Cardiac tissue engineering: current state-of-the-art materials, cells and tissue formation / Engenharia de tecidos cardíacos: atual estado da arte a respeito de materiais, células e formação tecidual

ABSTRACT Cardiovascular diseases are the major cause of death worldwide. The heart has limited capacity of regeneration, therefore, transplantation is the only solution in some cases despite presenting many disadvantages. Tissue engineering has been considered the ideal strategy for regenerative medicine in cardiology. It is an interdisciplinary field combining many techniques that aim to maintain, regenerate or replace a tissue or organ. The main approach of cardiac tissue engineering is to create cardiac grafts, either whole heart substitutes or tissues that can be efficiently implanted in the organism, regenerating the tissue and giving rise to a fully functional heart, without causing side effects, such as immunogenicity. In this review, we systematically present and compare the techniques that have drawn the most attention in this field and that generally have focused on four important issues: the scaffold material selection, the scaffold material production, cellular selection and in vitro cell culture. Many studies used several techniques that are herein presented, including biopolymers, decellularization and bioreactors, and made significant advances, either seeking a graft or an entire bioartificial heart. However, much work remains to better understand and improve existing techniques, to develop robust, efficient and efficacious methods.

RESUMO Doenças cardiovasculares são responsáveis pelo maior número de mortes no mundo. O coração possui capacidade de regeneração limitada, e o transplante, por consequência, representa a única solução em alguns casos, apresentando várias desvantagens. A engenharia de tecidos tem sido considerada a estratégia ideal para a medicina cardíaca regenerativa. Trata-se de uma área interdisciplinar, que combina muitas técnicas as quais buscam manter, regenerar ou substituir um tecido ou órgão. A abordagem principal da engenharia de tecidos cardíacos é criar enxertos cardíacos, sejam substitutos do coração inteiro ou de tecidos que podem ser implantados de forma eficiente no organismo, regenerando o tecido e dando origem a um coração completamente funcional, sem desencadear efeitos colaterais, como imunogenicidade. Nesta revisão, apresentase e compara-se sistematicamente as técnicas que ganharam mais atenção nesta área e que geralmente focam em quatro assuntos importantes: seleção do material a ser utilizado como enxerto, produção do material, seleção das células e cultura de células in vitro. Muitos estudos, fazendo uso de várias das técnicas aqui apresentadas, incluindo biopolímeros, descelularização e biorreatores, têm apresentado avanços significativos, seja para obter um enxerto ou um coração bioartifical inteiro. No entanto, ainda resta um grande esforço para entender e melhorar as técnicas existentes, para desenvolver métodos robustos, eficientes e eficazes.

Effects of tetrandrine on proliferation and activation of cardiac fibroblasts / 北京大学学报(医学版)

OBJECTIVE@#To investigate the effects of tetrandrine (Tet) on proliferation and activation of rat cardiac fibroblasts.@*METHODS@#Firstly, the cell counting kit-8 (cck-8) assay was applied to detect the effects of Tet with different concentrations on proliferation of cardiac fibroblasts. Secondly, transforming growth factor (TGF-β)with a concentration of 5 μg/L was used to induce the cardiac fibroblast activation, and Western blot was performed to measure the expression variation of β-catenin, vimentin (Vm), fibronectin (Fn) and smooth muscle α-actin (SMA). At last, the real-time PCR was conducted to measure the expression change of collagen-1(Col-1) and collagen-3(Col-3).@*RESULTS@#The cck-8 assay showed that the Tet with different concentrations respectively, which were 0.5 μmol/L, 1 μmol/L, 2 μmol/L, 4 μmol/L, and 8 μmol/L, significantly inhibited the proliferation of cardiac fibroblasts. The viability was decreased to 94.4%,84.9%,74.9%,63.8%and 50.3% respectively of the control group when the Tet concentration changed, and the difference was statistically significant, P=0.043, P<0.001, P<0.001, P<0.001, P<0.001 respectively. Western blot revealed that the expressions of β-catenin, Fn, SMA and Vm, were up-regulated by TGF-β(5 μg/L), the result showed that the difference was statistically significant, and the P values were 0.001,0.008,0.010,0.001 respectively. Then, the up-regulation of β-catenin, Fn and SMA was attenuated by pre-treatment of Tet, and the result also displayed that the difference was statistically significant, and the P values were 0.009, 0.005, 0.019,respectively. While there was no significant change in the expression of Vm, according to Western blotting, and P>0.05,at the same time, real-time PCR indicated that the up-regulations of Col-1 and Col-3 which were induced by TGF-β were blocked by pre-treatment of Tet, the result showed that the difference was statistically significant, P<0.001.@*CONCLUSION@#According to the experimental results, we can draw the conclusion that: the Tet can significantly inhibit the proliferation of cardiac fibroblasts, meanwhile, it can block the activation of cardiac fibroblasts, which is induced by TGF-β. It is supposed that the Tet may probably have anti myocardial fibrosis, which indicates that it may probably be a medicine which is used to block the cardiac remodeling.

