Secretion pattern of canine amniotic stem cells derived extracellular vesicles

Extracellular vesicles (EVs) derived from stem cells (SCs) have regenerative potential and the possibility of being used in treating chronic diseases. EVs present lower risk of tumorigenicity and easily to isolation and storage. Therefore, this research aims to compare the morphological characteristics of the EVs (up to 150nm) derived from stem cells obtained from canine amniotic membranes in different passages during the in vitro culture. For this, cells from the amniotic membranes were isolated, cultured, and characterized. In order to answer our aim, the number of cells was normalized at each passage to generate conditioned media for EVs separation. The cells were differentiated into adipogenic, chondrogenic, and osteogenic tissue, to characterize these cells as mesenchymal stem cells (MSC). Moreover, flow cytometry analysis was performed and showed that the MSC were positive for CD90, CD105 and negative for CD34, CD45, mesenchymal and hematopoietic markers, respectively. For EVs analysis, MSC in different passages (P0-P2) were culture until 80% of confluence, then the medium was replaced by EVs depleted medium. After 48h, culture medium was collected and centrifuged to separate EVs, followed by nanoparticle tracking analysis. The EVs were also characterized by western blot and transmission electron microscopy (TEM). EVs were positive for Alix and negative for Cytochrome C as well as presented the traditional cup-shape by transmission electronic microscopy. Our results demonstrated that the concentration in the different passages was increased in P0 compared to P1 and P2 (p<0.05). No differences were found in EVs size (P0=132nm, P1=130nm and P2=120nm). Together, these results demonstrate that P0 of MSC is enriched of EVs when compared to later passages, suggesting that this passage would be the best to be applied in pre-clinical tests. Despite that, more studies are necessary to identify the EVs content and how the cells will respond to treatment with them.(AU)

New therapeutic target for pediatric anaplastic ependymoma control: study of anti-tumor activity by a Kunitz-type molecule, Amblyomin-X.

EPNs comprise a heterogeneous group of neuroepithelial tumors, accounting for about 10% of all intracranial tumors in children and up to 30% of brain tumors in those younger than 3 years. Actually, the pattern therapy for low-grade EPNs includes complete surgical resection followed by radiation therapy. Total surgical excision is often not possible due to tumor location. The aim of this study was to evaluate, for the first time, the anti-tumor activity of Amblyomin-X in 4 primary cultures derived from pediatric anaplastic posterior fossa EPN, Group A (anaplastic, WHO grade III) and one primary culture of a high grade neuroepithelial tumor with MN1 alteration, which was initially misdiagnosed as EPN: i) by in vitro assays: comparisons of temozolomide and cisplatin; ii) by intracranial xenograft model. Amblyomin-X was able to induce cell death in EPN cells in a more significant percentage compared to cisplatin. The cytotoxic effects of Amblyomin-X were not detected on hFSCs used as control, as opposed to cisplatin-treatment, which promoted a substantial effect in the hAFSCs viability. TEM analysis showed ultrastructural alterations related to the process of cell death: mitochondrial degeneration, autophagosomes and aggregate-like structures. MRI and histopathological analyzes demonstrated significant tumor mass regression. Our results suggest that Amblyomin-X has a selective effect on tumor cells by inducing apoptotic cell death and may be a therapeutic option for Group AEPNs.

The role of fetal-maternal microchimerism as a natural-born healer in integrity improvement of maternal damaged kidney

ABSTRACT Purpose: To identify the fetal stem cell (FSC) response to maternal renal injury with emphasis on renal integrity improvement and Y chromosome detection in damaged maternal kidney. Materials and Methods: Eight non-green fluorescent protein (GFP) transgenic Sprague-Dawley rats were mated with GFP-positive transgenic male rats. Renal damage was induced on the right kidney at gestational day 11. The same procedure was performed in eight non-pregnant rats as control group. Three months after delivery, right ne- phrectomy was performed in order to evaluate the injured kidney. The fresh perfused kidneys were stained with anti-GFP antibody. Polymerase chain reaction (PCR) assay was also performed for the Y chromosome detection. Cell culture was performed to detect the GFP-positive cells. Technetium-99m-DMSA renal scan and single-photon emission computed tomography (SPECT) were performed after renal damage induction and 3 months later to evaluate the improvement of renal integrity. Results: The presence of FSCs was confirmed by immune histochemical staining as well as immunofluorescent imaging of the damaged part. Gradient PCR of female rat purified DNA demonstrated the presence of Y-chromosome in the damaged maternal kidney. Moreover, the culture of kidney cells showed GPF- positive cells by immuno- fluorescence microscopy. The acute renal scar was repaired and the integrity of dam- aged kidney reached to near normal levels in experimental group as shown in DMSA scan. However, no significant improvement was observed in control group. Conclusion: FSC seems to be the main mechanism in repairing of the maternal renal injury during pregnancy as indicated by Y chromosome and GFP-positive cells in the sub-cultured medium.

The role of fetal-maternal microchimerism as a natural-born healer in integrity improvement of maternal damaged kidney.

