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Li F, Li D, Liu J, Tang S, Yan J, Li H, Wan Z, Wang L, Yan X. Activation of Protease-Activated Receptor-1 Causes Chronic Pain in Lupus-Prone Mice Via Suppressing Spinal Glial Glutamate Transporter Function and Enhancing Glutamatergic Synaptic Activity. THE JOURNAL OF PAIN 2023; 24:1163-1180. [PMID: 36641029 DOI: 10.1016/j.jpain.2023.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 12/25/2022] [Accepted: 01/03/2023] [Indexed: 01/13/2023]
Abstract
Systemic lupus erythematosus (SLE) is an unpredictable autoimmune disease where the body's immune system mistakenly attacks healthy tissues in many parts of the body. Chronic pain is one of the most frequently reported symptoms among SLE patients. We previously reported that MRL lupus prone (MRL/lpr) mice develop hypersensitivity to mechanical and heat stimulation. In the present study, we found that the spinal protease-activated receptor-1(PAR1) plays an important role in the genesis of chronic pain in MRL/lpr mice. Female MRL/lpr mice with chronic pain had activation of astrocytes, over-expression of thrombin and PAR1, enhanced glutamatergic synaptic activity, as well as suppressed activity of adenosine monophosphate-activated protein kinase (AMPK) and glial glutamate transport function in the spinal cord. Intrathecal injection of either the PAR1 antagonist, or AMPK activator attenuated heat hyperalgesia and mechanical allodynia in MRL/lpr mice. Furthermore, we also identified that the enhanced glutamatergic synaptic activity and suppressed activity of glial glutamate transporters in the spinal dorsal horn of MRL/lpr mice are caused by activation of the PAR1 and suppression of AMPK signaling pathways. These findings suggest that targeting the PAR1 and AMPK signaling pathways in the spinal cord may be a useful approach for treating chronic pain caused by SLE. PERSPECTIVE: Our study provides evidence suggesting activation of PAR1 and suppression of AMPK in the spinal cord induces thermal hyperalgesia and mechanical allodynia in a lupus mouse model. Targeting signaling pathways regulating the PAR1 and AMPK could potentially provide a novel approach to the management of chronic pain caused by SLE.
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Affiliation(s)
- Fen Li
- Department of Neurology, Wuhan Third Hospital & Tongren Hospital of Wuhan University, Wuhan, Hubei, China
| | - Dongsheng Li
- Department of Cardiology, Wuhan Third Hospital & Tongren Hospital of Wuhan University, Wuhan, Hubei, China
| | - Jianguang Liu
- Department of Neurology, Wuhan Third Hospital & Tongren Hospital of Wuhan University, Wuhan, Hubei, China
| | - Shifan Tang
- Department of Cardiology, Wuhan Third Hospital & Tongren Hospital of Wuhan University, Wuhan, Hubei, China
| | - Jie Yan
- Department of Forensic Science, School of Basic Medical Science, Central South University, Changsha, Hunan, China
| | - Hongwei Li
- Department of Internal Medicine, School of Medicine, Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Zhengyun Wan
- Department of Internal Medicine, School of Medicine, Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Lian Wang
- Department of Internal Medicine, School of Medicine, Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Xisheng Yan
- Department of Cardiology, Wuhan Third Hospital & Tongren Hospital of Wuhan University, Wuhan, Hubei, China.
