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Thread: Chondroitinase improves locomotor and bladder function in after rat spinal cord contusion

  1. #1

    Chondroitinase improves locomotor and bladder function in after rat spinal cord contusion

    This study from Acorda Therapeutics reports that Chondroitinase ABC improves locomotion and bladder function following contusion injury in rats.

    Caggiano AO, Zimber MP, Ganguly A, Blight AR and Gruskin EA (2005). Chondroitinase ABCI Improves Locomotion and Bladder Function following Contusion Injury of the Rat Spinal Cord. J Neurotrauma 22: 226-39. Chondroitin sulfate proteoglycans are synthesized and deposited in the spinal cord following injury. These proteoglycans may restrict regeneration and plasticity and contribute to the limited recovery seen after an injury. Chondroitinase, a bacterial enzyme that catalyzes the hydrolysis of the chondroitin chains on proteoglycans, has been shown to improve motor and sensory function following partial transection lesions of the spinal cord. To assess the effects of chondroitinase in a clinically relevant model of spinal cord injury, 128 female Long-Evans rats received either a severe, moderate, or mild contusion injury at the vertebral level T9/T10 with a forceps model and were treated for 2 weeks with chondroitinase ABCI at 0.06 Units per dose, penicillinase, or vehicle control via an intrathecal catheter placed near the injury. Motor behavior was measured by open-field testing of locomotion and bladder function monitored by measuring daily residual urine volumes. Animals treated with chondroitinase showed significant improvements in open-field locomotor activity as measured by the Basso, Beattie and Bresnahan scoring system after both severe and moderate SCI (p < 0.05 and 0.01, respectively). No significant locomotor differences were observed in the mild injury group. In the moderate injury group, residual urine volumes were reduced with chondroitinase treatment by 2 weeks after injury [p < 0.05) and in the severe injury group, by 6 weeks after injury [NS). These results demonstrate that chondroitinase is effective at promoting both somatic and autonomic motor recovery following a clinically relevant contusion spinal cord injury and is a candidate as a therapeutic for human spinal cord injury. Acorda Therapeutics, Inc., Hawthorne, New York.

  2. #2
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    So Dr Young when are they going to start trials in humans and where do I signup.
    I am c3 c4 incomplete with central cord syndrome, seven years injured.

    "If neccessity is the mother of invention,Sci cure is one mother of a neccessity".

  3. #3
    Wobly,

    In the above study, the chondroitinase was given to animals shortly after injury. All the published studies to date have given the chondroitinase shortly after injury.

    Several laboratories are studying chondroitinase given to chronically injured spinal cords. I don't know of any laboratory that is finding that chondroitinase alone is useful for chronic spinal cord injury. Two recent reports suggest that chondroitinase is more effective when given in combination with some other therapy but please note that both of these studies involve acute spinal cord injury models:
    1. Schwann cells plus OEG plus chondroitinase (Fouad, et al. 2005). This confirms the work of Xiaoming Xu (Chau, et al., 2004) who had earlier reported that chondroitinase facilitated axonal growth out of Schwann cell bridges.
    2. Chondroitinase plus lithium (Yick, et al., 2004). This study from Hong Kong showed lithium (a commonly used treatment) markedly enhanced the regenerative effects of chondroitinase (Yick, et al., 2003; Yick, et al., 2000)

    Jerry Silver (the scientist who proposed that chondroitinase will stimulate regeneration) recently found a new enzyme that may be more effective than chondroitinase (Grimpe & Silver, 2004). Bradbury, et al. (2003) had reported that chondroitinase improved regeneration and functional recovery in rats. The Russians gave mixtures of enzymes to human spinal cords in the 1970's. The enzymes included hyaluronidase (a form of human chondroitinase). Kent Waldrep was one of the first Americans to get the treatment in the late 1970's. In the United States, Guth, et al., (1980) and Magness, et al. (1980) showed that the enzyme mix and hyaluronidase do not work in animals. There is a lot of interesting history but perhaps I can review that history some other time.

    Wise.

