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Sample records for human extracellular superoxide

  1. Characterization of heparin binding of human extracellular superoxide dismutase.

    PubMed

    Lookene, A; Stenlund, P; Tibell, L A

    2000-01-11

    The C-terminal domain of human extracellular superoxide dismutase (hEC-SOD) plays a crucial role in the protein's interaction with heparin. Here we investigated this interaction in more detail by comparing the heparin-binding characteristics of two variants of hEC-SOD: the two fusion proteins containing the hEC-SOD C-terminal domain and a synthetic peptide homologous to the C-terminal. The interaction studies were performed using a surface plasmon resonance based technique on a BIAcore system. It should be emphasized that this is a model system. However, the kinetic constants, as measured, are valid in a comparative sense. Comparison of affinities for size-fractionated heparins revealed that octa- or decasaccharides are the smallest heparin fragments that can efficiently interact with the C-terminal domain of hEC-SOD. At physiological salt concentration, and pH 7.4, the hEC-SOD/heparin interaction was found to be of a high-affinity type, with an equilibrium dissociation constant, K(d), of 0.12 microM, which is 700 and 10-20 times lower than the K(d) values for the synthetic peptide and the fusion proteins, respectively. However, when an alpha-helical structure was induced in the synthetic peptide, by addition of 10% trifluoroethanol, the K(d) decreased to 0.64 microM. The differences in the K(d) values were mainly governed by differences in the association rate constants (k(ass)). The hEC-SOD/heparin interaction itself was found to have a fairly high dissociation rate constant (0.1 s(-)(1)), and a very high association rate constant (8 x 10(5) M(-)(1) s(-)(1)), suggesting that the interaction is mainly controlled by the association. These results together with circular dichroism spectra of the synthetic peptide suggest that an alpha-helical structure in the C-terminal is essential for optimal binding to heparin and that other parts of hEC-SOD moderate the affinity. Our data also demonstrate that the tetramerization itself does not substantially increase the

  2. Cloning, Purification, and Characterization of Recombinant Human Extracellular Superoxide Dismutase in SF9 Insect Cells

    PubMed Central

    Shrestha, Pravesh; Yun, Ji-Hye; Kim, Woo Taek; Kim, Tae-Yoon; Lee, Weontae

    2016-01-01

    A balance between production and degradation of reactive oxygen species (ROS) is critical for maintaining cellular homeostasis. Increased levels of ROS during oxidative stress are associated with disease conditions. Antioxidant enzymes, such as extracellular superoxide dismutase (EC-SOD), in the extracellular matrix (ECM) neutralize the toxicity of superoxide. Recent studies have emphasized the importance of EC-SOD in protecting the brain, lungs, and other tissues from oxidative stress. Therefore, EC-SOD would be an excellent therapeutic drug for treatment of diseases caused by oxidative stress. We cloned both the full length (residues 1–240) and truncated (residues 19–240) forms of human EC-SOD (hEC-SOD) into the donor plasmid pFastBacHTb. After transposition, the bacmid was transfected into the Sf9-baculovirus expression system and the expressed hEC-SOD purified using FLAG-tag. Western blot analysis revealed that hEC-SOD is present both as a monomer (33 kDa) and a dimer (66 kDa), as detected by the FLAG antibody. A water-soluble tetrazolium (WST-1) assay showed that both full length and truncated hEC-SOD proteins were enzymatically active. We showed that a potent superoxide dismutase inhibitor, diethyldithiocarbamate (DDC), inhibits hEC-SOD activity. PMID:26912083

  3. Cloning, Purification, and Characterization of Recombinant Human Extracellular Superoxide Dismutase in SF9 Insect Cells.

    PubMed

    Shrestha, Pravesh; Yun, Ji-Hye; Kim, Woo Taek; Kim, Tae-Yoon; Lee, Weontae

    2016-03-01

    A balance between production and degradation of reactive oxygen species (ROS) is critical for maintaining cellular homeostasis. Increased levels of ROS during oxidative stress are associated with disease conditions. Antioxidant enzymes, such as extracellular superoxide dismutase (EC-SOD), in the extracellular matrix (ECM) neutralize the toxicity of superoxide. Recent studies have emphasized the importance of EC-SOD in protecting the brain, lungs, and other tissues from oxidative stress. Therefore, EC-SOD would be an excellent therapeutic drug for treatment of diseases caused by oxidative stress. We cloned both the full length (residues 1-240) and truncated (residues 19-240) forms of human EC-SOD (hEC-SOD) into the donor plasmid pFastBacHTb. After transposition, the bacmid was transfected into the Sf9-baculovirus expression system and the expressed hEC-SOD purified using FLAG-tag. Western blot analysis revealed that hEC-SOD is present both as a monomer (33 kDa) and a dimer (66 kDa), as detected by the FLAG antibody. A water-soluble tetrazolium (WST-1) assay showed that both full length and truncated hEC-SOD proteins were enzymatically active. We showed that a potent superoxide dismutase inhibitor, diethyldithiocarbamate (DDC), inhibits hEC-SOD activity. PMID:26912083

  4. The subunit composition of human extracellular superoxide dismutase (EC-SOD) regulate enzymatic activity

    PubMed Central

    Petersen, Steen V; Valnickova, Zuzana; Oury, Tim D; Crapo, James D; Chr Nielsen, Niels; Enghild, Jan J

    2007-01-01

    Background Human extracellular superoxide dismutase (EC-SOD) is a tetrameric metalloenzyme responsible for the removal of superoxide anions from the extracellular space. We have previously shown that the EC-SOD subunit exists in two distinct folding variants based on differences in the disulfide bridge pattern (Petersen SV, Oury TD, Valnickova Z, Thøgersen IB, Højrup P, Crapo JD, Enghild JJ. Proc Natl Acad Sci USA. 2003;100(24):13875–80). One variant is enzymatically active (aEC-SOD) while the other is inactive (iEC-SOD). The EC-SOD subunits are associated into covalently linked dimers through an inter-subunit disulfide bridge creating the theoretical possibility of 3 dimers (aa, ai or ii) with different antioxidant potentials. We have analyzed the quaternary structure of the endogenous EC-SOD disulfide-linked dimer to investigate if these dimers in fact exist. Results The analyses of EC-SOD purified from human tissue show that all three dimer combinations exist including two homo-dimers (aa and ii) and a hetero-dimer (ai). Because EC-SOD is a tetramer the dimers may combine to generate 5 different mature EC-SOD molecules where the specific activity of each molecule is determined by the ratio of aEC-SOD and iEC-SOD subunits. Conclusion This finding shows that the aEC-SOD and iEC-SOD subunits combine in all 3 possible ways supporting the presence of tetrameric enzymes with variable enzymatic activity. This variation in enzymatic potency may regulate the antioxidant level in the extracellular space and represent a novel way of modulating enzymatic activity. PMID:17937792

  5. Human extracellular superoxide dismutase (EC-SOD) expression in transgenic chicken

    PubMed Central

    Byun, Sung June; Ji, Mi-Ran; Jang, Ye-Jin; Hwang, A-In; Chung, Hee Kyoung; Kim, Jeom Sun; Kim, Kyung-Woon; Chung, Hak-Jae; Yang, Byoung-Chul; Jeon, Iksoo; Park, Jin-Ki; Yoo, Jae Gyu; Kim, Tae-Yoon

    2013-01-01

    Extracellular superoxide dismutase (EC-SOD) is a metalloprotein and functions as an antioxidant enzyme. In this study, we used lentiviral vectors to generate transgenic chickens that express the human EC-SOD gene. The recombinant lentiviruses were injected into the subgerminal cavity of freshly laid eggs. Subsequently, the embryos were incubated to hatch using phases II and III of the surrogate shell ex vivo culture system. Of 158 injected embryos, 16 chicks (G0) hatched and were screened for the hEC-SOD by PCR. Only 1 chick was identified as a transgenic bird containing the transgene in its germline. This founder (G0) bird was mated with wild-type hens to produce transgenic progeny, and 2 transgenic chicks (G1) were produced. In the generated transgenic hens (G2), the hEC-SOD protein was expressed in the egg white and showed antioxidant activity. These results highlight the potential of the chicken for production of biologically active proteins in egg white. [BMB Reports 2013; 46(8): 404-409] PMID:23977988

  6. Isolation and sequence of complementary DNA encoding human extracellular superoxide dismutase

    SciTech Connect

    Hjalmarsson, K.; Marklund, S.L.; Engstroem, A.; Edlund, T.

    1987-09-01

    A complementary DNA (cDNA) clone from a human placenta cDNA library encoding extracellular superoxide dismutase has been isolated and the nucleotide sequence determined. The cDNA has a very high G + C content. EC-SOD is synthesized with a putative 18-amino acid signal peptide, preceding the 222 amino acids in the mature enzyme, indicating that the enzyme is a secretory protein. The first 95 amino acids of the mature enzyme show no sequence homology with other sequenced proteins and there is one possible N-glycosylation site (Asn-89). The amino acid sequence from residues 96-193 shows strong homology (approx. 50%) with the final two-thirds of the sequences of all know eukaryotic CuZn SODs, whereas the homology with the P. leiognathi CuZn SOD is clearly lower. The ligands to Cu and Zn, the cysteines forming the intrasubunit disulfide bridge in the CuZn SODs, and the arginine found in all CuZn SODs in the entrance to the active site can all be identified in EC-SOD. A comparison with bovine CuZn SOD, the three-dimensional structure of which is known, reveals that the homologies occur in the active site and the divergencies are in the part constituting the subunit contact area in CuZn SOD. Amino acid sequence 194-222 in the carboxyl-terminal end of EC-SOD is strongly hydrophilic and contains nine amino acids with a positive charge. This sequence probably confers the affinity of EC-SOD for heparin and heparan sulfate. An analysis of the amino acid sequence homologies with CuZn SODs from various species indicates that the EC-SODs may have evolved form the CuZn SODs before the evolution of fungi and plants.

  7. Aerosolized human extracellular superoxide dismutase prevents hyperoxia-induced lung injury.

    PubMed

    Yen, Chih-Ching; Lai, Yi-Wen; Chen, Hsiao-Ling; Lai, Cheng-Wei; Lin, Chien-Yu; Chen, Wei; Kuan, Yu-Ping; Hsu, Wu-Huei; Chen, Chuan-Mu

    2011-01-01

    An important issue in critical care medicine is the identification of ways to protect the lungs from oxygen toxicity and reduce systemic oxidative stress in conditions requiring mechanical ventilation and high levels of oxygen. One way to prevent oxygen toxicity is to augment antioxidant enzyme activity in the respiratory system. The current study investigated the ability of aerosolized extracellular superoxide dismutase (EC-SOD) to protect the lungs from hyperoxic injury. Recombinant human EC-SOD (rhEC-SOD) was produced from a synthetic cassette constructed in the methylotrophic yeast Pichia pastoris. Female CD-1 mice were exposed in hyperoxia (FiO2>95%) to induce lung injury. The therapeutic effects of EC-SOD and copper-zinc SOD (CuZn-SOD) via an aerosol delivery system for lung injury and systemic oxidative stress at 24, 48, 72 and 96 h of hyperoxia were measured by bronchoalveolar lavage, wet/dry ratio, lung histology, and 8-oxo-2'-deoxyguanosine (8-oxo-dG) in lung and liver tissues. After exposure to hyperoxia, the wet/dry weight ratio remained stable before day 2 but increased significantly after day 3. The levels of oxidative biomarker 8-oxo-dG in the lung and liver were significantly decreased on day 2 (P<0.01) but the marker in the liver increased abruptly after day 3 of hyperoxia when the mortality increased. Treatment with aerosolized rhEC-SOD increased the survival rate at day 3 under hyperoxia to 95.8%, which was significantly higher than that of the control group (57.1%), albumin treated group (33.3%), and CuZn-SOD treated group (75%). The protective effects of EC-SOD against hyperoxia were further confirmed by reduced lung edema and systemic oxidative stress. Aerosolized EC-SOD protected mice against oxygen toxicity and reduced mortality in a hyperoxic model. The results encourage the use of an aerosol therapy with EC-SOD in intensive care units to reduce oxidative injury in patients with severe hypoxemic respiratory failure, including acute

  8. Plasma clearance of human extracellular-superoxide dismutase C in rabbits

    SciTech Connect

    Karlsson, K.; Marklund, S.L.

    1988-09-01

    Extracellular-superoxide dismutase (EC-SOD) is heterogenous in the vasculature with regard to heparin affinity and can be separated into three fractions: A, without affinity; B, with weak affinity; and C, with relatively strong heparin affinity. The plasma clearance of intravenously injected 125I-labeled and unlabeled human EC-SOD C was studied in rabbits. About 90% of injected 125I-EC-SOD C was eliminated from the blood within 5-10 min. Injection of heparin after 10 or 20 min led to an immediate release of all sequestered 125I-EC-SOD C back to the blood plasma. Later injections of heparin led to diminished release, although release could still be demonstrated after 72 h. A half-time of approximately 10 h could be calculated for heparin-releasable 125I-EC-SOD C. Unlabeled EC-SOD C, determined as enzymic activity and with ELISA, was likewise sequestered and released to the same degree as 125I-labeled EC-SOD C by heparin as tested at 20 min and 5 h. The immediacy of the heparin-induced release indicates that the sequestered enzyme had been bound to endothelial cell surfaces. The length of the half-time suggests that the putative cell surface binding has a physiological function and is not primarily a step in enzyme degradation. The distribution of sequestered 125I-labeled EC-SOD C to different organs was determined at times between 10 min and 24 h. Of the organs, the liver contained the most 125I-EC-SOD C, followed by kidney, spleen, heart, and lung. At all investigated times, the content in the analyzed organs was nearly as large as the amount that could be promptly released to plasma by intravenous heparin. This indicates that almost all 125I-EC-SOD C in the organs was present on endothelial cell surfaces and was not bound by other tissue cell surfaces, or was present within the cells.

  9. Histone deacetylation contributes to low extracellular superoxide dismutase expression in human idiopathic pulmonary arterial hypertension.

    PubMed

    Nozik-Grayck, Eva; Woods, Crystal; Stearman, Robert S; Venkataraman, Sujatha; Ferguson, Bradley S; Swain, Kalin; Bowler, Russell P; Geraci, Mark W; Ihida-Stansbury, Kaori; Stenmark, Kurt R; McKinsey, Timothy A; Domann, Frederick E

    2016-07-01

    Epigenetic mechanisms, including DNA methylation and histone acetylation, regulate gene expression in idiopathic pulmonary arterial hypertension (IPAH). These mechanisms can modulate expression of extracellular superoxide dismutase (SOD3 or EC-SOD), a key vascular antioxidant enzyme, and loss of vascular SOD3 worsens outcomes in animal models of pulmonary arterial hypertension. We hypothesized that SOD3 gene expression is decreased in patients with IPAH due to aberrant DNA methylation and/or histone deacetylation. We used lung tissue and pulmonary artery smooth muscle cells (PASMC) from subjects with IPAH at transplantation and from failed donors (FD). Lung SOD3 mRNA expression and activity was decreased in IPAH vs. FD. In contrast, mitochondrial SOD (Mn-SOD or SOD2) protein expression was unchanged and intracellular SOD activity was unchanged. Using bisulfite sequencing in genomic lung or PASMC DNA, we found the methylation status of the SOD3 promoter was similar between FD and IPAH. Furthermore, treatment with 5-aza-2'-deoxycytidine did not increase PASMC SOD3 mRNA, suggesting DNA methylation was not responsible for PASMC SOD3 expression. Though total histone deacetylase (HDAC) activity, histone acetyltransferase (HAT) activity, acetylated histones, and acetylated SP1 were similar between IPAH and FD, treatment with two selective class I HDAC inhibitors increased SOD3 only in IPAH PASMC. Class I HDAC3 siRNA also increased SOD3 expression. Trichostatin A, a pan-HDAC inhibitor, decreased proliferation in IPAH, but not in FD PASMC. These data indicate that histone deacetylation, specifically via class I HDAC3, decreases SOD3 expression in PASMC and HDAC inhibitors may protect IPAH in part by increasing PASMC SOD3 expression. PMID:27233998

  10. Expression, subcellular localization, and enzyme activity of a recombinant human extra-cellular superoxide dismutase in tobacco (Nicotiana benthamiana L.).

    PubMed

    Park, Ki Youl; Kim, Eun Yu; Lee, Weontae; Kim, Tae-Yoon; Kim, Woo Taek

    2016-03-01

    Human extracellular superoxide dismutase (hEC-SOD) is an enzyme that scavenges reactive oxygen species (ROS). Because of its antioxidant activity, hEC-SOD has been used as a therapeutic protein to treat skin disease and arthritis in mammalian systems. In this study, codon-optimized hEC-SOD was expressed in tobacco (Nicotiana benthamiana L.) via a plant-based transient protein expression system. Plant expression binary vectors containing full-length hEC-SOD (f-hEC-SOD) and modified hEC-SOD (m-hEC-SOD), in which the signal peptide and heparin-binding domain were deleted, were constructed for the cytosolic-, endoplasmic reticulum (ER)-, and chloroplast-localizations in tobacco leaf mesophyll cells. The results demonstrated that f-hEC-SOD was more efficiently expressed in the cytosolic fractions than in the ER or chloroplasts of tobacco cells. Our data further indicated that differently localized f-hEC-SOD and m-hEC-SOD displayed SOD enzyme activities, suggesting that the hEC-SODs expressed by plants may be functionally active. The f-hEC-SOD was expressed up to 3.8% of the total leaf soluble protein and the expression yield was calculated to be 313.7 μg f-hEC-SOD per g fresh weight of leaf. Overall, our results reveal that it was possible to express catalytically active hEC-SODs by means of a transient plant expression system in tobacco leaf cells. PMID:26611610

  11. Extracellular Superoxide Dismutase Activity and Plasma Malondialdehyde in Human Immunodeficiency Virus Subjects of Kano State as Surrogate Markers of CD4 Status

    PubMed Central

    Gwarzo, Muhammad Yalwa; Muhammad, Surajo Al-Kassim

    2010-01-01

    This study looked at the profile of plasma extracellular superoxide dismutase (SOD3) activity, malondialdehyde (MDA) vis-à-vis that of CD4 counts in human immunodeficiency virus subjects in Kano State, Nigeria. The subjects for this study comprised twenty (20) non-HIV infected volunteers as control and one hundred (100) HIV infected subjects. Forty nine (49) infected patients have not been on treatment, while fifty one (51) were at various stages of treatment. There was a negative correlation between the serum malondialdehyde concentration and CD4 count (Pearson r=−0.68, p<0.01). There was also a negative correlation between serum malondialdehyde concentration and extracellular superoxide dismutase activity ((Pearson r=−0.71, p<0.01) and Vitamin A concentration (Pearson r=−0.75; p<0.01). Conversely a positive correlation was observed between the CD4 counts in HIV infected patients and activity of extracellular superoxide dismutase (Pearson r=0.86, p<0.01). Similarly there was a positive correlation between CD4 count and serum vitamin A concentration (Pearson r=0.89 p<0.01). The possibility remains for using these indicators to monitor HIV patients not eligible for therapy in resource constrained facilities of our rural areas. PMID:23675205

  12. Inhibition of superoxide anion production by extracellular acidification in neutrophils.

    PubMed

    Murata, Naoya; Mogi, Chihiro; Tobo, Masayuki; Nakakura, Takashi; Sato, Koichi; Tomura, Hideaki; Okajima, Fumikazu

    2009-01-01

    Extracellular acidification inhibited formyl-Met-Leu-Phe- or C5a-induced superoxide anion (O(2)(-)) production in differentiated HL-60 neutrophil-like cells and human neutrophils. A cAMP-increasing agonist, prostaglandin E(1), also inhibited the formyl peptide-induced O(2)(-) production. The inhibitory action on the O(2)(-) production by extracellular acidic pH was associated with cAMP accumulation and partly attenuated by H89, a protein kinase A inhibitor. A significant amount of mRNAs for T-cell death-associated gene 8 (TDAG8) and other proton-sensing ovarian cancer G-protein-coupled receptor 1 (OGR1)-family receptors is expressed in these cells. These results suggest that cAMP/protein kinase A, possibly through proton-sensing G-protein-coupled receptors, may be involved in extracellular acidic pH-induced inhibition of O(2)(-) production. PMID:19539899

  13. Widespread Production of Extracellular Superoxide by Heterotrophic Bacteria

    NASA Astrophysics Data System (ADS)

    Diaz, Julia M.; Hansel, Colleen M.; Voelker, Bettina M.; Mendes, Chantal M.; Andeer, Peter F.; Zhang, Tong

    2013-06-01

    Superoxide and other reactive oxygen species (ROS) originate from several natural sources and profoundly influence numerous elemental cycles, including carbon and trace metals. In the deep ocean, the permanent absence of light precludes currently known ROS sources, yet ROS production mysteriously occurs. Here, we show that taxonomically and ecologically diverse heterotrophic bacteria from aquatic and terrestrial environments are a vast, unrecognized, and light-independent source of superoxide, and perhaps other ROS derived from superoxide. Superoxide production by a model bacterium within the ubiquitous Roseobacter clade involves an extracellular oxidoreductase that is stimulated by the reduced form of nicotinamide adenine dinucleotide (NADH), suggesting a surprising homology with eukaryotic organisms. The consequences of ROS cycling in immense aphotic zones representing key sites of nutrient regeneration and carbon export must now be considered, including potential control of carbon remineralization and metal bioavailability.

  14. Functional characterization and immune recognition of the extracellular superoxide dismutase from the human pathogenic parasite Onchocerca volvulus (OvEC-SOD).

    PubMed

    Ajonina-Ekoti, Irene; Ndjonka, Dieudonne; Tanyi, Manchang Kingsley; Wilbertz, Meike; Younis, Abuelhassan Elshazly; Boursou, Djafsia; Kurosinski, Marc Andre; Eberle, Raphael; Lüersen, Kai; Perbandt, Markus; Breloer, Minka; Brattig, Norbert W; Liebau, Eva

    2012-10-01

    Onchocerca volvulus is a human pathogenic filarial nematode causing chronic onchocerciasis, a disease characterized by chronic skin and eye lesions. Despite attempts to control this infection from many perspectives, it still remains a threat to public health because of adverse effects of available drugs and recent reports of drug resistance. Under control of an intact immune system, O. volvulus survives for a long time in the host by employing a variety of strategies including the utility of antioxidant enzymes. In the present study, we focus on the extracellular superoxide dismutase from O. volvulus (OvEC-SOD) found in the excretory/secretory products of adult worms. Contrary to previous studies, the OvEC-SOD was found to have a 19 amino acid long signal peptide that is cleaved off during the process of maturation. To validate this result, we designed a novel method based on Caenorhabditis elegans cup5(ar465) mutants to specifically evaluate signal peptide-mediated secretion of nematodal proteins. Following purification, the recombinant OvEC-SOD was active as a dimer. Site-directed mutagenesis of the three cysteines present in the OvEC-SOD shows that enzyme activity is markedly reduced in the Cys-192 mutant. A homology model of the OvEC-SOD underlines the importance of Cys-192 for the stabilization of the adjacent active site channel. The generation of a humoral immune response to secretory OvEC-SOD was indicated by demonstrating IgG reactivity in sera from patients infected with O. volvulus while the cross-reactivity of IgG in plasma samples from cows, infected with the most closely related parasite Onchocerca ochengi, occurred only marginally. High IgG1 and IgM titres were recorded in sera from mice infected with the filaria Litomosoides sigmodontis, however, low or no cellular proliferative responses were observed. Thus, the present data suggest that secretory OvEC-SOD is a target of the humoral immune response in human onchocerciasis and induced strongest Ig

  15. Extracellular Superoxide Dismutase: Growth Promoter or Tumor Suppressor?

    PubMed Central

    Laukkanen, Mikko O.

    2016-01-01

    Extracellular superoxide dismutase (SOD3) gene transfer to tissue damage results in increased healing, increased cell proliferation, decreased apoptosis, and decreased inflammatory cell infiltration. At molecular level, in vivo SOD3 overexpression reduces superoxide anion (O2−) concentration and increases mitogen kinase activation suggesting that SOD3 could have life-supporting characteristics. The hypothesis is further strengthened by the observations showing significantly increased mortality in conditional knockout mice. However, in cancer SOD3 has been shown to either increase or decrease cell proliferation and survival depending on the model system used, indicating that SOD3-derived growth mechanisms are not completely understood. In this paper, the author reviews the main discoveries in SOD3-dependent growth regulation and signal transduction. PMID:27293512

  16. Extracellular Superoxide Dismutase: Growth Promoter or Tumor Suppressor?

    PubMed

    Laukkanen, Mikko O

    2016-01-01

    Extracellular superoxide dismutase (SOD3) gene transfer to tissue damage results in increased healing, increased cell proliferation, decreased apoptosis, and decreased inflammatory cell infiltration. At molecular level, in vivo SOD3 overexpression reduces superoxide anion (O2 (-)) concentration and increases mitogen kinase activation suggesting that SOD3 could have life-supporting characteristics. The hypothesis is further strengthened by the observations showing significantly increased mortality in conditional knockout mice. However, in cancer SOD3 has been shown to either increase or decrease cell proliferation and survival depending on the model system used, indicating that SOD3-derived growth mechanisms are not completely understood. In this paper, the author reviews the main discoveries in SOD3-dependent growth regulation and signal transduction. PMID:27293512

  17. Mice lacking extracellular superoxide dismutase are more sensitive to hyperoxia.

    PubMed Central

    Carlsson, L M; Jonsson, J; Edlund, T; Marklund, S L

    1995-01-01

    Extracellular superoxide dismutase (EC-SOD; superoxide:superoxide oxidoreductase, EC 1.15.1.1) is a secreted Cu- and Zn-containing tetrameric glycoprotein, the bulk of which is bound to heparan sulfate proteoglycans in the interstitium of tissues. To test the function of EC-SOD in vivo, mice carrying a targeted disruption of the EC-SOD gene were generated. The EC-SOD null mutant mice develop normally and remain healthy until at least 14 months of age. No compensatory induction of other SOD isoenzymes or other antioxidant enzymes was observed. When stressed by exposure to > 99% oxygen, the EC-SOD null mutant mice display a considerable reduction in survival time compared to wild-type mice and an earlier onset of severe lung edema. These findings suggest that while under normal physiological conditions other antioxidant systems may substitute for the loss of EC-SOD; when the animal is stressed these systems are unable to provide adequate protection. Images Fig. 1 PMID:7603981

  18. Dual gene therapy with extracellular superoxide dismutase and catalase attenuates experimental optic neuritis

    PubMed Central

    Qi, Xiaoping; Hauswirth, William W.

    2007-01-01

    Purpose To ameliorate experimental optic neuritis by combining scavenging of superoxide by germ line increases in the extracellular superoxide dismutase (ECSOD) and hydrogen peroxide by viral-mediated gene transfer of the human catalase gene. Methods The human catalase gene inserted into recombinant adeno-associated virus (rAAV) was injected into the right eyes of transgenic mice overexpressing human ECSOD and wild-type littermates. Animals were simultaneously sensitized for experimental autoimmune encephalomyelitis (EAE) and then sacrificed one month later. The effects of antioxidant genes (ECSOD and catalase) on the histologic lesions of EAE were measured by computerized analysis of myelin area, optic disc area, extent of the cellular infiltrate, cerium derived H2O2 reaction product and extravasation of serum albumin detected by immunogold. Results Combined scavenging of H2O2 and superoxide with ECSOD and catalase suppressed demyelination by 72%, 54% due to catalase, and 19% due to ECSOD. Disruption of the blood-brain barrier was reduced 63% by the combined effects of catalase and ECSOD, 35% due to catalase and 29% due to ECSOD. Conclusions Transgene modulation of antioxidant enzyme defenses against both superoxide and its metabolite H2O2 provide a substantial suppressive effect against EAE in the optic nerve that may be a new therapeutic strategy for suppression of optic neuritis and multiple sclerosis. PMID:17242675

  19. A non-glycosylated extracellular superoxide dismutase variant.

    PubMed Central

    Edlund, A; Edlund, T; Hjalmarsson, K; Marklund, S L; Sandström, J; Strömqvist, M; Tibell, L

    1992-01-01

    The secretory tetrameric extracellular superoxide dismutase (EC-SOD) is the only glycosylated SOD isoenzyme. The importance of the carbohydrate moiety for the properties of the enzyme is unknown. An expression vector defining nonglycosylated EC-SOD (ngEC-SOD) was constructed by mutagenesis of the codon for Asn-89 into a codon for Gln. The vector was transfected into Chinese hamster ovary DXB-11 cells and ngEC-SOD was isolated to 70% purity from the culture media of selected clones. The absence of glycosylation was established by the lack of affinity for various lectins, the absence of staining with the periodic acid-Schiff reagent, the change in mobility and composition of the tryptic peptide containing the mutated glycosylation site, and the reduction in apparent molecular mass upon SDS/PAGE and size-exclusion chromatography. The tetrameric state was retained. The heparin affinity, a fundamental and distinguishing property of EC-SOD, was found to be slightly increased. The enzymic activity was essentially retained. The major difference from native glycosylated enzyme in physical properties was a marked reduction in solubility. Like glycosylated EC-SOD, ngEC-SOD was, after intravenous injection into rabbits, rapidly sequestered by the vessel endothelium, and was promptly released into plasma after injection of heparin. The only difference from glycosylated EC-SOD in this behaviour, was a slightly more rapid elimination of the mutant enzyme from the vasculature. It is concluded that no specific biological role for the EC-SOD carbohydrate moiety could be revealed. Images Fig. 1. PMID:1463450

  20. Extracellular Superoxide Dismutase Regulates Cardiac Function and Fibrosis

    PubMed Central

    Kliment, Corrine R; Suliman, Hagir B; Tobolewski, Jacob M; Reynolds, Crystal M; Day, Brian J; Zhu, Xiaodong; McTiernan, Charles F; McGaffin, Kenneth R; Piantadosi, Claude A; Oury, Tim D

    2009-01-01

    Aims Extracellular superoxide dismutase (EC-SOD) is an antioxidant that protects the heart from ischemia and the lung from inflammation and fibrosis. The role of cardiac EC-SOD under normal conditions and injury remains unclear. Cardiac toxicity, a common side effect of doxorubicin, involves oxidative stress. We hypothesize that EC-SOD is critical for normal cardiac function and protects the heart from oxidant-induced fibrosis and loss of function. Methods C57BL/6 and EC-SOD-null mice were treated with doxorubicin, 15 mg/kg (i.p.). After 15 days, echocardiography was used to assess cardiac function. Left ventricle (LV) tissue was used to assess fibrosis and inflammation by staining, western blot, and hydroxyproline analysis. Results At baseline EC-SOD-null mice have LV wall thinning and increases in LV end diastolic dimensions compared to wild type mice, but have normal cardiac function. After doxorubicin, EC-SOD-null mice have decreases in fractional shortening not apparent in WT mice. Lack of EC-SOD also leads to increases in myocardial apoptosis and significantly more LV fibrosis and inflammatory cell infiltration. Administration of the metalloporphyrin AEOL 10150 abrogates the loss of cardiac function, and potentially fibrosis, associated with doxorubicin treatment in both wild type and EC-SOD KO mice. Conclusions EC-SOD is critical for normal cardiac morphology and protects the heart from oxidant-induced fibrosis, apoptosis and loss of function. The antioxidant metalloporphyrin, AEOL 10150 effectively protects cardiac function from doxorubicin-induced oxidative stress, in vivo. These findings identify targets for the use of antioxidant agents in oxidant-induced cardiac fibrosis. PMID:19695260

  1. Extracellular superoxide dismutase in insects: characterization, function, and interspecific variation in parasitoid wasp venom.

    PubMed

    Colinet, Dominique; Cazes, Dominique; Belghazi, Maya; Gatti, Jean-Luc; Poirié, Marylène

    2011-11-18

    Endoparasitoid wasps inject venom proteins with their eggs to protect them from the host immune response and ensure successful parasitism. Here we report identification of Cu,Zn superoxide dismutase (SOD) transcripts for both intracellular SOD1 and extracellular SOD3 in the venom apparatus of two Leptopilina species, parasitoids of Drosophila. Leptopilina SODs show sequence and structure similarity to human SODs, but phylogenetic analyses indicate that the extracellular SODs are more related to cytoplasmic vertebrate SODs than to extracellular SODs, a feature shared by predicted insect extracellular SODs. We demonstrate that L. boulardi SOD3 is indeed secreted and active as monomeric glycosylated forms in venom. Our results also evidence quantitative variation in SOD3 venom contents between closely related parasitoid species, as sod3 is 100-fold less expressed in Leptopilina heterotoma venom apparatus and no protein and SOD activity are detected in its venom. Leptopilina recombinant SOD3s as well as a mammalian SOD in vitro inhibit the Drosophila phenoloxidase activity in a dose-dependent manner, demonstrating that SODs may interfere with the Drosophila melanization process and, therefore, with production of cytotoxic compounds. Although the recombinant L. boulardi SOD3 quantity needed to observe this effect precludes a systemic effect of the wasp venom SOD3, it is still consistent with a local action at oviposition. This work provides the first demonstration that insect extracellular SODs are indeed secreted and active in an insect fluid and can be used as virulence factors to counteract the host immune response, a strategy largely used by bacterial and fungal pathogens but also protozoan parasites during infection. PMID:21937434

  2. Molecular cloning of an Onchocerca volvulus extracellular Cu-Zn superoxide dismutase.

    PubMed Central

    James, E R; McLean, D C; Perler, F

    1994-01-01

    Onchocerca volvulus, a human parasitic nematode, is the third leading cause of preventable blindness worldwide. This study describes the molecular cloning of a novel superoxide dismutase (SOD) from the parasite. This putative O. volvulus extracellular SOD (OvEcSOD) is 628 nucleotides (nt) long, including a 22-nt 5' spliced leader (SL1) and a portion encoding an N-terminal hydrophobic 42-amino-acid signal peptide. The remainder of the cDNA shares 71% identity with an O. volvulus cytosolic SOD sequence and is 3 nt longer. All residues involved in metal ion binding, active site formation, folding, and dimer formation in SODs are conserved. Data indicate the OvEcSOD and O. volvulus cytosolic SOD are separate gene products and that the OvEcSOD appears to possess the characteristics of a membrane-bound or secreted enzyme which may be involved in the parasite defense against phagocyte-generated reactive oxygen species. Images PMID:8300230

  3. Extracellular Production and Degradation of Superoxide in the Coral Stylophora pistillata and Cultured Symbiodinium

    PubMed Central

    Saragosti, Eldad; Tchernov, Dan; Katsir, Adi; Shaked, Yeala

    2010-01-01

    Background Reactive oxygen species (ROS) are thought to play a major role in cell death pathways and bleaching in scleractinian corals. Direct measurements of ROS in corals are conspicuously in short supply, partly due to inherent problems with ROS quantification in cellular systems. Methodology/Principal Findings In this study we characterized the dynamics of the reactive oxygen species superoxide anion radical (O2−) in the external milieu of the coral Stylophora pistillata. Using a sensitive, rapid and selective chemiluminesence-based technique, we measured extracellular superoxide production and detoxification activity of symbiont (non-bleached) and aposymbiont (bleached) corals, and of cultured Symbiodinium (from clades A and C). Bleached and non-bleached Stylophora fragments were found to produce superoxide at comparable rates of 10−11–10−9 mol O2− mg protein−1 min−1 in the dark. In the light, a two-fold enhancement in O2− production rates was observed in non-bleached corals, but not in bleached corals. Cultured Symbiodinium produced superoxide in the dark at a rate of . Light was found to markedly enhance O2− production. The NADPH Oxidase inhibitor Diphenyleneiodonium chloride (DPI) strongly inhibited O2− production by corals (and more moderately by algae), possibly suggesting an involvement of NADPH Oxidase in the process. An extracellular O2− detoxifying activity was found for bleached and non-bleached Stylophora but not for Symbiodinium. The O2− detoxifying activity was partially characterized and found to resemble that of the enzyme superoxide dismutase (SOD). Conclusions/Significance The findings of substantial extracellular O2− production as well as extracellular O2− detoxifying activity may shed light on the chemical interactions between the symbiont and its host and between the coral and its environment. Superoxide production by Symbiodinium possibly implies that algal bearing corals are more susceptible to an internal

  4. Involvement of Extracellular Cu/Zn Superoxide Dismutase in Cotton Fiber Primary and Secondary Cell Wall Biosynthesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extracellular Cu/Zn superoxide dismutases (CSDs) that catalyze the conversion of superoxide to hydrogen peroxide have been suggested to be involved in lignification of secondary walls in spinach, pine and aspen. In cotton fibers, hydrogen peroxide was proposed to be involved in the induction of seco...

  5. A common theme in extracellular fluids of beetles: extracellular superoxide dismutases crucial for balancing ROS in response to microbial challenge

    PubMed Central

    Gretscher, René R.; Streicher, Priska E.; Strauß, Anja S.; Wielsch, Natalie; Stock, Magdalena; Wang, Ding; Boland, Wilhelm; Burse, Antje

    2016-01-01

    Extracellular Cu/Zn superoxide dismutases (SODs) are critical for balancing the level of reactive oxygen species in the extracellular matrix of eukaryotes. In the present study we have detected constitutive SOD activity in the haemolymph and defensive secretions of different leaf beetle species. Exemplarily, we have chosen the mustard leaf beetle, Phaedon cochleariae, as representative model organism to investigate the role of extracellular SODs in antimicrobial defence. Qualitative and quantitative proteome analyses resulted in the identification of two extracellular Cu/Zn SODs in the haemolymph and one in the defensive secretions of juvenile P. cochleariae. Furthermore, quantitative expression studies indicated fat body tissue and defensive glands as the main synthesis sites of these SODs. Silencing of the two SODs revealed one of them, PcSOD3.1, as the only relevant enzyme facilitating SOD activity in haemolymph and defensive secretions in vivo. Upon challenge with the entomopathogenic fungus, Metarhizium anisopliae, PcSOD3.1-deficient larvae exhibited a significantly higher mortality compared to other SOD-silenced groups. Hence, our results serve as a basis for further research on SOD regulated host-pathogen interactions. In defensive secretions PcSOD3.1-silencing affected neither deterrent production nor activity against fungal growth. Instead, we propose another antifungal mechanism based on MRJP/yellow proteins in the defensive exudates. PMID:27068683

  6. Extracellular superoxide dismutase deficiency impairs wound healing in advanced age by reducing neovascularization and fibroblast function

    PubMed Central

    Fujiwara, Toshihiro; Duscher, Dominik; Rustad, Kristine C.; Kosaraju, Revanth; Rodrigues, Melanie; Whittam, Alexander J.; Januszyk, Michael; Maan, Zeshaan N.; Gurtner, Geoffrey C.

    2016-01-01

    Advanced age is characterized by impairments in wound healing, and evidence is accumulating that this may be due in part to a concomitant increase in oxidative stress. Extended exposure to reactive oxygen species (ROS) is thought to lead to cellular dysfunction and organismal death via the destructive oxidation of intra-cellular proteins, lipids and nucleic acids. Extracellular superoxide dismutase (ecSOD/SOD3) is a prime antioxidant enzyme in the extracellular space that eliminates ROS. Here, we demonstrate that reduced SOD3 levels contribute to healing impairments in aged mice. These impairments include delayed wound closure, reduced neovascularization, impaired fibroblast proliferation and increased neutrophil recruitment. We further establish that SOD3 KO and aged fibroblasts both display reduced production of TGF-β1, leading to decreased differentiation of fibroblasts into myofibroblasts. Taken together, these results suggest that wound healing impairments in ageing are associated with increased levels of ROS, decreased SOD3 expression and impaired extracellular oxidative stress regulation. Our results identify SOD3 as a possible target to correct age-related cellular dysfunction in wound healing. PMID:26663425

  7. Ras Oncogene-Mediated Progressive Silencing of Extracellular Superoxide Dismutase in Tumorigenesis

    PubMed Central

    Cammarota, Francesca; de Vita, Gabriella; Salvatore, Marco; Laukkanen, Mikko O.

    2015-01-01

    Extracellular superoxide dismutase (SOD3) is a secreted enzyme that uses superoxide anion as a substrate in a dismutase reaction that results in the formation of hydrogen peroxide. Both of these reactive oxygen species affect growth signaling in cells. Although SOD3 has growth-supporting characteristics, the expression of SOD3 is downregulated in epithelial cancer cells. In the current work, we studied the mechanisms regulating SOD3 expression in vitro using thyroid cell models representing different stages of thyroid cancer. We demonstrate that a low level of RAS activation increases SOD3 mRNA synthesis that then gradually decreases with increasing levels of RAS activation and the decreasing degree of differentiation of the cancer cells. Our data indicate that SOD3 regulation can be divided into two classes. The first class involves RAS–driven reversible regulation of SOD3 expression that can be mediated by the following mechanisms: RAS GTPase regulatory genes that are responsible for SOD3 self-regulation; RAS-stimulated p38 MAPK activation; and RAS-activated increased expression of the mir21 microRNA, which inversely correlates with sod3 mRNA expression. The second class involves permanent silencing of SOD3 mediated by epigenetic DNA methylation in cells that represent more advanced cancers. Therefore, the work suggests that SOD3 belongs to the group of ras oncogene-silenced genes. PMID:26550576

  8. Extracellular haem peroxidases mediate Mn(II) oxidation in a marine Roseobacter bacterium via superoxide production.

    PubMed

    Andeer, Peter F; Learman, Deric R; McIlvin, Matt; Dunn, James A; Hansel, Colleen M

    2015-10-01

    Manganese (Mn) oxides are among the strongest sorbents and oxidants in environmental systems. A number of biotic and abiotic pathways induce the oxidation of Mn(II) to Mn oxides. Here, we use a combination of proteomic analyses and activity assays, to identify the enzyme(s) responsible for extracellular superoxide-mediated Mn oxide formation by a bacterium within the ubiquitous Roseobacter clade. We show that animal haem peroxidases (AHPs) located on the outer membrane and within the secretome are responsible for Mn(II) oxidation. These novel peroxidases have previously been implicated in direct Mn(II) oxidation by phylogenetically diverse bacteria. Yet, we show that in this Roseobacter species, AHPs mediate Mn(II) oxidation not through a direct reaction but by producing superoxide and likely also by degrading hydrogen peroxide. These findings point to a eukaryotic-like oscillatory oxidative-peroxidative enzymatic cycle by these AHPs that leads to Mn oxide formation by this organism. AHP expression appears unaffected by Mn(II), yet the large energetic investment required to produce and secrete these enzymes points to an as yet unknown physiological function. These findings are further evidence that bacterial peroxidases and secreted enzymes, in general, are unappreciated controls on the cycling of metals and reactive oxygen species (ROS), and by extension carbon, in natural systems. PMID:25923595

  9. Extracellular but not cytosolic superoxide dismutase protects against oxidant-mediated endothelial dysfunction.

    PubMed

    Foresman, Erin L; Miller, Francis J

    2013-01-01

    Superoxide (O2 (•-)) contributes to the development of cardiovascular disease. Generation of O2 (•-) occurs in both the intracellular and extracellular compartments. We hypothesized that the gene transfer of cytosolic superoxide dismutase (SOD1) or extracellular SOD (SOD3) to blood vessels would differentially protect against O2 (•-)-mediated endothelial-dependent dysfunction. Aortic ring segments from New Zealand rabbits were incubated with adenovirus (Ad) containing the gene for Escherichia coli β-galactosidase, SOD1, or SOD3. Activity assays confirmed functional overexpression of both SOD3 and SOD1 isoforms in aorta 24 h following gene transfer. Histochemical staining for β-galactosidase showed gene transfer occurred in the endothelium and adventitia. Next, vessels were prepared for measurement of isometric tension in Kreb's buffer containing xanthine. After precontraction with phenylephrine, xanthine oxidase impaired relaxation to the endothelium-dependent dilator acetylcholine (ACh, max relaxation 33±4% with XO vs. 64±3% without XO, p<0.05), whereas relaxation to the endothelium-independent dilator sodium nitroprusside was unaffected. In the presence of XO, maximal relaxation to ACh was improved in vessels incubated with AdSOD3 (55±2%, p<0.05 vs. control) but not AdSOD1 (34±4%). We conclude that adenoviral-mediated gene transfer of SOD3, but not SOD1, protects the aorta from xanthine/XO-mediated endothelial dysfunction. These data provide important insight into the location and enzymatic source of O2 (•-) production in vascular disease. PMID:24024163

  10. Cloning and expression analysis of Drosophila extracellular Cu Zn superoxide dismutase.

    PubMed

    Blackney, Michael J; Cox, Rebecca; Shepherd, David; Parker, Joel D

    2014-01-01

    In the present study, we cloned and sequenced the mRNAs of the Sod3 [extracellular Cu Zn SOD (superoxide dismutase)] gene in Drosophila and identified two mRNA products formed by alternative splicing. These products code for a long and short protein derived from the four transcripts found in global expression studies (Flybase numbers Dmel\\CG9027, FBgn0033631). Both mRNA process variants contain an extracellular signalling sequence, a region of high homology to the Sod1 (cytoplasmic Cu Zn SOD) including a conserved AUG start, with the longer form also containing a hydrophobic tail. The two fully processed transcripts are homologous to Caenorhabditis elegans Sod3 mRNA showing the same processing pattern. Using an established KG p-element+ insertion line (KG06029), we demonstrate that the Sod3 codes for an active Cu Zn SOD. We found differing expression patterns across sex with higher levels of expression of Sod3 in females. There is a correlation of Sod1 and Sod3 gene expression and activity that can explain why Sod3 was not seen in earlier studies of Sod1. Finally, we found no effect on lifespan with the Sod3 hypomorph mutation (Sod3KG06029) but did observe a significant increase in resistance to paraquat and H2O2 (hydrogen peroxide). PMID:25339624

  11. Hydropropidine: A novel, cell-impermeant fluorogenic probe for detecting extracellular superoxide

    PubMed Central

    Michalski, Radoslaw; Zielonka, Jacek; Hardy, Micael; Joseph, Joy; Kalyanaraman, Balaraman

    2013-01-01

    Here we report the synthesis and characterization of a membrane-impermeant fluorogenic probe, hydropropidine (HPr+), the reduction product of propidium iodide, for detecting extracellular superoxide (O2·−). HPr+ is a positively-charged water-soluble analog of hydroethidine (HE), a fluorogenic probe commonly used for monitoring intracellular O2·−. We hypothesized that the presence of a highly localized positive charge on the nitrogen atom would impede cellular uptake of HPr+ and allow for exclusive detection of extracellular O2·−. Our results indicate that O2·− reacts with HPr+ (k = 1.2 × 104 M−1s−1) to form exclusively 2-hydroxypropidium (2-OH-Pr++) in cell-free and cell-based systems. This reaction is analogous to the reaction between HE and O2·− (Zhao H et al. Free Radic Biol Med 34:1359-68, 2003). During the course of this investigation, we also reassessed the rate constants for the reactions of O2·− with HE and its mitochondria targeted analog (Mito-HE or Mito-SOX Red®) and addressed the discrepancies between the present values and those reported previously by us. Our results indicate that the rate constant between O2·− and HPr+ is slightly higher than that of HE and O2·− and is closer to that of Mito-HE and O2·−. Similar to HE, HPr+ undergoes oxidation in the presence of various oxidants (peroxynitrite – derived radicals, Fenton’s reagent, and ferricytochrome c) forming the corresponding propidium dication (Pr++) and the dimeric products (e.g., Pr++-Pr++). In contrast to HE, there was very little intracellular uptake of HPr+. We conclude that HPr+ is a useful probe for detecting O2·− and other one-electron oxidizing species in an extracellular milieu. PMID:23051008

  12. Extracellular Superoxide Dismutase Regulates the Expression of Small GTPase Regulatory Proteins GEFs, GAPs, and GDI

    PubMed Central

    Laukkanen, Mikko O.; Cammarota, Francesca; Esposito, Tiziana; Salvatore, Marco; Castellone, Maria D.

    2015-01-01

    Extracellular superoxide dismutase (SOD3), which catalyzes the dismutation of superoxide anions to hydrogen peroxide at the cell membranes, regulates the cellular growth in a dose-dependent manner. This enzyme induces primary cell proliferation and immortalization at low expression levels whereas it activates cancer barrier signaling through the p53-p21 pathway at high expression levels, causing growth arrest, senescence, and apoptosis. Because previous reports suggested that the SOD3–induced reduction in the rates of cellular growth and migration also occurred in the absence of functional p53 signaling, in the current study we investigated the SOD3-induced growth-suppressive mechanisms in anaplastic thyroid cancer cells. Based on our data, the robust over-expression of SOD3 increased the level of phosphorylation of the EGFR, ERBB2, RYK, ALK, FLT3, and EPHA10 receptor tyrosine kinases with the consequent downstream activation of the SRC, FYN, YES, HCK, and LYN kinases. However, pull-down experiments focusing on the small GTPase RAS, RAC, CDC42, and RHO revealed a reduced level of growth and migration signal transduction, such as the lack of stimulation of the mitogen pathway, in the SOD3 over-expressing cells, which was confirmed by MEK1/2 and ERK1/2 Western blotting analysis. Interestingly, the mRNA expression analyses indicated that SOD3 regulated the expression of guanine nucleotide-exchange factors (RHO GEF16, RAL GEF RGL1), GTPase-activating proteins (ARFGAP ADAP2, RAS GAP RASAL1, RGS4), and a Rho guanine nucleotide-disassociation inhibitor (RHO GDI 2) in a dose dependent manner, thus controlling signaling through the small G protein GTPases. Therefore, our current data may suggest the occurrence of dose-dependent SOD3–driven control of the GTP loading of small G proteins indicating a novel growth regulatory mechanism of this enzyme. PMID:25751262

  13. Extracellular superoxide dismutase regulates the expression of small gtpase regulatory proteins GEFs, GAPs, and GDI.

    PubMed

    Laukkanen, Mikko O; Cammarota, Francesca; Esposito, Tiziana; Salvatore, Marco; Castellone, Maria D

    2015-01-01

    Extracellular superoxide dismutase (SOD3), which catalyzes the dismutation of superoxide anions to hydrogen peroxide at the cell membranes, regulates the cellular growth in a dose-dependent manner. This enzyme induces primary cell proliferation and immortalization at low expression levels whereas it activates cancer barrier signaling through the p53-p21 pathway at high expression levels, causing growth arrest, senescence, and apoptosis. Because previous reports suggested that the SOD3-induced reduction in the rates of cellular growth and migration also occurred in the absence of functional p53 signaling, in the current study we investigated the SOD3-induced growth-suppressive mechanisms in anaplastic thyroid cancer cells. Based on our data, the robust over-expression of SOD3 increased the level of phosphorylation of the EGFR, ERBB2, RYK, ALK, FLT3, and EPHA10 receptor tyrosine kinases with the consequent downstream activation of the SRC, FYN, YES, HCK, and LYN kinases. However, pull-down experiments focusing on the small GTPase RAS, RAC, CDC42, and RHO revealed a reduced level of growth and migration signal transduction, such as the lack of stimulation of the mitogen pathway, in the SOD3 over-expressing cells, which was confirmed by MEK1/2 and ERK1/2 Western blotting analysis. Interestingly, the mRNA expression analyses indicated that SOD3 regulated the expression of guanine nucleotide-exchange factors (RHO GEF16, RAL GEF RGL1), GTPase-activating proteins (ARFGAP ADAP2, RAS GAP RASAL1, RGS4), and a Rho guanine nucleotide-disassociation inhibitor (RHO GDI 2) in a dose dependent manner, thus controlling signaling through the small G protein GTPases. Therefore, our current data may suggest the occurrence of dose-dependent SOD3-driven control of the GTP loading of small G proteins indicating a novel growth regulatory mechanism of this enzyme. PMID:25751262

  14. Superoxide radicals increase transforming growth factor-{beta}1 and collagen release from human lung fibroblasts via cellular influx through chloride channels

    SciTech Connect

    Qi Shufan Hartog, Gertjan J.M. den; Bast, Aalt

    2009-05-15

    Reactive oxygen species (ROS) have been implicated in the pathogenesis of fibrosis. However, it remains unclear which ROS is the major cause. We hypothesize that superoxide elicits specific toxicity to human lung fibroblasts and plays an important role in the development of pulmonary fibrosis. In this study, superoxide generated from xanthine and xanthine oxidase activated lung fibroblasts by increasing the release of TGF-{beta}1 and collagen. This was associated with increased levels of intracellular superoxide. SOD and tempol, by scavenging respectively extracellular and intracellular superoxide, prevented the activation of fibroblasts induced by exposure to exogenous superoxide, whereas catalase did not. Moreover, hydrogen peroxide did not activate fibroblasts. Apparently, superoxide rather than hydrogen peroxide is involved in the regulation of TGF-{beta}1 and collagen release in lung fibroblasts. The chloride channel blocker, DIDS, inhibited the increase of intracellular superoxide levels induced by exogenous superoxide and consequently prevented the activation of fibroblasts. This suggests that the cellular influx of superoxide through chloride channels is essential for superoxide-induced activation of fibroblasts. ERK1/2 and p38 MAPKs are involved in the intracellular pathway leading to superoxide-induced fibroblasts activation. Superoxide possesses until now undiscovered specific pro-fibrotic properties in human lung fibroblasts. This takes place via the cellular influx of superoxide through chloride channels rather than via the formation of hydrogen peroxide.

  15. Overexpression of extracellular superoxide dismutase decreases lung injury after exposure to oil fly ash.

    PubMed

    Ghio, Andrew J; Suliman, Hagir B; Carter, Jacqueline D; Abushamaa, Amir M; Folz, Rodney J

    2002-07-01

    The mechanism of tissue injury after exposure to air pollution particles is not known. The biological effect has been postulated to be mediated via an oxidative stress catalyzed by metals present in particulate matter (PM). We utilized a transgenic (Tg) mouse model that overexpresses extracellular superoxide dismutase (EC-SOD) to test the hypothesis that lung injury after exposure to PM results from an oxidative stress in the lower respiratory tract. Wild-type (Wt) and Tg mice were intratracheally instilled with either saline or 50 microg of residual oil fly ash (ROFA). Twenty-four hours later, specimens were obtained and included bronchoalveolar lavage (BAL) and lung for both homogenization and light histopathology. After ROFA exposure, EC-SOD Tg mice showed a significant reduction in BAL total cell counts (composed primarily of neutrophils) and BAL total protein compared with Wt. EC-SOD animals also demonstrated diminished concentrations of inflammatory mediators in BAL. There was no statistically significant difference in BAL lipid peroxidation; however, EC-SOD mice had lower concentrations of oxidized glutathione in the BAL. We conclude that enhanced EC-SOD expression decreased both lung inflammation and damage after exposure to ROFA. This supports a participation of oxidative stress in the inflammatory injury after PM exposure rather than reflecting a response to metals alone. PMID:12060579

  16. Oxidized low-density lipoprotein accelerates the destabilization of extracellular-superoxide dismutase mRNA during foam cell formation.

    PubMed

    Makino, Junya; Nii, Miyuki; Kamiya, Tetsuro; Hara, Hirokazu; Adachi, Tetsuo

    2015-06-01

    Extracellular-superoxide dismutase (EC-SOD) is one of the main anti-oxidative enzymes that protect cells against the damaging effects of superoxide. In the present study, we investigated the regulation of EC-SOD expression during the oxidized low density lipoprotein (oxLDL)-induced foam cell formation of THP-1-derived macrophages. The uptake of oxLDL into THP-1-derived macrophages was increased and EC-SOD expression was decreased in a time-dependent manner by oxLDL. Furthermore, EC-SOD suppression by oxLDL was mediated by the binding to scavenger receptors, especially CD36, from the results with siRNA experience. EC-SOD expression is known to be regulated by histone acetylation and binding of the transcription factor Sp1/3 to the EC-SOD promoter region in human cell lines. However, oxLDL did not affect these processes. On the other hand, the stability of EC-SOD mRNA was decreased by oxLDL. Moreover, oxLDL promoted destabilization of ectopically expressed mRNA from EC-SOD or chimeric Cu,Zn-SOD gene with the sequence corresponding to 3'UTR of EC-SOD mRNA, whereas oxLDL had no effect on ectopic mRNA produced from EC-SOD gene lacking the sequence. These results suggested that oxLDL decreased the expression of EC-SOD, which, in turn, accelerated the destabilization of EC-SOD mRNA, leading to weaker protection against oxidative stress and atherosclerosis. PMID:25906743

  17. Temperature and Light Effects on Extracellular Superoxide Production by Algal and Bacterial Symbionts in Corals: Implications for Coral Bleaching

    NASA Astrophysics Data System (ADS)

    Brighi, C.; Diaz, J. M.; Apprill, A.; Hansel, C. M.

    2014-12-01

    Increased surface seawater temperature due to global warming is one of the main causes of coral bleaching, a phenomenon in which corals lose their photosynthetic algae. Light and temperature induced production of superoxide and other reactive oxygen species (ROS) by these symbiotic algae has been implicated in the breakdown of their symbiotic association with the coral host and subsequent coral bleaching. Nevertheless, a direct link between Symbiodinium ROS production and coral bleaching has not been demonstrated. In fact, given the abundance and diversity of microorganisms within the coral holobiont, the concentration and fluxes of ROS within corals may involve several microbial sources and sinks. Here, we explore the role of increased light and temperature on superoxide production by coral-derived cultures of Symbiodinium algae and Oceanospirillales bacteria of the genus Endozoicomonas, which are globally common and abundant associates of corals. Using a high sensitivity chemiluminescent technique, we find that heat stress (exposure to 34°C vs. 23°C for 2hr or 24hr) has no significant effect on extracellular superoxide production by Symbiodinium isolates within clades B and C, regardless of the level of light exposure. Exposure to high light, however, increased superoxide production by these organisms at both 34°C and 23°C. On the other hand, extracellular superoxide production by Endozoicomonas bacteria tested under the same conditions was stimulated by the combined effects of thermal and light stress. The results of this research suggest that the sources and physical triggers for biological superoxide production within corals are more complex than currently assumed. Thus, further investigations into the biological processes controlling ROS dynamics within corals are required to improve our understanding of the mechanisms underpinning coral bleaching and to aid in the development of mitigation strategies.

  18. Extracellular superoxide dismutase protects against pulmonary emphysema by attenuating oxidative fragmentation of ECM

    PubMed Central

    Yao, Hongwei; Arunachalam, Gnanapragasam; Hwang, Jae-woong; Chung, Sangwoon; Sundar, Isaac K.; Kinnula, Vuokko L.; Crapo, James D.; Rahman, Irfan

    2010-01-01

    Extracellular superoxide dismutase (ECSOD or SOD3) is highly expressed in lungs and functions as a scavenger of O2• ─. ECM fragmentation, which can be triggered by oxidative stress, participates in the pathogenesis of chronic obstructive pulmonary disease (COPD) through attracting inflammatory cells into the lungs. The level of SOD3 is significantly decreased in lungs of patients with COPD. However, the role of endogenous SOD3 in the development/progression of emphysema is unknown. We hypothesized that SOD3 protects against emphysema by attenuating oxidative fragmentation of ECM in mice. To test this hypothesis, SOD3-deficient, SOD3-transgenic, and WT C57BL/6J mice were exposed to cigarette smoke (CS) for 3 d (300 mg total particulate matter/m3) to 6 mo (100 mg/m3 total particulate matter) or by intratracheal elastase injection. Airspace enlargement, lung inflammation, lung mechanical properties, and exercise tolerance were determined at different time points during CS exposure or after elastase administration. CS exposure and elastase administration caused airspace enlargement as well as impaired lung function and exercise capacity in SOD3-null mice, which were improved in mice overexpressing SOD3 and by pharmacological SOD mimetic. These phenomena were associated with SOD3-mediated protection against oxidative fragmentation of ECM, such as heparin sulfate and elastin, thereby attenuating lung inflammatory response. In conclusion, SOD3 attenuates emphysema and reduces oxidative fragmentation of ECM in mouse lung. Thus, pharmacological augmentation of SOD3 in the lung may have a therapeutic potential in the intervention of COPD/emphysema. PMID:20713693

  19. Effects of Altered Levels of Extracellular Superoxide Dismutase and Irradiation on Hippocampal Neurogenesis in Female Mice

    SciTech Connect

    Zou, Yani; Leu, David; Chui, Jennifer; Fike, John R.; Huang, Ting-Ting

    2013-11-15

    Purpose: Altered levels of extracellular superoxide dismutase (EC-SOD) and cranial irradiation have been shown to affect hippocampal neurogenesis. However, previous studies were only conducted in male mice, and it was not clear if there was a difference between males and females. Therefore, female mice were studied and the results compared with those generated in male mice from an earlier study. Methods and Materials: Female wild-type, EC-SOD-null (KO), and EC-SOD bigenic mice with neuronal-specific expression of EC-SOD (OE) were subjected to a single dose of 5-Gy gamma rays to the head at 8 weeks of age. Progenitor cell proliferation, differentiation, and long-term survival of newborn neurons were determined. Results: Similar to results from male mice, EC-SOD deficiency and irradiation both resulted in significant reductions in mature newborn neurons in female mice. EC-SOD deficiency reduced long-term survival of newborn neurons whereas irradiation reduced progenitor cell proliferation. Overexpression of EC-SOD corrected the negative impacts from EC-SOD deficiency and irradiation and normalized the production of newborn neurons in OE mice. Expression of neurotrophic factors brain-derived neurotrophic factor and neurotrophin-3 were significantly reduced by irradiation in wild-type mice, but the levels were not changed in KO and OE mice even though both cohorts started out with a lower baseline level. Conclusion: In terms of hippocampal neurogenesis, EC-SOD deficiency and irradiation have the same overall effects in males and females at the age the studies were conducted.

  20. Differential effects of superoxide dismutase and superoxide dismutase/catalase mimetics on human breast cancer cells.

    PubMed

    Shah, Manisha H; Liu, Guei-Sheung; Thompson, Erik W; Dusting, Gregory J; Peshavariya, Hitesh M

    2015-04-01

    Reactive oxygen species (ROS) such as superoxide and hydrogen peroxide (H2O2) have been implicated in development and progression of breast cancer. In the present study, we have evaluated the effects of the superoxide dismutase (SOD) mimetic MnTmPyP and the SOD/catalase mimetic EUK 134 on superoxide and H2O2 formation as well as proliferation, adhesion, and migration of MCF-7 and MDA-MB-231 cells. Superoxide and H2O2 production was examined using dihydroethidium and Amplex red assays, respectively. Cell viability and adhesion were measured using a tetrazolium-based MTT assay. Cell proliferation was determined using trypan blue assay. Cell cycle progression was analyzed using flow cytometry. Clonal expansion of a single cell was performed using a colony formation assay. Cell migration was measured using transwell migration assay. Dual luciferase assay was used to determine NF-κB reporter activity. EUK 134 effectively reduced both superoxide and H2O2, whereas MnTmPyP removed superoxide but enhanced H2O2 formation. EUK 134 effectively attenuated viability, proliferation, clonal expansion, adhesion, and migration of MCF-7 and MDA-MB-231 cells. In contrast, MnTmPyP only reduced clonal expansion of MCF-7 and MDA-MB-231 cells but had no effect on adhesion and cell cycle progression. Tumor necrosis factor-alpha-induced NF-κB activity was reduced by EUK 134, whereas MnTmPyP enhanced this activity. These data indicate that the SOD mimetic MnTmPyP and the SOD/catalase mimetic EUK 134 exert differential effects on breast cancer cell growth. Inhibition of H2O2 signaling using EUK 134-like compound might be a promising approach to breast cancer therapy. PMID:25794772

  1. Cu,Zn Superoxide Dismutase is a Peroxisomal Enzyme in Human Fibroblast and Hepatoma Cells

    NASA Astrophysics Data System (ADS)

    Keller, Gilbert-Andre; Warner, Thomas G.; Steimer, Kathelyn S.; Hallewell, Robert A.

    1991-08-01

    The intracellular localization of Cu,Zn superoxide dismutase (superoxide:superoxide oxidoreductase, EC 1.15.1.1) has been examined by immunofluorescence using four monoclonal anti-Cu,Zn superoxide dismutase antibodies raised against a recombinant human Cu,Zn superoxide dismutase derivative produced and purified from Escherichia coli. Colocalization with catalase, a peroxisomal matrix enzyme, was used to demonstrate the peroxisomal localization of Cu,Zn superoxide dismutase in human fibroblasts and hepatoma cells. In the fibroblasts of Zellweger syndrome patients, the enzyme is not transported to the peroxisomal ghosts but, like catalase, remains in the cytoplasm. In addition, immunocryoelectron microscopy of yeast cells expressing human Cu,Zn superoxide dismutase showed that the enzyme is translocated to the peroxisomes.

  2. Extracellular superoxide dismutase ameliorates house dust mite-induced atopic dermatitis-like skin inflammation and inhibits mast cell activation in mice.

    PubMed

    Lee, Yun Sang; Choi, Jung-Hye; Lee, Ji-Hyun; Lee, Han-Woong; Lee, Weontae; Kim, Woo Taek; Kim, Tae-Yoon

    2016-08-01

    Extracellular superoxide dismutase (EC-SOD) is an enzyme that catalyses the dismutation of superoxide anions. It has multiple functions, such as reactive oxygen species scavenging, anti-angiogenic, anti-inflammatory, antichemotatic and antitumor activities. Recently, we demonstrated that EC-SOD inhibits ovalbumin-induced allergic airway inflammation in mice. However, the anti-allergic effect of EC-SOD on skin tissue and the role of EC-SOD in mast cells, which are important for allergic responses, have not been well studied. In this study, we investigated whether EC-SOD can alleviate atopic dermatitis in mice and inhibit mast cell activation. Treatment with human recombinant EC-SOD ameliorated house dust mite-induced atopic dermatitis in mice. Furthermore, the levels of pro-allergic cytokine gene expression and histamine release increased in EC-SOD KO mast cells and decreased in EC-SOD overexpressing mast cells, suggesting that EC-SOD inhibits mast cell activation. Consistently, a passive cutaneous anaphylaxis experiment showed more blood leakage from EC-SOD KO mouse ear skin, implying that the lack of EC-SOD increases allergic responses. These results suggest that EC-SOD inhibits mast cell activation and atopic dermatitis and that the loss of EC-SOD causes more severe allergic responses, implying that EC-SOD might be a good drug candidate for treatment of allergic disorders, such as atopic dermatitis. PMID:27061078

  3. Different influences of extracellular and intracellular superoxide on relaxation through the NO/sGC/cGMP pathway in isolated rat iliac arteries.

    PubMed

    Tawa, Masashi; Shimosato, Takashi; Iwasaki, Hirotaka; Imamura, Takeshi; Okamura, Tomio

    2015-02-01

    Superoxide production is increased in diseased blood vessels, which is considered to lead to impairment of the nitric oxide (NO)/soluble guanylate cyclase (sGC)/cGMP pathway. To investigate the respective influence of extracellular and intracellular superoxide on vascular function through the NO/sGC/cGMP pathway, mechanical responses of rat external iliac arteries without endothelium were studied under exposure to a superoxide-generating agent, pyrogallol, or menadione. Exposure to pyrogallol impaired the relaxation induced by acidified NaNO2 (exogenous NO) but not that by nitroglycerin (organic nitrate), BAY 41-2272 (sGC stimulator), BAY 60-2770 (sGC activator), or 8-Br-cGMP (cGMP analog). Superoxide dismutase (SOD) and tempol restored the impaired relaxation by acidified NaNO2. Superoxide production in the bathing solution, but not in artery segments, was significantly increased by exposure to pyrogallol, which was abolished in the presence of SOD or tempol. However, exposure to menadione impaired the relaxant response to acidified NaNO2, nitroglycerin, or BAY 41-2272, whereas it augmented that to BAY 60-2770. Also, this exposure had no effect on the 8-Br-cGMP-induced vasorelxation. Superoxide production in artery segments was dramatically enhanced by exposure to menadione, whereas that in the bathing solution was not affected. This increase in vascular superoxide production was normalized by tempol but not by SOD. These findings suggest that extracellular superoxide reacts with NO only outside the cell, whereas intracellular superoxide not only scavenges NO inside the cell but also shifts the sGC redox equilibrium. PMID:25329747

  4. Skeletal muscle reperfusion injury is enhanced in extracellular superoxide dismutase knockout mouse.

    PubMed

    Park, Jong Woong; Qi, Wen-Ning; Cai, Yongting; Zelko, Igor; Liu, John Q; Chen, Long-En; Urbaniak, James R; Folz, Rodney J

    2005-07-01

    This study investigates the role of extracellular SOD (EC-SOD), the major extracellular antioxidant enzyme, in skeletal muscle ischemia and reperfusion (I/R) injury. Pedicled cremaster muscle flaps from homozygous EC-SOD knockout (EC-SOD-/-) and wild-type (WT) mice were subjected to 4.5-h ischemia and 90-min reperfusion followed by functional and molecular analyses. Our results revealed that EC-SOD-/- mice showed significantly profound I/R injury compared with WT littermates. In particular, there was a delayed and incomplete recovery of arterial spasm and blood flow during reperfusion, and more severe acute inflammatory reaction and muscle damage were noted in EC-SOD-/- mice. After 90-min reperfusion, intracellular SOD [copper- and zinc-containing SOD (CuZn-SOD) and manganese-containing (Mn-SOD)] mRNA levels decreased similarly in both groups. EC-SOD mRNA levels increased in WT mice, whereas EC-SOD mRNA was undetectable, as expected, in EC-SOD-/- mice. In both groups of animals, CuZn-SOD protein levels decreased and Mn-SOD protein levels remained unchanged. EC-SOD protein levels decreased in WT mice. Histological analysis showed diffuse edema and inflammation around muscle fibers, which was more pronounced in EC-SOD-/- mice. In conclusion, our data suggest that EC-SOD plays an important role in the protection from skeletal muscle I/R injury caused by excessive generation of reactive oxygen species. PMID:15778274

  5. Modifications of Superoxide Dismutase (SOD1) in Human Erythrocytes

    PubMed Central

    Wilcox, Kyle C.; Zhou, Li; Jordon, Joshua K.; Huang, Yi; Yu, Yanbao; Redler, Rachel L.; Chen, Xian; Caplow, Michael; Dokholyan, Nikolay V.

    2009-01-01

    Over 100 mutations in Cu/Zn-superoxide dismutase (SOD1) result in familial amyotrophic lateral sclerosis. Dimer dissociation is the first step in SOD1 aggregation, and studies suggest nearly every amino acid residue in SOD1 is dynamically connected to the dimer interface. Post-translational modifications of SOD1 residues might be expected to have similar effects to mutations, but few modifications have been identified. Here we show, using SOD1 isolated from human erythrocytes, that human SOD1 is phosphorylated at threonine 2 and glutathionylated at cysteine 111. A second SOD1 phosphorylation was observed and mapped to either Thr-58 or Ser-59. Cysteine 111 glutathionylation promotes SOD1 monomer formation, a necessary initiating step in SOD1 aggregation, by causing a 2-fold increase in the Kd. This change in the dimer stability is expected to result in a 67% increase in monomer concentration, 315 nm rather than 212 nm at physiological SOD1 concentrations. Because protein glutathionylation is associated with redox regulation, our finding that glutathionylation promotes SOD1 monomer formation supports a model in which increased oxidative stress promotes SOD1 aggregation. PMID:19299510

  6. Effect of fluticasone propionate on neutrophil chemotaxis, superoxide generation, and extracellular proteolytic activity in vitro.

    PubMed Central

    Llewellyn-Jones, C. G.; Hill, S. L.; Stockley, R. A.

    1994-01-01

    BACKGROUND--Corticosteroids are widely used in the treatment of many inflammatory conditions but the exact mode of action on neutrophil function is uncertain. Fluticasone propionate is a new topically active synthetic steroid which can be measured in body fluids and which undergoes first pass metabolism. METHODS--The effects of fluticasone propionate on the function of neutrophils isolated from normal, healthy control subjects and on the chemotactic activity of sputum sol phase were assessed. RESULTS--Preincubation of neutrophils with fluticasone propionate reduced the chemotactic response to 10(-8) mol/l F-Met-Leu-Phe (FMLP) and to a 1:5 dilution of sputum sol phase in a dose dependent manner. Furthermore, when fluticasone propionate was added to sputum from eight patients with stable chronic obstructive bronchitis the chemotactic activity of a 1:5 dilution of the sol phase fell from a mean (SE) value of 22.2 (1.21) cells/field to 19.6 (0.89), 17.1 (0.74), and 11.9 (0.6) cells field at 1 mumol/l, 10 mumol/l, and 100 mumol/l, respectively. In further experiments fluticasone propionate preincubated with neutrophils inhibited fibronectin degradation by resting cells and by cells stimulated by FMLP (15.2% inhibition of resting cells, 5.1% inhibition of stimulated cells with 1 mumol/l fluticasone propionate, 24% and 18.7% inhibition respectively at 100 mumol/l fluticasone propionate. Fluticasone propionate had no effect on generation of superoxide anion by resting or stimulated cells. CONCLUSIONS--These results indicate that fluticasone propionate has a direct suppressive effect on several aspects of neutrophil function and may suggest a role for this agent in the modulation of neutrophil mediated damage to connective tissue. PMID:8202875

  7. Increasing Superoxide Production and the Labile Iron Pool in Tumor Cells may Sensitize Them to Extracellular Ascorbate

    PubMed Central

    McCarty, Mark Frederick; Contreras, Francisco

    2014-01-01

    Low millimolar concentrations of ascorbate are capable of inflicting lethal damage on a high proportion of cancer cells lines, yet leave non-transformed cell lines unscathed. Extracellular generation of hydrogen peroxide, reflecting reduction of molecular oxygen by ascorbate, has been shown to mediate this effect. Although some cancer cell lines express low catalase activity, this cannot fully explain the selective sensitivity of cancer cells to hydrogen peroxide. Ranzato and colleagues have presented evidence for a plausible new explanation of this sensitivity – a high proportion of cancers, via NADPH oxidase complexes or dysfunctional mitochondria, produce elevated amounts of superoxide. This superoxide, via a transition metal-catalyzed transfer of an electron to the hydrogen peroxide produced by ascorbate, can generate deadly hydroxyl radical (Haber–Weiss reaction). It thus can be predicted that concurrent measures which somewhat selectively boost superoxide production in cancers will enhance their sensitivity to i.v. ascorbate therapy. One way to achieve this is to increase the provision of substrate to cancer mitochondria. Measures which inhibit the constitutive hypoxia-inducible factor-1 (HIF-1) activity in cancers (such as salsalate and mTORC1 inhibitors, or an improvement of tumor oxygenation), or that inhibit the HIF-1-inducible pyruvate dehydrogenase kinase (such as dichloroacetate), can be expected to increase pyruvate oxidation. A ketogenic diet should provide more lipid substrate for tumor mitochondria. The cancer-killing activity of 42°C hyperthermia is to some degree contingent on an increase in oxidative stress, likely of mitochondrial origin; reports that hydrogen peroxide synergizes with hyperthermia in killing cancer cells suggest that hyperthermia and i.v. ascorbate could potentiate each other’s efficacy. A concurrent enhancement of tumor oxygenation might improve results by decreasing HIF-1 activity while increasing the interaction of

  8. Leukocyte-derived extracellular superoxide dismutase does not contribute to airspace EC-SOD after interstitial pulmonary injury

    PubMed Central

    Manni, Michelle L.; Epperly, Michael W.; Han, Wei; Blackwell, Timothy S.; Duncan, Steven R.; Piganelli, Jon D.

    2012-01-01

    The antioxidant enzyme extracellular superoxide dismutase (EC-SOD) is abundant in the lung and is known to limit inflammation and fibrosis following numerous pulmonary insults. Previous studies have reported a loss of full-length EC-SOD from the pulmonary parenchyma with accumulation of proteolyzed EC-SOD in the airspace after an interstitial lung injury. However, following airspace only inflammation, EC-SOD accumulates in the airspace without a loss from the interstitium, suggesting this antioxidant may be released from an extrapulmonary source. Because leukocytes are known to express EC-SOD and are prevalent in the bronchoalveolar lavage fluid (BALF) after injury, it was hypothesized that these cells may transport and release EC-SOD into airspaces. To test this hypothesis, C57BL/6 wild-type and EC-SOD knockout mice were irradiated and transplanted with bone marrow from either wild-type mice or EC-SOD knockout mice. Bone marrow chimeric mice were then intratracheally treated with asbestos and killed 3 and 7 days later. At both 3 and 7 days following asbestos injury, mice without pulmonary EC-SOD expression but with EC-SOD in infiltrating and resident leukocytes did not have detectable levels of EC-SOD in the airspaces. In addition, leukocyte-derived EC-SOD did not significantly lessen inflammation or early stage fibrosis that resulted from asbestos injury in the lungs. Although it is not influential in the asbestos-induced interstitial lung injury model, EC-SOD is still known to be present in leukocytes and may play an influential role in attenuating pneumonias and other inflammatory diseases. PMID:22003088

  9. Leukocyte-derived extracellular superoxide dismutase does not contribute to airspace EC-SOD after interstitial pulmonary injury.

    PubMed

    Manni, Michelle L; Epperly, Michael W; Han, Wei; Blackwell, Timothy S; Duncan, Steven R; Piganelli, Jon D; Oury, Tim D

    2012-01-01

    The antioxidant enzyme extracellular superoxide dismutase (EC-SOD) is abundant in the lung and is known to limit inflammation and fibrosis following numerous pulmonary insults. Previous studies have reported a loss of full-length EC-SOD from the pulmonary parenchyma with accumulation of proteolyzed EC-SOD in the airspace after an interstitial lung injury. However, following airspace only inflammation, EC-SOD accumulates in the airspace without a loss from the interstitium, suggesting this antioxidant may be released from an extrapulmonary source. Because leukocytes are known to express EC-SOD and are prevalent in the bronchoalveolar lavage fluid (BALF) after injury, it was hypothesized that these cells may transport and release EC-SOD into airspaces. To test this hypothesis, C57BL/6 wild-type and EC-SOD knockout mice were irradiated and transplanted with bone marrow from either wild-type mice or EC-SOD knockout mice. Bone marrow chimeric mice were then intratracheally treated with asbestos and killed 3 and 7 days later. At both 3 and 7 days following asbestos injury, mice without pulmonary EC-SOD expression but with EC-SOD in infiltrating and resident leukocytes did not have detectable levels of EC-SOD in the airspaces. In addition, leukocyte-derived EC-SOD did not significantly lessen inflammation or early stage fibrosis that resulted from asbestos injury in the lungs. Although it is not influential in the asbestos-induced interstitial lung injury model, EC-SOD is still known to be present in leukocytes and may play an influential role in attenuating pneumonias and other inflammatory diseases. PMID:22003088

  10. Faropenem enhances superoxide anion production by human neutrophils in vitro.

    PubMed

    Sato, K; Sato, N; Shimizu, H; Tsutiya, T; Takahashi, H; Kakizaki, S; Takayama, H; Takagi, H; Mori, M

    1999-09-01

    Neutrophils are important cellular components in the defence against infections and many studies in vitro have shown that some antibiotics affect neutrophil function. We examined the effect of faropenem, a new oral penem antibiotic on neutrophil killing function by determining the generation of superoxide anion in vitro. The production of superoxide anion was measured by chemiluminescence amplified by a Cypridina luciferin analogue in the presence of N-formyl-Met-Leu-Phe (fMLP). Faropenem significantly enhanced chemiluminescence in a dose-dependent manner. The effect of faropenem was maximal at 5 min of incubation time and continued for at least 30 min. The effect of faropenem was also observed when neutrophils were stimulated by a calcium ionophore (ionomycin), while the effect of faropenem did not change in the presence of 12-O-tetra-decanoylphorbolmyristate acetate. Cytosol Ca2+ concentration ([Ca2+]i) monitored with Fura-2 increased in response to fMLP, however, faropenem did not influence the response of [Ca2+]i to fMLP. Our results suggest that faropenem enhanced the generation of superoxide anion by neutrophils, probably at the site where cytosol Ca2+ regulates NADPH oxidase. Faropenem might be potentially advantageous in the treatment of infections because a synergic interaction of antibodies and cytocidal neutrophils is necessary for the early eradication of the pathogenic bacteria. PMID:10511400

  11. Purification of human copper, zinc superoxide dismutase by copper chelate affinity chromatography

    SciTech Connect

    Weslake, R.J.; Chesney, S.L.; Petkau, A.; Friesen, A.D.

    1986-05-15

    Copper, zinc superoxide dismutase was isolated from human red blood cell hemolysate by DEAE-Sepharose and copper chelate affinity chromatography. Enzyme preparations had specific activities ranging from 3400 to 3800 U/mg and recoveries were approximately 60% of the enzyme activity in the lysate. Copper chelate affinity chromatography resulted in a purification factor of about 60-fold. The homogeneity of the superoxide dismutase preparation was analyzed by sodium dodecyl sulfate-gel electrophoresis, analytical gel filtration chromatography, and isoelectric focusing.

  12. Nitration and Inactivation of Manganese Superoxide Dismutase in Chronic Rejection of Human Renal Allografts

    NASA Astrophysics Data System (ADS)

    MacMillan-Crow, L. A.; Crow, John P.; Kerby, Jeffrey D.; Beckman, Joseph S.; Thompson, John A.

    1996-10-01

    Inflammatory processes in chronic rejection remain a serious clinical problem in organ transplantation. Activated cellular infiltrate produces high levels of both superoxide and nitric oxide. These reactive oxygen species interact to form peroxynitrite, a potent oxidant that can modify proteins to form 3-nitrotyrosine. We identified enhanced immunostaining for nitrotyrosine localized to tubular epithelium of chronically rejected human renal allografts. Western blot analysis of rejected tissue demonstrated that tyrosine nitration was restricted to a few specific polypeptides. Immunoprecipitation and amino acid sequencing techniques identified manganese superoxide dismutase, the major antioxidant enzyme in mitochondria, as one of the targets of tyrosine nitration. Total manganese superoxide dismutase protein was increased in rejected kidney, particularly in the tubular epithelium; however, enzymatic activity was significantly decreased. Exposure of recombinant human manganese superoxide dismutase to peroxynitrite resulted in a dose-dependent (IC50 = 10 μ M) decrease in enzymatic activity and concomitant increase in tyrosine nitration. Collectively, these observations suggest a role for peroxynitrite during development and progression of chronic rejection in human renal allografts. In addition, inactivation of manganese superoxide dismutase by peroxynitrite may represent a general mechanism that progressively increases the production of peroxynitrite, leading to irreversible oxidative injury to mitochondria.

  13. Extracellular RNAs: development as biomarkers of human disease

    PubMed Central

    Quinn, Joseph F.; Patel, Tushar; Wong, David; Das, Saumya; Freedman, Jane E.; Laurent, Louise C.; Carter, Bob S.; Hochberg, Fred; Keuren-Jensen, Kendall Van; Huentelman, Matt; Spetzler, Robert; Kalani, M. Yashar S.; Arango, Jorge; Adelson, P. David; Weiner, Howard L.; Gandhi, Roopali; Goilav, Beatrice; Putterman, Chaim; Saugstad, Julie A.

    2015-01-01

    Ten ongoing studies designed to test the possibility that extracellular RNAs may serve as biomarkers in human disease are described. These studies, funded by the NIH Common Fund Extracellular RNA Communication Program, examine diverse extracellular body fluids, including plasma, serum, urine and cerebrospinal fluid. The disorders studied include hepatic and gastric cancer, cardiovascular disease, chronic kidney disease, neurodegenerative disease, brain tumours, intracranial haemorrhage, multiple sclerosis and placental disorders. Progress to date and the plans for future studies are outlined. PMID:26320940

  14. Extracellular RNAs: development as biomarkers of human disease.

    PubMed

    Quinn, Joseph F; Patel, Tushar; Wong, David; Das, Saumya; Freedman, Jane E; Laurent, Louise C; Carter, Bob S; Hochberg, Fred; Van Keuren-Jensen, Kendall; Huentelman, Matt; Spetzler, Robert; Kalani, M Yashar S; Arango, Jorge; Adelson, P David; Weiner, Howard L; Gandhi, Roopali; Goilav, Beatrice; Putterman, Chaim; Saugstad, Julie A

    2015-01-01

    Ten ongoing studies designed to test the possibility that extracellular RNAs may serve as biomarkers in human disease are described. These studies, funded by the NIH Common Fund Extracellular RNA Communication Program, examine diverse extracellular body fluids, including plasma, serum, urine and cerebrospinal fluid. The disorders studied include hepatic and gastric cancer, cardiovascular disease, chronic kidney disease, neurodegenerative disease, brain tumours, intracranial haemorrhage, multiple sclerosis and placental disorders. Progress to date and the plans for future studies are outlined. PMID:26320940

  15. DOCK2 and DOCK5 Act Additively in Neutrophils To Regulate Chemotaxis, Superoxide Production, and Extracellular Trap Formation

    PubMed Central

    Watanabe, Mayuki; Terasawa, Masao; Miyano, Kei; Yanagihara, Toyoshi; Uruno, Takehito; Sanematsu, Fumiyuki; Nishikimi, Akihiko; Côté, Jean-François; Sumimoto, Hideki; Fukui, Yoshinori

    2015-01-01

    Neutrophils are highly motile leukocytes that play important roles in the innate immune response to invading pathogens. Neutrophils rapidly migrate to the site of infections and kill pathogens by producing reactive oxygen species (ROS). Neutrophil chemotaxis and ROS production require activation of Rac small GTPase. DOCK2, an atypical guanine nucleotide exchange factor (GEF), is one of the major regulators of Rac in neutrophils. However, because DOCK2 deficiency does not completely abolish fMLF-induced Rac activation, other Rac GEFs may also participate in this process. In this study, we show that DOCK5 acts with DOCK2 in neutrophils to regulate multiple cellular functions. We found that fMLF- and PMA-induced Rac activation were almost completely lost in mouse neutrophils lacking both DOCK2 and DOCK5. Although β2 integrin–mediated adhesion occurred normally even in the absence of DOCK2 and DOCK5, mouse neutrophils lacking DOCK2 and DOCK5 exhibited a severe defect in chemotaxis and ROS production. Similar results were obtained when human neutrophils were treated with CPYPP, a small-molecule inhibitor of these DOCK GEFs. Additionally, we found that DOCK2 and DOCK5 regulate formation of neutrophil extracellular traps (NETs). Because NETs are involved in vascular inflammation and autoimmune responses, DOCK2 and DOCK5 would be a therapeutic target for controlling NET-mediated inflammatory disorders. PMID:25339677

  16. Loss of extracellular superoxide dismutase leads to acute lung damage in the presence of ambient air: a potential mechanism underlying adult respiratory distress syndrome.

    PubMed

    Gongora, Maria Carolina; Lob, Heinrich E; Landmesser, Ulf; Guzik, Tomasz J; Martin, W David; Ozumi, Kiyoski; Wall, Susan M; Wilson, David Scott; Murthy, Niren; Gravanis, Michael; Fukai, Tohru; Harrison, David G

    2008-10-01

    The extracellular superoxide dismutase 3 (SOD3) is highly expressed in both blood vessels and lungs. In different models of pulmonary injury, SOD3 is reduced; however, it is unclear whether this contributes to lung injury. To study the role of acute SOD3 reduction in lung injury, the SOD3 gene was deleted in adult mice by using the Cre-Lox technology. Acute reduction of SOD3 led to a fivefold increase in lung superoxide, marked inflammatory cell infiltration, a threefold increase in the arterial-alveolar gradient, respiratory acidosis, histological changes similar to those observed in adult respiratory distress syndrome, and 85% mortality. Treatment with the SOD mimetic MnTBAP and intranasal administration of SOD-containing polyketal microparticles reduced mortality, prevented the histological alterations, and reduced lung superoxide levels. To understand how mice with the SOD3 embryonic deletion survived without lung injury, gene array analysis was performed. These data demonstrated the up-regulation of 37 genes and down-regulation of nine genes, including those involved in cell signaling, inflammation, and gene transcription in SOD3-/- mice compared with either mice with acute SOD3 reduction or wild-type controls. These studies show that SOD3 is essential for survival in the presence of ambient oxygen and that acute loss of this enzyme can lead to severe lung damage. Strategies either to prevent SOD3 inactivation or to augment its levels might prove useful in the treatment of acute lung injury. PMID:18787098

  17. Up-regulation of an extracellular superoxide dismutase-like activity in hibernating hamsters subjected to oxidative stress in mid- to late arousal from torpor.

