Navegando por Palavras-chave "dna damage"
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- ItemSomente MetadadadosAnálise dos aspectos funcionais dos espermatozoides e do perfil proteômico de plasma seminal de homens tabagistas(Universidade Federal de São Paulo (UNIFESP), 2014-02-12) Antoniassi, Mariana Pereira [UNIFESP]; Bertolla, Ricardo Pimenta Bertolla [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Objectives: To evaluate the effect of smoking on sperm functional aspects, semen oxidative stress and seminal plasma proteomic profile. Method: A cross-sectional observational study including 20 nonsmokers patients with normal semen quality, according to the World Health Organization (2010) (control group), and 20 smoking patients (study group). Beyond semen analysis, sperm function tests were performed on each patient: evaluation of DNA integrity by alkaline Comet assay; analysis of mitochondrial activity using 3,3' - diaminobenzidine (DAB) staining; and evaluation of acrosomal integrity by PNA (Peannut Agglutinin) binding to the outer acrosomal membrane. The seminal plasma was used to assess the level of oxidative stress by TBARS (Thiobarbituric acid reactive substances) quantification and label-free quantitative proteomic analysis by LC-MS/MS. Groups were compared using a Student?s T test (p <0.05), considering a minimum fold-change of 2.0 (or maximum of 0.5). Results: The group of smokers presented higher percentage of DNA damage (Comet class III and IV), partially and fully inactive mitochondria (DAB class III and IV) and non-intact acrosomes when compared to the control group. No difference in the level of oxidative stress among groups was observed. With respect to proteomic analysis, 422 proteins were identified and quantified, of which one protein was absent (Mammaglobin-B), 6 proteins were underexpressed (Prolargin, Poly(rC)- binding protein 1, Bile salt-activated lipase, Carbonyl reductase [NADPH] 1, Phospholipase A2, membrane associated, CD44 antigen) and 3 proteins were overexpressed among smokers (S100-A9, Neutrophil gelatinase-associated lipocalin e Alpha-1-acid glycoprotein 1). Conclusions: Cigarette smoking alters the functional quality of sperm and the seminal plasma proteomic profile of men, but does not alter the levels of oxidative stress. The overexpressed proteins have functions related to the metabolism of steroids and derivatives of arachidonic acid, as well as preservation of the extracellular scaffold. Among the overexpressed proteins, we highlight the immune function.
- ItemSomente MetadadadosEstudo das acetilações da histona h4 em trypanosoma cruzi(Universidade Federal de São Paulo (UNIFESP), 2015-05-27) Ramos, Thiago Cesar Prata [UNIFESP]; Schenkman, Sergio Schenkman [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Histones have a series of post-translational modifications such as acetylation, methylation, fosforizações, ADP-ribosilações and ubiquitinações, that modulate access of these factors regulating replication processes, repair and recombination of DNA and transcription of mRNA. Histones are conserved in most eukaryotes. However, trypanosoma, which include protozoan parasites that early diverged during evolution, have very different histones, differing in sequence, charge and / or size when compared to their counterparts in eukaryotes. In addition, trypanosomatides have specific mechanisms of control of gene expression. In our laboratory we found that the acetylated histone 4 can be in three different lysines (K4, K10 and K14) and obtained antibodies that specifically recognize each of these modifications. Unpublished results from our group show that acetylation at K10 and K14 vary during the cell cycle and in states where there is DNA repair. In this project, we aim to understand the role of these changes, especially in K10 and K14 in Trypanosoma cruzi. For this we plan to: 1) analyze the effect of deacetylase inhibitors, 2) change the susceptibility of histone H4 expressing this modified protein in the parasite itself, 3) to evaluate the effect on the over-expression of acetylation and knockout of proteins involved in repair DNA, 4) identify acetylases and deacilases directly involved in these changes, and 5) generate lines that over-express or have decreased expression for these acetylases. Together, we hope to understand the relationship between acetylation of histone H4 and replication processes, DNA repair and transcription Trypanosoma.