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Teng YD, Zafonte RD. Prelude to the special issue on novel neurocircuit, cellular and molecular targets for developing functional rehabilitation therapies of neurotrauma. Exp Neurol 2021; 341:113689. [PMID: 33745921 DOI: 10.1016/j.expneurol.2021.113689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 03/07/2021] [Indexed: 11/15/2022]
Abstract
The poor endogenous recovery capacity and other impediments to reinstating sensorimotor or autonomic function after adult neurotrauma have perplexed modern neuroscientists, bioengineers, and physicians for over a century. However, despite limited improvement in options to mitigate acute pathophysiological sequalae, the past 20 years have witnessed marked progresses in developing efficacious rehabilitation strategies for chronic spinal cord and brain injuries. The achievement is mainly attributable to research advancements in elucidating neuroplastic mechanisms for the potential to enhance clinical prognosis. Innovative cross-disciplinary studies have established novel therapeutic targets, theoretical frameworks, and regiments to attain treatment efficacy. This Special Issue contained eight papers that described experimental and human data along with literature reviews regarding the essential roles of the conventionally undervalued factors in neural repair: systemic inflammation, neural-respiratory inflammasome axis, modulation of glutamatergic and monoaminergic neurotransmission, neurogenesis, nerve transfer, recovery neurobiology components, and the spinal cord learning, respiration and central pattern generator neurocircuits. The focus of this work was on how to induce functional recovery from manipulating these underpinnings through their interactions with secondary injury events, peripheral and supraspinal inputs, neuromusculoskeletal network, and interventions (i.e., activity training, pharmacological adjuncts, electrical stimulation, and multimodal neuromechanical, brain-computer interface [BCI] and robotic assistance [RA] devices). The evidence suggested that if key neurocircuits are therapeutically reactivated, rebuilt, and/or modulated under proper sensory feedback, neurological function (e.g., cognition, respiration, limb movement, locomotion, etc.) will likely be reanimated after neurotrauma. The efficacy can be optimized by individualizing multimodal rehabilitation treatments via BCI/RA-integrated drug administration and neuromechanical protheses.
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Affiliation(s)
- Yang D Teng
- Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, MA, USA; Neurotrauma Recovery Research, Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital Network, Mass General Brigham, and Harvard Medical School, Boston, MA, USA; Spaulding Research Institute, Spaulding Rehabilitation Hospital Network, Boston, MA, USA.
| | - Ross D Zafonte
- Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, MA, USA; Neurotrauma Recovery Research, Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital Network, Mass General Brigham, and Harvard Medical School, Boston, MA, USA; Spaulding Research Institute, Spaulding Rehabilitation Hospital Network, Boston, MA, USA.
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Protein Degradome of Spinal Cord Injury: Biomarkers and Potential Therapeutic Targets. Mol Neurobiol 2020; 57:2702-2726. [PMID: 32328876 DOI: 10.1007/s12035-020-01916-3] [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: 09/24/2019] [Accepted: 03/31/2020] [Indexed: 12/13/2022]
Abstract
Degradomics is a proteomics sub-discipline whose goal is to identify and characterize protease-substrate repertoires. With the aim of deciphering and characterizing key signature breakdown products, degradomics emerged to define encryptic biomarker neoproteins specific to certain disease processes. Remarkable improvements in structural and analytical experimental methodologies as evident in research investigating cellular behavior in neuroscience and cancer have allowed the identification of specific degradomes, increasing our knowledge about proteases and their regulators and substrates along with their implications in health and disease. A physiologic balance between protein synthesis and degradation is sought with the activation of proteolytic enzymes such as calpains, caspases, cathepsins, and matrix metalloproteinases. Proteolysis is essential for development, growth, and regeneration; however, inappropriate and uncontrolled activation of the proteolytic system renders the diseased tissue susceptible to further neurotoxic processes. In this article, we aim to review the protease-substrate repertoires as well as emerging therapeutic interventions in spinal cord injury at the degradomic level. Several protease substrates and their breakdown products, essential for the neuronal structural integrity and functional capacity, have been characterized in neurotrauma including cytoskeletal proteins, neuronal extracellular matrix glycoproteins, cell junction proteins, and ion channels. Therefore, targeting exaggerated protease activity provides a potentially effective therapeutic approach in the management of protease-mediated neurotoxicity in reducing the extent of damage secondary to spinal cord injury.
