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Suo Z, Citron BA, Ameenuddin S, Andrade-Gordon P, Festoff BW. Protease-activated receptors (PARs), microglial reactivity and neurodegeneration. J Neurochem 2008. [DOI: 10.1046/j.1471-4159.81.s1.113.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Citron BA, Suo Z, Ameenuddin S, Davis JT, Festoff BW. Colloquium 15: Role of the Protease-Activated Receptors in Neural Development, Degeneration and Trauma. J Neurochem 2008. [DOI: 10.1046/j.1471-4159.81.s1.111.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Festoff BW, Wu M, Wong A, Citron BA, Suo Z. Selective neuronal vulnerability, protease-activated receptors (PARS) and thrombin signalling. J Neurochem 2008. [DOI: 10.1046/j.1471-4159.81.s1.116.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Farooque M, Suo Z, Arnold PM, Wulser MJ, Chou CT, Vancura RW, Fowler S, Festoff BW. Gender-related differences in recovery of locomotor function after spinal cord injury in mice. Spinal Cord 2006; 44:182-7. [PMID: 16130019 DOI: 10.1038/sj.sc.3101816] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
STUDY DESIGN In order to study the role of gender in recovery, we induced a thoracic compression spinal cord injury (SCI) separately in 2-month-old male and female C57Bl/6 mice. OBJECTIVES We intended to assess effects of gender on recovery of hindlimb motor function and to correlate these with histomorphologic profiles of injured spinal cord tissue. METHODS Locomotor function was evaluated by three means: a modified locomotor scoring system for rodents, beam walking and computerized activity meter. Histology was analyzed by comparison of hematoxylin and eosin-stained perfused specimens. RESULTS Locomotor scores were 2.2+/-0.9 on day 1 in male mice, while, in contrast, they were significantly higher, 7.3+/-1.7, in females (P<0.02). On day 14 Basso, Beattie and Bresnahan scores were 9.5+/-2.2 in male mice and 16.0+/-2.2 in females (P<0.03). Terminal histology showed that the spinal cord architecture was relatively better preserved in female mice and that the extent of necrosis and infiltration of inflammatory cells was less compared to males. SETTING Neurobiology Research Laboratory of University of Kansas Medical School in US Department of Veterans Affairs Medical Center, Kansas City, Missouri. CONCLUSION We found that the severity of the initial injury as well as the ultimate recovery of motor function after SCI is significantly influenced by gender, being remarkably better in females. The mechanism(s) of neuroprotection in females, although not yet elucidated, may be associated with the effects of estrogen on pathophysiological processes (blood flow, leukocyte migration inhibition, antioxidant properties, and inhibition of apoptosis). SPONSORSHIP Medical Research, US Department of Veterans Affairs, the Christopher Reeve Paralysis Foundation and NIH.
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Affiliation(s)
- M Farooque
- Neurobiology Research Laboratory, Department of Veterans Affairs Medical Center, Kansas City, MO 64128, USA
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Abstract
This review details the general physiology, biochemistry and molecular biology of insulin-like growth factor I (IGF-I), a pleiotropic factor, and the only one to date showing beneficial effects in a prototypic neurodegenerative disease, amyotrophic lateral sclerosis (ALS). The preclinical rationale for IGF-I use in treating patients with ALS stems from the fact that this molecule has endocrine, paracrine and autocrine effects on cells and acts through a receptor tyrosine kinase that is structurally and functionally similar to the insulin receptor. What has come to be known as the IGF signaling system is reviewed within the context of differences as well as similarities of IGF-I's actions within the peripheral and central nervous systems compared with other tissues. This signaling pathway is complex, involving several cell surface receptors, circulating and bound binding proteins and specific proteases that recognize and cleave individual binding proteins that serves to finely adjust the cellular responses to IGF-I. In order to explain why this trophic factor, unlike ciliary neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF), was found to have efficacy in large-scale clinical trials in ALS patients, evidence is offered that IGF-I affects all components of the motor unit: spinal cord motor neuron, axon, neuromuscular synapse and muscle fiber. A model is presented that shows life and death signals on motor neurons, with the serine protease, thrombin, representing an extracellular death signal and IGF-I, a potent life signal, on such cells.
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Affiliation(s)
- B W Festoff
- Neurobiology Research Laboratory, Kansas City Veterans Affairs Medical Center, Kansas City, Missouri 64128, USA
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Abstract
Thrombin is well known in its function as the ultimate serine protease in the coagulation cascade. Emerging evidence indicates that thrombin also functions as a potent signaling molecule that regulates physiologic and pathogenic responses alike in a large variety of cell populations and tissues. Accompanying CNS injury and other cerebral vascular damages, prothrombin activation and leakage of active thrombin into CNS parenchyma has been documented. Due to the irreplaceable feature of neurons, over-reactive inflammatory reactions in the CNS often cause irreversible neuronal damage. Therefore, particular attention is required to develop strategies that restrict CNS inflammatory responses to beneficial, in contrast to neurotoxic ones. In this regard, thrombin not only activates endothelial cells and induces leukocyte infiltration and edema but also activates astrocytes, and particularly microglia, as recently demonstrated, to propagate the focal inflammation and produce potential neurotoxic effects. Recently revealed molecular mechanisms underlying these thrombin effects appear to involve proteolytic activation of two different thrombin-responsive, protease-activated receptors (PARs), PAR1 and PAR4, possibly in concert. Potential therapeutic strategies based on appreciation of the current understanding of molecular mechanisms underlying thrombin-induced CNS inflammation are also discussed.
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Affiliation(s)
- Z Suo
- Laboratory for Alzheimer's Disease & Aging Research, Veterans Affairs Medical Center, Kansas City, Missouri and Department of Neurology, University of Kansas Medical School, Kansas City, Kansas, USA.
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Festoff BW, Suo Z, Citron BA. Plasticity and stabilization of neuromuscular and CNS synapses: interactions between thrombin protease signaling pathways and tissue transglutaminase. Int Rev Cytol 2002; 211:153-77. [PMID: 11597003 DOI: 10.1016/s0074-7696(01)11018-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The first association of the synapse as a potential site of neurodegenerative disease burden was suggested for Alzheimer's disease (AD) almost 30 years ago. Since then protease:protease inhibitor (P:PI) systems were first linked to functional regulation of synaptogenesis and synapse withdrawal at the neuromuscular junction (NMJ) more than 20 years ago. Confirmatory evidence for the involvement of the synapse, the rate-limiting or key unit in neural function, in AD did not become clear until the beginning of the 1990s. However, over the past 15 years evidence for participation of thrombin, related serine proteases and neural PIs, homologous and even identical to those of the plasma clot cascade, has been mounting. Throughout development a balance between stabilization forces, on the one hand, and breakdown influences, on the other, becomes established at synaptic junctions, just as it does in plasma clot proteins. The formation of protease-resistant cross-links by the transglutaminase (TGase) family of enzymes may add to the stability for this balance. The TGase family includes coagulation factor XIIIA and 8 other different genes, some of which may also influence the persistence of neural connections. Synaptic location of protease-activated, G-protein-coupled receptors (PARs) for thrombin and related proteases, their serpin and Kunitz-type PIs such as protease nexin I (PNI), alpha1-antichymotrypsin (alpha-ACT), and the Kunitz protease inhibitor (KPI)-containing secreted forms of beta-amyloid protein precursor (beta-APP), along with the TGases and their putative substrates, have all been amply documented. These findings strongly add to the conclusion that these molecules participate in the eventual structural stability of synaptic connections, as they do in coagulation cascades, and focus trophic activity on surviving terminals during periods of selective contact elimination. In disease states, this imbalance is likely to be shifted in favor of destabilizing forces: increased and/or altered protease activity, enhanced PAR influence, decreased and/or altered protease inhibitor function, reduction and/or alteration in tTG expression and activity, and alteration in its substrate profile. This imbalance further initiates a cascade of events leading to inappropriate programmed cell death and may well be considered evidence of synaptic apoptosis.
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Affiliation(s)
- B W Festoff
- Neurobiology Research Laboratory, University of Kansas Medical Center, Kansas City Veterans Affairs Medical Center, Missouri 64128, USA
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Smirnova IV, Citron BA, Arnold PM, Festoff BW. Neuroprotective signal transduction in model motor neurons exposed to thrombin: G-protein modulation effects on neurite outgrowth, Ca(2+) mobilization, and apoptosis. ACTA ACUST UNITED AC 2001. [PMID: 11438939 DOI: 10.1002/neu.1044] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Thrombin, the ultimate protease in the blood coagulation cascade, mediates its known cellular effects by unique proteolytic activation of G-protein-coupled protease-activated receptors (PARs), such as PAR1, PAR3, and PAR4, and a "tethered ligand" mechanism. PAR1 is variably expressed in subpopulations of neurons and largely determines thrombin's effects on morphology, calcium mobilization, and caspase-mediated apoptosis. In spinal cord motoneurons, PAR1 expression correlates with transient thrombin-mediated [Ca(2+)](i) flux, receptor cleavage, and elevation of rest [Ca(2+)](i) activating intracellular proteases. At nanomolar concentrations, thrombin retracts neurites via PAR1 activation of the monomeric, 21 kDa Ras G-protein RhoA, which is also involved in neuroprotection at lower thrombin concentrations. Such results suggest potential downstream targets for thrombin's injurious effects. Consequently, we employed several G-protein-specific modulators prior to thrombin exposure in an attempt to uncouple both heterotrimeric and monomeric G-proteins from motoneuronal PAR1. Cholera toxin, stimulating Gs, and lovastatin, which blocks isoprenylation of Rho, reduced thrombin-induced calcium mobilization. In contrast, pertussis toxin and mastoparan, inhibiting or stimulating G(o)/G(i), were found to exacerbate thrombin action. Effects on neuronal rounding and apoptosis were also detected, suggesting therapeutic utility may result from interference with downstream components of thrombin signaling pathways in human motor neuron disorders, and possibly other neurodegenerative diseases. Published 2001 John Wiley & Sons, Inc.