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Seo Y, Heo Y, Jo S, Park SH, Lee C, Chang J, Jeon DK, Kim TG, Han G, Namkung W. Novel positive allosteric modulator of protease-activated receptor 1 promotes skin wound healing in hairless mice. Br J Pharmacol 2021; 178:3414-3427. [PMID: 33837955 DOI: 10.1111/bph.15489] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 02/04/2021] [Accepted: 03/29/2021] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Protease-activated receptor 1 (PAR1) is a GPCR expressed in several skin cell types, including keratinocyte and dermal fibroblast. PAR1 activation plays a crucial role in the process of skin wound healing such as thrombosis, inflammation, proliferation and tissue repair. In the present study, we identified a novel positive allosteric modulator of PAR1, GB83, and investigated its effect on skin wound healing. EXPERIMENTAL APPROACH The enhancement of PAR1 activity by GB83 was measured using Fluo-4 calcium assay. In silico docking analysis of GB83 in PAR1 was performed using dock ligands method (CDOCKER) with CHARMm force field. Effects of GB83 on cell viability and gene expression were observed using MTS assay and quantitative real-time PCRs, respectively. SKH-1 hairless mice were used to investigate the wound healing effect of GB83. KEY RESULTS We demonstrated that GB83 did not activate PAR1 by itself but strongly enhanced PAR1 activation by thrombin and PAR1-activating peptide (AP). In silico docking analysis revealed that GB83 can bind to the PAR1 binding site of vorapaxar. GB83 significantly promoted PAR1-mediated cell viability and migration. In addition, the enhancement of PAR1 activity by GB83 strongly increased gene expression of TGF-β, fibronectin and type I collagen in vitro and promoted skin wound healing in vivo. CONCLUSION AND IMPLICATIONS Our results revealed that GB83 is the first positive allosteric modulator of PAR1 and it can be a useful pharmacological tool for studying PAR1 and a potential therapeutic agent for skin wound healing.
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Affiliation(s)
- Yohan Seo
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Republic of Korea.,Department of Integrated OMICS for Biomedical Science, WCU Program of Graduate School, Yonsei University, Seoul, Republic of Korea.,New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Republic of Korea
| | - Yunkyung Heo
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Republic of Korea
| | - Sungwoo Jo
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Republic of Korea
| | - So-Hyeon Park
- Graduate Program of Industrial Pharmaceutical Science, Yonsei University, Incheon, Republic of Korea
| | - Chulho Lee
- Department of Integrated OMICS for Biomedical Science, WCU Program of Graduate School, Yonsei University, Seoul, Republic of Korea.,Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea
| | - Jiwon Chang
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Republic of Korea
| | - Dong-Kyu Jeon
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Republic of Korea
| | - Tae Gun Kim
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea
| | - Gyoonhee Han
- Department of Integrated OMICS for Biomedical Science, WCU Program of Graduate School, Yonsei University, Seoul, Republic of Korea.,Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea
| | - Wan Namkung
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Republic of Korea.,Department of Integrated OMICS for Biomedical Science, WCU Program of Graduate School, Yonsei University, Seoul, Republic of Korea
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Treatment of Diabetic Neuropathy with A Novel PAR1-Targeting Molecule. Biomolecules 2020; 10:biom10111552. [PMID: 33203057 PMCID: PMC7698286 DOI: 10.3390/biom10111552] [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: 10/07/2020] [Revised: 11/04/2020] [Accepted: 11/10/2020] [Indexed: 12/21/2022] Open
Abstract
Diabetic peripheral neuropathy (DPN) is a disabling common complication of diabetes mellitus (DM). Thrombin, a coagulation factor, is increased in DM and affects nerve function via its G-protein coupled protease activated receptor 1 (PAR1). Methods: A novel PAR1 modulator (PARIN5) was designed based on the thrombin PAR1 recognition site. Coagulation, motor and sensory function and small fiber loss were evaluated by employing the murine streptozotocin diabetes model. Results: PARIN5 showed a safe coagulation profile and showed no significant effect on weight or glucose levels. Diabetic mice spent shorter time on the rotarod (p < 0.001), and had hypoalgesia (p < 0.05), slow conduction velocity (p < 0.0001) and reduced skin innervation (p < 0.0001). Treatment with PARIN5 significantly improved rotarod performance (p < 0.05), normalized hypoalgesia (p < 0.05), attenuated slowing of nerve conduction velocity (p < 0.05) and improved skin innervation (p <0.0001). Conclusion: PARIN5 is a novel pharmacological approach for prevention of DPN development, via PAR1 pathway modulation.
