RESUMO
Recent studies have demonstrated that the human placenta is a novel source of adult stem cells. We have provided laboratory evidence that transplantation of these human placenta-derived cells in vitro and in vivo stroke models promotes functional recovery. However, the mechanisms underlying these observed therapeutic benefits of human placenta-derived cells unfortunately remain poorly understood. Here, we examined the expression of two discrete types of melatonin receptors and their roles in proliferation and differentiation of cultured human amniotic epithelial cells (AECs). Cultured AECs express melatonin receptor type 1A (MT1), but not melatonin receptor type 1B (MT2). The proliferation of cultured AECs was increased in the melatonin-treated group in a dose-dependent manner, and the viability of cultured AECs could be further enhanced by melatonin. Moreover, the viability of AECs significantly decreased with H(2) O(2) exposure, which was reversed by pretreatment with melatonin, resulting in increased cell survival rate and cell proliferation. Immunocytochemically, administration of melatonin significantly suppressed nestin proliferation, but enhanced TUJ1 differentiation of MT1-expressing AECs. Additional experiments incorporating antibody blocking and synergistic AEC-melatonin treatments further showed AEC therapeutic benefits via MT1 modulation. Finally, analysis of trophic factors revealed cultured AECs secreted VEGF in the presence of melatonin. These data indicate that melatonin by stimulating MT1 increased cell proliferation and survival rate while enhancing neuronal differentiation of cultured AECs, which together with VEGF upregulation, rendered neuroprotection against experimental in vitro models of ischemic and oxidative stress injury.
Assuntos
Âmnio/citologia , Células Epiteliais/metabolismo , Receptor MT1 de Melatonina/metabolismo , Receptor MT2 de Melatonina/metabolismo , Antioxidantes/farmacologia , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Humanos , Imuno-Histoquímica , Melatonina/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Receptor MT1 de Melatonina/genética , Receptor MT2 de Melatonina/genéticaRESUMO
The emerging arthropod-borne flavivirus Zika virus (ZIKV) is associated with neurological complications. Innate immunity is essential for the control of virus infection, but the innate immune mechanisms that impact viral infection of neurons remain poorly defined. Using the genetically tractable Drosophila system, we show that ZIKV infection of the adult fly brain leads to NF-kB-dependent inflammatory signaling, which serves to limit infection. ZIKV-dependent NF-kB activation induces the expression of Drosophila stimulator of interferon genes (dSTING) in the brain. dSTING protects against ZIKV by inducing autophagy in the brain. Loss of autophagy leads to increased ZIKV infection of the brain and death of the infected fly, while pharmacological activation of autophagy is protective. These data suggest an essential role for an inflammation-dependent STING pathway in the control of neuronal infection and a conserved role for STING in antimicrobial autophagy, which may represent an ancestral function for this essential innate immune sensor.
Assuntos
Autofagia/fisiologia , Encéfalo/imunologia , Drosophila melanogaster/imunologia , Imunidade Inata , Inflamação/imunologia , Transdução de Sinais/imunologia , Infecção por Zika virus/imunologia , Animais , Anti-Infecciosos , Encéfalo/virologia , Linhagem Celular , Chlorocebus aethiops , Modelos Animais de Doenças , Drosophila melanogaster/genética , Drosophila melanogaster/virologia , Encefalite/imunologia , Encefalite/virologia , Feminino , Humanos , Masculino , NF-kappa B/imunologia , Neurônios/imunologia , Neurônios/virologia , Interferência de RNA/imunologia , Células Vero , Zika virus/patogenicidadeRESUMO
Zika virus is an emerging arthropod-borne flavivirus for which there are no vaccines or specific therapeutics. We screened a library of 2,000 bioactive compounds for their ability to block Zika virus infection in three distinct cell types with two different strains of Zika virus. Using a microscopy-based assay, we validated 38 drugs that inhibited Zika virus infection, including FDA-approved nucleoside analogs. Cells expressing high levels of the attachment factor AXL can be protected from infection with receptor tyrosine kinase inhibitors, while placental-derived cells that lack AXL expression are insensitive to this inhibition. Importantly, we identified nanchangmycin as a potent inhibitor of Zika virus entry across all cell types tested, including physiologically relevant primary cells. Nanchangmycin also was active against other medically relevant viruses, including West Nile, dengue, and chikungunya viruses that use a similar route of entry. This study provides a resource of small molecules to study Zika virus pathogenesis.