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Short-term inhibition of fibrinolytic system restores locomotor function after spinal cord injury in mice. Sci Rep 2019; 9:16024. [PMID: 31690812 PMCID: PMC6831600 DOI: 10.1038/s41598-019-52621-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 10/21/2019] [Indexed: 02/06/2023] Open
Abstract
Spinal cord injury (SCI) is caused by an initial mechanical insult followed by a series of deleterious events that promote the progressive damage of affected tissues. Fibrinolysis, the process by which plasmin degrades cross-linked fibrin clots, has numerous functions in the central nervous system. However, the roles of the fibrinolytic system in SCI pathophysiology remain unknown. We investigated the roles of fibrinolysis in SCI, and explored therapeutic applications targeting fibrinolysis. Plasminogen-deficient (Plg-/-) mice exhibited significantly improved locomotor function in the early phase of SCI (the first 7 days post injury), with significant inhibition of bleeding and vascular permeability, but failed to demonstrate conclusive functional recovery. Consistent with these findings, the short-term administration of tranexamic acid (TXA) in wild-type mice over the first 3 days post injury significantly improved locomotor function after SCI, whereas prolonged TXA administration did not. Prolonged TXA administration resulted in significantly lower levels of matrix metalloproteinase activities in the spinal cord, suggesting that inhibition of the fibrinolytic system impaired tissue remodeling. Our results indicate that the fibrinolytic system has time-dependent biphasic actions following SCI. The temporally optimised modulation of fibrinolytic activity may thus be a novel therapeutic strategy to improve functional outcomes after SCI.
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Van De Vijver S, Missault S, Van Soom J, Van Der Veken P, Augustyns K, Joossens J, Dedeurwaerdere S, Giugliano M. The effect of pharmacological inhibition of Serine Proteases on neuronal networks in vitro. PeerJ 2019; 7:e6796. [PMID: 31065460 PMCID: PMC6485206 DOI: 10.7717/peerj.6796] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 03/18/2019] [Indexed: 12/25/2022] Open
Abstract
Neurons are embedded in an extracellular matrix (ECM), which functions both as a scaffold and as a regulator of neuronal function. The ECM is in turn dynamically altered through the action of serine proteases, which break down its constituents. This pathway has been implicated in the regulation of synaptic plasticity and of neuronal intrinsic excitability. In this study, we determined the short-term effects of interfering with proteolytic processes in the ECM, with a newly developed serine protease inhibitor. We monitored the spontaneous electrophysiological activity of in vitro primary rat cortical cultures, using microelectrode arrays. While pharmacological inhibition at a low dosage had no significant effect, at elevated concentrations it altered significantly network synchronization and functional connectivity but left unaltered single-cell electrical properties. These results suggest that serine protease inhibition affects synaptic properties, likely through its actions on the ECM.
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Affiliation(s)
- Sebastiaan Van De Vijver
- Molecular, Cellular, and Network Excitability, Department of Biomedical Sciences and Institute Born-Bunge, University of Antwerp, Wilrijk, Flanders, Belgium
| | - Stephan Missault
- Experimental Laboratory of Translational Neuroscience and Otolaryngology, Department of Translational Neurosciences, University of Antwerp, Wilrijk, Flanders, Belgium
| | - Jeroen Van Soom
- Laboratory of Medicinal Chemistry, Department of Pharmaceutical Sciences, University of Antwerp, Wilrijk, Flanders, Belgium
| | - Pieter Van Der Veken
- Laboratory of Medicinal Chemistry, Department of Pharmaceutical Sciences, University of Antwerp, Wilrijk, Flanders, Belgium
| | - Koen Augustyns
- Laboratory of Medicinal Chemistry, Department of Pharmaceutical Sciences, University of Antwerp, Wilrijk, Flanders, Belgium
| | - Jurgen Joossens
- Laboratory of Medicinal Chemistry, Department of Pharmaceutical Sciences, University of Antwerp, Wilrijk, Flanders, Belgium
| | - Stefanie Dedeurwaerdere
- Laboratory of Experimental Haematology, VAXINFECTIO, University of Antwerp, Wilrijk, Flanders, Belgium
| | - Michele Giugliano
- Molecular, Cellular, and Network Excitability, Department of Biomedical Sciences and Institute Born-Bunge, University of Antwerp, Wilrijk, Flanders, Belgium
- Neuroscience sector, Scuola Internazionale Superiore di Studi Avanzati, Trieste, Italy
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5
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Leth JM, Mertens HDT, Leth-Espensen KZ, Jørgensen TJD, Ploug M. Did evolution create a flexible ligand-binding cavity in the urokinase receptor through deletion of a plesiotypic disulfide bond? J Biol Chem 2019; 294:7403-7418. [PMID: 30894413 DOI: 10.1074/jbc.ra119.007847] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 03/10/2019] [Indexed: 11/06/2022] Open
