Human Neural Stem Cells Differentiate and Promote Locomotor Recovery in an Early Chronic Spinal coRd Injury NOD-scid Mouse Model

Traumatic spinal cord injury (SCI) results in partial or complete paralysis and is characterized by a loss of neurons and oligodendrocytes, axonal injury, and demyelination/dysmyelination of spared axons. Approximately 1,250,000 individuals have chronic SCI in the U.S.; therefore treatment in the chronic stages is highly clinically relevant. Human neural stem cells (hCNS-SCns) were prospectively isolated based on fluorescence-activated cell sorting for a CD133(+) and CD24(-/lo) population from fetal brain, grown as neurospheres, and lineage restricted to generate neurons, oligodendrocytes and astrocytes. hCNS-SCns have recently been transplanted sub-acutely following spinal cord injury and found to promote improved locomotor recovery. We tested the ability of hCNS-SCns transplanted 30 days post SCI to survive, differentiate, migrate, and promote improved locomotor recovery.hCNS-SCns were transplanted into immunodeficient NOD-scid mice 30 days post spinal cord contusion injury. hCNS-SCns transplanted mice demonstrated significantly improved locomotor recovery compared to vehicle controls using open field locomotor testing and CatWalk gait analysis. Transplanted hCNS-SCns exhibited long-term engraftment, migration, limited proliferation, and differentiation predominantly to oligodendrocytes and neurons. Astrocytic differentiation was rare and mice did not exhibit mechanical allodynia. Furthermore, differentiated hCNS-SCns integrated with the host as demonstrated by co-localization of human cytoplasm with discrete staining for the paranodal marker contactin-associated protein.The results suggest that hCNS-SCns are capable of surviving, differentiating, and promoting improved locomotor recovery when transplanted into an early chronic injury microenvironment. These data suggest that hCNS-SCns transplantation has efficacy in an early chronic SCI setting and thus expands the "window of opportunity" for intervention

TBK1 mutation spectrum in an extended European patient cohort with frontotemporal dementia and amyotrophic lateral sclerosis

We investigated the mutation spectrum of the TANK-Binding Kinase 1 (TBK1) gene and its associated phenotypic spectrum by exonic resequencing of TBK1 in a cohort of 2,538 patients with frontotemporal dementia (FTD), amyotrophic lateral sclerosis (ALS), or FTD plus ALS, ascertained within the European Early-Onset Dementia Consortium. We assessed pathogenicity of predicted protein-truncating mutations by measuring loss of RNA expression. Functional effect of in-frame amino acid deletions and missense mutations was further explored in vivo on protein level and in vitro by an NFκB-induced luciferase reporter assay and measuring phosphorylated TBK1. The protein-truncating mutations led to the loss of transcript through nonsense-mediated mRNA decay. For the in-frame amino acid deletions, we demonstrated loss of TBK1 or phosphorylated TBK1 protein. An important fraction of the missense mutations compromised NFκB activation indicating that at least some functions of TBK1 are lost. Although missense mutations were also present in controls, over three times more mutations affecting TBK1 functioning were found in the mutation fraction observed in patients only, suggesting high-risk alleles (P = 0.03). Total mutation frequency for confirmed TBK1 LoF mutations in the European cohort was 0.7%, with frequencies in the clinical subgroups of 0.4% in FTD, 1.3% in ALS, and 3.6% in FTD-ALS

Experimental spinal cord injury : methodological and neuroimmunological contributions with some historical background [Elektronisk resurs]

Spinal cord injury (SCI) is an incurable neurotraumatic catastrophe that afflicts mostly young individuals with resultant functional impairment of varying degrees of severity. The single pharmacologic treatment option at present is systemic methylprednisolone administration within 8 hours postinjury oftentimes accompanied by neurosurgical interventions. As a rule, SCI becomes a chronic condition with significant handicap for the patient and socioeconomic repercussions for the affected families and health care system. Important discoveries in the field of central nervous system regeneration since the early 80‟s have led to diverse potential therapeutic approaches for neuroprotection and repair. Unfortunately, most envisioned treatment apporaches would only be applicable at the acute and subacute stages of SCI, thereby excluding the large patient base with chronic SCI. In the first part of this thesis work the methodological aspects of a neurosurgical treatment protocol in a rat model of acute and chronic SCI were explored. In complete spinal cord transection experiments in rat, the acute and chronic spinal cord lesions were characterized with high-resolution magnetic resonance technology. A microneurosurgical „repair‟ protocol was employed in both acute and chronic (at 2, 4 or 8 months postinjury) SCI. Behavioral evaluation of the operated animals with standard locomotor behavior tests and two novel behavioral tests, developed by the author, the Bipedal test and the Head-scratch test, demonstrated a statistically significant recovery for those animals that were subjected to the microsurgical reconstruction protocol. Partial functional recovery and histologically verifiable axonal regeneration was achieved in rats with both acute and chronic SCI. In the second part of this thesis work the neuroinflammatory and neuroimmunological correlates of peripheral and central nervous system injury were studied in mice. In one set of KO mice (TNFa, STAT4, STAT6) and their corresponding wild type controls, behavioral recovery and axonal regeneration were evaluated after spinal cord overhemisection. In another set of KO mice (STAT4, STAT6, IFNγ, IFNγR and IRF1) and their corresponding wild type controls inflammatory and glial cell reactions were assessed after unilateral facial nerve transection lesions. The results suggest a positive role for the TH2 subset of the adaptive immune response in anatomic recovery after SCI. Finally, in this thesis work the historical origins of the ‟inhibitory white matter hypothesis‟ were researched shedding light on the pioneering work of Lugaro. Future treatments will have to address the complexity of SCI with a multipronged approach in order to effect the appropriate type and degree of immunomodulation, achieve neuroprotection, and promote collateral sprouting and axonal regeneration ultimately resulting in tissue repair and functional recovery. This thesis suggests: 1) that complete, long-standing SCI can be amenable to therapy by demonstrating that the functional incapacity of experimental chronic paraplegia in rat is partially reversible, and 2) that judicious modulation of the immune response after SCI may have a role to play in axonal regeneration after SCI