scholarly journals Differential temporal expression of matrix metalloproteinases after spinal cord injury: relationship to revascularization and wound healing

2003 ◽  
Vol 99 (2) ◽  
pp. 188-197 ◽  
Author(s):  
Staci Goussev ◽  
Jung-Yu C. Hsu ◽  
Yong Lin ◽  
Tjoson Tjoa ◽  
Nino Maida ◽  
...  

Object. Matrix metalloproteinases (MMPs), particularly MMP-9/gelatinase B, promote early inflammation and barrier disruption after spinal cord injury (SCI). Early blockade of MMPs after injury provides neuroprotection and improves motor outcome. There is recent evidence, however, that MMP-9 and MMP-2/gelatinase A participate in later wound healing in the injured cord. The authors therefore examined the activity of these gelatinases during revascularization and glial scar formation in the contused murine spinal cord. Methods. Gelatinase activity was evaluated using gelatin zymography 24 hours after a mild, moderate, or severe contusion injury. The active form of MMP-2 was not detected, whereas MMP-9 activity was evident in all SCI groups and rose with increasing injury severity. The temporal expression of gelatinases was then examined using gelatin zymography after a moderate SCI. The active form of MMP-9 was most prominent at 1 day, extended through the early period of revascularization, and returned to control by 14 days. The active form of MMP-2 appeared at 7 days postinjury and remained elevated compared with that documented in sham-treated mice for at least 21 days. Increased MMP-2 activity coincided with both revascularization and glial scar formation. Using in situ zymography, gelatinolytic activity was detected in the meninges, vascular elements, glia, and macrophage-like cells in the injured cord. Results of immunolabeling confirmed the presence of gelatinase in vessels during revascularization and in reactive astrocytes associated with glial scar formation. Conclusions. These findings suggest that although MMP-9 and -2 exhibit overlapping expression during revascularization, the former is associated with acute injury responses and the latter with formation of a glial scar.

2005 ◽  
Vol 2 (3) ◽  
pp. 319-326 ◽  
Author(s):  
Sabine Conrad ◽  
Hermann J. Schluesener ◽  
Mehdi Adibzahdeh ◽  
Jan M. Schwab

Object. The glial scar composed of astrogliosis and extracellular matrix deposition represents a major impediment to axonal regeneration. The authors investigated the role of a novel profibrotic and angiogenic peptide connective tissue growth factor (CTGF [Hcs24/IGFBP-r2P]) in glial scar formation following spinal cord injury (SCI) in rats. Methods. The effects of SCI on CTGF expression during glial scar maturation 1 day to 1 month post-SCI were investigated using fluorescein-activated cell sorter (FACS) immunohistochemical analysis; these findings were compared with those obtained in sham-operated (control) spinal cords. The CTGF-positive cells accumulated at the spinal cord lesion site (p < 0.0001) corresponding to areas of glial scar formation. In the perilesional rim, CTGF expression was confined to invading vimentin-positive, glial fibrillary acidic protein (GFAP)—negative fibroblastoid cells, endothelial and smooth-muscle cells of laminin-positive vessels, and GFAP-positive reactive astrocytes. The CTGF-positive astrocytes coexpressed the activation-associated intermediate filaments nestin, vimentin (> 80%), and mesenchymal scar component fibronectin (50%). Conclusions. The restricted accumulation of CTGF-reactive astrocytes and CTGF-positive fibroblastoid cells lining the laminin-positive basal neolamina suggests participation of these cells in scar formation. In addition, perilesional upregulation of endothelial and smooth-muscle CTGF expression points to a role in blood—brain barrier function modulating edema-induced secondary damage.


2004 ◽  
Vol 100 (4) ◽  
pp. 343-352 ◽  
Author(s):  
Yi Ping Zhang ◽  
Christopher Iannotti ◽  
Lisa B. E. Shields ◽  
Yingchun Han ◽  
Darlene A. Burke ◽  
...  