Risk factors associated with the transmissionof Brazilian spotted fever in the Piracicaba river basin, State of São Paulo, Brazil

INTRODUCTION : Brazilian spotted fever (BSF) is a disease transmitted by ticks for which the etiological agent is Rickettsia rickettsii. The present essay evaluates the risk factors associated with the transmission of cases of BSF in the time period between 2003 and 2013 in the Piracicaba river basin, state of São Paulo. METHODS : This essay presents a retrospective study to identify the factors associated with the transmission of cases of BSF among all suspected cases identified by the System for Epidemiological Surveillance of São Paulo (CVE). After the description of temporal distribution (onset of symptoms) and the environmental and demographic variations of the confirmed and discarded cases, a multiple logistic regression model was applied. RESULTS : We searched 569 probable locations of infection (PLI) with 210 (37%) confirmed cases of BSF and 359 (63%) discarded cases. The associated variables for the confirmation of BSF in the multiple logistic model using a confidence interval (CI) of 95% were age (OR = 1.025 CI: 1.015-1.035), the presence of Amblyomma sculptum in the environment (OR = 1.629 CI: 1.097-2.439), the collection of ticks from horses (OR = 1.939 CI: 0.999-3.764), the presence of capybaras (OR = 1.467 CI: 1.009-2.138), an urban environment (OR = 1.515 CI: 1.036-2.231), and the existence of a dirty pasture (OR = 1.759 CI: 1.028-3.003). CONCLUSIONS : The factors associated with the confirmation of BSF cases included an urban environment, age, presence of the A. sculptum vector, the collection of ticks from horses, the presence of a capybara population, and a dirty pasture environment. .

Serum dosage of CPK-MB in dogs with ST deviation by chemiluminescence / A dosagem sérica de CPK-MB em cães com desvio ST por quimiluminescência

Although frequently in humans, hypoxic and ischemic heart diseases are poorly documented in dogs, with only few reports of acute myocardial infarction (AMI) in this species. Some electrocardiographic findings might suggest myocardium hypoxia/ischemia, like ST segment elevation or depression, but there are no studies showing whether deviations in ST segment are associated to myocardial injury and serum increase of creatine phosphokinase (CPK-MB). In order to investigate possible myocardial cells injury in poor perfusion conditions, 38 dogs were studied, 20 with normal electrocardiogram and 18 with ST segment elevation or depression, recorded in lead II, at a paper speed of 50 mm/sec and N sensibility (1mV=1cm). Serum measurement of creatine phosphokinase isoenzyme MB (CPK-MB) in normal dogs (group 1) determined control values (in ng/mL), which were compared to those obtained from dogs with deviation (group 2), which allowed confirmation or not of myocardial injury. CPK-MB mean values obtained from dogs in groups 1 and 2 were 0.540ng/ml (SD±0.890)ng/mL and 0.440ng/mL (SD±1.106), respectively. At a significance level of 5%, the relation of CPK-MB with age, mass and total creatine phosphokinase (CPK-T) was not significant in groups 1 and 2. CPK-MB showed no difference, at 5% level, between groups 1 and 2. In conclusion, it is possible to use the human chemiluminescent immunometric assay kit in canine species and that hypoxia/ischemia revealed by ST segment deviation does not mean significant myocardium injury.(AU)