PURPOSE: To identify the fetal stem cell (FSC) response to maternal renal injury with emphasis on renal integrity improvement and Y chromosome detection in damaged maternal kidney. MATERIALS AND METHODS: Eight non-green fluorescent protein (GFP) transgenic Sprague- Dawley rats were mated with GFP-positive transgenic male rats. Renal damage was induced on the right kidney at gestational day 11. The same procedure was performed in eight non-pregnant rats as control group. Three months after delivery, right nephrectomy was performed in order to evaluate the injured kidney. The fresh perfused kidneys were stained with anti-GFP antibody. Polymerase chain reaction (PCR) assay was also performed for the Y chromosome detection. Cell culture was performed to detect the GFP-positive cells. Technetium-99m-DMSA renal scan and single-photon emission computed tomography (SPECT) were performed after renal damage induction and 3 months later to evaluate the improvement of renal integrity. RESULTS: The presence of FSCs was confirmed by immune histochemical staining as well as immunofluorescent imaging of the damaged part. Gradient PCR of female rat purified DNA demonstrated the presence of Y-chromosome in the damaged maternal kidney. Moreover, the culture of kidney cells showed GPF- positive cells by immunofluorescence microscopy. The acute renal scar was repaired and the integrity of damaged kidney reached to near normal levels in experimental group as shown in DMSA scan. However, no significant improvement was observed in control group. CONCLUSION: FSC seems to be the main mechanism in repairing of the maternal renal injury during pregnancy as indicated by Y chromosome and GFP-positive cells in the sub-cultured medium.

Maturation of hematopoietic stem cells from prehematopoietic stem cells is accompanied by up-regulation of PD-L1.

Hematopoietic stem cells (HSCs) mature from pre-HSCs that originate in the major arteries of the embryo. To identify HSCs from in vitro sources, it will be necessary to refine markers of HSCs matured ex vivo. We purified and compared the transcriptomes of pre-HSCs, HSCs matured ex vivo, and fetal liver HSCs. We found that HSC maturation in vivo or ex vivo is accompanied by the down-regulation of genes involved in embryonic development and vasculogenesis, and up-regulation of genes involved in hematopoietic organ development, lymphoid development, and immune responses. Ex vivo matured HSCs more closely resemble fetal liver HSCs than pre-HSCs, but are not their molecular equivalents. We show that ex vivo-matured and fetal liver HSCs express programmed death ligand 1 (PD-L1). PD-L1 does not mark all pre-HSCs, but cell surface PD-L1 was present on HSCs matured ex vivo. PD-L1 signaling is not required for engraftment of embryonic HSCs. Hence, up-regulation of PD-L1 is a correlate of, but not a requirement for, HSC maturation.

Isolation, culture, characterization and cryopreservation of stem cells derived from amniotic mesenchymal layer and umbilical cord tissue of bovine fetuses / Isolamento, cultura, caracterização e criopreservação de células tronco derivadas de camada amniótica mesenquimal e de tecido do cordão umbilical de fetuses bovinos

Stem cells are undifferentiated cells with a high proliferation potential. These cells can be characterized by their in vivo ability to self-renew and to differentiate into specialized cell lines. The most used stem cell types, in both human and veterinary fields, are the mesenchymal stem cells (MSC) derived from bone marrow and adipose tissue. Nowadays, there is a great interest in using stem cells derived from fetal tissues, such as amniotic membrane (AM) and umbilical cord tissue (UCT), which can be obtained non-invasively at delivery time. Due to the scarcity of studies in bovine species, the aim of this study was to isolate, characterize, differentiate and cryopreserve MSC derived from the mesenchymal layer of amniotic membrane (AM), for the first time, and umbilical cord tissue (UCT) of dairy cow neonates after assisted delivery (AD) and from fetus at initial third of pregnancy (IT) obtained in slaughterhouse. Cells were isolated by enzymatic digestion of the tissue fragments with 0.1% collagenase solution. Six samples of AM and UCT at delivery time and six samples of AM and UCT at first trimester of pregnancy were subjected to morphology evaluation, imunophenotype characterization, in vitro osteogenic, adipogenic and chondrogenic differentiation and viability analysis after cryopreservation. All samples showed adherence to plastic and fibroblast-like morphology. Immunocytochemistry revealed expression of CD 44, NANOG and OCT-4 and lack of expression of MHC II in MSC from all samples. Flow cytometry demonstrated that cells from all samples expressed CD 44, did not or low expressed CD 34 (AM: IT-0.3%a, AD-3.4%b; UCT: 0.4%, 1.4%) and MHC II (AM: IT-1.05%a, AD-9.7%b; UCT: IT-0.7%a, AD-5.7%b). They were also capable of trilineage mesenchymal differentiation and showed 80% viability after cryopreservation. According to the results, bovine AM and UCT-derived cells, either obtained at delivery time or from slaughterhouse, [...](AU)

