Modulação da expressão da proteína XPA em resposta ao tratamento com azul de metileno fotossensibilizado

Reactive oxygen species (ROS) are produced by aerobic metabolism and react with biomolecules, such as lipids, proteins and DNA. In high concentration, they lead to oxidative stress. Among ROS, singlet oxygen (1O2) is one of the main ROS involved in oxidative stress and is one of the most reactive forms of molecular oxygen. The exposure of some dyes, such as methylene blue (MB) to light (MB+VL), is able to generate 1O2 and it is the principle involved in photodynamic therapy (PDT). 1O2 e other ROS have caused toxic and carcinogenic effects and have been associated with ageing, neurodegenerative diseases and cancer. Oxidative DNA damage is mainly repaired by base excision repair (BER) pathway. However, recent studies have observed the involvement of nucleotide excision repair (NER) factors in the repair of this type of injury. One of these factors is the Xeroderma Pigmentosum Complementation Group A (XPA) protein, which acts with other proteins in DNA damage recognition and in the recruitment of other repair factors. Moreover, oxidative agents such as 1O2 can induce gene expression. In this context, this study aimed at evaluating the response of XPA-deficient cells after treatment with photosensitized MB. For this purpose, we analyzed the cell viability and occurrence of oxidative DNA damage in cells lines proficient and deficient in XPA after treatment with MB+VL, and evaluated the expression of this enzyme in proficient and complemented cells. Our results indicate an increased resistance to treatment of complemented cells and a higher level of oxidative damage in the deficient cell lines. Furthermore, the treatment was able to modulate the XPA expression up to 24 hours later. These results indicate a direct evidence for the involvement of NER enzymes in the repair of oxidative damage. Besides, a better understanding of the effects of PDT on the induction of gene expression could be provided

Papel da proteína de reparo XPC na regulação das proteínas de reparo APE1, OGG1 e PARP-1 em células humanas e de camundongos

studies using UV as a source of DNA damage. However, even though unrepaired UV-induced DNA damages are related to mutagenesis, cell death and tumorigenesis, they do not explain phenotypes such as neurodegeneration and internal tumors observed in patients with syndromes like Xeroderma Pigmentosum (XP) and Cockayne Syndrome (CS) that are associated with NER deficiency. Recent evidences point to a role of NER in the repair of 8-oxodG, a typical substrate of Base Excision Repair (BER). Since deficiencies in BER result in genomic instability, neurodegenerative diseases and cancer, it was investigated in this research the impact of XPC deficiency on BER functions in human cells. It was analyzed both the expression and the cellular localization of APE1, OGG1 e PARP-1, the mainly BER enzymes, in different NER-deficient human fibroblasts. The endogenous levels of these enzymes are reduced in XPC deficient cells. Surprisingly, XP-C fibroblasts were more resistant to oxidative agents than the other NER deficient fibroblasts, despite presenting the highest of 8-oxodG. Furthermore, subtle changes in the nuclear and mitochondrial localization of APE1 were detected in XP-C fibroblasts. To confirm the impact of XPC deficiency in the regulation of APE1 and OGG1 expression and activity, we constructed a XPC-complemented cell line. Although the XPC complementation was only partial, we found that XPC-complemented cells presented increased levels of OGG1 than XPC-deficient cells. The extracts from XPC-complemented cells also presented an elevated OGG1 enzimatic activity. However, it was not observed changes in APE1 expression and activity in the XPCcomplemented cells. In addition, we found that full-length APE1 (37 kDa) and OGG1- α are in the mitochondria of XPC-deficient fibroblasts and XPC-complemented fibroblasts before and after induction of oxidative stress. On the other hand, the expression of APE1 and PARP-1 are not altered in brain and liver of XPC knockout mice. However, XPC deficiency changed the APE1 localization in hypoccampus and hypothalamus. We also observed a physical interaction between XPC and APE1 proteins in human cells. In conclusion, the data suggest that XPC protein has a role in the regulation of OGG1 expression and activity in human cells and is involved mainly in the regulation of APE1 localization in mice. Aditionally, the response of NER deficient cells under oxidative stress may not be only associated to the NER deficiency per se, but it may include the new functions of NER enzymes in regulation of expression and cell localization of BER proteins

