1
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Rahman MM, Jo YY, Kim YH, Park CK. Current insights and therapeutic strategies for targeting TRPV1 in neuropathic pain management. Life Sci 2024; 355:122954. [PMID: 39128820 DOI: 10.1016/j.lfs.2024.122954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 07/01/2024] [Accepted: 08/05/2024] [Indexed: 08/13/2024]
Abstract
Neuropathic pain, a common symptom of several disorders, exerts a substantial socioeconomic burden worldwide. Transient receptor potential vanilloid 1 (TRPV1), a non-selective cation channel predominantly ex-pressed in nociceptive neurons, plays a pivotal role in nociception, by detecting various endogenous and exogenous stimuli, including heat, pro-inflammatory mediators, and physical stressors. Dysregulation of TRPV1 signaling further contributes to the pathophysiology of neuropathic pain. Therefore, targeting TRPV1 is a promising strategy for developing novel analgesics with improved efficacy and safety profiles. Several pharmacological approaches to modulate TRPV1 activity, including agonists, antagonists, and biological TRPV1 RNA interference (RNAi, small interfering RNA [siRNA]) have been explored. Despite preclinical success, the clinical translation of TRPV1-targeted therapies has encountered challenges, including hyperthermia, hypothermia, pungency, and desensitization. Nevertheless, ongoing research efforts aim to refine TRPV1-targeted interventions through structural modifications, development of selective modulators, and discovery of natural, peptide-based drug candidates. Herein, we provide guidance for researchers and clinicians involved in the development of new interventions specifically targeting TRPV1 by reviewing the existing literature and highlighting current research activities. This study further discusses potential future research endeavors for enhancing the efficacy, safety, and tolerability of TRPV1 candidates, and thereby facilitates the translation of these discoveries into effective clinical interventions to alleviate neuropathic pain disorders.
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Affiliation(s)
- Md Mahbubur Rahman
- Gachon Pain Center and Department of Physiology, Gachon University College of Medicine, Incheon 21999, Republic of Korea
| | - Youn-Yi Jo
- Department of Anesthesiology and Pain Medicine, Gachon University, Gil Medical Center, Incheon 21565, Republic of Korea
| | - Yong Ho Kim
- Gachon Pain Center and Department of Physiology, Gachon University College of Medicine, Incheon 21999, Republic of Korea.
| | - Chul-Kyu Park
- Gachon Pain Center and Department of Physiology, Gachon University College of Medicine, Incheon 21999, Republic of Korea.
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2
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Etemadi A, Aghaie M, Sayar F, Chiniforush N. Effect of photobiomodulation therapy with 660 and 980 nm diode lasers on differentiation of periodontal ligament mesenchymal stem cells. Sci Rep 2024; 14:20587. [PMID: 39232133 PMCID: PMC11375153 DOI: 10.1038/s41598-024-71386-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 08/27/2024] [Indexed: 09/06/2024] Open
Abstract
This study aimed to compare the effects of photobiomodulation therapy (PBMT) with 660 and 980 nm diode lasers on differentiation of periodontal ligament mesenchymal stem cells (PDLMSCs). In this in vitro, experimental study, PDLMSCs were obtained from the Iranian Genetic Bank and cultured in osteogenic medium. They were then subjected to irradiation of 660 and 980 nm diode lasers, and their viability was assessed after one, two, and three irradiation cycles using the methyl thiazolyl tetrazolium (MTT) assay. The cells also underwent DAPI staining, cell apoptosis assay by using the Annexin V/PI, Alizarin Red staining, and real-time polymerase chain reaction (PCR) for assessment of the expression of osteogenic genes. Data were analyzed by two-way ANOVA. The two laser groups had no significant difference in cell apoptosis according to the results of DAPI staining. Both laser groups showed higher cell viability in the MTT assay at 4 and 6 days compared with the control group. Annexin V/PI results showed higher cell viability in both laser groups at 4 days compared with the control group. Rate of early and late apoptosis was lower in both laser groups than the control group at 4 days. Necrosis had a lower frequency in 980 nm laser group than the control group on day 6. Alizarin Red staining showed higher cell differentiation in both laser groups after 3 irradiation cycles than the control group. The highest expression of osteopontin (OPN), osteocalcin (OCN), and Runt-related transcription factor 2 (RUNX2) was noted in 660 nm laser group with 3 irradiation cycles at 14 days, compared with the control group. PBMT with 660 and 980 nm diode lasers decreased apoptosis and significantly increased PDLMSC differentiation after 3 irradiation cycles.
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Affiliation(s)
- Ardavan Etemadi
- Department of Periodontics, Faculty of Dentistry, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Milad Aghaie
- Department of Periodontics, Faculty of Dentistry, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Ferena Sayar
- Department of Periodontics, Faculty of Dentistry, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.
| | - Nasim Chiniforush
- Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy.
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3
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Pirouzram A, Wikström M, Larzon T, Tamás É, Nilsson KF. Induced Moderate Hypothermia in Aortic Rupture With Retroperitoneal Bleeding: A Randomized Porcine Study. INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY 2024; 19:395-401. [PMID: 38828939 DOI: 10.1177/15569845241253234] [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] [Indexed: 06/05/2024]
Abstract
OBJECTIVE Induced hypothermia improves outcome in aortic arch surgery, neonatal neurointensive care, and transplant surgery for example. In contrast, spontaneous hypothermia has been associated with worse outcomes in patients suffering from hemorrhagic shock, mostly explained by its adverse effects on the coagulation system. We investigated if induced hypothermia would impair short-term survival in experimental aortic rupture with retroperitoneal bleeding. METHODS Anesthetized pigs were randomized into 2 groups: hypothermia by peritoneal lavage of ice-cold Ringer's acetate and external cooling (n = 10) and normothermia (n = 10). Aortic rupture with retroperitoneal bleeding was induced by endovascular means creating a 6 mm hole in the retroperitoneal portion of abdominal aorta. Survival (primary outcome), hemodynamics, and arterial blood gases including lactate were collected and analyzed up to 180 min after aortic rupture. RESULTS The body temperature (mean ± standard deviation) in the hypothermic group was 31.5 ± 1.0 °C and 38.7 ± 0.4 °C in the normothermic group at the time for aortic rupture. Survival up to 180 min after the retroperitoneal bleeding was significantly higher in the hypothermic compared with the normothermic group (P = 0.023). CONCLUSIONS Induced hypothermia did not impair survival in this experimental retroperitoneal aortic bleeding model in anesthetized pigs. This finding may indicate a minor role for the coagulation system in this type of bleeding.
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Affiliation(s)
- Artai Pirouzram
- Department of Cardiothoracic and Vascular Surgery, and Department of Health, Medicine and Caring Sciences, Linköping University, Sweden
| | - Maria Wikström
- Department of General Surgery, Central Hospital in Karlstad, Sweden
- School of Medical Sciences, Örebro University, Sweden
| | - Thomas Larzon
- Department of Cardiothoracic and Vascular Surgery, Faculty of Medicine and Health, Örebro University, Sweden
| | - Éva Tamás
- Department of Cardiothoracic and Vascular Surgery, and Department of Health, Medicine and Caring Sciences, Linköping University, Sweden
| | - Kristofer F Nilsson
- School of Medical Sciences, Örebro University, Sweden
- Department of Cardiothoracic and Vascular Surgery, Faculty of Medicine and Health, Örebro University, Sweden
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4
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Esancy K, Dhaka A. Turning down the body heat: A novel mechanism for TRPV1 antagonist-induced hyperthermia. Neuron 2024; 112:1727-1729. [PMID: 38843778 DOI: 10.1016/j.neuron.2024.04.031] [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: 04/25/2024] [Revised: 04/25/2024] [Accepted: 04/25/2024] [Indexed: 06/18/2024]
Abstract
While effective analgesics, TRPV1 antagonists can dangerously alter thermoregulation. In this issue of Neuron, Huang et al.1 demonstrate that interaction with the S4-S5 linker of TRPV1 determines whether an antagonist affects core body temperature, with promising implications for analgesic development.
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Affiliation(s)
- Kali Esancy
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Ajay Dhaka
- Department of Biological Structure, University of Washington, Seattle, WA, USA; Department of Oral Health Sciences, University of Washington, Seattle, WA, USA.
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5
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Huang YZ, Ma JX, Bian YJ, Bai QR, Gao YH, Di SK, Lei YT, Yang H, Yang XN, Shao CY, Wang WH, Cao P, Li CZ, Zhu MX, Sun MY, Yu Y. TRPV1 analgesics disturb core body temperature via a biased allosteric mechanism involving conformations distinct from that for nociception. Neuron 2024; 112:1815-1831.e4. [PMID: 38492574 DOI: 10.1016/j.neuron.2024.02.016] [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: 09/11/2023] [Revised: 01/30/2024] [Accepted: 02/21/2024] [Indexed: 03/18/2024]
Abstract
Efforts on developing transient receptor potential vanilloid 1 (TRPV1) drugs for pain management have been hampered by deleterious hypo- or hyperthermia caused by TRPV1 agonists/antagonists. Here, we compared the effects of four antagonists on TRPV1 polymodal gating and core body temperature (CBT) in Trpv1+/+, Trpv1-/-, and Trpv1T634A/T634A. Neither the effect on proton gating nor drug administration route, hair coverage, CBT rhythmic fluctuations, or inflammation had any influence on the differential actions of TRPV1 drugs on CBT. We identified the S4-S5 linker region exposed to the vanilloid pocket of TRPV1 to be critical for hyperthermia associated with certain TRPV1 antagonists. PSFL2874, a TRPV1 antagonist we discovered, is effective against inflammatory pain but devoid of binding to the S4-S5 linker and inducing CBT changes. These findings implicate that biased allosteric mechanisms exist for TRPV1 coupling to nociception and CBT regulation, opening avenues for the development of non-opioid analgesics without affecting CBT.
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Affiliation(s)
- Yi-Zhe Huang
- Schools of Basic Medicine and Clinical Pharmacy and Traditional Chinese Pharmacy, and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Jing-Xian Ma
- Schools of Basic Medicine and Clinical Pharmacy and Traditional Chinese Pharmacy, and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Yu-Jing Bian
- Schools of Basic Medicine and Clinical Pharmacy and Traditional Chinese Pharmacy, and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Qin-Ru Bai
- Schools of Basic Medicine and Clinical Pharmacy and Traditional Chinese Pharmacy, and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Yu-Hao Gao
- Schools of Basic Medicine and Clinical Pharmacy and Traditional Chinese Pharmacy, and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Shu-Ke Di
- Schools of Basic Medicine and Clinical Pharmacy and Traditional Chinese Pharmacy, and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Yun-Tao Lei
- Schools of Basic Medicine and Clinical Pharmacy and Traditional Chinese Pharmacy, and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Hui Yang
- Tea Research Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, Hunan, China
| | - Xiao-Na Yang
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
| | - Chang-Yan Shao
- Schools of Basic Medicine and Clinical Pharmacy and Traditional Chinese Pharmacy, and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Wen-Hui Wang
- Schools of Basic Medicine and Clinical Pharmacy and Traditional Chinese Pharmacy, and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Peng Cao
- Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Chang-Zhu Li
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha 410004, Hunan, China
| | - Michael X Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Meng-Yang Sun
- Schools of Basic Medicine and Clinical Pharmacy and Traditional Chinese Pharmacy, and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
| | - Ye Yu
- Schools of Basic Medicine and Clinical Pharmacy and Traditional Chinese Pharmacy, and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
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Rumbus Z, Fekete K, Kelava L, Gardos B, Klonfar K, Keringer P, Pinter E, Pakai E, Garami A. Ammonium chloride-induced hypothermia is attenuated by transient receptor potential channel vanilloid-1, but augmented by ankyrin-1 in rodents. Life Sci 2024; 346:122633. [PMID: 38615746 DOI: 10.1016/j.lfs.2024.122633] [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: 01/02/2024] [Revised: 03/29/2024] [Accepted: 04/10/2024] [Indexed: 04/16/2024]
Abstract
AIMS Systemic administration of ammonium chloride (NH4Cl), an acidifying agent used in human patients and experimental conditions, causes hypothermia in mice, however, the mechanisms of the thermoregulatory response to NH4Cl and whether it develops in other species remained unknown. MAIN METHODS We studied body temperature (Tb) changes in rats and mice induced by intraperitoneal administration of NH4Cl after blockade of transient receptor potential vanilloid-1 (TRPV1) or ankyrin-1 (TRPA1) channels. KEY FINDINGS In rats, NH4Cl decreased Tb by 0.4-0.8°C (p < 0.05). The NH4Cl-induced hypothermia also developed in Trpv1 knockout (Trpv1-/-) and wild-type (Trpv1+/+) mice, however, the Tb drop was exaggerated in Trpv1-/- mice compared to Trpv1+/+ controls with maximal decreases of 4.0 vs. 2.1°C, respectively (p < 0.05). Pharmacological blockade of TRPV1 channels with AMG 517 augmented the hypothermic response to NH4Cl in genetically unmodified mice and rats (p < 0.05 for both). In contrast, when NH4Cl was infused to mice genetically lacking the TRPA1 channel, the hypothermic response was significantly attenuated compared to wild-type controls with maximal mean Tb difference of 1.0°C between the genotypes (p = 0.008). Pretreatment of rats with a TRPA1 antagonist (A967079) also attenuated the NH4Cl-induced Tb drop with a maximal difference of 0.7°C between the pretreatment groups (p = 0.003). SIGNIFICANCE TRPV1 channels limit, whereas TRPA1 channels exaggerate the development of NH4Cl-induced hypothermia in rats and mice, but other mechanisms are also involved. Our results warrant for regular Tb control and careful consideration of NH4Cl treatment in patients with TRPA1 and TRPV1 channel dysfunctions.