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Quantitative proteomic analysis of human plasma using tandem mass tags to identify novel biomarkers for herpes zoster. J Proteomics 2020; 225:103879. [PMID: 32585426 DOI: 10.1016/j.jprot.2020.103879] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 06/08/2020] [Accepted: 06/10/2020] [Indexed: 11/21/2022]
Abstract
Herpes zoster (HZ), commonly called shingles, it is a distinctive syndrome caused by reactivation of varicella zoster virus (VZV). A better understanding of the biological characteristics of HZ patients can help develop new targeted therapies to improve the prognosis. High-throughput proteomics technology can deeply study the molecular changes in the development and progression of HZ disease and integrate different levels of information, this is important to help make clinical decisions. Circulating blood contains a lot of biological information, we conducted a proteomics study of patient plasma, hoping to identify key proteins that could indicate the development of HZ. Compared to healthy human plasma, we found 44 differentially expressed proteins in the plasma of HZ patients, the main pathways involved in these molecules are MAPK signaling pathway, Neuroactive ligand-receptor interaction, Acute myeloid leukemia, Transcriptional misregulation in cancer. We found that 27 proteins have direct protein-protein interactions. Based on the comprehensive score, we identified six key molecules as candidate molecules for further study, and then validated another 80 plasma samples (40 HZ patient plasma and 40 healthy human plasma) using enzyme-linked immunosorbent assay (ELISA), immunoblot assay and receiver operating characteristic (ROC) curve analysis. Finally, we found that the expression levels of these three proteins (PLG, F2, VTN) were significantly lower than those of healthy controls (P < .05). To the best of our knowledge, we first used tandem mass tag (TMT) combined with liquid chromatography-mass spectrometry (LC-MS/MS) to screen for differentially expressed proteins in plasma between HZ patients and healthy individuals. It is preliminarily proved that the plasma protein expression profile of HZ patients is different from that of uninfected patients, it has also been found that these three altered key proteins may be used as biomarkers to test early HZ infection. This study reveals new insights into HZ that help to more accurately identify early HZ patients and to find new therapeutic targets. SIGNIFICANCE: Varicella-zoster virus (VZV; termed human alphaherpesvirus 3 by the International Committee on Taxonomy of Viruses) is a herpesvirus that is ubiquitous in humans and can cause chickenpox and herpes zoster (HZ). After the initial infection of varicella, the VZV goes into a dormant state in the sensory ganglia and cranial nerves. As age or immunosuppression increases, the cellular immunity to VZV decreases, and the virus reactivates and spreads along the sensory nerves to the skin, causing a unique prodromal pain followed by a rash. About one in five people around the world may be infected with VZV at some point in their lives. According to statistics, about one-third of infected people will develop HZ in their lifetime, and an estimated 1 million cases of herpes zoster occur in the United States each year. Herpes zoster can occur at any age and is usually less severe in children and young adults, but the greatest morbidity and mortality are observed in elderly and immunocompromised patients. 20% of patients with HZ have complications including vasculitis, increased risk of myocardial infarction, or postherpetic neuralgia, the overall mortality rate of patients with HZ in the United States is close to 5%. Considering the wide clinical severity and complications of this disease, there is a great need for biomarkers that contribute to early diagnosis, classification of risks, and prediction of outcomes, which will help elucidate the mechanisms underlying their clinical development. As a useful tool in biology, quantitative proteomics can repeatedly identify and accurately quantify proteins in a variety of biological samples. Proteomic analysis focuses on translational proteins, which play a direct role in most biological processes. Although a small number of proteins can be studied simultaneously with traditional methods, such as ELISA and Western blotting, typical proteomics studies can simultaneously analyze thousands of proteins for a more comprehensive identification. Proteomics has been successfully applied to human-based disease research, Analysis of exposed and unexposed subjects based on mass spectrometry (MS) has been found to reveal altered expression of proteins that can be identified as intermediate biomarkers of early disease effects. Tandem mass tags (TMTs) are chemical labels used for MS-based identification and quantification of biological molecules. TMTs play an important role in proteomic analysis in a variety of samples such as cells, tissues, and body fluids. The body fluids that are often detected clinically are blood, which are easy to obtain and contain abundant biological information related to physiological and pathological processes, we hope to develop protein biomarkers from these blood. Therefore, in order to better characterize the pathological process of HZ patients, we performed proteomic analysis of HZ patients and healthy human plasma using the TMT method. This comparison aims to identify specific processes in the development of HZ disease through protein profiling, which may help to improve our biological understanding of HZ.