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Affiliation(s)
- I V Smirnova
- Neurobiology Research Laboratory, Department of Veterans Affairs Heartland Network, Kansas City, Missouri 64128, USA
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Citron BA, SantaCruz KS, Davies PJ, Festoff BW. Intron-exon swapping of transglutaminase mRNA and neuronal Tau aggregation in Alzheimer's disease. J Biol Chem 2001; 276:3295-301. [PMID: 11013236 DOI: 10.1074/jbc.m004776200] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In order to understand the mechanism for insoluble neurotoxic protein polymerization in Alzheimer's disease (AD) brain neurons, we examined protein and gene expression for transglutaminase (TGase 2; tissue transglutaminase (tTG)) in hippocampus and isocortex. We found co-localization of tTG protein and activity with tau-positive neurofibrillary tangles, whereas mRNA and sequence analysis indicated an absolute increase in tTG synthesized. Although apoptosis in AD hippocampus is now an established mode of neuronal cell death, no definite underlying mechanism(s) is known. Since TGase-mediated protein aggregation is implicated in polyglutamine ((CAG)(n)/Q(n) expansion) disorder apoptosis, and expanded Q(n) repeats are excellent TGase substrates, a role for TGase in AD is possible. However, despite such suggestions almost 20 years ago, the molecular mechanism remained elusive. We now present one possible molecular mechanism for tTG-mediated, neurotoxic protein polymerization leading to neuronal apoptosis in AD that involves not its substrates (like Q(n) repeats) but rather the unique presence of alternative transcripts of tTG mRNA. In addition to a full-length (L) isoform in aged non-demented brains, we found a short isoform (S) lacking a binding domain in all AD brains. Our current results identify intron-exon "switching" between L and S isoforms, implicating G-protein-coupled signaling pathways associated with tTG that may help to determine the dual roles of this enzyme in neuronal life and death processes.
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Affiliation(s)
- B A Citron
- Neurobiology Research Lab, Heartland Veterans Integrated Service Network, Kansas City, Missouri 64128, USA
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Citron BA, Arnold PM, Sebastian C, Qin F, Malladi S, Ameenuddin S, Landis ME, Festoff BW. Rapid upregulation of caspase-3 in rat spinal cord after injury: mRNA, protein, and cellular localization correlates with apoptotic cell death. Exp Neurol 2000; 166:213-26. [PMID: 11085887 DOI: 10.1006/exnr.2000.7523] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although the precise mechanisms explaining loss of, and failure to regain, function after spinal cord injury are unknown, there is increasing interest in the role of "secondary cell death." One prevalent theme in cell loss in other regions of the CNS involves apoptosis executed by the intracellular caspase proteases. A recent study demonstrated that spinal cord injury rapidly increased the activation of caspase-3. Our previous studies demonstrated peak apoptosis in three of four cellular compartments 3 days after controlled contusion in the rat. We have extended these analyses to include enzyme and substrate studies of caspase subfamilies both in rostral and in caudal adjacent segments compared to the lesion site. Although presumed activation of programmed proenzyme is considered the mechanism for enhanced caspases, our novel analyses were designed to detect upregulation of gene expression. We surveyed traumatically injured spinal cord for caspase family messages with a modified differential mRNA display approach and found that the caspase-3 (CASP3) message was present and upregulated severalfold after injury. Our results clearly demonstrate that cell death in the spinal cord occurs after posttranslational activation of caspases that follow, at least for caspase-3, initial upregulation of CASP3 mRNA levels.
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Affiliation(s)
- B A Citron
- Neurobiology Research Laboratory, Department of Veterans Affairs Medical Center, Kansas City, Missouri, 64128, USA
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Citron BA, Smirnova IV, Arnold PM, Festoff BW. Upregulation of neurotoxic serine proteases, prothrombin, and protease-activated receptor 1 early after spinal cord injury. J Neurotrauma 2000; 17:1191-203. [PMID: 11186232 DOI: 10.1089/neu.2000.17.1191] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Apoptosis, well-established in development and now also in degenerative disease, occurs with regularity in several cell compartments early after controlled contusion spinal cord injury (SCI). Cell death in astrocytic, microglial, and neuronal populations peaks at 3 days, while oligodendroglial apoptosis is found 10-14 days later. In this regard, the executioners of apoptosis, the caspase proteases, are also activated within 3 days of SCI. On the other hand, serine proteases, which have been shown to initiate apoptosis and activate caspases in culture models, have not been extensively studied in regards to nervous system trauma. As part of an ongoing effort to examine the spectrum of genes that are up- and downregulated in the injured rat spinal cord, we synthesized serine protease family specific primers to take advantage of conserved residues in the charge relay system and the codon preferences of these mammalian genes. These primers were then employed in a modified, family-specific differential mRNA display technique. One specific serine protease gene we found that was upregulated after injury was prothrombin. Qualitative and quantitative RT-PCR techniques indicated that this increase occurred early, already evident at 8 h after injury, and reached a maximum level fourfold above baseline at 24 h. Peak expression for prothrombin mRNA occurred prior to peak levels of apoptosis in astrocytic, microglial and neuronal compartments at 72 h. Of additional interest, gene database mining revealed that prothrombin shared approximately 48% similarity with myelencephalon-specific protease (MSP), a neurotoxic serine protease previously found to be increased two- to threefold at 3 days after excitotoxic SCI. Since thrombin induces apoptosis in murine and chick motor and rat hippocampal neurons by activating a member of the novel protease-activated receptor (PAR) gene family known as PAR-1, we also analyzed PAR-1 by similar techniques and found that it, too, was upregulated after SCI with the same kinetics as prothrombin. We confirmed these results with gene array analyses that revealed more than one trypsin subfamily serine protease was activated by SCI. They imply the possibility of using specific, tissue-directed serine protease inhibition at translational or transcriptional levels, and offer a potential paradigm shift in drug discovery for SCI to limit the extent of apoptosis, and consequent functional loss, in the human spinal cord.
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Affiliation(s)
- B A Citron
- Neurobiology Research Laboratory, Heartland Veterans Integrated Service Network, VA Medical Center, Kansas City, Missouri 64128, USA
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Citron BA, Gregory EJ, Steigerwalt DS, Qin F, Festoff BW. Regulation of the dual function tissue transglutaminase/Galpha(h) during murine neuromuscular development: gene and enzyme isoform expression. Neurochem Int 2000; 37:337-49. [PMID: 10825574 DOI: 10.1016/s0197-0186(00)00044-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Coagulation Factor XIII (F. VIII), a member of the transglutaminase (TGase) superfamily, is activated by thrombin, cross-links fibrin and stabilizes clots. Another member of this family, tissue TGase (tTG), having similar enzymatic activity, is implicated in neural development and synapse stabilization. Our previous studies indicated that synapse formation and maintenance at the neuromuscular junction (NMJ) involved components of the coagulation cascade in development. Others then showed that either F. XIII or tTG were localized at NMJs in a developmentally-regulated fashion. In the current studies, we addressed the temporal course of skeletal muscle tTG gene expression and found maximal expression at birth and continuing into the immediate postnatal period. Subcellular fractionation revealed a relatively constant particulate isoform of TGase activity which predominated in early embryonic muscle development. In contrast, cytosolic TGase specific activity became the major isoform in the postnatal period. The timing of muscle TGase activity correlated well with expression of tTG mRNA and we now present novel data of Tgm 2 gene expression for tTG in skeletal muscle. Confirming and extending the previous studies, TGase becomes localized at NMJs in the early, further ramifying in the late, neonatal period. These data suggest that the early pulse of particulate activity could coincide with the period of myoblast cell death in embryonic muscle. On the other hand, the peak cytosolic TGase activity occurs in the neonatal period, correlating temporally with muscle prothrombin expression during activity-dependent synapse elimination and possibly the source of the enzyme localized to the NMJ extracellular matrix resulting in synaptic stabilization.
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Affiliation(s)
- B A Citron
- Neurobiology Research Lab, Heartland Veterans Health Network, VA Medical Center, Kansas City, MO 64123, USA
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Arnold PM, Ma JY, Citron BA, Zoubine MN, Festoff BW. Selective developmental regulation of gene expression for insulin-like growth factor-binding proteins in mouse spinal cord. Spine (Phila Pa 1976) 2000; 25:1765-70. [PMID: 10888943 DOI: 10.1097/00007632-200007150-00005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Prospective, randomized experimental study in mice. STUDY OBJECTIVE To determine whether insulin-like growth factor binding proteins (IGFBPs) are present in mouse spinal cord and, if so, what role they play in its development. SUMMARY OF BACKGROUND DATA Insulin-like growth factors are well recognized hormonal effectors of growth hormone and are expressed in the mammalian spinal cord. The IGFBPs are a group of six genetically distinct proteins that bind IGFs and modulate their bioactivity. They appear in the brain during development, localize to the neuromuscular junction, and promote motor neuron survival. The benefit of IGF-I in amyotrophic lateral sclerosis ALS and its potential use in preventing motor neuron apoptosis in spinal cord injury dictates that studies of the presence and response of IGFBPs in that tissue be performed. METHODS The IGFBPs in mouse spinal cord were analyzed by Western ligand blot, Western immunoblot, and reverse transcription-polymerase chain reaction at various time points from embryonic day 14 to postnatal day 30. RESULTS Three IGFBPs with molecular masses of 24, 28, and 32 kDa were found, the latter two being the most prominent. The data indicate that these are IGFBP-4, -5, and -2. CONCLUSION Both IGFBP-2 and BP-5 are developmentally regulated in mouse spinal cord, with higher levels of those at early embryonic stages indicating their potential role in development of the mouse spinal cord.
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Affiliation(s)
- P M Arnold
- Neurobiology Research and Spinal Cord Research Laboratories, Department of Veterans Affairs Medical Center, Kansas City, Missouri, USA.
