Table 4.
Rho Antagonists
| Study | Animal model and injury model | Intervention and timing | Experimental group | Outcome: histologic/biochemical/physiological/behavioral |
|---|---|---|---|---|
| Lord-Fontaine et al., 2008 | Model: female SD rats or female Balb-c mice Injury: T9 NYU impactor (rat), 10 g × 25 mm or T7 dorsal over-hemisection (mouse) |
BA-210 (Cethrin) • 15 μg in fibrin sealant applied extradurally (rat) at time of injury • 1 mg in fibrin sealant applied onto exposed cord (mouse) immediately or at 24 or 72 h PI |
Rat SCI + • BA-210 in fibrin sealant (n = 11) • Vehicle in fibrin sealant (n = 12) Mouse SCI + • BA-210 at 0 h PI (n = 4) • BA-210 at 24 h PI (n = 6) • BA-210 at 72 h PI (n = 6) • Fibrin sealant controls |
Histologic/biochemical/physiological: BA-210 reduced lesion extent and increased spared white matter in rat SCI model (with immediate treatment). No description of histologic outcomes in mouse SCI model. Behavioral: BA-210 significantly improved BBB scores in the rat SCI model at 6, 7, and 8 wk (∼9 vs. just under 8). There was no evidence of the induction of mechanical allodynia in BA-210 treated animals. BA-210 also significantly improved BBB scores in the mouse SCI model at 16 d PI when administered immediately or 24 h PI. No significant difference in locomotor function in the BA-210 vs. control animals with the 72 h PI treatment. |
| Nishio et al., 2006 | Model: male Wistar rats 205–245 g Injury: T9 NYU impactor, 10 g × 25 mm |
Fasudil, Rho-kinase inhibitor • Via an osmotic minipump, 15 μg/μL at rate of 12 μL/d, resulting in the infusion of 180 μg/day started 0 h PI or started 4 wk PI Saline • Started immediately or delayed |
SCI + • Fasudil (n = 5) • Saline (immediate, n = 5) • Saline (delayed, n = 7) |
Histologic/biochemical/physiological: CST sprouting by immediate, but not delayed, Fasudil treatment Behavioral: Immediate, but not delayed Fasudil treatment results in improved BBB hindlimb function. |
| Chan et al., 2005 | Model: adult male SD rats Injury: C4/C5 dorsal column transection |
Y-27632, Rho-kinase inhibitor • Via osmotic minipumps implanted into the subcutaneous space at the back of the neck, 2 mM, 160 μg (low dose), or 20 mM, 1600 μg (high dose) per animal over 2 wk, started 0 h PI |
SCI + • Low-dose Y27632 (n = 15) • High-dose Y-27632 (n = 20) • PBS (n = 18) |
Histologic/biochemical/physiological: High-dose Y27632 significantly increased the distance of the longest axon compared to controls. Low-dose Y27632-treated animals had decreased sprouting in the distal grey matter compared to controls, while high-dose-treated animals showed more sprouting. Behavioral: Low-dose Y27632 treatment appeared to be detrimental to neurological recovery. For the forepaw outward rotation angles, only the high-dose group showed significant recovery. Footslip and food pellet reaching tests indicated that high-dose Y27632 accelerated recovery, while low dose impeded it. |
| Yamagishi et al., 2005 | Model: female Wistar rats, 200–250 g Injury: T9/T10 transection |
Y-27632 • Via gel foam, 10 μL of 30 mM at 0 h PI |
SCI + • Y-27632 • PBS N = 6/group |
Histologic/biochemical/physiological: Immunostaining 3 d post-axotomy showed that Y-27632 significantly abolished breakdown of microtubules and neurofilaments as well as axolemma in transected spinal cords. Results suggest that Rho-kinase inhibition delays Wallerian degeneration in vivo. Rho-kinase inihibition also promotes increased integrity of the dorsal CST in rats with transection cord injuries, as demonstrated with increased anterograde labeling of the CST. Behavioral: not reported |
| Tanaka et al., 2004 | Model: male Wistar rats, 200–250 g Injury: T10 dorsal-hemisection, depth of 1.8 mm |
Y-27632 • 3 mg per animal, at 0 h PI, delivered via osmotic minipump over 2 wk Fasudil • 3 mg per animal, delivered via osmotic minipump over 2 wk Cytoplasmic p21Cip1/WAF1 fusion protein GST-ΔNLS-p21-PTD-myc • 20 nmol/kg/d, delivered via osmotic minipump over 2 wk |
SCI + • Y-27632 (n = 26) • HA-1077 (n = 26) • p21Cip1/WAF1 (n = 29) • GST-PTD-myc control (n = 28) |
Histologic/biochemical/physiological: HA-1077 or Y-27632 treatments led to significantly enhanced sprouting, and GST-ΔNLS-p21-PTD-myc protein was even more effective. Immunoreactivity for Tuj1 and GFAP revealed that HA-1077 and Y-27632 were as effective as GST-ΔNLS-p21-PTD-myc protein in reducing the cavity area. EMG recordings demonstrated that GST-ΔNLS-p21-PTD-myc protein, HA-1077, and Y-27632 decrease ratios of irregular contractions between the TA and the VL muscles in comparison to GST-PTD-myc-treated control rats. Behavioral: BBB scores of rats with HA-1077, Y-27632, and GST-ΔNLS-p21-PTD-myc protein were significantly improved over the GST-PTD-myc-treated control rats. |
