977 resultados para APOPTOTIC CELLS
Resumo:
We are interested in determining whether low maternal vitamin D-3 affects brain development in utero. Whilst the vitamin D receptor (VDR) has been identified in embryonic rat brains, the timing and magnitude of its expression across the brain remains unclear. In this study we have quantitated VDR expression during development as well correlated the timing of its appearance with two vital developmental events, apoptosis and mitosis. Brains from embryonic rats (embryonic days 15-23) were examined. We show that the well-described increase in apoptotic cells and decrease in mitotic cells during development correlates with the appearance of the VDR in brain tissue. Given that vitamin D-3 regulates mitosis and apoptosis in non-neuronal tissue we speculate that the timing of VDR expression in embryonic brain may directly or indirectly mediate features of neuronal apoptosis and mitosis.
Resumo:
The use of antioxidants during chemotherapy has been shown to reduce or prevent the undesirable effects experienced by healthy cells. Micronutrient selenium is well known for its antioxidant properties; however, selenium exhibits a bimodal nature in that both its beneficial and toxic properties lie within a limited and narrow dose range. The present study investigated the possible protective effects of selenomethionine (SM) on the cytotoxicity, genotoxicity and clastogenicity of the chemotherapic doxorubicin (DXR), a key chemotherapic used in cancer treatment. Human peripheral lymphocytes were treated in vitro with varying concentrations of SM (0.25 mu M, 0.5 mu M, 1.0 mu M and 2.0 mu M), tested in combination with DXR (0.15 mu g/mL). SM alone was not cytotoxic and when combined with DXR treatment, reduced the DNA damage index significantly, the frequency of chromosomal aberrations, the number of aberrant metaphases and the frequency of apoptotic cells. The mechanism of chemoprotection of SM may be related to its antioxidant properties as well as its ability to interfere with DNA repair pathways. Therefore this study showed that SM is effective in reducing the genetic damage induced by the antitumoral agent DXR. (C) 2007 Elsevier Ltd. All rights reserved.
Resumo:
Idiopathic pulmonary fibrosis is a distinctive, usually fatal, type of chronic fibrosing interstitial pneumonia of unknown cause that increases in prevalence with advanced age, characterized by failure of alveolar re-epithelization and progressive scar formation. Recently, limitation of the replicative capacity of tissues determined by telomerase/apoptosis balance has been implicated in pathogenesis of age-related diseases. In this study, we validated the importance of the expression of type 2 alveolar epithelial cells telomerase protein and studied the relationships between telomerase and apoptosis in early remodeling of usual interstitial pneumonia. We determined type 2 alveolar epithelial cells density, telomerase expression, and apoptosis in surgical lung biopsies from 24 patients with usual interstitial pneumonia, and in normal lung tissues from 18 subjects. We used immunohistochemistry, deoxynucleotidyl transferase method of end labeling, electron microscopy, and histomorphometry to evaluate the amount of type 2 alveolar epithelial cells staining for surfactant-A, telomerase, and in situ detection of apoptotic cells. Unaffected areas of usual interstitial pneumonia and normal lung tissue had similar densities of type 2 alveolar epithelial cells, but a significant minor subpopulation of type 2 alveolar epithelial cells was telomerase positive and a large population was telomerase negative. A significant inverse association was found between low type 2, alveolar. epithelial cell telomerase expression and high apoptosis in unaffected areas of usual interstitial pneumonia. Although type 2 alveolar epithelial cell telomerase expression was higher than apoptosis in NLT group, no significant association was found between them. Electron microscopy confirmed epithelial apoptosis, alveolar collapse, and initial fibroplasia. We conclude that abnormal type 2 alveolar epithelial cells telomerase/apoptosis balance may reduce alveolar epithelial regenerative capacity, thus contributing to the early remodeling response in usual interstitial pneumonia. (C) 2010 Elsevier Inc. All rights reserved.
