Anionic Sites, Fucose Residues and Class I Human Leukocyte Antigen Fate During Interaction of Toxoplasma gondii with Endothelial Cells

Toxoplasma gondii   invades and proliferates in human umbilical vein endothelial cells where it resides in a parasitophorous vacuole. In order to analyze which components of the endothelial cell plasma membrane are internalized and become part of the parasitophorous vacuole membrane, the culture of endothelial cells was labeled with cationized ferritin or UEA I lectin or anti Class I human leukocytte antigen (HLA) before or after infection with T. gondiii . The results showed no cationized ferritin and UEA I lectin in any parasitophorous vacuole membrane, however, the Class I HLA molecule labeling was observed in some endocytic vacuoles containing parasite until 1 h of interaction with T. gondiii . After 24 h parasite-host cell interaction, the labeling was absent on the vacuolar membrane, but presents only in small vesicles near parasitophorous vacuole. These results suggest the anionic site and fucose residues are excluded at the time of parasitophorous vacuole formation while Class I HLA molecules are present only on a minority of Toxoplasma-containig vacuoles

Mechanisms Underlying Cell Therapy in Liver Fibrosis : An Overview

Fibrosis is a common feature in most pathogenetic processes in the liver, and usually results from a chronic insult that depletes the regenerative capacity of hepatocytes and activates multiple inflammatory pathways, recruiting resident and circulating immune cells, endothelial cells, non-parenchymal hepatic stellate cells, and fibroblasts, which become activated and lead to excessive extracellular matrix accumulation. The ongoing development of liver fibrosis results in a clinically silent and progressive loss of hepatocyte function, demanding the constant need for liver transplantation in clinical practice, and motivating the search for other treatments as the chances of obtaining compatible viable livers become scarcer. Although initially cell therapy has emerged as a plausible alternative to organ transplantation, many factors still challenge the establishment of this technique as a main or even additional therapeutic tool. Herein, the authors discuss the most recent advances and point out the corners and some controversies over several protocols and models that have shown promising results as potential candidates for cell therapy for liver fibrosis, presenting the respective mechanisms proposed for liver regeneration in each case

Lymphocytes Mitochondrial Physiology as Biomarker of Energy Metabolism during Fasted and Fed Conditions

Mitochondria are central coordinators of energy metabolism, and changes of their physiology have long been associated with metabolic disorders. Thus, observations of energy dynamics in different cell types are of utmost importance. Therefore, tools with quick and easy handling are needed for consistent evaluations of such interventions. In this paper, our main hypothesis is that during different nutritional situations lymphocytes mitochondrial physiology could be associated with the metabolism of other cell types, such as cardiomyocytes, and consequently be used as metabolic biomarker. Blood lymphocytes and heart muscle fibers were obtained from both fed and 24 h-fasted mice, and mitochondrial analysis was assessed by high-resolution respirometry and western blotting. Carbohydrate-linked oxidation and fatty acid oxidation were significantly higher after fasting. Carnitine palmitoil transferase 1 and uncouple protein 2 contents were increased in the fasted group, while the glucose transporters 1 and 4 and the ratio phosphorylated AMP-activated protein kinase/AMPK did not change between groups. In summary, under a nutritional status modification, mitochondria demonstrated earlier adaptive capacity than other metabolic sensors such as glucose transporters and AMPK, suggesting the accuracy of mitochondria physiology of lymphocytes as biomarker for metabolic changes

Mitichrondial localization of non-histone protein HMGB1 during human endothelial cell - Toxoplasma gondii infection