Embora frequente em humanos, as doenças hipóxicas e isquêmicas do coração são pouco relatadas em cães, com poucos relatos de infarto agudo do miocárdio (IAM) nesta espécie. Alguns achados no eletrocardiograma podem sugerir hipóxia/isquemia miocárdica, como a elevação ou depressão do segmento ST, mas não há estudos que mostram se os desvios do segmento ST estão associados a lesões miocárdicas e aumento sérico da creatinafosfoquinase (CPK-MB). A fim de investigar possíveis lesões nas células miocárdicas em condições de má perfusão, 38 cães foram estudados, 20 com eletrocardiograma normal e 18 com elevação ou depressão do segmento ST, registrados em papel, na derivação II, velocidade de 50 mm/s e sensibilidade N (1mV = 1cm). A mensuração da creatinafosfoquinase isoenzima MB (CPK-MB) em cães normais (grupo 1) determinou os valores controle (em ng/ml), que foram comparados com os obtidos a partir de cães com desvio (grupo 2), permitindo a confirmação ou não da lesão miocárdica. Os valores médios de CPK-MB obtidos de cães nos grupos 1 e 2 foram 0,540ng/ml (DP±0,890) e 0,440ng / ml (DP ± 1.106), respectivamente. A um nível de significância de 5%, a relação de CPK-MB com a idade, massa e creatinofosfoquinase total (CPK-T) não foi significativa nos grupos 1 e 2. Não houve diferenças na CPK-MB, ao nível de 5%, entre os grupos 1 e 2. Conclui-se que é possível utilizar o kit de ensaio imunométrico por quimioluminescência humano na espécie canina e que a hipoxia/isquemia revelada pelos desvios do segmento ST, não significa lesão miocárdica.(AU)

Protective effects of intermedin preconditioning on hypoxic injury in rat's cardiac myocytes / 法医学杂志

OBJECTIVE@#To observe the effects of intermedin preconditioning on hypoxic injury in rat's cardiac myocytes and to provide the hypothetical mechanism of sudden cardiac death in the field of forensic pathology.@*METHODS@#The H9c2 cultured rat cardiac myocytes were randomly divided into control group, hypoxia group and IMD group. The myocardial cell viability, cellular ultrastructure, intracellular calcium concentration and apoptosis rate were determined by MTT assay, transmission electron microscopy, laser scanning confocal microscope and flow cytometry, respectively.@*RESULTS@#Compared with the control group, cell viability obviously decreased with inner ultrastructure injury in the hypoxia group (P<0.05), while cell viability significantly increased in the IMD group by reducing the hypoxia injury of cardiac myocytes (P<0.05). Compared with the control group, [Ca2+]i (fluorescence intensity) and apoptosis rate significantly increased in the hypoxia group, but decreased in the IMD group (P<0.05).@*CONCLUSION@#IMD increases the cell survival rate and decreases the cell apoptosis inhibited by intracellular calcium overload from hypoxia. This finding may reveal the mechanism of protective effects of myocardial hypoxia, and provide a scientific basis for the identification sudden cardiac death.

Expression levels of sarcolemmal membrane repair proteins following prolonged exercise training in mice.

Membrane repair is a conserved cellular process, where intracellular vesicles translocate to sites of plasma membrane injury to actively reseal membrane disruptions. Such membrane disruptions commonly occur in the course of normal physiology, particularly in skeletal muscles due to repeated contraction producing small tears in the sarcolemmal membrane. Here, we investigated whether prolonged exercise could produce adaptive changes in expression levels of proteins associated with the membrane repair process, including mitsugumin 53/tripartite motif-containing protein 72 (MG53/TRIM72), dysferlin and caveolin-3 (cav3). Mice were exercised using a treadmill running protocol and protein levels were measured by immunoblotting. The specificity of the antibodies used was established by immunoblot testing of various tissue lysates from both mice and rats. We found that MG53/TRIM72 immunostaining on isolated mouse skeletal muscle fibers showed protein localization at sites of membrane disruption created by the isolation of these muscle fibers. However, no significant changes in the expression levels of the tested membrane repair proteins were observed following prolonged treadmill running for eight weeks (30 to 80 min/day). These findings suggest that any compensation occurring in the membrane repair process in skeletal muscle following prolonged exercise does not affect the expression levels of these three key membrane repair proteins.