Object. Laceration-induced spinal cord injury (SCI) results in the invasion of a connective tissue scar, progressive damage to the spinal cord due to complex secondary injury mechanisms, and axonal dieback of descending motor pathways. The authors propose that preparation of the spinal cord for repair strategies should include hematoma removal and dural closure, resulting in apposition of the severed ends of the spinal cord. Such procedures may reduce the size of the postinjury spinal cord cyst as well as limit scar formation. Methods. Using a novel device, the Vibraknife, the authors created a dorsal hemisection of the spinal cord at C-6 in the adult rat. In Group 1 (eight rats), the dura mater was repaired with apposition of the two stumps of the spinal cord to reduce the lesion gap. In Group 2 (10 rats), the dura was not closed and the two cord stumps were not approximated. All rats were killed at 4 weeks postinjury, and the spinal cords from each group were removed and examined using histological, stereological, and immunohistochemical methods. In Group 1 rats a significant reduction of the total lesion volume and connective tissue scar was observed compared with those in Group 2 (Student t-test, p < 0.05). Approximation of the stumps did not promote the regeneration of corticospinal tract fibers or sensory axons through the lesion site. Conclusions. Apposition of the severed ends of the spinal cord by dural closure reduces the lesion gap, cystic cavitation, and connective tissue scar formation. These outcomes may collectively reduce secondary tissue damage at the injury site and shorten the length of the lesion gap, which will facilitate transplantation-mediated axonal regeneration after laceration-induced SCI.


1994 ◽  
Vol 80 (1) ◽  
pp. 97-111 ◽  
Author(s):  
Shlomo Constantini ◽  
Wise Young

✓ Recent clinical trials have reported that methylprednisolone sodium succinate (MP) or the monosialic ganglioside GM1 improves neurological recovery in human spinal cord injury. Because GM1 may have additive or synergistic effects when used with MP, the authors compared MP, GM1, and MP+GM1 treatments in a graded rat spinal cord contusion model. Spinal cord injury was caused by dropping a rod weighing 10 gm from a height of 1.25, 2.5, or 5.0 cm onto the rat spinal cord at T-10, which had been exposed via laminectomy. The lesion volumes were quantified from spinal cord Na and K shifts at 24 hours after injury and the results were verified histologically in separate experiments. A single dose of MP (30 mg/kg), given 5 minutes after injury, reduced 24-hour spinal cord lesion volumes by 56% (p = 0.0052), 28% (p = 0.0065), and 13% (p > 0.05) in the three injury-severity groups, respectively, compared to similarly injured control groups treated with vehicle only. Methylprednisolone also prevented injury-induced hyponatremia and increased body weight loss in the spine-injured rats. When used alone, GM1 (10 to 30 mg/kg) had little or no effect on any measured variable compared to vehicle controls; when given concomitantly with MP, GM1 blocked the neuroprotective effects of MP. At a dose of 3 mg/kg, GM1 partially prevented MP-induced reductions in lesion volumes, while 10 to 30 mg/kg of GM1 completely blocked these effects of MP. The effects of MP on injury-induced hyponatremia and body weight loss were also blocked by GM1. Thus, GM1 antagonized both central and peripheral effects of MP in spine-injured rats. Until this interaction is clarified, the authors recommend that MP and GM1 not be used concomitantly to treat acute human spinal cord injury. Because GM1 modulates protein kinase activity, protein kinases inhibit lipocortins, and lipocortins mediate anti-inflammatory effects of glucocorticoids, it is proposed that the neuroprotective effects of MP are partially due to anti-inflammatory effects and that GM1 antagonizes the effects of MP by inhibiting lipocortin. Possible beneficial effects of GM1 reported in central nervous system injury may be related to the effects on neural recovery rather than acute injury processes.


1984 ◽  
Vol 61 (5) ◽  
pp. 925-930 ◽  
Author(s):  
Ronald W. J. Ford ◽  
David N. Malm

✓ Hypocarbia, normocarbia, or hypercarbia was maintained for an 8-hour period beginning 30 minutes after acute threshold spinal cord injuries in cats. No statistically significant differences in neurological recovery or histologically assessed tissue preservation were found among the three groups of animals 6 weeks after injury. No animal recovered the ability to walk. It is concluded that maintenance of hypercarbia or hypocarbia during the early postinjury period is no more therapeutic than maintenance of normocarbia. Mortality rates and tissue preservation data suggest, however, that postinjury hypocarbia may be less damaging than hypercarbia.