As células tronco mesenquimais (CTMs) estão presentes na maioria dos tecidos adultos e possuem grande capacidade de multiplicação. Quando cultivadas in vitro são capazes de se auto renovar e dar origem a novos tipos celulares. As células tronco mais utilizadas, tanto na medicina humana como na medicina veterinária são as células tronco mesenquimais derivadas da medula óssea e do tecido adiposo. Atualmente, uma grande tendência para a utilização de CTMs obtidas de tecidos fetais, como a membrana amniótica (MA), matriz extravascular do cordão umbilical (TCU) e sangue do cordão umbilical (SCU) pode ser observada, já que estas fontes podem ser colhidas no momento do parto por uma técnica não invasiva. Dessa forma, o objetivo deste estudo foi isolar, caracterizar, diferenciar e criopreservar CTMs obtidas de MA e TCU de fetos bovinos colhidos no momento do parto e de fetos do terço inicial da gestação em abatedouro-frigorífico. As células foram recuperadas por meio de digestão enzimática tecidual, realizada com solução de colagenase 0,1%. Foram colhidas amostras de MA e TCU no momento do parto (n=6) e de MA e TCU no terço inicial de gestação (n=6), as quais foram submetidas às análises morfológicas, imunofenotípica por imunocitoquímica e citometria de fluxo, diferenciações in vitro nas linhagens osteogênica, adipogênica e condrogênica e ainda, avaliação da viabilidade após a criopreservação por citometria de fluxo. Todas as amostras dos diferentes grupos demonstraram adesão ao plástico e morfologia fibroblastóide. No ensaio imunocitoquímico todas as amostras foram imunomarcadas para CD44, NANOG e Oct-4, com ausência de marcação para MHC II. Na análise imunofenotipica por citometria de fluxo, todas as amostras apresentaram marcação para CD44, ausência de marcação para ou baixíssima expressão de CD34 (MA: TI-0,3%a, PA-3.4%b; TCU: TI-0,4%, PA-1.4%) e nula ou baixa expressão de MHC II (MA: TI-1.5%a, PA-9.7%b; UCT: TI-0.7%a, PA-5.7%b. [...](AU)

Isolation, culture, characterization and cryopreservation of stem cells derived from amniotic mesenchymal layer and umbilical cord tissue of bovine fetuses / Isolamento, cultura, caracterização e criopreservação de células tronco derivadas de camada amniótica mesenquimal e de tecido do cordão umbilical de fetuses bovinos

Stem cells are undifferentiated cells with a high proliferation potential. These cells can be characterized by their in vivo ability to self-renew and to differentiate into specialized cell lines. The most used stem cell types, in both human and veterinary fields, are the mesenchymal stem cells (MSC) derived from bone marrow and adipose tissue. Nowadays, there is a great interest in using stem cells derived from fetal tissues, such as amniotic membrane (AM) and umbilical cord tissue (UCT), which can be obtained non-invasively at delivery time. Due to the scarcity of studies in bovine species, the aim of this study was to isolate, characterize, differentiate and cryopreserve MSC derived from the mesenchymal layer of amniotic membrane (AM), for the first time, and umbilical cord tissue (UCT) of dairy cow neonates after assisted delivery (AD) and from fetus at initial third of pregnancy (IT) obtained in slaughterhouse. Cells were isolated by enzymatic digestion of the tissue fragments with 0.1% collagenase solution. Six samples of AM and UCT at delivery time and six samples of AM and UCT at first trimester of pregnancy were subjected to morphology evaluation, imunophenotype characterization, in vitro osteogenic, adipogenic and chondrogenic differentiation and viability analysis after cryopreservation. All samples showed adherence to plastic and fibroblast-like morphology. Immunocytochemistry revealed expression of CD 44, NANOG and OCT-4 and lack of expression of MHC II in MSC from all samples. Flow cytometry demonstrated that cells from all samples expressed CD 44, did not or low expressed CD 34 (AM: IT-0.3%a, AD-3.4%b; UCT: 0.4%, 1.4%) and MHC II (AM: IT-1.05%a, AD-9.7%b; UCT: IT-0.7%a, AD-5.7%b). They were also capable of trilineage mesenchymal differentiation and showed 80% viability after cryopreservation. According to the results, bovine AM and UCT-derived cells, either obtained at delivery time or from slaughterhouse, are a painless and non-invasive source of MSC and can be used for stem cell banking.(AU)

As células tronco mesenquimais (CTMs) estão presentes na maioria dos tecidos adultos e possuem grande capacidade de multiplicação. Quando cultivadas in vitro são capazes de se auto renovar e dar origem a novos tipos celulares. As células tronco mais utilizadas, tanto na medicina humana como na medicina veterinária são as células tronco mesenquimais derivadas da medula óssea e do tecido adiposo. Atualmente, uma grande tendência para a utilização de CTMs obtidas de tecidos fetais, como a membrana amniótica (MA), matriz extravascular do cordão umbilical (TCU) e sangue do cordão umbilical (SCU) pode ser observada, já que estas fontes podem ser colhidas no momento do parto por uma técnica não invasiva. Dessa forma, o objetivo deste estudo foi isolar, caracterizar, diferenciar e criopreservar CTMs obtidas de MA e TCU de fetos bovinos colhidos no momento do parto e de fetos do terço inicial da gestação em abatedouro-frigorífico. As células foram recuperadas por meio de digestão enzimática tecidual, realizada com solução de colagenase 0,1%. Foram colhidas amostras de MA e TCU no momento do parto (n=6) e de MA e TCU no terço inicial de gestação (n=6), as quais foram submetidas às análises morfológicas, imunofenotípica por imunocitoquímica e citometria de fluxo, diferenciações in vitro nas linhagens osteogênica, adipogênica e condrogênica e ainda, avaliação da viabilidade após a criopreservação por citometria de fluxo. Todas as amostras dos diferentes grupos demonstraram adesão ao plástico e morfologia fibroblastóide. No ensaio imunocitoquímico todas as amostras foram imunomarcadas para CD44, NANOG e Oct-4, com ausência de marcação para MHC II. Na análise imunofenotipica por citometria de fluxo, todas as amostras apresentaram marcação para CD44, ausência de marcação para ou baixíssima expressão de CD34 (MA: TI-0,3%a, PA-3.4%b; TCU: TI-0,4%, PA-1.4%) e nula ou baixa expressão de MHC II (MA: TI-1.5%a, PA-9.7%b; UCT: TI-0.7%a, PA-5.7%b. Apresentaram também capacidade de diferenciação in vitro nas três linhagens mesodermais e quando analisadas pós criopreservação por citometria de fluxo, todas as amostras apresentaram viabilidade de 80%. Estes resultados indicam que MA e TCU, obtidos tanto no momento de parto como em abatedouro, de fetos bovinos podem ser utilizados como fonte não invasiva e indolor de CTMs e possibilitam a formação de bancos de armazenamento de células.(AU)

