Chromosome mapping of retrotransposon AviRTE in a neotropical bird species: Trogon surrucura (Trogoniformes; Trogonidae).

Avian genomes are characterized as being more compact than other amniotes, with less diversity and density of transposable elements (TEs). In addition, birds usually show bimodal karyotypes, exhibiting a great variation in diploid numbers. Some species present unusually large sex chromosomes, possibly due to the accumulation of repetitive sequences. Avian retrotransposon-like element (AviRTE) is a long interspersed nuclear element (LINE) recently discovered in the genomes of birds and nematodes, and it is still poorly characterized in terms of chromosomal mapping and phylogenetic relationships. In this study, we mapped AviRTE isolated from the Trogon surrucura genome into the T. surrucura (TSU) karyotype. Furthermore, we analyzed the phylogenetic relationships of this LINE in birds and other vertebrates. Our results showed that the distribution pattern of AviRTE is not restricted to heterochromatic regions, with accumulation on the W chromosome of TSU, yet another species with an atypical sex chromosome and TE hybridization. The phylogenetic analysis of AviRTE sequences in birds agreed with the proposed phylogeny of species in most clades, and allowed the detection of this sequence in other species, expanding the distribution of the element.

Silencing the OCT4-PG1 pseudogene reduces OCT-4 protein levels and changes characteristics of the multidrug resistance phenotype in chronic myeloid leukemia.

Cancer stem cells show epigenetic plasticity and intrinsic resistance to anti-cancer therapy, rendering capable of initiating cancer relapse and progression. Transcription factor OCT-4 regulates various pathways in stem cells, but its expression can be regulated by pseudogenes. This work evaluated how OCT4-PG1 pseudogene can affect OCT-4 expression and mechanisms related to the multidrug resistance (MDR) phenotype in FEPS cells. Considering that OCT-4 protein is a transcription factor that regulates expression of ABC transporters, level of gene expression, activity of ABC proteins and cell sensitivity to chemotherapy were evaluated after OCT4-PG1 silencing. Besides we set up a STRING network. Results showed that after OCT4-PG1 silencing, cells expressed OCT-4 gene and protein to a lesser extent than mock cells. The gene and protein expression of ABCB1, as well as its activity were reduced. On the other hand, ALOX5 and ABCC1 genes was increased even as the activity of this transporter. Moreover, the silencing cells become sensitive to two chemotherapics tested. The network structure demonstrated that OCT4-PG1 protein interacts directly with OCT-4, SOX2, and NANOG and indirectly with ABC transporters. We conclude that OCT4-PG1 pseudogene plays a key role in the regulation OCT-4 transcription factor, which alters MDR phenotype in the FEPS cell line.

N-acetylcysteine inhibits Mancozeb-induced impairments to the normal development of zebrafish embryos.

Mancozeb (MZ), a manganese/zinc-containing ethylene-bis-dithiocarbamate (EBCD) fungicide has been claimed to present low acute toxicity and short environmental persistence, however, its effects on embryogenesis in non-target organisms is unclear. Here, we used zebrafish embryos (5 hpf) to assess the potential embryotoxic effects induced by MZ (up to 72 hpf) as well as the role of reactive oxygen species (ROS) in this process by pre-treatment with a classical antioxidant (N-acetylcysteine, NAC). Markers of reactive oxygen species production (ROS), glutathione (GSH) levels and glutathione S-transferase (GST) activity were measured along with genotoxicity (comet assay), cell death (Acridine Orange) and behavioral parameters (spontaneous movement, touch stimulation and swimming response), in order to determine potential mechanisms of embryotoxicity. According to results, MZ was able to induce morphological abnormalities such as body axis distortion, DNA damage, cell death, increased ROS generation and changes in behavioral endpoints during zebrafish development. All these toxic effects were inhibited by the pre-treatment with NAC indicating a key role of redox unbalance during MZ-induced embryotoxicity. At least in our knowledge, this is the first report on the deleterious effect of MZ to the normal embryogenesis of zebrafish. In addition, the importance of ROS generation during this pathophysiological condition was highlighted.

Multiple sex chromosome system in penguins (Pygoscelis, Spheniscidae).