    References

    Fouad K, Schnell L, Bunge MB, Schwab ME, Liebscher T and Pearse DD (2005). Combining Schwann cell bridges and olfactory-ensheathing glia grafts with chondroitinase promotes locomotor recovery after complete transection of the spinal cord. J Neurosci 25: 1169-78. Numerous obstacles to successful regeneration of injured axons in the adult mammalian spinal cord exist. Consequently, a treatment strategy inducing axonal regeneration and significant functional recovery after spinal cord injury has to overcome these obstacles. The current study attempted to address multiple impediments to regeneration by using a combinatory strategy after complete spinal cord transection in adult rats: (1) to reduce inhibitory cues in the glial scar (chondroitinase ABC), (2) to provide a growth-supportive substrate for axonal regeneration [Schwann cells (SCs)], and (3) to enable regenerated axons to exit the bridge to re-enter the spinal cord (olfactory ensheathing glia). The combination of SC bridge, olfactory ensheathing glia, and chondroitinase ABC provided significant benefit compared with grafts only or the untreated group. Significant improvements were observed in the Basso, Beattie, and Bresnahan score and in forelimb/hindlimb coupling. This recovery was accompanied by increased numbers of both myelinated axons in the SC bridge and serotonergic fibers that grew through the bridge and into the caudal spinal cord. Although prominent descending tracts such as the corticospinal and reticulospinal tracts did not successfully regenerate through the bridge, it appeared that other populations of regenerated fibers were the driving force for the observed recovery; there was a significant correlation between numbers of myelinated fibers in the bridge and improved coupling of forelimb and hindlimb as well as open-field locomotion. Our study tests how proven experimental treatments interact in a well-established animal model, thus providing needed direction for the development of future combinatory treatment regimens. University of Alberta, Faculty of Rehabilitation Medicine, Edmonton, Canada T6G 2G4. karim.fouad@ualberta.ca

    Yick LW, So KF, Cheung PT and Wu WT (2004). Lithium chloride reinforces the regeneration-promoting effect of chondroitinase ABC on rubrospinal neurons after spinal cord injury. J Neurotrauma 21: 932-43. After spinal cord injury, enzymatic digestion of chondroitin sulfate proteoglycans promotes axonal regeneration of central nervous system neurons across the lesion scar. We examined whether chondroitinase ABC (ChABC) promotes the axonal regeneration of rubrospinal tract (RST) neurons following injury to the spinal cord. The effect of a GSK-3beta inhibitor, lithium chloride (LiCl), on the regeneration of axotomized RST neurons was also assessed. Adult rats received a unilateral hemisection at the seventh cervical spinal cord segment (C7). Four weeks after different treatments, regeneration of RST axons across the lesion scar was examined by injection of Fluoro-Gold at spinal segment T2, and locomotor recovery was studied by a test of forelimb usage. Injured RST axons did not regenerate spontaneously after spinal cord injury, and intraperitoneal injection of LiCl alone did not promote the regeneration of RST axons. Administration of ChABC at the lesion site enhanced the regeneration of RST axons by 20%. Combined treatment of LiCl together with ChABC significantly increased the regeneration of RST axons to 42%. Animals receiving combined treatment used both forelimbs together more often than animals that received sham or single treatment. Immunoblotting and immunohistochemical analysis revealed that LiCl induced the expression of inactive GSK-3beta as well as the upregulation of Bcl-2 in injured RST neurons. These results indicate that in vivo, LiCl inhibits GSK-3beta and reinforces the regeneration-promoting function of ChABC through a Bcl-2-dependent mechanism. Combined use of LiCl together with ChABC could be a novel treatment for spinal cord injury. Department of Anatomy, Faculty of Medicine, The University of Hong Kong, Hong Kong.