Assuntos
Antivirais/farmacologia , Éteres/química , Compostos de Espiro/química , Zika virus/efeitos dos fármacos , Antivirais/química , Células Cultivadas , Vírus Chikungunya/efeitos dos fármacos , Vírus da Dengue/efeitos dos fármacos , Células Endoteliais/citologia , Células Endoteliais/virologia , Éteres/farmacologia , Humanos , Nucleosídeos/química , Nucleosídeos/farmacologia , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Compostos de Espiro/farmacologia , Trofoblastos/citologia , Trofoblastos/virologia , Internalização do Vírus/efeitos dos fármacos , Vírus do Nilo Ocidental/efeitos dos fármacos , Zika virus/fisiologiaRESUMO
We used a photoactive general anesthetic called meta-azi-propofol (AziPm) to test the selectivity and specificity of alkylphenol anesthetic binding in mammalian brain. Photolabeling of rat brain sections with [(3)H]AziPm revealed widespread but heterogeneous ligand distribution, with [(3)H]AziPm preferentially binding to synapse-dense areas compared to areas composed largely of cell bodies or myelin. With [(3)H]AziPm and propofol, we determined that alkylphenol general anesthetics bind selectively and specifically to multiple synaptic protein targets. In contrast, the alkylphenol anesthetics do not bind to specific sites on abundant phospholipids or cholesterol, although [(3)H]AziPm shows selectivity for photolabeling phosphatidylethanolamines. Together, our experiments suggest that alkylphenol anesthetic substrates are widespread in number and distribution, similar to those of volatile general anesthetics, and that multi-target mechanisms likely underlie their pharmacology.
Assuntos
Anestésicos/farmacologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Propofol/farmacologia , Anestésicos/farmacocinética , Animais , Encéfalo/citologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Feminino , Metabolismo dos Lipídeos , Lipídeos/química , Propofol/farmacocinética , Ligação Proteica , RatosRESUMO
BACKGROUND: This study aims to create a convenient reference for both clinicians and researchers so that vis-à-vis comparisons between brain disorders can be made quickly and accurately. We report here the incidence and prevalence of the major adult-onset brain disorders in the United States using a meta-analysis approach. MATERIAL AND METHODS: Epidemiological figures were collected from the most recent, reliable data available in the research literature. Population statistics were based on the most recent census from the US Census Bureau. Extrapolations were made only when necessary. The most current epidemiological studies for each disorder were chosen. All effort was made to use studies based on national cohorts. Studies reviewed were conducted between 1950 and 2009. The data of the leading studies for several neurological studies was compiled in order to obtain the most accurate extrapolations. Results were compared to commonly accepted values in order to evaluate validity. RESULTS: It was found that 6.75% of the American adult population is afflicted with brain disorders. This number was eclipsed by the 8.02% of Floridians with brain disorders, which is due to the large aged population residing in the state. CONCLUSIONS: There was a noticeable lack of epidemiological data concerning adult-onset brain disorders. Since approximately 1 out of every 7 households is affected by brain disorders, increased research into this arena is warranted.
Assuntos
Doenças do Sistema Nervoso/epidemiologia , Encefalopatias/epidemiologia , Coleta de Dados , Humanos , Incidência , Prevalência , Estados UnidosRESUMO
Cell therapy is a major discipline of regenerative medicine that has been continually growing over the last two decades. The aging of the population necessitates discovery of therapeutic innovations to combat debilitating disorders, such as stroke. Menstrual blood and Sertoli cells are two gender-specific sources of viable transplantable cells for stroke therapy. The use of autologous cells for the subacute phase of stroke offers practical clinical application. Menstrual blood cells are readily available, display proliferative capacity, pluripotency and angiogenic features, and, following transplantation in stroke models, have the ability to migrate to the infarct site, regulate the inflammatory response, secrete neurotrophic factors, and have the possibility to differentiate into neural lineage. Similarly, the testis-derived Sertoli cells secrete many growth and trophic factors, are highly immunosuppressive, and exert neuroprotective effects in animal models of neurological disorders. We highlight the practicality of experimental and clinical application of menstrual blood cells and Sertoli cells to treat stroke, from cell isolation and cryopreservation to administration.
Assuntos
Células Sanguíneas/transplante , Menstruação/sangue , Células de Sertoli/transplante , Transplante de Células-Tronco , Acidente Vascular Cerebral/terapia , Animais , Separação Celular , Criopreservação , Feminino , Humanos , Masculino , Acidente Vascular Cerebral/patologia , Transplante AutólogoRESUMO
The pathophysiological changes that occur during ischemic stroke can have a profound effect on the surrounding nerve tissue. To this end, we advance the hypothesis that retinal damage can occur as a consequence of ischemic stroke in animal models. We discuss the preclinical evidence over the last 3 decades supporting this hypothesis of retinal damage following ischemic stroke. In our evaluation of the hypothesis, we highlight the animal models providing evidence of pathological and mechanistic link between ischemic stroke and retinal damage. That retinal damage is closely associated with ischemic stroke, yet remains neglected in stroke treatment regimen, provides the impetus for recognizing the treatment of retinal damage as a critical component of stroke therapy.
