.1152/ajpregu.00394.2014] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Orexin A and B, orexigenic peptides produced primarily by the lateral hypothalamus that signal through two G protein-coupled receptors, orexin receptors 1/2, have been implicated in the regulation of several physiological processes in mammals. In avian (nonmammalian vertebrates) species; however, the physiological roles of orexin are not well defined. Here, we provide novel evidence that not only is orexin and its related receptors 1/2 (ORXR1/2) expressed in chicken muscle tissue and quail muscle (QM7) cell line, orexin appears to be a secretory protein in QM7 cells. In vitro administration of recombinant orexin A and B (rORX-A and B) differentially regulated prepro-orexin expression in a dose-dependent manner with up-regulation for rORX-A (P < 0.05) and downregulation for rORX-B (P < 0.05) in QM7 cells. While both peptides upregulated ORXR1 expression, only a high dose of rORX-B decreased the expression of ORXR2 (P < 0.05). The presence of orexin and its related receptors and the regulation of its own system in avian muscle cells indicate that orexin may have autocrine, paracrine, and/or endocrine roles. rORXs differentially regulated mitochondrial dynamics network. While rORX-A significantly induced the expression of mitochondrial fission-related genes (DNM1, MTFP1, MTFR1), rORX-B increased the expression of mitofusin 2, OPA1, and OMA1 genes that are involved in mitochondrial fusion. Concomitant with these changes, rORXs differentially regulated the expression of several mitochondrial metabolic genes (av-UCP, av-ANT, Ski, and NRF-1) and their related transcriptional regulators (PPARγ, PPARα, PGC-1α, PGC-1β, and FoxO-1) without affecting ATP synthesis. Taken together, our data represent the first evidence of the presence and secretion of orexin system in the muscle of nonmammalian species and its role in mitochondrial fusion and fission, probably through mitochondrial-related genes and their related transcription factors.
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Affiliation(s)
- Kentu Lassiter
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, Arkansas
| | - Elizabeth Greene
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, Arkansas
| | - Alissa Piekarski
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, Arkansas
| | - Olivia B Faulkner
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, Arkansas
| | - Billy M Hargis
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, Arkansas
| | - Walter Bottje
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, Arkansas
| | - Sami Dridi
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, Arkansas
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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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Butterick TA, Duffy CM, Lee RE, Billington CJ, Kotz CM, Nixon JP. Use of a caspase multiplexing assay to determine apoptosis in a hypothalamic cell model. J Vis Exp 2014. [PMID: 24797379 DOI: 10.3791/51305] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The ability to multiplex assays in studies of complex cellular mechanisms eliminates the need for repetitive experiments, provides internal controls, and decreases waste in costs and reagents. Here we describe optimization of a multiplex assay to assess apoptosis following a palmitic acid (PA) challenge in an in vitro hypothalamic model, using both fluorescent and luminescent based assays to measure viable cell counts and caspase-3/7 activity in a 96-well microtiter plate format. Following PA challenge, viable cells were determined by a resazurin-based fluorescent assay. Caspase-3/7 activity was then determined using a luminogenic substrate, DEVD, and normalized to cell number. This multiplexing assay is a useful technique for determining change in caspase activity following an apoptotic stimulus, such as saturated fatty acid challenge. The saturated fatty acid PA can increase hypothalamic oxidative stress and apoptosis, indicating the potential importance of assays such as that described here in studying the relationship between saturated fatty acids and neuronal function.
