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Maximiano TKE, Carneiro JA, Fattori V, Verri WA. TRPV1: Receptor structure, activation, modulation and role in neuro-immune interactions and pain. Cell Calcium 2024; 119:102870. [PMID: 38531262 DOI: 10.1016/j.ceca.2024.102870] [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: 11/30/2023] [Revised: 03/06/2024] [Accepted: 03/06/2024] [Indexed: 03/28/2024]
Abstract
In the 1990s, the identification of a non-selective ion channel, especially responsive to capsaicin, revolutionized the studies of somatosensation and pain that were to follow. The TRPV1 channel is expressed mainly in neuronal cells, more specifically, in sensory neurons responsible for the perception of noxious stimuli. However, its presence has also been detected in other non-neuronal cells, such as immune cells, β- pancreatic cells, muscle cells and adipocytes. Activation of the channel occurs in response to a wide range of stimuli, such as noxious heat, low pH, gasses, toxins, endocannabinoids, lipid-derived endovanilloid, and chemical agents, such as capsaicin and resiniferatoxin. This activation results in an influx of cations through the channel pore, especially calcium. Intracellular calcium triggers different responses in sensory neurons. Dephosphorylation of the TRPV1 channel leads to its desensitization, which disrupts its function, while its phosphorylation increases the channel's sensitization and contributes to the channel's rehabilitation after desensitization. Kinases, phosphoinositides, and calmodulin are the main signaling pathways responsible for the channel's regulation. Thus, in this review we provide an overview of TRPV1 discovery, its tissue expression as well as on the mechanisms by which TRPV1 activation (directly or indirectly) induces pain in different disease models.
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Affiliation(s)
- Thaila Kawane Euflazio Maximiano
- Laboratory of Pain, Inflammation, Neuropathy, and Cancer, Department of Pathology, Center of Biological Sciences, Londrina State University, Londrina, Paraná, Brazil
| | - Jessica Aparecida Carneiro
- Laboratory of Pain, Inflammation, Neuropathy, and Cancer, Department of Pathology, Center of Biological Sciences, Londrina State University, Londrina, Paraná, Brazil
| | - Victor Fattori
- Vascular Biology Program, Department of Surgery, Boston Children's Hospital-Harvard Medical School, Karp Research Building, 300 Longwood Ave, 02115, Boston, Massachusetts, United States.
| | - Waldiceu A Verri
- Laboratory of Pain, Inflammation, Neuropathy, and Cancer, Department of Pathology, Center of Biological Sciences, Londrina State University, Londrina, Paraná, Brazil.
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Bihlet AR, Balchen T, Goteti K, Sonne J, Ladel C, Karsdal MA, Ona V, Moreau F, Waterhouse R, Bay‐Jensen A, Guehring H. Safety, Tolerability, and Pharmacodynamics of the ADAMTS-5 Nanobody M6495: Two Phase 1, Single-Center, Double-Blind, Randomized, Placebo-Controlled Studies in Healthy Subjects and Patients With Osteoarthritis. ACR Open Rheumatol 2024; 6:205-213. [PMID: 38311369 PMCID: PMC11016567 DOI: 10.1002/acr2.11610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 06/23/2023] [Accepted: 06/27/2023] [Indexed: 02/10/2024] Open
Abstract
OBJECTIVE To assess the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of single and multiple injections of M6495, a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5) nanobody, in healthy volunteers and patients with osteoarthritis. METHODS Two randomized, placebo-controlled, double-blind studies were performed. Study 1 enrolled 54 healthy male volunteers who received one subcutaneous (s.c.) injection of M6495 (1-300 mg) or placebo (ratio 2:1), evaluating safety, PK, and PD as changes in the serum aggrecan fragment alanine-arginine-glycine-serine (ARGS). Study 2 enrolled 32 patients with osteoarthritis with Kellgren-Lawrence grades 2 to 4 and pain greater than or equal to 40 on the Western Ontario and McMaster Universities Arthritis Index pain subscale at screening and evaluated the safety, PK, and PD of three doses every two weeks (75-300 mg per dose) or six once-weekly M6495 s.c. doses (300 mg) or placebo (ratio 3:1) over 106 days' follow-up. RESULTS M6495 in single and multiple doses of less than or equal to 300 mg s.c. weekly was well tolerated with no clinically significant changes in any safety parameter. Adverse events more frequently reported in the M6495 groups were mostly mild cases of injection site reactions, myalgia, and nausea, which resolved after treatment cessation. The elimination half-life of single s.c. doses of M6495 ranged from 79 to 267 hours. M6495 administration substantially reduced serum ARGS levels, indicative of target engagement and indicating disease-modifying potential of M6495. CONCLUSION Treatment with M6495 in single and multiple doses up to and including 300 mg s.c. was found to be well tolerated and adequately safe for further clinical evaluation of potential disease-modifying effects.
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Affiliation(s)
| | | | | | - Jesper Sonne
- Bispebjerg Hospital and Copenhagen UniversityCopenhagenDenmark
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Cho KJ, Kim JC. Novel pharmacotherapeutic avenues for bladder storage dysfunction in men. Expert Opin Pharmacother 2024; 25:585-594. [PMID: 38651268 DOI: 10.1080/14656566.2024.2346278] [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: 02/21/2024] [Accepted: 04/18/2024] [Indexed: 04/25/2024]
Abstract
INTRODUCTION Bladder storage dysfunction is associated with low quality of life in men and remains a challenging field in pharmacotherapy because of low persistence followed by patient-perceived lack of efficacy and adverse effects. The persistent desire for the development of novel pharmacotherapy is evident, leading to numerous research efforts based on its pathophysiology. AREAS COVERED This review describes the pathophysiology, current pharmacotherapeutic strategies, and emerging novel drugs for male bladder storage dysfunction. The section on emerging pharmacotherapy provides an overview of current research, focusing on high-potential target molecules, particularly those being evaluated in ongoing clinical trials. EXPERT OPINION As pharmacotherapies targeting alpha-adrenergic, beta-adrenergic, and muscarinic receptors - the current primary targets for treating male bladder storage dysfunction - have demonstrated insufficient efficacy and side effects, researchers are exploring various alternative molecular targets. Numerous targets have been identified as central to regulating bladder afferent nerve activity, and their pharmacological effects and potential have been evaluated in animal-based experiments. However, there is a limited number of clinical trials for these new pharmacotherapies, and they have not demonstrated clear superiority over current treatments. Further research is needed to develop new effective pharmacotherapies for bladder storage dysfunction in men.