    Grimpe B and Silver J (2004). A novel DNA enzyme reduces glycosaminoglycan chains in the glial scar and allows microtransplanted dorsal root ganglia axons to regenerate beyond lesions in the spinal cord. J Neurosci 24: 1393-7. CNS lesions induce production of ECM molecules that inhibit axon regeneration. One major inhibitory family is the chondroitin sulfate proteoglycans (CSPGs). Reduction of their glycosaminoglycan (GAG) chains with chondroitinase ABC leads to increased axon regeneration that does not extend well past the lesion. Chondroitinase ABC, however, is unable to completely digest the GAG chains from the protein core, leaving an inhibitory "stub" carbohydrate behind. We used a newly designed DNA enzyme, which targets the mRNA of a critical enzyme that initiates glycosylation of the protein backbone of PGs, xylosyltransferase-1. DNA enzyme administration to TGF-beta-stimulated astrocytes in culture reduced specific GAG chains. The same DNA enzyme applied to the injured spinal cord led to a strong reduction of the GAG chains in the lesion penumbra and allowed axons to regenerate around the core of the lesion. Our experiments demonstrate the critical role of PGs, and particularly those in the penumbra, in causing regeneration failure in the adult spinal cord. Case Western Reserve University, School of Medicine, Department of Neurosciences, Cleveland, Ohio 44106, USA. bxg15@po.cwru.edu

    Chau CH, Shum DK, Li H, Pei J, Lui YY, Wirthlin L, Chan YS and Xu XM (2004). Chondroitinase ABC enhances axonal regrowth through Schwann cell-seeded guidance channels after spinal cord injury. Faseb J 18: 194-6. Grafting of Schwann cell-seeded channels into hemisected adult rat thoracic spinal cords has been tested as a strategy to bridge the injured cord. Despite success in guiding axonal growth into the graft, regeneration across the distal graft-host interface into the host spinal cord was limited. We hypothesized that chondroitin sulfate (CS) glycoforms deposited at the gliotic front of the interface constitute a molecular barrier to axonal growth into the host cord. Because CS glycoforms deposited by purified astrocytes in vitro were removable by digestion with chondroitinase ABC, we attempted to achieve likewise by infusion of the enzyme to the host side of the interface. By 1 month post-treatment, significant numbers of regenerating axons crossed an interface that was subdued in macrophage/microglia reaction and decreased in CS-immunopositivity. The axons extended as far into the caudal cord as 5 mm, in contrast to nil in vehicle-infused controls. Fascicular organizations of axon-Schwann cell units within the regenerated tissue cable were better-preserved in enzyme-treated cords than in vehicle-infused controls. We conclude that CS glycoforms deposited during gliosis at the distal graft-host interface could be cleared by the in vivo action of chondroitinase ABC to improve prospects of axonal regeneration into the host spinal cord. Department of Biochemistry, Faculty of Medicine, University of Hong Kong, Hong Kong, China.

    Yick LW, Cheung PT, So KF and Wu W (2003). Axonal regeneration of Clarke's neurons beyond the spinal cord injury scar after treatment with chondroitinase ABC. Exp Neurol 182: 160-8. We have previously demonstrated that enzymatic digestion of chondroitin sulfate proteoglycan (CSPG) at the scar promotes the axonal regrowth of Clarke's nucleus (CN) neurons into an implanted peripheral nerve graft after hemisection of the spinal cord. The present study examined whether degradation of CSPG using chondroitinase ABC promoted the regeneration of CN neurons through the scar into the rostral spinal cord in neonatal and adult rats. Following hemisection of the spinal cord at T11, either vehicle or chondroitinase ABC was applied onto the lesion site. The postoperative survival periods were 2 and 4 weeks. The regenerated CN neurons were retrogradely labeled by Fluoro-Gold injected at spinal cord level C7. In the sham group, there was no regeneration of injured CN neurons in both neonatal and adult rats. Treatment with 2.5 unit/ml chondroitinase ABC in neonates resulted in 11.8 and 8.3% of the injured CN neurons regenerated into the rostral spinal cord at 2 and 4 weeks, respectively. In adults, 9.4 and 12.3%, at 2 and 4 weeks, respectively, of the injured CN neurons regenerated their axons to the rostral spinal cord. The immunoreactivity for the carbohydrate epitope of CSPG was dramatically decreased around the lesion site after treatment with chondroitinase ABC compared to sham control in both neonatal and adult animals. Our results show that axonal regeneration in the spinal cord can be promoted by degradation of CSPG with chondroitinase ABC. This result further suggests that CSPG is inhibitory to the regeneration of neurons in the spinal cord after traumatic injury. Department of Anatomy, Faculty of Medicine, The University of Hong Kong, Hong Kong.

