RESUMEN
Endogenous brain repair occurs following an ischemic stroke but is transient, thus unable to fully mount a neuroprotective response against the evolving secondary cell death. Finding a treatment strategy that may render robust and long-lasting therapeutic effects stands as a clinically relevant therapy for stroke. Extracellular vesicles appear to be upregulated after stroke, which may represent a candidate target for neuroprotection. In this study, we probed whether transplanted stem cells could enhance the expression of extracellular vesicles to afford stable tissue remodeling in the ischemic stroke brain. Aged rats were initially exposed to the established ischemic stroke model of middle cerebral artery occlusion then received intravenous delivery of either bone marrow-derived mesenchymal stem cell transplantation or vehicle. A year later, the animals were assayed for brain damage, inflammation, and extracellular vesicle expression. Our findings revealed that while core infarction was not reduced, the stroke animals transplanted with stem cells displayed a significant reduction in peri-infarct cell loss that coincided with downregulated Iba1-labeled inflammatory cells and upregulated CD63-positive extracellular vesicles that appeared to be co-localized with GFAP-positive astrocytes. Interestingly, grafted stem cells were not detected at one year post-transplantation period, suggesting that the extracellular vesicles likely originated within the host brain. That long-lasting functional benefits persisted in the absence of surviving transplanted stem cells, but with upregulation of endogenous extracellular vesicles, advances the concept that transplantation of stem cells acutely after stroke propels host extracellular vesicles to the ischemic brain, altogether promoting chronic brain remodeling.
Asunto(s)
Encéfalo , Vesículas Extracelulares , Trasplante de Células Madre Mesenquimatosas , Accidente Cerebrovascular , Animales , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/trasplante , Ratas , Masculino , Trasplante de Células Madre Mesenquimatosas/métodos , Accidente Cerebrovascular/metabolismo , Accidente Cerebrovascular/terapia , Encéfalo/metabolismo , Infarto de la Arteria Cerebral Media/metabolismo , Accidente Cerebrovascular Isquémico/metabolismo , Ratas Sprague-Dawley , Modelos Animales de Enfermedad , Astrocitos/metabolismoRESUMEN
Ischemic brain injury represents a major cause of death worldwide with limited treatment options with a narrow therapeutic window. Accordingly, novel treatments that extend the treatment from the early neuroprotective stage to the late regenerative phase may accommodate a much larger number of stroke patients. To this end, stem cell-based regenerative therapies may address this unmet clinical need. Several stem cell therapies have been tested as potentially exhibiting the capacity to regenerate the stroke brain. Based on the long track record and safety profile of transplantable stem cells for hematologic diseases, bone marrow-derived mesenchymal stromal cells or mesenchymal stromal cells have been widely tested in stroke animal models and have reached clinical trials. However, despite the translational promise of MSCs, probing cell function remains to be fully elucidated. Recognizing the multi-pronged cell death and survival processes that accompany stroke, here we review the literature on MSC definition, characterization, and mechanism of action in an effort to gain a better understanding towards optimizing its applications and functional outcomes in stroke.
Asunto(s)
Lesiones Encefálicas , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas , Accidente Cerebrovascular , Animales , Encéfalo/metabolismo , Lesiones Encefálicas/metabolismo , Humanos , Células Madre Mesenquimatosas/metabolismo , Accidente Cerebrovascular/metabolismo , Accidente Cerebrovascular/terapiaRESUMEN
Stem cell therapy may present an effective treatment for metastatic brain cancer and glioblastoma. Here we posit the critical role of a leaky blood-brain barrier (BBB) as a key element for the development of brain metastases, specifically melanoma. By reviewing the immunological and inflammatory responses associated with BBB damage secondary to tumoral activity, we identify the involvement of this pathological process in the growth and formation of metastatic brain cancers. Likewise, we evaluate the hypothesis of regenerating impaired endothelial cells of the BBB and alleviating the damaged neurovascular unit to attenuate brain metastasis, using the endothelial progenitor cell (EPC) phenotype of bone marrow-derived mesenchymal stem cells. Specifically, there is a need to evaluate the efficacy for stem cell therapy to repair disruptions in the BBB and reduce inflammation in the brain, thereby causing attenuation of metastatic brain cancers. To establish the viability of stem cell therapy for the prevention and treatment of metastatic brain tumors, it is crucial to demonstrate BBB repair through augmentation of vasculogenesis and angiogenesis. BBB disruption is strongly linked to metastatic melanoma, worsens neuroinflammation during metastasis, and negatively influences the prognosis of metastatic brain cancer. Using stem cell therapy to interrupt inflammation secondary to this leaky BBB represents a paradigm-shifting approach for brain cancer treatment. In this review article, we critically assess the advantages and disadvantages of using stem cell therapy for brain metastases and glioblastoma.
RESUMEN
Stem cell transplantation with rehabilitation therapy presents an effective stroke treatment. Here, we discuss current breakthroughs in stem cell research along with rehabilitation strategies that may have a synergistic outcome when combined together after stroke. Indeed, stem cell transplantation offers a promising new approach and may add to current rehabilitation therapies. By reviewing the pathophysiology of stroke and the mechanisms by which stem cells and rehabilitation attenuate this inflammatory process, we hypothesize that a combined therapy will provide better functional outcomes for patients. Using current preclinical data, we explore the prominent types of stem cells, the existing theories for stem cell repair, rehabilitation treatments inside the brain, rehabilitation modalities outside the brain, and evidence pertaining to the benefits of combined therapy. In this review article, we assess the advantages and disadvantages of using stem cell transplantation with rehabilitation to mitigate the devastating effects of stroke.
Asunto(s)
Isquemia Encefálica/complicaciones , Isquemia Encefálica/terapia , Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/terapia , Animales , Encéfalo/patología , Microambiente Celular , Humanos , Trasplante de Células MadreRESUMEN
OBJECTIVE: The purpose of this study was to investigate the relationship between satisfaction with information about treatment-related and survivorship issues and mental health outcomes, including vitality, in long-term breast cancer survivors. METHODS: Participants who had finished treatment for breast cancer at least 3 months before enrollment completed a survey instrument designed to evaluate satisfaction with diagnostic and treatment information and satisfaction with survivorship information. Mental health and vitality were measured using the Medical Outcomes Study SF-36, and distress was measured using the impact of events scale. Bivariate analyses and linear regression analyses were performed to investigate the relationships between satisfaction with information, mental health, vitality, and distress controlling for clinical and treatment variables. RESULTS: The survey was completed by 231 participants (response rate 83%). More respondents were highly satisfied with treatment information (87%) than with survivorship information (30%, p=0.0001). There was a strong positive relationship between satisfaction with information (both treatment and survivorship issues) and vitality, mental health, and a strong negative relationship with distress. In multivariate analyses, satisfaction with treatment information was independently associated with mental health (p<0.01), and satisfaction with survivorship information was independently associated with vitality (p<0.05). CONCLUSION: Among patients who have completed treatment for breast cancer, satisfaction with diagnosis and treatment information is greater than satisfaction with survivorship issues and satisfaction with information may play an important role in mental health outcomes. PRACTICE IMPLICATIONS: Given the relationship between satisfaction with information and vitality, interventions to improve informational support regarding survivorship issues are warranted.