1
|
Protease Activated Receptor 1 and Its Ligands as Main Regulators of the Regeneration of Peripheral Nerves. Biomolecules 2021; 11:biom11111668. [PMID: 34827666 PMCID: PMC8615415 DOI: 10.3390/biom11111668] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/29/2021] [Accepted: 11/05/2021] [Indexed: 12/16/2022] Open
Abstract
In contrast with the brain and spinal cord, peripheral nerves possess a striking ability to regenerate after damage. This characteristic of the peripheral nervous system is mainly due to a specific population of glial cells, the Schwann cells. Schwann cells promptly activate after nerve injury, dedifferentiate assuming a repair phenotype, and assist axon regrowth. In general, tissue injury determines the release of a variety of proteases which, in parallel with the degradation of their specific targets, also activate plasma membrane receptors known as protease-activated receptors (PARs). PAR1, the prototypical member of the PAR family, is also known as thrombin receptor and is present at the Schwann cell plasma membrane. This receptor is emerging as a possible regulator of the pro-regenerative capacity of Schwann cells. Here, we summarize the most recent literature data describing the possible contribution of PAR1 and PAR1-activating proteases in regulating the regeneration of peripheral nerves.
Collapse
|
2
|
Role of the protease-activated receptor 1 in regulating the function of glial cells within central and peripheral nervous system. J Neural Transm (Vienna) 2019; 126:1259-1271. [DOI: 10.1007/s00702-019-02075-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 08/31/2019] [Indexed: 02/07/2023]
|
3
|
Kim S, Kim YE, Hong S, Kim KT, Sung DK, Lee Y, Park WS, Chang YS, Song MR. Reactive microglia and astrocytes in neonatal intraventricular hemorrhage model are blocked by mesenchymal stem cells. Glia 2019; 68:178-192. [PMID: 31441125 DOI: 10.1002/glia.23712] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 07/08/2019] [Accepted: 08/01/2019] [Indexed: 12/12/2022]
Abstract
Severe intraventricular hemorrhage (IVH) in premature infants triggers reactive gliosis, causing acute neuronal death and glial scar formation. Transplantation of mesenchymal stem cells (MSCs) has often showed improved CNS recovery in an IVH model, but whether this response is related to reactive glial cells is still unclear. Herein, we suggest that MSCs impede the response of reactive microglia rather than astrocytes, thereby blocking neuronal damage. Astrocytes alone showed mild reactiveness under hemorrhagic conditions mimicked by thrombin treatment, and this was not blocked by MSC-conditioned medium (MSC-CM) in vitro. In contrast, thrombin-induced microglial activation and release of proinflammatory cytokines were inhibited by MSC-CM. Interestingly, astrocytes showed greater reactive response when co-cultured with microglia, and this was abolished in the presence of MSC-CM. Gene expression profiles in microglia revealed that transcript levels of genes for immune response and proinflammatory cytokines were altered by thrombin treatment. This result coincided with the robust phosphorylation of STAT1 and p38 MAPK, which might be responsible for the production and release of proinflammatory cytokines. Furthermore, application of MSC-CM diminished thrombin-mediated phosphorylation of STAT1 and p38 MAPK, supporting the acute anti-inflammatory role of MSCs under hemorrhagic conditions. In line with this, activation of microglia and consequent cytokine release were impaired in Stat1-null mice. However, reactive response in Stat1-deficient astrocytes was maintained. Taken together, our results demonstrate that MSCs mainly block the activation of microglia involving STAT1-mediated cytokine release and subsequent reduction of reactive astrocytes.
