RESUMEN
Our previous study indicated that electroacupuncture (EA) could increase neurotrophin-3 (NT-3) levels in the injured spinal cord, stimulate the differentiation of transplanted bone marrow mesenchymal stem cells (MSCs), and improve functional recovery in the injured spinal cord of rats. However, the number of neuron-like cells derived from the MSCs is limited. It is known that NT-3 promotes the survival and differentiation of neurons by preferentially binding to its receptor TrkC. In this study, we attempted to transplant TrkC gene-modified MSCs (TrkC-MSCs) into the spinal cord with transection to investigate whether EA treatment could promote NT-3 secretion in the injured spinal cord and to determine whether increased NT-3 could further enhance transplanted MSCs overexpressing TrkC to differentiate into neuron-like cells, resulting in increased axonal regeneration and functional improvement in the injured spinal cord. Our results showed that EA increased NT-3 levels; furthermore, it promoted neuron-phenotype differentiation, synaptogenesis, and myelin formation of transplanted TrkC-MSCs. In addition, TrkC-MSC transplantation combined with EA (the TrkC-MSCs + EA group) treatment promoted the growth of the descending BDA-labeled corticospinal tracts (CSTs) and 5-HT-positive axonal regeneration across the lesion site into the caudal cord. In addition, the conduction of cortical motor-evoked potentials (MEPs) and hindlimb locomotor function increased as compared to controls (treated with the LacZ-MSCs, TrkC-MSCs, and LacZ-MSCs + EA groups). In the TrkC-MSCs + EA group, the injured spinal cord also showed upregulated expression of the proneurogenic factors laminin and GAP-43 and downregulated GFAP and chondroitin sulfate proteoglycans (CSPGs), major inhibitors of axonal growth. Together, our data suggest that TrkC-MSC transplantation combined with EA treatment spinal cord injury not only increased MSC survival and differentiation into neuron-like cells but also promoted CST regeneration across injured sites to the caudal cord and functional improvement, perhaps due to increase of NT-3 levels, upregulation of laminin and GAP-43, and downregulation of GFAP and CSPG proteins.
Asunto(s)
Trasplante de Médula Ósea/métodos , Electroacupuntura/métodos , Trasplante de Células Madre Mesenquimatosas/métodos , Células Madre Mesenquimatosas/citología , Neuronas/citología , Receptor trkC/biosíntesis , Traumatismos de la Médula Espinal/terapia , Animales , Diferenciación Celular/fisiología , Modelos Animales de Enfermedad , Femenino , Células Madre Mesenquimatosas/enzimología , Células Madre Mesenquimatosas/patología , Neuronas/enzimología , Neuronas/patología , Ratas , Ratas Sprague-Dawley , Ratas Transgénicas , Traumatismos de la Médula Espinal/enzimología , Traumatismos de la Médula Espinal/patología , Traumatismos de la Médula Espinal/cirugíaRESUMEN
Calcitonin gene-related peptide (CGRP) plays a variety of important roles within the nervous system. Increasing CGRP expression could improve the survival of injured neurons and prevent neuronal loss. In this study, we first evaluated in vitro the neuroprotective function of CGRP on mechanically injured cerebellar granule neurons (CGNs) of rats. We then verified this result through exogenous administration of CGRP in a spinal cord transected completely in rats. Finally, we investigated the effect of electro-acupuncture (EA) on CGRP expression following the spinal cord transected completely in rats. We found that EA can improve CGRP expression, and exogenous CGRP may promote the survival of injured neurons, both in vivo and in vitro. Our results suggest that CGRP may be a specific neuropeptide expressed in GV-EA treatment of spinal cord injuries (SCI), and that CGRP may play a neuroprotective role in survival of neurons injured mechanically.
Asunto(s)
Péptido Relacionado con Gen de Calcitonina/biosíntesis , Electroacupuntura , Fármacos Neuroprotectores/uso terapéutico , Traumatismos de la Médula Espinal/terapia , Animales , Péptido Relacionado con Gen de Calcitonina/genética , Péptido Relacionado con Gen de Calcitonina/farmacología , Péptido Relacionado con Gen de Calcitonina/fisiología , Péptido Relacionado con Gen de Calcitonina/uso terapéutico , Células Cultivadas/efectos de los fármacos , Cerebelo/citología , Terapia Combinada , Cordotomía , Implantes de Medicamentos , Femenino , Regulación de la Expresión Génica , Lidocaína/farmacología , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Nocicepción/fisiología , Células del Asta Posterior/metabolismo , Ratas , Ratas Sprague-Dawley , Regeneración , Rizotomía , Médula Espinal/fisiología , Traumatismos de la Médula Espinal/tratamiento farmacológico , Traumatismos de la Médula Espinal/genética , Traumatismos de la Médula Espinal/metabolismo , Regulación hacia ArribaRESUMEN
Our previous study has reported that electroacupuncture (EA) promotes survival, differentiation of bone marrow mesenchymal stem cells (MSCs), and functional improvement in spinal cord-transected rats. In this study, we further investigated the structural bases of this functional improvement and the potential mechanisms of axonal regeneration in injured spinal cord after MSCs and EA treatment. Five experimental groups, 1) sham control (Sham-control); 2) operated control (Op-control); 3) electroacupuncture treatment (EA); 4) MSCs transplantation (MSCs), and 5) MSCs transplantation combined with electroacupuncture (MSCs + EA), were designed for this study. Western blots and immunohistochemical staining were used to assess the fibrillary acidic protein (GFAP) and chondroitin sulfate proteoglycans (CSPGs) proteins expression. Basso, Beattie, Bresnahan (BBB) locomotion test, cortical motor evoked potentials (MEPs), and anterograde and retrograde tracing were utilized to assess cortical-spinal neuronal projection regeneration and functional recovery. In the MSCs + EA group, increased labeling descending corticospinal tract (CST) projections into the lesion site showed significantly improved BBB scales and enhanced motor evoked potentials after 10 weeks of MSCs transplant and EA treatment. The structural and functional recovery after MSCs + EA treatment may be due to downregulated GFAP and CSPGs protein expression, which prevented axonal degeneration as well as improved axonal regeneration.