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Affiliation(s)
- Kang Jun Cho
- Department of Urology, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Joon Chul Kim
- Department of Urology, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
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Liao Z, Umar M, Huang X, Qin L, Xiao G, Chen Y, Tong L, Chen D. Transient receptor potential vanilloid 1: A potential therapeutic target for the treatment of osteoarthritis and rheumatoid arthritis. Cell Prolif 2024; 57:e13569. [PMID: 37994506 PMCID: PMC10905355 DOI: 10.1111/cpr.13569] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 10/11/2023] [Accepted: 10/15/2023] [Indexed: 11/24/2023] Open
Abstract
This study aims to determine the molecular mechanisms and analgesic effects of transient receptor potential vanilloid 1 (TRPV1) in the treatments of osteoarthritis (OA) and rheumatoid arthritis (RA). We summarize and analyse current studies regarding the biological functions and mechanisms of TRPV1 in arthritis. We search and analyse the related literature in Google Scholar, Web of Science and PubMed databases from inception to September 2023 through the multi-combination of keywords like 'TRPV1', 'ion channel', 'osteoarthritis', 'rheumatoid arthritis' and 'pain'. TRPV1 plays a crucial role in regulating downstream gene expression and maintaining cellular function and homeostasis, especially in chondrocytes, synovial fibroblasts, macrophages and osteoclasts. In addition, TRPV1 is located in sensory nerve endings and plays an important role in nerve sensitization, defunctionalization or central sensitization. TRPV1 is a non-selective cation channel protein. Extensive evidence in recent years has established the significant involvement of TRPV1 in the development of arthritis pain and inflammation, positioning it as a promising therapeutic target for arthritis. TRPV1 likely represents a feasible therapeutic target for the treatment of OA and RA.
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Affiliation(s)
- Zhidong Liao
- Department of Bone and Joint Surgerythe First Affiliated Hospital of Guangxi Medical UniversityNanningChina
- Research Center for Computer‐aided Drug Discovery, Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenChina
- Faculty of Pharmaceutical SciencesShenzhen Institute of Advanced TechnologyShenzhenChina
- Collaborative Innovation Centre of Regenerative Medicine and Medical BioResource Development and Application Co‐constructed by the Province and MinistryGuangxi Medical UniversityNanningGuangxiChina
| | - Muhammad Umar
- Research Center for Computer‐aided Drug Discovery, Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenChina
- Faculty of Pharmaceutical SciencesShenzhen Institute of Advanced TechnologyShenzhenChina
| | - Xingyun Huang
- Research Center for Computer‐aided Drug Discovery, Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenChina
- Faculty of Pharmaceutical SciencesShenzhen Institute of Advanced TechnologyShenzhenChina
| | - Ling Qin
- Musculoskeletal Research Laboratory of Department of Orthopaedics & Traumatology and Innovative Orthopaedic Biomaterial & Drug Translational Research LaboratoryLi Ka Shing Institute of Health Sciences, The Chinese University of Hong KongHong KongChina
| | - Guozhi Xiao
- School of MedicineSouthern University of Science and TechnologyShenzhenChina
| | - Yan Chen
- Department of Bone and Joint Surgerythe First Affiliated Hospital of Guangxi Medical UniversityNanningChina
| | - Liping Tong
- Research Center for Computer‐aided Drug Discovery, Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenChina
| | - Di Chen
- Research Center for Computer‐aided Drug Discovery, Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenChina
- Faculty of Pharmaceutical SciencesShenzhen Institute of Advanced TechnologyShenzhenChina
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5
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Gezer HH, Ostor A. What is new in pharmacological treatment for osteoarthritis? Best Pract Res Clin Rheumatol 2023; 37:101841. [PMID: 37302928 DOI: 10.1016/j.berh.2023.101841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 05/10/2023] [Indexed: 06/13/2023]
Abstract
Osteoarthritis (OA) is a degenerative joint disease in which structural changes of hyaline articular cartilage, subchondral bone, ligaments, capsule, synovium, muscles, and periarticular changes are involved. The knee is the most commonly affected joint, followed by the hand, hip, spine, and feet. Different pathological mechanisms are at play in each of these various involvement sites. Although systemic inflammation is more prominent in hand OA, knee and hip OA have been associated with excessive joint load and injury. As OA has varied phenotypes and the primarily affected tissues differ, treatment options must be tailored accordingly. In recent years, ongoing efforts have been made to develop disease-modifying options that halt or slow disease progression. Many are still in clinical trials, and as insights into the pathogenesis of OA evolve, novel therapeutic strategies will be developed. In this chapter, we provide an overview of the novel and emerging strategies in the management of OA.
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Affiliation(s)
- Halise Hande Gezer
- Marmara University School of Medicine, PMR Department Rheumatology Division, Istanbul, Turkiye
| | - Andrew Ostor
- Cabrini Medical Centre, Monash University, Melbourne & ANU, Canberra, Australia.
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Peng JW, Gu YY, Wei J, Sun Y, Zhu CL, Zhang L, Song Y, Chen L, Chen X, Wang Q, Zhang HL. LncRNA MEG3-TRPV1 signaling regulates chronic inflammatory pain in rats. Mol Pain 2022; 18:17448069221144246. [PMID: 36424837 PMCID: PMC9726848 DOI: 10.1177/17448069221144246] [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] [Indexed: 11/27/2022] Open
Abstract
Osteoarthritis (OA) is a common osteoarthropathy with chronic inflammatory pain as the core symptom in middle-aged and elderly people. LncRNA MEG3 (Maternally expressed gene 3) is involved in the development of OA via regulation of angiogenesis, which causes the activation and overexpression of transient receptor potential vanilloid type-1 (TRPV1). In this study, we investigated the mechanism of MEG3-TRPV1 signaling in chronic inflammatory pain (CIP) of rat model. Chronic inflammatory pain was modeled using subcutaneous microinjection of complete Freund's adjuvant (CFA) into the left hind paw of rats. We showed that TRPV1 mRNA and protein were significantly increased, while MEG3 mRNA was significantly decreased, in the DRG and SDH of CFA-induced rats. In addition, intrathecal injection of MEG3-overexpressing lentivirus significantly downregulated TRPV1 expression and alleviated chronic inflammatory pain in CFA-induced rats. Treatment with a TRPV1 antagonist also significantly relieved chronic inflammatory pain in CFA-induced rats. In general, our results reveal that MEG3 alleviates chronic inflammatory pain by downregulating TRPV1 expression. These findings may provide new therapeutic targets in the treatment of patients with OA.
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Affiliation(s)
- Jing-Wei Peng
- Department of Traditional Chinese Medicine, Affiliated Zhangjiagang Hospital of Soochow University, Zhangjiagang, China,Center for Translational Medicine, Affiliated Zhangjiagang Hospital of Soochow University, Zhangjiagang, China
| | - Yin-Yin Gu
- Department of Traditional Chinese Medicine, Affiliated Zhangjiagang Hospital of Soochow University, Zhangjiagang, China
| | - Jia Wei
- Department of Traditional Chinese Medicine, Affiliated Zhangjiagang Hospital of Soochow University, Zhangjiagang, China
| | - Ye Sun
- Department of Traditional Chinese Medicine, Affiliated Zhangjiagang Hospital of Soochow University, Zhangjiagang, China
| | - Chun-Long Zhu
- Department of Traditional Chinese Medicine, Affiliated Zhangjiagang Hospital of Soochow University, Zhangjiagang, China
| | - Ling Zhang
- Center for Translational Medicine, Affiliated Zhangjiagang Hospital of Soochow University, Zhangjiagang, China
| | - Yu Song
- Center for Translational Medicine, Affiliated Zhangjiagang Hospital of Soochow University, Zhangjiagang, China
| | - Long Chen
- Center for Translational Medicine, Affiliated Zhangjiagang Hospital of Soochow University, Zhangjiagang, China
| | - Xia Chen
- Department of Anesthesiology, Children’s Hospital of Soochow University, Suzhou, China
| | - Qian Wang
- Department of Anesthesiology, Children’s Hospital of Soochow University, Suzhou, China,Qian Wang, Department of Anesthesiology, Children’s Hospital of Soochow University, Suzhou 215123, China.
| | - Hai-Long Zhang
- Center for Translational Medicine, Affiliated Zhangjiagang Hospital of Soochow University, Zhangjiagang, China,Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China,Hai-Long Zhang, Center for Translational Pain Medicine, Institute of Neuroscience, Soochow University, Suzhou, 215123, China.
