RESUMEN
While neural cell transplantation represents a promising therapy for neurodegenerative diseases, the formation of functional networks of transplanted cells with host neurons constitutes one of the challenging steps. Here, we introduce a magnetic guidance methodology that controls neurite growth signaling via magnetic nanoparticles (MNPs) conjugated with antibodies targeting the deleted in colorectal cancer (DCC) receptor (DCC-MNPs). Activation of the DCC receptors by clusterization and subsequent axonal growth of the induced neuronal (iN) cells was performed in a spatially controlled manner. In addition to the directionality of the magnetically controlled axon projection, axonal growth of the iN cells assisted the formation of functional connections with pre-existing primary neurons. Our results suggest magnetic guidance as a strategy for improving neuronal connectivity by spatially guiding the axonal projections of transplanted neural cells for synaptic interactions with the host tissue.
Asunto(s)
Anticuerpos/química , Axones/metabolismo , Reprogramación Celular , Receptor DCC/metabolismo , Células Madre Pluripotentes Inducidas/metabolismo , Campos Magnéticos , Nanopartículas de Magnetita/química , Receptor DCC/antagonistas & inhibidores , Humanos , Células Madre Pluripotentes Inducidas/citología , Neuritas/metabolismoRESUMEN
Multiple myeloma (MM) is an incurable disease; a better understanding of the molecular aspects of this hematological malignancy could contribute to the development of new treatment strategies and help to improve the survival rates of patients with MM. Previously, the methylation status of the deleted in colorectal cancer (DCC) gene was correlated with the survival rate of patients with MM, thus the main goal of this study was to understand DCC contribution to MM tumorigenesis, and to assess the impact of DCC inhibition in the MM response to treatment with bortezomib. Our results demonstrated that hypermethylation of the DCC promoter inhibits gene expression, and DCC silencing is significantly correlated with a reduction in cell viability and an increase in cell death induced by bortezomib. In conclusion, our results suggested that hypermethylation is an important mechanism of DCC expression regulation in MM and that the absence of DCC contributes to the enhanced sensitivity to treatment with bortezomib.
Asunto(s)
Bortezomib/farmacología , Receptor DCC/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Receptor DCC/antagonistas & inhibidores , Receptor DCC/genética , Metilación de ADN/efectos de los fármacos , Humanos , Mieloma Múltiple/metabolismo , Mieloma Múltiple/patología , Regiones Promotoras Genéticas , Interferencia de ARN , ARN Interferente Pequeño/metabolismoRESUMEN
Hippocampal neurogenesis in the dentate gyrus (DG) is controlled by diffusible molecules that modulate neurogenic processes, including cell proliferation, differentiation and survival. To elucidate the mechanisms underlying hippocampal neurogenesis, we investigated the function of draxin, originally identified as a neural chemorepellent, in the regulation of neuronal survival in the DG. Draxin was expressed in Tbr2 (+) late progenitors and NeuroD1 (+) neuroblasts in the dentate granule cell lineage, whereas expression of its receptor DCC (deleted in colorectal cancer) was mainly detectable in neuroblasts. Our phenotypic analysis revealed that draxin deficiency led to enhanced apoptosis of DCC-expressing neuroblasts in the neurogenic areas. Furthermore, in vitro assays using a hippocampal neural stem/progenitor cell (HNSPC) line indicated that draxin inhibited apoptosis in differentiating HNSPCs, which express DCC. Taken together, we postulate that draxin plays a pivotal role in postnatal DG neurogenesis as a dependence receptor ligand for DCC to maintain and promote survival of neuroblasts.
