RESUMEN
Intravenous transplantation of mesenchymal stem (stromal) cells (MSC) is a promising approach to the treatment of ischemic stroke. In the published reports of the already completed preclinical and clinical studies the dosages of transplanted MSC greatly vary. However, the optimal dosage has not been determined. The dose-dependent effect of intravenous MSC transplantation was studied, in rats with experimental cerebral infarction. To this end, 5×105 and 2×106 MSC were intravenously administered 24 h after modeling of acute focal ischemia followed by complex assessment of the therapeutic efficacy over 60 days. The rate and degree of the recovery of neurological functions in rats increased with increasing the dose of injected cells, which confirms the dose-dependent effect of intravenous MSC transplantation.
Asunto(s)
Isquemia Encefálica , Trasplante de Células Madre Mesenquimatosas , Accidente Cerebrovascular , Animales , Isquemia Encefálica/terapia , Modelos Animales de Enfermedad , Infarto de la Arteria Cerebral Media , RatasRESUMEN
Visualization of transplanted stem cells in the brain is an important issue in the study of the mechanisms of their therapeutic action. MRI allowing visualization of single transplanted cells previously labeled with superparamagnetic iron oxide particles is among the most informative methods of non-invasive intravital imaging. Verification of MRI data using pathomorphological examination at the microscopic level helps to avoid errors in data interpretation. However, making serial sections of the whole brain and searching for transplanted cells under the microscope is laborious and time-consuming. We have developed a method for 3D modeling of the distribution of transplanted cells in the brain allowing navigating through various brain structures and identifying the areas of accumulation of transplanted cells, which significantly increases the efficiency and reduces the time of histological examination.
Asunto(s)
Encéfalo/patología , Rastreo Celular/métodos , Accidente Cerebrovascular Isquémico/terapia , Trasplante de Células Madre Mesenquimatosas/métodos , Animales , Encéfalo/irrigación sanguínea , Encéfalo/metabolismo , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Compuestos Férricos/química , Compuestos Férricos/farmacocinética , Humanos , Imagenología Tridimensional , Infarto de la Arteria Cerebral Media/metabolismo , Infarto de la Arteria Cerebral Media/patología , Infarto de la Arteria Cerebral Media/terapia , Infusiones Intraarteriales , Accidente Cerebrovascular Isquémico/metabolismo , Accidente Cerebrovascular Isquémico/patología , Imagen por Resonancia Magnética , Nanopartículas de Magnetita/química , Masculino , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/metabolismo , Embarazo , Ratas , Ratas WistarRESUMEN
Exposure of cells or biological tissues to high-power pulses of terahertz (THz) radiation leads to changes in a variety of intracellular processes. However, the role of heating effects due to strong absorption of THz radiation by water molecules still stays unclear. In this study, we performed numerical modelling in order to estimate the thermal impact on water of a single THz pulse as well as a series of THz pulses. A finite-element (FE) model that provides numerical solutions for the heat conduction equation is employed to compute the temperature increase. A simple expression for temperature estimation in the center of the spot of THz radiation is presented for given frequency and fluence of the THz pulse. It has been demonstrated that thermal effect is determined by either the average power of radiation or by the fluence of a single THz pulse depending on pulse repetition rate. Human dermal fibroblasts have been exposed to THz pulses (with an energy of [Formula: see text] and repetition rate of 100 Hz) to estimate the thermal effect. Analysis of heat shock proteins expression has demonstrated no statistically significant difference ([Formula: see text]) between control and experimental groups after 3 h of irradiation.
Asunto(s)
Fibroblastos , Proteínas de Choque Térmico/metabolismo , Calor/efectos adversos , Piel , Radiación Terahertz/efectos adversos , Fibroblastos/citología , Fibroblastos/metabolismo , Humanos , Piel/citología , Piel/metabolismoRESUMEN
Human placenta mesenchymal stromal cells were injected to healthy rats either stereotaxically into the striatum or intra-arterially through the internal carotid artery. Some cells injected into the brain migrated along the corpus callosum both medially and laterally or concentrated around small blood vessels. A small fraction of MSC injected intra-arterially adhered to the endothelium and stayed inside blood vessels for up to 48 hours mostly in the basin of the middle cerebral artery. Neither stereotaxic, nor intra-arterial transplantation of mesenchymal stromal cells modulated the proliferation of neural stem cells in the subventricular zone of the brain, but stereotaxic transplantation suppressed activation of their proliferation in response to traumatization with the needle.