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Affiliation(s)
- Zoltan Rumbus
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs H-7624, Hungary
| | - Kata Fekete
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs H-7624, Hungary
| | - Leonardo Kelava
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs H-7624, Hungary
| | - Bibor Gardos
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs H-7624, Hungary
| | - Krisztian Klonfar
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs H-7624, Hungary
| | - Patrik Keringer
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs H-7624, Hungary
| | - Erika Pinter
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pecs, Pecs H-7624, Hungary
| | - Eszter Pakai
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs H-7624, Hungary
| | - Andras Garami
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs H-7624, Hungary.
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Nehr-Majoros AK, Király Á, Helyes Z, Szőke É. Lipid raft disruption as an opportunity for peripheral analgesia. Curr Opin Pharmacol 2024; 75:102432. [PMID: 38290404 DOI: 10.1016/j.coph.2024.102432] [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: 12/01/2023] [Revised: 12/17/2023] [Accepted: 01/02/2024] [Indexed: 02/01/2024]
Abstract
Chronic pain conditions are unmet medical needs, since the available drugs, opioids, non-steroidal anti-inflammatory/analgesic drugs and adjuvant analgesics do not provide satisfactory therapeutic effect in a great proportion of patients. Therefore, there is an urgent need to find novel targets and novel therapeutic approaches that differ from classical pharmacological receptor antagonism. Most ion channels and receptors involved in pain sensation and processing such as Transient Receptor Potential ion channels, opioid receptors, P2X purinoreceptors and neurokinin 1 receptor are located in the lipid raft regions of the plasma membrane. Targeting the membrane lipid composition and structure by sphingolipid or cholesterol depletion might open future perspectives for the therapy of chronic inflammatory, neuropathic or cancer pain, most importantly acting at the periphery.
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Affiliation(s)
- Andrea Kinga Nehr-Majoros
- Department of Pharmacology and Pharmacotherapy, Medical School & Centre for Neuroscience, University of Pécs, 12 Szigeti Street, H-7624, Pécs, Hungary; National Laboratory for Drug Research and Development, Budapest, Hungary; Hungarian Research Network, Chronic Pain Research Group, Pécs, Hungary
| | - Ágnes Király
- Department of Pharmacology and Pharmacotherapy, Medical School & Centre for Neuroscience, University of Pécs, 12 Szigeti Street, H-7624, Pécs, Hungary; National Laboratory for Drug Research and Development, Budapest, Hungary; Hungarian Research Network, Chronic Pain Research Group, Pécs, Hungary
| | - Zsuzsanna Helyes
- Department of Pharmacology and Pharmacotherapy, Medical School & Centre for Neuroscience, University of Pécs, 12 Szigeti Street, H-7624, Pécs, Hungary; National Laboratory for Drug Research and Development, Budapest, Hungary; Hungarian Research Network, Chronic Pain Research Group, Pécs, Hungary
| | - Éva Szőke
- Department of Pharmacology and Pharmacotherapy, Medical School & Centre for Neuroscience, University of Pécs, 12 Szigeti Street, H-7624, Pécs, Hungary; National Laboratory for Drug Research and Development, Budapest, Hungary; Hungarian Research Network, Chronic Pain Research Group, Pécs, Hungary.
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8
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Huang J, Korsunsky A, Yazdani M, Chen J. Targeting TRP channels: recent advances in structure, ligand binding, and molecular mechanisms. Front Mol Neurosci 2024; 16:1334370. [PMID: 38273937 PMCID: PMC10808746 DOI: 10.3389/fnmol.2023.1334370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 12/26/2023] [Indexed: 01/27/2024] Open
Abstract
Transient receptor potential (TRP) channels are a large and diverse family of transmembrane ion channels that are widely expressed, have important physiological roles, and are associated with many human diseases. These proteins are actively pursued as promising drug targets, benefitting greatly from advances in structural and mechanistic studies of TRP channels. At the same time, the complex, polymodal activation and regulation of TRP channels have presented formidable challenges. In this short review, we summarize recent progresses toward understanding the structural basis of TRP channel function, as well as potential ligand binding sites that could be targeted for therapeutics. A particular focus is on the current understanding of the molecular mechanisms of TRP channel activation and regulation, where many fundamental questions remain unanswered. We believe that a deeper understanding of the functional mechanisms of TRP channels will be critical and likely transformative toward developing successful therapeutic strategies targeting these exciting proteins. This endeavor will require concerted efforts from computation, structural biology, medicinal chemistry, electrophysiology, pharmacology, drug safety and clinical studies.
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Affiliation(s)
- Jian Huang
- Department of Chemistry, University of Massachusetts, Amherst, MA, United States
| | - Aron Korsunsky
- Department of Chemistry, University of Massachusetts, Amherst, MA, United States
| | - Mahdieh Yazdani
- Modeling and Informatics, Merck & Co., Inc., West Point, PA, United States
| | - Jianhan Chen
- Department of Chemistry, University of Massachusetts, Amherst, MA, United States
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9
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Zsombok A, Desmoulins LD, Derbenev AV. Sympathetic circuits regulating hepatic glucose metabolism: where we stand. Physiol Rev 2024; 104:85-101. [PMID: 37440208 PMCID: PMC11281813 DOI: 10.1152/physrev.00005.2023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 06/12/2023] [Accepted: 07/10/2023] [Indexed: 07/14/2023] Open
Abstract
The prevalence of metabolic disorders, including type 2 diabetes mellitus, continues to increase worldwide. Although newer and more advanced therapies are available, current treatments are still inadequate and the search for solutions remains. The regulation of energy homeostasis, including glucose metabolism, involves an exchange of information between the nervous systems and peripheral organs and tissues; therefore, developing treatments to alter central and/or peripheral neural pathways could be an alternative solution to modulate whole body metabolism. Liver glucose production and storage are major mechanisms controlling glycemia, and the autonomic nervous system plays an important role in the regulation of hepatic functions. Autonomic nervous system imbalance contributes to excessive hepatic glucose production and thus to the development and progression of type 2 diabetes mellitus. At cellular levels, change in neuronal activity is one of the underlying mechanisms of autonomic imbalance; therefore, modulation of the excitability of neurons involved in autonomic outflow governance has the potential to improve glycemic status. Tissue-specific subsets of preautonomic neurons differentially control autonomic outflow; therefore, detailed information about neural circuits and properties of liver-related neurons is necessary for the development of strategies to regulate liver functions via the autonomic nerves. This review provides an overview of our current understanding of the hypothalamus-ventral brainstem-liver pathway involved in the sympathetic regulation of the liver, outlines strategies to identify organ-related neurons, and summarizes neuronal plasticity during diabetic conditions with a particular focus on liver-related neurons in the paraventricular nucleus.
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Affiliation(s)
- Andrea Zsombok
- Department of Physiology, School of Medicine, Tulane University, New Orleans, Louisiana, United States
- Tulane Brain Institute, Tulane University, New Orleans, Louisiana, United States
| | - Lucie D Desmoulins
- Department of Physiology, School of Medicine, Tulane University, New Orleans, Louisiana, United States
| | - Andrei V Derbenev
- Department of Physiology, School of Medicine, Tulane University, New Orleans, Louisiana, United States
- Tulane Brain Institute, Tulane University, New Orleans, Louisiana, United States
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10
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Keihani A, Mayeli A, Ferrarelli F. Circadian Rhythm Changes in Healthy Aging and Mild Cognitive Impairment. Adv Biol (Weinh) 2023; 7:e2200237. [PMID: 36403250 PMCID: PMC10199146 DOI: 10.1002/adbi.202200237] [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: 08/29/2022] [Revised: 11/01/2022] [Indexed: 11/21/2022]
Abstract
Disruptions in circadian rhythms can occur in healthy aging; however, these changes are more severe and pervasive in individuals with age-related and neurodegenerative diseases, such as dementia. Circadian rhythm alterations are also present in preclinical stages of dementia, for example, in patients with mild cognitive impairments (MCI); thus, providing a unique window of opportunity for early intervention in neurodegenerative disorders. Nonetheless, there is a lack of studies examining the association between relevant changes in circadian rhythms and their relationship with cognitive dysfunctions in MCI individuals. In this review, circadian system alterations occurring in MCI patients are examined compared to healthy aging individuals while also considering their association with MCI neurocognitive alterations. The main findings are that abnormal circadian changes in rest-activity, core body temperature, melatonin, and cortisol rhythms appear in the MCI stage and that these circadian rhythm disruptions are associated with some of the neurocognitive deficits observed in MCI patients. In addition, preliminary evidence indicates that interventions aimed at restoring regular circadian rhythms may prevent or halt the progress of neurodegenerative diseases and mitigate their related cognitive impairments. Future longitudinal studies with repeated follow-up assessments are needed to establish the translational potential of these findings in clinical practice.
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Affiliation(s)
- Ahmadreza Keihani
- Department of Psychiatry, University of Pittsburgh, 3501 Forbes Ave, Pittsburgh, PA, 15213, USA
| | - Ahmad Mayeli
- Department of Psychiatry, University of Pittsburgh, 3501 Forbes Ave, Pittsburgh, PA, 15213, USA
| | - Fabio Ferrarelli
- Department of Psychiatry, University of Pittsburgh, 3501 Forbes Ave, Pittsburgh, PA, 15213, USA
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11
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Szallasi A. Resiniferatoxin: Nature's Precision Medicine to Silence TRPV1-Positive Afferents. Int J Mol Sci 2023; 24:15042. [PMID: 37894723 PMCID: PMC10606200 DOI: 10.3390/ijms242015042] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 09/27/2023] [Accepted: 10/07/2023] [Indexed: 10/29/2023] Open
Abstract
Resiniferatoxin (RTX) is an ultrapotent capsaicin analog with a unique spectrum of pharmacological actions. The therapeutic window of RTX is broad, allowing for the full desensitization of pain perception and neurogenic inflammation without causing unacceptable side effects. Intravesical RTX was shown to restore continence in a subset of patients with idiopathic and neurogenic detrusor overactivity. RTX can also ablate sensory neurons as a "molecular scalpel" to achieve permanent analgesia. This targeted (intrathecal or epidural) RTX therapy holds great promise in cancer pain management. Intra-articular RTX is undergoing clinical trials to treat moderate-to-severe knee pain in patients with osteoarthritis. Similar targeted approaches may be useful in the management of post-operative pain or pain associated with severe burn injuries. The current state of this field is reviewed, from preclinical studies through veterinary medicine to clinical trials.
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Affiliation(s)
- Arpad Szallasi
- Department of Pathology and Experimental Cancer Research, Semmelweis University, 1083 Budapest, Hungary
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12
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Liu L, Tian Y. Capsaicin Changes the Pattern of Brain Rhythms in Sleeping Rats. Molecules 2023; 28:4736. [PMID: 37375291 DOI: 10.3390/molecules28124736] [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: 03/16/2023] [Revised: 06/08/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023] Open
Abstract
The heat and capsaicin sensor TRPV1 ion channels were originally discovered in sensory neurons of dorsal root ganglia, and later found in many other tissues and organs. However, whether TRPV1 channels are present in brain regions other than the hypothalamus has been a subject of debate. Here, we addressed this issue with an unbiased functional test by recording electroencephalograms (EEGs) to examine whether capsaicin injection directly into the rat lateral ventricle could alter brain electrical activity. We observed that EEGs during the sleep stage could be significantly perturbed by capsaicin, whereas EEGs during the awake stage did not show a detectable change. Our results are consistent with TRPV1 expression in selective brain regions whose activities are dominative during the sleep stage.
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Affiliation(s)
- Lei Liu
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College, No. 1 Ningde Road, Qingdao 266073, China
| | - Yuhua Tian
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College, No. 1 Ningde Road, Qingdao 266073, China
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13
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Tang Y, Liu S, Xu L, Huang M, Zhang K. Arginine vasopressin effects on membrane potentials of preoptic area temperature-sensitive and -insensitive neurons in rat hypothalamic tissue slices. Neuropeptides 2023; 100:102344. [PMID: 37148733 DOI: 10.1016/j.npep.2023.102344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 04/15/2023] [Accepted: 04/25/2023] [Indexed: 05/08/2023]
Abstract
Arginine vasopressin (AVP) plays a hypothermic regulatory role in thermoregulation and is an important endogenous mediator in this mechanism. In the preoptic area (POA), AVP increases the spontaneous firing and thermosensitivity of warm-sensitive neurons and decreases those of cold-sensitive and temperature-insensitive neurons. Because POA neurons play a crucial role in precise thermoregulatory responses, these findings indicate that there is an association between the hypothermia and changes in the firing activity of AVP-induced POA neurons. However, the electrophysiological mechanisms by which AVP controls this firing activity remain unclear. Therefore, in the present study, using in vitro hypothalamic brain slices and whole-cell recordings, we elucidated the membrane potential responses of temperature-sensitive and -insensitive POA neurons to identify the applications of AVP or V1a vasopressin receptor antagonists. By monitoring changes in the resting potential and membrane potential thermosensitivity of the neurons before and during experimental perfusion, we observed that AVP increased the changes in the resting potential of 50% of temperature-insensitive neurons but reduced them in others. These changes are because AVP enhances the membrane potential thermosensitivity of nearly 50% of the temperature-insensitive neurons. On the other hand, AVP changes both the resting potential and membrane potential thermosensitivity of temperature-sensitive neurons, with no differences between the warm- and cold-sensitive neurons. Before and during AVP or V1a vasopressin receptor antagonist perfusion, no correlation was observed between changes in the thermosensitivity and membrane potential of all neurons. Furthermore, no correlation was observed between the thermosensitivity and membrane potential thermosensitivity of the neurons during experimental perfusion. In the present study, we found that AVP induction did not result in any changes in resting potential, which is unique to temperature-sensitive neurons. The study results suggest that AVP-induced changes in the firing activity and firing rate thermosensitivity of POA neurons are not controlled by resting potentials.
