Anti-fibrotic effects of thalidomide on hepatic stellate cells and dimethylnitrosamine-intoxicated rats.

PubMed

Chong, Lee-Won; Hsu, Yi-Chao; Chiu, Yung-Tsung; Yang, Kuo-Ching; Huang, Yi-Tsau

2006-05-01

Tumor necrosis factor-alpha (TNF-alpha) plays a central role in cellular necrosis, apoptosis, organ failure, tissue damage, inflammation and fibrosis. These processes, occurring in liver injury, may lead to cirrhosis. Thalidomide, alpha-N-phthalidoglutarimide, (C(13)H(10)N(2))(4), has been shown to have immunomodulatory and anti-inflammatory properties, possibly mediated through its anti-TNF-alpha effect. In this study, we investigated the in vitro and in vivo effects of thalidomide on hepatic fibrosis. A cell line of rat hepatic stellate cells (HSC-T6) was stimulated with transforming growth factor-beta1 (TGF-beta1) or TNF-alpha. The inhibitory effects of thalidomide on the NFkappaB signaling cascade and fibrosis markers including alpha-smooth muscle actin (alpha-SMA) and collagen, were assessed. An in vivo therapeutic study was conducted in dimethylnitrosamine (DMN)-treated rats, which were randomly assigned to 1 of 4 groups: vehicle (0.7% carboxyl methyl cellulose, CMC), thalidomide (40 mg/kg), thalidomide (200 mg/kg), or silymarin (50 mg/kg), each given by gavage twice daily for 3 weeks starting after 1 week of DMN administration. Thalidomide (100-800 nM) concentration-dependently inhibited NFkappaB transcriptional activity induced by TNF-alpha, including IKKalpha expression and IkappaBalpha phosphorylation in HSC-T6 cells. In addition, thalidomide also suppressed TGF-beta1-induced alpha-SMA expression and collagen deposition in HSC-T6 cells. Fibrosis scores of livers from DMN-treated rats receiving high dose of thalidomide (0.89 +/- 0.20) were significantly reduced in comparison with those of DMN-treated rats receiving vehicle (1.56 +/- 0.18). Hepatic collagen contents of DMN rats were also significantly reduced by either thalidomide or silymarin treatment. Immunohistochemical double staining results showed that alpha-SMA- and NFkappaB-positive cells were decreased in the livers from DMN rats receiving either thalidomide or silymarin treatment. In addition, real-time PCR analysis indicated that hepatic mRNA expressions of TGF-beta1, alpha-SMA, collagen 1alpha2, TNF-alpha and iNOS genes were attenuated by thalidomide treatment. In conclusion, our results showed that thalidomide inhibited activation of HSC-T6 cells by TNF-alpha and ameliorated liver fibrosis in DMN-intoxicated rats.

The three-dimensional structure of a T-cell antigen receptor V alpha V beta heterodimer reveals a novel arrangement of the V beta domain.

PubMed Central

Housset, D; Mazza, G; Grégoire, C; Piras, C; Malissen, B; Fontecilla-Camps, J C

1997-01-01

The crystal structure of a mouse T-cell antigen receptor (TCR) Fv fragment complexed to the Fab fragment of a specific anti-clonotypic antibody has been determined to 2.6 A resolution. The polypeptide backbone of the TCR V alpha domain is very similar to those of other crystallographically determined V alphas, whereas the V beta structure is so far unique among TCR V beta domains in that it displays a switch of the c" strand from the inner to the outer beta-sheet. The beta chain variable region of this TCR antigen-binding site is characterized by a rather elongated third complementarity-determining region (CDR3beta) that packs tightly against the CDR3 loop of the alpha chain, without leaving any intervening hydrophobic pocket. Thus, the conformation of the CDR loops with the highest potential diversity distinguishes the structure of this TCR antigen-binding site from those for which crystallographic data are available. On the basis of all these results, we infer that a significant conformational change of the CDR3beta loop found in our TCR is required for binding to its cognate peptide-MHC ligand. PMID:9250664

Estrogen-related receptor {alpha} modulates the expression of adipogenesis-related genes during adipocyte differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ijichi, Nobuhiro; Ikeda, Kazuhiro; Horie-Inoue, Kuniko

2007-07-06

Estrogen-related receptor {alpha} (ERR{alpha}) is an orphan nuclear receptor that regulates cellular energy metabolism by modulating gene expression involved in fatty acid oxidation and mitochondrial biogenesis in brown adipose tissue. However, the physiological role of ERR{alpha} in adipogenesis and white adipose tissue development has not been well studied. Here, we show that ERR{alpha} and ERR{alpha}-related transcriptional coactivators, peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) coactivator-1{alpha} (PGC-1{alpha}) and PGC-1{beta}, can be up-regulated in 3T3-L1 preadipocytes at mRNA levels under the adipogenic differentiation condition including the inducer of cAMP, glucocorticoid, and insulin. Gene knockdown by ERR{alpha}-specific siRNA results in mRNA down-regulation of fatty acidmore » binding protein 4, PPAR{gamma}, and PGC-1{alpha} in 3T3-L1 cells in the adipogenesis medium. ERR{alpha} and PGC-1{beta} mRNA expression can be also up-regulated in another preadipocyte lineage DFAT-D1 cells and a pluripotent mesenchymal cell line C3H10T1/2 under the differentiation condition. Furthermore, stable expression of ERR{alpha} in 3T3-L1 cells up-regulates adipogenic marker genes and promotes triglyceride accumulation during 3T3-L1 differentiation. These results suggest that ERR{alpha} may play a critical role in adipocyte differentiation by modulating the expression of various adipogenesis-related genes.« less

{beta}-Catenin regulates airway smooth muscle contraction.

PubMed

Jansen, Sepp R; Van Ziel, Anna M; Baarsma, Hoeke A; Gosens, Reinoud

2010-08-01

beta-Catenin is an 88-kDa member of the armadillo family of proteins that is associated with the cadherin-catenin complex in the plasma membrane. This complex interacts dynamically with the actin cytoskeleton to stabilize adherens junctions, which play a central role in force transmission by smooth muscle cells. Therefore, in the present study, we hypothesized a role for beta-catenin in the regulation of smooth muscle force production. beta-Catenin colocalized with smooth muscle alpha-actin (sm-alpha-actin) and N-cadherin in plasma membrane fractions and coimmunoprecipitated with sm-alpha-actin and N-cadherin in lysates of bovine tracheal smooth muscle (BTSM) strips. Moreover, immunocytochemistry of cultured BTSM cells revealed clear and specific colocalization of sm-alpha-actin and beta-catenin at the sites of cell-cell contact. Treatment of BTSM strips with the pharmacological beta-catenin/T cell factor-4 (TCF4) inhibitor PKF115-584 (100 nM) reduced beta-catenin expression in BTSM whole tissue lysates and in plasma membrane fractions and reduced maximal KCl- and methacholine-induced force production. These changes in force production were not accompanied by changes in the expression of sm-alpha-actin or sm-myosin heavy chain (MHC). Likewise, small interfering RNA (siRNA) knockdown of beta-catenin in BTSM strips reduced beta-catenin expression and attenuated maximal KCl- and methacholine-induced contractions without affecting sm-alpha-actin or sm-MHC expression. Conversely, pharmacological (SB-216763, LiCl) or insulin-induced inhibition of glycogen synthase kinase-3 (GSK-3) enhanced the expression of beta-catenin and augmented maximal KCl- and methacholine-induced contractions. We conclude that beta-catenin is a plasma membrane-associated protein in airway smooth muscle that regulates active tension development, presumably by stabilizing cell-cell contacts and thereby supporting force transmission between neighboring cells.

Regulated expression of the rat recombinant P2X(3) receptor in stably transfected CHO-K1 tTA cells.

PubMed

Lachnit, W G; Oglesby, I B; Gever, J R; Gever, M; Huang, C; Li, X C; Jin, H; McGivern, J G; Ford, A P

2000-07-03

In this report, the regulatable expression by tetracycline of the rat recombinant P2X(3) receptor in stably transfected Chinese hamster ovary (CHO-K1) expressing the tetracycline-controlled transactivator (tTA) is described. cDNA encoding the rat P2X(3)-receptor was subcloned into pTRE (a tetracycline-repressible expression vector) which was used to transfect stably CHO-K1 tTA cells. Using whole cell patch clamp techniques, 100 microM ATP evoked inward currents of 2.9+/-1.6 nA in transfected cells grown in the absence of tetracycline (tet-). The P2X(3) receptor protein was detectable by immunoblot as early as 24 h and protein expression levels continued to increase as much as 192 h following activation of tTA by the removal of the antibiotic. Saturation binding isotherms using [35S]ATP gamma S yielded a pK(d) of 8.2+/-0.1 and a B(max) of 31.9+/-3.5 pmol/mg protein in tet- cell membranes and a pK(d) of 8.1+/-0.1 and a B(max) of 5.8+/-0.8 pmol/mg protein in tet+ cell membranes. The agonist ligands 2MeSATP and alpha beta MeATP displaced the binding of [35S]ATP gamma S in tet- cell membranes with very high affinity, yielding pIC(50) values of 9.4+/-0.2 and 7.5+/-0. 2, respectively. In tet+ cell membrane, displacement of [35S]ATP gamma S by 2MeSATP and alpha beta MeATP was of much lower affinity (pIC(50) values of 7.8 and 6.2, respectively). ATP, ADP and UTP showed similar displacement of [35S]ATP gamma S binding in tet- and tet+ cell membranes. In other experiments, cytosolic Ca(2+) was monitored using the fluorescent indicator, fluo-3. Increases in cytosolic Ca(2+) were elicited by 100 nM alpha beta MeATP in tet- cells while no increases in cytosolic Ca(2+) were detected below 100 microM alpha beta MeATP in either tet+ cells or untransfected cells. These calcium responses to alpha beta MeATP had a pEC(50) of 6.7 and were transient, returning to baseline within 120 s. Suramin produced concentration-dependent, parallel, dextral shifts of E/[A] curves to alpha beta MeATP yielding a pK(B) of 5.6. PPADS produced non-parallel, dextral shifts of E/[A] curves to alpha beta MeATP which were insurmountable. These results show for the first time, expression of a functional, homomeric recombinant rat P2X(3) receptor which is under regulated expression in a stably transfected mammalian cell line.

Preferential V beta gene usage and lack of junctional sequence conservation among human T cell receptors specific for a tetanus toxin- derived peptide: evidence for a dominant role of a germline-encoded V region in antigen/major histocompatibility complex recognition

PubMed Central

1992-01-01

To investigate the structural and genetic basis of the T cell response to defined peptide/major histocompatibility (MHC) class II complexes in humans, we established a large panel of T cell clones (61) from donors of different HLA-DR haplotypes and reactive with a tetanus toxin- derived peptide (tt830-844) recognized in association with most DR molecules (universal peptide). By using a bacterial enterotoxin-based proliferation assay and cDNA sequencing, we found preferential use of a particular V beta region gene segment, V beta 2.1, in three of the individuals studied (64%, n = 58), irrespective of whether the peptide was presented by the DR6wcI, DR4w4, or DRw11.1 and DRw11.2 alleles, demonstrating that shared MHC class II antigens are not required for shared V beta gene use by T cell receptors (TCRs) specific for this peptide. V alpha gene use was more heterogeneous, with at least seven different V alpha segments derived from five distinct families encoding alpha chains able to pair with V beta 2.1 chains to form a tt830-844/DR- specific binding site. Several cases were found of clones restricted to different DR alleles that expressed identical V beta and (or very closely related) V alpha gene segments and that differed only in their junctional sequences. Thus, changes in the putative complementary determining region 3 (CDR3) of the TCR may, in certain cases, alter MHC specificity and maintain peptide reactivity. Finally, in contrast to what has been observed in other defined peptide/MHC systems, a striking heterogeneity was found in the junctional regions of both alpha and beta chains, even for TCRs with identical V alpha and/or V beta gene segments and the same restriction. Among 14 anti-tt830-844 clones using the V beta 2.1 gene segment, 14 unique V beta-D-J beta junctions were found, with no evident conservation in length and/or amino acid composition. One interpretation for this apparent lack of coselection of specific junctional sequences in the context of a common V element, V beta 2.1, is that this V region plays a dominant role in the recognition of the tt830-844/DR complex. PMID:1371303

Expression and function of CD8 alpha/beta chains on rat and human mast cells.

PubMed

Kim, Mi-Sun; Kim, Sung-Hoon; Lee, Hye-Jung; Kim, Hyung-Min

2004-03-01

The expression and functional role of CD8 glycoprotein, a marker of cytotoxic/suppressor T lymphocytes and NK cells, were not studied on freshly isolated connective tissue type rat peritoneal mast cells, a rat mucosal type mast cell line (RBL 2H3), or human mast cell line (HMC-1). We used the reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis, immunohistochemistry and enzyme-linked immunosorbent assay. RT-PCR and Western blot analysis identified the presence of CD8 alpha/beta chains on the mast cells, and immunohistochemistry confirmed CD8alpha expression on rat or human mast cells. Functional studies demonstrated that stimulation of CD8 alpha/beta chains on rat mast cells induced the secretion of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6), which are regarded as important mediators during infection. However, co-stimulation with stem cell factor had no effect on CD8-induced mediator secretion. Our findings demonstrate novel biological roles of CD8 molecules in mast cells.

Anti-retroviral therapy fails to restore the severe Th-17: Tc-17 imbalance observed in peripheral blood during simian immunodeficiency virus infection.

PubMed

Kader, M; Bixler, S; Piatak, M; Lifson, J; Mattapallil, J J

2009-10-01

Human immuno deficiency virus and simian immunodeficiency virus infections are characterized by a severe loss of Th-17 cells (IL-17(+)CD4(+) T cells) that has been associated with disease progression and systemic dissemination of bacterial infections. Anti-retroviral therapy (ART) has led to repopulation of CD4(+) T cells in peripheral tissues with little sustainable repopulation in mucosal tissues. Given the central importance of Th-17 cells in mucosal homeostasis, it is not known if the failure of ART to permanently repopulate mucosal tissues is associated with a failure to restore Th-17 cells that are lost during infection. Dynamics of alpha4(+)beta7(hi) CD4(+) T cells in peripheral blood of SIV infected rhesus macaques were evaluated and compared to animals that were treated with ART. The frequency of Th-17 and Tc-17 cells was determined following infection and after therapy. Relative expression of IL-21, IL-23, and TGFbeta was determined using Taqman PCR. Treatment of SIV infected rhesus macaques with anti-retroviral therapy was associated with a substantial repopulation of mucosal homing alpha4(+)beta7(hi)CD4(+) T cells in peripheral blood. This repopulation, however, was not accompanied by a restoration of Th-17 responses. Interestingly, SIV infection was associated with an increase in Tc-17 responses (IL-17(+)CD8(+) T cells) suggesting to a skewing in the ratio of Th-17: Tc-17 cells from a predominantly Th-17 phenotype to a predominantly Tc-17 phenotype. Surprisingly, Tc-17 responses remained high during the course of therapy suggesting that ART failed to correct the imbalance in Th-17 : Tc-17 responses induced following SIV infection. ART was associated with substantial repopulation of alpha4(+)beta7(hi) CD4(+) T cells in peripheral blood with little or no rebound of Th-17 cells. On the other hand, repopulation of alpha4(+)beta7(hi) CD4(+) T cells was accompanied by persistence of high levels of Tc-17 cells in peripheral blood. The dysregulation of Th-17 and Tc-17 responses likely plays a role in disease progression.

Alpha-latrotoxin induces exocytosis by inhibition of voltage-dependent K+ channels and by stimulation of L-type Ca2+ channels via latrophilin in beta-cells.

PubMed

Lajus, Sophie; Vacher, Pierre; Huber, Denise; Dubois, Mathilde; Benassy, Marie-Noëlle; Ushkaryov, Yuri; Lang, Jochen

2006-03-03

The spider venom alpha-latrotoxin (alpha-LTX) induces massive exocytosis after binding to surface receptors, and its mechanism is not fully understood. We have investigated its action using toxin-sensitive MIN6 beta-cells, which express endogenously the alpha-LTX receptor latrophilin (LPH), and toxin-insensitive HIT-T15 beta-cells, which lack endogenous LPH. alpha-LTX evoked insulin exocytosis in HIT-T15 cells only upon expression of full-length LPH but not of LPH truncated after the first transmembrane domain (LPH-TD1). In HIT-T15 cells expressing full-length LPH and in native MIN6 cells, alpha-LTX first induced membrane depolarization by inhibition of repolarizing K(+) channels followed by the appearance of Ca(2+) transients. In a second phase, the toxin induced a large inward current and a prominent increase in intracellular calcium ([Ca(2+)](i)) reflecting pore formation. Upon expression of LPH-TD1 in HIT-T15 cells just this second phase was observed. Moreover, the mutated toxin LTX(N4C), which is devoid of pore formation, only evoked oscillations of membrane potential by reversible inhibition of iberiotoxin-sensitive K(+) channels via phospholipase C, activated L-type Ca(2+) channels independently from its effect on membrane potential, and induced an inositol 1,4,5-trisphosphate receptor-dependent release of intracellular calcium in MIN6 cells. The combined effects evoked transient increases in [Ca(2+)](i) in these cells, which were sensitive to inhibitors of phospholipase C, protein kinase C, or L-type Ca(2+) channels. The latter agents also reduced toxin-induced insulin exocytosis. In conclusion, alpha-LTX induces signaling distinct from pore formation via full-length LPH and phospholipase C to regulate physiologically important K(+) and Ca(2+) channels as novel targets of its secretory activity.

Creep function of a single living cell.

PubMed

Desprat, Nicolas; Richert, Alain; Simeon, Jacqueline; Asnacios, Atef

2005-03-01

We used a novel uniaxial stretching rheometer to measure the creep function J(t) of an isolated living cell. We show, for the first time at the scale of the whole cell, that J(t) behaves as a power-law J(t) = At(alpha). For N = 43 mice myoblasts (C2-7), we find alpha = 0.24 +/- 0.01 and A = (2.4 +/- 0.3) 10(-3) Pa(-1) s(-alpha). Using Laplace Transforms, we compare A and alpha to the parameters G(0) and beta of the complex modulus G*(omega) = G(0)omega(beta) measured by other authors using magnetic twisting cytometry and atomic force microscopy. Excellent agreement between A and G(0) on the one hand, and between alpha and beta on the other hand, indicated that the power-law is an intrinsic feature of cell mechanics and not the signature of a particular technique. Moreover, the agreement between measurements at very different size scales, going from a few tens of nanometers to the scale of the whole cell, suggests that self-similarity could be a central feature of cell mechanical structure. Finally, we show that the power-law behavior could explain previous results first interpreted as instantaneous elasticity. Thus, we think that the living cell must definitely be thought of as a material with a large and continuous distribution of relaxation time constants which cannot be described by models with a finite number of springs and dash-pots.

Cloning and expression of a novel UDP-GlcNAc:alpha-D-mannoside beta1,2-N-acetylglucosaminyltransferase homologous to UDP-GlcNAc:alpha-3-D-mannoside beta1,2-N-acetylglucosaminyltransferase I.

PubMed Central

Zhang, Wenli; Betel, Doron; Schachter, Harry

2002-01-01

A TBLASTN search with human UDP-GlcNAc:alpha-3-d-mannoside beta-1,2-N-acetylglucosaminyltransferase I (GnT I; EC 2.4.1.101) as a probe identified human and mouse Unigenes encoding a protein similar to human GnT I (34% identity over 340 amino acids). The recombinant protein converted Man(alpha1-6)[Man(alpha1-3)]Man(beta1-)O-octyl to Man(alpha1-6)[GlcNAc(beta1-2)Man(alpha1-3)]Man(beta1-)O-octyl, the reaction catalysed by GnT I. The enzyme also added GlcNAc to Man(alpha1-6)[GlcNAc(beta1-2)Man(alpha1-3)]Man(beta1-)O-octyl (the substrate for beta-1,2-N-acetylglucosaminyltransferase II), Man(alpha1-)O-benzyl [with K(m) values of approximately 0.3 and >30 mM for UDP-GlcNAc and Man(alpha1-)O-benzyl respectively] and the glycopeptide CYA[Man(alpha1-)O-T]AV (K(m) approximately 12 mM). The product formed with Man(alpha1-)O-benzyl was identified as GlcNAc(beta1-2)Man(alpha1-)O-benzyl by proton NMR spectroscopy. The enzyme was named UDP-GlcNAc:alpha-d-mannoside beta-1,2-N-acetylglucosaminyltransferase I.2 (GnT I.2). The human gene mapped to chromosome 1. Northern-blot analysis showed a 3.3 kb message with a wide tissue distribution. The cDNA has a 1980 bp open reading frame encoding a 660 amino acid protein with a type-2 domain structure typical of glycosyltransferases. Man(beta1-)O-octyl, Man(beta1-)O-p-nitrophenyl and GlcNAc(beta1-2)Man(alpha1-6)[GlcNAc(beta1-2)Man(alpha1-3)]Man(beta1-4)GlcNAc(beta1-4)GlcNAc(beta1-)O-Asn were not acceptors, indicating that GnT I.2 is specific for alpha-linked terminal Man and does not have N-acetylglucosaminyltransferase III, IV, V, VII or VIII activities. CYA[Man(alpha1-)O-T]AV was between three and seven times more effective as an acceptor than the other substrates, suggesting that GnT I.2 may be responsible for the synthesis of the GlcNAc(beta1-2)Man(alpha1-)O-Ser/Thr moiety on alpha-dystroglycan and other O-mannosylated proteins. PMID:11742540

Expression of hemidesmosomal and extracellular matrix proteins by normal and malignant human prostate tissue.

PubMed Central

Nagle, R. B.; Hao, J.; Knox, J. D.; Dalkin, B. L.; Clark, V.; Cress, A. E.

1995-01-01

The progression of prostate carcinoma may be influenced by the biochemical nature of the basal lamina surrounding the primary carcinoma cells. As a first step toward understanding this process, the composition and structure of the basal lamina in normal prostate, prostatic intraepithelial neoplasia, and human carcinoma were determined. In addition, a comparison was made between the attachments of the normal basal cell to its underlying basal lamina and those made by primary prostate carcinoma. The normal basal cells form both focal adhesions and hemidesmosomal-like structures as observed by transmission electron microscopy. The normal basal cells exhibited a polarized distribution of hemidesmosomal associated proteins including BP180, BP230, HD1, plectin, laminin-gamma 2(B2t), collagen VII, and the corresponding integrin laminin receptors alpha 6 beta 1 and alpha 6 beta 4. The expression and distribution pattern of these proteins were retained in the prostate intraepithelial neoplasia lesions. In contrast, the carcinoma cells uniformly lacked hemidesmosomal structures, the integrin alpha 6 beta 4, BP180, laminin-gamma 2 (B2t), and collagen VII but did express BP230 (30%), plectin, HD1 (15%), and the integrin laminin receptors alpha 3 beta 1 and alpha 6 beta 1. These results suggest that, although a detectable basal lamina structure is present in carcinoma, its composition and cellular attachments are abnormal. The loss of critical cellular attachments may play a role in influencing the progression potential of prostate carcinoma. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:7778688

Alpha-beta T cells provide protection against lethal encephalitis in the murine model of VEEV infection

PubMed Central

Paessler, Slobodan; Yun, Nadezhda E.; Judy, Barbara M.; Dziuba, Natallia; Zacks, Michele A.; Grund, Anna H.; Frolov, Ilya; Campbell, Gerald A.; Weaver, Scott C.; Estes, D. Mark

2007-01-01

We evaluated the safety and immunogenicity of a chimeric alphavirus vaccine candidate in mice with selective immunodeficiencies. This vaccine candidate was highly attenuated in mice with deficiencies in the B and T cell compartments, as well as in mice with deficient gamma-interferon responsiveness. However, the level of protection varied among the strains tested. Wild type mice were protected against lethal VEEV challenge. In contrast, alpha/beta (αβ) TCR-deficient mice developed lethal encephalitis following VEEV challenge, while mice deficient in gamma/delta ( γδ) T cells were protected. Surprisingly, the vaccine potency was diminished by 50% in animals lacking interferon-gamma receptor alpha chain (R1)-chain and a minority of vaccinated immunoglobulin heavy chain-deficient (μMT) mice survived challenge, which suggests that neutralizing antibody may not be absolutely required for protection. Prolonged replication of encephalitic VEEV in the brain of pre-immunized mice is not lethal and adoptive transfer experiments indicate that CD3+ T cells are required for protection. PMID:17610927

Rearrangements of genes for the antigen receptor on T cells as markers of lineage and clonality in human lymphoid neoplasms.

PubMed

Waldmann, T A; Davis, M M; Bongiovanni, K F; Korsmeyer, S J

1985-09-26

The T alpha and T beta chains of the heterodimeric T-lymphocyte antigen receptor are encoded by separated DNA segments that recombine during T-cell development. We have used rearrangements of the T beta gene as a widely applicable marker of clonality in the T-cell lineage. We show that the T beta genes are used in both the T8 and T4 subpopulations of normal T cells and that Sézary leukemia, adult T-cell leukemia, and the non-B-lineage acute lymphoblastic leukemias are clonal expansions of T cells. Furthermore, circulating T cells from a patient with the T8-cell-predominantly lymphocytosis associated with granulocytopenia are shown to be monoclonal. Finally, the sensitivity and specificity of this tumor-associated marker have been exploited to monitor the therapy of a patient with adult T-cell leukemia. These unique DNA rearrangements provide insights into the cellular origin, clonality, and natural history of T-cell neoplasia.

Differentiation to adipocytes in accompanied by an increase in the amounts of Gi- and Go-proteins in 3T3-L1 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watkins, D.C.; Northup, J.K.; Malbon, C.C.

Treatment of cultures of 3T3-L1 cells with methylisobutyl-xanthine and dexamethasone has been shown to result in accumulation of lipid and conversion to the morphology of adipocytes in more than 90% of the cells. The status of the stimulatory (Gs), inhibitory (Gi) and Go-proteins during the course of 3T3-L1 differentiation was examined. The amount of alpha subunit of Gs (..cap alpha..Gs), assayed by radiolabeling in the presence of cholera toxin and (/sup 32/P)NAD/sup +/, increased upon differentiation as previously described by others. The amounts of ..cap alpha..Gi and ..cap alpha..Go assayed by radiolabeling in the presence of pertussis toxin and (/supmore » 32/P)NAD/sup +/ increased 3-fold upon differentiation. Immunoblots of cell membranes subjected to gel electrophoresis in sodium dodecyl sulfate were probed with two rabbit antisera raised against bovine brain ..cap alpha..Go and with one raised against the..beta..-subunit of the bovine rod-outer-segment G-protein, referred to as transducin. The immunoblotting data confirm the increase upon differentiation of ..cap alpha..Go and also demonstrate an increase in the amount of the ..beta..-subunit. Thus differentiation of 3T3-L1 cells is accompanied by dramatic changes in the complexion of G-proteins in the membranes.« less

Characterization of prmt7alpha and beta isozymes from Chinese hamster cells sensitive and resistant to topoisomerase II inhibitors.

