Avalia??o da atividade da frutose-1,6-bisfosfato em c?lulas GRX expostas a ferro livre

Made available in DSpace on 2015-04-14T14:51:35Z (GMT). No. of bitstreams: 1 461390.PDF: 2830978 bytes, checksum: c3b746f15a8c1946dc08a31f60e01821 (MD5) Previous issue date: 2014-03-10Hereditary hemochromatosis (HH) is a genetic disease where iron balance is deregulated and this metal accumulates in the liver, causing toxic effects and fibrosis. Fibrosis is an exacerbated wound-healing response with extracellular matrix (ECM) deposition. Hepatic stellate cells (HSC), when activated, are the main responsible for ECM production. Fructose-1,6-bisphosphate (FBP) is a sugar and possess innumerous beneficial effects, like enhance cell antioxidant potential, protects liver from damage and reverts the phenotype of activated HSC. Because of this, we aimed to test the effects of FBP in immortalized HSC line (GRX) exposed to free iron (Fe) tempting to simulate what occurs in patients with HH.Fe (1mg/L) treatment for 8 days increased cell growth, whereas Fe + FBP (1mg/L + 0.6mM) decreased cell proliferation to levels below of control. LDH activity, apoptosis rate and cell cycle were not altered in any group. Oil Red-O (ORO) staining showed a decrease in lipid content when GRX cells were Fe-treated (1mg/L) for 8 days. In Fe + FBP (1mg/L + 0.6mM), GRX cells showed increased lipid content and characteristics of quiescent HSC. PPAR-γ expression was diminished on Fe group and same as control on Fe + FBP group. On the contrary, Fe treatment rose Col-1 expression and Fe + FBP reversed it to control levels. TGF-β1 was unaltered in Fe group. However, on Fe + FBP group, TGF-β1 levelswas far bellow of control and Fe-treated group, showing an antifibrotic activity. FBP didn t present antioxidant activity by DPPH assay. Ferrozine assay showed a decreased absorbance after 120 min in all FBP-tested doses, demonstrating that FBP is an iron chelator. These data demonstrate that FBP reverse the phenotype of GRX cells even when in Fepresence and that this could be caused by regulation of PPAR-γ and COL-1. In conclusion, FBP diminished the growth rate and reversed the phenotype of GRX cell, showing a possible antifibrotic effect.Hemocromatose heredit?ria (HH) ? uma doen?a gen?tica onde o balan?o do ferro est? desregulado e esse metal se acumula no f?gado, causando efeitos t?xicos e, principalmente, fibrose. Fibrose ? uma resposta de cicatriza??o exacerbada com dep?sito de matriz extracelular (ECM). C?lulas estreladas hep?ticas (HSC) quando ativadas s?o as maiores respons?veis pela produ??o de ECM. Frutose-1,6-bisfosfato (FBP) ? um a??car e possui in?meros efeitos ben?ficos, como melhorar o potencial antioxidante da c?lula, proteger o f?gado de les?o e reverter o fen?tipo de HSC ativadas. Por causa disso, nosso objetivo foi testar os efeitos da FBP em uma linhagem imortalizada de HSC (GRX) expostas a ferro livre (Fe), na tentativa de simular o que ocorre em pacientes com HH.O tratamento com Fe (1mg/L) por 8 dias aumentou a prolifera??o celular enquanto o tratamento com Fe + FBP (1mg/L + 0.6mM) a diminuiu para n?veis menores que os do controle. A atividade da LDH, taxa de apoptose e ciclo celular n?o foi alterada em nenhum grupo. A colora??o com OilRed-O (ORO) mostrou uma diminui??o na quantidade de lip?dio intracelular quando as c?lulas foram tratadas com Fe por 8 dias. No grupo Fe + FBP, houve um aumento do conte?do lip?dico e as c?lulas apresentaram caracter?sticas morfol?gicas de c?lulas quiescentes. A express?o de PPAR-γ foi diminu?da no grupo Fe e igual ao controle no grupo Fe + FBP. Ao contr?rio, o Fe aumentou os n?veis de express?o de Col?geno tipo I (Col-1) e o tratamento concomitante com FBP reverteu esse efeito, ficando igual ao controle. A produ??o de TGF-β1 se manteve inalterada no grupo Fe e foi menor que o controle no tratamento com Fe + FBP, mostrando uma atividade antifibr?tica da FBP. O teste de DPPH mostrou que a FBP n?o possui atividade antioxidante em nenhuma dose testada. O teste de Ferrozine mostrou uma diminui??o da absorb?ncia depois de 120 minutos de incuba??o de FBP + Fe em todas as doses testadas, mostrando que a FBP ? um quelante de ferro.Esses dados demonstram que FBP reverte o fen?tipo das c?lulas GRX mesmo quando em presen?a do Fe e que isso pode ser causado pela regula??o da express?o do PPAR-γ e COL-1.Em conclus?o, a FBP diminuiu o crescimentoe reverteu o fen?tipo de c?lulas GRX, mostrando um poss?vel efeito antifibr?tico

Fructose-1,6-bisphosphate prevents pulmonary fibrosis by regulating extracellular matrix deposition and inducing phenotype reversal of lung myofibroblasts.

