FLAVIA RAMOS DE SIQUEIRA
Projetos de Pesquisa
Unidades Organizacionais
LIM/16 - Laboratório de Fisiopatologia Renal, Hospital das Clínicas, Faculdade de Medicina
11 resultados
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- Igf1 DNA methylation, epigenetics, and low-salt diet in fetal programming(2019) SIQUEIRA, F. R. De; FURUKAWA, L. N. S.; HEIMANN, J. C.All cells of an organism share the same DNA sequence from the time they are stem cells up to the time they are fully differentiated, distinct greatly in relation to the profile of expressed genes. Changes in gene expression which do not involve changes in DNA sequence of the nucleotides are currently known as an epigenetic phenomenon. Epigenetic changes play a fundamental role in the human gene expression and in the mechanism of association between events that occur early in life and alterations in adult life. Thus, in response to an adverse environment in which pregnant women are exposed during the perinatal or neonatal period, epigenetic modifications may lead to alterations in growth and metabolism in later life. Modification of histones (proteins found in eukaryotic cell nucleus) and DNA methylation (a process by which methyl groups are added to DNA) are the major epigenetic mechanisms involved in the regulation of gene expression. Maternal insults, mainly inadequate nutrition that may occur during sensitive or critical periods of fetal development (periods of rapid cell division), can program changes in the structure and functionality of cells, tissues, and/or organ systems. These changes may result in premature consequences in the offspring such as low birth weight and/or chronic diseases (hypertension, insulin resistance, obesity, etc.) in adulthood. A low-salt diet during pregnancy has been associated with low birth weight and chronic diseases in adult offspring, at least in the experimental setting. The expression of genes as insulin-like growth factors is regulated in a tissue-specific manner and can be altered by nutritional and endocrine conditions in utero. It is known that the major mediator of fetal growth is insulin-like growth factor type 1 (IGF-1) and insulin. The low birth weight may be due to low serum IGF-1 and/or by Igf1 epigenetic changes in fetus in response to low-salt intake during pregnancy. This observation might underlie the altered offspring phenotypes in this model since growth and insulin sensitivity are modulated by hepatic IGF-1. A low birth weight is related to low Igf1 gene expression and high Igf1 DNA methylation levels induced by low-salt intake during pregnancy. The variation in the IGF-1 serum levels may be due to changes in Igf1 gene promoter methylation. This concept is supported by increased methylation that is often associated with reduced gene expression. The methylation of genes changed as the offspring aged, indicating that epigenetic changes can occur and can be reversed during postnatal life. Further studies are needed to confirm or not if the observed results are reproducible in humans in order to recommend low dietary salt consumption during pregnancy. © Springer Nature Switzerland AG 2019. All rights reserved.
- FAM3B/PANDER inhibits cell death and increases prostate tumor growth by modulating the expression of Bcl-2 and Bcl-X-L cell survival genes(2018) MACIEL-SILVA, Paula; CALDEIRA, Izabela; SANTOS, Icaro de Assis; CARREIRA, Ana Claudia Oliveira; SIQUEIRA, Flavia Ramos; ANTONIOLI, Eliane; GOLDBERG, Anna Carla; BELIZARIO, Jose Ernesto; GARAY-MALPARTIDA, Humberto MiguelBackground: FAM3B/PANDER is a novel cytokine-like protein that induces apoptosis in insulin-secreting beta-cells. Since in silico data revealed that FAM3B can be expressed in prostate tumors, we evaluated the putative role of this cytokine in prostate tumor progression. Methods: FAM3B expression was analyzed by quantitative PCR in tumor tissue clinical samples and prostate tumor cell lines. Culture growth and viability of DU145 cell line were evaluated after treatment with either exogenous FAM3B protein obtained from conditioned media (CM) of 293 T cells overexpressing FAM3B or a recombinant FAM3B protein produced in a bacterial host. DU145 cells overexpressing FAM3B protein were produced by lentiviral-mediated transduction of full-length FAM3B cDNA. Cell viability and apoptosis were analyzed in DU145/FAM3B cells after treatment with several cell death inducers, such as TNF-alpha, staurosporine, etoposide, camptothecin, and serum starvation conditions. Anchorage-independent growth in soft agarose assay was used to evaluate in vitro tumorigenicity. In vivo tumorigenicity and invasiveness were evaluated by tumor xenograft growth in nude mice. Results: We observed an increase in FAM3B expression in prostate tumor samples when compared to normal tissues. DU145 cell viability and survival increased after exogenous treatment with recombinant FAM3B protein or FAM3B-secreted protein. Overexpression of FAM3B in DU145 cells promoted inhibition of DNA fragmentation and phosphatidylserine externalization in a time and dose-dependent fashion, upon apoptosis triggered by TNF-alpha. These events were accompanied by increased gene expression of anti-apoptotic Bcl-2 and Bcl-XL, decreased expression of pro-apoptotic Bax and diminished caspase-3, -8 and -9 proteolytic activities. Furthermore, inhibition of Bcl-2 antiapoptotic family proteins with small molecules antagonists decreases protective effects of FAM3B in DU145 cells. When compared to the respective controls, cells overexpressing FAM3B displayed a decreased anchorage-independent growth in vitro and increased tumor growth in xenografted nude mice. The immunohistochemistry analysis of tumor xenografts revealed a similar anti-apoptotic phenotype displayed by FAM3B-overexpressing tumor cells. Conclusions: Taken together, by activating pro-survival mechanisms FAM3B overexpression contributes to increased resistance to cell death and tumor growth in nude mice, highlighting a putative role for this cytokine in prostate cancer progression.