Resumo:
Immunoglobulin A deficiency (IgAD) is considered the most common form of primary immunodeficiency. The majority of IgA-deficient individuals are considered asymptomatic, even though IgAD has been associated with an increased frequency of recurrent infections, allergy, and autoimmune diseases. In this study we evaluate the Natural autoantibodies (NatAbs) reactivity to phosphorylcholine (PC) and to some pro-inflammatory molecules in IgAD with or without autoimmune disorders. We observed that in the absence of IgA there is an enhancement of IgG subclasses functioning as NatAbs against PC. Immunoglobulin G (IgG) against lipopolysaccharide, C-reactive protein, and IgA was found in IgAD, regardless of the autoimmune manifestations. Nonetheless, IgAD patients with autoimmune disease showed significantly higher IgG reactivity against pro-inflammatory molecules, such as cardiolipin, oxidized low-density lipoproteins, and phosphatidylserine, with positive correlation between them. In conclusion, the IgG NatAbs against PC may represent a compensatory defense mechanism against infections and control excess of inflammation, explaining the asymptomatic status in the IgA deficiency.
Resumo:
We tested the hypothesis that bone marrow-derived mononuclear cells (BMDMCs) at an early phase of cecal ligation and puncture (CLP)-induced sepsis may have lasting effects on: (1) lung mechanics and histology, (2) the structural remodelling of lung parenchyma, (3) lung, kidney, and liver cell apoptosis, and (4) pro- and anti-inflammatory cytokines and growth factors. At day 1, BMDMC significantly reduced mortality, as well as caspase-3, interleukin (IL)-6 and IL-1 beta vascular endothelial growth factor, platelet-derived growth factor, hepatocyte growth factor, and transforming growth factor-beta, but increased IL-10 mRNA expression in lung tissue in septic mice contributing to endothelium and epithelium alveolar repair and improvement of lung mechanics. BMDMC also prevented the increase of apoptotic cells in lung, liver, and kidney. At day 7, these early functional and morphological effects were preserved or further improved. In conclusion, in the present model of sepsis, the beneficial effects of early administration of BMDMCs on lung and distal organs were preserved, possibly by paracrine mechanisms. (C) 2011 Elsevier B.V. All rights reserved.
Resumo:
We tested the hypothesis that at the early phase of acute lung injury (ALI) the degree of endothelium injury may predict lung parenchyma remodelling For this purpose, two models of extrapulmonary ALI induced by Escherichia col: lipopolysaccharide (ALI-LPS) or cecal ligation and puncture (ALI-CLP) were developed in mice At day 1, these models had similar degrees of lung mechanical compromise, epithelial damage, and intraperitoneal inflammation, but endothelial lesion was greater in ALI-CLP A time course analysis revealed, at day 7 ALI-CLP had higher degrees of epithelial lesion, denudation of basement membrane, endothelial damage, elastic and collagen fibre content, neutrophils in bronchoalveolar lavage fluid (BALF), peritoneal fluid and blood, levels of interleukin-6, KC (murine analogue of IL-8), and transforming growth factor-beta in BALF Conversely, the number of lung apoptotic cells was similar in both groups In conclusion, the intensity of fibroelastogenesis was affected by endothelium injury in addition to the maintenance of epithelial damage and intraperitoneal inflammation. (C) 2010 Elsevier B V All rights reserved
Resumo:
In a cross-sectional study involving 62 patients with systemic lupus erythematosus (SLE), we found that patients with biopsy-proven lupus nephritis (LN) had higher titers of anti-C1q antibodies than active SLE without nephritis patients. Anti-C1q was associated with a negative predictive value of 94.59%, a positive predictive value of 52%, a sensitivity of 86.66% and a specificity of 74.47% for the diagnosis of LN. We conclude that high titers of anti-C1q antibodies are strongly associated with the presence of active LN, and the negative predictive value of this test for diagnosing LN is very high; therefore, it can influence therapeutic decisions and reduce the number of renal biopsies in patients with SLE. Copyright (C) 2011 S. Karger AG, Basel
Resumo:
Aims: Cisplatin (CP) promotes increased production of reactive oxygen species, which can activate p38 mitogen activated protein kinases (p38 MAPKs) leading to apoptosis and increased expression of proinflammatory mediators that intensify the cytotoxic effects of CP. We investigated the effect of the treatment with S13203580, a p38 MAPKs inhibitor, on oxidative stress, on the oxidation-associated signal, p38 MAPK and on apoptosis in U-injected rats, starting after the beginning of the renal damage. Main methods: Rats (n = 21) were injected with CP (5 mg/kg, i.p.) and 3 and 4 days after some of them (n = 8) were treated with SB203580 (0.5 mg/kg, i.p.). Controls (n = 6) received saline (i.p.). Two or five days after saline or CP injections, plasma creatinine, urinary volume, sodium and potassium fractional excretions, blood urea nitrogen and urinary lipid peroxidation were measured. The kidneys were removed for histological, apoptosis, immunohistochemical and Western blot studies. Key findings: CP caused abnormalities in kidney functions and structure associated with raised urinary peroxidation levels and higher number of apoptotic cells in the outer medulla. The immunostaining studies showed increased numbers of macrophages/monocytes and p-p38 MAPKs positive cells in the renal outer medulla. The increase of p-p38 MAPKs expression was confirmed by Western blot analysis. All of these alterations were attenuated by treatment with S13203580. Significance: These data suggest that the beneficial effect of SB203580 on CP-induced renal damage might be related, in part, to the blockade of p38 MAPK activation with reduction of the inflammatory process, oxidative stress and apoptotic cell death. (C) 2009 Elsevier Inc. All rights reserved.