Production of knowledge on myocardial, exercise andmenopause. Analysis of methodological approaches

Considering the importance of histological studies for the analysis of myocardial cell morphology and theeffects produced by this muscle exercise in postmenopausal women, a literature review was carried out toanalyze selected articles in PubMed, Medline, SciELO and Science Direct. 2001-2011 databases and to identifythe study design relating to morphological infarction, exercise and menopause published over the last 10 years.Materials and Methods:After the selection according to the proposed inclusion criteria, the journals andarticles were analyzed regarding the title, year of publication, country of origin, type of methodology, type ofauthorship and research subjects.Results:We foundthirty-four articles related to myocardium, menopauseand exercise from 2001-2011. In two of them the myocardium morphologically was evaluated, and in one ofthem there was a morphological and stereological cardiac muscle analysis.Conclusion: The main characteristicsof the publications are: multiple authorship, publications in journals from different areas, literature review andexperimental study as methodology, and all studies showed quantitative data analysis.

Morfologia e contratilidade em cardiomiócitos de ratos com baixo desempenho para o exercício físico / Morphology and contractility in cardiomyocytes of rats with low exercise performance

FUNDAMENTO: A capacidade aeróbica é fundamental para o desempenho físico, e a baixa capacidade aeróbica está relacionada ao desencadeamento de diversas doenças cardiovasculares. OBJETIVO: Comparar a contratilidade e a morfologia de cardiomiócitos isolados de ratos com baixo desempenho e desempenho padrão para o exercício físico. MÉTODOS: Ratos Wistar, com 10 semanas de idade, foram submetidos a um protocolo de corrida em esteira até a fadiga, e foram divididos em dois grupos: Baixo Desempenho (BD) e Desempenho Padrão (DP). Em seguida, após eutanásia, o coração foi removido rapidamente e, por meio de dissociação enzimática, os cardiomiócitos do ventrículo esquerdo foram isolados. O comprimento celular e dos sarcômeros e a largura dos cardiomiócitos foram medidos usando-se um sistema de detecção de bordas. Os cardiomiócitos isolados foram estimulados eletricamente a 1 e 3 Hz e a contração celular foi medida registrando-se a alteração do seu comprimento. RESULTADOS: O comprimento celular foi menor no grupo BD (157,2 ± 1,3µm; p < 0,05) em relação ao DP (161,4 ± 1,3 µm), sendo o mesmo resultado observado para o volume dos cardiomiócitos (BD, 25,5 ± 0,4 vs. DP, 26,8 ± 0,4 pL; p < 0,05). Os tempos para o pico de contração (BD, 116 ± 1 vs. DP, 111 ± 2ms) e para o relaxamento total (BD, 143 ± 3 vs. DP, 232 ± 3 ms) foram maiores no grupo BD. CONCLUSÃO: Conclui-se que os miócitos do ventrículo esquerdo dos animais de baixo desempenho para o exercício físico apresentam menores dimensões que os dos animais de desempenho padrão, além de apresentarem perdas na capacidade contrátil.