    PubMed

    Okamoto, Iwao; Kayano, Tohru; Hanaya, Toshiharu; Arai, Shigeyuki; Ikeda, Masao; Kurimoto, Masashi

    2006-09-01

    Torpor-arousal cycles, one of the inherent features in hibernators, are associated with a rapid increase in body temperature and respiration, and it would lead to elevation of reactive oxygen species (ROS) generation. However, hibernators apparently tolerate this oxidative stress. We have observed in Syrian hamsters (Mesocricetus auratus) a maximal temperature shift and respiratory rate in mid- to late arousal (16-33 degrees C rectal temperature) from torpor. To examine plasma antioxidant status during arousal, we studied total superoxide radical-scavenging activity in plasma by electron spin resonance. The superoxide radical-scavenging activity reached a maximum at 32 degrees C, coincident with a peak in plasma uric acid levels, a ROS generation indicator. The up-regulated activity at 32 degrees C was attributable to the peak of the activity eluted at 260-kDa on gel-filtration chromatography, but was not to small antioxidant molecules such as ascorbate and alpha-tocopherol. The activity eluted at 260-kDa increased 3-fold at 32 degrees C compared with that of the torpid state, and was not detected either at 6 h after the onset of arousal or in the euthermic state. Moreover, the activity exhibited extracellular SOD-like properties: its induction in plasma by heparin injection and its affinity for heparin. Our results suggest that the 260-kDa extracellular SOD-like activity plays a role in the tolerance for the oxidative stress during arousal from torpor. PMID:16807121

  18. Extracellular hydrogen peroxide, produced through a respiratory burst oxidase/superoxide dismutase pathway, directs ingrowth wall formation in epidermal transfer cells of Vicia faba cotyledons.

    PubMed

    Xia, Xue; Zhang, Hui-Ming; Andriunas, Felicity A; Offler, Christina E; Patrick, John W

    2012-09-01

    The intricate, and often polarized, ingrowth walls of transfer cells (TCs) amplify their plasma membrane surface areas to confer a transport function of supporting high rates of nutrient exchange across apo-/symplasmic interfaces. The TC ingrowth wall comprises a uniform wall layer on which wall ingrowths are deposited. Signals and signal cascades inducing trans-differentiation events leading to formation of TC ingrowth walls are poorly understood. Vicia faba cotyledons offer a robust experimental model to examine TC induction as, when placed into culture, their adaxial epidermal cells rapidly (h) and synchronously form polarized ingrowth walls accessible for experimental observations. Using this model, we recently reported findings consistent with extracellular hydrogen peroxide, produced through a respiratory burst oxidase homolog/superoxide dismutase pathway, initiating cell wall biosynthetic activity and providing directional information guiding deposition of the polarized uniform wall. Our conclusions rested on observations derived from pharmacological manipulations of hydrogen peroxide production and correlative gene expression data sets. A series of additional studies were undertaken, the results of which verify that extracellular hydrogen peroxide contributes to regulating ingrowth wall formation and is generated by a respiratory burst oxidase homolog/superoxide dismutase pathway. PMID:22899058

  19. Identification of a superoxide-generating NADPH oxidase system in human fibroblasts.

    PubMed Central

    Meier, B; Cross, A R; Hancock, J T; Kaup, F J; Jones, O T

    1991-01-01

    Human fibroblasts have the capacity to release superoxide radicals upon stimulation of an electron transport system similar to the NADPH oxidase of leukocytes. Two components of the NADPH oxidase system, (1) a flavoprotein of 45 kDa which binds diphenylene iodonium (a compound described as a specific inhibitor of the leukocyte NADPH oxidase), and (2) a low-potential cytochrome b, are present in fibroblast membranes. Fibroblasts exhibit these compounds at lower concentrations than do polymorphonuclear leukocytes or B-lymphocytes. The superoxide-generating system is rather uniformly associated with the outer cell membrane, as shown by light and electron microscopy. Superoxide release upon stimulation with various agents was prevented by the addition of micromolar concentrations of diphenylene iodonium, making an NADPH oxidase a likely source. Images Fig. 4. PMID:1850240

  20. Diverse human extracellular RNAs are widely detected in human plasma

    PubMed Central

    Freedman, Jane E.; Gerstein, Mark; Mick, Eric; Rozowsky, Joel; Levy, Daniel; Kitchen, Robert; Das, Saumya; Shah, Ravi; Danielson, Kirsty; Beaulieu, Lea; Navarro, Fabio C. P.; Wang, Yaoyu; Galeev, Timur R.; Holman, Alex; Kwong, Raymond Y.; Murthy, Venkatesh; Tanriverdi, Selim E.; Koupenova, Milka; Mikhalev, Ekaterina; Tanriverdi, Kahraman

    2016-01-01

    There is growing appreciation for the importance of non-protein-coding genes in development and disease. Although much is known about microRNAs, limitations in bioinformatic analyses of RNA sequencing have precluded broad assessment of other forms of small-RNAs in humans. By analysing sequencing data from plasma-derived RNA from 40 individuals, here we identified over a thousand human extracellular RNAs including microRNAs, piwi-interacting RNA (piRNA), and small nucleolar RNAs. Using a targeted quantitative PCR with reverse transcription approach in an additional 2,763 individuals, we characterized almost 500 of the most abundant extracellular transcripts including microRNAs, piRNAs and small nucleolar RNAs. The presence in plasma of many non-microRNA small-RNAs was confirmed in an independent cohort. We present comprehensive data to demonstrate the broad and consistent detection of diverse classes of circulating non-cellular small-RNAs from a large population. PMID:27112789

  1. Purification, identification, characterization, and cDNA cloning of a high molecular weight extracellular superoxide dismutase of hamster that transiently increases in plasma during arousal from hibernation.

    PubMed

    Akita, Kenji; Hanaya, Toshiharu; Arai, Shigeyuki; Ohta, Tsunetaka; Okamoto, Iwao; Fukuda, Shigeharu

    2007-02-01

    We previously studied antioxidant profiles in the plasma of hibernating Syrian hamsters and found a transient increase of a superoxide radical-scavenging activity during the arousal phase. In this report, we purified and identified the high molecular weight superoxide dismutase (SOD)-like factor from the plasma of arousing hamsters. The cyanide-sensitive 240 kDa SOD-like factor showed a significant homology to mammalian extracellular SOD (EC-SOD) reported, although the molecular mass of EC-SOD was 135 kDa. The cDNA cloning revealed that the 240 kDa SOD-like factor was identical to the hamster ortholog of EC-SOD. It consisted of 245 amino acid residues including a signal sequence of 20 amino acid residues. Five cysteine residues that would participate in inner- and inter-subunit bonds were well conserved among species. Interestingly, there were four potential N-glycosylation sites in hamster EC-SOD, whereas there is only one site in other species. The amino acid sequence analysis indicated that three of the four sites were modified. These results suggest that the anomalistically high molecular weight of hamster EC-SOD is ascribed, at least in part, to the addition of extra sugar chains. Furthermore, results obtained here also propose the involvement of EC-SOD in the antioxidative defense of hibernating hamsters. PMID:17157046

  2. Enzyme release and superoxide anion production by human alveolar macrophages stimulated with immunoglobulin E.

    PubMed Central

    Joseph, M; Tonnel, A B; Capron, A; Voisin, C

    1980-01-01

    Human alveolar macrophages specifically released lysosomal beta-glucuronidase and neutral proteases when successively incubated with IgE, and then, for 30 min, with anti-IgE. Superoxide anion O2- generation was obtained when anti-IgE-opsonized zymosan was added to IgE-incubated cells. Macrophages from smokers excreted twice as much enzymes and superoxide as cells from non-smokers. It was possible to induce the specific release of beta-glucuronidase with normal alveolar macrophages successively incubated with the serum of patients allergic to house dust or to grass pollen and then with the specific allergen. This characteristic opens the field to a direct test for allergic sera by analogy with the allergen-induced degranulation test of sensitized basophils. PMID:6254706

  3. High Extracellular Levels of Mycobacterium tuberculosis Glutamine Synthetase and Superoxide Dismutase in Actively Growing Cultures Are Due to High Expression and Extracellular Stability Rather than to a Protein-Specific Export Mechanism

    PubMed Central

    Tullius, Michael V.; Harth, Günter; Horwitz, Marcus A.

    2001-01-01

    Glutamine synthetase (GS) and superoxide dismutase (SOD), large multimeric enzymes that are thought to play important roles in the pathogenicity of Mycobacterium tuberculosis, are among the bacterium's major culture filtrate proteins in actively growing cultures. Although these proteins lack a leader peptide, their presence in the extracellular medium during early stages of growth suggested that they might be actively secreted. To understand their mechanism of export, we cloned the homologous genes (glnA1 and sodA) from the rapid-growing, nonpathogenic Mycobacterium smegmatis, generated glnA1 and sodA mutants of M. smegmatis by allelic exchange, and quantitated expression and export of both mycobacterial and nonmycobacterial GSs and SODs in these mutants. We also quantitated expression and export of homologous and heterologous SODs from M. tuberculosis. When each of the genes was expressed from a multicopy plasmid, M. smegmatis exported comparable proportions of both the M. tuberculosis and M. smegmatis GSs (in the glnA1 strain) or SODs (in the sodA strain), in contrast to previous observations in wild-type strains. Surprisingly, recombinant M. smegmatis and M. tuberculosis strains even exported nonmycobacterial SODs. To determine the extent to which export of these large, leaderless proteins is expression dependent, we constructed a recombinant M. tuberculosis strain expressing green fluorescent protein (GFP) at high levels and a recombinant M. smegmatis strain coexpressing the M. smegmatis GS, M. smegmatis SOD, and M. tuberculosis BfrB (bacterioferritin) at high levels. The recombinant M. tuberculosis strain exported GFP even in early stages of growth and at proportions very similar to those of the endogenous M. tuberculosis GS and SOD. Similarly, the recombinant M. smegmatis strain exported bacterioferritin, a large (∼500-kDa), leaderless, multimeric protein, in proportions comparable to GS and SOD. In contrast, high-level expression of the large, leaderless

  4. Extracellular potentials of myelinated and demyelinated human motor nerve fibres.

    PubMed

    Stephanova, D I; Daskalova, M

    2003-12-01

    The extracellular potentials of myelinated and demyelinated human motor nerve fibres in an unbounded volume conductor are studied. Using our previous double-cable models of normal and demyelinated human fibres, the spatial and temporal intracellular potentials are calculated in the cases of point polarization and adaptation of the fibres. The intracellular potentials are then used as input to a line source model that allows to calculate the corresponding spatial and temporal extracellular potentials at various radial distances in the surrounding volume conductor. Four fibre demyelinations (termed as internodal focal\\systematic and paranodal focal\\systematic demyelinations, respectively) are studied. In all investigated cases, the radial decline of the peak-to-peak amplitude of the extracellular potential depends on the radial distance of the field point and increases with the increase of the distance. The results are consistent with the interpretation that the considerably different spatial and temporal distributions of the extracellular potentials depend not only on the cable properties of the fibres, but on the methods of fibre stimulation. In the case of fibre adaptation, the temporal extracellular potentials in the normal and demyelinated cases correspond well with electromyograms (EMGs) from healthy subjects and patients with demyelinated disorders as reported in the literature. Simulation results indicate that the models used are rather promising tools in studying the main properties of compound action potentials in patients with demyelinated disorders which up till now have not been sufficiently well understood. PMID:14717030

  5. The modulation of extracellular superoxide dismutase in the specifically enhanced cellular immune response against secondary challenge of Vibrio splendidus in Pacific oyster (Crassostrea gigas).

    PubMed

    Liu, Conghui; Zhang, Tao; Wang, Lingling; Wang, Mengqiang; Wang, Weilin; Jia, Zhihao; Jiang, Shuai; Song, Linsheng

    2016-10-01

    Extracellular superoxide dismutase (EcSOD) is a copper-containing glycoprotein playing an important role in antioxidant defense of living cells exposed to oxidative stress, and also participating in microorganism internalization and cell adhesion in invertebrates. EcSOD from oyster (designated CgEcSOD) had been previously reported to bind lipopolysaccharides (LPS) and act as a bridge molecule in Vibrio splendidus internalization. Its mRNA expression pattern, PAMP binding spectrum and microorganism binding capability were examined in the present study. The mRNA expression of CgEcSOD in hemocytes was significantly up-regulated at the initial phase and decreased sharply at 48 h post V. splendidus stimulation. The recombinant CgEcSOD protein (rCgEcSOD) could bind LPS, PGN and poly (I:C), as well as various microorganisms including Micrococcus luteus, Staphylococcus aureus, Escherichia coli, Vibrio anguillarum, V. splendidus, Pastoris pastoris and Yarrowia lipolytica at the presence of divalent metal ions Cu(2+). After the secondary V. splendidus stimulation, the mRNA and protein of CgEcSOD were both down-regulated significantly. The results collectively indicated that CgEcSOD could not only function in the immune recognition, but also might contribute to the immune priming of oyster by inhibiting the foreign microbe invasion through a specific down-regulation. PMID:27268574

  6. Norepinephrine increases NADPH oxidase-derived superoxide in human peripheral blood mononuclear cells via α-adrenergic receptors

    PubMed Central

    Deo, Shekhar H.; Jenkins, Nathan T.; Padilla, Jaume; Parrish, Alan R.

    2013-01-01

    Many diseases associated with sympathoexcitation also exhibit elevated reactive oxygen species (ROS). A recent animal study indicated that exogenous administration of the sympathetic neurotransmitter norepinephrine (NE) increased systemic ROS via circulating leukocytes. The mechanisms contributing to this effect of NE and whether these findings can be translated to humans is unknown. Thus we tested the hypothesis that NE increases superoxide production in human peripheral blood mononuclear cells (PBMCs) via NADPH oxidase. Primary human PBMCs were freshly isolated from healthy young men and placed in culture. After NE (50 pg/ml, 50 ng/ml, and 50 μg/ml concentrations) or control treatments, NADPH oxidase mRNA expression (gp91phox, p22phox, and p67phox) was assessed using real-time RT-PCR, and intracellular superoxide production was measured using dihydroethidium fluorescence. PBMCs were also treated with selective adrenergic agonists-antagonists to determine the receptor population involved. In addition, CD14+ monocyte-endothelial cell adhesion was determined using a fluorescent-based assay. NE significantly increased NADPH oxidase gene expression and intracellular superoxide production in a time-dependent manner (superoxide: 0.9 ± 0.2 fold, 6 h vs. 3.0 ± 0.3 fold, 36 h; NE, 50 μg/ml; P < 0.05). The sustained increase in NE-induced superoxide production was primarily mediated via α-adrenergic receptors, preferentially α2-receptors. The NADPH oxidase blocker diphenylene iodonium and protein kinase C inhibitor Staurosporine significantly attenuated NE-induced increases in superoxide production. Importantly, NE treatment increased CD14+ monocyte-endothelial cell adhesion. These findings indicate for the first time that NE increases superoxide production in freshly isolated primary human PBMCs via NADPH oxidase through α-adrenergic receptors, an effect facilitating monocyte adhesion to the endothelium. PMID:24068047

  7. Improved human sperm recovery using superoxide dismutase and catalase supplementation in semen cryopreservation procedure.

    PubMed

    Rossi, T; Mazzilli, F; Delfino, M; Dondero, F

    2001-01-01

    The aim of this work was to evaluate the effects of ROS scavenger supplementation in human semen samples undergoing cryopreservation procedures.After screening out andrological pathologies, we selected 25 male partners of infertile couples with the following semen profile: volume >/= 2.0 ml, normal viscosity, sperm count >/=20 x 10(6)/ml, straight progressive motility (classes 1 and 2) >/= 40% (Mazzilli, Rossi, Delfino and Nofroni (1999) Andrologia 31: 187-194), atypical forms superoxide dismutase (SOD) was added to the second, 200 U/ml of catalase to the third and both SOD (100 U/ml) and catalase (100 U/ml) were added to the fourth aliquot. Each aliquot was mixed (v/v) with TEST yolk buffer freezing medium (Irvine Scientific) and then frozen at -196 degrees C. The percent recovery of progressive motile and swollen spermatozoa was evaluated after thawing.No significant variation in the recovery of progressive motility was seen in the aliquots with added SOD or catalase alone, compared to the control group. On the other hand, a significant improvement in sperm parameter recovery was seen in the aliquot with both SOD and catalase supplementation; perhaps because of their combined and simultaneous action on superoxide anion and hydrogen peroxide. These results suggest that, in some selected cases, SOD and catalase supplementation can contribute greatly to the prevention of sperm membrane lipid peroxidation by ROS and thus allow good sperm parameter recovery after freezing-thawing procedures. PMID:15256925

  8. Induction of manganese superoxide dismutase by tumour necrosis factor-alpha in human endometrial stromal cells.

    PubMed

    Karube-Harada, A; Sugino, N; Kashida, S; Takiguchi, S; Takayama, H; Yamagata, Y; Nakamura, Y; Kato, H

    2001-11-01

    The present study was undertaken to investigate the effect of tumour necrosis factor-alpha (TNFalpha) on superoxide dismutase (SOD) expression in human endometrial stromal cells (ESC) and to determine whether there is a difference in responsiveness to TNFalpha between ESC and decidualized ESC. TNFalpha increased manganese-SOD (Mn-SOD) mRNA level and Mn-SOD activity in a dose-dependent manner in ESC. The concentration of TNFalpha required for an effect was lower for decidualized ESC than for non-decidualized ESC. TNFalpha had no effect on copper-zinc-SOD (Cu,Zn-SOD) expression in either type of cell. Incubation of ESC with actinomycin D, an RNA synthesis inhibitor, blocked TNFalpha-induced Mn-SOD mRNA expression, but cycloheximide, a protein synthesis inhibitor, had no effect. H7, an inhibitor of protein kinase C (PKC), also inhibited TNFalpha-stimulated Mn-SOD mRNA expression in both types of cells. These findings suggest that TNFalpha-induced Mn-SOD expression is regulated at the transcription level and mediated by PKC-dependent phosphorylation and that de-novo protein synthesis is not required for the TNFalpha effect. In summary, TNFalpha induces Mn-SOD expression in human ESC. This phenomenon may be important for protection of ESC from cytokine-mediated oxidative stress. PMID:11675473

  9. Comparative transcriptomic analysis of human and Drosophila extracellular vesicles.

    PubMed

    Lefebvre, Fabio Alexis; Benoit Bouvrette, Louis Philip; Perras, Lilyanne; Blanchet-Cohen, Alexis; Garnier, Delphine; Rak, Janusz; Lécuyer, Éric

    2016-01-01

    Extracellular vesicles (EVs) are membrane-enclosed nanoparticles containing specific repertoires of genetic material. In mammals, EVs can mediate the horizontal transfer of various cargos and signaling molecules, notably miRNA and mRNA species. Whether this form of intercellular communication prevails in other metazoans remains unclear. Here, we report the first parallel comparative morphologic and transcriptomic characterization of EVs from Drosophila and human cellular models. Electronic microscopy revealed that human and Drosophila cells release similar EVs with diameters ranging from 30 to 200 nm, which contain complex populations of transcripts. RNA-seq identified abundant ribosomal RNAs, related pseudogenes and retrotransposons in human and Drosophila EVs. Vault RNAs and Y RNAs abounded in human samples, whereas small nucleolar RNAs involved in pseudouridylation were most prevalent in Drosophila EVs. Numerous mRNAs were identified, largely consisting of exonic sequences displaying full-length read coverage and enriched for translation and electronic transport chain functions. By analogy with human systems, these sizeable similarities suggest that EVs could potentially enable RNA-mediated intercellular communication in Drosophila. PMID:27282340

  10. Comparative transcriptomic analysis of human and Drosophila extracellular vesicles

    PubMed Central

    Lefebvre, Fabio Alexis; Benoit Bouvrette, Louis Philip; Perras, Lilyanne; Blanchet-Cohen, Alexis; Garnier, Delphine; Rak, Janusz; Lécuyer, Éric

    2016-01-01

    Extracellular vesicles (EVs) are membrane-enclosed nanoparticles containing specific repertoires of genetic material. In mammals, EVs can mediate the horizontal transfer of various cargos and signaling molecules, notably miRNA and mRNA species. Whether this form of intercellular communication prevails in other metazoans remains unclear. Here, we report the first parallel comparative morphologic and transcriptomic characterization of EVs from Drosophila and human cellular models. Electronic microscopy revealed that human and Drosophila cells release similar EVs with diameters ranging from 30 to 200 nm, which contain complex populations of transcripts. RNA-seq identified abundant ribosomal RNAs, related pseudogenes and retrotransposons in human and Drosophila EVs. Vault RNAs and Y RNAs abounded in human samples, whereas small nucleolar RNAs involved in pseudouridylation were most prevalent in Drosophila EVs. Numerous mRNAs were identified, largely consisting of exonic sequences displaying full-length read coverage and enriched for translation and electronic transport chain functions. By analogy with human systems, these sizeable similarities suggest that EVs could potentially enable RNA-mediated intercellular communication in Drosophila. PMID:27282340

  11. Reduction of Hexavalent Chromium by Human Cytochrome b5: Generation of Hydroxyl Radical and Superoxide

    PubMed Central

    Borthiry, Griselda R.; Antholine, William E.; Kalyanaraman, B.; Myers, Judith M.; Myers, Charles R.

    2007-01-01

    The reduction of hexavalent chromium, Cr(VI), can generate reactive Cr intermediates and various types of oxidative stress. The potential role of human microsomal enzymes in free radical generation was examined using reconstituted proteoliposomes (PLs) containing purified cytochrome b5 and NADPH:P450 reductase. Under aerobic conditions, the PLs reduced Cr(VI) to Cr(V) which was confirmed by ESR using isotopically pure 53Cr(VI). When 5-Diethoxyphos-phoryl-5-methyl-1-pyrroline-N-oxide (DEPMPO) was included as a spin trap, a very prominent signal for the hydroxyl radical (HO•) adduct was observed as well as a smaller signal for the superoxide (O2•−) adduct. These adducts were observed even at very low Cr(VI) concentrations (10 μM). NADPH, Cr(VI), O2 and the PLs were all required for significant HO• generation. Superoxide dismutase eliminated the O2• − adduct and resulted in a 30% increase in the HO• adduct. Catalase largely diminished the HO• adduct signal indicating its dependence on H2O2. Some sources of catalase were found to have Cr(VI)-reducing contaminants which could confound results, but a source of catalase free of these contaminants was used for these studies. Exogenous H2O2 was not needed, indicating that it was generated by the PLs. Adding exogenous H2O2, however, did increase the amount of DEPMPO/HO• adduct. The inclusion of formate yielded the carbon dioxide radical adduct of DEPMPO, and experiments with dimethylsulfoxide (DMSO) plus the spin trap α-phenyl-N-tert-butylnitrone (PBN) yielded the methoxy and methyl radical adducts of PBN, confirming the generation of HO•. Quantification of the various species over time was consistent with a stoichiometric excess of HO• relative to the net amount of Cr(VI) reduced. This also represents the first demonstration of a role for cytochrome b5 in the generation of HO•. Overall, the simultaneous generation of Cr(V) and H2O2 by the PLs and the resulting generation of HO• at low Cr

  12. Mechanism of the Reaction of Human Manganese Superoxide Dismutase with Peroxynitrite: Nitration of Critical Tyrosine 34.

    PubMed

    Demicheli, Verónica; Moreno, Diego M; Jara, Gabriel E; Lima, Analía; Carballal, Sebastián; Ríos, Natalia; Batthyany, Carlos; Ferrer-Sueta, Gerardo; Quijano, Celia; Estrı́n, Darío A; Martí, Marcelo A; Radi, Rafael

    2016-06-21

    Human Mn-containing superoxide dismutase (hMnSOD) is a mitochondrial enzyme that metabolizes superoxide radical (O2(•-)). O2(•-) reacts at diffusional rates with nitric oxide to yield a potent nitrating species, peroxynitrite anion (ONOO(-)). MnSOD is nitrated and inactivated in vivo, with active site Tyr34 as the key oxidatively modified residue. We previously reported a k of ∼1.0 × 10(5) M(-1) s(-1) for the reaction of hMnSOD with ONOO(-) by direct stopped-flow spectroscopy and the critical role of Mn in the nitration process. In this study, we further established the mechanism of the reaction of hMnSOD with ONOO(-), including the necessary re-examination of the second-order rate constant by an independent method and the delineation of the microscopic steps that lead to the regio-specific nitration of Tyr34. The redetermination of k was performed by competition kinetics utilizing coumarin boronic acid, which reacts with ONOO(-) at a rate of ∼1 × 10(6) M(-1) s(-1) to yield the fluorescence product, 7-hydroxycoumarin. Time-resolved fluorescence studies in the presence of increasing concentrations of hMnSOD provided a k of ∼1.0 × 10(5) M(-1) s(-1), fully consistent with the direct method. Proteomic analysis indicated that ONOO(-), but not other nitrating agents, mediates the selective modification of active site Tyr34. Hybrid quantum-classical (quantum mechanics/molecular mechanics) simulations supported a series of steps that involve the initial reaction of ONOO(-) with Mn(III) to yield Mn(IV) and intermediates that ultimately culminate in 3-nitroTyr34. The data reported herein provide a kinetic and mechanistic basis for rationalizing how MnSOD constitutes an intramitochondrial target for ONOO(-) and the microscopic events, with atomic level resolution, that lead to selective and efficient nitration of critical Tyr34. PMID:27227512

  13. Sources and Functions of Extracellular Small RNAs in Human Circulation.

    PubMed

    Fritz, Joëlle V; Heintz-Buschart, Anna; Ghosal, Anubrata; Wampach, Linda; Etheridge, Alton; Galas, David; Wilmes, Paul

    2016-07-17

    Various biotypes of endogenous small RNAs (sRNAs) have been detected in human circulation, including microRNAs, transfer RNAs, ribosomal RNA, and yRNA fragments. These extracellular sRNAs (ex-sRNAs) are packaged and secreted by many different cell types. Ex-sRNAs exhibit differences in abundance in several disease states and have, therefore, been proposed for use as effective biomarkers. Furthermore, exosome-borne ex-sRNAs have been reported to elicit physiological responses in acceptor cells. Exogenous ex-sRNAs derived from diet (most prominently from plants) and microorganisms have also been reported in human blood. Essential issues that remain to be conclusively addressed concern the (a) presence and sources of exogenous ex-sRNAs in human bodily fluids, (b) detection and measurement of ex-sRNAs in human circulation, (c) selectivity of ex-sRNA export and import, (d) sensitivity and specificity of ex-sRNA delivery to cellular targets, and (e) cell-, tissue-, organ-, and organism-wide impacts of ex-sRNA-mediated cell-to-cell communication. We survey the present state of knowledge of most of these issues in this review. PMID:27215587

  14. Cationic liposomes evoke proinflammatory mediator release and neutrophil extracellular traps (NETs) toward human neutrophils.

    PubMed

    Hwang, Tsong-Long; Hsu, Ching-Yun; Aljuffali, Ibrahim A; Chen, Chun-Han; Chang, Yuan-Ting; Fang, Jia-You

    2015-04-01

    Cationic liposomes are widely used as nanocarriers for therapeutic and diagnostic purposes. The cationic components of liposomes can induce inflammatory responses. This study examined the effect of cationic liposomes on human neutrophil activation. Cetyltrimethylammonium bromide (CTAB) or soyaethyl morpholinium ethosulfate (SME) was incorporated into liposomes as the cationic additive. The liposomes' cytotoxicity and their induction of proinflammatory mediators, intracellular calcium, and neutrophil extracellular traps (NETs) were investigated. The interaction of the liposomes with the plasma membrane triggered the stimulation of neutrophils. CTAB liposomes induced complete leakage of lactate dehydrogenase (LDH) at all concentrations tested, whereas SME liposomes released LDH in a concentration-dependent manner. CTAB liposomes proved to more effectively activate neutrophils compared with SME liposomes, as indicated by increased superoxide anion and elastase levels. Calcium influx increased 9-fold after treatment with CTAB liposomes. This influx was not changed by SME liposomes compared with the untreated control. Scanning electron microscopy (SEM) and immunofluorescence images indicated the presence of NETs after treatment with cationic liposomes. NETs could be quickly formed, within minutes, after CTAB liposomal treatment. In contrast to this result, NET formation was slowly and gradually increased by SME liposomes, within 4h. Based on the data presented here, it is important to consider the toxicity of cationic liposomes during administration in the body. This is the first report providing evidence of NET production induced by cationic liposomes. PMID:25731102

  15. Effects of Alchornea cordifolia on elastase and superoxide anion produced by human neutrophils.

    PubMed

    Kouakou-Siransy, Gisèle; Sahpaz, Sevser; Nguessan, G Irié; Datté, Jacques Yao; Brou, Jérome Kablan; Gressier, Bernard; Bailleul, François

    2010-02-01

    The ability of Alchornea cordifolia (Schum. and Thonn.) Müll. Arg. (Euphorbiaceae) leaves to inhibit human neutrophil elastase (HNE) and superoxide anion (O(2)(*-)) activities was evaluated on aqueous and ethyl acetate extracts as they allow for a targeted extraction of polyphenols. The direct effect of A. cordifolia extracts on HNE and O(2)(*-) was assessed in an acellular system. Results showed that extracts scavenge HNE and O(2)(*-) in a dose-dependent manner. Better activity was exhibited by the ethyl acetate extract with lower IC(50) (2.2 and 4. 1 mg/L for HNE and O(2)(*-), respectively) than for the aqueous extract. Cellular systems including isolated human polymorphonuclear neutrophils (PMN) were investigated to assess the effect of extracts on PMN metabolism. PMN were stimulated with 4beta-phorbol-12-myristate-13-acetate (PMA), calcium ionophore (CaI), or N-formyl-methionyl-leucine-phenylalanine (fMLP), each stimulant having its own stimulation pathway. From the IC(50) obtained, it can be concluded that A. cordifolia reduces HNE and O(2)(*-) liberation. Furthermore it was demonstrated that A. cordifolia extracts have no cytotoxic activity on PMN by measuring release of the cytosolic enzyme lactate dehydrogenase. As the ethyl acetate extract offers a higher rate of total phenols than the aqueous extract as well as better scavenging activity, it can be supposed that polyphenols, which are well known for their potent antioxidant and antielastase activity, are implicated in the activity of the plant. Phenolic substances such as quercetin, myricetin-3-glucopyranoside, myricetin-3-rhamnopyranoside, and proanthocyanidin A2 were identified in the ethyl acetate extract. In conclusion, the study provides proof of ethnomedical claims and partly explains the mechanisms of the anti-inflammatory action of A. cordifolia leaves. PMID:20645828

  16. Superoxide produced in the matrix of mitochondria enhances methylmercury toxicity in human neuroblastoma cells.

    PubMed

    Mailloux, Ryan J; Yumvihoze, Emmanuel; Chan, Hing Man

    2015-12-15

    The mechanism of intracellular metabolism of methylmercury (MeHg) is not fully known. It has been shown that superoxide (O2(-)), the proximal reactive oxygen species (ROS) generated by mitochondria, is responsible for MeHg demethylation. Here, we investigated the impact of different mitochondrial respiratory inhibitors, namely rotenone and antimycin A, on the O2(-)mediated degradation of MeHg in human neuroblastoma cells SH-K-SN. We also utilized paraquat (PQ) which generates O2(-) in the mitochondrial matrix. We found that the cleavage of the carbon-metal bond in MeHg was highly dependent on the topology of O2(-) production by mitochondria. Both rotenone and PQ, which increase O2(-) in the mitochondrial matrix at a dose-dependent manner, enhanced the conversion of MeHg to inorganic mercury (iHg). Surprisingly, antimycin A, which prompts emission of O2(-) into the intermembrane space, did not have the same effect even though antimycin A induced a dose dependent increase in O2(-) emission. Rotenone and PQ also enhanced the toxicity of sub-toxic doses (0.1 μM) MeHg which correlated with the accumulation of iHg in mitochondria and depletion of mitochondrial protein thiols. Taken together, our results demonstrate that MeHg degradation is mediated by mitochondrial O2(-), specifically within the matrix of mitochondria when O2(-) is in adequate supply. Our results also show that O2(-) amplifies MeHg toxicity specifically through its conversion to iHg and subsequent interaction with protein cysteine thiols (R-SH). The implications of our findings in mercury neurotoxicity are discussed herein. PMID:26545714

  17. The cytoprotective capacity of processed human cardiac extracellular matrix.

    PubMed

    Kappler, Benjamin; Anic, Petra; Becker, Matthias; Bader, Andreas; Klose, Kristin; Klein, Oliver; Oberwallner, Barbara; Choi, Yeong-Hoon; Falk, Volkmar; Stamm, Christof

    2016-07-01

    Freshly isolated human cardiac extracellular matrix sheets (cECM) have been shown to support stem cell proliferation and tissue-specific lineage commitment. We now developed a protocol for standardized production of durable, bio-functional hcECM microparticles and corresponding hydrogel, and tested its cytoprotective effects on contractile cells subjected to ischemia-like conditions. Human ventricular myocardium was decellularized by a 3-step protocol, including Tris/EDTA, SDS and serum incubation (cECM). Following snap-freezing and lyophilization, microparticles were created and characterized by laser diffraction, dynamic image analysis (DIA), and mass spectrometry. Moreover, cECM hydrogel was produced by pepsin digestion. Baseline cell-support characteristics were determined using murine HL-1 cardiomyocytes, and the cytoprotective effects of ECM products were tested under hypoxia and glucose/serum deprivation. In cECM, glycoproteins (thrombospondin 1, fibronectin, collagens and nidogen-1) and proteoglycans (dermatopontin, lumican and mimecan) were preserved, but residual intracellular and blood-borne proteins were also detected. The median particle feret diameter was 66 μm (15-157 μm) by laser diffraction, and 57 μm (20-182 μm) by DIA with crystal violet staining. HL-1 cells displayed enhanced metabolic activity (39 ± 12 %, P < 0.05) and proliferation (16 ± 3 %, P < 0.05) when grown on cECM microparticles in normoxia. During simulated ischemia, cECM microparticles exerted distinct cytoprotective effects (MTS conversion, 240 ± 32 %; BrdU uptake, 45 ± 14 %; LDH release, -72 ± 7 %; P < 0.01, each). When cECM microparticles were solubilized to form a hydrogel, the cytoprotective effect was initially abolished. However, modifying the preparation process (pepsin digestion at pH 2 and 25 °C, 1 mg/ml final cECM concentration) restored the cytoprotective cECM activity. Extracellular matrix from human myocardium can be processed to

  18. Simplified Human Neutrophil Extracellular Traps (NETs) Isolation and Handling.

    PubMed

    Najmeh, Sara; Cools-Lartigue, Jonathan; Giannias, Betty; Spicer, Jonathan; Ferri, Lorenzo E

    2015-01-01

    Neutrophil Extracellular Traps (NETs) have been recently identified as part of the neutrophil's antimicrobial armamentarium. Apart from their role in fighting infections, recent research has demonstrated that they may be involved in many other disease processes, including cancer progression. Isolating purified NETs is a crucial element to allow the study of these functions. In this video, we demonstrate a simplified method of cell free NET isolation from human whole blood using readily available reagents. Isolated NETs can then be used for immunofluorescence staining, blotting or various functional assays. This enables an assessment of their biologic properties in the absence of the potential confounding effects of neutrophils themselves. A density gradient separation technique is employed to isolate neutrophils from healthy donor whole blood. Isolated neutrophils are then stimulated by phorbol 12-myristate 13-acetate (PMA) to induce NETosis. Activated neutrophils are then discarded, and a cell-free NET stock is obtained. We then demonstrate how isolated NETs can be used in an adhesion assay with A549 human lung cancer cells. The NET stock is used to coat the wells of a 96 well cell culture plate O/N, and after ensuring an adequate NET monolayer formation on the bottom of the wells, CFSE labeled A549 cells are added. Adherent cells are quantified using a Nikon TE300 fluorescent microscope. In some wells, 1000U DNAse1 is added 10 min before counting to degrade NETs. PMID:25938591

  19. Characterization of the PGE receptor subtype mediating inhibition of superoxide production in human neutrophils.

    PubMed Central

    Talpain, E; Armstrong, R A; Coleman, R A; Vardey, C J

    1995-01-01

    1. The aims of this study were to characterize the EP receptor subtype mediating the inhibition of superoxide anion generation by formyl methionyl leucine phenylalanine (FMLP)-stimulated human neutrophils, and to test the hypothesis that adenosine 3':5'-cyclic monophosphate (cyclic AMP) is the second messenger mediating the inhibition of the neutrophil by prostaglandin (PG)E2. 2. PGE2 (0.001-10 microM) inhibited FMLP (100 nM)-induced O2-generation from human peripheral blood neutrophils in a concentration-dependent manner, with an EC50 of 0.15 +/- 0.03 microM, and a maximum effect ranging from 36-84% (mean inhibition of 68.7 +/- 2.5%, n = 32). 3. The EP2-receptor agonists, misoprostol, 11-deoxy PGE1, AH13205 and butaprost, all at 10 microM, inhibited O2- generation, causing 95.5 +/- 2.9%, 56.8 +/- 5.2%, 37.1 +/- 6.6% and 18.9 +/- 4.4% inhibition respectively, the latter two being much less effective than PGE2. Similarly, the EP1-receptor agonist, 17-phenyl PGE2 (10 microM), and the EP3/EP1-receptor agonist, sulprostone (10 microM), also inhibited O2- generation, causing 32.2 +/- 7.0% and 15.3 +/- 3.4% inhibition respectively. 4. The non-selective phosphodiesterase inhibitor, isobutyl methylxanthine (IBMX, 0.25 mM) inhibited the FMLP response by 54.5 +/- 5.0%. In addition, IBMX shifted concentration-effect curves for PGE2, misoprostol, 11-deoxy PGE1, butaprost, and AH 13205 to the left, to give EC50s of 0.04 +/- 0.03 (n = 13), 0.07 +/- 0.03 (n = 4), 0.08 +/- 0.03 (n = 4), 0.33 +/- 0.13 (n = 4) and 0.41 +/- 0.2 microM (n = 3) respectively, allowing equieffective concentration-ratios (EECs, PGE2 = 1) of 11.5, 5.3, 50.7 and 12.7 to be calculated.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7606349

  20. Human Manganese Superoxide Dismutase Tyrosine 34 Contribution to Structure and Catalysis

    PubMed Central

    Perry, J. Jefferson P.; Hearn, Amy S.; Cabelli, Diane E.; Nick, Harry S.; Tainer, John A.; Silverman, David N.

    2009-01-01

    Superoxide dismutase (SOD) enzymes are critical in controlling levels of reactive oxygen species (ROS) that are linked to aging, cancer and neurodegenerative disease. Superoxide (O2 •−) produced during respiration is removed by the product of the SOD2 gene, the homotetrameric manganese superoxide dismutase (MnSOD). Here, we examine the structural and catalytic roles of the highly conserved active-site residue Tyr34, based upon structure-function studies of MnSOD enzymes with mutations at this site. Substitution of Tyr34 with five different amino acids retained the active site protein structure and assembly, but causes a substantial decrease in the catalytic rate constant for the reduction of superoxide. The rate constant for formation of product inhibition complex also decreases but to a much lesser extent, resulting in a net increase in the product inhibition form of the mutant enzymes. Comparisons of crystal structures and catalytic rates also suggest that one mutation, Y34V, interrupts the hydrogen-bonded network, which is associated with a rapid dissociation of the product-inhibited complex. Notably, with three of the Tyr34 mutants we also observe an intermediate in catalysis, which has not been reported previously. Thus, these mutants establish a means to trap a catalytic intermediate that promises to help elucidate the mechanism of catalysis. PMID:19265433

  1. Superoxide Flashes

    PubMed Central

    Ma, Qi; Fang, Huaqiang; Shang, Wei; Liu, Lei; Xu, Zhengshuang; Ye, Tao; Wang, Xianhua; Zheng, Ming; Chen, Quan; Cheng, Heping

    2011-01-01

    Irreversible mitochondrial permeability transition and the resultant cytochrome c release signify the commitment of a cell to apoptotic death. However, the role of transient MPT (tMPT) because of flickering opening of the mitochondrial permeability transition pore remains elusive. Here we show that tMPT and the associated superoxide flashes (i.e. tMPT/superoxide flashes) constitute early mitochondrial signals during oxidative stress-induced apoptosis. Selenite (a ROS-dependent insult) but not staurosporine (a ROS-independent insult) stimulated an early and persistent increase in tMPT/superoxide flash activity prior to mitochondrial fragmentation and a global ROS rise, independently of Bax translocation and cytochrome c release. Selectively targeting tMPT/superoxide flash activity by manipulating cyclophilin D expression or scavenging mitochondrial ROS markedly impacted the progression of selenite-induced apoptosis while exerting little effect on the global ROS response. Furthermore, the tMPT/superoxide flash served as a convergence point for pro- and anti-apoptotic regulation mediated by cyclophilin D and Bcl-2 proteins. These results indicate that tMPT/superoxide flashes act as early mitochondrial signals mediating the apoptotic response during oxidative stress, and provide the first demonstration of highly efficacious local mitochondrial ROS signaling in deciding cell fate. PMID:21659534

  2. Entamoeba histolytica Trophozoites and Lipopeptidophosphoglycan Trigger Human Neutrophil Extracellular Traps.

    PubMed

    Ávila, Eva E; Salaiza, Norma; Pulido, Julieta; Rodríguez, Mayra C; Díaz-Godínez, César; Laclette, Juan P; Becker, Ingeborg; Carrero, Julio C

    2016-01-01

    Neutrophil defense mechanisms include phagocytosis, degranulation and the formation of extracellular traps (NET). These networks of DNA are triggered by several immune and microbial factors, representing a defense strategy to prevent microbial spread by trapping/killing pathogens. This may be important against Entamoeba histolytica, since its large size hinders its phagocytosis. The aim of this study was to determine whether E. histolytica and their lipopeptidophosphoglycan (EhLPPG) induce the formation of NETs and the outcome of their interaction with the parasite. Our data show that live amoebae and EhLPPG, but not fixed trophozoites, induced NET formation in a time and dose dependent manner, starting at 5 min of co-incubation. Although immunofluorescence studies showed that the NETs contain cathelicidin LL-37 in close proximity to amoebae, the trophozoite growth was only affected when ethylene glycol tetra-acetic acid (EGTA) was present during contact with NETs, suggesting that the activity of enzymes requiring calcium, such as DNases, may be important for amoeba survival. In conclusion, E. histolytica trophozoites and EhLPPG induce in vitro formation of human NETs, which did not affect the parasite growth unless a chelating agent was present. These results suggest that NETs may be an important factor of the innate immune response during infection with E. histolytica. PMID:27415627

  3. Oxidized Extracellular DNA as a Stress Signal in Human Cells

    PubMed Central

    Ermakov, Aleksei V.; Konkova, Marina S.; Kostyuk, Svetlana V.; Izevskaya, Vera L.; Veiko, Natalya N.

    2013-01-01

    The term “cell-free DNA” (cfDNA) was recently coined for DNA fragments from plasma/serum, while DNA present in in vitro cell culture media is known as extracellular DNA (ecDNA). Under oxidative stress conditions, the levels of oxidative modification of cellular DNA and the rate of cell death increase. Dying cells release their damaged DNA, thus, contributing oxidized DNA fragments to the pool of cfDNA/ecDNA. Oxidized cell-free DNA could serve as a stress signal that promotes irradiation-induced bystander effect. Evidence points to TLR9 as a possible candidate for oxidized DNA sensor. An exposure to oxidized ecDNA stimulates a synthesis of reactive oxygen species (ROS) that evokes an adaptive response that includes transposition of the homologous loci within the nucleus, polymerization and the formation of the stress fibers of the actin, as well as activation of the ribosomal gene expression, and nuclear translocation of NF-E2 related factor-2 (NRF2) that, in turn, mediates induction of phase II detoxifying and antioxidant enzymes. In conclusion, the oxidized DNA is a stress signal released in response to oxidative stress in the cultured cells and, possibly, in the human body; in particular, it might contribute to systemic abscopal effects of localized irradiation treatments. PMID:23533696

  4. Degenerated human intervertebral discs contain autoantibodies against extracellular matrix proteins.

    PubMed

    Capossela, S; Schläfli, P; Bertolo, A; Janner, T; Stadler, B M; Pötzel, T; Baur, M; Stoyanov, J V

    2014-01-01

    Degeneration of intervertebral discs (IVDs) is associated with back pain and elevated levels of inflammatory cells. It has been hypothesised that discogenic pain is a direct result of vascular and neural ingrowth along annulus fissures, which may expose the avascular nucleus pulposus (NP) to the systemic circulation and induce an autoimmune reaction. In this study, we confirmed our previous observation of antibodies in human degenerated and post-traumatic IVDs cultured in vitro. We hypothesised that the presence of antibodies was due to an autoimmune reaction against specific proteins of the disc. Furthermore we identified antigens which possibly trigger an autoimmune response in degenerative disc diseases. We demonstrated that degenerated and post-traumatic IVDs contain IgG antibodies against typical extracellular proteins of the disc, particularly proteins of the NP. We identified IgGs against collagen type II and aggrecan, confirming an autoimmune reaction against the normally immune privileged NP. We also found specific IgGs against collagens types I and V, but not against collagen type III. In conclusion, this study confirmed the association between disc degeneration and autoimmunity, and may open the avenue for future studies on developing prognostic, diagnostic and therapy-monitoring markers for degenerative disc diseases. PMID:24706108

  5. Entamoeba histolytica Trophozoites and Lipopeptidophosphoglycan Trigger Human Neutrophil Extracellular Traps

    PubMed Central

    Ávila, Eva E.; Rodríguez, Mayra C.; Díaz-Godínez, César; Laclette, Juan P.; Becker, Ingeborg; Carrero, Julio C.

    2016-01-01

    Neutrophil defense mechanisms include phagocytosis, degranulation and the formation of extracellular traps (NET). These networks of DNA are triggered by several immune and microbial factors, representing a defense strategy to prevent microbial spread by trapping/killing pathogens. This may be important against Entamoeba histolytica, since its large size hinders its phagocytosis. The aim of this study was to determine whether E. histolytica and their lipopeptidophosphoglycan (EhLPPG) induce the formation of NETs and the outcome of their interaction with the parasite. Our data show that live amoebae and EhLPPG, but not fixed trophozoites, induced NET formation in a time and dose dependent manner, starting at 5 min of co-incubation. Although immunofluorescence studies showed that the NETs contain cathelicidin LL-37 in close proximity to amoebae, the trophozoite growth was only affected when ethylene glycol tetra-acetic acid (EGTA) was present during contact with NETs, suggesting that the activity of enzymes requiring calcium, such as DNases, may be important for amoeba survival. In conclusion, E. histolytica trophozoites and EhLPPG induce in vitro formation of human NETs, which did not affect the parasite growth unless a chelating agent was present. These results suggest that NETs may be an important factor of the innate immune response during infection with E. histolytica. PMID:27415627

  6. Extracellular signal-regulated kinases modulate capacitation of human spermatozoa.

    PubMed

    Luconi, M; Barni, T; Vannelli, G B; Krausz, C; Marra, F; Benedetti, P A; Evangelista, V; Francavilla, S; Properzi, G; Forti, G; Baldi, E

    1998-06-01

    Recent evidence indicates the presence of p21 Ras and of a protein with characteristics similar to mitogen-activated protein kinases (MAPKs), also known as extracellular signal-regulated kinases (ERKs), in mammalian spermatozoa, suggesting the occurrence of the Ras/ERK cascade in these cells. In the present study we investigated the subcellular localization of ERKs and their biological functions in human spermatozoa. Immunohistochemistry, immunofluorescence, confocal microscopy, and immunoelectron microscopy demonstrated localization of ERKs in the postacrosomal region of spermatozoa. After stimulation of acrosome reaction with the calcium ionophore A23187 and progesterone, ERKs were mostly localized at the level of the equatorial region, indicating redistribution of these proteins in acrosome-reacted spermatozoa. Two proteins of 42 and 44 kDa that are tyrosine phosphorylated in a time-dependent manner during in vitro capacitation were identified as p42 (ERK-2) and p44 (ERK-1) by means of specific antibodies. The increase in tyrosine phosphorylation of these proteins during capacitation was accompanied by increased kinase activity, as determined by the ability of ERK-1 and ERK-2 to phosphorylate the substrate myelin basic protein. The role of this activity in the occurrence of sperm capacitation was also investigated by using PD098059, an inhibitor of the MAPK cascade. The presence of this compound during in vitro capacitation inhibits ERK activation and significantly reduces the ability of spermatozoa to undergo the acrosome reaction in response to progesterone. Since only capacitated spermatozoa are able to respond to progesterone, these data strongly indicate that ERKs are involved in the regulation of capacitation. In summary, our data demonstrate the presence of functional ERKs in human spermatozoa and indicate that these enzymes are involved in activation of these cells during capacitation, providing new insight in clarifying the molecular mechanisms and the

  7. Silibinin induces protective superoxide generation in human breast cancer MCF-7 cells.

    PubMed

    Wang, Hong-Jun; Jiang, Yuan-Yuan; Wei, Xiao-Feng; Huang, Huai; Tashiro, Shin-Ichi; Onodera, Satoshi; Ikejima, Takashi

    2010-01-01

    The pharmacological activity of polyphenolic silibinin from milk thistle (Silybum marianum) is primarily due to its antioxidant property. However, this study found that silibinin promoted sustained superoxide (O(2)(.-)) production that was specifically scavenged by exogenous superoxide dismutase (SOD) in MCF-7 cells, while the activity of endogenous SOD was not changed by silibinin. Previous work proved that silibinin induced MCF-7 cell apoptosis through mitochondrial pathway and this study further proved that O(2)(.-) generation induced by silibinin was also related to mitochondria. It was found that respiratory chain complexes I, II and III were all involved in silibinin-induced O(2)(.-) generation. Moreover, it was found that silibinin-induced O(2)(.-) had protective effect, as exogenous SOD markedly enhanced silibinin-induced apoptosis. PMID:19968587

  8. Human Mammospheres Secrete Hormone-Regulated Active Extracellular Vesicles

    PubMed Central

    Rodriguez-Suarez, Eva; Gil, David; Royo, Felix; Elortza, Felix; Falcon-Perez, Juan M.; Vivanco, Maria dM.

    2014-01-01

    Breast cancer is a leading cause of cancer-associated death worldwide. One of the most important prognostic factors for survival is the early detection of the disease. Recent studies indicate that extracellular vesicles may provide diagnostic information for cancer management. We demonstrate the secretion of extracellular vesicles by primary breast epithelial cells enriched for stem/progenitor cells cultured as mammospheres, in non-adherent conditions. Using a proteomic approach we identified proteins contained in these vesicles whose expression is affected by hormonal changes in the cellular environment. In addition, we showed that these vesicles are capable of promoting changes in expression levels of genes involved in epithelial-mesenchymal transition and stem cell markers. Our findings suggest that secreted extracellular vesicles could represent potential diagnostic and/or prognostic markers for breast cancer and support a role for extracellular vesicles in cancer progression. PMID:24404144

  9. 3D Extracellular Matrix from Sectioned Human Tissues

    PubMed Central

    Campbell, Catherine B; Cukierman, Edna; Artym, Vira V

    2014-01-01

    corneal endothelial cell lines produce an ECM mimicking an in vivo subendothelium, and the EHS tumor cell line produces a matrix that can be extracted to produce Matrigel, which simulates basement membrane molecular complexity including laminin, collagen IV and nidogen (Beacham, et al., 2007; Friedl and Brocker, 2000). To simulate a physiological environment even more closely, 3D matrices derived from mouse tissue slices from which cells were extracted have reportedly provided successful ECM replicas for studying in vivo cellular behavior (Cukierman, et al., 2001). Because of the important roles of the extracellular microenvironment on normal and tumor cells, we have developed protocols to produce cell-free (decellularized) 3D matrices from cryostat sections of normal and tumor human tissues. These extracted matrices can be used as a 3D tissue culture environment to analyze effects of various 3D matrices on normal and tumor cell responses and behavior. Using human pancreas and breast tissue samples, we have successfully prepared cell-free 3D ECM models, used them as cell culture substrates for a human breast cancer cell line, MDA-MB-231, and then performed immunofluorescence staining to characterize intracellular structures. A frequently observed difference between normal and tumor tissue-derived ECM environments involves the amount of deposited fibrillar collagen (Provenzano, 2008). Tumor tissues from both breast and pancreas often contain substantially more collagen than normal adjacent tissue, and this protocol preserves this difference in cell-free 3D matrices from these tissues (Vidi, et al., 2013). This 3D culture system we describe using cell-free 3D matrix provides an approach to studying cellular behavior and migratory mechanisms associated with cancer. The basic protocol describes methods for successfully extracting cells and cellular debris from human tissue cryostat sections to obtain a clean, cell-free 3D ECM for plating cell lines (Figure 1). Cellular

  10. Extracellular microRNAs as Biomarkers in Human Disease

    PubMed Central

    2015-01-01

    Dysregulation of microRNA (miRNA) levels is observed in diverse disease states. Early studies showed that by analyzing the expression profile of miRNAs in the tissue sample of a diseased person, it was possible to classify the disease into a specific subtype. To be used for diagnostic purposes more practically, however, a less invasive method than tissue biopsy is required. Surprisingly, it was discovered that a notable amount of extracellular miRNAs circulate throughout the body fluids with high stability. Moreover, the expression profile of miRNAs was shown to differ considerably between healthy and diseased people. In addition, evidence has been accumulating of extracellular miRNAs acting as signaling molecules between distantly located cells. If the expression profile faithfully reflects the disease states, the profiling of extracellular miRNAs will become a useful means of early warning or diagnosis of diverse diseases, replacing more invasive biopsy methods. PMID:26306299

  11. Mycobacterium tuberculosis Exploits Human Interferon γ to Stimulate Macrophage Extracellular Trap Formation and Necrosis

    PubMed Central

    Wong, Ka-Wing; Jacobs, Williams R.

    2013-01-01

    Human neutrophils form extracellular traps during M. tuberculosis infection, but a similar phenomenon has not been reported in human macrophages. Here we demonstrate that M. tuberculosis induces release of extracellular traps from human macrophages. This process is regulated by elastase activity, previously shown to regulate formation of extracellular traps by neutrophils. Interestingly, formation of extracellular traps by macrophages during M. tuberculosis infection is inducible by interferon γ (IFN-γ). These traps are mainly produced by heavily infected macrophages. Accordingly, IFN-γ is found to stimulate M. tuberculosis aggregation in macrophages. Both IFN-γ–inducible events, extracellular trap formation and mycobacterial aggregation, require the ESX-1 secretion system. In addition, IFN-γ is found to enhance ESX-1–mediated macrophage necrosis. In the absence of ESX-1, IFN-γ does not restore any extracellular trap formation, mycobacterial aggregation, or macrophage necrosis. Thus, initial characterization of macrophage extracellular trap formation due to M. tuberculosis infection led to the uncovering of a novel role for IFN-γ in amplifying multiple effects of the mycobacterial ESX-1. PMID:23475311

  12. Intermittent High Glucose Implements Stress-Induced Senescence in Human Vascular Endothelial Cells: Role of Superoxide Production by NADPH Oxidase

    PubMed Central

    Maeda, Morihiko; Hayashi, Toshio; Mizuno, Natsumi; Hattori, Yuichi; Kuzuya, Masafumi

    2015-01-01

    Impaired glucose tolerance characterized by postprandial hyperglycemia, which occurs frequently in elderly persons and represents an important preliminary step in diabetes mellitus, poses an independent risk factor for the development of atherosclerosis. Endothelial cellular senescence is reported to precede atherosclerosis. We reported that continuous high glucose stimulus causes endothelial senescence more markedly than hypertension or dyslipidemia stimulus. In the present study, we evaluated the effect of fluctuating glucose levels on human endothelial senescence. Constant high glucose increased senescence-associated-β-galactosidase(SA-β-gal) activity, a widely used marker for cellular senescence. Interestingly, in intermittent high glucose, this effect was more pronounced as well as increase of p21 and p16INK4a , senescence related proteins with DNA damage. However, telomerase was not activated and telomere length was not shortened, thus stress-induced senescence was shown. However, constant high glucose activated telomerase and shortened telomere length, which suggested replicative senescence. Intermittent but not constant high glucose strikingly up-regulated the expression of p22phox, an NADPH oxidase component, increasing superoxide. The small interfering RNA of p22phox undermined the increase in SA-β-gal activity induced by intermittent high glucose. Conclusively, intermittent high glucose can promote vascular endothelial senescence more than constant high glucose, which is in partially dependent on superoxide overproduction. PMID:25879533

  13. Aortic ascorbic acid, trace elements, and superoxide dismutase activity in human aneurysmal and occlusive disease

    SciTech Connect

    Dubick, M.A.; Hunter, G.C.; Casey, S.M.; Keen, C.L.

    1987-02-01

    Altered trace elements and ascorbic acid metabolism have been implicated in the pathogenesis of atherosclerotic cardiovascular disease. However, their role in the disease process, or the effect of atherosclerosis on their tissue levels within plaque, is poorly understood. The presence study analyzes the concentrations of Fe, Cu, Zn, and Mn, and ascorbic acid and superoxide dismutase (SOD) activity in tissue samples from 29 patients with abdominal aortic aneurysms (AAA) and 14 patients with atherosclerotic occlusive disease (AOD). It was observed that the Fe and Mn concentrations in AAA and AOD tissue were higher than the levels in nondiseased control aorta, whereas Cu and Zn levels in AAA and AOD tissue were similar to the levels in controls. The Zn:Cu ratio was significantly lower in the AAA tissue in comparison to both AOD and control tissue. In addition, AAA and AOD tissue had low ascorbic acid levels and low Cu, Zn-SOD activity with Cu,Zn-SOD:Mn-SOD ratios of 0.27 and 0.19, respectively, compared to a ratio of 3.20 in control aorta. These data indicate that aorta affected by aneurysms and occlusive disease have altered trace element and ascorbic acid concentrations, as well as low Cu,Zn-SOD activity. Although these observations do not directly support the hypothesis that AAA is associated with aortic Cu deficiency they do suggest a role for oxygen radicals or increased lipid peroxidation in occlusive and aneurysmal disease of the aorta.

  14. The impact of cationic solid lipid nanoparticles on human neutrophil activation and formation of neutrophil extracellular traps (NETs).

    PubMed

    Hwang, Tsong-Long; Aljuffali, Ibrahim A; Hung, Chi-Feng; Chen, Chun-Han; Fang, Jia-You

    2015-06-25

    Cationic solid lipid nanoparticles (cSLNs) are extensively employed as the nanocarriers for drug/gene targeting to tumors and the brain. Investigation into the possible immune response of cSLNs is still lacking. The aim of this study was to evaluate the impact of cSLNs upon the activation of human polymorphonuclear neutrophil cells (PMNs). The cytotoxicity, pro-inflammatory mediators, Ca(2+) mobilization, mitogen-activated protein kinases (MAPKs), and neutrophil extracellular traps (NETs) as the indicators of PMN stimulation were examined in this work. The cSLNs presented a diameter of 195 nm with a zeta potential of 44 mV. The cSLNs could interact with the cell membrane to produce a direct membrane lysis and the subsequent cytotoxicity according to lactate dehydrogenase (LDH) elevation. The interaction of cSLNs with the membrane also triggered a Ca(2+) influx, followed by the induction of oxidative stress and degranulation. The cationic nanoparticles elevated the levels of superoxide anion and elastase by 24- and 9-fold, respectively. The PMN activation by cSLNs promoted the phosphorylation of p38 and Jun-N-terminal kinases (JNK) but not extracellular signal-regulated kinases (ERK). The imaging of scanning electron microscopy (SEM) and immunofluorescence demonstrated the production of NETs by cSLNs. This phenomenon was not significant for the neutral SLNs (nSLNs), although histones in NETs also increased after treatment of nSLNs. Our results suggest an important role of cSLNs in governing the activation of human neutrophils. PMID:25920576

  15. All-trans retinoic acid and extracellular Ca2+ differentially influence extracellular matrix production by human skin in organ culture.

    PubMed Central

    Varani, J.; Larson, B. K.; Perone, P.; Inman, D. R.; Fligiel, S. E.; Voorhees, J. J.

    1993-01-01

    Two-mm full-thickness punch biopsies of human skin were placed in organ culture in a serum-free, growth factor-free basal medium. Under conditions of low extracellular Ca2+ (0.15 mmol/L), the tissue quickly degenerated. However, degeneration was prevented when the extracellular Ca2+ concentration was increased to 1.4 mmol/L. The tissue remained histologically normal in appearance and biochemically active for up to 12 days. The addition of 3 mumol/L all-trans retinoic acid (RA) to the low-Ca2+ culture medium also prevented tissue degeneration. However, in contrast to what was seen in the presence of 1.4 mmol/L Ca2+, epidermal differentiation did not occur normally in the presence of RA. Rather, the upper layers of the epidermis routinely separated from the underlying basal cells. Fibronectin production by the organ cultured skin was examined. Biosynthetic labeling/immunoprecipitation studies demonstrated that incubation of the tissue in basal medium containing 1.4 mmol/L Ca2+ resulted in a high level of fibronectin production relative to the amount produced in basal medium containing 0.15 mmol/L Ca2+. In contrast, the addition of 3 mumol/L RA to the low Ca2+ basal medium did not stimulate fibronectin production. Similar results were observed in enzyme-linked immunosorbent assays where the addition of Ca2+ to a final concentration of 1.4 mmol/L stimulated fibronectin and thrombospondin production whereas RA (3 mumol/L) did not. Although RA by itself failed to stimulate extracellular matrix production, the addition of 3 mumol/L RA to basal medium containing 1.4 mmol/L Ca2+ led to a further increase in fibronectin production over that seen in the presence of 1.4 mmol/L Ca2+ alone. Taken together, these data indicate that although either 1.4 mmol/L Ca2+ or 3 mumol/L RA facilitates survival of organ-cultured skin in basal medium, they have very different effects on extracellular matrix production. This supports the view, based on histological appearance, that the two

  16. Modified natural porcine surfactant inhibits superoxide anions and proinflammatory mediators released by resting and stimulated human monocytes.

    PubMed

    Walti, H; Polla, B S; Bachelet, M

    1997-01-01

    Pulmonary surfactant has a potential role in modulating inflammation in normal and injured lungs. In lung injury, monocytes become activated and participate in lung inflammation. We therefore, investigated the proinflammatory functions of stimulated human blood monocytes after an overnight preincubation period with modified natural porcine surfactant (Curosurf) (500-1000 micrograms/mL). Monocytes were stimulated either with phorbol myristate acetate (PMA), bacterial extract OM-85, lipopolysaccharide (LPS), or Ca2+ ionophore A23187. The present study shows that Curosurf significantly inhibits: 1) the production of superoxide anions stimulated with OM-85 (1 mg/mL, 30 min), but not with PMA (100 ng/mL, 30 min); 2) the release of cyclooxygenase metabolites prostaglandin E2 and thromboxane B2 stimulated with OM-85 (1 mg/mL, overnight); 3) the release of lipoxygenase metabolite leukotriene C4 stimulated with A23187 (10 microM, 10 min); 4) the release of the cytokine TNF-alpha stimulated overnight with either OM-85 (1 mg/mL) or LPS (10 micrograms/mL)) in a dose-dependent fashion. In addition, Curosurf decreases the spontaneous adherence of monocytes to plastic culture wells in a dose-dependent fashion. Experiments performed with staurosporine, an inhibitor of protein kinase C (PKC) indicate that, in contrast with PMA, the production of superoxide anions stimulated by OM-85 is not related to PKC activation. Consequently, we propose that the mechanism involved in the suppressive effects of Curosurf is PKC-independent. In summary, the present study provides experimental evidence that favors the anti-inflammatory role of modified natural porcine surfactant (Curosurf) in human monocytes in vitro. PMID:8979299

  17. Extracellular N-Acetylaspartate in Human Traumatic Brain Injury

    PubMed Central

    Shannon, Richard J.; Carter, Eleanor L.; Jalloh, Ibrahim; Menon, David K.; Hutchinson, Peter J.; Carpenter, Keri L.H.

    2016-01-01

    Abstract N-acetylaspartate (NAA) is an amino acid derivative primarily located in the neurons of the adult brain. The function of NAA is incompletely understood. Decrease in brain tissue NAA is presently considered symptomatic and a potential biomarker of acute and chronic neuropathological conditions. The aim of this study was to use microdialysis to investigate the behavior of extracellular NAA (eNAA) levels after traumatic brain injury (TBI). Sampling for this study was performed using cerebral microdialysis catheters (M Dialysis 71) perfused at 0.3 μL/min. Extracellular NAA was measured in microdialysates by high-performance liquid chromatography in 30 patients with severe TBI and for comparison, in radiographically “normal” areas of brain in six non-TBI neurosurgical patients. We established a detailed temporal eNAA profile in eight of the severe TBI patients. Microdialysate concentrations of glucose, lactate, pyruvate, glutamate, and glycerol were measured on an ISCUS clinical microdialysis analyzer. Here, we show that the temporal profile of microdialysate eNAA was characterized by highest levels in the earliest time-points post-injury, followed by a steady decline; beyond 70 h post-injury, average levels were 40% lower than those measured in non-TBI patients. There was a significant inverse correlation between concentrations of eNAA and pyruvate; eNAA showed significant positive correlations with glycerol and the lactate/pyruvate (L/P) ratio measured in microdialysates. The results of this on-going study suggest that changes in eNAA after TBI relate to the release of intracellular components, possibly due to neuronal death or injury, as well as to adverse brain energy metabolism. PMID:26159566

  18. Human mitochondrial manganese superoxide dismutase polymorphic variant Ile58Thr reduces activity by destabilizing the tetrameric interface

    SciTech Connect

    Borgstahl, G.E.O.; Hickey, M.J.; Johnson, M.J.

    1996-04-09

    Human manganese superoxide dismutase (MnSOD) is a homotetrameric enzyme which protects mitochondria against oxygen-mediated free radical damage. Within each subunit, both the N-terminal helical hairpin and C-terminal {alpha}/{beta} domains contribute ligands to the catalytic manganese site. Two identical four-helix bundles,symmetrically assembled form the N-terminal helical hairpins, form a novel tetrameric interface that stabilizes the active sites. The 2.5 {angstrom} crystallographic structure of the naturally occurring polymorphic variant Ile58Thr MnSOD reveals that the helical hairpin mutation Thr58 causes two packing defects in each of the two four-helix bundles of the tetrameric interface. Similar mutations, expected to cause packing defects in the Cu,ZnSOD dimer interface, are associated with the degenerative disease amyotrophic lateral sclerosis. Ile58Thr MnSOD is primarily dimeric in solution and is significantly less thermostable than the normal enzyme, with decreases of 15{degrees}C in the main melting temperature and 20{degrees}C in the heat-inactivation temperature. Consequently, this mutant MnSOD is compromised at normal body temperatures: thermal inactivation, predicted from the decrease in thermal stability, occurs with a theoretical half-life of only 3.2h at 37{degrees}C (1.4 h at 41 {degrees}C), compared with 3.1 years for native MnSOD. This prediction is supported by direct measurements: incubation at 41.7{degrees}C for 3 h has no effect on the activity of native MnSOD but completely inactivates mutant MnSOD. Rapid inactivation of Ile58Thr MnSOD at the elevated temperatures associated with fever and inflammation could provide an early advantage by killing infected cells, but also would increase superoxide-mediated oxidative damage and perhaps contribute to late-onset diseases. 63 refs., 7 figs., 2 tabs.

  19. Effect of cisplatin treatment on the urinary excretion of guanidinoacetic acid, creatinine and creatine in patients with urinary tract neoplasm, and on superoxide generation in human neutrophils.

    PubMed

    Yasuda, M; Sugahara, K; Zhang, J; Shuin, T; Kodama, H

    2000-01-01

    Production of guanidinoacetic acid, a precursor of creatinine is known to be reduced by metabolic disturbance when kidney function is damaged, and thus it may be a sensitive marker of renal damage. Therefore, the urinary levels of guanidinoacetic acid, creatinine and creatine from patients with urinary tract neoplasm who received cisplatin treatment were measured by liquid chromatography-mass spectrometry. Following the administration of cisplatin, the urinary excretion of guanidinoacetic acid decreased significantly, and the low concentration was maintained for at least five days. The concentrations of creatinine and creatine gradually decreased until the third day after cisplatin administration, and slightly increased on the fifth day. As superoxide might be concerned in renal damage by cisplatin, the effect of cisplatin on superoxide generation was also investigated using human neutrophils. Cisplatin significantly enhanced phorbol 12-myristate 13-acetate-induced superoxide generation in a concentration-dependent manner, but had no effect on the superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine and arachidonic acid. The superoxide generation increased by cisplatin was inhibited by staurosporine, an inhibitor of protein kinase C, but was rather enhanced by genistein, an inhibitor of protein tyrosine kinase. PMID:11383133

  20. Titanium dioxide nanoparticles enhance production of superoxide anion and alter the antioxidant system in human osteoblast cells

    PubMed Central

    Niska, Karolina; Pyszka, Katarzyna; Tukaj, Cecylia; Wozniak, Michal; Radomski, Marek Witold; Inkielewicz-Stepniak, Iwona

    2015-01-01

    Titanium dioxide (TiO2) nanoparticles (NPs) are manufactured worldwide for a variety of engineering and bioengineering applications. TiO2NPs are frequently used as a material for orthopedic implants. However, to the best of our knowledge, the biocompatibility of TiO2NPs and their effects on osteoblast cells, which are responsible for the growth and remodeling of the human skeleton, have not been thoroughly investigated. In the research reported here, we studied the effects of exposing hFOB 1.19 human osteoblast cells to TiO2NPs (5–15 nm) for 24 and 48 hours. Cell viability, alkaline phosphatase (ALP) activity, cellular uptake of NPs, cell morphology, superoxide anion (O2•−2) generation, superoxide dismutase (SOD) activity and protein level, sirtuin 3 (SIR3) protein level, correlation between manganese (Mn) SOD and SIR, total antioxidant capacity, and malondialdehyde were measured following exposure of hFOB 1.19 cells to TiO2NPs. Exposure of hFOB 1.19 cells to TiO2NPs resulted in: (1) cellular uptake of NPs; (2) increased cytotoxicity and cell death in a time- and concentration-dependent manner; (3) ultrastructure changes; (4) decreased SOD and ALP activity; (5) decreased protein levels of SOD1, SOD2, and SIR3; (6) decreased total antioxidant capacity; (7) increased O2•− generation; and (8) enhanced lipid peroxidation (malondialdehyde level). The linear relationship between the protein level of MnSOD and SIR3 and between O2•− content and SIR3 protein level was observed. Importantly, the cytotoxic effects of TiO2NPs were attenuated by the pretreatment of hFOB 1.19 cells with SOD, indicating the significant role of O2•− in the cell damage and death observed. Thus, decreased expression of SOD leading to increased oxidizing stress may underlie the nanotoxic effects of TiO2NPs on human osteoblasts. PMID:25709434

  1. Priming of Human Neutrophils Is Necessary for Their Activation by Extracellular DNA.

    PubMed

    Prikhodko, A S; Vitushkina, M V; Zinovkina, L A; Popova, E N; Zinovkin, R A

    2016-06-01

    Extracellular plasma DNA is thought to act as a damage-associated molecular pattern causing activation of immune cells. However, purified preparations of mitochondrial and nuclear DNA were unable to induce neutrophil activation in vitro. Thus, we examined whether granulocyte-macrophage colony-stimulating factor (GM-CSF) acting as a neutrophil priming agent can promote the activation of neutrophils by different types of extracellular DNA. GM-CSF pretreatment greatly increased p38 MAPK phosphorylation and promoted CD11b/CD66b expression in human neutrophils treated with mitochondrial and, to a lesser extent, with nuclear DNA. Our experiments clearly indicate that GM-CSF-induced priming of human neutrophils is necessary for their subsequent activation by extracellular DNA. PMID:27301289

  2. Extracellular matrix remodelling in response to venous hypertension: proteomics of human varicose veins

    PubMed Central

    Barallobre-Barreiro, Javier; Oklu, Rahmi; Lynch, Marc; Fava, Marika; Baig, Ferheen; Yin, Xiaoke; Barwari, Temo; Potier, David N.; Albadawi, Hassan; Jahangiri, Marjan; Porter, Karen E.; Watkins, Michael T.; Misra, Sanjay; Stoughton, Julianne; Mayr, Manuel

    2016-01-01

    Aims Extracellular matrix remodelling has been implicated in a number of vascular conditions, including venous hypertension and varicose veins. However, to date, no systematic analysis of matrix remodelling in human veins has been performed. Methods and results To understand the consequences of venous hypertension, normal and varicose veins were evaluated using proteomics approaches targeting the extracellular matrix. Varicose saphenous veins removed during phlebectomy and normal saphenous veins obtained during coronary artery bypass surgery were collected for proteomics analysis. Extracellular matrix proteins were enriched from venous tissues. The proteomics analysis revealed the presence of >150 extracellular matrix proteins, of which 48 had not been previously detected in venous tissue. Extracellular matrix remodelling in varicose veins was characterized by a loss of aggrecan and several small leucine-rich proteoglycans and a compensatory increase in collagen I and laminins. Gene expression analysis of the same tissues suggested that the remodelling process associated with venous hypertension predominantly occurs at the protein rather than the transcript level. The loss of aggrecan in varicose veins was paralleled by a reduced expression of aggrecanases. Chymase and tryptase β1 were among the up-regulated proteases. The effect of these serine proteases on the venous extracellular matrix was further explored by incubating normal saphenous veins with recombinant enzymes. Proteomics analysis revealed extensive extracellular matrix degradation after digestion with tryptase β1. In comparison, chymase was less potent and degraded predominantly basement membrane-associated proteins. Conclusion The present proteomics study provides unprecedented insights into the expression and degradation of structural and regulatory components of the vascular extracellular matrix in varicosis. PMID:27068509

  3. Superoxide Dismutase Structures, Stability, Mechanism and Insights into the Human Disease Amyotrophic Lateral Sclerosis from Eukaryotic Thermophile Alvinella pompejana

    PubMed Central

    Shin, David S.; DiDonato, Michael; Barondeau, David P.; Hura, Greg L.; Hitomi, Chiharu; Berglund, J. Andrew; Getzoff, Elizabeth D.; Cary, S. Craig; Tainer, John A.

    2009-01-01

    Summary Prokaroytic thermophiles supply stable human protein homologs for structural biology; yet, eukaryotic thermophiles would provide more similar macromolecules plus those missing in microbes. Alvinella pompejana is a deep-sea hydrothermal-vent worm that has been found in temperatures averaging as high as 68 °C, with spikes up to 84 °C. Here, we used Cu, Zn superoxide dismutase (SOD) to test if this eukaryotic thermophile can provide insights into macromolecular mechanisms and stability, by supplying better stable mammalian homologs for structural biology and other biophysical characterizations than those from prokaryotic thermophiles. Identification, cloning, characterization, X-ray scattering (SAXS) and crystal structure determinations show that Alvinella pompejana SOD (ApSOD) is super-stable, homologous, and informative. SAXS solution analyses identify the human-like ApSOD dimer. The crystal structure shows the active site at 0.99 Å resolution, plus anchoring interaction motifs in loops and termini accounting for enhanced stability of ApSOD versus human SOD. Such stabilizing features may reduce movements that promote inappropriate intermolecular interactions, such as amyloid-like filaments found in SOD mutants causing the neurodegenerative disease familial amyotrophic lateral sclerosis or Lou Gehrig’s disease. ApSOD further provides a long-sought SOD product complex at 1.35 Å resolution, suggesting a unified inner sphere mechanism for catalysis involving metal ion movement. Notably, this proposed mechanism resolves apparent paradoxes regarding electron transfer. These results extend knowledge of SOD stability and catalysis, and suggest that the eukaryote A. pompejana provides macromolecules highly similar to those from humans, but with enhanced stability more suitable for scientific and medical applications. PMID:19063897

  4. Natural human gene correction by small extracellular genomic DNA fragments.

    PubMed

    Yakubov, Leonid A; Rogachev, Vladimir A; Likhacheva, Anastasia C; Bogachev, Sergei S; Sebeleva, Tamara E; Shilov, Alexander G; Baiborodin, Sergei I; Petrova, Natalia A; Mechetina, Ludmila V; Shurdov, Mikhail A; Wickstrom, Eric

    2007-09-15

    Classical gene targeting employs natural homologous recombination for a gene correction using a specially designed and artificially delivered DNA construct but the method is very inefficient. On the other hand, small DNA fragments in the form of tiny chromatin-like particles naturally present in blood plasma can spontaneously penetrate into human cells and cell nuclei. We hypothesized that these natural DNA nanoparticles with recombinagenic free ends might be effective agents for gene replacement therapy. We demonstrate that a mixture of small fragments of total human chromatin from non-mutant cells added to a culture medium without transfection agents efficiently repaired a 47 base pair deletion in the CASP3 gene in 30% of treated human MCF7 breast cancer cells, as shown by restoration of caspase-3 apoptotic function and CASP3 DNA and mRNA structure. Such an innate gene replacement mechanism might function naturally in an organism using its own apoptotic DNA fragments. This mechanism might enable human cancer cell phenotype normalization in the presence of excess normal cells. PMID:17703110

  5. Copper-dependent metabolism of Cu,Zn-superoxide dismutase in human K562 cells. Lack of specific transcriptional activation and accumulation of a partially inactivated enzyme.

    PubMed Central

    Steinkühler, C; Carrì, M T; Micheli, G; Knoepfel, L; Weser, U; Rotilio, G

    1994-01-01

    The regulation of Cu,Zn-superoxide dismutase by copper was investigated in human K562 cells. Copper ions caused a dose- and time-dependent increase, up to 3-fold, of the steady-state level of Cu,Zu-superoxide dismutase mRNA. A comparable increase was also observed for actin and ribosomal protein L32 mRNAs, but not for metallothionein mRNA which was augmented more than 50-fold and showed a different induction pattern. The copper-induced mRNAs were actively translated as judged from their enhanced loading on polysomes, the concomitantly increased cellular protein levels and an augmented incorporation of [3H]lysine into acid-precipitable material. Cu,Zn-superoxide dismutase protein followed this general trend, as demonstrated by dose- and time-dependent increases in immunoreactive and enzymically active protein. However, a specific accumulation of Cu,Zn-superoxide dismutase was noticed in cells grown in the presence of copper, that was not detectable for other proteins. Purification of the enzyme demonstrated that Cu,Zn-superoxide dismutase was present as a reconstitutable, copper-deficient protein with high specific activity (kcat./Cu = 0.89 x 10(9) M-1.s-1) in untreated K562 cells and as a fully metallated protein with low specific activity (kcat./Cu = 0.54 x 10(9) M-1.s-1) in copper-treated cells. Pulse-chase experiments using [3H]lysine indicated that turnover rates of Cu,Zn-superoxide dismutase in K562 cells were not affected by growth in copper-enriched medium, whereas turnover of total protein was significantly enhanced as a function of metal supplementation. From these results we conclude that: (i) unlike in yeast [Carrì, Galiazzo, Ciriolo and Rotilio (1991) FEBS Lett. 278, 263-266] Cu,Zn-superoxide dismutase is not specifically regulated by copper at the transcriptional level in human K562 cells, suggesting that this type of regulation has not been conserved during the evolution of higher eukaryotes; (ii) copper ions cause an inactivation of the enzyme in

  6. Copper-dependent metabolism of Cu,Zn-superoxide dismutase in human K562 cells. Lack of specific transcriptional activation and accumulation of a partially inactivated enzyme.

    PubMed

    Steinkühler, C; Carrì, M T; Micheli, G; Knoepfel, L; Weser, U; Rotilio, G

    1994-09-15

    The regulation of Cu,Zn-superoxide dismutase by copper was investigated in human K562 cells. Copper ions caused a dose- and time-dependent increase, up to 3-fold, of the steady-state level of Cu,Zu-superoxide dismutase mRNA. A comparable increase was also observed for actin and ribosomal protein L32 mRNAs, but not for metallothionein mRNA which was augmented more than 50-fold and showed a different induction pattern. The copper-induced mRNAs were actively translated as judged from their enhanced loading on polysomes, the concomitantly increased cellular protein levels and an augmented incorporation of [3H]lysine into acid-precipitable material. Cu,Zn-superoxide dismutase protein followed this general trend, as demonstrated by dose- and time-dependent increases in immunoreactive and enzymically active protein. However, a specific accumulation of Cu,Zn-superoxide dismutase was noticed in cells grown in the presence of copper, that was not detectable for other proteins. Purification of the enzyme demonstrated that Cu,Zn-superoxide dismutase was present as a reconstitutable, copper-deficient protein with high specific activity (kcat./Cu = 0.89 x 10(9) M-1.s-1) in untreated K562 cells and as a fully metallated protein with low specific activity (kcat./Cu = 0.54 x 10(9) M-1.s-1) in copper-treated cells. Pulse-chase experiments using [3H]lysine indicated that turnover rates of Cu,Zn-superoxide dismutase in K562 cells were not affected by growth in copper-enriched medium, whereas turnover of total protein was significantly enhanced as a function of metal supplementation. From these results we conclude that: (i) unlike in yeast [Carrì, Galiazzo, Ciriolo and Rotilio (1991) FEBS Lett. 278, 263-266] Cu,Zn-superoxide dismutase is not specifically regulated by copper at the transcriptional level in human K562 cells, suggesting that this type of regulation has not been conserved during the evolution of higher eukaryotes; (ii) copper ions cause an inactivation of the enzyme in

  7. Raft lipids as common components of human extracellular amyloid fibrils

    PubMed Central

    Gellermann, Gerald P.; Appel, Thomas R.; Tannert, Astrid; Radestock, Anja; Hortschansky, Peter; Schroeckh, Volker; Leisner, Christian; Lütkepohl, Tim; Shtrasburg, Shmuel; Röcken, Christoph; Pras, Mordechai; Linke, Reinhold P.; Diekmann, Stephan; Fändrich, Marcus

    2005-01-01

    Amyloid fibrils are fibrillar polypeptide aggregates from several degenerative human conditions, including Alzheimer's and Creutzfeldt-Jakob diseases. Analysis of amyloid fibrils derived from various human diseases (AA, ATTR, Aβ2M, ALλ, and ALκ amyloidosis) shows that these are associated with a common lipid component that has a conserved chemical composition and that is specifically rich in cholesterol and sphingolipids, the major components of cellular lipid rafts. This pattern is not notably affected by the purification procedure, and no tight lipid interactions can be detected when preformed fibrils are mixed with lipids. By contrast, the early and prefibrillar aggregates formed in an AA amyloid-producing cell system interact with the raft marker ganglioside-1, and amyloid formation is impaired by addition of cholesterol-reducing agents. These data suggest the existence of common cellular mechanisms in the generation of different types of clinical amyloid deposits. PMID:15851687

  8. Extracellular depolymerization of hyaluronic acid in cultured human skin fibroblasts

    SciTech Connect

    Nakamura, T.; Takagaki, K.; Kubo, K.; Morikawa, A.; Tamura, S.; Endo, M. )

    1990-10-15

    The chain length of ({sup 3}H)hyaluronic acid synthesized by cultivating human skin fibroblasts in the presence of ({sup 3}H)glucosamine was investigated. ({sup 3}H)Hyaluronic acid obtained from the matrix fraction was excluded from a Sepharose CL-2B column irrespective of the incubation period, whereas that from the medium was depolymerized into a constant chain length (Mr = 40,000). The reducing and non-reducing terminals of the depolymerized hyaluronic acid were N-acetylglucosamine and glucuronic acid, respectively. Prolonged incubation produced no oligosaccharides as shown by examination of hyaluronidase digests, suggesting the presence of a novel endo-beta-N-acetylglucosaminidase in cultured human skin fibroblasts.

  9. Extracellular Matrix Molecular Remodeling in Human Liver Fibrosis Evolution

    PubMed Central

    Baiocchini, Andrea; Montaldo, Claudia; Conigliaro, Alice; Grimaldi, Alessio; Correani, Virginia; Mura, Francesco; Ciccosanti, Fabiola; Rotiroti, Nicolina; Brenna, Alessia; Montalbano, Marzia; D’Offizi, Gianpiero; Capobianchi, Maria Rosaria; Alessandro, Riccardo; Piacentini, Mauro; Schininà, Maria Eugenia; Maras, Bruno; Del Nonno, Franca; Tripodi, Marco; Mancone, Carmine

    2016-01-01

    Chronic liver damage leads to pathological accumulation of ECM proteins (liver fibrosis). Comprehensive characterization of the human ECM molecular composition is essential for gaining insights into the mechanisms of liver disease. To date, studies of ECM remodeling in human liver diseases have been hampered by the unavailability of purified ECM. Here, we developed a decellularization method to purify ECM scaffolds from human liver tissues. Histological and electron microscopy analyses demonstrated that the ECM scaffolds, devoid of plasma and cellular components, preserved the three-dimensional ECM structure and zonal distribution of ECM components. This method has been then applied on 57 liver biopsies of HCV-infected patients at different stages of liver fibrosis according to METAVIR classification. Label-free nLC-MS/MS proteomics and computation biology were performed to analyze the ECM molecular composition in liver fibrosis progression, thus unveiling protein expression signatures specific for the HCV-related liver fibrotic stages. In particular, the ECM molecular composition of liver fibrosis was found to involve dynamic changes in matrix stiffness, flexibility and density related to the dysregulation of predominant collagen, elastic fibers and minor components with both structural and signaling properties. This study contributes to the understanding of the molecular bases underlying ECM remodeling in liver fibrosis and suggests new molecular targets for fibrolytic strategies. PMID:26998606

  10. Stimulus-specific deactivation of chemotactic factor-induced cyclic AMP response and superoxide generation by human neutrophils.

    PubMed Central

    Simchowitz, L; Atkinson, J P; Spilberg, I

    1980-01-01

    The responses of isolated human peripheral neutrophils to either simultaneous or sequential additions of two chemotactic factors were studied. Simultaneous additions of formyl-methionyl-leucyl-phenylalanine (10-100 nM) and the fifth component of complement, C5a (1-10 microliters/ml), evoked partially additive responses of membrane depolarization as measured by the fluorescent dye 3,3'-dipropyl-thiocarbocyanine, a transient elevation of intracellular cyclic AMP (cAMP), and superoxide (O2-) generation as assessed by ferricytochrome c reduction. Preincubation of the cells with either formyl-methionyl-leucyl-phenylalanine or C5a alone caused dose-dependent inhibition of the depolarization, the cAMP increase, and O2- release induced by a subsequent exposure to an optimal dose of the same stimulus, i.e., deactivation occurred. In contrast, when cells were treated with one chemotactic factor and then exposed to the other stimulus, the cells exhibited a normal response of peak depolarization, the rise in cAMP, and O2-0 production i.e., cross-deactivation failed to occur. The results imply that deactivation of these phenomena is stimulus specific. Further, these observations are consistent with the hypothesis that cross-deactivation of chemotaxis is mediated by one or more processes that are irrelevant to O2- generation, and that occur distal to the depolarization and cAMP steps in the sequence of neutrophil activation: possibly microtubule polymerization and orientation. PMID:6252250

  11. In Vitro Effect of Sodium Fluoride on Malondialdehyde Concentration and on Superoxide Dismutase, Catalase, and Glutathione Peroxidase in Human Erythrocytes

    PubMed Central

    Gutiérrez-Salinas, José; García-Ortíz, Liliana; Morales González, José A.; Hernández-Rodríguez, Sergio; Ramírez-García, Sotero; Núñez-Ramos, Norma R.; Madrigal-Santillán, Eduardo

    2013-01-01

    The aim of this paper was to describe the in vitro effect of sodium fluoride (NaF) on the specific activity of the major erythrocyte antioxidant enzymes, as well as on the membrane malondialdehyde concentration, as indicators of oxidative stress. For this purpose, human erythrocytes were incubated with NaF (0, 7, 28, 56, and 100 μg/mL) or NaF (100 μg/mL) + vitamin E (1, 2.5, 5 and 10 μg/mL). The malondialdehyde (MDA) concentration on the surface of the erythrocytes was determined, as were the enzymatic activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GlPx). Our results demonstrated that erythrocytes incubated with increasing NaF concentrations had an increased MDA concentration, along with decreased activity of antioxidant enzymes. The presence of vitamin E partially reversed the toxic effects of NaF on erythrocytes. These findings suggest that NaF induces oxidative stress in erythrocytes in vitro, and this stress is partially reversed by the presence of vitamin E. PMID:24223512

  12. Increased digitalis-like activity in human cerebrospinal fluid after expansion of the extracellular fluid volume

    SciTech Connect

    Halperin, J.A.; Martin, A.M.; Malave, S.

