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García-Domínguez M. Enkephalins and Pain Modulation: Mechanisms of Action and Therapeutic Perspectives. Biomolecules 2024; 14:926. [PMID: 39199314 PMCID: PMC11353043 DOI: 10.3390/biom14080926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2024] [Revised: 07/28/2024] [Accepted: 07/29/2024] [Indexed: 09/01/2024] Open
Abstract
Enkephalins, a subclass of endogenous opioid peptides, play a pivotal role in pain modulation. Enkephalins primarily exert their effects through opioid receptors located widely throughout both the central and peripheral nervous systems. This review will explore the mechanisms by which enkephalins produce analgesia, emotional regulation, neuroprotection, and other physiological effects. Furthermore, this review will analyze the involvement of enkephalins in the modulation of different pathologies characterized by severe pain. Understanding the complex role of enkephalins in pain processing provides valuable insight into potential therapeutic strategies for managing pain disorders.
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Affiliation(s)
- Mario García-Domínguez
- Faculty of Education and Psychology, Universidad Francisco de Vitoria, 28223 Pozuelo de Alarcón, Spain
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2
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Scanes CG, Pierzchala-Koziec K. Disparate Effects of Stressors on Met-Enkephalin System Parameters and on Plasma Concentrations of Corticosterone in Young Female Chickens. Animals (Basel) 2024; 14:2201. [PMID: 39123727 PMCID: PMC11310960 DOI: 10.3390/ani14152201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Revised: 07/22/2024] [Accepted: 07/24/2024] [Indexed: 08/12/2024] Open
Abstract
The effects of stressors were examined on Met-enkephalin-related parameters and plasma concentrations of corticosterone in 14-week-old female chickens. Water deprivation for 24 h was accompanied by a tendency for increased plasma concentration of Met-enkephalin while plasma concentrations of corticosterone were elevated in water-deprived birds. Concentrations of Met-enkephalin were reduced in the anterior pituitary gland and adrenal gland in water-deprived pullets while proenkephalin (PENK) expression was increased in both tissues. There were changes in the plasma concentrations of Met-enkephalin and corticosterone in pullets subjected to either feed withholding or crowding. Concentrations of Met-enkephalin were increased in the anterior pituitary gland but decreased in adrenal glands in pullets subjected to crowding stress. The increase in the plasma concentrations of Met-enkephalin was ablated when the chickens were pretreated with naltrexone. However, naltrexone did not influence either basal or crowding on plasma concentrations of corticosterone. In vitro release of Met-enkephalin from the anterior pituitary or adrenal tissues was depressed in the presence of naltrexone. It was concluded that Met-enkephalin was part of the neuroendocrine response to stress in female chickens. It was concluded that stress influenced the release of both Met-enkephalin and corticosterone, but there was not complete parallelism.
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Affiliation(s)
- Colin Guy Scanes
- Department of Biological Science, University of Wisconsin Milwaukee, Milwaukee, WI 53211, USA
| | - Krystyna Pierzchala-Koziec
- Department of Animal Physiology and Endocrinology, University of Agriculture in Kraków, Mickiewicza 24/28, 30-059 Kraków, Poland
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3
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Hohenwarter L, Böttger R, Li SD. Modification and Delivery of Enkephalins for Pain Modulation. Int J Pharm 2023; 646:123425. [PMID: 37739096 DOI: 10.1016/j.ijpharm.2023.123425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 08/23/2023] [Accepted: 09/15/2023] [Indexed: 09/24/2023]
Abstract
Chronic pain negatively affects patient's quality of life and poses a significant economic burden. First line pharmaceutical treatment of chronic pain, including NSAIDs or antidepressants, is often inefficient to reduce pain, or produces intolerable adverse effects. In such cases, opioids are frequently prescribed for their potent analgesia, but chronic opioid use is also frequently associated with debilitating side effects that may offset analgesic benefits. Nonetheless, opioids continue to be widely utilized due to the lack of effective alternative analgesics. Since their discovery in 1975, a class of endogenous opioids called enkephalins (ENKs) have been investigated for their ability to relieve pain with significantly reduced adverse effects compared to conventional opioids. Their low metabolic stability and inability to cross biological membranes, however, make ENKs ineffective analgesics. Over past decades, much effort has been invested to overcome these limitations and develop ENK-based pain therapies. This review summarizes and describes chemical modifications and ENK delivery technologies utilizing ENK conjugates, nanoparticles and ENK gene delivery approaches and discusses valid lessons, challenges, and future directions of this evolving field.