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7
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Chen B, Hong H, Sun Y, Chen C, Wu C, Xu G, Bao G, Cui Z. Role of macrophage polarization in osteoarthritis (Review). Exp Ther Med 2022; 24:757. [PMID: 36561979 PMCID: PMC9748658 DOI: 10.3892/etm.2022.11693] [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: 06/12/2022] [Accepted: 09/12/2022] [Indexed: 11/11/2022] Open
Abstract
Osteoarthritis (OA) is a disease involving the whole joint that seriously reduces the living standards of individuals. Traditional treatments include physical therapy, administration of anti-inflammatory and analgesic drugs and injection of glucocorticoids or hyaluronic acid into the joints. However, these methods have limited efficacy and it is difficult to reverse the progression of OA, therefore it is urgent to find new effective treatment methods. Immune microenvironment is significant in the occurrence and development of OA. Recent studies have shown that macrophages are important targets for the treatment of OA. Macrophages are polarized into M1 pro-inflammatory phenotype and M2 anti-inflammatory phenotype under stimulation of different factors, which release and regulate inflammatory response and cartilage growth. Accumulating studies have tried to alleviate OA by regulating macrophage homeostasis. The present study summarized the related studies, discuss the mechanism of various therapeutic reagents on OA, expound the molecular mechanism of drug effect on OA and attempted to provide clues for the treatment of OA.
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Affiliation(s)
- Baisen Chen
- Department of Orthopedics, Nantong City No 1 People's Hospital and Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Hongxiang Hong
- Department of Orthopedics, Nantong City No 1 People's Hospital and Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Yuyu Sun
- Department of Orthopedic, Nantong Third People's Hospital, Nantong, Jiangsu 226003, P.R. China
| | - Chu Chen
- Department of Orthopedics, Nantong City No 1 People's Hospital and Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Chunshuai Wu
- Department of Orthopedics, Nantong City No 1 People's Hospital and Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Guanhua Xu
- Department of Orthopedics, Nantong City No 1 People's Hospital and Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Guofeng Bao
- Department of Orthopedics, Nantong City No 1 People's Hospital and Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Zhiming Cui
- Department of Orthopedics, Nantong City No 1 People's Hospital and Second Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, P.R. China,Correspondence to: Professor Zhiming Cui, Department of Orthopedics, Nantong City No 1 People's Hospital and Second Affiliated Hospital of Nantong University, 6 North Road, Haierxiang, Nantong, Jiangsu 226001, P.R. China
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8
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Minnema L, Gupta A, Mishra SK, Lascelles BDX. Investigating the Role of Artemin and Its Cognate Receptor, GFRα3, in Osteoarthritis Pain. Front Neurosci 2022; 16:738976. [PMID: 35153665 PMCID: PMC8829392 DOI: 10.3389/fnins.2022.738976] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 01/05/2022] [Indexed: 11/13/2022] Open
Abstract
Osteoarthritis (OA) associated pain (OA-pain) is a significant global problem. OA-pain limits limb use and mobility and is associated with widespread sensitivity. Therapeutic options are limited, and the available options are often associated with adverse effects. The lack of therapeutic options is partly due to a lack of understanding of clinically relevant underlying neural mechanisms of OA-pain. In previous work in naturally occurring OA-pain in dogs, we identified potential signaling molecules (artemin/GFRα3) that were upregulated. Here, we use multiple approaches, including cellular, mouse genetic, immunological suppression in a mouse model of OA, and clinically relevant measures of sensitivity and limb use to explore the functional role of artemin/GFRα3 signaling in OA-pain. We found the monoiodoacetate (MIA)-induced OA-pain in mice is associated with decreased limb use and hypersensitivity. Exogenous artemin induces mechanical, heat, and cold hypersensitivity, and systemic intraperitoneal anti-artemin monoclonal antibody administration reverses this hypersensitivity and restores limb use in mice with MIA-induced OA-pain. An artemin receptor GFRα3 expression is increased in sensory neurons in the MIA model. Our results provide a molecular basis of arthritis pain linked with artemin/GFRα3 signaling and indicate that further work is warranted to investigate the neuronal plasticity and the pathways that drive pain in OA.
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Affiliation(s)
- Laura Minnema
- Translational Research in Pain Program, Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
| | - Ankita Gupta
- Translational Research in Pain Program, Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
| | - Santosh K. Mishra
- Department of Molecular and Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
- Comparative Pain Research and Education Center, North Carolina State University, Raleigh, NC, United States
- *Correspondence: Santosh K. Mishra,
| | - B. Duncan X. Lascelles
- Translational Research in Pain Program, Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
- Comparative Pain Research and Education Center, North Carolina State University, Raleigh, NC, United States
- Thurston Arthritis Center, UNC School of Medicine, Chapel Hill, NC, United States
- B. Duncan X. Lascelles,
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Sadler KE, Moehring F, Shiers SI, Laskowski LJ, Mikesell AR, Plautz ZR, Brezinski AN, Mecca CM, Dussor G, Price TJ, McCorvy JD, Stucky CL. Transient receptor potential canonical 5 mediates inflammatory mechanical and spontaneous pain in mice. Sci Transl Med 2021; 13:13/595/eabd7702. [PMID: 34039739 DOI: 10.1126/scitranslmed.abd7702] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 02/05/2021] [Accepted: 03/01/2021] [Indexed: 12/18/2022]
Abstract
Tactile and spontaneous pains are poorly managed symptoms of inflammatory and neuropathic injury. Here, we found that transient receptor potential canonical 5 (TRPC5) is a chief contributor to both of these sensations in multiple rodent pain models. Use of TRPC5 knockout mice and inhibitors revealed that TRPC5 selectively contributes to the mechanical hypersensitivity associated with CFA injection, skin incision, chemotherapy induced peripheral neuropathy, sickle cell disease, and migraine, all of which were characterized by elevated concentrations of lysophosphatidylcholine (LPC). Accordingly, exogenous application of LPC induced TRPC5-dependent behavioral mechanical allodynia, neuronal mechanical hypersensitivity, and spontaneous pain in naïve mice. Lastly, we found that 75% of human sensory neurons express TRPC5, the activity of which is directly modulated by LPC. On the basis of these results, TRPC5 inhibitors might effectively treat spontaneous and tactile pain in conditions characterized by elevated LPC.