    1985-08-12

    The present study was designed to determine whether acute expansion of the extracellular fluid volume influenced the digitalis-like activity of human cerebrospinal fluid (CSF), previously described. Human CSF samples, drawn before and 30 minutes after the intravenous infusion of 1 liter of either saline or glucose solutions, were assayed for digitalis-like activity by inhibition of either the /sup 86/Rb/sup +/ uptake into human erythrocytes or by the activity of a purified Na/sup +/-K/sup +/ ATPase. The CSF inhibitory activity on both systems significantly increased after the infusion of sodium solutions but did not change after the infusion of glucose. These results indicate that the digitalis-like factor of human CSF might be involved in the regulation of the extracellular fluid volume and electrolyte content and thereby in some of the physiological responses to sodium loading. 31 references, 2 figures, 1 table.

  13. Superoxide anion radical (O2(-)) degrades methylmercury to inorganic mercury in human astrocytoma cell line (CCF-STTG1).

    PubMed

    Mailloux, Ryan J; Yumvihoze, Emmanuel; Chan, Hing Man

    2015-09-01

    Methylmercury (MeHg) is a global pollutant that is affecting the health of millions of people worldwide. However, the mechanism of MeHg toxicity still remains somewhat elusive and there is no treatment. It has been known for some time that MeHg can be progressively converted to inorganic mercury (iHg) in various tissues including the brain. Recent work has suggested that cleavage of the carbon-metal bond in MeHg in a biological environment is facilitated by reactive oxygen species (ROS). However, the oxyradical species that actually mediates this process has not been identified. Here, we provide evidence that superoxide anion radical (O2(-)) can convert MeHg to iHg. The calculated second-order rate constant for the degradation of 1μM MeHg by O2(-) generated by xanthine/xanthine oxidase was calculated to be 2×10(5)M(-1)s(-1). We were also able to show that this bioconversion can proceed in intact CCF-STTG1 human astrocytoma cells exposed to paraquat (PQ), a O2(-) generating viologen. Notably, exposure of cells to increasing amounts of PQ led to a dose dependent increase in both MeHg and iHg. Indeed, a 24h exposure to 500μM PQ induced a ∼13-fold and ∼18-fold increase in intracellular MeHg and iHg respectively. These effects were inhibited by superoxide dismutase mimetic MnTBAP. In addition, we also observed that a 24h exposure to a biologically relevant concentration of MeHg (1μM) did not induce cell death, oxidative stress, or even changes in cellular O2(-) and H2O2. However, co-exposure to PQ enhanced MeHg toxicity which was associated with a robust increase in cell death and oxidative stress. Collectively our results show that O2(-) can bioconvert MeHg to iHg in vitro and in intact cells exposed to conditions that simulate high intracellular O2(-) production. In addition, we show for the first time that O2(-) mediated degradation of MeHg to iHg enhances the toxicity of MeHg by facilitating an accumulation of both MeHg and iHg in the intracellular

  14. Differential effects of nylon fibre adherence on the production of superoxide anion by human polymorphonuclear neutrophilic granulocytes stimulated with chemoattractants, ionophore A23187 and phorbol myristate acetate.

    PubMed Central

    Kownatzki, E; Uhrich, S

    1987-01-01

    Human polymorphonuclear neutrophilic granulocytes were made adherent by passing them over protein-coated nylon fibre columns and compared with suspended cells for their production of superoxide anion as measured by cytochrome C reduction. The cells were stimulated with chemotactic factors, the ionophore A 23187, and the tumour promoter phorbol myristate acetate. There was no increased O2-. production by adherent cells in the absence of a stimulus. Adherent cells produced considerably higher amounts of superoxide than suspended cells when stimulated with formyl-methionyl-leucyl-phenylalanine, ionophore A 23187, C5a, C5adesArg, and the platelet activating factor 1-o-alkyl-2-acetyl-sn-glycero-3-phosphorylcholine. In contrast, stimulation with phorbol myristate acetate did not result in higher superoxide release from adherent than from suspended cells, and leukotriene B4 and a mononuclear cell-derived chemotaxin did not stimulate either cell to release significant amounts of superoxide. It is suggested that the augmented production of oxygen radicals with certain stimuli contributes to inflammatory symptoms in situations involving adherent granulocytes. PMID:2820637

  15. Extracellular potentials of human motor myelinated nerve fibers in normal case and in amyotrophic lateral sclerosis.

    PubMed

    Stephanova, D I; Daskalova, M

    2002-01-01

    The extracellular potentials of human motor myelinated fibres in an unbounded volume conductor, in normal case and in amyotrophic lateral sclerosis (ALS) are studied. Using our previous double-cable models of the fibres, the spatial and temporal distributions of the intracellular potentials are obtained. The intracellular potentials are then used as input to a line source model that allows to calculate the corresponding spatial and temporal distributions of the extracellular potentials at various radial distances in the surrounding volume conductor. For the normal and ALS cases, the radial decline of the peak-to-peak amplitude of the extracellular potential depends on the radial distance of the field point and increases with the increase of the distance. For given radial distances, two cases of spatial distributions of the extracellular potentials are investigated: the first case, based on the intracellular potentials at the times of nodal potential maxima and the second case, based on the intracellular potentials at the time interval from 0.2 ms to 1.0 ms at increments of 0.1 ms. For the same radial distances, the temporal distributions of the extracellular potentials are also explored. It is shown that in the case of adaptation, the temporal distributions of the extracellular potentials in the normal and ALS cases correspond well with electromyograms (EMG) from healthy subjects and ALS patients as reported in the literature. Simulation results indicate that the used models are rather promising tools in studying the main properties of compound action potentials in ALS patients which up till now have not been sufficiently well understood. PMID:12395619

  16. Modulatory effect of interleukin-10 on the production of platelet-activating factor and superoxide anions by human leucocytes.

    PubMed Central

    Bussolati, B; Mariano, F; Montrucchio, G; Piccoli, G; Camussi, G

    1997-01-01

    We observed that human monocytes (MO) and polymorphonuclear neutrophils (PMN) stimulated by lipopolysaccharide (LPS) produce platelet-activating factor (PAF) in a pattern characterized by an early and a delayed peak of synthesis. The early peak of PAF synthesis was due to a direct stimulation of these cells through mCD14 receptor as it was inhibited by anti-CD14 monoclonal antibody. The delayed and sustained peak of PAF synthesis was dependent on protein synthesis and cytokine production as shown by the inhibitory effect of cycloheximide on both MO and PMN, and of anti-tumour necrosis factor-alpha (anti-TNF-alpha) and of anti-interleukin-8 (anti-IL-8) neutralizing antibodies on MO and PMN respectively. IL-10 completely prevented this second, cytokine-dependent peak of PAF synthesis. In contrast, IL-10 markedly enhanced the first peak of PAF synthesis both in MO and PMN. Moreover, IL-10 was shown to modulate the production of superoxide anions (O2-) on both MO and PMN. As suggested by previous studies, IL-10 inhibited the delayed production of O2-. In the present study, we observed that IL-10 directly stimulated an early production of O2-. In addition, IL-10 enhanced the synthesis of O2- by MO and PMN challenged with LPS. The IL-10-induced O2- production was dependent, at least in part, from its effect on PAF synthesis, as it was inhibited by the PAF receptor antagonist WEB 2170. These results suggest that IL-10 may upregulate the early synthesis of PAF and O2- triggered by direct LPS stimulation, whereas it may downregulate the delayed production of these mediators. PMID:9155653

  17. A multinuclear copper(I) cluster forms the dimerization interface in copper-loaded human copper chaperone for superoxide dismutase.

    PubMed

    Stasser, Jay P; Siluvai, Gnana S; Barry, Amanda N; Blackburn, Ninian J

    2007-10-23

    Copper binding and X-ray aborption spectroscopy studies are reported on untagged human CCS (hCCS; CCS = copper chaperone for superoxide dismutase) isolated using an intein self-cleaving vector and on single and double Cys to Ala mutants of the hCCS MTCQSC and CSC motifs of domains 1 (D1) and 3 (D3), respectively. The results on the wild-type protein confirmed earlier findings on the CCS-MBP (maltose binding protein) constructs, namely, that Cu(I) coordinates to the CXC motif, forming a cluster at the interface of two D3 polypeptides. In contrast to the single Cys to Ser mutations of the CCS-MBP protein (Stasser, J. P., Eisses, J. F., Barry, A. N., Kaplan, J. H., and Blackburn, N. J. (2005) Biochemistry 44, 3143-3152), single Cys to Ala mutations in D3 were sufficient to eliminate cluster formation and significantly reduce CCS activity. Analysis of the intensity of the Cu-Cu cluster interaction in C244A, C246A, and C244/246A variants suggested that the nuclearity of the cluster was greater than 2 and was most consistent with a Cu4S6 adamantane-type species. The relationship among cluster formation, oligomerization, and metal loading was evaluated. The results support a model in which Cu(I) binding converts the apo dimer with a D2-D2 interface to a new dimer connected by cluster formation at two D3 CSC motifs. The predominance of dimer over tetramer in the cluster-containing species strongly suggests that the D2 dimer interface remains open and available for sequestering an SOD1 monomer. This work implicates the copper cluster in the reactive form and adds detail to the cluster nuclearity and how copper loading affects the oligomerization states and reactivity of CCS for its partner SOD1. PMID:17902702

  18. Topical application of superoxide dismutase mediated by HIV-TAT peptide attenuates UVB-induced damages in human skin.

    PubMed

    Chen, Xiaochao; Liu, Shutao; Rao, Pingfan; Bradshaw, Jeremy; Weller, Richard

    2016-10-01

    The purpose of this study was to evaluate whether topical application of superoxide dismutase with cell penetrating peptide (HIV-TAT) could protect against skin damage induced by UVB irradiation in humans. The permeability through stratum corneum of large proteins linked to TAT peptide was firstly confirmed by confocal microscopy and tape stripping. Ten healthy volunteers with either Fitzpatrick skin type II or III were recruited in this clinical study. TAT-SOD (300units/cm(2)) and vehicle cream were applied on two symmetric areas of both inner upper arms 1h prior to UVB irradiation. After one hour of pretreatment, subjects received 10 incremental doses of UVB on pretreated areas. 24h later, erythema, blood flow and apoptotic cells were measured. Pretreatment with TAT-SOD 1h prior to UVB radiation promoted a mean minimal erythema dose (MED) increase of 36.6±18.4% (p=0.013<0.05. n=10) compared to vehicle control. The median blood flow values of all subjects following 2 and 3-MED of UVB were 107.8±51.0units and 239.5±88.0units respectively, which account for 26% and 25% decrease with respect to vehicle groups. These data suggest that TAT-SOD significantly suppresses UVB induced erythema formation and blood flow rise. Furthermore, pretreatment with TAT-SOD 1h prior to 2-MED of UVB irradiation reduced the apoptotic sunburn cell formation by 47.6±8.6% (p<0.0001) in all subjects. Evaluating results generated from all measurements, we conclude that topical application of TAT-SOD significantly attenuates UVB-induced skin damage in man. These biological effects of TAT-SOD are probably mediated via its free radical scavenging properties, clearly differentiating it from other physical sunscreen agents. PMID:27460952

  19. A Multinuclear Copper(I) Cluster Forms the Dimerization Interface in Copper-Loaded Human Copper Chaperone for Superoxide Dismutase

    SciTech Connect

    Stasser, J.P.; Siluvai, G.S.; Barry, A.N.; Blackburn, N.J.

    2009-06-04

    Copper binding and X-ray aborption spectroscopy studies are reported on untagged human CCS (hCCS; CCS = copper chaperone for superoxide dismutase) isolated using an intein self-cleaving vector and on single and double Cys to Ala mutants of the hCCS MTCQSC and CSC motifs of domains 1 (D1) and 3 (D3), respectively. The results on the wild-type protein confirmed earlier findings on the CCS-MBP (maltose binding protein) constructs, namely, that Cu(I) coordinates to the CXC motif, forming a cluster at the interface of two D3 polypeptides. In contrast to the single Cys to Ser mutations of the CCS-MBP protein (Stasser, J. P., Eisses, J. F., Barry, A. N., Kaplan, J. H., and Blackburn, N. J. (2005) Biochemistry 44, 3143-3152), single Cys to Ala mutations in D3 were sufficient to eliminate cluster formation and significantly reduce CCS activity. Analysis of the intensity of the Cu-Cu cluster interaction in C244A, C246A, and C244/246A variants suggested that the nuclearity of the cluster was greater than 2 and was most consistent with a Cu4S6 adamantane-type species. The relationship among cluster formation, oligomerization, and metal loading was evaluated. The results support a model in which Cu(I) binding converts the apo dimer with a D2-D2 interface to a new dimer connected by cluster formation at two D3 CSC motifs. The predominance of dimer over tetramer in the cluster-containing species strongly suggests that the D2 dimer interface remains open and available for sequestering an SOD1 monomer. This work implicates the copper cluster in the reactive form and adds detail to the cluster nuclearity and how copper loading affects the oligomerization states and reactivity of CCS for its partner SOD1.

  20. Dynamic compressive behavior of human meniscus correlates with its extra-cellular matrix composition.

    PubMed

    Bursac, P; Arnoczky, S; York, A

    2009-01-01

    The menisci of the knee play a significant role in the complex biomechanics of the joint and are critically important in maintaining articular cartilage health. While a general form-function relationship has been identified for the structural orientation of the extra-cellular matrix of the meniscus, the role of individual biochemical components has yet to be fully explored. To determine if correlations exist between the dynamic and static compressive modulus of human menisci and their major extra-cellular matrix constituents (collagen, glycosoaminoglycan and water content), 12 lateral and 11 medial menisci from 13 adult donors were examined. The results showed that in dynamic compression at high loading frequencies (0.1-1 Hz) the menisci behave as a rubber-like elastic material while at lower frequencies (0.01-0.03 Hz) significant viscous dissipation occurs. While regional variations in compressive moduli and extra-cellular matrix composition were observed, the magnitude of both dynamic and static compressive moduli were found to be insensitive to collagen content (p>0.4). However, this magnitude was found to significantly increase with increasing glycosaminoglycan content (p<0.001) and significantly decrease with increasing water content (p<0.001). The results of this study identify significant relationships between the viscoelastic behavior of the meniscus and its extra-cellular matrix composition. PMID:19581729

  1. The extracellular interactome of the human adenovirus family reveals diverse strategies for immunomodulation.

    PubMed

    Martinez-Martin, Nadia; Ramani, Sree R; Hackney, Jason A; Tom, Irene; Wranik, Bernd J; Chan, Michelle; Wu, Johnny; Paluch, Maciej T; Takeda, Kentaro; Hass, Philip E; Clark, Hilary; Gonzalez, Lino C

    2016-01-01

    Viruses encode secreted and cell-surface expressed proteins essential to modulate host immune defenses and establish productive infections. However, to date there has been no systematic study of the extracellular interactome of any human virus. Here we utilize the E3 proteins, diverse and rapidly evolving transmembrane-containing proteins encoded by human adenoviruses, as a model system to survey the extracellular immunomodulatory landscape. From a large-scale protein interaction screen against a microarray of more than 1,500 human proteins, we find and validate 51 previously unidentified virus-host interactions. Our results uncover conserved strategies as well as substantial diversity and multifunctionality in host targeting within and between viral species. Prominent modulation of the leukocyte immunoglobulin-like and signalling lymphocyte activation molecule families and a number of inhibitory receptors were identified as hubs for viral perturbation, suggesting unrecognized immunoregulatory strategies. We describe a virus-host extracellular interaction map of unprecedented scale that provides new insights into viral immunomodulation. PMID:27145901

  2. The extracellular interactome of the human adenovirus family reveals diverse strategies for immunomodulation

    PubMed Central

    Martinez-Martin, Nadia; Ramani, Sree R.; Hackney, Jason A.; Tom, Irene; Wranik, Bernd J.; Chan, Michelle; Wu, Johnny; Paluch, Maciej T.; Takeda, Kentaro; Hass, Philip E.; Clark, Hilary; Gonzalez, Lino C.

    2016-01-01

    Viruses encode secreted and cell-surface expressed proteins essential to modulate host immune defenses and establish productive infections. However, to date there has been no systematic study of the extracellular interactome of any human virus. Here we utilize the E3 proteins, diverse and rapidly evolving transmembrane-containing proteins encoded by human adenoviruses, as a model system to survey the extracellular immunomodulatory landscape. From a large-scale protein interaction screen against a microarray of more than 1,500 human proteins, we find and validate 51 previously unidentified virus–host interactions. Our results uncover conserved strategies as well as substantial diversity and multifunctionality in host targeting within and between viral species. Prominent modulation of the leukocyte immunoglobulin-like and signalling lymphocyte activation molecule families and a number of inhibitory receptors were identified as hubs for viral perturbation, suggesting unrecognized immunoregulatory strategies. We describe a virus–host extracellular interaction map of unprecedented scale that provides new insights into viral immunomodulation. PMID:27145901

  3. Morphological Characterization of Organized Extracellular Matrix Deposition by Ascorbic Acid-Stimulated Human Corneal Fibroblasts

    PubMed Central

    Guo, Xiaoqing; Hutcheon, Audrey E. K.; Melotti, Suzanna A.; Zieske, James D.; Trinkaus-Randall, Vickery; Ruberti, Jeffrey W.

    2016-01-01

    Purpose To characterize the structure and morphology of extracellular matrix (ECM) synthesized by untransformed, cultured human corneal fibroblasts in long-term cultures. Methods Human corneal stromal keratocytes were expanded in transwell culture in the presence of fetal bovine serum and a stable derivative of Vitamin C. The cells were allowed to synthesize a fibrillar ECM for up to five weeks. Constructs were assessed via light (phase contrast and differential interference contrast) and transmission (standard and quick freeze/deep etch) microscopy. Results Electron micrographs revealed stratified constructs with multiple parallel layers of cells and an extracellular matrix comprising parallel arrays of small, polydisperse fibrils (27–51 nm) which often alternate in direction. Differential interference contrast images demonstrated oriented ECM fibril arrays parallel to the plane of the construct while quick-freeze deep etch micrographs showed the details of the matrix interaction with fibroblasts via arrays of membrane surface structures. Conclusions Human keratocytes, cultured in a stable Vitamin C derivative, are capable of assembling extracellular matrix which comprise parallel arrays of ECM fibrils. The resulting constructs, which are highly cellular, exhibit morphology similar to the developing mammalian stroma where organized matrix is derived. The appearance of arrays of structures on the cell membranes suggest a role in the local organization of synthesized ECM. This model could provide critical insight into the fundamental processes which govern the genesis of organized connective tissues such as the cornea and may provide a scaffolding suitable for tissue-engineering a biomimetic stroma. PMID:17724187

  4. Superoxide and peroxynitrite in atherosclerosis.

    PubMed Central

    White, C R; Brock, T A; Chang, L Y; Crapo, J; Briscoe, P; Ku, D; Bradley, W A; Gianturco, S H; Gore, J; Freeman, B A

    1994-01-01

    The role of reactive oxygen species in the vascular pathology associated with atherosclerosis was examined by testing the hypothesis that impaired vascular reactivity results from the reaction of nitric oxide (.NO) with superoxide (O2-), yielding the oxidant peroxynitrite (ONOO-). Contractility studies were performed on femoral arteries from rabbits fed a cholesterol-supplemented diet. Cholesterol feeding shifted the EC50 for acetylcholine (ACh)-induced relaxation and impaired the maximal response to ACh. We used pH-sensitive liposomes to deliver CuZn superoxide dismutase (SOD; superoxide:superoxide oxidoreductase, EC 1.15.1.1) to critical sites of .NO reaction with O2-. Intravenously injected liposomes (3000 units of SOD per ml) augmented ACh-induced relaxation in the cholesterol-fed group to a greater extent than in controls. Quantitative immunocytochemistry demonstrated enhanced distribution of SOD in both endothelial and vascular smooth muscle cells as well as in the extracellular matrix. SOD activity in vessel homogenates of liposome-treated rabbits was also increased. Incubation of beta very low density lipoprotein with ONOO- resulted in the rapid formation of conjugated dienes and thiobarbituric acid-reactive substances. Our results suggest that the reaction of O2- with .NO is involved in the development of atherosclerotic disease by yielding a potent mediator of lipoprotein oxidation, as well as by limiting .NO stimulation of vascular smooth muscle guanylate cyclase activity. Images PMID:8302829

  5. Superoxide dismutase C is required for intracellular survival and virulence of Burkholderia pseudomallei.

    PubMed

    Vanaporn, Muthita; Wand, Matthew; Michell, Stephen L; Sarkar-Tyson, Mitali; Ireland, Philip; Goldman, Stan; Kewcharoenwong, Chidchamai; Rinchai, Darawan; Lertmemongkolchai, Ganjana; Titball, Richard W

    2011-08-01

    Burkholderia pseudomallei is an intracellular pathogen and the causative agent of melioidosis, a life-threatening disease of humans. Within host cells, superoxide is an important mediator of pathogen killing. In this study, we have identified the B. pseudomallei K96243 sodC gene, shown that it has superoxide dismutase activity, and constructed an allelic deletion mutant of this gene. Compared with the wild-type, the mutant was more sensitive to killing by extracellular superoxide, but not to superoxide generated intracellularly. The sodC mutant showed a markedly decreased survival in J774A.1 mouse macrophages, and reduced numbers of bacteria were recovered from human polymorphonuclear neutrophils (PMNs) when compared with the wild-type. The numbers of wild-type or mutant bacteria recovered from human diabetic neutrophils were significantly lower than from normal human neutrophils. The sodC mutant was attenuated in BALB/c mice. Our results indicate that SodC plays a key role in the virulence of B. pseudomallei, but that diabetics are not more susceptible to infection because of a reduced ability of PMNs to kill by superoxide. PMID:21659326

  6. Virus activated filopodia promote human papillomavirus type 31 uptake from the extracellular matrix

    PubMed Central

    Smith, Jessica L.; Lidke, Diane S.; Ozbun, Michelle A.

    2011-01-01

    Human papillomaviruses (HPVs), etiological agents of epithelial tumors and cancers, initiate infection of basal human keratinocytes (HKs) facilitated by wounding. Virions bind to HKs and their secreted extracellular matrix (ECM), but molecular roles for wounding or ECM binding during infection are unclear. Herein we demonstrate HPV31 activates signals promoting cytoskeletal rearrangements and virion transport required for internalization and infection. Activation of tyrosine and PI3 kinases precedes induction of filopodia whereon virions are transported toward the cell body. Coupled with loss of ECM bound virions this supports a model whereby virus activated filopodial transport contributes to increased and protracted virion uptake into susceptible cells. PMID:18834609

  7. Extracellular Recordings of Patterned Human Pluripotent Stem Cell-Derived Cardiomyocytes on Aligned Fibers

    PubMed Central

    Minami, Itsunari; Yu, Leqian; Nakajima, Minako; Qiao, Jing; Shimono, Ken; Nakatsuji, Norio; Kotera, Hitetoshi; Chen, Yong

    2016-01-01

    Human induced pluripotent stem cell (hiPSC) derived cardiomyocytes (CMs) hold high potential for use in drug assessment and myocardial regeneration. To create tissue-like constructs of CMs for extracellular monitoring, we placed aligned fibers (AFs) on the surface of a microelectrode array and then seeded hiPSC-CMs for subsequent monitoring for 14 days. As expected, the CMs organized into anisotropic and matured tissue and the extracellular recordings showed reduced premature beating higher signal amplitude and a higher probability of T-wave detection as compared to the culture without fibers. The CMs on the aligned fibers samples also exhibited anisotropic propagation of the field potential. These results therefore suggest that the hiPSC-CMs cultured on AFs can be used more reliably for cell based assays. PMID:27446217

  8. Extracellular Recordings of Patterned Human Pluripotent Stem Cell-Derived Cardiomyocytes on Aligned Fibers.

    PubMed

    Li, Junjun; Minami, Itsunari; Yu, Leqian; Tsuji, Kiyotaka; Nakajima, Minako; Qiao, Jing; Suzuki, Masato; Shimono, Ken; Nakatsuji, Norio; Kotera, Hitetoshi; Liu, Li; Chen, Yong

    2016-01-01

    Human induced pluripotent stem cell (hiPSC) derived cardiomyocytes (CMs) hold high potential for use in drug assessment and myocardial regeneration. To create tissue-like constructs of CMs for extracellular monitoring, we placed aligned fibers (AFs) on the surface of a microelectrode array and then seeded hiPSC-CMs for subsequent monitoring for 14 days. As expected, the CMs organized into anisotropic and matured tissue and the extracellular recordings showed reduced premature beating higher signal amplitude and a higher probability of T-wave detection as compared to the culture without fibers. The CMs on the aligned fibers samples also exhibited anisotropic propagation of the field potential. These results therefore suggest that the hiPSC-CMs cultured on AFs can be used more reliably for cell based assays. PMID:27446217

  9. Extracellular Fibrils of Pathogenic Yeast Cryptococcus gattii Are Important for Ecological Niche, Murine Virulence and Human Neutrophil Interactions

    PubMed Central

    Springer, Deborah J.; Ren, Ping; Raina, Ramesh; Dong, Yimin; Behr, Melissa J.; McEwen, Bruce F.; Bowser, Samuel S.; Samsonoff, William A.; Chaturvedi, Sudha; Chaturvedi, Vishnu

    2010-01-01

    Cryptococcus gattii, an emerging fungal pathogen of humans and animals, is found on a variety of trees in tropical and temperate regions. The ecological niche and virulence of this yeast remain poorly defined. We used Arabidopsis thaliana plants and plant-derived substrates to model C. gattii in its natural habitat. Yeast cells readily colonized scratch-wounded plant leaves and formed distinctive extracellular fibrils (40–100 nm diameter ×500–3000 nm length). Extracellular fibrils were observed on live plants and plant-derived substrates by scanning electron microscopy (SEM) and by high voltage- EM (HVEM). Only encapsulated yeast cells formed extracellular fibrils as a capsule-deficient C. gattii mutant completely lacked fibrils. Cells deficient in environmental sensing only formed disorganized extracellular fibrils as apparent from experiments with a C. gattii STE12α mutant. C. gattii cells with extracellular fibrils were more virulent in murine model of pulmonary and systemic cryptococcosis than cells lacking fibrils. C. gattii cells with extracellular fibrils were also significantly more resistant to killing by human polymorphonuclear neutrophils (PMN) in vitro even though these PMN produced elaborate neutrophil extracellular traps (NETs). These observations suggest that extracellular fibril formation could be a structural adaptation of C. gattii for cell-to-cell, cell-to-substrate and/or cell-to- phagocyte communications. Such ecological adaptation of C. gattii could play roles in enhanced virulence in mammalian hosts at least initially via inhibition of host PMN– mediated killing. PMID:20539754

  10. Development of biomimetic nanocomposites as bone extracellular matrix for human osteoblastic cells.

    PubMed

    Bhowmick, Arundhati; Mitra, Tapas; Gnanamani, Arumugam; Das, Manas; Kundu, Patit Paban

    2016-05-01

    Here, we have developed biomimetic nanocomposites containing chitosan, poly(vinyl alcohol) and nano-hydroxyapatite-zinc oxide as bone extracellular matrix for human osteoblastic cells and characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction. Scanning electron microscopy images revealed interconnected macroporous structures. Moreover, in this study, the problem related to fabricating a porous composite with good mechanical strength has been resolved by incorporating 5wt% of nano-hydroxyapatite-zinc oxide into chitosan-poly(vinyl alcohol) matrix; the present composite showed high tensile strength (20.25MPa) while maintaining appreciable porosity (65.25%). These values are similar to human cancellous bone. These nanocomposites also showed superior water uptake, antimicrobial and biodegradable properties than the previously reported results. Compatibility with human blood and pH was observed, indicating nontoxicity of these materials to the human body. Moreover, proliferation of osteoblastic MG-63 cells onto the nanocomposites was also observed without having any negative effect. PMID:26876999

  11. Intracellular and extracellular pH dynamics in the human placenta from diabetes mellitus.

    PubMed

    Araos, Joaquín; Silva, Luis; Salsoso, Rocío; Sáez, Tamara; Barros, Eric; Toledo, Fernando; Gutiérrez, Jaime; Pardo, Fabián; Leiva, Andrea; Sanhueza, Carlos; Sobrevia, Luis

    2016-07-01

    The placenta is a vital organ whose function in diseases of pregnancy is altered, resulting in an abnormal supply of nutrients to the foetus. The lack of placental vasculature homeostasis regulation causes endothelial dysfunction and altered vascular reactivity. The proper distribution of acid- (protons (H(+))) and base-equivalents through the placenta is essential to achieve physiological homeostasis. Several membrane transport mechanisms that control H(+) distribution between the extracellular and intracellular spaces are expressed in the human placenta vascular endothelium and syncytiotrophoblast, including sodium (Na(+))/H(+) exchangers (NHEs). One member of the NHEs family is NHE isoform 1 (NHE1), whose activity results in an alkaline intracellular pH (high intracellular pH (pHi)) and an acidic extracellular pH (pHo). Increased NHE1 expression, maximal transport activity, and turnover are reported in human syncytiotrophoblasts and lymphocytes from patients with diabetes mellitus type I (DMT1), and a positive correlation between NHEs activity and plasma factors, such as that between thrombin and platelet factor 3, has been reported in diabetes mellitus type II (DMT2). However, gestational diabetes mellitus (GDM) could result in a higher sensitivity of the human placenta to acidic pHo. We summarized the findings on pHi and pHo modulation in the human placenta with an emphasis on pregnancies in which the mother diagnosed with diabetes mellitus. A potential role of NHEs, particularly NHE1, is proposed regarding placental dysfunction in DMT1, DMT2, and GDM. PMID:27324099

  12. Neutrophil extracellular traps form predominantly during the organizing stage of human venous thromboembolism development

    PubMed Central

    Savchenko, A. S.; Martinod, K.; Seidman, M. A.; Wong, S. L.; Borissoff, J. I.; Piazza, G.; Libby, P.; Goldhaber, S. Z.; Mitchell, R. N.; Wagner, D. D.

    2014-01-01

    Background A growing health problem, venous thromboembolism (VTE), including pulmonary embolism (PE) and deep vein thrombosis (DVT), requires refined diagnostic and therapeutic approaches. Neutrophils contribute to thrombus initiation and development in experimental DVT. Recent animal studies recognized neutrophil extracellular traps (NETs) as an important scaffold supporting thrombus stability. However, the hypothesis that human venous thrombi involve NETs has not undergone rigorous testing. Objective To explore the cellular composition and the presence of NETs within human venous thrombi at different stages of development. Patients and Methods We examined sixteen thrombi obtained from 11 patients during surgery or at autopsy using histomorphological, immunohistochemical and immunofluorescence analyses. Results We classified thrombus regions as unorganized, organizing, and organized according to their morphological characteristics. We then evaluated them focusing on neutrophil and platelet deposition as well as micro-vascularization of the thrombus body. We observed evidence of NET accumulation, including the presence of citrullinated histone H3 (H3Cit)-positive cells. NETs, defined as extracellular diffuse H3Cit areas associated with myeloperoxidase and DNA, localized predominantly during the phase of organization in human venous thrombi. Conclusions NETs are present in organizing thrombi in patients with VTE. They are associated with thrombus maturation in humans. Dissolution of NETs might thus facilitate thrombolysis. This finding provides new insights into the clinical development and pathology of thrombosis and provides new perspectives for therapeutic advances. PMID:24674135

  13. The Role of Reactive Oxygen Species (ROS) in the Formation of Extracellular Traps (ETs) in Humans

    PubMed Central

    Stoiber, Walter; Obermayer, Astrid; Steinbacher, Peter; Krautgartner, Wolf-Dietrich

    2015-01-01

    Extracellular traps (ETs) are reticulate structures of extracellular DNA associated with antimicrobial molecules. Their formation by phagocytes (mainly by neutrophils: NETs) has been identified as an essential element of vertebrate innate immune defense. However, as ETs are also toxic to host cells and potent triggers of autoimmunity, their role between pathogen defense and human pathogenesis is ambiguous, and they contribute to a variety of acute and chronic inflammatory diseases. Since the discovery of ET formation (ETosis) a decade ago, evidence has accumulated that most reaction cascades leading to ET release involve ROS. An important new facet was added when it became apparent that ETosis might be directly linked to, or be a variant of, the autophagy cell death pathway. The present review analyzes the evidence to date on the interplay between ROS, autophagy and ETosis, and highlights and discusses several further aspects of the ROS-ET relationship that are incompletely understood. These aspects include the role of NADPH oxidase-derived ROS, the molecular requirements of NADPH oxidase-dependent ETosis, the roles of NADPH oxidase subtypes, extracellular ROS and of ROS from sources other than NADPH oxidase, and the present evidence for ROS-independent ETosis. We conclude that ROS interact with ETosis in a multidimensional manner, with influence on whether ETosis shows beneficial or detrimental effects. PMID:25946076

  14. Bioactive secondary metabolites of a marine Bacillus sp. inhibit superoxide generation and elastase release in human neutrophils by blocking formyl peptide receptor 1.

    PubMed

    Yang, Shun-Chin; Lin, Chwan-Fwu; Chang, Wen-Yi; Kuo, Jimmy; Huang, Yin-Ting; Chung, Pei-Jen; Hwang, Tsong-Long

    2013-01-01

    It is well known that overwhelming neutrophil activation is closely related to acute and chronic inflammatory injuries. Formyl peptide receptor 1 (FPR1) plays an important role in activation of neutrophils and may represent a potent therapeutic target in inflammatory diseases. In the present study, we demonstrated that IA-LBI07-1 (IA), an extract of bioactive secondary metabolites from a marine Bacillus sp., has anti-inflammatory effects in human neutrophils. IA significantly inhibited superoxide generation and elastase release in formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP)-activated neutrophils, but failed to suppress the cell responses activated by non-FPR1 agonists. IA did not alter superoxide production and elastase activity in cell-free systems. IA also attenuated the downstream signaling from FPR1, such as the Ca2+, MAP kinases and AKT pathways. In addition, IA inhibited the binding of N-formyl-Nle-Leu-Phe-Nle-Tyr-Lys-fluorescein, a fluorescent analogue of FMLP, to FPR1 in human neutrophils and FPR1-transfected HEK293 cells. Taken together, these results show that the anti-inflammatory effects of IA in human neutrophils are through the inhibition of FPR1. Also, our data suggest that IA may have therapeutic potential to decrease tissue damage induced by human neutrophils. PMID:23736784

  15. Biological Superoxide In Manganese Oxide Formation

    NASA Astrophysics Data System (ADS)

    Hansel, C.; Learman, D.; Zeiner, C.; Santelli, C. M.

    2011-12-01

    Manganese (Mn) oxides are among the strongest sorbents and oxidants within the environment, controlling the fate and transport of numerous elements and the degradation of recalcitrant carbon. Both bacteria and fungi mediate the oxidation of Mn(II) to Mn(III/IV) oxides but the genetic and biochemical mechanisms responsible remain poorly understood. Furthermore, the physiological basis for microbial Mn(II) oxidation remains an enigma. We have recently reported that a common marine bacterium (Roseobacter sp. AzwK-3b) oxidizes Mn(II) via reaction with extracellular superoxide (O2-) produced during exponential growth. Here we expand this superoxide-mediated Mn(II) oxidation pathway to fungi, introducing a surprising homology between prokaryotic and eukaryotic metal redox processes. For instance, Stibella aciculosa, a common soil Ascomycete filamentous fungus, precipitates Mn oxides at the base of asexual reproductive structures (synnemata) used to support conidia (Figure 1). This distribution is a consequence of localized production of superoxide (and it's dismutation product hydrogen peroxide, H2O2), leading to abiotic oxidation of Mn(II) by superoxide. Disruption of NADPH oxidase activity using the oxidoreductase inhibitor DPI leads to diminished cell differentiation and subsequent Mn(II) oxidation inhibition. Addition of Cu(II) (an effective superoxide scavenger) leads to a concentration dependent decrease in Mn oxide formation. We predict that due to the widespread production of extracellular superoxide within the fungal and likely bacterial kingdoms, biological superoxide may be an important contributor to the cycling of Mn, as well as other metals (e.g., Hg, Fe). Current and future explorations of the genes and proteins involved in superoxide production and Mn(II) oxidation will ideally lend insight into the physiological and biochemical basis for these processes.

  16. Native Cardiac Extracellular Matrix Hydrogels for Cultivation of Human Stem Cell-Derived Cardiomyocytes

    PubMed Central

    Freytes, Donald O; O’Neill, John D; Duan-Arnold, Yi; Wrona, Emily; Vunjak-Novakovic, Gordana

    2015-01-01

    Summary Biomaterial scaffolds made of native and synthetic materials are designed to serve as a structural and informational template for cell attachment and tissue formation. The use of native extracellular matrix (ECM) is of special interest for the culture of cardiac stem and progenitor cells due to the presence of intrinsic regulatory factors regulating cardiac function. We describe here how to obtain native ECM hydrogels from porcine hearts for the culture of human embryonic, induced pluripotent, and somatic stem cells for cardiac tissue engineering and regenerative medicine applications. PMID:25070328

  17. Natural cardiac extracellular matrix hydrogels for cultivation of human stem cell-derived cardiomyocytes.

    PubMed

    Freytes, Donald O; O'Neill, John D; Duan-Arnold, Yi; Wrona, Emily A; Vunjak-Novakovic, Gordana

    2014-01-01

    Biomaterial scaffolds made of natural and synthetic materials are designed to serve as a structural and informational template for cell attachment and tissue formation. The use of native extracellular matrix (ECM) is of special interest for the culture of cardiac stem and progenitor cells due to the presence of intrinsic regulatory factors regulating cardiac function. We describe here how to obtain native ECM hydrogels from porcine hearts for the culture of human embryonic, induced pluripotent, and somatic stem cells for cardiac tissue engineering and regenerative medicine applications. PMID:25070328

  18. Neutrophils extracellular traps damage Naegleria fowleri trophozoites opsonized with human IgG.

    PubMed

    Contis-Montes de Oca, A; Carrasco-Yépez, M; Campos-Rodríguez, R; Pacheco-Yépez, J; Bonilla-Lemus, P; Pérez-López, J; Rojas-Hernández, S

    2016-08-01

    Naegleria fowleri infects humans through the nasal mucosa causing a disease in the central nervous system known as primary amoebic meningoencephalitis (PAM). Polymorphonuclear cells (PMNs) play a critical role in the early phase of N. fowleri infection. Recently, a new biological defence mechanism called neutrophil extracellular traps (NETs) has been attracting attention. NETs are composed of nuclear DNA combined with histones and antibacterial proteins, and these structures are released from the cell to direct its antimicrobial attack. In this work, we evaluate the capacity of N. fowleri to induce the liberation of NETs by human PMN cells. Neutrophils were cocultured with unopsonized or IgG-opsonized N. fowleri trophozoites. DNA, histone, myeloperoxidase (MPO) and neutrophil elastase (NE) were stained, and the formation of NETs was evaluated by confocal microscopy and by quantifying the levels of extracellular DNA. Our results showed N. fowleri induce the liberation of NETs including release of MPO and NE by human PMN cells as exposure interaction time is increased, but N. fowleri trophozoites evaded killing. However, when trophozoites were opsonized, they were susceptible to the neutrophils activity. Therefore, our study suggests that antibody-mediated PMNs activation through NET formation may be crucial for antimicrobial responses against N. fowleri. PMID:27189133

  19. Extracellular acidification stimulates GPR68 mediated IL-8 production in human pancreatic β cells

    PubMed Central

    Chandra, Vikash; Karamitri, Angeliki; Richards, Paul; Cormier, Françoise; Ramond, Cyrille; Jockers, Ralf; Armanet, Mathieu; Albagli-Curiel, Olivier; Scharfmann, Raphael

    2016-01-01

    Acute or chronic metabolic complications such as diabetic ketoacidosis are often associated with extracellular acidification and pancreatic β-cell dysfunction. However, the mechanisms by which human β-cells sense and respond to acidic pH remain elusive. In this study, using the recently developed human β-cell line EndoC-βH2, we demonstrate that β-cells respond to extracellular acidification through GPR68, which is the predominant proton sensing receptor of human β-cells. Using gain- and loss-of-function studies, we provide evidence that the β-cell enriched transcription factor RFX6 is a major regulator of GPR68. Further, we show that acidic pH stimulates the production and secretion of the chemokine IL-8 by β-cells through NF-кB activation. Blocking of GPR68 or NF-кB activity severely attenuated acidification induced IL-8 production. Thus, we provide mechanistic insights into GPR68 mediated β-cell response to acidic microenvironment, which could be a new target to protect β-cell against acidosis induced inflammation. PMID:27166427

  20. Extracellular acidification stimulates GPR68 mediated IL-8 production in human pancreatic β cells.

    PubMed

    Chandra, Vikash; Karamitri, Angeliki; Richards, Paul; Cormier, Françoise; Ramond, Cyrille; Jockers, Ralf; Armanet, Mathieu; Albagli-Curiel, Olivier; Scharfmann, Raphael

    2016-01-01

    Acute or chronic metabolic complications such as diabetic ketoacidosis are often associated with extracellular acidification and pancreatic β-cell dysfunction. However, the mechanisms by which human β-cells sense and respond to acidic pH remain elusive. In this study, using the recently developed human β-cell line EndoC-βH2, we demonstrate that β-cells respond to extracellular acidification through GPR68, which is the predominant proton sensing receptor of human β-cells. Using gain- and loss-of-function studies, we provide evidence that the β-cell enriched transcription factor RFX6 is a major regulator of GPR68. Further, we show that acidic pH stimulates the production and secretion of the chemokine IL-8 by β-cells through NF-кB activation. Blocking of GPR68 or NF-кB activity severely attenuated acidification induced IL-8 production. Thus, we provide mechanistic insights into GPR68 mediated β-cell response to acidic microenvironment, which could be a new target to protect β-cell against acidosis induced inflammation. PMID:27166427

  1. Novel human-derived extracellular matrix induces in vitro and in vivo vascularization and inhibits fibrosis

    PubMed Central

    Moore, Marc C; Pandolfi, Vittoria; McFetridge, Peter S

    2015-01-01

    The inability to vascularize engineered organs and revascularize areas of infarction has been a major roadblock to delivering successful regenerative medicine therapies to the clinic. These investigations detail an isolated human extracellular matrix derived from the placenta (hPM) that induces vasculogenesis in vitro and angiogenesis in vivo within bioengineered tissues, with significant immune reductive properties. Compositional analysis showed ECM components (fibrinogen, laminin), angiogenic cytokines (angiogenin, FGF), and immune-related cytokines (annexins, DEFA1) in near physiological ratios. Gene expression profiles of endothelial cells seeded onto the matrix displayed upregulation of angiogenic genes (TGFB1, VEGFA), remodeling genes (MMP9, LAMA5) and vascular development genes (HAND2, LECT1). Angiogenic networks displayed a time dependent stability in comparison to current in vitro approaches that degrade rapidly. In vivo, matrix-dosed bioscaffolds showed enhanced angiogenesis and significantly reduced fibrosis in comparison to current angiogenic biomaterials. Implementation of this human placenta derived extracellular matrix provides an alternative to Matrigel and, due to its human derivation, its development may have significant clinical applications leading to advances in therapeutic angiogenesis techniques and tissue engineering. PMID:25725553

  2. Isolation and culture of human trabecular meshwork cells by extracellular matrix digestion.

    PubMed

    Stamer, W D; Seftor, R E; Williams, S K; Samaha, H A; Snyder, R W

    1995-07-01

    Like corneal endothelial cells, human trabecular meshwork cells are believed to be of neural crest origin, but demonstrate physiological properties and an antithrombogenic surface similar to vascular endothelial cells. One current method for isolating trabecular meshwork cells utilizes the motile nature of these cells to migrate away from a trabecular meshwork explant in culture to more distal regions of the culture dish. This 'outgrowth' technique is limited in practice by the relatively small number of cells that migrate per explant per unit time, thus hindering the ability to gather sufficient numbers of cells for comprehensive experimentation. For this reason, we have modified an extracellular matrix digestion technique in current use for the isolation of microvascular endothelial cells to isolate human trabecular meshwork cells. This procedure is both efficient and rapid for isolating large numbers of trabecular meshwork cells and results in the availability of trabecular meshwork cells in sufficient quantities for subsequent experimentation. PMID:7587308

  3. Air Revitalization Using Superoxides

    NASA Technical Reports Server (NTRS)

    Wydeven, Theodore; Wood, Peter C.; Spitze, L. A.

    1988-01-01

    Pellets made from powder mixtures of potassium superoxide, KO2, and calcium superoxide, Ca(O2)2, proven markedly superior to pellets of pure KO2 for adding O2 to and removing CO2 from atmospheric-pressure flow of humidified CO2 in He. Superoxides used extensively to supply O2 and scrub CO2 in variety of ambient-pressure life-support applications, including portable self-contained breathing apparatuses, spacecraft, and undersea submersible craft.

  4. Increased mRNA expression of manganese superoxide dismutase in psoriasis skin lesions and in cultured human keratinocytes exposed to IL-1 beta and TNF-alpha.

    PubMed

    Löntz, W; Sirsjö, A; Liu, W; Lindberg, M; Rollman, O; Törmä, H

    1995-02-01

    Because reactive oxygen species have been implicated in the pathogenesis of various hyperproliferative and inflammatory diseases, the mRNA expression of the antioxidant enzyme superoxide dismutase was studied in psoriatic skin tissue. By using reverse transcription-PCR we found similar expression of copper, zinc superoxide dismutase (CuZnSOD) in the involved vs. uninvolved psoriatic skin. In contrast, the level of the manganese superoxide dismutase (MnSOD) mRNA message was consistently higher in lesional psoriatic skin as compared to adjacent uninvolved skin and healthy control skin. Parallel investigation of those cytokines that are thought to be direct or indirect inducers of the MnSOD activity revealed an increased mRNA expression of IL-1 beta, TNF-alpha, and GM-CSF in lesional psoriatic skin. To study if these cytokines exert a direct effect on dismutase expression in epidermal cells, human keratinocytes in culture were challenged with IL-1 beta, TNF-alpha, and GM-CSF. It was found that IL-1 beta and TNF-alpha, but not GM-CSF, induced the mRNA expression of MnSOD, and an additive effect was demonstrated for the two former cytokines. Further, the expression of both CuZnSOD and MnSOD transcripts was similar in cultured keratinocytes maintained at low differentiation (low Ca2+ medium) and cells forced to terminal differentiation (by high Ca2+ medium). Our results indicate that the abnormal expression of MnSOD mRNA in lesional psoriatic skin is not directly linked to the pathologic state of keratinocyte differentiation in the skin. It seems more likely that the cutaneous overexpression of MnSOD in psoriatic epidermis represents a protective cellular response evoked by cytokines released from inflammatory cells invading the diseased skin. PMID:7744320

  5. The extracellular calcium-sensing receptor regulates human fetal lung development via CFTR

    PubMed Central

    Brennan, Sarah C.; Wilkinson, William J.; Tseng, Hsiu-Er; Finney, Brenda; Monk, Bethan; Dibble, Holly; Quilliam, Samantha; Warburton, David; Galietta, Luis J.; Kemp, Paul J.; Riccardi, Daniela

    2016-01-01

    Optimal fetal lung growth requires anion-driven fluid secretion into the lumen of the developing organ. The fetus is hypercalcemic compared to the mother and here we show that in the developing human lung this hypercalcaemia acts on the extracellular calcium-sensing receptor, CaSR, to promote fluid-driven lung expansion through activation of the cystic fibrosis transmembrane conductance regulator, CFTR. Several chloride channels including TMEM16, bestrophin, CFTR, CLCN2 and CLCA1, are also expressed in the developing human fetal lung at gestational stages when CaSR expression is maximal. Measurements of Cl−-driven fluid secretion in organ explant cultures show that pharmacological CaSR activation by calcimimetics stimulates lung fluid secretion through CFTR, an effect which in humans, but not mice, was also mimicked by fetal hypercalcemic conditions, demonstrating that the physiological relevance of such a mechanism appears to be species-specific. Calcimimetics promote CFTR opening by activating adenylate cyclase and we show that Ca2+-stimulated type I adenylate cyclase is expressed in the developing human lung. Together, these observations suggest that physiological fetal hypercalcemia, acting on the CaSR, promotes human fetal lung development via cAMP-dependent opening of CFTR. Disturbances in this process would be expected to permanently impact lung structure and might predispose to certain postnatal respiratory diseases. PMID:26911344

  6. Gene Expression in Human Hippocampus from Cocaine Abusers Identifies Genes which Regulate Extracellular Matrix Remodeling

    PubMed Central

    Mash, Deborah C.; ffrench-Mullen, Jarlath; Adi, Nikhil; Qin, Yujing; Buck, Andrew; Pablo, John

    2007-01-01

    The chronic effects of cocaine abuse on brain structure and function are blamed for the inability of most addicts to remain abstinent. Part of the difficulty in preventing relapse is the persisting memory of the intense euphoria or cocaine “rush”. Most abused drugs and alcohol induce neuroplastic changes in brain pathways subserving emotion and cognition. Such changes may account for the consolidation and structural reconfiguration of synaptic connections with exposure to cocaine. Adaptive hippocampal plasticity could be related to specific patterns of gene expression with chronic cocaine abuse. Here, we compare gene expression profiles in the human hippocampus from cocaine addicts and age-matched drug-free control subjects. Cocaine abusers had 151 gene transcripts upregulated, while 91 gene transcripts were downregulated. Topping the list of cocaine-regulated transcripts was RECK in the human hippocampus (FC = 2.0; p<0.05). RECK is a membrane-anchored MMP inhibitor that is implicated in the coordinated regulation of extracellular matrix integrity and angiogenesis. In keeping with elevated RECK expression, active MMP9 protein levels were decreased in the hippocampus from cocaine abusers. Pathway analysis identified other genes regulated by cocaine that code for proteins involved in the remodeling of the cytomatrix and synaptic connections and the inhibition of blood vessel proliferation (PCDH8, LAMB1, ITGB6, CTGF and EphB4). The observed microarray phenotype in the human hippocampus identified RECK and other region-specific genes that may promote long-lasting structural changes with repeated cocaine abuse. Extracellular matrix remodeling in the hippocampus may be a persisting effect of chronic abuse that contributes to the compulsive and relapsing nature of cocaine addiction. PMID:18000554

  7. Trafficking Mechanisms of Extracellular Matrix Macromolecules: Insights from Vertebrate Development and Human Diseases

    PubMed Central

    Unlu, Gokhan; Levic, Daniel S.; Melville, David B.; Knapik, Ela W.

    2014-01-01

    Cellular life depends on protein transport and membrane traffic. In multicellular organisms, membrane traffic is required for extracellular matrix deposition, cell adhesion, growth factor release, and receptor signaling, which are collectively required to integrate the development and physiology of tissues and organs. Understanding the regulatory mechanisms that govern cargo and membrane flow presents a prime challenge in cell biology. Extracellular matrix (ECM) secretion remains poorly understood, although given its essential roles in the regulation of cell migration, differentiation, and survival, ECM secretion mechanisms are likely to be tightly controlled. Recent studies in vertebrate model systems, from fishes to mammals and in human patients, have revealed complex and diverse loss-of-function phenotypes associated with mutations in components of the secretory machinery. A broad spectrum of diseases from skeletal and cardiovascular to neurological deficits have been linked to ECM trafficking. These discoveries have directly challenged the prevailing view of secretion as an essential but monolithic process. Here, we will discuss the latest findings on mechanisms of ECM trafficking in vertebrates. PMID:24333299

  8. Retinoic acid stimulation of human dermal fibroblast proliferation is dependent on suboptimal extracellular Ca2+ concentration

    SciTech Connect

    Varani, J.; Shayevitz, J.; Perry, D.; Mitra, R.S.; Nickoloff, B.J.; Voorhees, J.J. )

    1990-06-01

    Human dermal fibroblasts failed to proliferate when cultured in medium containing 0.15 mmol/l (millimolar) Ca2+ (keratinocyte growth medium (KGM)) but did when the external Ca2+ concentration was raised to 1.4 mmol/l. All-trans retinoic acid (retinoic acid) stimulated proliferation in KGM but did not further stimulate growth in Ca2(+)-supplemented KGM. The ability of retinoic acid to stimulate proliferation was inhibited in KGM prepared without Ca2+ or prepared with 0.03 mmol/l Ca2+ and in KGM treated with 1 mmol/l ethylene-glycol-bis-(beta-aminoethyl ether)N,N'-tetra acetic acid. Using 45Ca2+ to measure Ca2+ influx and efflux, it was found that retinoic acid minimally increased Ca2+ uptake into fibroblasts. In contrast, retinoic acid treatment of fibroblasts that had been pre-equilibrated for 1 day with 45Ca2+ inhibited release of intracellular Ca2+ into the extracellular fluid. Retinoic acid also stimulated 35S-methionine incorporation into trichloroacetic acid-precipitable material but in contrast to its effect on proliferation, stimulation of 35S-methionine incorporation occurred in both high-Ca2+ and low-Ca2+ medium. These data indicate that retinoic acid stimulation of proliferation, but not protein synthesis, is dependent on the concentration of Ca2+ in the extracellular environment.

  9. Cloning and Characterization of Two Extracellular Heparin-degrading Endosulfatases in Mice and Humans*

    PubMed Central

    Morimoto-Tomita, Megumi; Uchimura, Kenji; Werb, Zena; Hemmerich, Stefan; Rosen, Steven D.

    2009-01-01

    Here we report the cloning of a full-length cDNA encoding the human ortholog (HSulf-1) of the developmentally regulated putative sulfatases QSulf-1 (Dhoot, G. K., Gustafsson, M. K., Ai, X., Sun, W., Standiford, D. M., and Emerson, C. P., Jr. (2001) Science 293, 1663–1666) and RSulfFP1 (Ohto, T., Uchida, H., Yamazaki, H., Keino-Masu, K., Matsui, A., and Masu, M. (2002) Genes Cells 7, 173–185) as well as a cDNA encoding a closely related protein, designated HSulf-2. We have also obtained cDNAs for the mouse orthologs of both Sulfs. We demonstrate that the proteins encoded by both classes of cDNAs are endoproteolytically processed in the secretory pathway and are released into conditioned medium of transfected CHO cells. We demonstrate that the mammalian Sulfs exhibit arylsulfatase activity with a pH optimum in the neutral range; moreover, they can remove sulfate from the C-6 position of glucosamine within specific subregions of intact heparin. Taken together, our results establish that the mammalian Sulfs are extracellular endosulfatases with strong potential for modulating the interactions of heparan sulfate proteoglycans in the extracellular microenvironment. PMID:12368295

  10. Scanning Electron Microscopic Examination of the Extracellular Matrix in the Decellularized Mouse and Human Cochlea.

    PubMed

    Santi, Peter A; Aldaya, Robair; Brown, Alec; Johnson, Shane; Stromback, Tyler; Cureoglu, Sebahattin; Rask-Andersen, Helge

    2016-06-01

    Decellularized tissues have been used to investigate the extracellular matrix (ECM) in a number of different tissues and species. Santi and Johnson JARO 14:3-15 (2013) first described the decellularized inner ear in the mouse, rat, and human using scanning thin-sheet laser imaging microscopy (sTSLIM). The purpose of the present investigation is to examine decellularized cochleas in the mouse and human at higher resolution using scanning electron microscopy (SEM). Fresh cochleas were harvested and decellularized using detergent extraction methods. Following decellularization, the ECM of the bone, basilar membrane, spiral limbus, and ligament remained, and all of the cells were removed from the cochlea. A number of similarities and differences in the ECM of the mouse and human were observed. A novel, spirally directed structure was present on the basilar membrane and is located at the border between Hensen and Boettcher cells. These septa-like structures formed a single row in the mouse and multiple rows in the human. The basal lamina of the stria vascularis capillaries was present and appeared thicker in the human compared with the mouse. In the mouse, numerous openings beneath the spiral prominence that previously housed the root processes of the external sulcus cells were observed but in the human there was only a single row of openings. These and other anatomical differences in the ECM between the mouse and human may reflect functional differences and/or be due to aging; however, decellularized cochleas provide a new way to examine the cochlear ECM and reveal new observations. PMID:27029011

  11. Extracellular dextranase activity produced by human oral strains of the genus Bifidobacterium.

    PubMed Central

    Kaster, A G; Brown, L R

    1983-01-01

    Three strains of anaerobic, dextranase-producing, gram-positive, rod-shaped bacteria were isolated from human dental plaque associated with root carious lesions. The isolates produced a molar ratio of acetate to lactate from glucose fermentation ranging from 1.1 to 1.9. Each strain also produced fructose-6-phosphate phosphoketolase. The isolates were identified as belonging to the genus Bifidobacterium, but from their carbohydrate fermentation patterns they did not appear to be strains of Bifidobacterium dentium. These microorganisms fermented high-molecular-weight dextrans. A partial characterization of the dextranase activity was included in this study and revealed an extracellular dextranase with a pH optimum of 7.1. Analysis of the dextran degradation products demonstrated the liberation of saccharides larger than 1 glucose unit. It was concluded that this enzyme used an endohydrolytic mode of dextran cleavage. PMID:6642650

  12. Cigarette smoke enhances proliferation and extracellular matrix deposition by human fetal airway smooth muscle

    PubMed Central

    Vogel, Elizabeth R.; VanOosten, Sarah K.; Holman, Michelle A.; Hohbein, Danielle D.; Thompson, Michael A.; Vassallo, Robert; Pandya, Hitesh C.; Prakash, Y. S.

    2014-01-01

    Cigarette smoke is a common environmental insult associated with increased risk of developing airway diseases such as wheezing and asthma in neonates and children. In adults, asthma involves airway remodeling characterized by increased airway smooth muscle (ASM) cell proliferation and increased extracellular matrix (ECM) deposition, as well as airway hyperreactivity. The effects of cigarette smoke on remodeling and contractility in the developing airway are not well-elucidated. In this study, we used canalicular-stage (18–20 wk gestational age) human fetal airway smooth muscle (fASM) cells as an in vitro model of the immature airway. fASM cells were exposed to cigarette smoke extract (CSE; 0.5–1.5% for 24–72 h), and cell proliferation, ECM deposition, and intracellular calcium ([Ca2+]i) responses to agonist (histamine 10 μM) were used to evaluate effects on remodeling and hyperreactivity. CSE significantly increased cell proliferation and deposition of ECM molecules collagen I, collagen III, and fibronectin. In contrast, [Ca2+]i responses were not significantly affected by CSE. Analysis of key signaling pathways demonstrated significant increase in extracellular signal-related kinase (ERK) and p38 activation with CSE. Inhibition of ERK or p38 signaling prevented CSE-mediated changes in proliferation, whereas only ERK inhibition attenuated the CSE-mediated increase in ECM deposition. Overall, these results demonstrate that cigarette smoke may enhance remodeling in developing human ASM through hyperplasia and ECM production, thus contributing to development of neonatal and pediatric airway disease. PMID:25344066

  13. Activation of a 66-kilodalton human endothelial cell matrix metalloprotease by Streptococcus pyogenes extracellular cysteine protease.

    PubMed

    Burns, E H; Marciel, A M; Musser, J M

    1996-11-01

    Human umbilical vein endothelial cells (HUVECs) were used to gain insight into the molecular mechanism whereby the major extracellular protease from group A streptococci damages host tissue. HUVECs exposed to streptococcal cysteine protease (SCP) for various times exhibited cytopathic effect and cell detachment from the culture vessel. Gelatin substrate zymography showed that a time- and concentration-dependent increase in the level of activity of an approximately 66-kDa gelatinase occurred in culture medium taken from cells exposed to enzymatically active SCP. This gelatinase comigrated in gelatin zymograms with the activated form of purified recombinant matrix metalloprotease 2 (MMP-2) and had type IV collagenase activity. In contrast, medium taken from cells exposed to inactivated (boiled) SCP and cells exposed to SCP inhibited by treatment with N-benzyloxycarbonyl-leucyl-valyl-glycine diazomethyl ketone lacked the 66-kDa gelatinase. Appearance of the 66-kDa gelatinase activity was also prevented by 1,10-phenanthroline, a zinc chelator and MMP inhibitor. Inasmuch as proteolytically active SCP is required for the emergence of this gelatinase and MMP activation occurs by proteolytic processing, the 66-kDa gelatinase may be a proteolytic cleavage product of a latent MMP expressed extracellularly by HUVECs. Direct SCP treatment of culture supernatant taken from HUVECs not exposed to SCP also produced the 66-kDa gelatinase. The data show that SCP activates an MMP produced by human endothelial cells, a process that may contribute to endothelial cell damage, tissue destruction, and hemodynamic derangement observed in some patients with severe, invasive group A streptococcal infection. PMID:8890235

  14. Activation of a 66-kilodalton human endothelial cell matrix metalloprotease by Streptococcus pyogenes extracellular cysteine protease.

    PubMed Central

    Burns, E H; Marciel, A M; Musser, J M

    1996-01-01

    Human umbilical vein endothelial cells (HUVECs) were used to gain insight into the molecular mechanism whereby the major extracellular protease from group A streptococci damages host tissue. HUVECs exposed to streptococcal cysteine protease (SCP) for various times exhibited cytopathic effect and cell detachment from the culture vessel. Gelatin substrate zymography showed that a time- and concentration-dependent increase in the level of activity of an approximately 66-kDa gelatinase occurred in culture medium taken from cells exposed to enzymatically active SCP. This gelatinase comigrated in gelatin zymograms with the activated form of purified recombinant matrix metalloprotease 2 (MMP-2) and had type IV collagenase activity. In contrast, medium taken from cells exposed to inactivated (boiled) SCP and cells exposed to SCP inhibited by treatment with N-benzyloxycarbonyl-leucyl-valyl-glycine diazomethyl ketone lacked the 66-kDa gelatinase. Appearance of the 66-kDa gelatinase activity was also prevented by 1,10-phenanthroline, a zinc chelator and MMP inhibitor. Inasmuch as proteolytically active SCP is required for the emergence of this gelatinase and MMP activation occurs by proteolytic processing, the 66-kDa gelatinase may be a proteolytic cleavage product of a latent MMP expressed extracellularly by HUVECs. Direct SCP treatment of culture supernatant taken from HUVECs not exposed to SCP also produced the 66-kDa gelatinase. The data show that SCP activates an MMP produced by human endothelial cells, a process that may contribute to endothelial cell damage, tissue destruction, and hemodynamic derangement observed in some patients with severe, invasive group A streptococcal infection. PMID:8890235

  15. Kallikrein-8 Proteolytically Processes Human Papillomaviruses in the Extracellular Space To Facilitate Entry into Host Cells

    PubMed Central

    Cerqueira, Carla; Samperio Ventayol, Pilar; Vogeley, Christian

    2015-01-01

    ABSTRACT The entry of human papillomaviruses into host cells is a complex process. It involves conformational changes at the cell surface, receptor switching, internalization by a novel endocytic mechanism, uncoating in endosomes, trafficking of a subviral complex to the Golgi complex, and nuclear entry during mitosis. Here, we addressed how the stabilizing contacts in the capsid of human papillomavirus 16 (HPV16) may be reversed to allow uncoating of the viral genome. Using biochemical and cell-biological analyses, we determined that the major capsid protein L1 underwent proteolytic cleavage during entry. In addition to a dispensable cathepsin-mediated proteolysis that occurred likely after removal of capsomers from the subviral complex in endosomes, at least two further proteolytic cleavages of L1 were observed, one of which was independent of the low-pH environment of endosomes. This cleavage occurred extracellularly. Further analysis showed that the responsible protease was the secreted trypsin-like serine protease kallikrein-8 (KLK8) involved in epidermal homeostasis and wound healing. Required for infection, the cleavage was facilitated by prior interaction of viral particles with heparan sulfate proteoglycans. KLK8-mediated cleavage was crucial for further conformational changes exposing an important epitope of the minor capsid protein L2. Occurring independently of cyclophilins and of furin that mediate L2 exposure, KLK8-mediated cleavage of L1 likely facilitated access to L2, located in the capsid lumen, and potentially uncoating. Since HPV6 and HPV18 also required KLK8 for entry, we propose that the KLK8-dependent entry step is conserved. IMPORTANCE Our analysis of the proteolytic processing of incoming HPV16, an etiological agent of cervical cancer, demonstrated that the capsid is cleaved extracellularly by a serine protease active during wound healing and that this cleavage was crucial for infection. The cleavage of L1 is one of at least four structural

  16. Effect of polyphenolic compounds from Solanum torvum on plasma lipid peroxidation, superoxide anion and cytochrome P450 2E1 in human liver microsomes.

    PubMed

    Kusirisin, Winthana; Jaikang, Churdsak; Chaiyasut, Chaiyavat; Narongchai, Paitoon

    2009-11-01

    Previous studies presented evidence that plants contain antioxidants that have free radical-scavenging properties. Overproduction of free radicals leads to oxidative stress, a factor associated with a variety of diseases, such as diabetes. Cytochrome P450 2E1 enzymes (CYP2E1) are involved in drug metabolism in the liver and metabolism of DNA-reaction generating intra-mitochondrial ROS, which leads to micro- and macro-vascular pathology in diabetes. Plant-based chemicals can affect CYP2E1 enzymes and related defense mechanisms, possibly leading to protection against oxidative stress. We investigated the effect of Solanum torvum (ST) extracts on the inhibition of CYP2E1 activity in human liver microsomes. ST extract was analyzed for antioxidant activity by the ABTS method. Polyphenolic compounds were measured by the total phenol content using the Folin-Ciocalteau reagent. Flavonoid and tannin content were analyzed by standard methods. Oxidative stress was evaluated by measuring lipid peroxidation by TBARS and superoxide anion scavenging levels in plasma from diabetic patients. Results showed that 10 mg/ml of ST had CYP2E1 catalytic inhibiting activity (57.16 %). The IC50 value of CYP2E1 catalytic inhibiting activity level was 5.14 mg/ml by concentration in a dependent manner. One gram of concentrated ST extract had an antioxidant activity index of 3.68 mg of trolox and 360.53 mg of ascorbic acid equivalent. Effects on free radical-scavenging, as measured by TBARS and superoxide anion, showed IC50 values of 20.60 and 10.26 microg/ml, respectively. Polyphenolic compounds found included phenol, flavonoid and tannin, measuring 160.30, 104.36 and 65.91 mg/g, respectively. These results imply that ST is a natural source of polyphenolic antioxidants, which have cytochrome P450 2E1 enzyme inhibiting and free radical scavenging properties, as related to lipid peroxidation and superoxide anion activity. ST could potentially be used for reducing oxidative stress in diabetes

  17. Crystal structure of the extracellular domain of human myelin protein zero

    SciTech Connect

    Liu, Zhigang; Wang, Yong; Yedidi, Ravikiran S.; Brunzelle, Joseph S.; Kovari, Iulia A.; Sohi, Jasloveleen; Kamholz, John; Kovari, Ladislau C.

    2012-03-27

    Charcot-Marie-Tooth disease (CMT), a hereditary motor and sensory neuropathy, is the most common genetic neuropathy with an incidence of 1 in 2600. Several forms of CMT have been identified arising from different genomic abnormalities such as CMT1 including CMT1A, CMT1B, and CMTX. CMT1 with associated peripheral nervous system (PNS) demyelination, the most frequent diagnosis, demonstrates slowed nerve conduction velocities and segmental demyelination upon nerve biopsy. One of its subtypes, CMT1A, presents a 1.5-Mb duplication in the p11-p12 region of the human chromosome 17 which encodes peripheral myelin protein 22 (PMP22). CMT1B, a less common form, arises from the mutations in the myelin protein zero (MPZ) gene on chromosome 1, region q22-q23, which encodes the major structural component of the peripheral myelin. A rare type of CMT1 has been found recently and is caused by point mutations in early growth response gene 2 (EGR2), encoding a zinc finger transcription factor in Schwann cells. In addition, CMTX, an X-linked form of CMT, arises from a mutation in the connexin-32 gene. Myelin protein zero, associated with CMT1B, is a transmembrane protein of 219 amino acid residues. Human MPZ consists of three domains: 125 residues constitute the glycosylated immunoglobulin-like extracellular domain; 27 residues span the membrane; and 67 residues comprise the highly basic intracellular domain. MPZ makes up approximately 50% of the protein content of myelin, and is expressed predominantly in Schwann cells, the myelinating cell of the PNS. Myelin protein zero, a homophilic adhesion molecule, is a member of the immunoglobulin super-family and is essential for normal myelin structure and function. In addition, MPZ knockout mice displayed abnormal myelin that severely affects the myelination pathway, and overexpression of MPZ causes congenital hypomyelination of peripheral nerves. Myelin protein zero mutations account for {approx}5% of patients with CMT. To date, over 125

  18. Identification of copper/zinc superoxide dismutase as a nitric oxide-regulated gene in human (HaCaT) keratinocytes: implications for keratinocyte proliferation.

    PubMed

    Frank, S; Kämpfer, H; Podda, M; Kaufmann, R; Pfeilschifter, J

    2000-03-15

    Recent studies have demonstrated an induction of expression of inducible nitric oxide synthase that is associated with several inflammatory diseases of the skin. To define the mechanisms of action of nitric oxide (NO) in the skin, we attempted to identify genes that are regulated by NO in keratinocytes. Using the human keratinocyte cell line HaCaT as a model system, we identified a Cu/Zn superoxide dismutase (SOD) that was strongly induced by high concentrations (500 microM) of NO-donating agents ¿S-nitrosoglutathione, sodium nitroprusside and (Z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl) amino] diazen-1-ium-1,2 -diolate (DETA-NO)¿, but not by serum or by single recombinant growth factors and inflammatory cytokines or by treatment with superoxide anions. Furthermore, endogenously produced NO increased the expression of Cu/Zn SOD mRNA in keratinocytes. Moreover, treatment of HaCaT cells with NO was associated with a biphasic effect on cell proliferation, because low doses (100 microM) of different NO donors (S-nitrosoglutathione and DETA-NO) mediated a proliferative signal to the cells, whereas high concentrations (500 microM) were cytostatic. To determine a possible correlation between the close regulation of Cu/Zn SOD expression and proliferation by NO in keratinocytes, we established a cell line (psp1CZ1N) carrying a human Cu/Zn SOD cDNA under the control of a ponasterone-inducible promoter construct. Ponasterone-induced overexpression of Cu/Zn SOD caused a cytostatic effect in proliferating psp1CZ1N cells. We therefore suggest that the up-regulation of Cu/Zn SOD expression by NO establishes an inhibitory mechanism on keratinocyte proliferation. PMID:10698699

  19. Extracellular guanosine regulates extracellular adenosine levels

    PubMed Central

    Cheng, Dongmei; Jackson, Travis C.; Verrier, Jonathan D.; Gillespie, Delbert G.

    2013-01-01

    The aim of this investigation was to test the hypothesis that extracellular guanosine regulates extracellular adenosine levels. Rat preglomerular vascular smooth muscle cells were incubated with adenosine, guanosine, or both. Guanosine (30 μmol/l) per se had little effect on extracellular adenosine levels. Extracellular adenosine levels 1 h after addition of adenosine (3 μmol/l) were 0.125 ± 0.020 μmol/l, indicating rapid disposition of extracellular adenosine. Extracellular adenosine levels 1 h after addition of adenosine (3 μmol/l) plus guanosine (30 μmol/l) were 1.173 ± 0.061 μmol/l, indicating slow disposition of extracellular adenosine. Cell injury increased extracellular levels of endogenous adenosine and guanosine, and the effects of cell injury on endogenous extracellular adenosine were modulated by altering the levels of endogenous extracellular guanosine with exogenous purine nucleoside phosphorylase (converts guanosine to guanine) or 8-aminoguanosine (inhibits purine nucleoside phosphorylase). Extracellular guanosine also slowed the disposition of extracellular adenosine in rat preglomerular vascular endothelial cells, mesangial cells, cardiac fibroblasts, and kidney epithelial cells and in human aortic and coronary artery vascular smooth muscle cells and coronary artery endothelial cells. The effects of guanosine on adenosine levels were not mimicked or attenuated by 5-iodotubericidin (adenosine kinase inhibitor), erythro-9-(2-hydroxy-3-nonyl)-adenine (adenosine deaminase inhibitor), 5-aminoimidazole-4-carboxamide (guanine deaminase inhibitor), aristeromycin (S-adenosylhomocysteine hydrolase inhibitor), low sodium (inhibits concentrative nucleoside transporters), S-(4-nitrobenzyl)−6-thioinosine [inhibits equilibrative nucleoside transporter (ENT) type 1], zidovudine (inhibits ENT type 2), or acadesine (known modulator of adenosine levels). Guanosine also increases extracellular inosine, uridine, thymidine, and cytidine, yet decreases

  20. Wnt interaction and extracellular release of prominin-1/CD133 in human malignant melanoma cells.

    PubMed

    Rappa, Germana; Mercapide, Javier; Anzanello, Fabio; Le, Thuc T; Johlfs, Mary G; Fiscus, Ronald R; Wilsch-Bräuninger, Michaela; Corbeil, Denis; Lorico, Aurelio

    2013-04-01

    Prominin-1 (CD133) is the first identified gene of a novel class of pentaspan membrane glycoproteins. It is expressed by various epithelial and non-epithelial cells, and notably by stem and cancer stem cells. In non-cancerous cells such as neuro-epithelial and hematopoietic stem cells, prominin-1 is selectively concentrated in plasma membrane protrusions, and released into the extracellular milieu in association with small vesicles. Previously, we demonstrated that prominin-1 contributes to melanoma cells pro-metastatic properties and suggested that it may constitute a molecular target to prevent prominin-1-expressing melanomas from colonizing and growing in lymph nodes and distant organs. Here, we report that three distinct pools of prominin-1 co-exist in cultures of human FEMX-I metastatic melanoma. Morphologically, in addition to the plasma membrane localization, prominin-1 is found within the intracellular compartments, (e.g., Golgi apparatus) and in association with extracellular membrane vesicles. The latter prominin-1-positive structures appeared in three sizes (small, ≤40 nm; intermediates ~40-80 nm, and large, >80 nm). Functionally, the down-regulation of prominin-1 in FEMX-I cells resulted in a significant reduction of number of lipid droplets as observed by coherent anti-Stokes Raman scattering image analysis and Oil red O staining, and surprisingly in a decrease in the nuclear localization of beta-catenin, a surrogate marker of Wnt activation. Moreover, the T-cell factor/lymphoid enhancer factor (TCF/LEF) promoter activity was 2 to 4 times higher in parental than in prominin-1-knockdown cells. Collectively, our results point to Wnt signaling and/or release of prominin-1-containing membrane vesicles as mediators of the pro-metastatic activity of prominin-1 in FEMX-I melanoma. PMID:23318676

  1. Eosinophil extracellular DNA trap cell death mediates lytic release of free secretion-competent eosinophil granules in humans

    PubMed Central

    Ueki, Shigeharu; Melo, Rossana C. N.; Ghiran, Ionita; Spencer, Lisa A.; Dvorak, Ann M.; Weller, Peter F.

    2013-01-01

    Eosinophils release their granule proteins extracellularly through exocytosis, piecemeal degranulation, or cytolytic degranulation. Findings in diverse human eosinophilic diseases of intact extracellular eosinophil granules, either free or clustered, indicate that eosinophil cytolysis occurs in vivo, but the mechanisms and consequences of lytic eosinophil degranulation are poorly understood. We demonstrate that activated human eosinophils can undergo extracellular DNA trap cell death (ETosis) that cytolytically releases free eosinophil granules. Eosinophil ETosis (EETosis), in response to immobilized immunoglobulins (IgG, IgA), cytokines with platelet activating factor, calcium ionophore, or phorbol myristate acetate, develops within 120 minutes in a reduced NADP (NADPH) oxidase-dependent manner. Initially, nuclear lobular formation is lost and some granules are released by budding off from the cell as plasma membrane–enveloped clusters. Following nuclear chromatolysis, plasma membrane lysis liberates DNA that forms weblike extracellular DNA nets and releases free intact granules. EETosis-released eosinophil granules, still retaining eosinophil cationic granule proteins, can be activated to secrete when stimulated with CC chemokine ligand 11 (eotaxin-1). Our results indicate that an active NADPH oxidase-dependent mechanism of cytolytic, nonapoptotic eosinophil death initiates nuclear chromatolysis that eventuates in the release of intact secretion-competent granules and the formation of extracellular DNA nets. PMID:23303825

  2. Inhibitory effects of extracellular products from oral bacteria on human fibroblasts and stimulated lymphocytes.

    PubMed Central

    Higerd, T B; Vesole, D H; Goust, J M

    1978-01-01

    Extracellular products of 12 strains of Streptococcus mutans and 5 additional species of oral bacteria were analyzed for their ability to inhibit proliferation of fibroblastoid cells (HeLa and AV3) and blast transformation of human peripheral blood lymphocytes obtained from normal individuals. Products from S. mutans strains AHT and BHT, Streptococcus intermedius, and Actinomyces viscosus inhibited [3H]thymidine uptake by fibroblastoid cells and phytohemagglutinin-stimulated lymphocytes. Products from S. mutans E49, Streptococcus salivarius, and Actinomyces naeslundii inhibited blast transformation of human lymphocytes but did not significantly inhibit the growth of fibroblastoid cells. Preparations from S. intermedius gave the greatest inhibitory activity against both target cell types; initial characterization of this preparation suggested a single factor active in both assays, in that the heat lability and Sephadex G-200 elution profile were similar for the inhibitory activity seen with the two cell types. The molecular weight of the inhibitor, estimated by gel filtration on Sephadex G-200 and Ultragel AcA34, was approximately 160,000. The results strongly suggest that oral bacteria produce heat-labile substances that interfere with fibroblast proliferation and alter the lymphocytic immunological response. Images PMID:689736

  3. Inhibitory effects of extracellular products from oral bacteria on human fibroblasts and stimulated lymphocytes.

    PubMed

    Higerd, T B; Vesole, D H; Goust, J M

    1978-08-01

    Extracellular products of 12 strains of Streptococcus mutans and 5 additional species of oral bacteria were analyzed for their ability to inhibit proliferation of fibroblastoid cells (HeLa and AV3) and blast transformation of human peripheral blood lymphocytes obtained from normal individuals. Products from S. mutans strains AHT and BHT, Streptococcus intermedius, and Actinomyces viscosus inhibited [3H]thymidine uptake by fibroblastoid cells and phytohemagglutinin-stimulated lymphocytes. Products from S. mutans E49, Streptococcus salivarius, and Actinomyces naeslundii inhibited blast transformation of human lymphocytes but did not significantly inhibit the growth of fibroblastoid cells. Preparations from S. intermedius gave the greatest inhibitory activity against both target cell types; initial characterization of this preparation suggested a single factor active in both assays, in that the heat lability and Sephadex G-200 elution profile were similar for the inhibitory activity seen with the two cell types. The molecular weight of the inhibitor, estimated by gel filtration on Sephadex G-200 and Ultragel AcA34, was approximately 160,000. The results strongly suggest that oral bacteria produce heat-labile substances that interfere with fibroblast proliferation and alter the lymphocytic immunological response. PMID:689736

  4. Differential Use of Human Neutrophil Fcγ Receptors for Inducing Neutrophil Extracellular Trap Formation

    PubMed Central

    Alemán, Omar Rafael; Mora, Nancy; Cortes-Vieyra, Ricarda; Uribe-Querol, Eileen; Rosales, Carlos

    2016-01-01

    Neutrophils (PMN) are the most abundant leukocytes in the blood. PMN migrate from the circulation to sites of infection, where they are responsible for antimicrobial functions. PMN use phagocytosis, degranulation, and formation of neutrophil extracellular traps (NETs) to kill microbes. NETs are fibers composed of chromatin and neutrophil-granule proteins. Several pathogens, including bacteria, fungi, and parasites, and also some pharmacological stimuli such as phorbol 12-myristate 13-acetate (PMA) are efficient inducers of NETs. Antigen-antibody complexes are also capable of inducing NET formation. However the particular Fcγ receptor involved in triggering this function is a matter of controversy. In order to provide some insight into what Fcγ receptor is responsible for NET formation, each of the two human Fcγ receptors was stimulated individually by specific monoclonal antibodies and NET formation was evaluated. FcγRIIa cross-linking did not promote NET formation. Cross-linking other receptors such as integrins also did not promote NET formation. In contrast FcγRIIIb cross-linking induced NET formation similarly to PMA stimulation. NET formation was dependent on NADPH-oxidase, PKC, and ERK activation. These data show that cross-linking FcγRIIIb is responsible for NET formation by the human neutrophil. PMID:27034964

  5. Expression of human AChR extracellular domain mutants with improved characteristics.

    PubMed

    Lazaridis, Konstantinos; Zisimopoulou, Paraskevi; Giastas, Petros; Bitzopoulou, Kalliopi; Evangelakou, Panagiota; Sideri, Anastasia; Tzartos, Socrates J

    2014-02-01

    The muscle nicotinic acetylcholine receptor (AChR) has a central role in neuromuscular transmission, and is the major target in the autoimmune disease myasthenia gravis (MG). We created mutants of the extracellular domains (ECDs) of the human α1, β1, δ and ε AChR subunits, whereby their Cys-loop was exchanged for that of the acetylcholine binding protein. The mutants were expressed in Pichia pastoris and had improved solubility resulting in 2- to 43-fold higher expression yields compared to the wild type. An additional mutant was created for the α1 ECD restoring its glycosylation site within the Cys-loop and its α-bungarotoxin binding ability. Furthermore, we constructed dimeric and pentameric concatamers of the mutant ECDs. All concatamers were successfully expressed as soluble secreted proteins, although the pentamers had about 10-fold lower expression than the dimers and were more susceptible to fragmentation. Initial crystallizations with the mutant ECDs were promising, and we reproducibly obtained crystals of the β1 ECD, diffracting at ~12 Å. Further optimization is underway to obtain crystals suitable for high resolution crystallography. The proteins described herein are useful tools in structural studies of the human muscle AChR and can be used in applications requiring high yields such as therapeutic adsorbents for MG autoantibodies. PMID:24246999

  6. Differential Use of Human Neutrophil Fcγ Receptors for Inducing Neutrophil Extracellular Trap Formation.

    PubMed

    Alemán, Omar Rafael; Mora, Nancy; Cortes-Vieyra, Ricarda; Uribe-Querol, Eileen; Rosales, Carlos

    2016-01-01

    Neutrophils (PMN) are the most abundant leukocytes in the blood. PMN migrate from the circulation to sites of infection, where they are responsible for antimicrobial functions. PMN use phagocytosis, degranulation, and formation of neutrophil extracellular traps (NETs) to kill microbes. NETs are fibers composed of chromatin and neutrophil-granule proteins. Several pathogens, including bacteria, fungi, and parasites, and also some pharmacological stimuli such as phorbol 12-myristate 13-acetate (PMA) are efficient inducers of NETs. Antigen-antibody complexes are also capable of inducing NET formation. However the particular Fcγ receptor involved in triggering this function is a matter of controversy. In order to provide some insight into what Fcγ receptor is responsible for NET formation, each of the two human Fcγ receptors was stimulated individually by specific monoclonal antibodies and NET formation was evaluated. FcγRIIa cross-linking did not promote NET formation. Cross-linking other receptors such as integrins also did not promote NET formation. In contrast FcγRIIIb cross-linking induced NET formation similarly to PMA stimulation. NET formation was dependent on NADPH-oxidase, PKC, and ERK activation. These data show that cross-linking FcγRIIIb is responsible for NET formation by the human neutrophil. PMID:27034964

  7. In vitro immunotoxicity assessment of culture-derived extracellular vesicles in human monocytes.

    PubMed

    Rosas, Lucia E; Elgamal, Ola A; Mo, Xiaokui; Phelps, Mitch A; Schmittgen, Thomas D; Papenfuss, Tracey L

    2016-09-01

    The potential to engineer extracellular vesicles (EV) that target specific cells and deliver a therapeutic payload has propelled a growing interest in their development as promising therapeutics. These EV are often produced from cultured cells. Very little is known about the interaction of cell culture-derived EV with cells of the immune system and their potential immunomodulatory effects. The present study evaluated potential immunotoxic effects of HEK293T-derived EV on the human monocytic cell lines THP-1 and U937. Incubation of cells with different doses of EV for 16-24 h was followed by assessment of cytotoxicity and cell function by flow cytometry. Changes in cell functionality were evaluated by the capacity of cells to phagocytize fluorescent microspheres. In addition, the internalization of labeled EV in THP-1 and U937 cells was evaluated. Exposure to EV did not affect the viability of THP-1 or U937 cells. Although lower doses of the EV increased phagocytic capacity in both cell lines, phagocytic efficiency of individual cells was not affected by EV exposure at any of the doses evaluated. This study also demonstrated that THP-1 and U937 monocytic cells are highly permissive to EV entry in a dose-response manner. These results suggest that, although HEK293T-derived EV are efficiently internalized by human monocytic cells, they do not exert a cytotoxic effect or alter phagocytic efficiency on the cell lines evaluated. PMID:27075513

  8. Capsular polysaccharides from Cryptococcus neoformans modulate production of neutrophil extracellular traps (NETs) by human neutrophils.

    PubMed

    Rocha, Juliana D B; Nascimento, Michelle T C; Decote-Ricardo, Debora; Côrte-Real, Suzana; Morrot, Alexandre; Heise, Norton; Nunes, Marise P; Previato, José Osvaldo; Mendonça-Previato, Lucia; DosReis, George A; Saraiva, Elvira M; Freire-de-Lima, Célio G

    2015-01-01

    In the present study, we characterized the in vitro modulation of NETs (neutrophil extracellular traps) induced in human neutrophils by the opportunistic fungus Cryptococcus neoformans, evaluating the participation of capsular polysaccharides glucuronoxylomanan (GXM) and glucuronoxylomannogalactan (GXMGal) in this phenomenon. The mutant acapsular strain CAP67 and the capsular polysaccharide GXMGal induced NET production. In contrast, the wild-type strain and the major polysaccharide GXM did not induce NET release. In addition, C. neoformans and the capsular polysaccharide GXM inhibited PMA-induced NET release. Additionally, we observed that the NET-enriched supernatants induced through CAP67 yeasts showed fungicidal activity on the capsular strain, and neutrophil elastase, myeloperoxidase, collagenase and histones were the key components for the induction of NET fungicidal activity. The signaling pathways associated with NET induction through the CAP67 strain were dependent on reactive oxygen species (ROS) and peptidylarginine deiminase-4 (PAD-4). Neither polysaccharide induced ROS production however both molecules blocked the production of ROS through PMA-activated neutrophils. Taken together, the results demonstrate that C. neoformans and the capsular component GXM inhibit the production of NETs in human neutrophils. This mechanism indicates a potentially new and important modulation factor for this fungal pathogen. PMID:25620354

  9. Constructing Human Skin Equivalents on Porcine Acellular Peritoneum Extracellular Matrix for In Vitro Irritation Testing.