PubMed

Gros, Laurent; Renodon-Cornière, Axelle; de Saint Vincent, Bruno Robert; Feder, Marcin; Bujnicki, Janusz M; Jacquemin-Sablon, Alain

2006-11-01

By selection of genetic suppressor elements (GSEs) conferring resistance to topoisomerase II inhibitors in Chinese hamster cells (DC-3F), we identified a gene encoding two proteins of 78 and 82 kDa which belong to the protein arginine methyltransferase (PRMT) family. Down-regulation of these enzymes (named PRMT7alpha and beta), either induced by an antisense GSE or as observed in the 9-OH-ellipticine (9-OH-E) resistant mutant DC-3F/9-OH-E, was responsible for cell resistance to various DNA damaging agents. Alternative splicing alterations in the 5'-terminal region and changes of the polyadenylation site of PRMT7 mRNAs were observed in these resistant mutant cells. PRMT7alpha and beta are isoforms of a highly conserved protein containing two copies of a module common to all PRMTs, comprising a Rossmann-fold domain and a beta-barrel domain. The C-terminal repeat appears to be degenerate and catalytically inactive. PRMT7alpha and beta form homo- and hetero-dimers but differ by their sub-cellular localization and in vitro recognize different substrates. PRMT7beta was only observed in Chinese hamster cells while mouse 10T1/2 fibroblasts only contain PRMT7alpha. Surprisingly, in human cells the anti-PRMT7 antibody essentially recognized an approximately 37 kDa peptide, which is not formed during extraction, and a faint band at 78 kDa. Analysis of in vitro and in vivo methylation patterns in cell lines under- or over-expressing PRMT7alpha and beta detected a discrete number of proteins which methylation and/or expression are under the control of these enzymes.

Sweet taste receptors in rat small intestine stimulate glucose absorption through apical GLUT2.

PubMed

Mace, Oliver J; Affleck, Julie; Patel, Nick; Kellett, George L

2007-07-01

Natural sugars and artificial sweeteners are sensed by receptors in taste buds. T2R bitter and T1R sweet taste receptors are coupled through G-proteins, alpha-gustducin and transducin, to activate phospholipase C beta2 and increase intracellular calcium concentration. Intestinal brush cells or solitary chemosensory cells (SCCs) have a structure similar to lingual taste cells and strongly express alpha-gustducin. It has therefore been suggested over the last decade that brush cells may participate in sugar sensing by a mechanism analogous to that in taste buds. We provide here functional evidence for an intestinal sensing system based on lingual taste receptors. Western blotting and immunocytochemistry revealed that all T1R members are expressed in rat jejunum at strategic locations including Paneth cells, SCCs or the apical membrane of enterocytes; T1Rs are colocalized with each other and with alpha-gustducin, transducin or phospholipase C beta2 to different extents. Intestinal glucose absorption consists of two components: one is classical active Na+-glucose cotransport, the other is the diffusive apical GLUT2 pathway. Artificial sweeteners increase glucose absorption in the order acesulfame potassium approximately sucralose > saccharin, in parallel with their ability to increase intracellular calcium concentration. Stimulation occurs within minutes by an increase in apical GLUT2, which correlates with reciprocal regulation of T1R2, T1R3 and alpha-gustducin versus T1R1, transducin and phospholipase C beta2. Our observation that artificial sweeteners are nutritionally active, because they can signal to a functional taste reception system to increase sugar absorption during a meal, has wide implications for nutrient sensing and nutrition in the treatment of obesity and diabetes.

alpha(4)beta(7) independent pathway for CD8(+) T cell-mediated intestinal immunity to rotavirus.

PubMed

Kuklin, N A; Rott, L; Darling, J; Campbell, J J; Franco, M; Feng, N; Müller, W; Wagner, N; Altman, J; Butcher, E C; Greenberg, H B

2000-12-01

Rotavirus (RV), which replicates exclusively in cells of the small intestine, is the most important cause of severe diarrhea in young children worldwide. Using a mouse model, we show that expression of the intestinal homing integrin alpha(4)ss(7) is not essential for CD8(+) T cells to migrate to the intestine or provide immunity to RV. Mice deficient in ss7 expression (ss7(-/-)) and unable to express alpha(4)ss(7) integrin were found to clear RV as quickly as wild-type (wt) animals. Depletion of CD8(+) T cells in ss7(-/-) animals prolonged viral shedding, and transfer of immune ss7(-/-) CD8(+) T cells into chronically infected Rag-2-deficient mice resolved RV infection as efficiently as wt CD8(+) T cells. Paradoxically, alpha(4)ss(7)(hi) memory CD8(+) T cells purified from wt mice that had been orally immunized cleared RV more efficiently than alpha(4)ss(7)(low) CD8(+) T cells. We explained this apparent contradiction by demonstrating that expression of alpha(4)ss(7) on effector CD8(+) T cells depends upon the site of initial antigen exposure: oral immunization generates RV-specific CD8(+) T cells primarily of an alpha(4)ss(7)(hi) phenotype, but subcutaneous immunization yields both alpha(4)ss(7)(hi) and alpha(4)ss(7)(low) immune CD8(+) T cells with anti-RV effector capabilities. Thus, alpha(4)ss(7) facilitates normal intestinal immune trafficking to the gut, but it is not required for effective CD8(+) T cell immunity.

Interleukins 1alpha and 1beta secreted by some melanoma cell lines strongly reduce expression of MITF-M and melanocyte differentiation antigens.

PubMed

Kholmanskikh, Olga; van Baren, Nicolas; Brasseur, Francis; Ottaviani, Sabrina; Vanacker, Julie; Arts, Nathalie; van der Bruggen, Pierre; Coulie, Pierre; De Plaen, Etienne

2010-10-01

We report that melanoma cell lines expressing the interleukin-1 receptor exhibit 4- to 10-fold lower levels of mRNA of microphthalmia-associated transcription factor (MITF-M) when treated with interleukin-1beta. This effect is NF-kappaB and JNK-dependent. MITF-M regulates the expression of melanocyte differentiation genes such as MLANA, tyrosinase and gp100, which encode antigens recognized on melanoma cells by autologous cytolytic T lymphocytes. Accordingly, treating some melanoma cells with IL-1beta reduced by 40-100% their ability to activate such antimelanoma cytolytic T lymphocytes. Finally, we observed large amounts of biologically active IL-1alpha or IL-1beta secreted by two melanoma cell lines that did not express MITF-M, suggesting an autocrine MITF-M downregulation. We estimate that approximately 13% of melanoma cell lines are MITF-M-negative and secrete IL-1 cytokines. These results indicate that the repression of melanocyte-differentiation genes by IL-1 produced by stromal cells or by tumor cells themselves may represent an additional mechanism of melanoma immune escape.

Mycophenolate mofetil modulates adhesion receptors of the beta1 integrin family on tumor cells: impact on tumor recurrence and malignancy

PubMed Central

Engl, Tobias; Makarević, Jasmina; Relja, Borna; Natsheh, Iyad; Müller, Iris; Beecken, Wolf-Dietrich; Jonas, Dietger; Blaheta, Roman A

2005-01-01

Background Tumor development remains one of the major obstacles following organ transplantation. Immunosuppressive drugs such as cyclosporine and tacrolimus directly contribute to enhanced malignancy, whereas the influence of the novel compound mycophenolate mofetil (MMF) on tumor cell dissemination has not been explored. We therefore investigated the adhesion capacity of colon, pancreas, prostate and kidney carcinoma cell lines to endothelium, as well as their beta1 integrin expression profile before and after MMF treatment. Methods Tumor cell adhesion to endothelial cell monolayers was evaluated in the presence of 0.1 and 1 μM MMF and compared to unstimulated controls. beta1 integrin analysis included alpha1beta1 (CD49a), alpha2beta1 (CD49b), alpha3beta1 (CD49c), alpha4beta1 (CD49d), alpha5beta1 (CD49e), and alpha6beta1 (CD49f) receptors, and was carried out by reverse transcriptase-polymerase chain reaction, confocal microscopy and flow cytometry. Results Adhesion of the colon carcinoma cell line HT-29 was strongly reduced in the presence of 0.1 μM MMF. This effect was accompanied by down-regulation of alpha3beta1 and alpha6beta1 surface expression and of alpha3beta1 and alpha6beta1 coding mRNA. Adhesion of the prostate tumor cell line DU-145 was blocked dose-dependently by MMF. In contrast to MMF's effects on HT-29 cells, MMF dose-dependently up-regulated alpha1beta1, alpha2beta1, alpha3beta1, and alpha5beta1 on DU-145 tumor cell membranes. Conclusion We conclude that MMF possesses distinct anti-tumoral properties, particularly in colon and prostate carcinoma cells. Adhesion blockage of HT-29 cells was due to the loss of alpha3beta1 and alpha6beta1 surface expression, which might contribute to a reduced invasive behaviour of this tumor entity. The enhancement of integrin beta1 subtypes observed in DU-145 cells possibly causes re-differentiation towards a low-invasive phenotype. PMID:15644133

High production of RANTES and MIP-1alpha in the tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM).

PubMed

Montanheiro, Patricia; Vergara, Maria Paulina Posada; Smid, Jerusa; da Silva Duarte, Alberto José; de Oliveira, Augusto César Penalva; Casseb, Jorge

2007-08-01

Human T cell lymphotropic virus type 1 (HTLV-1) infection is associated with progressive neurological disorders and tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM). The pathogenesis of TSP/HAM is considered as immune mediated, involving cytotoxic T cell (CTL) responses to a number of viral proteins and notably the regulation protein Tax. T CD8+ cells produce beta-chemokines, which are important in the anti-viral response. In the present study, we have analyzed the CC chemokines (RANTES, MIP-1beta and MIP-1alpha) production in retrovirus-infected subjects. A total of 191 subjects were studied: 52 healthy controls, 72 asymptomatic HTLV-1-infected carriers and 67 TSP/HAM patients. Peripheral blood mononuclear cells were maintained in the presence or absence of PHA, and supernatant fluids were assayed using EIA. MIP-1beta concentration was not significantly different across groups, but RANTES and MIP-1alpha concentrations showed significant differences when the three groups were compared. In TSP/HAM patients, the increase in the production of chemokines may lead to a recruitment of pro-inflammatory factors, contributing to the membrane's myelin damage.

Lysophospholipid presentation by CD1d and recognition by a human Natural Killer T-cell receptor

DOE Office of Scientific and Technical Information (OSTI.GOV)

López-Sagaseta, Jacinto; Sibener, Leah V.; Kung, Jennifer E.

2014-10-02

Invariant Natural Killer T (iNKT) cells use highly restricted {alpha}{beta} T cell receptors (TCRs) to probe the repertoire of lipids presented by CD1d molecules. Here, we describe our studies of lysophosphatidylcholine (LPC) presentation by human CD1d and its recognition by a native, LPC-specific iNKT TCR. Human CD1d presenting LPC adopts an altered conformation from that of CD1d presenting glycolipid antigens, with a shifted {alpha}1 helix resulting in an open A pocket. Binding of the iNKT TCR requires a 7-{angstrom} displacement of the LPC headgroup but stabilizes the CD1d-LPC complex in a closed conformation. The iNKT TCR CDR loop footprint onmore » CD1d-LPC is anchored by the conserved positioning of the CDR3{alpha} loop, whereas the remaining CDR loops are shifted, due in part to amino-acid differences in the CDR3{beta} and J{beta} segment used by this iNKT TCR. These findings provide insight into how lysophospholipids are presented by human CD1d molecules and how this complex is recognized by some, but not all, human iNKT cells.« less

A special repertoire of alpha:beta T cells in neonatal mice.

PubMed Central

Bogue, M; Candéias, S; Benoist, C; Mathis, D

1991-01-01

According to several functional criteria, the mature thymocytes of neonatal and adult mice are distinctly different. We wondered whether these differences in function might have a structural correlate: do neonates have a distinct repertoire of alpha:beta T cells? In this study, we have exploited the power of polymerase chain reaction technology to generate large numbers of T cell receptor sequences from sorted thymocyte populations from newborn and adult mice. The newborn-derived sequences show very few N nucleotide additions, usually the major source of diversity in T cell receptors. Most interestingly, the paucity of N insertions appears to be exaggerated by selection events that operate during T cell differentiation in the thymus. The significance of these results is largely: (i) that they parallel recent findings on the B cell repertoire in neonates, raising questions about the reactivities specified by such a special repertoire; and (ii) that they suggest a means to 'tag' T cells exported perinatally, allowing one to test the premise that autoreactive T cells derive preferentially from the newborn repertoire. Images PMID:1834457

Different susceptibility of rat pancreatic alpha and beta cells to hypoxia.

PubMed

Bloch, Konstantin; Vennäng, Julia; Lazard, Daniel; Vardi, Pnina

2012-06-01

Insulin-producing beta cells are known to be highly susceptible to hypoxia, which is a major factor in their destruction after pancreatic islet transplantation. However, whether the glucagon-producing pancreatic islet alpha cells are sensitive to hypoxia is not known. Our objective was to compare the sensitivity of alpha and beta cells to hypoxia. Isolated rat pancreatic islets were exposed to hypoxia (1% oxygen, 94% N(2), 5% CO(2)) for 3 days. The viability of the alpha and beta cells, as well as the stimulus-specific secretion of glucagon and insulin, was evaluated. A quantitative analysis of the proportion of beta to alpha cells indicated that, under normoxic conditions, islet cells were composed mainly of beta cells (87 ± 3%) with only 13 ± 3% alpha cells. Instead, hypoxia treatment significantly increased the proportion of alpha cells (40 ± 13%) and decreased the proportion of beta cells to 60 ± 13%. Using the fluorescent TUNEL assay we found that only a few percent of beta cells and alpha cells were apoptotic in normoxia. In contrast, hypoxia induced an abundance of apoptotic beta cells (61 ± 22%) and had no effect on the level of apoptosis in alpha cells. In conclusion, this study demonstrates that hypoxia results in severe functional abnormality in both beta and alpha cells while alpha cells display significantly decreased rate of apoptosis compared to intensive apoptotic injury of beta cells. These findings have implications for the understanding of the possible role of hypoxia in the pathophysiology of diabetes.

Induction of experimental bone metastasis in mice by transfection of integrin alpha 4 beta 1 into tumor cells.

PubMed Central

Matsuura, N.; Puzon-McLaughlin, W.; Irie, A.; Morikawa, Y.; Kakudo, K.; Takada, Y.

1996-01-01

Cell adhesion receptors (eg, integrins and CD44) play an important role in invasion and metastasis during tumor progression. The increase in integrin alpha 4 beta 1 expression on primary melanomas has been reported to significantly correlate with the development of metastases. alpha 4 beta 1 is a cell surface heterodimer that mediates cell-cell and cell-extracellular matrix interactions through adhesion to vascular cell adhesion molecule (VCAM)-1 and to the IIICS region of fibronectin. To test the effects of alpha 4 beta 1 expression on tumor cell metastasis, Chinese hamster ovary cells were transfected with human alpha 4 cDNA. Whereas alpha 4-negative Chinese hamster ovary cells developed only pulmonary metastasis, alpha 4-positive Chinese hamster ovary cells developed bone and pulmonary metastasis in 3 to 4 weeks when injected intravenously into nude mice. Bone metastasis was inhibited by antibody against alpha 4 or VCAM-1. Expression of alpha 3 beta 1, alpha 6 beta 1, or alpha V beta 1 did not induce bone metastasis. Expression of alpha 4 beta 1 also induced bone metastasis in K562 human erythroleukemia cells injected into SCID mice. These results demonstrate that alpha 4 beta 1 can induce tumor cell trafficking to bone, probably via interaction with VCAM-1 that is constitutively expressed on bone marrow stromal cells. Images Figure 1 Figure 3 PMID:8546226

Neomycin is a platelet-derived growth factor (PDGF) antagonist that allows discrimination of PDGF alpha- and beta-receptor signals in cells expressing both receptor types.

PubMed

Vassbotn, F S; Ostman, A; Siegbahn, A; Holmsen, H; Heldin, C H

1992-08-05

The aminoglycoside neomycin has recently been found to affect certain platelet-derived growth factor (PDGF) responses in C3H/10T1/2 C18 fibroblasts. Using porcine aortic endothelial cells transfected with PDGF alpha- or beta-receptors, we explored the possibility that neomycin interferes with the interaction between the different PDGF isoforms and their receptors. We found that neomycin (5 mM) inhibited the binding of 125I-PDGF-BB to the alpha-receptor with only partial effect on the binding of 125I-PDGF-AA; in contrast, the binding of 125I-PDGF-BB to the beta-receptor was not affected by the aminoglycoside. Scatchard analyses showed that neomycin (5 mM) decreased the number of binding sites for PDGF-BB on alpha-receptor-expressing cells by 87%. Together with cross-competition studies with 125I-labeled PDGF homodimers, the effect of neomycin indicates that PDGF-AA and PDGF-BB bind to both common and unique structures on the PDGF alpha-receptor. Neomycin specifically inhibited the autophosphorylation of the alpha-receptor by PDGF-BB, with less effect on the phosphorylation induced by PDGF-AA and no effect on the phosphorylation of the beta-receptor by PDGF-BB. Thus, neomycin is a PDGF isoform- and receptor-specific antagonist that provides a possibility to compare the signal transduction pathways of alpha- and beta-receptors in cells expressing both receptor types. This approach was used to show that activation of PDGF beta-receptors by PDGF-BB mediated a chemotactic response in human fibroblasts, whereas activation of alpha-receptors by the same ligand inhibited chemotaxis.

ADP-ribosylation of transducin by pertussis toxin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watkins, P.A.; Burns, D.L.; Kanaho, Y.

1985-11-05

Transducin, the guanyl nucleotide-binding regulatory protein of retinal rod outer segments that couples the photon receptor, rhodopsin, with the light-activated cGMP phosphodiesterase, can be resolved into two functional components, T alpha and T beta gamma. T alpha (39 kDa), which is (TSP)ADP-ribosylated by pertussis toxin and (TSP)NAD in rod outer segments and in purified transducin, was also labeled by the toxin after separation from T beta gamma (36 kDa and approximately 10 kDa); neither component of T beta gamma was a pertussis toxin substrate. Labeling of T alpha was enhanced by T beta gamma and was maximal at approximately 1:1more » molar ratio of T alpha : T beta gamma. Limited proteolysis by trypsin of T alpha in the presence of guanyl-5'-yl imidodiphosphate (Gpp(NH)p) resulted in the sequential appearance of proteins of 38 and TS kDa. The amino terminus of both 38- and TS-kDa proteins was leucine, whereas that of T alpha could not be identified and was assumed to be blocked. The TS-kDa peptide was not a pertussis toxin substrate. Labeling of the 38-kDa protein was poor and was not enhanced by T beta gamma. Trypsin treatment of (TSP)ADP-ribosyl-T alpha produced a labeled 37-38-kDa doublet followed by appearance of radioactivity at the dye front. It appears, therefore, that, although the 38-kDa protein was poor toxin substrate, it contained the ADP-ribosylation site. Without rhodopsin, labeling of T alpha (in the presence of T beta gamma) was unaffected by Gpp(NH)p, guanosine 5'-O-(thiotriphosphate) (GTP gamma S), GTP, GDP, and guanosine 5'-O-(thiodiphosphate) (GDP beta S) but was increased by ATP. When photolyzed rhodopsin and T beta gamma were present, Gpp(NH)p and GTP gamma S decreased (TSP)ADP-ribosylation by pertussis toxin. Thus, pertussis toxin-catalyzed (TSP)ADP-ribosylation of T alpha was affected by nucleotides, rhodopsin and light in addition to T beta gamma.« less

alpha-L-iduronidase, beta-D-glucuronidase, and 2-sulfo-L-iduronate 2-sulfatase: preparation and characterization of radioactive substrates from heparin.

PubMed

Hopwood, J J

1979-03-01

Radioactive disaccharide substrates for alpha-L-iduronidase, beta-D-glucuronidase, and 2-sulfo-L-iduronate 2-sulfatase have been prepared from heparin by deaminative cleavage followed by reduction with NaBT4. Six disaccharides were isolated from this reaction mixture and identified. Acid hydrolysis of the major disaccharide, O-(alpha-L-idopyranosyluronic acid 2-sulfate)-(1 linked to 4)-(2,5-anhydro-D-mannitol-l-t 6-sulfate (IdAs--Ms), produced 48% of O-(alpha-L-idopyranosyluronic acid)-(1 linked to 4)-(2,5-anhydro-D-mannitol-l-t 6-sulfate) (IdA--Ms) and 25% of O-(alpha-L-idopyranosyluronic acid)-(1 linked to 4)-2,5-anhydro-D-mannitol-l-t. The most-sensitive substrate for determining alpha-L-iduronidase activity was IdA--Ms which, when incubated with leucocyte and skin-fibroblast homogenates prepared from patients having a deficiency of alpha-L-iduronidase (Mucopolysaccharidosis Type I; MPS-I), was hydrolysed to yield 2,5-anhydro-D-mannitol-l-t 6-sulfate at a rate 50-times less than that found for normal control-preparations. Similarly, O-(beta-D-glucopyranosyluronic acid)-(1 linked to 4)-(2,5-anhydro-D-mannitol-l-t 6-sulfate) was degraded by whole-cell homogenates prepared from beta-D-glucuronidase-deficient (Mucopolysaccharidosis, Type VII) fibroblasts, to yield 2,5-anhydro-D-mannitol-l-t 5-sulfate at a rate 60-times less that that found for MPS-I and normal control-preparations. IdAs--Ms was degraded by 2-sulfo-L-iduronate 2-sulfatase at a rate more than 45-times greater than that found for O-(alpha-L-idopyranosyluronic acid 2-sulfate)-(1 linked to 4)-2,5-anhydro-D-mannitol-l-t. C-6 Sulfation of the anhydro-D-mannitol-l-t residue is an important structural determinant in the mechanism of action of both alpha-L-iduronidase and 2-sulfo-L-iduronate 2-sulfatase on disaccharide substrates.

Expression and in vitro regulation of integrins by normal human urothelial cells.

PubMed

Southgate, J; Kennedy, W; Hutton, K A; Trejdosiewicz, L K

1995-08-01

Integrins are thought to be essential adhesion receptors for the maintenance of tissue histioarchitecture. The purpose of this study was to determine integrin expression patterns in the human stratified transitional epithelium of the urinary tract (urothelium). In situ expression patterns were compared with in vitro expression, using a normal cell culture model system in which the effects of cell stratification can be studied independently of differentiation. By immunohistological criteria, the urothelia of bladder, ureter and renal pelvis expressed alpha 2 beta 1 and alpha 3 beta 1 integrins in all layers at intercellular junctions, and cytoplasmically in the lower strata. By contrast, alpha 6 beta 4 and occasionally alpha v beta 4 were expressed only by basal cells and localised to the basal lamina. These expression patterns were unaltered in specimens where an inflammatory cell infiltrate was present. In long-term cultures of normal urothelial cells maintained in a low-Ca++ serum-free medium, the monolayer cultures expressed alpha 2 beta 1, alpha 3 beta 1 and alpha 5 beta 1 integrins at intercellular junctions and in cytoplasmic inclusions, whereas alpha 6 beta 4 was distributed in a random pattern over the substratum. Increasing exogenous Ca++ concentrations induced cell stratification and desmosome formation, but not cytodifferentiation. Under these conditions, alpha 6 beta 4 became cell-, rather than substratum-associated, localising particularly to filopodia and lamellipodia. Quantitation of integrin expression by flow cytometry confirmed increased surface expression of alpha 6 beta 4 in high Ca++ media, and also of alpha 3 and alpha 5, but not alpha 2, subunits. These results suggest that alpha 2 beta 1 and alpha 3 beta 1 integrins, although differentially regulated, are mainly involved in homotypic cell-cell interactions and the maintenance of a stratified morphology, whereas alpha 6 beta 4 is the principal integrin involved in substratum adhesion.

Physical association and functional interaction between beta1 integrin and CD98 on human T lymphocytes

NASA Technical Reports Server (NTRS)

Miyamoto, Yuko J.; Mitchell, Jason S.; McIntyre, Bradley W.

2003-01-01

CD98 is a cell surface protein previously characterized as a cell activation marker, an amino acid transporter, and has recently been implicated in integrin-related functions. Integrins are cell surface proteins, important for homotypic cell aggregation, cell adhesion, and coactivation of T lymphocytes. We have previously shown that the anti-CD98 mAb 80A10, when coimmobilized with anti-CD3 mAb OKT3, is able to mediate human T cell coactivation that is inhibited by anti-beta1 integrin specific mAb 18D3. These results indicated a functional association of CD98 and beta1 integrin signaling but left open the question of a physical association. We now show the induction of homotypic aggregation through CD98 among human T cells and this aggregation was inhibited by anti-beta1 integrin mAb. Therefore, CD98-dependent lymphocyte proliferation and adhesion may involve integrins. Competitive binding assays and fluorescence colocalization analysis suggested that CD98 and beta1 integrin were physically associated. Differential extraction techniques and immunoprecipitations provided the first evidence that the alpha4beta1 integrin and CD98 are specifically associated on human T lymphocytes.

Disruption of alpha beta but not of gamma delta T cell development by overexpression of the helix-loop-helix protein Id3 in committed T cell progenitors.

PubMed Central

Blom, B; Heemskerk, M H; Verschuren, M C; van Dongen, J J; Stegmann, A P; Bakker, A Q; Couwenberg, F; Res, P C; Spits, H

1999-01-01

Enforced expression of Id3, which has the capacity to inhibit many basic helix-loop-helix (bHLH) transcription factors, in human CD34(+) hematopoietic progenitor cells that have not undergone T cell receptor (TCR) gene rearrangements inhibits development of the transduced cells into TCRalpha beta and gamma delta cells in a fetal thymic organ culture (FTOC). Here we document that overexpression of Id3, in progenitors that have initiated TCR gene rearrangements (pre-T cells), inhibits development into TCRalpha beta but not into TCRgamma delta T cells. Furthermore, Id3 impedes expression of recombination activating genes and downregulates pre-Talpha mRNA. These observations suggest possible mechanisms by which Id3 overexpression can differentially affect development of pre-T cells into TCRalpha beta and gamma delta cells. We also observed that cell surface CD4(-)CD8(-)CD3(-) cells with rearranged TCR genes developed from Id3-transduced but not from control-transduced pre-T cells in an FTOC. These cells had properties of both natural killer (NK) and pre-T cells. These findings suggest that bHLH factors are required to control T cell development after the T/NK developmental checkpoint. PMID:10329625

Islets of Langerhans in the parakeet, Psittacula krameri.

PubMed

Gupta, Y K; Kumar, S

1980-01-01

The pancreatic gland of Psittacula krameri is divisible into 4 lobes i.e. dorsal, ventral, third and splenic. The endocrine part is composed of alpha 1-, alpha 2- and beta-cells. The islets are of 4 kinds viz., alpha islets (having alpha 1- and alpha 2-cells), beta islets (having beta- and alpha 1-cells), pure beta islets (consisting of beta-cells exclusively) and mixed islets (with beta-, alpha 1- and alpha 2-cells). The distribution of alpha islets is mostly restricted to the splenic and third lobes whereas the beta islets are found in all 4 lobes. Though the alpha islets are only few in the dorsal lobe, their size is best developed in the third and dorsal lobes. Sometimes beta and alpha islets are present in very close proximity but their cells never mingle. An interesting feature was the complete absence of alpha islets from the ventral lobe.A relative abundance of alpha 2- cells in this bird seems to be associated with its comparatively higher blood glucose level and frugivorous habit. Tinctorial reactions suggest that the insulin content of the endocrine pancreas is low. There were no seasonal changes in the islet tissue of P. krameri.

Role of adapter function in oncoprotein-mediated activation of NF-kappaB. Human T-cell leukemia virus type I Tax interacts directly with IkappaB kinase gamma.

PubMed

Jin, D Y; Giordano, V; Kibler, K V; Nakano, H; Jeang, K T

1999-06-18

Mechanisms by which the human T-cell leukemia virus type I Tax oncoprotein activates NF-kappaB remain incompletely understood. Although others have described an interaction between Tax and a holo-IkappaB kinase (IKK) complex, the exact details of protein-protein contact are not fully defined. Here we show that Tax binds to neither IKK-alpha nor IKK-beta but instead complexes directly with IKK-gamma, a newly characterized component of the IKK complex. This direct interaction with IKK-gamma correlates with Tax-induced IkappaB-alpha phosphorylation and NF-kappaB activation. Thus, our findings establish IKK-gamma as a key molecule for adapting an oncoprotein-specific signaling to IKK-alpha and IKK-beta.

