Abstract Mesenchymal stem cells present clinical potential to recover and regenerate injured tissues in diverse pathologies. The in vitro expansion and characterization of these cells contribute to elucidation of the mechanisms of senescence and strategies involving cell therapies. This study aimed to compare specific characteristics between initial and advanced passages of mesenchymal stem cells derived from adipose tissue and bone marrow. Both cell types were characterized according to immunophenotype, osteogenic differentiation, genomic instability, migration assay, doubling population time and colony forming ability. Our results demonstrated that both cell types were able to maintain an immunophenotypic profile typical of mesenchymal stem cells during increasing passages. Adipose stem cells at initial passage presented greater migration capacity compared to advanced passage cells, and advanced passage cells proliferated faster than initial passage cells. Bone marrow stem cells at early passages presented higher osteogenic potential than advanced. At advanced passages they presented higher colony forming capacity and genetic damage than those at initial passage. These results suggest that mesenchymal stem cells maintained in culture presented characteristics of senescence that should be monitored prior the use in regenerative medicine and cells derived from bone marrow at initial passage have better potential for therapeutic use in bone tissue engineering.

Resumo: Lesões cutâneas crônicas afetam 15% dos pacientes diabéticos e humanos representam um risco 15 a 46 vezes maior de amputações de membros em comparação com as pessoas com a glicemia normal. Supõe-se que a metade destas amputações poderia ser evitada por meio do tratamento precoce das feridas cutâneas com, por exemplo, uma adequada terapia celular. Objetivos: Neste estudo, a ação do transplante autólogo de células estaminais mesenquimais (MSC) foi avaliada em comparação com o tratamento com plasma rico em plaquetas autólogo (PRP) na cicatrização de lesões cutâneas induzidas em camundongos diabéticos. Estes animais foram previamente tratados com estreptozotocina para induzir diabetes mellitus e feridas redondas de 1,5 cm de diâmetro foram criadas na região posterior. Os diâmetros dos ferimentos e tempo de cicatrização foram avaliados durante 30 dias e os resultados foram submetidos à análise de variância e média pelo teste de Tukey. Verificou-se que os animais tratados com MSC apresentam uma cicatrização mais acelerada da lesão cutânea que do que os animais tratados com PRP. No entanto, o tratamento com PRP apresentou melhores resultados do que apenas a assepsia das lesões diariamente com solução salina ou cobrindo-os com atadura semi-permeável. Além disso, a utilização de atadura semi-permeável mantidas as lesões cutâneas de camundongos diabéticos não interfere negativamente com a cicatrização, provou ser inofensiva para usar, mas manteve as lesões cutâneas hidratadas mais do que os expostos ao meio ambiente.

Abstract: Chronic cutaneous lesions affect 15% of diabetic human patients and represent a risk 15 to 46 times larger of limb amputations compared to people with normal glycemia. It is assumed that half of these amputations could be prevented by early treatment of wounds, for example, with proper cell therapy. Objectives: In this study, the action of the autologous transplant of mesenchymal stem-cells (MSC) was evaluated compared to the treatment with autologous platelet rich plasma (PRP) in the cicatrization of cutaneous lesions induced in diabetic mice. These animals were previously treated with streptozootocin to induce diabetes mellitus and round wounds of 1.5cm in diameter were created in the posterior region. Diameters of the wounds and healing time were evaluated during 30 days and the results were submitted to variance analysis and Tukey's test average. It was noticed that the animals treated with MSC presented a more accelerated cicatrization of the cutaneous lesion than the animals treated with PRP. However, the treatment with PRP presented better results than just the daily asepsis of the lesions with saline or covering them with semi-permeable bandage. Besides, the use of semi-permeable bandage kept the cutaneous lesions of diabetic mice did not interfere negatively with cicatrization, proved to be harmless to use, but kept the cutaneous lesions more hydrated than the ones exposed to the environment.