Assuntos
Encéfalo/fisiopatologia , Modelos Biológicos , Doenças Retinianas/etiologia , Doenças Retinianas/fisiopatologia , Vasos Retinianos/fisiopatologia , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/fisiopatologia , Animais , HumanosRESUMO
Cell-based therapy is a promising therapy for myocardial infarction. Endogenous repair of the heart muscle after myocardial infarction is a challenge because adult cardiomyocytes have a limited capacity to proliferate and replace damaged cells. Pre-clinical and clinical evidence has shown that cell based therapy may promote revascularization and replacement of damaged myocytes after myocardial infarction. Adult stem cells can be harvested from different sources including bone marrow, skeletal myoblast, and human umbilical cord blood cells. The use of these cells for the repair of myocardial infarction presents various advantages over other sources of stem cells. Among these are easy harvesting, unlimited differentiation capability, and robust angiogenic potential. In this review, we discuss the milestone findings and the most recent evidence demonstrating the therapeutic efficacy and safety of the transplantation of human umbilical cord blood cells as a stand-alone therapy or in combination with gene therapy, highlighting the importance of optimizing the timing, dose and delivery methods, and a better understanding of the mechanisms of action that will guide the clinical entry of this innovative treatment for ischemic disorders, specifically myocardial infarction.
RESUMO
Endothelial progenitor cells (EPCs) correspond to a population of cells with novel properties capable of angiogenesis and vasculogenesis, thus they are likely to display unique role in the reconstitution of the blood brain barrier (BBB) after stroke. Laboratory evidence supports safety and efficacy of cell therapy for stroke, with limited clinical trials recently initiated. This lab-to-clinic ascent of cell-based therapeutics has been aided by the establishment of consortium consisting of thought-leaders from academia, industry, National Institutes of Health (NIH) and the United States Food and Drug Administration (FDA). However, there remain unanswered questions prior to realization of large-scale application of cell transplantation in patients. This review article discusses translational challenges associated in cell therapy, emphasizing the need for optimizing both safety and efficacy profiles for advancing the clinical applications of EPC transplantation for stroke patients.
Assuntos
Células Endoteliais/citologia , Transplante de Células-Tronco , Acidente Vascular Cerebral/terapia , HumanosRESUMO
Stroke remains a significant unmet condition in the USA and throughout the world. To date, only approximately 3% of the population suffering an ischemic stroke benefit from the thrombolytic drug tissue plasminogen activator, largely due to the drug's narrow therapeutic window. The last decade has witnessed extensive laboratory studies suggesting the therapeutic potential of cell-based therapy for stroke. Limited clinical trials of cell therapy in stroke patients are currently being pursued. Bone marrow-derived stem cells are an attractive, novel transplantable cell source for stroke. There remain many unanswered questions in the laboratory before cell therapy can be optimized for transplantation in the clinical setting. Here, we discuss the various translational hurdles encountered in bringing cell therapy from the laboratory to the clinic, using stem cell therapeutics as an emerging paradigm for stroke as a guiding principle. In particular, we focus on the preclinical studies of cell transplantation in experimental stroke with emphasis on a better understanding of mechanisms of action in an effort to optimize efficacy and to build a safety profile for advancing cell therapy to the clinic. A forward looking strategy of combination therapy involving stem cell transplantation and pharmacologic treatment is also discussed.
RESUMO
Stem cells isolated from amniotic fluid are known to be able to differentiate into different cells types, thus being considered as a powerful tool for cellular therapy of different human diseases. In the last 4 years, amniotic fluid-derived stem (AFS) cells have been shown to express embryonic and adult stem cell markers. These cells can be considered an intermediate stage between embryonic stem cells and adult stem cells. AFS cells can give rise to adipogenic, osteogenic, myogenic, endothelial, neurogenic, and hepatic lineages, inclusive of all embryonic germ layers. AFS cells have a high renewal capacity and can be expanded for over 250 doublings without any detectable loss of chromosomal telomere length. Taken together, all these data provide evidence that amniotic fluid represents a new and very promising source of stem cells for research, as well as clinical applications. Certainly stem cells from amniotic fluid will be useful both for a customized cell supply for newly born children and for banking cells to be used for therapeutic cell transplantation in immunogically matched recipients. Further investigations are also warranted to fully explore the amniotic cells' potential for adult human disorders.