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Affiliation(s)
- Yu Tang
- Department of Anesthesiology, The Second Affiliated Hospital of Chengdu Medical College, CNNC 416th Hospital, Chengdu, Sichuan, PR China; Department of Physiology, Key Laboratory of Thermoregulatory and Inflammation of Sichuan Higher Education Institutes, Development and Regeneration Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan, PR China.
| | - Siyuan Liu
- Department of Anesthesiology, The Second Affiliated Hospital of Chengdu Medical College, CNNC 416th Hospital, Chengdu, Sichuan, PR China
| | - Lingzhi Xu
- School of clinical medicine, Chengdu Medical College, Chengdu, Sichuan, PR China
| | - Min Huang
- Department of Physiology, Key Laboratory of Thermoregulatory and Inflammation of Sichuan Higher Education Institutes, Development and Regeneration Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan, PR China
| | - Ke Zhang
- Department of Anesthesiology, The Second Affiliated Hospital of Chengdu Medical College, CNNC 416th Hospital, Chengdu, Sichuan, PR China.
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14
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Kim SE, Yin MZ, Roh JW, Kim HJ, Choi SW, Wainger BJ, Kim WK, Kim SJ, Nam JH. Multi-target modulation of ion channels underlying the analgesic effects of α-mangostin in dorsal root ganglion neurons. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2023; 115:154791. [PMID: 37094425 DOI: 10.1016/j.phymed.2023.154791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 03/15/2023] [Accepted: 03/28/2023] [Indexed: 05/03/2023]
Abstract
BACKGROUND α-Mangostin is a xanthone isolated from the pericarps of mangosteen fruit with, and has analgesic properties. Although the effects suggest an interaction of α-mangostin with ion channels in the nociceptive neurons, electrophysiological investigation of the underlying mechanism has not been performed. HYPOTHESIS We hypothesized that α-Mangostin exerts its analgesic effects by modulating the activity of various ion channels in dorsal root ganglion (DRG) neurons. METHODS We performed a whole-cell patch clamp study using mouse DRG neurons, HEK293T cells overexpressing targeted ion channels, and ND7/23 cells. Molecular docking (MD) and in silico absorption, distribution, metabolism, and excretion (ADME) analyses were conducted to obtain further insights into the binding sites and pharmacokinetics, respectively. RESULTS Application of α-mangostin (1-3 µM) hyperpolarized the resting membrane potential (RMP) of small-sized DRG neurons by increasing background K+ conductance and thereby inhibited action potential generation. At micromolar levels, α-mangostin activates TREK-1, TREK-2, or TRAAK, members of the two-pore domain K+ channel (K2P) family known to be involved in RMP formation in DRG neurons. Furthermore, capsaicin-induced TRPV1 currents were potently inhibited by α-mangostin (0.43 ± 0.27 µM), and partly suppressed tetrodotoxin-sensitive voltage-gated Na+ channel (NaV) currents. MD simulation revealed that multiple oxygen atoms in α-mangostin may form stable hydrogen bonds with TREKs, TRAAK, TRPV1, and NaV channels. In silico ADME tests suggested that α-mangostin may satisfy the drug-likeness properties without penetrating the blood-brain barrier. CONCLUSION The analgesic properties of α-mangostin might be mediated by the multi-target modulation of ion channels, including TREK/TRAAK activation, TRPV1 inhibition, and reduction of the tetrodotoxin-sensitive NaV current. The findings suggest that the phytochemical can be a multi-ion channel-targeting drug and an alternative drug for effective pain management.
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Affiliation(s)
- Sung Eun Kim
- Department of Physiology, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Ming Zhe Yin
- Department of Anesthesiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China
| | - Jae Won Roh
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Hyun Jong Kim
- Department of Physiology, Dongguk University College of Medicine, Gyeongju 38066, Republic of Korea; Channelopathy Research Center (CRC), Dongguk University College of Medicine, Gyeonggi-do 10326, Republic of Korea
| | - Seong Woo Choi
- Department of Physiology, Dongguk University College of Medicine, Gyeongju 38066, Republic of Korea
| | - Brian J Wainger
- Departments Anesthesia, Critical Care & Pain Medicine and Neurology, Massachusetts General Hospital, Harvard Medical School, Boston 02114, ts, USA
| | - Woo Kyung Kim
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, Gyeonggi-do 10326, Republic of Korea; Department of Internal Medicine Graduate School of Medicine, Dongguk University, Gyeonggi-do 10326, Republic of Korea.
| | - Sung Joon Kim
- Department of Physiology, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 03080, Republic of Korea.
| | - Joo Hyun Nam
- Department of Physiology, Dongguk University College of Medicine, Gyeongju 38066, Republic of Korea; Departments Anesthesia, Critical Care & Pain Medicine and Neurology, Massachusetts General Hospital, Harvard Medical School, Boston 02114, ts, USA; Channelopathy Research Center (CRC), Dongguk University College of Medicine, Gyeonggi-do 10326, Republic of Korea.
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15
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Garami A, Steiner AA, Pakai E, Wanner SP, Almeida MC, Keringer P, Oliveira DL, Nakamura K, Morrison SF, Romanovsky AA. The neural pathway of the hyperthermic response to antagonists of the transient receptor potential vanilloid-1 channel. Temperature (Austin) 2023; 10:136-154. [PMID: 37187834 PMCID: PMC10177699 DOI: 10.1080/23328940.2023.2171671] [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: 10/22/2022] [Revised: 01/13/2023] [Accepted: 01/18/2023] [Indexed: 01/27/2023] Open
Abstract
We identified the neural pathway of the hyperthermic response to TRPV1 antagonists. We showed that hyperthermia induced by i.v. AMG0347, AMG 517, or AMG8163 did not occur in rats with abdominal sensory nerves desensitized by pretreatment with a low i.p. dose of resiniferatoxin (RTX, TRPV1 agonist). However, neither bilateral vagotomy nor bilateral transection of the greater splanchnic nerve attenuated AMG0347-induced hyperthermia. Yet, this hyperthermia was attenuated by bilateral high cervical transection of the spinal dorsolateral funiculus (DLF). To explain the extra-splanchnic, spinal mediation of TRPV1 antagonist-induced hyperthermia, we proposed that abdominal signals that drive this hyperthermia originate in skeletal muscles - not viscera. If so, in order to prevent TRPV1 antagonist-induced hyperthermia, the desensitization caused by i.p. RTX should spread into the abdominal-wall muscles. Indeed, we found that the local hypoperfusion response to capsaicin (TRPV1 agonist) in the abdominal-wall muscles was absent in i.p. RTX-desensitized rats. We then showed that the most upstream (lateral parabrachial, LPB) and the most downstream (rostral raphe pallidus) nuclei of the intrabrain pathway that controls autonomic cold defenses are also required for the hyperthermic response to i.v. AMG0347. Injection of muscimol (inhibitor of neuronal activity) into the LPB or injection of glycine (inhibitory neurotransmitter) into the raphe blocked the hyperthermic response to i.v. AMG0347, whereas i.v. AMG0347 increased the number of c-Fos cells in the raphe. We conclude that the neural pathway of TRPV1 antagonist-induced hyperthermia involves TRPV1-expressing sensory nerves in trunk muscles, the DLF, and the same LPB-raphe pathway that controls autonomic cold defenses.
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Affiliation(s)
- Andras Garami
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), St. Joseph’s Hospital and Medical Center, Phoenix, AZ, USA
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Alexandre A. Steiner
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), St. Joseph’s Hospital and Medical Center, Phoenix, AZ, USA
- Departamento de Imunologia, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, São Paulo, Brazil
| | - Eszter Pakai
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), St. Joseph’s Hospital and Medical Center, Phoenix, AZ, USA
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Samuel P. Wanner
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), St. Joseph’s Hospital and Medical Center, Phoenix, AZ, USA
| | - M. Camila Almeida
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), St. Joseph’s Hospital and Medical Center, Phoenix, AZ, USA
| | - Patrik Keringer
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Daniela L. Oliveira
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), St. Joseph’s Hospital and Medical Center, Phoenix, AZ, USA
| | - Kazuhiro Nakamura
- Department of Integrative Physiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shaun F. Morrison
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR, USA
| | - Andrej A. Romanovsky
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), St. Joseph’s Hospital and Medical Center, Phoenix, AZ, USA
- School of Molecular Sciences, University of Arizona, Tempe, AZ, USA
- Zharko Pharma, Inc., Olympia, WA, USA
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16
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Rosales AM, Powers M, Walters MJ, McGlynn ML, Collins CW, Slivka DR. Influence of topical capsaicin cream on thermoregulation and perception during acute exercise in the heat. J Therm Biol 2023; 113:103535. [PMID: 37055138 DOI: 10.1016/j.jtherbio.2023.103535] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 02/01/2023] [Accepted: 02/22/2023] [Indexed: 03/05/2023]
Abstract
PURPOSE Determine if topical capsaicin, a transient receptor potential vanilloid heat thermoreceptor activator, alters thermoregulation and perception when applied topically prior to thermal exercise. METHODS Twelve subjects completed 2 treatments. Subjects walked (1.6 m s-1, 5% grade) for 30 min in the heat (38 °C, 60% relative humidity) with either a capsaicin (0.025% capsaicin) or control cream applied to the upper (shoulder to wrist) and lower (mid-thigh to ankle) limbs covering ∼50% body surface area. Skin blood flow (SkBF), sweat (rate, composition), heart rate, temperature (skin, core), and perceived thermal sensation were measured prior to and during exercise. RESULTS The relative change in SkBF was not different between treatments at any time point (p = 0.284). There were no differences in sweat rate between the capsaicin (1.23 ± 0.37 L h-1) and control (1.43 ± 0.43 L h-1, p = 0.122). There were no differences in heart rate between the capsaicin (122 ± 38 beats·min-1) and control (125 ± 39 beats·min-1, p = 0.431). There were also no differences in weighted surface (p = 0.976) or body temperatures (p = 0.855) between the capsaicin (36.0 ± 1.7 °C, 37.0 ± 0.8 °C, respectively) and control (36.0 ± 1.6 °C, 36.9 ± 0.8 °C, respectively). The capsaicin treatment was not perceived as hotter than the control treatment until minute 30 of exercise (2.8 ± 0.4, 2.5 ± 0.5, respectively, p = 0.038) CONCLUSIONS: Topical capsaicin application does not alter whole-body thermoregulation during acute exercise in the heat despite perceiving the treatment as hotter late in exercise.
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Affiliation(s)
- Alejandro M Rosales
- School of Health and Kinesiology, University of Nebraska at Omaha, 6001 Dodge Street, Omaha, NE, 68182, USA; School of Integrative Physiology and Athletic Training, Montana Center for Work Physiology and Exercise Metabolism, University of Montana, 32 Campus Drive, Missoula, MT, 59812, USA
| | - Marie Powers
- School of Health and Kinesiology, University of Nebraska at Omaha, 6001 Dodge Street, Omaha, NE, 68182, USA
| | - Matthias J Walters
- School of Health and Kinesiology, University of Nebraska at Omaha, 6001 Dodge Street, Omaha, NE, 68182, USA
| | - Mark L McGlynn
- School of Health and Kinesiology, University of Nebraska at Omaha, 6001 Dodge Street, Omaha, NE, 68182, USA
| | - Christopher W Collins
- School of Health and Kinesiology, University of Nebraska at Omaha, 6001 Dodge Street, Omaha, NE, 68182, USA
| | - Dustin R Slivka
- School of Health and Kinesiology, University of Nebraska at Omaha, 6001 Dodge Street, Omaha, NE, 68182, USA; School of Integrative Physiology and Athletic Training, Montana Center for Work Physiology and Exercise Metabolism, University of Montana, 32 Campus Drive, Missoula, MT, 59812, USA.
