The dynamics of genome size and GC contents evolution in genus Nicotiana / A dinâmica do tamanho do genoma e a evolução dos conteúdos de GC no gênero Nicotiana

Hybridization and Polyploidization are most common of the phenomenon observed in plants, especially in the genus Nicotiana leading to the duplication of genome. Although genomic changes associated with these events has been studied at various levels but the genome size and GC content variation is less understood because of absence of sufficient genomic data. In this study the flow cytometry technique was used to uncover the genome size and GC contents of 46 Nicotiana species and we compared the genomic changes associated with the hybridization events along evolutionary time scale. The genome size among Nicotiana species varied between 3.28 pg and 11.88 pg whereas GC contents varied between 37.22% and 51.25%. The tetraploid species in genus Nicotiana including section Polydiclae, Repandae, Nicotiana, Rustica and Sauveolentes revealed both up and downsizing in their genome sizes when compared to the sum of genomes of their ancestral species. The genome sizes of three homoploid hybrids were found near their ancestral species. Loss of large genome sequence was observed in the evolutionary more aged species (>10 Myr) as compared to the recently evolved one’s (<0.2 Myr). The GC contents were found homogenous with a mean difference of 2.46% among the Nicotiana species. It is concluded that genome size change appeared in either direction whereas the GC contents were found more homogenous in genus Nicotiana.

A hibridização e a poliploidização são os fenômenos mais comuns observados em plantas, principalmente no gênero Nicotiana, levando à duplicação do genoma. Embora as mudanças genômicas associadas a esses eventos tenham sido estudadas em vários níveis, o tamanho do genoma e a variação do conteúdo de GC são menos compreendidos devido à ausência de dados genômicos suficientes. Neste estudo, a técnica de citometria de fluxo foi usada para descobrir o tamanho do genoma e o conteúdo de GC de 46 espécies de Nicotiana, e comparamos as mudanças genômicas associadas aos eventos de hibridização ao longo da escala de tempo evolutiva. O tamanho do genoma entre as espécies de Nicotiana variou entre 3,28 pg e 11,88 pg, enquanto os conteúdos de GC variaramentre 37,22% e 51,25%. As espécies tetraploides do gênero Nicotiana, incluindo as seções Polydiclae, Repandae, Nicotiana, Rustica e Sauveolentes, revelaram aumento e redução do tamanho do genoma quando comparados à soma dos genomas de suas espécies ancestrais. Os tamanhos do genoma de três híbridos homoploides foram encontrados perto de suas espécies ancestrais. A perda da grande sequência do genoma foi observada nas espécies evolutivas mais velhas (> 10 Myr) em comparação com as que evoluíram recentemente (< 0,2 Myr). Os teores de GC foram homogêneos com diferença média de 2,46% entre as espécies de Nicotiana. Conclui-se que a mudança no tamanho do genoma apareceu em ambas as direções, enquanto os conteúdos de GC foram encontrados mais homogêneos no gênero Nicotiana.

Aislación y caracterización de las células epiteliales del amnios / Isolation and characterization of amniotic ephitelial cells

RESUMEN: Las células epiteliales del amnios (hAECs) son células madre pluripotenciales; tienen capacidad de diferenciarse en células de las tres capas embrionarias. Como tales, se utilizan en algunas terapias regenerativas en medicina. Este estudio tiene por objetivo describir un protocolo de aislación de las células epiteliales del amnios (hAECs) a partir de placentas humanas de partos por cesárea, así como su caracterización y comportamiento in vitro. Se aislaron hAECs de 20 placentas de partos por cesárea con un protocolo optimizado. Se caracterizaron las células mediante citometría de flujo, microscopia óptica y de fluorescencia, y se evaluó la proliferación de las células mediante MTT a los 1, 3, 5 y 7 días con y sin β-mercaptoetanol en el medio de cultivo. El análisis histológico del amnios mostró un desprendimiento prácticamente completo de las células después de la segunda digestión del amnios. El promedio de células obtenidas fue de 10.97 millones de células por gramo de amnios. Las hAECs mostraron una proliferación limitada, la cual no fue favorecida por la adición de β-mercaptoetanol en el cultivo. Se observó un cambio de morfología espontanea de epitelial a mesenquimal después del cuarto pasaje. Las células epiteliales del amnios pueden ser aisladas con un protocolo simple y efectivo, sin embargo, presentan escasa capacidad proliferativa. Bajo las condiciones de este estudio, la adición de β-mercaptoetanol no favorece la capacidad proliferativa de las células.