Asunto(s)
Cuerpo Estriado/citología , Ventrículos Laterales/citología , Trasplante de Células Madre Mesenquimatosas/métodos , Células Madre Mesenquimatosas/citología , Células-Madre Neurales/citología , Placenta/citología , Animales , Arteria Carótida Interna/citología , Movimiento Celular , Proliferación Celular , Cuerpo Estriado/cirugía , Femenino , Humanos , Inyecciones Intraarteriales , Inyecciones Intraventriculares , Ventrículos Laterales/cirugía , Masculino , Células Madre Mesenquimatosas/fisiología , Arteria Cerebral Media/citología , Células-Madre Neurales/fisiología , Placenta/fisiología , Embarazo , Cultivo Primario de Células , Ratas , Ratas Wistar , Técnicas Estereotáxicas , Trasplante HeterólogoRESUMEN
In in vitro experiments on cultures of human multipotent stem cells from the human bonearrow and dental pulp, we studied direct reprogramming towards neuro-glial lineage cells using a cocktail of small molecules. Reprogramming by the previously published protocol (with a cocktail containing ß-mercaptoethanol, LIF, VPA, CHIR99021, and RepSox) and by the optimized protocol (VPA, RG108, Ð83-01, dorsomorphin, thiazovivin, CHIR99021, forskolin, and Isx9) allows obtaining cells with immunophenotypic and genetic signs of neural stem cells. However, neither the former, nor the optimized protocols allowed preparing neural progenitors capable of adequate terminal differentiation from both bone marrow-derived mesenchymal stem cells and nestin-positive neural crest-derived mesenchymal stem cells. Real-time PCR demonstrated the expression of some neurogenesis markers, but neural stem cell-specific expression pattern was not observed. The findings lead us to a conclusion that reprogramming with small molecules without additional factors modifying gene expression does not allow reproducible production of human neural stem cell-like progenitors that can be used as the source of neural tissue for the regenerative therapy.
Asunto(s)
Células-Madre Neurales/citología , Diferenciación Celular/efectos de los fármacos , Reprogramación Celular/efectos de los fármacos , Humanos , Mercaptoetanol/farmacología , Células Madre Mesenquimatosas , Células-Madre Neurales/efectos de los fármacos , Neurogénesis/efectos de los fármacos , Pirazoles/farmacología , Piridinas/farmacología , Pirimidinas/farmacología , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
We have designed a novel two-component matrix (SPRPix) for the encapsulation of directly reprogrammed human neural precursor cells (drNPC). The matrix is comprised of 1) a solid anisotropic complex scaffold prepared by electrospinning a mixture of recombinant analogues of the spider dragline silk proteins - spidroin 1 (rS1/9) and spidroin 2 (rS2/12) - and polycaprolactone (PCL) (rSS-PCL), and 2) a "liquid matrix" based on platelet-rich plasma (PRP). The combination of PRP and spidroin promoted drNPC proliferation with the formation of neural tissue organoids and dramatically activated neurogenesis. Differentiation of drNPCs generated large numbers of ßIII-tubulin and MAP2 positive neurons as well as some GFAP-positive astrocytes, which likely had a neuronal supporting function. Interestingly the SPRPix microfibrils appeared to provide strong guidance cues as the differentiating neurons oriented their processes parallel to them. Implantation of the SPRPix matrix containing human drNPC into the brain and spinal cord of two healthy Rhesus macaque monkeys showed good biocompatibility: no astroglial and microglial reaction was present around the implanted construct. Importantly, the human drNPCs survived for the 3 month study period and differentiated into MAP2 positive neurons. Tissue engineered constructs based on SPRPix exhibits important attributes that warrant further examination in spinal cord injury treatment.