    PubMed

    Tsai, Pei-Chin; Zhang, Zheng; Florek, Charles; Michniak-Kohn, Bozena B

    2016-01-01

    The irritancy of topical products has to be investigated to ensure the safety and compliance. Although several reconstructed human epidermal models have been adopted by the Organization for Economic Cooperation and Development (OECD) to replace in vivo animal irritation testing, these models are based on a single cell type and lack dermal components, which may be insufficient to reflect all of the components of irritation. In our study, we investigated the use of acellular porcine peritoneum extracellular matrix as a substrate to construct full-thickness human skin equivalents (HSEs) for use as irritation screening tool. The acellular peritoneum matrix (APM) exhibited excellent skin cell attachment (>80%) and proliferation for human dermal fibroblasts (HDF) and immortalized human keratinocytes (HaCaT). APM-HSEs based on coculture of HDF and HaCaT were prepared. Increased HDF seeding density up to 5 × 10(4)/cm(2) resulted in APM-HSEs with a thicker and more organized epidermis. The epidermis of APM-HSEs expressed keratin 15, a keratinocyte proliferation marker, and involucrin, a differentiation marker, respectively. To assess the use of APM-HSEs for irritation testing, six proficiency chemicals, including three nonirritants (phosphate-buffered saline, polyethylene glycol 400, and isopropanol) and three irritants (1-bromohexane, heptanol, and sodium dodecyl sulfate) were applied. The APM-HSEs were able to discriminate nonirritants from irritants based on the viability. Levels of cytokines (interleukin [IL]-1α, IL-1ra, IL-6, IL-8, and granulocyte macrophage colony-stimulating factor [GM-CSF]) in these treatment groups further assisted the irritancy ranking. In conclusion, we have developed partially differentiated full-thickness APM-HSEs based on acellular porcine peritoneum matrix, and these APM-HSEs demonstrated utility as an in vitro irritation screening tool. PMID:26415037

  10. On-chip immunoelectrophoresis of extracellular vesicles released from human breast cancer cells.

    PubMed

    Akagi, Takanori; Kato, Kei; Kobayashi, Masashi; Kosaka, Nobuyoshi; Ochiya, Takahiro; Ichiki, Takanori

    2015-01-01

    Extracellular vesicles (EVs) including exosomes and microvesicles have attracted considerable attention in the fields of cell biology and medicine. For a better understanding of EVs and further exploration of their applications, the development of analytical methods for biological nanovesicles has been required. In particular, considering the heterogeneity of EVs, methods capable of measuring individual vesicles are desired. Here, we report that on-chip immunoelectrophoresis can provide a useful method for the differential protein expression profiling of individual EVs. Electrophoresis experiments were performed on EVs collected from the culture supernatant of MDA-MB-231 human breast cancer cells using a measurement platform comprising a microcapillary electrophoresis chip and a laser dark-field microimaging system. The zeta potential distribution of EVs that reacted with an anti-human CD63 (exosome and microvesicle marker) antibody showed a marked positive shift as compared with that for the normal immunoglobulin G (IgG) isotype control. Thus, on-chip immunoelectrophoresis could sensitively detect the over-expression of CD63 glycoproteins on EVs. Moreover, to explore the applicability of on-chip immunoelectrophoresis to cancer diagnosis, EVs collected from the blood of a mouse tumor model were analyzed by this method. By comparing the zeta potential distributions of EVs after their immunochemical reaction with normal IgG, and the anti-human CD63 and anti-human CD44 (cancer stem cell marker) antibodies, EVs of tumor origin circulating in blood were differentially detected in the real sample. The result indicates that the present method is potentially applicable to liquid biopsy, a promising approach to the low-invasive diagnosis of cancer. PMID:25928805

  11. Extracellular vesicle–depleted fetal bovine and human sera have reduced capacity to support cell growth

    PubMed Central

    Eitan, Erez; Zhang, Shi; Witwer, Kenneth W.; Mattson, Mark P.

    2015-01-01

    Background Fetal bovine serum (FBS) is the most widely used serum supplement for mammalian cell culture. It supports cell growth by providing nutrients, growth signals, and protection from stress. Attempts to develop serum-free media that support cell expansion to the same extent as serum-supplemented media have not yet succeeded, suggesting that FBS contains one or more as-yet-undefined growth factors. One potential vehicle for the delivery of growth factors from serum to cultured cells is extracellular vesicles (EVs). Methods EV-depleted FBS and human serum were generated by 120,000g centrifugation, and its cell growth–supporting activity was measured. Isolated EVs from FBS were quantified and characterized by nanoparticle tracking analysis, electron microscopy, and protein assay. EV internalization into cells was quantified using fluorescent plate reader analysis and microscopy. Results Most cell types cultured with EV-depleted FBS showed a reduced growth rate but not an increased sensitivity to the DNA-damaging agent etoposide and the endoplasmic reticulum stress–inducing chemical tunicamycin. Supplying cells with isolated FBS-derived EVs enhanced their growth. FBS-derived EVs were internalized by mouse and human cells wherein 65±26% of them interacted with the lysosomes. EV-depleted human serum also exhibited reduced cell growth–promoting activity. Conclusions EVs play a role in the cell growth and survival-promoting effects of FBS and human serum. Thus, it is important to take the effect of EV depletion under consideration when planning EV extraction experiments and while attempting to develop serum-free media that support rapid cell expansion. In addition, these findings suggest roles for circulating EVs in supporting cell growth and survival in vivo. PMID:25819213

  12. Superoxide Production by a Manganese-Oxidizing Bacterium Facilitates Iodide Oxidation

    PubMed Central

    Li, Hsiu-Ping; Daniel, Benjamin; Creeley, Danielle; Grandbois, Russell; Zhang, Saijin; Xu, Chen; Ho, Yi-Fang; Schwehr, Kathy A.; Kaplan, Daniel I.; Santschi, Peter H.; Hansel, Colleen M.

    2014-01-01

    The release of radioactive iodine (i.e., iodine-129 and iodine-131) from nuclear reprocessing facilities is a potential threat to human health. The fate and transport of iodine are determined primarily by its redox status, but processes that affect iodine oxidation states in the environment are poorly characterized. Given the difficulty in removing electrons from iodide (I−), naturally occurring iodide oxidation processes require strong oxidants, such as Mn oxides or microbial enzymes. In this study, we examine iodide oxidation by a marine bacterium, Roseobacter sp. AzwK-3b, which promotes Mn(II) oxidation by catalyzing the production of extracellular superoxide (O2−). In the absence of Mn2+, Roseobacter sp. AzwK-3b cultures oxidized ∼90% of the provided iodide (10 μM) within 6 days, whereas in the presence of Mn(II), iodide oxidation occurred only after Mn(IV) formation ceased. Iodide oxidation was not observed during incubations in spent medium or with whole cells under anaerobic conditions or following heat treatment (boiling). Furthermore, iodide oxidation was significantly inhibited in the presence of superoxide dismutase and diphenylene iodonium (a general inhibitor of NADH oxidoreductases). In contrast, the addition of exogenous NADH enhanced iodide oxidation. Taken together, the results indicate that iodide oxidation was mediated primarily by extracellular superoxide generated by Roseobacter sp. AzwK-3b and not by the Mn oxides formed by this organism. Considering that extracellular superoxide formation is a widespread phenomenon among marine and terrestrial bacteria, this could represent an important pathway for iodide oxidation in some environments. PMID:24561582

  13. CADM1 Controls Actin Cytoskeleton Assembly and Regulates Extracellular Matrix Adhesion in Human Mast Cells

    PubMed Central

    Moiseeva, Elena P.; Straatman, Kees R.; Leyland, Mark L.; Bradding, Peter

    2014-01-01

    CADM1 is a major receptor for the adhesion of mast cells (MCs) to fibroblasts, human airway smooth muscle cells (HASMCs) and neurons. It also regulates E-cadherin and alpha6beta4 integrin in other cell types. Here we investigated a role for CADM1 in MC adhesion to both cells and extracellular matrix (ECM). Downregulation of CADM1 in the human MC line HMC-1 resulted not only in reduced adhesion to HASMCs, but also reduced adhesion to their ECM. Time-course studies in the presence of EDTA to inhibit integrins demonstrated that CADM1 provided fast initial adhesion to HASMCs and assisted with slower adhesion to ECM. CADM1 downregulation, but not antibody-dependent CADM1 inhibition, reduced MC adhesion to ECM, suggesting indirect regulation of ECM adhesion. To investigate potential mechanisms, phosphotyrosine signalling and polymerisation of actin filaments, essential for integrin-mediated adhesion, were examined. Modulation of CADM1 expression positively correlated with surface KIT levels and polymerisation of cortical F-actin in HMC-1 cells. It also influenced phosphotyrosine signalling and KIT tyrosine autophosphorylation. CADM1 accounted for 46% of surface KIT levels and 31% of F-actin in HMC-1 cells. CADM1 downregulation resulted in elongation of cortical actin filaments in both HMC-1 cells and human lung MCs and increased cell rigidity of HMC-1 cells. Collectively these data suggest that CADM1 is a key adhesion receptor, which regulates MC net adhesion, both directly through CADM1-dependent adhesion, and indirectly through the regulation of other adhesion receptors. The latter is likely to occur via docking of KIT and polymerisation of cortical F-actin. Here we propose a stepwise model of adhesion with CADM1 as a driving force for net MC adhesion. PMID:24465823

  14. Extracellular matrix from human umbilical cord-derived mesenchymal stem cells as a scaffold for peripheral nerve regeneration

    PubMed Central

    Xiao, Bo; Rao, Feng; Guo, Zhi-yuan; Sun, Xun; Wang, Yi-guo; Liu, Shu-yun; Wang, Ai-yuan; Guo, Quan-yi; Meng, Hao-ye; Zhao, Qing; Peng, Jiang; Wang, Yu; Lu, Shi-bi

    2016-01-01

    The extracellular matrix, which includes collagens, laminin, or fibronectin, plays an important role in peripheral nerve regeneration. Recently, a Schwann cell-derived extracellular matrix with classical biomaterial was used to mimic the neural niche. However, extensive clinical use of Schwann cells remains limited because of the limited origin, loss of an autologous nerve, and extended in vitro culture times. In the present study, human umbilical cord-derived mesenchymal stem cells (hUCMSCs), which are easily accessible and more proliferative than Schwann cells, were used to prepare an extracellular matrix. We identified the morphology and function of hUCMSCs and investigated their effect on peripheral nerve regeneration. Compared with a non-coated dish tissue culture, the hUCMSC-derived extracellular matrix enhanced Schwann cell proliferation, upregulated gene and protein expression levels of brain-derived neurotrophic factor, glial cell-derived neurotrophic factor, and vascular endothelial growth factor in Schwann cells, and enhanced neurite outgrowth from dorsal root ganglion neurons. These findings suggest that the hUCMSC-derived extracellular matrix promotes peripheral nerve repair and can be used as a basis for the rational design of engineered neural niches.

  15. Canine degenerative myelopathy: biochemical characterization of superoxide dismutase 1 in the first naturally occurring non-human amyotrophic lateral sclerosis model.

    PubMed

    Crisp, Matthew J; Beckett, Jeffrey; Coates, Joan R; Miller, Timothy M

    2013-10-01

    Mutations in canine superoxide dismutase 1 (SOD1) have recently been shown to cause canine degenerative myelopathy, a disabling neurodegenerative disorder affecting specific breeds of dogs characterized by progressive motor neuron loss and paralysis until death, or more common, euthanasia. This discovery makes canine degenerative myelopathy the first and only naturally occurring non-human model of amyotrophic lateral sclerosis (ALS), closely paralleling the clinical, pathological, and genetic presentation of its human counterpart, SOD1-mediated familial ALS. To further understand the biochemical role that canine SOD1 plays in this disease and how it may be similar to human SOD1, we characterized the only two SOD1 mutations described in affected dogs to date, E40K and T18S. We show that a detergent-insoluble species of mutant SOD1 is present in spinal cords of affected dogs that increases with disease progression. Our in vitro results indicate that both canine SOD1 mutants form enzymatically active dimers, arguing against a loss of function in affected homozygous animals. Further studies show that these mutants, like most human SOD1 mutants, have an increased propensity to form aggregates in cell culture, with 10-20% of cells possessing visible aggregates. Creation of the E40K mutation in human SOD1 recapitulates the normal enzymatic activity but not the aggregation propensity seen with the canine mutant. Our findings lend strong biochemical support to the toxic role of SOD1 in canine degenerative myelopathy and establish close parallels for the role mutant SOD1 plays in both canine and human disorders. PMID:23707216

  16. Human mesenchymal stem cells seeded on extracellular matrix-scaffold: viability and osteogenic potential.

    PubMed

    Penolazzi, Letizia; Mazzitelli, Stefania; Vecchiatini, Renata; Torreggiani, Elena; Lambertini, Elisabetta; Johnson, Scott; Badylak, Stephen F; Piva, Roberta; Nastruzzi, Claudio

    2012-02-01

    The development and the optimization of novel culture systems of mesenchymal osteoprogenitors are some of the most important challenges in the field of bone tissue engineering (TE). A new combination between cells and extracellular matrix (ECM)-scaffold, containing ECM has here been analyzed. As source for osteoprogenitors, mesenchymal stem cells obtained from human umbilical cord Wharton's Jelly (hWJMSCs), were used. As ECM-scaffold, a powder form of isolated and purified porcine urinary bladder matrix (pUBM), was employed. The goals of the current work were: (1) the characterization of the in vitro hWJMSCs behavior, in terms of viability, proliferation, and adhesion to ECM-scaffold; (2) the effectiveness of ECM-scaffold to induce/modulate the osteoblastic differentiation; and (3) the proposal for a possible application of cells/ECM-scaffold construct to the field of cell/TE. In this respect, the properties of the pUBM-scaffold in promoting and guiding the in vitro adhesion, proliferation, and three-dimensional colonization of hWJMSCs, without altering viability and morphological characteristics of the cells, are here described. Finally, we have also demonstrated that pUBM-scaffolds positively affect the expression of typical osteoblastic markers in hWJMSCs. PMID:21830215

  17. Enhancement of Tenogenic Differentiation of Human Adipose Stem Cells by Tendon-Derived Extracellular Matrix

    PubMed Central

    Yang, Guang; Rothrauff, Benjamin B.; Lin, Hang; Gottardi, Riccardo; Alexander, Peter G.; Tuan, Rocky S.

    2014-01-01

    Mesenchymal stem cells (MSCs) have gained increasing research interest for their potential in improving healing and regeneration of injured tendon tissues. Developing functional three-dimensional (3D) scaffolds to promote MSC proliferation and differentiation is a critical requirement in tendon tissue engineering. Tendon extracellular matrix has been shown to maintain the tenogenic potential of tendon stem cells and stimulate tenogenesis of human adipose stem cells (hASCs) in 2D culture. This study aims at characterizing the biological composition of urea-extracted fraction of tendon ECM (tECM) and its tenogenic effect on hASCs cultured in a 3D collagen scaffold under uniaxial tension. The tECM obtained was cell-free and rich in ECM proteins. hASCs seeded in tECM supplemented scaffold exhibited significantly increased proliferation and tenogenic differentiation. The presence of tECM also greatly suppressed the osteogenic differentiation of hASCs triggered by uniaxial tension. In addition, tECM-supplemented constructs displayed enhanced mechanical strength, accompanied by reduced expression and activity of MMPs in the seeded hASCs, indicating a regulatory activity of tECM in cell-mediated scaffold remodeling. These findings support the utility of tECM in creating bio-functional scaffolds for tendon tissue engineering. PMID:24044998

  18. Clinical Application of Human Urinary Extracellular Vesicles in Kidney and Urologic Diseases

    PubMed Central

    De Palma, Giuseppe; Sallustio, Fabio; Schena, Francesco Paolo

    2016-01-01

    Extracellular vesicles (EVs) have been isolated in different body fluids, including urine. The cargo of urinary EVs is composed of nucleic acids and proteins reflecting the physiological and possibly pathophysiological state of cells lining the nephron and the urinary tract. Urinary EVs have been confirmed to contain low amounts of various types of RNA that play a role in intercellular communication by transferring genetic information. This communication through EV RNAs includes both continuation of normal physiological processes and conditioning in disease mechanisms. Although proteins included in urinary EVs represent only 3% of the whole-urine proteome, urinary EVs can influence cells in the renal epithelia not only by delivering RNA cargo, but also by delivering a wide range of proteins. Since urine is a readily available biofluid, the discovery of EVs has opened a new field of biomarker research. The potential use of urinary EV RNAs and proteins as diagnostic biomarkers for various kidney and urologic diseases is currently being explored. Here, we review recent studies that deal in identifying biomarker candidates for human kidney and urologic diseases using urinary EVs and might help to understand the pathophysiology. PMID:27376269

  19. Extracellular DNA traps are associated with the pathogenesis of TRALI in humans and mice

    PubMed Central

    Thomas, Grace M.; Carbo, Carla; Curtis, Brian R.; Martinod, Kimberly; Mazo, Irina B.; Schatzberg, Daphne; Cifuni, Stephen M.; Fuchs, Tobias A.; von Andrian, Ulrich H.; Hartwig, John H.; Aster, Richard H.

    2012-01-01

    Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related death. The biologic processes contributing to TRALI are poorly understood. All blood products can cause TRALI, and no specific treatment is available. A “2-event model” has been proposed as the trigger. The first event may include surgery, trauma, or infection; the second involves the transfusion of antileukocyte antibodies or bioactive lipids within the blood product. Together, these events induce neutrophil activation in the lungs, causing endothelial damage and capillary leakage. Neutrophils, in response to pathogens or under stress, can release their chromatin coated with granule contents, thus forming neutrophil extracellular traps (NETs). Although protective against infection, these NETs are injurious to tissue. Here we show that NET biomarkers are present in TRALI patients' blood and that NETs are produced in vitro by primed human neutrophils when challenged with anti–HNA-3a antibodies previously implicated in TRALI. NETs are found in alveoli of mice experiencing antibody-mediated TRALI. DNase 1 inhalation prevents their alveolar accumulation and improves arterial oxygen saturation even when administered 90 minutes after TRALI onset. We suggest that NETs form in the lungs during TRALI, contribute to the disease process, and thus could be targeted to prevent or treat TRALI. PMID:22596262

  20. Extracellular vesicles are rapidly purified from human plasma by PRotein Organic Solvent PRecipitation (PROSPR)

    PubMed Central

    Gallart-Palau, Xavier; Serra, Aida; Wong, Andrew See Weng; Sandin, Sara; Lai, Mitchell K. P.; Chen, Christopher P.; Kon, Oi Lian; Sze, Siu Kwan

    2015-01-01

    Extracellular vesicles (EVs) such as exosomes and microvesicles mediate intercellular communication and regulate a diverse range of crucial biological processes. Host cells that are damaged, infected or transformed release biomarker-containing EVs into the peripheral circulation, where they can be readily accessed for use in diagnostic or prognostic testing. However, current methods of EV isolation from blood plasma are complex and often require relatively large sample volumes, hence are inefficient for widespread use in clinical settings. Here, we report a novel and inexpensive method of rapidly isolating EVs from small volumes of human blood plasma by PRotein Organic Solvent PRecipitation (PROSPR). PROSPR encompasses a rapid three-step protocol to remove soluble proteins from plasma via precipitation in cold acetone, leaving the lipid-encapsulated EVs behind in suspension. This generates higher purity EVs that can then be obtained from filtration or classical ultracentrifugation methods. We foresee that PROSPR-based purification of EVs will significantly accelerate the discovery of new disease biomarkers and the characterization of EVs with potential for clinical applications. PMID:26419333

  1. Extracellular Vesicles Derived from Osteogenically Induced Human Bone Marrow Mesenchymal Stem Cells Can Modulate Lineage Commitment

    PubMed Central

    Martins, Margarida; Ribeiro, Diana; Martins, Albino; Reis, Rui Luís; Neves, Nuno Meleiro

    2016-01-01

    Summary The effective osteogenic commitment of human bone marrow mesenchymal stem cells (hBMSCs) is critical for bone regenerative therapies. Extracellular vesicles (EVs) derived from hBMSCs have a regenerative potential that has been increasingly recognized. Herein, the osteoinductive potential of osteogenically induced hBMSC-EVs was examined. hBMSCs secreted negatively charged nanosized vesicles (∼35 nm) with EV-related surface markers. The yield of EVs over 7 days was dependent on an osteogenic stimulus (standard chemical cocktail or RUNX2 cationic-lipid transfection). These EVs were used to sequentially stimulate homotypic uncommitted cells during 7 days, matching the seeding density of EV parent cells, culture time, and stimuli. Osteogenically committed hBMSC-EVs induced an osteogenic phenotype characterized by marked early induction of BMP2, SP7, SPP1, BGLAP/IBSP, and alkaline phosphatase. Both EV groups outperformed the currently used osteoinductive strategies. These data show that naturally secreted EVs can guide the osteogenic commitment of hBMSCs in the absence of other chemical or genetic osteoinductors. PMID:26923821

  2. Biocompatibility of pure titanium modified by human endothelial cell-derived extracellular matrix

    NASA Astrophysics Data System (ADS)

    Xue, Xiaoqing; Wang, Jin; Zhu, Ying; Tu, Qiufen; Huang, Nan

    2010-04-01

    Extracellular matrix (ECM) used to modify biomaterial surface is a promising method for improving cardiovascular material hemocompatibility. In the present work, human umbilical vein endothelial cells (HUVECs) are cultured and native ECM is obtained on pure titanium surface. Fourier infrared spectrum (FTIR) test proves the existence of amide I and amide II band on the modified titanium surface. X-ray photoelectron spectroscopy (XPS) further confirms the chemical composition and binding types of the ECM proteins on the titanium substrate. The results of light microscopy and atomic force microscopy (AFM) exhibit the morphology of HUVEC derived ECM. There are higher water contact angles on the ECM modified samples. Furthermore, some ECM components, including fibronectin (FN), laminin (LN) and type IV collagen (IV-COL) are presented on ECM-covered titanium surface by immunofluorescence staining. The biological behavior of cultured HUVECs and adherent platelets on different samples are investigated by in vitro HUVECs culture and platelet adhesion. Cells exhibit better morphology and their proliferation ability greatly improve on the ECM-covered titanium. At the same time, the platelet adhesion and spreading are inhibited on ECM-covered titanium surface. These investigations demonstrate that ECM produced by HUVECs cannot only improve adhesion and proliferation ability of endothelial cell but also inhibit adhesion and activation of platelets. Thus, the approach described here may provide a basis for preparation of modified surface in cardiovascular implants application.

  3. Specific adherence of Borrelia burgdorferi extracellular vesicles to human endothelial cells in culture.

    PubMed Central

    Shoberg, R J; Thomas, D D

    1993-01-01

    Borrelia burgdorferi produces extracellular vesicles which contain some of the outer surface proteins of the bacterium (e.g., OspA and OspB). Borrelial vesicles, isolated by differential centrifugation and filtration, were tested for the ability to bind to cultured human umbilical vein endothelial (HUVE) cells in culture. The recently described lipoprotein OspD was expressed on vesicles. Vesicles exhibited differential expression of OspB and OspD in a relationship with passage number and medium serum supplement type, respectively. Qualitative immunoblotting analyses demonstrated dose-dependent, passage number-dependent adsorption of vesicles by HUVE cells. This adsorption was demonstrated to be dependent upon a borrelial component of the vesicle and not due to the presence of minor contamination with intact spirochetes. Quantitative experiments examining inhibition of B. burgdorferi-HUVE association as a function of prior vesicle-HUVE association demonstrated dependence upon (i) a borrelial component(s) in the vesicle, (ii) low passage number, and (iii) vesicle protein concentration. However, vesicle pretreatment of the HUVE cell monolayer was not requisite for this inhibition. Vesicles from highly passaged borrelias were noninhibitory for B. burgdorferi-HUVE cell association, regardless of the serum used to supplement the medium. The use of vesicles as a tool for studying B. burgdorferi pathogenesis and/or physiology is proposed. Images PMID:8359911

  4. Second harmonic generation microscopy analysis of extracellular matrix changes in human idiopathic pulmonary fibrosis.

    PubMed

    Tilbury, Karissa; Hocker, James; Wen, Bruce L; Sandbo, Nathan; Singh, Vikas; Campagnola, Paul J

    2014-08-01

    Patients with idiopathic fibrosis (IPF) have poor long-term survival as there are limited diagnostic/prognostic tools or successful therapies. Remodeling of the extracellular matrix (ECM) has been implicated in IPF progression; however, the structural consequences on the collagen architecture have not received considerable attention. Here, we demonstrate that second harmonic generation (SHG) and multiphoton fluorescence microscopy can quantitatively differentiate normal and IPF human tissues. For SHG analysis, we developed a classifier based on wavelet transforms, principle component analysis, and a K-nearest-neighbor algorithm to classify the specific alterations of the collagen structure observed in IPF tissues. The resulting ROC curves obtained by varying the numbers of principal components and nearest neighbors yielded accuracies of >95%. In contrast, simpler metrics based on SHG intensity and collagen coverage in the image provided little or no discrimination. We also characterized the change in the elastin/collagen balance by simultaneously measuring the elastin autofluorescence and SHG intensities and found that the IPF tissues were less elastic relative to collagen. This is consistent with known mechanical consequences of the disease. Understanding ECM remodeling in IPF via nonlinear optical microscopy may enhance our ability to differentiate patients with rapid and slow progression and, thus, provide better prognostic information. PMID:25134793

  5. Random sequential adsorption of human adenovirus 2 onto polyvinylidene fluoride surface influenced by extracellular polymeric substances.

    PubMed

    Lu, Ruiqing; Li, Qi; Nguyen, Thanh H

    2016-03-15

    Virus removal by membrane bioreactors depends on virus-membrane and virus-foulant interactions. The adsorption of human adenovirus 2 (HAdV-2) on polyvinylidene fluoride (PVDF) membrane and a major membrane foulant, extracellular polymeric substances (EPS), were measured in a quartz crystal microbalance. In 3-100mM CaCl2 solutions, irreversible adsorption of HAdV-2 was observed on both pristine and EPS-fouled PVDF surfaces. The HAdV-2 adsorption kinetics was successfully fitted with the random sequential adsorption (RSA) model. The applicability of the RSA model for HAdV-2 adsorption is confirmed by comparing the two fitting parameters, adsorption rate constant k(a) and area occupied by each adsorbed HAdV-2 particle a, with experimentally measured parameters. A linear correlation between the fitting parameter k(a) and the measured attachment efficiency was found, suggesting that the RSA model correctly describes the interaction forces dominating the HAdV-2 adsorption. By comparing the fitting parameter d(ads) with the hydrodynamic diameter of HAdV-2, we conclude that virus-virus and virus-surface interactions determine the area occupied by each adsorbed HAdV-2 particle, and thus influence the adsorption capacity. These results provide insights into virus retention and will benefit improving virus removal in membrane filtration. PMID:26720514

  6. Isolation of human salivary extracellular vesicles by iodixanol density gradient ultracentrifugation and their characterizations

    PubMed Central

    Iwai, Kazuya; Minamisawa, Tamiko; Suga, Kanako; Yajima, Yasutomo; Shiba, Kiyotaka

    2016-01-01

    Diagnostic methods that focus on the extracellular vesicles (EVs) present in saliva have been attracting great attention because of their non-invasiveness. EVs contain biomolecules such as proteins, messenger RNA (mRNA) and microRNA (miRNA), which originate from cells that release EVs, making them an ideal source for liquid biopsy. Although there have been many reports on density-based fractionation of EVs from blood and urine, the number of reports on EVs from saliva has been limited, most probably because of the difficulties in separating EVs from viscous saliva using density gradient centrifugation. This article establishes a protocol for the isolation of EVs from human saliva using density gradient centrifugation. The fractionated salivary EVs were characterized by atomic force microscopy, western blot and reverse transcription polymerase chain reaction. The results indicate that salivary EVs have a smaller diameter (47.8±12.3 nm) and higher density (1.11 g/ml) than EVs isolated from conditioned cell media (74.0±23.5 nm and 1.06 g/ml, respectively). Additionally, to improve the throughput of density-based fractionation of EVs, the original protocol was further modified by using a fixed angle rotor instead of a swinging rotor. It was also confirmed that several miRNAs were expressed strongly in the EV-marker-expressing fractions. PMID:27193612

  7. Isolation of human salivary extracellular vesicles by iodixanol density gradient ultracentrifugation and their characterizations.

    PubMed

    Iwai, Kazuya; Minamisawa, Tamiko; Suga, Kanako; Yajima, Yasutomo; Shiba, Kiyotaka

    2016-01-01

    Diagnostic methods that focus on the extracellular vesicles (EVs) present in saliva have been attracting great attention because of their non-invasiveness. EVs contain biomolecules such as proteins, messenger RNA (mRNA) and microRNA (miRNA), which originate from cells that release EVs, making them an ideal source for liquid biopsy. Although there have been many reports on density-based fractionation of EVs from blood and urine, the number of reports on EVs from saliva has been limited, most probably because of the difficulties in separating EVs from viscous saliva using density gradient centrifugation. This article establishes a protocol for the isolation of EVs from human saliva using density gradient centrifugation. The fractionated salivary EVs were characterized by atomic force microscopy, western blot and reverse transcription polymerase chain reaction. The results indicate that salivary EVs have a smaller diameter (47.8±12.3 nm) and higher density (1.11 g/ml) than EVs isolated from conditioned cell media (74.0±23.5 nm and 1.06 g/ml, respectively). Additionally, to improve the throughput of density-based fractionation of EVs, the original protocol was further modified by using a fixed angle rotor instead of a swinging rotor. It was also confirmed that several miRNAs were expressed strongly in the EV-marker-expressing fractions. PMID:27193612

  8. Second harmonic generation microscopy analysis of extracellular matrix changes in human idiopathic pulmonary fibrosis

    PubMed Central

    Tilbury, Karissa; Hocker, James; Wen, Bruce L.; Sandbo, Nathan; Singh, Vikas; Campagnola, Paul J.

    2014-01-01

    Abstract. Patients with idiopathic fibrosis (IPF) have poor long-term survival as there are limited diagnostic/prognostic tools or successful therapies. Remodeling of the extracellular matrix (ECM) has been implicated in IPF progression; however, the structural consequences on the collagen architecture have not received considerable attention. Here, we demonstrate that second harmonic generation (SHG) and multiphoton fluorescence microscopy can quantitatively differentiate normal and IPF human tissues. For SHG analysis, we developed a classifier based on wavelet transforms, principle component analysis, and a K-nearest-neighbor algorithm to classify the specific alterations of the collagen structure observed in IPF tissues. The resulting ROC curves obtained by varying the numbers of principal components and nearest neighbors yielded accuracies of >95%. In contrast, simpler metrics based on SHG intensity and collagen coverage in the image provided little or no discrimination. We also characterized the change in the elastin/collagen balance by simultaneously measuring the elastin autofluorescence and SHG intensities and found that the IPF tissues were less elastic relative to collagen. This is consistent with known mechanical consequences of the disease. Understanding ECM remodeling in IPF via nonlinear optical microscopy may enhance our ability to differentiate patients with rapid and slow progression and, thus, provide better prognostic information. PMID:25134793

  9. Extracellular matrix signatures of human mammary carcinoma identify novel metastasis promoters

    PubMed Central

    Naba, Alexandra; Clauser, Karl R; Lamar, John M; Carr, Steven A; Hynes, Richard O

    2014-01-01

    The extracellular matrix (ECM) is a major component of tumors and a significant contributor to cancer progression. In this study, we use proteomics to investigate the ECM of human mammary carcinoma xenografts and show that primary tumors of differing metastatic potential differ in ECM composition. Both tumor cells and stromal cells contribute to the tumor matrix and tumors of differing metastatic ability differ in both tumor- and stroma-derived ECM components. We define ECM signatures of poorly and highly metastatic mammary carcinomas and these signatures reveal up-regulation of signaling pathways including TGFβ and VEGF. We further demonstrate that several proteins characteristic of highly metastatic tumors (LTBP3, SNED1, EGLN1, and S100A2) play causal roles in metastasis, albeit at different steps. Finally we show that high expression of LTBP3 and SNED1 correlates with poor outcome for ER−/PR−breast cancer patients. This study thus identifies novel biomarkers that may serve as prognostic and diagnostic tools. DOI: http://dx.doi.org/10.7554/eLife.01308.001 PMID:24618895

  10. Dissociations in the Effects of β2-Adrenergic Receptor Agonists on cAMP Formation and Superoxide Production in Human Neutrophils: Support for the Concept of Functional Selectivity

    PubMed Central

    Brunskole Hummel, Irena; Reinartz, Michael T.; Kälble, Solveig; Burhenne, Heike; Schwede, Frank; Buschauer, Armin; Seifert, Roland

    2013-01-01

    In neutrophils, activation of the β2-adrenergic receptor (β2AR), a Gs-coupled receptor, inhibits inflammatory responses, which could be therapeutically exploited. The aim of this study was to evaluate the effects of various β2AR ligands on adenosine-3′,5′-cyclic monophosphate (cAMP) accumulation and N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP)-induced superoxide anion (O2•−) production in human neutrophils and to probe the concept of ligand-specific receptor conformations (also referred to as functional selectivity or biased signaling) in a native cell system. This is an important question because so far, evidence for functional selectivity has been predominantly obtained with recombinant systems, due to the inherent difficulties to genetically manipulate human native cells. cAMP concentration was determined by HPLC/tandem mass spectrometry, and O2•− formation was assessed by superoxide dismutase-inhibitable reduction of ferricytochrome c. β2AR agonists were generally more potent in inhibiting fMLP-induced O2•− production than in stimulating cAMP accumulation. (−)-Ephedrine and dichloroisoproterenol were devoid of any agonistic activity in the cAMP assay, but partially inhibited fMLP-induced O2•− production. Moreover, (−)-adrenaline was equi-efficacious in both assays whereas the efficacy of salbutamol was more than two-fold higher in the O2•− assay. Functional selectivity was visualized by deviations of ligand potencies and efficacies from linear correlations for various parameters. We obtained no evidence for involvement of protein kinase A in the inhibition of fMLP-induced O2•− production after β2AR-stimulation although cAMP-increasing substances inhibited O2•− production. Taken together, our data corroborate the concept of ligand-specific receptor conformations with unique signaling capabilities in native human cells and suggest that the β2AR inhibits O2•− production in a cAMP-independent manner. PMID

  11. Wnt interaction and extracellular release of prominin-1/CD133 in human malignant melanoma cells

    SciTech Connect

    Rappa, Germana; Mercapide, Javier; Anzanello, Fabio; Le, Thuc T.; Johlfs, Mary G.; Fiscus, Ronald R.; Wilsch-Bräuninger, Michaela; Corbeil, Denis; Lorico, Aurelio

    2013-04-01

    Prominin-1 (CD133) is the first identified gene of a novel class of pentaspan membrane glycoproteins. It is expressed by various epithelial and non-epithelial cells, and notably by stem and cancer stem cells. In non-cancerous cells such as neuro-epithelial and hematopoietic stem cells, prominin-1 is selectively concentrated in plasma membrane protrusions, and released into the extracellular milieu in association with small vesicles. Previously, we demonstrated that prominin-1 contributes to melanoma cells pro-metastatic properties and suggested that it may constitute a molecular target to prevent prominin-1-expressing melanomas from colonizing and growing in lymph nodes and distant organs. Here, we report that three distinct pools of prominin-1 co-exist in cultures of human FEMX-I metastatic melanoma. Morphologically, in addition to the plasma membrane localization, prominin-1 is found within the intracellular compartments, (e.g., Golgi apparatus) and in association with extracellular membrane vesicles. The latter prominin-1–positive structures appeared in three sizes (small, ≤40 nm; intermediates ∼40–80 nm, and large, >80 nm). Functionally, the down-regulation of prominin-1 in FEMX-I cells resulted in a significant reduction of number of lipid droplets as observed by coherent anti-Stokes Raman scattering image analysis and Oil red O staining, and surprisingly in a decrease in the nuclear localization of beta-catenin, a surrogate marker of Wnt activation. Moreover, the T-cell factor/lymphoid enhancer factor (TCF/LEF) promoter activity was 2 to 4 times higher in parental than in prominin-1-knockdown cells. Collectively, our results point to Wnt signaling and/or release of prominin-1–containing membrane vesicles as mediators of the pro-metastatic activity of prominin-1 in FEMX-I melanoma. - Highlights: ► First report of release of prominin-1–containing microvesicles from cancer cells. ► Pro-metastatic role of prominin-1–containing microvesicles in

  12. Expression of functional NK1 receptors in human alveolar macrophages: superoxide anion production, cytokine release and involvement of NF-kappaB pathway.

    PubMed

    Bardelli, Claudio; Gunella, Gabriele; Varsaldi, Federica; Balbo, Pietro; Del Boca, Elisa; Bernardone, Ilaria Seren; Amoruso, Angela; Brunelleschi, Sandra

    2005-06-01

    1 Substance P (SP) is deeply involved in lung pathophysiology and plays a key role in the modulation of inflammatory-immune processes. We previously demonstrated that SP activates guinea-pig alveolar macrophages (AMs) and human monocytes, but a careful examination of its effects on human AMs is still scarce. 2 This study was undertaken to establish the role of SP in human AM isolated from healthy smokers and non-smokers, by evaluating the presence of tachykinin NK(1) receptors (NK-1R) and SP's ability to induce superoxide anion (O(2)(-)) production and cytokine release, as well as activation of the nuclear factor-kappaB (NF-kappaB) pathway. 3 By Western blot analysis and immunofluorescence, we demonstrate that authentic NK-1R are present on human AMs, a three-fold enhanced expression being observed in healthy smokers. These NK-1R are functional, as SP and NK(1) agonists dose-dependently induce O(2)(-) production and cytokine release. In AMs from healthy smokers, SP evokes an enhanced respiratory burst and a significantly increased release of tumor necrosis factor-alpha as compared to healthy non-smokers, but has inconsistent effects on IL-10 release. The NK(1) selective antagonist CP 96,345 ((2S,3S)-cis-2-diphenylmethyl-N[(2-methoxyphenyl)-methyl]-1-azabicyclo-octan-3-amine)) competitively antagonized SP-induced effects. 4 SP activates the transcription factor NF-kappaB, a three-fold increased nuclear translocation being observed in AMs from healthy smokers. This effect is receptor-mediated, as it is reproduced by the NK(1) selective agonist [Sar(9)Met(O(2))(11)]SP and reverted by CP 96,345. 5 These results clearly indicate that human AMs possess functional NK-1R on their surface, which are upregulated in healthy smokers, providing new insights on the mechanisms involved in tobacco smoke toxicity. PMID:15778738

  13. Expression of extracellular calcium-sensing receptor in human osteoblastic MG-63 cell line

    NASA Technical Reports Server (NTRS)

    Yamaguchi, T.; Chattopadhyay, N.; Kifor, O.; Ye, C.; Vassilev, P. M.; Sanders, J. L.; Brown, E. M.

    2001-01-01

    We have previously shown the expression of the extracellular calcium (Ca2+o)-sensing receptor (CaR) in osteoblast-like cell lines, and others have documented its expression in sections of murine, bovine, and rat bone. The existence of the CaR in osteoblasts remains controversial, however, since some studies have failed to document its expression in the same osteoblast-like cell lines. The goals of the present study were twofold. 1) We sought to determine whether the CaR is expressed in the human osteoblast-like cell line, MG-63, which has recently been reported by others not to express this receptor. 2) We investigated whether the CaR, if present in MG-63 cells, is functionally active, since most previous studies have not proven the role of the CaR in mediating known actions of Ca2+o on osteoblast-like cells. We used immunocytochemistry and Western blotting with the specific, affinity-purified anti-CaR antiserum 4637 as well as Northern blot analysis and RT-PCR using a riboprobe and PCR primers specific for the human CaR, respectively, to show readily detectable CaR protein and mRNA expression in MG-63 cells. Finally, we employed the patch-clamp technique to show that an elevation in Ca2+o as well as the specific, allosteric CaR activator NPS R-467 (0.5 microM), but not its less active stereoisomer NPS S-467 (0.5 microM), activate an outward K+ channel in MG-63 cells, strongly suggesting that the CaR in MG-63 cells is not only expressed but is functionally active.

  14. Extracellular matrix receptors and the differentiation of human megakaryocytes in vitro.

    PubMed

    Molla, A; Mossuz, P; Berthier, R

    1999-03-01

    We investigated the expression and functions of extracellular matrix receptors (or integrins) in the course of the differentiation of human megakaryocytes (Mks) leading to the formation of platelets. Integrins beta1 or Very Late Antigens (VLA) are specialized transmembrane receptors allowing the attachment of the cells to collagen (VLA-2), fibronectin (VLA-4 and -5) and laminin (VLA-6). A proportion of committed megakaryocytic progenitor cells (CFU-MK) adhere to fibronectin but not to collagen or laminin. The early immature Mks are retained on fibronectin (30%) and laminin (12%) but not on collagen whereas large mature Mks are still adherent to fibronectin and laminin and also acquired the capacity to adhere to collagen. The expression of the different VLA in the maturation of Mks correlates well with their adhesive properties. Hence, VLA-2 is not expressed on immature Mks but is present on the mature polyploid cells. VLA-4 is detected only on immature Mks which do not seem to bear VLA-5, while this last integrin appears on late Mks. VLA-6 showed a broad distribution from the early to late stages of Mks differentiation. Integrins beta3 of the cytoadhesin family are represented by alphaIIb beta3 that is the receptor for fibrinogen and alphaV beta3 which mediates adhesion to vitronectin. AlphaIIb beta3 is present on the CFU-MK and highly expressed throughout the Mks maturation stages while alphaV beta3 expression is much lower and seems to be detected only on the late Mks. The regulation of the expression of these receptors by cytokines and their respective roles in the maturation of Mks and the final production of platelets, are discussed. The development of efficient culture systems of human Mks in the presence of the recently cloned thrombopoietin will undoubtedly help to shed more light on the molecular mechanisms of their interactions via integrins with the BM microenvironment. PMID:10194117

  15. Ethylmercury and Hg2+ induce the formation of neutrophil extracellular traps (NETs) by human neutrophil granulocytes.

    PubMed

    Haase, Hajo; Hebel, Silke; Engelhardt, Gabriela; Rink, Lothar

    2016-03-01

    Humans are exposed to different mercurial compounds from various sources, most frequently from dental fillings, preservatives in vaccines, or consumption of fish. Among other toxic effects, these substances interact with the immune system. In high doses, mercurials are immunosuppressive. However, lower doses of some mercurials stimulate the immune system, inducing different forms of autoimmunity, autoantibodies, and glomerulonephritis in rodents. Furthermore, some studies suggest a connection between mercury exposure and the occurrence of autoantibodies against nuclear components and granulocyte cytoplasmic proteins in humans. Still, the underlying mechanisms need to be clarified. The present study investigates the formation of neutrophil extracellular traps (NETs) in response to thimerosal and its metabolites ethyl mercury (EtHg), thiosalicylic acid, and mercuric ions (Hg(2+)). Only EtHg and Hg(2+) triggered NETosis. It was independent of PKC, ERK1/2, p38, and zinc signals and not affected by the NADPH oxidase inhibitor DPI. Instead, EtHg and Hg(2+) triggered NADPH oxidase-independent production of ROS, which are likely to be involved in mercurial-induced NET formation. This finding might help understanding the autoimmune potential of mercurial compounds. Some diseases, to which a connection with mercurials has been shown, such as Wegener's granulomatosis and systemic lupus erythematosus, are characterized by high prevalence of autoantibodies against neutrophil-specific auto-antigens. Externalization in the form of NETs may be a source for exposure to these self-antigens. In genetically susceptible individuals, this could be one step in the series of events leading to autoimmunity. PMID:25701957

  16. Lipid peroxidation as pathway of aluminium cytotoxicity in human skin fibroblast cultures: prevention by superoxide dismutase+catalase and vitamins E and C.

    PubMed

    Anane, R; Creppy, E E

    2001-09-01

    Lipid peroxidation is one of the main manifestations of oxidative damage and has been found to play an important role in the toxicity and carcinogenicity of many xenobiotics. In the present study, we investigated the possible induction of lipid peroxidation by aluminium in human foreskin fibroblast cultures by assaying the malondialdehyde (MDA) produced inside the cells. The MDA-thiobarbituric acid (TBA) adduct was assayed by HPLC using fluorometric quantification after extraction in n-butanol. Lactate dehydrogenase (LDH) release was used as a marker of aluminium toxicity. MDA production was significantly increased after 24 h incubation with aluminium and paralleled LDH release. Superoxide dismutase (SOD)+catalase and vitamins C and E added in the culture medium as oxygen radical and free radical scavengers were efficient in preventing MDA production by aluminium, indicating that oxidative processes are one of the main pathways whereby this metal induces cytotoxicity. The latter is also largely prevented, thus confirming the link between oxidative stress induced by aluminium and its cytotoxicity in human skin fibroblasts. PMID:11776410

  17. Monocytes increase human cardiac myofibroblast-mediated extracellular matrix remodeling through TGF-β1.

    PubMed

    Mewhort, Holly E M; Lipon, Brodie D; Svystonyuk, Daniyil A; Teng, Guoqi; Guzzardi, David G; Silva, Claudia; Yong, V Wee; Fedak, Paul W M

    2016-03-15

    Following myocardial infarction (MI), cardiac myofibroblasts remodel the extracellular matrix (ECM), preventing mechanical complications. However, prolonged myofibroblast activity leads to dysregulation of the ECM, maladaptive remodeling, fibrosis, and heart failure (HF). Chronic inflammation is believed to drive persistent myofibroblast activity; however, the mechanisms are unclear. We assessed the influence of peripheral blood monocytes on human cardiac myofibroblast activity in a three-dimensional (3D) ECM microenvironment. Human cardiac myofibroblasts isolated from surgical biopsies of the right atrium and left ventricle were seeded into 3D collagen matrices. Peripheral blood monocytes were isolated from healthy human donors and cocultured with myofibroblasts. Monocytes increased myofibroblast activity measured by collagen gel contraction (baseline: 57.6 ± 5.9% vs. coculture: 65.2 ± 7.1% contraction; P < 0.01) and increased local ECM remodeling quantified by confocal microscopy. Under coculture conditions that allow indirect cellular interaction via paracrine factors but prevent direct cell-cell contact, monocytes had minimal effects on myofibroblast activity (17.9 ± 11.1% vs. 6.4 ± 7.0% increase, respectively; P < 0.01). When cells were cultured under direct contact conditions, multiplex analysis of the coculture media revealed an increase in the paracrine factors TGF-β1 and matrix metalloproteinase 9 compared with baseline (122.9 ± 10.1 pg/ml and 3,496.0 ± 190.4 pg/ml, respectively, vs. 21.5 ± 16.3 pg/ml and 183.3 ± 43.9 pg/ml; P < 0.001). TGF-β blockade abolished the monocyte-induced increase in cardiac myofibroblast activity. These data suggest that direct cell-cell interaction between monocytes and cardiac myofibroblasts stimulates TGF-β-mediated myofibroblast activity and increases remodeling of local matrix. Peripheral blood monocyte interaction with human cardiac myofibroblasts stimulates myofibroblast activity through release of TGF-β1

  18. Expression of extracellular calcium (Ca2+o)-sensing receptor in human peripheral blood monocytes

    NASA Technical Reports Server (NTRS)

    Yamaguchi, T.; Olozak, I.; Chattopadhyay, N.; Butters, R. R.; Kifor, O.; Scadden, D. T.; Brown, E. M.; O'Malley, B. W. (Principal Investigator)

    1998-01-01

    The calcium-sensing receptor (CaR) is a G protein-coupled receptor playing key roles in extracellular calcium ion (Ca2+o) homeostasis in parathyroid gland and kidney. Macrophage-like mononuclear cells appear at sites of osteoclastic bone resorption during bone turnover and may play a role in the "reversal" phase of skeletal remodeling that follows osteoclastic resorption and precedes osteoblastic bone formation. Bone resorption produces substantial local increases in Ca2+o that could provide a signal for such mononuclear cells present locally within the bone marrow microenvironment. Indeed, previous studies by other investigators have shown that raising Ca2+o either in vivo or in vitro stimulated the release of interleukin-6 (IL-6) from human peripheral blood monocytes, suggesting that these cells express a Ca2+o-sensing mechanism. In these earlier studies, however, the use of reverse transcription-polymerase chain reaction (RT-PCR) failed to detect transcripts for the CaR previously cloned from parathyroid and kidney in peripheral blood monocytes. Since we recently found that non-specific esterase-positive, putative monocytes isolated from murine bone marrow express the CaR, we reevaluated the expression of this receptor in human peripheral blood monocytes. Immunocytochemistry, flow cytometry, and Western blot analysis, performed using a polyclonal antiserum specific for the CaR, detected CaR protein in human monocytes. In addition, the use of RT-PCR with CaR-specific primers, followed by nucleotide sequencing of the amplified products, identified CaR transcripts in the cells. Therefore, taken together, our data show that human peripheral blood monocytes possess both CaR protein and mRNA very similar if not identical to those expressed in parathyroid and kidney that could mediate the previously described, direct effects of Ca2+o on these cells. Furthermore, since mononuclear cells isolated from bone marrow also express the CaR, the latter might play some role in

  19. Human resistin promotes neutrophil proinflammatory activation and neutrophil extracellular trap formation and increases severity of acute lung injury.

    PubMed

    Jiang, Shaoning; Park, Dae Won; Tadie, Jean-Marc; Gregoire, Murielle; Deshane, Jessy; Pittet, Jean Francois; Abraham, Edward; Zmijewski, Jaroslaw W

    2014-05-15

    Although resistin was recently found to modulate insulin resistance in preclinical models of type II diabetes and obesity, recent studies also suggested that resistin has proinflammatory properties. We examined whether the human-specific variant of resistin affects neutrophil activation and the severity of LPS-induced acute lung injury. Because human and mouse resistin have distinct patterns of tissue distribution, experiments were performed using humanized resistin mice that exclusively express human resistin (hRTN(+/-)(/-)) but are deficient in mouse resistin. Enhanced production of TNF-α or MIP-2 was found in LPS-treated hRtn(+/-/-) neutrophils compared with control Rtn(-/-/-) neutrophils. Expression of human resistin inhibited the activation of AMP-activated protein kinase, a major sensor and regulator of cellular bioenergetics that also is implicated in inhibiting inflammatory activity of neutrophils and macrophages. In addition to the ability of resistin to sensitize neutrophils to LPS stimulation, human resistin enhanced neutrophil extracellular trap formation. In LPS-induced acute lung injury, humanized resistin mice demonstrated enhanced production of proinflammatory cytokines, more severe pulmonary edema, increased neutrophil extracellular trap formation, and elevated concentration of the alarmins HMGB1 and histone 3 in the lungs. Our results suggest that human resistin may play an important contributory role in enhancing TLR4-induced inflammatory responses, and it may be a target for future therapies aimed at reducing the severity of acute lung injury and other inflammatory situations in which neutrophils play a major role. PMID:24719460

  20. Cadmium activates extracellular signal-regulated kinase 5 in HK-2 human renal proximal tubular cells

    SciTech Connect

    Kondo, Mio; Inamura, Hisako; Matsumura, Ken-ichi; Matsuoka, Masato

    2012-05-11

    Highlights: Black-Right-Pointing-Pointer Cadmium exposure induces ERK5 phosphorylation in HK-2 renal proximal tubular cells. Black-Right-Pointing-Pointer BIX02189 treatment suppresses cadmium-induced ERK5 but not ERK1/2 phosphorylation. Black-Right-Pointing-Pointer BIX02189 treatment suppresses cadmium-induced CREB and c-Fos phosphorylation. Black-Right-Pointing-Pointer ERK5 activation by cadmium exposure may play an anti-apoptotic role in HK-2 cells. -- Abstract: We examined the effects of cadmium chloride (CdCl{sub 2}) exposure on the phosphorylation and functionality of extracellular signal-regulated kinase 5 (ERK5), a recently identified member of the mitogen-activated protein kinase (MAPK) family, in HK-2 human renal proximal tubular cells. Following exposure to CdCl{sub 2}, ERK5 phosphorylation increased markedly, but the level of total ERK5 was unchanged. ERK5 phosphorylation following CdCl{sub 2} exposure was rapid and transient, similar to the time course of ERK1/2 phosphorylation. Treatment of HK-2 cells with the MAPK/ERK kinase 5 inhibitor, BIX02189, suppressed CdCl{sub 2}-induced ERK5 but not ERK1/2 phosphorylation. The CdCl{sub 2}-induced increase of phosphorylated cAMP response element-binding protein (CREB) and activating transcription factor-1 (ATF-1), as well as the accumulation of mobility-shifted c-Fos protein, were suppressed by BIX02189 treatment. Furthermore, BIX02189 treatment enhanced cleavage of poly(ADP-ribose) polymerase and increased the level of cytoplasmic nucleosomes in HK-2 cells exposed to CdCl{sub 2}. These findings suggest that ERK5 pathway activation by CdCl{sub 2} exposure might induce the phosphorylation of cell survival-transcription factors, such as CREB, ATF-1, and c-Fos, and may exert a partial anti-apoptotic role in HK-2 cells.

  1. Handling and storage of human body fluids for analysis of extracellular vesicles

    PubMed Central

    Yuana, Yuana; Böing, Anita N.; Grootemaat, Anita E.; van der Pol, Edwin; Hau, Chi M.; Cizmar, Petr; Buhr, Egbert; Sturk, Auguste; Nieuwland, Rienk

    2015-01-01

    Because procedures of handling and storage of body fluids affect numbers and composition of extracellular vesicles (EVs), standardization is important to ensure reliable and comparable measurements of EVs in a clinical environment. We aimed to develop standard protocols for handling and storage of human body fluids for EV analysis. Conditions such as centrifugation, single freeze–thaw cycle, effect of time delay between blood collection and plasma preparation and storage were investigated. Plasma is the most commonly studied body fluid in EV research. We mainly focused on EVs originating from platelets and erythrocytes and investigated the behaviour of these 2 types of EVs independently as well as in plasma samples of healthy subjects. EVs in urine and saliva were also studied for comparison. All samples were analysed simultaneously before and after freeze–thawing by resistive pulse sensing, nanoparticle tracking analysis, conventional flow cytometry (FCM) and transmission (scanning) electron microscopy. Our main finding is that the effect of centrifugation markedly depends on the cellular origin of EVs. Whereas erythrocyte EVs remain present as single EVs after centrifugation, platelet EVs form aggregates, which affect their measured concentration in plasma. Single erythrocyte and platelet EVs are present mainly in the range of 100–200 nm, far below the lower limit of what can be measured by conventional FCM. Furthermore, the effects of single freeze–thaw cycle, time delay between blood collection and plasma preparation up to 1 hour and storage up to 1 year are insignificant (p>0.05) on the measured concentration and diameter of EVs from erythrocyte and platelet concentrates and EVs in plasma, urine and saliva. In conclusion, in standard protocols for EV studies, centrifugation to isolate EVs from collected body fluids should be avoided. Freezing and storage of collected body fluids, albeit their insignificant effects, should be performed identically for

  2. Extracellular matrix remodeling and its contribution to protective adaptation following lengthening contractions in human muscle.

    PubMed

    Hyldahl, Robert D; Nelson, Brad; Xin, Ling; Welling, Tyson; Groscost, Logan; Hubal, Monica J; Chipkin, Stuart; Clarkson, Priscilla M; Parcell, Allen C

    2015-07-01

    This study determined the contribution of extracellular matrix (ECM) remodeling to the protective adaptation of human skeletal muscle known as the repeated-bout effect (RBE). Muscle biopsies were obtained 3 hours, 2 days, and 27 days following an initial bout (B1) of lengthening contractions (LCs) and 2 days following a repeated bout (B2) in 2 separate studies. Biopsies from the nonexercised legs served as controls. In the first study, global transcriptomic analysis indicated widespread changes in ECM structural, deadhesive, and signaling transcripts, 3 hours following LC. To determine if ECM remodeling is involved in the RBE, we conducted a second study by use of a repeated-bout paradigm. TNC immunoreactivity increased 10.8-fold following B1, was attenuated following B2, and positively correlated with LC-induced strength loss (r(2) = 0.45; P = 0.009). Expression of collagen I, III, and IV (COL1A1, COL3A1, COL4A1) transcripts was unchanged early but increased 5.7 ± 2.5-, 3.2 ± 0.9-, and 2.1 ± 0.4-fold (P < 0.05), respectively, 27 days post-B1 and were unaffected by B2. Likewise, TGF-β signaling demonstrated a delayed response following LC. Satellite cell content increased 80% (P < 0.05) 2 days post-B1 (P < 0.05), remained elevated 27 days post-B1, and was unaffected by B2. Collectively, the data suggest sequential ECM remodeling characterized by early deadhesion and delayed reconstructive activity that appear to contribute to the RBE. PMID:25808538

  3. Regulation of human mesenchymal stem cells differentiation into chondrocytes in extracellular matrix-based hydrogel scaffolds.

    PubMed

    Du, Mingchun; Liang, Hui; Mou, Chenchen; Li, Xiaoran; Sun, Jie; Zhuang, Yan; Xiao, Zhifeng; Chen, Bing; Dai, Jianwu

    2014-02-01

    To induce human mesenchymal stem cells (hMSCs) to differentiate into chondrocytes in three-dimensional (3D) microenvironments, we developed porous hydrogel scaffolds using the cartilage extracellular matrix (ECM) components of chondroitin sulfate (CS) and collagen (COL). The turbidity and viscosity experiments indicated hydrogel could form through pH-triggered co-precipitation when pH=2-3. Enzyme-linked immunosorbent assay (ELISA) confirmed the hydrogel scaffolds could controllably release growth factors as envisaged. Transforming growth factor-β (TGF-β) was released to stimulate hMSCs differentiation into chondrocytes; and then collagen binding domain-basic fibroblast growth factor (CBD-bFGF) was released to improve the differentiation and preserve the chondrocyte phenotype. In in vitro cell culture experiments, the differentiation processes were compared in different microenvironments: 2D culture in culture plate as control, 3D culture in the fabricated scaffolds without growth factors (CC), the samples with CBD-bFGF (CC-C), the samples with TGF-β (CC-T), the samples with CBD-bFGF/TGF-β (CC-CT). Real-time polymerase chain reaction (RT-PCR) revealed the hMSC marker genes of CD44 and CD105 decreased; at the same time the chondrocyte marker genes of collagen type II and aggrecan increased, especially in the CC-CT sample. Immunostaining results further confirmed the hMSC marker protein of CD 44 disappeared and the chondrocyte marker protein of collagen type II emerged over time in the CC-CT sample. These results imply the ECM-based hydrogel scaffolds with growth factors can supply suitable 3D cell niches for hMSCs differentiation into chondrocytes and the differentiation process can be regulated by the controllably released growth factors. PMID:24231133

  4. Silicon-based quantum dots induce inflammation in human lung cells and disrupt extracellular matrix homeostasis.

    PubMed

    Stan, Miruna-Silvia; Sima, Cornelia; Cinteza, Ludmila Otilia; Dinischiotu, Anca

    2015-08-01

    Quantum dots (QDs) are nanocrystalline semiconductor materials that have been tested for biological applications such as cancer therapy, cellular imaging and drug delivery, despite the serious lack of information of their effects on mammalian cells. The present study aimed to evaluate the potential of Si/SiO2 QDs to induce an inflammatory response in MRC-5 human lung fibroblasts. Cells were exposed to different concentrations of Si/SiO2 QDs (25-200 μg·mL(-1)) for 24, 48, 72 and 96 h. The results obtained showed that uptake of QDs was dependent on biocorona formation and the stability of nanoparticles in various biological media (minimum essential medium without or with 10% fetal bovine serum). The cell membrane damage indicated by the increase in lactate dehydrogenase release after exposure to QDs was dose- and time-dependent. The level of lysosomes increased proportionally with the concentration of QDs, whereas an accumulation of autophagosomes was also observed. Cellular morphology was affected, as shown by the disruption of actin filaments. The enhanced release of nitric oxide and the increase in interleukin-6 and interleukin-8 protein expression suggested that nanoparticles triggered an inflammatory response in MRC-5 cells. QDs decreased the protein expression and enzymatic activity of matrix metalloproteinase (MMP)-2 and MMP-9 and also MMP-1 caseinase activity, whereas the protein levels of MMP-1 and tissue inhibitor of metalloproteinase-1 increased. The present study reveals for the first time that silicon-based QDs are able to generate inflammation in lung cells and cause an imbalance in extracellular matrix turnover through a differential regulation of MMPs and tissue inhibitor of metalloproteinase-1 protein expression. PMID:26032556

  5. Extracellular ATP induces the rapid release of HIV-1 from virus containing compartments of human macrophages.

    PubMed

    Graziano, Francesca; Desdouits, Marion; Garzetti, Livia; Podini, Paola; Alfano, Massimo; Rubartelli, Anna; Furlan, Roberto; Benaroch, Philippe; Poli, Guido

    2015-06-23

    HIV type 1 (HIV-1) infects CD4(+) T lymphocytes and tissue macrophages. Infected macrophages differ from T cells in terms of decreased to absent cytopathicity and for active accumulation of new progeny HIV-1 virions in virus-containing compartments (VCC). For these reasons, infected macrophages are believed to act as "Trojan horses" carrying infectious particles to be released on cell necrosis or functional stimulation. Here we explored the hypothesis that extracellular ATP (eATP) could represent a microenvironmental signal potentially affecting virion release from VCC of infected macrophages. Indeed, eATP triggered the rapid release of infectious HIV-1 from primary human monocyte-derived macrophages (MDM) acutely infected with the CCR5-dependent HIV-1 strain. A similar phenomenon was observed in chronically infected promonocytic U1 cells differentiated to macrophage-like cells (D-U1) by costimulation with phorbol esters and urokinase-type plasminogen activator. Worthy of note, eATP did not cause necrotic, apoptotic, or pyroptotic cell death, and its effect on HIV-1 release was suppressed by Imipramine (an antidepressant agent known to inhibit microvesicle formation by interfering with membrane-associated acid sphingomyelinase). Virion release was not triggered by oxidized ATP, whereas the effect of eATP was inhibited by a specific inhibitor of the P2X7 receptor (P2X7R). Thus, eATP triggered the discharge of virions actively accumulating in VCC of infected macrophages via interaction with the P2X7R in the absence of significant cytopathicity. These findings suggest that the microvesicle pathway and P2X7R could represent exploitable targets for interfering with the VCC-associated reservoir of infectious HIV-1 virions in tissue macrophages. PMID:26056317

  6. High extracellular levels of potassium and trace metals in human brain abscess.

    PubMed

    Dahlberg, Daniel; Ivanovic, Jugoslav; Mariussen, Espen; Hassel, Bjørnar

    2015-03-01

    Brain abscesses frequently cause symptoms such as seizures, delirium, paresis and sensory deficits that could reflect brain edema, increased intracranial pressure, or tissue destruction. However, it is also possible that pus constituents could disturb neuronal function in the surrounding brain tissue. In pus from 16 human brain abscesses, extracellular potassium ([K(+)]o) was 10.6 ± 4.8 mmol/L (mean ± SD; maximum value 22.0 mmol/L). In cerebrospinal fluid (CSF), [K(+)]o was 2.7 ± 0.6 mmol/L (N = 14; difference from pus p < 0.001), which is similar to previous control values for [K(+)]o in CSF and brain parenchyma. Zinc and iron were >40-fold higher in pus than in CSF; calcium, copper, manganese, and chromium were also higher, whereas sodium and magnesium were similar. Pus from 10 extracerebral abscesses (empyemas) also had higher [K(+)]o, zinc, iron, calcium, copper, manganese, and chromium than did CSF. Brain abscess [K(+)]o was significantly higher than serum potassium (3.8 ± 0.5 mmol/L; p = 0.0001), indicating that the elevated abscess [K(+)]o originated from damaged cells (e.g. brain cells and leukocytes), not from serum. High [K(+)]o could depolarize neurons, high levels of zinc could inhibit glutamate and GABA receptors, and high levels of iron and copper could cause oxidative damage, all of which could contribute to neuronal dysfunction in brain abscess patients. PMID:25684071

  7. The CD11c antigen couples concanavalin A binding to generation of superoxide anion in human phagocytes.

    PubMed Central

    Lacal, P M; Balsinde, J; Cabañas, C; Bernabeu, C; Sánchez-Madrid, F; Mollinedo, F

    1990-01-01

    We have found that an anti-CD11c monoclonal antibody (MAb) inhibits the respiratory burst induced in phorbol 12-myristate 13-acetate (PMA)-differentiated U937 cells as well as in human peripheral blood monocytes and neutrophils upon cell stimulation with concanavalin A. The MAb had no effect, however, when the added stimulus was fMet-Leu-Phe or PMA. Flow cytometry analyses indicated that concanavalin A was able to interact with CD11c. The anti-CD11c MAb inhibited significantly concanavalin A binding to differentiated U937 cells, and concanavalin A blocked binding of anti-CD11c MAb to the cells. Binding of labelled concanavalin A to membrane proteins which were separated by PAGE and transferred to nitrocellulose paper indicated that proteins with apparent molecular masses similar to those of CD11c (150 kDa) and CD18 (95 kDa) molecules were the main concanavalin A-binding proteins in differentiated U937 cells as well as in mature neutrophils. Similar experiments carried out in the presence of the anti-CD11c MAb showed a specific and significant inhibition of concanavalin A binding to the CD11c molecule. These results indicate that concanavalin A binds to the CD11c molecule and this binding is responsible for the concanavalin A-induced respiratory burst in PMA-differentiated U937 cells as well as in human mature monocytes and neutrophils. Images Fig. 2. Fig. 3. PMID:1973035

  8. Activation of superoxide formation and lysozyme release in human neutrophils by the synthetic lipopeptide Pam3Cys-Ser-(Lys)4. Involvement of guanine-nucleotide-binding proteins and synergism with chemotactic peptides.

    PubMed Central

    Seifert, R; Schultz, G; Richter-Freund, M; Metzger, J; Wiesmüller, K H; Jung, G; Bessler, W G; Hauschildt, S

    1990-01-01

    Upon exposure to the bacterial chemotactic peptide fMet-Leu-Phe, human neutrophils release lysozyme and generate superoxide anions (O2.-). The synthetic lipoamino acid N-palmitoyl-S-[2,3-bis(palmitoyloxy)-(2RS)-propyl]-(R)-cysteine (Pam3Cys), which is derived from the N-terminus of bacterial lipoprotein, when attached to Ser-(Lys)4 [giving Pam3Cys-Ser-(Lys)4], activated O2.- formation and lysozyme release in human neutrophils with an effectiveness amounting to about 15% of that of fMet-Leu-Phe. Palmitic acid, muramyl dipeptide, lipopolysaccharide and the lipopeptides Pam3Cys-Ala-Gly, Pam3Cys-Ser-Gly, Pam3Cys-Ser, Pam3Cys-OMe and Pam3Cys-OH did not activate O2.- formation. Pertussis toxin, which ADP-ribosylates guanine-nucleotide-binding proteins (G-proteins) and functionally uncouples formyl peptide receptors from G-proteins, prevented activation of O2.- formation by fMet-Leu-Phe and inhibited Pam3Cys-Ser-(Lys)4-induced O2.- formation by 85%. Lipopeptide-induced exocytosis was pertussis-toxin-insensitive. O2.- formation induced by Pam3Cys-Ser-(Lys)4 and fMet-Leu-Phe was enhanced by cytochalasin B, by a phorbol ester and by a diacylglycerol kinase inhibitor. Addition of activators of adenylate cyclase and removal of extracellular Ca2+ inhibited O2.- formation by fMet-Leu-Phe and Pam3Cys-Ser-(Lys)4 to different extents. Pam3Cys-Ser-(Lys)4 synergistically enhanced fMet-Leu-Phe-induced O2.- formation and primed neutrophils to respond to the chemotactic peptide at non-stimulatory concentrations. Our data suggest the following. (1) Pam3Cys-Ser-(Lys)4 activates neutrophils through G-proteins, involving pertussis-toxin-sensitive and -insensitive processes. (2) The signal transduction pathways activated by fMet-Leu-Phe and Pam3Cys-Ser-(Lys)4 are similar but not identical. (3) In inflammatory processes, bacterial lipoproteins and chemotactic peptides may interact synergistically to activate O2.- formation, leading to enhanced bactericidal activity. PMID:2160237

  9. PPAR{gamma} activation abolishes LDL-induced proliferation of human aortic smooth muscle cells via SOD-mediated down-regulation of superoxide

    SciTech Connect

    Heo, Kyung-Sun; Kim, Dong-Uk; Ryoo, Sungwoo; Nam, Miyoung; Baek, Seung Tae; Kim, Lila; Park, Song-Kyu; Myung, Chang-Seon; Hoe, Kwang-Lae . E-mail: kwanghoe@kribb.re.kr

    2007-08-10

    Native LDL would be a mitogenic and chemotactic stimulus of VSMC proliferation and differentiation in the atherosclerotic lesion where endothelial disruption occurred. In previous studies, our group investigated the molecular mechanisms by which LDL induces IL-8 production and by which PPAR{alpha} activation abolishes LDL effects in human aortic SMCs (hAoSMCs). Herein is the first report of PPAR{gamma} activation by troglitazone (TG) exerting its inhibitory effects on LDL-induced cell proliferation via generation not of H{sub 2}O{sub 2}, but of O2?-, and the subsequent activation of Erk1/2 in hAoSMCs. Moreover, in this study TG abolished the LDL-accelerated G{sub 1}-S progression to control levels via down-regulation of active cyclinD1/CDK4 and cyclinE/CDK2 complexes and up-regulation of p21{sup Cip1} expression. TG exerted its anti-proliferative effects through the up-regulation of basal superoxide dismutase (SOD) expression. This data suggests that the regulation of O2?- is located at the crossroads between LDL signaling and cell proliferation.

  10. Architecture and anatomy of the chromosomal locus in human chromosome 21 encoding the Cu/Zn superoxide dismutase.

    PubMed Central

    Levanon, D; Lieman-Hurwitz, J; Dafni, N; Wigderson, M; Sherman, L; Bernstein, Y; Laver-Rudich, Z; Danciger, E; Stein, O; Groner, Y

    1985-01-01

    The SOD-1 gene on chromosome 21 and approximately 100 kb of chromosomal DNA from the 21q22 region have been isolated and characterized. The gene which is present as a single copy per haploid genome spans 11 kb of chromosomal DNA. Heteroduplex analysis and DNA sequencing reveals five rather small exons and four introns that interrupt the coding region. The donor sequence at the first intron contains an unusual variant dinucleotide 5'-G-C, rather than the highly conserved 5'-GT. The unusual splice junction is functional in vivo since it was detected in both alleles of the SOD-1 gene, which were defined by differences in the length of restriction endonuclease fragments (RFLPs) that hybridize to the cDNA probe. Genomic blots of human DNA isolated from cells trisomic for chromosome 21 (Down's syndrome patients) show the normal pattern of bands. At the 5' end of gene there are the 'TATA' and 'CAT' promoter sequences as well as four copies of the -GGCGGG- hexanucleotide. Two of these -GC- elements are contained within a 13 nucleotide inverted repeat that could form a stem-loop structure with stability of -33 kcal. The 3'-non coding region of the gene contains five short open reading-frames starting with ATG and terminating with stop codons. Images Fig. 1. Fig. 3. Fig. 7. PMID:3160582

  11. Extracellular materials in the endothelial meshwork of organcultured human trabecular meshwork. Morphologic and morphometric study.

    PubMed

    Urakawa, Y

    1991-01-01

    Twenty-three normal cadaver eyes were used in this study. Eight trabecular meshwork explants were dissected at 45-degree intervals from a 77-year-old donor eye and cultured for 2 weeks for studying circumferential differences in the amount of extracellular materials in the endothelial meshwork. One trabecular meshwork explant was dissected from each of 22 individual eyes (age range: 64-89 years) and cultured for 2 weeks to study the effect of age on the amount of the extracellular materials. Then, 5 consecutive electron micrographs in the endothelial meshwork were obtained from the individual specimens and subjected to morphometric studies. In the endothelial meshwork, the results revealed: (1) no statistically significant circumferential differences in the amount of extracellular materials and (2) no statistically significant changes associated with aging in the amount of these materials. PMID:1923311

  12. Expression of a functional extracellular calcium-sensing receptor in human aortic endothelial cells

    SciTech Connect

    Ziegelstein, Roy C.; Xiong Yali; He Chaoxia; Hu Qinghua . E-mail: qinghuaa@jhmi.edu

    2006-03-31

    Extracellular Ca{sup 2+} concentration ([Ca{sup 2+}]{sub o}) regulates the functions of many cell types through a G protein-coupled [Ca{sup 2+}]{sub o}-sensing receptor (CaR). Whether the receptor is functionally expressed in vascular endothelial cells is largely unknown. In cultured human aortic endothelial cells (HAEC), RT-PCR yielded the expected 555-bp product corresponding to the CaR, and CaR protein was demonstrated by fluorescence immunostaining and Western blot. RT-PCR also demonstrated the expression in HAEC of alternatively spliced variants of the CaR lacking exon 5. Although stimulation of fura 2-loaded HAEC by several CaR agonists (high [Ca{sup 2+}]{sub o}, neomycin, and gadolinium) failed to increase intracellular Ca{sup 2+} concentration ([Ca{sup 2+}]{sub i}), the CaR agonist spermine stimulated an increase in [Ca{sup 2+}]{sub i} that was diminished in buffer without Ca{sup 2+} and was abolished after depletion of an intracellular Ca{sup 2+} pool with thapsigargin or after blocking IP{sub 3}- and ryanodine receptor-mediated Ca{sup 2+} release with xestospongin C and with high concentration ryanodine, respectively. Spermine stimulated an increase in DAF-FM fluorescence in HAEC, consistent with NO production. Both the increase in [Ca{sup 2+}]{sub i} and in NO production were reduced or absent in HAEC transfected with siRNA specifically targeted to the CaR. HAEC express a functional CaR that responds to the endogenous polyamine spermine with an increase in [Ca{sup 2+}]{sub i}, primarily due to release of IP{sub 3}- and ryanodine-sensitive intracellular Ca{sup 2+} stores, leading to the production of NO. Expression of alternatively spliced variants of the CaR may result in the absence of a functional response to other known CaR agonists in HAEC.

  13. Dynamic Regulation of Cell Volume and Extracellular ATP of Human Erythrocytes

    PubMed Central

    Leal Denis, M. Florencia; Alvarez, H. Ariel; Lauri, Natalia; Alvarez, Cora L.; Chara, Osvaldo; Schwarzbaum, Pablo J.

    2016-01-01

    Introduction The peptide mastoparan 7 (MST7) triggered in human erythrocytes (rbcs) the release of ATP and swelling. Since swelling is a well-known inducer of ATP release, and extracellular (ATPe), interacting with P (purinergic) receptors, can affect cell volume (Vr), we explored the dynamic regulation between Vr and ATPe. Methods and Treatments We made a quantitative assessment of MST7-dependent kinetics of Vr and of [ATPe], both in the absence and presence of blockers of ATP efflux, swelling and P receptors. Results In rbcs 10 μM MST7 promoted acute, strongly correlated changes in [ATPe] and Vr. Whereas MST7 induced increases of 10% in Vr and 190 nM in [ATPe], blocking swelling in a hyperosmotic medium + MST7 reduced [ATPe] by 40%. Pre-incubation of rbcs with 10 μM of either carbenoxolone or probenecid, two inhibitors of the ATP conduit pannexin 1, reduced [ATPe] by 40–50% and swelling by 40–60%, while in the presence of 80 U/mL apyrase, an ATPe scavenger, cell swelling was prevented. While exposure to 10 μM NF110, a blocker of ATP-P2X receptors mediating sodium influx, reduced [ATPe] by 48%, and swelling by 80%, incubation of cells in sodium free medium reduced swelling by 92%. Analysis and Discussion Results were analyzed by means of a mathematical model where ATPe kinetics and Vr kinetics were mutually regulated. Model dependent fit to experimental data showed that, upon MST7 exposure, ATP efflux required a fast 1960-fold increase of ATP permeability, mediated by two kinetically different conduits, both of which were activated by swelling and inactivated by time. Both experimental and theoretical results suggest that, following MST7 exposure, ATP is released via two conduits, one of which is mediated by pannexin 1. The accumulated ATPe activates P2X receptors, followed by sodium influx, resulting in cell swelling, which in turn further activates ATP release. Thus swelling and P2X receptors constitute essential components of a positive feedback loop

  14. Cu/Zn superoxide dismutases in developing cotton fibers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydrogen peroxide (H2O2) and other reactive oxygen species (ROS) are important signaling molecules in diverse physiological processes. Previously, we discovered superoxide dismutase (SOD) activity in extracellular protein preparations from fiber-bearing cotton (Gossypium hirsutum L.) seeds. We sho...

  15. Adaptive regulation of human intestinal thiamine uptake by extracellular substrate level: a role for THTR-2 transcriptional regulation

    PubMed Central

    Nabokina, Svetlana M.; Subramanian, Veedamali S.; Valle, Judith E.

    2013-01-01

    The intestinal thiamine uptake process is adaptively regulated by the level of vitamin in the diet, but the molecular mechanism involved is not fully understood. Here we used the human intestinal epithelial Caco-2 cells exposed to different levels of extracellular thiamine to delineate the molecular mechanism involved. Our results showed that maintaining Caco-2 cells in a thiamine-deficient medium resulted in a specific and significant increase of [3H]thiamine uptake compared with cell exposure to a high level of thiamine (1 mM). This adaptive regulation was also associated with a higher level of mRNA expression of thiamine transporter-2 (THTR-2), but not thiamine transporter-1 (THTR-1), in the deficient condition and a higher level of promoter activity of gene encoding THTR-2 (SLC19A3). Using 5′-truncated promoter-luciferase constructs, we identified the thiamine level-responsive region in the SLC19A3 promoter to be between −77 and −29 (using transcriptional start site as +1). By means of mutational analysis, a key role for a stimulating protein-1 (SP1)/guanosine cytidine box in mediating the effect of extracellular thiamine level on SLC19A3 promoter was established. Furthermore, extracellular level of thiamine was found to affect SP1 protein expression and binding pattern to the thiamine level-responsive region of SLC19A3 promoter in Caco-2 cells as shown by Western blotting and electrophoretic mobility shift assay analysis, respectively. These studies demonstrate that the human intestinal thiamine uptake is adaptively regulated by the extracellular substrate level via transcriptional regulation of the THTR-2 system, and report that SP1 transcriptional factor is involved in this regulation. PMID:23989004

  16. Advances in time course extracellular production of human pre-miR-29b from Rhodovulum sulfidophilum.

    PubMed

    Pereira, Patrícia; Pedro, Augusto Q; Tomás, Joana; Maia, Cláudio J; Queiroz, João A; Figueiras, Ana; Sousa, Fani

    2016-04-01

    The present study reports the successful production of human pre-miR-29b both intra- and extracellularly in the marine phototrophic bacterium Rhodovulum sulfidophilum using recombinant RNA technology. In a first stage, the optimal transformation conditions (0.025 μg of plasmid DNA, with a heat-shock of 2 min at 35 °C) were established, in order to transfer the pre-miR-29b encoding plasmid to R. sulfidophilum host. Furthermore, the extracellular recovery of this RNA product from the culture medium was greatly improved, achieving quantities that are compatible with the majority of applications, namely for in vitro or in vivo studies. Using this system, the extracellular human pre-miR-29b concentration was approximately 182 μg/L, after 40 h of bacterial growth, and the total intracellular pre-miR-29b was of about 358 μg/L, at 32 h. At the end of the fermentation, it was verified that almost 87 % of cells were viable, indicating that cell lysis is minimized and that the extracellular medium is not highly contaminated with the host intracellular ribonucleases (RNases) and endotoxins, which is a critical parameter to guarantee the microRNA (miRNA) integrity. These findings demonstrate that pre-miRNAs can be produced by recombinant RNA technology, offering novel clues for the production of natural pre-miRNA agents for functional studies and RNA interference (RNAi)-based therapeutics. PMID:26860940

  17. Synthesis of calcium superoxide

    NASA Technical Reports Server (NTRS)

    Rewick, R. T.; Blucher, W. G.; Estacio, P. L.

    1972-01-01

    Efforts to prepare Ca(O2) sub 2 from reactions of calcium compounds with 100% O3 and with O(D-1) atoms generated by photolysis of O3 at 2537 A are described. Samples of Ca(OH) sub 2, CaO, CaO2, Ca metal, and mixtures containing suspected impurities to promote reaction have been treated with excess O3 under static and flow conditions in the presence and absence of UV irradiation. Studies with KO2 suggest that the superoxide anion is stable to radiation at 2537 A but reacts with oxygen atoms generated by the photolysis of O3 to form KO3. Calcium superoxide is expected to behave in an analogous.

  18. Recombinant human manganese superoxide dismutase (rMnSOD): a positive effect on the immunohematological state of mice irradiated with protons

    NASA Astrophysics Data System (ADS)

    Ambesi-Impiombato, Francesco Saverio; Belov, Oleg; Bulinina, Taisia; Ivanov, Alexander; Mancini, Aldo; Borrelli, Antonella; Krasavin, Eugene A.

    Protons represent the largest component of space radiation. In this regard screening of radioprotective drugs capable of increasing radioresistance of astronauts obligatory includes studying these compounds using proton radiation injury models. The recombinant human manganese superoxide dismutase (rMnSOD) had previously demonstrated its efficacy on an in vivo X-ray induced injury model, when multiple intraperitoneal treatments allowed the survival of mice irradiated with doses which were lethal for the control animals (Borrelli A et al. “A recombinant MnSOD is radioprotective for normal cells and radiosensitizing for tumor cells”. Free Radic Biol Med. 2009, 46, 110-6). Using the model of sublethal whole-body irradiation with protons available at Phasotron of Joint Institute for Nuclear Research (Dubna, Russia), we reconstruct the bone-marrow form of the acute radiation sickness to test the radioprotective effect of rMnSOD. Male (CBAxC57Bl6) F1 hybrid SPF mice weighting approximately 24 g were exposed to 171 MeV protons at the dose of 4 Gy. After irradiation, the sixfold daily subcutaneous treatment with rMnSOD has provided a statistically significant acceleration of the recovery of thymus and spleen mass and of the number of leukocytes in mice peripheral blood. In the control, untreated and irradiated mice, these positive effects were not observed even on day 7 after exposure. The number of karyocytes in bone marrow of irradiated mice has even exceeded its basal level in the control group 7 days after irradiation. The rMnSOD-treated group has thus demonstrated a significant hyper-restoration of this characteristic. In the presentation, several possibilities of using of rMnSOD in space medicine will be discussed, taking into account various biomedically relevant effects of this enzyme.

  19. Oxidation of the Tryptophan 32 Residue of Human Superoxide Dismutase 1 Caused by Its Bicarbonate-dependent Peroxidase Activity Triggers the Non-amyloid Aggregation of the Enzyme*

    PubMed Central

    Coelho, Fernando R.; Iqbal, Asif; Linares, Edlaine; Silva, Daniel F.; Lima, Filipe S.; Cuccovia, Iolanda M.; Augusto, Ohara

    2014-01-01

    The role of oxidative post-translational modifications of human superoxide dismutase 1 (hSOD1) in the amyotrophic lateral sclerosis (ALS) pathology is an attractive hypothesis to explore based on several lines of evidence. Among them, the remarkable stability of hSOD1WT and several of its ALS-associated mutants suggests that hSOD1 oxidation may precede its conversion to the unfolded and aggregated forms found in ALS patients. The bicarbonate-dependent peroxidase activity of hSOD1 causes oxidation of its own solvent-exposed Trp32 residue. The resulting products are apparently different from those produced in the absence of bicarbonate and are most likely specific for simian SOD1s, which contain the Trp32 residue. The aims of this work were to examine whether the bicarbonate-dependent peroxidase activity of hSOD1 (hSOD1WT and hSOD1G93A mutant) triggers aggregation of the enzyme and to comprehend the role of the Trp32 residue in the process. The results showed that Trp32 residues of both enzymes are oxidized to a similar extent to hSOD1-derived tryptophanyl radicals. These radicals decayed to hSOD1-N-formylkynurenine and hSOD1-kynurenine or to a hSOD1 covalent dimer cross-linked by a ditryptophan bond, causing hSOD1 unfolding, oligomerization, and non-amyloid aggregation. The latter process was inhibited by tempol, which recombines with the hSOD1-derived tryptophanyl radical, and did not occur in the absence of bicarbonate or with enzymes that lack the Trp32 residue (bovine SOD1 and hSOD1W32F mutant). The results support a role for the oxidation products of the hSOD1-Trp32 residue, particularly the covalent dimer, in triggering the non-amyloid aggregation of hSOD1. PMID:25237191

  20. Selenocysteine Positional Variants Reveal Contributions to Copper Binding From Cysteine Residues in Domains 2 And 3 of Human Copper Chaperone for Superoxide Dismutase

    SciTech Connect

    Barry, A.N.; Clark, K.M.; Otoikhian, A.; Donk, W.A.van der; Blackburn, N.J.

    2009-05-11

    The human copper chaperone for superoxide dismutase binds copper both in an Atx1-like MTCQSC motif in domain 1 and via a multinuclear cluster formed by two CXC motifs at the D3 dimer interface. The composition of the Cu(I) cluster has been investigated previously by mutagenesis of the CXC motif, and by construction of a CXU selenocysteine derivative, which has permitted XAS studies at both Cu and Se absorption edges. Here, we report the semisynthesis and spectroscopic characterization of a series of derivatives with the sequences 243-CACA, 243-CAUA, 243-UACA, and 243-UAUA in the D1 double mutant (C22AC25A) background, prepared by expressed protein ligation of Sec-containing tetrapeptides to an hCCS-243 truncation. By varying the position of the Se atom in the CXC motif, we have been able to show that Se is always bridging (2 Se-Cu) rather than terminal (1 Se-Cu). Substitution of both D3 Cys residues by Sec in the UAUA variant does not eliminate the Cu-S contribution, confirming our previous description of the cluster as most likely a Cu{sub 4}S{sub 6} species, and suggesting that D2 Cys residues contribute to the cluster. As predicted by this model, when Cys residues C141, C144, and C227 are mutated to alanine either individually or together as a triple mutant, the cluster nuclearity is dramatically attenuated. These data suggest that Cys residues in D2 of hCCS are involved in the formation, stability, and redox potential of the D3 cluster. The significance of these finding to the SOD1 thiol/disulfide oxidase activity are discussed in terms of a model in which a similar multinuclear cluster may form in the CCS-SOD heterodimer.

  1. HSP70 increases extracellular matrix production by human vascular smooth muscle through TGF-β1 up-regulation.

    PubMed

    González-Ramos, Marta; Calleros, Laura; López-Ongil, Susana; Raoch, Viviana; Griera, Mercedes; Rodríguez-Puyol, Manuel; de Frutos, Sergio; Rodríguez-Puyol, Diego

    2013-02-01

    The circulating levels of heat shock proteins (HSP) are increased in cardiovascular diseases; however, the implication of this for the fibrotic process typical of such diseases remains unclear. HSP70 can interact with the vascular smooth muscle cells (SMC), the major producer of extracellular matrix (ECM) proteins, through the Toll-like receptors 4 (TLR4). The transforming growth factor type-β1 (TGF-β1) is a well known vascular pro-fibrotic cytokine that is regulated in part by AP-1-dependent transcriptional mechanisms. We hypothesized that extracellular HSP70 could interact with SMCs, inducing TGF-β1 synthesis and subsequent changes in the vascular ECM. We demonstrate that extracellular HSP70 binds to human aorta SMC TLR4, which up-regulates the AP-1-dependent transcriptional activity of the TGF-β1 promoter. This is achieved through the mitogen activated protein kinases JNK and ERK, as demonstrated by the use of specific blockers and the knockdown of TLR4 with specific small interfering RNAs. The TGF-β1 upregulation increase the expression of the ECM proteins type I collagen and fibronectin. This novel observation may elucidate the mechanisms by which HSP70 contributes in the inflammation and fibrosis present in atherosclerosis and other fibrosis-related diseases. PMID:23084979

  2. Effects of a single exposure to UVB radiation on the activities and protein levels of copper-zinc and manganese superoxide dismutase in cultured human keratinocytes.