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17
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Horta NAC, Fernandes P, Cardoso TSR, Machado FSM, Drummond LR, Coimbra CC, Wanner SP, Maria L Castrucci A, Poletini MO. TRPV1 inactivation alters core body temperature and serum corticosterone levels: Impacts on clock genes expression in the liver and adrenal glands. J Therm Biol 2023. [DOI: 10.1016/j.jtherbio.2023.103514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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18
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Katz B, Zaguri R, Edvardson S, Maayan C, Elpeleg O, Lev S, Davidson E, Peters M, Kfir-Erenfeld S, Berger E, Ghazalin S, Binshtok AM, Minke B. Nociception and pain in humans lacking a functional TRPV1 channel. J Clin Invest 2023; 133:153558. [PMID: 36454632 PMCID: PMC9888381 DOI: 10.1172/jci153558] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 11/29/2022] [Indexed: 12/05/2022] Open
Abstract
BACKGROUNDChronic pain is a debilitating illness with currently limited therapy, in part due to difficulties in translating treatments derived from animal models to patients. The transient receptor potential vanilloid 1 (TRPV1) channel is associated with noxious heat detection and inflammatory pain, and reports of adverse effects in human trials have hindered extensive efforts in the clinical development of TRPV1 antagonists as novel pain relievers.METHODSWe examined 2 affected individuals (A1 and A2) carrying a homozygous missense mutation in TRPV1, rendering the channel nonfunctional. Biochemical and functional assays were used to analyze the mutant channel. To identify possible phenotypes of the affected individuals, we performed psychophysical and medical examinations.RESULTSWe demonstrated that diverse TRPV1 activators, acting at different sites of the channel protein, were unable to open the cloned mutant channel. This finding was not a consequence of impairment in the expression, cellular trafficking, or assembly of protein subunits. The affected individuals were insensitive to application of capsaicin to the mouth and skin and did not demonstrate aversive behavior toward capsaicin. Furthermore, quantitative sensory testing of A1 revealed an elevated heat-pain threshold but also, surprisingly, an elevated cold-pain threshold and extensive neurogenic inflammatory, flare, and pain responses following application of the TRPA1 channel activator mustard oil.CONCLUSIONOur study provides direct evidence in humans for pain-related functional changes linked to TRPV1, which is a prime target in the development of pain relievers.FUNDINGSupported by the Israel Science Foundation (368/19); Teva's National Network of Excellence in Neuroscience grant (no. 0394886) and Teva's National Network of Excellence in Neuroscience postdoctoral fellowship.
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Affiliation(s)
- Ben Katz
- Department of Medical Neurobiology, Faculty of Medicine and the Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University, Jerusalem, Israel
| | - Rachel Zaguri
- Department of Medical Neurobiology, Faculty of Medicine and the Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University, Jerusalem, Israel
| | - Simon Edvardson
- Pediatric Neurology Unit, Pediatric Department, Hadassah University Hospital, Mount Scopus, Jerusalem, Israel
| | - Channa Maayan
- Pediatric Neurology Unit, Pediatric Department, Hadassah University Hospital, Mount Scopus, Jerusalem, Israel
| | | | - Shaya Lev
- Department of Medical Neurobiology, Faculty of Medicine and the Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University, Jerusalem, Israel
| | - Elyad Davidson
- Pain Relief Unit, Department of Anesthesiology and Critical Care Medicine, and
| | - Maximilian Peters
- Department of Medical Neurobiology, Faculty of Medicine and the Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University, Jerusalem, Israel
| | - Shlomit Kfir-Erenfeld
- Department of Bone Marrow Transplantation and Cancer Immunology, Hadassah University Hospital, Ein Kerem, Jerusalem, Israel
| | - Esther Berger
- Department of Pathology, E. Wolfson Medical Center, Holon, Israel
| | - Shifa Ghazalin
- Department of Medical Neurobiology, Faculty of Medicine and the Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University, Jerusalem, Israel
| | - Alexander M. Binshtok
- Department of Medical Neurobiology, Faculty of Medicine and the Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University, Jerusalem, Israel
| | - Baruch Minke
- Department of Medical Neurobiology, Faculty of Medicine and the Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University, Jerusalem, Israel
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19
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Reis TO, Noronha SISR, Lima PMA, De Abreu ARR, Mesquita LBT, Ferreira FI, Silva FC, Chianca-Jr DA, De Menezes RC. Abdominal TRPV1 channel desensitization enhances stress-induced hyperthermia during social stress in rats. Auton Neurosci 2023; 246:103073. [PMID: 36736078 DOI: 10.1016/j.autneu.2023.103073] [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: 05/18/2022] [Revised: 12/22/2022] [Accepted: 01/24/2023] [Indexed: 01/28/2023]
Abstract
AIMS In rats, stress-induced hyperthermia caused by social interaction depends on brown adipose tissue (BAT) thermogenesis and peripheral vasoconstriction. However, the peripheral mechanisms responsible for regulating the level of hyperthermia during social stress are still unknown. The transient receptor potential vanilloid 1 (TRPV1) subfamily, expressed in sensory and visceral neurons, can serve as a thermoreceptor. Here, we tested the hypothesis that the abdominal TRPV1 is essential in regulating stress-induced hyperthermia during social stress. MAIN METHODS Male Wistar rats received an intraperitoneal injection of Resiniferatoxin (RTX) - an ultra-potent capsaicin analog, (i.e., to desensitize the TRPV1 channels) or vehicle. Seven days later, we evaluated the effects of abdominal TRPV1 channels desensitization on core body temperature (CBT), brown adipose tissue (BAT) temperature, tail skin temperature, and heart rate (HR) of rats subjected to a social stress protocol. KEY FINDINGS We found abdominal TRPV1 desensitization increased CBT and BAT temperature but did not change tail skin temperature and HR during rest. However, under social stress, we found that abdominal TRPV1 desensitization heightened the increase in CBT and BAT caused by stress. Also, it abolished the increase in tail skin temperature that occurs during and after social stress. TRPV1 desensitization also delayed the HR recovery after the exposure to the social stress. SIGNIFICANCE These results show that abdominal TRPV1 channels desensitization heightens stress-induced hyperthermia, causing heat dissipation during and after social stress, enabling optimal thermal control during social encounters.
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Affiliation(s)
- T O Reis
- Department of Biological Science, Laboratory of Cardiovascular Physiology, University of Ouro Preto, Ouro Preto, MG 35400-000, Brazil
| | - S I S R Noronha
- Department of Biological Science, Laboratory of Cardiovascular Physiology, University of Ouro Preto, Ouro Preto, MG 35400-000, Brazil
| | - P M A Lima
- Department of Biological Science, Laboratory of Cardiovascular Physiology, University of Ouro Preto, Ouro Preto, MG 35400-000, Brazil
| | - A R R De Abreu
- Department of Biological Science, Laboratory of Cardiovascular Physiology, University of Ouro Preto, Ouro Preto, MG 35400-000, Brazil
| | - L B T Mesquita
- Department of Biological Science, Laboratory of Cardiovascular Physiology, University of Ouro Preto, Ouro Preto, MG 35400-000, Brazil
| | - F I Ferreira
- Department of Biological Science, Laboratory of Cardiovascular Physiology, University of Ouro Preto, Ouro Preto, MG 35400-000, Brazil
| | - F C Silva
- Department of Biological Science, Laboratory of Cardiovascular Physiology, University of Ouro Preto, Ouro Preto, MG 35400-000, Brazil..
| | - D A Chianca-Jr
- Department of Biological Science, Laboratory of Cardiovascular Physiology, University of Ouro Preto, Ouro Preto, MG 35400-000, Brazil..
| | - R C De Menezes
- Department of Biological Science, Laboratory of Cardiovascular Physiology, University of Ouro Preto, Ouro Preto, MG 35400-000, Brazil..
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20
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Zayan U, Caccialupi Da Prato L, Muscatelli F, Matarazzo V. Modulation of the thermosensory system by oxytocin. Front Mol Neurosci 2023; 15:1075305. [PMID: 36698777 PMCID: PMC9868264 DOI: 10.3389/fnmol.2022.1075305] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 12/06/2022] [Indexed: 01/11/2023] Open
Abstract
Oxytocin (OT) is a neurohormone involved early in neurodevelopment and is implicated in multiple functions, including sensory modulation. Evidence of such modulation has been observed for different sensory modalities in both healthy and pathological conditions. This review summarizes the pleiotropic modulation that OT can exercise on an often overlooked sensory system: thermosensation. This system allows us to sense temperature variations and compensate for the variation to maintain a stable core body temperature. Oxytocin modulates autonomic and behavioral mechanisms underlying thermoregulation at both central and peripheral levels. Hyposensitivity or hypersensitivity for different sensory modalities, including thermosensitivity, is a common feature in autism spectrum disorder (ASD), recapitulated in several ASD mouse models. These sensory dysregulations occur early in post-natal development and are correlated with dysregulation of the oxytocinergic system. In this study, we discussed the potential link between thermosensory atypia and the dysregulation of the oxytocinergic system in ASD.
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21
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Chemotherapy-Induced Peripheral Neuropathy. Handb Exp Pharmacol 2023; 277:299-337. [PMID: 36253554 DOI: 10.1007/164_2022_609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Chemotherapy-induced peripheral neuropathy (CIPN) is a debilitating side effect of many common anti-cancer agents that can lead to dose reduction or treatment discontinuation, which decrease chemotherapy efficacy. Long-term CIPN can interfere with activities of daily living and diminish the quality of life. The mechanism of CIPN is not yet fully understood, and biomarkers are needed to identify patients at high risk and potential treatment targets. Metabolomics can capture the complex behavioral and pathophysiological processes involved in CIPN. This chapter is to review the CIPN metabolomics studies to find metabolic pathways potentially involved in CIPN. These potential CIPN metabolites are then investigated to determine whether there is evidence from studies of other neuropathy etiologies such as diabetic neuropathy and Leber hereditary optic neuropathy to support the importance of these pathways in peripheral neuropathy. Six potential biomarkers and their putative mechanisms in peripheral neuropathy were reviewed. Among these biomarkers, histidine and phenylalanine have clear roles in neurotransmission or neuroinflammation in peripheral neuropathy. Further research is needed to discover and validate CIPN metabolomics biomarkers in large clinical studies.
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Thermoregulatory heat-escape/cold-seeking behavior in mice and the influence of TRPV1 channels. PLoS One 2022; 17:e0276748. [DOI: 10.1371/journal.pone.0276748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 10/12/2022] [Indexed: 11/17/2022] Open
Abstract
The present study assessed heat-escape/cold-seeking behavior during thermoregulation in mice and the influence of TRPV1 channels. Mice received subcutaneous injection of capsaicin (50 mg/kg; CAP group) for desensitization of TRPV1 channels or vehicle (control [CON] group). In Experiment 1, heat-escape/cold-seeking behavior was assessed using a newly developed system comprising five temperature-controlled boards placed in a cross-shape. Each mouse completed three 90-min trials. In the trials, the four boards, including the center board, were set at either 36˚C, 38˚C, or 40˚C, while one corner board was set at 32˚C, which was rotated every 5 min. In Experiment 2, mice were exposed to an ambient temperature of 37˚C for 30 min. cFos expression in the preoptic area of the hypothalamus (POA) was assessed. In Experiment 1, the CON group stayed on the 32˚C board for the longest duration relative to that on other boards, and intra-abdominal temperature (Tabd) was maintained. In the CAP group, no preference for the 32˚C board was observed, and Tabd increased. In Experiment 2, cFos expression in the POA decreased in the CAP group. Capsaicin-induced desensitization of TRPV1 channels suppressed heat-escape/cold-seeking behavior in mice during heat exposure, resulting in hyperthermia. In conclusion, our findings suggest that heat sensation from the body surface may be a key inducer of thermoregulatory behaviors in mice.
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Abstract
Sleep is a fundamental, evolutionarily conserved, plastic behavior that is regulated by circadian and homeostatic mechanisms as well as genetic factors and environmental factors, such as light, humidity, and temperature. Among environmental cues, temperature plays an important role in the regulation of sleep. This review presents an overview of thermoreception in animals and the neural circuits that link this process to sleep. Understanding the influence of temperature on sleep can provide insight into basic physiologic processes that are required for survival and guide strategies to manage sleep disorders.
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Miyata S. Glial functions in the blood-brain communication at the circumventricular organs. Front Neurosci 2022; 16:991779. [PMID: 36278020 PMCID: PMC9583022 DOI: 10.3389/fnins.2022.991779] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
The circumventricular organs (CVOs) are located around the brain ventricles, lack a blood-brain barrier (BBB) and sense blood-derived molecules. This review discusses recent advances in the importance of CVO functions, especially glial cells transferring periphery inflammation signals to the brain. The CVOs show size-limited vascular permeability, allowing the passage of molecules with molecular weight <10,000. This indicates that the lack of an endothelial cell barrier does not mean the free movement of blood-derived molecules into the CVO parenchyma. Astrocytes and tanycytes constitute a dense barrier at the distal CVO subdivision, preventing the free diffusion of blood-derived molecules into neighboring brain regions. Tanycytes in the CVOs mediate communication between cerebrospinal fluid and brain parenchyma via transcytosis. Microglia and macrophages of the CVOs are essential for transmitting peripheral information to other brain regions via toll-like receptor 2 (TLR2). Inhibition of TLR2 signaling or depletion of microglia and macrophages in the brain eliminates TLR2-dependent inflammatory responses. In contrast to TLR2, astrocytes and tanycytes in the CVOs of the brain are crucial for initiating lipopolysaccharide (LPS)-induced inflammatory responses via TLR4. Depletion of microglia and macrophages augments LPS-induced fever and chronic sickness responses. Microglia and macrophages in the CVOs are continuously activated, even under normal physiological conditions, as they exhibit activated morphology and express the M1/M2 marker proteins. Moreover, the microglial proliferation occurs in various regions, such as the hypothalamus, medulla oblongata, and telencephalon, with a marked increase in the CVOs, due to low-dose LPS administration, and after high-dose LPS administration, proliferation is seen in most brain regions, except for the cerebral cortex and hippocampus. A transient increase in the microglial population is beneficial during LPS-induced inflammation for attenuating sickness response. Transient receptor potential receptor vanilloid 1 expressed in astrocytes and tanycytes of the CVOs is responsible for thermoregulation upon exposure to a warm environment less than 37°C. Alternatively, Nax expressed in astrocytes and tanycytes of the CVOs is crucial for maintaining body fluid homeostasis. Thus, recent findings indicate that glial cells in the brain CVOs are essential for initiating neuroinflammatory responses and maintaining body fluid and thermal homeostasis.