Resumo:
Introduction. After hematopoietic stem cell transplantation (HSCT), many patients present genital graft-vs.-host disease (GVHD) that can culminate with sexual problems, which are poorly dimensioned. Aim. We hope to draw attention to the need to perform genital biopsy to diagnose genital GVHD, and thus to call attention to the need to incorporate careful attention to sexual health in the treatment of these patients. Methods. Five allogeneic stem cell transplant recipients complaining of coital pain after HSCT were clinically diagnosed for genital GVHD. Genital biopsies were given for histological analysis, and microphotographs of the corresponding marked field in the slide were taken. Specimens were evaluated by the site pathologist and then sent to a reference pathologist, each blinded to the histological findings. A literature search was performed in PubMed/MEDLINE (1966-2009) for cross-sectional and cohort studies or trials related to genital GVHD. Expert opinions peer reviews and case reports were also considered. Main Outcome Measures. HSCT, genital GVHD, genital biopsy. Results. The biopsy showed evidence of dilated apoptotic cells in the basal layer and detachment of the epithelial lining of the mucosa, hyalinization and thickening of collagen fibers, capillary ectasia, and mononuclear inflammatory infiltrate of the submucosa. Three patients presented vulval lesion such as leucoplasia and ulcer on the large lip. Histological analyses showed evidence of epithelial hyperplasia and influx of inflammatory cells to the epithelial surface, intercellular edema and spongiosis, apoptotic bodies on the basal layer of the epithelium, spongiosis, and nuclear vacuolization. A common treatment based on corticotherapy resulted in complete remission of coetaneous or mucous genital lesions in all five patients. Conclusion. Genital biopsy is important to differentially diagnose GVHD and secondary symptoms due to hypoestrogenism. Prevention is the most important step in controlling the evolution GVHD in the vagina to prevent vaginal obstruction and sexual dysfunction. da Silva Lara LA, de Andrade JM, Mauad LMQ, Ferrarese SR, Marana HRC, Tiezzi DG, and de Sa Rosa e Silva ACJ. Genital manifestation of graft-vs.-host disease: A series of case reports. J Sex Med 2010;7:3216-3225.
Resumo:
The bovine maternal epithelium is composed of cuboidal cells interspersed with low columnar cells having centrally located nuclei. Bovine trophoblast is composed of two cell types: mononuclear trophoblastic and giant trophoblastic cells that can have two or more nuclei. Number of apoptotic cells and proliferative cells are variable in both cell populations. This study compared tissue growth and apoptosis by flow cytometry in the cell population found at distinct placental regions (central region of placentomes, <= 1-cm microplacentomes and the interplacentomal region) between normal and cloned near-term bovine pregnancies. After a morphological comparison between regions and groups (controls vs. clones), a lesser proportion of diploid to tetraploid cells was observed in the central region of placentomes and in microplacentomes from cloned-derived pregnancies. In addition, cloned animals had a fewer apoptotic cells in the central region of the placentome and in interplacentomal region and a greater proliferative capacity in all regions (cells in G(2)/M) near term as opposed to control animals. These results may reveal the existence of a relationship between such changes in the proportions of uterine and trophoblastic epithelial cells at the end of pregnancy and normal placental function. This could be related to faulty placentation in early pregnancy, placental insufficiency during pregnancy or lack of placental and/or fetal maturation in late pregnancy, which may contribute to someof the abnormalities after in vitro embryo manipulations, such as poor preparation and initiation of parturition, prolonged gestation and lesser post-natal survival in some cloned animals. (C) 2008 Elsevier B.V. All rights reserved.