| Dubreuil et al., 2003 | Model: female Long-Evans rats, 200–250 g and female Balb/c mice, 20–22 g Injury: • Rats: T10 dorsal over-hemisections, depth of 1.6 mm or NYU impactor, 25 g × cm • Mice: T8 dorsal over-hemisections |
C3 transferase • Clostridium botulium exozyme (C3-05) in a fibrin matrix, injection into transected spinal cord • 50 μg at 0 h PI (rats) • 10 μg at 0 h PI (mice) • 1 μg in fibrin at 0 h PI (for TUNEL experiment) |
SCI + • Rats, C3 treatment (n = 13) • Rats, untreated (n = 11) • Mice, C3 treatment (n = 5) • Mice, untreated (n = 5) Sham • Rats (n = 11) • Mice (n = 5) |
Histologic/biochemical/physiological: To determine if endogenous cells in the spinal cord were able to take up and retain C3–05 after treatment, rat spinal cord double-labeled with an antibody specific for C3 and with cell type-specific markers showed intracellular C3 immunoreaction in neurons, astrocytes, and oligodendrocytes. Treatment with the Rho antagonist C3–05 after contusion or transection of the spinal cord reverses RhoA activation after injury. In both mice and rats treated with C3–05, the number of TUNEL-labeled cells was significantly reduced by ∼50% after SCI. Behavioral: not reported |
| Fournier et al., 2003 | Model: female SD rats 250−300 g Injury: T3/T4 dorsal hemisection, depth of 1.5 mm |
C3 transferase • 300 μg per animal over 2 wk at a rate of 0.5 μL/h, delivered via intrathecal pump started at 0 h PIY-27632 • Rho-kinase inhibitor, 340 μg per animal over 2 wk started at 0 h PI |
SCI + • C3 transferase (n = 11) • Y-27632 (n = 12) • GST control (n = 10) • PBS (n = 15) |
Histologic/biochemical/physiological: C3 does not promote sprouting or long-distance regeneration of injured CST fibers after spinal cord lesions in the adult rat. The amount of scar tissue in C3-treated animals is significantly reduced in comparison to vehicle controls. Y-27632 enhances sprouting of rat CST fibers after dorsal hemisections. |
| GST • 340 μg per animal over 2 wk started at 0 h PI |
Behavioral: Rats were evaluated using the BBB score 2, 7, 14, 21, and 28 d postoperatively. C3 treatment resulted in delayed BBB locomotor recovery in comparison to GST treatment. Y-27632 treatment yields improved BBB locomotor recovery in comparison to PBS controls by 3 points in BBB scale in 2 wk. | |||
| Sung et al., 2003 | Model: female SD rats, 250–300 g Injury: T9/T10 NYU impactor, 10 g × 1.25 cm |
C3 transferase • Soaked in the gelfoam, directly to contused spinal cord, 10 μg dissolved in 0.1 cc PBS at 0 h PI Y-27632 oral • 10 mg/kg/day • At 0 h PI then × 10 d • At 5 d PI then × 10 d Fasudil IP, • 10 mg/kg in 1 cc saline at 0 h, then × 5 d |
SCI + • C3 (n = 5) • Y-27632 (n = 19) • Fasudil (n = 16) • Vehicle (n = 8) Sham (n = 5) |
Histologic/biochemical/physiological: Histological hematoxylin and eosin analysis of spinal cord 5 wk after a single dose of Fasudil showed less tissue damage when compared to control. Behavioral: At 1 wk post-SCI, 3 rats were severely emaciated and C3 was ended due to poor response. Motor function of rats receiving Fasudil improved significantly for both single dose and multiple dose regimens. Rats receiving Y-27632 immediately after spinal cord injury exhibited a reduction in BBB. |
| Dergham et al., 2002 | Model: female BALB-c mice, 20 g Injury: T7 dorsal over-hemisection |
C3 transferase • Via a fibrin adhesive delivery system (Tisseel VH kit), 50 μL of 1 mg/mL C3 in 25 μL of thrombin solution at 0 h PI or via collagen gels at 0 h PI Y27632 • In 25 μL of the thrombin solution at 0 h PI |
SCI + • Fibrin + C3 (n = 13) • Collagen + C3 (n = 12) • Fibrin + Y27632 (n = 5) • Fibrin (n = 10) • Collagen (n = 7) • No treatment (n = 13) SCI + (for behavioral testing) • C3 (n = 6) • Untreated (n = 6) |
Histologic/biochemical/physiological: After thoracic spinal cord lesion, only axons that regenerate long distances show upregulation of GAP-43 mRNA expression. In situ hybridization using 35S-labeled riboprobes on coronal brain sections revealed high levels of GAP-43 mRNA expression in neurons of the motor cortex of C3-treated animals whereas untreated animals showed GAP-43 signal similar to background. Behavioral: BBB hindlimb motor function testing revealed that mice treated with C3 or Y27632 had remarkable recovery within 24 h, already walking with weight support, which may be caused by increased neuroprotection in the lesioned spinal cord. |
BBB, Basso, Beattie and Bresnahan locomotor test; C5, cervical vertebra 5; GAP, growth-associated protein; GST, glutathione S-transferase; PI, post-injury; SCI, spinal cord injury; SD rats, Sprague-Dawley rats; T8, thoracic vertebra 8.