70 research outputs found
Neural activity control of neural stem cells and SVZ niche response to brain injury
Patricia Paez-Gonzalez
Kuo Lab, Dept. of Cell Biology, Duke University Medical Center, NC,USA.
Date: 11/16/2014
Utilizing stem cells in the adult brain hold great promise for regenerative medicine. Harnessing
ability of adult neural stem cells (NSCs) to generate new neurons or other types of brain cells may
provide much needed therapies for patients suffering from brain injuries or neuro-degenerative
diseases such as Parkinson’s, Scizophrenia, or Alzheimer’s disease. However, the treatments that
involve stem cells are based in NSC transplantation and its efficiency is really low.
The major barriers-to-progress in this area of research are immune-rejection of the implanted
cells, faulty tumorogenic growth, but mainly, a faulty integration of the improper progeny. To avoid the
problems that accompany NSC transplantation, we wanted to explore whether a new approach focused
on “modulating” the brain’s own resident stem cells to produce the appropriate cells after brain damage
was possible. In order to determine if “in situ” stem cell therapy was plausible, we first had to determine
whether 1)
Environment provides the right signals for the proper NSC function and generation of the
appropriate progeny, 2) whether in vivo NCSs are capable to elaborate an appropriate response under
different brain requirements, and 3) whether directed modulation of Neural Stem Cells function is
possible.
We found that using genetic alteration in only the neighboring ependymal cells has the profound
impact of nearly eliminating new neuron production in the lateral ventricular neurogenic region.
Secondly, we determined that cortical strokes that do not impact the neurogenic region induce
production on TSP4+ astrocytes that migrate to the injury site to produce the scar that stops cortical
bleeding. Thirdly, we have identified a novel cholinergic circuit that resides in the neurogenic region,
and that optogenetic stimulation or silencing of acetylcholine neurons can robustly up or down-regulate
new neuron production. These three discoveries have met the required conditions for using intrinsic
NSCs as therapy for brain regeneration and repair. I am now extending this line of research to
determine if this therapy is now a feasible technique for brain repair understanding how the local brain
circuits are modified as the NSCs transition to an injury response and back to normal production
following recovery. Together these data suggest that therapies utilizing the bodies own intrinsic control
mechanisms for NSC regulation may soon provide much needed avenues for future therapies that are
unattainable with other methods.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Neuropathological events in an animal model resembling human fetal post-hemorrhagic hydrocephalus
Introduction:
In premature newborns, intraventricular hemorrhages (IVH) probably trigger the disruption of the neurogenic ventricular zone. Most of the cases with severe IVH develop post-hemorrhagic hydrocephalus (PHH). A mouse model with IVH has been developed to research into the common neuropathological events present in PHH and into possible therapies.
Methods:
In two-day-old mice, the blood serum from littermates was injected into the ganglionic eminence of one hemisphere or both hemispheres. Fourteen days later, a histopathological analysis was carried out. In the case of injection in one hemisphere, the effects were compared with the contralateral non-injected hemisphere.
Results:
Mice with IVH developed the following neuropathological effects. The ependyma was found denuded and replaced by reactive astrocytes. A reaction of astrocytes over-expressing aquaporin-4 and of NG2 cells was also found developed in the white matter. Alterations in the neurogenesis were also common in the ventricular zone and in the white matter.
Conclusions:
The animal model of IVH developed shows similar neuropathological events to other forms of congenital hydrocephalus and can be used to research into therapies for PHH.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.
PI15/0619 (ISCIII/FEDER) to AJJ
IPSC differentiation into ependymal progenitors to treat ventricular damage during hydrocephalus
Introduction: During both obstructive congenital hydrocephalus and post-hemorrhagic hydrocephalus additional pathological events are intimately associated with their ethiology: a) a detrimental inflammatory response; b) severe damage of the underlying periventricular nervous tissue, including white matter, and c). Therapeutic approaches have been directed to overcome a) and b), however recovery of damaged neuroepithelium/ependyma is, in our present, an important therapeutic gap.