Objetivo: Testamos a hipótese de que a injeção intramiocárdica direta de células mononucleares de medula óssea em pacientes portadores de cardiomiopatia dilatada não-isquêmica pode melhorar a função ventricular e a capacidade física. Métodos: Trinta pacientes com cardiomiopatia dilatada não isquêmica e fração de ejeção 35% foram randomizados na razão 1:2 em grupos controle e tratado. Grupo células mononucleares de medula óssea recebeu 1,06 ± 108 células mononucleares de medula óssea por mini-toracotomia. Grupo controle não recebeu intervenção. Avaliação foi feita clinicamente e por teste de caminhada 6 minutos (T6m), ressonância magnética e ecocardiogramas. Resultados: Grupo células mononucleares de medula óssea mostrou tendência de melhora da Fração de ejeção - ressonância magnética aos 3 meses, 27,80±6,86% para 30,13±9,06% (P=0,08), retornando ao basal aos 9 meses (28,78%, P=0,77). Grupo controle não apresentou variação (28,00±4,32%; 27,42±7,41% e 29,57±4,50%). Ecocardiogramas - fração de ejeção melhorou no grupo células mononucleares de medula óssea aos 3 meses: 25,09±3,98 para 30,94±9,16 (P=0,01) e aos 12 meses (30,07±7,25%, P=0,001), enquanto o controle não variou: 26,1±4,4 vs. 26,5±4,7 e 30,2±7,39%, P=0,25 e 0,10, respectivamente). Células mononucleares de medula óssea melhorou classe funcional New York Heart Association: 3,40±0.50 para 2,41±0,79 (P=0,002); controles não mudaram (3,37±0,51 para 2,71±0,95; P=0,17). T6m melhorou no grupo células mononucleares de medula óssea (348,00±93,51 m inicial para 370,41±91,56 m aos 12 m, P=0,66) e declinou sem significância no controle (361,25±90,78 m para 330,00±123,42 m aos 12 meses, P=0,66). Não houve diferenças significativas entre os grupos. Conclusão: A tendência intragrupo de melhora funcional e subjetiva não se confirmou quando comparado com controle. Portanto, a injeção direta intramiocárdica de células mononucleares de medula óssea não se associou a mudança significativa na função ventricular. As diferenças observadas no grupo tratado poderiam ser devidas a efeito placebo ou a baixo poder estatístico.

Objective: We tested the hypothesis that direct intramyocardial injection of bone marrow mononuclear cells in patients with non-ischemic dilated cardiomyopathy can improve left ventricular function and physical capacity. Methods: Thirty non-ischemic dilated cardiomyopathy patients with left ventricular ejection fraction <35% were randomized at a 1:2 ratio into two groups, control and treated. The bone marrow mononuclear cells group received 1.06±108 bone marrow mononuclear cells through mini-thoracotomy. There was no intervention in the control group. Assessment was carried out through clinical evaluations as well as a 6-min walk test, nuclear magnectic resonance imaging and echocardiogram. Results: The bone marrow mononuclear cells group showed a trend toward left ventricular ejection fraction improvement, with magnectic resonance imaging - at 3 months, showing an increase from 27.80±6.86% to 30.13±9.06% (P=0.08) and returning to baseline at 9 months (28.78%, P=0.77). Magnectic resonance imaging showed no changes in left ventricular ejection fraction during follow-up of the control group (28.00±4.32%, 27.42±7.41%, and 29.57±4.50%). Echocardiogram showed left ventricular ejection fraction improved in the bone marrow mononuclear cells group at 3 months, 25.09±3.98 to 30.94±9.16 (P=0.01), and one year, 30.07±7.25% (P=0.001). The control group showed no change (26.1±4.4 vs 26.5±4.7 and 30.2±7.39%, P=0.25 and 0.10, respectively). Bone marrow mononuclear cells group showed improvement in New York Heart Association functional class, from 3.40±0.50 to 2.41±0.79 (P=0.002); patients in the control group showed no change (3.37±0.51 to 2.71±0.95; P=0.17). Six-minute walk test improved in the bone marrow mononuclear cells group (348.00±93.51m at baseline to 370.41±91.56m at 12 months, P=0.66) and there was a non-significant decline in the control group (361.25±90.78m to 330.00±123.42m after 12 months, P=0.66). Group comparisons were non-significant. Conclusion: The trend of intragroup functional and subjective improvement was not confirmed when compared to the control group. Direct intramyocardial application of bone marrow mononuclear cells in non-ischemic dilated cardiomyopathy was not associated with significant changes in left ventricular function. Differences observed within the bone marrow mononuclear cells group could be due to placebo effect or low statistical power.