Collapse
Affiliation(s)
- Seojeong Kim
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
| | - Young Eun Kim
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.,Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University, Seoul, Republic of Korea
| | - Sujeong Hong
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
| | - Kyung-Tai Kim
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
| | - Dong Kyung Sung
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Yunjeong Lee
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
| | - Won Soon Park
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Yun Sil Chang
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.,Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University, Seoul, Republic of Korea
| | - Mi-Ryoung Song
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
| |
Collapse
|
4
|
Pompili E, Fabrizi C, Somma F, Correani V, Maras B, Schininà ME, Ciraci V, Artico M, Fornai F, Fumagalli L. PAR1 activation affects the neurotrophic properties of Schwann cells. Mol Cell Neurosci 2017; 79:23-33. [PMID: 28064059 DOI: 10.1016/j.mcn.2017.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 12/14/2016] [Accepted: 01/01/2017] [Indexed: 01/02/2023] Open
Abstract
Protease-activated receptor-1 (PAR1) is the prototypic member of a family of four G-protein-coupled receptors that signal in response to extracellular proteases. In the peripheral nervous system, the expression and/or the role of PARs are still poorly investigated. High PAR1 mRNA expression was found in the rat dorsal root ganglia and the signal intensity of PAR1 mRNA increased in response to sciatic nerve transection. In the sciatic nerve, functional PAR1 receptor was reported at the level of non-compacted Schwann cell myelin microvilli of the nodes of Ranvier. Schwann cells are the principal population of glial cells of the peripheral nervous system which myelinate axons playing an important role during axonal regeneration and remyelination. The present study was undertaken in order to determine if the activation of PAR1 affects the neurotrophic properties of Schwann cells. Our results suggest that the stimulation of PAR1 could potentiate the Schwann cell ability to favour nerve regeneration. In fact, the conditioned medium obtained from Schwann cell cultures challenged with a specific PAR1 activating peptide (PAR1 AP) displays increased neuroprotective and neurotrophic properties with respect to the culture medium from untreated Schwann cells. The proteomic analysis of secreted proteins in untreated and PAR1 AP-treated Schwann cells allowed the identification of factors differentially expressed in the two samples. Some of them (such as macrophage migration inhibitory factor, matrix metalloproteinase-2, decorin, syndecan 4, complement C1r subcomponent, angiogenic factor with G patch and FHA domains 1) appear to be transcriptionally regulated after PAR1 AP treatment as shown by RT-PCR.
Collapse
Affiliation(s)
- Elena Pompili
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Sapienza University of Rome, Rome, Italy.
| | - Cinzia Fabrizi
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Sapienza University of Rome, Rome, Italy
| | - Francesca Somma
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Sapienza University of Rome, Rome, Italy
| | - Virginia Correani
- Department of Biochemical Sciences, Sapienza University of Rome, Rome, Italy
| | - Bruno Maras
- Department of Biochemical Sciences, Sapienza University of Rome, Rome, Italy
| | | | - Viviana Ciraci
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Sapienza University of Rome, Rome, Italy
| | - Marco Artico
- Department of Sensory Organs, Sapienza University of Rome, Rome, Italy
| | - Francesco Fornai
- Department of Human Morphology and Applied Biology, University of Pisa, Pisa, Italy; IRCCS Neuromed, Pozzilli, Italy
| | - Lorenzo Fumagalli
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Sapienza University of Rome, Rome, Italy
| |
Collapse
|
5
|
Interference with Protease-activated Receptor 1 Alleviates Neuronal Cell Death Induced by Lipopolysaccharide-Stimulated Microglial Cells through the PI3K/Akt Pathway. Sci Rep 2016; 6:38247. [PMID: 27910893 PMCID: PMC5133627 DOI: 10.1038/srep38247] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 11/07/2016] [Indexed: 12/21/2022] Open
Abstract
Excessive microglial cells activation in response to inflammatory stimuli leads to synaptic loss, dysfunction, and neuronal cell death. Activated microglia are involved in the pathogenesis of neurological conditions and frequently contribute to several complications. Accumulating evidence suggests that signaling through PAR-1 is involved in inflammation, however, its function has yet to be fully elucidated. Here, we have demonstrated that the suppression of PAR-1 leads to down-regulation of inflammatory factors including IL-1β, IL-6, TNF-α, NO, as well as the prevention of activation of NF-κB in BV2 cells. In addition, we found that a PAR-1 antagonist, SCH, prevented LPS-induced excessive microglial activation in a dose-dependent manner. As a result of SCH treatment, neuronal cell death via up-regulation of Akt-mediated pathways was reduced. Our results demonstrate that the beneficial effects of SCH are linked to its ability to block an inflammatory response. Further, we found that SCH inhibited the death of PC12 neurons from the cytotoxicity of activated BV2 cells via activation of the PI3K/Akt pathway. These neuro-protective effects appear to be related to inhibition of PAR-1, and represents a novel neuroprotective strategy that could has potential for use in therapeutic interventions of neuroinflammatory disease.