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Affiliation(s)
- Lukas Hohenwarter
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Roland Böttger
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Shyh-Dar Li
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada.
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4
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Yáñez-Gómez F, Ramos-Miguel A, García-Sevilla JA, Manzanares J, Femenía T. Regulation of Cortico-Thalamic JNK1/2 and ERK1/2 MAPKs and Apoptosis-Related Signaling Pathways in PDYN Gene-Deficient Mice Following Acute and Chronic Mild Stress. Int J Mol Sci 2023; 24:ijms24032303. [PMID: 36768626 PMCID: PMC9916432 DOI: 10.3390/ijms24032303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 01/13/2023] [Accepted: 01/19/2023] [Indexed: 01/26/2023] Open
Abstract
The crosstalk between the opioidergic system and mitogen-activated protein kinases (MAPKs) has a critical role in mediating stress-induced behaviors related to the pathophysiology of anxiety. The present study evaluated the basal status and stress-induced alterations of cortico-thalamic MAPKs and other cell fate-related signaling pathways potentially underlying the anxiogenic endophenotype of PDYN gene-deficient mice. Compared to littermates, PDYN knockout (KO) mice had lower cortical and or thalamic amounts of the phospho-activated MAPKs c-Jun N-terminal kinase (JNK1/2) and extracellular signal-regulated kinase (ERK1/2). Similarly, PDYN-KO animals displayed reduced cortico-thalamic densities of total and phosphorylated (at Ser191) species of the cell fate regulator Fas-associated protein with death domain (FADD) without alterations in the Fas receptor. Exposure to acute restraint and chronic mild stress stimuli induced the robust stimulation of JNK1/2 and ERK1/2 MAPKs, FADD, and Akt-mTOR pathways, without apparent increases in apoptotic rates. Interestingly, PDYN deficiency prevented stress-induced JNK1/2 and FADD but not ERK1/2 or Akt-mTOR hyperactivations. These findings suggest that cortico-thalamic MAPK- and FADD-dependent neuroplasticity might be altered in PDYN-KO mice. In addition, the results also indicate that the PDYN gene (and hence dynorphin release) may be required to stimulate JNK1/2 and FADD (but not ERK1/2 or Akt/mTOR) pathways under environmental stress conditions.
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Affiliation(s)
- Fernando Yáñez-Gómez
- Laboratorio de Neurofarmacología, IUNICS, Universitat de les Illes Balears, Crta. Valldemossa km 7.5, 07122 Palma de Mallorca, Spain
- Health Research Institute of the Balearic Islands (IdISBa), 07120 Palma de Mallorca, Spain
| | - Alfredo Ramos-Miguel
- Department of Pharmacology, University of the Basque Country (UPV/EHU), Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Barrio Sarriena S/N, 48940 Leioa, Spain
- BioCruces Bizkaia Health Research Institute, Plaza de Cruces 12, 48903 Barakaldo, Spain
- Correspondence:
| | - Jesús A. García-Sevilla
- Laboratorio de Neurofarmacología, IUNICS, Universitat de les Illes Balears, Crta. Valldemossa km 7.5, 07122 Palma de Mallorca, Spain
| | - Jorge Manzanares
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Avda. de Ramón y Cajal s/n, San Juan de Alicante, 03550 Alicante, Spain
- Redes de Investigación Cooperativa Orientada a Resultados en Salud (RICORS), Red de Investigación en Atención Primaria de Adicciones (RIAPAd), Instituto de Salud Carlos III, MICINN and FEDER, 28029 Madrid, Spain
- Instituto de Investigación Sanitaria y Biomédica de Alicante (ISABIAL), 03010 Alicante, Spain
| | - Teresa Femenía
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Avda. de Ramón y Cajal s/n, San Juan de Alicante, 03550 Alicante, Spain
- Redes de Investigación Cooperativa Orientada a Resultados en Salud (RICORS), Red de Investigación en Atención Primaria de Adicciones (RIAPAd), Instituto de Salud Carlos III, MICINN and FEDER, 28029 Madrid, Spain
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5
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Ha CM, Kim DH, Lee TH, Kim HR, Choi J, Kim Y, Kang D, Park JW, Ojeda SR, Jeong JK, Lee BJ. Transcriptional Regulatory Role of NELL2 in Preproenkephalin Gene Expression. Mol Cells 2022; 45:537-549. [PMID: 35950455 PMCID: PMC9385569 DOI: 10.14348/molcells.2022.2051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 03/28/2022] [Accepted: 04/03/2022] [Indexed: 12/23/2022] Open