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Festoff BW, D'Andrea MR, Citron BA, Salcedo RM, Smirnova IV, Andrade-Gordon P. Motor neuron cell death in wobbler mutant mice follows overexpression of the G-protein-coupled, protease-activated receptor for thrombin. Mol Med 2000; 6:410-29. [PMID: 10952021 PMCID: PMC1949954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
BACKGROUND Mechanisms underlying neurodegeneration are actively sought for new therapeutic strategies. Transgenic, knockout and genetic mouse models greatly aid our understanding of the mechanisms for neuronal cell death. A naturally occurring, autosomal recessive mutant, known as wobbler, and mice transgenic for familial amyotrophic lateral sclerosis (FALS) superoxide dismutase (SOD)1 mutations are available, but the molecular mechanisms remain equally unknown. Both phenotypes are detectable after birth. Wobbler is detectable in the third week of life, when homozygotes (wr/wr) exhibit prominent gliosis and significant motor neuron loss in the cervical, but not in lumbar, spinal cord segments. To address molecular mechanisms, we evaluated "death signals" associated with the multifunctional serine protease, thrombin, which leads to apoptotic motor neuronal cell death in culture by cleavage of a G-protein coupled, protease-activated receptor 1 (PAR-1). MATERIALS AND METHODS Thrombin activities were determined with chromogenic substrate assays, Western immunoblots and immunohistochemistry were performed with anti-PAR-1 to observe localizations of the receptor and anti-GFAP staining was used to monitor astrocytosis. PAR-1 mRNA levels and locations were determined by reverse transcription polymerase chain reaction (qRT-PCR) and in situ hybridizations. Cell death was monitored with in situ DNA fragmentation assays. RESULTS In preliminary studies we found a 5-fold increase in PAR-1 mRNA in cervical spinal cords from wr/wr, compared with wild-type (wt) littermates. Our current studies suggested that reactive astrocytosis and motor neuron cell death were causally linked with alterations in thrombin signaling. PAR-1 protein expression was increased, as demonstrated by immunocytochemistry and confirmed with in situ hybridization, in phenotypic wr/wr motor neurons, compared with wt, but not in astrocytes. This increase was much greater in cervical, compared with lumbar, segments, paralleling motor neuron degeneration. We also found, using reverse transcription polymerase chain reaction (qRT-PCR) with RNA from genotyped embryos, that PAR-1 was already increased in wr/wr cords at E12, the earliest time examined. CONCLUSIONS Thus, motor neuron degeneration and death follows PAR-1 expression both temporally and topographically in wobbler mice. Since our culture studies show that thrombin mobilized [Ca2+]i by activating PAR-1, eventually leading to motor neuron apoptosis, up-regulation of PAR-1 during development may contribute both to "appropriate" as well as "inappropriate" neuronal death in wobbler.
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Affiliation(s)
- B W Festoff
- Department of Veterans Affairs Medical Center, Kansas City, Missouri 64128, USA.
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Akaaboune M, Allinquant B, Farza H, Roy K, Magoul R, Fiszman M, Festoff BW, Hantaï D. Developmental regulation of amyloid precursor protein at the neuromuscular junction in mouse skeletal muscle. Mol Cell Neurosci 2000; 15:355-67. [PMID: 10845772 DOI: 10.1006/mcne.2000.0834] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Amyloid precursor protein (APP), associated with Alzheimer's disease plaques, is known to be present in synapses of the brain and in the adult neuromuscular junction (NMJ). In the present study we examined protein and gene expression of APP during the development of mouse skeletal muscle. Using immunocytochemical approaches, we found that APP is first detected in myotube cytoplasm at embryonic day 16 and becomes progressively concentrated at the NMJ beginning at birth until adulthood. The colocalization between APP and acetylcholine receptors at the NMJ is only partial at birth, but becomes complete upon reaching adulthood. We observed that all APP isoforms, including the Kunitz-containing (protease inhibitor or KPI) forms, are up-regulated from birth to postnatal day 5 and then decreased to reach the low levels observed in the adult. This suggests the involvement of APP during the events which lead to a mature mono-innervated synapse. A 92-kDa band, characteristic of a cleaved APP695 isoform and not due to a new muscle-specific alternative spliced form, was observed from postnatal day 15 following completion of polyneuronal synapse elimination. Taken together, these data suggest that skeletal muscle APP may well play a role in the differentiation of skeletal muscle and in the formation and maturation of NMJs.
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Affiliation(s)
- M Akaaboune
- INSERM Unité 523, Institut de Myologie, Paris, France
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Arnold PM, Ma JY, Citron BA, Festoff BW. Insulin-like growth factor binding proteins in cerebrospinal fluid during human development and aging. Biochem Biophys Res Commun 1999; 264:652-6. [PMID: 10543987 DOI: 10.1006/bbrc.1999.1555] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We analyzed samples of insulin-like growth factor binding proteins (IGFBPs) in human cerebrospinal fluid (CSF) in neurologically normal patients from one day after birth to age 76 years. CSF samples were separated on SDS-PAGE and then transferred to nitrocellulose membranes where IGFBPs were detected by Western ligand blot using [(125)I]-IGF-II, confirming other reports where we found the presence of IGFBP-2, 3, 4, 5. The 34 kDa IGFBP-2 was present in all samples, and progressively decreased with age. A broad 28- to 30-kDa IGFBP band, having the appearance of IGFBP-5, was triphasic: faint during infancy, barely detectable at 6 months, but intense in adult and aged individuals. The 24-kDa IGFBP-4 band was only seen in neonatal CSF samples, while the IGFBP-3 doublet gradually increased during aging. Thus, these present results show that IGFBP-2, 3, 4 and 5 in CSF are developmentally regulated, suggesting roles for these molecules in the development of the nervous system.
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Affiliation(s)
- P M Arnold
- Neurobiology Research, Department of Veterans Affairs Medical Center, Kansas City, Missouri, 64128, USA.
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Chou SM, Taniguchi A, Wang HS, Festoff BW. Serpin=serine protease-like complexes within neurofilament conglomerates of motoneurons in amyotrophic lateral sclerosis. J Neurol Sci 1998; 160 Suppl 1:S73-9. [PMID: 9851654 DOI: 10.1016/s0022-510x(98)00202-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Neurofilamentous conglomerates (NfCg), as axonal spheroids or conglomerates in motoneurons, are the histopathologic hallmarks for early stages of amyotrophic lateral sclerosis (ALS). We hypothesize that NfCg may be formed by post-translational modifications of altered Nf proteins that include: (1) hyperphosphorylation, (2) glycosylation (or glycoxidation), (3) nitration, (4) ubiquitination and/or (5) crosslinking by the Ca++-dependent transglutaminase (TGase). These, as well as other changes, are predicted to be initiated or accentuated by oxidative damage. The damaged Nf proteins then activate cascades of intracellular protein degradation which include ATP-dependent ubiquitin/proteasome proteolysis. Other proteolytic systems, either Ca++-dependent or independent, may also be activated, such as serine and cysteine protease systems. These enzymes, either lysosomal or non-lysosomal may also participate in the degradation of damaged Nf proteins being balanced by their cognate inhibitors. Protein complexes formed by these protease=inhibitor systems, along with damaged Nf proteins, may accumulate within the cell bodies as neuronal inclusions, since a number of intracellular inclusions are found in motor neurons in ALS. In the current study, we investigated the involvement of serine proteases and their serpins in NfCg formation. Pairs of three serine proteases (trypsin, chymotrypsin and thrombin) and their cognate serpins (alpha1-anti-trypsin, alpha1-anti-chymotrypsin, and protease nexin I) were probed in motoneurons with their antibodies for both NfCg and inclusions. Positive immunoreactivities for all serine proteases and their cognate serpins support the contention that the imbalance of serine proteases and internalized serpins may have a role in formation of NfCg and inclusions, and hence, the pathogenesis of ALS.
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Affiliation(s)
- S M Chou
- F. Norris ALS/MDA Research Center, California Pacific Medical Center, San Francisco 94115, USA
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18
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Turgeon VL, Lloyd ED, Wang S, Festoff BW, Houenou LJ. Thrombin perturbs neurite outgrowth and induces apoptotic cell death in enriched chick spinal motoneuron cultures through caspase activation. J Neurosci 1998; 18:6882-91. [PMID: 9712658 PMCID: PMC6792988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Increasing evidence indicates several roles for thrombin-like serine proteases and their cognate inhibitors (serpins) in normal development and/or pathology of the nervous system. In addition to its prominent role in thrombosis and/or hemostasis, thrombin inhibits neurite outgrowth in neuroblastoma and primary neuronal cells in vitro, prevents stellation of glial cells, and induces cell death in glial and neuronal cell cultures. Thrombin is known to act via a cell surface protease-activated receptor (PAR-1), and recent evidence suggests that rodent neurons express PAR-1. Previously, we have shown that the thrombin inhibitor, protease nexin-1, significantly prevents neuronal cell death both in vitro and in vivo. Here we have examined the effects of human alpha-thrombin and the presence and/or activation of PAR-1 on the survival and differentiation of highly enriched cultures of embryonic chick spinal motoneurons. We show that thrombin significantly decreased the mean neurite length, prevented neurite branching, and induced motoneuron death by an apoptosis-like mechanism in a dose-dependent manner. These effects were prevented by cotreatment with hirudin, a specific thrombin inhibitor. Treatment of the cultures with a synthetic thrombin receptor-activating peptide (SFLLRNP) mimicked the deleterious effects of thrombin on motoneurons. Furthermore, cotreatment of the cultures with inhibitors of caspase activities completely prevented the death of motoneurons induced by either thrombin or SFLLRNP. These findings indicate that (1) embryonic avian spinal motoneurons express functional PAR-1 and (2) activation of this receptor induces neuronal cell degeneration and death via stimulation of caspases. Together with previous reports, our results suggest that thrombin, its receptor(s), and endogenous thrombin inhibitors may be important regulators of neuronal cell fate during development, after injury, and in pathology of the nervous system.
