SAMANTHA VIEIRA OMAE
Índice h a partir de 2011
4
Projetos de Pesquisa
Unidades Organizacionais
Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina
LIM/13 - Laboratório de Genética e Cardiologia Molecular, Hospital das Clínicas, Faculdade de Medicina
LIM/13 - Laboratório de Genética e Cardiologia Molecular, Hospital das Clínicas, Faculdade de Medicina
6 resultados
Resultados de Busca
Agora exibindo 1 - 6 de 6
conferenceObject Angiotensin II decreases the levels of PKA-mediated NHE3 phosphorylation in renal proximal tubule(2012) ROSSETTO, Silmara Larissa; QUEIROZ-LEITE, Gabriella Duarte; CRAJOINAS, Renato Oliveira; OMAE, Samantha V.; MALNIC, Gerhard; GIRARDI, Adriana C.NHE3 transport function is inhibited by PKA. Binding of angiotensin II (ANG II) to AT1 receptor has been reported to activate Gi-protein signaling pathway, resulting in the inhibition of adenylyl cyclase, and consequently, in decreased PKA activation. We therefore tested the hypothesis that decrement of PKA-mediated NHE3 phosphorylation is one of the mechanisms by which ANG II acutely stimulates NHE3 activity in renal proximal tubule. To this end, OKP cells were treated with 100 μM Dopamine (DOP) for 30 min in the presence or absence of 10–10 M ANG II for 5, 15, and 30 min; or only with ANG II for 30 min. Extrusion of H+ from OKP cells was measured. DOP significantly inhibited NHE3 activity (0.2013 ± 0.009 vs. 0.3036 ± 0.0019 pH units/min in control). Simultaneous incubation of DOP with ANG II for 15 (0.2347 ± 0.044 pH units/min) and 30 min (0.3295 ± 0.032 pH units/min) completely blocked this inhibitory effect. As expected, ANG II stimulated NHE3 activity. DOP increased the levels of NHE3 phosphorylated at the PKA consensus phosphorylation sites [serines 552 and 605] by 64 ± 8% and 288 ± 37% respectively vs. control. ANG II treatment for 15 and 30 min prevented this increase. PKA activity was also measured in these groups of cells. We found that PKA activity was significantly increased in cells treated with DOP for 30 min and in cells treated with DOP plus ANG II for 5 min. Longer incubation times with ANG II (15 and 30 min) in the presence of DOP restored PKA activity near to control levels. Losartan blocked all the effects of ANG II here reported. Collectively, these data suggest that inhibition of PKA activity leading to lower levels of endogenous phosphorylation of NHE3 is one of the mechanisms by which ANG II stimulates NHE3 activity in the proximal tubule.- Thioredoxin interacting protein genetic variation is associated with diabetes and hypertension in the Brazilian general population(2012) FERREIRA, Noely E.; OMAE, Samantha; PEREIRA, Abel; RODRIGUES, Mariliza V.; MIYAKAWA, Ayumi A.; CAMPOS, Luciene C. G.; SANTOS, Paulo C. J. L.; DALLAN, Luiz A.; MARTINEZ, Tania L.; SANTOS, Raul D.; MILL, Jose G.; KRIEGER, Jose E.; PEREIRA, Alexandre C.Objective: To investigate the relationship between TXNIP polymorphisms, diabetes and hypertension phenotypes in the Brazilian general population. Methods: Five hundred seventy-six individuals randomly selected from the general urban population according to the MONICA-WHO project guidelines were phenotyped for cardiovascular risk factors. A second, independent, sample composed of 487 family-trios from a different site was also selected. Nine TXNIP polymorphisms were studied. The potential association between TXNIP variability and glucose-phenotypes in children was also explored. TXNIP expression was quantified by real-time PCR in 53 samples from human smooth muscle cells primary culture. Results: TXNIP rs7211 and rs7212 polymorphisms were significantly associated with glucose and blood pressure related phenotypes. In multivariate logistic regression models the studied markers remained associated with diabetes even after adjustment for covariates. TXNIP rs7211 T/rs7212 G haplotype (present in approximately 17% of individuals) was significantly associated to diabetes in both samples. In children, the TXNIP rs7211 T/rs7212 G haplotype was associated with fasting insulin concentrations. Finally, cells harboring TXNIP rs7212 G allele presented higher TXNIP expression levels compared with carriers of TXNIP rs7212 CC genotype (p = 0.02). Conclusion: Carriers of TXNIP genetic variants presented higher TXNIP expression, early signs of glucose homeostasis derangement and increased susceptibility to chronic metabolic conditions such as diabetes and hypertension. Our data suggest that genetic variation in the TXNIP gene may act as a ""common ground"" modulator of both traits: diabetes and hypertension.