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Affiliation(s)
- Katelyn E Sadler
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Francie Moehring
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Stephanie I Shiers
- School of Behavioral and Brain Sciences and Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Lauren J Laskowski
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Alexander R Mikesell
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Zakary R Plautz
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Allison N Brezinski
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Christina M Mecca
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Gregory Dussor
- School of Behavioral and Brain Sciences and Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Theodore J Price
- School of Behavioral and Brain Sciences and Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX 75080, USA
| | - John D McCorvy
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Cheryl L Stucky
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
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Transient Receptor Potential Vanilloid in the Brain Gliovascular Unit: Prospective Targets in Therapy. Pharmaceutics 2021; 13:pharmaceutics13030334. [PMID: 33806707 PMCID: PMC7999963 DOI: 10.3390/pharmaceutics13030334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/20/2021] [Accepted: 02/22/2021] [Indexed: 12/25/2022] Open
Abstract
The gliovascular unit (GVU) is composed of the brain microvascular endothelial cells forming blood–brain barrier and the neighboring surrounding “mural” cells (e.g., pericytes) and astrocytes. Modulation of the GVU/BBB features could be observed in a variety of vascular, immunologic, neuro-psychiatric diseases, and cancers, which can disrupt the brain homeostasis. Ca2+ dynamics have been regarded as a major factor in determining BBB/GVU properties, and previous studies have demonstrated the role of transient receptor potential vanilloid (TRPV) channels in modulating Ca2+ and BBB/GVU properties. The physiological role of thermosensitive TRPV channels in the BBB/GVU, as well as their possible therapeutic potential as targets in treating brain diseases via preserving the BBB are reviewed. TRPV2 and TRPV4 are the most abundant isoforms in the human BBB, and TRPV2 was evidenced to play a main role in regulating human BBB integrity. Interspecies differences in TRPV2 and TRPV4 BBB expression complicate further preclinical validation. More studies are still needed to better establish the physiopathological TRPV roles such as in astrocytes, vascular smooth muscle cells, and pericytes. The effect of the chronic TRPV modulation should also deserve further studies to evaluate their benefit and innocuity in vivo.
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11
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Design and conduct of confirmatory chronic pain clinical trials. Pain Rep 2020; 6:e845. [PMID: 33511323 PMCID: PMC7837951 DOI: 10.1097/pr9.0000000000000854] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 08/07/2020] [Accepted: 08/19/2020] [Indexed: 12/30/2022] Open
Abstract
The purpose of this article is to provide readers with a basis for understanding the emerging science of clinical trials and to provide a set of practical, evidence-based suggestions for designing and executing confirmatory clinical trials in a manner that minimizes measurement error. The most important step in creating a mindset of quality clinical research is to abandon the antiquated concept that clinical trials are a method for capturing data from clinical practice and shifting to a concept of the clinical trial as a measurement system, consisting of an interconnected set of processes, each of which must be in calibration for the trial to generate an accurate and reliable estimate of the efficacy (and safety) of a given treatment. The status quo of inaccurate, unreliable, and protracted clinical trials is unacceptable and unsustainable. This article gathers aspects of study design and conduct under a single broad umbrella of techniques available to improve the accuracy and reliability of confirmatory clinical trials across traditional domain boundaries.
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12
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Fischer MJM, Ciotu CI, Szallasi A. The Mysteries of Capsaicin-Sensitive Afferents. Front Physiol 2020; 11:554195. [PMID: 33391007 PMCID: PMC7772409 DOI: 10.3389/fphys.2020.554195] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 11/13/2020] [Indexed: 12/11/2022] Open
Abstract
A fundamental subdivision of nociceptive sensory neurons is named after their unique sensitivity to capsaicin, the pungent ingredient in hot chili peppers: these are the capsaicin-sensitive afferents. The initial excitation by capsaicin of these neurons manifested as burning pain sensation is followed by a lasting refractory state, traditionally referred to as "capsaicin desensitization," during which the previously excited neurons are unresponsive not only to capsaicin but a variety of unrelated stimuli including noxious heat. The long sought-after capsaicin receptor, now known as TRPV1 (transient receptor potential cation channel, subfamily V member 1), was cloned more than two decades ago. The substantial reduction of the inflammatory phenotype of Trpv1 knockout mice has spurred extensive efforts in the pharmaceutical industry to develop small molecule TRPV1 antagonists. However, adverse effects, most importantly hyperthermia and burn injuries, have so far prevented any compounds from progressing beyond Phase 2. There is increasing evidence that these limitations can be at least partially overcome by approaches outside of the mainstream pharmaceutical development, providing novel therapeutic options through TRPV1. Although ablation of the whole TRPV1-expressing nerve population by high dose capsaicin, or more selectively by intersectional genetics, has allowed researchers to investigate the functions of capsaicin-sensitive afferents in health and disease, several "mysteries" remain unsolved to date, including the molecular underpinnings of "capsaicin desensitization," and the exact role these nerves play in thermoregulation and heat sensation. This review tries to shed some light on these capsaicin mechanisms.
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Affiliation(s)
- Michael J. M. Fischer
- Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Cosmin I. Ciotu
- Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Arpad Szallasi
- 1st Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
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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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Silverman HA, Chen A, Kravatz NL, Chavan SS, Chang EH. Involvement of Neural Transient Receptor Potential Channels in Peripheral Inflammation. Front Immunol 2020; 11:590261. [PMID: 33193423 PMCID: PMC7645044 DOI: 10.3389/fimmu.2020.590261] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 09/30/2020] [Indexed: 12/11/2022] Open
Abstract
Transient receptor potential (TRP) channels are a superfamily of non-selective cation channels that act as polymodal sensors in many tissues throughout mammalian organisms. In the context of ion channels, they are unique for their broad diversity of activation mechanisms and their cation selectivity. TRP channels are involved in a diverse range of physiological processes including chemical sensing, nociception, and mediating cytokine release. They also play an important role in the regulation of inflammation through sensory function and the release of neuropeptides. In this review, we discuss the functional contribution of a subset of TRP channels (TRPV1, TRPV4, TRPM3, TRPM8, and TRPA1) that are involved in the body’s immune responses, particularly in relation to inflammation. We focus on these five TRP channels because, in addition to being expressed in many somatic cell types, these channels are also expressed on peripheral ganglia and nerves that innervate visceral organs and tissues throughout the body. Activation of these neural TRP channels enables crosstalk between neurons, immune cells, and epithelial cells to regulate a wide range of inflammatory actions. TRP channels act either through direct effects on cation levels or through indirect modulation of intracellular pathways to trigger pro- or anti-inflammatory mechanisms, depending on the inflammatory disease context. The expression of TRP channels on both neural and immune cells has made them an attractive drug target in diseases involving inflammation. Future work in this domain will likely yield important new pathways and therapies for the treatment of a broad range of disorders including colitis, dermatitis, sepsis, asthma, and pain.
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Affiliation(s)
- Harold A Silverman
- Laboratory of Biomedical Science, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States.,Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States
| | - Adrian Chen
- Laboratory of Biomedical Science, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States.,Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States
| | - Nigel L Kravatz
- Laboratory of Biomedical Science, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States.,Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States
| | - Sangeeta S Chavan
- Laboratory of Biomedical Science, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States.,Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States.,Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hofstra University, Hempstead, NY, United States
| | - Eric H Chang
- Laboratory of Biomedical Science, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States.,Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States.,Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hofstra University, Hempstead, NY, United States
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A 3-way Cross-over Study of Pregabalin, Placebo, and the Histamine 3 Receptor Inverse Agonist AZD5213 in Combination With Pregabalin in Patients With Painful Diabetic Neuropathy and Good Pain-reporting Ability. Clin J Pain 2020; 37:38-42. [PMID: 33086238 DOI: 10.1097/ajp.0000000000000886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES In this study, patients with painful diabetic neuropathy were trained using an experimental pain paradigm in an attempt to enroll a subset of patients who are "pain connoisseurs" and therefore more able to discriminate between active and placebo treatments. METHODS AZD5213, a novel histamine H3 receptor inverse agonist+pregabalin, pregabalin, and placebo were then tested in a 3-period cross-over. RESULTS The study did not provide any evidence of clinical efficacy for AZD5213 when combined with pregabalin in the treatment of painful diabetic neuropathy. DISCUSSION The training of study patients in pain reporting and subsequent enrichment with good pain reporters also did not enable the robust detection of the efficacy of pregabalin relative to placebo in a small sample size. Further work is required before recommending the use of "connoisseur" patients in future neuropathic pain studies.