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Upregulation of TRPM3 in bladder afferents is involved in chronic pain in CYP-induced cystitis. Pain 2022; 163:2200-2212. [DOI: 10.1097/j.pain.0000000000002616] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 01/05/2022] [Indexed: 11/26/2022]
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Lima PM, Reis TO, Wanner SP, Chianca-Jr DA, Menezes RC. The role of peripheral transient receptor potential vanilloid 1 channels in stress-induced hyperthermia in rats subjected to an anxiogenic environment. J Therm Biol 2022; 106:103191. [DOI: 10.1016/j.jtherbio.2022.103191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 11/26/2021] [Accepted: 01/19/2022] [Indexed: 10/19/2022]
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Kim HI, Lee JC, Kim DW, Shin MC, Cho JH, Ahn JH, Lim SS, Kang IJ, Park JH, Won MH, Lee TK. Hypothermia Induced by Oxcarbazepine after Transient Forebrain Ischemia Exerts Therapeutic Neuroprotection through Transient Receptor Potential Vanilloid Type 1 and 4 in Gerbils. Int J Mol Sci 2021; 23:ijms23010237. [PMID: 35008663 PMCID: PMC8745517 DOI: 10.3390/ijms23010237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 12/23/2021] [Accepted: 12/24/2021] [Indexed: 11/16/2022] Open
Abstract
In the present study, we investigated the neuroprotective effect of post-ischemic treatment with oxcarbazepine (OXC; an anticonvulsant compound) against ischemic injury induced by transient forebrain ischemia and its mechanisms in gerbils. Transient ischemia was induced in the forebrain by occlusion of both common carotid arteries for 5 min under normothermic conditions (37 ± 0.2 °C). The ischemic gerbils were treated with vehicle, hypothermia (whole-body cooling; 33.0 ± 0.2 °C), or 200 mg/kg OXC. Post-ischemic treatments with vehicle and hypothermia failed to attenuate and improve, respectively, ischemia-induced hyperactivity and cognitive impairment (decline in spatial and short-term memory). However, post-ischemic treatment with OXC significantly attenuated the hyperactivity and the cognitive impairment, showing that OXC treatment significantly reduced body temperature (to about 33 °C). When the hippocampus was histopathologically examined, pyramidal cells (principal neurons) were dead (lost) in the subfield Cornu Ammonis 1 (CA1) of the gerbils treated with vehicle and hypothermia on Day 4 after ischemia, but these cells were saved in the gerbils treated with OXC. In the gerbils treated with OXC after ischemia, the expression of transient receptor potential vanilloid type 1 (TRPV1; one of the transient receptor potential cation channels) was significantly increased in the CA1 region compared with that in the gerbils treated with vehicle and hypothermia. In brief, our results showed that OXC-induced hypothermia after transient forebrain ischemia effectively protected against ischemia–reperfusion injury through an increase in TRPV1 expression in the gerbil hippocampal CA1 region, indicating that TRPV1 is involved in OXC-induced hypothermia.
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Affiliation(s)
- Hyung-Il Kim
- Department of Emergency Medicine, Dankook University Hospital, College of Medicine, Dankook University, Cheonan 31116, Chungnam, Korea;
- Department of Emergency Medicine, Kangwon National University Hospital, School of Medicine, Kangwon National University, Chuncheon 24289, Gangwon, Korea; (M.C.S.); (J.H.C.)
| | - Jae-Chul Lee
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon 24341, Gangwon, Korea; (J.-C.L.); (J.H.A.)
| | - Dae Won Kim
- Department of Biochemistry and Molecular Biology, Research Institute of Oral Sciences, College of Dentistry, Gangnung-Wonju National University, Gangneung 25457, Gangwon, Korea;
| | - Myoung Cheol Shin
- Department of Emergency Medicine, Kangwon National University Hospital, School of Medicine, Kangwon National University, Chuncheon 24289, Gangwon, Korea; (M.C.S.); (J.H.C.)
| | - Jun Hwi Cho
- Department of Emergency Medicine, Kangwon National University Hospital, School of Medicine, Kangwon National University, Chuncheon 24289, Gangwon, Korea; (M.C.S.); (J.H.C.)
| | - Ji Hyeon Ahn
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon 24341, Gangwon, Korea; (J.-C.L.); (J.H.A.)
- Department of Physical Therapy, College of Health Science, Youngsan University, Yangsan 50510, Gyeongnam, Korea
| | - Soon-Sung Lim
- Department of Food Science and Nutrition, Hallym University, Chuncheon 24252, Gangwon, Korea; (S.-S.L.); (I.J.K.)
| | - Il Jun Kang
- Department of Food Science and Nutrition, Hallym University, Chuncheon 24252, Gangwon, Korea; (S.-S.L.); (I.J.K.)
| | - Joon Ha Park
- Department of Anatomy, College of Korean Medicine, Dongguk University, Gyeongju 38066, Gyeongbuk, Korea;
| | - Moo-Ho Won
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon 24341, Gangwon, Korea; (J.-C.L.); (J.H.A.)
- Correspondence: (M.-H.W.); (T.-K.L.); Tel.: +82-33-250-8891 (M.-H.W.); +82-33-248-2135 (T.-K.L.); Fax: +82-33-256-1614 (M.-H.W.); +82-33-255-4787 (T.-K.L.)
| | - Tae-Kyeong Lee
- Department of Food Science and Nutrition, Hallym University, Chuncheon 24252, Gangwon, Korea; (S.-S.L.); (I.J.K.)
- Correspondence: (M.-H.W.); (T.-K.L.); Tel.: +82-33-250-8891 (M.-H.W.); +82-33-248-2135 (T.-K.L.); Fax: +82-33-256-1614 (M.-H.W.); +82-33-255-4787 (T.-K.L.)
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Iozzo M, Sgrignani G, Comito G, Chiarugi P, Giannoni E. Endocannabinoid System and Tumour Microenvironment: New Intertwined Connections for Anticancer Approaches. Cells 2021; 10:cells10123396. [PMID: 34943903 PMCID: PMC8699381 DOI: 10.3390/cells10123396] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/24/2021] [Accepted: 11/30/2021] [Indexed: 01/01/2023] Open
Abstract
The tumour microenvironment (TME) is now recognised as a hallmark of cancer, since tumour:stroma crosstalk supports the key steps of tumour growth and progression. The dynamic co-evolution of the tumour and stromal compartments may alter the surrounding microenvironment, including the composition in metabolites and signalling mediators. A growing number of evidence reports the involvement of the endocannabinoid system (ECS) in cancer. ECS is composed by a complex network of ligands, receptors, and enzymes, which act in synergy and contribute to several physiological but also pathological processes. Several in vitro and in vivo evidence show that ECS deregulation in cancer cells affects proliferation, migration, invasion, apoptosis, and metastatic potential. Although it is still an evolving research, recent experimental evidence also suggests that ECS can modulate the functional behaviour of several components of the TME, above all the immune cells, endothelial cells and stromal components. However, the role of ECS in the tumour:stroma interplay remains unclear and research in this area is particularly intriguing. This review aims to shed light on the latest relevant findings of the tumour response to ECS modulation, encouraging a more in-depth analysis in this field. Novel discoveries could be promising for novel anti-tumour approaches, targeting the microenvironmental components and the supportive tumour:stroma crosstalk, thereby hindering tumour development.
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Rueda-Ruzafa L, Herrera-Pérez S, Campos-Ríos A, Lamas JA. Are TREK Channels Temperature Sensors? Front Cell Neurosci 2021; 15:744702. [PMID: 34690704 PMCID: PMC8526543 DOI: 10.3389/fncel.2021.744702] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 09/08/2021] [Indexed: 11/17/2022] Open
Abstract
Internal human body normal temperature fluctuates between 36.5 and 37.5°C and it is generally measured in the oral cavity. Interestingly, most electrophysiological studies on the functioning of ion channels and their role in neuronal behavior are carried out at room temperature, which usually oscillates between 22 and 24°C, even when thermosensitive channels are studied. We very often forget that if the core of the body reached that temperature, the probability of death from cardiorespiratory arrest would be extremely high. Does this mean that we are studying ion channels in dying neurons? Thousands of electrophysiological experiments carried out at these low temperatures suggest that most neurons tolerate this aggression quite well, at least for the duration of the experiments. This also seems to happen with ion channels, although studies at different temperatures indicate large changes in both, neuron and channel behavior. It is known that many chemical, physical and therefore physiological processes, depend to a great extent on body temperature. Temperature clearly affects the kinetics of numerous events such as chemical reactions or conformational changes in proteins but, what if these proteins constitute ion channels and these channels are specifically designed to detect changes in temperature? In this review, we discuss the importance of the potassium channels of the TREK subfamily, belonging to the recently discovered family of two-pore domain channels, in the transduction of thermal sensitivity in different cell types.
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Affiliation(s)
- Lola Rueda-Ruzafa
- CINBIO, Laboratory of Neuroscience, University of Vigo, Vigo, Spain.,Laboratory of Neuroscience, Galicia Sur Health Research Institute (IISGS), Vigo, Spain
| | - Salvador Herrera-Pérez
- CINBIO, Laboratory of Neuroscience, University of Vigo, Vigo, Spain.,Grupo de Neurofisiología Experimental y Circuitos Neuronales, Hospital Nacional de Parapléjicos, SESCAM, Toledo, Spain
| | - Ana Campos-Ríos
- CINBIO, Laboratory of Neuroscience, University of Vigo, Vigo, Spain.,Laboratory of Neuroscience, Galicia Sur Health Research Institute (IISGS), Vigo, Spain
| | - J A Lamas
- CINBIO, Laboratory of Neuroscience, University of Vigo, Vigo, Spain.,Laboratory of Neuroscience, Galicia Sur Health Research Institute (IISGS), Vigo, Spain
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Luu DD, Owens AM, Mebrat MD, Van Horn WD. A molecular perspective on identifying TRPV1 thermosensitive regions and disentangling polymodal activation. Temperature (Austin) 2021; 10:67-101. [PMID: 37187836 PMCID: PMC10177694 DOI: 10.1080/23328940.2021.1983354] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 09/10/2021] [Accepted: 09/16/2021] [Indexed: 10/20/2022] Open
Abstract
TRPV1 is a polymodal receptor ion channel that is best known to function as a molecular thermometer. It is activated in diverse ways, including by heat, protons (low pH), and vanilloid compounds, such as capsaicin. In this review, we summarize molecular studies of TRPV1 thermosensing, focusing on the cross-talk between heat and other activation modes. Additional insights from TRPV1 isoforms and non-rodent/non-human TRPV1 ortholog studies are also discussed in this context. While the molecular mechanism of heat activation is still emerging, it is clear that TRPV1 thermosensing is modulated allosterically, i.e., at a distance, with contributions from many distinct regions of the channel. Similarly, current studies identify cross-talk between heat and other TRPV1 activation modes, such as protons and capsaicin, and that these modes can generally be selectively disentangled. In aggregate, this suggests that future TRPV1 molecular studies should define allosteric pathways and provide mechanistic insight, thereby enabling mode-selective manipulation of the polymodal receptor. These advances are anticipated to have significant implications in both basic and applied biomedical sciences.
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Affiliation(s)
- Dustin D. Luu
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
- The Biodesign Institute Virginia G. Piper Center for Personalized Diagnostics,Arizona State University, Tempe, Arizona,USA
| | - Aerial M. Owens
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
- The Biodesign Institute Virginia G. Piper Center for Personalized Diagnostics,Arizona State University, Tempe, Arizona,USA
| | - Mubark D. Mebrat
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
- The Biodesign Institute Virginia G. Piper Center for Personalized Diagnostics,Arizona State University, Tempe, Arizona,USA
| | - Wade D. Van Horn
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
- The Biodesign Institute Virginia G. Piper Center for Personalized Diagnostics,Arizona State University, Tempe, Arizona,USA
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The Hypothermic Effect of Hydrogen Sulfide Is Mediated by the Transient Receptor Potential Ankyrin-1 Channel in Mice. Pharmaceuticals (Basel) 2021; 14:ph14100992. [PMID: 34681216 PMCID: PMC8538668 DOI: 10.3390/ph14100992] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 09/24/2021] [Accepted: 09/25/2021] [Indexed: 12/17/2022] Open
Abstract
Hydrogen sulfide (H2S) has been shown in previous studies to cause hypothermia and hypometabolism in mice, and its thermoregulatory effects were subsequently investigated. However, the molecular target through which H2S triggers its effects on deep body temperature has remained unknown. We investigated the thermoregulatory response to fast-(Na2S) and slow-releasing (GYY4137) H2S donors in C57BL/6 mice, and then tested whether their effects depend on the transient receptor potential ankyrin-1 (TRPA1) channel in Trpa1 knockout (Trpa1−/−) and wild-type (Trpa1+/+) mice. Intracerebroventricular administration of Na2S (0.5–1 mg/kg) caused hypothermia in C57BL/6 mice, which was mediated by cutaneous vasodilation and decreased thermogenesis. In contrast, intraperitoneal administration of Na2S (5 mg/kg) did not cause any thermoregulatory effect. Central administration of GYY4137 (3 mg/kg) also caused hypothermia and hypometabolism. The hypothermic response to both H2S donors was significantly (p < 0.001) attenuated in Trpa1−/− mice compared to their Trpa1+/+ littermates. Trpa1 mRNA transcripts could be detected with RNAscope in hypothalamic and other brain neurons within the autonomic thermoeffector pathways. In conclusion, slow- and fast-releasing H2S donors induce hypothermia through hypometabolism and cutaneous vasodilation in mice that is mediated by TRPA1 channels located in the brain, presumably in hypothalamic neurons within the autonomic thermoeffector pathways.