Resumo:
Background: Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) is a Gram-negative bacterium present in the oral cavity and is usually associated with localized aggressive periodontitis. Isolated antigens from A. actinomycetemcomitans can activate innate immune cells through Toll-like receptors (TLRs), which are molecules that recognize structural components conserved among microorganisms. In this study, we evaluate the role of TLR2 in the recognition of A. actinomycetemcomitans. Methods: Macrophages and neutrophils from knockout mice with targeted disruption of TLR2 (TLR2(-/-) mice) and wild-type mice were collected and used for the subsequent assays. The production of cytokines and chemokines was evaluated by enzyme-linked immunosorbent assay (ELISA), and the presence of apoptotic cells was determined by flow cytometry. In addition, the mechanisms that modulate the outcome of A. actinomycetemcomitans-induced periodontal disease in TLR2(-/-) mice were examined. Results: The results show that TLR2-deficient mice developed more severe periodontitis after A. actinomycetemcomitans infection, characterized by significantly higher bone loss and inflammatory cell migration to periodontal tissues. The inflammatory cell influx into the peritoneal cavities of TLR2(-/-) mice was three-fold lower than that observed for the littermate controls. A significantly diminished production of the cytokines tumor necrosis factor-alpha and interleukin-1 beta as well as the chemokine CC-ligand-5 in the peritoneal cavities of TLR2(-/-) mice was observed. In addition, a high frequency of apoptotic cells in the inflammatory exudates from TLR2(-/-) mice was observed. Phagocytosis and nitric oxide production was diminished in cells from TLR2(-/-) mice, facilitating the dissemination of the pathogen to the spleen. Conclusion: The results of this study highlight the involvement of TLR2 in recognizing A. actinomycetemcomitans and its essential role in controlling A. actinomycetemcomitans infection. J Periodontot 2009,80:2070-2019.
Resumo:
Subcutaneous Ehrlich tumor-bearing mice were treated with in situ inoculation of a P-glucan-rich extract of Agaricus brasiliensis (ATF), which reduced tumor growth. Histopathological analysis showed that the tumor masses of control mice (Ehr) presented giant tumor cells and many mitotic figures whereas the tumor tissue obtained from ATF-treated animals (Ehr-ATF) presented a lower frequency of both mitotic and giant cells, associated with a higher frequency of apoptotic cells than Ehr. Analysis of the lymphoproliferative activity of spleen cells showed that the treatment had a suppressive rather than a stimulatory effect. Spleen cells of the Ehr group produced higher in vitro levels of IL-10 than normal controls and this occurrence was partially avoided by treatment with ATF. Analysis of cytokine production by tumor-infiltrating cells (ELISpot) showed that ATF induced a higher number of IFN-gamma-producing cells at 7 and 14 days as well as reduction of IL-10-secreting cells at the latter time. Confocal microscopy analysis showed higher intensity of labeling of CD4+ and Mac-3+ cells in ATF-treated mice. Analysis of in situ expression of angiogenic growth factors showed a slight decrease of FGF-2 mRNA in Ehr-ATF animals (7th day) but not of VEGF-A or TGF-beta expression. This fraction could not directly lyse either lymphocytes or tumor cells and we speculate that antitumor effect of ATF could be due to induction of a selective migration of immunocompetent cells from the spleen to the tumor site and to the switch of cytokine production. (C) 2009 Elsevier Inc. All rights reserved.