Penguins are classified in the order Sphenisciformes into a single family, Spheniscidae. The genus Pygoscelis Wagler, 1832, is composed of three species, Pygoscelis antarcticus Forster, 1781, P. papua Forster, 1781 and P. adeliae Hombron & Jacquinot, 1841. In this work, the objective was to describe and to compare the karyotypes of Pygoscelis penguins contributing genetic information to Sphenisciformes. The metaphases were obtained by lymphocyte culture, and the diploid number and the C-banding pattern were determined. P. antarcticus has 2n = 92, P. papua 2n = 94 and P. adeliae exhibited 2n = 96 in males and 2n = 95 in females. The difference of diploid number in P. adeliae was identified as a multiple sex chromosome system where males have Z1Z1Z2Z2 and females Z1Z2W. The C-banding showed the presence of a heterochromatic block in the long arm of W chromosome and Z2 was almost entirely heterochromatic. The probable origin of a multiple system in P. adeliae was a translocation involving the W chromosome and the chromosome ancestral to Z2. The comparison made possible the identification of a high karyotype homology in Sphenisciformes which can be seen in the conservation of macrochromosomes and in the Z chromosome. The karyotypic divergences in Pygoscelis are restricted to the number of microchromosomes and W, which proved to be highly variable in size and morphology. The data presented in this work corroborate molecular phylogenetic proposals, supporting the monophyletic origin of penguins and intraspecific relations.

Molecular screening for 22Q11.2 deletion syndrome in patients with congenital heart disease.

Few studies have investigated the prevalence of 22q11.2 deletion syndrome (22q11.2DS) among patients with isolated heart defects or nonconotruncal heart defects. Polymerase chain reaction (PCR) followed by length polymorphism restriction fragment analysis (RFLP) is useful for low-cost molecular diagnosis and screening. This cross-sectional study included 392 patients with congenital heart disease, described clinical features, and performed PCR-RFLP for analysis of polymorphism in three loci with a high heterozygosity rate located in the typically deleted region of 1.5 megabases. Heterozygosity excluded 22q11.2DS. Patients with homozygosity for the three markers underwent multiplex ligation-dependent probe amplification (MLPA) and fluorescence in situ hybridization (FISH) for the final diagnosis, estimating the prevalence of 22q11.2DS. The use of PCR-RFLP excluded 22q11.2DS in 81.6 % (n = 320) of 392 patients. Of the remaining 72 patients, 65 underwent MLPA, showing 22q11.2DS in five cases (prevalence, 1.27 %). Four of these five patients underwent FISH, confirming the MLPA results. All five patients with the deletion had heart diseases commonly found with 22q11.2DS (interrupted aortic arch, persistent truncus arteriosus, tetralogy of Fallot, and ventricular septal defect plus atrial septal defect). Two patients had congenital extracardiac anomaly (one with arched palate and micrognathia and one with hypertelorism). Three patients reported recurrent respiratory infections, and one patient reported hypocalcemia. All were underweight or short in stature for their age. This study contributed to showing the prevalence of 22q11.2DS in patients with any congenital heart disease, with or without other features of the syndrome. Patients with 22q11.2DS may not have all the major features of the syndrome, and those that are found may be due to the heart defect.

Genetic modification of mesenchymal stem cells.

Mesenchymal stem cells (MSC) are currently considered the most promising type of adult stem cells for therapeutic applications, because they can be easily isolated from the bone marrow and other tissues, and manipulated for different applications. The genetic transformation of MSC using genes that enhance their homing ability, as well as their proliferation and survival capacities when transplanted to sites of injury, is an important alternative to improve MSC function, especially for tissue regeneration. This chapter describes protocols for the transformation of MSC using plasmid vectors by lipofection and electroporation, as well as retroviral vectors representing viral transformations.

Congenital heart diseases in a reference service: clinical evolution and associated illnesses.

BACKGROUND: Several factors, which include prenatal diagnosis and availability of new therapeutic procedures, have contributed to change the profile of patients with congenital heart disease (CHD). Knowing these changes is important to a better health care. OBJECTIVES: Description of profile of patients with CHD in a reference service in the State of Rio Grande do Sul, Brazil. METHODS: It is a cross-sectional study including 684 patients with CHD in a service of pediatric cardiology from January 2007 to May 2008. We interviewed the patients (and/or their parents) and examined these patients (congenital malformations, anthropometric measures). Moreover, their charts were reviewed in order to detail heart diseases, procedures and echocardiography. RESULTS: Patients were from 16 days to 66 years old, 51.8% were female, and 93.7% were Caucasian. The mean age at diagnosis was 15.8 +/- 46.8 months. Ventricular septal defect, patent ductus arteriosus and Tetralogy of Fallot were the most prevalent CHD. 59.1% of examined patients, whose average age was 44.3 +/- 71.2 months, have been undergoing therapeutic procedures; 30.4% had congenital extracardiac malformations; and 12 patients had genetic syndrome. Regarding development, 46.6% had low weight and height gain, and 13.7% had neuropsychomotor delay. Furthermore, 18.4% had family history of congenital heart disease. CONCLUSIONS: Neuropsychomotor delay and low weight and height gain may be related to CHD. Establishing a profile of patients with CHD, who were treated at an institution of reference, may function as a basis in which health care of this population can be planed appropriately.