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Shavit-Stein E, Aronovich R, Sylantiev C, Gofrit SG, Chapman J, Dori A. The role of thrombin in the pathogenesis of diabetic neuropathy. PLoS One 2019; 14:e0219453. [PMID: 31276565 PMCID: PMC6611599 DOI: 10.1371/journal.pone.0219453] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 06/24/2019] [Indexed: 02/05/2023] Open
Abstract
Diabetic neuropathy is common and disabling despite glycemic control. Novel neuroprotective approaches are needed. Thrombin and hypercoagulability are associated with diabetes and nerve conduction dysfunction. Our aim was to study the role of thrombin in diabetic neuropathy. We measured thrombin activity by a biochemical assay in streptozotocin (STZ)-induced diabetic neuropathy in male Sprague-Dawley rats. Neuropathy severity was assessed by thermal latency and nerve conduction measures. Thermal latencies were longer in diabetic rats, and improved with the non-specific serine-protease inhibitor Tosyl-L-lysine-chloromethyl ketone (TLCK) treatment (p<0.01). The tail nerve of diabetic rats showed slow conduction velocity (p˂0.01), and interestingly, increased thrombin activity was noted in the sciatic nerve (p˂0.001). Sciatic nodes of Ranvier and the thrombin receptor, protease activated receptor 1 (PAR1) reactivity showed abnormal morphology in diabetic animals by immunofluorescence staining (p<0.0001). Treatment of diabetic animals with either the specific thrombin inhibitor, N-alpha 2 naphtalenesulfonylglycyl alpha-4 amidino-phenylalaninepiperidide (NAPAP) or TLCK preserved normal conduction velocity, (p˂0.01 and p = 0.01 respectively), and prevented disruption of morphology (p˂0.05 and p˂0.03). The results establish for the first time an association between diabetic neuropathy and excessive activation of the thrombin pathway. Treatment of diabetic animals with thrombin inhibitors ameliorates both biochemical, structural and electrophysiological deficits. The thrombin pathway inhibition may be a novel neuroprotective therapeutic target in the diabetic neuropathy pathology.
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Affiliation(s)
- Efrat Shavit-Stein
- Department of Neurology, Sheba Medical Center, Tel HaShomer, Israel
- Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel HaShomer, Israel
- * E-mail:
| | - Ramona Aronovich
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | | | | | - Joab Chapman
- Department of Neurology, Sheba Medical Center, Tel HaShomer, Israel
- Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel HaShomer, Israel
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Neurology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
- Robert and Martha Harden Chair in Mental and Neurological Diseases, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Amir Dori
- Department of Neurology, Sheba Medical Center, Tel HaShomer, Israel
- Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel HaShomer, Israel
- Department of Neurology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
- Talpiot medical leadership program, Sheba Medical Center, Tel HaShomer, Israel
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Shavit-Stein E, Aronovich R, Sylantiev C, Gera O, Gofrit SG, Chapman J, Dori A. Blocking Thrombin Significantly Ameliorates Experimental Autoimmune Neuritis. Front Neurol 2019; 9:1139. [PMID: 30662428 PMCID: PMC6328627 DOI: 10.3389/fneur.2018.01139] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 12/10/2018] [Indexed: 12/18/2022] Open
Abstract