SUMMARY: human amnion epithelial cells (hAECs) are pluripotent stem cells; they have the ability to differentiate into cells of the three embryonic layers, and are used in various regenerative therapies in medicine. This study aims to describe a protocol for the isolation of amnion epithelial cells (hAECs) from human placentas from cesarean delivery, as well as their characterization and culture conditions in vitro. hAECs were isolated from 20 cesarean delivery placentas with an optimized protocol. The cells were characterized by flow cytometry, light and fluorescence microscopy, and the proliferation of the cells was evaluated by MTT at 1, 3, 5 and 7 days with and without β-mercaptoethanol in the culture medium. Histological analysis of the amnion showed a practically complete detachment of the cells of the underlying membrane after the second digestion. The average number of cells obtained was 10.97 million cells per amnion. The hAECs perform a limited proliferation rate, which was not favored by the addition of β-mercaptoethanol in the culture. A spontaneous morphology change from epithelial to mesenchymal morphology is exhibited after the fourth passage. The epithelial cells of the amnion can be isolated with a simple and effective protocol, however, they present little proliferative capacity. Under the conditions of this study, the addition of β-mercaptoethanol does not favor the proliferation of the cells.

Continuous purification and culture of rat type 1 and type 2 alveolar epithelial cells by magnetic cell sorting / 中华创伤杂志(英文版)

PURPOSE@#The incidence of acute lung injury (ALI) in severe trauma patients is 48% and the mortality rate following acute respiratory distress syndrome evolved from ALI is up to 68.5%. Alveolar epithelial type 1 cells (AEC1s) and type 2 cells (AEC2s) are the key cells in the repair of injured lungs as well as fetal lung development. Therefore, the purification and culture of AEC1s and AEC2s play an important role in the research of repair and regeneration of lung tissue.@*METHODS@#Sprague-Dawley rats (3-4 weeks, 120-150 g) were purchased for experiment. Dispase and DNase I were jointly used to digest lung tissue to obtain a single-cell suspension of whole lung cells, and then magnetic bead cell sorting was performed to isolate T1α positive cells as AEC1s from the single-cell suspension by using polyclonal rabbit anti-T1a (a specific AEC1s membrane protein) antibodies combined with anti-rabbit IgG microbeads. Afterwards, alveolar epithelial cell membrane marker protein EpCAM was designed as a key label to sort AEC2s from the remaining T1α-neg cells by another positive immunomagnetic selection using monoclonal mouse anti-EpCAM antibodies and anti-mouse IgG microbeads. Cell purity was identified by immunofluorescence staining and flow cytometry.@*RESULTS@#The purity of AEC1s and AEC2s was 88.3% ± 3.8% and 92.6% ± 2.7%, respectively. The cell growth was observed as follows: AEC1s stretched within the 12-16 h, but the cells proliferated slowly; while AEC2s began to stretch after 24 h and proliferated rapidly from the 2nd day and began to differentiate after 3 days.@*CONCLUSION@#AEC1s and AEC2s sorted by this method have high purity and good viability. Therefore, our method provides a new approach for the isolation and culture of AEC1s and AEC2s as well as a new strategy for the research of lung repair and regeneration.

Impact of cell harvesting methods on detection of cell surface proteins and apoptotic markers

Assays based on the flow cytometry technique allow a convenient analysis of multiple cellular parameters; however, their results should be interpreted cautiously due to a strong impact of confounding factors. Different techniques in cell culturing such as either enzymatic or mechanic detachment of adherent cells can heavily influence the structure of the cell membrane or presence of the surface antigens leading to strong false positive signals, and finally, substantial experimental bias. The aim of our study was to assess and compare the impact of cell harvesting methods (both enzymatic and non-enzymatic) on the apoptosis process and on the surface antigen cytometric analyses. We found significant differences in the quality of analysis in terms of the amount of detected surface markers determined by the detachment method. Our results demonstrated clearly how important it is to carefully choose the appropriate detachment method and may help to avoid mistakes in experiment planning. In conclusion, we recommend to adjust the detachment method to the type of analyzed markers (surface antigens or translocated phosphatidylserine).

Phenotype changes of oral epithelial stem cells after in vitro culture

Abstract The aim of our study was to isolate populations of keratinocyte stem cells based on the expression of cell surface markers and to investigate whether the culture could affect their phenotype. keratinocytes from human oral mucosa were sorted based on the expression of the epithelial stem cell markers p75NTR and CD71. We also examined the co-expression of other epithelial stem markers such as integrins β1 and α6 and their stem cell-like proprieties in in vitro assays. Three passages after being sorted by MACS, more than 93% of the p75NTR+ve cells lost the expression of p75NTR, while 5.46% of the p75NTR-ve gained it. Within the small population of the p75NTR+ve cells, 88% co-expressed other epithelial stem cell markers such as integrins β1 and α6, while only 28% of p75NTR-ve cells co-expressed these markers. These results were confirmed by sorting cells by FACS. Additionally, when double staining was used for sorting cells, 99% of the p75NTR+veCD71-ve and 33% of the p75NTR-veCD71+ve cells expressed both integrins, but just one week after culture, only 1.74% of the p75NTR+veCD71-ve cells still expressed p75NTR and only 0.32% still expressed CD71. Similar results were obtained when co-culturing p75NTR+ve and p75NTR-ve populations before analysis. Our results suggest that phenotype changes may be part of an intrinsic cellular mechanism to conserve levels of protein expression as they may found in the human body. In addition, in vitro culture may not offer ideal conditions for epithelial stem cell maintenance due to phenotype changes under standard culture conditions.