Collapse
|
6
|
Mhatre MV, Potter JA, Lockwood CJ, Krikun G, Abrahams VM. Thrombin Augments LPS-Induced Human Endometrial Endothelial Cell Inflammation via PAR1 Activation. Am J Reprod Immunol 2016; 76:29-37. [PMID: 27108773 DOI: 10.1111/aji.12517] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 04/07/2016] [Indexed: 12/29/2022] Open
Abstract
PROBLEM Risk factors for preterm birth include placental abruption, giving rise to excessive decidual thrombin, and intrauterine bacterial infection. Human endometrial endothelial cells (HEECs) express Toll-like receptors (TLRs), and infection-derived agonists trigger HEECs to generate specific inflammatory responses. As thrombin, in addition to inducing coagulation, can contribute to inflammation, its effect on HEEC inflammatory responses to the TLR4 agonist, bacterial lipopolysaccharide (LPS), was investigated. METHOD OF STUDY HEECs were pre-treated with or without thrombin or specific protease-activated receptor (PAR) agonists, followed by treatment with or without LPS. Supernatants were measured for cytokines and chemokines by ELISA and multiplex analysis. RESULTS Thrombin significantly and synergistically augmented LPS-induced HEEC secretion of interleukin (IL)-6, IL-8, granulocyte colony-stimulating factor (G-CSF), and growth-regulated oncogene-alpha (GRO-α), and significantly augmented monocyte chemotactic protein (MCP)-1, tumor necrosis factor-alpha (TNF-α), and vascular endothelial growth factor (VEGF) secretion additively. Similar to thrombin, a PAR1 agonist synergistically augmented the LPS-induced HEEC secretion of inflammatory IL-6, IL-8, G-CSF, and GRO-α. CONCLUSION Thrombin, via PAR1 activation, synergistically augments LPS-induced HEEC production of chemokines involved in immune cell recruitment and survival, suggesting a mechanism by which intrauterine abruption and bacterial infection may together be associated with an aggravated uterine inflammatory response.
Collapse
Affiliation(s)
- Mohak V Mhatre
- Department of Obstetrics, Gynecology & Reproductive Sciences, Yale University School of Medicine, New Haven, CT, USA
| | - Julie A Potter
- Department of Obstetrics, Gynecology & Reproductive Sciences, Yale University School of Medicine, New Haven, CT, USA
| | - Charles J Lockwood
- Department of Obstetrics & Gynecology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Graciela Krikun
- Department of Obstetrics, Gynecology & Reproductive Sciences, Yale University School of Medicine, New Haven, CT, USA
| | - Vikki M Abrahams
- Department of Obstetrics, Gynecology & Reproductive Sciences, Yale University School of Medicine, New Haven, CT, USA
| |
Collapse
|
7
|
Peña-Ortega F, Rivera-Angulo AJ, Lorea-Hernández JJ. Pharmacological Tools to Study the Role of Astrocytes in Neural Network Functions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 949:47-66. [DOI: 10.1007/978-3-319-40764-7_3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
8
|
Wu W, Shao J, Lu H, Xu J, Zhu A, Fang W, Hui G. Guard of delinquency? A role of microglia in inflammatory neurodegenerative diseases of the CNS. Cell Biochem Biophys 2015; 70:1-8. [PMID: 24633457 DOI: 10.1007/s12013-014-9872-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Activation of microglia and inflammation-mediated neurotoxicity are believed to play an important role in the pathogenesis of several neurodegenerative disorders, including multiple sclerosis. Studies demonstrate complex functions of activated microglia that can lead to either beneficial or detrimental outcomes, depending on the form and the timing of activation. Combined with genetic and environmental factors, overactivation and dysregulation of microglia cause progressive neurotoxic consequences which involve a vicious cycle of neuron injury and unregulated neuroinflammation. Thus, modulation of microglial activation appears to be a promising new therapeutic target. While current therapies do attempt to block activation of microglia, they indiscriminately inhibit inflammation thus also curbing beneficial effects of inflammation and delaying recovery. Multiple signaling cascades, often cross-talking, are involved in every step of microglial activation. One of the key challenges is to understand the molecular mechanisms controlling cytokine expression and phagocytic activity, as well as cell-specific consequences of dysregulated cytokine expression. Further, a better understanding of how the integration of multiple cytokine signals influences the function or activity of individual microglia remains an important research objective to identify potential therapeutic targets for clinical intervention to promote repair.