Thrombin and its protease-activated receptor 1 (PAR1) are potentially important in peripheral nerve inflammatory diseases. We studied the role of thrombin and PAR1 in rat experimental autoimmune neuritis (EAN), a model of the human Guillain-Barré syndrome (GBS). EAN was induced by bovine peripheral myelin with complete Freund's adjuvant (CFA). Thrombin activity in the sciatic nerves, clinical scores and rotarod performance were measured. Thrombin activity in the sciatic nerve was elevated in EAN compared to CFA control rats (sham rats) (p ≤ 0.004). The effect of blocking the thrombin-PAR1 pathway was studied using the non-selective thrombin inhibitor N-Tosyl-Lys-chloromethylketone (TLCK), and the highly specific thrombin inhibitor N-alpha 2 naphtalenesulfonylglycyl 4 amidino-phenylalaninepiperidide (NAPAP). In-vitro TLCK and NAPAP significantly inhibited specific thrombin activity in EAN rats sciatics (p<0.0001 for both inhibitors). Treatment with TLCK 4.4 mg/kg and NAPAP 69.8 mg/kg significantly improved clinical and rotarod scores starting at day 12 and 13 post immunization (DPI12, DPI13) respectively (p < 0.0001) compared to the untreated EAN rats. In nerve conduction studies, distal amplitude was significantly lower in EAN compared to sham rats (0.76 ± 0.34 vs. 9.8 ± 1.2, mV, p < 0.0001). Nerve conduction velocity was impaired in EAN rats (23.6 ± 2.6 vs. sham 43 ± 4.5, m/s p = 0.01) and was normalized by TLCK (41.2 ± 7.6 m/s, p < 0.05). PAR1 histology of the sciatic node of Ranvier indicated significant structural damage in the EAN rats which was prevented by TLCK treatment. These results suggest the thrombin-PAR1 pathway as a possible target for future intervention in GBS.
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Affiliation(s)
- Efrat Shavit-Stein
- Department of Neurology, The Chaim Sheba Medical Center, Ramat Gan, Israel
| | - Ramona Aronovich
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Constantin Sylantiev
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Orna Gera
- Department of Neurology, The Chaim Sheba Medical Center, Ramat Gan, Israel
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shany G. Gofrit
- Department of Neurology, The Chaim Sheba Medical Center, Ramat Gan, Israel
| | - Joab Chapman
- Department of Neurology, The Chaim Sheba Medical Center, Ramat Gan, Israel
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Joseph Sagol Neuroscience Center, Sheba Medical Center, Ramat Gan, Israel
- Department of Neurology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
- Robert and Martha Harden Chair in Mental and Neurological Diseases, Sackler Faculty of Medicine, Tel Aviv, Israel
| | - Amir Dori
- Department of Neurology, The Chaim Sheba Medical Center, Ramat Gan, Israel
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Joseph Sagol Neuroscience Center, Sheba Medical Center, Ramat Gan, Israel
- Department of Neurology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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Bao Y, Gao Y, Yang L, Kong X, Zheng H, Hou W, Hua B. New insights into protease-activated receptor 4 signaling pathways in the pathogenesis of inflammation and neuropathic pain: a literature review. Channels (Austin) 2015; 9:5-13. [PMID: 25664811 DOI: 10.4161/19336950.2014.995001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Pain is an unpleasant sensory and emotional experience that is commonly associated with actual or potential tissue damage. Despite decades of pain research, many patients continue to suffer from chronic pain that is refractory to current treatments. Accumulating evidence has indicated an important role of protease-activated receptor 4 (PAR4) in the pathogenesis of inflammation and neuropathic pain. Here we reviewed PAR4 expression and activation via intracellular signaling pathways and the role of PAR4 signaling pathways in the development and maintenance of pain. Understanding PAR4 and its corresponding signaling pathways will provide insight to further explore the molecular basis of pain, which will also help to identify new targets for pharmacological intervention for pain relief.