Cardiopatias congênitas em um serviço de referência: evolução clínica e doenças associadas / Congenital heart diseases in a reference service: clinical evolution and associated illnesses

FUNDAMENTO: Inúmeros fatores vêm contribuindo para a mudança do perfil do paciente com cardiopatia congênita (CC), incluindo o diagnóstico pré-natal e a disponibilidade de novos procedimentos terapêuticos. O conhecimento dessas mudanças é fundamental para um melhor atendimento. OBJETIVOS: Descrever o perfil dos pacientes com CC de um serviço de referência no Estado do Rio Grande do Sul, Brasil. MÉTODOS: Trata-se de um estudo transversal, com 684 pacientes portadores de CC, em um serviço de cardiologia pediátrica, de janeiro de 2007 a maio de 2008. Esses pacientes foram entrevistados (e/ou seus pais) e examinados (malformações congênitas, medidas antropométricas), além de terem seus prontuários revisados para mais detalhes sobre as cardiopatias, procedimentos e ecocardiografia. RESULTADOS: A idade dos pacientes variou de 16 dias a 66 anos, sendo 51,8 por cento do sexo feminino, com 93,7 por cento de brancos. A idade média determinada pelo diagnóstico foi de 15,8 ± 46,8 meses. As CC mais prevalentes foram a comunicação interventricular, a persistência do canal arterial e a Tetralogia de Fallot. Dos pacientes analisados, 59,1 por cento, com idade média de 44,3 ± 71,2 meses, realizaram algum procedimento terapêutico; 30,4 por cento tinham malformações congênitas extracardíacas; e 12 pacientes tinham síndrome genética comprovada. Quanto ao desenvolvimento, 46,6 por cento tiveram atraso ponderoestatural e 13,7 por cento atraso neuropsicomotor. Além disso, 18,4 por cento apresentaram história familiar de cardiopatia congênita. CONCLUSÕES: O atraso neuropsicomotor e o baixo ganho ponderoestatural podem estar associados às CC. Estabelecer um perfil dos pacientes com CC atendidos em uma instituição de referência pode servir como base para o planejamento adequado do atendimento desta população.

BACKGROUND: Several factors, which include prenatal diagnosis and availability of new therapeutic procedures, have contributed to change the profile of patients with congenital heart disease (CHD). Knowing these changes is important to a better health care. OBJECTIVES: Description of profile of patients with CHD in a reference service in the State of Rio Grande do Sul, Brazil. METHODS: It is a cross-sectional study including 684 patients with CHD in a service of pediatric cardiology from January 2007 to May 2008. We interviewed the patients (and/or their parents) and examined these patients (congenital malformations, anthropometric measures). Moreover, their charts were reviewed in order to detail heart diseases, procedures and echocardiography. RESULTS: Patients were from 16 days to 66 years old, 51.8 percent were female, and 93.7 percent were Caucasian. The mean age at diagnosis was 15.8 ± 46.8 months. Ventricular septal defect, patent ductus arteriosus and Tetralogy of Fallot were the most prevalent CHD. 59.1 percent of examined patients, whose average age was 44.3 ± 71.2 months, have been undergoing therapeutic procedures; 30.4 percent had congenital extracardiac malformations; and 12 patients had genetic syndrome. Regarding development, 46.6 percent had low weight and height gain, and 13.7 percent had neuropsychomotor delay. Furthermore, 18.4 percent had family history of congenital heart disease. CONCLUSIONS: Neuropsychomotor delay and low weight and height gain may be related to CHD. Establishing a profile of patients with CHD, who were treated at an institution of reference, may function as a basis in which health care of this population can be planed appropriately. (Arq Bras Cardiol 2010; 94(3):313-318)

Extracts of marine sponge Polymastia janeirensis induce oxidative cell death through a caspase-9 apoptotic pathway in human U138MG glioma cell line.