    PubMed

    Sasaki, H; Akamatsu, H; Horio, T

    1997-04-01

    Ultraviolet B irradiation has been believed to decrease or impair the activity of reactive oxygen species (ROS) scavenging enzymes such as superoxide dismutase (SOD) in the skin. It has been recently reported that two isozymes of SOD, namely copper-zinc SOD (Cu-Zn SOD) and manganese SOD (Mn SOD), exist in mammalian cells and that the two enzymes play different roles in living systems. The aim of this study was to investigate changes in SOD activities and protein levels in cultured human keratinocytes after acute UVB irradiation. In addition, the protein levels of Cu-Zn SOD and Mn SOD were quantified separately. A single exposure to UVB irradiation produced an increase in SOD activity and protein level that peaked immediately after UVB irradiation, after which a decline was observed, with subsequent recovery to baseline levels 24 h after irradiation. In individual assays of Mn SOD and Cu-Zn SOD, the amount of Mn SOD protein decreased and then gradually recovered 24 h after irradiation. In contrast, the amount of Cu-Zn SOD protein increased immediately after UVB irradiation, and then gradually declined. To evaluate the mechanisms of these changes, we examined the effects of the cytokines, interleukin-1 alpha (IL-1 alpha) and tumor necrosis factor-alpha (TNF-alpha), which can be secreted from keratinocytes after UVB irradiation, on the SOD activity and protein levels in keratinocytes. Interleukin-1 alpha and TNF-alpha enhanced both the SOD activity and protein level of Mn SOD, while these cytokines had no effect on Cu-Zn SOD protein levels in cultured human keratinocytes after incubation for 24 h. Furthermore, when neutralizing antibodies against IL-1 alpha and TNF-alpha were added separately or together to the culture medium before UVB irradiation, the recovery of total SOD activity and Mn SOD protein level were markedly inhibited 24 h after irradiation. Our results suggest that significant increases in SOD activity and protein level occur as a cutaneous antioxidant

  3. Importance of Thickness in Human Cardiomyocyte Network for Effective Electrophysiological Stimulation Using On-Chip Extracellular Microelectrodes

    NASA Astrophysics Data System (ADS)

    Hamada, Tomoyo; Nomura, Fumimasa; Kaneko, Tomoyuki; Yasuda, Kenji

    2012-06-01

    We have developed a three-dimensionally controlled in vitro human cardiomyocyte network assay for the measurements of drug-induced conductivity changes and the appearance of fatal arrhythmia such as ventricular tachycardia/fibrillation for more precise in vitro predictive cardiotoxicity. To construct an artificial conductance propagation model of a human cardiomyocyte network, first, we examined the cell concentration dependence of the cell network heights and found the existence of a height limit of cell networks, which was double-layer height, whereas the cardiomyocytes were effectively and homogeneously cultivated within the microchamber maintaining their spatial distribution constant and their electrophysiological conductance and propagation were successfully recorded using a microelectrode array set on the bottom of the microchamber. The pacing ability of a cardiomyocyte's electrophysiological response has been evaluated using microelectrode extracellular stimulation, and the stimulation for pacing also successfully regulated the beating frequencies of two-layered cardiomyocyte networks, whereas monolayered cardiomyocyte networks were hardly stimulated by the external electrodes using the two-layered cardiomyocyte stimulation condition. The stability of the lined-up shape of human cardiomyocytes within the rectangularly arranged agarose microchambers was limited for a two-layered cardiomyocyte network because their stronger force generation shrunk those cells after peeling off the substrate. The results indicate the importance of fabrication technology of thickness control of cellular networks for effective extracellular stimulation and the potential concerning thick cardiomyocyte networks for long-term cultivation.

  4. Superoxide is an associated signal for apoptosis in axonal injury

    PubMed Central

    Catrinescu, Maria-Magdalena; Kanamori, Noriko; Mears, Katrina A.; Beaubien, Rachel

    2010-01-01

    Optic neuropathy is the leading cause of irreversible blindness, and a paradigm for central nervous system axonal disease. The primary event is damage to retinal ganglion cell axons, with subsequent death of the cell body by apoptosis. Trials of neuroprotection for these and other neuronal diseases have mostly failed, primarily because mechanisms of neuroprotection in animals do not necessarily translate to humans. We developed a methodology for imaging an intracellular transduction pathway that signals neuronal death in the living animal. Using longitudinal confocal scanning multilaser ophthalmoscopy, we identified the production of superoxide within retrograde-labelled rat retinal ganglion cells after optic nerve transection. Superoxide was visualized by real-time imaging of its reaction product with intravitreally administered hydroethidine and confirmed by differential spectroscopy of the specific product 2-hydroxyethidium. Retinal ganglion cell superoxide increased within 24 h after axotomy, peaking at 4 days, and was not observed in contralateral untransected eyes. The superoxide signal preceded phosphatidylserine externalization, indicating that superoxide generation was an early event and preceded apoptosis. Intravitreal pegylated superoxide dismutase blocked superoxide generation after axotomy and delayed retinal ganglion cell death. Together, these results are consistent with superoxide being an upstream signal for retinal ganglion cell apoptosis after optic nerve injury. Early detection of axonal injury with superoxide could serve as a predictive biomarker for patients with optic neuropathy. PMID:20495185

  5. Microbiota/Host Crosstalk Biomarkers: Regulatory Response of Human Intestinal Dendritic Cells Exposed to Lactobacillus Extracellular Encrypted Peptide

    PubMed Central

    Al-Hassi, Hafid O.; Mann, Elizabeth R.; Urdaci, María C.; Knight, Stella C.; Margolles, Abelardo

    2012-01-01

    The human gastrointestinal tract is exposed to a huge variety of microorganisms, either commensal or pathogenic; at this site, a balance between immunity and immune tolerance is required. Intestinal dendritic cells (DCs) control the mechanisms of immune response/tolerance in the gut. In this paper we have identified a peptide (STp) secreted by Lactobacillus plantarum, characterized by the abundance of serine and threonine residues within its sequence. STp is encoded in one of the main extracellular proteins produced by such species, which includes some probiotic strains, and lacks cleavage sites for the major intestinal proteases. When studied in vitro, STp expanded the ongoing production of regulatory IL-10 in human intestinal DCs from healthy controls. STp-primed DC induced an immunoregulatory cytokine profile and skin-homing profile on stimulated T-cells. Our data suggest that some of the molecular dialogue between intestinal bacteria and DCs may be mediated by immunomodulatory peptides, encoded in larger extracellular proteins, secreted by commensal bacteria. These peptides may be used for the development of nutraceutical products for patients with IBD. In addition, this kind of peptides seem to be absent in the gut of inflammatory bowel disease patients, suggesting a potential role as biomarker of gut homeostasis. PMID:22606249

  6. Human VE-Cadherin Fusion Protein as an Artificial Extracellular Matrix Enhancing the Proliferation and Differentiation Functions of Endothelial Cell.

    PubMed

    Xu, Ke; Shuai, Qizhi; Li, Xiaoning; Zhang, Yan; Gao, Chao; Cao, Lei; Hu, Feifei; Akaike, Toshihiro; Wang, Jian-xi; Gu, Zhongwei; Yang, Jun

    2016-03-14

    In an attempt to enhance endothelial cell capture and promote the vascularization of engineered tissue, we biosynthesized and characterized the recombinant fusion protein consisting of human vascular endothelial-cadherin extracellular domain and immunoglobulin IgG Fc region (hVE-cad-Fc) to serve as a bioartificial extracellular matrix. The hVE-cad-Fc protein naturally formed homodimers and was used to construct hVE-cad-Fc matrix by stably adsorbing on polystyrene plates. Atomic force microscop assay showed uniform hVE-cad-Fc distribution with nanorod topography. The hVE-cad-Fc matrix markedly promoted human umbilical vein endothelial cells (HUVECs) adhesion and proliferation with fibroblastoid morphology. Additionally, the hVE-cad-Fc matrix improved HUVECs migration, vWF expression, and NO release, which are closely related to vascularization. Furthermore, the hVE-cad-Fc matrix activated endogenous VE-cadherin/β-catenin proteins and effectively triggered the intracellular signals such as F-actin stress fiber, p-FAK, AKT, and Bcl-2. Taken together, hVE-cad-Fc could be a promising bioartificial matrix to promote vascularization in tissue engineering. PMID:26859785

  7. Extracellular acidification induces connective tissue growth factor production through proton-sensing receptor OGR1 in human airway smooth muscle cells

    SciTech Connect

    Matsuzaki, Shinichi; Ishizuka, Tamotsu; Yamada, Hidenori; Kamide, Yosuke; Hisada, Takeshi; Ichimonji, Isao; Aoki, Haruka; Yatomi, Masakiyo; Komachi, Mayumi; Tsurumaki, Hiroaki; Ono, Akihiro; Koga, Yasuhiko; Dobashi, Kunio; Mogi, Chihiro; Sato, Koichi; Tomura, Hideaki; Mori, Masatomo; Okajima, Fumikazu

    2011-10-07

    Highlights: {yields} The involvement of extracellular acidification in airway remodeling was investigated. {yields} Extracellular acidification alone induced CTGF production in human ASMCs. {yields} Extracellular acidification enhanced TGF-{beta}-induced CTGF production in human ASMCs. {yields} Proton-sensing receptor OGR1 was involved in acidic pH-stimulated CTGF production. {yields} OGR1 may play an important role in airway remodeling in asthma. -- Abstract: Asthma is characterized by airway inflammation, hyper-responsiveness and remodeling. Extracellular acidification is known to be associated with severe asthma; however, the role of extracellular acidification in airway remodeling remains elusive. In the present study, the effects of acidification on the expression of connective tissue growth factor (CTGF), a critical factor involved in the formation of extracellular matrix proteins and hence airway remodeling, were examined in human airway smooth muscle cells (ASMCs). Acidic pH alone induced a substantial production of CTGF, and enhanced transforming growth factor (TGF)-{beta}-induced CTGF mRNA and protein expression. The extracellular acidic pH-induced effects were inhibited by knockdown of a proton-sensing ovarian cancer G-protein-coupled receptor (OGR1) with its specific small interfering RNA and by addition of the G{sub q/11} protein-specific inhibitor, YM-254890, or the inositol-1,4,5-trisphosphate (IP{sub 3}) receptor antagonist, 2-APB. In conclusion, extracellular acidification induces CTGF production through the OGR1/G{sub q/11} protein and inositol-1,4,5-trisphosphate-induced Ca{sup 2+} mobilization in human ASMCs.

  8. A functional polyester carrying free hydroxyl groups promotes the mineralization of osteoblast and human mesenchymal stem cell extracellular matrix.

    PubMed

    Bi, Xiaoping; You, Zhengwei; Gao, Jin; Fan, Xianqun; Wang, Yadong

    2014-06-01

    Functional groups can control biointerfaces and provide a simple way to make therapeutic materials. We recently reported the design and synthesis of poly(sebacoyl diglyceride) (PSeD) carrying a free hydroxyl group in its repeating unit. This paper examines the use of this polymer to promote biomineralization for application in bone tissue engineering. PSeD promoted more mineralization of extracellular matrix secreted by human mesenchymal stem cells and rat osteoblasts than poly(lactic-co-glycolic acid) (PLGA), which is currently widely used in bone tissue engineering. PSeD showed in vitro osteocompatibility and in vivo biocompatibility that matched or surpassed that of PLGA, as well as supported the attachment, proliferation and differentiation of rat osteoblasts and human mesenchymal stem cells. This demonstrates the potential of PSeD for use in bone regeneration. PMID:24560799

  9. Comparison of biomaterials and extracellular matrices as a culture platform for multiple, independently derived human embryonic stem cell lines.

    PubMed

    Hakala, Heidi; Rajala, Kristiina; Ojala, Marisa; Panula, Sarita; Areva, Sami; Kellomäki, Minna; Suuronen, Riitta; Skottman, Heli

    2009-07-01

    Long-term in vitro culture of undifferentiated human embryonic stem cells (hESCs) traditionally requires a fibroblast feeder cell layer. Using feeder cells in hESC cultures is highly laborious and limits large-scale hESC production for potential application in regenerative medicine. Replacing feeder cells with defined human extracellular matrix (ECM) components or synthetic biomaterials would be ideal for large-scale production of clinical-grade hESCs. We tested and compared different feeder cell-free hESC culture methods based on different human ECM proteins, human and animal sera matrices, and a Matrigel matrix. Also selected biomaterials were tested for feeder cell-free propagation of undifferentiated hESCs. The matrices were tested together with conventional and modified hESC culture media, human foreskin fibroblast-conditioned culture medium, chemically defined medium, TeSR1, and modified TeSR1 media. The results showed the undefined, xenogeneic Matrigel to be a superior matrix for hESC culture compared with the purified human ECM proteins, serum matrices, and the biomaterials tested. A long-term, feeder cell-free culture system was successful on Matrigel in combination with mTeSR1 culture medium, but a xeno-free, fully defined, and reproducible feeder cell-free hESC culture method still remains to be developed. PMID:19132919

  10. Glucosepane is a major protein cross-link of the senescent human extracellular matrix. Relationship with diabetes.

    PubMed

    Sell, David R; Biemel, Klaus M; Reihl, Oliver; Lederer, Markus O; Strauch, Christopher M; Monnier, Vincent M

    2005-04-01

    The extracellular matrix in most tissues is characterized by progressive age-related stiffening and loss of proteolytic digestibility that are accelerated in diabetes and can be duplicated by the nonenzymatic reaction of reducing sugars and extracellular matrix proteins. However, most cross-links of the Maillard reaction described so far are present in quantities too low to account for these changes. Here we have determined in human skin and glomerular basement membrane (GBM) collagen the levels of the recently discovered lysine-arginine cross-links derived from glucose, methylglyoxal, glyoxal, and 3-deoxyglucosone, i.e. glucosepane, MODIC, GODIC, and DOGDIC, respectively. Insoluble preparations of skin collagen (n = 110) and glomerular basement membrane (GBM, n = 28) were enzymatically digested, and levels were measured by isotope dilution technique using liquid chromatography/mass spectrometry. In skin, all cross-links increased with age (p < 0.0001) except DOGDIC (p = 0.34). In nondiabetic controls, levels at 90 years were 2000, 30, and 15 pmol/mg for glucosepane, MODIC, and GODIC, respectively. Diabetes, but not renal failure, increased glucosepane to 5000 pmol/mg (p < 0.0001), and for all others, increased it to <60 pmol/mg (p < 0.01). In GBMs, glucosepane reached up to 500 pmol/mg of collagen and was increased in diabetes (p < 0.0001) but not old age. In conclusion, glucosepane is the single major cross-link of the senescent extracellular matrix discovered so far, accounting for up to >120 mole% of triple helical collagen modification in diabetes. Its presence in high quantities may contribute to a number of structural and cell matrix dysfunctions observed in aging and diabetes. PMID:15677467

  11. Models of Superoxide Dismutases

    SciTech Connect

    Cabelli, Diane E.; Riley, Dennis; Rodriguez, Jorge A.; Valentine, Joan Selverstone; Zhu, Haining

    1998-05-20

    In this review we have focused much of our discussion on the mechanistic details of how the native enzymes function and how mechanistic developments/insights with synthetic small molecule complexes possessing SOD activity have influenced our understanding of the electron transfer processes involved with the natural enzymes. A few overriding themes have emerged. Clearly, the SOD enzymes operate at near diffusion controlled rates and to achieve such catalytic turnover activity, several important physical principles must be operative. Such fast electron transfer processes requires a role for protons; i.e., proton-coupled electron transfer (''H-atom transfer'') solves the dilemma of charge separation developing in the transition state for the electron transfer step. Additionally, outer-sphere electron transfer is likely a most important pathway for manganese and iron dismutases. This situation arises because the ligand exchange rates on these two ions in water never exceed {approx}10{sup +7} s{sup -1}; consequently, 10{sup +9} catalytic rates require more subtle mechanistic insights. In contrast, copper complexes can achieve diffusion controlled (>10{sup +9}) exchange rates in water; thus inner-sphere electron transfer processes are more likely to be operative in the Cu/Zn enzymes. Recent studies have continued to expand our understanding of the mechanism of action of this most important class of redox active enzymes, the superoxide dismutases, which have been critical in the successful adaptation of life on this planet to an oxygen-based metabolism. The design of SOD mimic drugs, synthetic models compounds that incorporate this superoxide dismutase catalytic activity and are capable of functioning in vivo, offers clear potential benefits in the control of diseases, ranging from the control of neurodegenerative conditions, such as Parkinson's or Alzheimer's disease, to cancer.

  12. The influence of biomimetic topographic features and the extracellular matrix peptide RGD on human corneal epithelial contact guidance

    PubMed Central

    Tocce, E.J.; Liliensiek, S.J.; Broderick, A.H.; Jiang, Y; Murphy, K.C.; Murphy, C.J.; Lynn, D.M.; Nealey, P.F

    2012-01-01

    A major focus in the field of tissue engineering is the regulation of essential cell behaviors through biophysical and biochemical cues from the local extracellular environment. The impact of nanotopographic cues on human corneal epithelial cell (HCEC) contact guidance, proliferation, migration and adhesion have previously been demonstrated. In the current report, we have expanded our study of HCEC response to include both biophysical and controlled biochemical extracellular cues. By exploiting methods for the layer-by-layer coating of substrates with reactive poly(ethylene imine) and poly(2-vinyl-4,4-dimethylazlactone) (PEI/PVDMA)-based multilayer thin films, we have incorporated a single adhesion peptide motif, Arg-Gly-Asp (RGD), onto topographically patterned substrates. This strategy eliminates protein adsorption onto the surface, thus decoupling the effects of the HCEC response to topographic cues from adsorbed proteins and the soluble media proteins. The direction of cell alignment was dependent on the scale of the topographic cues, and, to less of an extent, the culture medium. In EpiLife® medium, cell alignment to unmodified-NOA81 topographic features, which allowed for protein adsorption, differed significantly from cell alignment on RGD-modified features. These results demonstrate that the surface chemical composition affects significantly how HCECs respond to topographic cues. In summary, we demonstrate the modulation of the HCEC response to environmental cues through critical substrate and soluble parameters. PMID:23069317

  13. [Expression and analysis of the extracellular domain of human glucocorticoid-induced tumor necrosis factor receptor ligand in Escherichia coli].

    PubMed

    Jiao, Yanli; Zheng, Fang; Li, Xiaoxia; Wang, Baoli; Guo, Shanyi

    2009-05-01

    GITRL (Glucocorticoid-induced tumor necrosis factor receptor ligand) has been recently identified as a novel inhibitor of osteoclastogenesis and hence called Osteostat. In this study, we expressed recombinant extracellular domain of GITRL protein in Escherichia coli and analyzed its bioactivity. Using an Eco31I enzyme-based restriction and ligation method, we obtained an E. coli-preferred DNA sequence coding for the extracellular domain of human GITRL. The DNA was cloned into expression vector pQE-30Xa that encodes a fusion tag of 6xHis before the insert. The resultant recombinant expression vector pQE/GITRL was subsequently transformed into E. coli strain M15[pREP4]. After induction with Isopropyl beta-D-Thiogalactoside (IPTG), the cells produced the fusion protein mainly in the form of inclusion bodies as identified by SDS-PAGE. The recombinant protein was purified by affinity chromatography through Ni-NTA column and recognized by anti-His polyclonal antibody using Western blotting analysis. Moreover, we established a simple, efficient and sensitive reporter gene-based method to detect the activity of the recombinant protein. The results showed that the target protein was biologically active. PMID:19670639

  14. Loop Dynamics of the Extracellular Domain of Human Tissue Factor and Activation of Factor VIIa

    PubMed Central

    Minazzo, Agnese S.; Darlington, Reuben C.; Ross, J.B. Alexander

    2009-01-01

    Abstract In the crystal structure of the complex between the soluble extracellular domain of tissue factor (sTF) and active-site-inhibited VIIa, residues 91 and 92 in the Pro79-Pro92 loop of sTF interact with the catalytic domain of VIIa. It is not known, however, whether this loop has a role in allosteric activation of VIIa. Time-resolved fluorescence anisotropy measurements of probes covalently bound to sTF mutants E84C and T121C show that binding uninhibited Factor VIIa affects segmental motions in sTF. Glu84 resides in the Pro79-Pro92 loop, and Thr121 resides in the turn between the first and second antiparallel β-strands of the sTF subdomain that interacts with the Gla and EGF1 domains of VIIa; neither Glu84 nor Thr121 makes direct contact with VIIa. Probes bound to T121C report limited segmental flexibility in free sTF, which is lost after VIIa binding. Probes bound to E84C report substantial segmental flexibility in the Pro79-Pro92 loop in free sTF, which is greatly reduced after VIIa binding. Thus, VIIa binding reduces dynamic motions in sTF. In particular, the decrease in the Pro79-Pro92 loop motions indicates that loop entropy has a role in the thermodynamics of the protein-protein interactions involved in allosteric control of VIIa activation. PMID:19167313

  15. Expression of extracellular matrix molecules typical of articular cartilage in the human scapholunate interosseous ligament

    PubMed Central

    Milz, S; Aktas, T; Putz, R; Benjamin, M

    2006-01-01

    The scapholunate interosseous ligament (SLIL) connects the scaphoid and lunate bones and plays a crucial role in carpal kinematics. Its rupture leads to carpal instability and impairment of radiocarpal joint function. As the ligament is one of the first structures affected in rheumatoid arthritis, we conducted an immunohistochemical study of cadaveric tissue to determine whether it contains known autoantigens for rheumatoid arthritis. We immunolabelled the ligament from one hand in 12 cadavers with monoclonal antibodies directed against a wide range of extracellular matrix (ECM) molecules associated with both fibrous and cartilaginous tissues. The labelling profile has also enabled us to comment on how the molecular composition of the ligament relates to its mechanical function. All regions of the ligament labelled for types I, III and VI collagens, chondroitin 4 and 6 sulphates, keratan sulphate, dermatan sulphate, versican, tenascin and cartilage oligomeric matrix protein (COMP). However, both entheses labelled strongly for type II collagen, aggrecan and link protein and were distinctly fibrocartilaginous. In some regions, the ligament attached to bone via a region of hyaline cartilage that was continuous with articular cartilage. Labelling for cartilage molecules in the midsubstance was most evident dorsally. We conclude that the SLIL has an ECM which is typical of other highly fibrocartilaginous ligaments that experience both tensile load and shear. The presence of aggrecan, link protein, COMP and type II collagen could explain why the ligament may be a target for autoantigenic destruction in some forms of rheumatoid arthritis. PMID:16761970

  16. Comparative Proteomics of Human Monkeypox and Vaccinia Intracellular Mature and Extracellular Enveloped Virions

    SciTech Connect

    Manes, Nathan P.; Estep, Ryan D.; Mottaz, Heather M.; Moore, Ronald J.; Clauss, Therese RW; Monroe, Matthew E.; Du, Xiuxia; Adkins, Joshua N.; Wong, Scott; Smith, Richard D.

    2008-03-07

    Orthopoxviruses are the largest and most complex of the animal viruses. In response to the recent emergence of monkeypox in Africa and the threat of smallpox bioterrorism, virulent (monkeypox virus) and benign (vaccinia virus) orthopoxviruses were proteomically compared with the goal of identifying proteins required for pathogenesis. Orthopoxviruses were grown in HeLa cells to two different viral forms (intracellular mature virus and extracellular enveloped virus), purified by sucrose gradient ultracentrifugation, denatured using RapiGest™ surfactant, and digested with trypsin. Unfractionated samples and strong cation exchange HPLC fractions were analyzed by reversed-phase LC-MS/MS, and analyses of the MS/MS spectra using SEQUEST® and X! Tandem resulted in the identification of hundreds of monkeypox, vaccinia, and copurified host proteins. The unfractionated samples were additionally analyzed by LC-MS on an LTQ-Orbitrap™, and the accurate mass and elution time tag approach was used to perform quantitative comparisons. Possible pathophysiological roles of differentially expressed orthopoxvirus genes are discussed.

  17. A compact and autoclavable system for acute extracellular neural recording and brain pressure monitoring for humans.

    PubMed

    Angotzi, Gian Nicola; Baranauskas, Gytis; Vato, Alessandro; Bonfanti, Andrea; Zambra, Guido; Maggiolini, Emma; Semprini, Marianna; Ricci, Davide; Ansaldo, Alberto; Castagnola, Elisa; Ius, Tamara; Skrap, Miran; Fadiga, Luciano

    2015-02-01

    One of the most difficult tasks for the surgeon during the removal of low-grade gliomas is to identify as precisely as possible the borders between functional and non-functional brain tissue with the aim of obtaining the maximal possible resection which allows to the patient the longer survival. For this purpose, systems for acute extracellular recordings of single neuron and multi-unit activity are considered promising. Here we describe a system to be used with 16 microelectrodes arrays that consists of an autoclavable headstage, a built-in inserter for precise electrode positioning and a system that measures and controls the pressure exerted by the headstage on the brain with a twofold purpose: to increase recording stability and to avoid disturbance of local perfusion which would cause a degradation of the quality of the recording and, eventually, local ischemia. With respect to devices where only electrodes are autoclavable, our design permits the reduction of noise arising from long cable connections preserving at the same time the flexibility and avoiding long-lasting gas sterilization procedures. Finally, size is much smaller and set up time much shorter compared to commercial systems currently in use in surgery rooms, making it easy to consider our system very useful for intra-operatory mapping operations. PMID:25486648

  18. Changes in vascular extracellular matrix composition during decidual spiral arteriole remodeling in early human pregnancy.

    PubMed

    Smith, Samantha D; Choudhury, Ruhul H; Matos, Patricia; Horn, James A; Lye, Stephen J; Dunk, Caroline E; Aplin, John D; Jones, Rebecca L; Harris, Lynda K

    2016-05-01

    Uterine spiral arteriole (SA) remodeling in early pregnancy involves a coordinated series of events including decidual immune cell recruitment, vascular cell disruption and loss, and colonization by placental-derived extravillous trophoblast (EVT). During this process, decidual SA are converted from narrow, muscular vessels into dilated channels lacking vasomotor control. We hypothesized that this extensive alteration in SA architecture must require significant reorganization and/or breakdown of the vascular extracellular matrix (ECM). First trimester decidua basalis (30 specimens) was immunostained to identify spiral arterioles undergoing trophoblast-independent and -dependent phases of remodeling. Serial sections were then immunostained for a panel of ECM markers, to examine changes in vascular ECM during the remodeling process. The initial stages of SA remodeling were characterized by loss of laminin, elastin, fibrillin, collagen types III, IV and VI from the basement membrane, vascular media and/or adventitia, and surrounding decidual stromal cells. Loss of ECM correlated with disruption and disorganization of vascular smooth muscle cells, and the majority of changes occurred prior to extensive colonization of the vessel wall by EVT. The final stages of SA remodeling, characterized by the arrival of EVT, were associated with the increased mural deposition of fibronectin and fibrinoid. This study provides the first detailed analysis of the spatial and temporal loss of ECM from the walls of remodeling decidual SA in early pregnancy. PMID:26602431

  19. A Lipid Mediator Hepoxilin A3 Is a Natural Inducer of Neutrophil Extracellular Traps in Human Neutrophils

    PubMed Central

    Douda, David N.; Grasemann, Hartmut; Pace-Asciak, Cecil

    2015-01-01

    Pulmonary exacerbations in cystic fibrosis airways are accompanied by inflammation, neutrophilia, and mucous thickening. Cystic fibrosis sputum contains a large amount of uncleared DNA contributed by neutrophil extracellular trap (NET) formation from neutrophils. The exact mechanisms of the induction of NETosis in cystic fibrosis airways remain unclear, especially in uninfected lungs of patients with early cystic fibrosis lung disease. Here we show that Hepoxilin A3, a proinflammatory eicosanoid, and the synthetic analog of Hepoxilin B3, PBT-3, directly induce NETosis in human neutrophils. Furthermore, we show that Hepoxilin A3-mediated NETosis is NADPH-oxidase-dependent at lower doses of Hepoxilin A3, while it is NADPH-oxidase-independent at higher doses. Together, these results demonstrate that Hepoxilin A3 is a previously unrecognized inducer of NETosis in cystic fibrosis lungs and may represent a new therapeutic target for treating cystic fibrosis and other inflammatory lung diseases. PMID:25784781

  20. Iron-chelating agent desferrioxamine stimulates formation of neutrophil extracellular traps (NETs) in human blood-derived neutrophils.

    PubMed

    Völlger, Lena; Akong-Moore, Kathryn; Cox, Linda; Goldmann, Oliver; Wang, Yanming; Schäfer, Simon T; Naim, Hassan Y; Nizet, Victor; von Köckritz-Blickwede, Maren

    2016-07-01

    Neutrophil extracellular trap (NET) formation is a significant innate immune defense mechanism against microbial infection that complements other neutrophil functions including phagocytosis and degranulation of antimicrobial peptides. NETs are decondensed chromatin structures in which antimicrobial components (histones, antimicrobial peptides and proteases) are deployed and mediate immobilization of microbes. Here we describe an effect of iron chelation on the phenotype of NET formation. Iron-chelating agent desferrioxamine (DFO) showed a modest but significant induction of NETs by freshly isolated human neutrophils as visualized and quantified by immunocytochemistry against histone-DNA complexes. Further analyses revealed that NET induction by iron chelation required NADPH-dependent production of reactive oxygen species (ROS) as well as protease and peptidyl-arginine-deiminase 4 (PAD4) activities, three key mechanistic pathways previously linked to NET formation. Our results demonstrate that iron chelation by DFO contributes to the formation of NETs and suggest a target for pharmacological manipulation of NET activity. PMID:27129288

  1. Nitrite Modification of Extracellular Matrix Alters CD46 Expression and VEGF Release in Human Retinal Pigment Epithelium

    PubMed Central

    Fields, Mark A.; Cai, Hui; Bowrey, Hannah E.; Moreira, Ernesto F.; Beck Gooz, Monika; Kunchithapautham, Kannan; Gong, Jie; Vought, Emma; Del Priore, Lucian V.

    2015-01-01

    Purpose Loss of CD46 has recently been implicated in choroidal neovascularization in mice. Herein we investigated the effect of nitrite modification of the extracellular matrix (ECM) as an in vitro model of “aging” and its effect on CD46 expression and vascular endothelial growth factor (VEGF) release in cocultured human retinal pigment epithelium (RPE). Methods ARPE-19 cells were plated onto RPE-derived ECM conditions (untreated; nitrite modified; nitrite modified followed by washing with Triton X-100; or nitrite modified followed by washing with Triton X-100 and coated with extracellular matrix ligands). Cells were cultured for 7 days and CD46 expression was analyzed by immunohistochemistry and Western blot. Additionally, CD46 short interfering RNA (siRNA) was transfected into ARPE-19 cells, and VEGF levels were determined by ELISA. Finally, in the same ECM conditions, ARPE-19 cells were challenged with normal human serum and VEGF levels determined by ELISA. Results CD46 is expressed on the basolateral surface of ARPE-19 cells on RPE-derived ECM. Nitrite modification of ECM reduced the expression of CD46 on ARPE-19 cells by 0.5-fold (P = 0.003) and increased VEGF release in ARPE-19 cells by 1.7-fold (P < 0.001). CD46 knockdown also increased release of VEGF on the apical and basal sides of ARPE-19 cells in culture by 1.3- (P = 0.012) and 1.2-fold (P = 0.017), respectively. Conclusions Nitrite modification of the ECM decreased CD46 expression and increased the release of VEGF from ARPE-19 cells. Changes in CD46 expression may lead to changes in VEGF and play a pathologic role in the development of age-related macular degeneration. PMID:26161984

  2. Effects of extracellular plaque components on the chlorhexidine sensitivity of strains of Streptococcus mutans and human dental plaque

    SciTech Connect

    Wolinsky, L.E.; Hume, W.R.

    1985-08-01

    An in vitro study was undertaken to determine the effects of sucrose-derived extracellular plaque components on the sensitivity of selected oral bacteria to chlorhexidine (CX). Cultures of Streptococcus mutans HS-6, OMZ-176, Ingbritt C, 6715-wt13, and pooled human plaque were grown in trypticase soy media with or without 1% sucrose. The sensitivity to CX of bacteria grown in each medium was determined by fixed-time exposure to CX and subsequent measurement of /sup 3/H-thymidine uptake. One-hour exposure to CX at concentrations of 10(-4) M (0.01% w/v) or greater substantially inhibited subsequent cellular division among all the S. mutans strains and human plaque samples tested. An IC50 (the CX concentration which depressed /sup 3/H-thymidine incorporation to 50% of control level) of close to 10(-4) M was noted for S. mutans strains HS-6, OMZ-176, and 6715-wt13 when grown in the presence of sucrose. The same strains grown in cultures without added sucrose showed about a ten-fold greater sensitivity to CX (IC50 close to 10(-5) M). A three-fold difference was noted for S. mutans Ingbritt C. Only a slight increase in the IC50 was noted for the plaque samples cultured in sucrose-containing media, but their threshold for depression of /sup 3/H-thymidine uptake by CX was lower than that for the sucrose-free plaque samples. The study showed that extracellular products confer some protection against CX to the bacteria examined, and provided an explanation for the disparity between clinically-recommended concentrations for plaque suppression and data on in vitro susceptibility.

  3. Comparison of four decontamination treatments on porcine renal decellularized extracellular matrix structure, composition, and support of human renal cortical tubular epithelium cells.

    PubMed

    Poornejad, Nafiseh; Nielsen, Jeffery J; Morris, Ryan J; Gassman, Jason R; Reynolds, Paul R; Roeder, Beverly L; Cook, Alonzo D

    2016-03-01

    Engineering whole organs from porcine decellularized extracellular matrix and human cells may lead to a plentiful source of implantable organs. Decontaminating the porcine decellularized extracellular matrix scaffolds is an essential step prior to introducing human cells. However, decontamination of whole porcine kidneys is a major challenge because the decontamination agent or irradiation needs to diffuse deep into the structure to eliminate all microbial contamination while minimizing damage to the structure and composition of the decellularized extracellular matrix. In this study, we compared four decontamination treatments that could be applicable to whole porcine kidneys: 70% ethanol, 0.2% peracetic acid in 1 M NaCl, 0.2% peracetic acid in 4% ethanol, and gamma (γ)-irradiation. Porcine kidneys were decellularized by perfusion of 0.5% (w/v) aqueous solution of sodium dodecyl sulfate and the four decontamination treatments were optimized using segments (n = 60) of renal tissue to ensure a consistent comparison. Although all four methods were successful in decontamination, γ-irradiation was very damaging to collagen fibers and glycosaminoglycans, leading to less proliferation of human renal cortical tubular epithelium cells within the porcine decellularized extracellular matrix. The effectiveness of the other three optimized solution treatments were then all confirmed using whole decellularized porcine kidneys (n = 3). An aqueous solution of 0.2% peracetic acid in 1 M NaCl was determined to be the best method for decontamination of porcine decellularized extracellular matrix. PMID:26589294

  4. Extracellular matrix-regulated neural differentiation of human multipotent marrow progenitor cells enhances functional recovery after spinal cord injury

    PubMed Central

    Deng, Win-Ping; Yang, Chi-Chiang; Yang, Liang-Yo; Chen, Chun-Wei D.; Chen, Wei-Hong; Yang, Charn-Bing; Chen, Yu-Hsin; Lai, Wen-Fu T.; Renshaw, Perry F.

    2015-01-01

    BACKGROUND CONTEXT Recent advanced studies have demonstrated that cytokines and extracellular matrix (ECM) could trigger various types of neural differentiation. However, the efficacy of differentiation and in vivo transplantation has not yet thoroughly been investigated. PURPOSE To highlight the current understanding of the effects of ECM on neural differentiation of human bone marrow-derived multipotent progenitor cells (MPCs), regarding state-of-art cure for the animal with acute spinal cord injury (SCI), and explore future treatments aimed at neural repair. STUDY DESIGN A selective overview of the literature pertaining to the neural differentiation of the MSCs and experimental animals aimed at improved repair of SCI. METHODS Extracellular matrix proteins, tenascin-cytotactin (TN-C), tenascin-restrictin (TN-R), and chondroitin sulfate (CS), with the cytokines, nerve growth factor (NGF)/brain-derived neurotrophic factor (BDNF)/retinoic acid (RA) (NBR), were incorporated to induce transdifferentiation of human MPCs. Cells were treated with NBR for 7 days, and then TN-C, TN-R, or CS was added for 2 days. The medium was changed every 2 days. Twenty-four animals were randomly assigned to four groups with six animals in each group: one experimental and three controls. Animals received two (bilateral) injections of vehicle, MPCs, NBR-induced MPCs, or NBR/TN-C-induced MPCs into the lesion sites after SCI. Functional assessment was measured using the Basso, Beattie, and Bresnahan locomotor rating score. Data were analyzed using analysis of variance followed by Student-Newman-Keuls (SNK) post hoc tests. RESULTS Results showed that MPCs with the transdifferentiation of human MPCs to neurons were associated with increased messenger-RNA (mRNA) expression of neuronal markers including nestin, microtubule-associated protein (MAP) 2, glial fibrillary acidic protein, βIII tubulin, and NGF. Greater amounts of neuronal morphology appeared in cultures incorporated with TN-C and TN

  5. Prostate-specific extracellular vesicles as a novel biomarker in human prostate cancer.

    PubMed

    Park, Yong Hyun; Shin, Hyun Woo; Jung, Ae Ryang; Kwon, Oh Sung; Choi, Yeong-Jin; Park, Jaesung; Lee, Ji Youl

    2016-01-01

    Extracellular vesicles (EVs) may play an important role in cancer development and progression. We aimed to investigate the prognostic potential of prostate-specific EVs in prostate cancer (PCa) patients. Plasma and prostate tissue were collected from patients who underwent surgery for PCa (n = 82) or benign prostatic hyperplasia (BPH, n = 28). To analyze the quantity of EVs in prostate, we performed transmission electron microscopy (TEM), immuno-TEM with CD63 and prostate-specific membrane antigen (PSMA), and immunofluorescence staining. After EV isolation from plasma, CD63 and PSMA concentration was measured using ELISA kits. PSMA-positive areas in prostate differed in patients with BPH, and low-, intermediate-, and high-risk PCa (2.4, 8.2, 17.5, 26.5%, p < 0.001). Plasma PSMA-positive EV concentration differed in patients with BPH, and low-, intermediate-, and high-risk PCa (21.9, 43.4, 49.2, 59.9 ng/mL, p < 0.001), and ROC curve analysis indicated that plasma PSMA-positive EV concentration differentiated PCa from BPH (AUC 0.943). Patients with lower plasma PSMA-positive EV concentration had greater prostate volume (50.2 vs. 33.4 cc, p < 0.001) and lower pathologic Gleason score (p = 0.025). During the median follow-up of 18 months, patients with lower plasma PSMA-positive EV concentration tended to have a lower risk of biochemical failure than those with higher levels of prostate-specific EVs (p = 0.085). PMID:27503267

  6. Prostate-specific extracellular vesicles as a novel biomarker in human prostate cancer

    PubMed Central

    Park, Yong Hyun; Shin, Hyun Woo; Jung, Ae Ryang; Kwon, Oh Sung; Choi, Yeong-Jin; Park, Jaesung; Lee, Ji Youl

    2016-01-01

    Extracellular vesicles (EVs) may play an important role in cancer development and progression. We aimed to investigate the prognostic potential of prostate-specific EVs in prostate cancer (PCa) patients. Plasma and prostate tissue were collected from patients who underwent surgery for PCa (n = 82) or benign prostatic hyperplasia (BPH, n = 28). To analyze the quantity of EVs in prostate, we performed transmission electron microscopy (TEM), immuno-TEM with CD63 and prostate-specific membrane antigen (PSMA), and immunofluorescence staining. After EV isolation from plasma, CD63 and PSMA concentration was measured using ELISA kits. PSMA-positive areas in prostate differed in patients with BPH, and low-, intermediate-, and high-risk PCa (2.4, 8.2, 17.5, 26.5%, p < 0.001). Plasma PSMA-positive EV concentration differed in patients with BPH, and low-, intermediate-, and high-risk PCa (21.9, 43.4, 49.2, 59.9 ng/mL, p < 0.001), and ROC curve analysis indicated that plasma PSMA-positive EV concentration differentiated PCa from BPH (AUC 0.943). Patients with lower plasma PSMA-positive EV concentration had greater prostate volume (50.2 vs. 33.4 cc, p < 0.001) and lower pathologic Gleason score (p = 0.025). During the median follow-up of 18 months, patients with lower plasma PSMA-positive EV concentration tended to have a lower risk of biochemical failure than those with higher levels of prostate-specific EVs (p = 0.085). PMID:27503267

  7. Extracellular complexes of the hematopoietic human and mouse CSF-1 receptor are driven by common assembly principles

    PubMed Central

    Elegheert, Jonathan; Desfosses, Ambroise; Shkumatov, Alexander V.; Wu, Xiongwu; Bracke, Nathalie; Verstraete, Kenneth; Van Craenenbroeck, Kathleen; Brooks, Bernard R.; Svergun, Dmitri I.; Vergauwen, Bjorn; Gutsche, Irina; Savvides, Savvas N.

    2011-01-01

    SUMMARY The hematopoietic Colony Stimulating Factor-1 receptor (CSF-1R or FMS) is essential for the development of diverse cell types central to the immune system. Here we report a structural and mechanistic consensus for the assembly of hematopoietic human and mouse CSF-1:CSF-1R complexes. The EM structure of the complete extracellular assembly of the human CSF-1:CSF-1R complex reveals how receptor dimerization by CSF-1 invokes a ternary complex featuring extensive homotypic receptor contacts that contribute 15-fold to the affinity of the complex, and striking structural plasticity at the extremities of the complex. Small-angle X-ray scattering analysis of unliganded hCSF-1R points to large domain rearrangements upon CSF-1 binding, and provides structural evidence for the relevance of receptor predimerization at the cell-surface. Comparative structural and binding studies of human and mouse CSF-1R complexes, including a quantification of the CSF-1/CSF-1R species cross-reactivity, show that bivalent cytokine binding to receptor is a common denominator in complex formation independent of receptor homotypic interactions. PMID:22153499

  8. In vitro elastogenesis: instructing human vascular smooth muscle cells to generate an elastic fiber-containing extracellular matrix scaffold.

    PubMed

    Hinderer, Svenja; Shena, Nian; Ringuette, Léa-Jeanne; Hansmann, Jan; Reinhardt, Dieter P; Brucker, Sara Y; Davis, Elaine C; Schenke-Layland, Katja

    2015-06-01

    Elastic fibers are essential for the proper function of organs including cardiovascular tissues such as heart valves and blood vessels. Although (tropo)elastin production in a tissue-engineered construct has previously been described, the assembly to functional elastic fibers in vitro using human cells has been highly challenging. In the present study, we seeded primary isolated human vascular smooth muscle cells (VSMCs) onto 3D electrospun scaffolds and exposed them to defined laminar shear stress using a customized bioreactor system. Increased elastin expression followed by elastin deposition onto the electrospun scaffolds, as well as on newly formed fibers, was observed after six days. Most interestingly, we identified the successful deposition of elastogenesis-associated proteins, including fibrillin-1 and -2, fibulin-4 and -5, fibronectin, elastin microfibril interface located protein 1 (EMILIN-1) and lysyl oxidase (LOX) within our engineered constructs. Ultrastructural analyses revealed a developing extracellular matrix (ECM) similar to native human fetal tissue, which is composed of collagens, microfibrils and elastin. To conclude, the combination of a novel dynamic flow bioreactor and an electrospun hybrid polymer scaffold allowed the production and assembly of an elastic fiber-containing ECM. PMID:25784676

  9. Differentiation of human embryonic stem cells to hepatocyte-like cells on a new developed xeno-free extracellular matrix.

    PubMed

    Farzaneh, Zahra; Pakzad, Mohammad; Vosough, Massoud; Pournasr, Behshad; Baharvand, Hossein

    2014-08-01

    Human embryonic stem cells (hESCs) provide a new source for hepatocyte production in translational medicine and cell replacement therapy. The reported hESC-derived hepatocyte-like cells (HLCs) were commonly generated on Matrigel, a mouse cell line-derived extracellular matrix (ECM). Here, we performed the hepatic lineage differentiation of hESCs following a stepwise application of growth factors on a newly developed serum- and xeno-free, simple and cost-benefit ECM, designated "RoGel," which generated from a modified conditioned medium of human fibroblasts. In comparison with Matrigel, the differentiated HLCs on both ECMs expressed similar levels of hepatocyte-specific genes, secreted α-fetoprotein, and metabolized ammonia, showed glycogen storage activity as well as low-density lipoprotein and indocyanine green uptake. The transplantation of hESC-HLCs into the carbon tetrachloride-injured liver demonstrated incorporation of the cells into the host mouse liver and the expression of albumin. The results suggest that the xeno-free and cost-benefit matrix may be applicable in bioartificial livers and also may facilitating a clinical application of human pluripotent stem cell-derived hepatocytes in the future. PMID:24477550

  10. CsrRS and environmental pH regulate group B streptococcus adherence to human epithelial cells and extracellular matrix.

    PubMed

    Park, Su Eun; Jiang, Shengmei; Wessels, Michael R

    2012-11-01

    Streptococcus agalactiae (group B Streptococcus or GBS) is a common colonizer of the gastrointestinal and genital tracts and an important cause of invasive infections in newborn infants and in adults with predisposing chronic conditions or advanced age. Attachment to epithelial surfaces at mucosal sites is a critical step in the successful colonization of a human host, and regulation of this process is likely to play an important role in both commensalism and dissemination to cause invasive disease. We found that inactivation of the CsrRS (or CovRS) two-component system increased GBS adherence to epithelial cells derived from human vaginal, cervical, and respiratory epithelium, as well as increasing adherence to extracellular matrix proteins and increasing biofilm formation on polystyrene. Neutral (as opposed to acidic) pH enhanced GBS binding to vaginal epithelial cells and to fibrinogen and fibronectin, effects that were partially dependent on CsrRS. The regulatory effects of CsrRS and environmental pH on bacterial adherence correlated with their effects on the expression of multiple surface adhesins, as assessed by quantitative reverse transcription-PCR. We conclude that GBS adherence to epithelial and abiotic surfaces is regulated by the CsrRS two-component system and by environmental pH through their regulatory effects on the expression of bacterial surface adhesins. Dynamic regulation of GBS adherence enhances the organism's adaptability to survival in multiple niches in the human host. PMID:22949550

  11. CsrRS and Environmental pH Regulate Group B Streptococcus Adherence to Human Epithelial Cells and Extracellular Matrix

    PubMed Central

    Park, Su Eun; Jiang, Shengmei

    2012-01-01

    Streptococcus agalactiae (group B Streptococcus or GBS) is a common colonizer of the gastrointestinal and genital tracts and an important cause of invasive infections in newborn infants and in adults with predisposing chronic conditions or advanced age. Attachment to epithelial surfaces at mucosal sites is a critical step in the successful colonization of a human host, and regulation of this process is likely to play an important role in both commensalism and dissemination to cause invasive disease. We found that inactivation of the CsrRS (or CovRS) two-component system increased GBS adherence to epithelial cells derived from human vaginal, cervical, and respiratory epithelium, as well as increasing adherence to extracellular matrix proteins and increasing biofilm formation on polystyrene. Neutral (as opposed to acidic) pH enhanced GBS binding to vaginal epithelial cells and to fibrinogen and fibronectin, effects that were partially dependent on CsrRS. The regulatory effects of CsrRS and environmental pH on bacterial adherence correlated with their effects on the expression of multiple surface adhesins, as assessed by quantitative reverse transcription-PCR. We conclude that GBS adherence to epithelial and abiotic surfaces is regulated by the CsrRS two-component system and by environmental pH through their regulatory effects on the expression of bacterial surface adhesins. Dynamic regulation of GBS adherence enhances the organism's adaptability to survival in multiple niches in the human host. PMID:22949550

  12. Heterogeneous Differentiation of Human Mesenchymal Stem Cells in 3D Extracellular Matrix Composites

    PubMed Central

    Jung, Jangwook P.; Bache-Wiig, Meredith K.; Provenzano, Paolo P.; Ogle, Brenda M.

    2016-01-01

    Abstract Extracellular matrix (ECM) proteins are structural elements of tissue and also potent signaling molecules. Previously, our laboratory showed that ECM of 2D coatings can trigger differentiation of bone marrow-derived mesenchymal stem cells (MSCs) into mesodermal lineages in an ECM-specific manner over 14 days, in some cases comparable to chemical induction. To test whether a similar effect was possible in a 3D, tissue-like environment, we designed a synthetic-natural biomaterial composite. The composite can present whole-molecule ECM proteins to cells, even those that do not spontaneously form hydrogels ex vivo, in 3D. To this end, we entrapped collagen type I, laminin-111, or fibronectin in ECM composites with MSCs and directly compared markers of mesodermal differentiation including cardiomyogenic (ACTC1), osteogenic (SPP1), adipogenic (PPARG), and chondrogenic (SOX9) in 2D versus 3D. We found the 3D condition largely mimicked the 2D condition such that the addition of type I collagen was the most potent inducer of differentiation to all lineages tested. One notable difference between 2D and 3D was pronounced adipogenic differentiation in 3D especially in the presence of exogenous collagen type I. In particular, PPARG gene expression was significantly increased ∼16-fold relative to chemical induction, in 3D and not in 2D. Unexpectedly, 3D engagement of ECM proteins also altered immunomodulatory function of MSCs in that expression of IL-6 gene was elevated relative to basal levels in 2D. In fact, levels of IL-6 gene expression in 3D composites containing exogenously supplied collagen type I or fibronectin were statistically similar to levels attained in 2D with tumor necrosis factor-α (TNF-α) stimulation and these levels were sustained over a 2-week period. Thus, this novel biomaterial platform allowed us to compare the biochemical impact of whole-molecule ECM proteins in 2D versus 3D indicating enhanced adipogenic differentiation and IL-6 expression

  13. Heterogeneous Differentiation of Human Mesenchymal Stem Cells in 3D Extracellular Matrix Composites.

    PubMed

    Jung, Jangwook P; Bache-Wiig, Meredith K; Provenzano, Paolo P; Ogle, Brenda M

    2016-01-01

    Extracellular matrix (ECM) proteins are structural elements of tissue and also potent signaling molecules. Previously, our laboratory showed that ECM of 2D coatings can trigger differentiation of bone marrow-derived mesenchymal stem cells (MSCs) into mesodermal lineages in an ECM-specific manner over 14 days, in some cases comparable to chemical induction. To test whether a similar effect was possible in a 3D, tissue-like environment, we designed a synthetic-natural biomaterial composite. The composite can present whole-molecule ECM proteins to cells, even those that do not spontaneously form hydrogels ex vivo, in 3D. To this end, we entrapped collagen type I, laminin-111, or fibronectin in ECM composites with MSCs and directly compared markers of mesodermal differentiation including cardiomyogenic (ACTC1), osteogenic (SPP1), adipogenic (PPARG), and chondrogenic (SOX9) in 2D versus 3D. We found the 3D condition largely mimicked the 2D condition such that the addition of type I collagen was the most potent inducer of differentiation to all lineages tested. One notable difference between 2D and 3D was pronounced adipogenic differentiation in 3D especially in the presence of exogenous collagen type I. In particular, PPARG gene expression was significantly increased ∼16-fold relative to chemical induction, in 3D and not in 2D. Unexpectedly, 3D engagement of ECM proteins also altered immunomodulatory function of MSCs in that expression of IL-6 gene was elevated relative to basal levels in 2D. In fact, levels of IL-6 gene expression in 3D composites containing exogenously supplied collagen type I or fibronectin were statistically similar to levels attained in 2D with tumor necrosis factor-α (TNF-α) stimulation and these levels were sustained over a 2-week period. Thus, this novel biomaterial platform allowed us to compare the biochemical impact of whole-molecule ECM proteins in 2D versus 3D indicating enhanced adipogenic differentiation and IL-6 expression of MSC in

  14. Extracellular matrix components supporting human islet function in alginate-based immunoprotective microcapsules for treatment of diabetes.

    PubMed

    Llacua, Alberto; de Haan, Bart J; Smink, Sandra A; de Vos, Paul

    2016-07-01

    In the pancreas, extracellular matrix (ECM) components play an import role in providing mechanical and physiological support, and also contribute to the function of islets. These ECM-connections are damaged during islet-isolation from the pancreas and are not fully recovered after encapsulation and transplantation. To promote the functional survival of human pancreatic islets, we tested different ECMs molecules in alginate-encapsulated human islets. These were laminin derived recognition sequences, IKVAV, RGD, LRE, PDSGR, collagen I sequence DGEA (0.01 - 1.0 mM), and collagen IV (50 - 200 µg/mL). Interaction with RGD and PDSGR promoted islet viability and glucose induced insulin secretion (GIIS) when it was applied at concentrations ranging from 0.01 - 1.0 mM (p < 0.05). Also the laminin sequence LRE contributed to enhanced GIIS but only at higher concentrations of 1 mM (p < 0.05). Collagen IV also had beneficial effects but only at 50 µg/ml and no further improvement was observed at higher concentrations. IKVAV and DGEA had no effects on human islets. Synergistic effects were observed by adding Collagen(IV)-RGD, Collagen(IV)-LRE, and Collagen(IV)-PDSGR to encapsulated human islets. Our results demonstrate the potential of specific ECM components in support of functional survival of human encapsulated and free islet grafts. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1788-1796, 2016. PMID:26990360

  15. Oxidized LDL induced extracellular trap formation in human neutrophils via TLR-PKC-IRAK-MAPK and NADPH-oxidase activation.

    PubMed

    Awasthi, Deepika; Nagarkoti, Sheela; Kumar, Amit; Dubey, Megha; Singh, Abhishek Kumar; Pathak, Priya; Chandra, Tulika; Barthwal, Manoj Kumar; Dikshit, Madhu

    2016-04-01

    Neutrophil extracellular traps (NETs) formation was initially linked with host defence and extracellular killing of pathogens. However, recent studies have highlighted their inflammatory potential. Oxidized low density lipoprotein (oxLDL) has been implicated as an independent risk factor in various acute or chronic inflammatory diseases including systemic inflammatory response syndrome (SIRS). In the present study we investigated effect of oxLDL on NETs formation and elucidated the underlying signalling mechanism. Treatment of oxLDL to adhered PMNs led to a time and concentration dependent ROS generation and NETs formation. OxLDL induced free radical formation and NETs release were significantly prevented in presence of NADPH oxidase (NOX) inhibitors suggesting role of NOX activation in oxLDL induced NETs release. Blocking of both toll like receptor (TLR)-2 and 6 significantly reduced oxLDL induced NETs formation indicating requirement of both the receptors. We further identified Protein kinase C (PKC), Interleukin-1 receptor associated kinase (IRAKs), mitogen-activated protein kinase (MAPK) pathway as downstream intracellular signalling mediators involved in oxLDL induced NETs formation. OxLDL components such as oxidized phospholipids (lysophosphatidylcholine (LPC) and oxidized 1-palmitoyl-2-arachidonyl-sn-glycero-3-phosphorylcholine (oxPAPC)) were most potent NETs inducers and might be crucial for oxLDL mediating NETs release. Other components like, oxysterols, malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) were however less potent as compared to oxidized phospholipids. This study thus demonstrates for the first time that treatment of human PMNs with oxLDL or its various oxidized phopholipid component mediated NETs release, implying their role in the pathogenesis of inflammatory diseases such as SIRS. PMID:26774674

  16. Superoxide dismutases in chronic gastritis.

    PubMed

    Švagelj, Dražen; Terzić, Velimir; Dovhanj, Jasna; Švagelj, Marija; Cvrković, Mirta; Švagelj, Ivan

    2016-04-01

    Human gastric diseases have shown significant changes in the activity and expression of superoxide dismutase (SOD) isoforms. The aim of this study was to detect Mn-SOD activity and expression in the tissue of gastric mucosa, primarily in chronic gastritis (immunohistochemical Helicobacter pylori-negative gastritis, without other pathohistological changes) and to evaluate their possible connection with pathohistological diagnosis. We examined 51 consecutive outpatients undergoing endoscopy for upper gastrointestinal symptoms. Patients were classified based on their histopathological examinations and divided into three groups: 51 patients (archive samples between 2004-2009) with chronic immunohistochemical Helicobacter pylori-negative gastritis (mononuclear cells infiltration were graded as absent, moderate, severe) divided into three groups. Severity of gastritis was graded according to the updated Sydney system. Gastric tissue samples were used to determine the expression of Mn-SOD with anti-Mn-SOD Ab immunohistochemically. The Mn-SOD expression was more frequently present in specimens with severe and moderate inflammation of gastric mucosa than in those with normal mucosa. In patients with normal histological finding, positive immunoreactivity of Mn-SOD was not found. Our results determine the changes in Mn-SOD expression occurring in the normal gastric mucosa that had undergone changes in the intensity of chronic inflammatory infiltrates in the lamina propria. PMID:26765960

  17. Mannosylerythritol lipid, a yeast extracellular glycolipid, shows high binding affinity towards human immunoglobulin G

    PubMed Central

    Im, Jae Hong; Nakane, Takashi; Yanagishita, Hiroshi; Ikegami, Toru; Kitamoto, Dai

    2001-01-01

    Background There have been many attempts to develop new materials with stability and high affinity towards immunoglobulins. Some of glycolipids such as gangliosides exhibit a high affinity toward immunoglobulins. However, it is considerably difficult to develop these glycolipids into the practical separation ligand due to their limited amounts. We thus focused our attention on the feasible use of "mannosylerythritol lipid A", a yeast glycolipid biosurfactant, as an alternative ligand for immunoglobulins, and undertook the investigation on the binding between mannosylerythritol lipid A (MEL-A) and human immunoglobulin G (HIgG). Results In ELISA assay, MEL-A showed nearly the same binding affinity towards HIgG as that of bovine ganglioside GM1. Fab of human IgG was considered to play a more important role than Fc in the binding of HIgG by MEL-A. The bound amount of HIgG increased depending on the attached amount of MEL-A onto poly (2-hydroxyethyl methacrylate) (polyHEMA) beads, whereas the amount of human serum albumin slightly decreased. Binding-amount and -selectivity of HIgG towards MEL-A were influenced by salt species, salt concentration and pH in the buffer solution. The composite of MEL-A and polyHEMA, exhibited a significant binding constant of 1.43 × 106 (M-1) for HIgG, which is approximately 4-fold greater than that of protein A reported. Conclusions MEL-A shows high binding-affinity towards HIgG, and this is considered to be due to "multivalent effect" based on the binding molar ratio. This is the first report on the binding of a natural human antibody towards a yeast glycolipid. PMID:11604104

  18. The generation of hybrid electrospun nanofiber layer with extracellular matrix derived from human pluripotent stem cells, for regenerative medicine applications.

    PubMed

    Shtrichman, Ronit; Zeevi-Levin, Naama; Zaid, Rinat; Barak, Efrat; Fishman, Bettina; Ziskind, Anna; Shulman, Rita; Novak, Atara; Avrahami, Ron; Livne, Erella; Lowenstein, Lior; Zussman, Eyal; Itskovitz-Eldor, Joseph

    2014-10-01

    Extracellular matrix (ECM) has been utilized as a biological scaffold for tissue engineering applications in a variety of body systems, due to its bioactivity and biocompatibility. In the current study we developed a modified protocol for the efficient and reproducible derivation of mesenchymal progenitor cells (MPCs) from human embryonic stem cells as well as human induced pluripotent stem cells (hiPSCs) originating from hair follicle keratinocytes (HFKTs). ECM was produced from these MPCs and characterized in comparison to adipose mesenchymal stem cell ECM, demonstrating robust ECM generation by the excised HFKT-iPSC-MPCs. Exploiting the advantages of electrospinning we generated two types of electrospun biodegradable nanofiber layers (NFLs), fabricated from polycaprolactone (PCL) and poly(lactic-co-glycolic acid) (PLGA), which provide mechanical support for cell seeding and ECM generation. Elucidating the optimized decellularization treatment we were able to generate an available "off-the-shelf" implantable product (NFL-ECM). Using rat subcutaneous transplantation model we demonstrate that this stem-cell-derived construct is biocompatible and biodegradable and holds great potential for tissue regeneration applications. PMID:25185111

  19. Osteoblasts secrete miRNA-containing extracellular vesicles that enhance expansion of human umbilical cord blood cells.

    PubMed

    Morhayim, Jess; van de Peppel, Jeroen; Braakman, Eric; Rombouts, Elwin W J C; Ter Borg, Mariette N D; Dudakovic, Amel; Chiba, Hideki; van der Eerden, Bram C J; Raaijmakers, Marc H; van Wijnen, Andre J; Cornelissen, Jan J; van Leeuwen, Johannes P

    2016-01-01

    Osteolineage cells represent one of the critical bone marrow niche components that support maintenance of hematopoietic stem and progenitor cells (HSPCs). Recent studies demonstrate that extracellular vesicles (EVs) regulate stem cell development via horizontal transfer of bioactive cargo, including microRNAs (miRNAs). Using next-generation sequencing we show that human osteoblast-derived EVs contain highly abundant miRNAs specifically enriched in EVs, including critical regulators of hematopoietic proliferation (e.g., miR-29a). EV treatment of human umbilical cord blood-derived CD34(+) HSPCs alters the expression of candidate miRNA targets, such as HBP1, BCL2 and PTEN. Furthermore, EVs enhance proliferation of CD34(+) cells and their immature subsets in growth factor-driven ex vivo expansion cultures. Importantly, EV-expanded cells retain their differentiation capacity in vitro and successfully engraft in vivo. These discoveries reveal a novel osteoblast-derived EV-mediated mechanism for regulation of HSPC proliferation and warrant consideration of EV-miRNAs for the development of expansion strategies to treat hematological disorders. PMID:27585950

  20. Regeneration of Cartilage in Human Knee Osteoarthritis with Autologous Adipose Tissue-Derived Stem Cells and Autologous Extracellular Matrix

    PubMed Central

    Pak, Jaewoo; Lee, Jung Hun; Park, Kwang Seung; Jeong, Byeong Chul; Lee, Sang Hee

    2016-01-01

    Abstract This clinical case series demonstrates that percutaneous injections of autologous adipose tissue-derived stem cells (ADSCs) and homogenized extracellular matrix (ECM) in the form of adipose stromal vascular fraction (SVF), along with hyaluronic acid (HA) and platelet-rich plasma (PRP) activated by calcium chloride, could regenerate cartilage-like tissue in human knee osteoarthritis (OA) patients. Autologous lipoaspirates were obtained from adipose tissue of the abdominal origin. Afterward, the lipoaspirates were minced to homogenize the ECM. These homogenized lipoaspirates were then mixed with collagenase and incubated. The resulting mixture of ADSCs and ECM in the form of SVF was injected, along with HA and PRP activated by calcium chloride, into knees of three Korean patients with OA. The same affected knees were reinjected weekly with additional PRP activated by calcium chloride for 3 weeks. Pretreatment and post-treatment magnetic resonance imaging (MRI) data, functional rating index, range of motion (ROM), and pain score data were then analyzed. All patients' MRI data showed cartilage-like tissue regeneration. Along with MRI evidence, the measured physical therapy outcomes in terms of ROM, subjective pain, and functional status were all improved. This study demonstrates that percutaneous injection of ADSCs with ECM contained in autologous adipose SVF, in conjunction with HA and PRP activated by calcium chloride, is a safe and potentially effective minimally invasive therapy for OA of human knees. PMID:27588219

  1. Establishment and characterization of intraperitoneal xenograft models by co-injection of human tumor cells and extracellular matrix gel

    PubMed Central

    YAO, YUQIN; ZHOU, YONGJUN; SU, XIAOLAN; DAI, LEI; YU, LIN; DENG, HONGXIN; GOU, LANTU; YANG, JINLIANG

    2015-01-01

    Establishing a feasible intraperitoneal (i.p.) xenograft model in nude mice is a good strategy to evaluate the antitumor effect of drugs in vivo. However, the manipulation of human cancer cells in establishing a stable peritoneal carcinomatosis model in nude mice is problematic. In the present study, the ovarian and colorectal peritoneal tumor models were successfully established in nude mice by co-injection of human tumor cells and extracellular matrix gel. In ovarian tumor models, the mean number tumor nodes was significantly higher in the experimental group (intraperitoneal tumor cell co-injection with ECM gel) compared with the PBS control group on the 30th day (21.0±3.0 vs. 3.6±2.5; P<0.05). The same results were observed in the colorectal peritoneal tumor models on the 28th day. The colorectal peritoneal tumor model was further used to evaluate the chemotherapy effect of irinotecan (CPT-11). The mean weight of peritoneal tumor nodes in CPT-11 treatment group was significantly less than that of the control group (0.81±0.16 vs. 2.18±0.21 g; P<0.05). The results confirmed the value of these i.p. xenograft models in nude mice as efficient and feasible tools for preclinical evaluation. PMID:26788149

  2. Meniscus Tissue Engineering Using a Novel Combination of Electrospun Scaffolds and Human Meniscus Cells Embedded within an Extracellular Matrix Hydrogel

    PubMed Central

    Baek, Jihye; Chen, Xian; Sovani, Sujata; Jin, Sungho; Grogan, Shawn P; D’Lima, Darryl D

    2015-01-01

    Meniscus injury and degeneration have been linked to the development of secondary osteoarthritis (OA). Therapies that successfully repair or replace the meniscus are therefore likely to prevent or delay OA progression. We investigated the novel approach of building layers of aligned polylactic acid (PLA) electrospun (ES) scaffolds with human meniscus cells embedded in extracellular matrix (ECM) hydrogel to lead to formation of neotissues that resemble meniscus-like tissue. PLA ES scaffolds with randomly oriented or aligned fibers were seeded with human meniscus cells derived from vascular or avascular regions. Cell viability, cell morphology, and gene expression profiles were monitored via confocal microscopy, scanning electron microscopy (SEM), and real-time PCR, respectively. Seeded scaffolds were used to produce multilayered constructs and were examined via histology and immunohistochemistry. Morphology and mechanical properties of PLA scaffolds (with and without cells) were influenced by fiber direction of the scaffolds. Both PLA scaffolds supported meniscus tissue formation with increased COL1A1, SOX9, COMP, yet no difference in gene expression was found between random and aligned PLA scaffolds. Overall, ES materials, which possess mechanical strength of meniscus and can support neotissue formation, show potential for use in cell-based meniscus regeneration strategies. PMID:25640671

  3. Bioprinting 3D cell-laden hydrogel microarray for screening human periodontal ligament stem cell response to extracellular matrix.

    PubMed

    Ma, Yufei; Ji, Yuan; Huang, Guoyou; Ling, Kai; Zhang, Xiaohui; Xu, Feng

    2015-01-01

    Periodontitis is an inflammatory disease negatively affecting up to 15% of adults worldwide. Periodontal ligament stem cells (PDLSCs) hold great promises for periodontal tissue regeneration, where it is necessary to find proper extracellular matrix (ECM) materials (e.g., composition, concentration). In this study, we proposed a bioprinting-based approach to generate nano-liter sized three-dimensional (3D) cell-laden hydrogel array with gradient of ECM components, through controlling the volume ratio of two hydrogels, such as gelatin methacrylate (GelMA) and poly(ethylene glycol) (PEG) dimethacrylate. The resulting cell-laden array with a gradient of GelMA/PEG composition was used to screen human PDLSC response to ECM. The behavior (e.g., cell viability, spreading) of human PDLSCs in GelMA/PEG array were found to be depended on the volume ratios of GelMA/PEG, with cell viability and spreading area decreased along with increasing the ratio of PEG. The developed approach would be useful for screening cell-biomaterial interaction in 3D and promoting regeneration of functional tissue. PMID:26696269

  4. Autoimmune disease-associated variants of extracellular endoplasmic reticulum aminopeptidase 1 induce altered innate immune responses by human immune cells

    PubMed Central

    Aldhamen, Yasser A.; Pepelyayeva, Yuliya; Rastall, David P.W.; Seregin, Sergey S.; Zervoudi, Efthalia; Koumantou, Despoina; Aylsworth, Charles F.; Quiroga, Dionisia; Godbehere, Sarah; Georgiadis, Dimitris; Stratikos, Efstratios; Amalfitano, Andrea

    2015-01-01

    ERAP1 gene polymorphisms have been linked to several autoimmune diseases; however, the molecular mechanisms underlying these associations are not well understood. Recently, we have demonstrated that ERAP1 regulates key aspects of the innate immune response. Moreover, previous studies show ERAP1 to be ER-localized and secreted during inflammation. Herein, we investigate the possible roles that ERAP1 polymorphic variants may have in modulating innate immune responses of human PBMCs using two experimental methods: extracellular exposure of hPBMCs to ERAP1 variants and adenovirus-based ERAP1 expression. We found that exposure of hPBMCs to ERAP1 variant proteins as well as ERAP1 overexpression by Ad vectors increased inflammatory cytokine and chemokine production, and enhanced immune cell activation. Investigating the molecular mechanisms behind these responses revealed that ERAP1 is able to activate innate immunity via multiple pathways, including the NLRP3 inflammasome. Importantly, these responses varied if autoimmune-disease-associated variants of ERAP1 were examined in the assay systems. Unexpectedly, blocking ERAP1 cellular internalization augmented IL-1β production. To our knowledge, this is the first report identifying ERAP1 as being involved in modulating innate responses of human immune cells, a finding that may explain why ERAP1 has been genetically associated with several autoimmune diseases. PMID:25591727

  5. Shell Extracts from the Marine Bivalve Pecten maximus Regulate the Synthesis of Extracellular Matrix in Primary Cultured Human Skin Fibroblasts

    PubMed Central

    Latire, Thomas; Legendre, Florence; Bigot, Nicolas; Carduner, Ludovic; Kellouche, Sabrina; Bouyoucef, Mouloud; Carreiras, Franck; Marin, Frédéric; Lebel, Jean-Marc; Galéra, Philippe; Serpentini, Antoine

    2014-01-01

    Mollusc shells are composed of more than 95% calcium carbonate and less than 5% of an organic matrix consisting mostly of proteins, glycoproteins and polysaccharides. Previous studies have elucidated the biological activities of the shell matrices from bivalve molluscs on skin, especially on the expression of the extracellular matrix components of fibroblasts. In this work, we have investigated the potential biological activities of shell matrix components extracted from the shell of the scallop Pecten maximus on human fibroblasts in primary culture. Firstly, we demonstrated that shell matrix components had different effects on general cellular activities. Secondly, we have shown that the shell matrix components stimulate the synthesis of type I and III collagens, as well as that of sulphated GAGs. The increased expression of type I collagen is likely mediated by the recruitment of transactivating factors (Sp1, Sp3 and human c-Krox) in the −112/−61 bp COL1A1 promoter region. Finally, contrarily to what was obtained in previous works, we demonstrated that the scallop shell extracts have only a small effect on cell migration during in vitro wound tests and have no effect on cell proliferation. Thus, our research emphasizes the potential use of shell matrix of Pecten maximus for dermo-cosmetic applications. PMID:24949635

  6. Shell extracts from the marine bivalve Pecten maximus regulate the synthesis of extracellular matrix in primary cultured human skin fibroblasts.

    PubMed

    Latire, Thomas; Legendre, Florence; Bigot, Nicolas; Carduner, Ludovic; Kellouche, Sabrina; Bouyoucef, Mouloud; Carreiras, Franck; Marin, Frédéric; Lebel, Jean-Marc; Galéra, Philippe; Serpentini, Antoine

    2014-01-01

    Mollusc shells are composed of more than 95% calcium carbonate and less than 5% of an organic matrix consisting mostly of proteins, glycoproteins and polysaccharides. Previous studies have elucidated the biological activities of the shell matrices from bivalve molluscs on skin, especially on the expression of the extracellular matrix components of fibroblasts. In this work, we have investigated the potential biological activities of shell matrix components extracted from the shell of the scallop Pecten maximus on human fibroblasts in primary culture. Firstly, we demonstrated that shell matrix components had different effects on general cellular activities. Secondly, we have shown that the shell matrix components stimulate the synthesis of type I and III collagens, as well as that of sulphated GAGs. The increased expression of type I collagen is likely mediated by the recruitment of transactivating factors (Sp1, Sp3 and human c-Krox) in the -112/-61 bp COL1A1 promoter region. Finally, contrarily to what was obtained in previous works, we demonstrated that the scallop shell extracts have only a small effect on cell migration during in vitro wound tests and have no effect on cell proliferation. Thus, our research emphasizes the potential use of shell matrix of Pecten maximus for dermo-cosmetic applications. PMID:24949635

  7. Regeneration of Cartilage in Human Knee Osteoarthritis with Autologous Adipose Tissue-Derived Stem Cells and Autologous Extracellular Matrix.

    PubMed

    Pak, Jaewoo; Lee, Jung Hun; Park, Kwang Seung; Jeong, Byeong Chul; Lee, Sang Hee

    2016-01-01

    This clinical case series demonstrates that percutaneous injections of autologous adipose tissue-derived stem cells (ADSCs) and homogenized extracellular matrix (ECM) in the form of adipose stromal vascular fraction (SVF), along with hyaluronic acid (HA) and platelet-rich plasma (PRP) activated by calcium chloride, could regenerate cartilage-like tissue in human knee osteoarthritis (OA) patients. Autologous lipoaspirates were obtained from adipose tissue of the abdominal origin. Afterward, the lipoaspirates were minced to homogenize the ECM. These homogenized lipoaspirates were then mixed with collagenase and incubated. The resulting mixture of ADSCs and ECM in the form of SVF was injected, along with HA and PRP activated by calcium chloride, into knees of three Korean patients with OA. The same affected knees were reinjected weekly with additional PRP activated by calcium chloride for 3 weeks. Pretreatment and post-treatment magnetic resonance imaging (MRI) data, functional rating index, range of motion (ROM), and pain score data were then analyzed. All patients' MRI data showed cartilage-like tissue regeneration. Along with MRI evidence, the measured physical therapy outcomes in terms of ROM, subjective pain, and functional status were all improved. This study demonstrates that percutaneous injection of ADSCs with ECM contained in autologous adipose SVF, in conjunction with HA and PRP activated by calcium chloride, is a safe and potentially effective minimally invasive therapy for OA of human knees. PMID:27588219

  8. Autoimmune disease-associated variants of extracellular endoplasmic reticulum aminopeptidase 1 induce altered innate immune responses by human immune cells.

    PubMed

    Aldhamen, Yasser A; Pepelyayeva, Yuliya; Rastall, David P W; Seregin, Sergey S; Zervoudi, Efthalia; Koumantou, Despoina; Aylsworth, Charles F; Quiroga, Dionisia; Godbehere, Sarah; Georgiadis, Dimitris; Stratikos, Efstratios; Amalfitano, Andrea

    2015-01-01

    Endoplasmic reticulum aminopeptidase 1 (ERAP1) gene polymorphisms have been linked to several autoimmune diseases; however, the molecular mechanisms underlying these associations are not well understood. Recently, we demonstrated that ERAP1 regulates key aspects of the innate immune response. Previous studies show ERAP1 to be endoplasmic reticulum-localized and secreted during inflammation. Herein, we investigate the possible roles that ERAP1 polymorphic variants may have in modulating the innate immune responses of human peripheral blood mononuclear cells (hPBMCs) using two experimental methods: extracellular exposure of hPBMCs to ERAP1 variants and adenovirus (Ad)-based ERAP1 expression. We found that exposure of hPBMCs to ERAP1 variant proteins as well as ERAP1 overexpression by Ad5 vectors increased inflammatory cytokine and chemokine production, and enhanced immune cell activation. Investigating the molecular mechanisms behind these responses revealed that ERAP1 is able to activate innate immunity via multiple pathways, including the NLRP3 (NOD-like receptor, pyrin domain-containing 3) inflammasome. Importantly, these responses varied if autoimmune disease-associated variants of ERAP1 were examined in the assay systems. Unexpectedly, blocking ERAP1 cellular internalization augmented IL-1β production. To our knowledge, this is the first report identifying ERAP1 as being involved in modulating innate responses of human immune cells, a finding that may explain why ERAP1 has been genetically associated with several autoimmune diseases. PMID:25591727

  9. Characterization of human recombinant α2A-adrenoceptors expressed in Chinese hamster lung cells using extracellular acidification rate changes

    PubMed Central

    MacLennan, S J; Reynen, P H; Martin, R S; Eglen, R M; Martin, G R

    2000-01-01

    Human α2A-adrenoceptors heterologously expressed in Chinese hamster lung (CHL) fibroblasts have been characterized pharmacologically using a cytosensor microphysiometer to measure ligand-induced extracellular acidification rate changes.In untransfected CHL cells, noradrenaline had no effect at concentrations up to 100 μM. In α2A-adrenoceptor transfected cells the rank order of agonist potency was A-54741 (mean pEC50=8.96)>dexmedetomidine (8.88)>UK-14304 (8.42)>B-HT 920 (7.05)>noradrenaline (6.92). A-54741, UK-14304 and noradrenaline had the same maximum response while dexmedetomidine and B-HT 920 behaved as partial agonists.The selective α2-adrenoceptor ligand rauwolscine antagonized acidification rate changes with an affinity independent of the agonist used; the affinity (mean pKB) against noradrenaline was 8.43.The selective α1-adrenoceptor ligands prazosin and doxazosin (each 3 μM) had no effect on noradrenaline responses.Acidification rate changes induced by each agonist were abolished by pre-treatment of cells with pertussis toxin.These data suggest that agonist-induced acidification rate responses in CHL cells transfected with the human α2A-adrenoceptor are mediated exclusively by the recombinant protein, via pertussis toxin sensitive Gi/o proteins. PMID:10742288

  10. Osteoblasts secrete miRNA-containing extracellular vesicles that enhance expansion of human umbilical cord blood cells

    PubMed Central

    Morhayim, Jess; van de Peppel, Jeroen; Braakman, Eric; Rombouts, Elwin W. J. C.; ter Borg, Mariette N. D.; Dudakovic, Amel; Chiba, Hideki; van der Eerden, Bram C. J.; Raaijmakers, Marc H.; van Wijnen, Andre J.; Cornelissen, Jan J.; van Leeuwen, Johannes P.

    2016-01-01

    Osteolineage cells represent one of the critical bone marrow niche components that support maintenance of hematopoietic stem and progenitor cells (HSPCs). Recent studies demonstrate that extracellular vesicles (EVs) regulate stem cell development via horizontal transfer of bioactive cargo, including microRNAs (miRNAs). Using next-generation sequencing we show that human osteoblast-derived EVs contain highly abundant miRNAs specifically enriched in EVs, including critical regulators of hematopoietic proliferation (e.g., miR-29a). EV treatment of human umbilical cord blood-derived CD34+ HSPCs alters the expression of candidate miRNA targets, such as HBP1, BCL2 and PTEN. Furthermore, EVs enhance proliferation of CD34+ cells and their immature subsets in growth factor-driven ex vivo expansion cultures. Importantly, EV-expanded cells retain their differentiation capacity in vitro and successfully engraft in vivo. These discoveries reveal a novel osteoblast-derived EV-mediated mechanism for regulation of HSPC proliferation and warrant consideration of EV-miRNAs for the development of expansion strategies to treat hematological disorders. PMID:27585950

  11. Superoxide production by phagocytic leukocytes.

    PubMed

    Drath, D B; Karnovsky, M L

    1975-01-01

    Mononuclear phagocytic leukocytes, as well as polymorphonuclear leukocytes, produce and release superoxide at rest, and this is stimulated by phagocytosis. Of the mouse monocytic cells studied, alveolar macrophages released the largest amounts of superoxide during phagocytosis, followed by normal peritoneal macrophages. Casein-elicited and "activated" macrophages released smaller quantities. In the guinea pig, polymorphonuclear leukocytes and casein-elicited macrophages were shown to release superoxide during phagocytosis whereas alveolar macrophages did not. Superoxide release accounted for only a small fraction of the respiratory burst of phagocytosis in all but the normal mouse peritoneal macrophage, the guinea pig polymorphonuclear leukocyte, and probably the mouse alveolar macrophage. There are obviously considerable species differences in O2-release by various leukocytes that might reflect both the production and/or destruction (e.g. by dismutase) of that substance. PMID:804030

  12. Temporal changes of mechanical signals and extracellular composition in human intervertebral disc during degenerative progression

    PubMed Central

    Zhu, Qiaoqiao; Gao, Xin; Gu, Weiyong

    2014-01-01

    In this study, a three-dimensional finite element model was used to investigate the changes in tissue composition and mechanical signals within human lumbar intervertebral disc during the degenerative progression. This model was developed based on the cell-activity coupled mechano-electrochemical mixture theory. The disc degeneration was simulated by lowering nutrition levels at disc boundaries, and the temporal and spatial distributions of the fixed charge density, water content, fluid pressure, Von Mises stress, and disc deformation were analyzed. Results showed that fixed charge density, fluid pressure, and water content decreased significantly in the nucleus pulposus (NP) and the inner to middle annulus fibrosus (AF) regions of the degenerative disc. It was found that, with degenerative progression, the Von Mises stress (relative to that at healthy state) increased within the disc, with a larger increase in the outer AF region. Both the disc volume and height decreased with the degenerative progression. The predicted results of fluid pressure change in the NP were consistent with experimental findings in the literature. The knowledge of the variations of temporal and spatial distributions of composition and mechanical signals within the human IVDs provide a better understanding of the progression of disc degeneration. PMID:25305690

  13. Cytotoxicity of three commercial mouthrinses on extracellular matrix metabolism and human gingival cell behaviour.

    PubMed

    Balloni, Stefania; Locci, Paola; Lumare, Alessandro; Marinucci, Lorella

    2016-08-01

    This study evaluated the effects of commercially available antiseptic mouthrinses on human gingival fibroblast and keratinocyte behaviour and metabolism. Three mouthrinses containing essential oil (EO), chlorhexidine (CHX) and amine fluoride/stannous fluoride (AFSF), were tested in an in vitro study. Human gingival fibroblasts and keratinocytes were washed with 10% or 30% concentration of the commercial mouthrinses and their effects on cell adhesion and proliferation were investigated as well as the specific gene expression of markers involved in oral mucosa metabolism. As markers of cell metabolism, type I and IV collagens, laminin, fibronectin, fibromodulin and integrins were studied with real-time PCR. Moreover, interleukin-1 secretion, one of the major pro-inflammatory cytokines, was evaluated. The results showed that CHX significantly reduced fibroblast and keratinocyte substrate adhesion capacities and CHX and EO inhibited cell proliferation better than AFSF rinse. The gene expression of several matrix components and cell adhesion receptors was downregulated in cells washed with CHX and EO compared with those washed with AFSF rinse. In conclusion, the AFSF mouthrinse does not induce or induces to a lesser extent the onset of irritation and/or cytotoxicity than CHX or EO. These findings and those of future studies will enable us to gain further insight into the clinical significance and effects of commercial mouthrinses. Pending further investigations, clinicians should be aware of the potentially adverse effects of mouthrinses and warn their patients against making improper use of these products. PMID:27039991

  14. 5-Azacytidine Induces Cardiac Differentiation of Human Umbilical Cord-Derived Mesenchymal Stem Cells by Activating Extracellular Regulated Kinase

    PubMed Central

    Qian, Qian; Qian, Hui; Zhang, Xu; Zhu, Wei; Yan, Yongmin; Ye, Shengqin; Peng, Xiujuan; Li, Wei; Xu, Zhe; Sun, Lingyun

    2012-01-01

    5-Azacytidine (5-Aza) induces differentiation of mesenchymal stem cells (MSCs) into cardiomyocytes. However, the underlying mechanisms are not well understood. Our previous work showed that 5-Aza induces human bone marrow-derived MSCs to differentiate into cardiomyocytes. Here, we demonstrated that 5-Aza induced cardiac differentiation of human umbilical cord-derived MSCs (hucMSCs) and explored the potential signaling pathway. Our results showed that hucMSCs had cardiomyocyte phenotypes after 5-Aza treatment. In addition, myogenic cells differentiated from hucMSCs were positive for mRNA and protein of desmin, β-myosin heavy chain, cardiac troponin T, A-type natriuretic peptide, and Nkx2.5. Human diploid lung fibroblasts treated with 5-Aza expressed no cardiac-specific genes. 5-Aza did not induce hucMSCs to differentiate into osteoblasts. Further study revealed that 5-Aza treatment activated extracellular signal related kinases (ERK) in hucMSCs, but protein kinase C showed no response to 5-Aza administration. U0126, a specific inhibitor of ERK, could inhibit 5-Aza-induced expression of cardiac-specific genes and proteins in hucMSCs. Increased phosphorylation of signal transducers and activators of transcription 3, and up-regulation of myocyte enhancer-binding factor-2c and myogenic differentiation antigen in 5-Aza-treated hucMSCs were also suppressed by U0126. Taken together, these results suggested that sustained activation of ERK by 5-Aza contributed to the induction of the differentiation of hucMSCs into cardiomyocytes in vitro. PMID:21476855

  15. Mn(II) oxidation by an ascomycete fungus is linked to superoxide production during asexual reproduction

    PubMed Central

    Hansel, Colleen M.; Zeiner, Carolyn A.; Santelli, Cara M.; Webb, Samuel M.

    2012-01-01

    Manganese (Mn) oxides are among the most reactive minerals within the environment, where they control the bioavailability of carbon, nutrients, and numerous metals. Although the ability of microorganisms to oxidize Mn(II) to Mn(III/IV) oxides is scattered throughout the bacterial and fungal domains of life, the mechanism and physiological basis for Mn(II) oxidation remains an enigma. Here, we use a combination of compound-specific chemical assays, microspectroscopy, and electron microscopy to show that a common Ascomycete filamentous fungus, Stilbella aciculosa, oxidizes Mn(II) to Mn oxides by producing extracellular superoxide during cell differentiation. The reactive Mn oxide phase birnessite and the reactive oxygen species superoxide and hydrogen peroxide are colocalized at the base of asexual reproductive structures. Mn oxide formation is not observed in the presence of superoxide scavengers (e.g., Cu) and inhibitors of NADPH oxidases (e.g., diphenylene iodonium chloride), enzymes responsible for superoxide production and cell differentiation in fungi. Considering the recent identification of Mn(II) oxidation by NADH oxidase-based superoxide production by a common marine bacterium (Roseobacter sp.), these results introduce a surprising homology between some prokaryotic and eukaryotic organisms in the mechanisms responsible for Mn(II) oxidation, where oxidation appears to be a side reaction of extracellular superoxide production. Given the versatility of superoxide as a redox reactant and the widespread ability of fungi to produce superoxide, this microbial extracellular superoxide production may play a central role in the cycling and bioavailability of metals (e.g., Hg, Fe, Mn) and carbon in natural systems. PMID:22802654

  16. Mn(II) oxidation by an ascomycete fungus is linked to superoxide production during asexual reproduction

    SciTech Connect

    Hansel, C. M.; Zeiner, C. A.; Santelli, C. M.; Webb, S. M.