Systemic inflammatory response indicators in rabbits (Oryctolagus cuniculus) experimentally infected with sporulated oocysts of Eimeria stiedai (Apicomplexa: Eimeriidae)

Hemograms and acute-phase proteins in adult male New Zealand White rabbits that had been experimentally infected orally with sporulated oocysts of Eimeria stiedai were evaluated over a 28-day period. Fifty animals were used, divided into two groups: group A infected with 1 x 10(4) sporulated oocysts of E. stiedai and group B inoculated with distilled water. on the seventh day after infection, the infected animals presented anemia and leukocytosis with neutrophilia and monocytosis. Protein fractionation by means of electrophoresis identified 19 acute-phase proteins with molecular weights ranging from 24 to 238 kD. Ceruloplasmin, transferrin and haptoglobin showed high levels on the seventh day after infection, with gradual increases in their concentrations until the end of the experimental period. Thus, from the data of the present study, E. stiedai is considered to be a pyogenic etiological agent for which the infection level can be monitored through the leukocyte count and serum concentrations of ceruloplasmin, transferrin and haptoglobin, and these can be recommended as complementary tests.

Adenosine deaminase activity as a biochemical marker of inflammatory response in goats infected by caprine arthritis-encephalitis virus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Kinetics of cellular component in inflammatory response induced by different stimuli in the swim bladder of pacu, Piaractus mesopotamicus Holmberg 1887 (Characidae)

The present study assessed the kinetics of cell accumulation at the site of inflammation induced by thioglycolate, Escherichia coli lipopolysaccharide (LPS) and heat-inactivated Aeromonas hydrophila, in the pacu, Piaractus mesopotamicus (Characidae), swim bladder. A quantitative, as well as qualitative, assessment was done of all the cells present in the exudate at 6, 24, and 48 h (n = 8) after inoculation of inflammatory agents. The results show that the thioglycolate was the irritant to induce higher total inflammatory cell accumulation when compared to the control group, 6 h after insult (P < 0.05). Inoculation of heat-inactivated Aeromonas hydrophila induced progressive accumulation of total inflammatory cells, with cell number peaking after 24 h and being significantly higher than observed in the other groups (P < 0.05). Injection of LPS also induced greater cell accumulation when compared to the control group (P < 0.05), although in lower numbers than those induced by the other two irritants. All irritants injected induced significantly greater accumulation of lymphocytes and thrombocytes when compared to the control group (P < 0.05).

Vitamin C and endogenous cortisol in foreign-body inflammatory response in pacus

O objetivo deste trabalho foi avaliar o efeito da suplementação com vitamina C no aumento da atividade de macrófagos e células gigantes multinucleadas (CGM), em pacus mantidos em duas densidades de estocagem. O experimento foi realizado em parcelas subdivididas, em arranjo fatorial 2x2x3 com: 0 e 500 mg kg-1 de vitamina C; densidade de estocagem de 5 e 20 kg m-3; e tempos de avaliação de 3, 6 e 12 dias após o implante subcutâneo (DPI) de lamínulas de vidro. Foram determinados o número de macrófagos e de CGM, bem como os níveis de cortisol e glicose no plasma. O número de macrófagos e de CGM com 2 a 5 núcleos foi significativamente maior nos peixes suplementados com vitamina C, à densidade 5 kg m-3, aos 3 DPI, em relação aos não suplementados. Constatou-se menor quantidade de macrófagos e CGM em peixes com baixa concentração plasmática de cortisol. A suplementação com 500 mg de vitamina C por quilograma de ração beneficia a atividade de macrófagos em inflamações do tipo corpo estranho, e a elevada concentração de cortisol circulante tem efeito supressor nesta resposta.