We have studied the apoptotic pathway activated in response to marine sponge extracts of Polymastia janeirensis. The effect on intracellular ROS production was also examined. Exposure of U138MG glioma cell line to doses higher than 5 microg/mL has decreased glioma cell viability, with an IC(50) <15 microg/mL for both aqueous and organic extracts. However, extracts at higher doses (50 and 100 microg/mL) have stronger cytotoxic effects, decreasing more than 90% of glioma cell viability. The antioxidant Trolox (100 microM) reversed the cell death percentage induced by extracts at 10 and 25 microg/mL. The type of cell death induced by such high doses was predominantly necrosis, while a high percentage of apoptotic glioma cells was found at 10 microg/mL. Moreover, inhibition of caspase-8 with Z-IETD (a caspase-8 inhibitor) had no effect on the amount of apoptosis induced by 10 microg/mL, but inhibition of caspase-9 with Z-LEHD (a caspase-9 inhibitor) decreased apoptosis. We also observed a dose-dependent increase in ROS production, and similarly to effects observed on viability of glioma cells, and on cell death, higher doses also had more severe effects. Co-treatment with Trolox significantly reduced ROS production by extracts at doses lower than 50 microg/mL. This is a first report demonstrating that marine sponge extracts of P. janeirensis induce oxidative cell death through a caspase-9 apoptotic pathway.

Brazilian marine sponge Polymastia janeirensis induces apoptotic cell death in human U138MG glioma cell line, but not in a normal cell culture.

Marine sponges have been prominently featured in the area of cancer research. Here, we examined the anti-proliferative effects of crude extracts (aqueous and organic) of the Brazilian marine sponge Polymastia janeirensis in the U138MG human glioma cell line. Moreover, we examined the effects of extracts on selective cytotoxicity in the glioma cells in comparison with a normal cell culture. Exposure of glioma cells to treatments (24 h) resulted in cell number decrease at all doses tested, with both aqueous and organic extracts (IC(50) <20 and <30 microg/ml, respectively). Parallel to this result, sponge extracts reduced glioma cell viability (IC(50) <15 microg/ml for both extracts). However, higher doses (50 and 100 microg/ml) induced a stronger cytotoxic effect when compared to the lower dose tested (10 microg/ml), inhibiting more than 80% of cellular growth and viability. Propidium iodide uptake and flow cytometry analysis further showed that sponge extracts caused necrosis in the glioma cell line at higher doses, while a high percentage of apoptotic glioma cells were observed at 10 microg/ml. Moreover, apoptosis was prevented by the pan-caspase inhibitor Z-VAD, suggesting that marine sponge extracts, at lower doses, induce caspase-dependent apoptosis in U138MG glioma cells. Surprisingly the extracts herein tested were more effective than temozolomide, a potent inductor of apoptosis used for the treatment of malignant gliomas. Furthermore, our results suggested a selectivity cytotoxic effect on glioma cell line in comparison with a normal cell culture, since the effect on viability found in glioma cells was not observed in astrocyte cultures with the lower dose (10 microg/ml). Thus, this marine sponge may be considered a good candidate for development of new cancer medicines with antitumor activity against gliomas.

Antiproliferative effect of quercetin in the human U138MG glioma cell line.

Recent epidemiological and dietary intervention studies in animals and humans have suggested that diet-derived flavonoids, in particular quercetin, may play a beneficial role by preventing or inhibiting tumorigenesis. The aim of this study was to evaluate whether quercetin may act differently on cancer and normal neuronal tissue. In order to investigate this, the U138MG human glioma cell line and hippocampal organotypic cultures were used. The study showed that quercetin induced in glioma cell cultures results in (a) a decrease in cell proliferation and viability, (b) necrotic and apoptotic cell death, (c) arrest in the G2 checkpoint of the cell cycle, and (d) a decrease of the mitotic index. Furthermore, we demonstrated that while quercetin promotes cancer regression it was able to protect the hippocampal organotypic cultures from ischemic damage. To sum up, our results suggest that quercetin induced growth inhibition and cell death in the U138MG human glioma cell line, while exerting a cytoprotective effect in normal cell cultures.

Interaction between normal and CML hematopoietic progenitors and stroma influences abnormal hematopoietic development.

Several studies have shown defective progenitor-stromal interactions in chronic myeloid leukemia (CML), and adhesive defects induced by BCR/ABL have been described. However, controversial results have been reported, and the role of the stroma in abnormal development of the hematopoietic system is not clear. In this study, CML hematopoietic and irradiated stromal cells were co-cultured in different combinations for 10 or 21 days. Maintenance of viable cells was dependent both on the sources of hematopoietic progenitors and stromal adherent layers, with normal cells performing better than their leukemic counterparts. The frequency of CD34(+) CD38(-) cells in the non-adherent fraction was more related to the source of hematopoietic cells than of stroma, and hematopoietic cells from normal subjects showed better performance. The simultaneous analysis of different combinations of normal and leukemic precursor cells and stromal layers, as done in the present work, suggests that the outcome of the interaction depends on characteristics of both compartments. This hematopoietic system development is influenced by intrinsic qualities of both hematopoietic stem cells and the supportive stroma.