    Bradbury EJ, Moon LD, Popat RJ, King VR, Bennett GS, Patel PN, Fawcett JW and McMahon SB (2002). Chondroitinase ABC promotes functional recovery after spinal cord injury. Nature 416: 636-40. The inability of axons to regenerate after a spinal cord injury in the adult mammalian central nervous system (CNS) can lead to permanent paralysis. At sites of CNS injury, a glial scar develops, containing extracellular matrix molecules including chondroitin sulphate proteoglycans (CSPGs). CSPGs are inhibitory to axon growth in vitro, and regenerating axons stop at CSPG-rich regions in vivo. Removing CSPG glycosaminoglycan (GAG) chains attenuates CSPG inhibitory activity. To test the functional effects of degrading chondroitin sulphate (CS)-GAG after spinal cord injury, we delivered chondroitinase ABC (ChABC) to the lesioned dorsal columns of adult rats. We show that intrathecal treatment with ChABC degraded CS-GAG at the injury site, upregulated a regeneration-associated protein in injured neurons, and promoted regeneration of both ascending sensory projections and descending corticospinal tract axons. ChABC treatment also restored post-synaptic activity below the lesion after electrical stimulation of corticospinal neurons, and promoted functional recovery of locomotor and proprioceptive behaviours. Our results demonstrate that CSPGs are important inhibitory molecules in vivo and suggest that their manipulation will be useful for treatment of human spinal injuries. Sensory Function Group, Centre for Neuroscience Research, Hodgkin Building, Kings College London, Guy's Campus, London Bridge, London SE1 1UL, UK. elizabeth.bradbury@kcl.ac.uk

    Yick LW, Wu W, So KF, Yip HK and Shum DK (2000). Chondroitinase ABC promotes axonal regeneration of Clarke's neurons after spinal cord injury. Neuroreport 11: 1063-7. We examined whether enzymatic digestion of chondroitin sulfate (CS) promoted the axonal regeneration of neurons in Clarke's nucleus (CN) into a peripheral nerve (PN) graft following injury of the spinal cord. After hemisection at T11, a segment of PN graft was implanted at the lesion site. Either vehicle, brain-derived neurotrophic factor (BDNF) or chondroitinase ABC was applied at the implantation site. The postoperative survival period was 4 weeks. Treatment with vehicle or BDNF did not promote the axonal regeneration of CN neurons into the PN graft. Application of 2.5 unit/ml chondroitinase ABC resulted in a significant increase (12.8%) in the number of regenerated CN neurons. Double labeling with Fluoro-Gold and NADPH-diaphorase histochemistry showed that the regenerated CN neurons did not express nitric oxide synthase (NOS). Our results suggest that CS is inhibitory to the regeneration of CN neurons following injury of the spinal cord. Department of Anatomy, Faculty of Medicine, University of Hong Kong, Hong Kong.

    Lemons ML, Howland DR and Anderson DK (1999). Chondroitin sulfate proteoglycan immunoreactivity increases following spinal cord injury and transplantation. Exp Neurol 160: 51-65. Extrinsic factors appear to contribute to the lack of regeneration in the injured adult spinal cord. It is likely that these extrinsic factors include a group of putative growth inhibitory molecules known as chondroitin sulfate proteoglycans (CSPGs). The aims of this study were to determine: (1) the consequences of spinal cord contusion injury on CSPG expression, (2) if CSPGs can be degraded in vivo by exogenous enzyme application, and (3) the effects of intraspinal transplantation on the expression of CSPGs. Chondroitin 6-sulfate proteoglycan immunoreactivity (CSPG-IR) dramatically increased following spinal cord contusion injury both at and adjacent to the injury site compared to normal controls (no surgical procedure) and laminectomy-only controls by 4 days postinjury. The dramatic increase in CSPG-IR persisted around the lesion and in the dorsal one-half to two-thirds of the spinal cord for at least 40 days postinjury. Glial fibrillary acidic protein (GFAP)-IR patterns were similarly intensified and spatially restricted as CSPG-IR patterns. These results suggest that: (1) CSPGs may contribute to the lack of regeneration following spinal cord injury and (2) astrocytes may contribute to the production of CSPGs. In addition, our results show that CSPGs could be cleaved in vivo with exogenous chondroitinase ABC application. This demonstration of cleavage may the basis for a model to directly assess CSPGs' role in growth inhibition in vivo (studies in progress) and hold potential as a therapeutic approach to enhance growth. Interestingly, the robust, injury-induced CSPG-IR patterns were not altered by intraspinal grafts of fetal spinal cord. The CSPG expression profile in the host spinal cord was similar to time-matched contusion-only animals. This was also true of GFAP-IR patterns. Furthermore, the fetal spinal cord tissue, which was generally CSPG negative at the time of transplantation, developed robust CSPG expression by 30 days posttransplantation. This increase in CSPG expression in the graft was paired with a moderate increase in GFAP-IR. CSPG-IR patterns suggest that these molecules may contribute to the limited regeneration seen following intraspinal transplantation. In addition, it suggests that the growth permissiveness of the graft may change overtime as CSPG expression develops within the graft. These correlations in the injured and transplanted spinal cord support CSPGs' putative growth inhibitory effect in the adult spinal cord. Department of Neuroscience, University of Florida College of Medicine, Gainesville 36210, USA.