Characterization of the acute inflammatory response in the hybrid tambacu (Piaractus mesopotamicus male × Colossoma macropomum female) (Osteichthyes)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Caracterização de dois cDNAs homológos e uma AP endonuclease em cana-de-açúcar

The genome of all organisms is subject to injuries that can be caused by endogenous and environmental factors. If these lesions are not corrected, it can be fixed generating a mutation which can be lethal to the organisms. In order to prevent this, there are different DNA repair mechanisms. These mechanisms are well known in bacteria, yeast, human, but not in plants. Two plant models Oriza sativa and Arabidopsis thaliana had the genome sequenced and due to this some DNA repair genes have been characterized. The aim of this work is to characterized two sugarcane cDNAs that had homology to AP endonuclease: scARP1 and scARP3. In silico has been done with these two sequences and other from plants. It has been observed domain conservation on these sequences, but the cystein at 65 position that is a characteristic from the redox domain in APE1 protein was not so conservated in plants. Phylogenetic relationship showed two branches, one branch with dicots and monocots sequence and the other branch with only monocots sequences. Another approach in order to characterized these two cDNAs was to construct overexpression cassettes (sense and antisense orientation) using the 35S promoter. After that, these cassettes were transferred to the binary vector pPZP211. Furthermore, previously in the laboratory was obtained a plant from nicotiana tabacum containing the overexpression cassette in anti-sense orientation. It has been observed that this plant had a slow development and problems in setting seeds. After some manual crossing, some seeds were obtained (T2) and it was analyzed the T2 segregation. The third approach used in this work was to clone the promoter region from these two cDNAs by PCR walking. The sequences obtained were analyzed using the program PLANTCARE. It was observed in these sequences some motives that may be related to oxidative stress response

Analysis of systemic inflammatory response in the carcinogenic process of uterine cervical neoplasia

The inflammatory response is an active process in cervical cancer and may act in the progression and/or regression of the lesion. At the site of inflammation, macrophages and neutrophils are present as well as cytokines such as TNF-alpha and IFN-gamma. This study aims to evaluate the inflammatory response levels in women with cervical intraepithelial lesions (CIN) and with squamous cell carcinoma (SCC) of the cervix. Serum samples obtained from women without evidence of disease (n = 30), with CIN (n = 30) and with SCC of the cervix (n = 30) were analyzed for the activities of N-acetylglucosaminidase (NAG) and myeloperoxidase (MPO) by enzymatic assay and the serum levels of TNF-alpha and IFN-gamma by ELISA assay. The activities of NAG and MPO and the level of TNF-alpha were higher in women with CIN compared to the women with SCC. The levels of IFN-gamma were lower in the group of women with CIN compared to the group with SCC. There was not a significant association between the degree of the CIN and the staging of the SCC of the cervix and the degree of inflammation as assessed by the levels of inflammatory markers. The inflammatory response was inversely correlated with the progression of the carcinogenic process. In the three groups, the control group, women with CIN and women with invasive SCC, there was no association between the degree of preinvasive lesions and staging of the SCC of the cervix. (C) 2011 Elsevier Masson SAS. All rights reserved.

Inflammatory Response Patterns in ICSI Patients: A Comparative Study Between Chronic Anovulating and Normally Ovulating Women

The aim of this study was to evaluate inflammatory response in chronic anovulating infertility women undergoing intracytoplasmic sperm injection. Thirteen infertile women with chronic anovulation and 23 normally ovulating women were prospectively evaluated. N-acetylglucosaminidase (NAG), myeloperoxidase (MPO), monocyte chemoattractant protein 1 (MCP-1), and C-reactive protein (CRP) concentrations were evaluated in serum and follicular fluid. Women with chronic anovulation presented higher NAG and MPO activity in follicular fluid when compared with normally ovulating women. Serum MPO activity was higher in the control group compared to the chronic anovulation group. Both serum and follicular fluid CRP concentrations were higher in women with chronic anovulation in comparison with the control group. Higher MCP-1 follicular fluid concentrations and serum levels of CRP were associated with the occurrence of ovarian hyperstimulation syndrome. Patients with chronic anovulation exhibited significantly higher follicle macrophage/neutrophil activation as well as unspecific inflammatory response by comparison with normally ovulating women.