BACKGROUND: Aerobic capacity is essential to physical performance, and low aerobic capacity is related to the triggering of various cardiovascular diseases. OBJECTIVE: To compare the morphology and contractility of isolated rat cardiomyocytes with low performance and standard performance for exercise. METHODS: Wistar rats with 10 weeks of age underwent a protocol of treadmill running to fatigue, and were divided into two groups: Low Performance (LP) and Standard Performance (SP). Then, the animals were sacrificed, the heart was quickly removed and, by means of enzymatic dissociation, left ventricular cardiomyocytes were isolated. The cell and sarcomeres length and width of cardiomyocytes were measured using an edge detection system. The isolated cardiomyocytes were electrically stimulated at 1 and 3 Hz and cell contraction was measured by registering the change of their length. RESULTS: The cell length was shorter in the LP group (157.2 1.3µm; p < 0.05) compared to SP (161.4 1.3µm), and the same result was observed for the volume of cardiomyocytes (LP, 25.5 0.4. vs. SP, 26.8 ± 0.4 pL; p < 0.05). The time to peak contraction (LP, 116 1 vs. SP 111 2ms) and total relaxation (LP, 143 3 vs. SP 232 3ms) were higher in the LP group. CONCLUSION: We conclude that left ventricular myocytes of animals with low performance for exercise are smaller than animals with standard performance. In addition to that, they present losses in contractile capacity.

Development and characterization of two new cell lines from common carp, Cyprinus carpio (Linn)

Two new cell lines (CCF and CCH) were established from fin and heart tissues of common carp, Cyprinus carpio. The cells were optimally maintained in Leibovitz-15 medium supplemented with 10 percent fetal bovine serum (FBS) and 10 ng/ml of basic fibroblastic growth factor (bFGF). The effects of temperature, concentration of FBS and bFGF on the growth of CCF and CCH cells were examined. The temperature ranged from 24 to 32 °C for good growth of the cells. The growth rate of cells was higher in medium containing 10 percent FBS and the addition of bFGF to the medium significantly increased the growth rate. The CCF cells were found to be epithelial, while the CCH cells were fibroblastic in nature. The cytogenetic analysis of the cell lines revealed a diploid number of 100 chromosomes in C. carpio. The viability of CCF and CCH cell lines were 70 and 72 percent, respectively, after six months of storage in liquid nitrogen (-196 ° C). Molecular characterization of the cell lines using 16S rRNA and Cytochrome Oxidase Subunit I (COI) revealed the origin of the cell lines. These new cell lines will be useful for isolation of fish viruses and other in vitro biotechnological studies.

Strategies for ensuring that regenerative cardiomyocytes function properly and in cooperation with the host myocardium

In developed countries, in which people have nutrient-rich diets, convenient environments, and access to numerous medications, the disease paradigm has changed. Nowadays, heart failure is one of the major causes of death. In spite of this, the therapeutic efficacies of medications are generally unsatisfactory. Although whole heart transplantation is ideal for younger patients with heart failure, many patients are deemed to be unsuitable for this type of surgery due to complications and/or age. The need for therapeutic alternatives to heart transplantation is great. Regenerative therapy is a strong option. For this purpose, several cell sources have been investigated, including intrinsic adult stem or progenitor cells and extrinsic pluripotent stem cells. Most intrinsic stem cells seem to contribute to a regenerative environment via paracrine factors and/or angiogenesis, whereas extrinsic pluripotent stem cells are unlimited sources of cardiomyocytes. In this review, we summarize the various strategies for using regenerative cardiomyocytes including our recent progressions: non-genetic approaches for the purification of cardiomyocytes and efficient transplantation. We expect that use of intrinsic and extrinsic stem cells in combination will enhance therapeutic effectiveness.

High-Resolution Diffusion Tensor MR Imaging for Evaluating Myocardial Anisotropy and Fiber Tracking at 3T: the Effect of the Number of Diffusion-Sensitizing Gradient Directions

OBJECTIVE: We wanted to evaluate the effect of the number of diffusion-sensitizing gradient directions on the image quality for evaluating myocardial anisotropy and fiber tracking by using in vitro diffusion tensor MR imaging (DT-MRI). MATERIALS AND METHODS: The DT-MR images, using a SENSE-based echoplanar imaging technique, were acquired from ten excised porcine hearts by using a 3T MR scanner. With a b-value of 800 s/mm2, the diffusion tensor images were obtained for 6, 15 and 32 diffusion-sensitizing gradient directions at the midventricular level. The number of tracked fibers, the fractional anisotropy (FA), and the length of the tracked fibers were measured for the quantitative analysis. Two radiologists assessed the image quality of the fiber tractography for the qualitative analysis. RESULTS: By increasing the number of diffusion-sensitizing gradient directions from 6 to 15, and then to 32, the FA and standard deviation were significantly reduced (p < 0.01), and the number of tracked fibers and the length of the tracked fibers were significantly increased (p < 0.01). The image quality of the fiber tractography was significantly increased with the increased number of diffusion-sensitizing gradient directions (p < 0.01). CONCLUSION: The image quality of in vitro DT-MRI is significantly improved as the number of diffusion-sensitizing gradient directions is increased.