Characterization of Decellularized Human Pericardium for Tissue Engineering and Regenerative Medicine Applications / Caracterização do Pericárdio Humano Descelularizado para Engenharia de Tecidos e Aplicações de Medicina Regenerativa

Abstract Background: Pericardium tissue allograft can be used for surgical repair in several procedures. One of the tissue engineering strategies is the process of decellularization. This process decreases immunogenic response, but it may modify the natural extracellular matrix composition and behavior. Objective: The aim of this study was to evaluate the effectiveness of cell removal, maintenance of extracellular matrix properties and mechanical integrity of decellularized human pericardium using a low concentration solution of sodium dodecyl sulfate. Methods: Decellularization was performed with sodium dodecyl sulfate and ethylenediaminetetraacetic acid. Histological analysis, DNA quantification, evaluation of glycosaminoglycans and collagen were performed. Biomechanical assay was performed using tensile test to compare the decellularization effects on tissue properties of tensile strength, elongation and elastic modulus. P < 0.05 was considered significant. Results: There was reduction in visible nuclei present in pericardium tissue after decellularization, but it retained collagen and elastin bundles similar to fresh pericardium. The DNA contents of the decellularized pericardium were significantly reduced to less than 511.23 ± 120.4 ng per mg of dry weight (p < 0.001). The biomechanical assay showed no significant difference for fresh or decellularized tissue. Conclusion: The decellularization process reduces cell content as well as extracellular matrix components without changing its biomechanical properties.

Resumo Fundameto: O enxerto de pericárdio pode ser usado em muitos procedimentos de correção cirúrgica. Uma das estratégias da engenharia tecidual é o processo de descelularização. No entanto, embora esse processo diminua a resposta imunogênica, a descelularização pode modificar tanto o comportamento como a composição da matriz extracelular natural. Objetivos: Avaliar a eficácia da descelularização usando baixa concentração de dodecil sulfato de sódio na remoção celular, na manutenção das propriedades da matriz extracelular e na integridade mecânica do pericárdio humano descelularizado. Métodos: A descelularização foi realizada com dodecil sulfato de sódio e ácido etilenodiamino tetra-acético. Foi realizada análise histológica, quantificação de DNA, e avaliação de glicosaminoglicanos e colágeno. O estudo biomecânico foi conduzido pelo teste de tração para comparar os efeitos da descelularização sobre as propriedades teciduais de resistência à tração, alongamento e módulo de elasticidade. Foi considerado um valor de p < 0,05 como estatisticamente significativo. Resultados: Observou-se uma redução na quantidade de núcleos presentes no pericárdio após a descelularização, apesar de manter quantidades similares de feixes de elastina e de colágeno. As concentrações de DNA do pericárdio descelularizado foram significativamente reduzidas para menos que 511,23 ± 120,4 ng por mg de peso seco (p < 0,001). O teste biomecânico não apontou diferenças entre os tecidos fresco e descelularizado. Conclusão: A descelularização reduziu a concentração de células bem como os componentes da matriz extracelular sem afetar suas propriedades biomecânicas.

Citometría de flujo en reticulocitos de sangre periférica como indicador de inestabilidad cromosómica en pacientes con gliomas de alto grado / Flow cytometry in peripheral blood reticulocytes as a marker of chromosome instability in highgrade glioma patients

Resumen Introducción. La cuantificación de la inestabilidad cromosómica es un parámetro importante para evaluar la genotoxicidad y la radiosensibilidad. Las técnicas convencionales requieren cultivos celulares o laboriosos análisis microscópicos de cromosomas o núcleos. La citometría de flujo en reticulocitos ha surgido como una alternativa para los estudios in vivo, ya que reduce los tiempos de análisis e incrementa hasta en 20 veces el número de células analizables. Objetivos. Estandarizar los parámetros de citometría de flujo requeridos para seleccionar y cuantificar reticulocitos micronucleados (RET-MN) a partir de muestras de sangre periférica, y cuantificar la frecuencia de esta subpoblación anormal como medida de inestabilidad citogenética en sendas poblaciones de voluntarios sanos (n=25) y pacientes (n=25) recién diagnosticados con gliomas de alto grado antes de iniciar el tratamiento. Materiales y métodos. Las células sanguíneas se marcaron con anti-CD71-PE para reticulocitos, anti- CD61-FITC para la exclusión de plaquetas y yoduro de propidio para detectar el ADN en reticulocitos. La fracción celular MN-RETCD71+ se seleccionó y se cuantificó con un citómetro de flujo automático. Resultados. Se describió detalladamente la estandarización de los parámetros citométricos, con énfasis en la selección y la cuantificación de la subpoblación celular MN-RETCD71+. Se establecieron los niveles basales de MN-RETCD71+ en la población de control y en los pacientes se encontró un incremento de 5,2 veces antes de iniciar el tratamiento (p<0,05). Conclusión. Los resultados evidenciaron la utilidad de la citometría de flujo acoplada a la marcación de las células RETCD71+ como método eficiente para cuantificar la inestabilidad cromosómica in vivo. Se sugieren posibles razones del incremento de micronúcleos en células RETCD71+ de pacientes con gliomas.