Enhanced natural killer activity and production of pro-inflammatory cytokines in mice selected for high acute inflammatory response (AIRmax)

Strains of mice with maximal and minimal acute inflammatory responsiveness (AIRmax and AIRmin, respectively) were developed through selective breeding based on their high- or low-acute inflammatory responsiveness. Previous reports have shown that AIRmax mice are more resistant to the development of a variety of tumours than AIRmin mice, including spontaneous metastasis of murine melanoma. Natural killer activity is involved in immunosurveillance against tumour development, so we analysed the number and activity of natural killer cells (CD49b(+)), T-lymphocyte subsets and in vitro cytokine production by spleen cells of normal AIRmax and AIRmin mice. Analysis of lymphocyte subsets by flow cytometry showed that AIRmax mice had a higher relative number of CD49b(+) cells than AIRmin mice, as well as cytolytic activity against Yac.1 target cells. The number of CD3(+) CD8(+) cells was also higher in AIRmax mice. These findings were associated with the ability of spleen cells from AIRmax mice in vitro to produce higher levels of the pro-inflammatory cytokines tumour necrosis factor-alpha, interleukin-12p40 and interferon-gamma but not the anti-inflammatory interleukin-10. Taken together, our data suggest that the selective breeding to achieve the AIRmax and AIRmin strains was able to polarize the genes associated with cytotoxic activity, which can be responsible for the antitumour resistance observed in AIRmax mice.

Use of corticosteroid therapy on the modulation of uterine inflammatory response in mares after artificial insemination with frozen semen

In order to modulate uterine inflammatory response and evaluate the effect of corticosteroid therapy on fertility, 90 cycles of 45 mares were used for artificial insemination with frozen semen, using three different protocols: G1 - inseminated with frozen semen (800 x 10(6) viable spermatozoa pre-freezing) + 20 mL of seminal plasma; G2 - inseminated with frozen semen (800 x 10(6) viable spermatozoa pre-freezing) + corticosteroid therapy; G3 - inseminated with frozen semen (800 x 10(6) viable spermatozoa pre-freezing) + 20 mL of seminal plasma + corticosteroid therapy. Corticosteroid therapy consisted on one administration of prednisolone acetate (0.1 mg/Kg - Predef (R)) when mares presented 35mm follicles and uterine edema, concomitantly with the unique dose of hCG (human chorionic gonadotropin), then repeated each 12 hours until ovulation. on first fertility trial, with normal mares, there was no difference between control and treated groups (p>0.05), using seminal plasma associated with corticosteroid therapy (40 vs. 38%, respectively) or corticosteroid therapy alone (40 vs. 45% respectively). The second fertility trial, performed with mares with previous history of post-insemination endometritis, demonstrated a significant increase of pregnancy rate when mares were submitted to corticosteroid therapy (0.0 vs. 64.5%, respectively; p<0.05). Corticosteroid therapy was shown to be safe, with no physical or reproductive alterations on treated mares, demonstrating to be an adequate option to those animals with history of post-breeding or post-insemination endometritis. Further clinical research is necessary to confirm these results and contribute to the establishment of preventive therapy for cases of post-insemination endometritis.

Influence of experimental inflammatory response on hepatic hepcidin gene expression and plasma iron concentration in sheep

Hepcidin is a highly conserved disulfide-bonded peptide that plays a central role in iron homeostasis. During systemic inflammation, hepcidin up-regulation is responsible for hypoferremia. This study aimed to analyze the influence of the inflammatory process induced by complete Freund's adjuvant (CFA) or lipopolysaccharide (LPS) on the liver expression of hepcidin mRNA transcripts and plasma iron concentration of sheep. The expression levels of hepcidin transcripts were up-regulated after CFA or LPS. Hypoferremic response was observed at 12 h (15.46 +/- 6.05 mu mol/L) or 6 h (14.59 +/- 4.38 mu mol/L) and iron reached its lowest level at 96 h (3.08 +/- 1.18 mu mol/L) or 16 h (4.06 +/- 1.58 mu mol/L) after CFA administration or LPS infusion, respectively. This study demonstrated that the iron regulatory hormone hepcidin was up-regulated in sheep liver in response to systemic inflammation. These findings extend our knowledge on the relationship between the systemic inflammatory response, hepcidin and iron, and provide a starting point for additional studies on iron metabolism and the inflammatory process in sheep. (C) 2011 Elsevier B.V. All rights reserved.