Avances en la medicina reconstructiva: células madre y células madre inducidas / Advances in reconstructive medicine: stem cells and induced stem cells

La utilización de células indiferenciadas embrionarias y de células diferenciadas inducidas para que se comporten como las anteriores permite dar origen adiferentes tejidos que pueden ser usados en medicina reconstructiva en reemplazo de los deteriorados...

CD24 and CD44 in salivary gland pleomorphic adenoma and in human salivary gland morphogenesis: differential markers of glandular structure or stem cell indicators?

AIMS: Salivary gland neoplasms originate from salivary gland compartments, to which they are histologically related. Pleomorphic adenoma (PA) is a benign salivary gland neoplasm that comprises epithelial and myoepithelial cells and a complex stroma, whose structure, architecture and origin (from intercalated ducts) suggest stem cell participation. We compared the expression of CD24 and CD44 in PA and in developing human salivary glands to investigate whether these markers can be considered as cancer stem cell markers. METHODS AND RESULTS: One hundred and one cases of PA and salivary gland specimens from 20 human fetuses were examined by immunohistochemistry and real-time reverse transcription polymerase chain reaction (RT-PCR). All PAs were positive for CD24 and CD44 by immunohistochemistry: neoplastic luminal structures were positive for CD24; modified myoepithelial cells were positive for CD44. In fetal salivary glands, these markers were restricted to the intercalated duct region. Real-time RT-PCR assays detected increased expression of CD44, but not CD24, in PA specimens in comparison with normal salivary gland controls. CONCLUSIONS: PA and stem cells share the expression of CD24 and CD44; their value as markers of neoplastic cell multipotency and the implications of their expression for tumour behaviour are yet to be determined.

Identificação do nicho de progenitores mesenquimais no fígado de embriões e fetos caninos: uma fonte de células-tronco para terapia celular / Identification of mesenchymal progenitor niches from liver of embryo and fetuses of canines: a source of stem cells for cell therapy

As células-tronco (CT) derivadas dos tecidos fetais (TF) foram as mais recentes descobertas entre as CT, e ultimamente tem demonstrado amplo potencial terapêutico, dentre os TF o fígado fetal (FF) apresenta grande potencial terapêutico. Este órgão durante o período fetal em mamíferos é um nicho hematopoético transitório, sendo o principal órgão responsável pela hematopoese no feto, além de contribuir com a formação do nicho definitivo na medula óssea adulta, portanto pode ser considerado um nicho de células-tronco mesenquimais (CTM) e progenitores. No entanto, pouco se sabe sobre a localização destas células no FF, desta forma o presente estudo visa identificar o nicho de CTM e progenitores em FF de cães, a fim de contribuir com as técnicas de isolamento e extração celular. Em conjunto foi realizada a verificação da expressão do fator de transcrição Oct-3/4 e da proteína delta polimerase do DNA (PCNA). Para a análise foram utilizados cinco embriões e 11 fetos caninos com idades gestacionais variando de 25-60 dias. Os resultados elucidaram a partir de 25 dias de gestação o FF apresentou-se volumoso e composto por todas as estruturas típicas, dentre elas a tríade portal, ductos biliares e ramos das artérias hepáticas. Com 30 dias de gestação foram identificados os primeiros sitos de progenitores mesenquimais (PM) enquanto que aos 60 dias os nichos estavam completamente formados com localização semelhante ao fígado adulto (FA). No entanto, células imunopositivas para Oct-3/4 não foram identificadas; sendo assim, destacamos que o FF é uma fonte de PM, apresentando-se como uma alternativa para a utilização terapêutica, bem como para os estudos da biologia do desenvolvimento das CTM e progenitores.(AU)

Stem cells (SC) derived from fetal tissues (FT) were the most recent discoveries among the SC, and lately had demonstrated broad therapeutic potential; the FT from the fetal liver (FL) presents great therapeutic potential. This organ during the fetal period in mammals acts as a transient hematopoietic niche, being the main organ responsible for hematopoiesis in the fetus, and contribute to the formation of permanent niche in the adult bone marrow, thus can be considered a niche for mesenchymal stem cells (MSC) and parents. However, little is known about the location of these cells in FF, so the present study aims to identify the niche of mesenchymal progenitors in FF and dogs in order to contribute to the techniques of cell isolation and extraction. Together was performed to verify the expression of the transcription factor Oct-3/4 of the protein and DNA polymerase delta (PCNA). For the analysis of five embryos were used and 11 canine fetuses with gestational ages ranging from 25-60 days. The results elucidated from 25 days of gestation showed the FF is bulky and composed of all the typical structures, among them the portal triad, bile ducts and hepatic artery branches. With 30 days of gestation were identified the first requirements of mesenchymal progenitors (MP) at 60 days while the niches were completely formed with location similar to adult liver (AL). However, cells immunoreactives for Oct-3/4 were not identified, therefore, point out that the FL is a source of PM, presenting as an alternative for therapeutic purposes as well as for studying the developmental biology of MSC and parents.(AU)