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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: 49] [Impact Index Per Article: 12.3] [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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17
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Wang G, Wang X, Gao Q, Zhou M, Wang N. Effects of Heating-Conduction Dry Needling Therapy on Rats with Chronic Myofascial Pain Syndrome. J Manipulative Physiol Ther 2020; 43:506-514. [PMID: 32928569 DOI: 10.1016/j.jmpt.2019.05.008] [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: 10/12/2018] [Revised: 04/11/2019] [Accepted: 05/02/2019] [Indexed: 11/19/2022]
Abstract
OBJECTIVE This study aimed to investigate the effect of dry needling (DN) with 44°C heating on the pressure pain threshold (PPT) of rats with chronic myofascial pain syndrome (MPS) by regulating the transient receptor potential V1 channel. METHODS A total of 80 rats were divided into 5 groups: A, B, C, D, and E (16 in each group). The rats in Group A recovered naturally, while those in other groups received the DN treatment. The needles were heated to 40°C for the rats in Groups B and E and 44°C for the rats in Groups C and D. In addition, both Groups D and E received local capsaicin injection. PPTs of the gastrocnemius muscle and tolerance time of the plantar hot plate were measured before modeling, 1 day before the intervention, 24 hours after the intervention, and 7 days after the intervention. RESULTS PPTs of the gastrocnemius muscle for rats with MPS increased 7 days after DN and heating to 40°C. For the rats receiving DN at 44°C heating, PPTs increased 24 hours and 7 days after the intervention. Further, 44°C heating and capsaicin injection improved PPT. DN and 40°C heating followed by capsaicin injection improved PPT. CONCLUSION DN and 44°C heating had therapeutic effects on rats with MPS at 24 hours and at 7 days after the intervention. DN and 40°C heating had therapeutic effects 7 days after the intervention. DN and 44°C heating might exert therapeutic effects by regulating the transient receptor potential V1 channel.
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Affiliation(s)
- Gang Wang
- Department of Rehabilitation Medicine, The Chinese PLA General Hospital, Beijing, China
| | - Xinglin Wang
- Department of Rehabilitation Medicine, The Chinese PLA General Hospital, Beijing, China.
| | - Qian Gao
- Department of Rehabilitation Medicine, The Chinese PLA General Hospital, Beijing, China
| | - Ming Zhou
- Department of Rehabilitation Medicine, The Chinese PLA General Hospital, Beijing, China
| | - Ning Wang
- Department of Rehabilitation Medicine, The Chinese PLA General Hospital, Beijing, China
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18
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A deeper look at pain variability and its relationship with the placebo response: results from a randomized, double-blind, placebo-controlled clinical trial of naproxen in osteoarthritis of the knee. Pain 2020; 160:1522-1528. [PMID: 30817436 DOI: 10.1097/j.pain.0000000000001538] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Previous studies have shown a robust correlation between variability of clinical pain scores and responsiveness to placebo (but not active drug) in pain studies, but explanations for these relationships are lacking. We investigated this further by assessing relationship between the Focused Analgesia Selection Test (FAST), a psychophysical method that quantifies pain reporting variability in response to experimental stimuli, variability of daily clinical pain scores as captured using diary, and response to treatment in the context of a randomized controlled crossover trial of naproxen vs placebo in knee osteoarthritis. Evoked pain using the Staircase-Evoked Pain Procedure served as the primary efficacy endpoint. Variability of daily pain scores and the FAST were assessed at baseline. Fifty-five subjects completed the study and were included in the analyses. Our results indicated a statistically significant, moderate linear relationship between variability of clinical and experimental pain reports (r = -0.416, P = 0.004). Both correlated with the placebo response (r = 0.393, P = 0.004; r =-0.371, P = 0.009; respectively), but only the FAST predicted the treatment difference between naproxen and placebo, as demonstrated both in a regression model (P = 0.002, Beta = 0.456, t = 3.342) and in a receiver operating characteristic curve (0.721) analysis. Our results extend previous findings to include a correlation between experimental pain variability and the placebo response and suggest that experimental pain variability is a better predictor of patients who respond preferentially to drug over placebo. A theoretical model unifying these observations is proposed, and practical implications are discussed.
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19
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An update on targets for treating osteoarthritis pain: NGF and TRPV1. CURRENT TREATMENT OPTIONS IN RHEUMATOLOGY 2020; 6:129-145. [PMID: 34178580 DOI: 10.1007/s40674-020-00146-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Purpose of review a)Osteoarthritis (OA) is the most common form of arthritis, and pain is the primary symptom of the disease, yet analgesic options for treating OA pain remain limited. In this review, we aimed to give an update on the current clinical and preclinical studies targeting two pathways that are being investigated for treating OA pain: the nerve growth factor (NGF) pathway and the transient receptor potential vanilloid-1 (TRPV1) pathway. Recent findings b)Antibodies against NGF, small molecule inhibitors of TrkA, TRPV1 agonists, and TRPV1 antagonists are all in different stages of clinical and pre-clinical testing for the treatment of OA pain. NGF antibodies have shown efficacy in the primary endpoints tested compared to placebo, however, rapidly progressive OA has been consistently observed in a subset of patients and the cause remains unclear. TRPV1 agonists have also demonstrated reduced pain with no serious adverse events - the most common adverse events include a burning or warming sensation upon administration. Summary c)Targeting the NGF and TRPV1 pathways appear effective for reducing OA pain, but further work is needed to better understand which patients may benefit most from these treatments. The anti-NGF antibody tanezumab and the TRPV1 agonist CNTX-4975 have both received fast-track designation from the FDA for the treatment of OA pain.
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20
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Abstract
Osteoarthritis (OA) is one of the most debilitating diseases and is associated with a high personal and socioeconomic burden. So far, there is no therapy available that effectively arrests structural deterioration of cartilage and bone or is able to successfully reverse any of the existing structural defects. Efforts to identify more tailored treatment options led to the development of strategies that enabled the classification of patient subgroups from the pool of heterogeneous phenotypes that display distinct common characteristics. To this end, the classification differentiates the structural endotypes into cartilage and bone subtypes, which are predominantly driven by structure-related degenerative events. In addition, further classifications have highlighted individuals with an increased inflammatory contribution (inflammatory phenotype) and pain-driven phenotypes as well as senescence and metabolic syndrome phenotypes. Most probably, it will not be possible to classify individuals by a single definite subtype, but it might help to identify groups of patients with a predominant pathology that would more likely benefit from a specific drug or cell-based therapy. Current clinical trials addressed mainly regeneration/repair of cartilage and bone defects or targeted pro-inflammatory mediators by intra-articular injections of drugs and antibodies. Pain was treated mostly by antagonizing nerve growth factor (NGF) activity and its receptor tropomyosin-related kinase A (TrkA). Therapies targeting metabolic disorders such as diabetes mellitus and senescence/aging-related pathologies are not specifically addressing OA. However, none of these therapies has been proven to modify disease progression significantly or successfully prevent final joint replacement in the advanced disease stage. Within this review, we discuss the recent advances in phenotype-specific treatment options and evaluate their applicability for use in personalized OA therapy.