Methods: Human and mouse induced pluripotent stem cells (iPSC) have been artificially differented into ependymal progenitors. Intracerebroventricular (ICV) injections of iPCS are performed ex vivo and in vivo in the damaged ventricular wall. Their integration and differentiation has been studied by immunohistochemistry and histopathological analysis.
Results: Mice and human ependymal progenitors are able to integrate and differentiate into ependyma in damaged ventricular wall. Stage of ependymal differentiation by the time of the injection defined different degrees of integration.
Conclusions: IPSC appear to be a good ependymal progenitor source with no ethical controversy associated.RyC 2014-16980
Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Análisis económico-financiero del sector hotelero y la oferta complementaria de Adeje y Puerto de la Cruz
El sector turístico es un factor clave para el desarrollo de la economía canaria. Debido a ello, este
Trabajo de Fin de Grado analiza determinados aspectos de dicho sector, como es la rentabilidad
económico-financiera de una selección de hoteles de Adeje y Puerto de la Cruz, centros clave del
turismo tinerfeño, así como, su oferta complementaria.
Las herramientas empleadas son el análisis vertical y horizontal de las cuentas anuales y los
principales ratios económico-financieros. Además, se procede a estudiar los factores externos que
repercuten en la muestra objeto de estudio, a través de diversas fuentes de datos y de una
encuesta realizada a la población.
En conclusión, este trabajo arroja nueva información sobre el sector turístico en Tenerife,
concretamente, la existencia de una relación directa entre la rentabilidad económico-financiera, y
la oferta de actividades de ocio, como es el caso de Adeje y Puerto de la Cruz.The tourist sector is a key factor for the development of the Canarian economy. For this reason,
this BA Thesis analyzes a set of specific issues of this sector, for example, the economic and
financial profitability of certain hotels of Adeje and Puerto de la Cruz, which are key areas for the
Tenerife tourism, as well as, their complementary offer.
The methodology used requires a vertical and horizontal analysis of annual accounts and the
economic and financial ratios. Furthermore, it is important to study the external factors that have
an impact on the operation of hotels through different data sources and a population survey.
In conclusion, this project sheds new information on the tourist sector of Tenerife, specifically, the
direct relation between the economic and financial profitability, and the offer of leisure activities, as
it is the case of Adeje and Puerto de la Cru
Long-time effects of an experimental therapy with mesenchymal stem cells in congenital hydrocephalus
Introduction:
Bone marrow-derived mesenchymal stem cells (BM-MSC) are a potential therapeutic tool due to their ability for migrating and producing neuroprotector factors when they are transplanted in other neurodegenerative diseases. Moreover, some investigations have shown that BM-MSC are able to modulate astrocyte activation and neuroprotector factor production. The aim of this study was to evaluate the long-time effects of a BM-MSC experimental therapy in the hyh mouse model of congenital hydrocephalus.
Methods:
BM-MSC were characterized in vitro and then transplanted into the ventricles of young hydrocephalic hyh mice, before they develop the severe hydrocephalus. Non-hydrocephalic normal mice (wt) and hydrocephalic hyh mice sham-injected (sterile saline serum) were used as controls. Samples were studied by analyzing and comparing mRNA, protein level expressions and immunoreaction related with the progression and severity of hydrocephalus.
Results:
Fourteen days after transplantation, hydrocephalic hyh mice with BM-MSC showed lower ventriculomegaly. In these animals, BM-MSC were found undifferentiated and spread into the periventricular astrocyte reaction. There, BM-MSC were detected producing several neuroprotector factors (BDNF, GDNF, NGF, VEGF), in the same way as reactive astrocytes. Total neocortical levels of NGF, TGF-β and VEGF were found increased in hydrocephalic hyh mice transplanted with BM-MSC. Furthermore, astrocytes showed increased expressions of aquaporin-4 (water channel protein) and Slit-2 (neuroprotective and anti-inflammatory molecule).