Utilização de células tronco da medula óssea de fetos caninos em cães adultos com lesão medular crônica toracolombar / The use of fetus boné marrow stem cells in adult dogs with chronic spinal cord compression

As lesões medulares acometem anualmente milhares de pessoas e animais em todo o mundo, causando diversos prejuízos econômicos e psicológicos. [...] Neste trabalho buscamos avaliar a reposta do tratamento com células-tronco de medula óssea fetal canina em cães com lesão medular crônica toracolombar. Nosso trabalho se baseia em parâmetros clínicos, comportamentais, de imagem e fisioterápicos. Antes de adentrar no experimento, todos os cães foram submetidos a vários exames pré-operatórios (hemograma, exames bioquímicos, eletrocardiograma) para então serem encaminhados para o exame de ressonância nuclear magnética visando um diagnostico mais preciso da lesão. Após esse exame, os cães foram avaliados por fisioterapeutas veterinários que não pertenciam ao nosso grupo de pesquisa para se estabelecer uma pontuação no teste comportamental de Olby. [...] Durante o procedimento foram injetados 1x106 células diretamente em 3 pontos distintos da medula espinhal. Após o procedimento os cães foram encaminhados para a fisioterapia, e por 3 meses, foram submetidos a diversos exercícios de reabilitação com o intuito de potencializar um possível efeito benéfico da terapia celular. Durante a fisioterapia, os animais foram filmados com o intuito de acompanhar a sua evolução, e após o termino da fisioterapia foram novamente avaliados pelos fisioterapeutas. Ao final do experimento 7 animais foram operados e os resultados obtidos demonstraram um aumento do reflexo de marcha em 6 deles. O único animal que não apresentou essa melhora da marcha foi aquele acometido por outra patologia associada à compressão medular. Esses resultados nos levam a sugerir uma ação benéfica da terapia celular em cães portadores de lesão medular crônica. Por outro lado sugere continuar recrutando animais com o objetivo de aprimorar as técnicas utilizadas, para conseguir resultados cada vez melhores

Spinal cord injuries annually involve thousands of people and animals worldwide, causing economic and psychological damages. [...] In this article we aimed to evaluate clinical responses to the treatment using canine fetal bone marrow stem cells in dogs with thoracolumbar chronic spinal cord injury. Our study was based on the evaluation of clinical signs, animal behavior, imaging and physiotherapy aspects. Before clinical-surgery trial, all dogs underwent to preoperative tests as hemogram, blood chemistry, electrocardiogram and to nuclear magnetic resonance exam, in order to stablish more accurate diagnosis of the injury. Following clinical exams, Olby score was determined by evaluating animal behavior. Olby tests were performed by external scientific research group, composed by veterinary phisiotherapists, in order to guarantee blind evaluation. Animals were also tested to deep pain and panniculus reflexes. s, After being evaluated, animals underwent surgical spinal cord decompression and to a 1x106 stem cells injection in three different sites of the spinal cord. After the procedure, dogs were referred to physiotherapy for three months, undergoing to a variety of rehabilitation exercises in order to improve cell therapy hypothetical benefic effect. During therapy, animals were filmed in order to monitor their evolution, and after the end of physiotherapy they were re-evaluated by physiotherapists. At the end of the experiment, 7 animals were operated and had resulted in an increase of reflex motion in 6 of them. The only animal that showed no such improvement was the one whos had other pathology associated with the spinal cord compression, these results lead us to believe in a beneficial action of cell therapy in dogs with chronic spinal cord injury and suggests continue recruiting animas with the aim of improving the techniques used to achieve better results

Estabelecimento e caracterização de células-tronco fetais de membrana amniótica canina em diferentes estágios gestacionais / Establishment and characterization of stem cells from fetal canine amniotic membrane at different stages of gestation

A membrana amniótica é uma membrana translucida sendo a membrana mais interna da cavidade amniótica, formada por uma monocamada de células epiteliais disposta sobre uma membrana basal. Com o crescente interesse na utilização de células-tronco provenientes de anexos fetais, esta se torna uma promissora fonte de células-tronco. Sendo assim em trabalho anterior realizado pelo nosso grupo tivemos como objetivo, o estabelecimento da cultura celular e caracterização das células-tronco fetais de membrana amniótica de cão para verificar se a mesma pudesse ser uma nova fonte celular a ser usada nos protocolos de terapia celular, uma vez que os cães têm sido considerados modelos animais atraentes para avaliar novas drogas ou realizar ensaios pré-clínicos. As células de membrana amniótica obtidas a partir do trabalho anterior foram caracterizadas in vitro, observando-se características semelhantes a outras células-tronco mesenquimais. Porém, quando foi analisado o seu o seu potencial carcinogênico observamos a formação de um tumor de crescimento rápido, aproximadamente um mês, após o inóculo dessas células em 10 camundongos imunossuprimidos nude, sendo o tumor identificado histologicamente como um carcinoma embrionário. [...] As células obtidas nestas novas coletas têm características de células-tronco mesenquimais expressando alguns marcadores, tem curva de crescimento semelhante às células-tronco mesenquimais, se aderem ao plástico e se diferenciaram em adipócitos. Diferentemente das células obtidas no estudo anterior estas células não geraram tumor quando injetadas em camundongos imunossuprimidos, nude em até 60 dias após inoculação