Collapse
Affiliation(s)
- Weijiang Wu
- Department of Neurosurgery, Wuxi Third People's Hospital, Wuxi, Jiangsu, China
| | | | | | | | | | | | | |
Collapse
|
9
|
Jackson MT, Moradi B, Zaki S, Smith MM, McCracken S, Smith SM, Jackson CJ, Little CB. Depletion of protease-activated receptor 2 but not protease-activated receptor 1 may confer protection against osteoarthritis in mice through extracartilaginous mechanisms. Arthritis Rheumatol 2015; 66:3337-48. [PMID: 25200274 DOI: 10.1002/art.38876] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 09/04/2014] [Indexed: 01/03/2023]
Abstract
OBJECTIVE To explore the involvement of protease-activated receptor 1 (PAR-1) and PAR-2 in the pathologic processes of osteoarthritis (OA) and to identify the cells/tissues primarily affected by ablation of PAR-1 or PAR-2 in mice. METHODS OA was induced in the joints of wild-type (WT), PAR-1(+/+) , PAR-1(-/-) , and PAR-2(-/-) mice by destabilization of the medial meniscus (DMM), and scores of histologic features (cartilage aggrecan loss and erosion, subchondral bone sclerosis, osteophytes, and synovitis) were compared at 1, 4, and 8 weeks post-DMM. The effects of PAR ablation on cartilage degradation and chondrocyte metalloproteinase expression/activity were studied in cultures of mouse femoral head tissue with or without interleukin-1α (IL-1α). At 1 week post-DMM, synovial expression of cytokines and metalloproteinase genes was measured by reverse transcription-polymerase chain reaction, and populations of inflammatory cells were quantified by flow cytometry. RESULTS Deletion of PAR-2, but not that of PAR-1, in mice significantly delayed the progression of cartilage damage and inhibited subchondral bone sclerosis following DMM. There was no inhibitory effect of PAR-1 or PAR-2 ablation on IL-1α-induced cartilage degradation or chondrocyte metalloproteinase expression/activation. A low but significant level of synovitis persisted in mice subjected to DMM compared to that in control mice subjected to sham surgery, but no differences between the genotypes were seen 4 or 8 weeks post-DMM. One week after DMM, increased synovial expression of proinflammatory cytokines and metalloproteinase genes, along with increased levels of CD4+ T cells, inflammatory monocytes, and activated macrophages, were seen in all genotypes. However, there was a significant reduction in the percentage of activated macrophages in PAR-2(-/-) mice compared to PAR-1(-/-) and WT mice. CONCLUSION Deletion of PAR-2, but not that of PAR-1, results in a significant decrease in DMM-induced cartilage damage. The chondroprotection in PAR-2(-/-) mice appears to occur indirectly through modulation of extracartilaginous events such as subchondral bone remodeling and synovial macrophage activation, rather than through alteration of chondrocyte catabolic responses.
Collapse
Affiliation(s)
- Miriam T Jackson
- Kolling Institute of Medical Research and the University of Sydney at Royal North Shore Hospital, St. Leonards, New South Wales, Australia
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Abstract
The coagulation cascade is activated during viral infections. This response may be part of the host defense system to limit spread of the pathogen. However, excessive activation of the coagulation cascade can be deleterious. In fact, inhibition of the tissue factor/factor VIIa complex reduced mortality in a monkey model of Ebola hemorrhagic fever. Other studies showed that incorporation of tissue factor into the envelope of herpes simplex virus increases infection of endothelial cells and mice. Furthermore, binding of factor X to adenovirus serotype 5 enhances infection of hepatocytes but also increases the activation of the innate immune response to the virus. Coagulation proteases activate protease-activated receptors (PARs). Interestingly, we and others found that PAR1 and PAR2 modulate the immune response to viral infection. For instance, PAR1 positively regulates TLR3-dependent expression of the antiviral protein interferon β, whereas PAR2 negatively regulates expression during coxsackievirus group B infection. These studies indicate that the coagulation cascade plays multiple roles during viral infections.