As células-tronco mesenquimais (MSC) estão presentes em nichos especializados nas regiões perivasculares dos tecidos adultos e são capazes de se diferenciar em diversos tipos celulares, dentre eles, os comprometidos com processos de reparação óssea. MSC oriundas da medula óssea de oito camundongos jovens C57BL/6 gfp+ foram expandidas em culturas e utilizadas na reparação de defeitos críticos produzidos em calvária de 24 camundongos isogênicos C57BL/6 adultos. Os animais foram submetidos a um defeito craniano de 6,0mm de diâmetro e separados em dois grupos experimentais iguais. O grupo controle não recebeu tratamento e no grupo tratado foi administrado, no interior do defeito, pellet de MSC contendo 1,0 x 10(7) células/mL. O grupo tratado com MSC exibiu aumento da angiogênese e maior quantidade de novo osso depositado nas bordas do defeito, comparando-se ao grupo controle. Nas condições experimentais apresentadas nesse estudo, constatou-se que o transplante de células-tronco mesenquimais (MSC) derivadas da medula óssea de camundongos C57BL/6 gfp+, aplicadas em defeitos ósseos críticos, produzidos em calvária de camundongos contribui positivamente para o processo de reparação óssea. As MSC apresentam habilidades de influenciar o correto funcionamento dos osteoblastos, aumentar a quantidade de células mobilizadas nos processos de reparação, aumentar a liberação de fatores de crescimento e aumentar a deposição de matriz óssea.

Mesenchymal stem cells (MSC) are present in specialized niches in perivascular regions of adult tissues and are able to differentiate into various cell types, such as those committed to repairing. Bone marrow derived MSC from eight young mice C57BL/ 6 gfp+ were expanded in culture for repairing critical defects in calvarial bone produced in twenty-four young isogenic adult C57BL/6 mice. The animals were subjected to a cranial defect of 6.0mm diameter and divided into two equal experimental groups. Control group did not receive any treatment and the treated group received a MSC pellet containing 1.0 x 10(7) cells/mL into the defects. The group treated with MSC showed increased angiogenesis and amount of new bone deposited on the defect limits than that observed in the control group. The results demonstrated that transplantation of bone marrow-derived MSC of C57BL/6 gfp+ mice to bone critical defects produced in mice calvarial contributes positively to the bone repair process. MSC presets ability to influence the correct functioning of osteoblasts, increases the amount of mobilized cells for the repairing process, speeds up growth, and increases deposition of bone matrix.

Cardiopatia isquêmica grave com angina refratária a formas convencionais de tratamento apresenta-se em uma crescente incidência. Para tratar angina refratária, terapias alternativas na tentativa de redução da isquemia miocárdica e alívio de sintomas têm sido estudadas. Neste contexto, a terapia gênica representa uma opção, pela possibilidade de induzir angiogênese, estabelecer circulação colateral e reperfundir miocárdio isquêmico. Diversos ensaios clínicos têm sido conduzidos e, com exceção de casos isolados e específicos de efeitos adversos, há indicação de segurança, viabilidade e potencial eficácia da terapia. O benefício clínico não está bem definido. Neste artigo, revisamos os ensaios clínicos que utilizaram terapia gênica para tratamento de pacientes cardiopatas isquêmicos. A abordagem inclui: (1) isquemia miocárdica e angiogênese, sobre os aspectos fisiopatológicos envolvidos; (2) fatores de crescimento, tratando sobre aspectos específicos e justificando a utilização em pacientes cardiopatas isquêmicos sem opções pela terapêutica convencional; (3) ensaios clínicos controlados, onde é apresentado um resumo dos principais estudos envolvendo terapia gênica para tratamento da cardiopatia isquêmica grave; (4) nossa experiência, especialmente sobre resultados preliminares do primeiro ensaio clínico de terapia gênica do Brasil e (5) perspectivas.