Abstract
The urokinase receptor (uPAR) is a founding member of a small protein family with multiple Ly6/uPAR (LU) domains. The motif defining these LU domains contains five plesiotypic disulfide bonds stabilizing its prototypical three-fingered fold having three protruding loops. Notwithstanding the detailed knowledge on structure-function relationships in uPAR, one puzzling enigma remains unexplored. Why does the first LU domain in uPAR (DI) lack one of its consensus disulfide bonds, when the absence of this particular disulfide bond impairs the correct folding of other single LU domain-containing proteins? Here, using a variety of contemporary biophysical methods, we found that reintroducing the two missing half-cystines in uPAR DI caused the spontaneous formation of the corresponding consensus 7-8 LU domain disulfide bond. Importantly, constraints due to this cross-link impaired (i) the binding of uPAR to its primary ligand urokinase and (ii) the flexible interdomain assembly of the three LU domains in uPAR. We conclude that the evolutionary deletion of this particular disulfide bond in uPAR DI may have enabled the assembly of a high-affinity urokinase-binding cavity involving all three LU domains in uPAR. Of note, an analogous neofunctionalization occurred in snake venom α-neurotoxins upon loss of another pair of the plesiotypic LU domain half-cystines. In summary, elimination of the 7-8 consensus disulfide bond in the first LU domain of uPAR did have significant functional and structural consequences.
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Affiliation(s)
- Julie M Leth
- From the Finsen Laboratory, Rigshospitalet, DK-2200 Copenhagen N, Denmark.,the Biotech Research and Innovation Centre (BRIC), University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Haydyn D T Mertens
- the European Molecular Biology Laboratory Hamburg, Notkestrasse 85, D-22607 Hamburg, Germany, and
| | - Katrine Zinck Leth-Espensen
- From the Finsen Laboratory, Rigshospitalet, DK-2200 Copenhagen N, Denmark.,the Biotech Research and Innovation Centre (BRIC), University of Copenhagen, DK-2200 Copenhagen N, Denmark.,the Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5320 Odense M, Denmark
| | - Thomas J D Jørgensen
- the Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5320 Odense M, Denmark
| | - Michael Ploug
- From the Finsen Laboratory, Rigshospitalet, DK-2200 Copenhagen N, Denmark, .,the Biotech Research and Innovation Centre (BRIC), University of Copenhagen, DK-2200 Copenhagen N, Denmark
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6
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Crivello M, O'Riordan SL, Woods I, Cannon S, Halang L, Coughlan KS, Hogg MC, Lewandowski SA, Prehn JHM. Pleiotropic activity of systemically delivered angiogenin in the SOD1 G93A mouse model. Neuropharmacology 2018; 133:503-511. [PMID: 29486168 DOI: 10.1016/j.neuropharm.2018.02.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 02/06/2018] [Accepted: 02/22/2018] [Indexed: 12/25/2022]
Abstract
Loss-of-function mutations in the angiogenin (ANG) gene have been identified in familial and sporadic ALS patients. Previous work from our group identified human ANG (huANG) to protect motoneurons in vitro, and provided proof-of-concept that daily intraperitoneal (i.p.) huANG injections post-symptom onset increased lifespan and delayed disease progression in SOD1G93A mice. huANG's mechanism of action remains less well understood. Here, we implemented a preclinical in vivo design to validate our previous results, provide pharmacokinetic and protein distribution data after systemic administration, and explore potential pleiotropic activities of huANG in vivo. SOD1G93A mice (n = 45) and non-transgenic controls (n = 31) were sex- age- and litter-matched according to the 2010 European ALS/MND group guidelines, and treated with huANG (1 μg, i.p., 3 times/week) or vehicle from 90 days on. huANG treatment increased survival and delayed motor dysfunction as assessed by rotarod in SOD1G93A mice. Increased huANG serum levels were detectable 2 and 24 h after i.p. injection equally in transgenic and non-transgenic mice. Exogenous huANG localized to spinal cord astrocytes, supporting a glia-mediated, paracrine mechanism of action; uptake into endothelial cells was also observed. 1 μg huANG or vehicle were administered from 90 to 115 days of age for histological analysis. Vehicle-treated SOD1G93A mice showed decreased motoneuron numbers and vascular length per ventral horn area, while huANG treatment resulted in improved vascular network maintenance and motoneuron survival. Our data suggest huANG represents a new class of pleiotropic ALS therapeutic that acts on the spinal cord vasculature and glia to delay motoneuron degeneration and disease progression.