Abstract Introduction: The quantification of chromosomal instability is an important parameter to assess genotoxicity and radiosensitivity. Most conventional techniques require cell cultures or laborious microscopic analyses of chromosomes or nuclei. However, a flow cytometry that selects the reticulocytes has been developed as an alternative for in vivo studies, which expedites the analytical procedures and increases up to 20 times the number of target cells to be analyzed. Objectives: To standardize the flow cytometry parameters for selecting and quantifying the micronucleated reticulocytesCD71+ (MN-RET) from freshly drawn peripheral blood and to quantify the frequency of this abnormal cell subpopulation as a measure of cytogenetic instability in populations of healthy volunteers (n =25), and patients (n=25), recently diagnosed with high-grade gliomas before the onset of treatment. Materials and methods: Blood cells were methanol-fixed and labeled with anti-CD-71-PE for reticulocytes, antiCD-61-FITC for platelet exclusion, and propidium iodide for DNA detection in reticulocytes. The MN-RETCD71+ cell fraction was selected and quantified with an automatic flow cytometer. Results: The standardization of cytometry parameters was described in detail, emphasizing the selection and quantification of the MN-RETCD71+ cellular fraction. The micronuclei basal level was established in healthy controls. In patients, a 5.2-fold increase before the onset of treatment was observed (p <0.05). Conclusion: The data showed the usefulness of flow cytometry coupled with anti-CD-71-PE and anti- CD-61-FITC labeling in circulating reticulocytes as an efficient and high resolution method to quantify chromosome instability in vivo. Finally, possible reasons for the higher average of micronuclei in RETCD71+ cells from untreated high-grade glioma patients were discussed.

A modified method by differential adhesion for enrichment of bladder cancer stem cells

ABSTRACT Purpose: In a previous study the vaccine was effective against bladder cancer in a mouse model. However, a small portion of tumors regrew because the vaccine could not eliminate bladder cancer stem cells (CSCs). In this study, we showed a modified method for the isolation of bladder CSCs using a combination of differential adhesion method and serum-free culture medium (SFM) method. Materials and Methods: Trypsin-resistant cells and trypsin-sensitive cells were isolated from MB49, EJ and 5637 cells by a combination of differential adhesion method and SFM method. The CSCs characterizations of trypsin-resistant cells were verified by the flow cytometry, the western blotting, the quantitative polymerase chain reaction, the resistance to chemotherapy assay, the transwell assay, and the tumor xenograft formation assay. Results: Trypsin-resistant cells were isolated and identified in CSCs characters, with high expression of CSCs markers, higher resistance to chemotherapy, greater migration in vitro, and stronger tumorigenicity in vivo. Conclusion: Trypsin-resistant cells displayed specific CSCs properties. Our study showed trypsin-resistant cells were isolated successfully with a modified method using a combination of differential adhesion method and SFM method.

Lacrimal gland primary acinar cell culture: the role of insulin / Células acinares de glândula lacrimal em cultura primária: o papel da insulina

ABSTRACT Purpose: The goal of the present study was to establish a protocol for primary culture of lacrimal gland acinar cells (LGACs) and to assess the effect of adding insulin to the culture media. Methods: LGACs were isolated and cultured from lacrimal glands of Wistar male rats. The study outcomes included cell number, viability, and peroxidase release over time and in response to three concentrations of insulin (0.5, 5.0, and 50.0 μg/mL). Results: In LGAC primary culture, cells started to form clusters by day 3. There was a time-response pattern of peroxidase release, which rose by day 6, in response to carbachol. Culture viability lasted for 12 days. An insulin concentration of 5.0 μg/mL in the culture medium resulted in higher viability and secretory capacity. Conclusions: The present method simplifies the isolation and culture of LGACs. The data confirmed the relevance of adding insulin to maintain LGACs in culture.