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Affiliation(s)
- Susanne Grässel
- Department of Orthopedic Surgery, Exp. Orthopedics, ZMB/Biopark 1, Am Biopark 9, University of Regensburg, Regensburg, 93053, Germany
| | - Dominique Muschter
- Department of Orthopedic Surgery, Exp. Orthopedics, ZMB/Biopark 1, Am Biopark 9, University of Regensburg, Regensburg, 93053, Germany
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21
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Staircase-evoked Pain May be More Sensitive Than Traditional Pain Assessments in Discriminating Analgesic Effects: A Randomized, Placebo-controlled Trial of Naproxen in Patients With Osteoarthritis of the Knee. Clin J Pain 2020; 35:50-55. [PMID: 30222614 DOI: 10.1097/ajp.0000000000000651] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Analgesic trials often fail to show a significant effect even when medications with known efficacy are tested. This could be attributed to insufficient assay sensitivity of analgesic trials, which may be due, in part, to the insensitivity of pain-related outcome measures. The aim of this methodological study was to assess the responsiveness of evoked pain generated by the staircase procedure compared with other commonly used pain outcomes in knee osteoarthritis. METHODS This was a randomized, double-blind, placebo-controlled, cross-over trial of 1-week treatment of naproxen versus placebo. Participants were assigned to one of the 2 treatment sequences (naproxen-placebo or placebo-naproxen). Pain-at-rest, evoked pain using the Staircase-Evoked Pain Procedure (StEPP), pain diary, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) data were collected before and at the end of each treatment sequence. RESULTS A total of 55 osteoarthritis patients (30 M, 25 F) completed the study. Among all pain assessments, evoked pain was the most sensitive outcome to detect treatment effects, with Standardized Effect Size (SES) of 0.47 followed by the WOMAC and pain-at-rest with SES of 0.43 and 0.36, respectively. Sample size calculations demonstrated that compared with spontaneous pain, the evoked pain model reduces required number of subjects by 40%. DISCUSSION Study results support our hypothesis that evoked pain using the StEPP may demonstrate greater responsiveness to treatment effects compared with traditional pain-related outcome measures. Accordingly, these results may facilitate development and validation of other chronic pain-related evoked pain models, which could contribute to future research and development of new analgesics.
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22
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Garami A, Shimansky YP, Rumbus Z, Vizin RCL, Farkas N, Hegyi J, Szakacs Z, Solymar M, Csenkey A, Chiche DA, Kapil R, Kyle DJ, Van Horn WD, Hegyi P, Romanovsky AA. Hyperthermia induced by transient receptor potential vanilloid-1 (TRPV1) antagonists in human clinical trials: Insights from mathematical modeling and meta-analysis. Pharmacol Ther 2020; 208:107474. [PMID: 31926897 DOI: 10.1016/j.pharmthera.2020.107474] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 12/23/2019] [Indexed: 02/06/2023]
Abstract
Antagonists of the transient receptor potential vanilloid-1 (TRPV1) channel alter body temperature (Tb) in laboratory animals and humans: most cause hyperthermia; some produce hypothermia; and yet others have no effect. TRPV1 can be activated by capsaicin (CAP), protons (low pH), and heat. First-generation (polymodal) TRPV1 antagonists potently block all three TRPV1 activation modes. Second-generation (mode-selective) TRPV1 antagonists potently block channel activation by CAP, but exert different effects (e.g., potentiation, no effect, or low-potency inhibition) in the proton mode, heat mode, or both. Based on our earlier studies in rats, only one mode of TRPV1 activation - by protons - is involved in thermoregulatory responses to TRPV1 antagonists. In rats, compounds that potently block, potentiate, or have no effect on proton activation cause hyperthermia, hypothermia, or no effect on Tb, respectively. A Tb response occurs when a TRPV1 antagonist blocks (in case of hyperthermia) or potentiates (hypothermia) the tonic TRPV1 activation by protons somewhere in the trunk, perhaps in muscles, and - via the acido-antithermogenic and acido-antivasoconstrictor reflexes - modulates thermogenesis and skin vasoconstriction. In this work, we used a mathematical model to analyze Tb data from human clinical trials of TRPV1 antagonists. The analysis suggests that, in humans, the hyperthermic effect depends on the antagonist's potency to block TRPV1 activation not only by protons, but also by heat, while the CAP activation mode is uninvolved. Whereas in rats TRPV1 drives thermoeffectors by mediating pH signals from the trunk, but not Tb signals, our analysis suggests that TRPV1 mediates both pH and thermal signals driving thermoregulation in humans. Hence, in humans (but not in rats), TRPV1 is likely to serve as a thermosensor of the thermoregulation system. We also conducted a meta-analysis of Tb data from human trials and found that polymodal TRPV1 antagonists (ABT-102, AZD1386, and V116517) increase Tb, whereas the mode-selective blocker NEO6860 does not. Several strategies of harnessing the thermoregulatory effects of TRPV1 antagonists in humans are discussed.
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Affiliation(s)
- Andras Garami
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary.
| | - Yury P Shimansky
- Department of Neurobiology, Barrow Neurological Institute, Dignity Health, Phoenix, AZ, USA
| | - Zoltan Rumbus
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Robson C L Vizin
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Dignity Health, Phoenix, AZ, USA
| | - Nelli Farkas
- Institute for Translational Medicine, Medical School and Szentagothai Research Centre, University of Pecs, Pecs, Hungary
| | - Judit Hegyi
- Institute for Translational Medicine, Medical School and Szentagothai Research Centre, University of Pecs, Pecs, Hungary
| | - Zsolt Szakacs
- Institute for Translational Medicine, Medical School and Szentagothai Research Centre, University of Pecs, Pecs, Hungary
| | - Margit Solymar
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Alexandra Csenkey
- Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, Pecs, Hungary
| | | | | | | | - Wade D Van Horn
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA
| | - Peter Hegyi
- Institute for Translational Medicine, Medical School and Szentagothai Research Centre, University of Pecs, Pecs, Hungary; Department of Translational Medicine, First Department of Medicine, Medical School, University of Pecs, Pecs, Hungary
| | - Andrej A Romanovsky
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Dignity Health, Phoenix, AZ, USA; School of Molecular Sciences, Arizona State University, Tempe, AZ, USA; Zharko Pharma Inc., Olympia, WA, USA.