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Affiliation(s)
- Martin Crivello
- Department of Physiology and Medical Physics, Centre for the Study of Neurological Disorders, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland.
| | - Saidhbhe L O'Riordan
- Department of Physiology and Medical Physics, Centre for the Study of Neurological Disorders, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland.
| | - Ina Woods
- Department of Physiology and Medical Physics, Centre for the Study of Neurological Disorders, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland.
| | - Sarah Cannon
- Department of Physiology and Medical Physics, Centre for the Study of Neurological Disorders, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland.
| | - Luise Halang
- Department of Physiology and Medical Physics, Centre for the Study of Neurological Disorders, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland.
| | - Karen S Coughlan
- Department of Physiology and Medical Physics, Centre for the Study of Neurological Disorders, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland.
| | - Marion C Hogg
- Department of Physiology and Medical Physics, Centre for the Study of Neurological Disorders, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland.
| | - Sebastian A Lewandowski
- Tissue Biology Laboratory, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Scheeles v. 2, 17177, Stockholm, Sweden.
| | - Jochen H M Prehn
- Department of Physiology and Medical Physics, Centre for the Study of Neurological Disorders, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland.
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7
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Missault S, Peeters L, Amhaoul H, Thomae D, Van Eetveldt A, Favier B, Thakur A, Van Soom J, Pitkänen A, Augustyns K, Joossens J, Staelens S, Dedeurwaerdere S. Decreased levels of active uPA and KLK8 assessed by [111In]MICA-401 binding correlate with the seizure burden in an animal model of temporal lobe epilepsy. Epilepsia 2017; 58:1615-1625. [DOI: 10.1111/epi.13845] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2017] [Indexed: 01/02/2023]
Affiliation(s)
- Stephan Missault
- Experimental Laboratory of Translational Neuroscience and Otolaryngology; Faculty of Medicine and Health Sciences; University of Antwerp; Wilrijk Belgium
| | - Lore Peeters
- Experimental Laboratory of Translational Neuroscience and Otolaryngology; Faculty of Medicine and Health Sciences; University of Antwerp; Wilrijk Belgium
- Bio-Imaging Lab; Faculty of Pharmaceutical, Biomedical and Veterinary Sciences; University of Antwerp; Wilrijk Belgium
| | - Halima Amhaoul
- Experimental Laboratory of Translational Neuroscience and Otolaryngology; Faculty of Medicine and Health Sciences; University of Antwerp; Wilrijk Belgium
| | - David Thomae
- Molecular Imaging Center Antwerp; Faculty of Medicine and Health Sciences; University of Antwerp; Wilrijk Belgium
- Laboratory of Medicinal Chemistry; Faculty of Pharmaceutical, Biomedical and Veterinary Sciences; University of Antwerp; Wilrijk Belgium
| | - Annemie Van Eetveldt
- Experimental Laboratory of Translational Neuroscience and Otolaryngology; Faculty of Medicine and Health Sciences; University of Antwerp; Wilrijk Belgium
| | - Barbara Favier
- Experimental Laboratory of Translational Neuroscience and Otolaryngology; Faculty of Medicine and Health Sciences; University of Antwerp; Wilrijk Belgium
| | - Anagha Thakur
- Experimental Laboratory of Translational Neuroscience and Otolaryngology; Faculty of Medicine and Health Sciences; University of Antwerp; Wilrijk Belgium
| | - Jeroen Van Soom
- Laboratory of Medicinal Chemistry; Faculty of Pharmaceutical, Biomedical and Veterinary Sciences; University of Antwerp; Wilrijk Belgium
| | - Asla Pitkänen
- Department of Neurobiology; A.I. Virtanen Institute for Molecular Sciences; University of Eastern Finland; Kuopio Finland
| | - Koen Augustyns
- Laboratory of Medicinal Chemistry; Faculty of Pharmaceutical, Biomedical and Veterinary Sciences; University of Antwerp; Wilrijk Belgium
| | - Jurgen Joossens
- Laboratory of Medicinal Chemistry; Faculty of Pharmaceutical, Biomedical and Veterinary Sciences; University of Antwerp; Wilrijk Belgium
| | - Steven Staelens
- Molecular Imaging Center Antwerp; Faculty of Medicine and Health Sciences; University of Antwerp; Wilrijk Belgium
| | - Stefanie Dedeurwaerdere
- Experimental Laboratory of Translational Neuroscience and Otolaryngology; Faculty of Medicine and Health Sciences; University of Antwerp; Wilrijk Belgium
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8
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Stabilizing a Flexible Interdomain Hinge Region Harboring the SMB Binding Site Drives uPAR into Its Closed Conformation. J Mol Biol 2015; 427:1389-1403. [DOI: 10.1016/j.jmb.2015.01.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 01/02/2015] [Accepted: 01/27/2015] [Indexed: 01/04/2023]
