Cannabinoid rescue of striatal progenitor cells in chronic Borna disease viral encephalitis in rats.
ABSTRACT A growing number of environmental and pharmacologic manipulations have been shown to influence adult neurogenesis. Borna disease virus (BDV) in rats causes cortical and subcortical infection with extrapyramidal motor symptoms, and hippocampal infection suppresses neurogenesis. Given the known effects of cannabinoids in promoting neural progenitor cell survival, the authors examined in vivo effects of chronic BDV infection in rats on BrdU-positive progenitor cells in striatum, together with neuroprotective actions of cannabinoids. Birth and survival of BrdU-positive progenitor cells in striatum of BDV-infected rats treated with a general cannabinoid agonist (WIN 55,212 1 mg/kg i.p. b.i.d. x 7 days) were examined, as well as anti-inflammatory, antiviral, and nutritional effects of cannabinoids. Cannabinoid treatment protected BrdU-positive progenitor cells in striatum that were susceptible to virus-induced injury (p < .01) through suppression of microglia activation (p < .001). As a consequence of their anti-inflammatory actions and support of neural progenitor cell survival, cannabinoids may be adjunctive treatment for encephalitides with microglial inflammation and neurodegeneration.
- SourceAvailable from: Maria Grazia Morgese[Show abstract] [Hide abstract]
ABSTRACT: Chronic CNS infection by several families of viruses can produce deficits in prefrontal cortex (PFC) and striatal function. Cannabinoid drugs have been long known for their anti-inflammatory properties and their ability to modulate adult neuro and gliogenesis. Therefore, we explored the effects of systemic administration of the cannabinoid agonist WIN55,212-2(WIN) on prefrontal cortex (PFC) and striatal cytogenesis in a viral model of CNS injury and inflammation based on Borna Disease (BD) virus encephalitis. Active BrdU(+) progenitor populations were significantly decreased 1 week after BrdU labeling in BD rats [p<0.001 compared to uninfected (NL) controls] while less than 5% of BrdU(+) cells colabeled for BDV protein. Systemic WIN (1mg/kg i.p. twice daily×7 days) increased the survival of BrdU(+) cells in striatum (p<0.001) and PFC of BD rats, with differential regulation of labeled oligodendroglia precursors vs microglia/macrophages. WIN increased the percentage of BrdU(+) oligodendrocyte precursor cells and decreased BrdU(+) ED-1-labeled phagocytic cells, without producing pro- or antiviral effects. BDV infection decreased the levels of the endocannabinoid anandamide (AEA) in striatum (p<0.05 compared to NL rats), whereas 2-AG levels were unchanged. Our findings indicate that: 1) viral infection is accompanied by alterations of AEA transmission in the striatum, but new cell protection by WIN appears independent of its effect on endocannabinoid levels; and 2) chronic WIN treatment alters the gliogenic cascades associated with CNS injury, promoting oligodendrocyte survival. Limiting reactive gliogenesis and macrophage activity in favor of oliogodendroglia development has significance for demyelinating diseases. Moreover, the ability of cannabinoids to promote the development of biologically supportive or symbiotic oligodendroglia may generalize to other microglia-driven neurodegenerative syndromes including NeuroAIDS and diseases of aging.Experimental Neurology 11/2010; 226(1):231-41. · 4.62 Impact Factor
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ABSTRACT: Cannabinoids are promising therapies to support neurogenesis and decelerate disease progression in neuroinflammatory and degenerative disorders. Whether neuroprotective effects of cannabinoids are sustainable during persistent viral infection of the CNS is not known. Using a rodent model of chronic viral encephalitis based on Borna Disease (BD) virus, in which 1 week treatment with the general cannabinoid WIN 55,212-2 has been shown to be neuroprotective (Solbrig et al., 2010), we examine longer term (2 week treatment) effects of a general (CB1 and CB2) cannabinoid receptor agonist WIN55,212-2 (1mg/kg ip twice per day) or a specific (CB2) cannabinoid receptor agonist HU-308 (5mg/kg ip once daily) on histopathology, measures of frontostriatal neurogenesis and gliogenesis, and viral load. We find WIN and HU-308 differ in their ability to protect new BrdU(+) cells. The selective CB2 agonist HU increases BrdU(+) cells in prefrontal cortex (PFC), significantly increases BrdU(+) cells in striatum, differentially regulates polydendrocytes vs microglia/macrophages, and reduces immune activation at a time WIN-treated rats appear tolerant to the anti-inflammatory effect of their cannabinoid treatment. WIN and HU had little direct viral effect in PFC and striatum, yet reduced viral signal in hippocampus. Thus, HU-308 action on CB2 receptors, receptors known to be renewed during microglia proliferation and action, is a nontolerizing mechanism of controlling CNS inflammation during viral encephalitis by reducing microglia activation, as well as partially limiting viral infection, and uses a nonpsychotropic cannabinoid agonist.Brain research 09/2013; · 2.83 Impact Factor
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ABSTRACT: Understanding the complex mechanisms by which infectious agents can disrupt behavior represents a major challenge. The Borna disease virus (BDV), a potential human pathogen, provides a unique model to study such mechanisms. Because BDV induces neurodegeneration in brain areas that are still undergoing maturation at the time of infection, we tested the hypothesis that BDV interferes with neurogenesis. We showed that human neural stem/progenitor cells are highly permissive to BDV, although infection does not alter their survival or undifferentiated phenotype. In contrast, upon the induction of differentiation, BDV is capable of severely impairing neurogenesis by interfering with the survival of newly generated neurons. Such impairment was specific to neurogenesis, since astrogliogenesis was unaltered. In conclusion, we demonstrate a new mechanism by which BDV might impair neural function and brain plasticity in infected individuals. These results may contribute to a better understanding of behavioral disorders associated with BDV infection.Journal of Virology 12/2011; 86(5):2512-22. · 4.65 Impact Factor