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Affiliation(s)
- V L Turgeon
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA
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19
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Akaaboune M, Hantaï D, Smirnova I, Lachkar S, Kapsimali M, Verdière-Sahuqué M, Festoff BW. Developmental regulation of the serpin, protease nexin I, localization during activity-dependent polyneuronal synapse elimination in mouse skeletal muscle. J Comp Neurol 1998; 397:572-9. [PMID: 9699917 DOI: 10.1002/(sici)1096-9861(19980810)397:4<572::aid-cne9>3.0.co;2-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
During vertebrate neuromuscular development, all muscle fibers are transiently innervated by more than one neuron. Among the numerous factors shown to potentially influence the passage from poly- to mononeuronal innervation, serine proteases and their inhibitors appear to play important roles. In this regard, protease nexin I (PNI), a potent inhibitor of the serine protease, thrombin, is highly localized to the neuromuscular junction (NMJ). In turn, thrombin is responsible for activity-dependent synapse elimination both in an in vitro model, and in vivo. In the present study, we used a monospecific anti-PNI polyclonal antibody to study the developmental kinetics of PNI expression in mouse leg skeletal muscle. By using immunoblotting, we detected PNI at embryonic day 16 (E16), as a 48-kDa band. This 48-kDa PNI band became prominent in leg muscle extracts at postnatal day 5 (P5) and remained so in extracts from adult muscle. In contrast, a higher molecular weight immunoreactive PNI band, which was sodium dodecyl sulfate- and beta-mercaptoethanol-resistant, was first detected at E16, increased at birth (P0), and then decreased at P15, i.e., after the wave of polyneuronal synapse elimination had occurred in these muscles. The results of an enzyme-linked immunosorbent assay, measuring active, complexed, and truncated PNI, correlated with Western blot data. We used immunocytochemistry to probe the localization of PNI at the NMJ and found that PNI was present in the cytoplasm of myotubes at E16, but neither then nor at birth did it colocalize with acetylcholine receptors. PNI became localized at NMJs by P5 and increased by P15, after which it remained stably concentrated there in the adult. Finally, we studied the gene expression of PNI mRNA, by using Northern blotting, and showed that PNI mRNA was present in skeletal muscle and remained stable throughout the time-course studies, suggesting that developmental regulation of muscle PNI occurs principally at the translational and/or post-translational levels. These results suggest that the localization of PNI, through a binding site or "receptor" may play an important role in differentiation and maintenance of synapse.
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MESH Headings
- Aging/metabolism
- Aging/physiology
- Amyloid beta-Protein Precursor
- Animals
- Animals, Newborn/growth & development
- Animals, Newborn/metabolism
- Blotting, Northern
- Blotting, Western
- Carrier Proteins/genetics
- Carrier Proteins/metabolism
- Embryo, Mammalian/metabolism
- Mice/embryology
- Mice/growth & development
- Mice/metabolism
- Muscle Development
- Muscle, Skeletal/embryology
- Muscle, Skeletal/growth & development
- Muscle, Skeletal/physiology
- Neurons/physiology
- Protease Nexins
- RNA, Messenger/metabolism
- Receptors, Cell Surface
- Synapses/physiology
- Tissue Distribution
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Affiliation(s)
- M Akaaboune
- Développement, Pathologie, Régénération du Système Neuromusculaire, INSERM U.153, Institut de Myologie, Hôpital de la Salpêtrière, Paris, France.
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20
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Abstract
Exogenous or endogenous injuries of the central nervous system trigger astrogliosis characterized by proliferation of astrocytes and changes in their morphology from stellate to flat polygonal. Astrocytes in culture are very sensitive to thrombin, a serine protease, which through its proteolytically activated receptor (PAR-1) induces proliferation and morphological changes comparable to astrogliosis. Evaluation of the thrombin signal-transduction pathway in the reversal of astrocyte stellation might help to understand astrogliosis. For this purpose, primary cultured murine cortical astrocytes were treated with H7, a protein-kinase inhibitor, and thrombin, which resulted in an inhibition of stellation reversal. Treatments with phorbol 12-myristate 13-acetate (PMA), a protein kinase C (PKC) activator, mimicked the action of thrombin. Subsequently, direct assay of astrocyte PKC activity after thrombin or PMA treatment demonstrated involvement of PKC in thrombin signaling associated with shape change. Western blotting showed that PKC isoform beta-1 was involved in this pathway, while PKC alpha was only weakly activated and PKC beta-2 was not activated by thrombin. PKC beta-1 translocation was also elicited by a thrombin-receptor active peptide (SFLLRN), demonstrating the involvement of PAR-1 in this process. PKC delta and epsilon were located constitutively in the membrane fraction in stellate astrocytes. Isoforms gamma, eta, theta, and zeta were absent from astrocytes. These results suggest that astrogliosis in vitro might be regulated by modulating the activity of thrombin, PAR-1, or specific PKC isoforms.
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Affiliation(s)
- A Pindon
- Institut National de la Santé et de la Recherche Médicale Unité 153, Hôpital de la Salpêtrière, Paris, France.
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21
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Smirnova IV, Zhang SX, Citron BA, Arnold PM, Festoff BW. Thrombin is an extracellular signal that activates intracellular death protease pathways inducing apoptosis in model motor neurons. J Neurobiol 1998; 36:64-80. [PMID: 9658339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Apoptosis, often also termed "programmed cell death", occurs in normal development in the brain and spinal cord. Important to concepts of disease and potential intervention is the exciting finding that apoptosis is also found after neurotrauma and in a number of neurodegenerative diseases. Although the precise mechanism of neuronal cell loss remains unknown, much emphasis has been placed recently on the activation of cell death protease cascades within the cell. How these cascades may be activated, especially from extracellular influences, is currently poorly understood. Thrombin, the multifunctional coagulation protease, is an early phase modulator at sites of tissue injury and has been shown to induce cell death in neurons by an apoptotic mechanism by activating its receptor, PAR-1. Using a model motor neuronal cell line, NSC19, which we have shown undergoes apoptosis after treatment with classic apoptosis inducers such as the topoisomerase inhibitors camptothecin and etoposide, we unambiguously found that nanomolar thrombin induced characteristic signs of apoptosis. Strikingly, endonucleolysis was accompanied by an increase in caspase-3-like activity in cellular extracts, which correlated with both detection of caspase-induced signature cleavage of the cortical cytoskeleton component nonerythroid spectrin (alpha-fodrin) and identification of increased accessibility of a caspase cleavage domain, using an antibody (Ab127) made against a synthetic peptide KGDEVD. Demonstrating that thrombin activation of death proteases was linked to cell death, we were able to inhibit thrombin-induced apoptosis by using a caspase family inhibitor, benzyloxycarbonyl-Asp-(oMe)-fluoromethyl ketone (Boc-D-FMK). These novel results demonstrate that thrombin serves as an extracellular "death signal" to activate intracellular protease pathways. These pathways lead to apoptotic cell death and can be modulated by inhibiting caspase activity downstream to PAR-1.
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Affiliation(s)
- I V Smirnova
- Neurobiology Research Laboratory (151R), Department of Veterans Affairs Medical Center, Kansas City, Missouri 64128, USA
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22
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Yong C, Arnold PM, Zoubine MN, Citron BA, Watanabe I, Berman NE, Festoff BW. Apoptosis in cellular compartments of rat spinal cord after severe contusion injury. J Neurotrauma 1998; 15:459-72. [PMID: 9674550 DOI: 10.1089/neu.1998.15.459] [Citation(s) in RCA: 157] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Following a controlled, severe contusion lesion to the lower thoracic spinal cord in adult rats, we found that apoptosis occurred in cells located in both gray and white matter. This suggested that both nonneuronal cells, including astrocytes, oligodendroglia and microglia, as well as neurons, might participate in programmed cell death (PCD) following spinal cord injury (SCI). Determination of which cell populations participate, and the kinetics and extent of their involvement might reveal new paradigms for approaches to therapy. Consequently, we assessed the functional deficit, comparing a comprehensive locomotor rating scale (LRS) with the inclined plane test at various times after injury. Using standard histology, along with cell-specific markers, we assessed PCD in different spinal cord segments using several parameters of apoptosis. Our results indicate that hind limb motor function was lost at day 1, and then only gradually and ineffectively (about 10-15%) recovered over the next month. Evidence for increased cell number was present for astrocytes and microglia beginning at day 1 after injury. Over the postinjury time period, apoptotic cells appeared (from day 1 to 14), and peaked (in terms of apoptotic index) on day 3. About one-third were microglia, whereas neurons, both large and small, also underwent apoptosis, again peaking at day 3. However, neurons continued to die and were not replaced by proliferation, so that at day 7, three times as many neurons (as a percentage) underwent PCD compared with the glial compartment. Oligodendrocytes also underwent apoptosis, with a biphasic curve, both at days 3 and 14 following injury. Thus, in addition to immediate, passive necrosis, delayed and apoptotic PCD also occurred in all cell populations in severely injured spinal cord.
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Affiliation(s)
- C Yong
- Neurobiology Research Laboratory, Veterans Affairs Medical Center, Kansas City, Missouri 64128, USA
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23
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Salcedo RM, Festoff BW, Citron BA. Quantitative reverse transcriptase PCR to gauge increased protease-activated receptor 1 (PAR-1) mRNA copy numbers in the Wobbler mutant mouse. J Mol Neurosci 1998; 10:113-9. [PMID: 9699152 DOI: 10.1007/bf02737122] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Thrombin acts on cells through the surface protease-activated receptor 1 (PAR-1), a G-protein-coupled member of the seven-transmembrane domain superfamily. On neural cells, thrombin has deleterious effects, killing neurons through apoptosis. Consequently, knowledge of PAR-1 expression in the nervous system may help to elucidate the role of thrombin in neurodegenerative disease. We developed a mimic construct to facilitate the highly sensitive technique of quantitative reverse transcriptase to PCR (qRT-PCR) to measure the differential expression of low copy number PAR-1 mRNA in neurodegenerative model systems. In this article, we report our results comparing homozygous wobbler (wr/wr) mice and normal littermates. By optimizing the transcription and quantitative PCR procedures to facilitate rapid copy number determination in small RNA samples, we documented a fivefold greater level of PAR-1 mRNA in the cervical spinal cord of wr/wr.