conferenceObject Characterization Of Pulmonary Artery Cells In Culture From Patients SuBMItted To Pulmonary Thromboendarterectomy In Sao Paulo, Brazil(2013) LAPA, M.; SALIBE FILHO, W.; OMAE, S.; BASSANEZE, V.; TEIXEIRA, R. O. B.; JATENE, F. B.; TERRA-FILHO, M.- Using gene-network landscape to dissect genotype effects of TCF7L2 genetic variant on diabetes and cardiovascular risk(2012) VAQUERO, Andre R.; FERREIRA, Noely E.; OMAE, Samantha V.; RODRIGUES, Mariliza V.; TEIXEIRA, Samantha K.; KRIEGER, Jose E.; PEREIRA, Alexandre C.Vaquero AR, Ferreira NE, Omae SV, Rodrigues MV, Teixeira SK, Krieger JE, Pereira AC. Using gene-network landscape to dissect genotype effects of TCF7L2 genetic variant on diabetes and cardiovascular risk. Physiol Genomics 44: 903-914, 2012. First published August 7, 2012; doi:10.1152/physiolgenomics.00030.2012.-The single nucleotide polymorphism (SNP) within the TCF7L2 gene, rs7903146, is, to date, the most significant genetic marker associated with Type 2 diabetes mellitus (T2DM) risk. Nonetheless, its functional role in disease pathology is poorly understood. The aim of the present study was to investigate, in vascular smooth muscle cells from 92 patients undergoing aortocoronary bypass surgery, the contribution of this SNP in T2DM using expression levels and expression correlation comparison approaches, which were visually represented as gene interaction networks. Initially, the expression levels of 41 genes (seven TCF7L2 splice forms and 40 other T2DM relevant genes) were compared between rs7903146 wild-type (CC) and T2DM-risk (CT + TT) genotype groups. Next, we compared the expression correlation patterns of these 41 genes between groups to observe if the relationships between genes were different. Five TCF7L2 splice forms and nine genes showed significant expression differences between groups. RXR alpha gene was pinpointed as showing the most different expression correlation pattern with other genes. Therefore, T2DM risk alleles appear to be influencing TCF7L2 splice form's expression in vascular smooth muscle cells, and RXR alpha gene is pointed out as a treatment target candidate for risk reduction in individuals with high risk of developing T2DM, especially individuals harboring TCF7L2 risk genotypes.
- Vascular smooth muscle cells exhibit a progressive loss of rigidity with serial culture passaging(2012) DINARDO, Carla Luana; VENTURINI, Gabriela; OMAE, Samantha Vieira; ZHOU, Enhua H.; MOTTA-LEAL-FILHO, Joaquim Maurcio da; DARIOLLI, Rafael; KRIEGER, Jose Eduardo; ALENCAR, Adriano Mesquita; PEREIRA, Alexandre CostaOne drawback of in vitro cell culturing is the dedifferentiation process that cells experience. Smooth muscle cells (SMC) also change molecularly and morphologically with long term culture. The main objective of this study was to evaluate if culture passages interfere in vascular SMC mechanical behavior. SMC were obtained from five different porcine arterial beds. Optical magnetic twisting cytometry (OMTC) was used to characterize mechanically vascular SMC from different cultures in distinct passages and confocal microscopy/western blotting, to evaluate cytoskeleton and extracellular matrix proteins. We found that vascular SMC rigidity or viscoelastic complex modulus (G) decreases with progression of passages. A statistically significant negative correlation between G and passage was found in four of our five cultures studied. Phalloidin-stained SMC from higher passages exhibited lower mean signal intensity per cell (confocal microscopy) and quantitative western blotting analysis showed a decrease in collagen I content throughout passages. We concluded that vascular SMC progressively lose their stiffness with serial culture passaging. Thus, limiting the number of passages is essential for any experiment measuring viscoelastic properties of SMC in culture.
- Porcine Adipose Tissue-Derived Mesenchymal Stem Cells Retain Their Proliferative Characteristics, Senescence, Karyotype and Plasticity after Long-Term Cryopreservation(2013) DARIOLLI, Rafael; BASSANEZE, Vinicius; NAKAMUTA, Juliana Sanajotti; OMAE, Samantha Vieira; CRISTINA, Luciene; CAMPOS, Gastalho; KRIEGER, Jose E.We and others have provided evidence that adipose tissue-derived mesenchymal stem cells (ASCs) can mitigate rat cardiac functional deterioration after myocardial ischemia, even though the mechanism of action or the relevance of these findings to human conditions remains elusive. In this regard, the porcine model is a key translational step, because it displays heart anatomic-physiological features that are similar to those found in the human heart. Towards this end, we wanted to establish the cultural characteristics of porcine ASCs (pASCs) with or without long-term cryostorage, considering that allogeneic transplantation may also be a future option. Compared to fresh pASCs, thawed cells displayed 90-95% viability and no changes in morphological characteristics or in the expression of surface markers (being pASCs characterized by positive markers CD29(+); CD90(+); CD44(+); CD140b(+); CD105(+); and negative markers CD31(-); CD34(-); CD45(-) and SLA-DR-; n = 3). Mean population doubling time was also comparable (64.26 +/- 15.11 hours to thawed cells vs. 62.74 +/- 18.07 hours to fresh cells) and cumulative population doubling increased constantly until Passage 10 (P10) in the entire cell population, with a small and gradual increase in senescence (P5, 3.25% +/- 0.26 vs. 3.47%+/- 0.32 and P10, 9.6%+/- 0.29 vs. 10.67%+/- 1.25, thawed vs. fresh; SA-beta-Gal staining). Chromosomal aberrations were not observed. In addition, under both conditions pASCs responded to adipogenic and osteogenic chemical cues in vitro. In conclusion, we have demonstrated the growth characteristics, senescence, and the capacity of pASCs to respond to chemical cues in vitro and have provided evidence that these properties are not influenced by cryostorage in 10% DMSO solution.