Overexpression of IL-7R alpha provides a competitive advantage during early T-cell development.

PubMed

Laouar, Yasmina; Crispe, I Nicholas; Flavell, Richard A

2004-03-15

Critical checkpoints controlling early thymic T-cell development and homeostasis are set by the proper signaling function of the interleukin 7 receptor (IL-7R) and the pre-T-cell antigen receptor. Although alpha beta T-cell development is observed in IL-7- and IL-7R alpha-deficient mice, the number of thymocytes is significantly reduced, implying a role for the IL-7R in controlling the size of the thymic T-cell compartment. Here, we report the overexpression of IL-7R alpha that occurs in the early T-cell compartment from AKR/J mice, animals that are highly susceptible to the spontaneous development of thymoma. Increased IL-7R alpha was revealed by surface staining, and increased IL-7R alpha mRNA was documented by using reverse transcriptase-polymerase chain reaction (RT-PCR). This resulted in increased survival of AKR/J early thymocytes, shown by the decreased frequency of TUNEL(+) (terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate [dUTP]-fluorescein nick end labeling) cells. In an in vivo thymocyte repopulation model, AKR/J thymocytes had a selective advantage over healthy thymocytes. This advantage occurred at early stages of T-cell development. Our findings support the model that overexpression of growth factor receptors can contribute to proliferation and malignancy.

The role of IL-1beta in reduced IL-7 production by stromal and epithelial cells: a model for impaired T-cell numbers in the gut during HIV-1 infection.

PubMed

Thang, P H; Ruffin, N; Brodin, D; Rethi, B; Cam, P D; Hien, N T; Lopalco, L; Vivar, N; Chiodi, F

2010-08-01

Interleukin (IL)-7 is a key cytokine in T-cell homeostasis. Stromal cells, intestinal epithelial cells and keratinocytes are known to produce this cytokine. The mechanisms and cellular factors regulating IL-7 production are still unclear. We assessed whether IL-1beta and interferon (IFN)-gamma, cytokines produced during inflammatory conditions, may impact on IL-7 production. We used human intestinal epithelial cells (DLD-1 cell line) and bone marrow stromal cells (HS27 cell line), known to produce IL-7; IL-7 production was evaluated at the mRNA and protein levels. To assess whether treatment of HS27 cells with IL-1beta and/or IFN-gamma leads to changes in the gene expression of cytokines, Toll-like receptors (TLRs) and chemokines, we analysed gene expression profiles using the whole-genome microarray Human Gene 1.0 ST. We found that IFN-gamma enhanced the expression of IL-7 mRNA (P < 0.001) in both cell lines. IL-1beta treatment led to a significant down-regulation (P < 0.001) of IL-7 mRNA expression in both cell lines. The IL-7 concentration in supernatants collected from treated DLD-1 and HS27 cell cultures reflected the trend of IL-7 mRNA levels. The gene profiles revealed dramatic changes in expression of cytokines and their receptors (IL-7/IL-7R alpha; IL-1alpha,IL-1beta/IL-1R1; IFN-gamma/IFN-gammaR1), of IFN regulatory factors (IRF-1 and 2), of TLRs and of important chemo-attractants for T cells. The microarray results were verified by additional methods. Our results are discussed in the setting of inflammation and T-cell survival in the gut compartment during HIV-1 infection where stromal and epithelial cells may produce factors that contribute to impaired IL-7 homeostasis and homing of T cells.

Immunological characterization of eristostatin and echistatin binding sites on alpha IIb beta 3 and alpha V beta 3 integrins.

PubMed Central

Marcinkiewicz, C; Rosenthal, L A; Mosser, D M; Kunicki, T J; Niewiarowski, S

1996-01-01

Two disintegrins with a high degree of amino acid sequence similarity, echistatin and eristostatin, showed a low level of interaction with Chinese hamster ovary (CHO) cells, but they bound to CHO cells transfected with alpha IIb beta 3 genes (A5 cells) and to CHO cells transfected with alpha v beta 3 genes (VNRC3 cells) in a reversible and saturable manner. Scatchard analysis revealed that eristostatin bound to 816000 sites per A5 cell (Kd 28 nM) and to 200000 sites (Kd 14 nM) per VNRC3 cell respectively. However, VNRC3 cells did not bind to immobilized eristostatin. Echistatin bound to 495000 sites (Kd 53 nM) per A5 cell and to 443000 sites (Kd 20 nM) per VNRC3 cell. As determined by flow cytometry, radiobinding assay and adhesion studies, binding of both disintegrins to A5 cells and resting platelets and binding of echistatin to VNRC3 cells resulted in the expression of ligand-induced binding sites (LIBS) on the beta 3 subunit. Eristostatin inhibited, more strongly than echistatin, the binding of three monoclonal antibodies: OPG2 (RGD motif dependent), A2A9 (alpha IIb beta 3 complex dependent) and 7E3 (alpha IIb beta 3 and alpha v beta 3 complex dependent) to A5 cells, to resting and to activated platelets and to purified alpha IIb beta 3. Experiments in which echistatin and eristostatin were used alone or in combination to inhibit the binding of 7E3 and OPG2 antibodies to resting platelets suggested that these two disintegrins bind to different but overlapping sites on alpha IIb beta 3 integrin. Monoclonal antibody LM 609 and echistatin seemed to bind to different sites on alpha v beta 3 integrin. However, echistatin inhibited binding of 7E3 antibody to VNRC3 cells and to purified alpha v beta 3 suggesting that alpha v beta 3 and alpha IIb beta 3 might share the same epitope to which both echistatin and 7E3 bind. Eristostatin had no effect in these systems, providing further evidence that it binds to a different epitope on alpha v beta 3. PMID:8760368

Intraarticular glucocorticoid treatment reduces inflammation in synovial cell infiltrations more efficiently than in synovial blood vessels.

PubMed

af Klint, Erik; Grundtman, Cecilia; Engström, Marianne; Catrina, Anca Irinel; Makrygiannakis, Dimitrios; Klareskog, Lars; Andersson, Ulf; Ulfgren, Ann-Kristin

2005-12-01

To investigate whether intraarticular (IA) glucocorticoid (GC) therapy diminishes synovial cell infiltration, vascularity, expression of proinflammatory cytokines, and adhesion molecule levels in patients with chronic arthritides. Thirty-one patients with chronic arthritides received a single IA injection of triamcinolone hexacetonide to treat active large-joint inflammation. Synovial biopsy specimens were obtained with arthroscopic guidance before and 9-15 days after injection. The presence of T lymphocytes, macrophages, intercellular adhesion molecule 1 (ICAM-1), vascular endothelial growth factor (VEGF), the pan-endothelial marker CD31, and the proinflammatory cytokines interleukin-1alpha (IL-1alpha), IL-1beta, tumor necrosis factor (TNF), and high mobility group box chromosomal protein 1 (HMGB-1) was studied by immunohistochemistry and real-time reverse transcriptase-polymerase chain reaction. IA GC treatment resulted in good clinical response in 29 of 31 joints. After therapeutic intervention, the number of synovial T lymphocytes declined, whereas the number of macrophages remained unchanged. Overall synovial protein expression of TNF, IL-1beta, extranuclear HMGB-1, VEGF, and ICAM-1 was reduced at followup tissue sampling, while no significant effects were observed regarding vascularity. In contrast, expression of IL-1alpha, VEGF, and cytoplasmic HMGB-1 protein in vascular endothelial cells was not affected. GC therapy down-regulated levels of messenger RNA encoding IL-1alpha and IL-1beta, but not TNF or HMGB-1. Synovial cell infiltration and proinflammatory cytokine expression were affected in a multifaceted manner by IA GC treatment. Marked reduction of synovial T lymphocytes, TNF, IL-1beta, extranuclear HMGB-1, ICAM-1, and VEGF occurred in association with beneficial clinical effects. Unexpectedly, macrophage infiltration and proinflammatory endothelial cytokine expression remained unchanged. These findings may reflect mechanisms controlling the transiency of clinical improvement frequently observed after IA GC injection.

Lewis type 1 antigen synthase (beta3Gal-T5) is transcriptionally regulated by homeoproteins.

PubMed

Isshiki, Soichiro; Kudo, Takashi; Nishihara, Shoko; Ikehara, Yuzuru; Togayachi, Akira; Furuya, Akiko; Shitara, Kenya; Kubota, Tetsuro; Watanabe, Masahiko; Kitajima, Masaki; Narimatsu, Hisashi

2003-09-19

The type 1 carbohydrate chain, Galbeta1-3GlcNAc, is synthesized by UDP-galactose:beta-N-acetylglucosamine beta1,3-galactosyltransferase (beta3Gal-T). Among six beta3Gal-Ts cloned to date, beta3Gal-T5 is an essential enzyme for the synthesis of type 1 chain in epithelium of digestive tracts or pancreatic tissue. It forms the type 1 structure on glycoproteins produced from such tissues. In the present study, we found that the transcriptional regulation of the beta3Gal-T5 gene is controlled by homeoproteins, i.e. members of caudal-related homeobox protein (Cdx) and hepatocyte nuclear factor (HNF) families. We found an important region (-151 to -121 from the transcription initiation site), named the beta3Gal-T5 control element (GCE), for the promoter activity. GCE contained the consensus sequences for members of the Cdx and HNF families. Mutations introduced into this sequence abolished the transcriptional activity. Four factors, Cdx1, Cdx2, HNF1alpha, and HNF1beta, could bind to GCE and transcriptionally activate the beta3Gal-T5 gene. Transcriptional regulation of the beta3Gal-T5 gene was consistent with that of members of the Cdx and HNF1 families in two in vivo systems. 1) During in vitro differentiation of Caco-2 cells, transcriptional up-regulation of beta3Gal-T5 was observed in correlation with the increase in transcripts for Cdx2 and HNF1alpha. 2) Both transcript and protein levels of beta3Gal-T5 were determined to be significantly reduced in colon cancer. This down-regulation was correlated with the decrease of Cdx1 and HNF1beta expression in cancer tissue. This is the first finding that a glycosyltransferase gene is transcriptionally regulated under the control of homeoproteins in a tissue-specific manner. beta3Gal-T5, controlled by the intestinal homeoproteins, may play an important role in the specific function of intestinal cells by modifying the carbohydrate structure of glycoproteins.

Integrin expression and integrin-mediated adhesion in vitro of human multipotent stromal cells (MSCs) to endothelial cells from various blood vessels.

PubMed

Semon, Julie A; Nagy, Lauren H; Llamas, Claire B; Tucker, H Alan; Lee, Ryang Hwa; Prockop, Darwin J

2010-07-01

Multipotent mesenchymal stromal cells (MSCs) home to damaged tissue by processes partly regulated by integrins. Integrin subunits expressed by MSCs were identified by flow cytometry (FC), immunocytochemistry (IC), and a panel of integrin-binding antibodies. In subconfluent cultures, over 80% of MSCs expressed integrin subunits beta1, beta2, and alpha3, 20%-55% expressed alpha1, alpha2, alpha4, alpha5, alpha6, and alphaV, and about 10% expressed beta3 when assayed by FC. None of the cells expressed significant levels of 13 other integrins as assayed by FC, but seven of the 13 integrins were detected by IC: beta5, alpha7, alpha8, alpha9, alpha11, alphaX, and alphaD. Expression of some integrins changed with MSC confluency: integrins beta3, alpha1, alpha3, alpha5, and alphaV increased, and alpha6 decreased. Furthermore, alpha4 was the only integrin to vary among preparations of MSCs from different donors. The results resolved some discrepancies in the literature concerning integrin expression by MSCs. We also investigated the role of specific integrins in MSC adhesion to endothelial cells (ECs) from the pulmonary artery (HPAEC), cardiac-derived microvasculature (HMVEC-C), and umbilical veins (HUVEC). In experiments with blocking antibodies to beta integrins, anti-beta5 reduced MSC adhesion to all types of ECs, anti-beta1 to both HUVEC and HPAEC, anti-beta3 to HUVEC, and anti-beta2 to HMVEC-C. With blocking antibodies to alpha integrins, anti-alphaX reduced adhesion to HPAEC and HMVEC-C, anti-alphaV to HPAEC, and both anti-alpha7 and anti-alphaD to HMVEC-C. Thus, MSCs use diverse integrins to adhere to EC from various blood vessels in vitro.

The relationships between half-life (t1/2) and mean residence time (MRT) in the two-compartment open body model.

PubMed

Sobol, Eyal; Bialer, Meir

2004-05-01

In the one-compartment model following i.v. administration the mean residence time (MRT) of a drug is always greater than its half-life (t(1/2)). However, following i.v. administration, drug plasma concentration (C) versus time (t) is best described by a two-compartment model or a two exponential equation:C=Ae(-alpha t)+Be(-beta t), where A and B are concentration unit-coefficients and alpha and beta are exponential coefficients. The relationships between t(1/2) and MRT in the two-compartment model have not been explored and it is not clear whether in this model too MRT is always greater than t(1/2). In the current paper new equations have been developed that describe the relationships between the terminal t(1/2) (or t(1/2 beta)) and MRT in the two-compartment model following administration of i.v. bolus, i.v. infusion (zero order input) and oral administration (first order input). A critical value (CV) equals to the quotient of (1-ln2) and (1-beta/alpha) (CV=(1-ln2)/(1-beta/alpha)=0.307/(1-beta/alpha)) has been derived and was compared with the fraction (f(1)) of drug elimination or AUC (AUC-area under C vs t curve) associated with the first exponential term of the two-compartment equation (f(1)=A/alpha/AUC). Following i.v. bolus, CV ranges between a minimal value of 0.307 (1-ln2) and infinity. As long as f(1)t(1/2) and vice versa, and when f(1)=CV, then MRT=t(1/2). Following i.v. infusion and oral administration the denominator of the CV equation does not change but its numerator increases to (0.307+beta T/2) (T-infusion duration) and (0.307+beta/ka) (ka-absorption rate constant), respectively. Examples of various drugs are provided. For every drug that after i.v. bolus shows two-compartment disposition kinetics the following conclusions can be drawn (a) When f(1)<0.307, then f(1)t(1/2). (b) When beta/alpha>ln2, then CV>1>f(1) and thus(,) MRT>t(1/2). (c) When ln2>beta/alpha>(ln4-1), then 1>CV>0.5 and thus, in order for t(1/2)>MRT, f(1) has to be greater than its complementary fraction f(2) (f(1)>f(2)). (d) When beta/alpha<(ln4-1), it is possible that t(1/2)>MRT even when f(2)>f(1), as long as f(1)>CV. (e) As beta gets closer to alpha, CV approaches its maximal value (infinity) and therefore, the chances of MRT>t(1/2) are growing. (f) As beta becomes smaller compared with alpha, beta/alpha approaches zero, the denominator approaches unity and consequently, CV gets its minimal value and thus, the chances of t(1/2)>MRT are growing. (g) Following zero and first order input MRT increases compared with i.v. bolus and so does CV and thus, the chances of MRT>t(1/2) are growing. Copyright 2004 John Wiley & Sons, Ltd.

Characterization of resident lymphocytes in human pancreatic islets

PubMed Central

Radenkovic, M.; Uvebrant, K.; Skog, O.; Sarmiento, L.; Avartsson, J.; Storm, P.; Vickman, P.; Bertilsson, P.‐A.; Fex, M.; Korgsgren, O.

2016-01-01

Summary The current view of type 1 diabetes (T1D) is that it is an immune‐mediated disease where lymphocytes infiltrate the pancreatic islets, promote killing of beta cells and cause overt diabetes. Although tissue resident immune cells have been demonstrated in several organs, the composition of lymphocytes in human healthy pancreatic islets have been scarcely studied. Here we aimed to investigate the phenotype of immune cells associated with human islets of non‐diabetic organ donors. A flow cytometry analysis of isolated islets from perfused pancreases (n = 38) was employed to identify alpha, beta, T, natural killer (NK) and B cells. Moreover, the expression of insulin and glucagon transcripts was evaluated by RNA sequencing. Up to 80% of the lymphocytes were CD3+ T cells with a remarkable bias towards CD8+ cells. Central memory and effector memory phenotypes dominated within the CD8+ and CD4+ T cells and most CD8+ T cells were positive for CD69 and up to 50–70% for CD103, both markers of resident memory cells. The frequency of B and NK cells was low in most islet preparations (12 and 3% of CD45+ cells, respectively), and the frequency of alpha and beta cells varied between donors and correlated clearly with insulin and glucagon mRNA expression. In conclusion, we demonstrated the predominance of canonical tissue resident memory CD8+ T cells associated with human islets. We believe that these results are important to understand more clearly the immunobiology of human islets and the disease‐related phenotypes observed in diabetes. PMID:27783386

Human dendritic cells produce TGF-beta 1 under the influence of lung carcinoma cells and prime the differentiation of CD4+CD25+Foxp3+ regulatory T cells.

PubMed

Dumitriu, Ingrid E; Dunbar, Donald R; Howie, Sarah E; Sethi, Tariq; Gregory, Christopher D

2009-03-01

Dendritic cells (DCs) have a central role in the development of adaptive immune responses, including antitumor immunity. Factors present in the tumor milieu can alter the maturation of DCs and inhibit their capacity to activate T cells. Using gene expression analysis, we found that human DCs increased the expression of TGF-beta1 transcripts following culture with human lung carcinoma cells (LCCs). These DCs produced increased amounts of TGF-beta1 protein compared with DCs not exposed to tumor cells. LCCs also decreased the expression of CD86 and HLA-DR by immature DCs. Furthermore, LCCs decreased CD86 expression and the production of TNF-alpha and IL-12 p70 by mature DCs. Moreover, LCCs also converted mature DCs into cells producing TGF-beta1. These TGF-beta1-producing DCs were poor at eliciting the activation of naive CD4(+) T cells and sustaining their proliferation and differentiation into Th1 (IFN-gamma(+)) effectors. Instead, TGF-beta1-producing DCs demonstrated an increased ability to generate CD4(+)CD25(+)Foxp3(+) regulatory T cells that suppress the proliferation of T lymphocytes. These results identify a novel mechanism by which the function of human DCs is altered by tumor cells and contributes to the evasion of the immune response.

Immunological alterations during the clinical and recovery phases of experimental swine dysentery.

PubMed

Jonasson, Robert; Andersson, Märit; Råsbäck, Therese; Johannisson, Anders; Jensen-Waern, Marianne

2006-07-01

The aim of this study was to examine changes in the systemic immune response during the incubation period and following the onset of clinical swine dysentery, including the recovery period. Ten healthy conventional pigs were inoculated with Brachyspira hyodysenteriae. Blood was sampled at pre-inoculation, at days 4 and 14 post-inoculation, during the first 4 days with clinical signs of dysentery and at days 1, 3, 7, 11 and 15 of the recovery period. Eight pigs developed haemorrhagic diarrhoea. Flow-cytometric analyses of lymphocyte subpopulations showed that all animals, including the two that remained healthy, had an increase in CD8alpha+ CD4- cells and gammadelta T cells at days 4 and 14 post-inoculation. In addition, an increase in CD4+ CD8alpha+ cells and CD8alpha+ CD8beta+ cells was observed at days 4 and 14 post-inoculation in animals that developed dysentery. During clinical signs of dysentery, the acute-phase protein serum amyloid A was increased. There was a two- to threefold increase in both neutrophils and monocytes during signs of dysentery and at the beginning of the recovery period. The numbers of CD8alpha+ CD8beta- CD4-, CD45RA- lymphocytes also increased during the dysentery period. Circulating CD21+ cells and CD21+ CD45RA- cells decreased at the end of the incubation period, during signs of dysentery and at the beginning of the recovery period. The dysentery-affected animals developed antibodies to B. hyodysenteriae-specific antigens (approximately 16 kDa and approximately 30 kDa) from the first day of recovery, and gammadelta T cells showed an increase during the recovery period. In comparison with pre-inoculation, increased numbers of monocytes, neutrophils, CD8alpha+ CD8beta- CD4- lymphocytes and CD45RA- lymphocytes were observed during clinical dysentery. Increased numbers of neutrophils, gammadelta T cells and specific antibodies were seen during the recovery period.

Beta3 subunits promote expression and nicotine-induced up-regulation of human nicotinic alpha6* nicotinic acetylcholine receptors expressed in transfected cell lines.

PubMed

Tumkosit, Prem; Kuryatov, Alexander; Luo, Jie; Lindstrom, Jon

2006-10-01

Nicotinic acetylcholine receptors (AChRs) containing alpha6 subunits are typically found at aminergic nerve endings where they play important roles in nicotine addiction and Parkinson's disease. alpha6* AChRs usually contain beta3 subunits. beta3 subunits are presumed to assemble only in the accessory subunit position within AChRs where they do not participate in forming acetylcholine binding sites. Assembly of subunits in the accessory position may be a critical final step in assembly of mature AChRs. Human alpha6 AChRs subtypes were permanently transfected into human tsA201 human embryonic kidney (HEK) cell lines. alpha6beta2beta3 and alpha6beta4beta3 cell lines were found to express much larger amounts of AChRs and were more sensitive to nicotine-induced increase in the amount of AChRs than were alpha6beta2 or alpha6beta4 cell lines. The increased sensitivity to nicotine-induced up-regulation was due not to a beta3-induced increase in affinity for nicotine but probably to a direct effect on assembly of AChR subunits. HEK cells express only a small amount of mature alpha6beta2 AChRs, but many of these subunits are on the cell surface. This contrasts with Xenopus laevis oocytes, which express a large amount of incorrectly assembled alpha6beta2 subunits that bind cholinergic ligands but form large amorphous intracellular aggregates. Monoclonal antibodies (mAbs) were made to the alpha6 and beta3 subunits to aid in the characterization of these AChRs. The alpha6 mAbs bind to epitopes C-terminal of the extracellular domain. These data demonstrate that both cell type and the accessory subunit beta3 can play important roles in alpha6* AChR expression, stability, and up-regulation by nicotine.

[Molecular mechanisms of thymocyte differentiation].

PubMed

Kuklina, E M

2003-01-01

A review of the main molecular events occurring during differentiation of T-lymphocytes in the thymus: T-cell specialization of early intrathymic precursors, formation and expression of antigen receptor, formation of antigen recognizing cell repertoire, and alpha beta/gamma beta- and CD4/CD8-commitment. The mechanisms of glucocorticoid-induced apoptosis of thymocytes and its blockade during antigen-dependent activation are considered. A special attention is paid to the analysis of intracellular signals underlying the clonal selection of thymocytes.

Meprin A and meprin {alpha} generate biologically functional IL-1{beta} from pro-IL-1{beta}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herzog, Christian; University of Arkansas for Medical Sciences, Department of Medicine, Little Rock, AR 72205; Haun, Randy S.

The present study demonstrates that both oligomeric metalloendopeptidase meprin A purified from kidney cortex and recombinant meprin {alpha} are capable of generating biologically active IL-1{beta} from its precursor pro-IL-1{beta}. Amino-acid sequencing analysis reveals that meprin A and meprin {alpha} cleave pro-IL-1{beta} at the His{sup 115}-Asp{sup 116} bond, which is one amino acid N-terminal to the caspase-1 cleavage site and five amino acids C-terminal to the meprin {beta} site. The biological activity of the pro-IL-1{beta} cleaved product produced by meprin A, determined by proliferative response of helper T-cells, was 3-fold higher to that of the IL-1{beta} product produced by meprin {beta}more » or caspase-1. In a mouse model of sepsis induced by cecal ligation puncture that results in elevated levels of serum IL-1{beta}, meprin inhibitor actinonin significantly reduces levels of serum IL-1{beta}. Meprin A and meprin {alpha} may therefore play a critical role in the production of active IL-1{beta} during inflammation and tissue injury.« less

Modulation of cardiac myocyte phenotype in vitro by the composition and orientation of the extracellular matrix.

PubMed

Simpson, D G; Terracio, L; Terracio, M; Price, R L; Turner, D C; Borg, T K

1994-10-01

Cellular phenotype is the result of a dynamic interaction between a cell's intrinsic genetic program and the morphogenetic signals that serve to modulate the extent to which that program is expressed. In the present study we have examined how morphogenetic information might be stored in the extracellular matrix (ECM) and communicated to the neonatal heart cell (NHC) by the cardiac alpha 1 beta 1 integrin molecule. A thin film of type I collagen (T1C) was prepared with a defined orientation. This was achieved by applying T1C to the peripheral edge of a 100 mm culture dish. The T1C was then drawn across the surface of the dish in a continuous stroke with a sterile cell scraper and allowed to polymerize. When NHCs were cultured on this substrate, they spread, as a population, along a common axis in parallel with the gel lattice and expressed an in vivo-like phenotype. Individual NHCs displayed an elongated, rod-like shape and disclosed parallel arrays of myofibrils. These phenotypic characteristics were maintained for at least 4 weeks in primary culture. The evolution of this tissue-like organizational pattern was dependent upon specific interactions between the NHCs and the collagen-based matrix that were mediated by the cardiac alpha 1 beta 1 integrin complex. This conclusion was supported by a variety of experimental results. Altering the tertiary structure of the matrix or blocking the extracellular domains of either the cardiac alpha 1 or beta 1 integrin chain inhibited the expression of the tissue-like pattern of organization. Neither cell-to-cell contact or contractile function were necessary to induce the formation of the rod-like cell shape. However, beating activity was necessary for the assembly of a well-differentiated myofibrillar apparatus. These data suggest that the cardiac alpha 1 beta 1 integrin complex serves to detect and transduce phenotypic information stored within the tertiary structure of the surrounding matrix.

Expression of tumour necrosis factor alpha and accumulation of fibronectin in coronary artery restenotic lesions retrieved by atherectomy.

PubMed Central

Clausell, N.; de Lima, V. C.; Molossi, S.; Liu, P.; Turley, E.; Gotlieb, A. I.; Adelman, A. G.; Rabinovitch, M.

1995-01-01

BACKGROUND--The formation of coronary artery neointima experimentally induced in piglets after cardiac transplantation is related to an immune-inflammatory reaction associated with increased expression of T cells and inflammatory mediators (tumour necrosis factor alpha and interleukin 1 beta) and upregulation of fibronectin. In vivo blockade of tumour necrosis factor alpha in rabbits after cardiac transplantation results in reduced neointimal formation. The objective of this study was to investigate the hypothesis that coronary restenosis after atherectomy or percutaneous balloon angioplasty is associated with a similar inflammatory cascade initiated by mechanical injury. METHODS--Specimens taken at coronary atherectomy were analysed from 16 patients. Nine had had the procedure performed twice, firstly, to remove a primary lesion, and secondly, to remove a restenotic lesion. Seven had percutaneous balloon angioplasty after removal of restenotic tissue. Coronary atherectomy specimens were analysed by immunohistochemistry for the presence of T cells, macrophages, major histocompatibility complex II, interleukin 1 beta, tumour necrosis factor alpha, fibronectin, and the receptor for hyaluronan mediated motility. RESULTS--The groups were clinically and angiographically similar with equivalent lumens before and after atherectomy. Restenotic lesions had increased expression of tumour necrosis factor alpha and fibronectin compared with the primary lesions (P < 0.05 for both). There was also a trend towards a greater number of T cells and increased expression of interleukin 1 beta. CONCLUSIONS--Restenosis is associated with increased expression of tumour necrosis factor alpha and fibronectin, suggesting that an immune-inflammatory reaction probably contributes to neointimal formation and may represent a form of wound healing and repair secondary to mechanical injury. Images PMID:7626352

In vitro immunomodulatory effects of cuphiin D1 on human mononuclear cells.