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Affiliation(s)
- R M Salcedo
- Department of Veterans Affairs Medical Center, Kansas City, MO, USA
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24
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Smirnova IV, Vamos S, Wiegmann T, Citron BA, Arnold PM, Festoff BW. Calcium mobilization and protease-activated receptor cleavage after thrombin stimulation in motor neurons. J Mol Neurosci 1998; 10:31-44. [PMID: 9589368 DOI: 10.1007/bf02737083] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Thrombin, the ultimate enzyme in the blood coagulation cascade, has prominent actions on various cells, including neurons. As in platelets, thrombin increases [Ca2+]i mobilization in neurons, and also retracts neurites. Both these effects are mediated through a G protein-coupled, proteolytically activated receptor for thrombin (PAR-1). Prolonged exposure to thrombin kills neurons via apoptosis, that may also involve PAR-1 activation. Increased [Ca2+]i has been a unifying mechanism proposed for cell death in several neurodegenerative diseases. Thrombin-elevated calcium levels may activate intracellular cascades in neurons leading to cell death. Since thrombin mediates its diverse effects on cells through both heterotrimeric and monomeric G proteins, we also explored what effect altering differential G protein coupling would have on the neuronal response to thrombin. We studied calcium mobilization by thrombin in a model motor neuronal cell line, NSC19, using fluorescence image analysis. Confirming effects in other neuronal types, thrombin caused dramatic increases in [Ca2+]i levels, both transiently and after prolonged exposure, which involved activation and cleavage of the PAR-1 receptor. Using enzyme linked immunosorbent assay (ELISA) and dot-blot analysis, we found that the N-terminal fragment of PAR-1 was released into the medium after exposure to thrombin. We confirmed that PAR-1 protein and mRNA expression occurred in motor neurons. We found that cholera toxin inhibited thrombin-mediated Ca2+ influx, pertussis toxin did not significantly alter thrombin action, and lovastatin, a small 21-kDa Ras GTPase (Rho) modulator, showed a tendency to reduce the thrombin effect. These data indicate that thrombin-increased [Ca2+]i, sufficient to trigger cell death in motor neurons, might be approached in vivo by modulating thrombin signaling through PAR-1.
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Affiliation(s)
- I V Smirnova
- Fluorescence Imaging Laboratories Department of Veterans Affairs Medical Center, Kansas City, MO 64128, USA
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25
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Abstract
STUDY DESIGN Serum withdrawal was introduced to a spinal cord motor neuron cell line to investigate the mode of cell death. OBJECTIVES To characterize the death of motor neurons in culture, to gain insight into mechanisms that could be important in spinal cord diseases. SUMMARY OF BACKGROUND DATA Normal reduction of cell number during central nervous system development is brought about by programmed cell death. These same apoptotic processes probably play a role in a variety of central nervous system disorders, including traumatic injury. Although certain proteolytic processes are involved, the molecular details involved in the apoptotic induction have not been fully elucidated. METHODS To identify apoptosis, several criteria were used, including analysis of chromatin condensation with DNA-specific stains (propidium iodide and Hoechst 33342); in situ end-labeling of DNA fragments in apoptotic nuclei with terminal deoxynucleotidyl transferase; fragmentation of DNA separated on agarose gel electrophoresis; and cleavage of a characteristic substrate for apoptotic proteases, alpha-fodrin, into signature cleavage fragments. RESULTS The NSC19 cell line exhibited motor neuron characteristics morphologically, with typical cellular structure, and biochemically, by synthesizing choline acetyl transferase. Under various treatments including serum withdrawal (loss of trophic factors), cell loss occurred through an apoptotic cell death pathway. CONCLUSIONS A murine motor neuron cell line, NSC19, has been used to investigate apoptosis in this in vitro system. Cell death occurs by apoptosis, suggesting that this cell line may provide a useful model for studying apoptotic mechanisms in spinal cord degeneration and injury.
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Affiliation(s)
- I V Smirnova
- Department of Veterans Affairs Medical Center, Kansas City, Missouri, USA
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26
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Smirnova IV, Salazar A, Arnold PM, Glatt S, Handler M, Festoff BW. Thrombin and its precursor in human cerebrospinal fluid. Thromb Haemost 1997; 78:1473-9. [PMID: 9423797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The blood coagulation cascade proteolytic enzyme, thrombin, affects many cell types, including neurons and astrocytes, in which it prevents process outgrowth and induces significant morphological degeneration and even cell death. Since thrombin may contribute significantly to pathological conditions in the central nervous system (CNS), where it is synthesized locally, we measured the levels of thrombin and its precursor, prothrombin, in the cerebrospinal fluid (CSF) of 67 individuals from 6 groups: non-neurologic controls (NNC); spinal degenerative disease (SDD); peripheral nerve disease (PND); cerebrovascular, neuroimmune and seizure disorders and tumor (CNSD); traumatic brain injury (TBI) and neurodegenerative disorders (NDD). We employed a sensitive chromogenic assay utilizing the thrombin specific tripeptide substrate, S-2238, to evaluate CSF levels of thrombin and prothrombin. The latter estimated after its conversion to active enzyme by the snake venom prothrombinase, ecarin. No measurable active thrombin was detected in these CSF samples. However, activatable prothrombin was measured in all groups. The mean activatable prothrombin concentrations (in nM) were 7.26 +/- 3.39 (NNC); 8.85 +/- 3.09 (SDD); 6.78 +/- 2.58 (PND); 6.33 +/- 3.87 (CNSD); 5.10 +/- 1.86 (TBI), and 7.80 +/- 3.27 (NDD). Duncan's multiple comparison test showed significant reduction (p <0.05) in prothrombin levels of the TBI group. Our data suggests that the prothrombin zymogen gains access to the CSF, likely across either an intact or compromised blood-brain barrier (BBB), in increased amounts with age. Reduced levels in TBI patients may have diagnostic and/or prognostic value.
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Affiliation(s)
- I V Smirnova
- Neurobiology Research Laboratory, Department of Veterans Affairs Medical Center, Kansas City, MO 64128, USA
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27
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Lai EC, Felice KJ, Festoff BW, Gawel MJ, Gelinas DF, Kratz R, Murphy MF, Natter HM, Norris FH, Rudnicki SA. Effect of recombinant human insulin-like growth factor-I on progression of ALS. A placebo-controlled study. The North America ALS/IGF-I Study Group. Neurology 1997; 49:1621-30. [PMID: 9409357 DOI: 10.1212/wnl.49.6.1621] [Citation(s) in RCA: 275] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The objective of this study was to investigate the safety and efficacy of recombinant human insulinlike growth factor-I (rhIGF-I) in the treatment of sporadic ALS. A double-blind, placebo-controlled, randomized study of 266 patients was conducted at eight centers in North America. Placebo or rhIGF-I (0.05 mg/kg/day or 0.10 mg/kg/day) was administered for 9 months. The primary outcome measure was disease symptom progression, assessed by the rate of change (per patient slope) in the Appel ALS rating scale total score. The Sickness Impact Profile (SIP), a patient-perceived, health-related quality of life assessment, was a secondary outcome variable. Progression of functional impairment in patients receiving high-dose (0.10 mg/kg/day) rhIGF-I was 26% slower than in patients receiving placebo (p = 0.01). The high-dose treatment group was less likely to terminate the study due to protocol-defined markers of disease symptom progression, and members in this group exhibited a slower decline in quality of life, as assessed by the SIP. Patients receiving 0.05 mg/kg/day of rhIGF-I exhibited trends similar to those associated with high-dose treatment, suggesting a dose-dependent response. The incidence of clinically significant adverse experiences was comparable among the three treatment groups. Recombinant human insulin-like growth factor-I slowed the progression of functional impairment and the decline in health-related quality of life in patients with ALS with no medically important adverse effects.
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Affiliation(s)
- E C Lai
- Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
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28
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Citron BA, Smirnova IV, Zoubine MN, Festoff BW. Quantitative PCR analysis reveals novel expression of prothrombin mRNA and regulation of its levels in developing mouse muscle. Thromb Res 1997; 87:303-13. [PMID: 9263397 DOI: 10.1016/s0049-3848(97)00132-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Precise determination of mRNA levels is an essential element in any investigation of complex regulatory systems. Classical methodologies such as Northern hybridization suffer from requirements for significant samples of material and also a degree of nonspecificity. Recently, quantitative techniques involving PCR amplification have been devised. We have developed and applied such procedures to the determination of prothrombin messages in skeletal muscle cells during development. In addition to its role in the blood coagulation cascade, the serine protease thrombin has been shown to participate in several signaling events in the neuromuscular system. The inactive precursor, prothrombin, primarily produced in the liver, has also been shown to be synthesized and developmentally-regulated in the brain. In skeletal muscle, thrombin is a mediator of activity-dependent polyneuronal synapse elimination (ADPSE) which occurs in early postnatal development. Recent experiments showing that thrombin is released from myotubes in culture under the influence of acetylcholine suggest that locally-synthesized prothrombin may be the source of this Hebbian synaptic interaction. We have determined that prothrombin is expressed in skeletal muscle, as the likely source of thrombin involved in ADPSE, and the current results show the quantitative expression of muscle prothrombin during this time of intense synapse remodeling.
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MESH Headings
- Animals
- Cells, Cultured
- Cloning, Molecular
- Gene Expression Regulation, Developmental
- Liver/metabolism
- Mice
- Mice, Inbred BALB C
- Muscle Development
- Muscle Proteins/biosynthesis
- Muscle Proteins/genetics
- Muscle, Skeletal/embryology
- Muscle, Skeletal/growth & development
- Muscle, Skeletal/metabolism
- Organ Specificity
- Polymerase Chain Reaction
- Prothrombin/biosynthesis
- Prothrombin/genetics
- RNA, Messenger/analysis
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Synapses/metabolism
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Affiliation(s)
- B A Citron
- Neurobiology Research Laboratory, VA Medical Center, Kansas City, MO 64128-2295, USA.