    2012-07-16

    Manganese (Mn) oxides are among the most reactive minerals within the environment, where they control the bioavailability of carbon, nutrients, and numerous metals. Although the ability of microorganisms to oxidize Mn(II) to Mn(III/IV) oxides is scattered throughout the bacterial and fungal domains of life, the mechanism and physiological basis for Mn(II) oxidation remains an enigma. Here, we use a combination of compound-specific chemical assays, microspectroscopy, and electron microscopy to show that a common Ascomycete filamentous fungus, Stilbella aciculosa, oxidizes Mn(II) to Mn oxides by producing extracellular superoxide during cell differentiation. The reactive Mn oxide phase birnessite and the reactive oxygen species superoxide and hydrogen peroxide are colocalized at the base of asexual reproductive structures. Mn oxide formation is not observed in the presence of superoxide scavengers (e.g., Cu) and inhibitors of NADPH oxidases (e.g., diphenylene iodonium chloride), enzymes responsible for superoxide production and cell differentiation in fungi. Considering the recent identification of Mn(II) oxidation by NADH oxidase-based superoxide production by a common marine bacterium (Roseobacter sp.), these results introduce a surprising homology between some prokaryotic and eukaryotic organisms in the mechanisms responsible for Mn(II) oxidation, where oxidation appears to be a side reaction of extracellular superoxide production. Finally, given the versatility of superoxide as a redox reactant and the widespread ability of fungi to produce superoxide, this microbial extracellular superoxide production may play a central role in the cycling and bioavailability of metals (e.g., Hg, Fe, Mn) and carbon in natural systems.

  17. Tinospora cordifolia, a novel source of extracellular disaccharidases, useful for human disaccharidase deficiency therapy.

    PubMed

    Sengupta, Subhasree; Mukherjee, Abhishek; Ray, Lalitagauri; Sengupta, Subhabrata

    2013-05-01

    Disaccharide intolerance is the inability to digest certain carbohydrates due to a lack of one or more intestinal disaccharidases (e.g., lactase, maltase, isomaltase and sucrase). Symptoms include diarrhea, abdominal distention and flatulence. Management of the disorder by external enzymes supplementation has not yet been attempted. We report that the medicinal plant Tinospora cordifolia contains substantial amounts of all disaccharidases required for intestinal digestion of carbohydrates. The plant is also a rich source of saccharifying amylase. We recovered (units/100 g fresh stem) amylase: 49,000+500, maltase: 400+50, isomaltase: 130+50, sucrase: 4500+500, acid lactase: 350+30, cellobiase: 35+10 and trehalase: 40+10 by buffer extraction of the blended stem. Crude enzymes in the forms of stem powder, lyophilized aqueous extract and ethanol precipitated protein were found to be stable. Disaccharidases were optimally active at 50 (0) C in the pH range of 4-5. Lactase was an acid lactase similar to the type linked with human lactose intolerance. Enzymes were catalytically stable in the pH range of 2-7 and temperature range of up to 40 (0) C. T. cordifolia enzyme was non-toxic up to a dose of 200 mg protein/kg body weight. PMID:22807302

  18. Multilocus analysis of extracellular putative virulence proteins made by group A Streptococcus: population genetics, human serologic response, and gene transcription.

    PubMed

    Reid, S D; Green, N M; Buss, J K; Lei, B; Musser, J M

    2001-06-19

    Species of pathogenic microbes are composed of an array of evolutionarily distinct chromosomal genotypes characterized by diversity in gene content and sequence (allelic variation). The occurrence of substantial genetic diversity has hindered progress in developing a comprehensive understanding of the molecular basis of virulence and new therapeutics such as vaccines. To provide new information that bears on these issues, 11 genes encoding extracellular proteins in the human bacterial pathogen group A Streptococcus identified by analysis of four genomes were studied. Eight of the 11 genes encode proteins with a LPXTG(L) motif that covalently links Gram-positive virulence factors to the bacterial cell surface. Sequence analysis of the 11 genes in 37 geographically and phylogenetically diverse group A Streptococcus strains cultured from patients with different infection types found that recent horizontal gene transfer has contributed substantially to chromosomal diversity. Regions of the inferred proteins likely to interact with the host were identified by molecular population genetic analysis, and Western immunoblot analysis with sera from infected patients confirmed that they were antigenic. Real-time reverse transcriptase-PCR (TaqMan) assays found that transcription of six of the 11 genes was substantially up-regulated in the stationary phase. In addition, transcription of many genes was influenced by the covR and mga trans-acting gene regulatory loci. Multilocus investigation of putative virulence genes by the integrated approach described herein provides an important strategy to aid microbial pathogenesis research and rapidly identify new targets for therapeutics research. PMID:11416223

  19. Skip Regulates TGF- β 1-Induced Extracellular Matrix Degrading Proteases Expression in Human PC-3 Prostate Cancer Cells.

    PubMed

    Villar, Victor; Kocic, Jelena; Santibanez, Juan F

    2013-01-01

    Purpose. To determine whether Ski-interacting protein (SKIP) regulates TGF- β 1-stimulated expression of urokinase-type plasminogen activator (uPA), matrix metalloproteinase-9 (MMP-9), and uPA Inhibitor (PAI-1) in the androgen-independent human prostate cancer cell model. Materials and Methods. PC-3 prostate cancer cell line was used. The role of SKIP was evaluated using synthetic small interference RNA (siRNA) compounds. The expression of uPA, MMP-9, and PAI-1 was evaluated by zymography assays, RT-PCR, and promoter transactivation analysis. Results. In PC-3 cells TGF- β 1 treatment stimulated uPA, PAI-1, and MMP-9 expressions. The knockdown of SKIP in PC-3 cells enhanced the basal level of uPA, and TGF- β 1 treatment inhibited uPA production. Both PAI-1 and MMP-9 production levels were increased in response to TGF- β 1. The ectopic expression of SKIP inhibited both TGF- β 1-induced uPA and MMP-9 promoter transactivation, while PAI-1 promoter response to the factor was unaffected. Conclusions. SKIP regulates the expression of uPA, PAI-1, and MMP-9 stimulated by TGF- β 1 in PC-3 cells. Thus, SKIP is implicated in the regulation of extracellular matrix degradation and can therefore be suggested as a novel therapeutic target in prostate cancer treatment. PMID:23766912

  20. Immobilized immune complexes induce neutrophil extracellular trap release by human neutrophil granulocytes via FcγRIIIB and Mac-1.

    PubMed

    Behnen, Martina; Leschczyk, Christoph; Möller, Sonja; Batel, Tobit; Klinger, Matthias; Solbach, Werner; Laskay, Tamás

    2014-08-15

    Canonical neutrophil antimicrobial effector mechanisms, such as degranulation, production of reactive oxygen species, and release of neutrophil extracellular traps (NETs), can result in severe pathology. Activation of neutrophils through immune complexes (ICs) plays a central role in the pathogenesis of many autoimmune inflammatory diseases. In this study, we report that immobilized ICs (iICs), which are hallmarks of several autoimmune diseases, induce the release of NETs from primary human neutrophils. The iIC-induced NET formation was found to require production of reactive oxygen species by NADPH oxidase and myeloperoxidase and to be mediated by FcγRIIIb. Blocking of the β2 integrin macrophage-1 Ag but not lymphocyte function-associated Ag-1 abolished iIC-induced NET formation. This suggests that FcγRIIIb signals in association with macrophage-1 Ag. As intracellular signaling pathways involved in iIC-induced NET formation we identified the tyrosine kinase Src/Syk pathway, which downstream regulates the PI3K/Akt, p38 MAPK, and ERK1/2 pathways. To our knowledge, the present study shows for the first time that iICs induce NET formation. Thus, we conclude that NETs contribute to pathology in autoimmune inflammatory disorders associated with surface-bound ICs. PMID:25024378

  1. Crystal structures of free and antagonist-bound states of human α9 nicotinic receptor extracellular domain.

    PubMed

    Zouridakis, Marios; Giastas, Petros; Zarkadas, Eleftherios; Chroni-Tzartou, Dafni; Bregestovski, Piotr; Tzartos, Socrates J

    2014-11-01

    We determined the X-ray crystal structures of the extracellular domain (ECD) of the monomeric state of human neuronal α9 nicotinic acetylcholine receptor (nAChR) and of its complexes with the antagonists methyllycaconitine and α-bungarotoxin at resolutions of 1.8 Å, 1.7 Å and 2.7 Å, respectively. The structure of the monomeric α9 ECD superimposed well with the structures of homologous proteins in pentameric assemblies, denoting native folding, despite the absence of a complementary subunit and transmembrane domain. The interaction motifs of both antagonists were similar to those in the complexes with homologous pentameric proteins, thus highlighting the major contribution of the principal side of α9 ECD to their binding. The structures revealed a functionally important β7-β10 strand interaction in α9-containing nAChRs, involving their unique Thr147, a hydration pocket similar to that of mouse α1 ECD and a membrane-facing network coordinated by the invariant Arg210. PMID:25282151

  2. Non-Linear and Flexible Regions of the Human Notch1 Extracellular Domain Revealed by High-Resolution Structural Studies

    PubMed Central

    Weisshuhn, Philip C.; Sheppard, Devon; Taylor, Paul; Whiteman, Pat; Lea, Susan M.; Handford, Penny A.; Redfield, Christina

    2016-01-01

    Summary The Notch receptor is a key component of a core metazoan signaling pathway activated by Delta/Serrate/Lag-2 ligands expressed on an adjacent cell. This results in a short-range signal with profound effects on cell-fate determination, cell proliferation, and cell death. Key to understanding receptor function is structural knowledge of the large extracellular portion of Notch which contains multiple repeats of epidermal growth factor (EGF)-like domains. Here we investigate the EGF4-13 region of human Notch1 (hN1) using a multidisciplinary approach. Ca2+-binding measurements, X-ray crystallography, {1H}-15N heteronuclear nuclear Overhauser effects, and residual dipolar couplings support a non-linear organization for the EGF4-13 region with a rigid, bent conformation for EGF4-7 and a single flexible linkage between EGF9 and EGF10. These data allow us to construct an informed model for EGF10-13 which, in conjunction with comparative binding studies, demonstrates that EGF10 has an important role in determining Notch receptor sensitivity to Dll-4. PMID:26996961

  3. Activation of the Extracellular Signal-Regulated Kinase Signaling Is Critical for Human Umbilical Cord Mesenchymal Stem Cell Osteogenic Differentiation

    PubMed Central

    Li, Chen-Shuang; Zheng, Zhong; Su, Xiao-Xia; Wang, Fei; Ling, Michelle; Zou, Min; Zhou, Hong

    2016-01-01

    Human umbilical cord mesenchymal stem cells (hUCMSCs) are recognized as candidate progenitor cells for bone regeneration. However, the mechanism of hUCMSC osteogenesis remains unclear. In this study, we revealed that mitogen-activated protein kinases (MAPKs) signaling is involved in hUCMSC osteogenic differentiation in vitro. Particularly, the activation of c-Jun N-terminal kinases (JNK) and p38 signaling pathways maintained a consistent level in hUCMSCs through the entire 21-day osteogenic differentiation period. At the same time, the activation of extracellular signal-regulated kinases (ERK) signaling significantly increased from day 5, peaked at day 9, and declined thereafter. Moreover, gene profiling of osteogenic markers, alkaline phosphatase (ALP) activity measurement, and alizarin red staining demonstrated that the application of U0126, a specific inhibitor for ERK activation, completely prohibited hUCMSC osteogenic differentiation. However, when U0126 was removed from the culture at day 9, ERK activation and osteogenic differentiation of hUCMSCs were partially recovered. Together, these findings demonstrate that the activation of ERK signaling is essential for hUCMSC osteogenic differentiation, which points out the significance of ERK signaling pathway to regulate the osteogenic differentiation of hUCMSCs as an alternative cell source for bone tissue engineering. PMID:26989682

  4. Chrysin inhibits human airway smooth muscle cells proliferation through the extracellular signal-regulated kinase 1/2 signaling pathway.

    PubMed

    Yao, Jing; Zhang, Yun-Shi; Feng, Gan-Zhu; Du, Qiang

    2015-11-01

    Asthma is a chronic airway inflammatory disease characterized by an increased mass of airway smooth muscle (ASM). Chrysin (5,7-dihydroxyflavone), a natural flavonoid, has been shown to exert multiple biological activities, including anti-inflammatory, anti-proliferative and anti-oxidant effects, as well as the potency to ameliorate asthma in animal models. The objective of the present study was to identify the underlying mechanism of the therapeutic effects of chrysin. The impact of chrysin on basal and platelet-derived growth factor (PDGF)-induced proliferation and apoptosis of human airway smooth muscle cells (HASMCs) was investigated. Furthermore, the activation of the extracellular signal-regulated protein kinase (ERK) signaling pathway was evaluated in HASMCs. The results revealed that chrysin significantly inhibited basal as well as PDGF-induced HASMC proliferation, most likely through the suppression of ERK1/2 phosphorylation. However, chrysin did not significantly reduce PDGF-induced apoptosis of HASMCs. The present study indicated that chrysin may be a promising medication for controlling airway remodeling and clinical manifestations of asthma. PMID:26502995

  5. Flavonoids suppress human glioblastoma cell growth by inhibiting cell metabolism, migration, and by regulating extracellular matrix proteins and metalloproteinases expression.

    PubMed

    Santos, Balbino L; Oliveira, Mona N; Coelho, Paulo L C; Pitanga, Bruno P S; da Silva, Alessandra B; Adelita, Taís; Silva, Victor Diógenes A; Costa, Maria de F D; El-Bachá, Ramon S; Tardy, Marcienne; Chneiweiss, Hervé; Junier, Marie-Pierre; Moura-Neto, Vivaldo; Costa, Silvia L

    2015-12-01

    The malignant gliomas are very common primary brain tumors with poor prognosis, which require more effective therapies than the current used, such as with chemotherapy drugs. In this work, we investigated the effects of several polyhydroxylated flavonoids namely, rutin, quercetin (F7), apigenin (F32), chrysin (F11), kaempferol (F12), and 3',4'-dihydroxyflavone (F2) in human GL-15 glioblastoma cells. We observed that all flavonoids decreased the number of viable cells and the mitochondrial metabolism. Furthermore, they damaged mitochondria and rough endoplasmic reticulum, inducing apoptosis. Flavonoids also induced a delay in cell migration, related to a reduction in filopodia-like structures on the cell surface, reduction on metalloproteinase (MMP-2) expression and activity, as well as an increase in intra- and extracellular expression of fibronectin, and intracellular expression of laminin. Morphological changes were also evident in adherent cells characterized by the presence of a condensed cell body with thin and long cellular processes, expressing glial fibrillary acidic protein (GFAP). Therefore, these flavonoids should be tested as potential antitumor agents in vitro and in vivo in other malignant glioma models. PMID:26408079

  6. Neutrophil extracellular trap formation is increased in psoriasis and induces human β-defensin-2 production in epidermal keratinocytes.

    PubMed

    Hu, Stephen Chu-Sung; Yu, Hsin-Su; Yen, Feng-Lin; Lin, Chi-Ling; Chen, Gwo-Shing; Lan, Cheng-Che E

    2016-01-01

    Neutrophil extracellular traps (NETs) have been implicated in the development of certain immune-mediated diseases, but their role in psoriasis has not been clearly defined. Human β-defensin-2 (HBD-2) is an important antimicrobial peptide overexpressed in psoriasis epidermis. We evaluated whether the amount of NETs is increased in psoriasis and determined the effect of NETs on HBD-2 production in epidermal keratinocytes. Using fluorescent microscopy, we found that patients with psoriasis (n = 48) had higher amount of NETotic cells in their peripheral blood compared to healthy controls (n = 48) and patients with eczema (n = 35). Psoriasis sera showed increased ability to induce NET formation in control neutrophils but normal NET degradation ability. The amount of NETs in the peripheral blood correlated with psoriasis disease severity. NETosis was also observed in the majority (18 of 20) of psoriasis skin specimens. Furthermore, NETs induced HBD-2 mRNA and protein production in keratinocytes, and immunohistochemical analysis confirmed strong expression of HBD-2 in psoriasis lesional skin. In summary, NET formation is increased in peripheral blood and lesional skin of psoriasis patients and correlates with disease severity. Additionally, NET-induced HBD-2 production may provide a novel mechanism for the decreased susceptibility of psoriasis plaques to microbial infections. PMID:27493143

  7. Extracellular matrix remodeling by dynamic strain in a three-dimensional tissue-engineered human airway wall model.

    PubMed

    Choe, Melanie M; Sporn, Peter H S; Swartz, Melody A

    2006-09-01

    Airway wall remodeling is a hallmark of asthma, characterized by subepithelial thickening and extracellular matrix (ECM) remodeling. Mechanical stress due to hyperresponsive smooth muscle cells may contribute to this remodeling, but its relevance in a three-dimensional environment (where the ECM plays an important role in modulating stresses felt by cells) is unclear. To characterize the effects of dynamic compression in ECM remodeling in a physiologically relevant three-dimensional environment, a tissue-engineered human airway wall model with differentiated bronchial epithelial cells atop a collagen gel containing lung fibroblasts was used. Lateral compressive strain of 10 or 30% at 1 or 60 cycles per hour was applied using a novel straining device. ECM remodeling was assessed by immunohistochemistry and zymography. Dynamic strain, particularly at the lower magnitude, induced airway wall remodeling, as indicated by increased deposition of types III and IV collagen and increased secretion of matrix metalloproteinase-2 and -9. These changes paralleled increased myofibroblast differentiation and were fibroblast-dependent. Furthermore, the spatial pattern of type III collagen deposition correlated with that of myofibroblasts; both were concentrated near the epithelium and decreased diffusely away from the surface, indicating some epithelial control of the remodeling response. Thus, in a physiologically relevant three-dimensional model of the bronchial wall, dynamic compressive strain induced tissue remodeling that mimics many features of remodeling seen in asthma, in the absence of inflammation and dependent on epithelial-fibroblast signaling. PMID:16601241

  8. Influence of Culture Conditions and Extracellular Matrix Alignment on Human Mesenchymal Stem Cell Invasion into Decellularized Engineered Tissues

    PubMed Central

    Weidenhamer, Nathan K.; Moore, Dusty L.; Lobo, Fluvio L.; Klair, Nathaniel T.; Tranquillo, Robert T.

    2015-01-01

    The variables that influence the in vitro recellularization potential of decellularized engineered tissues, such as cell culture conditions and scaffold alignment, have yet to be explored. The goal of this work was to explore the influence of insulin and ascorbic acid and extracellular matrix alignment on the recellularization of decellularized engineered tissue by human mesenchymal stem cells (hMSCs). Aligned and non-aligned tissues were created by specifying the geometry and associated mechanical constraints to fibroblast-mediated fibrin gel contraction and remodeling using circular and C-shaped molds. Decellularized tissues (matrices) of the same alignment were created by decellularization with detergents. Ascorbic acid promoted the invasion of hMSCs into the matrices due to a stimulated increase in motility and proliferation. Invasion correlated with hyaluronic acid secretion, α-smooth muscle actin expression, and decreased matrix thickness. Furthermore, hMSC invasion into aligned and non-aligned matrices was not different, although there was a difference in cell orientation. Finally, we show that hMSCs on the matrix surface appear to be differentiating toward a smooth muscle cell or myofibroblast phenotype with ascorbic acid treatment. These results inform the strategy of recellularizing decellularized engineered tissue with hMSCs. PMID:25556358

  9. Calciotropic hormones and lipolysis of human adipose tissue: role of extracellular calcium as conditioning but not regulating factor.

    PubMed

    Ziegler, R; Jobst, W; Minne, H; Faulhaber, J D

    1980-01-01

    The influences of different calcium concentrations (0, 0.924 and 2.772 mMol/l) on lipolysis of in vitro incubated human adipose tissue slices or adipocytes were studied under the conditions of stimulation with isoproterenol and parathyroid hormone preparations or inhibition by insulin. Extractive bovine PTH (as well as synthetic PTH 1--34) stimulated glycerol release in a biphasic pattern similarly to isoproterenol; PTH was about half as potent as isoproterenol. The optimal conditions for lipolysis were observed using a calcium concentration of 0.924 mMol/l, whereas lipolysis was distinctly impaired at concentrations of 0 or 2.772 mMol/l; this was true for basal as well as isoproterenol- and PTH stimulated lipolysis or the inhibitory effect of insulin. In contrast to partially purified extractive calcitonin, pure synthetic calcitonin did not inhibit lipolysis. Isoproterenol- and PTH-administrations led to cAMP accumulation in the adipose tissue, this process was also diminished at the non-optimal calcium concentrations. The results suggest a conditioning, but not a regulating significance of extracellular calcium for lipolysis, whereas the importance of the lipolytic potency of PTH remains to be elucidated. PMID:6245862

  10. Propyl Gallate Inhibits Adipogenesis by Stimulating Extracellular Signal-Related Kinases in Human Adipose Tissue-Derived Mesenchymal Stem Cells

    PubMed Central

    Lee, Jeung-Eun; Kim, Jung-Min; Jang, Hyun-Jun; Lim, Se-young; Choi, Seon-Jeong; Lee, Nan-Hee; Suh, Pann-Ghill; Choi, Ung-Kyu

    2015-01-01

    Propyl gallate (PG) used as an additive in various foods has antioxidant and anti-inflammatory effects. Although the functional roles of PG in various cell types are well characterized, it is unknown whether PG has effect on stem cell differentiation. In this study, we demonstrated that PG could inhibit adipogenic differentiation in human adipose tissue-derived mesenchymal stem cells (hAMSCs) by decreasing the accumulation of intracellular lipid droplets. In addition, PG significantly reduced the expression of adipocyte-specific markers including peroxisome proliferator-activated receptor-γ (PPAR-γ), CCAAT enhancer binding protein-α (C/EBP-α), lipoprotein lipase (LPL), and adipocyte fatty acid-binding protein 2 (aP2). PG inhibited adipogenesis in hAMSCs through extracellular regulated kinase (ERK) pathway. Decreased adipogenesis following PG treatment was recovered in response to ERK blocking. Taken together, these results suggest a novel effect of PG on adipocyte differentiation in hAMSCs, supporting a negative role of ERK1/2 pathway in adipogenic differentiation. PMID:25813451

  11. A defined epitope on the human choriogonadotropin alpha-subunit interacts with the second extracellular loop of the transmembrane domain of the lutropin/choriogonadotropin receptor.

    PubMed

    Couture, L; Remy, J J; Rabesona, H; Troalen, F; Pajot-Augy, E; Bozon, V; Haertle, T; Bidart, J M; Salesse, R

    1996-10-15

    The monoclonal antibody, HT13 recognizes human choriogonadotropin (CG) bound to the extracellular domain of its receptor, but not to the full-length receptor. The HT13 epitope is located in the regions of residues 15-17 and 73-75 of the human CG alpha-subunit. Only one synthetic peptide, lutropin (LH)/CG-receptor-(481-497)-peptide (EL2 peptide), which spans the second putative extracellular loop of the LH/CG-receptor endodomain, prevents recognition of human CG by HT13 mAb. EL2 peptide decreases hormone-induced cAMP production, but not high-affinity binding. An anti-EL2 serum also displays the capacity to inhibit human CG-stimulated cAMP production. These results suggest that the second extracellular loop of the receptor is in contact with the HT13 epitope of human CG alpha-subunit and is involved in signal transduction. A relative orientation of the hormone versus the endodomain is proposed. PMID:8917465

  12. Therapeutic Targeting of Mitochondrial Superoxide in Hypertension

    PubMed Central

    Dikalova, Anna E.; Bikineyeva, Alfiya T.; Budzyn, Klaudia; Nazarewicz, Rafal R.; McCann, Louise; Lewis, William; Harrison, David G.; Dikalov, Sergey I.

    2010-01-01

    Rationale: Superoxide (O2∸) has been implicated in the pathogenesis of many human diseases including hypertension, however commonly employed antioxidants have proven ineffective in clinical trials. It is possible that these agents are not adequately delivered to the subcellular sites of superoxide production. Objective: Because the mitochondria are important sources of reactive oxygen species, we postulated that mitochondrial targeting of superoxide scavenging would have therapeutic benefit. Methods and Results: In this study, we found that the hormone angiotensin II increased endothelial mitochondrial superoxide production. Treatment with the mitochondrial targeted antioxidant mitoTEMPO decreased mitochondrial O2∸, inhibited the total cellular O2∸, reduced cellular NADPH oxidase activity and restored the level of bioavailable NO. These effects were mimicked by overexpressing the mitochondrial MnSOD (SOD2), while SOD2 depletion with siRNA increased both basal and angiotensin II-stimulated cellular O2∸. Treatment of mice in vivo with mitoTEMPO attenuated hypertension when given at the onset of angiotensin II infusion and decreased blood pressure by 30 mm Hg following establishment of both angiotensin II-induced and DOCA-salt hypertension, while a similar dose of non-targeted TEMPOL was not effective. In vivo, mitoTEMPO decreased vascular O2∸, increased vascular NO• production and improved endothelial-dependent relaxation. Interestingly, transgenic mice overexpressing mitochondrial SOD2 demonstrated attenuated angiotensin II-induced hypertension and vascular oxidative stress similar to mice treated with mitoTEMPO. Conclusions: These studies show that mitochondrial O2∸ is important for the development of hypertension and that antioxidant strategies specifically targeting this organelle could have therapeutic benefit in this and possibly other diseases. PMID:20448215

  13. Suppression of neutrophil superoxide production by conventional peritoneal dialysis solution.

    PubMed

    Ing, B L; Gupta, D K; Nawab, Z M; Zhou, F Q; Rahman, M A; Daugirdas, J T

    1988-09-01

    The pH of conventional peritoneal dialysis solution is normally in the range of 5.0 to 5.5, because acid has been added during the manufacturing process to prevent caramelization of dextrose during sterilization. We studied the effects of normalizing the pH of conventional peritoneal dialysis solution on superoxide production by normal human neutrophils. At a pH of 6.0, superoxide generation was 4.07 +/- 2.56 (SD) nanomoles per million cells. With normalization of pH to 7.4, superoxide production was 19.3 +/- 7.3 (p less than 0.001). The results suggest that the unphysiologic acidity of conventional peritoneal dialysis solution has deleterious consequences on neutrophil superoxide formation. PMID:2847987

  14. Differential β3 Integrin Expression Regulates the Response of Human Lung and Cardiac Fibroblasts to Extracellular Matrix and Its Components.

    PubMed

    Merna, Nick; Fung, Kelsey M; Wang, Jean J; King, Cristi R; Hansen, Kirk C; Christman, Karen L; George, Steven C

    2015-08-01

    Extracellular matrix (ECM) derived from whole organ decellularization has been successfully used in a variety of tissue engineering applications. ECM contains a complex mixture of functional and structural molecules that are ideally suited for the tissue from which the ECM is harvested. However, decellularization disrupts the structural properties and protein composition of the ECM, which may impact function when cells such as the fibroblast are reintroduced during recellularization. We hypothesized that the ECM structure and composition, fibroblast source, and integrin expression would influence the fibroblast phenotype. Human cardiac fibroblasts (HCFs) and normal human lung fibroblasts (NHLFs) were cultured on intact cardiac ECM, collagen gels, and coatings composed of cardiac ECM, lung ECM, and individual ECM components (collagen and fibronectin [FN]) for 48 h. COL1A expression of HCFs and NHLFs cultured on ECM and FN coatings decreased to <50% of that of untreated cells; COL1A expression for HCFs cultured on ECM coatings was one- to twofold higher than HCFs cultured on intact ECM. NHLFs cultured on ECM and FN coatings expressed 12- to 31-fold more alpha-smooth muscle actin (αSMA) than HCFs; the αSMA expression for HCFs and NHLFs cultured on ECM coatings was ∼2- to 5-fold higher than HCFs and NHLFs cultured on intact ECM. HCFs expressed significantly higher levels of β3 and β4 integrins when compared to NHLFs. Inhibition of the β3 integrin, but not β4, resulted in a 16- to 26-fold increase in αSMA expression in HCFs cultured on ECM coatings and FN. Our results demonstrate that β3 integrin expression depends on the source of the fibroblast and that its expression inhibits αSMA expression (and thus the myofibroblast phenotype). We conclude that the fibroblast source and integrin expression play important roles in regulating the fibroblast phenotype. PMID:25926101

  15. Importance of the Extracellular Loop 4 in the Human Serotonin Transporter for Inhibitor Binding and Substrate Translocation.

    PubMed

    Rannversson, Hafsteinn; Wilson, Pamela; Kristensen, Kristina Birch; Sinning, Steffen; Kristensen, Anders Skov; Strømgaard, Kristian; Andersen, Jacob

    2015-06-01

    The serotonin transporter (SERT) terminates serotonergic neurotransmission by performing reuptake of released serotonin, and SERT is the primary target for antidepressants. SERT mediates the reuptake of serotonin through an alternating access mechanism, implying that a central substrate site is connected to both sides of the membrane by permeation pathways, of which only one is accessible at a time. The coordinated conformational changes in SERT associated with substrate translocation are not fully understood. Here, we have identified a Leu to Glu mutation at position 406 (L406E) in the extracellular loop 4 (EL4) of human SERT, which induced a remarkable gain-of-potency (up to >40-fold) for a range of SERT inhibitors. The effects were highly specific for L406E relative to six other mutations in the same position, including the closely related L406D mutation, showing that the effects induced by L406E are not simply charge-related effects. Leu(406) is located >10 Å from the central inhibitor binding site indicating that the mutation affects inhibitor binding in an indirect manner. We found that L406E decreased accessibility to a residue in the cytoplasmic pathway. The shift in equilibrium to favor a more outward-facing conformation of SERT can explain the reduced turnover rate and increased association rate of inhibitor binding we found for L406E. Together, our findings show that EL4 allosterically can modulate inhibitor binding within the central binding site, and substantiates that EL4 has an important role in controlling the conformational equilibrium of human SERT. PMID:25903124

  16. Cross-Talk Between Human Tenocytes and Bone Marrow Stromal Cells Potentiates Extracellular Matrix Remodeling In Vitro

    PubMed Central

    Ekwueme, Emmanuel C.; Shah, Jay V.; Mohiuddin, Mahir; Ghebes, Corina A.; Crispim, João F.; Saris, Daniël B.F.; Fernandes, Hugo A.M.; Freeman, Joseph W.

    2016-01-01

    Tendon and ligament (T/L) pathologies account for a significant portion of musculoskeletal injuries and disorders. Tissue engineering has emerged as a promising solution in the regeneration of both tissues. Specifically, the use of multipotent human mesenchymal stromal cells (hMSC) has shown great promise to serve as both a suitable cell source for tenogenic regeneration and a source of trophic factors to induce tenogenesis. Using four donor sets, we investigated the bidirectional paracrine tenogenic response between human hamstring tenocytes (hHT) and bone marrow-derived hMSC. Cell metabolic assays showed that only one hHT donor experienced sustained notable increases in cell metabolic activity during co-culture. Histological staining confirmed that co-culture induced elevated collagen protein levels in both cell types at varying time-points in two of four donor sets assessed. Gene expression analysis using qPCR showed the varied up-regulation of anabolic and catabolic markers involved in extracellular matrix maintenance for hMSC and hHT. Furthermore, analysis of hMSC/hHT co-culture secretome using a reporter cell line for TGF-β, a potent inducer of tenogenesis, revealed a trend of higher TGF-β bioactivity in hMSC secretome compared to hHT. Finally, hHT cytoskeletal immunostaining confirmed that both cell types released soluble factors capable of inducing favorable tenogenic morphology, comparable to control levels of soluble TGF-β1. These results suggest a potential for TGF-β-mediated signaling mechanism that is involved during the paracrine interplay between the two cell types that is reminiscent of T/L matrix remodeling/ turnover. These findings have significant implications in the clinical use of hMSC for common T/L pathologies. PMID:26308651

  17. Importance of the Extracellular Loop 4 in the Human Serotonin Transporter for Inhibitor Binding and Substrate Translocation*

    PubMed Central

    Rannversson, Hafsteinn; Wilson, Pamela; Kristensen, Kristina Birch; Sinning, Steffen; Kristensen, Anders Skov; Strømgaard, Kristian; Andersen, Jacob

    2015-01-01

    The serotonin transporter (SERT) terminates serotonergic neurotransmission by performing reuptake of released serotonin, and SERT is the primary target for antidepressants. SERT mediates the reuptake of serotonin through an alternating access mechanism, implying that a central substrate site is connected to both sides of the membrane by permeation pathways, of which only one is accessible at a time. The coordinated conformational changes in SERT associated with substrate translocation are not fully understood. Here, we have identified a Leu to Glu mutation at position 406 (L406E) in the extracellular loop 4 (EL4) of human SERT, which induced a remarkable gain-of-potency (up to >40-fold) for a range of SERT inhibitors. The effects were highly specific for L406E relative to six other mutations in the same position, including the closely related L406D mutation, showing that the effects induced by L406E are not simply charge-related effects. Leu406 is located >10 Å from the central inhibitor binding site indicating that the mutation affects inhibitor binding in an indirect manner. We found that L406E decreased accessibility to a residue in the cytoplasmic pathway. The shift in equilibrium to favor a more outward-facing conformation of SERT can explain the reduced turnover rate and increased association rate of inhibitor binding we found for L406E. Together, our findings show that EL4 allosterically can modulate inhibitor binding within the central binding site, and substantiates that EL4 has an important role in controlling the conformational equilibrium of human SERT. PMID:25903124

  18. Differential β3 Integrin Expression Regulates the Response of Human Lung and Cardiac Fibroblasts to Extracellular Matrix and Its Components

    PubMed Central

    Merna, Nick; Fung, Kelsey M.; Wang, Jean J.; King, Cristi R.; Hansen, Kirk C.; Christman, Karen L.

    2015-01-01

    Extracellular matrix (ECM) derived from whole organ decellularization has been successfully used in a variety of tissue engineering applications. ECM contains a complex mixture of functional and structural molecules that are ideally suited for the tissue from which the ECM is harvested. However, decellularization disrupts the structural properties and protein composition of the ECM, which may impact function when cells such as the fibroblast are reintroduced during recellularization. We hypothesized that the ECM structure and composition, fibroblast source, and integrin expression would influence the fibroblast phenotype. Human cardiac fibroblasts (HCFs) and normal human lung fibroblasts (NHLFs) were cultured on intact cardiac ECM, collagen gels, and coatings composed of cardiac ECM, lung ECM, and individual ECM components (collagen and fibronectin [FN]) for 48 h. COL1A expression of HCFs and NHLFs cultured on ECM and FN coatings decreased to <50% of that of untreated cells; COL1A expression for HCFs cultured on ECM coatings was one- to twofold higher than HCFs cultured on intact ECM. NHLFs cultured on ECM and FN coatings expressed 12- to 31-fold more alpha-smooth muscle actin (αSMA) than HCFs; the αSMA expression for HCFs and NHLFs cultured on ECM coatings was ∼2- to 5-fold higher than HCFs and NHLFs cultured on intact ECM. HCFs expressed significantly higher levels of β3 and β4 integrins when compared to NHLFs. Inhibition of the β3 integrin, but not β4, resulted in a 16- to 26-fold increase in αSMA expression in HCFs cultured on ECM coatings and FN. Our results demonstrate that β3 integrin expression depends on the source of the fibroblast and that its expression inhibits αSMA expression (and thus the myofibroblast phenotype). We conclude that the fibroblast source and integrin expression play important roles in regulating the fibroblast phenotype. PMID:25926101

  19. Acute effect of the anti-addiction drug bupropion on extracellular dopamine concentrations in the human striatum: an [11C]raclopride PET study.

    PubMed

    Egerton, Alice; Shotbolt, John P; Stokes, Paul R A; Hirani, Ella; Ahmad, Rabia; Lappin, Julia M; Reeves, Suzanne J; Mehta, Mitul A; Howes, Oliver D; Grasby, Paul M

    2010-03-01

    Bupropion is an effective medication in treating addiction and is widely used as an aid to smoking cessation. Bupropion inhibits striatal dopamine reuptake via dopamine transporter blockade, but it is unknown whether this leads to increased extracellular dopamine levels at clinical doses in man. The effects of bupropion on extracellular dopamine levels in the striatum were investigated using [(11)C]raclopride positron emission tomography (PET) imaging in rats administered saline, 11 or 25 mg/kg bupropion i.p. and in healthy human volunteers administered either placebo or 150 mg bupropion (Zyban Sustained-Release). A cognitive task was used to stimulate dopamine release in the human study. In rats, bupropion significantly decreased [(11)C]raclopride specific binding in the striatum, consistent with increases in extracellular dopamine concentrations. In man, no significant decreases in striatal [(11)C]raclopride specific binding were observed. Levels of dopamine transporter occupancy in the rat at 11 and 25 mg/kg bupropion i.p. were higher than predicted to occur in man at the dose used. Thus, these data indicate that, at the low levels of dopamine transporter occupancy achieved in man at clinical doses, bupropion does not increase extracellular dopamine levels. These findings have important implications for understanding the mechanism of action underlying bupropions' therapeutic efficacy and for the development of novel treatments for addiction and depression. PMID:19969097

  20. 1,25-Dihydroxyvitamin D3 Reduces Extracellular Matrix-Associated Protein Expression in Human Uterine Fibroid Cells1

    PubMed Central

    Halder, Sunil K.; Osteen, Kevin G.; Al-Hendy, Ayman

    2013-01-01

    ABSTRACT Uterine fibroids (leiomyomas) are the most common benign tumors associated with excessive deposition of extracellular matrix (ECM)-associated proteins that increase fibroid tumorigenicity. Herein, we determined the expression levels of vitamin D receptor (VDR) protein in human uterine fibroids and compared these levels to those in adjacent normal myometrium. Using Western blot analysis, we found that more than 60% of uterine fibroids analyzed (25 of 40) expressed low levels of VDR. We also found that the biologically active 1,25-dihydroxyvitamin D3 (1,25[OH]2D3), which functions via binding to its nuclear VDR, induced VDR in a concentration-dependent manner and reduced ECM-associated fibrotic and proteoglycans expression in immortalized human uterine fibroid cell line (HuLM). At 1–10 nM concentrations, 1,25(OH)2D3 significantly induced (P < 0.05) nuclear VDR, which was further stimulated by higher concentrations of 1,25(OH)2D3 in HuLM cells. 1,25(OH)2D3 at 10 nM also significantly reduced (P < 0.05) the protein expression of ECM-associated collagen type 1, fibronectin, and plasminogen activator inhibitor-1 (PAI-1) in HuLM cells. We also found that 1,25(OH)2D3 reduced mRNA and protein expressions of proteoglycans such as fibromodulin, biglycan, and versican in HuLM cells. Moreover, the aberrant expression of structural smooth muscle actin fibers was reduced by 1,25(OH)2D3 treatment in a concentration-dependent manner in HuLM cells. Taken together, our results suggest that human uterine fibroids express reduced levels of VDR compared to the adjacent normal myometrium and that treatment with 1,25(OH)2D3 can potentially reduce the aberrant expression of major ECM-associated proteins in HuLM cells. Thus, 1,25(OH)2D3 might be an effective, safe, nonsurgical treatment option for human uterine fibroids. PMID:24174578

  1. A Central Role for JNK/AP-1 Pathway in the Pro-Oxidant Effect of Pyrrolidine Dithiocarbamate through Superoxide Dismutase 1 Gene Repression and Reactive Oxygen Species Generation in Hematopoietic Human Cancer Cell Line U937

    PubMed Central

    Collin, Pascal; Lomri, Abderrahim

    2015-01-01

    Pyrrolidine dithiocarbamate (PDTC) known as antioxidant and specific inhibitor of NF-κB was also described as pro-oxidant by inducing cell death and reactive oxygen species (ROS) accumulation in cancer. However, the mechanism by which PDTC indices its pro-oxidant effect is unknown. Therefore, we aimed to evaluate the effect of PDTC on the human Cu/Zn superoxide dismutase 1 (SOD1) gene transcription in hematopoietic human cancer cell line U937. We herein show for the first time that PDTC decreases SOD1 transcripts, protein and promoter activity. Furthermore, SOD1 repression by PDTC was associated with an increase in oxidative stress as evidenced by ROS production. Electrophoretic mobility-shift assays (EMSA) show that PDTC increased binding of activating protein-1 (AP-1) in dose dependent-manner suggesting that the MAPkinase up-stream of AP-1 is involved. Ectopic NF-κB p65 subunit overexpression had no effect on SOD1 transcription. In contrast, in the presence of JNK inhibitor (SP600125), p65 induced a marked increase of SOD1 promoter, suggesting that JNK pathway is up-stream of NF-κB signaling and controls negatively its activity. Indeed, using JNK deficient cells, PDTC effect was not observed nether on SOD1 transcription or enzymatic activity, nor on ROS production. Finally, PDTC represses SOD1 in U937 cells through JNK/c-Jun phosphorylation. Taken together, these results suggest that PDTC acts as pro-oxidant compound in JNK/AP-1 dependent-manner by repressing the superoxide dismutase 1 gene leading to intracellular ROS accumulation. PMID:25996379

  2. Mechanical overloading causes mitochondrial superoxide and SOD2 imbalance in chondrocytes resulting in cartilage degeneration.

    PubMed

    Koike, Masato; Nojiri, Hidetoshi; Ozawa, Yusuke; Watanabe, Kenji; Muramatsu, Yuta; Kaneko, Haruka; Morikawa, Daichi; Kobayashi, Keiji; Saita, Yoshitomo; Sasho, Takahisa; Shirasawa, Takuji; Yokote, Koutaro; Kaneko, Kazuo; Shimizu, Takahiko

    2015-01-01

    Mechanical stress and aging are major risk factors of cartilage degeneration. Human studies have previously reported that oxidative damage increased, while SOD2 protein was reciprocally downregulated in osteoarthritic degenerated cartilage. However, it remains unclear whether mitochondrial superoxide imbalance in chondrocytes causes cartilage degeneration. We herein demonstrate that mechanical loading promoted mitochondrial superoxide generation and selective Sod2 downregulation in chondrocytes in vivo and that mitochondrial superoxide inducer also downregulated Sod2 expression in chondrocytes in vitro. A genetically manipulated model revealed that Sod2 deficiency in chondrocytes also resulted in mitochondrial superoxide overproduction and dysfunction, thus leading to cartilage degeneration. Intra-articular injection of a permeable antioxidant effectively suppressed the mechanical loading-induced mitochondrial superoxide generation and cartilage degeneration in mice. Our findings demonstrate that mitochondrial superoxide plays a pivotal role in the development and progression of osteoarthritis, and the mitochondrial superoxide balance may therefore be a promising target for the treatment of cartilage degeneration. PMID:26108578

  3. Mechanical overloading causes mitochondrial superoxide and SOD2 imbalance in chondrocytes resulting in cartilage degeneration

    PubMed Central

    Koike, Masato; Nojiri, Hidetoshi; Ozawa, Yusuke; Watanabe, Kenji; Muramatsu, Yuta; Kaneko, Haruka; Morikawa, Daichi; Kobayashi, Keiji; Saita, Yoshitomo; Sasho, Takahisa; Shirasawa, Takuji; Yokote, Koutaro; Kaneko, Kazuo; Shimizu, Takahiko

    2015-01-01

    Mechanical stress and aging are major risk factors of cartilage degeneration. Human studies have previously reported that oxidative damage increased, while SOD2 protein was reciprocally downregulated in osteoarthritic degenerated cartilage. However, it remains unclear whether mitochondrial superoxide imbalance in chondrocytes causes cartilage degeneration. We herein demonstrate that mechanical loading promoted mitochondrial superoxide generation and selective Sod2 downregulation in chondrocytes in vivo and that mitochondrial superoxide inducer also downregulated Sod2 expression in chondrocytes in vitro. A genetically manipulated model revealed that Sod2 deficiency in chondrocytes also resulted in mitochondrial superoxide overproduction and dysfunction, thus leading to cartilage degeneration. Intra-articular injection of a permeable antioxidant effectively suppressed the mechanical loading-induced mitochondrial superoxide generation and cartilage degeneration in mice. Our findings demonstrate that mitochondrial superoxide plays a pivotal role in the development and progression of osteoarthritis, and the mitochondrial superoxide balance may therefore be a promising target for the treatment of cartilage degeneration. PMID:26108578

  4. Extracellular Protease Inhibition Alters the Phenotype of Chondrogenically Differentiating Human Mesenchymal Stem Cells (MSCs) in 3D Collagen Microspheres

    PubMed Central

    Han, Sejin; Li, Yuk Yin; Chan, Barbara Pui

    2016-01-01

    Matrix remodeling of cells is highly regulated by proteases and their inhibitors. Nevertheless, how would the chondrogenesis of mesenchymal stem cells (MSCs) be affected, when the balance of the matrix remodeling is disturbed by inhibiting matrix proteases, is incompletely known. Using a previously developed collagen microencapsulation platform, we investigated whether exposing chondrogenically differentiating MSCs to intracellular and extracellular protease inhibitors will affect the extracellular matrix remodeling and hence the outcomes of chondrogenesis. Results showed that inhibition of matrix proteases particularly the extracellular ones favors the phenotype of fibrocartilage rather than hyaline cartilage in chondrogenically differentiating hMSCs by upregulating type I collagen protein deposition and type II collagen gene expression without significantly altering the hypertrophic markers at gene level. This study suggests the potential of manipulating extracellular proteases to alter the outcomes of hMSC chondrogenesis, contributing to future development of differentiation protocols for fibrocartilage tissues for intervertebral disc and meniscus tissue engineering. PMID:26760956

  5. Extracellular Cl(-) regulates human SO4 (2-)/anion exchanger SLC26A1 by altering pH sensitivity of anion transport.

    PubMed

    Wu, Meng; Heneghan, John F; Vandorpe, David H; Escobar, Laura I; Wu, Bai-Lin; Alper, Seth L

    2016-08-01

    Genetic deficiency of the SLC26A1 anion exchanger in mice is known to be associated with hyposulfatemia and hyperoxaluria with nephrolithiasis, but many aspects of human SLC26A1 function remain to be explored. We report here the functional characterization of human SLC26A1, a 4,4'-diisothiocyanato-2,2'-stilbenedisulfonic acid (DIDS)-sensitive, electroneutral sodium-independent anion exchanger transporting sulfate, oxalate, bicarbonate, thiosulfate, and (with divergent properties) chloride. Human SLC26A1-mediated anion exchange differs from that of its rodent orthologs in its stimulation by alkaline pHo and inhibition by acidic pHo but not pHi and in its failure to transport glyoxylate. SLC26A1-mediated transport of sulfate and oxalate is highly dependent on allosteric activation by extracellular chloride or non-substrate anions. Extracellular chloride stimulates apparent V max of human SLC26A1-mediated sulfate uptake by conferring a 2-log decrease in sensitivity to inhibition by extracellular protons, without changing transporter affinity for extracellular sulfate. In contrast to SLC26A1-mediated sulfate transport, SLC26A1-associated chloride transport is activated by acid pHo, shows reduced sensitivity to DIDS, and exhibits cation dependence of its DIDS-insensitive component. Human SLC26A1 resembles SLC26 paralogs in its inhibition by phorbol ester activation of protein kinase C (PKC), which differs in its undiminished polypeptide abundance at or near the oocyte surface. Mutation of SLC26A1 residues corresponding to candidate anion binding site-associated residues in avian SLC26A5/prestin altered anion transport in patterns resembling those of prestin. However, rare SLC26A1 polymorphic variants from a patient with renal Fanconi Syndrome and from a patient with nephrolithiasis/calcinosis exhibited no loss-of-function phenotypes consistent with disease pathogenesis. PMID:27125215

  6. Extracellular respiration

    PubMed Central

    Gralnick, Jeffrey A.; Newman, Dianne K.

    2009-01-01

    Summary Although it has long been known that microbes can generate energy using diverse strategies, only recently has it become clear that a growing number involve electron transfer to or from extracellular substrates. The best-known example of what we will term ‘extracellular respiration’ is electron transfer between microbes and minerals, such as iron and manganese (hydr)oxides. This makes sense, given that these minerals are sparingly soluble. What is perhaps surprising, however, is that a number of substrates that might typically be classified as ‘soluble’ are also respired at the cell surface. There are several reasons why this might be the case: the substrate, in its ecological context, might be associated with a solid surface and thus effectively insoluble; the substrate, while soluble, might simply be too large to transport inside the cell; or the substrate, while benign in one redox state, might become toxic after it is metabolized. In this review, we discuss various examples of extracellular respiration, paying particular attention to what is known about the molecular mechanisms underlying these processes. As will become clear, much remains to be learned about the biochemistry, cell biology and regulation of extracellular respiration, making it a rich field of study for molecular microbiologists. PMID:17581115

  7. Reduction of Renal Superoxide Dismutase in Progressive Diabetic Nephropathy

    PubMed Central

    Fujita, Hiroki; Fujishima, Hiromi; Chida, Shinsuke; Takahashi, Keiko; Qi, Zhonghua; Kanetsuna, Yukiko; Breyer, Matthew D.; Harris, Raymond C.; Yamada, Yuichiro; Takahashi, Takamune

    2009-01-01

    Superoxide excess plays a central role in tissue damage that results from diabetes, but the mechanisms of superoxide overproduction in diabetic nephropathy (DN) are incompletely understood. In the present study, we investigated the enzyme superoxide dismutase (SOD), a major defender against superoxide, in the kidneys during the development of murine DN. We assessed SOD activity and the expression of SOD isoforms in the kidneys of two diabetic mouse models (C57BL/6-Akita and KK/Ta-Akita) that exhibit comparable levels of hyperglycemia but different susceptibility to DN. We observed down-regulation of cytosolic CuZn-SOD (SOD1) and extracellular CuZn-SOD (SOD3), but not mitochondrial Mn-SOD (SOD2), in the kidney of KK/Ta-Akita mice which exhibit progressive DN. In contrast, we did not detect a change in renal SOD expression in DN-resistant C57BL/6-Akita mice. Consistent with these findings, there was a significant reduction in total SOD activity in the kidney of KK/Ta-Akita mice compared with C57BL/6-Akita mice. Finally, treatment of KK/Ta-Akita mice with a SOD mimetic, tempol, ameliorated the nephropathic changes in KK/Ta-Akita mice without altering the level of hyperglycemia. Collectively, these results indicate that down-regulation of renal SOD1 and SOD3 may play a key role in the pathogenesis of DN. PMID:19470681

  8. Extracellular nucleotides regulate CCL20 release from human primary airway epithelial cells, monocytes and monocyte-derived dendritic cells.

    PubMed

    Marcet, Brice; Horckmans, Michael; Libert, Frédérick; Hassid, Sergio; Boeynaems, Jean-Marie; Communi, Didier

    2007-06-01

    Extracellular nucleotides regulate ion transport and mucociliary clearance in human airway epithelial cells (HAECs) via the activation of P2 receptors, especially P2Y(2). Therefore, P2Y(2) receptor agonists represent potential pharmacotherapeutic agents to treat cystic fibrosis (CF). Nucleotides also modulate inflammatory properties of immune cells like dendritic cells (DCs), which play an important role in mucosal immunity. Using DNA-microarray experiments, quantitative RT-PCR and cytokine measurements, we show here that UTP up-regulated approximately 2- to 3-fold the antimicrobial chemokine CCL20 expression and release in primary HAECs cultured on permeable supports at an air-liquid interface (ALI). Both P2Y(2) (ATPgammaS, UTP, INS365) and P2Y(6) (UDP, INS48823) agonists increased CCL20 release. UTP-induced CCL20 release was insensitive to NF-kappaB pathway inhibitors but sensitive to inhibitors of ERK1/2 and p38/MAPK pathways. Furthermore, UTP had no effect on interleukin-(IL)-8 release and reduced the release of both CCL20 and IL-8 induced by TNF-alpha and LPS. Accordingly, UTP reduced the capacity of basolateral supernatants of HAECs treated with TNF-alpha or LPS to induce the chemoattraction of both CD4(+) T lymphocytes and neutrophils. In addition, we show that, in monocyte-derived DCs, ATPgammaS, and UDP but not UTP/INS365-stimulated CCL20 release. Likewise, UDP but not ATPgammaS was also able to increase CCL20 release from monocytes. Pharmacological experiments suggested an involvement of P2Y(11) or P2Y(6) receptors through NF-kappaB, ERK1/2, and p38/MAPK pathways. Altogether, our data demonstrate that nucleotides may modulate chemokine release and leukocyte recruitment in inflamed airways by acting on both epithelial and immune cells. Our results could be relevant for further clinical investigations in CF. PMID:17295217

  9. Three-Dimensional Adult Cardiac Extracellular Matrix Promotes Maturation of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes.

    PubMed

    Fong, Ashley H; Romero-López, Mónica; Heylman, Christopher M; Keating, Mark; Tran, David; Sobrino, Agua; Tran, Anh Q; Pham, Hiep H; Fimbres, Cristhian; Gershon, Paul D; Botvinick, Elliot L; George, Steven C; Hughes, Christopher C W

    2016-08-01

    Pluripotent stem cell-derived cardiomyocytes (CMs) have great potential in the development of new therapies for cardiovascular disease. In particular, human induced pluripotent stem cells (iPSCs) may prove especially advantageous due to their pluripotency, their self-renewal potential, and their ability to create patient-specific cell lines. Unfortunately, pluripotent stem cell-derived CMs are immature, with characteristics more closely resembling fetal CMs than adult CMs, and this immaturity has limited their use in drug screening and cell-based therapies. Extracellular matrix (ECM) influences cellular behavior and maturation, as does the geometry of the environment-two-dimensional (2D) versus three-dimensional (3D). We therefore tested the hypothesis that native cardiac ECM and 3D cultures might enhance the maturation of iPSC-derived CMs in vitro. We demonstrate that maturation of iPSC-derived CMs was enhanced when cells were seeded into a 3D cardiac ECM scaffold, compared with 2D culture. 3D cardiac ECM promoted increased expression of calcium-handling genes, Junctin, CaV1.2, NCX1, HCN4, SERCA2a, Triadin, and CASQ2. Consistent with this, we find that iPSC-derived CMs in 3D adult cardiac ECM show increased calcium signaling (amplitude) and kinetics (maximum upstroke and downstroke) compared with cells in 2D. Cells in 3D culture were also more responsive to caffeine, likely reflecting an increased availability of calcium in the sarcoplasmic reticulum. Taken together, these studies provide novel strategies for maturing iPSC-derived CMs that may have applications in drug screening and transplantation therapies to treat heart disease. PMID:27392582

  10. Mapping Molecular Differences and Extracellular Matrix Gene Expression in Segmental Outflow Pathways of the Human Ocular Trabecular Meshwork

    PubMed Central

    Vranka, Janice A.; Bradley, John M.; Yang, Yong-Feng; Keller, Kate E.; Acott, Ted S.

    2015-01-01

    Elevated intraocular pressure (IOP) is the primary risk factor for glaucoma, and lowering IOP remains the only effective treatment for glaucoma. The trabecular meshwork (TM) in the anterior chamber of the eye regulates IOP by generating resistance to aqueous humor outflow. Aqueous humor outflow is segmental, but molecular differences between high and low outflow regions of the TM are poorly understood. In this study, flow regions of the TM were characterized using fluorescent tracers and PCR arrays. Anterior segments from human donor eyes were perfused at physiological pressure in an ex vivo organ culture system. Fluorescently-labeled microspheres of various sizes were perfused into anterior segments to label flow regions. Actively perfused microspheres were segmentally distributed, whereas microspheres soaked passively into anterior segments uniformly labeled the TM and surrounding tissues with no apparent segmentation. Cell-tracker quantum dots (20 nm) were localized to the outer uveal and corneoscleral TM, whereas larger, modified microspheres (200 nm) localized throughout the TM layers and Schlemm’s canal. Distribution of fluorescent tracers demonstrated a variable labeling pattern on both a macro- and micro-scale. Quantitative PCR arrays allowed identification of a variety of extracellular matrix genes differentially expressed in high and low flow regions of the TM. Several collagen genes (COL16A1, COL4A2, COL6A1 and 2) and MMPs (1, 2, 3) were enriched in high, whereas COL15A1, and MMP16 were enriched in low flow regions. Matrix metalloproteinase activity was similar in high and low regions using a quantitative FRET peptide assay, whereas protein levels in tissues showed modest regional differences. These gene and protein differences across regions of the TM provide further evidence for a molecular basis of segmental flow routes within the aqueous outflow pathway. New insight into the molecular mechanisms of segmental aqueous outflow may aid in the design

  11. The effect of acute and long-term physical activity on extracellular matrix and serglycin in human skeletal muscle

    PubMed Central

    Hjorth, Marit; Norheim, Frode; Meen, Astri J; Pourteymour, Shirin; Lee, Sindre; Holen, Torgeir; Jensen, Jørgen; Birkeland, Kåre I; Martinov, Vladimir N; Langleite, Torgrim M; Eckardt, Kristin; Drevon, Christian A; Kolset, Svein O

    2015-01-01

    Remodeling of extracellular matrix (ECM), including regulation of proteoglycans in skeletal muscle can be important for physiological adaptation to exercise. To investigate the effects of acute and long-term exercise on the expression of ECM-related genes and proteoglycans in particular, 26 middle-aged, sedentary men underwent a 12 weeks supervised endurance and strength training intervention and two acute, 45 min bicycle tests (70% VO2max), one at baseline and one after 12 weeks of training. Total gene expression in biopsies from m. vastus lateralis was measured with deep mRNA sequencing. After 45 min of bicycling approximately 550 gene transcripts were >50% upregulated. Of these, 28 genes (5%) were directly related to ECM. In response to long-term exercise of 12 weeks 289 genes exhibited enhanced expression (>50%) and 20% of them were ECM related. Further analyses of proteoglycan mRNA expression revealed that more than half of the proteoglycans expressed in muscle were significantly enhanced after 12 weeks intervention. The proteoglycan serglycin (SRGN) has not been studied in skeletal muscle and was one of few proteoglycans that showed increased expression after acute (2.2-fold, P < 0.001) as well as long-term exercise (1.4-fold, P < 0.001). Cultured, primary human skeletal muscle cells expressed and secreted SRGN. When the expression of SRGN was knocked down, the expression and secretion of serpin E1 (SERPINE1) increased. In conclusion, acute and especially long-term exercise promotes enhanced expression of several ECM components and proteoglycans. SRGN is a novel exercise-regulated proteoglycan in skeletal muscle with a potential role in exercise adaptation. PMID:26290530

  12. Preparation, Characterization, and Clinical Implications of Human Decellularized Adipose Tissue Extracellular Matrix (hDAM): A Comprehensive Review.

    PubMed

    Banyard, Derek A; Borad, Vedant; Amezcua, Eduardo; Wirth, Garrett A; Evans, Gregory R D; Widgerow, Alan D

    2016-03-01

    Fat grafting is commonly employed by plastic and reconstructive surgeons to address contour abnormalities and soft-tissue defects; however, because retention rates and thus volume filling effects are unpredictable, there is a search for new and innovative approaches. Initial studies on the use of human decellularized adipose tissue extracellular matrix (hDAM) show promise for its use not only in tissue engineering, but also in fat grafting. In this review, we examine and analyze the literature for the preparation, characterization, and use of hDAM and its derivatives in tissue engineering and plastic surgery applications. All studies reviewed involve physical, chemical, and/or biological treatment stages for the preparation of hDAM; however a distinction should be made between detergent and nondetergent-based processing, the latter of which appears to preserve the native integrity of the hDAM while most-efficiently achieving complete decellularization. Methods of hDAM characterization vary among groups and included simple and immunohistochemical staining, biochemical assays, 3-dimensional (3D) imaging, and mechano-stress testing, all of which are necessary to achieve a comprehensive description of this novel tissue. Finally, we examine the various preclinical models utilized to optimize hDAM performance, which primarily include the addition of adipose-derived stem cells or cross-linking agents. Overall, hDAM appears to be a promising adjunct in fat-grafting applications or even possibly as a stand-alone soft-tissue filler with off-the-shelf potential for commercial applications. PMID:26333991

  13. The mechanical properties of human adipose tissues and their relationships to the structure and composition of the extracellular matrix.

    PubMed

    Alkhouli, Nadia; Mansfield, Jessica; Green, Ellen; Bell, James; Knight, Beatrice; Liversedge, Neil; Tham, Ji Chung; Welbourn, Richard; Shore, Angela C; Kos, Katarina; Winlove, C Peter

    2013-12-01

    Adipose tissue (AT) expansion in obesity is characterized by cellular growth and continuous extracellular matrix (ECM) remodeling with increased fibrillar collagen deposition. It is hypothesized that the matrix can inhibit cellular expansion and lipid storage. Therefore, it is important to fully characterize the ECM's biomechanical properties and its interactions with cells. In this study, we characterize and compare the mechanical properties of human subcutaneous and omental tissues, which have different physiological functions. AT was obtained from 44 subjects undergoing surgery. Force/extension and stress/relaxation data were obtained. The effects of osmotic challenge were measured to investigate the cellular contribution to tissue mechanics. Tissue structure and its response to tensile strain were determined using nonlinear microscopy. AT showed nonlinear stress/strain characteristics of up to a 30% strain. Comparing paired subcutaneous and omental samples (n = 19), the moduli were lower in subcutaneous: initial 1.6 ± 0.8 (means ± SD) and 2.9 ± 1.5 kPa (P = 0.001), final 11.7 ± 6.4 and 32 ± 15.6 kPa (P < 0.001), respectively. The energy dissipation density was lower in subcutaneous AT (n = 13): 0.1 ± 0.1 and 0.3 ± 0.2 kPa, respectively (P = 0.006). Stress/relaxation followed a two-exponential time course. When the incubation medium was exchanged for deionized water in specimens held at 30% strain, force decreased by 31%, and the final modulus increased significantly. Nonlinear microscopy revealed collagen and elastin networks in close proximity to adipocytes and a larger-scale network of larger fiber bundles. There was considerable microscale heterogeneity in the response to strain in both cells and matrix fibers. These results suggest that subcutaneous AT has greater capacity for expansion and recovery from mechanical deformation than omental AT. PMID:24105412

  14. Ability of sodium copper chlorophyllin complex to repair photoaged skin by stimulation of biomarkers in human extracellular matrix

    PubMed Central

    McCook, John P; Stephens, Thomas J; Jiang, Lily I; Law, Robert M; Gotz, Vincent

    2016-01-01

    Purpose To examine the effect of sodium copper chlorophyllin complex on the expression of biomarkers of photoaged dermal extracellular matrix indicative of skin repair. Patients and methods Following a previously published 12-day clinical assessment model, skin biopsy samples from the forearms of four healthy females with signs of photoaged skin were obtained and samples were analyzed by immunohistochemistry for key biomarkers of aging skin after each subject was treated with a test material consisting of a gel containing a liposomal dispersion of sodium copper chlorophyllin complex 0.05%, a positive control of tretinoin cream 0.025%, and an untreated negative control. Results There was a statistically significantly greater amount of fibrillin/amyloid P and epidermal mucins found for skin treated with the test material containing 0.05% sodium copper chlorophyllin complex and the reference control tretinoin 0.025% cream compared to the negative control (untreated site). Expression of procollagen 1 and dermal mucin also showed a greater presence in the samples treated with the test material and the reference control compared to the negative control, though the differences were not statistically significant. No adverse events were observed or reported by the subjects during the course of the study. Conclusion The results of this human biopsy study suggest that both retinoids and sodium copper chlorophyllin complex have beneficial effects on biomarkers of photoaged skin. Products containing both sodium copper chlorophyllin complex and retinols may provide a dual approach to reversing age-related decreases in hyaluronic acid (HA) in the skin: inhibition of the breakdown of HA via sodium copper chlorophyllin complex by inhibition of hyaluronidase, and stimulation of HA synthases by retinol. PMID:27524916

  15. Inhibition by a retinoic acid receptor γ agonist of extracellular matrix remodeling mediated by human Tenon fibroblasts

    PubMed Central

    Liu, Yang; Orita, Tomoko; Suzuki, Katsuyoshi; Teranishi, Shinichiro; Mori, Takuya; Sonoda, Koh-Hei

    2015-01-01

    Purpose Scar formation is most frequently responsible for the failure of glaucoma filtration surgery. Retinoic acids are vitamin A derivatives that play diverse roles in development, immunity, and tissue repair. The effects of the retinoic acid receptor (RAR) γ agonist R667 on the contractility of human Tenon fibroblasts (HTFs) cultured in a three-dimensional collagen gel as well as on intraocular pressure (IOP) in a rat model of glaucoma filtration surgery were investigated. Methods HTFs were cultured in a type I collagen gel, the contraction of which was evaluated by measurement of the gel diameter. The release of matrix metalloproteinases (MMPs) into culture supernatants was assessed with immunoblot analysis and gelatin zymography. Phosphorylation of focal adhesion kinase (FAK) was examined with immunoblot analysis, and production of fibronectin and type I collagen was measured with immunoassays. Results R667 inhibited transforming growth factor-β1 (TGF-β1)-induced collagen gel contraction mediated by HTFs in a concentration- and time-dependent manner, whereas an RARα agonist inhibited this process to a lesser extent and an RARβ agonist had no effect. TGF-β1-induced MMP-1 and MMP-3 release, FAK phosphorylation, and fibronectin and type I collagen production in HTFs were also attenuated by R667. Furthermore, R667 lowered IOP in rats after glaucoma filtration surgery. Conclusions R667 inhibited TGF-β1-induced contraction and extracellular matrix synthesis in HTFs. Such effects might have contributed to the lowering of IOP by R667 in a rat model of glaucoma filtration surgery. RARγ agonists might thus prove effective for inhibition of scar formation after such surgery. PMID:26788029

  16. Recovery of extracellular vesicles from human breast milk is influenced by sample collection and vesicle isolation procedures.

    PubMed

    Zonneveld, Marijke I; Brisson, Alain R; van Herwijnen, Martijn J C; Tan, Sisareuth; van de Lest, Chris H A; Redegeld, Frank A; Garssen, Johan; Wauben, Marca H M; Nolte-'t Hoen, Esther N M

    2014-01-01

    Extracellular vesicles (EV) in breast milk carry immune relevant proteins and could play an important role in the instruction of the neonatal immune system. To further analyze these EV and to elucidate their function it is important that native populations of EV can be recovered from (stored) breast milk samples in a reproducible fashion. However, the impact of isolation and storage procedures on recovery of breast milk EV has remained underexposed. Here, we aimed to define parameters important for EV recovery from fresh and stored breast milk. To compare various protocols across different donors, breast milk was spiked with a well-defined murine EV population. We found that centrifugation of EV down into density gradients largely improved density-based separation and isolation of EV, compared to floatation up into gradients after high-force pelleting of EV. Using cryo-electron microscopy, we identified different subpopulations of human breast milk EV and a not previously described population of lipid tubules. Additionally, the impact of cold storage on breast milk EV was investigated. We determined that storing unprocessed breast milk at -80°C or 4°C caused death of cells present in breast milk, leading to contamination of the breast milk EV population with storage-induced EV. Here, an alternative method is proposed to store breast milk samples for EV analysis at later time points. The proposed adaptations to the breast milk storage and EV isolation procedures can be applied for EV-based biomarker profiling of breast milk and functional analysis of the role of breast milk EV in the development of the neonatal immune system. PMID:25206958

  17. Recovery of extracellular vesicles from human breast milk is influenced by sample collection and vesicle isolation procedures

    PubMed Central

    Zonneveld, Marijke I.; Brisson, Alain R.; van Herwijnen, Martijn J. C.; Tan, Sisareuth; van de Lest, Chris H. A.; Redegeld, Frank A.; Garssen, Johan; Wauben, Marca H. M.; Nolte-'t Hoen, Esther N. M.

    2014-01-01

    Extracellular vesicles (EV) in breast milk carry immune relevant proteins and could play an important role in the instruction of the neonatal immune system. To further analyze these EV and to elucidate their function it is important that native populations of EV can be recovered from (stored) breast milk samples in a reproducible fashion. However, the impact of isolation and storage procedures on recovery of breast milk EV has remained underexposed. Here, we aimed to define parameters important for EV recovery from fresh and stored breast milk. To compare various protocols across different donors, breast milk was spiked with a well-defined murine EV population. We found that centrifugation of EV down into density gradients largely improved density-based separation and isolation of EV, compared to floatation up into gradients after high-force pelleting of EV. Using cryo-electron microscopy, we identified different subpopulations of human breast milk EV and a not previously described population of lipid tubules. Additionally, the impact of cold storage on breast milk EV was investigated. We determined that storing unprocessed breast milk at −80°C or 4°C caused death of cells present in breast milk, leading to contamination of the breast milk EV population with storage-induced EV. Here, an alternative method is proposed to store breast milk samples for EV analysis at later time points. The proposed adaptations to the breast milk storage and EV isolation procedures can be applied for EV-based biomarker profiling of breast milk and functional analysis of the role of breast milk EV in the development of the neonatal immune system. PMID:25206958

  18. Extracellular signal-regulated kinase activation and endothelin-1 production in human endothelial cells exposed to vibration

    PubMed Central

    White, Charles R; Haidekker, Mark A; Stevens, Hazel Y; Frangos, John A

    2004-01-01

    Hand–arm vibration syndrome is a vascular disease of occupational origin and a form of secondary Raynaud's phenomenon. Chronic exposure to hand-held vibrating tools may cause endothelial injury. This study investigates the biomechanical forces involved in the transduction of fluid vibration in the endothelium. Human endothelial cells were exposed to direct vibration and rapid low-volume fluid oscillation. Rapid low-volume fluid oscillation was used to simulate the effects of vibration by generating defined temporal gradients in fluid shear stress across an endothelial monolayer. Extracellular signal-regulated kinase (ERK1/2) phosphorylation and endothelin-1 (ET-1) release were monitored as specific biochemical markers for temporal gradients and endothelial response, respectively. Both vibrational methods were found to phosphorylate ERK1/2 in a similar pattern. At a fixed frequency of fluid oscillation where the duration of each pulse cycle remained constant, ERK1/2 phosphorylation increased with the increasing magnitude of the applied temporal gradient. However, when the frequency of flow oscillation was increased (thus decreasing the duration of each pulse cycle), ERK1/2 phosphorylation was attenuated across all temporal gradient flow profiles. Fluid oscillation significantly stimulated ET-1 release compared to steady flow, and endothelin-1 was also attenuated with the increase in oscillation frequency. Taken together, these results show that both the absolute magnitude of the temporal gradient and the frequency/duration of each pulse cycle play a role in the biomechanical transduction of fluid vibrational forces in endothelial cells. Furthermore, this study reports for the first time a link between the ERK1/2 signal transduction pathway and transmission of vibrational forces in the endothelium. PMID:14724194

  19. Transfer of the Cystic Fibrosis Transmembrane Conductance Regulator to Human Cystic Fibrosis Cells Mediated by Extracellular Vesicles.

    PubMed

    Vituret, Cyrielle; Gallay, Kathy; Confort, Marie-Pierre; Ftaich, Najate; Matei, Constantin I; Archer, Fabienne; Ronfort, Corinne; Mornex, Jean-François; Chanson, Marc; Di Pietro, Attilio; Boulanger, Pierre; Hong, Saw See

    2016-02-01

    Cystic fibrosis (CF) is a genetic disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, resulting in a deficiency in chloride channel activity. In this study, extracellular vesicles (EVs), microvesicles, and exosomes were used as vehicles to deliver exogenous CFTR glycoprotein and its encoding mRNA (mRNA(GFP-CFTR)) to CF cells to correct the CFTR chloride channel function. We isolated microvesicles and exosomes from the culture medium of CFTR-positive Calu-3 cells, or from A549 cells transduced with an adenoviral vector overexpressing a GFP-tagged CFTR (GFP-CFTR). Both microvesicles and exosomes had the capacity to package and deliver the GFP-CFTR glycoprotein and mRNA(GFP-CFTR) to target cells in a dose-dependent manner. Homologous versus heterologous EV-to-cell transfer was studied, and it appeared that the cellular uptake of EVs was significantly more efficient in homologous transfer. The incubation of CF15 cells, a nasal epithelial cell line homozygous for the ΔF508 CFTR mutation, with microvesicles or exosomes loaded with GFP-CFTR resulted in the correction of the CFTR function in CF cells in a dose-dependent manner. A time-course analysis of EV-transduced CF cells suggested that CFTR transferred as mature glycoprotein was responsible for the CFTR-associated channel activity detected at early times posttransduction, whereas GFP-CFTR translated from exogenous mRNA(GFP-CFTR) was responsible for the CFTR function at later times. Collectively, this study showed the potential application of microvesicles and exosomes as vectors for CFTR transfer and functional correction of the genetic defect in human CF cells. PMID:26886833

  20. High-mobility group box 1 promotes extracellular matrix synthesis and wound repair in human bronchial epithelial cells.

    PubMed

    Ojo, Oluwaseun O; Ryu, Min Hyung; Jha, Aruni; Unruh, Helmut; Halayko, Andrew J

    2015-12-01

    High mobility group box 1 (HMGB1) is a damage-associated molecular pattern (DAMP) protein that binds Toll-like receptors (e.g., TLR4) and the receptor for advanced glycated end products (RAGE). The direct effects of HMGB1 on airway structural cells are not fully known. As epithelial cell responses are fundamental drivers of asthma, including abnormal repair-restitution linked to changes in extracellular matrix (ECM) synthesis, we tested the hypothesis that HMGB1 promotes bronchial epithelial cell wound repair via TLR4 and/or RAGE signaling that regulates ECM (fibronectin and the γ2-chain of laminin-5) and integrin protein abundance. To assess impact of HMGB1 we used molecular and pharmacological inhibitors of RAGE or TLR4 signaling in scratch wound, immunofluorescence, and immunoblotting assays to assess wound repair, ECM synthesis, and phosphorylation of intracellular signaling. HMGB1 increased wound closure, and this effect was attenuated by blocking RAGE and TLR4 signaling. HMGB1-induced fibronectin and laminin-5 (γ2 chain) was diminished by blocking RAGE and/or blunting TLR4 signaling. Similarly, induction of α3-integrin receptor for fibronectin and laminin-5 was also diminished by blocking TLR4 signaling and RAGE. Lastly, rapid and/or sustained phosphorylation of SMAD2, ERK1/2, and JNK signaling modulated HMGB1-induced wound closure. Our findings suggest a role for HMGB1 in human airway epithelial cell repair and restitution via multiple pathways mediated by TLR4 and RAGE that underpin increased ECM synthesis and modulation of cell-matrix adhesion. PMID:26432865

  1. Detection and Imaging of Superoxide in Roots by an Electron Spin Resonance Spin-Probe Method

    PubMed Central

    Warwar, Nasim; Mor, Avishai; Fluhr, Robert; Pandian, Ramasamy P.; Kuppusamy, Periannan; Blank, Aharon

    2011-01-01

    The detection, quantification, and imaging of short-lived reactive oxygen species, such as superoxide, in live biological specimens have always been challenging and controversial. Fluorescence-based methods are nonspecific, and electron spin resonance (ESR) spin-trapping methods require high probe concentrations and lack the capability for sufficient image resolution. In this work, a novel (to our knowledge), sensitive, small ESR imaging resonator was used together with a stable spin probe that specifically reacts with superoxide with a high reaction rate constant. This ESR spin-probe-based methodology was used to examine superoxide generated in a plant root as a result of an apical leaf injury. The results show that the spin probe rapidly permeated the plant's extracellular space. Upon injury of the plant tissue, superoxide was produced and the ESR signal decreased rapidly in the injured parts as well as in the distal part of the root. This is attributed to superoxide production and thus provides a means of quantifying the level of superoxide in the plant. The spin probe's narrow single-line ESR spectrum, together with the sensitive imaging resonator, facilitates the quantitative measurement of superoxide in small biological samples, such as the plant's root, as well as one-dimensional imaging along the length of the root. This type of methodology can be used to resolve many questions involving the production of apoplastic superoxide in plant biology. PMID:21943435

  2. Development of a Rat Plasma and Brain Extracellular Fluid Pharmacokinetic Model for Bupropion and Hydroxybupropion Based on Microdialysis Sampling, and Application to Predict Human Brain Concentrations.

    PubMed

    Cremers, Thomas I F H; Flik, Gunnar; Folgering, Joost H A; Rollema, Hans; Stratford, Robert E

    2016-05-01

    Administration of bupropion [(±)-2-(tert-butylamino)-1-(3-chlorophenyl)propan-1-one] and its preformed active metabolite, hydroxybupropion [(±)-1-(3-chlorophenyl)-2-[(1-hydroxy-2-methyl-2-propanyl)amino]-1-propanone], to rats with measurement of unbound concentrations by quantitative microdialysis sampling of plasma and brain extracellular fluid was used to develop a compartmental pharmacokinetics model to describe the blood-brain barrier transport of both substances. The population model revealed rapid equilibration of both entities across the blood-brain barrier, with resultant steady-state brain extracellular fluid/plasma unbound concentration ratio estimates of 1.9 and 1.7 for bupropion and hydroxybupropion, respectively, which is thus indicative of a net uptake asymmetry. An overshoot of the brain extracellular fluid/plasma unbound concentration ratio at early time points was observed with bupropion; this was modeled as a time-dependent uptake clearance of the drug across the blood-brain barrier. Translation of the model was used to predict bupropion and hydroxybupropion exposure in human brain extracellular fluid after twice-daily administration of 150 mg bupropion. Predicted concentrations indicate that preferential inhibition of the dopamine and norepinephrine transporters by the metabolite, with little to no contribution by bupropion, would be expected at this therapeutic dose. Therefore, these results extend nuclear imaging studies on dopamine transporter occupancy and suggest that inhibition of both transporters contributes significantly to bupropion's therapeutic efficacy. PMID:26916207

  3. Quantification of the Contribution of Extracellular Sodium to 23Na Multiple-Quantum-Filtered NMR Spectra of Suspensions of Human Red Blood Cells

    NASA Astrophysics Data System (ADS)

    Knubovets, Tatyana; Shinar, Hadassah; Navon, Gil

    1998-03-01

    23Na double-quantum-filtered (DQF) NMR enables the detection of anisotropic motion of sodium ions due to their interaction with ordered structures in biological tissues. Using the technique, anisotropic motion was found for sodium ions in mammalian red blood cell suspensions (RBC) and the effect was shown to correlate with the integrity of membrane cytoskeleton. In the present study relative contributions to the DQF and triple-quantum-filtered (TQF) spectra of sodium bound to anisotropic and isotropic binding sites in the intra- and extracellular sodium pools (Na content being 15 and 150 mM, respectively) of human RBC were quantified for different hematocrits. DQF spectra were measured by a modified Jeener-Broekaert pulse sequence which enabled exclusive detection of anisotropically moving sodium ions. The relative contributions of the extracellular sodium to the TQF and DQF spectra decreased as the hematocrit increased, but their efficiency relative to the sodium content increased. The contribution of the extracellular sodium to the TQF signal was found to dominate the spectrum of the RBC suspension at all hematocrits studied. The contribution of the extracellular sodium to the DQF was significantly smaller than that to the TQF and was only 22% at a high hematocrit of about 90%.

  4. Economical synthesis of potassium superoxide

    NASA Technical Reports Server (NTRS)

    Bell, A. T.; Sadhukhan, P.

    1979-01-01

    High-frequency discharge in oxygen can be used to prepare superoxides of alkali and alkaline-earth metals. Since no direct-current discharge at the electrodes is present, no sputtering can contaminate the product, hence a high conversion efficiency.

  5. Localization of superoxide dismutases in Alzheimer's disease and Down's syndrome neocortex and hippocampus.

    PubMed Central

    Furuta, A.; Price, D. L.; Pardo, C. A.; Troncoso, J. C.; Xu, Z. S.; Taniguchi, N.; Martin, L. J.

    1995-01-01

    Abnormalities in the cellular regulation and expression of antioxidant enzymes may have a role in mechanisms of central nervous system aging and neurodegeneration. We therefore examined, using isozyme-specific antibodies and immunohistochemistry, the localization of copper, zinc-superoxide dismutase and manganese-superoxide dismutase in the frontal and temporal neocortices and hippocampi of aged controls and individuals with Alzheimer's disease or Down's syndrome. Two different antibodies to copper, zinc-superoxide dismutase and one antibody to manganese-superoxide dismutase were evaluated by immunoblotting of homogenates of human brain before use in immunohistochemistry. The copper, zinc-superoxide dismutase antibodies recognized a single band of proteins at 16 kd. The manganese-superoxide dismutase antibody detected a single band of proteins at 25 kd. Immunohistochemically, copper, zinc-superoxide dismutase and manganese-superoxide dismutase immunoreactivities were localized predominantly to neocortical and hippocampal pyramidal neurons and scarcely seen in glial cells in controls. In Alzheimer's disease and Down's syndrome, the distributions and intensities of these two forms of superoxide dismutase immunoreactivities were different as compared with controls. Copper, zinc-superoxide dismutase was enriched in pyramidal neurons undergoing degeneration, whereas manganese-superoxide dismutase was more enriched in reactive astrocytes than in neurons. In senile plaques, copper, zinc-superoxide dismutase-positive globular structures were surrounded by astrocytes highly enriched in manganese-superoxide dismutase. By double label immunohistochemistry, some pyramidal neurons coexpressed superoxide dismutases and tau, and a few copper, zinc-superoxide dismutase-positive structures in senile plaques colocalized with tau. Amyloid cores, diffuse plaques, and microglia scarcely showed colocalization with superoxide dismutase-positive structures. The observed changes in the

  6. Extracellular Mutant SOD1 Induces Microglial-Mediated Motoneuron Injury

    PubMed Central

    Zhao, Weihua; Beers, David R.; Henkel, Jenny S.; Zhang, Wei; Urushitani, Makoto; Julien, Jean-Pierre; Appel, Stanley H.

    2009-01-01

    Through undefined mechanisms, dominant mutations in (Cu/Zn) superoxide dismutase-1 (mSOD1) cause the non-cell-autonomous death of motoneurons in inherited amyotrophic lateral sclerosis (ALS). Microgliosis at sites of motoneuron injury is a neuropathological hallmark of ALS. Extracellular mSOD1 causes motoneuron injury and triggers microgliosis in spinal cord cultures, but it is unclear whether the injury results from extracellular mSOD1 directly interacting with motoneurons or is mediated through mSOD1-activated microglia. To dissociate these potential mSOD1-mediated neurotoxic mechanisms, the effects of extracellular human mSOD1G93A or mSOD1G85R were assayed using primary cultures of motoneurons and microglia. The data demonstrate that exogenous mSOD1G93A did not cause detectable direct killing of motoneurons. In contrast, mSOD1G93A or mSOD1G85R did induce the morphological and functional activation of microglia, increasing their release of pro-inflammatory cytokines and free radicals. Furthermore, only when microglia were co-cultured with motoneurons did extracellular mSOD1G93A injure motoneurons. The microglial activation mediated by mSOD1G93A was attenuated using toll-like receptors (TLR) 2, TLR4 and CD14 blocking antibodies, or when microglia lacked CD14 expression. These data suggest that extracellular mSOD1G93A is not directly toxic to motoneurons but requires microglial activation for toxicity, utilizing CD14 and TLR pathways. This link between mSOD1 and innate immunity may offer novel therapeutic targets in ALS. PMID:19672969

  7. Cupric yersiniabactin is a virulence-associated superoxide dismutase mimic.

    PubMed

    Chaturvedi, Kaveri S; Hung, Chia S; Giblin, Daryl E; Urushidani, Saki; Austin, Anthony M; Dinauer, Mary C; Henderson, Jeffrey P

    2014-02-21

    Many Gram-negative bacteria interact with extracellular metal ions by expressing one or more siderophore types. Among these, the virulence-associated siderophore yersiniabactin (Ybt) is an avid copper chelator, forming stable cupric (Cu(II)-Ybt) complexes that are detectable in infected patients. Here we show that Ybt-expressing E. coli are protected from intracellular killing within copper-replete phagocytic cells. This survival advantage is highly dependent upon the phagocyte respiratory burst, during which superoxide is generated by the NADPH oxidase complex. Chemical fractionation links this phenotype to a previously unappreciated superoxide dismutase (SOD)-like activity of Cu(II)-Ybt. Unlike previously described synthetic copper-salicylate (Cu(II)-SA) SOD mimics, the salicylate-based natural product Cu(II)-Ybt retains catalytic activity at physiologically plausible protein concentrations. These results reveal a new virulence-associated adaptation based upon spontaneous assembly of a non-protein catalyst. PMID:24283977

  8. Cupric Yersiniabactin Is a Virulence-Associated Superoxide Dismutase Mimic

    PubMed Central

    2013-01-01

    Many Gram-negative bacteria interact with extracellular metal ions by expressing one or more siderophore types. Among these, the virulence-associated siderophore yersiniabactin (Ybt) is an avid copper chelator, forming stable cupric (Cu(II)-Ybt) complexes that are detectable in infected patients. Here we show that Ybt-expressing E. coli are protected from intracellular killing within copper-replete phagocytic cells. This survival advantage is highly dependent upon the phagocyte respiratory burst, during which superoxide is generated by the NADPH oxidase complex. Chemical fractionation links this phenotype to a previously unappreciated superoxide dismutase (SOD)-like activity of Cu(II)-Ybt. Unlike previously described synthetic copper-salicylate (Cu(II)-SA) SOD mimics, the salicylate-based natural product Cu(II)-Ybt retains catalytic activity at physiologically plausible protein concentrations. These results reveal a new virulence-associated adaptation based upon spontaneous assembly of a non-protein catalyst. PMID:24283977

  9. Gene delivery and expression in human retinal pigment epithelial cells: effects of synthetic carriers, serum, extracellular matrix and viral promoters.

    PubMed

    Urtti, A; Polansky, J; Lui, G M; Szoka, F C

    2000-01-01

    Non-viral gene therapy is a potential treatment to many incurable retinal diseases. To fulfill this promise, plasmid DNA must be delivered to the retinal target cells. We evaluated the efficacy of synthetic DNA complexing compounds in transfecting primary human retinal pigment epithelial (RPE) cells in vitro. Fetal human RPE cells were cultured with or without extracellular matrix (ECM), produced using calf corneal endothelial cells. Plasmids encoding nuclear localizing beta galactosidase or luciferase (pRSVLuc, pCLuc4, pSV2Luc) were complexed in water at various +/- charge ratios using cationic lipids (Lipofectin, DOTAP, DOGS), polyethylene imines (25 and 750 kDa), and with degraded 6th generation starburst polyamidoamine dendrimers. Luciferase was quantified using a luminometric assay and beta galactosidase with X-gal staining. Toxicities of transfections were evaluated with the MTT-assay. Using beta galactosidase as the reporter gene naked DNA did not transfect RPE cells at measurable levels whereas 1-5% of the cells expressed histochemically detectable amounts of the gene after transfection with cationic lipid DNA complexes. In RPE cells, Rous sarcoma virus and cytomegalovirus (CMV) were more efficient promoters than SV40 in driving luciferase expression, and CMV was chosen for further experiments. At optimal complex charge ratios, expression levels of luciferase were > 10(9) light units/mg protein after transfection using dendrimers and PEI25, while transfection mediated with the other carriers resulted in luciferase expression levels of 10(7)-10(9) light units/mg protein or less. In general, dendrimers and large molecular weight PEI were less toxic than cationic lipids or PEI25 to RPE cells. Serum and ECM decreased gene expression to the RPE cells with all carriers. Despite low percentage of transfected cells the transgene expression per RPE cell is high, important feature in the retinal tissue with small dimensions, in particular in the case of secreted gene

  10. A perfusion chamber developed to investigate platelet interaction in flowing blood with human vessel wall cells, their extracellular matrix, and purified components.

    PubMed

    Sakariassen, K S; Aarts, P A; de Groot, P G; Houdijk, W P; Sixma, J J

    1983-10-01

    A flat perfusion chamber was developed to study the interaction of blood platelets in flowing blood with cultured human vessel wall cells, their connective tissue matrix, and isolated connective tissue components at defined shear rate conditions. A cover slip covered with endothelial cells or extracellular matrix components was introduced into the chamber. Laser-Doppler velocimetry showed a symmetrical flow profile at flow rates between 50 and 150 ml/min (wall shear rate 300 to 1100 sec-1). Platelet deposition was estimated by using blood platelets labeled with indium-111 or by a morphometric method. Blood platelets did not adhere to endothelial cells at wall shear rates of 765 sec-1 and the endothelial cells remained attached for at least 10 min of perfusion. In preconfluent cultures of endothelial cells, blood platelets adhered to extracellular material in areas between the cells. Removal of endothelial cells by treatment with 0.5% Triton X-100 induced increased platelet adherence with a preference for certain, as yet unidentified, fibrillar structures of the extracellular matrix. Platelet adherence to equine collagen was also studied after coating the cover slips by spraying of small collagen droplets followed by air drying. Platelet adherence and the subsequent platelet aggregate formation occurred predominantly along visible collagen fibers. These studies showed that this perfusion chamber has a laminar and symmetrical flow allowing qualitative and quantitative investigation of platelet interaction with endothelial cells, their extracellular matrix, and pure connective tissue components. A variety of wall shear rates and exposure times can be applied at controlled conditions without removing cells or extracellular material. PMID:6619647

  11. Co-transfection of decorin and interleukin-10 modulates pro-fibrotic extracellular matrix gene expression in human tenocyte culture

    PubMed Central

    Abbah, Sunny A.; Thomas, Dilip; Browne, Shane; O’Brien, Timothy; Pandit, Abhay; Zeugolis, Dimitrios I.