PubMed

Wang, Ching-Chiung; Chen, Lih-Geeng; Yang, Ling-Ling

2002-01-01

Cuphiin D1 (CD1), a macrocyclic hydrolyzable tannin isolated from Cuphea hyssopifolia, has been shown to exert antitumor activity both in vitro and in vivo. Moreover, the antitumor effects of CD1 are not only related to its cytotoxicity to carcinoma cell lines, but also depend on host-mediated mechanisms. In the present study, CD1 was investigated for its effects on the proliferation and cytokine secretion of human peripheral blood mononuclear cells (PBMCs). At concentrations of from 6.25 to 50 micrograms/ml, it enhanced the 3H-thymidine incorporation of concanavalin A (Con A)-stimulated PBMCs in a dose-dependent manner. Excretion of IL-1 beta, IL-2 and TNF-alpha by CD1-stimulated PBMCs was markedly increased in a dose-dependent manner. The results show that CD1 could stimulate PBMCs release of IL-1 beta, IL-2 and TNF-alpha and then activate T cells. Therefore, CD1-activated T cells via IL-1 beta in vitro might account for the host-mediated CD1 mechanism of action.

A kinetic comparison of the processing and secretion of the alpha beta dimer and the uncombined alpha and beta subunits of chorionic gonadotropin synthesized by human choriocarcinoma cells.

PubMed

Peters, B P; Krzesicki, R F; Hartle, R J; Perini, F; Ruddon, R W

1984-12-25

Human choriocarcinoma cells (JAR) synthesize the alpha and beta subunits of the glycoprotein hormone chorionic gonadotropin (hCG) (R.W. Ruddon, C.A. Hanson, A. H. Bryan, G.J. Putterman, E.L. White, F. Perini, K. S. Meade, and P.H. Aldenderfer (1980) J. Biol. Chem. 255, 1000-1007). In addition to the hCG dimer (alpha beta), JAR cells secrete uncombined alpha and beta subunits into the culture medium (L.A. Cole, R.J. Hartle, J.A. Laferla, and R.W. Ruddon (1983) Endocrinology 113, 1176-1178). Pulse-chase studies with [35S]methionine or [3H]mannose were carried out in order to compare free alpha, free beta, and the alpha beta dimer with regard to the kinetics of synthesis, N-linked oligosaccharide processing, and secretion and to determine the kinetics of alpha-beta subunit combination. A panel of three antisera was used to immunoprecipitate directly the free subunits and the alpha beta dimer sequentially from the same cell lysates and culture media. The alpha subunit of hCG was synthesized in a slight molar excess (1.2-1.5-fold) over the beta subunit, and alpha beta dimer was rapidly formed by combination of the intracellular alpha and beta precursors. Dimer formation was already apparent in JAR cells following a 10-min biosynthetic labeling incubation with [35S]methionine. The combination of subunits ceased by 30 min of chase even though 51% of alpha and 44% of beta remained free within the cells. Combination of the alpha and beta precursors had occurred before their N-linked oligosaccharides were processed beyond the Man8GlcNAc2 structure. The initial trimming of glucosyl and mannosyl units from the high-mannose oligosaccharides of the hCG precursors occurred more rapidly for free alpha and CG-alpha than for free beta and CG-beta. JAR cells accumulated alpha precursors bearing mostly Man8GlcNAc2 units and beta precursors bearing Man8GlcNAc2 units that represent the substrates of the rate-limiting step in the secretory pathway. In spite of the fact that their N-linked oligosaccharides were trimmed at different rates, free alpha, free beta, and alpha beta dimer were all secreted into the medium at the same rate, with a half-time of 35 min. The secreted hCG forms were stable in the chase medium between 4 and 8h, indicating that extracellular degradation, combination of free subunits to form dimer, or dissociation of dimer to form free subunits did not occur.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of alternative glycosylation on insulin receptor processing.

PubMed

Hwang, J B; Frost, S C

1999-08-06

The mature insulin receptor is a cell surface heterotetrameric glycoprotein composed of two alpha- and two beta-subunits. In 3T3-L1 adipocytes as in other cell types, the receptor is synthesized as a single polypeptide consisting of uncleaved alpha- and beta-subunits, migrating as a 190-kDa glycoprotein. To examine the importance of N-linked glycosylation on insulin receptor processing, we have used glucose deprivation as a tool to alter protein glycosylation. Western blot analysis shows that glucose deprivation led to a time-dependent accumulation of an alternative proreceptor of 170 kDa in a subcellular fraction consistent with endoplasmic reticulum localization. Co-precipitation assays provide evidence that the alternative proreceptor bound GRP78, an endoplasmic reticulum molecular chaperone. N-Glycosidase F treatment shows that the alternative proreceptor contained N-linked oligosaccharides. Yet, endoglycosidase H insensitivity indicates an aberrant oligosaccharide structure. Using pulse-chase methodology, we show that the synthetic rate was similar between the normal and alternative proreceptor. However, the normal proreceptor was processed into alpha- and beta-subunits (t((1)/(2)) = 1.3 +/- 0.6 h), while the alternative proreceptor was degraded (t((1)/(2)) = 5.1 +/- 0.6 h). Upon refeeding cells that were initially deprived of glucose, the alternative proreceptor was processed to a higher molecular weight form and gained sensitivity to endoglycosidase H. This "intermediate" form of the proreceptor was also degraded, although a small fraction escaped degradation, resulting in cleavage to the alpha- and beta-subunits. These data provide evidence for the first time that glucose deprivation leads to the accumulation of an alternative proreceptor, which can be post-translationally glycosylated with the readdition of glucose inducing both accelerated degradation and maturation.

Tocopherol and tocotrienol levels of foods consumed in Hawaii.

PubMed

Franke, Adrian A; Murphy, Suzanne P; Lacey, Rochelle; Custer, Laurie J

2007-02-07

Because of the individual biological effects and the uncertain or missing information on levels of tocopherols (T) and tocotrienols (T3) in foods frequently consumed in Hawaii, 79 food items (50 in duplicate) were analyzed for alpha-, beta-, gamma-, and delta-tocopherol (alphaT, betaT, gammaT, and deltaT) and alpha-, beta-, gamma-, and delta-tocotrienol (alphaT3, betaT3, gammaT3, and deltaT3) in addition to alpha-tocopheryl acetate (alphaTac). Foods from local markets were stored according to usual household habits, freeze-dried, homogenized, and extracted three times with hexane containing butylated hydroxytoluene as a preservative and tocol as an internal standard. A normal-phase high-pressure liquid chromatography system was applied with fluorescence and photodiode array detection that resulted in baseline separation of all eight analytes and the internal standard tocol (To). The sum of all E vitamer concentrations, or total E vitamers (TEV), in all foods analyzed ranged an average from 0.6 to 828 mg/kg (T < or = 542 mg/kg and T3 < or = 432 mg/kg) and showed the following ranges: oils, 497-828 mg/kg (mainly alphaT and gammaT); margarines, 359-457 mg/kg (mainly gammaT); salad dressings, 20-291 mg/kg (mainly gammaT, except alphaT when soy oil was the main ingredient); cookies, 54-138 mg/kg (mainly gammaT); snacks, 101-220 mg/kg (mainly gammaT); nuts, 22-201 mg/kg (mainly alphaT); vegetables, 2-152 mg/kg (mainly alphaT); pasta, 24-90 mg/kg; cereals, 4-56 mg/kg (mainly betaT3 followed by alphaT); fish, 2-39 mg/kg (mainly alphaT); fried tofu, 64 mg/kg (mainly gammaT); breads, 20-22 mg/kg (mainly betaT3); fat-free mayonnaise, 5 mg/kg (mainly alphaT); poi (fermented taro root), 2 mg/kg (mostly alphaT); and fruits, 2 (papaya) to 13 mg/kg (canned pumpkin) with alphaT predominating. Cereals fortified with alphaTac ranked third and eighth among all foods assayed regarding alphaT and TEV levels, respectively. As compared to the few data available in the literature, our values agreed with some (corn flakes, mango fruit, fat-free mayonnaise, dry-roasted macadamia nuts, dry-roasted peanuts, mixed nuts, spaghetti/marinara pasta sauce, oils, and red bell pepper) but differed for many other items. Our results provide new information on the E vitamer content in foods, emphasize the vast differences of bioactivities of individual E vitamers, and confirm the need for analyses of foods consumed in specific study populations.

Both alpha(1A)- and alpha(1B)-adrenergic receptors crosstalk to down regulate beta(1)-ARs in mouse heart: coupling to differential PTX-sensitive pathways.

PubMed

Rorabaugh, Boyd R; Gaivin, Robert J; Papay, Robert S; Shi, Ting; Simpson, Paul C; Perez, Dianne M

2005-11-01

Adrenergic receptors (ARs) play an important role in the regulation of cardiac function. Cardiac inotropy is primarily regulated by beta(1)-ARs. However, alpha(1)-ARs may play an important role in inotropy during heart failure. Previous work has suggested that the alpha(1B)-AR modulates beta(1)-AR function in the heart. The potential role of the alpha(1A)-AR has not been previously studied. We used transgenic mice that express constitutively active mutant (CAM) forms of the alpha(1A)-AR or alpha(1B)-AR regulated by their endogenous promoters. Expression of the CAM alpha(1A)-AR or CAM alpha(1B)-AR had no effect on basal cardiac function (developed pressure, +dP/dT, -dP/dT, heart rate, flow rate). However, both alpha(1)-AR subtypes significantly decreased isoproterenol-stimulated +dP/dT. Pertussis toxin had no effect on +dP/dT in CAM alpha(1A)-AR hearts but restored +dP/dT to non-transgenic values in CAM alpha(1B)-AR hearts. Radioligand binding indicated a selective decrease in the density of beta(1)-ARs in both CAM mice. However, G-proteins, cAMP, or the percentage of high and low affinity states were unchanged in either transgenic compared with control. These data demonstrate that CAM alpha(1A)- and alpha(1B)-ARs both down regulate beta(1)-AR-mediated inotropy in the mouse heart. However, alpha(1)-AR subtypes are coupled to different beta-AR mediated signaling pathways with the alpha(1B)-AR being pertussis toxin sensitive.

T1alpha/podoplanin shows raft-associated distribution in mouse lung alveolar epithelial E10 cells.

PubMed

Barth, Kathrin; Bläsche, Robert; Kasper, Michael

2010-01-01

T1alpha/(podoplanin) is abundantly expressed in the alveolar epithelial type I cells (ATI) of rodent and human lungs. Caveolin-1 is a classical primary structural protein of plasmalemal invaginations, so-called caveolae, which represent specialized lipid rafts, and which are particularly abundant in ATI cells. The biological functions of T1alpha in the alveolar epithelium are unknown. Here we report on the characteristics of raft domains in the microplicae/microvillar protrusions of ATI cells, which contain T1alpha. Detergent resistant membranes (DRMs) from cell lysates of the mouse epithelial ATI-like cell line E10 were prepared using different detergents followed by flotation in a sucrose gradient and tested by Western and dot blots with raft markers (caveolin-1, GM1) and nonraft markers (transferrin receptor, PDI and beta-Cop). Immunocytochemistry was employed for the localization of T1alpha in E10 cells and in situ in rat lungs. Our biochemical results showed that the solubility or insolubility of T1alpha and caveolin-1 differs in Triton X-100 and Lubrol WX, two distinct non-ionic detergents. Caveolin-1 was unsoluble in both detergents, whereas T1alpha was Triton X-100 soluble but Lubrol WX insoluble. Immunofluorescence double stainings revealed that both proteins were colocalized with GM1, while caveolin-1 and T1alpha were not colocalized in the plasma membrane. Cholesterol depletion modified the segregation of T1alpha in Lubrol WX DRMs. Cellular processes in ultrathin sections of cultured mouse E10 cells were immunogold positive. Immunoelectron microscopy (postembedding) of rat lung tissue revealed the preferential localization of T1alpha on apical microvillar protrusions of ATI cells. We conclude that T1alpha and caveolin-1 are located in distinct plasma membrane microdomains, which differ in their protein-lipid interactions. The raft-associated distribution of T1alpha may have an impact on a specific, not yet clarified function of this protein in the alveolar epithelium. 2010 S. Karger AG, Basel

Urocortin 3 Marks Mature Human Primary and Embryonic Stem Cell-Derived Pancreatic Alpha and Beta Cells

PubMed Central

van der Meulen, Talitha; Xie, Ruiyu; Kelly, Olivia G.; Vale, Wylie W.; Sander, Maike; Huising, Mark O.

2012-01-01

The peptide hormone Urocortin 3 (Ucn 3) is abundantly and exclusively expressed in mouse pancreatic beta cells where it regulates insulin secretion. Here we demonstrate that Ucn 3 first appears at embryonic day (E) 17.5 and, from approximately postnatal day (p) 7 and onwards throughout adult life, becomes a unifying and exclusive feature of mouse beta cells. These observations identify Ucn 3 as a potential beta cell maturation marker. To determine whether Ucn 3 is similarly restricted to beta cells in humans, we conducted comprehensive immunohistochemistry and gene expression experiments on macaque and human pancreas and sorted primary human islet cells. This revealed that Ucn 3 is not restricted to the beta cell lineage in primates, but is also expressed in alpha cells. To substantiate these findings, we analyzed human embryonic stem cell (hESC)-derived pancreatic endoderm that differentiates into mature endocrine cells upon engraftment in mice. Ucn 3 expression in hESC-derived grafts increased robustly upon differentiation into mature endocrine cells and localized to both alpha and beta cells. Collectively, these observations confirm that Ucn 3 is expressed in adult beta cells in both mouse and human and appears late in beta cell differentiation. Expression of Pdx1, Nkx6.1 and PC1/3 in hESC-derived Ucn 3+ beta cells supports this. However, the expression of Ucn 3 in primary and hESC-derived alpha cells demonstrates that human Ucn 3 is not exclusive to the beta cell lineage but is a general marker for both the alpha and beta cell lineages. Ucn 3+ hESC-derived alpha cells do not express Nkx6.1, Pdx1 or PC1/3 in agreement with the presence of a separate population of Ucn 3+ alpha cells. Our study highlights important species differences in Ucn 3 expression, which have implications for its utility as a marker to identify mature beta cells in (re)programming strategies. PMID:23251699

Proliferation of Estrogen Receptor alpha Positive Mammary Epithelial Cells is Restrained by TGFbeta1 in Adult Mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ewan, Kenneth B.R.; Oketch-Rabah, Hellen A.; Ravani, Shraddha A.

2005-03-03

Transforming growth factor {beta}1 (TGF{beta}1) is a potent inhibitor of mammary epithelial proliferation. In human breast, estrogen receptor {alpha} (ER{alpha}) cells rarely co-localize with markers of proliferation, but their increased frequency correlates with breast cancer risk. To determine whether TGF{beta}1 is necessary for the quiescence of ER{alpha}-positive population, we examined mouse mammary epithelial gland at estrus. Approximately 35% of cells showed TGF{beta}1 activation, which co-localized with nuclear receptor-phosphorylated Smad 2/3, indicating that TGF{beta} signaling is autocrine. Furthermore, nuclear Smad co-localized with nuclear ER{alpha}. To test whether TGF{beta} was functional, we examined genetically engineered mice with different levels of TGF{beta}1. ER{alpha}more » co-localization with markers of proliferation (i.e. Ki-67 or BrdU) at estrus was significantly increased in the mammary glands of Tgf{beta}1 C57/bl/129SV heterozygote mice. This relationship was maintained following pregnancy, but was absent at puberty. Conversely, mammary epithelial expression of constitutively active TGF{beta}1 via the MMTV promoter suppressed proliferation of ER{alpha} positive cells. Thus, TGF{beta}1 activation functionally restrains ER{alpha} positive cells from proliferating in adult mammary gland. Accordingly, we propose that TGF{beta}1 dysregulation may promote proliferation of ER{alpha} positive cells associated with breast cancer risk in humans.« less

A structural basis for antigen recognition by the T cell-like lymphocytes of sea lamprey

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deng, Lu; Velikovsky, C. Alejandro; Xu, Gang

Adaptive immunity in jawless vertebrates is mediated by leucine-rich repeat proteins called 'variable lymphocyte receptors' (VLRs). Two types of VLR (A and B) are expressed by mutually exclusive lymphocyte populations in lamprey. VLRB lymphocytes resemble the B cells of jawed vertebrates; VLRA lymphocytes are similar to T cells. We determined the structure of a high-affinity VLRA isolated from lamprey immunized with hen egg white lysozyme (HEL) in unbound and antigen-bound forms. The VLRA-HEL complex demonstrates that certain VLRAs, like {gamma}{delta} T-cell receptors (TCRs) but unlike {alpha}{beta} TCRs, can recognize antigens directly, without a requirement for processing or antigen-presenting molecules. Thus,more » these VLRAs feature the nanomolar affinities of antibodies, the direct recognition of unprocessed antigens of both antibodies and {gamma}{delta} TCRs, and the exclusive expression on the lymphocyte surface that is unique to {alpha}{beta} and {gamma}{delta} TCRs.« less

Effects of alpha/beta-androstenediol immune regulating hormones on bone remodeling and apoptosis in osteoblasts.

PubMed

Urban, Nicole H; Chamberlin, Brett; Ramage, Samuel; Roberts, Zachary; Loria, Roger M; Beckman, Matthew J

2008-06-01

A large body of evidence suggests that the immune system directly impacts bone physiology. We tested whether immune regulating hormones (IRH), 17beta-androstenediol (beta-AED), 7beta,17beta-androstenetriol (beta-AET) or the 17alpha-androstenediol (alpha-AED), and 7alpha,17beta-androstenetriol (alpha-AET) metabolites could directly influence bone remodeling in vitro using human fetal osteoblasts (FOB-9). The impact on bone remodeling was examined by comparing the ratio of RANKL/OPG gene expression in response to AED and AET compounds. The alpha-AED was found to significantly increase in the ratio of RANKL/OPG gene expression and altering the morphology of RANKL stained FOB-9 cells. Cell viability was assessed using a Live/Dead assay. Again alpha-AED was unique in its ability to reduce the proportion of viable cells, and to induce mild apoptosis of FOB-9 cells. Treatment of FOB-9 cells with WY14643, an activator of PPAR-alpha and -gamma, also significantly elevated the percentage of dead cells. This increase was abolished by co-treatment with GW9962, a specific inhibitor of PPAR-gamma. Analysis of PPAR-gamma mRNA by Quantitative RT-PCR and its activation by DNA binding demonstrated that alpha-AED increased PPAR-gamma activation by 19%, while beta-AED conferred a 37% decrease in PPAR-gamma activation. In conclusion, alpha-AED opposed beta-AED by elevating a bone resorption scenario in osteoblast cells. The increase in RANKL/OPG is modulated by an activation of PPAR-gamma that in turn caused mild apoptosis of FOB-9 cells.

Sorting of tropomyosin isoforms in synchronised NIH 3T3 fibroblasts: evidence for distinct microfilament populations.

PubMed

Percival, J M; Thomas, G; Cock, T A; Gardiner, E M; Jeffrey, P L; Lin, J J; Weinberger, R P; Gunning, P

2000-11-01

The nonmuscle actin cytoskeleton consists of multiple networks of actin microfilaments. Many of these filament systems are bound by the actin-binding protein tropomyosin (Tm). We investigated whether Tm isoforms could be cell cycle regulated during G0 and G1 phases of the cell cycle in synchronised NIH 3T3 fibroblasts. Using Tm isoform-specific antibodies, we investigated protein expression levels of specific Tms in G0 and G1 phases and whether co-expressed isoforms could be sorted into different compartments. Protein levels of Tms 1, 2, 5a, 6, from the alpha Tm(fast) and beta-Tm genes increased approximately 2-fold during mid-late G1. Tm 3 levels did not change appreciably during G1 progression. In contrast, Tm 5NM gene isoform levels (Tm 5NM-1-11) increased 2-fold at 5 h into G1 and this increase was maintained for the following 3 h. However, Tm 5NM-1 and -2 levels decreased by a factor of three during this time. Comparison of the staining of the antibodies CG3 (detects all Tm 5NM gene products), WS5/9d (detects only two Tms from the Tm 5NM gene, Tm 5NM-1 and -2) and alpha(f)9d (detects specific Tms from the alpha Tm(fast) and beta-Tm genes) antibodies revealed 3 spatially distinct microfilament systems. Tm isoforms detected by alpha(f)9d were dramatically sorted from isoforms from the Tm 5NM gene detected by CG3. Tm 5NM-1 and Tm 5NM-2 were not incorporated into stress fibres, unlike other Tm 5NM isoforms, and marked a discrete, punctate, and highly polarised compartment in NIH 3T3 fibroblasts. All microfilament systems, excluding that detected by the WS5/9d antibody, were observed to coalign into parallel stress fibres at 8 h into G1. However, Tms detected by the CG3 and alpha(f)9d antibodies were incorporated into filaments at different times indicating distinct temporal control mechanisms. Microfilaments in NIH 3T3 cells containing Tm 5NM isoforms were more resistant to cytochalasin D-mediated actin depolymerisation than filaments containing isoforms from the alpha Tm(fast) and beta-Tm genes. This suggests that Tm 5NM isoforms may be in different microfilaments to alpha Tm(fast) and beta-Tm isoforms even when present in the same stress fibre. Staining of primary mouse fibroblasts showed identical Tm sorting patterns to those seen in cultured NIH 3T3 cells. Furthermore, we demonstrate that sorting of Tms is not restricted to cultured cells and can be observed in human columnar epithelial cells in vivo. We conclude that the expression and localisation of Tm isoforms are differentially regulated in G0 and G1 phase of the cell cycle. Tms mark multiple microfilament compartments with restricted tropomyosin composition. The creation of distinct microfilament compartments by differential sorting of Tm isoforms is observable in primary fibroblasts, cultured 3T3 cells and epithelial cells in vivo. Copyright 2000 Wiley-Liss, Inc.

Immune alterations in male and female mice after 2-deoxy-D-glucose administration

NASA Technical Reports Server (NTRS)

Dreau, D.; Morton, D. S.; Foster, M.; Swiggett, J. P.; Sonnenfeld, G.

1997-01-01

Administration of 2-deoxy-D-glucose (2-DG) induces acute cellular glucoprivation. In the current study, we examined differences in immune parameters after 2-DG administration in both sexes. Male and female BDF1 mice were injected three times, 48 h apart, either with a saline solution (control group) or with 2-DG in saline (500 mg/kg). Two hours after the last injection, blood and spleens were collected. Plasma levels of interleukin-1beta, and interferon-gamma levels were measured. Additionally, the levels of the specific leukocyte antigens CD3, CD4, CD8, T cell receptor (TCR) alpha/beta, I-Ad, and H-2Ld/H-2Db were evaluated by flow cytometry on both blood and spleen cells. The blastogenic response of leukocytes from both tissues to mitogens was assessed. Levels of glucose, corticosterone, testosterone, progesterone, 17beta-estradiol, follicle-stimulating hormone, and luteinizing hormone were also determined. Increases in the percentage of cells bearing TCR alpha/beta and I-Ad in the blood and H-2Ld/H-2Db in the spleen were observed in the 2-DG-treated group for both sexes. In contrast, higher corticosterone and IL-1beta plasma concentrations, as well as higher percentages of splenocytes bearing TCR alpha/beta and I-Ad, and lower mitogen-induced proliferation of mature T splenocytes (79%) were observed in female but not in male mice injected with 2-DG compared with those injected with saline (p < 0.05). Taken together, these results suggest that female mice are more sensitive than male mice to immune alterations induced by 2-DG administration.

Expression of {beta}{sub 1} integrins in human endometrial stromal and decidual cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shiokawa, Shigetatsu; Yoshimura, Yasunori; Nakamura, Yukio

The present study was undertaken to investigate the expression of {beta}{sub 1} integrins in human endometrium and decidua using flow cytometry, immunohistochemistry, and immunoprecipitation. Fluorescence-activated flow cytometry demonstrated the greater expression of the {beta}{sub 1}, {alpha}{sub 1}, {alpha}{sub 2}, and {alpha}{sub 5} subunits of the {beta}{sub 1} integrin family in cultured stromal cells from the midsecretory phase, than in those of the early proliferative phase. The addition of estradiol (E{sub 2}) and progesterone (P) to cultured stromal cells in the early proliferative phase increased the expression of {beta}{sub 1} integrins in vitro. Flow cytometry also demonstrated the expression of themore » {beta}{sub 1}, {alpha}{sub 1}, {alpha}{sub 2}, {alpha}{sub 3}, {alpha}{sub 5}, and {alpha}{sub 6} subunits of {beta}{sub 1} integrin family in cultured decidual cells, and the enriched-fraction of prolactin (PRL)-producing decidual cells isolated by Percoll gradients showed high levels of {beta}{sub 1} integrins expression. Immunohistochemistry confirmed the {beta}{sub 1} integrin cell surface phenotypes in cultured decidual cells observed by flow cytometry. In summary, the present study demonstrated that endometrial stromal and decidual cells expressed {beta}{sub 1} integrin subunits at their surfaces. The expression exhibited a variability throughout the menstrual cycles, being predominantly detected in the secretory phase, and was maintained highly in the decidua. Thus, {beta}{sub 1} integrins in human endometrium and decidua may be important in mediating the organization of extracellular matrix proteins derived from embryos during the early stage of implantation. 43 refs., 7 figs., 2 tabs.« less

Spontaneous quaternary and tertiary T-R transitions of human hemoglobin in molecular dynamics simulation.

PubMed

Hub, Jochen S; Kubitzki, Marcus B; de Groot, Bert L

2010-05-06

We present molecular dynamics simulations of unliganded human hemoglobin (Hb) A under physiological conditions, starting from the R, R2, and T state. The simulations were carried out with protonated and deprotonated HC3 histidines His(beta)146, and they sum up to a total length of 5.6 micros. We observe spontaneous and reproducible T-->R quaternary transitions of the Hb tetramer and tertiary transitions of the alpha and beta subunits, as detected from principal component projections, from an RMSD measure, and from rigid body rotation analysis. The simulations reveal a marked asymmetry between the alpha and beta subunits. Using the mutual information as correlation measure, we find that the beta subunits are substantially more strongly linked to the quaternary transition than the alpha subunits. In addition, the tertiary populations of the alpha and beta subunits differ substantially, with the beta subunits showing a tendency towards R, and the alpha subunits showing a tendency towards T. Based on the simulation results, we present a transition pathway for coupled quaternary and tertiary transitions between the R and T conformations of Hb.

Modulation of Mycoplasma arthritidis-derived superantigen-induced cytokine gene expression by dexamethasone and interleukin-4.

PubMed

Mehindate, K; al-Daccak, R; Rink, L; Mecheri, S; Hébert, J; Mourad, W

1994-11-01

Activation of human monocytes or monocytic cell lines with all known stimuli coordinately induces the gene expression of various cytokines, including tumor necrosis factor alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and the IL-1 receptor antagonist (IL-1Ra). In contrast, superantigens induce TNF-alpha and IL-1 beta but fail to affect IL-1Ra gene expression, suggesting that activation of monocytes via major histocompatibility complex class II is distinct from other signal transduction pathways. In the present study, we analyzed the regulation of the Mycoplasma arthritidis-derived superantigen (MAM)-induced IL-1 beta and TNF-alpha gene expression by studying the effects of two different anti-inflammatory agents: dexamethasone (DEX) and the T-cell-derived cytokine IL-4. Both agents contributed to the downregulation of MAM-induced IL-1 beta and TNF-alpha gene expression. They accelerated the normal decline of the gene expression of both MAM-induced cytokines by decreasing the stability of mRNAs via the induction or enhanced synthesis of one or more regulatory proteins. In addition, IL-4, but not DEX, induced a strong and rapid expression of IL-1Ra mRNA in MAM-stimulated and unstimulated THP-1 cells in a de novo protein synthesis-independent manner. The capacity of IL-4 to induce IL-1Ra gene expression reinforces its anti-inflammatory activity. This study illustrates some of the mechanisms by which MAM-induced proinflammatory monokine gene expression can be downregulated by IL-4 and DEX.