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29
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Abstract
In order to develop in vitro models of CNS injury, astrocytes have been mechanically injured in culture to study reactive astrocytosis. However, scratch injury models of pure neuronal cultures have not yet been exploited to study programmed cell death (PCD). For this study, we examined model motor neurons (NSC19 cells) in culture and found time-dependent cell death in proximity (within 2.5 mm) to a physical scratch injury. Injury-induced cell death was apoptotic verified by positively-stained nuclei using both the in situ end-labeling (ISEL) procedure and Hoechst 33342. Unexpectedly, cells proximal to the injury site were not affected by the injury until 3 days later suggesting that adjacent motor neuron loss was dependent on a 'death signal' produced by direct injury to sister neurons. 'Executioners' in apoptosis include free radicals, cell cycle kinases and cysteine proteases (caspases). Extracellular serine proteases, such as thrombin and granzyme B, may activate such intracellular pathways and several inhibitors (serpins), such as CrmA, are effective in blocking apoptosis. Since protease nexin I (PNI), a serpin homologous with CrmA, prevents apoptosis of lumbar motor neurons and is increased after nerve injury, we examined mRNA by RT-PCR for PNI expression. Of interest, although we were unable to find significant levels of PNI message in NSC19 cells, we did detect it in the parent neuroblastoma.
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Affiliation(s)
- B A Citron
- Neurobiology Research Lab, VA Medical Center, Kansas City, MO 64128-2295, USA
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30
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Abstract
Subnanomolar concentrations of VIP elicit a survival-producing action in CNS cultures composed of both astroglia and neurons. This neurotrophic action is mediated by a complex array of substances released by VIP from astrocytes. Included in this glial protein mixture is a cytokine (interleukin-1 alpha), a serine protease inhibitor (protease nexin I), and an extracellular stress protein (activity-dependent neurotrophic factor). In dissociated spinal cord cultures, all of these substances exhibit neuroprotection from neuronal cell death produced by electrical blockade with tetrodotoxin. All these substances produce neuronal cell death when test cultures are treated with neutralizing antisera to any one of them. They are all apparently necessary for the survival of a subpopulation of neurons that are dependent on spontaneous, excitatory neurotransmission. Our view is that these substances are components of a glia-derived environment that regulates, together with target-derived growth factors, the survival fate of developing neurons. In addition, it is our belief that some of these glia-derived substances will be found to have active roles in the injury response to the CNS or in the regulation of VIP-mediated growth in other tissues. Drugs based on these substances may provide therapeutic agents for the treatment of neurodegeneration and tumor growth.
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Affiliation(s)
- D E Brenneman
- Section on Developmental and Molecular Pharmacology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
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31
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Pindon A, Hantai D, Jandrot-Perrus M, Festoff BW. Novel expression and localization of active thrombomodulin on the surface of mouse brain astrocytes. Glia 1997; 19:259-68. [PMID: 9063732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Thrombin's potent effects on astrocytes are mediated by a specific receptor and inhibited by a serpin, protease nexin I (PNI). Thrombomodulin (TM), a membrane protein that forms complexes with thrombin, changing its enzymatic specificity, has not been studied in astrocytes. In primary astrocyte cultures, using Western blotting and immunocytochemistry, we found a 70 kDa TM band and TM localized to the surface with an anti-mouse TM monoclonal antibody. By reverse transcriptase coupled with polymerase chain reaction (RT-PCR), we found the correct sequence for mouse TM mRNA in astrocytes. Finally, we documented calcium-dependent activation of protein C by a thrombin:TM complex with thrombin added to the astrocytes. These results indicate the presence of functionally active TM at the astrocyte surface and add support to a role for thrombin signaling in the nervous system.
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Affiliation(s)
- A Pindon
- I.N.S.E.R.M. Unité 153, Paris, France
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Smirnova IV, Ma JY, Citron BA, Ratzlaff KT, Gregory EJ, Akaaboune M, Festoff BW. Neural thrombin and protease nexin I kinetics after murine peripheral nerve injury. J Neurochem 1996; 67:2188-99. [PMID: 8863530 DOI: 10.1046/j.1471-4159.1996.67052188.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We addressed the balance between thrombin and its serpin protease nexin I (PNI) after sciatic nerve injury in the mouse. Prothrombin levels increased twofold 24 h after nerve crush, as measured by a specific chromogenic assay, and peaked at day 3. Thrombin activity also increased 2-4 days after injury in distal sciatic nerve segments. Nerve RNA analysis using reverse transcriptase--polymerase chain reaction (RT-PCR) assay confirmed that prothrombin was synthesized locally. We also monitored PNI levels in these injured nerve samples by complex formation with an 125I-labeled target protease and found peak activity occurring later, 6-9 days after the thrombin induction. These data indicate that nerve injury first induces the synthesis of prothrombin, which is subsequently converted to active thrombin. Nerve crush-induced thrombin is followed by the generation of functionally active PNI and may be directly responsible for its induction. By immunocytochemistry with anti-PNI antibody, we found that activated Schwann cells were the source of induced PNI. These results support the concept that the balance between serine proteases and their serpins is dysregulated during nerve injury and suggests a role for its reestablishment in nerve damage repair.
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Affiliation(s)
- I V Smirnova
- Neurobiology Research Laboratory, Department of Veterans Affairs Medical Center, Kansas City, Missouri 64128, USA
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Zoubine MN, Ma JY, Smirnova IV, Citron BA, Festoff BW. A molecular mechanism for synapse elimination: novel inhibition of locally generated thrombin delays synapse loss in neonatal mouse muscle. Dev Biol 1996; 179:447-57. [PMID: 8903359 DOI: 10.1006/dbio.1996.0274] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Activity-dependent, polyneuronal synapse elimination (ADPSE) is a programmed, regressive event in the development of the nervous system and readily studied at the neuromuscular junction, where it is complete 15-20 days after birth. Local excess, or imbalanced, protease activity is one of several possible underlying mechanisms. In this regard, thrombin mediates activity-dependent synapse loss in an in vitro model of ADPSE. To test the involvement of thrombin in vivo, we locally applied the leech thrombin-specific inhibitor, hirudin. We monitored neuromuscular behavior, correlated with acetylcholinesterase and silver nitrate histochemistry at endplates, for changes in the timecourse of in vivo synapse elimination and assayed both thrombin activity and prothrombin expression in developing muscle. Hirudin retarded elimination, without altering motor performance, uniquely at Postnatal Day 5 (P5) and maximally at P9. Reverse transcription-polymerase chain reaction (PCR) showed that neonatal muscle was a source of local prothrombin, with peak expression during the first week after birth. A specific chromogenic assay revealed that local thrombin, activated from muscle-derived prothrombin, peaked during maximal synapse remodeling.
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Affiliation(s)
- M N Zoubine
- Neurobiology Research Laboratory, Department of Veterans Affairs Medical Center, Kansas City, Missouri 64128, USA
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34
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Lange DJ, Felice KJ, Festoff BW, Gawel MJ, Gelinas DF, Kratz R, Lai EC, Murphy MF, Natter HM, Norris FH, Rudnicki S. Recombinant human insulin-like growth factor-I in ALS: description of a double-blind, placebo-controlled study. North American ALS/IGF-I Study Group. Neurology 1996; 47:S93-4; discussion S94-5. [PMID: 8858058 DOI: 10.1212/wnl.47.4_suppl_2.93s] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- D J Lange
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
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35
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Citron BA, Ratzlaff KT, Smirnova IV, Festoff BW. Protease nexin I (PNI) in mouse brain is expressed from the same gene as in seminal vesicle. J Mol Neurosci 1996; 7:183-91. [PMID: 8906614 DOI: 10.1007/bf02736839] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Protease nexin I (PNI), a serine protease inhibitor (serpin), is the most potent tissue inhibitor of thrombin. In the nervous system, PNI has been shown to participate in processes related to synaptic plasticity and neuronal survival. We assigned the human gene for PNI (P17) to chromosome 2q33-35, and to syntenic regions in mouse chromosome 1. Others showed that a similar serpin was expressed in mouse seminal vesicle, which presented the possibility of a "duplicate" gene. The data also raised controversy over the quantity of PNI mRNA expressed in the brain vs peripheral tissues, such as seminal vesicle. In order to further our investigations of PNI regulation and its influence on neuronal survival and neuroprotection, it was necessary to confirm whether the nexin observed in mouse brain samples was identical to the published protease nexin I sequences. To accomplish this, we performed DNA sequence analysis of cDNAs made from RNAs isolated from mouse forebrain and hindbrain as well as from seminal vesicle. These confirmed the identity of the mouse PNI gene (SPI4) in brain and peripheral tissues. Furthermore, Northern hybridization studies indicated that the PNI message is present at lower levels in the adult brain compared to the adult seminal vesicle. Western immunoblotting showed no differences between brain and seminal vesicle PNI proteins. The PNI cDNAs generated will serve as useful probes for the continued characterization of the serpin:protease balance as it relates to nerve cell function.
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Affiliation(s)
- B A Citron
- Neurobiology Research Laboratory, VA Medical Center, Kansas City, MO, USA
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36
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Festoff BW. Erratum to Amyotrophic lateral sclerosis: current and future treatment strategies. Drugs 1996. [DOI: 10.1007/bf03259130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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37
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Festoff BW, Nelson PG, Brenneman DE. Prevention of activity-dependent neuronal death: vasoactive intestinal polypeptide stimulates astrocytes to secrete the thrombin-inhibiting neurotrophic serpin, protease nexin I. J Neurobiol 1996; 30:255-66. [PMID: 8738754 DOI: 10.1002/(sici)1097-4695(199606)30:2<255::aid-neu7>3.0.co;2-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Neuronal cell death occurs as a programmed, naturally occurring mechanism and is the primary regressive event in central nervous system development. Death of neurons also occurs on an injury-induced basis after trauma and in human neurodegenerative diseases. Classical neurotrophic factors can reverse this phenomenon in experimental models prompting initiation of clinical trials in conditions such as amyotrophic lateral sclerosis and Alzheimer's disease. The glial-derived protease nexin I (PNI), a known promoter of neurite outgrowth in cell culture and a potent inhibitor of serine proteases, also enhances neuronal cell survival. PNI, in nanomolar concentrations, rescues spinal cord motor neurons from both naturally-occurring programmed cell death in the chick embryo as well as following injury in the neonatal mouse. The potent neuromodulator, vasoactive intestinal polypeptide (VIP), influences neuronal survival through glial-mediated factors and also induces secretion of newly synthesized astrocyte PNI. We now report that subnanomolar amounts of PNI enhance neuronal survival in mixed spinal cord cell culture, especially when neuronal cells were made electrically silent by administration of tetrodotoxin. The mediation of this effect is by inhibition of the multifunctional serine protease, thrombin, because hirudin, a thrombin-specific inhibitor, has the same effect. In addition, spinal cord neurons are exquisitely sensitive to thrombin because picomolar and lower levels of the coagulation factor causes neuronal death. Thus, PNI is an astrocyte-derived, thrombin-inhibiting, activity-dependent neurotrophic agent, enhanced secretion of which by VIP may be one approach to treat neurological disorders.