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Affiliation(s)
- Tammy A Butterick
- Department of Veterans Affairs, Minneapolis Veterans Affairs Health Care System; Department of Food Science and Nutrition, University of Minnesota;
| | - Cayla M Duffy
- Department of Veterans Affairs, Minneapolis Veterans Affairs Health Care System; Department of Food Science and Nutrition, University of Minnesota
| | - Rachel E Lee
- Department of Integrative Biology and Physiology, University of Minnesota
| | - Charles J Billington
- Department of Veterans Affairs, Minneapolis Veterans Affairs Health Care System; Department of Food Science and Nutrition, University of Minnesota; Department of Medicine, University of Minnesota Medical School, University of Minnesota
| | - Catherine M Kotz
- Department of Veterans Affairs, Minneapolis Veterans Affairs Health Care System; Department of Food Science and Nutrition, University of Minnesota
| | - Joshua P Nixon
- Department of Veterans Affairs, Minneapolis Veterans Affairs Health Care System; Department of Food Science and Nutrition, University of Minnesota
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Xu TR, Yang Y, Ward R, Gao L, Liu Y. Orexin receptors: Multi-functional therapeutic targets for sleeping disorders, eating disorders, drug addiction, cancers and other physiological disorders. Cell Signal 2013; 25:2413-23. [DOI: 10.1016/j.cellsig.2013.07.025] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 07/26/2013] [Indexed: 12/29/2022]
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Abstract
Obesity has increased in prevalence worldwide, attributed in part to the influences of an obesity-promoting environment and genetic factors. While obesity and overweight increasingly seem to be the norm, there remain individuals who resist obesity. We present here an overview of data supporting the idea that hypothalamic neuropeptide orexin A (OXA; hypocretin 1) may be a key component of brain mechanisms underlying obesity resistance. Prior work with models of obesity and obesity resistance in rodents has shown that increased orexin and/or orexin sensitivity is correlated with elevated spontaneous physical activity (SPA), and that orexin-induced SPA contributes to obesity resistance via increased non-exercise activity thermogenesis (NEAT). However, central hypothalamic orexin signaling mechanisms that regulate SPA remain undefined. Our ongoing studies and work of others support the hypothesis that one such mechanism may be upregulation of a hypoxia-inducible factor 1 alpha (HIF-1α)-dependent pathway, suggesting that orexin may promote obesity resistance both by increasing SPA and by influencing the metabolic state of orexin-responsive hypothalamic neurons. We discuss potential mechanisms based on both animal and in vitro pharmacological studies, in the context of elucidating potential molecular targets for obesity prevention and therapy.
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Affiliation(s)
- Tammy A. Butterick
- Minneapolis Veterans Affairs Health Care System, Research 151, One Veterans Drive, Minneapolis, MN USA 55417
| | - Charles J. Billington
- Minneapolis Veterans Affairs Health Care System, Research 151, One Veterans Drive, Minneapolis, MN USA 55417
- Department of Food Science and Nutrition, University of Minnesota, 225 Food Science and Nutrition, 1334 Eckles Avenue, St. Paul, MN USA 55108
- Department of Medicine, University of Minnesota Medical School, Suite 14-110 Phillips-Wangensteen Bldg, 420 Delaware Street SE, MMC 194, Minneapolis, MN USA 55455
| | - Catherine M. Kotz
- Minneapolis Veterans Affairs Health Care System, Research 151, One Veterans Drive, Minneapolis, MN USA 55417
- Department of Food Science and Nutrition, University of Minnesota, 225 Food Science and Nutrition, 1334 Eckles Avenue, St. Paul, MN USA 55108
| | - Joshua P. Nixon
- Minneapolis Veterans Affairs Health Care System, Research 151, One Veterans Drive, Minneapolis, MN USA 55417
- Department of Food Science and Nutrition, University of Minnesota, 225 Food Science and Nutrition, 1334 Eckles Avenue, St. Paul, MN USA 55108
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Sokołowska P, Urbańska A, Biegańska K, Wagner W, Ciszewski W, Namiecińska M, Zawilska JB. Orexins protect neuronal cell cultures against hypoxic stress: an involvement of Akt signaling. J Mol Neurosci 2013; 52:48-55. [PMID: 24243084 PMCID: PMC3929148 DOI: 10.1007/s12031-013-0165-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 10/24/2013] [Indexed: 12/28/2022]
Abstract
Orexins A and B are peptides produced mainly by hypothalamic neurons that project to numerous brain structures. We have previously demonstrated that rat cortical neurons express both types of orexin receptors, and their activation by orexins initiates different intracellular signals. The present study aimed to determine the effect of orexins on the Akt kinase activation in the rat neuronal cultures and the significance of that response in neurons subjected to hypoxic stress. We report the first evidence that orexins A and B stimulated Akt in cortical neurons in a concentration- and time-dependent manner. Orexin B more potently than orexin A increased Akt phosphorylation, but the maximal effect of both peptides on the kinase activation was very similar. Next, cultured cortical neurons were challenged with cobalt chloride, an inducer of reactive oxygen species and hypoxia-mediated signaling pathways. Under conditions of chemical hypoxia, orexins potently increased neuronal viability and protected cortical neurons against oxidative stress. Our results also indicate that Akt kinase plays an important role in the pro-survival effects of orexins in neurons, which implies a possible mechanism of the orexin-induced neuroprotection.
