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In JoVE (1)
Other Publications (4)
Articles by Wolfram Tetzlaff in JoVE
JoVE Clinical and Translational Medicine
A Contusive Model of Unilateral Cervical Spinal Cord Injury Using the Infinite Horizon Impactor
1International Collaboration on Repair Discoveries (ICORD), University of British Columbia, 2Department of Orthopaedics, University of British Columbia
A reliable and repeatable way to produce a cervical unilateral spinal cord injury using the Infinite Horizon impactor is described. The method takes advantage of a custom designed frame and clamp to stabilize the spine. The standardized procedure and biomechanical injury parameters result in sufficient and sustained injuries.
Other articles by Wolfram Tetzlaff on PubMed
Local Self-renewal Can Sustain CNS Microglia Maintenance and Function Throughout Adult Life
Microgliosis is a common response to multiple types of damage in the CNS. However, the origin of the cells involved in this process is still controversial and the relative importance of local expansion versus recruitment of microglia progenitors from the bloodstream is unclear. Here, we investigated the origin of microglia using chimeric animals obtained by parabiosis. We found no evidence of microglia progenitor recruitment from the circulation in denervation or CNS neurodegenerative disease, suggesting that maintenance and local expansion of microglia are solely dependent on the self-renewal of CNS resident cells in these models.
Bilirubin Possesses Powerful Immunomodulatory Activity and Suppresses Experimental Autoimmune Encephalomyelitis
Bilirubin, an abundant bile pigment in mammalian serum, was once considered a toxic waste product and has more recently been recognized as a potent antioxidant of physiological importance. However, its potential biological functions in other fields are not well understood. Herein we show that bilirubin is also a powerful immunomodulatory agent. Bilirubin significantly inhibited Ag-specific and polyclonal T cell responses, while other similar antioxidants completely lacked this effect. Bilirubin suppressed CD4(+) T cell responses at multiple steps. High levels of bilirubin could induce apoptosis in reactive CD4(+) T cells. Bilirubin at nonapoptotic concentrations suppressed CD4(+) T cell reactivity through a wide range of actions, including inhibition of costimulator activities, suppression of immune transcription factor activation, and down-regulation of inducible MHC class II expression. Further studies suggest that bilirubin actions were direct, rather than via induction of immune deviation or regulatory T cells. In vivo, treatment with bilirubin effectively suppressed experimental autoimmune encephalomyelitis in SJL/J mice. In contrast, depletion of endogenous bilirubin dramatically exacerbated this disease. In summary, our results identify bilirubin as an important immunomodulator that may protect mammals against autoimmune diseases, thereby indicating its potential in the treatment of multiple sclerosis and other immune disorders.
Biomarkers for Severity of Spinal Cord Injury in the Cerebrospinal Fluid of Rats
One of the major challenges in management of spinal cord injury (SCI) is that the assessment of injury severity is often imprecise. Identification of reliable, easily quantifiable biomarkers that delineate the severity of the initial injury and that have prognostic value for the degree of functional recovery would significantly aid the clinician in the choice of potential treatments. To find such biomarkers we performed quantitative liquid chromatography-mass spectrometry (LC-MS/MS) analyses of cerebrospinal fluid (CSF) collected from rats 24 h after either a moderate or severe SCI. We identified a panel of 42 putative biomarkers of SCI, 10 of which represent potential biomarkers of SCI severity. Three of the candidate biomarkers, Ywhaz, Itih4, and Gpx3 were also validated by Western blot in a biological replicate of the injury. The putative biomarkers identified in this study may potentially be a valuable tool in the assessment of the extent of spinal cord damage.
A Grading System to Evaluate Objectively the Strength of Pre-clinical Data of Acute Neuroprotective Therapies for Clinical Translation in Spinal Cord Injury
The past three decades have seen an explosion of research interest in spinal cord injury (SCI) and the development of hundreds of potential therapies that have demonstrated some promise in pre-clinical experimental animal models. A growing number of these treatments are seeking to be translated into human clinical trials. Conducting such a clinical trial, however, is extremely costly, not only for the time and money required to execute it, but also for the limited resources that will then no longer be available to evaluate other promising therapies. The decision about what therapies have sufficient pre-clinical evidence of efficacy to justify testing in humans is therefore of utmost importance. Here, we have developed a scoring system for objectively grading the body of pre-clinical literature on neuroprotective treatments for acute SCI. The components of the system include an evaluation of a number of factors that are thought to be important in considering the "robustness" of a therapy's efficacy, including the animal species and injury models that have been used to test it, the time window of efficacy, the types of functional improvements effected by it, and whether efficacy has been independently replicated. The selection of these factors was based on the results of a questionnaire that was performed within the SCI research community. A modified Delphi consensus-building exercise was then conducted with experts in pre-clinical SCI research to refine the criteria and decide upon how to score them. Finally, the grading system was applied to a series of potential neuroprotective treatments for acute SCI. This represents a systematic approach to developing an objective method of evaluating the extent to which the pre-clinical literature supports the translation of a particular experimental treatment into human trials.