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Affiliation(s)
- B W Festoff
- Neurobiology Research Laboratory, Veterans Affairs Medical Center, Kansas City, Missouri 64128, USA.
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38
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Abstract
The multifunctional serine protease, thrombin, the principal component of the blood coagulation cascade, is also active in nervous system growth and maintenance. In neural tissue culture, it prevents neurite outgrowth and modulates morphologic changes in both neurons and astrocytes. In recent studies, we found that it mediates polyneuronal synapse elimination, both in vivo and in vitro. Of relevance to neurologic disease, as well as to development, evidence also implicates thrombin in apoptosis of these cells. As with other serine proteases, thrombin is in "balance" with one or more endogenous protein inhibitors, members of the serpin superfamily of proteins. The most potent vertebrate inhibitor for thrombin is protease nexin I (PNI), which regulates thrombin's effect by forming post-translational, covalent complexes with the protease. We review some of the nervous system effects of the thrombin:PNI balance, and also present results of a recent study of this balance after peripheral nerve injury. We measured thrombin and prothrombin activity in extracts from adult mouse sciatic nerve using a specific chromogenic assay. We also performed reverse transcription polymerase chain reaction of RNA from nerve crush samples. We found a burst of activity at 3 days following injury distal to the crush site that was inhibited by thrombin specific inhibitors. It is possible that a significant fraction of the increased prothrombin in injured nerve was synthesized locally. Active PNI levels increased in these crush samples 6 to 9 days after the thrombin induction. These data suggest that nerve injury first induces the synthesis of prothrombin, which is subsequently converted to active thrombin. Nerve crush-induced thrombin is followed by the generation of functionally active PNI and may be directly responsible for its induction. These results suggest that the balance between serine proteases and their serpins is dysregulated during nerve injury and support a role for its reestablishment in nerve damage repair.
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Affiliation(s)
- B W Festoff
- Neurobiology Research Laboratory, Kansas City Veterans Affairs Medical Center, Missouri, USA
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Verdière-Sahuquè M, Akaaboune M, Lachkar S, Festoff BW, Jandrot-Perrus M, García L, Barlovatz-Meimon G, Hantai D. Myoblast fusion promotes the appearance of active protease nexin I on human muscle cell surfaces. Exp Cell Res 1996; 222:70-6. [PMID: 8549675 DOI: 10.1006/excr.1996.0009] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Protease nexin I (PNI) is a 43- to 50-kDa glycoprotein capable of inhibiting a number of serine proteases and belongs to the serpin superfamily. PNI is identical to glia-derived nexin, a neurite outgrowth promoter by virtue of its thrombin-inhibiting activity. Of particular relevance to neuromuscular biology and pathology, PNI was the first serpin shown to be highly localized to the neuromuscular junction and it maps to precisely the same locus as autosomal recessive amyotrophic lateral sclerosis (ALSJ) at chromosome 2q33-35. In the present report, we now show that in cultures of human skeletal muscle, PNI protein is expressed only after myoblast fusion into multinuclear myotubes and is localized in patches on their surfaces. We performed complex formation experiments with labeled thrombin, another target protease for PNI, with intact human muscle cells in culture. We detected specific SDS-stable PNI/thrombin complexes in myotube extracts only, indicating that active PNI was bound to their surfaces. We studied the gene expression of PNI mRNA using a 300-bp cDNA synthesized from the published sequence of human PNI. Confirming the protein data, upregulation of PNI appears in myotubes using Northern blot analysis. The current results reinforce the hypothesis that the regulation of the balance of serine proteases and serpins, such as PNI, is involved in muscle differentiation. They also prompt us to explore PNI abnormalities in several neuromuscular diseases, including ALSJ.
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Affiliation(s)
- M Verdière-Sahuquè
- Développement, Pathologie, Régénération du Système Neuromusculaire, INSERM U. 153, Paris, France
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Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal, enigmatic disorder characterised by relentless progression of muscle wasting and weakness until death ensues due to respiratory muscle failure. Intellectual functions are usually spared. ALS, known also as motor neuron disease (MND) in the UK, maladie de Charcot in France and Lou Gehrig's disease in the US, is usually sporadic, but between 5 and 10% of all cases are hereditary, usually inherited as autosomal dominant. Previously thought to be untreatable, as well as incurable, just in the last 3 years ALS has been the greatest clinical application of recent exciting break-throughs in preclinical neurobiology research. Although definitive information regarding the cause(s) and pathogenesis of ALS still escapes us, meaningful demonstration of intercession in the downhill course with specific therapy has been suggested, giving reason to be hopeful, if cautiously and critically optimistic. This review focuses on the recent work from the fields of growth/trophic factors, glutamate/neurotoxicity, neuroprotection and proteases and inhibitors, as well as the approaches to measuring specific effects in patients with the illness. It ends with a eye to the horizon, and the future, and where ALS treatment strategies may be heading after the millennium.
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Affiliation(s)
- B W Festoff
- Neurobiology Research Laboratory, Veterans Affairs Medical Center, Kansas City, Missouri, USA
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41
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Akaaboune M, Verdière-Sahuqué M, Lachkar S, Festoff BW, Hantaï D. Serine proteinase inhibitors in human skeletal muscle: expression of beta-amyloid protein precursor and alpha 1-antichymotrypsin in vivo and during myogenesis in vitro. J Cell Physiol 1995; 165:503-11. [PMID: 7593229 DOI: 10.1002/jcp.1041650308] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The balance of serine proteases and inhibitors in nerve and muscle is altered during programmed- and injury-induced remodeling. A serpin, alpha 1-antichymotrypsin (alpha 1-ACT), and Kunitz-inhibitor containing forms of the beta-amyloid precursor protein (beta APP) may be important components of this balance. In the present study, we analyzed their expression in primary cultures of human myogenic (satellite) cells that mimic myogenic differentiation using Western blotting and immunocytochemistry. In vitro results were compared to in vivo results from normal adult human skeletal muscle biopsies. Using an anti-alpha 1-ACT polyclonal antibody, we detected a 62 kDa immunoreactive band both in cultured human myogenic cells (mononucleated myoblasts as well as multi-nucleated myotubes) and in extracts of human muscle biopsies. With a polyclonal anti-beta APP antibody we found two bands (105 and 120 kDa) in myoblasts and myotubes in culture. However, the same antibody recognized only a single band at 92 kDa in biopsies. By immunocytochemistry, both alpha 1-ACT and beta APP were indistinctly present on localized to the surface of myoblasts in culture. In contrast, these inhibitors were dense on myotube surfaces, where they often formed distinct aggregates and frequently co-localized. In permeabilized muscle cells, alpha 1-ACT and beta APP appeared to be localized to the perikarya of both myoblasts and myotubes. Confirming previous results, both alpha 1-ACT and beta APP were present at the neuromuscular junction in human muscle sections. These developmental changes found during in vitro myogenesis for alpha 1-ACT and beta APP, both serine protease inhibitors, reinforce the hypothesis that regulation of the serine proteases and serine protease inhibitors plays an important role in neuromuscular differentiation.
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42
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Hantaï D, Akaaboune M, Lagord C, Murawsky M, Houenou LJ, Festoff BW, Vaught JL, Rieger F, Blondet B. Beneficial effects of insulin-like growth factor-I on wobbler mouse motoneuron disease. J Neurol Sci 1995; 129 Suppl:122-6. [PMID: 7595602 DOI: 10.1016/0022-510x(95)00081-c] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Recombinant human insulin-like growth factor-I (IGF-I) is being considered as a possible therapeutic agent for the treatment of motoneuron diseases like amyotrophic lateral sclerosis. The neurological mutant mouse wobbler, carries an autosomal recessive gene (wr) and has been characterized as a model of lower motoneuron disorders with associated muscle atrophy, denervation and reinnervation. The purpose of the present study was to determine the possible beneficial effect of IGF-I administration in this mouse model. Upon diagnosis at 4 weeks of age, affected mice and their control normal littermates received human recombinant IGF-I (1 mg/kg) or vehicle solution, once a day, for 6 weeks. Body weight and grip strength were evaluated periodically during the treatment period. Mean muscle fiber diameter on biceps brachii sections, choline acetyltransferase activity in muscle extracts, and motoneuron numbers in spinal cord sections were determined. IGF-I treated wobbler mice showed a marked weight increase from 3 to 6 weeks of treatment in comparison with placebo treated mutant mice. At the end of the treatment, grip strength, estimated by dynamometer resistance, was 40% higher in IGF-I treated versus placebo treated animals. Mean muscle fiber diameter which is smaller in wobbler mice than in normal mice was increased in IGF-I treated mutants. However, in this study the muscle choline acetyltransferase activity and the number of spinal cord motoneurons were unchanged. Thus, IGF-I administration mainly results in a significant effect on the behavioral and skeletal muscle histochemical parameters of the wobbler mouse mutant.
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Carter RE, Cerosaletti KM, Burkin DJ, Fournier RE, Jones C, Greenberg BD, Citron BA, Festoff BW. The gene for the serpin thrombin inhibitor (PI7), protease nexin I, is located on human chromosome 2q33-q35 and on syntenic regions in the mouse and sheep genomes. Genomics 1995; 27:196-9. [PMID: 7665170 DOI: 10.1006/geno.1995.1025] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Protease nexin I (PNI) is the most important physiologic regulator of alpha-thrombin in tissues. PNI is highly expressed and developmentally regulated in the nervous system where it is concentrated at neuromuscular junctions and also central synapses in the hippocampus and striatum. Approximately 10% of identified proteins at mammalian neuromuscular junctions are serine protease inhibitors, consistent with their central role in balancing serine protease activity to develop, maintain, and remodel synapses. Southern blot hybridization of PNI cDNA to somatic cell hybrids placed the structural gene for PNI (locus PI7) on human chromosome 2q33-q35 and to syntenic chromosomes in the mouse (chromosome 1) and sheep (chromosome 2).