    Zuo J, Neubauer D, Dyess K, Ferguson TA and Muir D (1998). Degradation of chondroitin sulfate proteoglycan enhances the neurite-promoting potential of spinal cord tissue. Exp Neurol 154: 654-62. The contribution of chondroitin sulfate proteoglycan (CSPG) in the suppression of axonal growth in rat spinal cord has been examined by means of an in vitro bioassay in which regenerating neurons are grown on tissue section substrata. Dissociated embryonic chick dorsal root ganglionic neurons were grown on normal and injured adult spinal cord tissue sections treated with chondroitinases. Neuritic growth on normal spinal cord tissue was meager. However, both the percentage of neurons with neurites and the average neurite length were substantially greater on sections treated with chondroitinase ABC. Enzymes that specifically degraded dermatan sulfate or hyaluronan were ineffective. Neuritic growth was significantly greater on injured (compared to normal) spinal cord and a further dramatic increase resulted from chondroitinase ABC treatment. Neurites grew equally within white and gray matter regions after chondroitinase treatment. Observed increases in neurite outgrowth on chondroitinase-treated tissues were largely inhibited in the presence of function-blocking laminin antibodies. These findings indicate that inhibitory CSPG is widely distributed and predominant in both normal and injured spinal cord tissues. Additionally, inhibitory CSPG is implicated in negating the potential stimulatory effects of laminin that might otherwise support spinal cord regeneration. Department of Pediatrics, University of Florida Brain Institute and College of Medicine, Gainesville, Florida, 32610-0296, USA.

    Grijalva I, Guizar-Sahagun G, Salgado-Ceballos H, Ibarra A, Franco-Bourland R, Espitia L and Madrazo I (1996). Improvement of host-graft adhesion by enzymatic manipulation of the subacute spinal cord contusion area in the rat. Transplant Proc 28: 3340-2. Medical Research Unit, Hospital de Especialidades, Centro Medico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico.

    Magness AP, 2nd, Barnes KL, Ferrario CM, Cox W and Dohn DF (1980). Effect of hyaluronidase on acute spinal cord injury. Surg Neurol 13: 157-9. Three control and five experimental dogs were subjected to 500 gm-cm injury of the midthoracic spinal cord by the weight dropping technique. Five hundred units per kilogram of hyaluronidase injected intravenously 20 minutes after injury in the experimental animals did not alter the loss of dorsal column evoked potentials (nonaveraged) or improve the pathological results up to three hours. These results imply that hyaluronidase will not significantly alter the functional outcome of trauma of the spinal cord in dogs.

    Guth L, Albuquerque EX, Deshpande SS, Barrett CP, Donati EJ and Warnick JE (1980). Ineffectiveness of enzyme therapy on regeneration in the transected spinal cord of the rat. J Neurosurg 52: 73-86.

    [This message was edited by Wise Young on 02-21-05 at 06:29 AM.]

  4. #4
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    Sorry it's taken so long, but thanks for that Dr Young.

    "If neccessity is the mother of invention,Sci cure is one mother of a neccessity".

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