Amniotic membrane is a membrane translucent with the inner membrane of the amniotic cavity, formed by a monolayer of epithelial cells disposed on a basal membrane. With the growing interest in the use of stem cells from fetal membranes, this becomes a promising source of stem cells. So in a previous study conducted by our group we aim, the establishment of cell culture and characterization of fetal stem cells from amniotic membrane from dog to see if it could be a new source cell to be used in cell therapy protocols, Once the dogs have been considered attractive animal models to evaluate new drugs or performing pre-clinical tests. The cells from amniotic membrane obtained from previous work were characterized in vitro, observing characteristics similar to other mesenchymal stem cells. But when it was analyzed its its carcinogenic potential observed the formation of a fast-growing tumor, approximately one month after inoculation of these cells into immunocompromised nude mice 10, and the tumor identified histologically as embryonal carcinoma. Given this behavior we believe is extremely important to analyze cells from new collections by checking if the same can behave like those previously studied. With this, we aim of this work to establish and characterize the cells from two new collections at different gestational periods to verify whether these cells behave the same as the previous ones is that when inoculated into animals form tumor and thus be able to make sure that these cells are either not good alternatives for cell therapy. The cells obtained in these new collections has characteristics of mesenchymal stem cells expressing some markers, growth curve is similar to mesenchymal stem cells, adhere to plastic and differentiated into adipocytes. Unlike the cells obtained in the previous study these cells did not generate tumors when injected into immunocompromised mice, nude within 60 days after inoculation

Protective effects of human amniotic fluid stem cells in a model of aorta allograft vasculopathy in rats.

BACKGROUND: Chronic allograft vasculopathy (CAV) is an important cause of graft loss. Considering the immune inflammatory events involved in the development of CAV, therapeutic approaches to target this process are of relevance. Human amniotic fluid-derived stem cells (hAFSCs), a class of fetal, pluripotent stem cells with intermediate characteristics between embryonic and adult stem cells, display immunomodulatory properties. hAFSCs express mesenchymal and embryonic markers, show high proliferation rates; however, they do not induce tumor formation, and their use does not raise ethical issues. Thus, we sought to investigate the effect of hAFSC on CAV in a model of aorta transplantation. METHODS: Orthotopic aorta transplantation was performed using Fisher (F344) rats as donors and Lewis rats as recipients. Rats were divided into three groups: syngeneic (SYNG), untreated F344 receiving aorta from F344 (n = 8); allogeneic (ALLO), Lewis rats receiving allogeneic aorta from F344 (n = 8); and ALLO + hAFSC, ALLO rats treated with hAFSC (10(6) cells; n = 8). Histological analysis and immunohistochemistry were performed 30 days posttransplantation. RESULTS: The ALLO group developed a robust aortic neointimal formation (208.7 ± 25.4 µm) accompanied by a significant high number of ED1+ (4845 ± 841 cells/mm2) and CD43+ cells (4064 ± 563 cells/mm2), and enhanced expression of α-smooth muscle actin in the neointima (25 ± 6%). Treatment with hAFSC diminished neointimal thickness (180.7 ± 23.7 µm) and induced a significant decrease of ED1+ (1100 ± 276 cells/mm2), CD43+ cells (1080 ± 309 cells/µm2), and α-smooth muscle actin expression 8 ± 3% in the neointima. CONCLUSIONS: These preliminary results showed that hAFSC suppressed inflammation and myofibroblast migration to the intima, which may contribute to ameliorate vascular changes in CAV.

O intervalo de tempo entre coleta e processamento do sangue de cordão umbilical influencia na qualidade da amostra? / Does the time between collecting and processing umbilical cord bloodsamples affect the quality of the sample?

Objective: To assess the association between the time from umbilical cord blood collection until processing and the quality of the sample. Methods: Umbilical cord blood samples collected during the third stage of labor were placed in temperature-controlled boxes for the transport of biological material and sent to an umbilical cord blood bank, where the number of nucleated cells, viable cells and CD34+ cells were counted, and samples were additionally tested for contamination at the following time intervals: up to 24 hours, up to 48 hours and up to 72 hours following sampling. Data were analyzed using the multivariate analysis of variance (MANOVA) and compared using McNemar's X2 test. Significance was defined at p < 0.05. Results: Means and medians of the number of nucleated cells, viable cells and CD34+ cells decreased significantly (p < 0.0001) as a function of the increased time between sampling and analysis, the difference between 24 and 48 hours being less than the difference between 24 and 72 hours. A linear correlation was found between the mean number of viable cells and CD34+ cells at the three moments of analysis. Contamination testing was negative in all samples. Conclusion: The increase in time interval from sampling until analysis negatively affected the number of nucleated cells, viable cells and CD34+ cells but was not associated with specimen contamination. A linear correlation was found between decrease in the number of viable cells and CD34+ cells.