Expression of S100 beta in sensory and secretory cells of the vertebrate inner ear

NASA Technical Reports Server (NTRS)

Fermin, C. D.; Martin, D. S.

1995-01-01

We evaluated anti-S100 beta expression in the chick (Gallus domesticus) inner ear and determined that: 1) the monomer anti-S100 beta is expressed differentially in the vestibular and auditory perikarya; 2) expression of S100 beta in the afferent nerve terminals is time-related to synapse and myelin formation; 3) the expression of the dimer anti-S100 alpha alpha beta beta and monomer anti-S100 beta overlaps in most inner ear cell types. Most S100 alpha alpha beta beta positive cells express S100 beta, but S100 beta positive cells do not always express S100 alpha alpha beta beta. 4) the expression of S100 beta is diffused over the perikaryal cytoplasm and nuclei of the acoustic ganglia but is concentrated over the nuclei of the vestibular perikarya. 6) S100 beta is expressed in secretory cells, and it is co-localized with GABA in sensory cells. 7) Color thresholding objective quantitation indicates that the amount of S100 beta was higher (mean 22, SD +/- 4) at E19 than at E9 (mean 34, SD +/- 3) in afferent axons. 8) Moreover, S100 beta was unchanged between E11-E19 in the perikaryal cytoplasm, but did change over the nuclei. At E9, 74%, and at E21, 5% of vestibular perikarya were positive. The data suggest that S100 beta may be physically associated with neuronal and ionic controlling cells of the vertebrate inner ear, where it could provide a dual ionic and neurotrophic modulatory function.

Anchorage mediated by integrin alpha6beta4 to laminin 5 (epiligrin) regulates tyrosine phosphorylation of a membrane-associated 80-kD protein

PubMed Central

1996-01-01

Detachment of basal keratinocytes from basement membrane signals a differentiation cascade. Two integrin receptors alpha6beta4 and alpha3beta1 mediate adhesion to laminin 5 (epiligrin), a major extracellular matrix protein in the basement membrane of epidermis. By establishing a low temperature adhesion system at 4 degrees C, we were able to examine the exclusive role of alpha6beta4 in adhesion of human foreskin keratinocyte (HFK) and the colon carcinoma cell LS123. We identified a novel 80-kD membrane-associated protein (p80) that is tyrosine phosphorylated in response to dissociation of alpha6beta4 from laminin 5. The specificity of p80 phosphorylation for laminin 5 and alpha6beta4 was illustrated by the lack of regulation of p80 phosphorylation on collagen, fibronectin, or poly-L-lysine surfaces. We showed that blocking of alpha3beta1 function using inhibitory mAbs, low temperature, or cytochalasin D diminished tyrosine phosphorylation of focal adhesion kinase but not p80 phosphorylation. Therefore, under our assay conditions, p80 phosphorylation is regulated by alpha6beta4, while motility via alpha3beta1 causes phosphorylation of focal adhesion kinase. Consistent with a linkage between p80 dephosphorylation and alpha6beta4 anchorage to laminin 5, we found that phosphatase inhibitor sodium vanadate, which blocked the p80 dephosphorylation, prevented the alpha6beta4-dependent cell anchorage to laminin 5 at 4degreesC. In contrast, adhesion at 37 degrees C via alpha3beta1 was unaffected. Furthermore, by in vitro kinase assay, we identified a kinase activity for p80 phosphorylation in suspended HFKs but not in attached cells. The kinase activity, alpha6beta4, and its associated adhesion structure stable anchoring contacts were all cofractionated in the Triton- insoluble cell fraction that lacks alpha3beta1. Thus, regulation of p80 phosphorylation, through the activities of p80 kinase and phosphatase, correlates with alpha6beta4-SAC anchorage to laminin 5 at 4 degrees C in epithelial cells of the skin and intestine. Transmembrane signaling through p80 is an early tyrosine phosphorylation event responsive to and possibly required for anchorage to laminin 5 by HFK and LS123 epithelial cells. PMID:8647901

The VP35 protein of Ebola virus impairs dendritic cell maturation induced by virus and lipopolysaccharide.

PubMed

Jin, Huali; Yan, Zhipeng; Prabhakar, Bellur S; Feng, Zongdi; Ma, Yijie; Verpooten, Dustin; Ganesh, Balaji; He, Bin

2010-02-01

Ebola virus causes rapidly progressive haemorrhagic fever, which is associated with severe immuosuppression. In infected dendritic cells (DCs), Ebola virus replicates efficiently and inhibits DC maturation without inducing cytokine expression, leading to impaired T-cell proliferation. However, the underlying mechanism remains unclear. In this study, we report that Ebola virus VP35 impairs the maturation of mouse DCs. When expressed in mouse immature DCs, Ebola virus VP35 prevents virus-stimulated expression of CD40, CD80, CD86 and major histocompatibility complex class II. Further, it suppresses the induction of cytokines such as interleukin (IL)-6, IL-12, tumour necrosis factor alpha and alpha/beta interferon (IFN-alpha/beta). Notably, Ebola VP35 attenuates the ability of DCs to stimulate the activation of CD4(+) T cells. Addition of type I IFN to mouse DCs only partially reverses the inhibitory effects of VP35. Moreover, VP35 perturbs mouse DC functions induced by lipopolysaccharide, an agonist of Toll-like receptor 4. Deletion of the amino terminus abolishes its activity, whereas a mutation in the RNA binding motif has no effect. Our work highlights a critical role of VP35 in viral interference in DC function with resultant deficiency in T-cell function, which may contribute to the profound virulence of Ebola virus infection.

Expression of cutaneous lymphocyte-associated antigen (CLA) in tonsillar T-cells and its induction by in vitro stimulation with alpha-streptococci in patients with pustulosis palmaris et plantaris (PPP).

PubMed

Nozawa, Hayabusa; Kishibe, Kan; Takahara, Miki; Harabuchi, Yasuaki

2005-07-01

Pustulosis palmaris et plantaris (PPP) is known to be a one of the tonsil-related diseases because tonsillectomy is quite effective in curing this condition. However etiological association between tonsils and PPP have not fully clarified yet. Cutaneous lymphocyte-associated antigen (CLA) is known to be a specific homing receptor that facilitates T-cell migration into skin. In this study, we investigated the expression of CLA on T-cells in tonsil, peripheral blood, and skin from patients with PPP. Two-color flow cytometric and two-color immunohistological analyses revealed that the numbers of CLA/CD3 double-positive cells in freshly isolated tonsillar mononuclear cells (TMC) and in tonsillar tissues were significantly higher in patients with PPP than in patients without PPP (P<0.01, each). In vitro stimulus with alpha-streptococcal antigens enhanced CLA expression of tonsillar T-cells and TGF-beta production of TMC in patients with PPP (P<0.01, each), but did not in patients without PPP. In peripheral blood from PPP patients, the number of the CLA/CD3 double-positive cells significantly decreased at 6 months after tonsillectomy (P<0.05). The CLA/CD3 double-positive cells and the postcapillary venule that expressed with a ligand of CLA, E-selectin, were found more frequently in the plantar skin from patients with PPP as compared to that from healthy volunteers (P<0.01, each). These data suggest that a novel immune response to alpha-streptococci may enhance CLA expression on tonsillar T-cells through TGF-beta production in patients with PPP, resulting in moving of CLA-positive tonsillar T-cells to skin and tissue damages. This may play a key role in pathogenesis of PPP.

Contrasting effects of TGF-beta 1 and TNF-alpha on the development of dendritic cells from progenitors in mouse bone marrow.

PubMed

Yamaguchi, Y; Tsumura, H; Miwa, M; Inaba, K

1997-01-01

Dendritic cells (DC) are a distinct population of leukocytes and specialized antigen-presenting cells for T cell responses. Prior work has shown that GM-CSF can induce the development of large numbers of DC from proliferating progenitors in mouse bone marrow. We have monitored the effects of potentially enhancing and suppressive cytokines in these cultures. In this system, many immature DC develop from proliferating precursors during the first six days of culture, and between days 6-8 maturation of typical nonadherent and nonreplicating DC takes place. The maturation is accompanied by a large increase in the expression of major histocompatibilities complex class II (MHC II) and B7-2/CD86, and in mixed leukocyte reaction stimulating activity. Tumor necrosis factor-alpha (TNF-alpha), previously shown to be required for development of human DC, was found to enhance the maturation of mouse DC in the last two days of culture. Transforming growth factor-beta 1 (TGF-beta 1), on the other hand, almost totally blocked DC maturation, but it had to be given in the first six days of culture when the DC were actively proliferating. TGF-beta 1 did not block the production of immature, MHC II-positive but B7-2/CD86-negative DC. Maturation would take place between days 6-8 as long as the cultures were depleted of Fc-receptor-bearing cells, or if TNF-alpha were added. In both instances, maturation was not blocked even when TGF-beta 1 remained in the culture. We conclude that the development of DC, in response to GM-CSF, can be modified by other cytokines. TGF-beta 1 is suppressive but only indirectly via Fc-receptor-bearing suppressive cells, presumably suppressive macrophages, while TNF-alpha enhances the final maturation of DC.

Induction of an interleukin-1 receptor (IL-1R) on monocytic cells. Evidence that the receptor is not encoded by a T cell-type IL-1R mRNA.

PubMed

Spriggs, M K; Lioubin, P J; Slack, J; Dower, S K; Jonas, U; Cosman, D; Sims, J E; Bauer, J

1990-12-25

Primary human monocytes and the human monocytic cell line THP-1 were induced to express receptors for interleukin-1 alpha (IL-1 alpha) and IL-1 beta. Treatment of primary monocytes with dexamethasone resulted in a 10-fold increase in receptor number over untreated cells, to approximately 2,000 receptors/cell. Treatment of THP-1 cells with phorbol ester followed by prostaglandin E2 and dexamethasone resulted in the expression of approximately 30,000 receptors/cell. Competitive binding assays on THP-1 cells showed that both IL-1 alpha and IL-1 beta bind to the same receptor. The monocyte IL-1R is significantly smaller (63 kDa) than the T cell IL-1R (80 kDa) and is immunologically distinct. However, induction of monocytes and monocytic cell lines leads to the appearance of an abundant mRNA of approximately 5,000 bases which hybridizes to a cDNA probe from the T cell-type IL-1R. Sequence data obtained from a cDNA clone of this mRNA indicate that the message is identical to the T cell IL-1R mRNA throughout the coding region. A smaller mRNA, also homologous to the T cell IL-1R mRNA, accumulated in induced THP-1 cells and has a shorter 3'-untranslated region than the larger. Data are presented which suggest that neither form of this message encodes the 63-kDa IL-1R, but rather that this protein is the product of a separate nonhomologous mRNA.

Heterodimerization with beta2-adrenergic receptors promotes surface expression and functional activity of alpha1D-adrenergic receptors.

PubMed

Uberti, Michelle A; Hague, Chris; Oller, Heide; Minneman, Kenneth P; Hall, Randy A

2005-04-01

The alpha1D-adrenergic receptor (alpha1D-AR) is a G protein-coupled receptor (GPCR) that is poorly trafficked to the cell surface and largely nonfunctional when heterologously expressed by itself in a variety of cell types. We screened a library of approximately 30 other group I GPCRs in a quantitative luminometer assay for the ability to promote alpha1D-AR cell surface expression. Strikingly, these screens revealed only two receptors capable of inducing robust increases in the amount of alpha1D-AR at the cell surface: alpha1B-AR and beta2-AR. Confocal imaging confirmed that coexpression with beta2-AR resulted in translocation of alpha1D-AR from intracellular sites to the plasma membrane. Additionally, coimmunoprecipitation studies demonstrated that alpha1D-AR and beta2-AR specifically interact to form heterodimers when coexpressed in HEK-293 cells. Ligand binding studies revealed an increase in total alpha1D-AR binding sites upon coexpression with beta2-AR, but no apparent effect on the pharmacological properties of the receptors. In functional studies, coexpression with beta2-AR significantly enhanced the coupling of alpha1D-AR to norepinephrine-stimulated Ca2+ mobilization. Heterodimerization of beta2-AR with alpha1D-AR also conferred the ability of alpha1D-AR to cointernalize upon beta2-AR agonist stimulation, revealing a novel mechanism by which these different adrenergic receptor subtypes may regulate each other's activity. These findings demonstrate that the selective association of alpha1D-AR with other receptors is crucial for receptor surface expression and function and also shed light on a novel mechanism of cross talk between alpha1- and beta2-ARs that is mediated through heterodimerization and cross-internalization.

Construction and characterization of the hetero-oligomer of the group II chaperonin from the hyperthermophilic archaeon, Thermococcus sp. strain KS-1.

PubMed

Sahlan, Muhamad; Kanzaki, Taro; Yohda, Masafumi

2009-05-01

The hyperthermophilic archaeon Thermococcus sp. strain KS-1 (T. KS-1) expresses two different chaperonin subunits, alpha and beta, for the folding of its proteins. The composition of the subunits in the hexadecameric double ring changes with temperature. The content of the beta subunit significantly increases according to the increase in temperature. The homo-oligomer of the beta subunit, Cpn beta, is more thermostable than that of the alpha subunit, Cpn alpha. Since Cpn alpha and Cpn beta also have different protein folding activities and interactions with prefoldin, the hetero-oligomer is thought to exhibit different characteristics according to the content of subunits. The hetero-oligomer of the T. KS-1 chaperonin has not been studied, however, because the alpha and beta subunits form hetero-oligomers of varying compositions when they are expressed simultaneously. In this study, we characterized the T. KS-1 chaperonin hetero-oligomer, Cpn alphabeta, containing both alpha and beta in the alternate order, which was constructed by the expression of alpha and beta subunits in a coordinated fashion and protease digestion. Cpn alphabeta protected citrate synthase from thermal aggregation, promoted the folding of acid-denatured GFP in an ATP-dependent manner, and exhibited an ATP-dependent conformational change. The yield of refolded GFP generated by Cpn alphabeta was almost equivalent to that generated by Cpn beta but lower than that generated by Cpn alpha. In contrast, Cpn alphabeta exhibited almost the same level of thermal stability as Cpn alpha, which was lower than that of Cpn beta. The affinity of Cpn alphabeta to prefoldin was found to be between those of Cpn alpha and Cpn beta, as expected.

The emergence of non-cytolytic NK1.1+ T cells in the long-term culture of murine tumour-infiltrating lymphocytes: a possible role of transforming growth factor-beta.

PubMed

Tamada, K; Harada, M; Ito, O; Takenoyama, M; Mori, T; Matsuzaki, G; Nomoto, K

1996-12-01

The mechanism by which murine tumour-infiltrating lymphocytes (TIL) decreased their anti-tumour activity during an in vitro culture with interleukin-2 (IL-2) was investigated. A phenotype analysis revealed that the TIL cultured for 7 days (TIL-d7) were exclusively NKI.1- CD4- CD8+ CD3+ cells and that this population was replaced by natural killer (NK)1.1+ CD4- CD8 CD3+ cells by day 27 (TIL-d27) during the culture of TIL. The TIL-d7 cells showed a cytolytic activity against B16 melanoma, whereas the TIL-d27 cells had lost this activity, suggesting that the decrease in the anti tumour effect of TIL during the culture with IL-2 was due to their populational change. Analysis on the characteristics of the TIL-d27 cells revealed that they expressed skewed T-cell receptor (TCR) V beta 5 and increased mRNA expression of V alpha 14. In addition, they expressed transforming growth factor beta (TGF-beta) mRNA. Interestingly, TGF-beta augmented the proliferation of TIL-d27 cells under the presence of IL-2, but suppressed that of TIL-d7 cells. Moreover, the proliferation of TIL-d27 cells was suppressed by anti-TGF-beta monoclonal antibody. Collectively, these results suggest that, in contrast to its suppressive effect on anti-tumour effector T cells. TGF-beta could be an autocrine growth factor for NKL1.1+ T cells and thereby induce non-cytolytic NK1.1+ T cells in the long-term culture of TIL.

The emergence of non-cytolytic NK1.1+ T cells in the long-term culture of murine tumour-infiltrating lymphocytes: a possible role of transforming growth factor-beta.

PubMed Central

Tamada, K; Harada, M; Ito, O; Takenoyama, M; Mori, T; Matsuzaki, G; Nomoto, K

1996-01-01

The mechanism by which murine tumour-infiltrating lymphocytes (TIL) decreased their anti-tumour activity during an in vitro culture with interleukin-2 (IL-2) was investigated. A phenotype analysis revealed that the TIL cultured for 7 days (TIL-d7) were exclusively NKI.1- CD4- CD8+ CD3+ cells and that this population was replaced by natural killer (NK)1.1+ CD4- CD8 CD3+ cells by day 27 (TIL-d27) during the culture of TIL. The TIL-d7 cells showed a cytolytic activity against B16 melanoma, whereas the TIL-d27 cells had lost this activity, suggesting that the decrease in the anti tumour effect of TIL during the culture with IL-2 was due to their populational change. Analysis on the characteristics of the TIL-d27 cells revealed that they expressed skewed T-cell receptor (TCR) V beta 5 and increased mRNA expression of V alpha 14. In addition, they expressed transforming growth factor beta (TGF-beta) mRNA. Interestingly, TGF-beta augmented the proliferation of TIL-d27 cells under the presence of IL-2, but suppressed that of TIL-d7 cells. Moreover, the proliferation of TIL-d27 cells was suppressed by anti-TGF-beta monoclonal antibody. Collectively, these results suggest that, in contrast to its suppressive effect on anti-tumour effector T cells. TGF-beta could be an autocrine growth factor for NKL1.1+ T cells and thereby induce non-cytolytic NK1.1+ T cells in the long-term culture of TIL. Images Figure 4 Figure 6 PMID:9014832

A recombinant tail-less integrin beta 4 subunit disrupts hemidesmosomes, but does not suppress alpha 6 beta 4-mediated cell adhesion to laminins

PubMed Central

1995-01-01

To examine the function of the alpha 6 beta 4 integrin we have determined its ligand-binding ability and overexpressed two potentially dominant negative mutant beta 4 subunits, lacking either the cytoplasmic or extracellular domain, in bladder epithelial 804G cells. The results of cell adhesion and radioligand-binding assays showed that alpha 6 beta 4 is a receptor for several laminin isoforms, including laminin 1, 2, 4, and 5. Overexpression of the tail-less or head-less mutant beta 4 subunit did not suppress alpha 6 beta 4-mediated adhesion to laminins, as both types of transfectants adhered to these ligands in the presence of blocking anti-beta 1 antibodies as well as the controls. However, immunofluorescence experiments indicated that the endogenous alpha 6 beta 4 integrin and other hemidesmosomal markers were not concentrated in hemidesmosomes in cells overexpressing tail- less beta 4, while the distribution of these molecules was not altered in cells overexpressing the head-less subunit. Electron microscopic studies confirmed that cells overexpressing tail-less beta 4 had a drastically reduced number of hemidesmosomes, while cells expressing the head-less subunit had a normal number of these structures. Thus, expression of a tail-less, but not a head-less mutant beta 4 subunit leads to a dominant negative effect on hemidesmosome assembly without suppressing initial adhesion to laminins. We conclude that the alpha 6 beta 4 integrin binds to several laminins and plays an essential role in the assembly and/or stability of hemidesmosomes, that alpha 6 beta 4- mediated adhesion and hemidesmosome assembly have distinct requirements, and that it is possible to use a dominant negative approach to selectively interfere with a specific function of an integrin. PMID:7721947

Regulatory T cell frequency in patients with melanoma with different disease stage and course, and modulating effects of high-dose interferon-alpha 2b treatment.

PubMed

Ascierto, Paolo A; Napolitano, Maria; Celentano, Egidio; Simeone, Ester; Gentilcore, Giusy; Daponte, Antonio; Capone, Mariaelena; Caracò, Corrado; Calemma, Rosa; Beneduce, Gerardo; Cerrone, Margherita; De Rosa, Vincenzo; Palmieri, Giuseppe; Castello, Giuseppe; Kirkwood, John M; Marincola, Francesco M; Mozzillo, Nicola

2010-08-16

High-dose interferon-alpha 2b (IFN-alpha 2b) is the only approved systemic therapy in the United States for the adjuvant treatment of melanoma. The study objective was to explore the immunomodulatory mechanism of action for IFN-alpha 2b by measuring serum regulatory T cell (Treg), serum transforming growth factor-beta (TGF-beta), interleukin (IL)-10, and autoantibody levels in patients with melanoma treated with the induction phase of the high-dose IFN-alpha 2b regimen. Patients with melanoma received IFN-alpha 2b administered intravenously (20 MU/m2 each day from day 1 to day 5 for 4 consecutive weeks). Serum Treg levels were measured as whole lymphocytes in CD4+ cells using flow cytometry while TGF-beta, IL-10, and autoantibody levels were measured using enzyme-linked immunosorbent assays. Twenty-two patients with melanoma received IFN-alpha 2b treatment and were evaluated for Treg levels. Before treatment, Treg levels were significantly higher in patients with melanoma when compared with data from 20 healthy subjects (P = 0.001; Mann-Whitney test). Although a trend for reduction of Treg levels following IFN-α 2b treatment was observed (average decrease 0.29% per week), statistical significance was not achieved. Subgroup analyses indicated higher baseline Treg levels for stage III versus IV disease (P = 0.082), early recurrence versus no recurrence (P = 0.017), deceased versus surviving patients (P = 0.021), and preoperative neoadjuvant versus postoperative adjuvant treatment groups (not significant). No significant effects were observed on the levels of TGF-beta, IL-10, and autoantibodies in patients with melanoma treated with IFN-alpha 2b. Patients with melanoma in this study showed increased basal levels of Treg that may be relevant to their disease and its progression. Treg levels shifted in patients with melanoma treated with IFN-alpha 2b, although no firm conclusions regarding the role of Tregs as a marker of treatment response or outcome can be made at present.

Expression of TNF-alpha, TGF-beta, IP-10 and IL-10 mRNA in kidneys of hamsters infected with pathogenic Leptospira.

PubMed

Lowanitchapat, Alisa; Payungporn, Sunchai; Sereemaspun, Amornpun; Ekpo, Pattama; Phulsuksombati, Duangporn; Poovorawan, Yong; Chirathaworn, Chintana

2010-09-01

Leptospirosis is a worldwide zoonosis caused by pathogenic Leptospira. Although several components of this organism have been identified, the molecular mechanisms underlying pathogenesis of this infectious disease are still poorly understood. Besides, direct injury by microbial factors, cytokines produced in response to infection have been proposed to be involved in pathogenesis of leptospirosis. In this study, cytokine gene expression in kidneys was investigated. Hamsters were injected with pathogenic Leptospira interrogans serovar Pyrogenes and were sacrificed on days 3, 5 and 7 after infection. RNA was extracted from kidney tissues. Real-time PCR was performed to demonstrate expression of TNF-alpha, TGF-beta, IP-10 and IL-10 mRNA in kidneys. TNF-alpha, TGF-beta and IP-10 expression could be demonstrated since day 3 post-infection whereas IL-10 expression was detected later on day 5. Leptospira infection resulted in not only expression of a proinflammatory cytokine, TNF-alpha, but also a T cell chemokine, IP-10. Detection of IP-10 suggested the involvement of T cell recruitment in the immune response or pathology in infected kidneys. Expressions of anti-inflammatory cytokines, TGF-beta and IL-10 were also observed. However, the level of TGF-beta expression was prominent since day 3 post-infection whereas IL-10 expression was clearly observed on day 5. Further experiments will provide additional information whether there is a correlation between the expression of these cytokines and pathologies found in an affected organ. Copyright 2009 Elsevier Ltd. All rights reserved.

T-cell receptor accessory and co-receptor molecules in channel catfish

USDA-ARS?s Scientific Manuscript database

T cell receptor (TCR) associated invariant chains CD3gamma/delta,epsilon, and zeta as well as TCR co-receptors CD8alpha and CD8beta were isolated from the channel catfish, Ictalurus punctatus, at both the gene and cDNA levels. All of catfish CD3 sequences encode for proteins that resemble their resp...

Integrin alpha 3 beta 1 participates in the phagocytosis of extracellular matrix molecules by human breast cancer cells.

PubMed

Coopman, P J; Thomas, D M; Gehlsen, K R; Mueller, S C

1996-11-01

The mechanisms and receptors involved in phagocytosis by nonhematopoietic cells are not well understood. The involvement of the alpha 3 beta 1 integrin in phagocytosis of the extracellular matrix by human breast cancer cells was studied. The possible role of this integrin was suggested since alpha 3 and beta 1 but not alpha 2 subunits are concentrated at membrane sites where local degradation of fluorescently labeled gelatin occurs. Strikingly, anti-alpha 3 integrin monoclonal antibodies (mAbs) stimulate the phagocytosis of fluorescently labeled gelatin films, gelatin beads, and Matrigel films in a quantitative phagocytosis assay. Stimulation of the gelatin uptake by the anti-alpha 3 mAb is dose responsive, saturable, and time dependent. Antibodies against other integrin subunits have a lower stimulatory effect (anti-beta 1) or no significant effect (anti-alpha 2, -alpha 5, -alpha 6, and -alpha v) on gelatin phagocytosis. The synthetic HGD-6 human laminin peptide that binds specifically the alpha 3 beta 1 integrin, but not the scrambled HSGD-6 control peptide, also markedly stimulates gelatin uptake in a dose-responsive way. Furthermore, the stimulatory effects of the HGD-6 peptide and the anti-alpha 3 mAb are additive, suggesting that they might promote phagocytosis in different ways. Other laminin (YIGSR, IKVAV) and fibronectin (GRGDS) peptides have no effect on gelatin phagocytosis. Immunofluorescence shows that the alpha 3 and the beta 1, but not the alpha 2 integrin subunit, concentrate into patches on the cell surface after treatment with their respective mAbs. And, both gelatin and the alpha 3 beta 1 but not the alpha 2 beta 1 integrin are cointernalized and routed to acidic vesicles such as lysosomes. In conclusion, we demonstrate that human breast cancer cells locally degrade and phagocytose the extracellular matrix and show for the first time that the alpha 3 beta 1 integrin participates in this phagocytosis. We hypothesize that the anti-alpha 3 antibodies and the laminin peptide HGD-6 activate the alpha 3 beta 1 integrin, which results in a downstream signaling cascade stimulating phagocytosis.

Discovery, SAR, and Radiolabeling of Halogenated Benzimidazole Carboxamide Antagonists as Useful Tools for (alpha)4(beta)1 Integrin Expressed on T- and B-cell Lymphomas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carpenter, R D; Natarajan, A; Lau, E Y

2010-02-08

The cell surface receptor {alpha}{sub 4}{beta}{sub 1} integrin is an attractive yet poorly understood target for selective diagnosis and treatment of T- and B-cell lymphomas. This report focuses on the rapid microwave preparation of medicinally pertinent benzimidazole heterocycles, structure-activity relationships (SAR) of novel halobenzimidazole carboxamide antagonists 3-6, and preliminary biological evaluation of radioiodinated agents 7, 8, and 18. The I-125 derivative 18 had good tumor uptake (12 {+-} 1% ID/g at 24 h; 4.5 {+-} 1% ID/g at 48 h) and tumor:kidney ratio ({approx}4:1 at 24 h; 2.5:1 at 48 h) in xenograft murine models of B-cell lymphoma. Molecular homologymore » models of {alpha}{sub 4}{beta}{sub 1} integrin have predicted that docked halobenzimidazole carboxamides have the halogen atom in a suitable orientation for halogen-hydrogen bonding. These high affinity ({approx} pM binding) halogenated ligands are attractive tools for medicinal and biological use; the fluoro and iodo derivatives are potential radiodiagnostic ({sup 18}F) or radiotherapeutic ({sup 131}I) agents, whereas the chloro and bromo analogues could provide structural insight into integrin-ligand interactions through photoaffinity cross-linking/mass spectroscopy experiments, as well as co-crystallization X-ray studies.« less

Anti-inflammatory effect of linear polarized infrared irradiation on interleukin-1beta-induced chemokine production in MH7A rheumatoid synovial cells.