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Affiliation(s)
- Yanju Bao
- a Department of Oncology ; Guang'anmen Hospital ; China Academy of Chinese Medical Sciences; Beixiange 5 ; Xicheng District , Beijing , P. R. China
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Bao Y, Hou W, Hua B. Protease-activated receptor 2 signalling pathways: a role in pain processing. Expert Opin Ther Targets 2013; 18:15-27. [PMID: 24147628 DOI: 10.1517/14728222.2014.844792] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
INTRODUCTION Pain is a complex biological phenomenon that includes intricate neurophysiological, behavioural, psychosocial and affective components. Despite decades of pain research, many patients continue suffering from chronic pain that may be refractory to current medical regimens. Accumulating evidence has indicated an important role of protease-activated receptor 2 (PAR2) in the pathogenesis of pain, including inflammation, neuropathic and cancer pain. AREAS COVERED In this review, the role of the PAR2 signalling pathway in pain processes, basic mechanism of PAR2 activation and expression of PAR2 in the nervous system is covered. Furthermore, intracellular signalling pathways that are activated by PAR2 are also described. EXPERT OPINION The role of PAR2 in pain processing is becoming increasingly clear, and although causal implication remains to be established, PAR2 activation has been observed in several disease model systems. Since PAR2 is activated after nerve injury as well as by trypsin and related serine proteases, and PAR2 plays an important role in pain development and maintenance, exploring PAR2 and its corresponding signalling pathways will provide unfathomable knowledge in understanding the molecular basis of pain. This will also help to identify new targets for pharmacological intervention; however, in the context of potential PAR2-directed therapies, several aspects should be clarified.
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Affiliation(s)
- Yanju Bao
- Guang'anmen Hospital, China Academy of Chinese Medical Science, Department of Oncology , Beixiange 5, Xicheng District, Beijing 100053 , China +86 10 88001221 ; +86 10 88001430 ; ; ;
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Amini AR, Wallace JS, Nukavarapu SP. Short-term and long-term effects of orthopedic biodegradable implants. J Long Term Eff Med Implants 2012; 21:93-122. [PMID: 22043969 DOI: 10.1615/jlongtermeffmedimplants.v21.i2.10] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Presently, orthopedic and oral/maxillofacial implants represent a combined $2.8 billion market, a figure expected to experience significant and continued growth. Although traditional permanent implants have been proved clinically efficacious, they are also associated with several drawbacks, including secondary revision and removal surgeries. Non-permanent, biodegradable implants offer a promising alternative for patients, as they provide temporary support and degrade at a rate matching tissue formation, and thus, eliminate the need for secondary surgeries. These implants have been in clinical use for nearly 25 years, competing directly with, or maybe even exceeding, the performance of permanent implants. The initial implantation of biodegradable materials, as with permanent materials, mounts an acute host inflammatory response. Over time, the implant degradation profile and possible degradation product toxicity mediate long-term biodegradable implant-induced inflammation. However, unlike permanent implants, this inflammation is likely to cease once the material disappears. Implant-mediated inflammation is a critical determinant for implant success. Thus, for the development of a proactive biodegradable implant that has the ability to promote optimal bone regeneration and minimal detrimental inflammation, a thorough understanding of short- and long-term inflammatory events is required. Here, we discuss an array of biodegradable orthopedic implants, their associated short- and long- term inflammatory effects, and methods to mediate these inflammatory events.
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Affiliation(s)
- Ami R Amini
- Department of Orthopaedic Surgery, University of Connecticut Health Center, Farmington, CT, USA
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Taneja K, Pareek A, Verma P, Jain V, Ratan Y, Ashawat MS. Nanocomposite: An emerging tool for bone tissue transplantation and drug delivery. INDIAN JOURNAL OF TRANSPLANTATION 2012. [DOI: 10.1016/j.ijt.2012.07.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Wen Y, Gallego MR, Nielsen LF, Jorgensen L, Everland H, Møller EH, Nielsen HM. Biodegradable nanocomposite microparticles as drug delivering injectable cell scaffolds. J Control Release 2011; 156:11-20. [DOI: 10.1016/j.jconrel.2011.07.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 07/07/2011] [Accepted: 07/09/2011] [Indexed: 12/12/2022]
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