RESUMEN
Recent studies have implicated the inflammatory process during experimental allergic encephalomyelitis (EAE) in triggering migration and differentiation of transplanted neural precursors cells (NPCs) into the inflamed white matter. The pro-inflammatory cytokines tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma are key factors in the pathogenesis of brain inflammation in EAE and were shown to enhance NPCs migration in vitro. As cell migration is dependent on extracellular matrix remodeling, involving proteolytic enzyme members of the matrix metalloproteinase (MMPs) family, we characterized the profile of expression of MMPs and their endogenous inhibitors (TIMPs) in rat NPCs, and evaluated the effects of TNF-alpha, IFN-gamma and IFN-beta, a clinically proven modulator of brain inflammation, on the expression of these molecules. Newborn rat striatal NPCs were expanded in spheres as nestin+, PSA-NCAM+ and NG2(-) cells, which can differentiate into astrocytes, oligodendrocytes and neurons. NPCs' gelatinase activities of MMP-2 and MMP-9, as determined by zymography, were increased by TNF-alpha, and to a lesser extent by IFN-gamma. Semi-quantitative RT-PCR indicated that TNF-alpha also upregulated MMP-9 mRNA levels. IFN-beta suppressed the TNF-alpha-induced levels of secreted MMP-9 and MMP-2, while enhancing the expression of TIMP-1 and TIMP-2 mRNA. These results suggest that MMPs activity is induced in NPCs by pro-inflammatory cytokines to mobilize them for promoting reparative processes. IFN-beta, on the other hand, appears to have an anti-proteolytic influence that may attenuate such NPC-mediated repair processes.
Asunto(s)
Citocinas/fisiología , Metaloproteinasa 2 de la Matriz/fisiología , Metaloproteinasa 9 de la Matriz/fisiología , Neuronas/enzimología , Neuronas/inmunología , Células Madre/enzimología , Células Madre/inmunología , Inhibidores Tisulares de Metaloproteinasas/fisiología , Animales , Células Cultivadas , Regulación hacia Abajo/inmunología , Inducción Enzimática/inmunología , Gelatinasas/biosíntesis , Gelatinasas/metabolismo , Interferón beta/fisiología , Interferón gamma/fisiología , Metaloproteinasa 2 de la Matriz/biosíntesis , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/biosíntesis , Metaloproteinasa 9 de la Matriz/genética , Neuronas/citología , ARN Mensajero/biosíntesis , Ratas , Ratas Endogámicas Lew , Células Madre/citología , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Factor de Necrosis Tumoral alfa/fisiologíaRESUMEN
Overproduction of interleukin-1 within the brain is associated with Alzheimer's disease and other neurological conditions. We report that peripheral administration of the acetylcholinesterase inhibitors tacrine, rivastigmine, neostigmine, or EN101 (an antisense oligonucleotide directed at acetylcholinesterase messenger RNA) to mice significantly attenuated the production of interleukin-1beta in the hippocampus and blood, concomitantly with the reduction in acetylcholinesterase activity. These findings demonstrate that cholinergic enhancement produces central and peripheral antiinflammatory effects and suggest a novel therapeutic mechanism for acetylcholinesterase inhibitors.
Asunto(s)
Química Encefálica/efectos de los fármacos , Inhibidores de la Colinesterasa/farmacología , Interleucina-1/biosíntesis , Animales , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Interleucina-1/sangre , Lipopolisacáridos/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Neostigmina/farmacología , Oligodesoxirribonucleótidos , Oligonucleótidos/farmacología , Oligonucleótidos Antisentido/farmacología , Fenilcarbamatos/farmacología , Rivastigmina , Tacrina/farmacologíaRESUMEN
We have recently shown that the inflammatory process during experimental allergic encephalomyelitis (EAE), the animal model of MS, attracts transplanted NPC migration into the inflamed white matter. Here we studied how the proinflammatory cytokines tumor necrosis factor-alpha (TNFalpha) and interferon-gamma (IFNgamma) affect NPC growth, survival, differentiation, and migration. Newborn rat striatal NPCs were expanded in spheres as nestin+, PSA-NCAM+, NG2(-) cells, which differentiated into astrocytes, oligodendrocytes, and neurons. NPCs expressed receptors of TNFalpha and IFNgamma but not interleukin-1. TNFalpha and IFNgamma inhibited sphere cell proliferation, determined by [(3)H]thymidine and BrdU incorporation. IFNgamma increased apoptotic cell death (determined by TUNEL stains); this effect partially blocked by TNFalpha. Neither cytokine affected NPC lineage fate, determined by percentage of GFAP+, neurofilament+, and GalC+ cells after differentiation. TNFalpha and IFNgamma increased outward migration of cells from spheres in vitro. Thus, TNFalpha and IFNgamma, key players in MS and EAE, inhibit NPC proliferation and induce their migration.
Asunto(s)
Movimiento Celular/inmunología , Citocinas/inmunología , Neuroglía/inmunología , Neuronas/inmunología , Células Madre/inmunología , Animales , Animales Recién Nacidos , Apoptosis/efectos de los fármacos , Apoptosis/inmunología , Biomarcadores/análisis , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/inmunología , División Celular/efectos de los fármacos , División Celular/inmunología , Linaje de la Célula/efectos de los fármacos , Linaje de la Célula/inmunología , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Citocinas/farmacología , Mediadores de Inflamación/inmunología , Mediadores de Inflamación/farmacología , Interferón gamma/inmunología , Interferón gamma/farmacología , Modelos Biológicos , Esclerosis Múltiple/inmunología , Esclerosis Múltiple/metabolismo , Esclerosis Múltiple/fisiopatología , Proteínas del Tejido Nervioso/metabolismo , Neuroglía/efectos de los fármacos , Neuroglía/metabolismo , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Ratas , Ratas Endogámicas Lew , Esferoides Celulares , Células Madre/efectos de los fármacos , Células Madre/metabolismo , Factor de Necrosis Tumoral alfa/inmunología , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
Transplanted neural precursor cells remyelinate efficiently acutely demyelinated focal lesions. However, the clinical value of cell transplantation in a chronic, multifocal disease like multiple sclerosis will depend on the ability of transplanted cells to migrate to the multiple disease foci in the brain. Here, we expanded newborn rat neural precursor cells in spheres and transplanted them intracerebroventricularly or intrathecally in rats. The cells were labeled by the nuclear fluorescent dye Hoechst or by incubation with BrdU to enable their identification at 2 days and 2 weeks after transplantation, respectively. Spheres consisted of PSA-NCAM(+), nestin(+), NG2(-) undifferentiated precursor cells that differentiated in vitro into astrocytes, oligodendrocytes, and neurons. Spheres that were transplanted into intact rats remained mostly in the ventricles or in the spinal subarachnoid space. Following transplantation at peak of experimental autoimmune encephalomyelitis, cells migrated into the brain or spinal cord parenchyma, exclusively into inflamed white matter but not into adjacent gray matter regions. After 2 weeks, many transplanted cells had migrated into distant white matter tracts and acquired specific markers of the astroglial and oligodendroglial lineages. Thus, the inflammatory process may attract targeted migration of transplanted precursor cells into the brain parenchyma.