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Affiliation(s)
- R E Carter
- Eleanor Roosevelt Institute for Cancer Research, Denver, Colorado 80206, USA
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44
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Tian WH, Festoff BW, Blot S, Diaz J, Hantaï D. Synaptic transmission blockade increases plasminogen activator activity in mouse skeletal muscle poisoned with botulinum toxin type A. Synapse 1995; 20:24-32. [PMID: 7624826 DOI: 10.1002/syn.890200105] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Experimental denervation, either by nerve crush or axotomy, leads to a dramatic increase in muscle plasminogen activator (PA) activity, suggesting a regulation of muscle PA levels by some neural influence (Festoff et al., 1986, J. Cell Biol., 103:1415-1421; Hantaï et al., 1990, Proc. Natl. Acad. Sci. U.S.A., 87:2926-2930). The Botulinum toxin (BoTx) type A is known to selectively interrupt the release of acetylcholine without structurally altering synaptic morphology. In the present study we have used acute BoTx poisoning of hind limb muscles to further explore the neural regulation of muscle PA activities directly after poisoning and during the process of collateral reinnervation. Electromyographic recording and study of ultraterminal sprouting after zinc iodideosmium and silver-cholinesterase staining were used to monitor "denervation" and reinnervation. Muscle choline acetyltransferase activity did not decrease, as is observed after experimental denervation, but in contrast increased and, therefore, reflected the functional integrity of intramuscular nerve endings. Within 2 days of BoTx poisoning, muscle urokinase-PA, and to a lesser extent, tissue-PA activities, rose in muscle extracts as shown by an amidolytic assay and fibrin zymography. When reinnervation occurred, muscle urokinase-PA activity decreased but did not return to baseline levels within the 80 days of our study. These results suggest that cholinergic transmission-regulated events determine activity of muscle PAs and that PAs likely have a role in neuromuscular formation and plasticity.
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Affiliation(s)
- W H Tian
- Développement, Pathologie, Régénération du Système Neuromusculaire, INSERM U.153, CNRS ERS 64, Paris, France
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45
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Festoff BW, Yang SX, Vaught J, Bryan C, Ma JY. The insulin-like growth factor signaling system and ALS neurotrophic factor treatment strategies. J Neurol Sci 1995; 129 Suppl:114-21. [PMID: 7595601 DOI: 10.1016/0022-510x(95)00080-l] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Because of its multi-faceted potential as a neurotrophic factor, insulin-like growth factor I (IGF-I) has been given to hundreds of ALS patients world-wide. Unlike some patients with post-polio syndrome and fragile elderly males, it is unclear whether any of these patients possess disturbances in IGF signaling. We found that about 25% of ALS patients in a controlled trial of human growth hormone (hGH) had lower or higher than normal IGF-I serum levels. Many ALS patients do have some of the characteristics of type II diabetes mellitus, where IGF-I therapy is also under way. In addition, in type I diabetes significant increase in a circulating molecule that binds IGF-I, IGF-I binding protein 1 (IGFBP-1), occurs along with reduced IGF-I, when neuropathic complications are prominent. We have studied the response of IGFBPs in ALS patients to subcutaneous rhIGF-I and found transient induction of IGFBP-1. Studies related to the IGFBPs have not been done in familial ALS (FALS) patients. However, the gene for another IGFBP, BP-2, co-localizes with the gene for juvenile ALS (ALSJ) on chromosome 2. IGF-I has been given to several models of motor neuron degeneration in the mouse, including motor neuron disease and wobbler, with beneficial effects. However, it is also not known whether any accepted genetic mouse model of motor neuron degeneration possesses any disturbance in the IGF signaling system.
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Affiliation(s)
- B W Festoff
- Neurobiology Research Laboratory (151), VA Medical Center, Kansas City, MO 64128, USA
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46
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Houenou LJ, Turner PL, Li L, Oppenheim RW, Festoff BW. A serine protease inhibitor, protease nexin I, rescues motoneurons from naturally occurring and axotomy-induced cell death. Proc Natl Acad Sci U S A 1995; 92:895-9. [PMID: 7846074 PMCID: PMC42727 DOI: 10.1073/pnas.92.3.895] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Protease nexin I (PNI) is a member of the family of serine protease inhibitors (serpins) that have been shown to promote neurite outgrowth in vitro from different neuronal cell types. These include neuroblastoma cells, hippocampal neurons, and sympathetic neurons. Free PNI protein is markedly decreased in various anatomical brain regions, including hippocampus, of patients with Alzheimer disease. Here, we report that PNI rescued spinal motoneurons during the period of naturally occurring (programmed) cell death in the chicken in a dose-dependent fashion. Furthermore, PNI prevented axotomy-induced spinal motoneuron death in the neonatal mouse. The survival effect of PNI on motoneurons during the period of programmed cell death was not associated with increased intramuscular nerve branching. PNI also significantly increased the nuclear size of motoneurons during the period of programmed cell death and prevented axotomy-induced atrophy of surviving motoneurons. These results are consistent with the possible role of PNI as a neurotrophic agent. They also support the idea that serine proteases or, more precisely, the balance of proteases and serpins may be involved in regulating the fate of neuronal cells during development.
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Affiliation(s)
- L J Houenou
- Department of Neurobiology and Anatomy, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27157
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47
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Abstract
Thrombospondin (TSP), an endogenous extracellular matrix (ECM) glycoprotein, is secreted from platelet alpha-granules after thrombin stimulation. Alterations in blood TSP levels occur in different pathologic conditions, suggesting it is a marker for certain disorders. We previously found a marked increase in TSP deposition in the muscle ECM of patients with amyotrophic lateral sclerosis (ALS) in comparison with controls. Because the mechanism for this increase is unknown, we compared serum TSP levels in 11 patients to 15 controls using three different site-specific monoclonal antibodies (MA-I, MA-II and A6.1). We found mean serum TSP concentrations by indirect ELISA to be significantly decreased in the ALS patients. Using laser densitometry we calculated the ratio of fragmented to native TSP from Western immunoblots probed with A6.1, where a higher ratio corresponds to increased fragments. Mean values for this ratio were 6.3 +/- 4.9 and 18.3 +/- 8.2 for controls and patients, respectively. Thus significant decrease in native TSP and increase in its proteolytic fragments in ALS is consistent with increased proteolytic enzyme activity. Dysregulation of the protease: inhibitor balance in this degenerative condition may be reflected in the quantitative and qualitative changes in TSP.
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Affiliation(s)
- I V Smirnova
- Neurobiology Research Laboratory (151R), Department of VA Medical Center, Kansas City, MO 64128
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48
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Ma J, Yang SX, Ho GJ, Festoff BW. Insulin-like growth factor binding protein-1 is pre-synaptic at mouse neuromuscular synapses and is transported in nerve. Neurochem Res 1994; 19:1363-8. [PMID: 7534873 DOI: 10.1007/bf00972464] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In a previous study, we localized insulin-like growth factor binding protein 1 (IGFBP-1) to mouse neuromuscular junctions, and intramuscular nerves. To determine if pre-synaptic accumulation of IGFBP-1 occurred, we used double ligation of sciatic nerve in adult mice at different time points. IGFBPs were detected by Western ligand blot (WLB) with 125I-IGF-I. WLB and Western immunoblot (WIB) analysis of extracts from double-ligated nerves showed a delayed (6 days) increase of IGFBP-1 in the soluble fraction between the ligatures and distal to the distal ligature. For comparison we evaluated transport of neurofilament components, using WIB and confirmed the primarily anterograde transport of these intraaxonal proteins. These data suggest that expression of IGFBP-1 is both by activated Schwann cells as well as retrograde axonal transport with likely entry into the axon at the synapse.
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Affiliation(s)
- J Ma
- Neurobiology Research Lab (151R), VA Medical Center, Kansas City, MO 64128
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Liu Y, Fields RD, Festoff BW, Nelson PG. Proteolytic action of thrombin is required for electrical activity-dependent synapse reduction. Proc Natl Acad Sci U S A 1994; 91:10300-4. [PMID: 7524091 PMCID: PMC45007 DOI: 10.1073/pnas.91.22.10300] [Citation(s) in RCA: 115] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Molecular mechanisms of activity-dependent synapse reduction were studied in an in vitro mammalian neuromuscular preparation. Synapse reduction in this model is activity-dependent and is substantially reduced by the broad-spectrum protease inhibitor, leupeptin, suggesting the role of activity-dependent proteolytic action in the process. Our present experiments show that a potent and specific thrombin inhibitor, hirudin, at nanomolar concentration completely blocked the activity-dependent synapse reduction. Furthermore, a naturally occurring serine protease inhibitor, protease nexin I (PNI), which closely colocalizes with acetylcholine receptors at the neuromuscular junction, inhibited the synapse reduction at the same low concentration. In contrast, neither cystatin, a cysteine protease inhibitor, nor aprotinin, a serine protease inhibitor that does not inhibit thrombin, blocked the synapse reduction. Similarly, neither of the inhibitors of the calcium-activated proteases calpain I and II prevented the reduction of synapses. These results strongly suggest that serine proteolytic action by thrombin or thrombin-like molecules is required for synapse reduction in our in vitro model of the mammalian neuromuscular junction.
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Affiliation(s)
- Y Liu
- Laboratory of Developmental Neurobiology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
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Abstract
Widely recognized as components of the blood coagulation cascade, serine proteases and their natural inhibitors, specific serpins known as the protease nexins, also regulate the maintenance of normal function in the nervous system. Increasingly, evidence has accumulated as to regulation of their synthesis and functional roles within both the CNS and peripheral nervous system. Our review focuses on the localization and activity of TH and PN I in the nervous system, as well as on the impact of the protease/inhibitor balance for the pathogenesis of neurodegenerative disorders such as AD.
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Affiliation(s)
- I V Smirnova
- Neurobiology Research Laboratory, Veterans Affairs Medical Center, Kansas City, Missouri 64128
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