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Roman K, Hall C, Schaeffer AJ, Thumbikat P. TRPV1 in experimental autoimmune prostatitis. Prostate 2020; 80:28-37. [PMID: 31573117 PMCID: PMC7313375 DOI: 10.1002/pros.23913] [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: 09/05/2018] [Accepted: 09/18/2019] [Indexed: 12/27/2022]
Abstract
BACKGROUND Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a disorder that is characterized by persistent pelvic pain in men of any age. Although several studies suggest that the transient receptor potential vanilloid 1 (TRPV1) channel is involved in various pathways of chronic pain, the TRPV1 channel has not been implicated in chronic pelvic pain associated with CP/CPPS. METHODS Male C57BL/6J (B6) and TRPV1 knockout (TRPV1 KO) mice (5-7 weeks old) were used to study the development of pelvic allodynia in a murine model of CP/CPPS called experimental autoimmune prostatitis (EAP). The prostate lobes, dorsal root ganglia (DRG), and spinal cord were excised at day 20. The prostate lobes were assessed for inflammation, TRPV1 expression, and mast cell activity. DRG and spinal cord, between the L6-S4 regions, were analyzed to determine the levels of phosphorylated ERK1/2 (p-ERK 1/2). To examine the therapeutic potential of TRPV1, B6 mice with EAP received intraurethral infusion of a TRPV1 antagonist at day 20 (repeated every 2 days) and pelvic pain was evaluated at days 20, 25, 30, and 35. RESULTS Our data showed that B6 mice with EAP developed pelvic tactile allodynia at days 7, 14, and 20. In contrast, TRPV1 KO mice with EAP do not develop pelvic tactile allodynia at any time point. Although we observed no change in the levels of TRPV1 protein expression in the prostate from B6 mice with EAP, there was evidence of significant inflammation and elevated mast cell activation. Interestingly, the prostate from TRPV1 KO mice with EAP showed a lack of mast cell activation despite evidence of prostate inflammation. Next, we observed a significant increase of p-ERK1/2 in the DRG and spinal cord from B6 mice with EAP; however, p-ERK1/2 expression was unaltered in TRPV1 KO mice with EAP. Finally, we confirmed that intraurethral administration of a TRPV1 antagonist peptide reduced pelvic tactile allodynia in B6 mice with EAP after day 20. CONCLUSIONS We demonstrated that in a murine model of CP/CPPS, the TRPV1 channel is key to persistent pelvic tactile allodynia and blocking TRPV1 in the prostate may be a promising strategy to quell chronic pelvic pain.
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Affiliation(s)
- Kenny Roman
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Christel Hall
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Anthony J. Schaeffer
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Praveen Thumbikat
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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Phoneutria toxin PnTx3-5 inhibits TRPV1 channel with antinociceptive action in an orofacial pain model. Neuropharmacology 2020; 162:107826. [DOI: 10.1016/j.neuropharm.2019.107826] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 09/05/2019] [Accepted: 10/18/2019] [Indexed: 12/12/2022]
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Meske DS, Vaughn BJ, Kopecky EA, Katz N. Number Of Clinical Trial Study Sites Impacts Observed Treatment Effect Size: An Analysis Of Randomized Controlled Trials Of Opioids For Chronic Pain. J Pain Res 2019; 12:3161-3165. [PMID: 31819600 PMCID: PMC6875508 DOI: 10.2147/jpr.s201751] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 10/22/2019] [Indexed: 12/31/2022] Open
Abstract
Background Many aspects of study conduct impact the observed effect size of treatment. Data were utilized from a recently published meta-analysis of randomized, double-blind, placebo-controlled, clinical trials performed for the United States Food and Drug Administration (FDA) approval of full mu-agonist opioids for the treatment of chronic pain. Methods The number of study sites in each clinical trial and standardized effect size (SES) were extracted and computed. Standardized effect size was plotted against number of sites, and a two-piece linear model was fit to the plot. Ten studies were included. Results The SES decreased linearly by 0.13 units for every 10 sites (p=0.037), from 0.75 to 0.36, until an inflection point of 60 sites, after which SES did not decline further. The total number of subjects required for 90% power to discriminate drug from placebo increased from 78 to 336 subjects going from 30 to 60 sites. Conclusion Results showed that the number of sites was a source of loss of assay sensitivity in clinical trials, which may contribute to the well-known problem of failure to successfully transition from Phase 2 to Phase 3 clinical development. Potential solutions include minimizing the number of sites, more rigorous and validated training, central statistical monitoring with rapid correction of performance issues, and more rigorous subject and site selection.
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Affiliation(s)
| | | | | | - Nathaniel Katz
- WCG Analgesic Solutions, Wayland, MA, USA.,Department of Anesthesia, Tufts University School of Medicine, Boston, MA, USA
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26
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Sjögren E, Ståhle L, Quiding H, Jonzon B, Halldin MM, Sundgren AK. The effect of intradermal microdosing of a transient receptor potential cation channel subfamily V member 1 antagonist on heat evoked pain and thermal thresholds in normal and ultraviolet‐C exposed skin in healthy volunteers. Eur J Pain 2019; 23:1767-1779. [DOI: 10.1002/ejp.1451] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 06/28/2019] [Accepted: 06/30/2019] [Indexed: 12/22/2022]
Affiliation(s)
- Erik Sjögren
- Department of Pharmacy Uppsala University Uppsala Sweden
| | - Lars Ståhle
- CLINTECKarolinska University Hospital HuddingeKarolinska Institute Solna Sweden
| | | | | | - Magnus M. Halldin
- AlzeCure FoundationKarolinska Institute Science Park Huddinge Sweden
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Manitpisitkul P, Flores CM, Moyer JA, Romano G, Shalayda K, Tatikola K, Hutchison JS, Mayorga AJ. A multiple-dose double-blind randomized study to evaluate the safety, pharmacokinetics, pharmacodynamics and analgesic efficacy of the TRPV1 antagonist JNJ-39439335 (mavatrep). Scand J Pain 2019; 18:151-164. [PMID: 29794306 DOI: 10.1515/sjpain-2017-0184] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 01/30/2018] [Indexed: 11/15/2022]
Abstract
BACKGROUND AND AIMS This double-blind (DB), randomized, placebo-controlled, sequential-group, multiple-ascending dose, phase 1 study evaluated safety, pharmacokinetics and pharmacodynamics of JNJ-39439335 in healthy men (part 1), and in participants with knee osteoarthritis (part 2). METHODS Both parts 1 and 2 consisted of screening (upto 21 days), 21-day DB treatment phase [eight participants/group: JNJ-39439335 (part 1: 2-50 mg; part 2: 10-50 mg): n=6; placebo: n=2] and follow-up (total study duration ~10 weeks). RESULTS Plasma concentrations and systemic exposure of JNJ-39439335 increased in slightly higher than dose-proportional fashion (steady-state reached by day 14). Renal excretion of JNJ-39439335 was negligible. Marked dose-related increases in pharmacodynamic heat pain assessments were observed in JNJ-39439335-treated participants, which persisted throughout the treatment with no signs of tolerance with repeated dosing. No effect on pharmacodynamic cold pain or mechanical pain assessments were seen. Effects on pharmacodynamic capsaicin-induced flare assessments in JNJ-39439335-treated participants versus placebo were consistent with effects observed with single-dose, and did not demonstrate tolerance with multiple dosing. In participants with knee osteoarthritis, significant improvements versus placebo were observed in a stair-climbing-induced pain model. All JNJ-39439335-treated participants reported ≥1 treatment-emergent adverse events (TEAE); most common (≥50% incidence) TEAEs in part 1 were feeling hot (79%), thermohypoesthesia (71%), paresthesia (58%) and feeling cold (50%), and in part 2, were minor thermal burns (50%). CONCLUSIONS JNJ-39439335 (doses 2-50 mg) was well-tolerated, and associated with acceptable multiple-dose pharmacokinetic profile. JNJ-39439335 demonstrated sustained pharmacodynamic effects (heat pain perception, heat pain latency, capsaicin-induced flare), and an efficacy signal in participants with osteoarthritis pain. IMPLICATIONS Given the efficacy signal observed and the unique safety profile, larger phase 2 studies are needed to better understand the potential of JNJ-39439335 in the treatment of chronic pain. Analgesic efficacy of lower doses administered over a longer period of time and improved patient counseling techniques to reduce the minor thermal burns can be explored to minimize the adverse events.