Objetivo: Avaliar a associação do intervalo de tempo entre coleta e processamento do sangue de cordão umbilical e a qualidade da amostra. Métodos: As amostras de sangue de cordão umbilical, colhidas no terceiro período do parto, foram acondicionadas em caixas homologadas para transporte de material biológico, com monitoração da temperatura, e enviadas a um banco de sangue de cordão umbilical, onde foram submetidas à contagem do número de células nucleadas, do número de células viáveis, do número de células CD 34+ e pesquisa de contaminação, nos intervalos de tempo de até 24, até 48 e até 72 horas. Os dados foram analisados pelo teste de variância para medidas repetidas MANOVA e comparados por meio do teste do X2 de Mc Nemar, considerando-se nível de significância de 5%. Resultados: As médias e as medianas do número de células nucleadas, número de células viáveis e número de células CD34+ tiveram quedas significativas (p < 0,0001) com o aumento do intervalo de tempo de coleta/processamento, sendo entre 24 e 48 horas menor do que a comparação entre 24 e 72 horas. Constatada correlação linear entre as médias de células viáveis e células CD34+ nos três momentos da análise. A pesquisa de contaminação foi negativa em todas as amostras. Conclusão: O aumento do intervalo de tempo de coleta/processamento influenciou negativamente na contagem de células nucleadas, células viáveis e CD34+ e não esteve associado à contaminação das amostras. Foi constatada correlação linear entre a queda do número de células viáveis e de células CD34+.

Fetal membranes stem cells application in pets

Background: Stem cells are precursor cells that have the capacity for self-renewal and could generate cells with characteristics similar to cells and differentiation, generating varied cell lines. Considering the plasticity of cells can be classified into totipotent, pluripotent or multipotent. According to the isolation period, the stem cells can be classified as embryonic, fetal and adult. In the embryo stage are considered totipotent because they can rebuild any tissue in the body and adulthood are considered multipotent, since they have a more limited plasticity. The fetal tissues and the fetus is a potential source for stem cells, since they expand more rapidly compared to the cells after birth. Stem cells of fetal membranes are derived from extraembryonic tissues with high capacity to differentiate into various tissues. The cord blood stem cells have mesenchymal and hematopoietic, and mesenchymal cells have the potential to proliferate and differentiate into multiple cell lineages. The yolk sac in dogs is morphologically composed of three layers: a single layer of endoderm, a simple mesothelium, and intermediate to them, the vascular mesenchyme. Work identified a population of pluripotent cells in the yolk sac can differentiate into hematopoietic cells, however, can be isolated mesenchymal stem cells. In this review we aim to focus new isolations of cells from umbilical cord blood and yolk sac of dogs, reviewing the main literature on this species. The importance of using dogs out of work has intensified in recent years, since many diseases can manifest itself in a similar way to humans. Additionally, the dog is a pet, and interest in the treatment of diseases and improved quality of life of this species has been accentuated in veterinary medicine. Thus, identifying the cellular sources in the dog opens new horizons for preclinical studies and new therapies for veterinary medicine. Review: This study is related to morphological biology multipotent stem cells, focusing its expansion and use in cell therapy in animal models that have different pathologies. A widely studied model for muscular dystrophy is the GRMD (Golden Retriever Muscular Dystrophy), which is homologous to DMD (Duchenne Muscular Dystrophy) that affects humans. It is a recessive genetic disease, X chromosome which affects approximately 1 in every 3500 boys. It is characterized by a progressive muscle degeneration, resulting from the absence or reduction in the production of dystrophin protein present in the sarcoplasmic membrane of muscle fibers. Conclusion: The use of cells derived from fetal tissue are strong candidates for veterinary regenerative medicine, since they have high capacity for cellular differentiation. The use of fetuses and fetal tissues of humans still has limitations, so the dog is a viable alternative for studies of fetal stem cells. Thus, it is extremely important to know the characteristics of morphology and proliferation of cells derived from fetuses and fetal annexes canines, including yolk sac and umbilical cord as well as know the feasibility of clinical application of these cells in preclinical testing in animal models and eventually in human medicine, thus contributing to regenerative medicine.

Establishment of a protocol for obtention of neuronal stem cells lineages from the dog olfactory epithelium / Estabelecimento de um protocolo para obtenção de linhagens de células-tronco neuronais a partir do epitélio olfatório de cães

A morphological and cell culture study from nasal mucosa of dogs was performed in order to establish a protocol to obtain a cell population committed to neuronal lineage, as a proposal for the treatment of traumatic and degenerative lesions in these animals, so that in the future these results could be applied to the human species. Twelve mongrel dogs of 60-day aged pregnancy were collected from urban pound dogs in São Paulo. Tissue from cribriform ethmoidal lamina of the fetuses was collected at necropsy under sterile conditions around 1h to 2h postmortem by uterine sections and sections from the fetal regions described above. Isolated cells of this tissue were added in DMEM/F-12 medium under standard conditions of incubation (5 percent CO², >37ºC). Cell culture based on isolated cells from biopsies of the olfactory epithelium showed rapid growth when cultured for 24 hours, showing phase-bright sphere cells found floating around the fragments, attached on culture flasks. After 20 days, a specific type of cells, predominantly ellipsoids or fusiform cells was characterized in vitro. The indirect immunofluorescence examination showed cells expressing markers of neuronal precursors (GFAP, neurofilament, oligodendrocyte, and III â-tubulin). The cell proliferation index showed Ki67 immunostaining with a trend to label cell groups throughout the apical region, while PCNA immunostaining label predominantly cell groups lying above the basal lamina. (AU)