Caracterización de células serotoninérgicas en el tejido cardiaco fetal / Characterization of serotonergic cells in fetal heart tissue

Objetivo: Caracterizar morfológica y bioquímicamente células productoras de serotonina durante el desarrollo del tejido cardiaco. Material y métodos: Se utilizaron ratas gestantes de la cepa Wistar. A los días 10, 12, 16 y 20 de gestación se obtuvieron los fetos por cesárea, a los cuales se les disecaron los corazones, que se fijaron para los ensayos de inmunohistoquímica para triptófano- 5-hidroxilasa (Tph), además se efectuó Western Blot para la enzima; se determinó la concentración de serotonina y la actividad de Tph por cromatografía de líquidos de alta resolución. Los resultados fueron analizados mediante U de Mann-Whitney, aceptando un nivel de significación de p < 0.05. Resultados: En los cortes de corazón fetal, desde el día 10 de gestación se observaron células inmunorreactivas para Tph, con metacromasia en su interior. Fibras nerviosas inmunorreactivas para la misma enzima que hacen contacto probablemente con las células serotoninérgicas. La actividad enzimática y la concentración de la serotonina aumentaron con la edad gestacional, además, se encontró la proteína enzimática por Western- Blot en el corazón fetal de 16 días de gestación. Conclusiones: Se demostró la presencia de células productoras de serotonina en el miocardio fetal, cuyo fenotipo corresponde a mastocitos cardiacos, lo cual sugiere que la serotonina puede ser importante en el desarrollo del tejido cardiaco y que también participa en los mecanismos fisiopatológicos de los defectos cardiacos estructurales o en la predisposición a enfermedades cardiovasculares en el adulto.

BACKGROUND: We undertook this study to present biochemical and morphological characterization of serotonergic cells during fetal heart development. METHODS: Wistar rats (10, 12, 16 and 20 days of gestation) were used. After obtaining the fetuses by Cesarean section, the hearts were removed and fixed for immunohistochemical assay of tryptophan-5-hydroxylase (Tph), in addition to Western blot for enzyme. Serotonin concentration and Tph were also evaluated with high-performance liquid chromatography. Results were analyzed using Mann-Whitney U test with a significance level of p <0.05. RESULTS: Metachromatic cells immunoreactive for Tph were observed from day 10 of gestation. Nerve fibers were also labeled, apparently making contact with serotonergic cells. Tph activity was measurable and serotonin levels increased with gestational age. The presence of Tph protein was confirmed by Western blot on day 16. CONCLUSIONS: The present results support the existence of cells located in the fetal myocardium, capable of producing serotonin whose phenotype belongs to cardiac mast cells. Their presence in this tissue strongly suggests that serotonin may play a key role in normal and abnormal development of cardiac tissue.

Trypanosoma cruzi: parasite antigens sequestered in heart interstitial dendritic cells are related to persisting myocarditis in benznidazole-treated mice