Abstract
Preproenkephalin (PPE) is a precursor molecule for multiple endogenous opioid peptides Leu-enkephalin (ENK) and Met-ENK, which are involved in a wide variety of modulatory functions in the nervous system. Despite the functional importance of ENK in the brain, the effect of brain-derived factor(s) on PPE expression is unknown. We report the dual effect of neural epidermal growth factor (EGF)-likelike 2 (NELL2) on PPE gene expression. In cultured NIH3T3 cells, transfection of NELL2 expression vectors induced an inhibition of PPE transcription intracellularly, in parallel with downregulation of protein kinase C signaling pathways and extracellular signal-regulated kinase. Interestingly, these phenomena were reversed when synthetic NELL2 was administered extracellularly. The in vivo disruption of NELL2 synthesis resulted in an increase in PPE mRNA level in the rat brain, suggesting that the inhibitory action of intracellular NELL2 predominates the activation effect of extracellular NELL2 on PPE gene expression in the brain. Biochemical and molecular studies with mutant NELL2 structures further demonstrated the critical role of EGF-like repeat domains in NELL2 for regulation of PPE transcription. These are the first results to reveal the spatio-specific role of NELL2 in the homeostatic regulation of PPE gene expression.
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Affiliation(s)
- Chang Man Ha
- Brain Research Core Facilities and Global Relation Center of Research Strategy Office, Korea Brain Research Institute, Daegu 41068, Korea
| | - Dong Hee Kim
- Department of Biological Sciences, University of Ulsan, Ulsan 44610, Korea
| | - Tae Hwan Lee
- Department of Biological Sciences, University of Ulsan, Ulsan 44610, Korea
| | - Han Rae Kim
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Jungil Choi
- Bioenvironmental Science & Technology Division, Korea Institute of Toxicology, Jinju 52834, Korea
| | - Yoonju Kim
- Brain Research Core Facilities and Global Relation Center of Research Strategy Office, Korea Brain Research Institute, Daegu 41068, Korea
| | - Dasol Kang
- Department of Biological Sciences, University of Ulsan, Ulsan 44610, Korea
| | - Jeong Woo Park
- Department of Biological Sciences, University of Ulsan, Ulsan 44610, Korea
| | - Sergio R. Ojeda
- Division of Neuroscience, Oregon National Primate Research Center/Oregon Health & Science University, Beaverton, OR 97006, USA
| | - Jin Kwon Jeong
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Byung Ju Lee
- Department of Biological Sciences, University of Ulsan, Ulsan 44610, Korea
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Puri S, Kenyon BM, Hamrah P. Immunomodulatory Role of Neuropeptides in the Cornea. Biomedicines 2022; 10:1985. [PMID: 36009532 PMCID: PMC9406019 DOI: 10.3390/biomedicines10081985] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/11/2022] [Accepted: 08/12/2022] [Indexed: 12/21/2022] Open
Abstract
The transparency of the cornea along with its dense sensory innervation and resident leukocyte populations make it an ideal tissue to study interactions between the nervous and immune systems. The cornea is the most densely innervated tissue of the body and possesses both immune and vascular privilege, in part due to its unique repertoire of resident immune cells. Corneal nerves produce various neuropeptides that have a wide range of functions on immune cells. As research in this area expands, further insights are made into the role of neuropeptides and their immunomodulatory functions in the healthy and diseased cornea. Much remains to be known regarding the details of neuropeptide signaling and how it contributes to pathophysiology, which is likely due to complex interactions among neuropeptides, receptor isoform-specific signaling events, and the inflammatory microenvironment in disease. However, progress in this area has led to an increase in studies that have begun modulating neuropeptide activity for the treatment of corneal diseases with promising results, necessitating the need for a comprehensive review of the literature. This review focuses on the role of neuropeptides in maintaining the homeostasis of the ocular surface, alterations in disease settings, and the possible therapeutic potential of targeting these systems.