Foi realizado um estudo morfológico e por cultivo celular a partir de células provenientes da mucosa olfatória de cães, como forma de estabelecer um protocolo de cultivo, como uma proposta para o tratamento de lesões traumáticas e nervosas degenerativas nestes animais e futuramente, para que tais resultados possam ser aplicados a espécie humana. Foram utilizados doze cães sem raça definida, a termo, oriundos de castrações do Centro de Controle de Zoonoses de São Paulo. O tecido da lâmina cribiforme do etmóide dos fetos foi coletado sob necropsia, em condições estéreis, 1 a 2 horas post mortem, por meio de incisão uterina e acesso da região fetal supracitada. Depois as células isoladas desse tecido foram adicionadas em médio DMEM/F-12 sob condições padrão (5 por cento CO2, >37ºC). As células obtidas a partir de biópsias do epitélio olfatório de cães apresentaram rápido crescimento após 24 horas de cultivo, demonstrando morfologia esférica, sendo encontradas flutuando ao redor do fragmento aderido à garrafa de cultura. Após 20 dias, foram verificados tipos celulares específicos, predominantemente elipsóides ou fusiformes, foram observadas in vitro. Sob avaliação por imunofluorescência indireta observaram-se células com expressão positiva para marcadores de precursores neuronais (GFAP, Neurofilamentos, oligodendrócitos e â-tubulina III). O índice de proliferação celular mostrou-se positivo para Ki67 com uma tendência de marcação de grupos celulares ao longo da região apical, enquanto a imunomarcação para PCNA mostrou-se predominantemente em grupos celulares residentes sobre a lâmina basal. A microscopia eletrônica de transmissão do epitélio olfatório de cães revelou células com citoplasma eletrodenso e mesma distribuição das células marcadas positivamente para PCNA. A atividade metabólica foi confirmada pela presença de eucromatina em muitas regiões celulares. Todos estes aspectos sustentam a hipotese sobre a presença de células progenitoras ...(AU)

Viabilidade de células do sistema nervoso central fetal no tratamento da lesão medular em ratos / Viability of fetal central nervous system cells in the treatment of spinal cord injury in rats

OBJETIVOS: Propor um modelo experimental de transplante de células do sistema nervoso fetal de ratos Wistar para o sítio de lesão medular de ratos adultos que permitisse sua sobrevivência e integração para possibilitar protocolos de pesquisa que identificarão outros fatores de regeneração e recuperação funcional pós trauma raquimedular. MÉTODOS: Vinte ratos adultos foram submetidos a laminectomia, e lesão de 5mm de hemimedula realizada com auxílio de microscópio óptico. Quinze deste ratos tiveram seu sítio de lesão medular transplantado com células do sistema nervoso central de fetos de rato; os ratos foram monitorados por 2 dias e tiveram sua coluna vertebral extraída para análise histológica. RESULTADOS: Evidenciou-se que em 60 por cento dos casos as células transplantadas permaneciam viáveis no sítio da lesão e que a reação inflamatória no grupo transplantado era sempre maior que no grupo controle. CONCLUSÃO: O presente trabalho demonstrou a possibilidade de contar com o modelo de pesquisa para transplante de células fetais que permanecem viáveis 2 dias após seu implante.

OBJECTIVE: To propose an experimental model for transplantation of fetal cells from the nervous system of Wistar rats to the site of spinal cord injury in adult rats, to enable their survival and integration for research protocols that identify other factors of regeneration and functional recovery following spinal cord trauma. METHODS: Twenty adult rats were submitted to laminectomy and a 5mm incision was made, using an optical microscope, In fifteen of these rats, the site of the spinal cord lesion was transplanted with cells from the fetal rat central nervous system; the rats were monitored for two days, then the spinal cord was removed for histological analysis. RESULTS: In 60 percent of cases, the transplanted cells remained viable in the site of the lesion; the inflammatory response in the transplanted group was always greater than in the control group. CONCLUSION: This study demonstrates the potential use of this research model for use in the transplantation of fetal cells that remain viable two days after their implantation.

Análise de células mesenquimais de saco vitelino, figado e medula óssea de fetos caninos / Analysis of mesenchymal cells from yolk, sac, liver and bone marrow of the canine fetus

Em vistas das limitações éticas em torno da obtenção de celulas - tronco de fetos humanos o cão e uma alternativa para esses estudos. Alem disso, a terapia celular proporciona novas exectativas para o tratamento da especie. Realizamos o estudo comparativo das celulas isoladas de saco vitelino, figado e medula ossea de fetos caninos...

The use of the human fetuses for stem cells isolation have etical limitations. In this context the dog is an excellent candidate to fetal stem cells.Furthemore, these cells can be used in cell therapy of canine diseases. We aimed at isolation and comparative characterization of progenitor cells from yolk sac, liver and bone marrow of canine fetuses...