RESUMO Objetivo: O objetivo do estudo foi estabelecer um protocolo de cultura primária para o isolamento de células acinares da glândula lacrimal (CAGL) e avaliar a relevância de insulina no meio de cultura. Métodos: CAGL foram isoladas e cultivadas a partir das glândulas lacrimais de ratos Wistar machos. Os parâmetros analisados foram: o número de células, viabilidade e secreção da peroxidase ao longo do tempo e em resposta a três concentrações de insulina (0,5; 5,0 e 50,0 μg/ml). Resultados: Na cultura primária de CAGL as células passaram a se agrupar por volta do dia 3. A secreção de peroxidase em resposta ao carbacol aumentou no dia 6. O período de cultura viável foi limitado à 12 dias. Insulina à 5,0 μg/ml no meio de cultura resultou em viabilidade e capacidade secretora maior. Conclusão: o estudo descreveu um método para simplificar o isolamento e cultivo de CAGL. Os dados apresentados confirmam a importância da insulina na manutenção da cultura de CAGL.

Rabbit olfactory stem cells. Isolation protocol and characterization

PURPOSE: To describe a new technique for isolation of a mesenchymal stem cells (MSCs) population from the olfactory mucosa in rabbits. METHODS: Olfactory stem cells (OSCs) were retrieved from under the cribriform plate of the Ethmoid bone. Several assays were accomplished to characterize the cell population and attest its viability in vitro. The cells were submitted to flow cytometry with the antibodies CD34, CD45, CD73, CD79, CD90 and CD105 and also they were induced to differentiate in three lineages. Functional evaluation involved analysis of in vitro growth behavior, colony forming unit like fibroblasts (CFU-f) and cryopreservation response. Further transduction with Green Fluorescent Protein (GFP) was also performed. RESULTS: The OSCs showed mesenchymal features, as positive response to CD34, CD73 and CD90 antibodies and plasticity. Additionally, these cells have high proliferated rate, and they could be cultured through many passages and kept the ability to proliferate and differentiate after cryopreservation. The positive response to the transduction signalizes the possibility of cellular tracking in vivo. This is a desirable feature in case those cells are used for pre-clinical trials. CONCLUSION: The cells harvested were mesenchymal stem cells and the technique described is therefore efficient for rabbit olfactory stem cells isolation.

Human pancreatic islet transplantation: an update and description of the establishment of a pancreatic islet isolation laboratory

Type 1 diabetes mellitus (T1DM) is associated with chronic complications that lead to high morbidity and mortality rates in young adults of productive age. Intensive insulin therapy has been able to reduce the likelihood of the development of chronic diabetes complications. However, this treatment is still associated with an increased incidence of hypoglycemia. In patients with “brittle T1DM”, who have severe hypoglycemia without adrenergic symptoms (hypoglycemia unawareness), islet transplantation may be a therapeutic option to restore both insulin secretion and hypoglycemic perception. The Edmonton group demonstrated that most patients who received islet infusions from more than one donor and were treated with steroid-free immunosuppressive drugs displayed a considerable decline in the initial insulin independence rates at eight years following the transplantation, but showed permanent C-peptide secretion, which facilitated glycemic control and protected patients against hypoglycemic episodes. Recently, data published by the Collaborative Islet Transplant Registry (CITR) has revealed that approximately 50% of the patients who undergo islet transplantation are insulin independent after a 3-year follow-up. Therefore, islet transplantation is able to successfully decrease plasma glucose and HbA1c levels, the occurrence of severe hypoglycemia, and improve patient quality of life. The goal of this paper was to review the human islet isolation and transplantation processes, and to describe the establishment of a human islet isolation laboratory at the Endocrine Division of the Hospital de Clínicas de Porto Alegre – Rio Grande do Sul, Brazil.

Experimental model of obtaining tissue adipose, mesenchymal stem cells isolation and distribution in surgery flaps in rats

PURPOSE: To investigate the experimental model for obtaining adipose tissue, isolation, characterization of mesenchymal stem cells and evaluation of their distribution in the tram flap in rats. METHODS: Five rats of Wistar were randomly assigned to two groups. In group I, three animals underwent removal of adipose tissue in the groin procedure to establish the experimental model and obtain a cell lineage. The animals of group II (n = 2) underwent surgical flap procedure, and satisfaction injection of mesenchymal stem cells pretreated with marker fluorescente. RESULTS: obtaining adipose tissue of the inguinal region of the rat proved to be possible. The isolated cells were characterized as mesenchymal stem cells and fluorescence microscopy showed the presence of multiple cells arranged around blood vessels and capillaries. CONCLUSION: It was possible to establish an experimental model for obtaining adipose tissue for isolation of mesenchymal stem cells and their distribution in the TRAM flap in rats. .