Conclusions:
BM-MSC seem to lead to recovery of the severe neurodegenerative conditions associated to congenital hydrocephalus mediated by reactive astrocytes.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. PI15/0619 (ISCIII/FEDER
Optical manipulation of lanthanide-doped nanoparticles: how to overcome their limitations
Since Ashkin's pioneering work, optical tweezers have become an essential tool to immobilize and manipulate microscale and nanoscale objects. The use of optical tweezers is key for a variety of applications, including single-molecule spectroscopy, colloidal dynamics, tailored particle assembly, protein isolation, high-resolution surface studies, controlled investigation of biological processes, and surface-enhanced spectroscopy. In recent years, optical trapping of individual sub-100-nm objects has got the attention of the scientific community. In particular, the three-dimensional manipulation of single lanthanide-doped luminescent nanoparticles is of great interest due to the sensitivity of their luminescent properties to environmental conditions. Nevertheless, it is really challenging to trap and manipulate single lanthanide-doped nanoparticles due to the weak optical forces achieved with conventional optical trapping strategies. This limitation is caused, firstly, by the diffraction limit in the focusing of the trapping light and, secondly, by the Brownian motion of the trapped object. In this work, we summarize recent experimental approaches to increase the optical forces in the manipulation of lanthanide-doped nanoparticles, focusing our attention on their surface modification and providing a critical review of the state of the art and future prospectsThis work was supported by the Ministerio de Ciencia e Innovación de España (PID2019-105195RA-I00) and by Universidad Autónoma de Madrid,Comunidad Autónoma de Madrid(SI1/PJI/2019-00052)
Multiciliated ependyma recovery through a sequential cell therapy in posthemorrhagic hydrocephalus.
Posthemorrhagic hydrocephalus (PHH) is a significant cause for premature children’s morbidity, mortality, and
peri/postnatal neurodevelopmental impairment. PHH is mainly triggered by germinal matrix hemorrhages (GMH)
and causes germinal matrix and ependyma disfunction. Ependyma constitutes a relevant tissue barrier with roles in
cerebrospinal fluid homeostasis, circulation, and neurogenesis, hence situating ependyma as a main target when
treating PHH. Clinical treatments are directed to eliminate immediate inflammatory condition triggered by the
bleeding, to drain excess of CSF if needed, but not to treat or recover ependyma structure. Ependymal progenitors
were obtained from P0 mice. Cells were cultured under specific conditions to enhance either ependymal
proliferation or differentiation status. Different GMH/IVH neuroinflammatory conditions were mimed in the
ependyma cultures, different stem cell therapies tested and effect on the ependymal differentiation measured.
Additionally, ventricular wall explants from mice with induced PHH were obtained and cultured as ex-vivo system of
PHH. A combination of stem cells was applied on the tissue to probe its regenerative capabilities on the
multiciliated ependyma. All samples were analyzed through immunofluorescence and laser confocal microscopy
and quantified. Results show that (i) ependymal progenitors’ maturation is hindered under neuroinflammatory
conditions, showing no multiciliated ependyma and (ii) the tested stem cell combination promotes ependymal
progenitors’ survival albeit does not alter the differentiation of the selfsame. In summary, it can be stated that the
final differentiation of the ependyma is disrupted by the molecular conditions triggered by GMH/IVH, which our
proposed cell therapy is able to counteract through increased survival and differentiation in a murine model of
experimental PHHJunta de Andalucia (UMA18-FEDERJA-277) and Instituto de Salud Carlos III
(PI19/00778), Spain; co-financed by FEDER funds from the European Union, Spain. Also, II-PPITD, Universidad de
Malaga, Spain (to JL-dSS); and I-PPITD, Universidad de Málaga, Spain (to LMR-P)
Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
A metabolite profile reveals the presence of neurodegenerative conditions according to severity of hydrocephalus
Introduction: In obstructive congenital hydrocephalus, cerebrospinal fluid accumulation is associated with high intracranial pressure (ICP), ischemia/hypoxia, metabolic impairment, neuronal damage and astrocytic reaction. The hyh mutant mice exhibit two different forms of hydrocephalus evolution: severe and moderate. A study was carried out in hyh mice to detect a metabolite profile that define the tissue response in each hydrocephalus form.