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Inhibition of nNOS in the paraventricular nucleus of hypothalamus decreases exercise-induced hyperthermia. Brain Res Bull 2021; 177:64-72. [PMID: 34536522 DOI: 10.1016/j.brainresbull.2021.09.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/21/2021] [Accepted: 09/10/2021] [Indexed: 11/23/2022]
Abstract
The paraventricular nucleus of the hypothalamus (PVN) is an important site for autonomic control, which integrates thermoregulation centers and sympathetic outflow to thermoeffector organs. PVN neurons express the neuronal isoform of nitric oxide synthase (nNOS) whose expression is locally upregulated by physical exercise. Thus, the aim of the present study was to evaluate the role of nNOS in the PVN in the exercise-induced hyperthermia. Seven days after surgery, male Wistar rats received bilateral intra-PVN microinjections of the selective nNOS inhibitor Nw-Propyl-L-Arginine (NPLA) or vehicle (saline) and were submitted to an acute progressive exercise session on a treadmill until fatigue. Abdominal and tail skin temperature (Tabd and Ttail, respectively) were measured, and the threshold (Hthr; °C) and sensitivity (Hsen) for heat dissipation calculated. Performance variables were also collected. During the progressive exercise protocol, all animals displayed an increase in the Tabd. However, compared to vehicle group, the microinjection of NPLA in the PVN attenuated the exercise-induced hyperthermia. There was no difference in Ttail or Hthr between NPLA and control rats. In contrast, Hsen was increased in the NPLA group compared to vehicle. In addition, heat storage was lower in NPLA-treated animals. Despite the temperature differences, inhibition of nNOS in the PVN did not affect running performance on the treadmill. These results suggest that nitrergic signaling within the PVN, under nNOS activation, drives the increase of body temperature, being necessary for the proper thermal regulatory mechanisms during progressive exercise-induced hyperthermia.
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Advances in TRP channel drug discovery: from target validation to clinical studies. Nat Rev Drug Discov 2021; 21:41-59. [PMID: 34526696 PMCID: PMC8442523 DOI: 10.1038/s41573-021-00268-4] [Citation(s) in RCA: 256] [Impact Index Per Article: 85.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/07/2021] [Indexed: 12/20/2022]
Abstract
Transient receptor potential (TRP) channels are multifunctional signalling molecules with many roles in sensory perception and cellular physiology. Therefore, it is not surprising that TRP channels have been implicated in numerous diseases, including hereditary disorders caused by defects in genes encoding TRP channels (TRP channelopathies). Most TRP channels are located at the cell surface, which makes them generally accessible drug targets. Early drug discovery efforts to target TRP channels focused on pain, but as our knowledge of TRP channels and their role in health and disease has grown, these efforts have expanded into new clinical indications, ranging from respiratory disorders through neurological and psychiatric diseases to diabetes and cancer. In this Review, we discuss recent findings in TRP channel structural biology that can affect both drug development and clinical indications. We also discuss the clinical promise of novel TRP channel modulators, aimed at both established and emerging targets. Last, we address the challenges that these compounds may face in clinical practice, including the need for carefully targeted approaches to minimize potential side-effects due to the multifunctional roles of TRP channels.
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Physiological and Behavioral Mechanisms of Thermoregulation in Mammals. Animals (Basel) 2021; 11:ani11061733. [PMID: 34200650 PMCID: PMC8227286 DOI: 10.3390/ani11061733] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/06/2021] [Accepted: 06/07/2021] [Indexed: 12/11/2022] Open
Abstract
This review analyzes the main anatomical structures and neural pathways that allow the generation of autonomous and behavioral mechanisms that regulate body heat in mammals. The study of the hypothalamic neuromodulation of thermoregulation offers broad areas of opportunity with practical applications that are currently being strengthened by the availability of efficacious tools like infrared thermography (IRT). These areas could include the following: understanding the effect of climate change on behavior and productivity; analyzing the effects of exercise on animals involved in sporting activities; identifying the microvascular changes that occur in response to fear, pleasure, pain, and other situations that induce stress in animals; and examining thermoregulating behaviors. This research could contribute substantially to understanding the drastic modification of environments that have severe consequences for animals, such as loss of appetite, low productivity, neonatal hypothermia, and thermal shock, among others. Current knowledge of these physiological processes and complex anatomical structures, like the nervous systems and their close relation to mechanisms of thermoregulation, is still limited. The results of studies in fields like evolutionary neuroscience of thermoregulation show that we cannot yet objectively explain even processes that on the surface seem simple, including behavioral changes and the pathways and connections that trigger mechanisms like vasodilatation and panting. In addition, there is a need to clarify the connection between emotions and thermoregulation that increases the chances of survival of some organisms. An increasingly precise understanding of thermoregulation will allow us to design and apply practical methods in fields like animal science and clinical medicine without compromising levels of animal welfare. The results obtained should not only increase the chances of survival but also improve quality of life and animal production.
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Kelava L, Nemeth D, Hegyi P, Keringer P, Kovacs DK, Balasko M, Solymar M, Pakai E, Rumbus Z, Garami A. Dietary supplementation of transient receptor potential vanilloid-1 channel agonists reduces serum total cholesterol level: a meta-analysis of controlled human trials. Crit Rev Food Sci Nutr 2021; 62:7025-7035. [PMID: 33840333 DOI: 10.1080/10408398.2021.1910138] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Abnormal cholesterol level is a major risk factor in the development of atherosclerosis, which is a fundamental derangement in cardiovascular diseases. Any efforts should be undertaken to lower blood cholesterol levels. Among dietary interventions, capsaicinoid supplementation is also considered as a novel cholesterol-lowering approach, but human studies concluded contradictory results about its effectiveness. The present meta-analysis aimed at determining the effects of capsaicinoids on serum lipid profile in humans. We searched the PubMed, EMBASE, and CENTRAL databases from inception to February 2021. We included 10 controlled studies, which involved 398 participants. We found that dietary capsaicinoid supplementation alone or in combination with other substances significantly (p = 0.004 and 0.001, respectively) reduced serum total cholesterol level compared to controls with an overall standardized mean difference of -0.52 (95% confidence interval: -0.83, -0.21). Capsaicinoids also decreased low-density lipoprotein level significantly (p = 0.035), whereas no effect was observed on serum levels of high-density lipoprotein and triglycerides. Our findings provide novel quantitative evidence for the efficacy of dietary capsaicin supplementation in lowering serum total cholesterol and low-density lipoprotein levels in humans. To validate our conclusion, further randomized controlled trials in a diverse population of adult humans receiving dietary capsaicinoid supplementation are warranted.
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Affiliation(s)
- Leonardo Kelava
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - David Nemeth
- Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Peter Hegyi
- Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary.,Szentagothai Research Centre, University of Pecs, Pecs, Hungary.,Department of Translational Medicine, First Department of Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Patrik Keringer
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Dora K Kovacs
- Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Marta Balasko
- Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Margit Solymar
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Eszter Pakai
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Zoltan Rumbus
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Andras Garami
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
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Hot-Water Bathing Improves Symptoms in Patients with Cyclic Vomiting Syndrome and Is Modulated by Chronic Cannabis Use. Dig Dis Sci 2021; 66:1153-1161. [PMID: 32472256 DOI: 10.1007/s10620-020-06343-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 05/12/2020] [Indexed: 01/19/2023]
Abstract
BACKGROUND Cyclic vomiting syndrome (CVS) is a chronic functional GI disorder; a characteristic compulsive "hot-water bathing" pattern is reported to alleviate symptoms during an acute episode. There is limited data on this bathing pattern: proposed mechanisms include core temperature increase via effects on cannabinoid type 1 receptors in the brain, skin transient receptor potential vanilloid 1 receptor stimulation, and blood flow shift from viscera to skin. AIMS We thus sought to characterize the hot-water bathing pattern in patients with CVS and identify differences between heavy cannabis users in comparison to occasional and non-users. METHODS We conducted a cross-sectional study of 111 patients with CVS at a single tertiary referral center. Questionnaires regarding clinical characteristics, hot-water bathing, and cannabis use were administered. Patients were classified based on cannabis usage into regular cannabis users (≥ 4 times/week), and occasional + non-users (< 4 times/week and no current use). RESULTS A total of 81 (73%) respondents reported the hot-water bathing behavior during an episode. The majority (> 80%) noted a marked improvement in nausea, vomiting, abdominal pain and symptoms associated with panic. Regular cannabis users were more likely to use "very-hot" water (50% vs. 16%, p = 0.01) and time to relief of symptoms was longer (> 10 min) in this group, compared to the rest of the cohort. CONCLUSIONS Hot-water bathing relieves both GI and symptoms related to panic in most patients which appear to be modulated by chronic cannabis use. These findings can help inform future physiologic studies in CVS pathogenesis.
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Wu J, Liu D, Li J, Sun J, Huang Y, Zhang S, Gao S, Mei W. Central Neural Circuits Orchestrating Thermogenesis, Sleep-Wakefulness States and General Anesthesia States. Curr Neuropharmacol 2021; 20:223-253. [PMID: 33632102 PMCID: PMC9199556 DOI: 10.2174/1570159x19666210225152728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 02/01/2021] [Accepted: 02/24/2021] [Indexed: 11/22/2022] Open
Abstract
Great progress has been made in specifically identifying the central neural circuits (CNCs) of the core body temperature (Tcore), sleep-wakefulness states (SWs), and general anesthesia states (GAs), mainly utilizing optogenetic or chemogenetic manipulations. We summarize the neuronal populations and neural pathways of these three CNCs, which gives evidence for the orchestration within these three CNCs, and the integrative regulation of these three CNCs by different environmental light signals. We also outline some transient receptor potential (TRP) channels that function in the CNCs-Tcore and are modulated by some general anesthetics, which makes TRP channels possible targets for addressing the general-anesthetics-induced-hypothermia (GAIH). We suggest this review will provide new orientations for further consummating these CNCs and elucidating the central mechanisms of GAIH.
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Affiliation(s)
- Jiayi Wu
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030. China
| | - Daiqiang Liu
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030. China
| | - Jiayan Li
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030. China
| | - Jia Sun
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030. China
| | - Yujie Huang
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030. China
| | - Shuang Zhang
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030. China
| | - Shaojie Gao
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030. China
| | - Wei Mei
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Jiefang Ave 1095, Wuhan 430030. China
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Logashina YA, Palikova YA, Palikov VA, Kazakov VA, Smolskaya SV, Dyachenko IA, Tarasova NV, Andreev YA. Anti-Inflammatory and Analgesic Effects of TRPV1 Polypeptide Modulator APHC3 in Models of Osteo- and Rheumatoid Arthritis. Mar Drugs 2021; 19:md19010039. [PMID: 33477357 PMCID: PMC7830295 DOI: 10.3390/md19010039] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/07/2021] [Accepted: 01/13/2021] [Indexed: 12/26/2022] Open
Abstract
Arthritis is a widespread inflammatory disease associated with progressive articular surface degradation, ongoing pain, and hyperalgesia causing the development of functional limitations and disability. TRPV1 channel is one of the high-potential targets for the treatment of inflammatory diseases. Polypeptide APHC3 from sea anemone Heteractis crispa is a mode-selective TRPV1 antagonist that causes mild hypothermia and shows significant anti-inflammatory and analgesic activity in different models of pain. We evaluated the anti-inflammatory properties of APHC3 in models of monosodium iodoacetate (MIA)-induced osteoarthritis and complete Freund’s adjuvant (CFA)-induced rheumatoid monoarthritis in comparison with commonly used non-steroidal anti-inflammatory drugs (NSAIDs) such as diclofenac, ibuprofen, and meloxicam. Subcutaneous administration of APHC3 (0.1 mg/kg) significantly reversed joint swelling, disability, grip strength impairment, and thermal and mechanical hypersensitivity. The effect of APHC3 was equal to or better than that of reference NSAIDs. Protracted treatment with APHC3 decreased IL-1b concentration in synovial fluid, reduced inflammatory changes in joints, and prevented the progression of cartilage degradation. Therefore, polypeptide APHC3 has the potential to be an analgesic and anti-inflammatory substance for the alleviation of arthritis symptoms.
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Affiliation(s)
- Yulia A. Logashina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia;
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Trubetskaya str. 8, bld. 2, 119991 Moscow, Russia; (S.V.S.); (N.V.T.)
| | - Yulia A. Palikova
- Branch of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Prospekt Nauki, 6, 142290 Pushchino, Russia; (Y.A.P.); (V.A.P.); (V.A.K.); (I.A.D.)
| | - Viktor A. Palikov
- Branch of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Prospekt Nauki, 6, 142290 Pushchino, Russia; (Y.A.P.); (V.A.P.); (V.A.K.); (I.A.D.)
| | - Vitaly A. Kazakov
- Branch of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Prospekt Nauki, 6, 142290 Pushchino, Russia; (Y.A.P.); (V.A.P.); (V.A.K.); (I.A.D.)
| | - Sviatlana V. Smolskaya
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Trubetskaya str. 8, bld. 2, 119991 Moscow, Russia; (S.V.S.); (N.V.T.)
| | - Igor A. Dyachenko
- Branch of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Prospekt Nauki, 6, 142290 Pushchino, Russia; (Y.A.P.); (V.A.P.); (V.A.K.); (I.A.D.)
| | - Nadezhda V. Tarasova
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Trubetskaya str. 8, bld. 2, 119991 Moscow, Russia; (S.V.S.); (N.V.T.)
| | - Yaroslav A. Andreev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia;
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Trubetskaya str. 8, bld. 2, 119991 Moscow, Russia; (S.V.S.); (N.V.T.)