We investigated whether sequestered Trypanosoma cruzi antigens found in heart interstitial dendritic cells (IDCs) contribute to the residual myocarditis found in mice following treatment with benznidazole, a specific chemotherapeutic drug. IDCs are antigen-presenting cells that are MHC-II-receptor dependent. Swiss mice were divided into two experimental groups: the 1st group was infected with the Colombian strain of T. cruzi, which is resistant to treatment with benznidazole, and the 2nd group was infected with clone 21SF-C 3, which has a medium susceptibility to the drug. Treatment of the Colombian strain group started on the 120th day post-infection and for the 21SF-C3 strain group treatment was started on the 90th day. In both groups, treatment lasted for 90 days. The animals were sacrificed either 150 or 200 days post-treatment. The myocardium was analysed by immunohistochemistry using anti-MAC3, 33D1, CD11b and CD11c monoclonal antibodies for IDCs or anti-T. cruzi purified antibodies. Parasite antigens were expressed on the IDC membranes in both treated and untreated mice. Myocarditis subsided following treatment, evidenced by both histological and morphometrical evaluation. A reduction in the number of IDCs carrying T. cruzi antigens in the treated group indicates that the elimination of parasites influences antigen presentation with concomitant decreases in inflammation. There is a correlation between the presence of T. cruzi antigens in these cells and the chronic focal, residual myocarditis seen in treated mice.

Safety of umbilical cord blood-derived mesenchymal stem cells [MSCs] following 5-azaserine induction and inhibition of human cardiac myocyte apoptosis by MSCs

To further study the safety and effect of the umbilical cord blood [UCB]-derived mesenchymal stem cells [MSCs] on apoptosis of human cardiac myocyte [HCM]. The UCB was collected at the time of delivery with informed consent obtained from 10 donors. The UCB-derived MSCs was treated with 5-azaserine [5-AZA], and further introduced differentiation into cardiomyocytes. The telomerase activity, G-banding patterns of chromosomal karyotypes, tumor formation in nude mice, reverse transcription polymerase chain reaction [RT-PCR], and the inhibited apoptosis of UCB-derived MSCs were further investigated. This study was carried out in the laboratory of Beijing Shijitan Hospital, Beijing, China and Inheritance Research Section of Chinese Medical Institute, Beijing, China from July 2005 to December 2007. The MSCs-derived from UCB were differentiated into cardiomyocytes in vitro, possessed telomerase activity after 5-AZA induction, and no abnormal chromosomal karyotypes were observed. Expression of p53, cyclinA, cdk2, beta-actin, C-fos, h-TERT and c-myc were similar in MSCs before and after 5-AZA treatment. There was no tumor formation injected into nude mice. The UCB-derived MSCs significantly inhibited apoptosis of human cardiomyocytes. Umbilical cord blood-derived MSCs are safe and effective source of cell-transplantation treatment, and can inhibit the apoptosis of human cardiomyocytes in co-cultured

Sodium tanshinone IIA sulfonate attenuates angiotensin II-induced collagen type I expression in cardiac fibroblasts in vitro

Cardiac fibrosis occurs after pathological stimuli to the cardiovascular system. One of the most important factors that contribute to cardiac fibrosis is angiotensin II (Ang II). Accumulating studies have suggested that reactive oxygen species (ROS) plays an important role in cardiac fibrosis and sodium tanshinone IIA sulfonate (STS) possesses antioxidant action. We therefore examined whether STS depresses Ang II-induced collagen type I expression in cardiac fibroblasts. In this study, Ang II significantly enhanced collagen type I expression and collagen synthesis. Meanwhile, Ang II depressed matrix metalloproteinase-1 (MMP-1) expression and activity. These responses were attenuated by STS. Furthermore, STS depressed the intracellular generation of ROS, NADPH oxidase activity and subunit p47(phox) expression. In addition, N-acetylcysteine the ROS scavenger, depressed effects of Ang II in a manner similar to STS. In conclusion, the current studies demonstrate that anti-fibrotic effects of STS are mediated by interfering with the modulation of ROS.