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Affiliation(s)
| | | | | | - Gary Romano
- Janssen Research and Development, LLC, NJ, USA
| | | | | | | | - Arthur J Mayorga
- Neuroscience Therapeutic Area, Janssen Research and Development, LLC, NJ, USA, Tel.: 609-730-6779
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NEO6860, modality-selective TRPV1 antagonist: a randomized, controlled, proof-of-concept trial in patients with osteoarthritis knee pain. Pain Rep 2018; 3:e696. [PMID: 30706039 PMCID: PMC6344137 DOI: 10.1097/pr9.0000000000000696] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/14/2018] [Accepted: 09/19/2018] [Indexed: 02/07/2023] Open
Abstract
Introduction NEO6860 is a TRPV1 antagonist when activated by capsaicin but not by heat or pH, developed to relieve pain without the adverse events reported with non-modality-selective TRPV1 antagonists. Objective The primary Objective of this study was to evaluate the analgesic efficacy and safety of NEO6860 after 1 day oral dosing in patients with Kellgren-Lawrence stage I, II or III osteoarthritis of the knee. Method This randomized, double-blinded, 3-period crossover, phase II study compared 1 day (2 doses) of NEO6860 (500 mg twice a day), placebo, and naproxen in 54 patients with osteoarthritis knee pain. Primary endpoint was reduction in pain intensity (PI) on Numerical Rating Scale after exercise, using the staircase test, 8 hours after dose. Results Level of PI, compared with baseline, was numerically lower during NEO6860 and naproxen periods vs placebo at 3 and 24 hours, but not at 8 hours after first dose. A statistically significant effect for naproxen and a trend for NEO6860 were observed at 3 and 24 hours. Least square means' (95% confidence interval) change in PI at 24 hours was -0.67 (-1.09 to -0.26), -0.97 (-1.39 to -0.55), -0.29 (-0.71 to 0.13) for NEO6860, naproxen, and placebo, respectively. NEO6860 exposure was ∼1.6 times higher compared with previous phase I. In this study, NEO6860 safety profile was less favorable than naproxen or placebo. Possibly NEO6860-related adverse events included: feel hot, headache, nausea, dizziness, fatigue, hypoaesthesia, and increased blood pressure. Conclusion In this exploratory study, NEO6860 did not statistically significantly outperform placebo but showed an analgesic trend, without impacting body temperature and heat pain perception. Further studies are warranted to explore the potential of NEO6860 in other pain indications. We intent to optimize the dose and evaluate analgesic synergism with other mechanism.
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Treister R, Lawal OD, Shecter JD, Khurana N, Bothmer J, Field M, Harte SE, Kruger GH, Katz NP. Accurate pain reporting training diminishes the placebo response: Results from a randomised, double-blind, crossover trial. PLoS One 2018; 13:e0197844. [PMID: 29795665 PMCID: PMC5993117 DOI: 10.1371/journal.pone.0197844] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Accepted: 04/25/2018] [Indexed: 12/01/2022] Open
Abstract
Analgesic trials frequently fail to demonstrate efficacy of drugs known to be efficacious. Poor pain reporting accuracy is a possible source for this low essay-sensitivity. We report the effects of Accurate-Pain-Reporting-Training (APRT) on the placebo response in a trial of Pregabalin for painful-diabetic-neuropathy. The study was a two-stage randomized, double-blind trial: In Stage-1 (Training) subjects were randomized to APRT or No-Training. The APRT participants received feedback on the accuracy of their pain reports in response to mechanical stimuli, measured by R-square score. In Stage-2 (Evaluation) all subjects entered a placebo-controlled, cross-over trial. Primary (24-h average pain intensity) and secondary (current, 24-h worst, and 24-h walking pain intensity) outcome measures were reported. Fifty-one participants completed the study. APRT patients (n = 28) demonstrated significant (p = 0.036) increases in R-square scores. The APRT group demonstrated significantly (p = 0.018) lower placebo response (0.29 ± 1.21 vs. 1.48 ± 2.21, mean difference ± SD = -1.19±1.73). No relationships were found between the R-square scores and changes in pain intensity in the treatment arm. In summary, our training successfully increased pain reporting accuracy and resulted in a diminished placebo response. Theoretical and practical implications are discussed.
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Affiliation(s)
- Roi Treister
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa, Israel
- Analgesic Solutions, Natick, Massachusetts, United States of America
- * E-mail:
| | | | | | - Nevil Khurana
- Analgesic Solutions, Natick, Massachusetts, United States of America
| | | | | | - Steven E. Harte
- Chronic Pain and Fatigue Research Center, Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Grant H. Kruger
- Chronic Pain and Fatigue Research Center, Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Nathaniel P. Katz
- Analgesic Solutions, Natick, Massachusetts, United States of America
- Department of Anaesthesiology and Perioperative Medicine, Tufts University School of Medicine, Boston, Massachusetts, United States of America
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Lascelles BDX, Brown DC, Maixner W, Mogil JS. Spontaneous painful disease in companion animals can facilitate the development of chronic pain therapies for humans. Osteoarthritis Cartilage 2018; 26:175-183. [PMID: 29180098 DOI: 10.1016/j.joca.2017.11.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/17/2017] [Accepted: 11/13/2017] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To outline the role that spontaneous osteoarthritis (OA) in companion animals can play in translational research and therapeutic pharmacological development. OUTLINE Narrative review summarizing the opportunities and limitations of naturally occurring, spontaneous OA as models of human OA pain, with a focus on companion animal pets. The background leading to considering inserting spontaneous disease models in the translational paradigm is provided. The utility of this model is discussed in terms of outcome measures that have been validated as being related to pain, and in terms of the potential for target discovery is outlined. The limitations to using companion animal pets as models of human disease are discussed. CONCLUSIONS Although many steps along the translational drug development pathway have been identified as needing improvement, spontaneous painful OA in companion animals offers translational potential. Such 'models' may better reflect the complex genetic, environmental, temporal and physiological influences present in humans and current data suggests the predictive validity of the models are good. The opportunity for target discovery exists but is, as yet, unproven.
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Affiliation(s)
- B D X Lascelles
- Comparative Pain Research Program, Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA; Comparative Medicine Institute, North Carolina State University, Raleigh, NC, USA; Center for Pain Research and Innovation, UNC School of Dentistry, Chapel Hill, NC, USA; Center for Translational Pain Research, Department of Anesthesiology, Duke University, Durham, NC, USA.
| | - D C Brown
- Translational Comparative Medicine Research, Elanco Animal Health, Greenfield, IN, USA
| | - W Maixner
- Center for Translational Pain Research, Department of Anesthesiology, Duke University, Durham, NC, USA
| | - J S Mogil
- Department of Psychology, Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada; Department of Anesthesia, Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada
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Karlsten R. Finally a promising analgesic signal in a long-awaited new class of drugs: TRPV1 antagonist mavatrep in patients with osteoarthritis (OA). Scand J Pain 2017; 17:154-155. [PMID: 28961519 DOI: 10.1016/j.sjpain.2017.08.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Rolf Karlsten
- Multidisciplinary Pain Center, Dept of Surgical Sciences/Anaesthesiology, Uppsala University Hospital, Uppsala, Sweden.
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