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Affiliation(s)
- Paulina Sokołowska
- Institute of Medical Biology, Polish Academy of Sciences, Lodowa 106, 93-232, Łódź, Poland
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Esmaeili-Mahani S, Vazifekhah S, Pasban-Aliabadi H, Abbasnejad M, Sheibani V. Protective effect of orexin-A on 6-hydroxydopamine-induced neurotoxicity in SH-SY5Y human dopaminergic neuroblastoma cells. Neurochem Int 2013; 63:719-25. [PMID: 24135219 DOI: 10.1016/j.neuint.2013.09.022] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 08/26/2013] [Accepted: 09/02/2013] [Indexed: 12/20/2022]
Abstract
Parkinson's disease (PD) is a progressive neurodegenerative disease characterized by progressive and selective death of midbrain dopaminergic neurons. Pharmacologic treatment of PD can be divided into symptomatic and neuroprotective therapies. Orexin-A (hypocretin-1) is a hypothalamic peptide that exerts its biological effects by stimulation of two specific, membrane-bound orexin receptors. Recent studies have shown that orexin-A has a protective role during neuronal damage. Here, we investigated the effects of orexin-A on 6-OHDA-induced neurotoxicity in human neuroblastoma SH-SY5Y cell line as an in vitro model of Parkinson's disease. Cell damage was induced by 150μM 6-OHDA and the cells viability was examined by MTT assay. Intracellular reactive oxygen species (ROS) was determined by fluorescence spectrophotometry method. Immunoblotting and DNA analysis were also employed to determine the levels of biochemical markers of apoptosis in the cells. The data showed that 6-OHDA could decrease the viability of the cells. In addition, intracellular ROS, activated caspase 3, Bax/Bcl-2 ratio, cytochrome c as well as DNA fragmentation were significantly increased in 6-OHDA-treated cells. Pretreatment of cells with orexin-A (80pM) elicited protective effect and reduced biochemical markers of cell death. The results suggest that orexin-A has protective effects against 6-OHDA-induced neurotoxicity and its protective effects are accompanied by its antioxidant and anti-apoptotic properties and contribute to our knowledge of the pharmacology of orexin-A.
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Affiliation(s)
- Saeed Esmaeili-Mahani
- Laboratory of Molecular Neuroscience, Kerman Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran; Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran.
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48
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Kukkonen JP. Physiology of the orexinergic/hypocretinergic system: a revisit in 2012. Am J Physiol Cell Physiol 2012; 304:C2-32. [PMID: 23034387 DOI: 10.1152/ajpcell.00227.2012] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The neuropeptides orexins and their G protein-coupled receptors, OX(1) and OX(2), were discovered in 1998, and since then, their role has been investigated in many functions mediated by the central nervous system, including sleep and wakefulness, appetite/metabolism, stress response, reward/addiction, and analgesia. Orexins also have peripheral actions of less clear physiological significance still. Cellular responses to the orexin receptor activity are highly diverse. The receptors couple to at least three families of heterotrimeric G proteins and other proteins that ultimately regulate entities such as phospholipases and kinases, which impact on neuronal excitation, synaptic plasticity, and cell death. This article is a 10-year update of my previous review on the physiology of the orexinergic/hypocretinergic system. I seek to provide a comprehensive update of orexin physiology that spans from the molecular players in orexin receptor signaling to the systemic responses yet emphasizing the cellular physiological aspects of this system.
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Affiliation(s)
- Jyrki P Kukkonen
- Dept. of Veterinary Biosciences, University of Helsinki, Finland.
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