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Mantilla CB, Greising SM, Stowe JM, Zhan WZ, Sieck GC. TrkB kinase activity is critical for recovery of respiratory function after cervical spinal cord hemisection. Exp Neurol 2014; 261:190-5. [PMID: 24910201 DOI: 10.1016/j.expneurol.2014.05.027] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 05/27/2014] [Accepted: 05/30/2014] [Indexed: 01/24/2023]
Abstract
Neuroplasticity following spinal cord injury contributes to spontaneous recovery over time. Recent studies highlight the important role of brain-derived neurotrophic factor (BDNF) signaling via the high-affinity tropomyosin-related kinase (Trk) receptor subtype B (TrkB) in recovery of rhythmic diaphragm activity following unilateral spinal hemisection at C2 (C2SH). We hypothesized that TrkB kinase activity is necessary for spontaneous recovery of diaphragm activity post-C2SH. A chemical-genetic approach employing adult male TrkB(F616A) mice (n=49) was used to determine the impact of inhibiting TrkB kinase activity by the phosphoprotein phosphatase 1 inhibitor derivative 1NMPP1 on recovery of ipsilateral hemidiaphragm EMG activity. In mice, C2SH was localized primarily to white matter tracts comprising the lateral funiculus. The extent of damaged spinal cord (~27%) was similar regardless of the presence of functional recovery, consistent with spontaneous recovery reflecting neuroplasticity primarily of contralateral spared descending pathways to the phrenic motor pools. Ipsilateral hemidiaphragm EMG activity was verified as absent in all mice at 3days post-C2SH. By 2weeks after C2SH, ipsilateral hemidiaphragm EMG activity was present in 39% of vehicle-treated mice compared to 7% of 1NMPP1-treated mice (P=0.03). These data support the hypothesis that BDNF/TrkB signaling involving TrkB kinase activity plays a critical role in spontaneous recovery of diaphragm activity following cervical spinal cord injury.
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Affiliation(s)
- Carlos B Mantilla
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905, USA; Department of Anesthesiology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
| | - Sarah M Greising
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - Jessica M Stowe
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - Wen-Zhi Zhan
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - Gary C Sieck
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905, USA; Department of Anesthesiology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
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10
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Angiogenin induces modifications in the astrocyte secretome: Relevance to amyotrophic lateral sclerosis. J Proteomics 2013; 91:274-85. [DOI: 10.1016/j.jprot.2013.07.028] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 07/18/2013] [Accepted: 07/26/2013] [Indexed: 11/19/2022]
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Almholt K, Juncker-Jensen A, Lærum OD, Johnsen M, Rømer J, Lund LR. Spontaneous metastasis in congenic mice with transgenic breast cancer is unaffected by plasminogen gene ablation. Clin Exp Metastasis 2012; 30:277-88. [PMID: 22996753 DOI: 10.1007/s10585-012-9534-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 09/12/2012] [Indexed: 11/25/2022]
Abstract
Plasminogen (Plg) plays a central role in tissue remodeling during ontogeny, development, and in pathological tissue remodeling following physical injury, inflammation and cancer. Plg/plasmin is, however, not critical for these processes, as they all occur to a varying extent in its absence, suggesting that there is a functional redundancy with other proteases. To explore this functional overlap in the transgenic MMTV-PyMT breast cancer metastasis model, we have combined Plg deficiency and a pharmacological metalloprotease inhibitor, which is known to reduce metastasis in this model, and has been shown to synergistically inhibit other tissue remodeling events in Plg-deficient mice. While metalloprotease inhibition dramatically reduced metastasis, we found no effect of Plg deficiency on metastasis, either independently or in combination with metalloprotease inhibition. We further show that Plg gene deficiency is of no significant consequence in this metastasis model, when analyzed in two different congenic strains: the FVB strain, and a F1 hybrid of the FVB and C57BL/6J strains. We suggest that the extensive backcrossing performed prior to our studies has eliminated the confounding effect of a known polymorphic metastasis modifier gene region located adjacent to the Plg gene.