Methods: Metabolites levels in brain cortex were analyzed with 1H High Resolution Magic Angle Spinning Nuclear Magnetic Resonance (1H HR-MAS) spectroscopy. The study was complemented with ICP recording and histopathological analysis.
Results: Mice with severe hydrocephalus were found to have higher ICP and stronger astrocytic reaction. Several metabolites including glutamate and glutamine were found to correlate with the severity of hydrocephalus. The whole metabolite profile may be explained based in differential astrocyte reactions, neurodegenerative and ischemic conditions. The glutamate transporter EAAT2 and the metabolite taurine were found as key histopathological markers for the damaged parenchyma. Conclusions: Spectroscopy allowed the detection of a metabolite profile related to intracranial pressure and hydrocephalus severity, and therefore can be useful to monitor the efficacy of experimental therapies.
Supported by Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech, and PI15/0619 (ISCIII/FEDER).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.
Supported by Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech, and PI15/0619 (ISCIII/FEDER)
Correlation of the Epworth somnolence scale with the diagnosis andseverity of the obstructive sleep apnea-hypopnea syndrome (osahs)
Introducción: diferentes publicaciones han cuestionado la utilidad de la escala de Epworth de somnolencia y sugieren falta de correlación con la severidad del SAHOS dado por el índice de apnea hipopnea y con desenlaces clínicos.
Objetivos: determinar el índice de correlación del puntaje de la escala de Epworth y el índice de apnea hipopnea del sueño. Identificar el punto de corte mediante curva ROC para el puntaje de la escala y el índice de apnea hipopnea (IAH) del polisomnograma. Identificar qué variables de la escala se correlacionan mejor con el diagnóstico de SAHOS.
Diseño: estudio descriptivo de corte transversal, estudio de correlación. Determinación de puntos de corte mediante curvas ROC.
Materiales y métodos: se usó la base de datos de los pacientes a los que se les realizó polisomnograma basal en la Clínica de Marly desde marzo de 2005 hasta julio de 2009 y en el Hospital Universitario San Ignacio desde marzo de 2005 a febrero de 2013. Previo al procedimiento todos los pacientes fueron entrevistados por un Neumólogo especialista en sueño y se llenó una encuesta estandarizada. Mediante el programa de estadística STATA 12.0 se hallaron los datos demográficos de la población y se estudió la correlación entre IAH y el puntaje de Epworth. Igualmente, se evaluaron diferentes puntos de corte mediante la curva ROC. Se hicieron análisis parciales retirando, en un proceso secuencial, variables de la escala de Epworth para repetir los análisis, y se analizaron los diferentes grados de severidad, por separado en el IAH, para la búsqueda de correlación.
Resultados: se analizaron los datos de 3.093 pacientes (46,57% mujeres), con un promedio de edad de 56,52 años. El peso promedio fue de 81,9±17,6 kg con un IMC promedio de 31,91 (± 6,54) kg/m2. El 87,78% tenía IMC mayor o igual a 25. El diagnóstico de SAHOS se realizó en 2.667 pacientes (86,23%), con un IAH de 5 o más. El IAH en promedio fue de 32,76 (± 29,05). El análisis de correlación entre el puntaje de la escala de Epworth y el IAH (Rho de Spearman) es de 0,075 (p=0,0001) lo cual indica que no hay correlación. La curva ROC no permitió elegir ningún punto de corte apropiado para la escala de Epworth en relación con el diagnóstico de SAHOS (área bajo la curva 0,52).