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Affiliation(s)
- Sudan Puri
- Center for Translational Ocular Immunology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
- Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Brendan M. Kenyon
- Center for Translational Ocular Immunology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
- Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Pedram Hamrah
- Center for Translational Ocular Immunology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
- Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
- Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
- Departments of Immunology and Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
- Cornea Service, Tufts New England Eye Center, Boston, MA 02111, USA
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7
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Endogenous Opioids and Their Role in Stem Cell Biology and Tissue Rescue. Int J Mol Sci 2022; 23:ijms23073819. [PMID: 35409178 PMCID: PMC8998234 DOI: 10.3390/ijms23073819] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 01/25/2023] Open
Abstract
Opioids are considered the oldest drugs known by humans and have been used for sedation and pain relief for several centuries. Nowadays, endogenous opioid peptides are divided into four families: enkephalins, dynorphins, endorphins, and nociceptin/orphanin FQ. They exert their action through the opioid receptors (ORs), transmembrane proteins belonging to the super-family of G-protein-coupled receptors, and are expressed throughout the body; the receptors are the δ opioid receptor (DOR), μ opioid receptor (MOR), κ opioid receptor (KOR), and nociceptin/orphanin FQ receptor (NOP). Endogenous opioids are mainly studied in the central nervous system (CNS), but their role has been investigated in other organs, both in physiological and in pathological conditions. Here, we revise their role in stem cell (SC) biology, since these cells are a subject of great scientific interest due to their peculiar features and their involvement in cell-based therapies in regenerative medicine. In particular, we focus on endogenous opioids’ ability to modulate SC proliferation, stress response (to oxidative stress, starvation, or damage following ischemia–reperfusion), and differentiation towards different lineages, such as neurogenesis, vasculogenesis, and cardiogenesis.
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García-López C, Gómez-Huertas C, Sánchez-González JM, Borroni D, Rodríguez-Calvo-de-Mora M, Romano V, Rachwani-Anil R, Ramos-López JF, Ortiz-Pérez S, Rocha-de-Lossada C. Opioids and Ocular Surface Pathology; A Literature Review of New Treatments Horizons. J Clin Med 2022; 11:jcm11051424. [PMID: 35268515 PMCID: PMC8911328 DOI: 10.3390/jcm11051424] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 03/02/2022] [Accepted: 03/03/2022] [Indexed: 12/01/2022] Open
Abstract
This review discusses the role of opioids in the corneal surface and the different pathways and therapeutic methods of management. A literature review was performed using PubMed database. For the database search, the main searching words “opioid” and “topical opioid treatment” were used with the descriptors “cornea”, “ocular surface”, “neuropathic corneal pain”, “corneal sensitivity” and “naltrexone”; original scientific articles and reviews were included to achieve the purpose of the review. The endogenous opioid system has relevant functions in the organism, and in daily use, opioids are used as painkillers. However, these drugs may be employed for other indications as opioid pathways have a wide spectrum. The corneal surface for topical treatment is easily accessible, hence sparing the side effects of systemic opioids. Instillation of opioid antagonist substances, such as naltrexone, increases corneal healing rates and stimulates the division of corneal epithelium cells without deleterious effects. The natural modulation of endogenous opioids controls different forms of pain, including inflammatory and neuropathic pain, both in the ocular surface and in the central nervous system. There are diverse methods in controlling pain using opioids, especially in refractory forms. This review attempts to collect the literature about corneal surface and opioid pathways to provide an overview image and a possible direction of the news treatments.