Growth Inhibition After Exposure to Transforming Growth Factor-beta1 in Human Bladder Cancer Cell Lines

PURPOSE: Transforming growth factor-beta1 (TGF-beta1) plays a dual role in apoptosis and in proapoptotic responses in the support of survival in a variety of cells. The aim of this study was to determine the function of TGF-beta1 in bladder cancer cells. MATERIALS AND METHODS: The role of TGF-beta1 in bladder cancer cells was examined by observing cell viability by using the tetrazolium dye (MTT) assay after treating the bladder cancer cell lines 253J, 5637, T24, J82, HT1197, and HT1376 with TGF-beta1. Among these cell lines, the 253J and T24 cell lines were coincubated with TGF-beta1 and the pan anti-TGF-beta antibody. Fluorescence-activated cell sorter (FACS) analysis was performed to determine the mechanism involved after TGF-beta1 treatment in 253J cells. RESULTS: All six cell lines showed inhibited cellular growth after TGF-beta1 treatment. Although the T24 and J82 cell lines also showed inhibited cellular growth, the growth inhibition was less than that observed in the other 4 cell lines. The addition of pan anti-TGF-beta antibodies to the culture media restored the growth properties that had been inhibited by TGF-beta1. FACS analysis was performed in the 253J cells and the 253J cells with TGF-beta1. There were no significant differences in the cell cycle between the two treatments. However, there were more apoptotic cells in the TGF-beta1-treated 253J cells. CONCLUSIONS: TGF-beta1 did not stimulate cellular proliferation but was a growth inhibitory factor in bladder cancer cells. However, the pattern of its effects depended on the cell line. TGF-beta1 achieved growth inhibition by enhancing the level of apoptosis.

Isolation of bovine spermatogonial cells and co-culture with prepubertal sertoli cells in the presence of colony stimulating factor-1

Spermatogonial stem cells [SSCs] are infrequent self-renewing cells among the type A spermatogonia within the seminiferous tubules and are the basis of spermatogenesis in mammalian testis. An adequate number of SSCs is a primary requirement for the study of their behavior, regulation, and further biomanipulation. In this paper, we studied the development of the primary co-cultures of type A spermatogonia and prepubertal bovine sertoli cells in the presence of Colony Stimulating Factor 1 [CSF1], a potential contributor in the SSC niche. The effect of different concentrations of CSF1 [0, 10, 50 and 100 ng/mL] on the colonization activity of spermatogonial cells was assessed 4, 7 and 11 days after the beginning of the culture by counting the total number of colonies and measuring their area in each group of the present experiment. Immunofluorescent staining against OCT4 and vimentin led to the confirmation of the nature of both the SSCs and sertoli cells. Results showed that the total number of colonies from day 4 to 11 increased significantly in all groups, independent of CSF1 concentration. In addition, the total number and total area of colonies were higher [not significant] in 10 and 50 ng/mL CSF1 treatments than the control and 100 ng/mL CSF1 groups in all the three evaluations during the experiment. However, this difference was only significant [p<0.05] between the total area of colonies in the control and 10 ng/mLCSF1 groups at day 4 of co-culture. It was concluded that CSF1 can be a suitable growth factor for improving SSCs colonization in vitro, particularly during the first days of culture where accompanying sertoli cells still have not proliferated sufficiently to support the propagating spermatogonial cells

Very small embryonic-like stem-cell optimization of isolation protocols: an update of molecular signatures and a review of current in vivo applications

As the theory of stem cell plasticity was first proposed, we have explored an alternative hypothesis for this phenomenon: namely that adult bone marrow (BM) and umbilical cord blood (UCB) contain more developmentally primitive cells than hematopoietic stem cells (HSCs). In support of this notion, using multiparameter sorting we were able to isolate small Sca1+Lin-CD45- cells and CD133+Lin-CD45- cells from murine BM and human UCB, respectively, which were further enriched for the detection of various early developmental markers such as the SSEA antigen on the surface and the Oct4 and Nanog transcription factors in the nucleus. Similar populations of cells have been found in various organs by our team and others, including the heart, brain and gonads. Owing to their primitive cellular features, such as the high nuclear/cytoplasm ratio and the presence of euchromatin, they are called very small embryonic-like stem cells (VSELs). In the appropriate in vivo models, VSELs differentiate into long-term repopulating HSCs, mesenchymal stem cells (MSCs), lung epithelial cells, cardiomyocytes and gametes. In this review, we discuss the most recent data from our laboratory and other groups regarding the optimal isolation procedures and describe the updated molecular characteristics of VSELs.

Low volume amplification in single cell separation and inspection / 法医学杂志

OBJECTIVE@#To establish optimal amplification conditions with the application of 0.2 mL test tube in single cell separation and inspection.@*METHODS@#Oral epithelium cell suspension was prepared. Five or ten cells were collected with 0.2 mL test tube. Then DNA were amplified with Identifiler Plus kit in three different conditions in which the proteinase K addition, gold enzyme concentration in PCR reaction, and PCR reaction cycles were adjusted separately. Finally the detection rate, allelic dropout rate and artificial alleles were compared among the groups.@*RESULTS@#In these 3 different conditions: addition of proteinase K, addition of 0.4 microL gold enzyme in PCR reaction, and use of 32 cycles, the detection rate was higher and allelic dropout rate was lower than the other conditions.@*CONCLUSION@#In single cell separation and inspection, the usage of 0.2 mL test tube could be an effective supplement to chip-low volume amplification.