bookPart 0 Citação(ões) na Scopus Impact of low-salt diet(2019) SIQUEIRA, F. R. De; OLIVEIRA, K. C. De; HEIMANN, J. C.; FURUKAWA, L. N. S.Studies in experimental animals and in groups of humans and epidemiological studies have shown that the sodium chloride or salt (sodium, Na, NaCl) plays an important role mainly in the regulation of blood pressure and represents an important environmental factor involved in the genesis of cardiovascular diseases. Therefore, salt intake in the population has been a constant concern. Variable blood pressure responses to different content in sodium intake are found in experimental hypertension models and in humans, and the reasons for such heterogeneity are not fully elucidated. The reduction of dietary sodium intake is recommended by public health as one of the non-medicated treatments for hypertension and consequently reducing the risk of cardiovascular diseases. However, some studies have demonstrated side effects of salt dietary restriction, reporting changes in glucose metabolism (hyperinsulinemia and insulin resistance), and these alterations are gender and time specific in experimental and population studies. © Springer Nature Switzerland AG 2019.- Comparison of clinical, biochemical and histomorphometric analysis of bone biopsies in dialysis patients with and without fractures(2019) SANTOS, Melissa F. P.; HERNANDEZ, Mariel J.; OLIVEIRA, Ivone B. de; SIQUEIRA, Flavia R.; DOMINGUEZ, Wagner V.; REIS, Luciene M. dos; CARVALHO, Aluizio B.; MOYSES, Rosa M. A.; JORGETTI, VandaChronic kidney disease-mineral bone disorders (CKD-MBD) are associated with increased risk of fracture. Studies report about 3% of fractures in CKD patients, and these occur earlier than in the general population, namely 16 and 13years earlier for men and women, respectively. Better understanding of the pathophysiology offractures would probably contribute to new therapeutic approaches. This study aimed to evaluatereport oflong bone fractures from a bone biopsies bank from patients on hemodialysis and compare clinical and biochemical characteristics, as well as the results of the histomorphometric analysis of trabecular and cortical bone of these patients with a control group (without fractures), paired for age, gender, and time on hemodialysis. Bone proteins (SOST, DMP1 and MEPE) were evaluated by immunohistochemistry. Seventeen patients with fracture and controls were studied. Fracture prevalence was 0.82/1000 patients/year. Serum phosphorus levels were significantly lower in the fracture group. Histomorphometric analysis revealed that all the patients had high turnover disease,and the fracture group had smaller volume and trabecular thickness, greater osteoid surface, smaller eroded surface, smaller mineralizing surface, formation rate and longer mineralization lag time when compared to controls; the DMP1 expression in the cortical bone was smaller and the SOST in the trabecular bone was higher in fractured patients. As conclusion, we found low prevalence of fractures. Both groups had high turnover disease, but the fractured ones presentedmore impairedbone microarchitecture, as well as lower formation and greatermineralization defect. Bone proteins expression correlated with parameters involved in bone remodeling.