PubMed

Shibata, Yasuko; Ogura, Naomi; Yamashiro, Keisuke; Takashiba, Shogo; Kondoh, Toshirou; Miyazawa, Keiji; Matsui, Masaru; Abiko, Yoshimitsu

2005-12-01

We examined the anti-inflammatory effect of infrared linear polarized light irradiation on the MH7A rheumatoid fibroblast-like synoviocytes (FLS) stimulated with the proinflammatory cytokine interleukin (IL)-1beta. Expression of messenger ribonucleic acids (mRNAs) encoding IL-8, RANTES (regulated upon activation, normal T cell expressed and secreted), growth-related gene alpha (GROalpha), and macrophage inflammatory protein-1alpha (MIP1alpha) was measured using real-time reverse transcription polymerase chain reaction, and the secreted proteins were measured in the conditioned media using enzyme-linked immunosorbent assays. We found that irradiation with linear polarized infrared light suppressed IL-1beta-induced expression of IL-8 mRNA and, correspondingly, the synthesis and release of IL-8 protein in MH7A cells. This anti-inflammatory effect was equivalent to that obtained with the glucocorticoid dexamethasone. Likewise, irradiation suppressed the IL-1beta-induced expression of RANTES and GROalpha mRNA. These results suggest that the irradiation of the areas around the articular surfaces of joints affected by rheumatoid arthritis (RA) using linear polarized light may represent a useful new approach to treatment.

C/EBP beta regulation of the tumor necrosis factor alpha gene.

PubMed Central

Pope, R M; Leutz, A; Ness, S A

1994-01-01

Activated macrophages contribute to chronic inflammation by the secretion of cytokines and proteinases. Tumor necrosis factor alpha (TNF alpha) is particularly important in this process because of its ability to regulate other inflammatory mediators in an autocrine and paracrine fashion. The mechanism(s) responsible for the cell type-specific regulation of TNF alpha is not known. We present data to show that the expression of TNF alpha is regulated by the transcription factor C/EBP beta (NF-IL6). C/EBP beta activated the TNF alpha gene promoter in cotransfection assays and bound to it at a site which failed to bind the closely related protein C/EBP alpha. Finally, a dominant-negative version of C/EBP beta blocked TNF alpha promoter activation in myeloid cells. Our results implicate C/EBP beta as an important regulator of TNF alpha by myelomonocytic cells. Images PMID:7929820

Structural and photophysical considerations of singlet fission organic thin films for solar photochemistry

NASA Astrophysics Data System (ADS)

Ryerson, Joseph L.

Singlet fission (SF) is a multichromophore charge multiplication process in organic systems in which a singlet exciton shares its energy with a neighboring chromophore, thus generating two triplet excitons from one photon. SF chromophores can boost photocurrent in solar cells, raising the maximum theoretical power conversion efficiency of a single-junction solar cell from ˜33% to ˜45. Thin film (TF) preparation techniques, steady-state and time-resolved spectroscopic methods, and numerous advanced calculations were used to study the three systems presented here, all of which exhibit polymorphism. TFs of 1,3-diphenylisobenzofuran (1), were prepared and two polymorphs, alpha1 and beta-1, were discovered and characterized. alpha-1films exhibit phiTnear 200% and low phiF, whereas the dominant photophysical processes in the beta-1 polymorph are prompt and excimer emissions, with phi T around 10%. Absorption fitting revealed that the S1 state of beta-1 is lower than alpha-1, and therefore SF and the correlated triplet 1(TT) is energetically inaccessible to beta-1. The SF mechanism in TFs of each polymorph is outlined in great detail. Polymorphism in tetracene (Tc), a near 200% phiT SF material, has been previously documented, although morphology considerations have been neglected. While crystallite size has been shown to affect dynamics, the two Tc polymorphs, I and II, have not been analyzed in a thorough comparison of dynamics and photophysics. Tc II films show SF rates that are independent of crystallite size and SF occurs more rapidly than in Tc I. The slower Tc I SF rates are highly dependent on grain size. Coupling calculations suggested that Tc I should be faster, but these calculations are limited, and more sophisticated, multimolecule calculations are needed to support experimental results. Two extremely stable indigo derivatives, Cibalackrot (2) and a tert-butylated derivative(3) were structurally and photophysically characterized in solution and in TFs. Two crystalline polymorphs ( 2alpha, 2beta) and an amorphous phase (2a), as well as a crystalline (3alpha) and amorphous (3a) phase of 3 were deposited by thermal evaporation. phiT values of less than 25% were observed for all morphologies, except in 2beta(phi T= 50%). Excimer formation dominates relaxation pathways in TFs of 2 and 3.

Modulation of Mycoplasma arthritidis-derived superantigen-induced cytokine gene expression by dexamethasone and interleukin-4.

PubMed Central

Mehindate, K; al-Daccak, R; Rink, L; Mecheri, S; Hébert, J; Mourad, W

1994-01-01

Activation of human monocytes or monocytic cell lines with all known stimuli coordinately induces the gene expression of various cytokines, including tumor necrosis factor alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and the IL-1 receptor antagonist (IL-1Ra). In contrast, superantigens induce TNF-alpha and IL-1 beta but fail to affect IL-1Ra gene expression, suggesting that activation of monocytes via major histocompatibility complex class II is distinct from other signal transduction pathways. In the present study, we analyzed the regulation of the Mycoplasma arthritidis-derived superantigen (MAM)-induced IL-1 beta and TNF-alpha gene expression by studying the effects of two different anti-inflammatory agents: dexamethasone (DEX) and the T-cell-derived cytokine IL-4. Both agents contributed to the downregulation of MAM-induced IL-1 beta and TNF-alpha gene expression. They accelerated the normal decline of the gene expression of both MAM-induced cytokines by decreasing the stability of mRNAs via the induction or enhanced synthesis of one or more regulatory proteins. In addition, IL-4, but not DEX, induced a strong and rapid expression of IL-1Ra mRNA in MAM-stimulated and unstimulated THP-1 cells in a de novo protein synthesis-independent manner. The capacity of IL-4 to induce IL-1Ra gene expression reinforces its anti-inflammatory activity. This study illustrates some of the mechanisms by which MAM-induced proinflammatory monokine gene expression can be downregulated by IL-4 and DEX. Images PMID:7927746

Glassy aging with modified Kohlrausch-Williams-Watts form

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sen Gupta, Bhaskar; Das, Shankar P.

2007-12-15

In this paper, we address the question of whether aging in the nonequilibrium glassy state is controlled by the equilibrium {alpha}-relaxation process, which occurs at temperatures above T{sub g}. Recently, Lunkenheimer et al. [Phys. Rev. Lett. 95, 055702 (2005)] proposed a model for the glassy aging data of dielectric relaxation using a modified Kohlrausch-Williams-Watts form exp[-(t{sub age}/{tau}{sub age}){sup {beta}{sub age}}]. The aging time t{sub age} dependence of the relaxation time {tau}{sub age} is defined by these authors through a functional relation involving the corresponding frequency {nu}(t{sub age})=1/(2{pi}{tau}{sub age}), but the stretching exponent {beta}{sub age} is the same as {beta}{sub {alpha}},more » the {alpha}-relaxation stretching exponent. We present here an alternative functional form for {tau}{sub age}(t{sub age}) directly involving the relaxation time itself. The proposed model fits the data of Lunkenheimer et al. perfectly with a stretching exponent {beta}{sub age} different from {beta}{sub {alpha}}.« less

Co-culture of clonal beta cells with GLP-1 and glucagon-secreting cell line impacts on beta cell insulin secretion, proliferation and susceptibility to cytotoxins.

PubMed

Green, Alastair D; Vasu, Srividya; Moffett, R Charlotte; Flatt, Peter R

2016-06-01

We investigated the direct effects on insulin releasing MIN6 cells of chronic exposure to GLP-1, glucagon or a combination of both peptides secreted from GLUTag L-cell and αTC1.9 alpha-cell lines in co-culture. MIN6, GLUTag and αTC1.9 cell lines exhibited high cellular hormone content and release of insulin, GLP-1 and glucagon, respectively. Co-culture of MIN6 cells with GLUTag cells significantly increased cellular insulin content, beta-cell proliferation, insulin secretory responses to a range of established secretogogues and afforded protection against exposure cytotoxic concentrations of glucose, lipid, streptozotocin or cytokines. Benefits of co-culture of MIN6 cells with αTC1.9 alphacells were limited to enhanced beta-cell proliferation with marginal positive actions on both insulin secretion and cellular protection. In contrast, co-culture of MIN6 with GLUTag cells plus αTC1.9 cells, markedly enhanced both insulin secretory responses and protection against beta-cell toxins compared with co-culture with GLUTag cells alone. These data indicate important long-term effects of conjoint GLP-1 and glucagon exposure on beta-cell function. This illustrates the possible functional significance of alpha-cell GLP-1 production as well as direct beneficial effects of dual agonism at beta-cell GLP-1 and glucagon receptors. Copyright © 2016 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.

Novel function of STAT1beta in B cells: induction of cell death by a mechanism different from that of STAT1alpha.

PubMed

Najjar, Imen; Schischmanoff, Pierre Olivier; Baran-Marszak, Fanny; Deglesne, Pierre-Antoine; Youlyouz-Marfak, Ibtissam; Pampin, Mathieu; Feuillard, Jean; Bornkamm, Georg W; Chelbi-Alix, Mounira K; Fagard, Remi

2008-12-01

Alternate splicing of STAT1 produces two isoforms: alpha, known as the active form, and beta, previously shown to act as a dominant-negative factor. Most studies have dealt with STAT1alpha, showing its involvement in cell growth control and cell death. To examine the specific function of either isoform in cell death, a naturally STAT1-deficient human B cell line was transfected to express STAT1alpha or STAT1beta. STAT1alpha, expressed alone, enhanced cell death, potentiated the fludarabine-induced apoptosis, and enhanced the nuclear location, the phosphorylation, and the transcriptional activity of p53. Unexpectedly, STAT1beta, expressed alone, induced cell death through a mechanism that was independent of the nuclear function of p53. Indeed, in STAT1beta-expressing B cells, p53 was strictly cytoplasmic where it formed clusters, and there was no induction of the transcriptional activity of p53. These data reveal a novel role of STAT1beta in programmed cell death, which is independent of p53.

A functional thyrotropin- and growth hormone-secreting pituitary adenoma with a ultrastructurally monomorphic feature: a case study.

PubMed

Ozawa, Y; Kameya, T; Kasuga, A; Naritaka, H; Kanda, N; Maruyama, H; Saruta, T

1998-04-01

A 38-yr-old female with a TSH- and GH-secreting pituitary adenoma is described, who had both overt symptoms, hyperthyroidism and acromegaly. Her serum TSH was not suppressed despite high concentrations of free T3 and free T4, and her alpha-subunit/TSH molar ratio was high. Her serum GH was consistently high, and was not suppressed by an oral glucose tolerance test. Preoperative testing revealed that, although the TSH response was impaired, TSH, alpha-subunit and GH were increased by TRH injection, and that these hormones were reduced by bromocriptine or somatostatin analog. Although she did not have hyperprolactinemia, the in vitro culture and immunohistochemical studies revealed that the adenoma cells produced and released PRL, in addition to TSH, alpha-subunit and GH. Immunohistochemical studies showed the presence of GH in the cytoplasm of many adenoma cells. TSH beta-positive adenoma cells were less frequently seen than GH-positive adenoma cells. No cells showed the coexistence of GH and TSH beta, and a few cells were positive for PRL. By electron microscopy, the adenoma was found to be composed of a single cell type resembling thyrotrophs, and did not have any characteristics of somatotrophs. This case was considered to be of interest, because the adenoma was ultrastructurally monomorphous, but immunohistochemically polymorphous.

Expression of the leukemia-associated CBF{beta}/SMMHC chimeric gene causes transformation of 3T3 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hajra, A.; Liu, P.; Collins, E.S.

1994-09-01

A pericentric inversion of chromosome 16 (inv(16)(p13;q22)) is consistently seen in acute myeloid leukemia of the M4Eo subtype. This inversion fuses almost the entire coding region of the gene encoding of the {beta} subunit of the heterodimeric transcription factor CBF/PEBP2 to the region of the MYH11 gene encoding the rod domain for the smooth muscle myosin heavy chain (SMMHC). To investigate the biological properties of the CBF{beta}/SMMHC fusion protein, we have generated 3T3 cell lines that stably express the CBF{beta}/SMMHC chimeric cDNA or the normal, nonchimeric CBF{beta} and SMMHC cDNAs. 3T3 cells expressing CBF{beta}/SMMHC acquire a transformed phenotype, as indicatedmore » by altered cell morphology, formation of foci, and growth in soft agar. Cells constitutively overexpressing the normal CBF{beta} cDNA or the rod region of SMMHC remain nontransformed. Western blot analysis using antibodies to CBF{beta} and the SMMHC rod demonstrates that stably transfected cells express the appropriate chimeric or normal protein. Electrophoretic mobility shift assays reveal that cells transformed by the chimeric cDNA do not have a CBF-DNA complex of the expected mobility, but instead contain a large complex with CBF DNA-binding activity that fails to migrate out of the gel wells. In order to define the regions of CBF{beta}/SMMHC necessary for 3T3 transformation, we have stably transfected cells with mutant CBF{beta}/SMMHC cDNAs containing various deletions of the coding region. Analysis of these cell lines indicates that the transformation property of CBF{beta}/SMMHC requires regions of CBF{beta} known to be necessary for association with the DNA-binding CBF{alpha} subunit, and also requires an intact SMMHC carboxyl terminus, which is necessary for formation of the coiled coil domain of the myosin rod.« less

Efficient triple helix formation by oligodeoxyribonucleotides containing alpha- or beta-2-amino-5-(2-deoxy-D-ribofuranosyl) pyridine residues.

PubMed

Bates, P J; Laughton, C A; Jenkins, T C; Capaldi, D C; Roselt, P D; Reese, C B; Neidle, S

1996-11-01

Triple helices containing C+xGxC triplets are destabilised at physiological pH due to the requirement for base protonation of 2'-deoxycytidine (dC), which has a pKa of 4.3. The C nucleoside 2-amino-5-(2'-deoxy-beta-D-ribofuranosyl)pyridine (beta-AP) is structurally analogous to dC but is considerably more basic, with a pKa of 5.93. We have synthesised 5'-psoralen linked oligodeoxyribonucleotides (ODNs) containing thymidine (dT) and either beta-AP or its alpha-anomer (alpha-AP) and have assessed their ability to form triplexes with a double-stranded target derived from standard deoxynucleotides (i.e. beta-anomers). Third strand ODNs derived from dT and beta-AP were found to have considerably higher binding affinities for the target than the corresponding ODNs derived from dT and either dC or 5-methyl-2'-deoxycytidine (5-Me-dC). ODNs containing dT and alpha-AP also showed enhanced triplex formation with the duplex target and, in addition are more stable in serum-containing medium than standard oligopyrimidine-derived ODNs or ODNs derived from dT and beta-AP. Molecular modelling studies showed that an alpha-anomeric AP nucleotide can be accommodated within an otherwise beta-anomeric triplex with only minor perturbation of the triplex structure. Molecular dynamics (MD) simulations on triplexes containing either the alpha- or beta-anomer of (N1-protonated) AP showed that in both cases the base retained two standard hydrogen bonds to its associated guanine when the 'A-type' model of the triplex was used as the start-point for the simulation, but that bifurcated hydrogen bonds resulted when the alternative 'B-type' triplex model was used. The lack of a differential stability between alpha-AP- and beta-AP-containing triplexes at pH >7, predicted from the behaviour of the B-type models, suggests that the A-type models are more appropriate.

Functional characterization of recombinant prefoldin complexes from a hyperthermophilic archaeon, Thermococcus sp. strain KS-1.

PubMed

Iizuka, Ryo; Sugano, Yuri; Ide, Naoki; Ohtaki, Akashi; Yoshida, Takao; Fujiwara, Shinsuke; Imanaka, Tadayuki; Yohda, Masafumi

2008-03-28

Prefoldin is a heterohexameric molecular chaperone complex that is found in the eukaryotic cytosol and also in archaea. It captures a nonnative protein and subsequently delivers it to a group II chaperonin for proper folding. Archaeal prefoldin is a heterocomplex containing two alpha subunits and four beta subunits with the structure of a double beta-barrel assembly, with six long coiled coils protruding from it like a jellyfish with six tentacles. We have studied the protein folding mechanism of group II chaperonin using those of Thermococcus sp. strain KS-1 (T. KS-1) because they exhibit high protein folding activity in vitro. We have also demonstrated functional cooperation between T. KS-1 chaperonins and prefoldin from Pyrococcus horikoshii OT3. Recent genome analysis has shown that Thermococcus kodakaraensis KOD1 contains two pairs of prefoldin subunit genes, correlating with the existence of two different chaperonin subunits. In this study, we characterized four different recombinant prefoldin complexes composed of two pairs of prefoldin subunits (alpha1, alpha2, beta1, and beta2) from T. KS-1. All of them (alpha1-beta1, alpha2-beta1, alpha1-beta2, and alpha2-beta2) exist as alpha(2)beta(4) heterohexamers and can protect several proteins from forming aggregates with different activities. We have also compared the collaborative activity between the prefoldin complexes and the cognate chaperonins. Prefoldin complexes containing the beta1 subunit interacted with the chaperonins more strongly than those with the beta2 subunit. The results suggest that Thermococcus spp. express different prefoldins for different substrates or conditions as chaperonins.

Vesicle-associated membrane protein 2 mediates trafficking of {alpha}5{beta}1 integrin to the plasma membrane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hasan, Nazarul; Hu, Chuan, E-mail: chuan.hu@louisville.edu

2010-01-01

Integrins are major receptors for cell adhesion to the extracellular matrix (ECM). As transmembrane proteins, the levels of integrins at the plasma membrane or the cell surface are ultimately determined by the balance between two vesicle trafficking events: endocytosis of integrins at the plasma membrane and exocytosis of the vesicles that transport integrins. Here, we report that vesicle-associated membrane protein 2 (VAMP2), a SNARE protein that mediates vesicle fusion with the plasma membrane, is involved in the trafficking of {alpha}5{beta}1 integrin. VAMP2 was present on vesicles containing endocytosed {beta}1 integrin. Small interfering RNA (siRNA) silencing of VAMP2 markedly reduced cellmore » surface {alpha}5{beta}1 and inhibited cell adhesion and chemotactic migration to fibronectin, the ECM ligand of {alpha}5{beta}1, without altering cell surface expression of {alpha}2{beta}1 integrin or {alpha}3{beta}1 integrin. By contrast, silencing of VAMP8, another SNARE protein, had no effect on cell surface expression of the integrins or cell adhesion to fibronectin. In addition, VAMP2-mediated trafficking is involved in cell adhesion to collagen but not to laminin. Consistent with disruption of integrin functions in cell proliferation and survival, VAMP2 silencing diminished proliferation and triggered apoptosis. Collectively, these data indicate that VAMP2 mediates the trafficking of {alpha}5{beta}1 integrin to the plasma membrane and VAMP2-dependent integrin trafficking is critical in cell adhesion, migration and survival.« less

Regulation of dendritic cell function through Toll-like receptors.

PubMed

Kaisho, Tsuneyasu; Akira, Shizuo

2003-06-01

Higher animals establish host defense by orchestrating innate and adaptive immunity. This is mediated by professional antigen presenting cells, i.e. dendritic cells (DCs). DCs can incorporate pathogens, produce a variety of cytokines, maturate, and present pathogen-derived peptides to T cells, thereby inducing T cell activation and differentiation. These responses are triggered by microbial recognition through type I transmembrane proteins, Toll-like receptors (TLRs) on DCs. TLRs consist of ten members and each TLR is involved in recognizing a variety of microorganism-derived molecular structures. TLR ligands include cell wall components, proteins, nucleic acids, and synthetic chemical compounds, all of which can activate DCs as immune adjuvants. Each TLR can activate DCs in a similar, but distinct manner. For example, TLRs can be divided into subgroups according to their type I interferon (IFN) inducing ability. TLR2 cannot induce IFN-alpha or IFN-beta, but TLR4 can lead to IFN-beta production. Meanwhile, TLR3, TLR7, and TLR9 can induce both IFN-alpha and IFN-beta. Recent evidences suggest that cytoplamic adapters for TLRs are especially crucial for this functional heterogeneity. Clarifying how DC function is regulated by TLRs should provide us with critical information for manipulating the host defense against a variety of diseases.

Optimization of the temporal pattern of radiation: An IMRT based study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Altman, Michael B.; Chmura, Steven J.; Deasy, Joseph O.

Purpose: To investigate how the temporal pattern of dose applied during a single-intensity modulated radiation therapy (IMRT) fraction can be arranged to maximize or minimize cell kill. Methods and Materials: Using the linear-quadratic repair-time model and a simplified IMRT delivery pattern model, the surviving fraction of cells for a single fraction was calculated for all permutations of the dose delivery pattern for an array of clinically based IMRT cases. Maximization of cell kill was achieved by concentrating the highest doses in the middle of a fraction, while minimization was achieved by spreading the highest doses between the beginning and end.more » The percent difference between maximum and minimum cell kill (%Diff{sub min/max}) and the difference between maximum and minimum total doses normalized to 2 Gy/fx ({delta}NTD{sub 2Gy}) was calculated for varying fraction durations (T), {alpha}/{beta} ratios, and doses/fx. Results: %Diff{sub min/max} and {delta}NTD{sub 2Gy} both increased with increasing T and with decreasing {alpha}/{beta}. The largest increases occurred with dose/fx. With {alpha}/{beta} = 3 Gy and 30 min/fx, %Diff{sub min/max} ranged from 2.7-5.3% for 2 Gy/fx to 48.6-74.1% for 10 Gy/fx, whereas {delta}NTD{sub 2Gy} ranged from 1.2 Gy-2.4 Gy for 30 fractions of 2 Gy/fx to 2.3-4.8 Gy for 2 fractions of 10.84 Gy/fx. Using {alpha}/{beta} = 1.5 Gy, an analysis of prostate hypofractionation schemes yielded differences in clinical outcome based on the pattern of applied dose ranging from 3.2%-6.1% of the treated population. Conclusions: Rearrangement of the temporal pattern of dose for a single IMRT fraction could be used to optimize cell kill and to directly, though modestly, affect treatment outcome.« less

Antiapoptotic property of human alpha-synuclein in neuronal cell lines is associated with the inhibition of caspase-3 but not caspase-9 activity.

PubMed

Li, Wenxue; Lee, Michael K

2005-06-01

Abnormalities of alpha-synuclein (alpha-Syn) are mechanistically linked to Parkinson's disease (PD) and other alpha-synucleinopathies. To gain additional insights into the relationships between alpha-Syn expression and cell death, we examined the effects of expressing human alpha-Syn (Hualpha-Syn) variants on the cellular vulnerability to apoptotic stimuli. We show that the expression of wild-type (WT) and A30P mutant, but not A53T mutant, Hualpha-Syn leads to the protection of neuronal cell lines from apoptosis but not necrosis. Significantly, Hualpha-Syn did not protect non-neuronal cell lines from apoptosis. We also show that A53T mutant is a loss of function in regards to the antiapoptotic property since the expression of WT Hualpha-Syn with an excess of A53T mutant Hualpha-Syn leads to protection of the cells from apoptosis. The antiapoptotic property is specific to human alpha-Syn as neither beta-Syn nor mouse alpha-Syn protected cells from apoptosis, and the carboxy-terminal 20 amino acids are required for the antiapoptotic property. Analyses of capase-3 and caspase-9 activation reveal that the antiapoptotic property of Hualpha-Syn in neuronal cell lines is associated with the attenuation of caspase-3 activity without affecting the caspase-9 activity or the levels of cleaved, active caspase-3. We conclude that Hualpha-Syn modulates the activity of cleaved caspase-3 product in neuronal cell lines.

Chondrocyte heterogeneity: immunohistologically defined variation of integrin expression at different sites in human fetal knees.

PubMed

Salter, D M; Godolphin, J L; Gourlay, M S

1995-04-01

During development and at maturity different forms of cartilage vary in morphology and macromolecular content. This reflects heterogeneity of chondrocyte activity, in part involving differential interactions with the adjacent extracellular matrix via specialized cell surface receptors such as integrins. We undertook an immunohistological study on a series of human fetal knee joints to assess variation in the expression of integrins by chondrocytes and potential matrix ligands in articular, epiphyseal, growth plate, and meniscal cartilage. The results show that articular chondrocytes (beta 1+, beta 5 alpha V+, alpha 1+, alpha 2+/-, alpha 5+, weakly alpha 6+, alpha V+) differed from epiphyseal (beta 1+, beta 5 alpha V+, alpha 1+/-, alpha 2+/-, alpha 5+, alpha 6+, alpha V+) growth plate (beta 1+, beta 5 alpha V+, alpha 1-, alpha 2-, alpha 5+, alpha 6+, alpha V+), and meniscal cells (beta 1+, beta 5 alpha V+, alpha 1+, strongly alpha 2+, alpha 5+, alpha 6+, alpha V+ in expression of integrin subunits. There was no expression of beta 3, beta 4, beta 6, or alpha 3 by chondrocytes. These results differ from previous reports on the expression of integrins by adult articular cartilage, where alpha 2 and alpha 6 are not seen. Variation in distribution of matrix ligands was also seen. Fibronectin, laminin and Type VI collagen were expressed in all cartilages but there was restricted expression of tenascin, ED-A and ED-B fibronectin isoforms (articular cartilage and meniscus), and vitronectin (absent from growth plate cartilage). Regulated expression of integrins by chondrocytes, associated with changes in the pericellular matrix composition, is of potential importance in control of cartilage differentiation and function in health and disease.

beta subunits influence the biophysical and pharmacological differences between P- and Q-type calcium currents expressed in a mammalian cell line.

PubMed

Moreno, H; Rudy, B; Llinás, R

1997-12-09

Human epithelial kidney cells (HEK) were prepared to coexpress alpha1A, alpha2delta with different beta calcium channel subunits and green fluorescence protein. To compare the calcium currents observed in these cells with the native neuronal currents, electrophysiological and pharmacological tools were used conjointly. Whole-cell current recordings of human epithelial kidney alpha1A-transfected cells showed small inactivating currents in 80 mM Ba2+ that were relatively insensitive to calcium blockers. Coexpression of alpha1A, betaIb, and alpha2delta produced a robust inactivating current detected in 10 mM Ba2+, reversibly blockable with low concentration of omega-agatoxin IVA (omega-Aga IVA) or synthetic funnel-web spider toxin (sFTX). Barium currents were also supported by alpha1A, beta2a, alpha2delta subunits, which demonstrated the slowest inactivation and were relatively insensitive to omega-Aga IVA and sFTX. Coexpression of beta3 with the same combination as above produced inactivating currents also insensitive to low concentration of omega-Aga IVA and sFTX. These data indicate that the combination alpha1A, betaIb, alpha2delta best resembles P-type channels given the rate of inactivation and the high sensitivity to omega-Aga IVA and sFTX. More importantly, the specificity of the channel blocker is highly influenced by the beta subunit associated with the alpha1A subunit.

Imaging of alpha(v)beta(3) expression by a bifunctional chimeric RGD peptide not cross-reacting with alpha(v)beta(5).