Submitted by Sandra Infurna ([email protected]) on 2019-04-10T13:49:31Z No. of bitstreams: 1 HeleneS_BarbosaLPorto_etal_IOC_2008.pdf: 562357 bytes, checksum: c7eff3721586cf8e27dd6c1c398f5b87 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2019-04-10T13:58:43Z (GMT) No. of bitstreams: 1 HeleneS_BarbosaLPorto_etal_IOC_2008.pdf: 562357 bytes, checksum: c7eff3721586cf8e27dd6c1c398f5b87 (MD5)Made available in DSpace on 2019-04-10T13:58:43Z (GMT). No. of bitstreams: 1 HeleneS_BarbosaLPorto_etal_IOC_2008.pdf: 562357 bytes, checksum: c7eff3721586cf8e27dd6c1c398f5b87 (MD5) Previous issue date: 2008Universidade do Estado do Rio de Janeiro. Instituto de Biologia. Departamento de Histologia e Embriologia. Laboratório de Cultura de Células. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro. Instituto de Biologia. Departamento de Histologia e Embriologia. Laboratório de Cultura de Células. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Tecnologia em Fármacos. Laboratório de Farmacologia Aplicada. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Tecnologia em Fármacos. Laboratório de Farmacologia Aplicada. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro. Instituto de Biologia. Departamento de Histologia e Embriologia. Laboratório de Cultura de Células. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Estrutural. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro. Instituto de Biologia. Departamento de Histologia e Embriologia. Laboratório de Cultura de Células. Rio de Janeiro, RJ, Brasil.Toxoplasma gondii is an obligate intracellular pathogen, replicating only within a specialized membrane-bounded cytoplasmic vacuole, the parasitophorous vacuole (PV), which interacts with host cell mitochondria. High mobility group box 1 (HMGB1), a known nuclear transcription factor, also may be involved in pathological conditions, whose function is to signal tissue damage. Using confocal microscopy, we have investigated the localization of HMGB1 and the mitochondria performance during interaction between human umbilical vein endothelial cells (HUVEC) and Toxoplasma. Immunofluorescence showed HMGB1 localization in HUVEC tubular mitochondria stained with Mito Tracker (MT). At 2 h post-infection, MT labeled spherical structures scattered throughout the cytoplasm and HMGB1 were still present. After 24 h of infection, long and tubular structures were localized around PVs and were double labeled by MT and HMGB1, suggesting a structural reorganization of the mitochondria over a long period of infection. For the first time, these results show there is HMGB1 in HUVEC mitochondria and that this protein could be playing a part in mitochondrial DNA events which are important for fission and fusion processes reported here during HUVEC-T. gondii infection

Cytokines, hepatic cell profiling and cell interactions during bone marrow cell therapy for liver fibrosis in cholestatic mice

<div><p>Bone marrow cells (BMC) migrate to the injured liver after transplantation, contributing to regeneration through multiple pathways, but mechanisms involved are unclear. This work aimed to study BMC migration, characterize cytokine profile, cell populations and proliferation in mice with liver fibrosis transplanted with GFP⁺ BMC. Confocal microscopy analysis showed GFP⁺ BMC near regions expressing HGF and SDF-1 in the fibrotic liver. Impaired liver cell proliferation in fibrotic groups was restored after BMC transplantation. Regarding total cell populations, there was a significant reduction in CD68⁺ cells and increased Ly6G⁺ cells in transplanted fibrotic group. BMC contributed to the total populations of CD144, CD11b and Ly6G cells in the fibrotic liver, related to an increment of anti-fibrotic cytokines (IL-10, IL-13, IFN-γ and HGF) and reduction of pro-inflammatory cytokines (IL-17A and IL-6). Therefore, HGF and SDF-1 may represent important chemoattractants for transplanted BMC in the injured liver, where these cells can give rise to populations of extrahepatic macrophages, neutrophils and endothelial progenitor cells that can interact synergistically with other liver cells towards the modulation of an anti-fibrotic cytokine profile promoting the onset of liver regeneration.</p></div

GFP⁺ BMC correlation tests.

<p>(A) Correlation between GFP⁺ BMC marked with PE and total cell populations marked with CD144, CD68, CD11b and Ly6G. Positive correlation for CD144, CD11b and Ly6G in transplanted normal and fibrotic groups (N+BMC7d and F7d+BMC7d).</p

Cytokine profiling.

<p>IL-10, IL-17A, IFN-γ, IL-6, IL-4 and IL-2 protein content was analyzed using a flow cytometry-adapted cytokine kit. ***P = <0.0001, **P = <0.001 and *P<0.05.</p