Collapse
|
11
|
Proteinase-activated receptor-1 and immunomodulatory effects of a PAR1-activating peptide in a mouse model of prostatitis. Mediators Inflamm 2014; 2013:748395. [PMID: 24459330 PMCID: PMC3891427 DOI: 10.1155/2013/748395] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 10/07/2013] [Indexed: 11/17/2022] Open
Abstract
Background. Nonbacterial prostatitis has no established etiology. We hypothesized that proteinase-activated receptor-1 (PAR1) can play a role in prostatitis. We therefore investigated the effects of PAR1 stimulation in the context of a new model of murine nonbacterial prostatitis. Methods. Using a hapten (ethanol-dinitrobenzene sulfonic acid- (DNBS-)) induced prostatitis model with both wild-type and PAR1-null mice, we examined (1) the location of PAR1 in the mouse prostate and (2) the impact of a PAR1-activating peptide (TFLLR-NH2: PAR1-TF) on ethanol-DNBS-induced inflammation. Results. Ethanol-DNBS-induced inflammation was maximal at 2 days. In the tissue, PAR1 was expressed predominantly along the apical acini of prostatic epithelium. Although PAR1-TF on its own did not cause inflammation, its coadministration with ethanol-DNBS reduced all indices of acute prostatitis. Further, PAR1-TF administration doubled the prostatic production of interleukin-10 (IL-10) compared with ethanol-DNBS treatment alone. This enhanced IL-10 was not observed in PAR1-null mice and was not caused by the reverse-sequence receptor-inactive peptide, RLLFT-NH2. Surprisingly, PAR1-TF, also diminished ethanol-DNBS-induced inflammation in PAR1-null mice. Conclusions. PAR1 is expressed in the mouse prostate and its activation by PAR1-TF elicits immunomodulatory effects during ethanol-DNBS-induced prostatitis. However, PAR1-TF also diminishes ethanol-DNBS-induced inflammation via a non-PAR1 mechanism by activating an as-yet unknown receptor.
Collapse
|
12
|
Ronaldson PT, Davis TP. Blood-brain barrier integrity and glial support: mechanisms that can be targeted for novel therapeutic approaches in stroke. Curr Pharm Des 2012; 18:3624-44. [PMID: 22574987 DOI: 10.2174/138161212802002625] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 03/06/2012] [Indexed: 12/31/2022]
Abstract
The blood-brain barrier (BBB) is a critical regulator of brain homeostasis. Additionally, the BBB is the most significant obstacle to effective CNS drug delivery. It possesses specific charcteristics (i.e., tight junction protein complexes, influx and efflux transporters) that control permeation of circulating solutes including therapeutic agents. In order to form this "barrier," brain microvascular endothelial cells require support of adjacent astrocytes and microglia. This intricate relationship also occurs between endothelial cells and other cell types and structures of the CNS (i.e., pericytes, neurons, extracellular matrix), which implies existence of a "neurovascular unit." Ischemic stroke can disrupt the neurovascular unit at both the structural and functional level, which leads to an increase in leak across the BBB. Recent studies have identified several pathophysiological mechanisms (i.e., oxidative stress, activation of cytokine-mediated intracellular signaling systems) that mediate changes in the neurovascular unit during ischemic stroke. This review summarizes current knowledge in this area and emphasizes pathways (i.e., oxidative stress, cytokine-mediated intracellular signaling, glial-expressed receptors/targets) that can be manipulated pharmacologically for i) preservation of BBB and glial integrity during ischemic stroke and ii) control of drug permeation and/or transport across the BBB. Targeting these pathways present a novel opportunity for optimization of CNS delivery of therapeutics in the setting of ischemic stroke.