PubMed

Zannetti, Antonella; Del Vecchio, Silvana; Iommelli, Francesca; Del Gatto, Annarita; De Luca, Stefania; Zaccaro, Laura; Papaccioli, Angela; Sommella, Jvana; Panico, Mariarosaria; Speranza, Antonio; Grieco, Paolo; Novellino, Ettore; Saviano, Michele; Pedone, Carlo; Salvatore, Marco

2009-08-15

To test whether a novel bifunctional chimeric peptide comprising a cyclic Arg-Gly-Asp pentapeptide covalently bound to an echistatin domain can discriminate alpha(v)beta(3) from alpha(v)beta(5) integrin, thus allowing the in vivo selective visualization of alpha(v)beta(3) expression by single-photon and positron emission tomography (PET) imaging. The chimeric peptide was preliminarily tested for inhibition of alpha(v)beta(3)-dependent cell adhesion and competition of 125I-echistatin binding to membrane of stably transfected K562 cells expressing alpha(v)beta(3) (Kalpha(v)beta(3)) or alpha(v)beta(5) (Kalpha(v)beta(5)) integrin. The chimeric peptide was then conjugated with diethylenetriaminepentaacetic acid and labeled with 111In for single-photon imaging, whereas a one-step procedure was used for labeling the full-length peptide and a truncated derivative, lacking the last five C-terminal amino acids, with 18F for PET imaging. Nude mice bearing tumors from Kalpha(v)beta(3), Kalpha(v)beta(5), U87MG human glioblastoma, and A431 human epidermoid cells were subjected to single-photon and PET imaging. Adhesion and competitive binding assays showed that the novel chimeric peptide selectively binds to alpha(v)beta(3) integrin and does not cross-react with alpha(v)beta(5). In agreement with in vitro findings, single-photon and PET imaging studies showed that the radiolabeled chimeric peptide selectively localizes in tumor xenografts expressing alphavbeta3 and fails to accumulate in those expressing alpha(v)beta(5) integrin. When 18F-labeled truncated derivative was used for PET imaging, alphavbeta3- and alpha(v)beta(5)-expressing tumors were visualized, indicating that the five C-terminal amino acids are required to differentially bind the two integrins. Our findings indicate that the novel chimeric Arg-Gly-Asp peptide, having no cross-reaction with alphavbeta5 integrin, allows highly selective alphavbeta3 expression imaging and monitoring.

Regulatory T cells generated during cytomegalovirus in vitro stimulation of mononuclear cells from HIV-infected individuals on HAART correlate with decreased lymphocyte proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jesser, Renee D.; Li, Shaobing; Weinberg, Adriana

2006-09-01

HIV-infected patients fail to fully recover cell-mediated immunity despite HAART. To identify regulatory factors, we studied the phenotype and function of in vitro cytomegalovirus (CMV)-stimulated T cells from HAART recipients. CFSE-measured proliferation showed CD4{sup +} and CD8{sup +} cells dividing in CMV-stimulated cultures. Compared with healthy controls, CMV-stimulated lymphocytes from HAART recipients had lower {sup 3}H-thymidine incorporation; lower IFN{gamma} and TNF{alpha} production; higher CD4{sup +}CD27{sup -}CD28{sup -} and CD8{sup +}CD27{sup -}CD28{sup -} frequencies; lower CD4{sup +}CD25{sup hi}; and higher FoxP3 expression in CD8{sup +}CD25{sup hi} cells. CMV-specific proliferation correlated with higher IFN{gamma}, TNF{alpha} and IL10 levels and higher CD4{sup +}perforin{supmore » +} and CD8{sup +}perforin{sup +} frequencies. Decreased proliferation correlated with higher CD4{sup +}CD27{sup -}CD28{sup -} frequencies and TGF{beta}1 production, which also correlated with each other. Anti-TGF{beta}1 neutralizing antibodies restored CMV-specific proliferation in a dose-dependent fashion. In HIV-infected subjects, decreased proliferation correlated with higher CMV-stimulated CD8{sup +}CD25{sup hi} frequencies and their FoxP3 expression. These data indicate that FoxP3- and TGF{beta}1-expressing regulatory T cells contribute to decreased immunity in HAART recipients.« less

Solution structure for Pandinus toxin K-alpha (PiTX-K alpha), a selective blocker of A-type potassium channels.

PubMed

Tenenholz, T C; Rogowski, R S; Collins, J H; Blaustein, M P; Weber, D J

1997-03-11

PiTX-K alpha, a 35-residue peptide recently isolated from the venom of Pandinus imperator, blocks the rapidly inactivating (A-type) K+ channel(s) in rat brain synaptosomes and the cloned Kv 1.2 potassium channel at very low toxin concentrations (6 nM and 32 pM, respectively) [Rogowski, R. S., Collins, J. H., O'Neil, T. J., Gustafson, T. A., Werkman, T. A., Rogawski, M. A., Tenenholz, T. C., Weber, D. J., & Blaustein, M. P. (1996) Mol. Pharmacol. 50, 1167-1177]. The three-dimensional structure of PiTX-K alpha was determined using NMR spectroscopy in order to understand its selectivity and affinity toward K+ channels. PiTX-K alpha was found to have an alpha-helix from residues 10 to 21 and two beta-strands (betaI, 26-28; betaII, 33-35) connected by a type II beta-turn to form a small antiparallel beta-sheet. Three disulfide bonds, which are conserved in all members of the charybdotoxin family (alpha-K toxins), anchor one face of the alpha-helix to the beta-sheet. The N-terminal portion of PiTX-K alpha has three fewer residues than other alpha-K toxins such as charybdotoxin. Rather than forming a third beta-strand as found for other alpha-K toxins, the N-terminal region of PiTX-K alpha adopts an extended conformation. This structural difference in PiTX-K alpha together with differences in sequence at Pro-10, Tyr-14, and Asn-25 (versus Ser-10, Trp-14, and Arg-25 in CTX) may explain why PiTX-K alpha does not block maxi-K+ channels. Differences in three-dimensional structure between PiTX-K alpha and charybdotoxin are also observed in both the tight turn and the loop that connects the first beta-strand to the alpha-helix. As a result, side chains of two residues (Tyr-23 and Arg-31) are in regions of PiTX-K alpha that probably interact with rapidly inactivating A-type K+ channels. The analogous residues in charybdotoxin are positioned differently on the toxin surface. Thus, the locations of Tyr-23 and Arg-31 side chains in PiTX-K alpha could explain why this toxin blocks A-type channels at much lower concentrations than does charybdotoxin.

Effect of Interleukin-1beta and Tumor Necrosis Factor-alpha on Gene Expression in Human Endothelial Cells

DTIC Science & Technology

2003-06-01

type Ill, alpha 1 ( Ehlers - Danlos syndrome type IV, autosomal dominant) T98612 multimerin AA423867 ribonuclease, RNase A family, 1 (pancreatic...tax-responsive enhancer element 967) AA600217 jagged1 (Alagille syndrome ) R70685 TNF receptor-associated factor 1 R71691 glycyl-tRNA synthetase...in patients succumbing to sepsis and systemic inflamma- tion. The effects of removing one syndrome -causing agent may be compensated by others with

Steady-state levels of G-protein beta-subunit expression are regulated by treatment of cells with bacterial toxins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watkins, D.C.; Northup, J.K.; Malbon, C.C.

1987-05-01

Cultures of 3T3-L1 cells were incubated with either 10 ng/ml cholera toxin or 10 ng/ml pertussis toxin from 4 days prior to the initiation of differentiation and throughout the subsequent incubation. Toxin concentrations were sufficient to completely prevent the labelling of alpha-subunits with (/sup 32/P)NAD/sup +/ and pertussis toxin and to prevent by more than 90% the labelling with (/sup 32/P)NAD/sup +/ and cholera toxin in membranes prepared from these cells. Neither toxin prevented the differentiation to the adipocyte phenotype. Neither toxin prevented the increases in the relative amounts of G-proteins which occur upon differentiation. Both toxins dramatically decreased themore » amount of beta-subunits. As measured by quantitative immunoblotting with antisera specific for both the 35 kDa and 36 kDa beta-subunits, levels of beta-subunit were decreased by more than 50% of steady-state level of control cells. Thus, bacterial toxins which modifies G-protein alpha-subunits are capable of modulating the levels of beta-subunits in vivo. The basis for the regulation of G-protein subunit expression by bacterial toxins is under study.« less

Rab-coupling protein coordinates recycling of alpha5beta1 integrin and EGFR1 to promote cell migration in 3D microenvironments.

PubMed

Caswell, Patrick T; Chan, May; Lindsay, Andrew J; McCaffrey, Mary W; Boettiger, David; Norman, Jim C

2008-10-06

Here we show that blocking the adhesive function of alphavbeta3 integrin with soluble RGD ligands, such as osteopontin or cilengitide, promoted association of Rab-coupling protein (RCP) with alpha5beta1 integrin and drove RCP-dependent recycling of alpha5beta1 to the plasma membrane and its mobilization to dynamic ruffling protrusions at the cell front. These RCP-driven changes in alpha5beta1 trafficking led to acquisition of rapid/random movement on two-dimensional substrates and to a marked increase in fibronectin-dependent migration of tumor cells into three-dimensional matrices. Recycling of alpha5beta1 integrin did not affect its regulation or ability to form adhesive bonds with substrate fibronectin. Instead, alpha5beta1 controlled the association of EGFR1 with RCP to promote the coordinate recycling of these two receptors. This modified signaling downstream of EGFR1 to increase its autophosphorylation and activation of the proinvasive kinase PKB/Akt. We conclude that RCP provides a scaffold that promotes the physical association and coordinate trafficking of alpha5beta1 and EGFR1 and that this drives migration of tumor cells into three-dimensional matrices.

Differential cytokine modulation and T cell activation by two distinct classes of thalidomide analogues that are potent inhibitors of TNF-alpha.

PubMed

Corral, L G; Haslett, P A; Muller, G W; Chen, R; Wong, L M; Ocampo, C J; Patterson, R T; Stirling, D I; Kaplan, G

1999-07-01

TNF-alpha mediates both protective and detrimental manifestations of the host immune response. Our previous work has shown thalidomide to be a relatively selective inhibitor of TNF-alpha production in vivo and in vitro. Additionally, we have recently reported that thalidomide exerts a costimulatory effect on T cell responses. To develop thalidomide analogues with increased anti-TNF-alpha activity and reduced or absent toxicities, novel TNF-alpha inhibitors were designed and synthesized. When a selected group of these compounds was examined for their immunomodulatory activities, different patterns of cytokine modulation were revealed. The tested compounds segregated into two distinct classes: one class of compounds, shown to be potent phosphodiesterase 4 inhibitors, inhibited TNF-alpha production, increased IL-10 production by LPS-induced PBMC, and had little effect on T cell activation; the other class of compounds, similar to thalidomide, were not phosphodiesterase 4 inhibitors and markedly stimulated T cell proliferation and IL-2 and IFN-gamma production. These compounds inhibited TNF-alpha, IL-1beta, and IL-6 and greatly increased IL-10 production by LPS-induced PBMC. Similar to thalidomide, the effect of these agents on IL-12 production was dichotomous; IL-12 was inhibited when PBMC were stimulated with LPS but increased when cells were stimulated by cross-linking the TCR. The latter effect was associated with increased T cell CD40 ligand expression. The distinct immunomodulatory activities of these classes of thalidomide analogues may potentially allow them to be used in the clinic for the treatment of different immunopathological disorders.

The extent of polylactosamine glycosylation of MDCK LAMP-2 is determined by its Golgi residence time.

PubMed

Nabi, I R; Dennis, J W

1998-09-01

The increased polylactosamine glycosylation of LAMP-2 in MDCK cells cultured for 1 day relative to cells cultured for 3 days has been correlated with its slower rate of Golgi transit (Nabi and Rodriguez-Boulan, 1993, Mol. Biol. Cell., 4, 627-635). To determine if the differential polylactosamine glycosylation of LAMP-2 is a consequence of glycosyltransferase expression levels, the activities of beta1-6GlcNAc-TV, beta1-3GlcNAc-T(i), beta1-2GlcNAc-TI, beta1, 4Gal-T, alpha2-6sialyl-T, and alpha2-3sialyl-T were assayed and no significant differences in the activities of these enzymes in 1 and 3 day cell extracts were detected. During MDCK epithelial polarization, the Golgi apparatus undergoes morphological changes and apiconuclear Golgi networks were more evident in 3 day cells. Treatment with nocodazole disrupted Golgi networks and generated numerous Golgi clusters in both 1 day and 3 day cells. In the presence of nocodazole the differential migration of LAMP-2 in 1 and 3 day MDCK cells was maintained and could be eliminated by treatment with endo-beta-galactosidase, indicating that gross Golgi morphology did not influence the extent of LAMP-2 polylactosamine glycosylation. Nocodazole treatment did, however, result in the faster migration of LAMP-2 which was not due to modification of core N-glycans as the precursor form of the glycoprotein migrated with an identical molecular size. Following incubation at 20 degrees C, which prevents the exit of proteins from the trans-Golgi network, the molecular size of LAMP-2 increased to a similar extent in both 1 and 3 day MDCK cells. Extending the time of incubation at 20 degrees C did not influence the size of LAMP-2, demonstrating that its glycosylation is modified not by its retention within the Golgi but rather by its equivalent slower Golgi passage at the lower temperature in both 1 and 3 day cells. An identical effect was observed in nocodazole treated cells, demonstrating that Golgi residence time determines the extent of LAMP-2 polylactosamine glycosylation, even in isolated Golgi clusters.

SU-E-J-03: A Comprehensive Comparison Between Alpha and Beta Emitters for Cancer Radioimmunotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, C.Y.; Guatelli, S; Oborn, B

2014-06-01

Purpose: The purpose of this study is to perform a comprehensive comparison of the therapeutic efficacy and cytotoxicity of alpha and beta emitters for Radioimmunotherapy (RIT). For each stage of cancer development, specific models were built for the separate objectives of RIT to be addressed:a) kill isolated cancer cells in transit in the lymphatic and vascular circulation,b) regress avascular cell clusters,c) regress tumor vasculature and tumors. Methods: Because of the nature of short range, high LET alpha and long energy beta radiation and heterogeneous antigen expression among cancer cells, the microdosimetric approach is essential for the RIT assessment. Geant4 basedmore » microdosimetric models are developed for the three different stages of cancer progression: cancer cells, cell clusters and tumors. The energy deposition, specific energy resulted from different source distribution in the three models was calculated separately for 4 alpha emitting radioisotopes ({sup 211}At, {sup 213}Bi, {sup 223}Ra and {sup 225}Ac) and 6 beta emitters ({sup 32}P, {sup 33}P, {sup 67}Cu, {sup 90}Y, {sup 131}I and {sup 177}Lu). The cell survival, therapeutic efficacy and cytotoxicity are determined and compared between alpha and beta emitters. Results: We show that internal targeted alpha radiation has advantages over beta radiation for killing isolated cancer cells, regressing small cell clusters and also solid tumors. Alpha particles have much higher dose specificity and potency than beta particles. They can deposit 3 logs more dose than beta emitters to single cells and solid tumor. Tumor control probability relies on deep penetration of radioisotopes to cancer cell clusters and solid tumors. Conclusion: The results of this study provide a quantitative understanding of the efficacy and cytotoxicity of RIT for each stage of cancer development.« less

Dissecting the role of matrix metalloproteinases (MMP) and integrin alpha(v)beta3 in angiogenesis in vitro: absence of hemopexin C domain bioactivity, but membrane-Type 1-MMP and alpha(v)beta3 are critical.

PubMed

Nisato, Riccardo E; Hosseini, Ghamartaj; Sirrenberg, Christian; Butler, Georgina S; Crabbe, Thomas; Docherty, Andrew J P; Wiesner, Matthias; Murphy, Gillian; Overall, Christopher M; Goodman, Simon L; Pepper, Michael S

2005-10-15

Matrix metalloproteinase (MMP)-2 and its hemopexin C domain autolytic fragment (also called PEX) have been proposed to be crucial for angiogenesis. Here, we have investigated the dependency of in vitro angiogenesis on MMP-mediated extracellular proteolysis and integrin alpha(v)beta3-mediated cell adhesion in a three-dimensional collagen I model. The hydroxamate-based synthetic inhibitors BB94, CT1399, and CT1847 inhibited endothelial cell invasion, as did neutralizing anti-membrane-type 1-MMP (MT1-MMP) antibodies and tissue inhibitor of MMP (TIMP)-2 and TIMP-3 but not TIMP-1. This confirmed the pivotal importance of MT1-MMP over other MMPs in this model. Invasion was also inhibited by a nonpeptidic antagonist of integrin alpha(v)beta3, EMD 361276. Although PEX strongly inhibited pro-MMP-2 activation, when contaminating lipopolysaccharide was neutralized, PEX neither affected angiogenesis nor bound integrin alpha(v)beta(3). Moreover, no specific binding of pro-MMP-2 to integrin alpha(v)beta3 was found, whereas only one out of four independently prepared enzymatically active MMP-2 preparations could bind integrin alpha(v)beta3 , and this in a PEX-independent manner. Likewise, integrin alpha(v)beta3 -expressing cells did not bind MMP-2-coated surfaces. Hence, these findings show that endothelial cell invasion of collagen I gels is MT1-MMP and alpha(v)beta3 - dependent but MMP-2 independent and does not support a role for PEX in alpha(v)beta3 integrin binding or in modulating angiogenesis in this system.

The ectopic expression of Pax4 in the mouse pancreas converts progenitor cells into alpha and subsequently beta cells.

PubMed

Collombat, Patrick; Xu, Xiaobo; Ravassard, Philippe; Sosa-Pineda, Beatriz; Dussaud, Sébastien; Billestrup, Nils; Madsen, Ole D; Serup, Palle; Heimberg, Harry; Mansouri, Ahmed

2009-08-07

We have previously reported that the loss of Arx and/or Pax4 gene activity leads to a shift in the fate of the different endocrine cell subtypes in the mouse pancreas, without affecting the total endocrine cell numbers. Here, we conditionally and ectopically express Pax4 using different cell-specific promoters and demonstrate that Pax4 forces endocrine precursor cells, as well as mature alpha cells, to adopt a beta cell destiny. This results in a glucagon deficiency that provokes a compensatory and continuous glucagon+ cell neogenesis requiring the re-expression of the proendocrine gene Ngn3. However, the newly formed alpha cells fail to correct the hypoglucagonemia since they subsequently acquire a beta cell phenotype upon Pax4 ectopic expression. Notably, this cycle of neogenesis and redifferentiation caused by ectopic expression of Pax4 in alpha cells is capable of restoring a functional beta cell mass and curing diabetes in animals that have been chemically depleted of beta cells.

Transforming growth factor-{beta} inhibits CCAAT/enhancer-binding protein expression and PPAR{gamma} activity in unloaded bone marrow stromal cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahdjoudj, S.; Kaabeche, K.; Holy, X.

2005-02-01

The molecular mechanisms regulating the adipogenic differentiation of bone marrow stromal cells in vivo remain largely unknown. In this study, we investigated the regulatory effects of transforming growth factor beta-2 (TGF-{beta}2) on transcription factors involved in adipogenic differentiation induced by hind limb suspension in rat bone marrow stromal cells in vivo. Time course real-time quantitative reverse-transcription polymerase chain reaction (RT-PCR) analysis of gene expression showed that skeletal unloading progressively increases the expression of CCAAT/enhancer-binding protein (C/EBP){alpha} and C/EBP{beta} {alpha} at 5 days in bone marrow stromal cells resulting in increased peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}2) transcripts at 7 days. TGF-{beta}2more » administration in unloaded rats corrected the rise in C/EBP{alpha} and C/EBP{beta} transcripts induced by unloading in bone marrow stromal cells. This resulted in inhibition of PPAR{gamma}2 expression that was associated with increased Runx2 expression. Additionally, the inhibition of C/EBP{alpha} and C/EBP{beta} expression by TGF-{beta}2 was associated with increased PPAR{gamma} serine phosphorylation in bone marrow stromal cells, a mechanism that inhibits PPAR{gamma} transactivating activity. The sequential inhibitory effect of TGF-{beta}2 on C/EBP{alpha}, C/EBP{beta}, and PPAR{gamma}2 resulted in reduced LPL expression and abolition of bone marrow stromal cell adipogenic differentiation, which contributed to prevent bone loss induced by skeletal unloading. We conclude that TGF-{beta}2 inhibits the excessive adipogenic differentiation of bone marrow stromal cells induced by skeletal unloading by inhibiting C/EBP{alpha}, C/EBP{beta}, and PPAR{gamma} expression and activity, which provides a sequential mechanism by which TGF-{beta}2 regulates adipogenic differentiation of bone marrow stromal cells in vivo.« less

Nicotine promotes cell proliferation via {alpha}7-nicotinic acetylcholine receptor and catecholamine-synthesizing enzymes-mediated pathway in human colon adenocarcinoma HT-29 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wong, Helen Pui Shan; Yu Le; Lam, Emily Kai Yee

Cigarette smoking has been implicated in colon cancer. Nicotine is a major alkaloid in cigarette smoke. In the present study, we showed that nicotine stimulated HT-29 cell proliferation and adrenaline production in a dose-dependent manner. The stimulatory action of nicotine was reversed by atenolol and ICI 118,551, a {beta}{sub 1}- and {beta}{sub 2}-selective antagonist, respectively, suggesting the role of {beta}-adrenoceptors in mediating the action. Nicotine also significantly upregulated the expression of the catecholamine-synthesizing enzymes [tyrosine hydroxylase (TH), dopamine-{beta}-hydroxylase (D{beta}H) and phenylethanolamine N-methyltransferase]. Inhibitor of TH, a rate-limiting enzyme in the catecholamine-biosynthesis pathway, reduced the actions of nicotine on cell proliferationmore » and adrenaline production. Expression of {alpha}7-nicotinic acetylcholine receptor ({alpha}7-nAChR) was demonstrated in HT-29 cells. Methyllycaconitine, an {alpha}7-nAChR antagonist, reversed the stimulatory actions of nicotine on cell proliferation, TH and D{beta}H expression as well as adrenaline production. Taken together, through the action on {alpha}7-nAChR nicotine stimulates HT-29 cell proliferation via the upregulation of the catecholamine-synthesis pathway and ultimately adrenaline production and {beta}-adrenergic activation. These data reveal the contributory role {alpha}7-nAChR and {beta}-adrenoceptors in the tumorigenesis of colon cancer cells and partly elucidate the carcinogenic action of cigarette smoke on colon cancer.« less

Cytotoxic triterpenoid saponins from the fruits of Aesculus pavia L.

PubMed

Zhang, Zhizhen; Li, Shiyou

2007-08-01

Continued chemical investigation on the fruits of North American Aesculus pavia L. resulted in the isolation and identification of 13 polyhydroxyoleanene pentacyclic triterpenoid saponins, named aesculiosides IIe-IIk (1-7), and IIIa-IIIf (8-13), together with 18 known compounds: aesculiosides Ia-Ie (14-18), IIa-IId (19-22), IVa-IVc (23-25), 3-O-[beta-D-galactopyranosyl(1-->2)]-alpha-L-arabinofuranosyl(1-->3)-beta-D-glucuronopyranosyl-21,22-O-diangeloyl-3beta,15 alpha,16 alpha,21 beta,22 alpha,28-hexahydroxyolean-12-ene (26), 3-O-[beta-D-glucopyranosyl(1-->2)]-alpha-L-arabinofuranosyl(1-->3)-beta-D-glucuronopyranosyl-21,22-O-diangeloyl-3beta,16 alpha,21 beta,22 alpha,24 beta,28-hexahydroxyolean-12-ene (27), 3-O-[beta-D-galactopyranosyl(1-->2)]-alpha-L-arabinofuranosyl(1-->3)-beta-D-glucuronopyranosyl-21,22-O-diangeloyl-3beta,16 alpha,21 beta,22 alpha,28-pentahydroxyolean-12-ene (28), R(1)-barrigenol (29), scopolin (30), and 5-methoxyscopolin (31). The structures of these compounds were elucidated by spectroscopic and chemical analyses. Compounds 14-22 and 26-28 were tested in vitro for their activity against 59 cell lines from nine different human cancers including leukemia, non-small cell lung, colon, CNS, melanoma, ovarian, renal, prostate, and breast. It was found that compounds with two-acyl groups at C-21 and C-22 had cytotoxic activity for all cell lines tested with GI(50) 0.175-8.71 microM, while compounds without acyl groups at C-21 and C-22 had weak or no cytotoxic activity. These results suggest that the acyl groups at C-21 and C-22 are essential for their activity.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seomun, Young; Joo, Choun-Ki

Lumican is a major proteoglycans of the human cornea. Lumican knock-out mice have been shown to lose corneal transparency and to display delayed wound healing. The purpose of this study was to define the role of lumican in corneal epithelial cell migration. Over-expression of lumican in human corneal epithelial (HCE-T) cells increased both cell migration and proliferation, and increased levels of integrins {alpha}2 and {beta}1. ERK 1/2 was also activated in lumican over-expressed cells. When we treated HCE-T cells with the ERK-specific inhibitor U0126, cell migration and the expression of integrin {beta}1 were completely blocked. These data provide evidence thatmore » lumican stimulates cell migration in the corneal epithelium by activating ERK 1/2, and point to a novel signaling pathway implicated in corneal epithelial cell migration.« less

Anticancer and antioxidant tannins from Pimenta dioica leaves.

PubMed

Marzouk, Mohamed S A; Moharram, Fatma A; Mohamed, Mona A; Gamal-Eldeen, Amira M; Aboutabl, Elsayed A

2007-01-01

Two galloylglucosides, 6-hydroxy-eugenol 4-O-(6'-O-galloyl)-beta-D-4C1-glucopyranoside (4) and 3-(4-hydroxy-3-methoxyphenyl)-propane-1,2-diol-2-O-(2',6'-di-O-galloyl)-beta-D -4C1-glucopyranoside (7), and two C-glycosidic tannins, vascalaginone (10) and grandininol (14), together with fourteen known metabolites, gallic acid (1), methyl gallate (2), nilocitin (3), 1-O-galloyl-4,6-(S)-hexahydroxydiphenoyl-(alpha/beta)-D-glucopyranose (5), 4,6-(S)-hexahydroxydiphenoyl-(alpha/beta)-D-glucopyranose (6), 3,4,6-valoneoyl-(alpha/beta)-D-glucopyranose (8), pedunculagin (9), casuariin (11), castalagin (12), vascalagin (13), casuarinin (15), grandinin (16), methyl-flavogallonate (17) and ellagic acid (18), were identified from the leaves of Pimenta dioica (Merr.) L. (Myrtaceae) on the basis of their chemical and physicochemical analysis (UV, HRESI-MS, 1D and 2D NMR). It was found that 9 is the most cytotoxic compound against solid tumour cancer cells, the most potent scavenger against the artificial radical DPPH and physiological radicals including ROO*, OH*, and O2-*, and strongly inhibited the NO generation and induced the proliferation of T-lymphocytes and macrophages. On the other hand, 3 was the strongest NO inhibitor and 16 the highest stimulator for the proliferation of T-lymphocytes, while 10 was the most active inducer of macrophage proliferation.

Proteomic profiling of bone marrow mesenchymal stem cells upon TGF-beta stimulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Daojing; Park, Jennifer S.; Chu, Julia S.F.

