RESUMO
INTRODUCTION: Both target skeletal muscle (SKM) cells and neurotrophins (NTs) are essential for the maintenance of neuronal function and nerve-muscle communication. The effects of different NTs and SKM cells on growth-associated protein-43 (GAP-43) expression in dorsal root ganglion (DRG) neurons have not been clarified. METHODS: The morphological relationship between DRG neurons and SKM cells in neuromuscular cocultures was observed by scanning electron microscopy. The levels of GAP-43 and its mRNA were determined after administration of different NTs. RESULTS: DRG neurons demonstrated dense neurite outgrowth in the presence of NTs. Distinct NTs promoted GAP-43 and its mRNA expression in neuromuscular cocultures of DRG neurons and SKM cells. CONCLUSIONS: These results offer new clues for a better understanding of the effects of distinct NTs on GAP-43 expression in DRG sensory neurons in the presence of target SKM cells and implicate NTs and target SKM cells in DRG neuronal regeneration.
Assuntos
Proteína GAP-43/metabolismo , Gânglios Espinais/citologia , Fibras Musculares Esqueléticas/fisiologia , Fatores de Crescimento Neural/farmacologia , Células Receptoras Sensoriais/metabolismo , Animais , Fator Neurotrófico Derivado do Encéfalo/farmacologia , Células Cultivadas , Técnicas de Cocultura , Proteína GAP-43/efeitos dos fármacos , Proteína GAP-43/fisiologia , Microscopia Eletrônica de Varredura , Fator de Crescimento Neural/farmacologia , Neuritos/efeitos dos fármacos , Neuritos/ultraestrutura , Neurotrofina 3/farmacologia , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , Células Receptoras Sensoriais/efeitos dos fármacos , Células Receptoras Sensoriais/ultraestruturaRESUMO
In this study, a series of photocrosslinked hydrogels were designed composed of both poly(lactide)-poly(ethylene glycol)-poly(lactide) (PEL) and poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) (PEC) macromers. The PEL/PEC hydrogels at ratios of 100:0, 75:25, 50;50, 25:75 and 0:100 were studied for their degradation characteristics and their ability to support chondrogenesis of encapsulated chondrocytes. Difference in hydrolytic susceptibility between copolymers led to different degradation patterns where higher PEC content correlated with slower degradation. Increased chondrogenic gene expression was observed in chondrocyte-laden hydrogels within a 4-week culture period. Biochemical and histological evaluations revealed significant accumulation of extracellular matrix proteins such as glycosaminoglycans and collagen in the 50/50 hydrogel owing to appropriate tuning of hydrogel degradation. These results demonstrate that the dual-component photocrosslinked hydrogel system is suitable for use as scaffold to support chondrogenesis and, moreover, the tunability of these systems opens up possibilities for use in different cell culturing applications. Copyright © 2014 John Wiley & Sons, Ltd.