- Folic acid supplementation modulates offspring genes involved in energy metabolism: In vivo study(2022) PAULA, B. M. F. de; PINHEL, M. A. de Souza; NICOLETTI, C. F.; NONINO, C. B.; SIQUEIRA, F.; VANNUCCHI, H.Background: Nutritional epigenetics involves essential mechanisms for proper embryonic development in mammals. Changes in this stage cause various metabolic disorders. Under healthy conditions, epigenetic processes and adequate homeostasis, especially energy metabolism, are balanced. However, interruption or imbalance of metabolic homeostasis, or both, leads to several pathologies, such as insulin resistance, cardiovascular diseases, and obesity. This study investigates the methylation and expression patterns of the peroxisome proliferator-activated receptor gamma (Pparγ) and forkhead Box 1 (Foxo1) genes in rat offspring submitted to folate-deficient or folate-supplemented diet. Methods: Groups of male and female Wistar rat offspring (n=40 per group, 3 groups) were fed folate-normal (control), a folate-deficient, or a folate-supplemented diet (2.0, 0.5, or 8.0 mg of folic acid/kg of feed, respectively) for 13 weeks. The diet was the same diet the mothers had received during pregnancy and lactation. Liver, white adipose tissue (WAT), and brown adipose tissue (BAT) samples were collected. Specific commercial kits were used to extract RNA, DNA, and protein from these samples. Gene expression, DNA methylation, and protein expression were analyzed by polymerase chain reaction (PCR), Pyrosequencing, and Western Blot, respectively. Results: In liver, the Pparγ and Foxo1 genes did not differ in terms of DNA methylation; however, Pparγ gene expression was higher (P=0.03) in the folate-supplemented diet group than in the other groups. Hepatic Pparγ protein expression was higher (P=0.00) in the folate-supplemented and folate-deficient diet groups than in the control diet group. Hepatic Foxo1 protein expression was lower (P=0.01) in the folate-supplemented diet group than in the other groups. In WAT, Foxo1 methylation was lower (P=0.00) in the folate-supplemented diet group than in the control diet group; Pparγ methylation was lower (P=0.02) in the folate-deficient diet group than in the control diet group; and Foxo1 gene expression was higher (P=0.01) in the folate-supplemented diet group than in the folate-deficient diet group. In BAT, the folate-deficient and folate-supplemented diet groups had lower Pparγ gene expression (P=0.00) and protein (P=0.00) expression than the control diet group. Conclusion: Depending on offspring sex and tissue, folate-supplemented diet generally modulates genes in a beneficial way because these genes are involved in energy metabolism and may participate in some pathways related to metabolic diseases. © 2022
- Effect of variations in dietary Pi intake on intestinal Pi transporters (NaPi-IIb, PiT-1, and PiT-2) and phosphate-regulating factors (PTH, FGF-23, and MEPE)(2018) ANITELI, Tatiana Martins; SIQUEIRA, Flavia Ramos de; REIS, Luciene Machado dos; DOMINGUEZ, Wagner Vasques; OLIVEIRA, Elizabeth Maria Costa de; CASTELUCCI, Patricia; MOYSES, Rosa Maria Affonso; JORGETTI, VandaHyperphosphatemia is a common condition in patients with chronic kidney disease (CKD) and can lead to bone disease, vascular calcification, and increased risks of cardiovascular disease and mortality. Inorganic phosphate (P-i) is absorbed in the intestine, an important step in the maintenance of homeostasis. In CKD, it is not clear to what extent P-i absorption is modulated by dietary P-i. Thus, we investigated 5/6 nephrectomized (Nx) Wistar rats to test whether acute variations in dietary P-i concentration over 2 days would alter hormones involved in P-i metabolism, expression of sodium-phosphate cotransporters, apoptosis, and the expression of matrix extracellular phosphoglycoprotein (MEPE) in different segments of the small intestine. The animals were divided into groups receiving different levels of dietary phosphate: low (Nx/LPi), normal (Nx/NPi), and high (Nx/HPi). Serum phosphate, fractional excretion of phosphate, intact serum fibroblast growth factor 23 (FGF-23), and parathyroid hormone (PTH) were significantly higher and ionized calcium was significantly lower in the Nx/HPi group than in the Nx/LPi group. The expression levels of NaPi-IIb and PiT-1/2 were increased in the total jejunum mucosa of the Nx/LPi group compared with the Nx/HPi group. Modification of P-i concentration in the diet affected the apoptosis of enterocytes, particularly with P-i overload. MEPE expression was higher in the Nx/HPi group than in the Nx/NPi. These data reveal the importance of early control of P-i in uremia to prevent an increase in serum PTH and FGF-23. Uremia may be a determining factor that explains the expressional modulation of the cotransporters in the small intestine segments.
conferenceObject Low salt intake during pregnancy alters glucose metabolism and DNA methylation in the offspring(2014) SIQUEIRA, F. R.; FURUKAWA, L. N. S.; OLIVEIRA, I. B.; HEIMANN, J. C.- Glucose metabolism and hepatic Igf1 DNA methylation are altered in the offspring of dams fed a low-salt diet during pregnancy(2016) SIQUEIRA, Flavia R.; FURUKAWA, Luzia N. S.; OLIVEIRA, Ivone B.; HEIMANN, Joel C.A low-salt (LS) diet during pregnancy has been linked to insulin resistance in adult offspring, at least in the experimental setting. However, it remains unclear if this effect is due to salt restriction during early or late pregnancy. To better understand this phenomenon, 12-week-old female Wistar rats were fed a LS or normal-salt (NS) diet during gestation or a LS diet during either the first (LS10) or second (LS20) half of gestation. Glucose tolerance test, HOMA-IR, gene expression analysis and DNA methylation measurements were conducted for the Insr, Igf1, Igf1r, Ins1 and Ins2 genes in the livers of neonates and in the liver, white adipose tissue and muscle of 20-week-old male offspring. Birth weight was lower in the IS20 and IS animals compared with the NS and LS10 rats. In the liver, the Igf1 levels in the LS10, LS20 and IS neonates were lower than those in the NS neonates. Methylation of the Insr, Igf1r, Ins1 and Ins2 genes was influenced in a variable manner by low salt intake during pregnancy. Increased liver Igf1 methylation was observed in the LS and LS20 neonates compared with their NS and LS10 counterparts. Glucose intolerance was observed in adult offspring as an effect of low salt intake over the duration of pregnancy. Compared to the NS animals, the HOMA-IR was higher in the 12-week-old IS and 20-week-old LS-10 rats. Based on these results, it appears that the reason a LS diet during pregnancy induces a low birth weight is its negative correlation with Igf1 DNA methylation in neonates.