Collapse
Affiliation(s)
- Patrick T Ronaldson
- Department of Medical Pharmacology, College of Medicine, University of Arizona, 1501 North Campbell Avenue, P.O. Box 245050, Tucson, AZ 85724-5050, USA.
| | | |
Collapse
|
13
|
Łabuzek K, Suchy D, Gabryel B, Pierzchała O, Okopień B. Role of the SOCS in monocytes/macrophages-related pathologies. Are we getting closer to a new pharmacological target? Pharmacol Rep 2012; 64:1038-54. [DOI: 10.1016/s1734-1140(12)70902-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2012] [Revised: 06/08/2012] [Indexed: 12/11/2022]
|
14
|
Chen CW, Chen QB, Ouyang Q, Sun JH, Liu FT, Song DW, Yuan HB. Transient early neurotrophin release and delayed inflammatory cytokine release by microglia in response to PAR-2 stimulation. J Neuroinflammation 2012; 9:142. [PMID: 22731117 PMCID: PMC3419072 DOI: 10.1186/1742-2094-9-142] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 05/23/2012] [Indexed: 12/17/2022] Open
Abstract
Activated microglia exerts both beneficial and deleterious effects on neurons, but the signaling mechanism controlling these distinct responses remain unclear. We demonstrated that treatment of microglial cultures with the PAR-2 agonist, 2-Furoyl-LIGRLO-NH2, evoked early transient release of BDNF, while sustained PAR-2 stimulation evoked the delayed release of inflammatory cytokines (IL-1 β and TNF-α) and nitric oxide. Culture medium harvested during the early phase (at 1 h) of microglial activation induced by 2-Furoyl-LIGRLO-NH2 (microglial conditioned medium, MCM) had no deleterious effects on cultured neurons, while MCM harvested during the late phase (at 72 h) promoted DNA fragmentation and apoptosis as indicated by TUNEL and annexin/PI staining. Blockade of PAR-1 during the early phase of PAR-2 stimulation enhanced BDNF release (by 11%, small but significant) while a PAR-1 agonist added during the late phase (24 h after 2-Furoyl-LIGRLO-NH2 addition) suppressed the release of cytokines and NO. The neuroprotective and neurotoxic effects of activated microglial exhibit distinct temporal profiles that are regulated by PAR-1 and PAR-2 stimulation. It may be possible to facilitate neuronal recovery and repair by appropriately timed stimulation and inhibition of microglial PAR-1 and PAR-2 receptors.
Collapse
Affiliation(s)
- Chen-Wen Chen
- Department of Anesthesiology, Changzheng Hospital, Second Military Medical University, Shanghai 200003, China.
| | | | | | | | | | | | | |
Collapse
|
15
|
Xue M, Chan YKA, Shen K, Dervish S, March L, Sambrook PN, Jackson CJ. Protease-activated receptor 2, rather than protease-activated receptor 1, contributes to the aggressive properties of synovial fibroblasts in rheumatoid arthritis. ACTA ACUST UNITED AC 2011; 64:88-98. [DOI: 10.1002/art.33323] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
16
|
Ma L, Dorling A. The roles of thrombin and protease-activated receptors in inflammation. Semin Immunopathol 2011; 34:63-72. [PMID: 21809138 DOI: 10.1007/s00281-011-0281-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 07/20/2011] [Indexed: 12/11/2022]
Abstract
Inflammation and coagulation constitute two host defence systems with complementary physiological roles in limiting tissue damage, restoring homeostasis and eliminating invading pathogens, functions reliant on effective regulation of both processes at a variety of levels. Dysfunctional activation or regulation of either pathway may lead to pathology and contribute to human diseases as diverse as myocardial infarction and septic shock. The serine protease thrombin, a key protein in the coagulation pathway, can activate cellular signalling directly via proteolytic cleavage of the N-terminal domain of a family of G protein-coupled receptors or indirectly through the generation of molecules such as activated protein C. These events transmit signals to many cell types and can elicit the production of various pro-inflammatory mediators such as cytokines, chemokines and growth factors, thereby influencing cell activation, differentiation, survival and migration. This review discusses recent progress in understanding how thrombin and protease-activated receptors influence biological processes, highlighting the detrimental and protective cellular effects of thrombin and its signalling pathways.
