The systemic inflammatory response after spinal cord injury in the rat is decreased by α4β1 integrin blockade

The systemic inflammatory response syndrome (SIRS) follows spinal cord injury (SCI) and causes damage to the lungs, kidney, and liver due to an influx of inflammatory cells from the circulation. After SCI in rats, the SIRS develops within 12 h and is sustained for at least 3 days. We have previously shown that blockade of CD11d/CD18 integrin reduces inflammation-driven secondary damage to the spinal cord. This treatment reduces the SIRS after SCI. In another study we found that blockade of α4β1 integrin limited secondary cord damage more effectively than blockade of CD11d/CD18. Therefore we considered it important to assess the effects of anti-α4β1 treatment on the SIRS in the lung, kidney, and liver after SCI. An anti-α4 antibody was given IV at 2 h after SCI at the fourth thoracic segment and the effects on the organs were evaluated at 24 h post-injury. The migration of neutrophils into the lungs and liver was markedly reduced and all three organs contained fewer macrophages. In the lungs and liver, the activation of the oxidative enzymes myeloperoxidase (MPO), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and gp91 phox, the production of free radicals, lipid peroxidation, and cell death were substantially and similarly reduced. Treatment effects were less robust in the kidney. Overall, the efficacy of the anti-α4β1 treatment did not differ greatly from that of the anti-CD11d antibody, although details of the results differed. The SIRS after SCI impedes recovery, and attenuation of the SIRS with an anti-integrin treatment is an important, clinically-relevant finding. © Mary Ann Liebert, Inc. 2012

CD11d integrin blockade reduces the systemic inflammatory response syndrome after spinal cord injury

Traumatic injury to the spinal cord triggers a systemic inflammatory response syndrome (SIRS), in which inflammatory cells from the circulation invade organs such as the liver, lung and kidney, leading to damage of these organs. Our previous study (Gris, et al, Exp. Neurol, 2008) demonstrated that spinal cord injury (SCI) activates circulating neutrophils that then invade the lung and kidney from 2 to 24. h after injury, increasing myeloperoxidase activity, cyclooxygenase-2 and matrix metalloproteinase-9 expression and lipid peroxidation in these organs. The present study was designed to ascertain whether a treatment that limits the influx of leukocytes into the injured spinal cord would also be effective in reducing the SIRS after SCI. This treatment is intravenous delivery of a monoclonal antibody (mAb) against the CD11d subunit of the CD11d/CD18 integrin expressed by neutrophils and monocytes. We delivered the anti-CD11d mAb at 2. h post moderate clip compression SCI at the 4th or 12th thoracic segments and assessed inflammation, oxidative activity and cellular damage within the lung, kidney and liver at 12. h post-injury. In some analyses we compared high and low thoracic injuries to evaluate the importance of injury level on the intensity of the SIRS. After T4 injury, treatment with the anti-integrin mAb reduced the presence of neutrophils and macrophages in the lung, with associated decreases in expression of NF-κB and oxidative enzymes and in the concentration of free radicals in this organ. The treatment also reduced lipid peroxidation, protein nitration and cell death in the lung. The anti-CD11d treatment also reduced the inflammatory cells within the kidney after T4 injury, as well as the free radical concentration and amount of lipid peroxidation. In the liver, the mAb treatment reduced the influx of neutrophils but most of the other measures examined were unaffected by SCI. The inflammatory responses within the lung and kidney were often greater after T4 than T12 injury. Clinical studies show that SIRS, with its associated organ failure, contributes significantly to the morbidity and mortality of SCI patients. This anti-integrin treatment may block the onset of SIRS after SCI. © 2011 Elsevier Inc

A CD11d monoclonal antibody treatment reduces tissue injury and improves neurological outcome after fluid percussion brain injury in rats

Traumatic brain injury (TBI) is an international health concern often resulting in chronic neurological abnormalities, including cognitive deficits, emotional disturbances, and motor impairments. An anti-CD11d monoclonal antibody that blocks the CD11d/CD18 integrin and vascular cell adhesion molecule (VCAM)-1 interaction following experimental spinal cord injury improves functional recovery, while reducing the intraspinal number of neutrophils and macrophages, oxidative activity, and tissue damage. Since the mechanisms of secondary injury in the brain and spinal cord are similar, we designed a study to evaluate fully the effects of anti-CD11d treatment after a moderate lateral fluid percussion TBI in the rat. Rats were treated at 2 h after TBI with either the anti-CD11d antibody or an isotype-matched control antibody 1B7, and both short (24-to 72-h) and long (4-week) recovery periods were examined. The anti-CD11d integrin treatment reduced neutrophil and macrophage levels in the injured brain, with concomitant reductions in lipid peroxidation, astrocyte activation, amyloid precursor protein accumulation, and neuronal loss. The reduced neuroinflammation seen in anti-CD11d-treated rats correlated with improved performance on a number of behavioral tests. At 24 h, the anti-CD11d group performed significantly better than the 1B7 controls on several water maze measures of spatial cognition. At 4 weeks post-injury the anti-CD11d-treated rats had better sensorimotor function as assessed by the beam task, and reduced anxiety-like behaviors, as evidenced by elevated-plus maze testing, compared to 1B7 controls. These findings suggest that neuroinflammation is associated with behavioral deficits after TBI, and that anti-CD11d antibody treatment is a viable strategy to improve neurological outcomes after TBI. © 2012, Mary Ann Liebert, Inc

