Establishing preconditions for Baló's concentric sclerosis

[Neurological catastrophes in demyelinating diseases]

Demyelinating diseases may cause neurological catastrophes in several ways. Rapidly progressing disease or severe acute bouts may seriously threaten the patient's life. Diagnostic procedures, errors in identifying the clinical picture and even treatments themselves may result in a catastrophe. This article reviews the most frequent catastrophic scenarios.

Preconditioning with cobalt chloride or desferrioxamine protects oligodendrocyte cell line (MO3.13) from tumor necrosis factor-alpha-mediated cell death

Hypoxia-inducible factor-1alpha (HIF-1alpha) is a transcription factor induced under hypoxic conditions. HIF-1alpha promotes the expression of genes encoding proteins that increase the cellular supply of oxygen and promote survival in periods of cellular stress and availability of cellular energy. We examined the effect of desferrioxamine (DFO) and cobalt chloride (CoCl(2)), two agents known to increase the stability of HIF-1alpha, and its effect on the survivability of an oligodendroglial cell line, MO3.13, when cultured with tumor necrosis factor-alpha (TNFalpha). Our studies showed that, unlike a murine microglial cell line (BV-2), MO3.13 cells do not induce HIF-1alpha in the presence of TNFalpha. MO3.13 cells do stabilize HIF-1alpha in the presence of DFO or CoCl(2). When MO3.13 cell were preconditioned with either DFO or CoCl(2), addition of TNFalpha further increased protein levels of HIF-1alpha. The mechanisms that underlie the increase in protein levels of HIF -1alpha seen, following addition of TNFalpha in preconditioned cells is due to an increase in transcription of the HIF-1alpha gene. Increased cellular levels of HIF-1alpha is associated with improved survival of MO3.13 cells, when cultured with TNFalpha after a period of preconditioning by DFO or CoCl(2). These studies suggest that compoundsthat increase HIF-1alpha can function as neuroprotective agents in inflammatory disorders of the CNS.

Bacterial cell wall products increases stabilization of HIF-1 alpha in an oligodendrocyte cell line preconditioned by cobalt chloride or desferrioxamine

We examined the effect of lipopolysaccharide (LPS) or lipotechoic acid (LTA) on the regulation of hypoxia inducible factor (HIF-1) alpha on the MO3.13 cells, a human oligodendroglial cell line. Our study shows that MO3.13 cells express the toll like receptors (TLR's) but do not increase cellular levels of HIF-1 alpha following exposure to bacterial cell wall products. When MO3.13 cells were preconditioned by desferrioxamine (DFO) or cobalt chloride (CoCl(2)) and then treated with either LPS or LTA, HIF-1 alpha levels were higher than that induced by DFO or CoCl(2) alone. The increase in HIF-1 alpha was due to increased protein stability that was mediated by activation of the ERK-MAP kinase pathway.

Stem cells for the treatment of myelin loss

Treatment of myelin loss is particularly suited to therapeutic strategies based on cell replacement. Demyelination represents a defined and functionally debilitating deficit, and remyelination can be accomplished by supplying regions of demyelination with myelinogenic cell populations. Clinical interest in stem cells as a source of myelinogenic cells arises from their ability to provide an apparently unlimited cell supply for transplantation, and from recent demonstrations that they can be directed to myelinogenic phenotypes with high purity. Here, I present the emerging perspective that stem-cell-mediated remyelination of the adult CNS is a viable therapeutic strategy, and discuss the challenges to remyelination posed by the environment of acute and chronic injuries.