Asunto(s)
Axones/fisiología , Electroacupuntura/métodos , Trasplante de Células Madre Mesenquimatosas/métodos , Células Madre Mesenquimatosas/fisiología , Regeneración Nerviosa/fisiología , Traumatismos de la Médula Espinal/terapia , Animales , Células de la Médula Ósea/citología , Células de la Médula Ósea/metabolismo , Proteoglicanos Tipo Condroitín Sulfato/biosíntesis , Modelos Animales de Enfermedad , Regulación hacia Abajo , Femenino , Proteína Ácida Fibrilar de la Glía/biosíntesis , Inmunohistoquímica , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/metabolismo , Ratas , Ratas Sprague-Dawley , Traumatismos de la Médula Espinal/metabolismo , Análisis de SupervivenciaRESUMEN
BACKGROUND: Bone marrow mesenchymal stem cells (MSCs) are one of the potential tools for treatment of the spinal cord injury; however, the survival and differentiation of MSCs in an injured spinal cord still need to be improved. In the present study, we investigated whether Governor Vessel electro-acupuncture (EA) could efficiently promote bone marrow mesenchymal stem cells (MSCs) survival and differentiation, axonal regeneration and finally, functional recovery in the transected spinal cord. RESULTS: The spinal cords of adult Sprague-Dawley (SD) rats were completely transected at T10, five experimental groups were performed: 1. sham operated control (Sham-control); 2. operated control (Op-control); 3. electro-acupuncture treatment (EA); 4. MSCs transplantation (MSCs); and 5. MSCs transplantation combined with electro-acupuncture (MSCs+EA). After 2-8 weeks of MSCs transplantation plus EA treatment, we found that the neurotrophin-3 (NT-3), cAMP level, the differentiation of MSCs, the 5-HT positive and CGRP positive nerve fibers in the lesion site and nearby tissue of injured spinal cord were significantly increased in the MSCs+EA group as compared to the group of the MSCs transplantation or the EA treated alone. Furthermore, behavioral test and spinal cord evoked potentials detection demonstrated a significantly functional recovery in the MSCs +EA group. CONCLUSION: These results suggest that EA treatment may promote grafted MSCs survival and differentiation; MSCs transplantation combined with EA treatment could promote axonal regeneration and partial locomotor functional recovery in the transected spinal cord in rats and indicate a promising avenue of treatment of spinal cord injury.
Asunto(s)
Diferenciación Celular/fisiología , Electroacupuntura/métodos , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/citología , Traumatismos de la Médula Espinal/cirugía , Análisis de Varianza , Animales , Células de la Médula Ósea/citología , Supervivencia Celular , Terapia Combinada , Potenciales Evocados/fisiología , Femenino , Actividad Motora/fisiología , Regeneración Nerviosa/fisiología , Neuronas/citología , Ratas , Ratas Sprague-Dawley , Recuperación de la Función , Traumatismos de la Médula Espinal/terapia , Estadísticas no Paramétricas , Resultado del TratamientoRESUMEN
This study investigated whether electro-acupuncture (EA) would improve the survival and migration of neural stem cells (NSCs) transplanted in injured spinal cord as well as the potential mechanisms. T10 spinal cord segments of 50 adult Sprague-Dawley (SD) rats were completely transected, and then NSCs were immediately transplanted into the transected site of the experimental animals, while control animals were sham operated without transplantation. Five days post-operation, electro-acupuncture treatment on GV9 (Zhiyang), GV6 (Jizhong), GV2 (Yaoshu) and GV1 (Changqiang) acupoints was applied for 14 days (EA+NSCs 14d) and 30 days (EA+NSCs 30d). ELISA and immunohistochemical staining were used to assess the content of neurotrophine-3 (NT-3) and the characteristics of transplanted NSCs. We found that the number of transplanted NSCs the survived in EA+NSCs14d group was significantly increased as compared to that of the NSCs30d group (5825.20 +/- 819.01 vs 4781.40 +/- 500.49, P<0.05). Immunostaining indicated that some transplanted NSCs developed into microtubule association protein 2 (MAP2) positive cells and many of them developed into glial fibrillary acidic protein (GFAP) positive cells in the NSCs30d group. Further, the migration length of transplanted NSCs toward caudal tissue in the injured site was longer in the EA+NSCs30d group than that in NSCs30d group (5.98 +/- 0.79 mm vs 3.96 +/- 1.72 mm; P<0.05). Also NT-3 in injured spinal cord tissue was 23% increased in the EA+NSCs14d group. These results suggest that the combination of EA and NSCs improves the survival and migration of NSCs in injured spinal cord in rats.