- Correspondence:
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Danladi J, Sabir H. Perinatal Infection: A Major Contributor to Efficacy of Cooling in Newborns Following Birth Asphyxia. Int J Mol Sci 2021; 22:ijms22020707. [PMID: 33445791 PMCID: PMC7828225 DOI: 10.3390/ijms22020707] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 01/05/2021] [Accepted: 01/09/2021] [Indexed: 12/19/2022] Open
Abstract
Neonatal encephalopathy (NE) is a global burden, as more than 90% of NE occurs in low- and middle-income countries (LMICs). Perinatal infection seems to limit the neuroprotective efficacy of therapeutic hypothermia. Efforts made to use therapeutic hypothermia in LMICs treating NE has led to increased neonatal mortality rates. The heat shock and cold shock protein responses are essential for survival against a wide range of stressors during which organisms raise their core body temperature and temporarily subject themselves to thermal and cold stress in the face of infection. The characteristic increase and decrease in core body temperature activates and utilizes elements of the heat shock and cold shock response pathways to modify cytokine and chemokine gene expression, cellular signaling, and immune cell mobilization to sites of inflammation, infection, and injury. Hypothermia stimulates microglia to secret cold-inducible RNA-binding protein (CIRP), which triggers NF-κB, controlling multiple inflammatory pathways, including nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasomes and cyclooxygenase-2 (COX-2) signaling. Brain responses through changes in heat shock protein and cold shock protein transcription and gene-expression following fever range and hyperthermia may be new promising potential therapeutic targets.
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Affiliation(s)
- Jibrin Danladi
- Department of Neonatology and Pediatric Intensive Care, Children’s Hospital University of Bonn, 53127 Bonn, Germany;
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
- Correspondence:
| | - Hemmen Sabir
- Department of Neonatology and Pediatric Intensive Care, Children’s Hospital University of Bonn, 53127 Bonn, Germany;
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
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Modi M, Dhillo WS. The neuroendocrinology of the preoptic area in menopause: Symptoms and therapeutic strategies. HANDBOOK OF CLINICAL NEUROLOGY 2021; 179:455-460. [PMID: 34225982 DOI: 10.1016/b978-0-12-819975-6.00029-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The preoptic area of the hypothalamus is the central hub of thermoregulation in mammals, coordinating autonomic heat-effector pathways in response to sensory information from the ambient and internal environment. This aims to maintain temperature homeostasis at a predetermined thermoregulatory set-point. However, hormonal and neuronal changes during the menopause, including estrogen deficiency, disrupt these normal thermoregulatory responses. This results in abnormal activation of heat dissipation effectors, manifesting clinically as hot flush symptoms. Neurokinin B (NKB) signaling via the neurokinin-3 receptor (NK3R) within the preoptic area is thought to play an important role in the pathophysiology of hot flushes. Therefore attenuation of the NKB/NK3R signaling pathway has garnered much interest as a novel therapeutic target for the amelioration of menopausal hot flushes. Recent clinical trials have demonstrated that NK3R antagonists can produce rapid and sustained improvements in hot flush frequency, severity, and quality of life, without the need for estrogen exposure. Therefore NK3R antagonists are fast emerging as a safe and efficacious alternative to hormone replacement therapy, the current gold standard of treatment.
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Affiliation(s)
- Manish Modi
- Section of Endocrinology and Investigative Medicine, Imperial College London, London, United Kingdom
| | - Waljit Singh Dhillo
- Section of Endocrinology and Investigative Medicine, Imperial College London, London, United Kingdom.
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Abstract
The transient receptor potential vanilloid-1 (TRPV1) is a non-specific cation channel known for its sensitivity to pungent vanilloid compound (i.e. capsaicin) and noxious stimuli, including heat, low pH or inflammatory mediators. TRPV1 is found in the somatosensory system, particularly primary afferent neurons that respond to damaging or potentially damaging stimuli (nociceptors). Stimulation of TRPV1 evokes a burning sensation, reflecting a central role of the channel in pain. Pharmacological and genetic studies have validated TRPV1 as a therapeutic target in several preclinical models of chronic pain, including cancer, neuropathic, postoperative and musculoskeletal pain. While antagonists of TRPV1 were found to be a valuable addition to the pain therapeutic toolbox, their clinical use has been limited by detrimental side effects, such as hyperthermia. In contrast, capsaicin induces a prolonged defunctionalisation of nociceptors and thus opened the door to the development of a new class of therapeutics with long-lasting pain-relieving effects. Here we review the list of TRPV1 agonists undergoing clinical trials for chronic pain management, and discuss new indications, formulations or combination therapies being explored for capsaicin. While the analgesic pharmacopeia for chronic pain patients is ancient and poorly effective, modern TRPV1-targeted drugs could rapidly become available as the next generation of analgesics for a broad spectrum of pain conditions.
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Affiliation(s)
- Mircea Iftinca
- Department of Physiology and Pharmacology, Inflammation Research Network-Snyder Institute for Chronic Diseases and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, Alberta, T2N 4N1, Canada
| | - Manon Defaye
- Department of Physiology and Pharmacology, Inflammation Research Network-Snyder Institute for Chronic Diseases and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, Alberta, T2N 4N1, Canada
| | - Christophe Altier
- Department of Physiology and Pharmacology, Inflammation Research Network-Snyder Institute for Chronic Diseases and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, Alberta, T2N 4N1, Canada.
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Leisengang S, Nürnberger F, Ott D, Murgott J, Gerstberger R, Rummel C, Roth J. Primary culture of the rat spinal dorsal horn: a tool to investigate the effects of inflammatory stimulation on the afferent somatosensory system. Pflugers Arch 2020; 472:1769-1782. [PMID: 33098464 PMCID: PMC7691309 DOI: 10.1007/s00424-020-02478-y] [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: 04/22/2020] [Revised: 08/28/2020] [Accepted: 10/14/2020] [Indexed: 02/06/2023]
Abstract
One maladaptive consequence of inflammatory stimulation of the afferent somatosensory system is the manifestation of inflammatory pain. We established and characterized a neuroglial primary culture of the rat superficial dorsal horn (SDH) of the spinal cord to test responses of this structure to neurochemical, somatosensory, or inflammatory stimulation. Primary cultures of the rat SDH consist of neurons (43%), oligodendrocytes (35%), astrocytes (13%), and microglial cells (9%). Neurons of the SDH responded to cooling (7%), heating (18%), glutamate (80%), substance P (43%), prostaglandin E2 (8%), and KCl (100%) with transient increases in the intracellular calcium [Ca2+]i. Short-term stimulation of SDH primary cultures with LPS (10 μg/ml, 2 h) caused increased expression of pro-inflammatory cytokines, inflammatory transcription factors, and inducible enzymes responsible for inflammatory prostaglandin E2 synthesis. At the protein level, increased concentrations of tumor necrosis factor-α (TNFα) and interleukin-6 (IL-6) were measured in the supernatants of LPS-stimulated SDH cultures and enhanced TNFα and IL-6 immunoreactivity was observed specifically in microglial cells. LPS-exposed microglial cells further showed increased nuclear immunoreactivity for the inflammatory transcription factors NFκB, NF-IL6, and pCREB, indicative of their activation. The short-term exposure to LPS further caused a reduction in the strength of substance P as opposed to glutamate-evoked Ca2+-signals in SDH neurons. However, long-term stimulation with a low dose of LPS (0.01 μg/ml, 24 h) resulted in a significant enhancement of glutamate-induced Ca2+ transients in SDH neurons, while substance P-evoked Ca2+ signals were not influenced. Our data suggest a critical role for microglial cells in the initiation of inflammatory processes within the SDH of the spinal cord, which are accompanied by a modulation of neuronal responses.
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Affiliation(s)
- Stephan Leisengang
- Department of Veterinary Physiology and Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, 35392, Giessen, Germany.,Center for Mind, Brain and Behavior - CMBB, Philipps-University Marburg, Marburg, Germany.,Center for Mind, Brain and Behavior - CMBB, Justus-Liebig-University of Giessen, Giessen, Germany
| | - Franz Nürnberger
- Department of Veterinary Physiology and Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, 35392, Giessen, Germany
| | - Daniela Ott
- Department of Veterinary Physiology and Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, 35392, Giessen, Germany
| | - Jolanta Murgott
- Department of Veterinary Physiology and Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, 35392, Giessen, Germany
| | - Rüdiger Gerstberger
- Department of Veterinary Physiology and Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, 35392, Giessen, Germany
| | - Christoph Rummel
- Department of Veterinary Physiology and Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, 35392, Giessen, Germany.,Center for Mind, Brain and Behavior - CMBB, Philipps-University Marburg, Marburg, Germany.,Center for Mind, Brain and Behavior - CMBB, Justus-Liebig-University of Giessen, Giessen, Germany
| | - Joachim Roth
- Department of Veterinary Physiology and Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, 35392, Giessen, Germany. .,Center for Mind, Brain and Behavior - CMBB, Philipps-University Marburg, Marburg, Germany. .,Center for Mind, Brain and Behavior - CMBB, Justus-Liebig-University of Giessen, Giessen, Germany.
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Uchida Y, Tsunekawa C, Sato I. Systemic acyl-ghrelin increases tail skin temperature in rats without affecting their thermoregulatory behavior in a cold environment. Neurosci Lett 2020; 737:135306. [PMID: 32822766 DOI: 10.1016/j.neulet.2020.135306] [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: 05/09/2020] [Revised: 07/06/2020] [Accepted: 08/12/2020] [Indexed: 10/23/2022]
Abstract
Fasting increases ghrelin that is a peptide hormone with two circulating isoforms, acyl and des-acyl ghrelin. We reported that fasting or des-acyl ghrelin facilitates behavioral thermoregulation in the cold in rats assessed by tail-hiding behavior that was the indicator of rats' thermoregulatory behavior in the cold; however, the effect of acyl-ghrelin on the same process remains to be elucidated. We investigated the effect of acyl-ghrelin on thermoregulatory behavior in the cold in rats. The animals received an intraperitoneal saline or 24 μg acyl-ghrelin injection and were exposed to 27 °C or 15 °C for 2 h, while their body temperature, tail skin temperature, and tail-hiding behavior were constantly monitored. cFos immunoreactive (cFos-IR) cells in the median preoptic area, medial preoptic area, paraventricular nucleus (PVN), and arcuate nucleus were counted. Body temperature and the duration of thermoregulatory behavior did not show a significant difference between the acyl-ghrelin-treated and control groups at 15 °C; however, tail skin temperature in the acyl-ghrelin-treated group was higher than that in the control group. The number of cFos-IR cells in the PVN was greater in the control group than that in the acyl-ghrelin-treated group at 27 °C. These results indicate that acyl-ghrelin did not affect behavioral thermoregulation but might affect tail skin temperature in rats in the cold.
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Affiliation(s)
- Yuki Uchida
- Women's Environmental Science Laboratory, Department of Health Sciences, Faculty of Human Life and Environment, Nara Women's University, Nara, Japan.
| | - Chinami Tsunekawa
- Women's Environmental Science Laboratory, Department of Health Sciences, Faculty of Human Life and Environment, Nara Women's University, Nara, Japan
| | - Izumi Sato
- Women's Environmental Science Laboratory, Department of Health Sciences, Faculty of Human Life and Environment, Nara Women's University, Nara, Japan
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Manaserh IH, Maly E, Jahromi M, Chikkamenahalli L, Park J, Hill J. Insulin sensing by astrocytes is critical for normal thermogenesis and body temperature regulation. J Endocrinol 2020; 247:39-52. [PMID: 32698146 PMCID: PMC7456332 DOI: 10.1530/joe-20-0052] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 07/13/2020] [Indexed: 12/23/2022]
Abstract
The important role of astrocytes in the central control of energy balance and glucose homeostasis has recently been recognized. Changes in thermoregulation can lead to metabolic dysregulation, but the role of astrocytes in this process is not yet clear. Therefore, we generated mice congenitally lacking insulin receptors (Ir) in astrocytes (IrKOGFAP mice) to investigate the involvement of astrocyte insulin signaling. IrKOGFAP mice displayed significantly lower energy expenditure and a strikingly lower basal and fasting body temperature. When exposed to cold, however, they were able to mount a thermogenic response. IrKOGFAP mice displayed sex differences in metabolic function and thermogenesis that may contribute to the development of obesity and type II diabetes as early as 2 months of age. While brown adipose tissue exhibited higher adipocyte size in both sexes, more apoptosis was seen in IrKOGFAP males. Less innervation and lower BAR3 expression levels were also observed in IrKOGFAP brown adipose tissue. These effects have not been reported in models of astrocyte Ir deletion in adulthood. In contrast, body weight and glucose regulatory defects phenocopied such models. These findings identify a novel role for astrocyte insulin signaling in the development of normal body temperature control and sympathetic activation of BAT. Targeting insulin signaling in astrocytes has the potential to serve as a novel target for increasing energy expenditure.