Severe ischemic heart disease with refractory angina, occurs in increasing incidence. Alternative forms of treatment, in an attempt to reduce myocardial ischemia and relief of symptoms has been studied. In this context, gene therapy is an option, for the possibility of inducing angiogenesis, establish collateral circulation and reperfuse ischemic myocardium. Several clinical trials have been conducted and, except for specific cases of adverse effects, there is indication of safety, feasibility and potential effectiveness of therapy. The clinical benefit, however, is not yet well established. In this article we review the clinical trials of gene therapy for patients with ischemic heart disease. The approach includes: (1) myocardial ischemia and angiogenesis on the pathophysiological aspects involved, (2) growth factors, dealing with specific aspects and justifying the use in cardiac patients with no option for conventional therapy, (3) controlled clinical trials, where a summary of the main studies involving gene therapy for severe ischemic heart disease is presented, (4) our experience, especially on preliminary results of the first gene therapy clinical trial in Brazil and (5) future prospects.

The multidrug resistance (MDR) phenotype is associated with the expression of P-glycoprotein (Pgp), coded by the multigenic mdr family. Mice present the isoforms mdr1 and mdr3, which are responsible for multidrug resistance, and mdr2, that is involved in the transport of phospholipids. mdr1 expression has more recently been associated also with the secretion of steroid hormones. This work presents an RT-PCR analysis of the expression of mdr isoforms, in several organs of mice during different phases of the estrous cycle. Additionally, females were ovariectomized, submitted to different hormone treatments, and their uterus was analyzed for the expression of mdr isoforms. The results show that in the adrenal gland and ovaries mdr1 is the main isoform during proestrus, and that progesterone or a combination of progesterone and estrogen induce the expression of all mdr isoforms in the uterus of ovariectomized females. We suggest that the functions of mdr1 and mdr3 are overlapping, that mdr3 may be the more efficient isoform in the detoxification function, and that mdr1 may be more closely related to the secretion of steroid hormones.

OBJECTIVE: To assess the transfection of the gene that encodes green fluorescent protein (GFP) through direct intramyocardial injection. METHODS: The pREGFP plasmid vector was used. The EGFP gene was inserted downstream from the constitutive promoter of the Rous sarcoma virus. Five male dogs were used (mean weight 13.5 kg), in which 0.5 mL of saline solution (n=1) or 0.5 mL of plasmid solution containing 0.5 µg of pREGFP/dog (n=4) were injected into the myocardium of the left ventricular lateral wall. The dogs were euthanized 1 week later, and cardiac biopsies were obtained. RESULTS: Fluorescence microscopy showed differences between the cells transfected and not transfected with pREGFP plasmid. Mild fluorescence was observed in the cardiac fibers that received saline solution; however, the myocardial cells transfected with pREGFP had overt EGFP expression. CONCLUSION: Transfection with the EGFP gene in healthy canine myocardium was effective. The reproduction of this efficacy using vascular endothelial growth factor (VEGF) instead of EGFP aims at developing gene therapy for ischemic heart disease.

As células-mãe são encontradas no sangue do cordão umbilical humano (HUCB), além de na medula óssea e no sangue periférico, e há um crescente interesse no uso desse material como uma fonte alternativa para transplante de medula óssea e terapia gênica. A hematopoiese in vitro tem sido mantida por até 16 semanas em culturas de HUCB, mas o estabelecimento de uma camada estromal aderente tem invariavelmente falhado. Precursores de células aderentes foram pesquisados entre células mononucleares do HUCB em culturas a longo prazo. Células mononucleares obtidas do sangue do cordão depois de partos normais a termo foram cultivadas em diferentes concentrações em meio Dulbecco modificado por Iscove, com alimentação semanal. Uma camada aderente foi detectada em 16 de 30 culturas, 12 das quais em concentrações celulares maiores que 2 x 10(6) células/ml. Ao contrário das culturas de medula óssea, em que o estroma é detectado precocemente, na maioria (10/16) das culturas positivas do HUCB a camada aderente foi identificada apenas depois da quarta semana de cultura. As células nunca atingiram a confluência e se destacaram da placa aproximadamente quatro semanas após sua detecção. A coloração de culturas positivas por May-Grünwald-Giemsa revelou células aderentes semelhantes a fibroblastos ou semelhantes a células endoteliais em um arranjo diferente daquele do estroma da medula óssea em 13 amostras. Em duas dessas, as células aderentes estavam organizadas em cordões característicos e delimitados de células. Ao contrário das culturas de medula óssea, células gordurosas nunca foram observadas nas camadas aderentes. Um rápido desenvolvimento de grandes células mielóides na primeira semana de cultura foi característico de culturas negativas e essas células mantiveram-se por até 12 semanas. HUCB contém precursores de células aderentes que ocorrem em números menores do que na medula óssea e podem estar em um estágio diferente (possivelmente menos maduro) de diferenciação.