Pulmonary fibrosis (PF) is the result of chronic injury where fibroblasts become activated and secrete large amounts of extracellular matrix (ECM), leading to impaired fibroblasts degradation followed by stiffness and loss of lung function. Fructose-1,6-bisphosphate (FBP), an intermediate of glycolytic pathway, decreases PF development, but the underlying mechanism is unknown. To address this issue, PF was induced in vivo using a mouse model, and pulmonary fibroblasts were isolated from healthy and fibrotic animals. In PF model mice, lung function was improved by FBP as revealed by reduced collagen deposition and downregulation of ECM gene expression such as collagens and fibronectin. Fibrotic lung fibroblasts (FLF) treated with FBP for 3 days in vitro showed decreased proliferation, contraction, and migration, which are characteristic of myofibroblast to fibroblast phenotype reversal. ECM-related genes and proteins such as collagens, fibronectin and α-smooth muscle actin, were also downregulated in FBP-treated FLF. Moreover, matrix metalloproteinase (MMP) 1, responsible for ECM degradation, was produced only in fibroblasts obtained from healthy lungs (HLF) and FBP did not alter its expression. On the other hand, tissue inhibitor of metalloproteinase (TIMP)-1, a MMP1 inhibitor, and MMP2, related to fibroblast tissue-invasion, were predominantly produced by FLF and FBP was able to downregulate its expression. These results demonstrate that FBP may prevent bleomycin-induced PF development through reduced expression of collagen and other ECM components mediated by a reduced TIMP-1 and MMP2 expression

Assessment of alamandine in pulmonary fibrosis and respiratory mechanics in rodents

INTRODUCTION: Pulmonary fibrosis (PF) is characterized by an accelerated decline in pulmonary function and has limited treatment options. Alamandine (ALA) is a recently described protective peptide of the renin-angiotensin system (RAS) with essential tasks in several conditions. Our group previously demonstrated that ALA is reduced by 365% in the plasma of patients with idiopathic PF, and thus, it is plausible to believe that stimulation of this peptide could represent an important therapeutic target. In this sense, this study investigates the effects of ALA in an experimental model of PF. MATERIALS AND METHODS: Bleomycin (BLM) was administrated in Wistar rats, and these fibrotic animals were treated with ALA for 14 days. Body weight, histology, respiratory, and hemodynamic parameters were analyzed to study the effects of ALA. RESULTS: ALA treatment attenuated the development of fibrosis (P < 0.0001), reduced respiratory system elastance (P < 0.0001), and preserved weight gain (P < 0.0001) in fibrotic animals without affecting the autonomic control of blood pressure and heart rate. CONCLUSION: The data from this study demonstrate the potential of ALA to alleviate pulmonary fibrosis and improve respiratory system mechanics in vivo. The promising results encourage more detailed investigations of the potential of ALA as a future and efficient antifibrotic

El Eco de Santiago : diario independiente: Año XVI Número 9135 - 1911 Diciembre 28

Background: During radiation therapy, unwanted scatter to healthy tissues outside the target field may occur. Children and adolescents are more sensitive to radiation injury, and the thyroid gland is particularly susceptible to these effects. Purpose: To assess acute changes in thyroid function and volume in children and adolescents undergoing radiotherapy for a variety of non-thyroid cancers. Materials and Methods: Thirty-one children and adolescents underwent radiation therapy of various body areas in which the thyroid was not included. Thyroid-stimulating hormone (TSH), thyroxine (T4), free thyroxine (fT4), triiodothyronine (T3), anti-thyroperoxidase antibodies and thyroglobulin were measured before, on the last day and at 1 and 3 months after the end of radiotherapy. Ultrasound scans were taken and 6- and 24-hour¹³¹I uptake was measured before and after treatment. The scattered dose to the thyroid region was estimated with a treatment planning system or measured with thermoluminescent dosimeters. Results: The median radiation dose scattered to the thyroid was 296∙6 cGy (IQR 16∙7–1,709∙0). Levels of TSH (p=0∙575), T4 (p=0∙950), fT4 (p=0∙510), T3 (p=0∙842), thyroglobulin (p=0∙620) and anti-thyroid peroxidase antibodies (p=0∙546) were statistically similar at all four time points. There were no differences between pre- and post-radiotherapy thyroid volume and ¹³¹I uptake (p=0∙692 and 0∙92, respectively). Conclusion: More sensitive methods may be required to ascertain whether acute injury to the follicular epithelium occurs with lower radiation doses scattered to the thyroid

Therapeutic effect of Baccharis anomala DC. extracts on activated hepatic stellate cells

The therapeutic potential of Baccharis anomala DC. extracts was evaluated through its cytotoxic and antiproliferative effect and their phenotypic reversion property in activated hepatic stellate cells (HSCs). Baccharis anomala is distributed in Brazil (southeastern and south regions) and used for diuretic effect in folk medicine. Four fractions were obtained from the fractionation of the methanolic extract. Fractions III and IV decreased cell proliferation without increasing cell necrosis markers levels and induced cell cycle arrest in G1 phase. Fraction III induced phenotypic reversion through PPAR-γ activation pathway, while fraction IV did not alter PPAR-α/γ expression levels, suggesting that there is an independent PPAR-α/γ pathway involved. Hydroxybenzoic, chlorogenic and coumaric acids were identified. Fractions III and IV showed antiproliferative effect and ability to induce reversion of activated phenotype of HSCs