2002 ◽  
Vol 97 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Erkan Kaptanoglu ◽  
Selcuk Palaoglu ◽  
H. Selcuk Surucu ◽  
Mutlu Hayran ◽  
Etem Beskonakli

Object. There is a need for an accurate quantitative histological technique that also provides information on neurons, axons, vascular endothelium, and subcellular organelles after spinal cord injury (SCI). In this paper the authors describe an objective, quantifiable technique for determining the severity of SCI. The usefulness of ultrastructural scoring of acute SCI was assessed in a rat model of contusion injury. Methods. Spinal cords underwent acute contusion injury by using varying weights to produce graded SCI. Adult Wistar rats were divided into five groups. In the first group control animals underwent laminectomy only, after which nontraumatized spinal cord samples were obtained 8 hours postsurgery. The weight-drop technique was used to produce 10-, 25-, 50-, and 100-g/cm injuries. Spinal cord samples were also obtained in the different trauma groups 8 hours after injury. Behavioral assessment and ultrastructural evaluation were performed in all groups. When the intensity of the traumatic injury was increased, behavioral responses showed a decreasing trend. A similar significant negative correlation was observed between trauma-related intensity and ultrastructural scores. Conclusions. In the present study the authors characterize quantitative ultrastructural scoring of SCI in the acute, early postinjury period. Analysis of these results suggests that this method is useful in evaluating the degree of trauma and the effectiveness of pharmacotherapy in neuroprotection studies.


2005 ◽  
Vol 3 (4) ◽  
pp. 302-307 ◽  
Author(s):  
Christopher B. Shields ◽  
Y. Ping Zhang ◽  
Lisa B. E. Shields ◽  
Yingchun Han ◽  
Darlene A. Burke ◽  
...  

Object. There are no clinically based guidelines to direct the spine surgeon as to the proper timing to undertake decompression after spinal cord injury (SCI) in patients with concomitant stenosis-induced cord compression. The following three factors affect the prognosis: 1) severity of SCI; 2) degree of extrinsic spinal cord compression; and 3) duration of spinal cord compression. Methods. To elucidate further the relationship between varying degrees of spinal stenosis and a mild contusion-induced SCI (6.25 g-cm), a rat SCI/stenosis model was developed in which 1.13- and 1.24-mm-thick spacers were placed at T-10 to create 38 and 43% spinal stenosis, respectively. Spinal cord damage was observed after the stenosis—SCI that was directly proportional to the duration of spinal cord compression. The therapeutic window prior to decompression was 6 and 12 hours in the 43 and 38% stenosis—SCI lesions, respectively, to maintain locomotor activity. A significant difference in total lesion volume was observed between the 2-hour and the delayed time(s) to decompression (38% stenosis—SCI, 12 and 24 hours, p < 0.05; 43% stenosis—SCI, 24 hours, p < 0.05) indicating a more favorable neurological outcome when earlier decompression is undertaken. This finding was further supported by the animal's ability to support weight when decompression was performed by 6 or 12 hours compared with 24 hours after SCI. Conclusions. Analysis of the findings in this study suggests that early decompression in the rat improves locomotor function. Prolongation of the time to decompression may result in irreversible damage that prevents locomotor recovery.


1986 ◽  
Vol 65 (1) ◽  
pp. 108-110 ◽  
Author(s):  
Daniel Dumitru ◽  
James E. Lang

✓ A rare case of cruciate paralysis is reported in a 39-year-old man following a motor-vehicle accident. The differentiation of this syndrome from a central cervical spinal cord injury is delineated.


2004 ◽  
Vol 100 (1) ◽  
pp. 56-61
Author(s):  
Pierre-Yves Mure ◽  
Mark Galdo ◽  
Nathalie Compagnone

Object. The authors conducted a study to establish outcomes associated with bladder function in a mouse model of spinal cord injury (SCI) and to assess the sensitivity of these outcomes in determining the efficacy of pharmacological treatments. Methods. A mouse model of moderate contusive SCI was used. Outcome parameters included physiological, behavioral, and morphological measurements. To test the sensitivity of these outcomes, the authors used a dehydroepiandrosterone (DHEA) treatment that they had previously shown to promote neurological recovery effectively after SCI. A behavioral scale was used to identify the day at which autonomic function of the bladder was recovered. The reduction in the daily volume of urine during the period of functional recovery paralleled this scale. They then determined the day postinjury at which the functional differences between the vehicle- and DHEA-treated mice exhibited the maximal amplitude. Changes were measured in the composition of the extracellular matrix relative to collagen expression in the layer muscularis of the detrusor at this time point. They found that SCI increases the ratio of collagen type III to collagen type I in the detrusor. Moreover, in the DHEA-treated group, this ratio was similar to that demonstrated in sham-operated mice, establishing the sensitivity of this outcome to assess therapeutic benefits to the bladder function. They next examined the relationship between measurements of neurological recovery and controlled voiding by using cluster analysis. Conclusions. The authors found that early recovery of controlled voiding is predictive of motor recovery.


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