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Affiliation(s)
- Iyad H Manaserh
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, The University of Toledo, Toledo, Ohio, USA
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, The University of Toledo, Toledo, Ohio, USA
| | - Emily Maly
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, The University of Toledo, Toledo, Ohio, USA
| | - Marziyeh Jahromi
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, The University of Toledo, Toledo, Ohio, USA
| | - Lakshmikanth Chikkamenahalli
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, The University of Toledo, Toledo, Ohio, USA
| | - Joshua Park
- Department of Neuroscience, College of Medicine and Life Sciences, The University of Toledo, Toledo, Ohio, USA
| | - Jennifer Hill
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, The University of Toledo, Toledo, Ohio, USA
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, The University of Toledo, Toledo, Ohio, USA
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Bamps D, Vriens J, de Hoon J, Voets T. TRP Channel Cooperation for Nociception: Therapeutic Opportunities. Annu Rev Pharmacol Toxicol 2020; 61:655-677. [PMID: 32976736 DOI: 10.1146/annurev-pharmtox-010919-023238] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chronic pain treatment remains a sore challenge, and in our aging society, the number of patients reporting inadequate pain relief continues to grow. Current treatment options all have their drawbacks, including limited efficacy and the propensity of abuse and addiction; the latter is exemplified by the ongoing opioid crisis. Extensive research in the last few decades has focused on mechanisms underlying chronic pain states, thereby producing attractive opportunities for novel, effective and safe pharmaceutical interventions. Members of the transient receptor potential (TRP) ion channel family represent innovative targets to tackle pain sensation at the root. Three TRP channels, TRPV1, TRPM3, and TRPA1, are of particular interest, as they were identified as sensors of chemical- and heat-induced pain in nociceptor neurons. This review summarizes the knowledge regarding TRP channel-based pain therapies, including the bumpy road of the clinical development of TRPV1 antagonists, the current status of TRPA1 antagonists, and the future potential of targeting TRPM3.
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Affiliation(s)
- Dorien Bamps
- Center for Clinical Pharmacology, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | - Joris Vriens
- Laboratory of Endometrium, Endometriosis and Reproductive Medicine, Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium
| | - Jan de Hoon
- Center for Clinical Pharmacology, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | - Thomas Voets
- Laboratory of Ion Channel Research, VIB-KU Leuven Center for Brain and Disease Research, 3000 Leuven, Belgium; .,Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
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Horváth Á, Biró-Sütő T, Kántás B, Payrits M, Skoda-Földes R, Szánti-Pintér E, Helyes Z, Szőke É. Antinociceptive Effects of Lipid Raft Disruptors, a Novel Carboxamido-Steroid and Methyl β-Cyclodextrin, in Mice by Inhibiting Transient Receptor Potential Vanilloid 1 and Ankyrin 1 Channel Activation. Front Physiol 2020; 11:559109. [PMID: 33071817 PMCID: PMC7539994 DOI: 10.3389/fphys.2020.559109] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 08/18/2020] [Indexed: 12/29/2022] Open
Abstract
Transient Receptor Potential Vanilloid 1 and Ankyrin 1 (TRPV1, TRPA1) cation channels are expressed in nociceptive primary sensory neurons, and play an integrative role in pain processing and inflammatory functions. Lipid rafts are liquid-ordered plasma membrane microdomains rich in cholesterol, sphingomyelin, and gangliosides. We earlier proved that lipid raft disintegration by cholesterol depletion using a novel carboxamido-steroid compound (C1) and methyl β-cyclodextrin (MCD) significantly and concentration-dependently inhibit TRPV1 and TRPA1 activation in primary sensory neurons and receptor-expressing cell lines. Here we investigated the effects of C1 compared to MCD in mouse pain models of different mechanisms. Both C1 and MCD significantly decreased the number of the TRPV1 activation (capsaicin)-induced nocifensive eye-wiping movements in the first hour by 45% and 32%, respectively, and C1 also in the second hour by 26%. Furthermore, C1 significantly decreased the TRPV1 stimulation (resiniferatoxin)-evoked mechanical hyperalgesia involving central sensitization processes, while its inhibitory effect on thermal allodynia was not statistically significant. In contrast, MCD did not affect these resiniferatoxin-evoked nocifensive responses. Both C1 and MCD had inhibitory action on TRPA1 activation (formalin)-induced acute nocifensive reactions (paw liftings, lickings, holdings, and shakings) in the second, neurogenic inflammatory phase by 36% and 51%, respectively. These are the first in vivo data showing that our novel lipid raft disruptor carboxamido-steroid compound exerts antinociceptive and antihyperalgesic effects by inhibiting TRPV1 and TRPA1 ion channel activation similarly to MCD, but in 150-fold lower concentrations. It is concluded that C1 is a useful experimental tool to investigate the effects of cholesterol depletion in animal models, and it also might open novel analgesic drug developmental perspectives.
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Affiliation(s)
- Ádám Horváth
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, Pécs, Hungary
- János Szentágothai Research Centre and Centre for Neuroscience, University of Pécs, Pécs, Hungary
| | - Tünde Biró-Sütő
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, Pécs, Hungary
- János Szentágothai Research Centre and Centre for Neuroscience, University of Pécs, Pécs, Hungary
| | - Boglárka Kántás
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, Pécs, Hungary
- János Szentágothai Research Centre and Centre for Neuroscience, University of Pécs, Pécs, Hungary
| | - Maja Payrits
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, Pécs, Hungary
- János Szentágothai Research Centre and Centre for Neuroscience, University of Pécs, Pécs, Hungary
| | - Rita Skoda-Földes
- Department of Organic Chemistry, Institute of Chemistry, University of Pannonia, Veszprém, Hungary
| | - Eszter Szánti-Pintér
- Department of Organic Chemistry, Institute of Chemistry, University of Pannonia, Veszprém, Hungary
| | - Zsuzsanna Helyes
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, Pécs, Hungary
- János Szentágothai Research Centre and Centre for Neuroscience, University of Pécs, Pécs, Hungary
| | - Éva Szőke
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, Pécs, Hungary
- János Szentágothai Research Centre and Centre for Neuroscience, University of Pécs, Pécs, Hungary
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Yonghak P, Miyata S, Kurganov E. TRPV1 is crucial for thermal homeostasis in the mouse by heat loss behaviors under warm ambient temperature. Sci Rep 2020; 10:8799. [PMID: 32472067 PMCID: PMC7260197 DOI: 10.1038/s41598-020-65703-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 05/04/2020] [Indexed: 11/12/2022] Open
Abstract
Thermal homeostasis in mammalians is a self-regulating process by which biological systems maintain an internal thermal stability, even under different temperature conditions; however, the molecular mechanisms involved under warm ambient temperature remain unclear. Here, we aimed to clarify functional significance of transient receptor potential vanilloid receptor 1 (TRPV1) under warm ambient temperature. TRPV1 KO mice exhibited transient hyperthermia when exposed to 30.0 and 32.5 °C, whereas wild-type (WT) mice did not. TRPV1 KO mice exhibited prolonged and prominent hyperthermia upon exposure to 35.0 °C, whereas WT mice showed transient hyperthermia. Hyperthermia also occurs in WT mice that received intracerebroventricular injection of TRPV1 antagonist AMG9810 upon exposure to 35.0 °C. Heat loss behaviors, sleeping and body licking, were deficient in TRPV1 KO mice exposed to warm temperatures. Therefore, the present results indicate that central TRPV1 is crucial for maintaining a constant body temperature via the initiation of heat loss behaviors under warm ambient temperature.
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Affiliation(s)
- Park Yonghak
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
| | - Seiji Miyata
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
| | - Erkin Kurganov
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan.
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Jeong KY. Changes in TRPV1-Mediated Physiological Function in Rats Systemically Treated With Capsaicin on the Neonate. Int J Mol Sci 2020; 21:3143. [PMID: 32365623 PMCID: PMC7247669 DOI: 10.3390/ijms21093143] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 12/15/2022] Open
Abstract
Capsaicin is the active component of chili peppers and is a hydrophobic, colorless, odorless, and crystalline to waxy compound. The transient receptor potential vanilloid 1 (TRPV1) is the capsaicin receptor channels that are involved in a variety of functions like transduction and transmission of the physiological stimulus. Subcutaneous injection of capsaicin to a newborn rat leads to involuntary lifelong TRPV1 desensitization. Various physiological changes including sensory and homeostatic actions in the body associated with neonatal capsaicin treatment are induced by direct TRPV1 channel targeting. Interesting changes include unique phenomena such as the reduction in pain perception, abnormal body temperature, increase in infection, infectious or neuropathological itching, and irregular circadian core body temperature rhythm. These symptoms are associated with relatively higher fever or loss of sensory c-fiber related to TRPV1 desensitization. The aforementioned outcomes not only provide a warning about the risk of capsaicin exposure in newborns but also indicate the possible occurrence of relatively rare diseases that are difficult to diagnose. Therefore, Therefore, the present review aims to summarize the unique phenomena caused by systemic capsaicin administration in neonatal rats.
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Affiliation(s)
- Keun-Yeong Jeong
- MetiMedi Pharmaceuticals Co., Research Center, Incheon 22006, Korea
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49
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Changes in TRPV1-Mediated Physiological Function in Rats Systemically Treated With Capsaicin on the Neonate. Int J Mol Sci 2020. [PMID: 32365623 DOI: 10.3390/ijms21093143.] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Capsaicin is the active component of chili peppers and is a hydrophobic, colorless, odorless, and crystalline to waxy compound. The transient receptor potential vanilloid 1 (TRPV1) is the capsaicin receptor channels that are involved in a variety of functions like transduction and transmission of the physiological stimulus. Subcutaneous injection of capsaicin to a newborn rat leads to involuntary lifelong TRPV1 desensitization. Various physiological changes including sensory and homeostatic actions in the body associated with neonatal capsaicin treatment are induced by direct TRPV1 channel targeting. Interesting changes include unique phenomena such as the reduction in pain perception, abnormal body temperature, increase in infection, infectious or neuropathological itching, and irregular circadian core body temperature rhythm. These symptoms are associated with relatively higher fever or loss of sensory c-fiber related to TRPV1 desensitization. The aforementioned outcomes not only provide a warning about the risk of capsaicin exposure in newborns but also indicate the possible occurrence of relatively rare diseases that are difficult to diagnose. Therefore, Therefore, the present review aims to summarize the unique phenomena caused by systemic capsaicin administration in neonatal rats.
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50
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Hu J, Chen W, Qiu Z, Lv H. Robust expression of SIRT6 inhibits pulpitis via activation of the TRPV1 channel. Cell Biochem Funct 2020; 38:676-682. [PMID: 32236974 DOI: 10.1002/cbf.3528] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/02/2020] [Accepted: 03/13/2020] [Indexed: 12/20/2022]
Abstract
Invasion of dentinal tubules and pulp tissue by pathogenic bacteria may cause infection leading to pulpitis. Sirtuin 6 (SIRT6) is a NAD-dependent protein deacetylase encoded by the SIRT6 gene. The effect of SIRT6 on lipopolysaccharide (LPS)-induced pulpitis and its mechanism of action were discussed in this study. Dental pulp cells (DPCs) were extracted from human teeth and injected with LPS to induce inflammation. The cells injected with LPS showed substantially decreased expression of SIRT6. The overexpression of SIRT6, induced by plasmid-transfection of DPCs with SIRT6 overexpressing vector, led to a marked decrease in proinflammatory cytokines (IL-6, IL-1β, and TNF-α) and deactivation of NF kappa B pathway. Additionally, dentin matrix protein-1 (DMP1), a promoter of inflammation in dental pulp tissues, was downregulated. Further investigation revealed that SIRT6 promotes ubiquitination of the transient receptor potential vanilloid 1 (TRPV1) channel, leading to its degradation and deactivation. The role of TRPV1 in the anti-inflammatory effects of SIRT6 was determined through incubation of SIRT6-expressing dental pulp stem cells (DPSCs) with capsaicin. This incubation counteracted the effect of SIRT6 on cytokines and DMP1. The injection of lentivirus-SIRT6 attenuated LPS-induced pulpitis in vivo by suppressing TRPV1 activity. Thus, SIRT6 inhibits the TRPV1 channel during LPS-induced inflammation of dental pulp. SIGNIFICANCE OF THE STUDY: This study discussed the effect of sirtuin 6 (SIRT6) on lipopolysaccharide (LPS)-induced pulpitis as well as its mechanism of action and found that SIRT6 may be a negative regulator of pulpitis. Additionally, low expression of SIRT6 and high expression of transient receptor potential vanilloid 1 (TRPV1) in LPS-treated human dental pulp cells are closely associated with proinflammatory cytokines, dentin matrix protein 1 expression, and activation of the NF-κB pathway, which indicated that TRPV1 may be a biomarker for pulpitis and the SIRT6-TRPV1-CGRP axis maybe a clinical target due to their role regulating inflammation and neuropathic pain.
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Affiliation(s)
- Jia Hu
- Department of Endodontics, Affiliated Stomatological Hospital of Fujian Medical University, Fuzhou, Fujian, China.,Fujian Provincial Key Laboratory of Stomatology, Fuzhou, Fujian, China
| | - Weiran Chen
- Fujian Provincial Key Laboratory of Stomatology, Fuzhou, Fujian, China.,Affiliated Stomatological Hospital of Fujian Medical University, Fuzhou, Fujian, China
| | - Zailing Qiu
- Fujian Provincial Key Laboratory of Stomatology, Fuzhou, Fujian, China.,Affiliated Stomatological Hospital of Fujian Medical University, Fuzhou, Fujian, China
| | - Hongbing Lv
- Department of Endodontics, Affiliated Stomatological Hospital of Fujian Medical University, Fuzhou, Fujian, China.,Fujian Provincial Key Laboratory of Stomatology, Fuzhou, Fujian, China
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