Modulation of the caveolin-3 localization to caveolae and STAT3 to mitochondria by catecholamine-induced cardiac hypertrophy in H9c2 cardiomyoblasts

We investigated the effect of phenylephrine (PE)- and isoproterenol (ISO)-induced cardiac hypertrophy on subcellular localization and expression of caveolin-3 and STAT3 in H9c2 cardiomyoblast cells. Caveolin-3 localization to plasma membrane was attenuated and localization of caveolin-3 to caveolae in the plasma membrane was 24.3% reduced by the catecholamine-induced hypertrophy. STAT3 and phospho-STAT3 were up-regulated but verapamil and cyclosporin A synergistically decreased the STAT3 and phospho-STAT3 levels in PE- and ISO-induced hypertrophic cells. Both expression and activation of STAT3 were increased in the nucleus by the hypertrophy. Immunofluorescence analysis revealed that the catecholamine-induced hypertrophy promoted nuclear localization of pY705-STAT3. Of interest, phosphorylation of pS727-STAT3 in mitochondria was significantly reduced by catecholamine-induced hypertrophy. In addition, mitochondrial complexes II and III were greatly down-regulated in the hypertrophic cells. Our data suggest that the alterations in nuclear and mitochondrial activation of STAT3 and caveolae localization of caveolin-3 are related to the development of the catecholamine-induced cardiac hypertrophy.

In vitro cardiogenesis can be initiated in human CD34+ cells.

BACKGROUND: The extensive damage that occurs in the cardiac tissue after myocardial infarct is the major concern in post infarct management. It is very well known that adult stem cells mobilized by administration of G-CSF result in homing of stem cells into the damaged myocardium. This is because of the fact that stem cells have the ability to proliferate and capacity to generate into multiple cell lineages. METHOD: A healthy donor was selected as per the guidelines given by the institutional ethical committee and Helsinki declaration. The donor was given G-CSF 5 microg/kg/day and stem cells were harvested from the peripheral blood using Fresenius ASTec204 cell separator. The PBSC were then evaluated by immunohistochemical staining using anti-human CD34 monoclonal antibodies. The cells were then cultured in DMEM with 10% FCS for 17 weeks and in vitro cardiogenesis was initiated by adding 4 microM/l 5'Azacytidine. RESULTS: In vitro cardiogenesis was initiated in pure CD34+ cells with 5' Azacytidine. The cells showed spontaneous beating after 24 hours of treatment and after 5 weeks, the cells connected with the adjoining cells by a myotube. In these cells, expression of myosin light chain (MLC2v) gene and GATA-4 transcription factor validated the development of cardiomyocytes. CONCLUSION: It is observed that the transplantation of autologous stem cells/fetal cardiomyocytes in the heart scar tissue developed due to infarct, limited the scar expansion, and prevented post infarct heart failures. Homing process due to the transplantation of autologous stem cells is time consuming; therefore, transplantation of cardiomyocytes developed from autologous stem cells could be the future method of correcting the infracted myocardium.

In vitro differentiation of embryonic stem cells into cardiac-like and neuronal-like cells / Indução de diferenciação in vitro de células-tronco embrionárias em células de tecido cardíaco e nervoso

Embryonic stem cells are pluripotent cell lines with the capacity of self-renewal and a broad differentiation plasticity. They are isolated from preimplantation embryos and can be cultured in vitro for long time without losing their pluripotency. Embryonic stem cells can also differentiate in vitro with the proper combination of growth and differentiation factors, cells will differentiate into more advanced stages of embryogenesis generating different adult cell type. In the present study, we induced the in vitro differentiation of mouse embryonic stem cells (line R1) into cardiomyocytes and neuronal cells. These differentiations were evaluated by reverse transcription-polymerase chain reaction to verify presence of tissue-specific markers.

Células-tronco embrionárias são linhagens celulares pluripotentes capazes de se multiplicar indefinidamente e com grande capacidade de diferenciação celular. São isoladas de embriões em estágio pré-implantacional e podem ser cultivadas por longo tempo em laboratório sem perder sua pluripotencialidade. Células-tronco embrionárias podem, ainda, se diferenciar in vitro através da adição de fatores de crescimento e diferenciação ao meio de cultivo. As células se diferenciarão em estágios mais avançados de embriogênese, gerando tipos diferentes de células adultas. No presente estudo, induzimos a diferenciação in vitro de células-tronco embrionárias de camundongos (linhagem R1) em células de tecido cardíaco e nervoso. A diferenciação foi avaliada pela reação em cadeia da polimerase precedida de transcrição reversa para verificar a presença de marcadores tecido-específicos.