    2016-01-01

    Extracellular matrix synthesis and remodelling are driven by increased activity of transforming growth factor beta 1 (TGF-β1). In tendon tissue repair, increased activity of TGF-β1 leads to progressive fibrosis. Decorin (DCN) and interleukin 10 (IL-10) antagonise pathological collagen synthesis by exerting a neutralising effect via downregulation of TGF-β1. Herein, we report that the delivery of DCN and IL-10 transgenes from a collagen hydrogel system supresses the constitutive expression of TGF-β1 and a range of pro-fibrotic extracellular matrix genes. PMID:26860065

  12. Co-transfection of decorin and interleukin-10 modulates pro-fibrotic extracellular matrix gene expression in human tenocyte culture

    NASA Astrophysics Data System (ADS)

    Abbah, Sunny A.; Thomas, Dilip; Browne, Shane; O'Brien, Timothy; Pandit, Abhay; Zeugolis, Dimitrios I.

    2016-02-01

    Extracellular matrix synthesis and remodelling are driven by increased activity of transforming growth factor beta 1 (TGF-β1). In tendon tissue repair, increased activity of TGF-β1 leads to progressive fibrosis. Decorin (DCN) and interleukin 10 (IL-10) antagonise pathological collagen synthesis by exerting a neutralising effect via downregulation of TGF-β1. Herein, we report that the delivery of DCN and IL-10 transgenes from a collagen hydrogel system supresses the constitutive expression of TGF-β1 and a range of pro-fibrotic extracellular matrix genes.

  13. An Active Form of Sphingosine Kinase-1 Is Released in the Extracellular Medium as Component of Membrane Vesicles Shed by Two Human Tumor Cell Lines

    PubMed Central

    Rigogliuso, Salvatrice; Donati, Chiara; Cassarà, Donata; Taverna, Simona; Salamone, Monica; Bruni, Paola; Vittorelli, Maria Letizia

    2010-01-01

    Expression of sphingosine kinase-1 (SphK-1) correlates with a poor survival rate of tumor patients. This effect is probably due to the ability of SphK-1 to be released into the extracellular medium where it catalyzes the biosynthesis of sphingosine-1-phosphate (S1P), a signaling molecule endowed with profound proangiogenic effects. SphK-1 is a leaderless protein which is secreted by an unconventional mechanism. In this paper, we will show that in human hepatocarcinoma Sk-Hep1 cells, extracellular signaling is followed by targeting the enzyme to the cell surface and parallels targeting of FGF-2 to the budding vesicles. We will also show that SphK-1 is present in a catalitycally active form in vesicles shed by SK-Hep1 and human breast carcinoma 8701-BC cells. The enzyme substrate sphingosine is present in shed vesicles where it is produced by neutral ceramidase. Shed vesicles are therefore a site for S1P production in the extracellular medium and conceivably also within host cell following vesicle endocytosis. PMID:20508814

  14. Nuclear extrusion precedes discharge of genomic DNA fibers during tunicamycin-induced neutrophil extracellular trap-osis (NETosis)-like cell death in cultured human leukemia cells.

    PubMed

    Nakayama, Tomofumi; Saitoh, Noriko; Morotomi-Yano, Keiko; Yano, Ken-Ichi; Nakao, Mitsuyoshi; Saitoh, Hisato

    2016-05-01

    We previously reported that the nucleoside antibiotic tunicamycin (TN), a protein glycosylation inhibitor triggering unfolded protein response (UPR), induced neutrophil extracellular trap-osis (NETosis)-like cellular suicide and, thus, discharged genomic DNA fibers to extracellular spaces in a range of human myeloid cell lines under serum-free conditions. In this study, we further evaluated the effect of TN on human promyelocytic leukemia HL-60 cells using time-lapse microscopy. Our assay revealed a previously unappreciated early event induced by TN-exposure, in which, at 30-60 min after TN addition, the cells extruded their nuclei into the extracellular space, followed by discharge of DNA fibers to form NET-like structures. Intriguingly, neither nuclear extrusion nor DNA discharge was observed when cells were exposed to inducers of UPR, such as brefeldin A, thapsigargin, or dithiothreitol. Our findings revealed novel nuclear dynamics during TN-induced NETosis-like cellular suicide in HL-60 cells and suggested that the toxicological effect of TN on nuclear extrusion and DNA discharge was not a simple UPR. PMID:26888435

  15. Parasitization by Scleroderma guani influences expression of superoxide dismutase genes in Tenebrio molitor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Superoxide dismutase (SOD) is an antioxidant enzyme involved in detoxifying reactive oxygen species. In this study, we identified genes encoding the extracellular and intracellular copper-zinc SODs (ecCuZnSOD and icCuZnSOD) and a manganese SOD (MnSOD) in the yellow mealworm beetle, Tenebrio molitor....

  16. Complex coordinated extracellular metabolism: Acid phosphatases activate diluted human leukocyte proteins to generate energy flow as NADPH from purine nucleotide ribose.

    PubMed

    Hibbs, John B; Vavrin, Zdenek; Cox, James E

    2016-08-01

    Complex metabolism is thought to occur exclusively in the crowded intracellular environment. Here we report that diluted enzymes from lysed human leukocytes produce extracellular energy. Our findings involve two pathways: the purine nucleotide catabolic pathway and the pentose phosphate pathway, which function together to generate energy as NADPH. Glucose6P fuel for NADPH production is generated from structural ribose of purine ribonucleoside monophosphates, ADP, and ADP-ribose. NADPH drives glutathione reductase to reduce an oxidized glutathione disulfide-glutathione redox couple. Acid phosphatases initiate ribose5P salvage from purine ribonucleoside monophosphates, and transaldolase controls the direction of carbon chain flow through the nonoxidative branch of the pentose phosphate pathway. These metabolic control points are regulated by pH. Biologically, this energy conserving metabolism could function in perturbed extracellular spaces. PMID:26895212

  17. Complex coordinated extracellular metabolism: Acid phosphatases activate diluted human leukocyte proteins to generate energy flow as NADPH from purine nucleotide ribose

    PubMed Central

    Hibbs, John B.; Vavrin, Zdenek; Cox, James E.

    2016-01-01

    Complex metabolism is thought to occur exclusively in the crowded intracellular environment. Here we report that diluted enzymes from lysed human leukocytes produce extracellular energy. Our findings involve two pathways: the purine nucleotide catabolic pathway and the pentose phosphate pathway, which function together to generate energy as NADPH. Glucose6P fuel for NADPH production is generated from structural ribose of purine ribonucleoside monophosphates, ADP, and ADP-ribose. NADPH drives glutathione reductase to reduce an oxidized glutathione disulfide-glutathione redox couple. Acid phosphatases initiate ribose5P salvage from purine ribonucleoside monophosphates, and transaldolase controls the direction of carbon chain flow through the nonoxidative branch of the pentose phosphate pathway. These metabolic control points are regulated by pH. Biologically, this energy conserving metabolism could function in perturbed extracellular spaces. PMID:26895212

  18. The cysteines of the extracellular loop are crucial for trafficking of human organic cation transporter 2 to the plasma membrane and are involved in oligomerization

    PubMed Central

    Brast, Sabine; Grabner, Alexander; Sucic, Sonja; Sitte, Harald H.; Hermann, Edwin; Pavenstädt, Hermann; Schlatter, Eberhard; Ciarimboli, Giuliano

    2015-01-01

    Human organic cation transporter 2 (hOCT2) is involved in transport of many endogenous and exogenous organic cations, mainly in kidney and brain cells. Because the quaternary structure of transmembrane proteins plays an essential role for their cellular trafficking and function, we investigated whether hOCT2 forms oligomeric complexes, and if so, which part of the transporter is involved in the oligomerization. A yeast 2-hybrid mating-based split-ubiquitin system (mbSUS), fluorescence resonance energy transfer, Western blot analysis, cross-linking experiments, immunofluorescence, and uptake measurements of the fluorescent organic cation 4-(4-(dimethylamino) styryl)-N-methylpyridinium were applied to human embryonic kidney 293 (HEK293) cells transfected with hOCT2 and partly also to freshly isolated human proximal tubules. The role of cysteines for oligomerization and trafficking of the transporter to the plasma membranes was investigated in cysteine mutants of hOCT2. hOCT2 formed oligomers both in the HEK293 expression system and in native human kidneys. The cysteines of the large extracellular loop are important to enable correct folding, oligomeric assembly, and plasma membrane insertion of hOCT2. Mutation of the first and the last cysteines of the loop at positions 51 and 143 abolished oligomer formation. Thus, the cysteines of the extracellular loop are important for correct trafficking of the transporter to the plasma membrane and for its oligomerization.—Brast, S., Grabner, A., Sucic, S., Sitte, H. H., Hermann, E., Pavenstädt, H., Schlatter, E., and Ciarimboli, G. The cysteines of the extracellular loop are crucial for trafficking of human organic cation transporter 2 to the plasma membrane and are involved in oligomerization. PMID:22085643

  19. Superoxide dismutase: an evolutionary puzzle

    SciTech Connect

    Lee, Y.M.; Friedman, D.J.; Ayala, F.J.

    1985-02-01

    The authors have obtained the complete amino acid sequence of copper/zinc-containing superoxide dismutase (SOD, superoxide:superoxide oxidoreductase, EC 1.15.1.1) from Drosophila melanogaster. The sequence of this enzyme is also known for man, horse, cow, and the yeast Saccharomyces cerevisiae. The rate of evolution of this enzyme is far from constant. The number of amino acid substitutions per 100 residues per 100 million years is 30.9 when the three mammals are compared to each other, 10.6 when Drosophila is compared to the three mammals, and 5.8 when the yeast is compared to the four animals. The first value represents one of the fastest evolutionary rates for any protein, the second is similar to the globin rate, and the third is similar to some cytochromes and other slowly evolving proteins. Hence, SOD is not acceptable evolutionary clock. Another peculiarity of this enzyme is that a two-amino-acid deletion must have occurred independently in the lineages going to the cow and to Drosophila. The authors conclude that using the primary structure of a single gene or protein to time evolutionary events or to reconstruct phylogenetic relationships is potentially fraught with error.

  20. Growth hormone activation of human monocytes for superoxide production but not tumor necrosis factor production, cell adherence, or action against Mycobacterium tuberculosis.

    PubMed Central

    Warwick-Davies, J; Lowrie, D B; Cole, P J

    1995-01-01

    We have previously demonstrated that growth hormone (GH) is a human macrophage-activating factor which primes monocytes for enhanced production of H2O2 in vitro. This report extends our observations to other monocyte functions relevant to infection. We find that GH also primes monocytes for O2- production, to a degree similar to the effect of gamma interferon. Neither macrophage-activating factor alone stimulates monocytes to release bioactive tumor necrosis factor. However, GH, unlike gamma interferon, does not synergize with endotoxin for enhanced tumor necrosis factor production. In further contrast, GH does not alter monocyte adherence or morphology, while phagocytosis and killing of Mycobacterium tuberculosis by GH-treated monocytes are also unaffected. Therefore, despite the multiplicity of the effects of GH on the immune system in vivo, its effects on human monocytes in vitro appear to be limited to priming for the release of reactive oxygen intermediates. PMID:7591064

  1. Enzymatic Production of Extracellular Reactive Oxygen Species by Marine Microorganisms

    NASA Astrophysics Data System (ADS)

    Diaz, J. M.; Andeer, P. F.; Hansel, C. M.

    2014-12-01

    Reactive oxygen species (ROS) serve as intermediates in a myriad of biogeochemically important processes, including cell signaling pathways, cellular oxidative stress responses, and the transformation of both nutrient and toxic metals such as iron and mercury. Abiotic reactions involving the photo-oxidation of organic matter were once considered the only important sources of ROS in the environment. However, the recent discovery of substantial biological ROS production in marine systems has fundamentally shifted this paradigm. Within the last few decades, marine phytoplankton, including diatoms of the genus Thalassiosira, were discovered to produce ample extracellular quantities of the ROS superoxide. Even more recently, we discovered widespread production of extracellular superoxide by phylogenetically and ecologically diverse heterotrophic bacteria at environmentally significant levels (up to 20 amol cell-1 hr-1), which has introduced the revolutionary potential for substantial "dark" cycling of ROS. Despite the profound biogeochemical importance of extracellular biogenic ROS, the cellular mechanisms underlying the production of this ROS have remained elusive. Through the development of a gel-based assay to identify extracellular ROS-producing proteins, we have recently found that enzymes typically involved in antioxidant activity also produce superoxide when molecular oxygen is the only available electron acceptor. For example, large (~3600 amino acids) heme peroxidases are involved in extracellular superoxide production by a bacterium within the widespread Roseobacter clade. In Thalassiosira spp., extracellular superoxide is produced by flavoproteins such as glutathione reductase and ferredoxin NADP+ reductase. Thus, extracellular ROS production may occur via secreted and/or cell surface enzymes that modulate between producing and degrading ROS depending on prevailing geochemical and/or ecological conditions.

  2. Superoxide production by phagocytosing macrophages in relation to the intracellular distribution of oxygen.

    PubMed

    James, P E; Grinberg, O Y; Swartz, H M

    1998-07-01

    We simultaneously measured the concentration of oxygen ([O2]) within the phagosomal and extracellular compartments of macrophages. By combining electron paramagnetic resonance (EPR) oximetry techniques with that of spin-trapping, we found that a significant difference in oxygen concentration ([O2]) exists between these two compartments and we were able to monitor (1) how [O2] in the extracellular compartment and the rate of mitochondrial consumption affected this difference in [O2], and (2) to what extent this gradient of [O2] influenced production of reactive oxygen species by phagosomes. Under conditions where the [O2] in the inflowing gas was high (210 microM; air), the [O2] in the extracellular and phagosomal compartments was 180 and 141 microM, respectively. This was sufficient to maintain maximum superoxide production in these cells. When extracellular [O2] was reduced to 84 or 36 microM, the [O2] in phagosomes within the cells (31.7 and 7.7 microM, respectively) was too low to maintain superoxide production by the NADPH-oxidase system within the phagosomes. The [O2] in the extracellular compartments of these samples, however, was always sufficient to maintain superoxide production by phagosomes at the cell surface. Our findings suggest that the distribution of oxygen surrounding and within macrophages can influence their ability to perform microbicidal and tumoricidal functions, even at an [O2] in the media that appears to be adequate. PMID:9665279

  3. Systemic Administration of Human Bone Marrow-Derived Mesenchymal Stromal Cell Extracellular Vesicles Ameliorates Aspergillus Hyphal Extract-Induced Allergic Airway Inflammation in Immunocompetent Mice

    PubMed Central

    Cruz, Fernanda F.; Borg, Zachary D.; Goodwin, Meagan; Sokocevic, Dino; Wagner, Darcy E.; Coffey, Amy; Antunes, Mariana; Robinson, Kristen L.; Mitsialis, S. Alex; Kourembanas, Stella; Thane, Kristen; Hoffman, Andrew M.; McKenna, David H.; Rocco, Patricia R.M.

    2015-01-01

    An increasing number of studies demonstrate that administration of either conditioned media (CM) or extracellular vesicles (EVs) released by mesenchymal stromal cells (MSCs) derived from bone marrow and other sources are as effective as the MSCs themselves in mitigating inflammation and injury. The goal of the current study was to determine whether xenogeneic administration of CM or EVs from human bone marrow-derived MSCs would be effective in a model of mixed Th2/Th17, neutrophilic-mediated allergic airway inflammation, reflective of severe refractory asthma, induced by repeated mucosal exposure to Aspergillus hyphal extract (AHE) in immunocompetent C57Bl/6 mice. Systemic administration of both CM and EVs isolated from human and murine MSCs, but not human lung fibroblasts, at the onset of antigen challenge in previously sensitized mice significantly ameliorated the AHE-provoked increases in airway hyperreactivity (AHR), lung inflammation, and the antigen-specific CD4 T-cell Th2 and Th17 phenotype. Notably, both CM and EVs from human MSCs (hMSCs) were generally more potent than those from mouse MSCs (mMSCs) in most of the outcome measures. The weak cross-linking agent 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride was found to inhibit release of both soluble mediators and EVs, fully negating effects of systemically administered hMSCs but only partly inhibited the ameliorating effects of mMSCs. These results demonstrate potent xenogeneic effects of CM and EVs from hMSCs in an immunocompetent mouse model of allergic airway inflammation and they also show differences in mechanisms of action of hMSCs versus mMSCs to mitigate AHR and lung inflammation in this model. Significance There is a growing experience demonstrating benefit of mesenchymal stromal cell (MSC)-based cell therapies in preclinical models of asthma. In the current study, conditioned media (CM) and, in particular, the extracellular vesicle fraction obtained from the CM were as potent as the

  4. Human ovarian tumor cell interactions with extracellular matrix: development of a model to study tumor cell invasion

    SciTech Connect

    Niedbala, M.J.

    1986-01-01

    In order to investigate the mechanisms involved in ovarian carcinoma cell implantation and the associated tumor cell-host interactions, a model system was developed employing a mesothelial cell line grown on bovine corneal endothelial cell extracellular matrix (ECM), in an attempt to reconstruct the mesothelium in vitro. Morphologic alterations of the reconstructed mesothelium induced by OCC were observed using immunohistochemical staining, light and electron microscopy. A relationship was observed between extracellular ..beta..-N-acetylhexosaminidase activity and (1) the ability of OCC to morphologically degrade ECM; (2) the capacity of OCC to degrade (/sup 3/H)-glucosamine radiolabelled ECM. The rate of accumulation of extracellular hexosaminidase in cell free-conditioned medium was progressive and closely paralleled the rate of OCC mediated release of (/sup 3/H)-glucosamine from ECM. Purified hexosaminidase (placental and/or OCC) was observed to directly hydrolzye (/sup 3/H)-glucosamine radiolabelled structurally intact ECM (up to 70% radiolabel) and resulted in the cumulative release of free (/sup 3/H)-N-acetylglucosamine.

  5. Cloning, expression, and characterization of a soluble calcium-activated nucleotidase, a human enzyme belonging to a new family of extracellular nucleotidases.

    PubMed

    Smith, Thomas M; Hicks-Berger, Carrie A; Kim, Sunkyu; Kirley, Terence L

    2002-10-01

    The salivary apyrases of blood-feeding arthropods are nucleotide-hydrolyzing enzymes implicated in the inhibition of host platelet aggregation through the hydrolysis of extracellular adenosine diphosphate. A human cDNA homologous to the apyrase cDNA of the blood-feeding bed bug was identified, revealing an open reading frame encoding a 371-amino acid protein. A cleavable signal peptide generates a secreted protein of 333 residues with a predicted core molecular mass of 37,193 Da. Expression in COS-1 cells produced a secreted apyrase in the cell media. The ADPase and ATPase activities were dependent upon calcium, with a pH optimum between pH 6.2 and 7.2. Interestingly, the preferred substrate was not ADP, as might be expected for an enzyme modulating platelet aggregation, but rather UDP, followed by GDP, UTP, GTP, ADP, and ATP. The nucleotidase did not hydrolyze nucleoside monophosphates. Size-exclusion chromatography and Western blot analysis revealed a molecular mass of approximately 34-37 kDa. Treatment of the enzyme with peptide N-glycosidase F indicated that the protein is glycosylated. Northern analysis identified the transcript in a range of human tissues, including testis, placenta, prostate, and lung. No traditional apyrase-conserved regions or nucleotide-binding domains were identified in this human enzyme, indicating membership in a new family of extracellular nucleotidases. PMID:12234496

  6. Superoxide radical and iron modulate aconitase activity in mammalian cells.

    PubMed

    Gardner, P R; Raineri, I; Epstein, L B; White, C W

    1995-06-01

    Aconitase is a member of a family of iron-sulfur-containing (de)hydratases whose activities are modulated in bacteria by superoxide radical (O2-.)-mediated inactivation and iron-dependent reactivation. The inactivation-reactivation of aconitase(s) in cultured mammalian cells was explored since these reactions may impact important and diverse aconitase functions in the cytoplasm and mitochondria. Conditions which increase O2-. production including exposure to the redox-cycling agent phenazine methosulfate (PMS), inhibitors of mitochondrial ubiquinol-cytochrome c oxidoreductase, or hyperoxia inactivated aconitase in mammalian cells. Overproduction of mitochondrial Mn-superoxide dismutase protected aconitase from inactivation by PMS or inhibitors of ubiquinol-cytochrome c oxidoreductase, but not from normobaric hyperoxia. Aconitase activity was reactivated (t1/2 of 12 +/- 3 min) upon removal of PMS. The iron chelator deferoxamine impaired reactivation and increased net inactivation of aconitase by O2-.. The ability of ubiquinol-cytochrome c oxidoreductase-generated O2-. to inactivate aconitase in several cell types correlated with the fraction of the aconitase activity localized in mitochondria. Extracellular O2-. generated with xanthine oxidase did not affect aconitase activity nor did exogenous superoxide dismutase decrease aconitase inactivation by PMS. The results demonstrate a dynamic and cyclical O2-.-mediated inactivation and iron-dependent reactivation of the mammalian [4Fe-4S] aconitases under normal and stress conditions and provide further evidence for the membrane compartmentalization of O2-.. PMID:7768942

  7. Staphylococcus aureus Leukocidin A/B (LukAB) Kills Human Monocytes via Host NLRP3 and ASC when Extracellular, but Not Intracellular

    PubMed Central

    DuMont, Ashley L.; Torres, Victor J.; Duncan, Joseph A.

    2015-01-01

    Staphylococcus aureus infections are a growing health burden worldwide, and paramount to this bacterium’s pathogenesis is the production of virulence factors, including pore-forming leukotoxins. Leukocidin A/B (LukAB) is a recently discovered toxin that kills primary human phagocytes, though the underlying mechanism of cell death is not understood. We demonstrate here that LukAB is a major contributor to the death of human monocytes. Using a variety of in vitro and ex vivo intoxication and infection models, we found that LukAB activates Caspase 1, promotes IL-1β secretion and induces necrosis in human monocytes. Using THP1 cells as a model for human monocytes, we found that the inflammasome components NLRP3 and ASC are required for LukAB-mediated IL-1β secretion and necrotic cell death. S. aureus was shown to kill human monocytes in a LukAB dependent manner under both extracellular and intracellular ex vivo infection models. Although LukAB-mediated killing of THP1 monocytes from extracellular S. aureus requires ASC, NLRP3 and the LukAB-receptor CD11b, LukAB-mediated killing from phagocytosed S. aureus is independent of ASC or NLRP3, but dependent on CD11b. Altogether, this study provides insight into the nature of LukAB-mediated killing of human monocytes. The discovery that S. aureus LukAB provokes differential host responses in a manner dependent on the cellular contact site is critical for the development of anti-infective/anti-inflammatory therapies that target the NLRP3 inflammasome. PMID:26069969

  8. Mitochondrial Disease-related Mutation G167P in Cytochrome b of Rhodobacter capsulatus Cytochrome bc1 (S151P in Human) Affects the Equilibrium Distribution of [2Fe-2S] Cluster and Generation of Superoxide*

    PubMed Central

    Borek, Arkadiusz; Kuleta, Patryk; Ekiert, Robert; Pietras, Rafał; Sarewicz, Marcin; Osyczka, Artur

    2015-01-01

    Cytochrome bc1 is one of the key enzymes of many bioenergetic systems. Its operation involves a large scale movement of a head domain of iron-sulfur protein (ISP-HD), which functionally connects the catalytic quinol oxidation Qo site in cytochrome b with cytochrome c1. The Qo site under certain conditions can generate reactive oxygen species in the reaction scheme depending on the actual position of ISP-HD in respect to the Qo site. Here, using a bacterial system, we show that mutation G167P in cytochrome b shifts the equilibrium distribution of ISP-HD toward positions remote from the Qo site. This renders cytochrome bc1 non-functional in vivo. This effect is remediated by addition of alanine insertions (1Ala and 2Ala) in the neck region of the ISP subunit. These insertions, which on their own shift the equilibrium distribution of ISP-HD in the opposite direction (i.e. toward the Qo site), also act in this manner in the presence of G167P. Changes in the equilibrium distribution of ISP-HD in G167P lead to an increased propensity of cytochrome bc1 to generate superoxide, which becomes evident when the concentration of quinone increases. This result corroborates the recently proposed model in which “semireverse” electron transfer back to the Qo site, occurring when ISP-HD is remote from the site, favors reactive oxygen species production. G167P suggests possible molecular effects of S151P (corresponding in sequence to G167P) identified as a mitochondrial disease-related mutation in human cytochrome b. These effects may be valid for other human mutations that change the equilibrium distribution of ISP-HD in a manner similar to G167P. PMID:26245902

  9. Mitochondrial Disease-related Mutation G167P in Cytochrome b of Rhodobacter capsulatus Cytochrome bc1 (S151P in Human) Affects the Equilibrium Distribution of [2Fe-2S] Cluster and Generation of Superoxide.

    PubMed

    Borek, Arkadiusz; Kuleta, Patryk; Ekiert, Robert; Pietras, Rafał; Sarewicz, Marcin; Osyczka, Artur

    2015-09-25

    Cytochrome bc1 is one of the key enzymes of many bioenergetic systems. Its operation involves a large scale movement of a head domain of iron-sulfur protein (ISP-HD), which functionally connects the catalytic quinol oxidation Qo site in cytochrome b with cytochrome c1. The Qo site under certain conditions can generate reactive oxygen species in the reaction scheme depending on the actual position of ISP-HD in respect to the Qo site. Here, using a bacterial system, we show that mutation G167P in cytochrome b shifts the equilibrium distribution of ISP-HD toward positions remote from the Qo site. This renders cytochrome bc1 non-functional in vivo. This effect is remediated by addition of alanine insertions (1Ala and 2Ala) in the neck region of the ISP subunit. These insertions, which on their own shift the equilibrium distribution of ISP-HD in the opposite direction (i.e. toward the Qo site), also act in this manner in the presence of G167P. Changes in the equilibrium distribution of ISP-HD in G167P lead to an increased propensity of cytochrome bc1 to generate superoxide, which becomes evident when the concentration of quinone increases. This result corroborates the recently proposed model in which "semireverse" electron transfer back to the Qo site, occurring when ISP-HD is remote from the site, favors reactive oxygen species production. G167P suggests possible molecular effects of S151P (corresponding in sequence to G167P) identified as a mitochondrial disease-related mutation in human cytochrome b. These effects may be valid for other human mutations that change the equilibrium distribution of ISP-HD in a manner similar to G167P. PMID:26245902

  10. The extracellular matrix proteins laminin and fibronectin contain binding domains for human plasminogen and tissue plasminogen activator.

    PubMed

    Moser, T L; Enghild, J J; Pizzo, S V; Stack, M S

    1993-09-01

    This study describes the binding of plasminogen and tissue-type plasminogen activator (t-PA) to the extracellular matrix proteins fibronectin and laminin. Plasminogen bound specifically and saturably to both fibronectin and laminin immobilized on microtiter wells, with Kd(app) values of 115 and 18 nM, respectively. Limited proteolysis by endoproteinase V8 coupled with ligand blotting analysis showed that both plasminogen and t-PA preferentially bind to a 55-kDa fibronectin fragment and a 38-kDa laminin fragment. Amino acid sequence analysis demonstrated that the 5-kDa fragment originates with the fibronectin amino terminus whereas the laminin fragment was derived from the carboxyl-terminal globular domain of the laminin A chain. Ligand blotting experiments using isolated plasminogen domains were also used to identify distinct regions of the plasminogen molecule involved in fibronectin and laminin binding. Solution phase fibronectin binding to immobilized plasminogen was mediated primarily via lysine binding site-dependent interactions with plasminogen kringles 1-4. Lysine binding site-dependent binding of soluble laminin to immobilized plasminogen kringles 1-5 as well as an additional lysine binding site-independent interaction between mini-plasminogen and the 38-kDa laminin A chain fragment were also observed. These studies demonstrate binding of plasminogen and tissue-type plasminogen activator to specific regions of the extracellular matrix glycoproteins laminin and fibronectin and provide further insight into the mechanism of regulation of plasminogen activation by components of the extracellular matrix. PMID:8360181

  11. Dynamics of Superoxide Production and Decay in Natural Trichodesmium Colonies from the Sargasso Sea: Implications for Cell Signaling

    NASA Astrophysics Data System (ADS)

    Hansel, C. M.; Buchwald, C.; Diaz, J. M.; Dyhrman, S.; Van Mooy, B. A. S.

    2014-12-01

    Reactive oxygen species (ROS) are key players in the biogeochemistry of the ocean, where they serve a critical role in the cycling of carbon and metals. Research in the past decade has introduced phytoplankton and, most recently, heterotrophic bacteria as significant sources of ROS, including superoxide, within both photic and aphotic regions of the ocean. ROS are both beneficial and detrimental to life. For instance, superoxide is a vital inter- and intra-cellular signaling molecule, yet at high concentrations it induces lipid peroxidation and initiates programmed cell death (PCD). In fact, superoxide has been implicated in PCD in the nitrogen-fixing diazotroph Trichodesmium, presumably leading to the demise of blooms within oligotrophic marine systems. Here, we explore the rates of superoxide production and decay by natural Trichodesmium populations obtained from various surface waters in the Sargasso Sea. We investigate also the role of light and colony density and morphology (puff v. raft) on superoxide fluxes. We find that Trichodesmium colonies produce extracellular superoxide at extremely high rates in the dark that are on par with those of the toxic raphidophyte Chattonella. The rates of superoxide production, however, rapidly decline with increasing cell density pointing to a role for superoxide in cell signaling in these organisms. We also find extremely rapid extracellular superoxide degradation by Trichodesmium. Together, this likely reflects a need for these organisms to maintain ROS at levels that will support signaling but below the threshold level that triggers PCD or oxidative damage. We also show differences in the effect of light on superoxide fluxes as a function of Trichodesmium colony morphology, suggesting differences in either colony physiology or associated bacterial symbionts. These findings point to complex physiological, ecological, and physical influences on ROS dynamics in phytoplankton that require further exploration.

  12. Fluid shear stress regulates metalloproteinase-1 and 2 in human periodontal ligament cells: involvement of extracellular signal-regulated kinase (ERK) and P38 signaling pathways.

    PubMed

    Zheng, Lisha; Huang, Yan; Song, Wei; Gong, Xianghui; Liu, Meili; Jia, Xiaolin; Zhou, Gang; Chen, Luoping; Li, Ang; Fan, Yubo

    2012-09-21

    Matrix metalloproteinase (MMP)-1, 2, with their endogenous inhibitors, tissue inhibitor of metalloproteinase (TIMP)-1, 2 are critical for extracellular matrix remodeling in human periodontal ligament (PDL) and their expression are sensitive to mechanical stresses. Shear stress as the main type of mechanical stress in tooth movement is involved in matrix turnover. However, how shear stress regulates MMPs and TIMPs system is still unclear. In this study, we investigated the effect of fluid shear stress on expression of MMP-1, 2 and TIMP-1, 2 in human PDL cells and the possible roles of mitogen-activated protein kinases in this process. Three levels of fluid shear stresses (6, 9 and 12 dyn/cm(2)) were loaded on PDL cells for 2, 4, 8 and 12h. The results indicated that fluid shear stress rearranged cytoskeleton in PDL cells. Fluid shear stress increased expression of MMP-1, 2, TIMP-1 and suppressed TIMP-2 expression. MAP kinases including extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 were activated rapidly by fluid shear stress. The ERK inhibitor blocked fluid shear stress induced MMP-1 expression and P38 inhibitor reduced fluid shear stress stimulated MMP-2 expression. Our study suggested that fluid shear stress involved in PDL remodeling via regulating MMP-1, 2 and TIMP-1, 2 expression. ERK regulated fluid shear stress induced MMP-1 expression and P38 play a role in fluid shear stress induced MMP-2 upregulation. PMID:22863019

  13. Flax Fiber Hydrophobic Extract Inhibits Human Skin Cells Inflammation and Causes Remodeling of Extracellular Matrix and Wound Closure Activation

    PubMed Central

    Styrczewska, Monika; Kostyn, Anna; Kulma, Anna; Majkowska-Skrobek, Grazyna; Augustyniak, Daria; Prescha, Anna; Czuj, Tadeusz; Szopa, Jan

    2015-01-01

    Inflammation is the basis of many diseases, with chronic wounds amongst them, limiting cell proliferation and tissue regeneration. Our previous preclinical study of flax fiber applied as a wound dressing and analysis of its components impact on the fibroblast transcriptome suggested flax fiber hydrophobic extract use as an anti-inflammatory and wound healing preparation. The extract contains cannabidiol (CBD), phytosterols, and unsaturated fatty acids, showing great promise in wound healing. In in vitro proliferation and wound closure tests the extract activated cell migration and proliferation. The activity of matrix metalloproteinases in skin cells was increased, suggesting activation of extracellular components remodeling. The expression of cytokines was diminished by the extract in a cannabidiol-dependent manner, but β-sitosterol can act synergistically with CBD in inflammation inhibition. Extracellular matrix related genes were also analyzed, considering their importance in further stages of wound healing. The extract activated skin cell matrix remodeling, but the changes were only partially cannabidiol- and β-sitosterol-dependent. The possible role of fatty acids also present in the extract is suggested. The study shows the hydrophobic flax fiber components as wound healing activators, with anti-inflammatory cannabidiol acting in synergy with sterols, and migration and proliferation promoting agents, some of which still require experimental identification. PMID:26347154

  14. Different EV enrichment methods suitable for clinical settings yield different subpopulations of urinary extracellular vesicles from human samples

    PubMed Central

    Royo, Felix; Zuñiga-Garcia, Patricia; Sanchez-Mosquera, Pilar; Egia, Ainara; Perez, Amparo; Loizaga, Ana; Arceo, Raquel; Lacasa, Isabel; Rabade, Ainara; Arrieta, Edurne; Bilbao, Roberto; Unda, Miguel; Carracedo, Arkaitz; Falcon-Perez, Juan M.

    2016-01-01

    Urine sample analysis is irreplaceable as a non-invasive method for disease diagnosis and follow-up. However, in urine samples, non-degraded protein and RNA may be only found in urinary extracellular vesicles (uEVs). In recent years, various methods of uEV enrichment using low volumes of urine and unsophisticated equipment have been developed, with variable success. We compared the results of the differential ultracentrifugation procedure with 4 of these methods. The methods tested were a lectin-based purification, Exoquick (System Biosciences), Total Exosome Isolation from Invitrogen and an in-house modified procedure employing the Exosomal RNA Kit from Norgen Biotek Corp. The analysis of selected gene transcripts and protein markers of extracellular vesicles (EVs) revealed that each method isolates a different mixture of uEV protein markers. In our conditions, the extraction with Norgen's reagent achieved the best performance in terms of gene transcript and protein detection and reproducibility. By using this method, we were able to detect alterations of EVs protein markers in urine samples from prostate cancer adenoma patients. Taken together, our results show that the isolation of uEVs is feasible from small volumes of urine and avoiding ultracentrifugation, making easier the analysis in a clinical facility. However, caution should be taken in the selection of the enrichment method since they have a differential affinity for protein uEVs markers and by extension for different subpopulation of EVs. PMID:26895490

  15. Flax Fiber Hydrophobic Extract Inhibits Human Skin Cells Inflammation and Causes Remodeling of Extracellular Matrix and Wound Closure Activation.

    PubMed

    Styrczewska, Monika; Kostyn, Anna; Kulma, Anna; Majkowska-Skrobek, Grazyna; Augustyniak, Daria; Prescha, Anna; Czuj, Tadeusz; Szopa, Jan

    2015-01-01

    Inflammation is the basis of many diseases, with chronic wounds amongst them, limiting cell proliferation and tissue regeneration. Our previous preclinical study of flax fiber applied as a wound dressing and analysis of its components impact on the fibroblast transcriptome suggested flax fiber hydrophobic extract use as an anti-inflammatory and wound healing preparation. The extract contains cannabidiol (CBD), phytosterols, and unsaturated fatty acids, showing great promise in wound healing. In in vitro proliferation and wound closure tests the extract activated cell migration and proliferation. The activity of matrix metalloproteinases in skin cells was increased, suggesting activation of extracellular components remodeling. The expression of cytokines was diminished by the extract in a cannabidiol-dependent manner, but β-sitosterol can act synergistically with CBD in inflammation inhibition. Extracellular matrix related genes were also analyzed, considering their importance in further stages of wound healing. The extract activated skin cell matrix remodeling, but the changes were only partially cannabidiol- and β-sitosterol-dependent. The possible role of fatty acids also present in the extract is suggested. The study shows the hydrophobic flax fiber components as wound healing activators, with anti-inflammatory cannabidiol acting in synergy with sterols, and migration and proliferation promoting agents, some of which still require experimental identification. PMID:26347154

  16. Extracellular calcium sensing and extracellular calcium signaling

    NASA Technical Reports Server (NTRS)

    Brown, E. M.; MacLeod, R. J.; O'Malley, B. W. (Principal Investigator)

    2001-01-01

    The cloning of a G protein-coupled extracellular Ca(2+) (Ca(o)(2+))-sensing receptor (CaR) has elucidated the molecular basis for many of the previously recognized effects of Ca(o)(2+) on tissues that maintain systemic Ca(o)(2+) homeostasis, especially parathyroid chief cells and several cells in the kidney. The availability of the cloned CaR enabled the development of DNA and antibody probes for identifying the CaR's mRNA and protein, respectively, within these and other tissues. It also permitted the identification of human diseases resulting from inactivating or activating mutations of the CaR gene and the subsequent generation of mice with targeted disruption of the CaR gene. The characteristic alterations in parathyroid and renal function in these patients and in the mice with "knockout" of the CaR gene have provided valuable information on the CaR's physiological roles in these tissues participating in mineral ion homeostasis. Nevertheless, relatively little is known about how the CaR regulates other tissues involved in systemic Ca(o)(2+) homeostasis, particularly bone and intestine. Moreover, there is evidence that additional Ca(o)(2+) sensors may exist in bone cells that mediate some or even all of the known effects of Ca(o)(2+) on these cells. Even more remains to be learned about the CaR's function in the rapidly growing list of cells that express it but are uninvolved in systemic Ca(o)(2+) metabolism. Available data suggest that the receptor serves numerous roles outside of systemic mineral ion homeostasis, ranging from the regulation of hormonal secretion and the activities of various ion channels to the longer term control of gene expression, programmed cell death (apoptosis), and cellular proliferation. In some cases, the CaR on these "nonhomeostatic" cells responds to local changes in Ca(o)(2+) taking place within compartments of the extracellular fluid (ECF) that communicate with the outside environment (e.g., the gastrointestinal tract). In others

  17. Role of the Extracellular Loops of G Protein-Coupled Receptors in Ligand Recognition: A Molecular Modeling Study of the Human P2Y1 Receptor

    PubMed Central

    Moro, Stefano; Hoffmann, Carsten; Jacobson, Kenneth A.

    2016-01-01

    The P2Y1 receptor is a G protein-coupled receptor (GPCR) and is stimulated by extracellular ADP and ATP. Site-directed mutagenesis of the three extracellular loops (ELs) of the human P2Y1 receptor indicates the existence of two essential disulfide bridges (Cys124 in EL1 and Cys202 in EL2; Cys42 in the N-terminal segment and Cys296 in EL3) and several specific ionic and H-bonding interactions (involving Glu209 and Arg287). Through molecular modeling and molecular dynamics simulations, an energetically sound conformational hypothesis for the receptor has been calculated that includes transmembrane (TM) domains (using the electron density map of rhodopsin as a template), extracellular loops, and a truncated N-terminal region. ATP may be docked in the receptor, both within the previously defined TM cleft and within two other regions of the receptor, termed meta-binding sites, defined by the extracellular loops. The first meta-binding site is located outside of the TM bundle, between EL2 and EL3, and the second higher energy site is positioned immediately underneath EL2. Binding at both the principal TM binding site and the lower energy meta-binding sites potentially affects the observed ligand potency. In meta-binding site I, the side chain of Glu209 (EL2) is within hydrogen-bonding distance (2.8 Å) of the ribose O3′, and Arg287 (EL3) coordinates both α- and β-phosphates of the triphosphate chain, consistent with the insensitivity in potency of the 5′-monophosphate agonist, HT-AMP, to mutation of Arg287 to Lys. Moreover, the selective reduction in potency of 3′NH2-ATP in activating the E209R mutant receptor is consistent with the hypothesis of direct contact between EL2 and nucleotide ligands. Our findings support ATP binding to at least two distinct domains of the P2Y1 receptor, both outside and within the TM core. The two disulfide bridges present in the human P2Y1 receptor play a major role in the structure and stability of the receptor, to constrain the

  18. Regional differences in the distribution of the proteoglycans biglycan and decorin in the extracellular matrix of atherosclerotic and restenotic human coronary arteries.

    PubMed Central

    Riessen, R.; Isner, J. M.; Blessing, E.; Loushin, C.; Nikol, S.; Wight, T. N.

    1994-01-01

    Proteoglycans are important constituents of blood vessels and accumulate in various forms of vascular disease. Little is known concerning the proteoglycan composition of restenotic lesions formed after angioplasty and whether the proteoglycan composition of these lesions differs from that of primary atherosclerosis. Accordingly, we sought to characterize the distribution of two proteoglycans, biglycan and decorin, in primary atherosclerotic and restenotic lesions of human coronary arteries. Restenosis (n = 37) and primary (n = 11) lesions obtained from 48 patients by directional atherectomy of human coronary arteries were stained with antibodies against biglycan and decorin. To further characterize the extracellular matrix of restenotic tissues, we studied the co-distribution of these proteoglycans with collagen types I, III, and IV. The loose fibroproliferative tissue seen predominantly in restenosis lesions consistently stained positively for biglycan in patterns of deposition ranging from disseminated to homogeneous. The density and intensity of biglycan staining was correlated with the density of collagen type I and III fiber networks, both of which were observed to interweave among the loose fibroproliferative tissue. The compact connective tissue of primary atherosclerotic plaque was characterized by strong biglycan staining which co-localized with intense collagen type I and III staining. Only basement membrane-like structures rich in collagen type IV demonstrated negative biglycan staining. In contrast, loose fibroproliferative tissue exhibited no significant staining for decorin. Strong immunostaining for decorin, however, was found in primary atherosclerotic plaque. There are thus regional differences in the distribution of extracellular matrix proteoglycans of restenotic and primary human atherosclerotic lesions; these observations suggest that differences established for the biological roles of biglycan and decorin in other organ systems may extend as

  19. Global Substrate Profiling of Proteases in Human Neutrophil Extracellular Traps Reveals Consensus Motif Predominantly Contributed by Elastase

    PubMed Central

    Knudsen, Giselle M.; Perera, Natascha C.; Jenne, Dieter E.; Murphy, John E.; Craik, Charles S.; Hermiston, Terry W.

    2013-01-01

    Neutrophil extracellular traps (NETs) consist of antimicrobial molecules embedded in a web of extracellular DNA. Formation of NETs is considered to be a defense mechanism utilized by neutrophils to ensnare and kill invading pathogens, and has been recently termed NETosis. Neutrophils can be stimulated to undergo NETosis ex vivo, and are predicted to contain high levels of serine proteases, such as neutrophil elastase (NE), cathepsin G (CG) and proteinase 3 (PR3). Serine proteases are important effectors of neutrophil-mediated immunity, which function directly by degrading pathogenic virulent factors and indirectly via proteolytic activation or deactivation of cytokines, chemokines and receptors. In this study, we utilized a diverse and unbiased peptide library to detect and profile protease activity associated with NETs induced by phorbol-12-myristate-13-acetate (PMA). We obtained a “proteolytic signature” from NETs derived from healthy donor neutrophils and used proteomics to assist in the identification of the source of this proteolytic activity. In addition, we profiled each neutrophil serine protease and included the newly identified enzyme, neutrophil serine protease 4 (NSP4). Each enzyme had overlapping yet distinct endopeptidase activities and often cleaved at unique sites within the same peptide substrate. The dominant proteolytic activity in NETs was attributed to NE; however, cleavage sites corresponding to CG and PR3 activity were evident. When NE was immunodepleted, the remaining activity was attributed to CG and to a lesser extent PR3 and NSP4. Our results suggest that blocking NE activity would abrogate the major protease activity associated with NETs. In addition, the newly identified substrate specificity signatures will guide the design of more specific probes and inhibitors that target NET-associated proteases. PMID:24073241

  20. Is Dynamic Autocrine Insulin Signaling Possible? A Mathematical Model Predicts Picomolar Concentrations of Extracellular Monomeric Insulin within Human Pancreatic Islets

    PubMed Central

    Wang, Minghu; Li, Jiaxu; Lim, Gareth E.; Johnson, James D.

    2013-01-01

    Insulin signaling is essential for -cell survival and proliferation in vivo. Insulin also has potent mitogenic and anti-apoptotic actions on cultured -cells, with maximum effect in the high picomolar range and diminishing effect at high nanomolar doses. In order to understand whether these effects of insulin are constitutive or can be subjected to physiological modulation, it is essential to estimate the extracellular concentration of monomeric insulin within an intact islet. Unfortunately, the in vivo concentration of insulin monomers within the islet cannot be measured directly with current technology. Here, we present the first mathematical model designed to estimate the levels of monomeric insulin within the islet extracellular space. Insulin is released as insoluble crystals that exhibit a delayed dissociation into hexamers, dimers, and eventually monomers, which only then can act as signaling ligands. The rates at which different forms of insulin dissolve in vivo have been estimated from studies of peripheral insulin injection sites. We used this and other information to formulate a mathematical model to estimate the local insulin concentration within a single islet as a function of glucose. Model parameters were estimated from existing literature. Components of the model were validated using experimental data, if available. Model analysis predicted that the majority of monomeric insulin in the islet is that which has been returned from the periphery, and the concentration of intra-islet monomeric insulin varies from 50–300 pM when glucose is in the physiological range. Thus, our results suggest that the local concentration of monomeric insulin within the islet is in the picomolar ‘sweet spot’ range of insulin doses that activate the insulin receptor and have the most potent effects on -cells in vitro. Together with experimental data, these estimations support the concept that autocrine/paracrine insulin signalling within the islet is dynamic, rather

  1. Human immunodeficiency virus coinfection with hepatitis B virus leads to a decrease in extracellular and intracellular hepatitis B antigen.

    PubMed

    Pan, Wei; Wu, Zuoqiao; Wu, Shuwen; Guo, Deyin; Gong, Xiaoyan; Po, Tien

    2015-04-01

    Chronic hepatitis B virus (HBV) infection could cause severe liver disease including cirrhosis, hepatocellular carcinoma, and end-stage liver failure in HIV-positive individuals. The available data from clinical studies suggest that HIV infection modulates the HBV-specific T cell response. However, the virological and molecular aspects of HIV-HBV coinfection are currently poorly understood due to the lack of appropriate model systems. In this study, the effect of HIV infection on the life cycle of HBV was explored using an in vitro model system. The present data show that the extracellular and intracellular hepatitis B surface antigen (HBsAg) and e antigen (HBeAg) decrease significantly in HepG2 cells cotransfected with HIV NL4-3 and pHBV1.3 as compared to those cells transfected only with pHBV1.3. Moreover, a significant decrease in HBV DNA and mRNA expression was also observed in the cotransfected cells. HIV Rev protein, an RNA-bound regulatory protein, could significantly decrease the expression levels of extracellular and intracellular HBsAg and HBeAg by mediating the expression of HBV mRNA in cells cotransfected with plasmids containing HIV-1 Rev and pHBV1.3. Further experiments demonstrate that HIV Rev manipulated neither the promoters of HBV nor the nuclear export of HBV mRNA. These results from the in vitro model system might provide clues to further understand the rapid progression of liver disease in HIV-HBV-coinfected patients. PMID:25517882

  2. Complement factor H modulates the activation of human neutrophil granulocytes and the generation of neutrophil extracellular traps.

    PubMed

    Schneider, Andrea E; Sándor, Noémi; Kárpáti, Éva; Józsi, Mihály

    2016-04-01

    Factor H (FH) is a major inhibitor of the alternative pathway of complement activation in plasma and on certain host surfaces. In addition to being a complement regulator, FH can bind to various cells via specific receptors, including binding to neutrophil granulocytes through complement receptor type 3 (CR3; CD11b/CD18), and modulate their function. The cellular roles of FH are, however, poorly understood. Because neutrophils are important innate immune cells in inflammatory processes and the host defense against pathogens, we aimed at studying the effects of FH on various neutrophil functions, including the generation of extracellular traps. FH co-localized with CD11b on the surface of neutrophils isolated from peripheral blood of healthy individuals, and cell-bound FH retained its cofactor activity and enhanced C3b degradation. Soluble FH supported neutrophil migration and immobilized FH induced cell spreading. In addition, immobilized but not soluble FH enhanced IL-8 release from neutrophils. FH alone did not trigger the cells to produce neutrophil extracellular traps (NETs), but NET formation induced by PMA and by fibronectin plus fungal β-glucan were inhibited by immobilized, but not by soluble, FH. Moreover, in parallel with NET formation, immobilized FH also inhibited the production of reactive oxygen species induced by PMA and by fibronectin plus β-glucan. Altogether, these data indicate that FH has multiple regulatory roles on neutrophil functions. While it can support the recruitment of neutrophils, FH may also exert anti-inflammatory effects and influence local inflammatory and antimicrobial reactions, and reduce tissue damage by modulating NET formation. PMID:26938503

  3. Agglutination of human erythrocytes by the interaction of Zn(2+)ion with histidine-651 on the extracellular domain of band 3.

    PubMed

    Kiyotake, Kento; Ochiai, Hideharu; Yamaguchi, Takeo

    2016-05-01

    Clustering of band 3, chloride/bicarbonate exchanger, has been reported in Zn(2+)-treated human erythrocytes. However, the agglutination of human erythrocytes is also induced by the interaction of Zn(2+)ion with histidine on band 3. Identification of histidine that interacts with Zn(2+)ion remains to be determined. The Zn(2+)-induced agglutination of human erythrocytes was unaffected by chymotrypsin cleavage of the small loop region containing His-547 in the extracellular domain of band 3. On the other hand, papain digestion of the large loop region containing His-651 in band 3 inhibited such Zn(2+)-induced agglutination. Moreover, Zn(2+)-induced erythrocyte agglutination was inhibited by the peptide (ARGWVIHPLG) containing His-651, but not by the peptide such as ARGWVIRPLG, which His-651 was substituted by arginine. Among 10 kinds of animal erythrocytes tested, interestingly, no agglutination by Zn(2+)ions was observed in cow cells only that the forth amino acid in the upstream from His-669 on the large loop of cow band 3 is aspartate (Asp-665) instead of glycine. As expected, the agglutination of human erythrocytes by Zn(2+) ions was inhibited in the presence of aspartate. These data indicate that the interaction of Zn(2+) ion with His-651 residue of band 3 plays an important role in the Zn(2+)-induced agglutination of human erythrocytes. PMID:26859120

  4. Congenital Heart Block Maternal Sera Autoantibodies Target an Extracellular Epitope on the α1G T-Type Calcium Channel in Human Fetal Hearts

    PubMed Central

    Rath, Arianna; Liu, Jie; Silverman, Earl D.; Liu, Xiaoru; Siragam, Vinayakumar; Ackerley, Cameron; Su, Brenda Bin; Yan, Jane Yuqing; Capecchi, Marco; Biavati, Luca; Accorroni, Alice; Yuen, William; Quattrone, Filippo; Lung, Kalvin; Jaeggi, Edgar T.; Backx, Peter H.; Deber, Charles M.; Hamilton, Robert M.

    2013-01-01

    Background Congenital heart block (CHB) is a transplacentally acquired autoimmune disease associated with anti-Ro/SSA and anti-La/SSB maternal autoantibodies and is characterized primarily by atrioventricular (AV) block of the fetal heart. This study aims to investigate whether the T-type calcium channel subunit α1G may be a fetal target of maternal sera autoantibodies in CHB. Methodology/Principal Findings We demonstrate differential mRNA expression of the T-type calcium channel CACNA1G (α1G gene) in the AV junction of human fetal hearts compared to the apex (18–22.6 weeks gestation). Using human fetal hearts (20–22 wks gestation), our immunoprecipitation (IP), Western blot analysis and immunofluorescence (IF) staining results, taken together, demonstrate accessibility of the α1G epitope on the surfaces of cardiomyocytes as well as reactivity of maternal serum from CHB affected pregnancies to the α1G protein. By ELISA we demonstrated maternal sera reactivity to α1G was significantly higher in CHB maternal sera compared to controls, and reactivity was epitope mapped to a peptide designated as p305 (corresponding to aa305–319 of the extracellular loop linking transmembrane segments S5–S6 in α1G repeat I). Maternal sera from CHB affected pregnancies also reacted more weakly to the homologous region (7/15 amino acids conserved) of the α1H channel. Electrophysiology experiments with single-cell patch-clamp also demonstrated effects of CHB maternal sera on T-type current in mouse sinoatrial node (SAN) cells. Conclusions/Significance Taken together, these results indicate that CHB maternal sera antibodies readily target an extracellular epitope of α1G T-type calcium channels in human fetal cardiomyocytes. CHB maternal sera also show reactivity for α1H suggesting that autoantibodies can target multiple fetal targets. PMID:24039792

  5. Generation of specific monoclonal antibodies against the extracellular loops of human claudin-3 by immunizing mice with target-expressing cells.

    PubMed

    Ando, Hiroshi; Suzuki, Masayo; Kato-Nakano, Mariko; Kawamoto, Shinobu; Misaka, Hirofumi; Kimoto, Naoya; Furuya, Akiko; Nakamura, Kazuyasu

    2015-01-01

    Human claudin-3 (CLDN3) is a tetraspanin transmembrane protein of tight junction structures and is known to be over-expressed in some malignant tumors. Although a specific monoclonal antibody (MAb) against the extracellular domains of CLDN3 would be a valuable tool, generation of such MAbs has been regarded as difficult using traditional hybridoma techniques, because of the conserved sequence homology of CLDN3s among various species. In addition, high sequence similarity is shared among claudin family members, and potential cross-reactivity of MAb should be evaluated carefully. To overcome these difficulties, we generated CLDN3-expressing Chinese hamster ovary and Sf9 cells to use an immunogens and performed cell-based screening to eliminate cross-reactive antibodies. As a result, we generated MAbs that recognized the extracellular loops of CLDN3 but not those of CLDN4, 5, 6, or 9. Further in vitro studies suggested that the isolated MAbs possessed the desired binding properties for the detection or targeting of CLDN3. PMID:25744656

  6. Inflammation Determines the Pro-Adhesive Properties of High Extracellular D-Glucose in Human Endothelial Cells In Vitro and Rat Microvessels In Vivo

    PubMed Central

    Azcutia, Verónica; Abu-Taha, May; Romacho, Tania; Vázquez-Bella, Marta; Matesanz, Nuria; Luscinskas, Francis W.; Rodríguez-Mañas, Leocadio; Sanz, María Jesús; Sánchez-Ferrer, Carlos F.; Peiró, Concepción

    2010-01-01

    Background Hyperglycemia is acknowledged as an independent risk factor for developing diabetes-associated atherosclerosis. At present, most therapeutic approaches are targeted at a tight glycemic control in diabetic patients, although this fails to prevent macrovascular complications of the disease. Indeed, it remains highly controversial whether or not the mere elevation of extracellular D-glucose can directly promote vascular inflammation, which favors early pro-atherosclerotic events. Methods and Findings In the present work, increasing extracellular D-glucose from 5.5 to 22 mmol/L was neither sufficient to induce intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression, analyzed by flow cytometry, nor to promote leukocyte adhesion to human umbilical vein endothelial cells (HUVEC) in vitro, measured by flow chamber assays. Interestingly, the elevation of D-glucose levels potentiated ICAM-1 and VCAM-1 expression and leukocyte adhesion induced by a pro-inflammatory stimulus, such as interleukin (IL)-1β (5 ng/mL). In HUVEC, high D-glucose augmented the activation of extracellular signal-regulated kinase 1/2 (ERK 1/2) and nuclear transcription factor-κB (NF-κB) elicited by IL-1β, measured by Western blot and electromobility shift assay (EMSA), respectively, but had no effect by itself. Both ERK 1/2 and NF-κB were necessary for VCAM-1 expression, but not for ICAM-1 expression. In vivo, leukocyte trafficking was evaluated in the rat mesenteric microcirculation by intravital microscopy. In accordance with the in vitro data, the acute intraperitoneal injection of D-glucose increased leukocyte rolling flux, adhesion and migration, but only when IL-1β was co-administered. Conclusions These results indicate that the elevation of extracellular D-glucose levels is not sufficient to promote vascular inflammation, and they highlight the pivotal role of a pro-inflammatory environment in diabetes, as a critical factor

  7. Extracellular Calcium Modulates Chondrogenic and Osteogenic Differentiation of Human Adipose-Derived Stem Cells: A Novel Approach for Osteochondral Tissue Engineering Using a Single Stem Cell Source

    PubMed Central

    Mellor, Liliana F.; Mohiti-Asli, Mahsa; Williams, John; Kannan, Arthi; Dent, Morgan R.; Guilak, Farshid

    2015-01-01

    We have previously shown that elevating extracellular calcium from a concentration of 1.8 to 8 mM accelerates and increases human adipose-derived stem cell (hASC) osteogenic differentiation and cell-mediated calcium accretion, even in the absence of any other soluble osteogenic factors in the culture medium. However, the effects of elevated calcium on hASC chondrogenic differentiation have not been reported. The goal of this study was to determine the effects of varied calcium concentrations on chondrogenic differentiation of hASC. We hypothesized that exposure to elevated extracellular calcium (8 mM concentration) in a chondrogenic differentiation medium (CDM) would inhibit chondrogenesis of hASC when compared to basal calcium (1.8 mM concentration) controls. We further hypothesized that a full osteochondral construct could be engineered by controlling local release of calcium to induce site-specific chondrogenesis and osteogenesis using only hASC as the cell source. Human ASC was cultured as micromass pellets in CDM containing transforming growth factor-β1 and bone morphogenetic protein 6 for 28 days at extracellular calcium concentrations of either 1.8 mM (basal) or 8 mM (elevated). Our findings indicated that elevated calcium induced osteogenesis and inhibited chondrogenesis in hASC. Based on these findings, stacked polylactic acid nanofibrous scaffolds containing either 0% or 20% tricalcium phosphate (TCP) nanoparticles were electrospun and tested for site-specific chondrogenesis and osteogenesis. Histological assays confirmed that human ASC differentiated locally to generate calcified tissue in layers containing 20% TCP, and cartilage in the layers with no TCP when cultured in CDM. This is the first study to report the effects of elevated calcium on chondrogenic differentiation of hASC, and to develop osteochondral nanofibrous scaffolds using a single cell source and controlled calcium release to induce site-specific differentiation. This approach

  8. The Arg-Gly-Asp-containing peptide, rhodostomin, inhibits in vitro cell adhesion to extracellular matrices and platelet aggregation caused by saos-2 human osteosarcoma cells.

    PubMed Central

    Chiang, H. S.; Yang, R. S.; Huang, T. F.

    1995-01-01

    Saos-2 cells, derived from a primary human osteosarcoma, caused dose-dependent platelet aggregation in heparinised human platelet-rich plasma. Saos-2 tumour cell-induced platelet aggregation (TCIPA) was completely inhibited by hirudin but unaffected by apyrase. The cell suspension shortened the plasma recalcification times of normal, factor VIII-deficient and factor IX-deficient human plasmas in a dose-dependent manner. However, the cell suspension did not affect the recalcification time of factor VII-deficient plasma. Moreover, a monoclonal antibody (MAb) against human tissue factor completely abolished TCIPA. Flow cytometric analysis using anti-integrin MAbs as the primary binding ligands demonstrated that the integrin receptors alpha v beta 3, alpha 5 beta 1 and alpha 6 beta 1 were present of Saos-2 cells, which might mediate tumour cell adhesion to extracellular matrix. Rhodostomin, an Arg-Gly-Asp (RGD)-containing snake venom peptide which antagonises the binding of fibrinogen to platelet membrane glycoprotein IIb/IIIa, prevented Saos-2 TCIPA as well as tumour cell adhesion to vitronectin, fibronectin and collagen type I. Likewise, the synthetic peptide Gly-Arg-Gly-Asp-Ser (GRGDS) showed a similar effect. On a molar basis, rhodostomin was about 18,000 and 1000 times, respectively, more potent than GRGDS in inhibiting TCIPA and tumour cell adhesion. PMID:7841039

  9. Constitutive hypophosphorylation of extracellular signal-regulated kinases-1/2 and down-regulation of c-Jun in human gastric adenocarcinoma

    SciTech Connect

    Wu, William Ka Kei; Sung, Joseph Joe Yiu; Yu Le; Li Zhijie; Chu, Kent Man; Cho, C.H.

    2008-08-22

    Hyperphosphorylation of extracellular signal-regulated protein kinases-1/2 (ERK1/2) is known to promote cancer cell proliferation. We therefore investigated the constitutive phosphorylation levels of ERK1/2 and the expression of its downstream targets c-Fos, c-Jun, and cyclooxygenase-2 (COX-2) in biopsied human gastric cancer tissues. Results showed that ERK1/2 phosphorylation and c-Jun expression were significantly lowered in gastric cancer compared with the non-cancer adjacent tissues. The expression of c-Fos, however, was not altered while COX-2 was significantly up-regulated. To conclude, we demonstrate that hypophosphorylation of ERK1/2 may occur in gastric cancer. Such discovery may have implication in the application of pathway-directed therapy for this malignant disease.

  10. Expression at a 20L scale and purification of the extracellular domain of the Schistosoma mansoni TSP-2 recombinant protein: a vaccine candidate for human intestinal schistosomiasis.

    PubMed

    Curti, Elena; Kwityn, Clifford; Zhan, Bin; Gillespie, Portia; Brelsford, Jill; Deumic, Vehid; Plieskatt, Jordan; Rezende, Wanderson C; Tsao, Eric; Kalampanayil, Bose; Hotez, Peter J; Bottazzi, Maria Elena

    2013-11-01

    A novel recombinant protein vaccine for human schistosomiasis caused by Schistosoma mansoni is under development. The Sm-TSP-2 schistosomiasis vaccine is comprised of a 9 kDa recombinant protein corresponding to the extracellular domain of a unique S. mansoni tetraspanin. Here, we describe the cloning and the expression of the external loop of Sm-TSP-2 recombinant protein secreted by Pichia Pink the process development at 20L scale fermentation, and the two-steps purification, which resulted in a protein recovery yield of 31% and a protein purity of 97%. The developed processes are suitable for the production of purified protein for subsequent formulation and Phase 1 clinical studies. PMID:23899507

  11. Expression and Characterization of the Extracellular Domain of Human HER2 from Escherichia Coli, and Production of Polyclonal Antibodies Against the Recombinant Proteins.

    PubMed

    Sun, Yong; Feng, Xue; Qu, Jiao; Han, Wenqi; Liu, Zi; Li, Xu; Zou, Ming; Zhen, Yuhong; Zhu, Jie

    2015-06-01

    Human epidermal growth factor receptor 2 (HER2) is a member of the epidermal growth factor receptor (EGFR) family. In this study, the whole extracellular domain gene of HER2 was amplified by RT-PCR from human breast cancer cell line SK-BR-3. The genes of membrane-distal region (A) and membrane proximal region (B) of HER2 extracellular domain were amplified from the cloned template, and then inserted into the expression vector pET-28a and pET-30a, respectively. The recombinant expression vectors were transformed into Escherichia coli BL21 (DE3) cells and induced by isopropyl-b-D-thiogalactopyranoside (IPTG) for expression of proteins His-A and His-B. The expressed proteins were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blot. The optimization of culture conditions led us to accomplish the recombinant protein induction with 1.0 mM IPTG at 37 °C for 8 h, and both proteins were expressed in the insoluble form. Both proteins were purified under the denaturing condition using Ni-NTA sepharose column. Balb/c mice were immunized with the purified proteins and then effectively produced polyclonal antibodies, which reached to a relatively high titer by ELISA testing and had good specificity by western blot detection. The HER2 ECD proteins His-A and His-B could be expressed in E. coli and were suitable for production of high titer antibodies against HER2 ECD. PMID:25906688

  12. Human ASIC3 channel dynamically adapts its activity to sense the extracellular pH in both acidic and alkaline directions

    PubMed Central

    Delaunay, Anne; Gasull, Xavier; Salinas, Miguel; Noël, Jacques; Friend, Valérie; Lingueglia, Eric; Deval, Emmanuel

    2012-01-01

    In rodent sensory neurons, acid-sensing ion channel 3 (ASIC3) has recently emerged as a particularly important sensor of nonadaptive pain associated with tissue acidosis. However, little is known about the human ASIC3 channel, which includes three splice variants differing in their C-terminal domain (hASIC3a, hASIC3b, and hASIC3c). hASIC3a transcripts represent the main mRNAs expressed in both peripheral and central neuronal tissues (dorsal root ganglia [DRG], spinal cord, and brain), where a small proportion of hASIC3c transcripts is also detected. We show that hASIC3 channels (hASIC3a, hASIC3b, or hASIC3c) are able to directly sense extracellular pH changes not only during acidification (up to pH 5.0), but also during alkalization (up to pH 8.0), an original and inducible property yet unknown. When the external pH decreases, hASIC3 display a transient acid mode with brief activation that is relevant to the classical ASIC currents, as previously described. On the other hand, an external pH increase activates a sustained alkaline mode leading to a constitutive activity at resting pH. Both modes are inhibited by the APETx2 toxin, an ASIC3-type channel inhibitor. The alkaline sensitivity of hASIC3 is an intrinsic property of the channel, which is supported by the extracellular loop and involves two arginines (R68 and R83) only present in the human clone. hASIC3 is thus able to sense the extracellular pH in both directions and therefore to dynamically adapt its activity between pH 5.0 and 8.0, a property likely to participate in the fine tuning of neuronal membrane potential and to neuron sensitization in various pH environments. PMID:22829666

  13. Fibroblast-Derived Extracellular Matrix Induces Chondrogenic Differentiation in Human Adipose-Derived Mesenchymal Stromal/Stem Cells in Vitro

    PubMed Central

    Dzobo, Kevin; Turnley, Taegyn; Wishart, Andrew; Rowe, Arielle; Kallmeyer, Karlien; van Vollenstee, Fiona A.; Thomford, Nicholas E.; Dandara, Collet; Chopera, Denis; Pepper, Michael S.; Parker, M. Iqbal

    2016-01-01

    Mesenchymal stromal/stem cells (MSCs) represent an area being intensively researched for tissue engineering and regenerative medicine applications. MSCs may provide the opportunity to treat diseases and injuries that currently have limited therapeutic options, as well as enhance present strategies for tissue repair. The cellular environment has a significant role in cellular development and differentiation through cell–matrix interactions. The aim of this study was to investigate the behavior of adipose-derived MSCs (ad-MSCs) in the context of a cell-derived matrix so as to model the in vivo physiological microenvironment. The fibroblast-derived extracellular matrix (fd-ECM) did not affect ad-MSC morphology, but reduced ad-MSC proliferation. Ad-MSCs cultured on fd-ECM displayed decreased expression of integrins α2 and β1 and subsequently lost their multipotency over time, as shown by the decrease in CD44, Octamer-binding transcription factor 4 (OCT4), SOX2, and NANOG gene expression. The fd-ECM induced chondrogenic differentiation in ad-MSCs compared to control ad-MSCs. Loss of function studies, through the use of siRNA and a mutant Notch1 construct, revealed that ECM-mediated ad-MSCs chondrogenesis requires Notch1 and β-catenin signaling. The fd-ECM also showed anti-senescence effects on ad-MSCs. The fd-ECM is a promising approach for inducing chondrogenesis in ad-MSCs and chondrogenic differentiated ad-MSCs could be used in stem cell therapy procedures. PMID:27527147

  14. Fibroblast-Derived Extracellular Matrix Induces Chondrogenic Differentiation in Human Adipose-Derived Mesenchymal Stromal/Stem Cells in Vitro.

    PubMed

    Dzobo, Kevin; Turnley, Taegyn; Wishart, Andrew; Rowe, Arielle; Kallmeyer, Karlien; van Vollenstee, Fiona A; Thomford, Nicholas E; Dandara, Collet; Chopera, Denis; Pepper, Michael S; Parker, M Iqbal

    2016-01-01

    Mesenchymal stromal/stem cells (MSCs) represent an area being intensively researched for tissue engineering and regenerative medicine applications. MSCs may provide the opportunity to treat diseases and injuries that currently have limited therapeutic options, as well as enhance present strategies for tissue repair. The cellular environment has a significant role in cellular development and differentiation through cell-matrix interactions. The aim of this study was to investigate the behavior of adipose-derived MSCs (ad-MSCs) in the context of a cell-derived matrix so as to model the in vivo physiological microenvironment. The fibroblast-derived extracellular matrix (fd-ECM) did not affect ad-MSC morphology, but reduced ad-MSC proliferation. Ad-MSCs cultured on fd-ECM displayed decreased expression of integrins α2 and β1 and subsequently lost their multipotency over time, as shown by the decrease in CD44, Octamer-binding transcription factor 4 (OCT4), SOX2, and NANOG gene expression. The fd-ECM induced chondrogenic differentiation in ad-MSCs compared to control ad-MSCs. Loss of function studies, through the use of siRNA and a mutant Notch1 construct, revealed that ECM-mediated ad-MSCs chondrogenesis requires Notch1 and β-catenin signaling. The fd-ECM also showed anti-senescence effects on ad-MSCs. The fd-ECM is a promising approach for inducing chondrogenesis in ad-MSCs and chondrogenic differentiated ad-MSCs could be used in stem cell therapy procedures. PMID:27527147

  15. Differential impact of mechanical unloading on structural and nonstructural components of the extracellular matrix in advanced human heart failure.

    PubMed

    Sakamuri, Siva S V P; Takawale, Abhijit; Basu, Ratnadeep; Fedak, Paul W M; Freed, Darren; Sergi, Consolato; Oudit, Gavin Y; Kassiri, Zamaneh

    2016-06-01

    Adverse remodeling of the extracellular matrix (ECM) is a significant characteristic of heart failure. Reverse remodeling of the fibrillar ECM secondary to mechanical unloading of the left ventricle (LV) by left ventricular assist device (LVAD) has been subject of intense investigation; however, little is known about the impacts on nonfibrillar ECM and matricellular proteins that also contribute to disease progression. Explanted failing hearts were procured from patients with nonischemic dilated cardiomyopathy (DCM) with or without LVAD support, and compared to nonfailing control hearts. LV free wall specimens were formalin-fixed, flash-frozen or optimum cutting temperature-mount frozen. Histologic and biochemical assessment of fibrillar ECM showed that LVAD support was associated with lower levels of insoluble collagen, collagen type I mRNA, and collagen I/III ratio compared with no-LVAD hearts. A disintegrin and Metalloproteinase with Thrombospondin Motifs-2 (ADAM-TS2), a procollagen endopeptidase, was reduced in no-LVAD but not in LVAD hearts. The rise in ECM proteolytic activities was significantly lower in LVAD hearts. Matrix metalloproteinases (MMP1, MMP2, MMP8, MMP13, and MT1-MMP/MMP14) were comparable between DCM hearts. Tissue inhibitor of metalloproteinase (TIMP)3 and TIMP4 messenger RNA and protein showed the greatest reduction in no-LVAD hearts. Basement membrane proteins exhibited less severe disarray of laminin and fibronectin-1 in LVAD-supported hearts. The rise in matricellular protein, osteopontin, was suppressed in LVAD hearts, whereas secreted protein, acidic, cysteine-rich (SPARC) levels was unaffected by LVAD. Mechanical unloading of the failing DCM hearts can restore the fibrillar ECM and the basement membrane, contributing toward improved clinical outcomes. However, persistent elevation of matricellular proteins such as SPARC could contribute to the relapse of failing hearts on removal of LVAD support. PMID:26963743

  16. Superoxide targets calcineurin signaling in vascular endothelium

    SciTech Connect

    Namgaladze, Dmitry . E-mail: dmitry@zbc.kgu.de; Shcherbyna, Ivanna; Kienhoefer, Joachim; Hofer, H. Werner; Ullrich, Volker

    2005-09-09

    Superoxide emerges as key regulatory molecule in many aspects of vascular physiology and disease, but identification of superoxide targets in the vasculature remains elusive. In this work, we investigated the possibility of inhibition of protein phosphatase calcineurin by superoxide in endothelial cells. We employed a redox cycler 2,3-dimethoxy-1,4-naphthoquinone (DMNQ) to generate superoxide inside the cells. DMNQ caused inhibition of cellular calcineurin phosphatase activity, which was reversible upon DMNQ removal. Inhibition was suppressed by pre-incubating the cells with copper/zinc superoxide dismutase (Cu,ZnSOD). In addition, reducing cellular Cu,ZnSOD activity by diethylthiocarbamic acid treatment resulted in calcineurin inhibition and enhanced sensitivity to DMNQ. Further, we could show that DMNQ inhibits calcineurin-dependent nuclear translocation and transcriptional activation of NFAT transcription factor, and Cu,ZnSOD or superoxide scavenger Tiron reduced the inhibition. Thus, superoxide generation in endothelial cells results in inhibition of calcineurin signaling, which could have important pathophysiological implications in the vasculature.

  17. Exposure to an Environmental Neurotoxicant Hastens the Onset of Amyotrophic Lateral Sclerosis-Like Phenotype in Human Cu2+/Zn2+ Superoxide Dismutase 1 G93A Mice: Glutamate-Mediated Excitotoxicity

    PubMed Central

    Johnson, Frank O.; Yuan, Yukun; Hajela, Ravindra K.; Chitrakar, Alisha; Parsell, Dawn M.

    2011-01-01

    Mice expressing the human Cu2+/Zn2+ superoxide dismutase 1 (hSOD1) gene mutation (hSOD1G93A; G93A) were exposed to methylmercury (MeHg) at concentrations that did not cause overt motor dysfunction. We hypothesized that low concentrations of MeHg could hasten development of the amyotrophic lateral sclerosis (ALS)-like phenotype in G93A mice. MeHg (1 or 3 ppm/day in drinking water) concentration-dependently accelerated the onset of rotarod failure in G93A, but not wild-type, mice. At the time of rotarod failure, MeHg increased Fluo-4 fluorescence (free intracellular calcium concentration [Ca2+]i) in soma of brainstem-hypoglossal nucleus. These motor neurons control intrinsic and some extrinsic tongue function and exhibit vulnerability in bulbar-onset ALS. The α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA)/kainic acid receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione reduced [Ca2+]i in all G93A mice, irrespective of MeHg treatment. N-acetyl spermine, which antagonizes Ca2+-permeable AMPA receptors, further reduced [Ca2+]i more effectively in MeHg-treated than untreated G93A mice, suggesting that MeHg-treated mice have a greater Ca2+-permeable AMPA receptor contribution. The non-Ca2+ divalent cation chelator N,N,N′,N′-tetrakis(pyridylmethyl)ethylenediamine reduced Fluo-4 fluorescence in all G93A mice; FluoZin-(Zn2+ indicator) fluorescence was increased in all MeHg-treated mice. Thus in G93A mice Zn2+ apparently contributed measurably to the MeHg-induced effect. This is the initial demonstration of accelerated onset of ALS-like phenotype in a genetically susceptible organism by exposure to low concentrations of an environmental neurotoxicant. Increased [Ca2+]i induced by the G93A-MeHg interaction apparently was associated with Ca2+-permeable AMPA receptors and may contribute to the hastened development of ALS-like phenotypes by subjecting motor neurons to excessive elevation of [Ca2+]i, leading to excitotoxic cell death. PMID:21586603

  18. Human galectins induce conversion of dermal fibroblasts into myofibroblasts and production of extracellular matrix: potential application in tissue engineering and wound repair.

    PubMed

    Dvořánková, Barbora; Szabo, Pavol; Lacina, Lukas; Gal, Peter; Uhrova, Jana; Zima, Tomas; Kaltner, Herbert; André, Sabine; Gabius, Hans-Joachim; Sykova, Eva; Smetana, Karel

    2011-01-01

    Members of the galectin family of endogenous lectins are potent adhesion/growth-regulatory effectors. Their multifunctionality opens possibilities for their use in bioapplications. We studied whether human galectins induce the conversion of human dermal fibroblasts into myofibroblasts (MFBs) and the production of a bioactive extracellular matrix scaffold is suitable for cell culture. Testing a panel of galectins of all three subgroups, including natural and engineered variants, we detected activity for the proto-type galectin-1 and galectin-7, the chimera-type galectin-3 and the tandem-repeat-type galectin-4. The activity of galectin-1 required the integrity of the carbohydrate recognition domain. It was independent of the presence of TGF-β1, but it yielded an additive effect. The resulting MFBs, relevant, for example, for tumor progression, generated a matrix scaffold rich in fibronectin and galectin-1 that supported keratinocyte culture without feeder cells. Of note, keratinocytes cultured on this substratum presented a stem-like cell phenotype with small size and keratin-19 expression. In vivo in rats, galectin-1 had a positive effect on skin wound closure 21 days after surgery. In conclusion, we describe the differential potential of certain human galectins to induce the conversion of dermal fibroblasts into MFBs and the generation of a bioactive cell culture substratum. PMID:21494018

  19. Differential expression of extracellular-signal-regulated kinase 5 (ERK5) in normal and degenerated human nucleus pulposus tissues and cells

    SciTech Connect

    Liang, Weiguo; Fang, Dejian; Ye, Dongping; Zou, Longqiang; Shen, Yan; Dai, Libing; Xu, Jiake

    2014-07-11

    Highlights: • ERK5 involved in NP cells. • ERK5 involved in NP tissue. • It was important modulator. - Abstract: Extracellular-signal-regulated kinase 5 (ERK5) is a member of the mitogen-activated protein kinase (MAPK) family and regulates a wide variety of cellular processes such as proliferation, differentiation, necrosis, apoptosis and degeneration. However, the expression of ERK5 and its role in degenerated human nucleus pulposus (NP) is hitherto unknown. In this study, we observed the differential expression of ERK5 in normal and degenerated human nucleus pulposus tissues by using immunohistochemical staining and Western blot. Treatment of NP cells with Pro-inflammatory cytokine, TNF-α decreased ERK5 gene expression as well as NP marker gene expression; including the type II collagen and aggrecan. Suppression of ERK5 gene expression in NP cells by ERK5 siRNA resulted in decreased gene expression of type II collagen and aggrecan. Furthermore, inhibition of ERK5 activation by BIX02188 (5 μM) decreased the gene expression of type II collagen and aggrecan in NP cells. Our results document the expression of ERK5 in degenerated nucleus pulposus tissues, and suggest a potential involvement of ERK5 in human degenerated nucleus pulposus.

  20. Metal Uptake by Manganese Superoxide Dismutase

    PubMed Central

    Whittaker, James W.

    2009-01-01

    Manganese superoxide dismutase is an important antioxidant defense metalloenzyme that protects cells from damage by the toxic oxygen metabolite, superoxide free radical, formed as an unavoidable by-product of aerobic metabolism. Many years of research have gone into understanding how the metal cofactor interacts with small molecules in its catalytic role. In contrast, very little is presently known about how the protein acquires its metal cofactor, an important step in the maturation of the protein and one that is absolutely required for its biological function. Recent work is beginning to provide insight into the mechanisms of metal delivery to manganese superoxide dismutase in vivo and in vitro. PMID:19699328

  1. Molecular characterization of two superoxide dismutases from Hydra vulgaris

    PubMed Central

    Dash, Bhagirathi; Metz, Richard; Huebner, Henry J.; Porter, Weston; Phillips, Timothy D.

    2007-01-01

    Apparent full-length cDNA sequences coding for manganese superoxide dismutase (HvMnSOD) and extracellular superoxide dismutase (HvEC-SOD) were isolated from Hydra vulgaris in order to understand their expression and 3D structures; and explore their possibility of being used as for biomarkers for environmental stress and toxicity. The deduced HvMnSOD protein consists of 219 amino acids of which first 21 amino acids constitute a presumed mitochondria-targeting signal peptide whereas HvEC-SOD protein consists of 189 amino acids of which first 19 amino acids constitute a presumed signal peptide. Molecular model generated for HvMnSOD displayed the N-terminal long alpha antiparallel hairpin and the C-terminal mixed alpha/beta fold characteristic of MnSODs and that for HvEC-SOD displayed the characteristic CuZnSOD beta-barrel fold. Hydrae subjected to thermal, starvation, metal and oxidative stress responded by regulating MnSOD and EC-SOD mRNA transcription. These results indicated that these genes are involved in the cellular stress response and (anti)oxidative processes triggered by stressor and contaminant exposure. Hence the expression of these SODs in hydra may have potential as molecular biomarkers for assessing stress, toxicity and pro-oxidant quality of chemicals and aquatic environmental quality. PMID:17150313

  2. Superoxide overproduction and kidney fibrosis: a new animal model

    PubMed Central

    Guimarães-Souza, Nadia Karina; Yamaleyeva, Liliya Marsovna; Lu, Baisong; Ramos, Ana Claudia Mallet de Souza; Bishop, Colin Edward; Andersson, Karl Erik

    2015-01-01

    Objective To establish whether the mutation in the Immp2L gene induces renal fibrosis and whether aging exacerbates renal morphology in mice. Methods Female mutant mice with mutation in the inner mitochondrial membrane peptidase 2-like protein at 3 and 18 months of age were used. Renal fibrosis was analyzed using classic fibrosis score, Masson’s trichrome staining, and analysis of profibrotic markers using real time polymerase chain reaction (superoxide dismutase 1, metalloproteinase-9, erythropoietin, transforming growth factor beta), and immunostaining (fibroblasts and Type IV collagen). Oxidative stress markers were determined by immunohistochemistry. The number of renal apoptotic cells was determined. Renal function was estimated by serum creatinine. Results Young mutant mice had significantly more glomerulosclerosis than age-matched mice (p=0.034). Mutant mice had more tubular casts (p=0.025), collagen deposition (p=0.019), and collagen type IV expression (p<0.001). Superoxide dismutase 1 expression was significantly higher in young mutants (p=0.038). Old mutants exhibited significantly higher expression of the fibroblast marker and macrophage marker (p=0.007 and p=0.012, respectively). The real time polymerase chain reaction of metalloproteinase-9 and erythropoietin were enhanced 2.5- and 6-fold, respectively, in old mutants. Serum creatinine was significantly higher in old mutants (p<0.001). Conclusion This mutation altered renal architecture by increasing the deposition of extracellular matrix, oxidative stress, and inflammation, suggesting a protective role of Immp2L against renal fibrosis. PMID:25993073

  3. Microfluidic analysis of extracellular matrix-bFGF crosstalk on primary human myoblast chemoproliferation, chemokinesis, and chemotaxis

    PubMed Central

    Ferreira, Meghaan M.; Dewi, Ruby E.; Heilshorn, Sarah C.

    2015-01-01

    Exposing myoblasts to basic fibroblast growth factor (bFGF), which is released after muscle injury, results in receptor phosphorylation, faster migration, and increased proliferation. These effects occur on time scales that extend across three orders of magnitude (100 – 103 minutes). Finite element modeling of Transwell assays, which are traditionally used to assess chemotaxis, revealed that the bFGF gradient formed across the membrane pore is short-lived and diminishes 45% within the first minute. Thus, to evaluate bFGF-induced migration over 102 minutes, we employed a microfluidic assay capable of producing a stable, linear concentration gradient to perform single-cell analyses of chemokinesis and chemotaxis. We hypothesized that the composition of the underlying extracellular matrix (ECM) may affect the behavioral response of myoblasts to soluble bFGF, as previous work with other cell types has suggested crosstalk between integrin and fibroblast growth factor (FGF) receptors. Consistent with this notion, we found that bFGF significantly reduced the doubling time of myoblasts cultured on laminin but not fibronectin or collagen. Laminin also promoted significantly faster migration speeds (13.4 μm/h) than either fibronectin (10.6 μm/h) or collagen (7.6 μm/h) without bFGF stimulation. Chemokinesis driven by bFGF further increased migration speed in a strictly additive manner, resulting in an average increase of 2.3 μm/h across all ECMs tested. We observed relatively mild chemoattraction (~ 67% of myoblast population) in response to bFGF gradients of 3.2 ng/mL/mm regardless of ECM identity. Thus, while ECM-bFGF crosstalk did impact chemoproliferation, it did not have a significant effect on chemokinesis or chemotaxis. These data suggest that the main physiological effect of bFGF on myoblast migration is chemokinesis and that changes in the surrounding ECM, resulting from aging and/or disease may impact muscle regeneration by altering myoblast migration and

  4. THE RESPONSE OF A HUMAN BRONCHIAL EPITHELIAL CELL LINE TO HISTAMINE: INTRACELLULAR CALCIUM CHANGES AND EXTRACELLULAR RELEASE OF INFLAMMATORY

    EPA Science Inventory

    The contribution of airway epithelium-derived factors to inflammation and tissue repair is unclear. ecause human airway epithelia are infrequently available for in vitro studies, transformed epithelial cell lines are of interest as models. e therefore investigated the response of...

  5. Extracellular CADM1 interactions influence insulin secretion by rat and human islet β-cells and promote clustering of syntaxin-1.