Collapse
Affiliation(s)
- Liang Ma
- Medical Research Council (MRC) Centre for Transplantation, King's College London, King's Health Partners, Guy's Hospital, London, UK
| | | |
Collapse
|
17
|
Li J, Ye L, Cook DR, Wang X, Liu J, Kolson DL, Persidsky Y, Ho WZ. Soybean-derived Bowman-Birk inhibitor inhibits neurotoxicity of LPS-activated macrophages. J Neuroinflammation 2011; 8:15. [PMID: 21324129 PMCID: PMC3046894 DOI: 10.1186/1742-2094-8-15] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Accepted: 02/15/2011] [Indexed: 12/12/2022] Open
Abstract
Background Lipopolysaccharide (LPS), the major component of the outer membrane of gram-negative bacteria, can activate immune cells including macrophages. Activation of macrophages in the central nervous system (CNS) contributes to neuronal injury. Bowman-Birk inhibitor (BBI), a soybean-derived protease inhibitor, has anti-inflammatory properties. In this study, we examined whether BBI has the ability to inhibit LPS-mediated macrophage activation, reducing the release of pro-inflammatory cytokines and subsequent neurotoxicity in primary cortical neural cultures. Methods Mixed cortical neural cultures from rat were used as target cells for testing neurotoxicity induced by LPS-treated macrophage supernatant. Neuronal survival was measured using a cell-based ELISA method for expression of the neuronal marker MAP-2. Intracellular reactive oxygen species (ROS) production in macrophages was measured via 2', 7'-dichlorofluorescin diacetate (DCFH2DA) oxidation. Cytokine expression was determined by quantitative real-time PCR. Results LPS treatment of macrophages induced expression of proinflammatory cytokines (IL-1β, IL-6 and TNF-α) and of ROS. In contrast, BBI pretreatment (1-100 μg/ml) of macrophages significantly inhibited LPS-mediated induction of these cytokines and ROS. Further, supernatant from BBI-pretreated and LPS-activated macrophage cultures was found to be less cytotoxic to neurons than that from non-BBI-pretreated and LPS-activated macrophage cultures. BBI, when directly added to the neuronal cultures (1-100 μg/ml), had no protective effect on neurons with or without LPS-activated macrophage supernatant treatment. In addition, BBI (100 μg/ml) had no effect on N-methyl-D-aspartic acid (NMDA)-mediated neurotoxicity. Conclusions These findings demonstrate that BBI, through its anti-inflammatory properties, protects neurons from neurotoxicity mediated by activated macrophages.
Collapse
Affiliation(s)
- Jieliang Li
- Department of Pathology & Laboratory Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Pompili E, Fabrizi C, Nori SL, Panetta B, Geloso MC, Corvino V, Michetti F, Fumagalli L. Protease-activated receptor-1 expression in rat microglia after trimethyltin treatment. J Histochem Cytochem 2011; 59:302-11. [PMID: 21378284 DOI: 10.1369/0022155410397996] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In the nervous system, protease-activated receptors (PARs), which are activated by thrombin and other extracellular proteases, are expressed widely at both neuronal and glial levels and have been shown to be involved in several brain pathologies. As far as the glial receptors are concerned, previous experiments performed in rat hippocampus showed that expression of PAR-1, the prototypic member of the PAR family, increased in astrocytes both in vivo and in vitro following treatment with trimethyltin (TMT). TMT is an organotin compound that induces severe hippocampal neurodegeneration associated with astrocyte and microglia activation. In the present experiments, the authors extended their investigation to microglial cells. In particular, by 7 days following TMT intoxication in vivo, confocal immunofluorescence revealed an evident PAR-1-related specific immunoreactivity in OX-42-positive microglial cells of the CA3 and hilus hippocampal regions. In line with the in vivo results, when primary rat microglial cells were treated in vitro with TMT, a strong upregulation of PAR-1 was observed by immunocytochemistry and Western blot analysis. These data provide further evidence that PAR-1 may be involved in microglial response to brain damage.
Collapse
Affiliation(s)
- Elena Pompili
- Department of Human Anatomy, University of Rome "La Sapienza," Rome, Italy
| | | | | | | | | | | | | | | |
Collapse
|