Evaluation of castor oil-based polyurethane membranes in rat bone-marrow cell culturey / Avaliação de membranas à base de óleo de polímero de mamona em culturas de células de medula óssea de ratos

PURPOSE: To evaluate three methods to isolate rats MSCs and to analyze the potential of a castor oil polyurethane base membrane as a scaffold for MSCs. METHODS: Four male Wistar rats, aged 20-30 days were used. Bone marrow aspirates from femur and tibia were harvested using DMEM high glucose and heparin. The cell culture was performed in three different ways: direct culture and two types of density gradients. After 15 days, was made the 1st passage and analyzed cell viability with markers Hoerscht 33342 and propidium iodide. The MSCs were characterized by surface markers with the aid of flow cytometry. After this, three types of castor oil polyurethane membranes associated with the MSCs were kept on the 6-well plate for 5 days and were analyzed by optical microscopy to confirm cell aggregation and growth. RESULTS: Separation procedures 1 and 2 allowed adequate isolation of MSCs and favored cell growth with the passage being carried out at 70 percent confluence after 15 days in culture. The cells could not be isolated using procedure 3. When the 3 castor oil polyurethane membrane types were compared it was possible to observe that the growth of MSCs was around 80 percent in membrane type 3, 20 percent in type 2, and 10 percent in type 1. CONCLUSION: Both Ficoll-Hypaque densities allow isolation of rat MSCs, and especially castor oil-based membrane type 3 may be used as a scaffold for MSCs.

OBJETIVO: Avaliar três formas de cultivo de células-tronco mesenquimais de ratos; e analisar o potencial do polímero de mamona na forma de membrana como arcabouço para CTMs. MÉTODOS: Foram utilizados quatro ratos machos Wistar, de 20 a 30 dias de idade. Aspirados da medula óssea do fêmur e da tíbia foram colhidos com DMEM alta glicose e heparina. As células foram isoladas de três formas diferentes: cultivo direto e com dois tipos de gradientes de densidade. Após 15 dias, foi feita a 1ª passagem e analisada a viabilidade celular com os marcadores Hoerscht 33342 e Iodeto de Propídio. As CTMs foram então caracterizadas por marcadores de superfície, com o auxílio de citômetro de fluxo. Após, três tipos de membrana à base de óleo de polímero de mamona associadas com as CTMS foram mantidas em cultivo por cinco dias, e analisados por microscópio ótico para confirmar o crescimento e a adesão celular. RESULTADOS: Após 15 dias, Os procedimentos que utilizaram gradientes de densidade permitiram o isolamento das CTMs e favoreceram o crescimento celular com a passagem, sendo obtido 70 por cento de confluência após 15 dias em cultura. O procedimento direto não se mostrou eficaz para o isolamento das células. O crescimento das CTMs foi aproximadamente 80 por cento sobre a membrana tipo 3, 20 por cento na tipo 2 e 10 por cento na membrana tipo 1. CONCLUSÃO: Os dois gradientes de concentração Ficoll-Hypaque permitem isolar CTMs de ratos; e especialmente a membrana de polímero de mamona tipo 3 pode ser usada como um bom arcabouço para as CTMs.

Protocols for obtainment and isolation of two mesenchymal stem cell sources in sheep / Protocolos para obtenção e isolamento de células tronco mesenquimais de duas fontes em ovinos

PURPOSE: To evaluate different protocols to isolate stem cells from ovine umbilical cord blood and adipose tissue. METHODS: There were used 5 samples of umbilical blood and 5 samples of perirenal adipose tissue from 10 female sheep. All the samples were obtained through surgery, to harvest aseptic samples. There were used 3 protocols for obtainment and culture of umbilical cord blood stem cells and 4 protocols for ovine adipose tissue stem cells. RESULTS: It was possible to observe only one successful protocol for the obtainment of umbilical cord blood stem cells. When analyzing the techniques used to obtain adipose tissue stem cells, only one of the methods was effective as well. Through colony forming unit assay, there were obtained 58 colonies of cells after seven days in culture. Flow citometry tests revealed the cells were positive to CD44 and exhibited negative reaction to CD38, CD45, CD41/61. These cells showed a growth curve with very well defined phases LOG, LAG and PLATEAU. This phases are typically seem in mesenchymal stem cells growth curves. CONCLUSIONS: The isolation and culture of mesenchymal stem cells from ovine umbilical cord blood are complex and request more detailed assays. Stem cells from fat tissue sheep showed mesenchymal characteristics, according to their cell growth curve, ability to origin colonies of fibroblastoid cells and positive reactivity with the antibody CD44 by flow citometry.