    PubMed

    Zhang, Charles; Caldwell, Thomas A; Mirbolooki, M Reza; Duong, Diana; Park, Eun Jee; Chi, Nai-Wen; Chessler, Steven D

    2016-06-01

    Contact between β-cells is necessary for their normal function. Identification of the proteins mediating the effects of β-cell-to-β-cell contact is a necessary step toward gaining a full understanding of the determinants of β-cell function and insulin secretion. The secretory machinery of the β-cells is nearly identical to that of central nervous system (CNS) synapses, and we hypothesize that the transcellular protein interactions that drive maturation of the two secretory machineries upon contact of one cell (or neural process) with another are also highly similar. Two such transcellular interactions, important for both synaptic and β-cell function, have been identified: EphA/ephrin-A and neuroligin/neurexin. Here, we tested the role of another synaptic cleft protein, CADM1, in insulinoma cells and in rat and human islet β-cells. We found that CADM1 is a predominant CADM isoform in β-cells. In INS-1 cells and primary β-cells, CADM1 constrains insulin secretion, and its expression decreases after prolonged glucose stimulation. Using a coculture model, we found that CADM1 also influences insulin secretion in a transcellular manner. We asked whether extracellular CADM1 interactions exert their influence via the same mechanisms by which they influence neurotransmitter exocytosis. Our results suggest that, as in the CNS, CADM1 interactions drive exocytic site assembly and promote actin network formation. These results support the broader hypothesis that the effects of cell-cell contact on β-cell maturation and function are mediated by the same extracellular protein interactions that drive the formation of the presynaptic exocytic machinery. These interactions may be therapeutic targets for reversing β-cell dysfunction in diabetes. PMID:27072493

  6. Odontogenic Differentiation of Human Dental Pulp Stem Cells on Hydrogel Scaffolds Derived from Decellularized Bone Extracellular Matrix and Collagen Type I

    PubMed Central

    White, Lisa J.; Shakesheff, Kevin M.; Tatullo, Marco

    2016-01-01

    Objectives The aim of this study was to evaluate the level of odontogenic differentiation of dental pulp stem cells (DPSCs) on hydrogel scaffolds derived from bone extracellular matrix (bECM) in comparison to those seeded on collagen I (Col-I), one of the main components of dental pulp ECM. Methods DPSCs isolated from human third molars were characterized for surface marker expression and odontogenic potential prior to seeding into bECM or Col-I hydrogel scaffolds. The cells were then seeded onto bECM and Col-I hydrogel scaffolds and cultured under basal conditions or with odontogenic and growth factor (GF) supplements. DPSCs cultivated on tissue culture polystyrene (TCPS) with and without supplements were used as controls. Gene expression of dentin sialophosphoprotein (DSPP), dentin matrix protein 1 (DMP-1) and matrix extracellular phosphoglycoprotein (MEPE) was evaluated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and mineral deposition was observed by Von Kossa staining. Results When DPSCs were cultured on bECM hydrogels, the mRNA expression levels of DSPP, DMP-1 and MEPE genes were significantly upregulated with respect to those cultured on Col-I scaffolds or TCPS in the absence of extra odontogenic inducers. In addition, more mineral deposition was observed on bECM hydrogel scaffolds as demonstrated by Von Kossa staining. Moreover, DSPP, DMP-1 and MEPE mRNA expressions of DPSCs cultured on bECM hydrogels were further upregulated by the addition of GFs or osteo/odontogenic medium compared to Col-I treated cells in the same culture conditions. Significance These results demonstrate the potential of the bECM hydrogel scaffolds to stimulate odontogenic differentiation of DPSCs. PMID:26882351

  7. Manganese Superoxide Dismutase in Cancer Prevention

    PubMed Central

    Robbins, Delira

    2014-01-01

    Abstract Significance: Cancer is the second leading cause of death in the United States. Considering the quality of life and treatment cost, the best way to fight against cancer is to prevent or suppress cancer development. Cancer is preventable as indicated by human papilloma virus (HPV) vaccination and tamoxifen/raloxifen treatment in breast cancer prevention. The activities of superoxide dismutases (SODs) are often lowered during early cancer development, making it a rational candidate for cancer prevention. Recent Advances: SOD liposome and mimetics have been shown to be effective in cancer prevention animal models. They've also passed safety tests during early phase clinical trials. Dietary supplement-based SOD cancer prevention provides another opportunity for antioxidant-based cancer prevention. New mechanistic studies have revealed that SOD inhibits not only oncogenic activity, but also subsequent metabolic shifts during early tumorigenesis. Critical Issues: Lack of sufficient animal model studies targeting specific cancers; and lack of clinical trials and support from pharmaceutical industries also hamper efforts in further advancing SOD-based cancer prevention. Future Directions: To educate and obtain support from our society that cancer is preventable. To combine SOD-based therapeutics with other cancer preventive agents to obtain synergistic effects. To formulate a dietary supplementation-based antioxidant approach for cancer prevention. Lastly, targeting specific populations who are prone to carcinogens, which can trigger oxidative stress as the mechanism of carcinogenesis. Antioxid. Redox Signal. 20, 1628–1645. PMID:23706068

  8. Oxygen plasmas used to synthesize superoxides

    NASA Technical Reports Server (NTRS)

    Hollahan, J. R.; Wydeven, T.

    1972-01-01

    Production of alkali metal superoxides by interaction of molecular oxygen with alkali metals or their salts is discussed. Diagram of reactor to show components and operating principles is provided. Analysis of chemical reactions involved is developed.

  9. Improved production of recombinant human Fas ligand extracellular domain in Pichia pastoris: yield enhancement using disposable culture-bag and its application to site-specific chemical modifications

    PubMed Central

    2014-01-01

    Background A useful heterologous production system is required to obtain sufficient amounts of recombinant therapeutic proteins, which are often necessary for chemical characterization and engineering studies on the development of molecules with improved properties. Human Fas ligand extracellular domain (hFasLECD) is an agonistic death ligand protein that has potential applications for medical purposes. Site-specific chemical modifications can provide a powerful means for the development of engineered proteins with beneficial functions. This study aimed to enhance the yield of hFasLECD using a Pichia pastoris secretory expression system suitable for efficient production on a small laboratory scale, and further to provide procedures for its site-specific chemical modification without impairing the biological functions based on the developed production system. Results A convenient cultivation system using a disposable plastic bag provided a three-fold increase in purification yield of tag-free hFasLECD as compared with the conventional system using a baffled glass flask. The system was further applied to the production of a mutant, which contains an additional reactive cysteine residue in the N-terminal tag-sequence region. Site-specific conjugations and cross-linking without impairing biological functions were achieved by reaction of the mutant hFasLECD with single maleimide group containing compounds and a linear polyethylene glycol derivative containing two maleimide groups at either end, respectively. All purified tag-free and chemically modified hFasLECDs showed an evident receptor binding activity in co-immunoprecipitation experiments mediated by wild-type and N-glycosylation site deficient mutant human Fas receptor extracellular domain derivatives. An N-Ethylmaleimide conjugated hFasLECD derivative demonstrated a significant cytotoxic activity against human HT-29 colorectal cancer cells. Conclusions A new, efficient cultivation system for enhanced secretory

  10. Effects of extracellular calcium and of the calcium entry blockers flunarizine and nimodipine on contractile responses in human temporal arteries.

    PubMed

    Jansen, I; Edvinsson, L

    1986-12-01

    Contraction induced by 124 mM potassium followed the depolarization of smooth-muscle cells and activation of potential-operated calcium channels in human temporal arteries. The contraction elicited consisted of two phases, one rapid and one slowly developing stable phase; both were affected by the two calcium entry blockers flunarizine and nimodipine but at significantly different concentrations. In calcium-free medium 124 mM potassium resulted in a weak contraction. Addition of calcium caused a concentration-dependent contraction that was attenuated by the calcium entry blockers at concentrations comparable to those inhibiting the second phase. The results suggested that in human temporal arteries flunarizine and nimodipine act as calcium entry blockers; there was good correlation with the therapeutic plasma concentration for nimodipine but not for flunarizine. PMID:3802190

  11. Antimycobacterial spectrum of sparfloxacin and its activities alone and in association with other drugs against Mycobacterium avium complex growing extracellularly and intracellularly in murine and human macrophages.

    PubMed Central

    Rastogi, N; Labrousse, V; Goh, K S; De Sousa, J P

    1991-01-01

    The MICs and MBCs of the new difluorinated quinolone drug sparfloxacin against type strains belonging to 21 species of mycobacteria were screened. The MICs and MBCs were within the range of 0.1 to 2.0 and 0.1 to 4.0 micrograms/ml, respectively (with an MBC/MIC ratio of 1 to 2), and against 18 of the 21 species tested, the drug showed significant bactericidal activity (at least 99% killing or more of the initial inoculum added) at concentrations well within the reported peak concentrations in serum (Cmax) in humans. MICs of sparfloxacin for 7 of 10 Mycobacterium avium complex strains were below the Cmax, with MBC/MIC ratios within the range of 2 to 4. Enhancement of its activity by ethambutol, rifampin, amikacin, and clarithromycin (which were used at sublethal concentrations) assessed by using BACTEC radiometry revealed that its activity was further enhanced in 2 of 10 strains by rifampin and in 7 of 10 strains by ethambutol. The bactericidal effects of various drugs used alone as well as two-drug combinations used at Cmax levels were also screened against four strains of M. avium complex growing intracellularly in two different macrophage systems, namely, mouse bone marrow-derived macrophages and peripheral blood monocyte-derived human macrophages. Our results showed a satisfactory correlation between the extracellular and intracellular drug activity data. PMID:1667250

  12. Expression and characterization of group A Streptococcus extracellular cysteine protease recombinant mutant proteins and documentation of seroconversion during human invasive disease episodes.

    PubMed

    Gubba, S; Low, D E; Musser, J M

    1998-02-01

    A recent study with isogenic strains constructed by recombinant DNA strategies unambiguously documented that a highly conserved extracellular cysteine protease expressed by Streptococcus pyogenes (group A Streptococcus [GAS]) is a critical virulence factor in a mouse model of invasive disease (S. Lukomski, S. Sreevatsan, C. Amberg, W. Reichardt, M. Woischnik, A. Podbielski, and J. M. Musser, J. Clin. Invest. 99:2574-2580, 1997). To facilitate further investigations of the streptococcal cysteine protease, recombinant proteins composed of a 40-kDa zymogen containing a C192S amino acid substitution that ablates enzymatic activity, a 28-kDa mature protein with the C192S replacement, and a 12-kDa propeptide were purified from Escherichia coli containing His tag expression vectors. The recombinant C192S zymogen retained apparently normal structural integrity, as assessed by the ability of purified wild-type streptococcal cysteine protease to process the 40-kDa molecule to the 28-kDa mature form. All three recombinant purified proteins retained immunologic reactivity with polyclonal and monoclonal antibodies. Humans with a diverse range of invasive disease episodes (erysipelas, cellulitis, pneumonia, bacteremia, septic arthritis, streptococcal toxic shock syndrome, and necrotizing fasciitis) caused by six distinct M types of GAS seroconverted to the streptococcal cysteine protease. These results demonstrate that this GAS protein is expressed in vivo during the course of human infections and thereby provide additional evidence that the cysteine protease participates in host-pathogen interactions in some patients. PMID:9453639

  13. Expression and Characterization of Group A Streptococcus Extracellular Cysteine Protease Recombinant Mutant Proteins and Documentation of Seroconversion during Human Invasive Disease Episodes

    PubMed Central

    Gubba, Siddeswar; Low, Donald E.; Musser, James M.

    1998-01-01

    A recent study with isogenic strains constructed by recombinant DNA strategies unambiguously documented that a highly conserved extracellular cysteine protease expressed by Streptococcus pyogenes (group A Streptococcus [GAS]) is a critical virulence factor in a mouse model of invasive disease (S. Lukomski, S. Sreevatsan, C. Amberg, W. Reichardt, M. Woischnik, A. Podbielski, and J. M. Musser, J. Clin. Invest. 99:2574–2580, 1997). To facilitate further investigations of the streptococcal cysteine protease, recombinant proteins composed of a 40-kDa zymogen containing a C192S amino acid substitution that ablates enzymatic activity, a 28-kDa mature protein with the C192S replacement, and a 12-kDa propeptide were purified from Escherichia coli containing His tag expression vectors. The recombinant C192S zymogen retained apparently normal structural integrity, as assessed by the ability of purified wild-type streptococcal cysteine protease to process the 40-kDa molecule to the 28-kDa mature form. All three recombinant purified proteins retained immunologic reactivity with polyclonal and monoclonal antibodies. Humans with a diverse range of invasive disease episodes (erysipelas, cellulitis, pneumonia, bacteremia, septic arthritis, streptococcal toxic shock syndrome, and necrotizing fasciitis) caused by six distinct M types of GAS seroconverted to the streptococcal cysteine protease. These results demonstrate that this GAS protein is expressed in vivo during the course of human infections and thereby provide additional evidence that the cysteine protease participates in host-pathogen interactions in some patients. PMID:9453639

  14. A bilayer composite composed of TiO2-incorporated electrospun chitosan membrane and human extracellular matrix sheet as a wound dressing.

    PubMed

    Woo, Chang Hee; Choi, Young Chan; Choi, Ji Suk; Lee, Hee Young; Cho, Yong Woo

    2015-01-01

    We designed bilayer composites composed of an upper layer of titanium dioxide (TiO2)-incorporated chitosan membrane and a sub-layer of human adipose-derived extracellular matrix (ECM) sheet as a wound dressing for full-thickness wound healing. The dense and fibrous top layer, which aims to protect the wound from bacterial infection, was prepared by electrospinning of chitosan solution followed by immersion in TiO2 solution. The sponge-like sub-layer, which aims to promote new tissue regeneration, was prepared with acellular ECM derived from human adipose tissue. Using a modified drop plate method, there was a 33.9 and 69.6% reduction in viable Escherichia coli and Staphylococcus aureus on the bilayer composite, respectively. In an in vivo experiment using rats, the bilayer composites exhibited good biocompatibility and provided proper physicochemical and compositional cues at the wound site. Changes in wound size and histological examination of full-thickness wounds showed that the bilayer composites induced faster regeneration of granulation tissue and epidermis with less scar formation, than control wounds. Overall results suggest that the TiO2-incorporated chitosan/ECM bilayer composite can be a suitable candidate as a wound dressing, with an excellent inhibition of bacterial penetration and wound healing acceleration effects. PMID:26096447

  15. The response of a human bronchial epithelial cell line to histamine: Intracellular calcium changes and extracellular release of inflammatory mediators

    SciTech Connect

    Noah, T.L.; Paradiso, A.M.; Madden, M.C.; McKinnon, K.P.; Devlin, R.B. )

    1991-11-01

    Epithelial cells are likely to modulate inflammation and tissue repair in the airways, but the factors responsible for these processes remain unclear. Because human airway epithelia are infrequently available for in vitro studies, transformed epithelial cell lines are of interest as models. The authors therefore investigated the response of an SV-40/adenovirus-transformed human bronchial epithelial cell line (BEAS-2B) to histamine, a mediator with relevance for airway diseases. The intracellular calcium response to histamine (10(-4) M) was measured, using Fura-2 and microspectrofluorimetry. Histamine induced a transient increase in intracellular calcium that originated from intracellular sources; this effect was inhibited by the H1 receptor antagonist diphenhydramine, suggesting that BEAS cells retain functioning histamine receptors. BEAS cells were grown to confluence on microporous, collagen-coated filters, allowing measurement of vectorial release of soluble mediators. Monolayers exposed to histamine for 30 min released interleukin-6 and fibronectin in the apical direction, in a dose-dependent manner. Little eicosanoid production was induced by histamine, either in the apical or the basolateral direction, although BEAS cells constitutively produced small amounts of prostaglandin E2 and 15-HETE. However, these cells formed large amounts of eicosanoids in response to ozone exposure as a positive control. Comparison of their data with published reports for human airway epithelia in primary culture suggests that the BEAS cell line is, in a number of respects, a relevant model for the study of airway epithelial responses to a variety of stimuli.

  16. Acellular human glans extracellular matrix as a scaffold for tissue engineering: in vitro cell support and biocompatibility

    PubMed Central

    Egydio, Fernanda M.; Freitas, Luiz G.; Sayeg, Kleber; Laks, Marcus; Oliveira, Andréia S.; Almeida, Fernando G.

    2015-01-01

    ABSTRACT Objectives: Diseases of the genitourinary tract can lead to significant damage. Current reconstructive techniques are limited by tissue availability and compatibility. This study aims to assess if the decellularized human glans can be used as a biomaterial for penile reconstruction. Materials and Methods: Samples of the glans matrices were descellularized. We evaluate the presence of collagen type I and III, and elastic fibers. Biocompatibility assays were performed to assess the cytotoxic and non-cytotoxic interactions between the acellular matrix and 3T3 cells. The matrices were seeded with mesenchymal stem cells and were assessed for viability and integration of these cells. Biomechanical tests in native tissue, descellularized matrix and seeded matrix were performed to characterize their biomechanical properties. Results: The tissue architecture of the decellularized matrix of human glans was preserved as well as the maintenance of the biomechanical and biological properties. The analyzes of glans seeded with mesenchymal stem cells revealed the integration of these cells to the matrices, and its viability during two weeks “in vitro”. Conclusion: The decellularization process did not alter the biological and biomechanical characteristics of the human glans. When these matrices were seeded they were able to maintain the cells integrity and vitality. PMID:26689526

  17. A Human Pluripotent Stem Cell Surface N-Glycoproteome Resource Reveals Markers, Extracellular Epitopes, and Drug Targets

    PubMed Central

    Boheler, Kenneth R.; Bhattacharya, Subarna; Kropp, Erin M.; Chuppa, Sandra; Riordon, Daniel R.; Bausch-Fluck, Damaris; Burridge, Paul W.; Wu, Joseph C.; Wersto, Robert P.; Chan, Godfrey Chi Fung; Rao, Sridhar; Wollscheid, Bernd; Gundry, Rebekah L.

    2014-01-01

    Summary Detailed knowledge of cell-surface proteins for isolating well-defined populations of human pluripotent stem cells (hPSCs) would significantly enhance their characterization and translational potential. Through a chemoproteomic approach, we developed a cell-surface proteome inventory containing 496 N-linked glycoproteins on human embryonic (hESCs) and induced PSCs (hiPSCs). Against a backdrop of human fibroblasts and 50 other cell types, >100 surface proteins of interest for hPSCs were revealed. The >30 positive and negative markers verified here by orthogonal approaches provide experimental justification for the rational selection of pluripotency and lineage markers, epitopes for cell isolation, and reagents for the characterization of putative hiPSC lines. Comparative differences between the chemoproteomic-defined surfaceome and the transcriptome-predicted surfaceome directly led to the discovery that STF-31, a reported GLUT-1 inhibitor, is toxic to hPSCs and efficient for selective elimination of hPSCs from mixed cultures. PMID:25068131

  18. Isolation, characterization and potential role in beta cell-endothelium cross-talk of extracellular vesicles released from human pancreatic islets.

    PubMed

    Figliolini, Federico; Cantaluppi, Vincenzo; De Lena, Michela; Beltramo, Silvia; Romagnoli, Renato; Salizzoni, Mauro; Melzi, Raffaella; Nano, Rita; Piemonti, Lorenzo; Tetta, Ciro; Biancone, Luigi; Camussi, Giovanni

    2014-01-01

    The cross-talk between beta cells and endothelium plays a key role in islet physiopathology and in the revascularization process after islet transplantation. However, the molecular mechanisms involved in this cross-talk are not fully elucidated. Extracellular vesicles (EVs) are secreted membrane nanoparticles involved in inter-cellular communication through the transfer of proteins and nucleic acids. The aims of this study were: 1) isolation and characterization of EVs from human islets; 2) evaluation of the pro-angiogenic effect of islet-derived EVs on human islet endothelial cells (IECs). EVs were isolated by ultracentrifugation from conditioned medium of human islets and characterized by nanotrack analysis (Nanosight), FACS, western blot, bioanalyzer, mRNA/microRNA RT-PCR array. On IECs, we evaluated EV-induced insulin mRNA transfer, proliferation, resistance to apoptosis, in vitro angiogenesis, migration, gene and protein profiling. EVs sized 236±54 nm, expressed different surface molecules and islet-specific proteins (insulin, C-peptide, GLP1R) and carried several mRNAs (VEGFa, eNOS) and microRNAs (miR-27b, miR-126, miR-130 and miR-296) involved in beta cell function, insulin secretion and angiogenesis. Purified EVs were internalized into IECs inducing insulin mRNA expression, protection from apoptosis and enhancement of angiogenesis. Human islets release biologically active EVs able to shuttle specific mRNAs and microRNAs (miRNAs) into target endothelial cells. These results suggest a putative role for islet-derived EVs in beta cell-endothelium cross-talk and in the neoangiogenesis process which is critical for engraftment of transplanted islets. PMID:25028931

  19. Isolation, Characterization and Potential Role in Beta Cell-Endothelium Cross-Talk of Extracellular Vesicles Released from Human Pancreatic Islets

    PubMed Central

    De Lena, Michela; Beltramo, Silvia; Romagnoli, Renato; Salizzoni, Mauro; Melzi, Raffaella; Nano, Rita; Piemonti, Lorenzo; Tetta, Ciro; Biancone, Luigi; Camussi, Giovanni

    2014-01-01

    The cross-talk between beta cells and endothelium plays a key role in islet physiopathology and in the revascularization process after islet transplantation. However, the molecular mechanisms involved in this cross-talk are not fully elucidated. Extracellular vesicles (EVs) are secreted membrane nanoparticles involved in inter-cellular communication through the transfer of proteins and nucleic acids. The aims of this study were: 1) isolation and characterization of EVs from human islets; 2) evaluation of the pro-angiogenic effect of islet-derived EVs on human islet endothelial cells (IECs). EVs were isolated by ultracentrifugation from conditioned medium of human islets and characterized by nanotrack analysis (Nanosight), FACS, western blot, bioanalyzer, mRNA/microRNA RT-PCR array. On IECs, we evaluated EV-induced insulin mRNA transfer, proliferation, resistance to apoptosis, in vitro angiogenesis, migration, gene and protein profiling. EVs sized 236±54 nm, expressed different surface molecules and islet-specific proteins (insulin, C-peptide, GLP1R) and carried several mRNAs (VEGFa, eNOS) and microRNAs (miR-27b, miR-126, miR-130 and miR-296) involved in beta cell function, insulin secretion and angiogenesis. Purified EVs were internalized into IECs inducing insulin mRNA expression, protection from apoptosis and enhancement of angiogenesis. Human islets release biologically active EVs able to shuttle specific mRNAs and microRNAs (miRNAs) into target endothelial cells. These results suggest a putative role for islet-derived EVs in beta cell-endothelium cross-talk and in the neoangiogenesis process which is critical for engraftment of transplanted islets. PMID:25028931

  20. The Superoxide Reductase from the Early Diverging Eukaryote Giardia Intestinalis

    SciTech Connect

    Cabelli, D.E.; Testa, F.; Mastronicola, D.; Bordi, E.; Pucillo, L.P.; Sarti, P.; Saraiva, L.M.; Giuffre, A.; Teixeira, M.

    2011-10-15

    Unlike superoxide dismutases (SODs), superoxidereductases (SORs) eliminate superoxide anion (O{sub 2}{sup {sm_bullet}-}) not through its dismutation, but via reduction to hydrogen peroxide (H{sub 2}O{sub 2}) in the presence of an electron donor. The microaerobic protist Giardia intestinalis, responsible for a common intestinal disease in humans, though lacking SOD and other canonical reactive oxygen species-detoxifying systems, is among the very few eukaryotes encoding a SOR yet identified. In this study, the recombinant SOR from Giardia (SOR{sub Gi}) was purified and characterized by pulse radiolysis and stopped-flow spectrophotometry. The protein, isolated in the reduced state, after oxidation by superoxide or hexachloroiridate(IV), yields a resting species (T{sub final}) with Fe{sup 3+} ligated to glutamate or hydroxide depending on pH (apparent pK{sub a} = 8.7). Although showing negligible SOD activity, reduced SOR{sub Gi} reacts with O{sub 2}{sup {sm_bullet}-} with a pH-independent second-order rate constant k{sub 1} = 1.0 x 10{sup 9} M{sup -1} s{sup -1} and yields the ferric-(hydro)peroxo intermediate T{sub 1}; this in turn rapidly decays to the T{sub final} state with pH-dependent rates, without populating other detectable intermediates. Immunoblotting assays show that SOR{sub Gi} is expressed in the disease-causing trophozoite of Giardia. We propose that the superoxide-scavenging activity of SOR in Giardia may promote the survival of this air-sensitive parasite in the fairly aerobic proximal human small intestine during infection.

  1. Tetraorganylammonium superoxide compounds: close to unperturbed superoxide ions in the solid state.

    PubMed

    Dietzel, Pascal D C; Kremer, Reinhard K; Jansen, Martin

    2004-04-14

    Trimethylphenylammonium superoxide (1) and tetrabutylammonium superoxide (2) were prepared by ion-exchange reaction in liquid ammonia. Both compounds were structurally characterized by single-crystal X-ray diffraction. The crystal structure of 2 contains solvent ammonia molecules that are hydrogen bonded to the superoxide ion and therefore may influence the bonding properties of the superoxide ion. The crystal structure of 1 does not contain any solvent molecules. Therefore, it represents the best known approximation to the virtually isolated superoxide ion in the solid state to date. The O-O bond length is 1.332(2) A in 1 and 1.312(2) A in 2. Magnetization measurements show that the susceptibilities of both compounds follow an ideal Curie law down to 2 K reflecting an absence of intermolecular exchange effects between the superoxide ions. The effective magnetic moments of both compounds are larger than the spin-only value due to contributions of the orbital momentum in the superoxide ion. The values of the magnetic moment comply well with the g factors obtained from electron paramagnetic resonance spectra. The g tensors themselves reflect the anisotropic environment of the superoxide ions. The Pi(g) energy levels which are degenerate in the free superoxide ion split up in crystal fields of lower than tetragonal symmetry. The energy splitting is estimated from the diagonal elements of the g tensor of 1. PMID:15070387

  2. Evidence for the role of superoxide radicals in neutrophil-mediated cytotoxicity.

    PubMed Central

    Simchowitz, L; Spilberg, I

    1979-01-01

    Human peripheral neutrophils became cytotoxic to chicken red blood cells (CRBC) in the presence of lectins as assessed by release of 51chromium from labelled target cells. Phytohaemagglutinin (PHA) and concanavalin A (Con A), which caused time-dependent and dose-dependent cytotoxicity over a concentration range of 25--400 microgram/ml, also caused significant generation of superoxide radicals as measured by ferricytochrome C reduction. Pokeweed mitogen, which does not induce cytotoxicity over the same concentration range, was unable to promote superoxide generation by neutrophils. PHA-induced generation of superoxide paralleled and appeared to precede PHA-dependent cytotoxicity. Superoxide dismutase (SOD), which enzymatically destroys superoxide, caused moderate inhibition of PHA-dependent cytotoxicity over the concentration range of 100--500 microgram/ml whereas catalytically inactive enzyme had no effect. Incubation under oxygen-depleted conditions caused a marked decrease in both PHA-induced superoxide generation and cytotoxicity relative to that obtained with neutrophils incubated aerobically. These findings suggest a central role for superoxide radicals in causing target cell damage in this model of neutrophil-mediated cytotoxicity. PMID:223976

  3. Elevated extracellular calcium increases expression of bone morphogenetic protein-2 gene via a calcium channel and ERK pathway in human dental pulp cells

    SciTech Connect

    Tada, Hiroyuki; Nemoto, Eiji; Kanaya, Sousuke; Hamaji, Nozomu; Sato, Hisae; Shimauchi, Hidetoshi

    2010-04-16

    Dental pulp cells, which have been shown to share phenotypical features with osteoblasts, are capable of differentiating into odontoblast-like cells and generating a dentin-like mineral structure. Elevated extracellular Ca{sup 2+}Ca{sub o}{sup 2+} has been implicated in osteogenesis by stimulating the proliferation and differentiation of osteoblasts; however, the role of Ca{sub o}{sup 2+} signaling in odontogenesis remains unclear. We found that elevated Ca{sub o}{sup 2+} increases bone morphogenetic protein (BMP)-2 gene expression in human dental pulp cells. The increase was modulated not only at a transcriptional level but also at a post-transcriptional level, because treatment with Ca{sup 2+} increased the stability of BMP-2 mRNA in the presence of actinomycin D, an inhibitor of transcription. A similar increase in BMP-2 mRNA level was observed in other human mesenchymal cells from oral tissue; periodontal ligament cells and gingival fibroblasts. However, the latter cells exhibited considerably lower expression of BMP-2 mRNA compared with dental pulp cells and periodontal ligament cells. The BMP-2 increase was markedly inhibited by pretreatment with an extracellular signal-regulated kinase (ERK) inhibitor, PD98059, and partially inhibited by the L-type Ca{sup 2+} channels inhibitor, nifedipine. However, pretreatment with nifedipine had no effect on ERK1/2 phosphorylation triggered by Ca{sup 2+}, suggesting that the Ca{sup 2+} influx from Ca{sup 2+} channels may operate independently of ERK signaling. Dental pulp cells do not express the transcript of Ca{sup 2+}-sensing receptors (CaSR) and only respond slightly to other cations such as Sr{sup 2+} and spermine, suggesting that dental pulp cells respond to Ca{sub o}{sup 2+} to increase BMP-2 mRNA expression in a manner different from CaSR and rather specific for Ca{sub o}{sup 2+} among cations.

  4. Combined modification of intracellular and extracellular loci on human gonadotropin-releasing hormone receptor provides a mechanism for enhanced expression.

    PubMed

    Maya-Núñez, G; Janovick, J A; Conn, P M

    2000-12-01

    The mammalian gonadotropin-releasing hormone (GnRH) receptor (GnRH-R) has been a therapeutic target for human and animal medicine. This receptor is a unique G-protein-coupled receptor that lacks the intracellular C-terminal domain commonly associated with this family. Development of highthrough put screens for agents active in humans has been hampered by low expression levels of the hGnRH-R in cellular models. Two sites have attracted the interest of laboratories studying regulation of expression. The chimeric addition of the C-terminal tail from catfish GnRH-R (cfGnRH-R) to the rat GnRH-R significantly augmented receptor expression in GH3 cells. In addition, rodent GnRH-R contains 327 amino acids, but cow, sheep, and human GnRH-R (hGnRH-R) contain 328 residues, the "additional" residue being a Lys 191. Deletion of Lys 191 (del 191) from the hGnRH-R resulted in increased receptor expression levels and decreased internalization rates in both COS-7 and HEK 293 cells. In this study, the combined effect of the addition of the C-tail from cfGnRH-R and deletion of the Lys 191 from the hGnRH-R was compared to expression of the wild-type (WT) or either alteration alone in a transient expression system using primate cells. The altered receptor (hGnRH-R[del 191]-C-tail) showed significantly increased receptor expression at the cell surface compared with the WT or either modification alone. The inositol phosphate response to stimulation was also significantly elevated in response to GnRH agonist. After treatment with a GnRH agonist, the altered receptors showed a slower internalization rate. The homologous steady-state regulation of the WT and the altered receptors was similar, although the response of the altered receptors was significantly decreased. These results suggest that the conformational change in the receptor as a result of the deletion of Lys 191 and the addition of the C-terminus tail substantially increased the steady-state receptor expression and decreased

  5. Glutathione peroxidase 3 localizes to the epithelial lining fluid and the extracellular matrix in interstitial lung disease.

    PubMed

    Schamberger, Andrea C; Schiller, Herbert B; Fernandez, Isis E; Sterclova, Martina; Heinzelmann, Katharina; Hennen, Elisabeth; Hatz, Rudolf; Behr, Jürgen; Vašáková, Martina; Mann, Matthias; Eickelberg, Oliver; Staab-Weijnitz, Claudia A

    2016-01-01

    Aberrant antioxidant activity and excessive deposition of extracellular matrix (ECM) are hallmarks of interstitial lung diseases (ILD). It is known that oxidative stress alters the ECM, but extracellular antioxidant defence mechanisms in ILD are incompletely understood. Here, we extracted abundance and detergent solubility of extracellular antioxidant enzymes from a proteomic dataset of bleomycin-induced lung fibrosis in mice and assessed regulation and distribution of glutathione peroxidase 3 (GPX3) in murine and human lung fibrosis. Superoxide dismutase 3 (Sod3), Gpx3, and Gpx activity were increased in mouse BALF during bleomycin-induced lung fibrosis. In lung tissue homogenates, Gpx3, but not Sod3, was upregulated and detergent solubility profiling indicated that Gpx3 associated with ECM proteins. Immunofluorescence analysis showed that Gpx3 was expressed by bronchial epithelial cells and interstitial fibroblasts and localized to the basement membrane and interstitial ECM in lung tissue. As to human ILD samples, BALF of some patients contained high levels of GPX3, and GPX3 was upregulated in lung homogenates from IPF patients. GPX3 expression in primary human bronchial epithelial cells and lung fibroblasts was downregulated by TNF-α, but more variably regulated by TGF-β1 and menadione. In conclusion, the antioxidant enzyme GPX3 localizes to lung ECM and is variably upregulated in ILD. PMID:27435875

  6. Glutathione peroxidase 3 localizes to the epithelial lining fluid and the extracellular matrix in interstitial lung disease

    PubMed Central

    Schamberger, Andrea C.; Schiller, Herbert B.; Fernandez, Isis E.; Sterclova, Martina; Heinzelmann, Katharina; Hennen, Elisabeth; Hatz, Rudolf; Behr, Jürgen; Vašáková, Martina; Mann, Matthias; Eickelberg, Oliver; Staab-Weijnitz, Claudia A.

    2016-01-01

    Aberrant antioxidant activity and excessive deposition of extracellular matrix (ECM) are hallmarks of interstitial lung diseases (ILD). It is known that oxidative stress alters the ECM, but extracellular antioxidant defence mechanisms in ILD are incompletely understood. Here, we extracted abundance and detergent solubility of extracellular antioxidant enzymes from a proteomic dataset of bleomycin-induced lung fibrosis in mice and assessed regulation and distribution of glutathione peroxidase 3 (GPX3) in murine and human lung fibrosis. Superoxide dismutase 3 (Sod3), Gpx3, and Gpx activity were increased in mouse BALF during bleomycin-induced lung fibrosis. In lung tissue homogenates, Gpx3, but not Sod3, was upregulated and detergent solubility profiling indicated that Gpx3 associated with ECM proteins. Immunofluorescence analysis showed that Gpx3 was expressed by bronchial epithelial cells and interstitial fibroblasts and localized to the basement membrane and interstitial ECM in lung tissue. As to human ILD samples, BALF of some patients contained high levels of GPX3, and GPX3 was upregulated in lung homogenates from IPF patients. GPX3 expression in primary human bronchial epithelial cells and lung fibroblasts was downregulated by TNF-α, but more variably regulated by TGF-β1 and menadione. In conclusion, the antioxidant enzyme GPX3 localizes to lung ECM and is variably upregulated in ILD. PMID:27435875

  7. GC-Rich Extracellular DNA Induces Oxidative Stress, Double-Strand DNA Breaks, and DNA Damage Response in Human Adipose-Derived Mesenchymal Stem Cells

    PubMed Central

    Kostyuk, Svetlana; Smirnova, Tatiana; Kameneva, Larisa; Porokhovnik, Lev; Speranskij, Anatolij; Ershova, Elizaveta; Stukalov, Sergey; Izevskaya, Vera; Veiko, Natalia

    2015-01-01

    Background. Cell free DNA (cfDNA) circulates throughout the bloodstream of both healthy people and patients with various diseases. CfDNA is substantially enriched in its GC-content as compared with human genomic DNA. Principal Findings. Exposure of haMSCs to GC-DNA induces short-term oxidative stress (determined with H2DCFH-DA) and results in both single- and double-strand DNA breaks (comet assay and γH2AX, foci). As a result in the cells significantly increases the expression of repair genes (BRCA1 (RT-PCR), PCNA (FACS)) and antiapoptotic genes (BCL2 (RT-PCR and FACS), BCL2A1, BCL2L1, BIRC3, and BIRC2 (RT-PCR)). Under the action of GC-DNA the potential of mitochondria was increased. Here we show that GC-rich extracellular DNA stimulates adipocyte differentiation of human adipose-derived mesenchymal stem cells (haMSCs). Exposure to GC-DNA leads to an increase in the level of RNAPPARG2 and LPL (RT-PCR), in the level of fatty acid binding protein FABP4 (FACS analysis) and in the level of fat (Oil Red O). Conclusions. GC-rich fragments in the pool of cfDNA can potentially induce oxidative stress and DNA damage response and affect the direction of mesenchymal stem cells differentiation in human adipose—derived mesenchymal stem cells. Such a response may be one of the causes of obesity or osteoporosis. PMID:26273425

  8. Comparison of osteoclastogenesis and resorption activity of human osteoclasts on tissue culture polystyrene and on natural extracellular bone matrix in 2D and 3D.

    PubMed

    Kleinhans, C; Schmid, F F; Schmid, F V; Kluger, P J

    2015-07-10

    Bone homeostasis is maintained by osteoblasts (bone formation) and osteoclasts (bone resorption). While there have been numerous studies investigating mesenchymal stem cells and their potential to differentiate into osteoblasts as well as their interaction with different bone substitute materials, there is only limited knowledge concerning in vitro generated osteoclasts. Due to the increasing development of degradable bone-grafting materials and the need of sophisticated in vitro test methods, it is essential to gain deeper insight into the process of osteoclastogenesis and the resorption functionality of human osteoclasts. Therefore, we focused on the comparison of osteoclastogenesis and resorption activity on tissue culture polystyrene (TCPS) and bovine extracellular bone matrices (BMs). Cortical bone slices were used as two-dimensional (2D) substrates, whereas a thermally treated cancellous bone matrix was used for three-dimensional (3D) experiments. We isolated primary human monocytes and induced osteoclastogenesis by medium supplementation. Subsequently, the expression of the vitronectin receptor (αVβ3) and cathepsin K as well as the characteristic actin formation on TCPS and the two BMs were examined. The cell area of human osteoclasts was analyzed on TCPS and on BMs, whereas significantly larger osteoclasts could be detected on BMs. Additionally, we compared the diameter of the sealing zones with the measured diameter of the resorption pits on the BMs and revealed similar diameters of the sealing zones and the resorption pits. We conclude that using TCPS as culture substrate does not affect the expression of osteoclast-specific markers. The analysis of resorption activity can successfully be conducted on cortical as well as on cancellous bone matrices. For new in vitro test systems concerning bone resorption, we suggest the establishment of a 2D assay for high throughput screening of new degradable bone substitute materials with osteoclasts. PMID:25562421

  9. Detection of superoxide production in stimulated and unstimulated living cells using new cyclic nitrone spin traps.

    PubMed

    Abbas, Kahina; Hardy, Micael; Poulhès, Florent; Karoui, Hakim; Tordo, Paul; Ouari, Olivier; Peyrot, Fabienne

    2014-06-01

    Reactive oxygen species (ROS), including superoxide anion and hydrogen peroxide (H2O2), have a diverse array of physiological and pathological effects within living cells depending on the extent, timing, and location of their production. For measuring ROS production in cells, the ESR spin trapping technique using cyclic nitrones distinguishes itself from other methods by its specificity for superoxide and hydroxyl radical. However, several drawbacks, such as the low spin trapping rate and the spontaneous and cell-enhanced decomposition of the spin adducts to ESR-silent products, limit the application of this method to biological systems. Recently, new cyclic nitrones bearing a triphenylphosphonium (Mito-DIPPMPO) or a permethylated β-cyclodextrin moiety (CD-DIPPMPO) have been synthesized and their spin adducts demonstrated increased stability in buffer. In this study, a comparison of the spin trapping efficiency of these new compounds with commonly used cyclic nitrone spin traps, i.e., 5,5-dimethyl-1-pyrroline N-oxide (DMPO), and analogs BMPO, DEPMPO, and DIPPMPO, was performed on RAW 264.7 macrophages stimulated with phorbol 12-myristate 13-acetate. Our results show that Mito-DIPPMPO and CD-DIPPMPO enable a higher detection of superoxide adduct, with a low (if any) amount of hydroxyl adduct. CD-DIPPMPO, especially, appears to be a superior spin trap for extracellular superoxide detection in living macrophages, allowing measurement of superoxide production in unstimulated cells for the first time. The main rationale put forward for this extreme sensitivity is that the extracellular localization of the spin trap prevents the reduction of the spin adducts by ascorbic acid and glutathione within cells. PMID:24662195

  10. A cytoplasmic Cu-Zn superoxide dismutase SOD1 contributes to hyphal growth and virulence of Fusarium graminearum.

    PubMed

    Yao, Sheng-Hua; Guo, Yan; Wang, Yan-Zhang; Zhang, Dong; Xu, Ling; Tang, Wei-Hua

    2016-06-01

    Superoxide dismutases (SODs) are scavengers of superoxide radicals, one of the main reactive oxygen species (ROS) in the cell. SOD-based ROS scavenging system constitutes the frontline defense against intra- and extracellular ROS, but the roles of SODs in the important cereal pathogen Fusarium graminearum are not very clear. There are five SOD genes in F. graminearum genome, encoding cytoplasmic Cu-Zn SOD1 and MnSOD3, mitochondrial MnSOD2 and FeSOD4, and extracellular CuSOD5. Previous studies reported that the expression of SOD1 increased during infection of wheat coleoptiles and florets. In this work we showed that the recombinant SOD1 protein had the superoxide dismutase activity in vitro, and that the SOD1-mRFP fusion protein localized in the cytoplasm of F. graminearum. The Δsod1 mutants had slightly reduced hyphal growth and markedly increased sensitivity to the intracellular ROS generator menadione. The conidial germination under extracellular oxidative stress was significantly delayed in the mutants. Wheat floret infection assay showed that the Δsod1 mutants had a reduced pathogenicity. Furthermore, the Δsod1 mutants had a significant reduction in production of deoxynivalenol mycotoxin. Our results indicate that the cytoplasmic Cu-Zn SOD1 affects fungal growth probably depending on detoxification of intracellular superoxide radicals, and that SOD1-mediated deoxynivalenol production contributes to the virulence of F. graminearum in wheat head infection. PMID:27037138

  11. Micropatterning Extracellular Matrix Proteins on Electrospun Fibrous Substrate Promote Human Mesenchymal Stem Cell Differentiation Toward Neurogenic Lineage.

    PubMed

    Li, Huaqiong; Wen, Feng; Chen, Huizhi; Pal, Mintu; Lai, Yuekun; Zhao, Allan Zijian; Tan, Lay Poh

    2016-01-13

    In this study, hybrid micropatterned grafts constructed via a combination of microcontact printing and electrospinning techniques process were utilized to investigate the influencing of patterning directions on human mesenchymal stem cells (hMSCs) differentiation to desired phenotypes. We found that the stem cells could align and elongate along the direction of the micropattern, where they randomly distributed on nonmicropatterned surfaces. Concomitant with patterning effect of component on stem cell alignment, a commensurate increase on the expression of neural lineage commitment markers, such as microtubule associated protein 2 (MAP2), Nestin, NeuroD1, and Class III β-Tubulin, were revealed from mRNA expression by quantitative Real Time PCR (qRT-PCR) and MAP2 expression by immunostaining. In addition, the effect of electrospun fiber orientation on cell behaviors was further examined. An angle of 45° between the direction of micropatterning and orientation of aligned fibers was verified to greatly prompt the outgrowth of filopodia and neurogenesis of hMSCs. This study demonstrates that the significance of hybrid components and electrospun fiber alignment in modulating cellular behavior and neurogenic lineage commitment of hMSCs, suggesting promising application of porous scaffolds with smart component and topography engineering in clinical regenerative medicine. PMID:26654444

  12. Agonist-like activity of antibodies directed against the second extracellular loop of the human cardiac serotonin 5-HT4(e) receptor in transfected COS-7 cells.

    PubMed

    Bozon, V; Di Scala, E; Eftekhari, P; Hoebeke, J; Lezoualc'h, F; Fischmeister, R; Argibay, J

    2002-01-01

    We have previously reported that antipeptide antibodies directed against the second extracellular loop of the cardiac h5-HT4 receptor could block the activation of the L-type Ca channel in human atrial cardiomyocytes. In this paper we investigate the immunological and physiological activity of these antibodies, in a cell system expressing a larger amount of receptors than the atrial cells. The recombinant receptor was expressed at the surface of COS-7 cells under an active form (serotonin, EC50 = 1.81 x 10(-7) M), at a high level (375 +/- 25 fmol receptor/mg total protein) and was able to bind a specific ligand (GR113808) with a high affinity (Kd = 0.28 +/- 0.05 nM). In this system, the same anti-peptide antibodies used for the cardiac cells induced an "agonist-like" effect on the recombinant h5-HT4 receptor. These results are in line with those shown for others G-protein coupled receptors, as adrenoreceptors. In addition, this work showed that the effect of the antibodies is not only dependent on the epitopic region recognised but also on the molecular density and/or the cellular environment of the target receptors. Finally, our results support the hypothesis that the h5-HT4 receptor could be a new target for autoantibodies in patients with atrial arrhythmia. PMID:12448792

  13. Essential role of extracellular charged residues of the human CCK(1) receptor for interactions with SR 146131, SR 27897 and CCK-8S.

    PubMed

    Gouldson, P; Legoux, P; Carillon, C; Dumont, X; Le Fur, G; Ferrara, P; Shire, D

    2000-02-18

    We hypothesized that charge-charge interactions may be important for the binding of the human cholecystokinin type 1 (CCK(1)) receptor-specific non-peptide full agonist SR 146131, (2-[4-(4-chloro-2, 5-dimethoxyphenyl)-5-(2-cyclohexyl-ethyl)-thiazol-2-ylcarbamoyl ]-5, 7-dimethyl-indol-1-yl-1-acetic acid), the competitive antagonist SR 27897, (1-[2-(4-(2-chlorophenyl)thiazol-2-yl) aminocarbonyl indoyl] acetic acid) and the natural octapeptide CCK-8S to the CCK(1) receptor. Alanine replacement studies of positively charged residues in the extracellular domains of the receptor showed that only the R336A mutation affected SR 146131 potency of mutated receptors transiently expressed in monkey kidney epithelial COS-7 cells. Two residues, Lys(115) and Lys(187), were implicated in SR 27897 binding. Only the replacement of Lys(115), Arg(197) and Arg(336) significantly affected CCK-8S binding or activity. These results clearly indicated the importance of certain charged residues, but not others, in SR 146131, SR 27897 and CCK-8S binding. Furthermore, although these molecules probably occupy different binding sites on the CCK(1) receptor, we show that a small non-peptide agonist, SR 146131, can stimulate the dual signaling pathways mediated by the CCK(1) receptor. PMID:10688974

  14. Crystal structure of a human neuronal nAChR extracellular domain in pentameric assembly: Ligand-bound α2 homopentamer.

    PubMed

    Kouvatsos, Nikolaos; Giastas, Petros; Chroni-Tzartou, Dafni; Poulopoulou, Cornelia; Tzartos, Socrates J

    2016-08-23

    In this study we report the X-ray crystal structure of the extracellular domain (ECD) of the human neuronal α2 nicotinic acetylcholine receptor (nAChR) subunit in complex with the agonist epibatidine at 3.2 Å. Interestingly, α2 was crystallized as a pentamer, revealing the intersubunit interactions in a wild type neuronal nAChR ECD and the full ligand binding pocket conferred by two adjacent α subunits. The pentameric assembly presents the conserved structural scaffold observed in homologous proteins, as well as distinctive features, providing unique structural information of the binding site between principal and complementary faces. Structure-guided mutagenesis and electrophysiological data confirmed the presence of the α2(+)/α2(-) binding site on the heteromeric low sensitivity α2β2 nAChR and validated the functional importance of specific residues in α2 and β2 nAChR subunits. Given the pathological importance of the α2 nAChR subunit and the high sequence identity with α4 (78%) and other neuronal nAChR subunits, our findings offer valuable information for modeling several nAChRs and ultimately for structure-based design of subtype specific drugs against the nAChR associated diseases. PMID:27493220

  15. Extracellular matrix-remodeling metalloproteinases and infection of the central nervous system with retrovirus human T-lymphotropic virus type I (HTLV-I).

    PubMed

    Giraudon, P; Buart, S; Bernard, A; Thomasset, N; Belin, M F

    1996-06-01

    Matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) are involved in physiological processes and contribute to the phenotype of several pathological conditions associated with uncontrolled tissue degradation. In the central nervous system (CNS), MMPs are thought to play a role in cell migration and synaptic plasticity. We have investigated the expression, regulation and possible role of MMPs and TIMPs during infection of glial cells with human T-lymphotropic virus type I (HTLV-I), the causative agent of a progressive chronic myelopathy, TSP/HAM. The major alteration consists in a high increase in MMP-9 secretion and TIMP-2 mRNA expression. Cytokines TNF alpha and IL1 alpha, induced in glial cells during HTLV-I infection, promote the upregulation of MMP-9. In addition, cerebrospinal fluid from TSP/HAM patients contain high MMP-9 level. The exact role of dysregulated MMPs/TIMPs in the pathogenesis of TSP/HAM is not known; however, functions of these proteases in physiological processes should provide valuable clues. MMPs can affect the blood-brain barrier and the intercellular connectivity by degrading the extracellular matrix of endothelial and neural cells. They can be involved in autoimmunity by generating preformed specific peptides from myelin components. Finally, they can direct and prolong TNF activity in the CNS by converting its inactive precursor into active molecules. PMID:8844825

  16. Human periosteal-derived cell expansion in a perfusion bioreactor system: proliferation, differentiation and extracellular matrix formation.

    PubMed

    Sonnaert, M; Papantoniou, I; Bloemen, V; Kerckhofs, G; Luyten, F P; Schrooten, J

    2014-09-01

    Perfusion bioreactor systems have shown to be a valuable tool for the in vitro development of three-dimensional (3D) cell-carrier constructs. Their use for cell expansion, however, has been much less explored. Since maintenance of the initial cell phenotype is essential in this process, it is imperative to obtain insight into the bioreactor-related variables determining cell fate. Therefore, this study investigated the influence of fluid flow-induced shear stress on the proliferation, differentiation and matrix deposition of human periosteal-derived cells in the absence of additional differentiation-inducing stimuli; 120 000 cells were seeded on additive manufactured 3D Ti6Al4V scaffolds and cultured for up to 28 days at different flow rates in the range 0.04-6 ml/min. DNA measurements showed, on average, a three-fold increase in cell content for all perfused conditions in comparison to static controls, whereas the magnitude of the flow rate did not have an influence. Contrast-enhanced nanofocus X-ray computed tomography showed substantial formation of an engineered neotissue in all perfused conditions, resulting in a filling (up to 70%) of the total internal void volume, and no flow rate-dependent differences were observed. The expression of key osteogenic markers, such as RunX2, OCN, OPN and Col1, did not show any significant changes in comparison to static controls after 28 days of culture, with the exception of OSX at high flow rates. We therefore concluded that, in the absence of additional osteogenic stimuli, the investigated perfusion conditions increased cell proliferation but did not significantly enhance osteogenic differentiation, thus allowing for this process to be used for cell expansion. Copyright © 2014 John Wiley & Sons, Ltd. PMID:25186024

  17. Unique Organization of Extracellular Amylases into Amylosomes in the Resistant Starch-Utilizing Human Colonic Firmicutes Bacterium Ruminococcus bromii

    PubMed Central

    Ze, Xiaolei; Ben David, Yonit; Laverde-Gomez, Jenny A.; Dassa, Bareket; Sheridan, Paul O.; Duncan, Sylvia H.; Louis, Petra; Henrissat, Bernard; Juge, Nathalie; Koropatkin, Nicole M.; Bayer, Edward A.

    2015-01-01

    ABSTRACT Ruminococcus bromii is a dominant member of the human gut microbiota that plays a key role in releasing energy from dietary starches that escape digestion by host enzymes via its exceptional activity against particulate “resistant” starches. Genomic analysis of R. bromii shows that it is highly specialized, with 15 of its 21 glycoside hydrolases belonging to one family (GH13). We found that amylase activity in R. bromii is expressed constitutively, with the activity seen during growth with fructose as an energy source being similar to that seen with starch as an energy source. Six GH13 amylases that carry signal peptides were detected by proteomic analysis in R. bromii cultures. Four of these enzymes are among 26 R. bromii proteins predicted to carry dockerin modules, with one, Amy4, also carrying a cohesin module. Since cohesin-dockerin interactions are known to mediate the formation of protein complexes in cellulolytic ruminococci, the binding interactions of four cohesins and 11 dockerins from R. bromii were investigated after overexpressing them as recombinant fusion proteins. Dockerins possessed by the enzymes Amy4 and Amy9 are predicted to bind a cohesin present in protein scaffoldin 2 (Sca2), which resembles the ScaE cell wall-anchoring protein of a cellulolytic relative, R. flavefaciens. Further complexes are predicted between the dockerin-carrying amylases Amy4, Amy9, Amy10, and Amy12 and two other cohesin-carrying proteins, while Amy4 has the ability to autoaggregate, as its dockerin can recognize its own cohesin. This organization of starch-degrading enzymes is unprecedented and provides the first example of cohesin-dockerin interactions being involved in an amylolytic system, which we refer to as an “amylosome.” PMID:26419877

  18. Periplasmic Superoxide Dismutase in Meningococcal Pathogenicity

    PubMed Central

    Wilks, Kathryn E.; Dunn, Kate L. R.; Farrant, Jayne L.; Reddin, Karen M.; Gorringe, Andrew R.; Langford, Paul R.; Kroll, J. Simon

    1998-01-01

    Meningococcal sodC encodes periplasmic copper- and zinc-cofactored superoxide dismutase (Cu,Zn SOD) which catalyzes the conversion of the superoxide radical anion to hydrogen peroxide, preventing a sequence of reactions leading to production of toxic hydroxyl free radicals. From its periplasmic location, Cu,Zn SOD was inferred to acquire its substrate from outside the bacterial cell and was speculated to play a role in preserving meningococci from the action of microbicidal oxygen free radicals produced in the context of host defense. A sodC mutant was constructed by allelic exchange and was used to investigate the role of Cu,Zn SOD in pathogenicity. Wild-type and mutant meningococci grew at comparable rates and survived equally long in aerobic liquid culture. The mutant showed no increased sensitivity to paraquat, which generates superoxide within the cytosol, but was approximately 1,000-fold more sensitive to the toxicity of superoxide generated in solution by the xanthine/xanthine oxidase system. These data support a role for meningococcal Cu,Zn SOD in protection against exogenous superoxide. In experiments to translate this into a role in pathogenicity, wild-type and mutant organisms were used in an intraperitoneal mouse infection model. The sodC mutant was significantly less virulent. We conclude that periplasmic Cu,Zn SOD contributes to the virulence of Neisseria meningitidis, most likely by reducing the effectiveness of toxic oxygen host defenses. PMID:9423860

  19. Real-time monitoring of superoxide accumulation and antioxidant activity in a brain slice model using an electrochemical cytochrome c biosensor

    PubMed Central

    Ganesana, Mallikarjunarao; Erlichman, Joseph S.; Andreescu, Silvana

    2012-01-01

    The overproduction of reactive oxygen species and resulting damage are central to the pathology of many diseases. The study of the temporal and spatial accumulation of reactive oxygen species has been limited due to the lack of specific probes and techniques capable of continuous measurement. We demonstrate the use of a miniaturized electrochemical cytochrome C (Cyt C) biosensor for real-time measurements and quantitative assessment of superoxide production and inactivation by natural and engineered antioxidants in acutely prepared brain slices from mice. During control conditions, superoxide radicals produced from the hippocampal region of the brain in 400 μm thick sections were well within the range of detection of the electrode. Exposure of the slices to ischemic conditions increased the superoxide production two fold and measurements from the slices were stable over a 3–4 hour period. The stilbene derivative and anion channel inhibitor, 4,4′-diisothiocyano-2,2′-disulfonic stilbene (DIDS), markedly reduced the extracellular superoxide signal under control conditions suggesting that a transmembrane flux of superoxide into the extracellular space may occur as part of normal redox signaling. The specificity of the electrode for superoxide released by cells in the hippocampus was verified by the exogenous addition of superoxide dismutase (SOD) which decreased the superoxide signal in a dose-dependent manner. Similar results were seen with the addition of the SOD-mimetic, cerium oxide nanoparticles (nanoceria) where the superoxide anion radical scavenging activity of nanoceria with an average diameter of 15 nm was equivalent to 527 U of SOD for each 1 μg/ml of nanoceria added. This study demonstrates the potential of electrochemical biosensors for studying real-time dynamics of reactive oxygen species in a biological model and the utility of these measurements in defining the relative contribution of superoxide to oxidative injury. PMID:23085519

  20. Sialylation and glycosylation modulate cell adhesion and invasion to extracellular matrix in human malignant lymphoma: Dependency on integrin and the Rho GTPase family

    PubMed Central

    SUZUKI, OSAMU; ABE, MASAFUMI; HASHIMOTO, YUKO

    2015-01-01

    division control protein 42 homolog (Cdc42) markedly inhibited cell invasion of galectin-1 and galectin-3 suggesting that Rac 1 and Cdc42 may be involved in the regulation of H-ALCL cell invasion of galectins. In conclusion, artificial modification of cell surface glycosylation revealed the biological roles of glycosylation in the adhesion to and invasion of the extracellular matrix (ECM) by human malignant lymphoma cell lines. These findings will provide new insight into the glycobiology of human malignant lymphoma. PMID:26497328

  1. Sialylation and glycosylation modulate cell adhesion and invasion to extracellular matrix in human malignant lymphoma: Dependency on integrin and the Rho GTPase family.

    PubMed

    Suzuki, Osamu; Abe, Masafumi; Hashimoto, Yuko

    2015-12-01

    Cell division control protein 42 homolog (Cdc42) markedly inhibited cell invasion of galectin-1 and galectin-3 suggesting that Rac 1 and Cdc42 may be involved in the regulation of H-ALCL cell invasion of galectins. In conclusion, artificial modification of cell surface glycosylation revealed the biological roles of glycosylation in the adhesion to and invasion of the extracellular matrix (ECM) by human malignant lymphoma cell lines. These findings will provide new insight into the glycobiology of human malignant lymphoma. PMID:26497328

  2. Manganese superoxide dismutase: beyond life and death

    PubMed Central

    Holley, Aaron K.; Dhar, Sanjit Kumar; Xu, Yong

    2010-01-01

    Manganese superoxide dismutase (MnSOD) is a nuclear-encoded antioxidant enzyme that localizes to the mitochondria. Expression of MnSOD is essential for the survival of aerobic life. Transgenic mice expressing a luciferase reporter gene under the control of the human MnSOD promoter demonstrate that the level of MnSOD is reduced prior to the formation of cancer. Overexpression of MnSOD in transgenic mice reduces the incidences and multiplicity of papillomas in a DMBA/TPA skin carcinogenesis model. However, MnSOD deficiency does not lead to enhanced tumorigenicity of skin tissue similarly treated because MnSOD can modulate both the p53-mediated apoptosis and AP-1-mediated cell proliferation pathways. Apoptosis is associated with an increase in mitochondrial levels of p53 suggesting a link between MnSOD deficiency and mitochondrial-mediated apoptosis. Activation of p53 is preventable by application of a SOD mimetic (MnTE-2-PyP5+). Thus, p53 translocation to mitochondria and subsequent inactivation of MnSOD explain the observed mitochondrial dysfunction that leads to transcription-dependent mechanisms of p53-induced apoptosis. Administration of MnTE-2-PyP5+ following apoptosis but prior to proliferation leads to suppression of protein carbonyls and reduces the activity of AP-1 and the level of the proliferating cellular nuclear antigen, without reducing the activity of p53 or DNA fragmentation following TPA treatment. Remarkably, the incidence and multiplicity of skin tumors are drastically reduced in mice that receive MnTE-2-PyP5+ prior to cell proliferation. The results demonstrate the role of MnSOD beyond its essential role for survival and suggest a novel strategy for an antioxidant approach to cancer intervention. PMID:20454814

  3. Degradation of heparan sulfate in the subendothelial extracellular matrix by a readily released heparanase from human neutrophils. Possible role in invasion through basement membranes.

    PubMed Central

    Matzner, Y; Bar-Ner, M; Yahalom, J; Ishai-Michaeli, R; Fuks, Z; Vlodavsky, I

    1985-01-01

    Freshly isolated human neutrophils were investigated for their ability to degrade heparan sulfate proteoglycans in the subendothelial extracellular matrix (ECM) produced by cultured corneal and vascular endothelial cells. The ECM was metabolically labeled with Na2(35S)O4 and labeled degradation products were analyzed by gel filtration over Sepharose 6B. More than 90% of the released radioactivity consisted of heparan sulfate fragments 5-6 times smaller than intact heparan sulfate side chains released from the ECM by either papain or alkaline borohydride. These fragments were sensitive to deamination with nitrous acid and were not produced in the presence of either heparin or serine protease inhibitors. In contrast, degradation of soluble high molecular weight heparan sulfate proteoglycan, which was first released from the ECM, was inhibited by heparin but there was no effect of protease inhibitors. These results indicate that interaction of human neutrophils with the subendothelial ECM is associated with degradation of its heparan sulfate by means of a specific, newly identified, heparanase activity and that this degradation is facilitated to a large extent by serine proteases. The neutrophil heparanase was readily and preferentially released (15-25% of the cellular content in 60 min) by simply incubating the cells at 4 degrees C in the absence of added stimuli. Under these conditions, less than 5% of the cellular content of lactate dehydrogenase, lysozyme, and globin degrading proteases was released. Further purification of the neutrophil heparanase was achieved by its binding to heparin-Sepharose and elution at 1 M NaCl. It is suggested that heparanase activity is involved in the early events of extravasation and diapedesis of neutrophils in response to a threshold signal from an extravascular inflamed organ. PMID:2997275

  4. Controlled Growth and the Maintenance of Human Pluripotent Stem Cells by Cultivation with Defined Medium on Extracellular Matrix-Coated Micropatterned Dishes

    PubMed Central

    Takenaka, Chiemi; Miyajima, Hiroshi; Yoda, Yusuke; Imazato, Hideo; Yamamoto, Takako; Gomi, Shinichi; Ohshima, Yasuhiro; Kagawa, Kenichi; Sasaki, Tetsuji; Kawamata, Shin

    2015-01-01

    Here, we introduce a new serum-free defined medium (SPM) that supports the cultivation of human pluripotent stem cells (hPSCs) on recombinant human vitronectin-N (rhVNT-N)-coated dishes after seeding with either cell clumps or single cells. With this system, there was no need for an intervening sequential adaptation process after moving hPSCs from feeder layer-dependent conditions. We also introduce a micropatterned dish that was coated with extracellular matrix by photolithographic technology. This procedure allowed the cultivation of hPSCs on 199 individual rhVNT-N-coated small round spots (1 mm in diameter) on each 35-mm polystyrene dish (termed “patterned culture”), permitting the simultaneous formation of 199 uniform high-density small-sized colonies. This culture system supported controlled cell growth and maintenance of undifferentiated hPSCs better than dishes in which the entire surface was coated with rhVNT-N (termed “non-patterned cultures”). Non-patterned cultures produced variable, unrestricted cell proliferation with non-uniform cell growth and uneven densities in which we observed downregulated expression of some self-renewal-related markers. Comparative flow cytometric studies of the expression of pluripotency-related molecules SSEA-3 and TRA-1-60 in hPSCs from non-patterned cultures and patterned cultures supported this concept. Patterned cultures of hPSCs allowed sequential visual inspection of every hPSC colony, giving an address and number in patterned culture dishes. Several spots could be sampled for quality control tests of production batches, thereby permitting the monitoring of hPSCs in a single culture dish. Our new patterned culture system utilizing photolithography provides a robust, reproducible and controllable cell culture system and demonstrates technological advantages for the mass production of hPSCs with process quality control. PMID:26115194

  5. Two Interferons Alpha Influence Each Other During Their Interaction With the Extracellular Domain of Human Type I Interferon Receptor Subunit 2

    PubMed Central

    Schmeisser, Hana; Gorshkova, Inna; Brown, Patrick H.; Kontsek, Peter; Schuck, Peter; Zoon, Kathryn C.

    2008-01-01

    The interaction between two human interferons alpha (IFN-αs) and the extracellular (EC) domain of human type I IFN receptor subunit 2 (IFNAR2) was analyzed. Previous experiments using Daudi cells showed that IFN-α21b and some IFN-α hybrids (made from IFN-α2c and 21b) competed poorly for the IFN-α2b binding site. This study examined the causes of the poor competition between these IFN-αs. IFN-α2c and the IFN hybrid CM3 {IFN-α21b(1-75)(81-95)/IFN-α2c(76-80)(96-166), Y86K} were selected for this study based on their cell binding and biological properties. Competitive binding ELISA, native electrophoresis followed by Western blot, electrospray ionization mass spectrometry (ESI-MS), surface plasmon resonance biosensor (SPR) analysis, as well as neutralization of antiproliferative activities on Daudi cells in the presence of soluble IFNAR2-EC show evidence that each of the described IFN-α subtypes affected the binding of the other IFN-α to IFNAR2-EC by affecting the stability of the complex, i.e. dissociation of the complex. Moreover, native electrophoresis with different IFNAR2-EC mutants showed that IFN-α2c and CM3 utilize different amino acids in the binding domain of IFNAR2-EC. In addition to that, analytical ultracentrifugation (AUC) revealed differences in the oligomeric state of the two studied interferons. Our results demonstrated that two individual IFN-αs interact differentially with IFNAR2-EC and influence each other during this interaction. This study contributes to the understanding of the mutual interaction between multiple IFN-α subtypes during the competition for binding to the receptor. PMID:18027911

  6. Methyl gallate isolated from Spondias pinnata exhibits anticancer activity against human glioblastoma by induction of apoptosis and sustained extracellular signal-regulated kinase 1/2 activation

    PubMed Central

    Chaudhuri, Dipankar; Ghate, Nikhil Baban; Singh, Sudhir Shankar; Mandal, Nripendranath

    2015-01-01

    Background: Spondias pinnata has been reported for its efficient anticancer effects, but the studies were mostly focused on its extract. Objective: Since its bioactive compounds are largely unknown, this study was designed to characterize the lead components present in it and their anticancer activity against human glioblastoma cell line (U87). Materials and Methods: Major compounds from the ethyl acetate fraction were isolated by column chromatography and their anticancer potentials against U87 cells were evaluated. Furthermore, flow cytometric and immunoblotting analyses were performed to demonstrate the mechanism of apoptosis inducing activity of methyl gallate (MG) against U87 cell line. Results: Four major compounds were isolated from the ethyl acetate fraction. Amongst these, two compounds showed promising activities and with the help of different spectroscopic methods they were identified as gallic acid and MG. Flow cytometric studies revealed that MG-induced apoptosis in U87 cells dose-dependently; the same was confirmed by activation of caspases through cleavage of endogenous substrate poly (adenosine diphosphate-ribose) polymerase. MG treatment also induced the expression of p53 and B-cell lymphoma-2-associated X and cleavage of BH3 interacting-domain with a concomitant decrease in B-cell lymphoma-2 expression. Moreover, MG-induced sustained phosphorylation of extracellular signal-regulated kinase (ERK1/2) in U87 cells with no change in the phosphorylation of other mitogen-activated protein kinases (c-Jun N-terminal of stress-activated protein kinases, p38). Conclusion: MG is a potent antioxidant and it induces sustained ERK1/2 activation and apoptosis in human glioblastoma U87, and provide a rationale for evaluation of MG for other brain carcinoma cell lines for the advancement of glioblastoma therapy. PMID:25829764

  7. Process for the preparation of calcium superoxide

    NASA Technical Reports Server (NTRS)

    Ballou, E. V.; Wood, P. C.; Wydeven, T. J.; Spitze, L. A. (Inventor)

    1978-01-01

    Calcium superoxide is prepared in high yields by spreading a quantity of calcium peroxide diperoxyhydrate on the surface of a container, positioning said container in a vacuum chamber on a support structure through which a coolant fluid can be circulated, partially evacuating said vacuum chamber, allowing the temperature of the diperoxyhydrate to reach the range of about 0 to about 40 C; maintaining the temperature selected for a period of time sufficient to complete the disproproriation of the diperoxyhydrate to calcium superoxide, calcium hydroxide, oxygen, and water; constantly and systematically removing the water as it is formed by sweeping the reacting material with a current of dry inert gas and/or by condensation of said water on a cold surface; backfilling the chamber with a dry inert gas; and finally, recovering the calcium superoxide produced.

  8. Synoviocyte Derived-Extracellular Matrix Enhances Human Articular Chondrocyte Proliferation and Maintains Re-Differentiation Capacity at Both Low and Atmospheric Oxygen Tensions

    PubMed Central

    Kean, Thomas J.; Dennis, James E.

    2015-01-01

    Background Current tissue engineering methods are insufficient for total joint resurfacing, and chondrocytes undergo de-differentiation when expanded on tissue culture plastic. De-differentiated chondrocytes show poor re-differentiation in culture, giving reduced glycosaminoglycan (GAG) and collagen matrix accumulation. To address this, porcine synoviocyte-derived extracellular matrix and low (5%) oxygen tension were assessed for their ability to enhance human articular chondrocyte expansion and maintain re-differentiation potential. Methods Porcine synoviocyte matrices were devitalized using 3 non-detergent methods. These devitalized synoviocyte matrices were compared against tissue culture plastic for their ability to support human chondrocyte expansion. Expansion was further compared at both low (5%), and atmospheric (20%) oxygen tension on all surfaces. Expanded cells then underwent chondrogenic re-differentiation in aggregate culture at both low and atmospheric oxygen tension. Aggregates were assessed for their GAG and collagen content both biochemically and histologically. Results Human chondrocytes expanded twice as fast on devitalized synoviocyte matrix vs. tissue culture plastic, and cells retained their re-differentiation capacity for twice the number of population doublings. There was no significant difference in growth rate between low and atmospheric oxygen tension. There was significantly less collagen type I, collagen type II, aggrecan and more MMP13 expression in cells expanded on synoviocyte matrix vs. tissue culture plastic. There were also significant effects due to oxygen tension on gene expression, wherein there was greater collagen type I, collagen type II, SOX9 and less MMP13 expression on tissue culture plastic compared to synoviocyte matrix. There was a significant increase in GAG, but not collagen, accumulation in chondrocyte aggregates re-differentiated at low oxygen tension over that achieved in atmospheric oxygen conditions. Conclusions

  9. Superoxide radical production by sponges Sycon sp.

    PubMed

    Peskin, A V; Labas, Y A; Tikhonov, A N

    1998-08-28

    Using the catechol Tiron as an O2-. scavenger, we showed that sea sponges (Sycon sp.) produce superoxide radicals in sea water at a high rate without any stimuli added. The rate of O2-. outflow from sponges to their water surroundings reaches a value of 0.5 nmol/min per sponge at pH 6.5. The generation of O2-. was inhibited by Cu,Zn-superoxide dismutase, and restored by the addition of KCN. We also confirmed the abiotic production of O2-. in sea water, detected earlier with a different method by Petasne and Zika [Nature 325 (1987) 516-518]. PMID:9738478

  10. Curcumin Rescues Diabetic Renal Fibrosis by Targeting Superoxide-Mediated Wnt Signaling Pathways.

    PubMed

    Ho, Cheng; Hsu, Yung-Chien; Lei, Chen-Chou; Mau, Shu-Ching; Shih, Ya-Hsueh; Lin, Chun-Liang

    2016-03-01

    The purposes of this study were to investigate whether curcumin can weaken diabetic nephropathy by modulating both oxidative stress and renal injury from Wnt signaling mediation. Wnt5a/β-catenin depression and induction of superoxide synthesis are associated with high glucose (HG) induced transforming growth factor (TGF)-β1 and fibronectin expression in mesangial cells. Curcumin resumes HG depression of Wnt/β-catenin signaling and alleviates HG induction of superoxide, TGF-β1 and fibronectin expression in renal mesangial cell. Exogenous curcumin alleviated urinary total proteinuria and serum superoxide level in diabetic rats. Based on laser-captured microdissection for quantitative real-time polymerase chain reaction, it was found that diabetes significantly increased TGF-β1 and fibronectin expression in line with depressed Wnt5a expression. Curcumin treatment reduced the TGF-β1 and fibronectin activation and the inhibiting effect of diabetes on Wnt5a/β-catenin expression in renal glomeruli. Immunohistochemistry showed that curcumin treatment significantly reduced 8-hydroxy-2'-deoxyguanosine, TGF-β1 and fibronectin, and was in line with the restoration of the suppressed Wnt5a expression immunoreactivities in glomeruli of diabetic rats. Curcumin alleviated extracellular matrix accumulation in diabetic nephropathy by not only preventing the diabetes-mediated superoxide synthesis but also resuming downregulation of Wnt/β-catenin signaling. These findings suggest that regulation of Wnt activity by curcumin is a feasible alternative strategy to rescue diabetic renal injury. PMID:26992258

  11. A titanium surface with nano-ordered spikes and pores enhances human dermal fibroblastic extracellular matrix production and integration of collagen fibers.

    PubMed

    Yamada, Masahiro; Kato, Eiji; Yamamoto, Akiko; Sakurai, Kaoru

    2016-02-01

    The acquisition of substantial dermal sealing determines the prognosis of percutaneous titanium-based medical devices or prostheses. A nano-topographic titanium surface with ordered nano-spikes and pores has been shown to induce periodontal-like connective tissue attachment and activate gingival fibroblastic functions. This in vitro study aimed to determine whether an alkali-heat (AH) treatment-created nano-topographic titanium surface could enhance human dermal fibroblastic functions and binding strength to the deposited collagen on the titanium surface. The surface topographies of commercially pure titanium machined discs exposed to two different AH treatments were evaluated. Human dermal fibroblastic cultures grown on the discs were evaluated in terms of cellular morphology, proliferation, extracellular matrix (ECM) and proinflammatory cytokine synthesis, and physicochemical binding strength of surface-deposited collagen. An isotropically-patterned, shaggy nano-topography with a sponge-like inner network and numerous well-organized, anisotropically-patterned fine nano-spikes and pores were observed on each nano-topographic surface type via scanning electron microscopy. In contrast to the typical spindle-shaped cells on the machined surfaces, the isotropically- and anisotropically-patterned nano-topographic titanium surfaces had small circular/angular cells containing contractile ring-like structures and elongated, multi-shaped cells with a developed cytoskeletal network and multiple filopodia and lamellipodia, respectively. These nano-topographic surfaces enhanced dermal-related ECM synthesis at both the protein and gene levels, without proinflammatory cytokine synthesis or reduced proliferative activity. Deposited collagen fibers were included in these surfaces and sufficiently bound to the nano-topographies to resist the physical, enzymatic and chemical detachment treatments, in contrast to machined surfaces. Well-organized, isotropically

  12. Serine protease inhibitors block priming of monocytes for enhanced release of superoxide.

    PubMed Central

    Megyeri, P; Pabst, K M; Pabst, M J

    1995-01-01

    Monocytes freshly isolated from human blood produced large amounts of superoxide when triggered by phorbol ester. After monocytes were cultured for 18-24 hr in endotoxin-free, non-adherent conditions, they produced low amounts of superoxide. Addition of lipopolysaccharide (LPS), interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha), or platelet-activating factor (PAF) at the beginning of culture 'primed' the monocytes, causing them to maintain a high superoxide response for at least 96 hr. Also, in response to LPS, monocytes secreted TNF-alpha. The ability of LPS, IFN-gamma, TNF-alpha or PAF to maintain the high superoxide response was blocked by addition of inhibitors of serine proteases, either 4-(2-aminoethyl)-benzenesulphonyl fluoride (AEBSF) or 3,4-dichloroisocoumarin. AEBSF was most effective at 200 microns, and required 6 hr for maximum effect. AEBSF did not affect phorbol-triggered superoxide release by unprimed monocytes. AEBSF did not affect cell viability, nor did it interfere with the TNF-alpha secretion in response to LPS. An analogue of AEBSF that lacked ability to inhibit proteases did not affect monocyte responses. 3,4-Dichloroisocoumarin blocked priming at a low concentration, 1 microM. We conclude that activity of a monocyte serine protease is required to maintain the high superoxide response in monocytes primed with LPS, IFN-gamma, TNF-alpha, or PAF. PMID:8567031

  13. Superoxide dismutases of heavy metal resistant streptomycetes.

    PubMed

    Schmidt, Astrid; Schmidt, André; Haferburg, Götz; Kothe, Erika

    2007-02-01

    Heavy metal tolerant and resistant strains of streptomycetes isolated from a former uranium mining site were screened for their superoxide dismutase expression. From the strains tolerating high concentrations of different heavy metals, one was selected for its tolerance of concentrations of heavy metals (Ni, Cu, Cd, Cr, Mn, Zn, Fe). This strain, Streptomyces acidiscabies E13, was chosen for the purpose of superoxide dismutase analysis. Gel electrophoresis and activity staining revealed only one each of a nickel (NiSOD) and an iron (FeZnSOD) containing superoxide dismutase as shown by differential enzymatic repression studies. The gene for nickel containing superoxide dismutase, sodN, was cloned and sequenced from this strain. The genomic sequence shows 92.7% nucleotide identity and 96.1% amino acid identity to sodN of S. coelicolor. Expression can be activated by nickel as well as other heavy metals and active enzyme is produced in media lacking nickel but containing copper, iron or zinc. Thus, the selected strain is well suited for further characterization of the enzyme encoded by sodN. PMID:17304620

  14. Click Grafting of Alkyne-containing Vinyl Polymers onto Biosynthesized Extracellular Matrix Protein Containing Azide Functionality and Adhesion Control of Human Umbilical Vein Endothelial Cells

    PubMed Central

    Yamada, Tomoki

    2015-01-01

    In vivo incorporation of a phenylalanine (Phe) analogue, p-azidophenylalanine (p-N3Phe) into an artificial extracellular matrix protein (aECM-CS5-ELF) was accomplished using a bacterial expression host that harbors the mutant phenylalanyl-tRNA synthetase (PheRS) with an enlarged binding pocket, in which the Ala294Gly/Thr251Gly mutant PheRS (PheRS**) was expressed under the control of T7 promoters. In this study, biosynthesized aECM-CS5-ELF containing p-N3Phe (aECM-CS5-ELF-N3) was coupled with alkyne-containing vinyl polymers prepared via controlled radical polymerization of three vinyl monomers, (styrene, acrylamide, and N-isopropylacrylamide) using a trithiocarbonate as the RAFT agent. Grafting of the vinyl polymers onto the aECM was accomplished via a copper-catalyzed alkyne-azide click reaction. The lower critical transition temperature (LCST) was evaluated, as well as the solubility in aqueous and organic media, which are dependent on the incorporation ratio of p-N3Phe and species of graft chains, in which the LCST behavior was altered remarkably when poly(N-isopropylacrylamide) moieties were attached as side chains. Circular dichroism measurements indicate conformational change was not induced by the grafting. Specific adhesion of human umbilical vein endothelial cells (HUVECs) onto the aECM-CS5-ELF-N3-graft-poly(N-isopropylacrylamide) composite surface and subsequent temperature-sensitive detachment were also demonstrated. PMID:26294960

  15. Interaction of human papillomavirus type 16 particles with heparan sulfate and syndecan-1 molecules in the keratinocyte extracellular matrix plays an active role in infection

    PubMed Central

    Sterkand, Rosa T.; Ozbun, Michelle A.

    2015-01-01

    Oncogenic human papillomaviruses (HPVs) attach predominantly to extracellular matrix (ECM) components during infection of cultured keratinocytes and in the rodent vaginal challenge model in vivo. However, the mechanism of virion transfer from the ECM to receptors that mediate entry into host cells has not been determined. In this work we strove to assess the role of heparan sulfate (HS) chains in HPV16 binding to the ECM and determine how HPV16 release from the ECM is regulated. We also assessed the extent to which capsids released from the ECM are infectious. We show that a large fraction of HPV16 particles binds to the ECM via HS chains, and that syndecan-1 (snd-1) molecules present in the ECM are involved in virus binding. Inhibiting the normal processing of snd-1 and HS molecules via matrix metalloproteinases and heparanase dramatically reduces virus release from the ECM, cellular uptake and infection. Conversely, exogenous heparinase activates each of these processes. We confirm that HPV16 released from the ECM is infectious in keratinocytes. Use of a specific inhibitor shows furin is not involved in HPV16 release from ECM attachment factors and corroborates other studies showing only the intracellular activity of furin is responsible for modulating HPV infectivity. These data suggest that our recently proposed model, describing the action of HS proteoglycan processing enzymes in releasing HPV16 from the cell surface in complex with the attachment factor snd-1, is also relevant to the release of HPV16 particles from the ECM to promote efficient infection of keratinocytes. PMID:26289843

  16. Rosuvastatin Attenuates CD40L-Induced Downregulation of Extracellular Matrix Production in Human Aortic Smooth Muscle Cells via TRAF6-JNK-NF-κB Pathway

    PubMed Central

    Wang, Xiao-Lin; Zhou, Yuan-Li; Sun, Wei; Li, Li

    2016-01-01

    CD40L and statins exhibit pro-inflammatory and anti-inflammatory effects, respectively. They are both pleiotropic and can regulate extracellular matrix (ECM) degeneration in an atherosclerotic plaque. Statins can decrease both the CD40 expression and the resulting inflammation. However, the effects of CD40L and stains on atherosclerotic plaque ECM production and the underlying mechanisms are not well established. Moreover, prolyl-4-hydroxylase α1 (P4Hα1) is involved in collagen synthesis but its correlations with CD40L and statins are unknown. In the present study, CD40L suppressed P4Hα1 expression in human aortic smooth muscle cells (HASMCs) in a dose- and time-dependent manner, with insignificant changes in MMP2 expression and negative enzymatic activity of MMP9. CD40L increased TRAF6 expression, JNK phosphorylation, NF-κB nuclear translocation as well as DNA binding. Furthermore, silencing TRAF6, JNK or NF-κB genes abolished CD40L-induced suppression of P4Hα1. Lower NF-κB nuclear import rates were observed when JNK or TRAF6 silenced HASMCs were stimulated with CD40L compared to HASMCs with active JNK or TRAF6. Together, these results indicate that CD40L suppresses P4Hα1 expression in HASMCs by activating the TRAF6-JNK- NF-κB pathway. We also found that rosuvastatin inhibits CD40L-induced activation of the TRAF6-JNK- NF-κB pathway, thereby significantly rescuing the CD40L stimulated P4Hα1 inhibition. The results from this study will help find potential targets for stabilizing vulnerable atherosclerotic plaques. PMID:27120457

  17. Transcriptional repression of Mad-Max complex by human umbilical cord blood stem cells downregulates extracellular signal-regulated kinase in glioblastoma.

    PubMed

    Velpula, Kiran Kumar; Dasari, Venkata Ramesh; Tsung, Andrew J; Dinh, Dzung H; Rao, Jasti S

    2012-07-01

    Previously, we have shown that human umbilical cord blood stem cell (hUCBSC) treatment downregulate cyclin D1 in glioma cells. To study the cell cycle progression and investigate the upstream molecules regulating cyclin D1 expression, we analyzed the involvement of extracellular signal-regulated kinase (ERK) and its functionality after treatment with hUCBSC. We observed downregulation of pERK after hUCBSC treatment at both transcriptional and translational levels. Increased translocation of ERK from cytoplasm to the nucleus was observed in glioma cells, whereas hUCBSC cocultures with glioma cells showed suppressed nuclear translocation. This finding suggests that hUCBSC regulates ERK by suppressing its phosphorylation at phospho-Thr(202)/Tyr(204) retarding pERK nuclear translocation. ERK promoter analysis has shown c-Myc binding sites, indicative of possible transcriptional interactions that regulate cyclin D1 and ERK expression levels. Treatment of U251 and 5310 glioma cells with U0126, a MEK/ERK inhibitor receded pERK and c-Myc levels. In another experiment, U251 and 5310 cells treated with 10074-G5, c-Myc/Max inhibitor displayed reduction in pERK and c-Myc levels suggestive of a positive feedback loop between ERK/c-Myc/Max molecules. In the present study, we show that glioma cells exhibit abundant c-Myc expression and increased c-Myc/Max activity. In contrast, the glioma cells cocultured with hUCBSC demonstrated high Mad1 expression that competitively binds to Max to repress the c-Myc/Max mediated gene transcription. Our studies thus elucidate the potential role of hUCBSC in controlling glioma cell cycle progression and invasion by limiting Max binding to c-Myc, thus regulating the expression of glioma cell cycle and invasion associated molecules such as ERK, integrins via increased levels of Mad1 expression. PMID:21933022

  18. Transcriptional Repression of Mad-Max Complex by Human Umbilical Cord Blood Stem Cells Downregulates Extracellular Signal-Regulated Kinase in Glioblastoma

    PubMed Central

    Velpula, Kiran Kumar; Dasari, Venkata Ramesh; Tsung, Andrew J.; Dinh, Dzung H.

    2012-01-01

    Previously, we have shown that human umbilical cord blood stem cell (hUCBSC) treatment downregulate cyclin D1 in glioma cells. To study the cell cycle progression and investigate the upstream molecules regulating cyclin D1 expression, we analyzed the involvement of extracellular signal-regulated kinase (ERK) and its functionality after treatment with hUCBSC. We observed downregulation of pERK after hUCBSC treatment at both transcriptional and translational levels. Increased translocation of ERK from cytoplasm to the nucleus was observed in glioma cells, whereas hUCBSC cocultures with glioma cells showed suppressed nuclear translocation. This finding suggests that hUCBSC regulates ERK by suppressing its phosphorylation at phospho-Thr202/Tyr204 retarding pERK nuclear translocation. ERK promoter analysis has shown c-Myc binding sites, indicative of possible transcriptional interactions that regulate cyclin D1 and ERK expression levels. Treatment of U251 and 5310 glioma cells with U0126, a MEK/ERK inhibitor receded pERK and c-Myc levels. In another experiment, U251 and 5310 cells treated with 10074-G5, c-Myc/Max inhibitor displayed reduction in pERK and c-Myc levels suggestive of a positive feedback loop between ERK/c-Myc/Max molecules. In the present study, we show that glioma cells exhibit abundant c-Myc expression and increased c-Myc/Max activity. In contrast, the glioma cells cocultured with hUCBSC demonstrated high Mad1 expression that competitively binds to Max to repress the c-Myc/Max mediated gene transcription. Our studies thus elucidate the potential role of hUCBSC in controlling glioma cell cycle progression and invasion by limiting Max binding to c-Myc, thus regulating the expression of glioma cell cycle and invasion associated molecules such as ERK, integrins via increased levels of Mad1 expression. PMID:21933022

  19. The Extracellular Wall-Bound β-N-Acetylglucosaminidase from Lactobacillus casei Is Involved in the Metabolism of the Human Milk Oligosaccharide Lacto-N-Triose

    PubMed Central

    Bidart, Gonzalo N.; Rodríguez-Díaz, Jesús

    2015-01-01

    Human milk oligosaccharides (HMOs) are considered to play a key role in establishing and maintaining the infant gut microbiota. Lacto-N-triose forms part of both type 1 and type 2 HMOs and also of the glycan moieties of glycoproteins. Upstream of the previously characterized gene cluster involved in lacto-N-biose and galacto-N-biose metabolism from Lactobacillus casei BL23, there are two genes, bnaG and manA, encoding a β-N-acetylglucosaminidase precursor and a mannose-6-phosphate isomerase, respectively. In this work, we show that L. casei is able to grow in the presence of lacto-N-triose as a carbon source. Inactivation of bnaG abolished the growth of L. casei on this oligosaccharide, demonstrating that BnaG is involved in its metabolism. Interestingly, whole cells of a bnaG mutant were totally devoid of β-N-acetylglucosaminidase activity, suggesting that BnaG is an extracellular wall-attached enzyme. In addition to hydrolyzing lacto-N-triose into N-acetylglucosamine and lactose, the purified BnaG enzyme also catalyzed the hydrolysis of 3′-N-acetylglucosaminyl-mannose and 3′-N-acetylgalactosaminyl-galactose. L. casei can be cultured in the presence of 3′-N-acetylglucosaminyl-mannose as a carbon source, but, curiously, the bnaG mutant strain was not impaired in its utilization. These results indicate that the assimilation of 3′-N-acetylglucosaminyl-mannose is independent of BnaG. Enzyme activity and growth analysis with a manA-knockout mutant showed that ManA is involved in the utilization of the mannose moiety of 3′-N-acetylglucosaminyl-mannose. Here we describe the physiological role of a β-N-acetylglucosaminidase in lactobacilli, and it supports the metabolic adaptation of L. casei to the N-acetylglucosaminide-rich gut niche. PMID:26546429

  20. The Extracellular Wall-Bound β-N-Acetylglucosaminidase from Lactobacillus casei Is Involved in the Metabolism of the Human Milk Oligosaccharide Lacto-N-Triose.

    PubMed

    Bidart, Gonzalo N; Rodríguez-Díaz, Jesús; Yebra, María J

    2016-01-01

    Human milk oligosaccharides (HMOs) are considered to play a key role in establishing and maintaining the infant gut microbiota. Lacto-N-triose forms part of both type 1 and type 2 HMOs and also of the glycan moieties of glycoproteins. Upstream of the previously characterized gene cluster involved in lacto-N-biose and galacto-N-biose metabolism from Lactobacillus casei BL23, there are two genes, bnaG and manA, encoding a β-N-acetylglucosaminidase precursor and a mannose-6-phosphate isomerase, respectively. In this work, we show that L. casei is able to grow in the presence of lacto-N-triose as a carbon source. Inactivation of bnaG abolished the growth of L. casei on this oligosaccharide, demonstrating that BnaG is involved in its metabolism. Interestingly, whole cells of a bnaG mutant were totally devoid of β-N-acetylglucosaminidase activity, suggesting that BnaG is an extracellular wall-attached enzyme. In addition to hydrolyzing lact