Towards a Non-Human Primate Model of Alpha-Synucleinopathy for Development of Therapeutics for Parkinson’s Disease: Optimization of AAV1/2 Delivery Parameters to Drive Sustained Expression of Alpha Synuclein and Dopaminergic Degeneration in Macaque

<div><p>Recent failures in clinical trials for disease modification in Parkinson’s disease have highlighted the need for a non-human primate model of the synucleinopathy underpinning dopaminergic neuron degeneration. The present study was defined to begin the development of such a model in cynomolgus macaque. We have validated surgical and vector parameters to define a means to provide a robust over-expression of alpha-synuclein which is associated with Lewy-like pathology and robust degeneration of the nigrostriatal pathway. Thus, an AAV1/2 vector incorporating strong transcription and transduction regulatory elements was used to deliver the gene for the human A53T mutation of alpha-synuclein. When injected into 4 sites within each substantia nigra (7 μl per site, 1.7 x 10¹² gp/ml), this vector provided expression lasting at least 4 months, and a 50% loss of nigral dopaminergic neurons and a 60% reduction in striatal dopamine. Further studies will be required to develop this methodology into a validated model of value as a drug development platform.</p></div

Summary of results from Experiment 2.

<p>Summary of results from Experiment 2.</p

No significant loss of substantia nigra dopamine neurons.

<p>Cell counting stereology was performed on tyrosine hydroxylase immunoreactive neurons within the borders of the substantia nigra from animals exposed to 17 weeks of either AAV1/2 driven overexpression of human A53T alpha-synuclein (A) or GFP (B) (both 20 μl of 1.7 x 10¹² gp/ml). No significant difference in total estimated numbers was observed, while a 15% reduction between the groups was calculated (P>0.05, NS) (C, mean ±SEM).</p

Transgene expression in the substantia nigra and putamen 17 weeks post surgical delivery of AAV1/2 hA53T alpha synuclein.

<p>Panel A shows wide spread overexpression of alpha synuclein (aSyn) in dopamine neurons within the macaque substantia nigra (SN). This was evident throughout the anatomical boundaries of the SN (Panels A-D). The inset of Panel A and Panel E shows high power magnification of the accumulation of aSyn in SN cell bodies. Transport and expression of aSyn was observed throughout the putamen in animals that received SN injections of AAV1/2 hA53T alpha synuclein (Panel G) compared to endogenous expression of aSyn in the SN (Panel F) and putamen (Panel H) of AAV1/2 GFP injected controls. Scale bars: in inset of panel A, 50 μm; in panel E, 25 μm and in panel F-H, 50 μm.</p

No changes on measures of dopamine neurochemistry or dopamine transporter levels in the putamen.

<p>Seventeen weeks following AAV1/2 delivery of hA53T alpha-synuclein or GFP (20 μl of 1.7 x 10¹² gp/ml) to the macaque substantia nigra, levels of dopamine and its metabolites (3,4-Dihydroxyphenylacetic acid; DOPAC and homovanillic acid; HVA) were quantified by HPLC (A-C, mean ±SEM). No significant changes were observed on either measure. Dopamine transporter levels were determined by autoradiography and also showed no significant differences between groups (D, mean ±SEM).</p

Kingston Allergy Birth Cohort (KABC); Exposome Characteristics and Parentally- Reported Respiratory Outcomes to Age 2

Background: The Kingston Allergy Birth Cohort (KABC) is a prenatally-recruited cohort initiated to study the developmental origins of allergic disease. Kingston General Hospital was chosen for recruitment, as it serves a population with notable diversity in exposures relevant to the emerging concept of the exposome. Objective: Establish a profile of the KABC cohort using the exposome framework, and examine parentally-reported respiratory symptoms to age 2. Methods: Data on phase 1 of the cohort (n=560 deliveries) were compiled and multivariate Cox proportional hazard models were used to determine associations with respiratory symptoms. Results: The KABC exhibits diversity within the three exposome domains; “general external” (SES, rural/urban residency), “specific external” (cigarette smoke, breastfeeding, mold/dampness), and “internal” (respiratory health, gestational age). We demonstrate relationships between exposome domains, as residential locale and SES significantly affected characteristics of the home environment. Significant associations emerged between parental reports of wheeze/cough without a cold and exposures within all three domains, including SES, 70 breastfeeding, gestational age, prenatal cigarette smoke exposure, and mold/dampness. Conclusions: The KABC is a unique cohort with diversity that can be leveraged for exposomics- based studies, and a notably high prevalence of prenatal smoke exposure. This study demonstrated the impacts of all three domains of the exposome on the respiratory health of KABC children. Ongoing studies using phase 1 of the KABC are further exploring the internal exposome through allergy skin testing and epigenetic analyses, and the specific external domain through in-home environmental analyses, air pollution modeling and ultimately the potential convergence of the two.MLN; J.A. Stewart Award, Department of Medicine, Queen’s University, Ontario Ministry of Research & Innovation Award, and AllerGen N.C.E. Canadian Allergy and Immune Diseases Advanced Training Initiative (CAIDATI). The study was supported by an Ontario Thoracic Society & Canadian Lung Association Grant-in aid of Research, an Allergy/Asthma Information Association (AAIA) and Canadian Allergy, Asthma & Immunology Foundation (CAAIF) Award for Ontario Research in Food Allergy, and an American College of Allergy, Asthma & Immunology (ACAAI) Young Faculty Support Award