Optimization of immunosuppressive therapy for spinal grafting of human spinal stem cells in a rat model of ALS

Previous rodent studies employing monotherapy or combined immunosuppressive regimens have demonstrated a variable degree of spinal xenograft survival in several spinal neurodegenerative models including spinal ischemia, trauma, or amyotrophic lateral sclerosis (ALS). Accordingly, the characterization of optimal immunosuppressive protocols for the specific neurodegenerative model is critical to ensure reliable assessment of potential long-term therapeutic effects associated with cell replacement. In the present study we characterized the survival of human spinal stem cells when grafted into the lumbar spinal cords of a rodent model of ALS, SOD1 (G93A) male and female rats (60-67 days old). Four different immunosuppressive protocols were studied: i) FK506 (q12h); ii) FK506 (qd) + mycophenolate (PO; q12h, up to 7 days postop); iii) FK506 (qd) + mycophenolate (IP; q12h, up to 7 days postop); and iv) FK506 (qd) + mycophenolate (IP; qd, up to 7 days postop). Three weeks after cell grafting the number of surviving human cells was then systematically assessed. The highest density of grafted cells was seen in animals treated with FK506 (qd) and mycophenolate (IP; qd; an average 915 ± 95 grafted cells per spinal cord section). The majority of hNUMA-positive cells colocalized with doublecortin (DCX) immunoreactivity. DCX-positive neurons showed extensive axodendritic sprouting toward surrounding host neurons. In addition, migrating grafted cells were identified up to 500 μm from the graft. In animals treated with FK506 (q12h), FK506 (qd) + mycophenolate (PO; q12h) or FK506 (qd) + mycophenolate (IP; q12h), 11.8 ± 3.4%, 61.2 ± 7.8%, and 99.4 ± 8.9% [expressed as percent of the FK506 (qd) and mycophenolate (IP; qd)] cell survival was seen, respectively. In contrast to animals treated with a combination of FK506 + mycophenolate, robust CD4/8 immunoreactivity was identified in the vicinity of the injection tract in animals treated with FK506 only. These data suggest that a combined, systemically delivered immunosuppression regimen including FK506 and mycophenolate can significantly improve survival of human spinal stem cells after intraspinal transplantation in SOD1 (G93A) rats.     

Development of AMPA receptor and GABA B receptor-sensitive spinal hyper-reflexia after spinal air embolism in rat: A systematic neurological, electrophysiological and qualitative histopathological study

Decompression sickness results from formation of bubbles in the arterial and venous system, resulting in spinal disseminated neurodegenerative changes and may clinically be presented by motor dysfunction, spinal segmental stretch hyper-reflexia (i.e., spasticity) and muscle rigidity. In our current study, we describe a rat model of spinal air embolism characterized by the development of similar spinal disseminated neurodegenerative changes and functional deficit. In addition, the anti-spastic potency of systemic AMPA receptor antagonist (NGX424) or GABA B receptor agonist (baclofen) treatment was studied. To induce spinal air embolism, animals received an intra-aortic injection of air (50-200μl/kg). After embolism, the development of spasticity was measured using computer-controlled ankle rotation. Animals receiving 150 or 200μl of intra-aortic air injections displayed motor dysfunction with developed spastic (50-60% of animals) or flaccid (25-35% of animals) paraplegia at 5-7days. MRI and spinal histopathological analysis showed disseminated spinal cord infarcts in the lower thoracic to sacral spinal segments. Treatment with NGX424 or baclofen provided a potent anti-spasticity effect (i.e., stretch hyper-reflexia inhibition). This model appears to provide a valuable experimental tool to study the pathophysiology of air embolism-induced spinal injury and permits the assessment of new treatment efficacy targeted to modulate neurological symptoms resulting from spinal air embolism.     

Chronic spinal compression model in minipigs: a systematic behavioral, qualitative, and quantitative neuropathological study