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Affiliation(s)
- Celia García-López
- Department of Ophthalmology, Hospital Universitario Virgen de las Nieves, 18014 Granada, Spain; (C.G.-L.); (C.G.-H.); (J.-F.R.-L.); (S.O.-P.); (C.R.-d.-L.)
| | - Carmen Gómez-Huertas
- Department of Ophthalmology, Hospital Universitario Virgen de las Nieves, 18014 Granada, Spain; (C.G.-L.); (C.G.-H.); (J.-F.R.-L.); (S.O.-P.); (C.R.-d.-L.)
| | - José-María Sánchez-González
- Department of Physics of Condensed Matter, Optics Area, University of Seville, 41004 Seville, Spain
- Correspondence: ; Tel.: +34-955-42-08-61
| | - Davide Borroni
- Department of Doctoral Studies, Riga Stradins University, LV-1007 Riga, Latvia;
- Cornea Research Unit, ADVALIA Vision, 20145 Milan, Italy
| | - Marina Rodríguez-Calvo-de-Mora
- Department of Ophthalmology, Hospital Regional Universitario de Málaga, 29010 Málaga, Spain;
- Department of Ophthalmology (Qvision), Vithas Almería, 04120 Almería, Spain
| | - Vito Romano
- Department of Eye and Vision Science Ophthalmology, St Paul’s Eye Hospital, Liverpool L7 8XP, UK;
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L69 3BX, UK
- Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, Ophthalmology Clinic, University of Brescia, 25121 Brescia, Italy
| | | | - Juan-Francisco Ramos-López
- Department of Ophthalmology, Hospital Universitario Virgen de las Nieves, 18014 Granada, Spain; (C.G.-L.); (C.G.-H.); (J.-F.R.-L.); (S.O.-P.); (C.R.-d.-L.)
| | - Santiago Ortiz-Pérez
- Department of Ophthalmology, Hospital Universitario Virgen de las Nieves, 18014 Granada, Spain; (C.G.-L.); (C.G.-H.); (J.-F.R.-L.); (S.O.-P.); (C.R.-d.-L.)
- Department of Surgery, Faculty of Medicine, University of Granada, 18010 Granada, Spain
| | - Carlos Rocha-de-Lossada
- Department of Ophthalmology, Hospital Universitario Virgen de las Nieves, 18014 Granada, Spain; (C.G.-L.); (C.G.-H.); (J.-F.R.-L.); (S.O.-P.); (C.R.-d.-L.)
- Department of Ophthalmology (Qvision), Vithas Almería, 04120 Almería, Spain
- Department of Ophthalmology, Ceuta Medical Center, 51001 Ceuta, Spain
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Dual Enkephalinase Inhibitors and Their Role in Chronic Pain Management. Curr Pain Headache Rep 2021; 25:29. [PMID: 33761014 DOI: 10.1007/s11916-021-00949-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Dual enkephalinase inhibitors (DENKIs) are pain medications that indirectly activate opioid receptors and can be used as an alternative to traditional opioids. Understanding the physiology of enkephalins and their inhibitors and the pharmacology of these drugs will allow for proper clinical application for chronic pain patients in the future. RECENT FINDINGS DENKIs can be used as an alternative mode of analgesia for patients suffering from chronic pain by preventing the degradation of endogenous opioid ligands. By inhibiting the two major enkephalin-degrading enzymes (neprilysin and aminopeptidase N), DENKIs can provide analgesia with less adverse effects than nonendogenous opioids. The purpose of this paper is to review the current literature investigating DENKIs and explore their contribution to chronic pain management.