Resumo:
The interrelationship between myofibroblasts and fibrogenic growth factors in the pathogenesis of renal fibrosis is poorly defined. A temporal and spatial analysis of myofibroblasts, their proliferation and death, and presence of transforming growth factor-beta1 (TGF-beta1) and platelet-derived growth factor-B (PDGF-B) was carried out in an established rodent model in which chronic renal scarring and fibrosis occurs after healed renal papillary necrosis (RPN), similar to that seen with analgesic nephropathy. Treated and control groups (N = 6 and 4, respectively) were compared at 2, 4, 8 and 12 weeks. A positive relationship was found between presence of tubulo-interstitial myofibroblasts and development of fibrosis. Apoptotic myofibroblasts were identified in the interstitium and their incidence peaked 2 weeks after treatment. Levels of interstitial cell apoptosis and fibrosis were negatively correlated over time (r = -0.57, p < 0.01 ), suggesting that as apoptosis progressively failed to limit myofibroblast numbers, fibrosis increased. In comparison with the diminishing apoptosis in the interstitium, the tubular epithelium had progressively increasing levels of apoptosis over time, indicative of developing atrophy of nephrons. TGF-beta1 protein expression had a close spatial and temporal association with fibrosis and myofibroblasts, whilst PDGF-B appeared to have a closer link with populations of other chronic inflammatory cells such as infiltrating lymphocytes. Peritubular myofibroblasts were often seen near apoptotic cells in the tubular epithelium, suggestive of a paracrine toxic effect of factor/s secreted by the myofibroblasts. In vitro , TGF-beta1 was found to be toxic to renal tubular epithelial cells. These findings suggest an interaction between myofibroblasts, their deletion by apoptosis, and the presence of the fibrogenic growth factor TGF-beta1 in renal fibrosis, whereby apoptotic deletion of myofibroblasts could act as a controlling factor in progression of fibrosis.
Resumo:
Caveolae and their proteins, the caveolins, transport macromolecules; compartmentalize signalling molecules; and are involved in various repair processes. There is little information regarding their role in the pathogenesis of significant renal syndromes such as acute renal failure (ARF). In this study, an in vivo rat model of 30 min bilateral renal ischaemia followed by reperfusion times from 4 h to 1 week was used to map the temporal and spatial association between caveolin-1 and tubular epithelial damage (desquamation, apoptosis, necrosis). An in vitro model of ischaemic ARF was also studied, where cultured renal tubular epithelial cells or arterial endothelial cells were subjected to injury initiators modelled on ischaemia-reperfusion (hypoxia, serum deprivation, free radical damage or hypoxia-hyperoxia). Expression of caveolin proteins was investigated using immunohistochemistry, immunoelectron microscopy, and immunoblots of whole cell, membrane or cytosol protein extracts. In vivo, healthy kidney had abundant caveolin-1 in vascular endothelial cells and also some expression in membrane surfaces of distal tubular epithelium. In the kidneys of ARF animals, punctate cytoplasmic localization of caveolin-1 was identified, with high intensity expression in injured proximal tubules that were losing basement membrane adhesion or were apoptotic, 24 h to 4 days after ischaemia-reperfusion. Western immunoblots indicated a marked increase in caveolin-1 expression in the cortex where some proximal tubular injury was located. In vitro, the main treatment-induced change in both cell types was translocation of caveolin-1 from the original plasma membrane site into membrane-associated sites in the cytoplasm. Overall, expression levels did not alter for whole cell extracts and the protein remained membrane-bound, as indicated by cell fractionation analyses. Caveolin-1 was also found to localize intensely within apoptotic cells. The results are indicative of a role for caveolin-1 in ARF-induced renal injury. Whether it functions for cell repair or death remains to be elucidated. Copyright (C) 2003 John Wiley Sons, Ltd.
Resumo:
Aqueous extracts and organic solvent extracts of isolated marine cyanobacteria strains were tested for antimicrobial activity against a fungus, Gram-positive and Gram-negative bacteria and for cytotoxic activity against primary rat hepatocytes and HL-60 cells. Antimicrobial activity was based on the agar diffusion assay. Cytotoxic activity was measured by apoptotic cell death scored by cell surface evaluation and nuclear morphology. A high percentage of apoptotic cells were observed for HL-60 cells when treated with cyanobacterial organic extracts. Slight apoptotic effects were observed in primary rat hepatocytes when exposed to aqueous cyanobacterial extracts. Nine cyanobacteria strains were found to have antibiotic activity against two Gram-positive bacteria, Clavibacter michiganensis subsp. insidiosum and Cellulomonas uda. No inhibitory effects were found against the fungus Candida albicans and Gram-negative bacteria. Marine Synechocystis and Synechococcus extracts induce apoptosis in eukaryotic cells and cause inhibition of Gram-positive bacteria. The different activity in different extracts suggests different compounds with different polarities.