OBJETIVO: Testar diferentes protocolos para o isolamento de células tronco a partir de sangue de cordão umbilical e tecido adiposo de ovinos. MÉTODOS: Foram utilizadas cinco amostras de sangue de cordão umbilical e cinco amostras de tecido adiposo perirrenal de 10 fêmeas de ovelha. A coleta das amostras foi realizada através de procedimento cirúrgico para coleta do material de forma mais asséptica possível. Foram realizados três protocolos de isolamento e cultivo das células-tronco do cordão umbilical e quatro protocolos para o isolamento e cultivo das células-tronco de gordura de ovinos RESULTADOS: Somente um dos protocolos utilizados para o isolamento das células-tronco de cordão umbilical foi efetivo. Dos quatro protocolos utilizados para isolamento das células-tronco de gordura, da mesma forma, apenas um obteve sucesso. Foi realizado o ensaio de unidades formadoras de colônias destas células, sendo contadas 58 colônias ao final de sete dias. Na citometria de fluxo essas células mostraram-se positivas para CD44 e negativas para CD38, CD45, CD41/61. Estas células apresentaram curva de crescimento com fases de LOG, LAG e PLATEAU bem definidas, características das curvas de crescimento das células-tronco de origem mesenquimal. CONCLUSÕES: O isolamento e cultivo das células-tronco mesenquimais do cordão umbilical de ovinos é de difícil realização, exigindo maiores ensaios e estudos profundos. Células tronco do tecido adiposo de ovelhas demonstraram características mesenquimais, de acordo com a curva de crescimento, habilidade de formação de colônias, células com morfologia fibroblastóide e reação positiva ao anticorpo CD44.

Dimensionamiento de los sistemas de microfiltración y ultrafiltración para la producción de la toxina tetánica elaborada en el Instituto Nacional de Higiene Rafael Rangel / Microfiltration and ultrafiltration systems dimension for using in tetanus toxin production in the Instituto Nacional de Higiene "Rafael Rangel"

Se evaluó el uso de la tecnología de Flujo de Filtración Tan gencial (FFT), para obtener la toxina tetánica a partir de cultivos de la bacteria Clostridium tetani, usando el proceso de Micro filtración (MF), para eliminar el paquete celular y posteriormente, a partir del filtrado obtenido, concentrar y diafiltrar la Toxina Tetánica usando el proceso de Ultrafiltración (UF). Se determinaron las características de los filtros, condiciones de trabajo y el dimensionamiento de los equipos a adquirir para la nueva producción industrial de Toxina Tetánica. Se evaluaron el flujo, tiempo, rendimiento del proceso y las características del producto obtenido. Utilizando cultivos con Toxina Tetánica en un equipo de filtración de laboratorio, diseñado para producir el efecto de FFT. Se seleccionó las membranas tipo cassettes, formato Suspended Screen, porosidad 0,2μm, como las adecuadas para el proceso de MF, ya que mostraron un 100% de transmisión de la Toxina Tetánica, ausencia de restos celulares y flujo promedio de filtrado de 73.30 L/m2h. Así mismo, se seleccionaron las membranas tipo cassettes, formato Omega, porosidad 50 y 70 kDa, como las adecuadas para el proceso de UF, ya que mostraron 100% de recuperación de la toxina, ausencia de toxina en el filtrado y adecuados flujos de filtrado (106,7 y 104,4 L/m2h, respectivamente). Estos resultados permitieron dimensionar, considerando las variables a utilizar en la producción industrial (Volumen 650 a 950 litros, tiempo de procesos, 3 horas), el área de filtración de los equipos de MF y UF a adquirir, estimados en 20m2 y 5m2, respectivamente.

Tangential Flow Filtration (TFF) technology was evaluated to process tetanus toxin which is produced by Clostridium tetani bacterium. Microfiltration (MF) is used to retain cells while allowing passage of the toxin to the filtrate stream. The filtrate is co - llected and further processed by Ultrafiltration (UF) to concentrate the toxin and to maximize the wash of small species by a Dia filtration step. Both, MF and UF processes were evaluated to specify the filters and corresponding critical process parameters to scale-up the application. As part of the evaluation, flow ra te, processing time, yield and product attributes were characterized. The cell harvest containing the tetanus toxin was processed using a laboratory scale TFF system designed to product the TFF effect. The evaluation demonstrated that a cassette in sus pended screen format and membrane with 0.2μm pore is the right selection for the MF step. It showed 100% of toxin transmission without the presence of cellular debris and average process flux of 73.30 L/m2h. The UF step was conducted using the same system with cassettes in me dium screen format with pores of 50 and 70kDa. It showed 100% retention of the toxin with a process flux of 106,7 and 104,4L/m2h, respectively. To maximise product retention during UF, the 50 kDa membrane was selected. These results were used to scale-up the application to process the industrial volume of 650 a 950 liters in 3 hours of processing time. Membrane area sizing of MF and UF to be acquired is estimated in 20m2 and 5m2, respectively.