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10
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A Rationale for Hypoxic and Chemical Conditioning in Huntington's Disease. Int J Mol Sci 2021; 22:ijms22020582. [PMID: 33430140 PMCID: PMC7826574 DOI: 10.3390/ijms22020582] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/23/2020] [Accepted: 01/05/2021] [Indexed: 12/17/2022] Open
Abstract
Neurodegenerative diseases are characterized by adverse cellular environments and pathological alterations causing neurodegeneration in distinct brain regions. This development is triggered or facilitated by conditions such as hypoxia, ischemia or inflammation and is associated with disruptions of fundamental cellular functions, including metabolic and ion homeostasis. Targeting intracellular downstream consequences to specifically reverse these pathological changes proved difficult to translate to clinical settings. Here, we discuss the potential of more holistic approaches with the purpose to re-establish a healthy cellular environment and to promote cellular resilience. We review the involvement of important molecular pathways (e.g., the sphingosine, δ-opioid receptor or N-Methyl-D-aspartate (NMDA) receptor pathways) in neuroprotective hypoxic conditioning effects and how these pathways can be targeted for chemical conditioning. Despite the present scarcity of knowledge on the efficacy of such approaches in neurodegeneration, the specific characteristics of Huntington’s disease may make it particularly amenable for such conditioning techniques. Not only do classical features of neurodegenerative diseases like mitochondrial dysfunction, oxidative stress and inflammation support this assumption, but also specific Huntington’s disease characteristics: a relatively young age of neurodegeneration, molecular overlap of related pathologies with hypoxic adaptations and sensitivity to brain hypoxia. The aim of this review is to discuss several molecular pathways in relation to hypoxic adaptations that have potential as drug targets in neurodegenerative diseases. We will extract the relevance for Huntington’s disease from this knowledge base.
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11
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Zhao N, Mu L, Chang X, Zhu L, Geng Y, Li G. Effects of varying intensities of heat stress on neuropeptide Y and proopiomelanocortin mRNA expression in rats. Biomed Rep 2020; 13:39. [PMID: 32934812 DOI: 10.3892/br.2020.1346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Accepted: 07/20/2020] [Indexed: 12/13/2022] Open
Abstract
The aim of the present study was to investigate the effects of varying intensities of heat stress on the mRNA expression levels of neuropeptide Y (NPY), proopiomelanocortin (POMC) and stress hormones in rats. To establish a rat model of heat stress, the temperature and time were adjusted in a specialized heating chamber. Sprague-Dawley (SD) rats were randomly divided into four groups; control (CN; temperature, 24±1˚C); moderate strength 6 h (MS6; temperature, 32±1˚C time, 6 h), moderate strength 24 h (MS24; temperature, 32±1˚C; time, 24 h) and high strength 6 h (HS6; temperature, 38±1˚C; time, 6 h) groups. SD rats were exposed to heat for 14 consecutive days. The levels of heat stress-related factors, including corticotropin-releasing hormone (CRH), cortisol (COR), epinephrine (EPI) and heat shock protein 70 (HSP70), were measured in the rat blood using ELISA. In addition, the weight of the spleen, thymus, hypophysis and hypothalamus were determined. The mRNA expressions levels of NPY and POMC were detected using quantitative PCR. The results showed that the CRH, COR and HSP70 levels were increased in the three heat stress groups compared with the CN group. Notably, the levels of CRH, EPI and HSP70 were increased in the HS6 group compared with the CN and MS6 groups (P<0.05). Furthermore, the weights of the hypophysis and hypothalamus in the HS6 group were significantly lower compared with the CN group (P<0.05). In addition, NPY and POMC expression levels were downregulated in the MS24 group compared with the CN group. The mRNA expression levels of NPY and POMC were altered in response to different intensities of heat stress. Therefore, their levels were downregulated and upregulated following long-time and moderate-time heat exposure, respectively. The results of the present study suggested that the reduced mRNA expression levels of NPY may be partially responsible for the heat-induced injuries in rats following long-time heat exposure.
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Affiliation(s)
- Nan Zhao
- School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, Ningxia 750004, P.R. China.,Institute of Translational Medicine, First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning 121000, P.R. China
| | - Le Mu
- School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, Ningxia 750004, P.R. China
| | - Xiaoyu Chang
- School of Public Health and Management, Ningxia Medical University, Yinchuan, Ningxia 750004, P.R. China
| | - Lingqing Zhu
- School of Public Health and Management, Ningxia Medical University, Yinchuan, Ningxia 750004, P.R. China
| | - Yao Geng
- School of Nursing, Ningxia Medical University, Yinchuan, Ningxia 750004, P.R. China
| | - Guanghua Li
- School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, Ningxia 750004, P.R. China.,School of Public Health and Management, Ningxia Medical University, Yinchuan, Ningxia 750004, P.R. China
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