- Effect of parathyroidectomy on bone tissue biomarkers and body composition in patients with chronic kidney disease and secondary hyperparathyroidism(2021) SIQUEIRA, Flavia Ramos de; OLIVEIRA, Karin Carneiro de; DOMINGUEZ, Wagner Vasques; TRUYTS, Cesar Augusto Madid; MOYSES, Rosa Maria Affonso; REIS, Luciene Machado dos; JORGETTI, VandaBackground/objective Loss of renal function may induce secondary hyperparathyroidism (s-HPT), which triggers several complications leading to an extreme decline in quality of life and increased mortality in affected patients. We evaluated whether parathyroidectomy (PTx), as surgical treatment for s-HPT, modifies body composition, and hormones involved in the protein-energy metabolism of affected patients. Subjects/methods Overall, 30 s-HPT patients were evaluated at two times, before PTx (pre PTx) and 6 months after PTx (post PTx). Patients were evaluated by biochemistry analysis, anthropometry, electrical bioimpedance (BIA), food intake diary, handgrip strength, and modified global subjective nutritional assessment (SGA). Results After PTx, patients showed decreased serum levels of total and ionic calcium, as well as decreased alkaline phosphatase and PTH, and increased 25 (OH) vitamin D. These results demonstrate that PTx was efficient to correct part of the mineral disorder. We also observed an increase in caloric intake, body weight, body mass index (BMI), phase angle, handgrip strength, SGA score, and a decreasing in the percentage of weight loss. The osteocalcin concentration of both carboxylated (cOC) and undercarboxylated form was diminished post PTx. The cOC correlated with bone metabolism markers and SGA score. Conclusions PTx modified body composition improving nutritional status and preventing the progression of weight loss with increased of energy intake, BMI, handgrip strength, phase angle of BIA, and SGA score. The present study also suggests an association of cOC with bone markers and SGA score. Further studies are needed to better clarify these associations with larger sample size.
conferenceObject Glucose metabolism and DNA methylation of offspring are altered by maternal sodium restriction(2013) SIQUEIRA, Flavia Ramos; PhuongSon Nguyen; KOBZIK, Lester; OLIVEIRA, Ivone Braga de; HEIMANN, Joel Claudio; FURUKAWA, Luzia Naoko ShinoharaObjective: To evaluate glucose metabolism of adult offspring of dams fed low sodium diet during pregnancy. Methods: Female Wistar rats (n= 6 – 8/group) were fed low (LS- 0.15%) or normal (NS-1.3% NaCl) salt diet since the 1st day of gestation until delivery or LS during 1st (LS10) or 2 nd half of gestation (LS20). Body weight (BW), circulating glucose, insulin, leptin and C-peptide levels, glucose (GTT) and insulin tolerance test (ITT) and leptin receptor (LR) methylation were measured in male (M) and female (F) offspring at 12 weeks of age Results (mean±SEM, p< 0.05): BW, at birth (g, n=14 – 27/group) (M: NS = 6.5±0.1, LS = 5.5±0.1, LS10 = 6±0.1, LS20 = 4.8±0.1, F: NS = 6±0.2, LS = 5±0.1, LS10 = 6±0.1, LS20 = 4±0.1) was lower in LS, LS10 and LS20 than in NS, while at adulthood it was not different. Glucose was higher in LS (M=115±3; F=110±4) than in the other groups (M: NS=103±1; LS10=100±2; LS20=96±2; F:NS=101±2; LS10=100±2; 108±2). C-peptide was higher in LS (M=1117±152; F=509±27) than in NS (M=375±41; F=233±63) and lower in LS20 (M=97±15; F=76±9) compared to LS10 (M=528±112; F=378±45).Glucose was higher in LS M and F at 5 minutes of the GTT compared to NS offspring. Leptin, insulin, and ITT were not different. But LR methylation was increased in LS20. Conclusion: Sodium restriction during pregnancy leads to low birth weight and to modifications of glucose metabolism and LR methylation.