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Affiliation(s)
- Kasper Almholt
- Finsen Laboratory, Rigshospitalet, Copenhagen Biocenter, Copenhagen, Denmark.
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12
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Veeravalli KK, Dasari VR, Rao JS. Regulation of proteases after spinal cord injury. J Neurotrauma 2012; 29:2251-62. [PMID: 22709139 DOI: 10.1089/neu.2012.2460] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Spinal cord injury is a major medical problem worldwide. Unfortunately, we still do not have suitable therapeutic agents for the treatment of spinal cord injury and prevention of its devastating consequences. Scientists and physicians are baffled by the challenges of controlling progressive neurodegeneration in spinal cord injury, which has not been healed with any currently-available treatments. Although extensive work has been carried out to better understand the pathophysiology of spinal cord injury, our current understanding of the repair mechanisms of secondary injury processes is still meager. Several investigators reported the crucial role played by various proteases after spinal cord injury. Understanding the beneficial and harmful roles these proteases play after spinal cord injury will allow scientists to plan and design appropriate treatment strategies to improve functional recovery after spinal cord injury. This review will focus on various proteases such as matrix metalloproteinases, cysteine proteases, and serine proteases and their inhibitors in the context of spinal cord injury.
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Affiliation(s)
- Krishna Kumar Veeravalli
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, Illinois 61605, USA
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13
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Gårdsvoll H, Kjaergaard M, Jacobsen B, Kriegbaum MC, Huang M, Ploug M. Mimicry of the regulatory role of urokinase in lamellipodia formation by introduction of a non-native interdomain disulfide bond in its receptor. J Biol Chem 2011; 286:43515-26. [PMID: 22025616 DOI: 10.1074/jbc.m111.300020] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The high-affinity interaction between the urokinase-type plasminogen activator (uPA) and its glycolipid-anchored receptor (uPAR) plays a regulatory role for both extravascular fibrinolysis and uPAR-mediated adhesion and migration on vitronectin-coated surfaces. We have recently proposed that the adhesive function of uPAR is allosterically regulated via a "tightening" of its three-domain structure elicited by uPA binding. To challenge this proposition, we redesigned the uPAR structure to limit its inherent conformational flexibility by covalently tethering domains DI and DIII via a non-natural interdomain disulfide bond (uPAR(H47C-N259C)). The corresponding soluble receptor has 1) a smaller hydrodynamic volume, 2) a higher content of secondary structure, and 3) unaltered binding kinetics towards uPA. Most importantly, the purified uPAR(H47C-N259C) also displays a gain in affinity for the somatomedin B domain of vitronectin compared with uPAR(wt), thus recapitulating the improved affinity that accompanies uPA-uPAR(wt) complex formation. This functional mimicry is, intriguingly, operational also in a cellular setting, where it controls lamellipodia formation in uPAR-transfected HEK293 cells adhering to vitronectin. In this respect, the engineered constraint in uPAR(H47C-N259C) thus bypasses the regulatory role of uPA binding, resulting in a constitutively active uPAR. In conclusion, our data argue for a biological relevance of the interdomain dynamics of the glycolipid-anchored uPAR on the cell surface.
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Affiliation(s)
- Henrik Gårdsvoll
- Finsen Laboratory, Rigshospitalet & Biotech Research and Innovation Centre, Copenhagen Biocenter, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
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