In addition to bone marrow and peripheral blood, stem cells also occur in human umbilical cord blood (HUCB), and there is an increasing interest in the use of this material as an alternative source for bone marrow transplantation and gene therapy. In vitro hematopoiesis has been maintained for up to 16 weeks in HUCB cultures, but the establishment of an adherent, stromal layer has consistently failed. Adherent cell precursors among mononuclear cells from HUCB were sought for in long-term cultures. Mononuclear cells obtained from cord blood after full term, normal deliveries were cultivated at different concentrations in Iscove's modified Dulbecco's medium (IMDM) with weekly feeding. An adherent layer was detected in 16 of 30 cultures, 12 of which were plated at cell concentrations higher than 2 x 10(6) cells/ml. In contrast to bone marrow cultures, in which the stroma is detected early, in most (10/16) positive cultures from HUCB the adherent layer was identified only after the fourth week of culture. The cells never reached confluence and detached from the plate approximately four weeks after detection. May-Grünwald-Giemsa staining of positive cultures revealed fibroblast- or endothelial-like adherent cells in an arrangement different from that of bone marrow stroma in 13 samples. In two of these, the adherent cells were organized into characteristic, delimited cords of cells. Unlike bone marrow cultures, fat cells were never observed in the adherent layers. A rapid development of large myeloid cells in the first week of culture was characteristic of negative cultures and these cells were maintained for up to 12 weeks. HUCB contains adherent cell precursors which occur in lower numbers than in bone marrow and may be at a different (possibly less mature) stage of differentiation.

Neste trabalho foi analisado por RT-PCR o tipo de junção no mRNA BCR/ABL híbrido, que caracteriza a leucemia mielóide crônica (CML), em material proveniente de 33 pacientes (22 homens e 11 mulheres). Em 14 dos casos (42,4%) foi observado mRNA do tipo b3a2, em 13 (39,4%) mRNA b2a2 e em 6 (18,2%) ambos os tipos, mas com predomínio de b3a2. Não foram observadas correlações estatisticamente significantes entre tipo de mRNA e idade, teor de hemoglobina, contagem de leucócitos e plaquetas, porcentagem de blastos ou basófilos e esplenomegalia, todos ao diagnóstico, assim como sexo do paciente ou duração da fase crônica. Foram realizadas ainda análises combinando os dados obtidos neste estudo com outros publicados para os seguintes parâmetros: idade ao diagnóstico, índice Sokal, sexo e linhagem celular da crise blástica. Apenas no estudo combinado sexo X tipo de mRNA foi verificada associação estatisticamente significante (P = 0,029), com predominância de homens nos grupos que expressam b2a2 (2,68:1) e b3a2 (1,33:1). Conclui-se que a categorização dos pacientes quanto ao tipo de mRNA não homogeneiza os dados clínicos e hematológicos dentro de cada grupo, onde a variância é grande, nem os diferencia.

The nature of BCR/ABL hybrid mRNA was analyzed by RT-PCR in cells from 33 patients (22 males, 11 females) with chronic myeloid leukemia (CML). b3a2 mRNA was found in 14 cases, whereas 13 patients had b2a2 mRNA and six had both kinds of mRNA, with a predominance of the b3a2 type. The type of mRNA present showed no significant correlation with age, hemoglobin level, number of leukocytes and platelets, percentage of blasts or basophils or the presence of splenomegaly at diagnosis. There was also no correlation with sex or duration of the chronic phase. When these results were combined with those reported by other groups, a significant association (P = 0.029) was observed for mRNA type vs. sex, with a predominance of men in the groups expressing b2a2 (2.68:1) and b3a2 (1.33:1). We conclude that the classification of patients according to mRNA type does not homogenize the clinical and hematological data within groups, where variance is large, nor does it allow a differentiation between groups.