Conclusiones: el resultado del estudio muestra que la escala de Epworth no tiene correlación con el IAH medido por polisomnograma. No se encontró algún punto de corte que muestre mejor sensibilidad ni especificidad. La valoración multidisciplinaria y la alta sospecha diagnóstica continúan siendo el mejor método para seleccionar los pacientes que deben ser llevados a estudio polisomnográfico.Artículo original10-15Introduction: several publications have questioned the usefulness of the Epworth somnolence scale and suggest a lack of
correlation with the severity of OSAHS given by the apnea-hypopnea index and with clinical outcomes.
Objectives: to determine the correlation index of the Epworth scale score and the sleep apnea-hypopnea index (AHI). To
identify the cut point through the ROC Curve for the scale’s score and the AHI of the polysomnogram. To identify which
variables of the scale correlate better with the diagnosis of OSAHS.
Design: descriptive cross-sectional study, correlation study. Determination of cut points by ROC curves.
Materials and methods: the database of patients who underwent baseline polysomnograms at the Clínica de Marly over
the period from March 2005 to July 2009 and at the Hospital Universitario San Ignacio from March 2005 to February 2013
was used. Before the procedure, each patient was interviewed by a pulmonologist specializing in sleep, and a standardized
survey was filled out. The demographic data of the population were established with the STATA 12.0 statistical program, and
the correlation between the AHI and the Epworth score was studied. Different cut points were likewise studied by the ROC
curve. Partial analyses were done by withdrawing, in a sequential process, variables of the Epworth scale in order to repeat
the analyses, and the different degrees of severity were analyzed, separately in the AHI, in search of correlation.
Results: the data of 3093 patients (46,57% women) were analyzed. Their mean age was 56,52 years. The mean weight
was 81,9±17.6 Kg with a mean BMI of 31,91 (±6,54) kg/m2
. 87,78% of the patients had a BMI ≥ 25. OSAHS was diagnosed
in 2667 patients (86,23%), with an AHI of 5 or more. The mean AHI was 32,76 (±29,05). On analysis, the correlation between the Epworth scale score and the AHI (Spearman’s rho) was 0,075 (p=0,0001), which shows there is no correlation.
The ROC curve did not allow to choose any adequate cut point for the Epworth scale in regard to the diagnosis of OSAHS
(area under the curve 0,52).
Conclusions: the result of the study shows us that the Epworth scale has no correlation with the AHI measured by polysomnography. No cut point with better sensitivity or specificity was found. Multidisciplinary evaluation and high diagnostic
suspicion continue to be the best method for selecting patients who should undergo polysomnographic stud
Testing exosomes as a treatment for posthemorrhagic hydrocephalus.
Germinal matrix hemorrhages and intraventricular hemorrhages (GMH/IVH) lead to posthemorrhagic hydrocephalus (PHH), a severe cause of morbidity and mortality in premature neonates. GMH/IVH disrupts the ependyma, which forms a physical and functional barrier between the brain parenchyma and the cerebrospinal fluid (CSF). CSF circulation and physiology is also affected by ependyma disruption. Thus, ependyma is a key target when designing PHH treatments. Despite this, hydrocephalus treatments are surgical and focused on alleviating ventricular pressure by draining CSF. No therapy is currently aimed to recover the ependyma. Nevertheless, bone marrow derived mesenchymal stem cells (MSCs) are known to be great agents when dealing with inflammation. Also, exosomes have proven to be promising tools when designing anti-inflammatory treatments. Therefore, gaining insight in the treating capabilities of MSCs exosomes in PHH can be valuable.
Results
Differential effects in edema progression and ependymal cells ciliogenesis are found when analyzing treatments with conditioned and non-conditioned exosomes in moderate PHH and severe PHH.- Universidad de Malaga. Campus de Excelencia Internacional Andalucia Tech.
- Junta de Andalucia (UMA18-FEDERJA-277)
- Instituto de Salud Carlos III (PI19/00778)
- Cofinanciado por fondos FEDER - UE
- …