The goal of the present study was to develop a porcine spinal cord injury (SCI) model, and to describe the neurological outcome and characterize the corresponding quantitative and qualitative histological changes at 4-9 months after injury. Adult Gottingen-Minnesota minipigs were anesthetized and placed in a spine immobilization frame. The exposed T12 spinal segment was compressed in a dorso-ventral direction using a 5-mm-diameter circular bar with a progressively increasing peak force (1.5, 2.0, or 2.5?kg) at a velocity of 3?cm/sec. During recovery, motor and sensory function were periodically monitored. After survival, the animals were perfusion fixed and the extent of local SCI was analyzed by (1) post-mortem MRI analysis of dissected spinal cords, (2) qualitative and quantitative analysis of axonal survival at the epicenter of injury, and (3) defining the presence of local inflammatory changes, astrocytosis, and schwannosis. Following 2.5-kg spinal cord compression the animals demonstrated a near complete loss of motor and sensory function with no recovery over the next 4-9 months. Those that underwent spinal cord compression with 2 kg force developed an incomplete injury with progressive partial neurological recovery characterized by a restricted ability to stand and walk. Animals injured with a spinal compression force of 1.5?kg showed near normal ambulation 10 days after injury. In fully paralyzed animals (2.5?kg), MRI analysis demonstrated a loss of spinal white matter integrity and extensive septal cavitations. A significant correlation between the magnitude of loss of small and medium-sized myelinated axons in the ventral funiculus and neurological deficits was identified. These data, demonstrating stable neurological deficits in severely injured animals, similarities of spinal pathology to humans, and relatively good post-injury tolerance of this strain of minipigs to spinal trauma, suggest that this model can successfully be used to study therapeutic interventions targeting both acute and chronic stages of SCI.     

Rapid onset of efficacy of rasagiline in early Parkinson’s disease

Rasagiline is a monoamine oxidase type-B inhibitor used as monotherapy or in addition to levodopa in the treatment of Parkinson’s disease (PD). This naturalistic single-blind study was aimed at evaluating the rapidity of onset effect of rasagiline on motor symptoms in a cohort of early relatively elderly PD patients. 102 outpatients (55 males, median age 71 years) have been selected: 26 were PD therapy-naive and 76 received rasagiline as add-on therapy. The third section of the Unified Parkinson’s Disease Rating Scale (UPDRSIII) and the Hoehn–Yahr (HY) scale were assessed at baseline and after 1 and 4 weeks thereafter. The mean UPDRS III total score (?6.7 at week 1 and ?8.9 at week 4) and single items, as well as mean HY score (?0.40 at week 1 and ?0.67 at week 4), significantly decreased from baseline (p < 0.001). Improvements were significant in both therapy-naive and add-on therapy patients: the mean decreases from baseline to week 4 in UPDRSIII and HY score were ?8.8 and ?0.46, and ?9.0 and ?0.74, respectively, in the two subgroups. The mean decrease from baseline in UPDRSIII and HY score did not significantly differ in patients aged > or ≤71 years. Rasagiline had a rapid therapeutic effect from the first week of therapy, which further improved at 4 weeks. The rapid onset of action and the absence of a dose titration are important issues in the management of the PD patient.     

Relevance of sleep quality on caregiver burden in Parkinson’s disease

Neurological Sciences - Parkinson’s disease (PD) is a neurodegenerative disorder which affects the quality of life of patient and their family. Sleep disorders appear in 80–90% of PD...     

Characterization of spinal HSP72 induction and development of ischemic tolerance after spinal ischemia in rats

Induction of heat shock protein (HSP72) has been implicated in the development of ischemic tolerance in several tissue organs including brain and spinal cord. In the present study, using an aortic balloon occlusion model in rats, we characterized the effect of transient noninjurious (3 or 6 min) or injurious intervals (10 min) of spinal ischemia followed by 4-72 h of reflow on spinal expression of HSP72 and GFAP protein. In a separate group of animals, the effect of ischemic preconditioning (3 or 6 min) on the recovery of function after injurious interval of spinal ischemia (10 min) was studied. After 3 min of ischemia, there was a modest increase in HSP72 protein immunoreactivity in the dorsal horn neurons at 12 h after reperfusion. After 6 min of ischemia, a more robust and wide spread HSP72 protein expression in both dorsal and ventral horn neurons was detected. The peak of the expression was seen at 24 h after ischemia. At the same time point, a significant increase in spinal tissue GFAP expression was measured with Western blots and corresponded morphologically with the presence of activated astrocytes in spinal segments that had been treated similarly. After 10 min of ischemia and 24 h of reflow, a significant increase in spinal neuronal HSP72 expression in perinecrotic regions was seen. Behaviorally, 3 min preconditioning ischemia led to the development of a biphasic ischemic tolerance (the first at 30 min and the second at 24 h after preconditioning) and was expressed as a significantly better recovery of motor function after exposure to a second 10-min interval of spinal ischemia. After 6 min ischemic preconditioning, a more robust ischemic tolerance at 24 h after preconditioning then seen after 3-min preconditioning was detected. These data indicate that 3 min of spinal ischemia represents a threshold for spinal neuronal HSP72 induction, however, a longer sublethal interval (6 min) of preconditioning ischemia is required for a potent neuronal HSP72 induction. More robust neurological protection, seen after 6 min of preconditioning ischemia, also indicates that HSP72 expression in spinal interneurons seen at 24 h after preconditioning may represent an important variable in modulating ischemic tolerance observed during this time frame.