Bone marrow mesenchymal stem cells (MSCs) can differentiate into different types of cells, and have tremendous potential for cell therapy and tissue engineering. Transforming growth factor {beta}1 (TGF-{beta}) plays an important role in cell differentiation and vascular remodeling. We showed that TGF-{beta} induced cell morphology change and an increase in actin fibers in MSCs. To determine the global effects of TGF-{beta} on MSCs, we employed a proteomic strategy to analyze the effect of TGF-{beta} on the human MSC proteome. By using two-dimensional gel electrophoresis and electrospray ionization coupled to Quadrupole/time-of-flight tandem mass spectrometers, we have generated a proteome reference mapmore » of MSCs, and identified {approx}30 proteins with an increase or decrease in expression or phosphorylation in response to TGF-{beta}. The proteins regulated by TGF-{beta} included cytoskeletal proteins, matrix synthesis proteins, membrane proteins, metabolic enzymes, etc. TGF-{beta} increased the expression of smooth muscle (SM) {alpha}-actin and decreased the expression of gelsolin. Over-expression of gelsolin inhibited TGF-{beta}-induced assembly of SM {alpha}-actin; on the other hand, knocking down gelsolin expression enhanced the assembly of {alpha}-actin and actin filaments without significantly affecting {alpha}-actin expression. These results suggest that TGF-{beta} coordinates the increase of {alpha}-actin and the decrease of gelsolin to promote MSC differentiation. This study demonstrates that proteomic tools are valuable in studying stem cell differentiation and elucidating the underlying molecular mechanisms.« less

Altered expression of extracellular matrix molecules and their receptors in chronic pancreatitis and pancreatic adenocarcinoma in comparison with normal pancreas.

PubMed

Shimoyama, S; Gansauge, F; Gansauge, S; Oohara, T; Beger, H G

1995-12-01

The aim of this study was to elucidate the expression and distribution patterns of both integrins and extracellular matrix (ECM) molecules in chronic pancreatitis (CP) and pancreatic adenocarcinoma (PC) compared with normal pancreas (NP). Expression of nine alpha-subunits (alpha 2-alpha 6, alpha V, alpha L, alpha M, and alpha X), four beta-subunits (beta 1, beta 3-beta 5), and four ECM molecules (type IV collagen, laminin, fibronectin, and vitronectin) was investigated immunohistochemically. In CP, all integrins except alpha V showed nearly the same staining patterns compared with NP. Some acinar cells in CP expressed alpha V. Whereas alpha 2, alpha 3, and alpha 6 expression was stronger and diffuse, no alpha 5 expression was seen in PC. Basement membrane (BM) showed continuous staining in CP, whereas it showed discontinuous/absent staining in PC with antitype IV collagen, laminin, and vitronectin antibodies. Some carcinoma cells showed reverse correlation between alpha 2, alpha 3, and alpha 6 expression and type IV collagen and laminin expression. Fibronectin showed diffuse stromal expression in CP and PC. Some acinar cells or duct cells in CP carcinoma cells in PC showed intracellular VN expression. These results suggest that these integrins and ECM molecules are involved in inflammatory and malignant processes in pancreas.

Uroepithelial cells are part of a mucosal cytokine network.

PubMed Central

Hedges, S; Agace, W; Svensson, M; Sjögren, A C; Ceska, M; Svanborg, C

1994-01-01

This study compared the cytokine production of uroepithelial cell lines in response to gram-negative bacteria and inflammatory cytokines. Human kidney (A498) and bladder (J82) epithelial cell lines were stimulated with either Escherichia coli Hu734, interleukin 1 alpha (IL-1 alpha), or tumor necrosis factor alpha (TNF-alpha). Supernatant samples were removed, and the RNA was extracted from cells at 0, 2, 6, and 24 h. The secreted cytokine levels were determined by bioassay or immunoassay; mRNA was examined by reverse transcription-PCR. The two cell lines secreted IL-6 and IL-8 constitutively. IL-6 and IL-8 mRNA were constitutively produced in both cell lines; IL-1 beta mRNA was detected in J82 cells. IL-1 alpha induced significantly higher levels of IL-6 secretion than did E. coli Hu734 or TNF-alpha. IL-1 alpha and TNF-alpha induced significantly higher levels of IL-8 secretion than did E. coli Hu734. Secreted IL-1 beta was not detected; IL-1 alpha and TNF-alpha were not detected above the levels used for stimulation. IL-1 alpha, IL-1 beta, IL-6, and IL-8 mRNAs were detected in both cell lines after exposure to the stimulants. TNF-alpha mRNA was occasionally detected in the J82 cell line after TNF-alpha stimulation. Cytokine (IL-6 and IL-8) and control (glyceraldehyde 3-phosphate dehydrogenase [G3PDH] and beta-actin) mRNA concentrations were quantitated with internal PCR standards. Cytokine mRNA levels relative to beta-actin mRNA levels were the highest in E. coli-stimulated cells. In comparison, the cytokine mRNA levels relative to G3PDH mRNA levels were the highest in IL-1 alpha-stimulated cells. beta-Actin mRNA levels decreased after bacterial stimulation but not after cytokine stimulation, while G3PDH mRNA levels increased in response to all of the stimulants tested. These results suggested that E. coli Hu734 lowered the beta-actin mRNA levels in uroepithelial cells, thus distorting the IL-6 and IL-8 mRNA levels relative to this control. In summary, E. coli IL-1 alpha and TNF-alpha were found to activate the de novo synthesis and secretion of IL-6 and IL-8 in uroepithelial cells. These results emphasize the role of epithelial cells in cytokine-mediated responses during the early stages of infection. Images PMID:8188354

Cellular localization and expression of template-activating factor I in different cell types.

PubMed

Nagata, K; Saito, S; Okuwaki, M; Kawase, H; Furuya, A; Kusano, A; Hanai, N; Okuda, A; Kikuchi, A

1998-05-01

Template-activating factors I (TAF-I) alpha and beta have been identified as chromatin remodeling factors from human HeLa cells. TAF-I beta corresponds to the protein encoded by the set gene, which was found in an acute undifferentiated leukemia as a fusion version with the can gene via chromosomal translocation. To determine the localization of TAF-I, we raised both polyclonal and monoclonal antibodies against TAF-I. The proteins that react to the antibodies are present not only in human cells but also in mouse, frog, insect, and yeast cells. The mouse TAF-I homologue is ubiquitous in a variety of tissue cells, including liver, kidney, spleen, lung, heart, and brain. It is of interest that the amounts of TAF-I alpha and beta vary among hemopoietic cells and some specific cell types do not contain TAF-I alpha. The level of the TAF-I proteins does not change significantly during the cell cycle progression in either HeLa cells synchronized with an excess concentration of thymidine or NIH 3T3 cells released from the serum-depleted state. TAF-I is predominantly located in nuclei, while TAF-I that is devoid of its acidic region, the region which is essential for the TAF-I activity, shows both nuclear and cytoplasmic localization. The localization of TAF-I in conjunction with the regulation of its activity is discussed.

Lysosomal isoenzyme profiles used to classify a case of acute undifferentiated leukaemia.

PubMed

Eden, O B; Darbyshire, P; Simpson, R M; Besley, G T; Moss, S; Gentle, T

1985-01-01

Lysosomal enzyme activities and isoenzyme profiles were measured in lymphoid and non-lymphoid leukaemic cells from childhood patients. High activities, especially of beta-hexosaminidase and alpha-mannosidase, were associated with leukaemic cells of myeloid or monocytic origin. Leukaemic cells from two children with acute myeloid leukaemia had a relative reduction in the B isoenzyme of beta-hexosaminidase activity, whereas in patients with non T, non B cell acute lymphoblastic leukaemia, intermediate beta-hexosaminidase isoenzymes were expressed. A patient is described on whom conventional marker studies were either negative or equivocal, but lysosomal enzyme markers were consistent with a myeloid leukaemia. This observation was supported by the clinical course of this patient.

Murine Ia-associated invariant chain's processing to complex oligosaccharide forms and its dissociation from the I-Ak complex.

PubMed

Holt, G D; Swiedler, S J; Freed, J H; Hart, G W

1985-07-01

The processing of murine invariant chain (Ii) to a cell surface form bearing complex N-linked oligosaccharides has been demonstrated in the B cell lymphoma, AKTB-1b. In addition, the rate of processing of pulse-labeled Ii has been determined relative to its rate of dissociation from the alpha/beta complex of I-Ak. Ii, alpha-, and beta-chains were immunoprecipitated with anti-I-Ak or anti-Ii monoclonal antibodies. The heretofore uncharacterized complex oligosaccharide form of Ii (Ii-c) was identified in gel-purified immunoprecipitates by peptide mapping with reverse-phase HPLC. Ii-c is resistant to deglycosylation by Endo H, which is specific for high-mannose N-linkages, but can be digested with Endo F, a glycosidase capable of cleaving both complex and high-mannose N-linked oligosaccharides. Immunoprecipitation of surface iodinated cells indicates that Ii-c is expressed on the plasma membrane. Pulse-chase metabolic labeling data show that the processing of Ii to Ii-c occurs with a t1/2 of about 120 min. In contrast, the processing of both alpha- and beta-chains of I-Ak to complex forms occurs with a t1/2 of 15 to 20 min. Our data show that Ii-hm begins to dissociate rapidly from the I-Ak complex after 100 to 120 min of chase. Only a small amount (less than 5% on a per mole basis) of Ii-c was found associated with the I-Ak complexes after 300 min of continuous metabolic labeling. These results are consistent with Ii serving as a carrier for Ia antigens as they are transported to the cell surface. In addition, they suggest that the processing of Ii to Ii-c, or a late processing event of the alpha- and beta-chains, such as their sialylation, may be a possible mechanism for inducing the dissociation of Ii from the I-Ak complex.

Mycobacterium leprae-Infected Macrophages Preferentially Primed Regulatory T Cell Responses and Was Associated with Lepromatous Leprosy.

PubMed

Yang, Degang; Shui, Tiejun; Miranda, Jake W; Gilson, Danny J; Song, Zhengyu; Chen, Jia; Shi, Chao; Zhu, Jianyu; Yang, Jun; Jing, Zhichun

2016-01-01

The persistence of Mycobacterium leprae (M. leprae) infection is largely dependent on the types of host immune responses being induced. Macrophage, a crucial modulator of innate and adaptive immune responses, could be directly infected by M. leprae. We therefore postulated that M. leprae-infected macrophages might have altered immune functions. Here, we treated monocyte-derived macrophages with live or killed M. leprae, and examined their activation status and antigen presentation. We found that macrophages treated with live M. leprae showed committed M2-like function, with decreased interleukin 1 beta (IL-1beta), IL-6, tumor necrosis factor alpha (TNF-alpha) and MHC class II molecule expression and elevated IL-10 and CD163 expression. When incubating with naive T cells, macrophages treated with live M. leprae preferentially primed regulatory T (Treg) cell responses with elevated FoxP3 and IL-10 expression, while interferon gamma (IFN-gamma) expression and CD8+ T cell cytotoxicity were reduced. Chromium release assay also found that live M. leprae-treated macrophages were more resistant to CD8+ T cell-mediated cytotoxicity than sonicated M. leprae-treated monocytes. Ex vivo studies showed that the phenotype and function of monocytes and macrophages had clear differences between L-lep and T-lep patients, consistent with the in vitro findings. Together, our data demonstrate that M. leprae could utilize infected macrophages by two mechanisms: firstly, M. leprae-infected macrophages preferentially primed Treg but not Th1 or cytotoxic T cell responses; secondly, M. leprae-infected macrophages were more effective at evading CD8+ T cell-mediated cytotoxicity.

Influence of somatic cell count and breed on capillary electrophoretic protein profiles of ewes' milk: a chemometric study.

PubMed

Rodríguez-Nogales, J M; Vivar-Quintana, A M; Revilla, I

2007-07-01

Bulk tank ewe milk from the Assaf, Castellana, and Churra breeds categorized into 3 somatic cell count (SCC) groups (<500,000; 1,000,000 to 1,500,000; and >2,500,000 cells/mL) was used to investigate changes in chemical composition and capillary electrophoresis protein profiles. The results obtained indicated that breed affected fat, protein, and total solids levels, and differences were also observed for the following milk proteins: beta-, beta1-, beta2-, and alpha(s1)-III-casein, alpha-lactalbumin, and beta-lactoglobulin. High SCC affected fat and protein contents and bacterial counts. The level of beta1-, beta2-, and alpha(s1)-I-casein, and alpha-lactalbumin were significantly lower in milk with SCC scores >2,500,000 cells/mL. A preliminary study of the chemical, microbiological, and electrophoretic data was performed by cluster analysis and principal components analysis. Applying discriminant analysis, it was possible to group the milk samples according to breed and level of SCC, obtaining a prediction of 100 and 97% of the samples, respectively.

RANTES release by human airway smooth muscle: effects of prostaglandin E(2) and fenoterol.

PubMed

Lazzeri, N; Belvisi, M G; Patel, H J; Chung, K F; Yacoub, M H; Mitchell, J A

2001-12-21

In human airway smooth muscle cells, the levels of RANTES were increased upon stimulation with interleukin-1beta together with tumour necrosis factor-alpha (TNF-alpha) (10 ng ml(-1) for each). In this study, we have assessed the effects of prostaglandin E(2) and the beta(2)-adrenoceptor agonist, fenoterol on RANTES (regulated upon activation, normal T cell expressed and secreted) release by these cells. The levels of RANTES released by human airway smooth muscle cells were measured after 24 h of treatment. Prostaglandin E(2) and fenoterol, only in presence of a cyclo-oxygenase inhibitor indomethacin (10(-6) M), provoked a concentration-dependent reduction in RANTES release. These data suggest that, in settings where cyclo-oxygenase activity is low, both drugs may relieve the symptoms of airway diseases by reducing RANTES production.

Rift valley fever virus nonstructural protein NSs promotes viral RNA replication and transcription in a minigenome system.

PubMed

Ikegami, Tetsuro; Peters, C J; Makino, Shinji

2005-05-01

Rift Valley fever virus (RVFV), which belongs to the genus Phlebovirus, family Bunyaviridae, has a tripartite negative-strand genome (S, M, and L segments) and is an important mosquito-borne pathogen for domestic animals and humans. We established an RVFV T7 RNA polymerase-driven minigenome system in which T7 RNA polymerase from an expression plasmid drove expression of RNA transcripts for viral proteins and minigenome RNA transcripts carrying a reporter gene between both termini of the M RNA segment in 293T cells. Like other viruses of the Bunyaviridae family, replication and transcription of the RVFV minigenome required expression of viral N and L proteins. Unexpectedly, the coexpression of an RVFV nonstructural protein, NSs, with N and L proteins resulted in a significant enhancement of minigenome RNA replication. Coexpression of NSs protein with N and L proteins also enhanced minigenome mRNA transcription in the cells expressing viral-sense minigenome RNA transcripts. NSs protein expression increased the RNA replication of minigenomes that originated from S and L RNA segments. Enhancement of minigenome RNA synthesis by NSs protein occurred in cells lacking alpha/beta interferon (IFN-alpha/beta) genes, indicating that the effect of NSs protein on minigenome RNA replication was unrelated to a putative NSs protein-induced inhibition of IFN-alpha/beta production. Our finding that RVFV NSs protein augmented minigenome RNA synthesis was in sharp contrast to reports that Bunyamwera virus (genus Bunyavirus) NSs protein inhibits viral minigenome RNA synthesis, suggesting that RVFV NSs protein and Bunyamwera virus NSs protein have distinctly different biological roles in viral RNA synthesis.

Evolution and Function of the TCR Vgamma9 Chain Repertoire: It’s Good to be Public

PubMed Central

Pauza, C. David; Cairo, Cristiana

2015-01-01

Lymphocytes expressing a T cell receptor (TCR) composed of Vgamma9 and Vdelta2 chains represent a minor fraction of human thymocytes. Extrathymic selection throughout post-natal life causes the proportion of cells with a Vgamma9-JP rearrangement to increase and elevates the capacity for responding to non-peptidic phosphoantigens. Extrathymic selection is so powerful that phosphoantigen-reactive cells comprise about 1 in 40 circulating memory T cells from healthy adults and the subset can be expanded rapidly upon infection or in response to malignancy. Skewing of the gamma delta TCR repertoire is accompanied by selection for public gamma chain sequences such that many unrelated individuals overlap extensive in their circulating repertoire. This type of selection implies the presence of a monomorphic antigen-presenting molecule that is an object of current research but remains incompletely defined. While selection on a monomorphic presenting molecule may seem unusual, similar mechanisms shape the alpha beta T cell repertoire including the extreme examples of NKT or mucosal-associated invariant T cells (MAIT) and the less dramatic amplification of public Vbeta chain rearrangements driven by individual MHC molecules and associated with resistance to viral pathogens. Selecting and amplifying public T cell receptors whether alpha beta or gamma delta, are important steps in developing an anticipatory TCR repertoire. Cell clones expressing public TCR can accelerate the kinetics of response to pathogens and impact host survival. PMID:25769734

Isolation of mouse pancreatic alpha, beta, duct and acinar populations with cell surface markers.

PubMed

Dorrell, Craig; Grompe, Maria T; Pan, Fong Cheng; Zhong, Yongping; Canaday, Pamela S; Shultz, Leonard D; Greiner, Dale L; Wright, Chris V; Streeter, Philip R; Grompe, Markus

2011-06-06

Tools permitting the isolation of live pancreatic cell subsets for culture and/or molecular analysis are limited. To address this, we developed a collection of monoclonal antibodies with selective surface labeling of endocrine and exocrine pancreatic cell types. Cell type labeling specificity and cell surface reactivity were validated on mouse pancreatic sections and by gene expression analysis of cells isolated using FACS. Five antibodies which marked populations of particular interest were used to isolate and study viable populations of purified pancreatic ducts, acinar cells, and subsets of acinar cells from whole pancreatic tissue or of alpha or beta cells from isolated mouse islets. Gene expression analysis showed the presence of known endocrine markers in alpha and beta cell populations and revealed that TTR and DPPIV are primarily expressed in alpha cells whereas DGKB and GPM6A have a beta cell specific expression profile. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Proteomic characterization of paired non-malignant and malignant African-American prostate epithelial cell lines distinguishes them by structural proteins.

PubMed

Myers, Jennifer S; Vallega, Karin A; White, Jason; Yu, Kaixian; Yates, Clayton C; Sang, Qing-Xiang Amy

2017-07-11

While many factors may contribute to the higher prostate cancer incidence and mortality experienced by African-American men compared to their counterparts, the contribution of tumor biology is underexplored due to inadequate availability of African-American patient-derived cell lines and specimens. Here, we characterize the proteomes of non-malignant RC-77 N/E and malignant RC-77 T/E prostate epithelial cell lines previously established from prostate specimens from the same African-American patient with early stage primary prostate cancer. In this comparative proteomic analysis of RC-77 N/E and RC-77 T/E cells, differentially expressed proteins were identified and analyzed for overrepresentation of PANTHER protein classes, Gene Ontology annotations, and pathways. The enrichment of gene sets and pathway significance were assessed using Gene Set Enrichment Analysis and Signaling Pathway Impact Analysis, respectively. The gene and protein expression data of age- and stage-matched prostate cancer specimens from The Cancer Genome Atlas were analyzed. Structural and cytoskeletal proteins were differentially expressed and statistically overrepresented between RC-77 N/E and RC-77 T/E cells. Beta-catenin, alpha-actinin-1, and filamin-A were upregulated in the tumorigenic RC-77 T/E cells, while integrin beta-1, integrin alpha-6, caveolin-1, laminin subunit gamma-2, and CD44 antigen were downregulated. The increased protein level of beta-catenin and the reduction of caveolin-1 protein level in the tumorigenic RC-77 T/E cells mirrored the upregulation of beta-catenin mRNA and downregulation of caveolin-1 mRNA in African-American prostate cancer specimens compared to non-malignant controls. After subtracting race-specific non-malignant RNA expression, beta-catenin and caveolin-1 mRNA expression levels were higher in African-American prostate cancer specimens than in Caucasian-American specimens. The "ECM-Receptor Interaction" and "Cell Adhesion Molecules", and the "Tight Junction" and "Adherens Junction" pathways contained proteins are associated with RC-77 N/E and RC-77 T/E cells, respectively. Our results suggest RC-77 T/E and RC-77 N/E cell lines can be distinguished by differentially expressed structural and cytoskeletal proteins, which appeared in several pathways across multiple analyses. Our results indicate that the expression of beta-catenin and caveolin-1 may be prostate cancer- and race-specific. Although the RC-77 cell model may not be representative of all African-American prostate cancer due to tumor heterogeneity, it is a unique resource for studying prostate cancer initiation and progression.

Endosulfan in China 2-emissions and residues.

PubMed

Jia, Hongliang; Sun, Yeqing; Li, Yi-Fan; Tian, Chongguo; Wang, Degao; Yang, Meng; Ding, Yongshen; Ma, Jianmin

2009-05-01

Endosulfan is one of the organochlorine pesticides (OCPs) and also a candidate to be included in a group of new persistent organic pollutants (UNEP 2007). The first national endosulfan usage inventories in China with 1/4 degrees longitude by 1/6 degrees latitude resolution has been reported in an accompanying paper. In the second part of the paper, we compiled the gridded historical emissions and soil residues of endosulfan in China from the usage inventories. Based on the residue/emission data, gridded concentrations of endosulfan in Chinese soil and air have been calculated. These inventories will provide valuable data for the further study of endosulfan. Emission and residue of endosulfan were calculated from endosulfan usage by using a simplified gridded pesticide emission and residue model-SGPERM, which is an integrated modeling system combining mathematical model, database management system, and geographic information system. By using the emission and residue inventories, annual air and soil concentrations of endosulfan in each cell were determined. Historical gridded emission and residue inventories of alpha- and beta-endosulfan in agricultural soil in China with 1/4 degrees longitude by 1/6 degrees latitude resolution have been created. Total emissions were around 10,800 t, with alpha-endosulfan at 7,400 t and beta-endosulfan at 3,400 t from 1994 to 2004. The highest residues were 140 t for alpha-endosulfan and 390 t for beta-endosulfan, and the lowest residues were 0.7 t for alpha-endosulfan and 170 t for beta-endosulfan in 2004 in Chinese agricultural soil where endosulfan was applied. Based on the emission and residue inventories, concentrations of alpha- and beta-endosulfan in Chinese air and agricultural surface soil were also calculated for each grid cell. We have estimated annual averaged air concentrations and the annual minimum and maximum soil concentrations across China. The real concentrations will be different from season to season. Although our model does not consider the transport of the insecticide in the atmosphere, which could be very important in some areas during some special time, the estimated concentrations of endosulfan in Chinese air and soil derived from the endosulfan emission and residue inventories are in general consistent with the published monitoring data. To our knowledge, this work is the first inventory of this kind for endosulfan published on a national scale. Concentrations of the chemical in Chinese air and agricultural surface soil were calculated for each grid cell. Results show that the estimated concentrations of endosulfan in Chinese air and soil agree reasonably well with the monitoring data in general. The gridded endosulfan emission/residue inventories and also the air and soil concentration inventories created in this study will be updated upon availability of new information, including usage and monitoring data. The establishment of these inventories for the OCP is important for both scientific communities and policy makers.

Human common acute lymphoblastic leukemia-derived cell lines are competent to recombine their T-cell receptor delta/alpha regions along a hierarchically ordered pathway.

PubMed

Hansen-Hagge, T E; Yokota, S; Reuter, H J; Schwarz, K; Bartram, C R

1992-11-01

Rearrangements of the T-cell receptor (TCR) delta locus are observed in the majority of human B-cell precursor acute lymphoblastic leukemias (ALL) with a striking predominance of V delta 2(D)D delta 3 recombinations in common ALL (cALL) patients. Recently, we and others showed that almost 20% of cALL cases are characterized by further recombination of V delta 2(D)D delta 3 segments to J alpha elements, thereby deleting the TCR delta locus in analogy to the delta Rec/psi J alpha pathway in differentiating alpha/beta-positive T cells. We report here that two human cALL-derived cell lines, REH and Nalm-6, are competent to recombine the TCR delta/alpha locus under standard tissue culture conditions. Analysis of different REH subclones obtained by limiting dilution of the initial culture showed a biased recombination of V delta 2D delta 3 to distinct J alpha elements. During prolonged tissue culture, a subclone acquired growth advantage and displaced parental cells as well as other subclones. Frequently, the DJ junctions of REH subclones contained extended stretches of palindromic sequences derived from modified D delta 3 coding elements. The other cell line, Nalm-6, started the TCR delta/alpha recombination with an unusual signal joint of a cryptic recombinase signal sequence (RSS) upstream of D delta 3 to the 3' RSS of D delta 3. The RSS dimer was subsequently rearranged in all investigated subclones to an identical J alpha element. Both cell lines might become valuable tools to unravel the complex regulation of TCR delta/alpha recombination pathways in malignant and normal lymphopoiesis.

p38 Mitogen-Activated Protein Kinase in Metastasis Associated with Transforming Growth Factor Beta

DTIC Science & Technology

2006-06-01

Functional Analysis of cells • Expression of HA-tagged TβRI • Signaling (p-Smad2, p- HSP27 , p-p38) • Transcription (SBE-Lux, 3TP-Lux) • Proliferation...when they also affected lls expressing DN-p38alpha phosphorylation of HSP27 was effectively blocked (data not shown). However, cells e studies show...231-ALK5-T204D cells treated with kinase inhibitors U0126, SB202190, SP600125 (JNK). (B) Immunoblot of phospho-Smad2/3, phospho- HSP27 , and alpha

Integrin-mediated transforming growth factor-beta activation regulates homeostasis of the pulmonary epithelial-mesenchymal trophic unit.

PubMed

Araya, Jun; Cambier, Stephanie; Morris, Alanna; Finkbeiner, Walter; Nishimura, Stephen L

2006-08-01

Trophic interactions between pulmonary epithelial and mesenchymal cell types, known as the epithelial-mesenchymal trophic unit (EMTU), are crucial in lung development and lung disease. Transforming growth factor (TGF)-beta is a key factor in mediating these interactions, but it is expressed in a latent form that requires activation to be functional. Using intact fetal tracheal tissue and primary cultures of fetal tracheal epithelial cells and fibroblasts, we demonstrate that a subset of integrins, alpha(v)beta(6) and alpha(v)beta(8), are responsible for almost all of the TGF-beta activation in the EMTU. Both alpha(v)beta(8) and alpha(v)beta(6) contribute to fetal tracheal epithelial activation of TGF-beta, whereas only alpha(v)beta(8) contributes to fetal tracheal fibroblast activation of TGF-beta. Interestingly, fetal tracheal epithelial alpha(v)beta(8)-mediated TGF-beta activation can be enhanced by phorbol esters, likely because of the increased activity of MT1-MMP, an essential co-factor in alpha(v)beta(8)-mediated activation of TGF-beta. Autocrine alpha(v)beta(8)-mediated TGF-beta activation by fetal tracheal fibroblasts results in suppression of both transcription and secretion of hepatocyte growth factor, which is sufficient to affect phosphorylation of the airway epithelial hepatocyte growth factor receptor, c-Met, as well as airway epithelial proliferation in a co-culture model of the EMTU. These findings elucidate the function and complex regulation of integrin-mediated activation of TGF-beta within the EMTU.

[Chemical constituents of leaves of Psidium guajava].

PubMed

Shao, Meng; Wang, Ying; Jian, Yu-Qing; Sun, Xue-Gang; Huang, Xiao-Jun; Zhang, Xiao-Qi; Ye, Wen-Cai

2014-03-01

To study the chemical constituents of the 95% ethanol extract of Psidium guajava. Compounds were separated by using a combination of various chromatographic methods including silica gel, D101 macroporous resin, ODS, Sephadex LH-20 and preparative HPLC. Their structures were elucidated by physicochemical properties and spectral data Eighteen compounds were isolated and identified as (+) -globulol (1), clovane-2beta, 9alpha-diol (2), 2beta-acetoxyclovan-9alpha-ol (3), (+) -caryolane-1 ,9beta-diol (4), ent-T-muurolol (5), clov-2-ene-9alpha-ol (6), isophytol (7), tamarixetin (8), gossypetin (9), quercetin (10), kaempferol (11), guajaverin (12), avicularin (13), chrysin 6-C-glucoside (14), 3'-O-methyl-3, 4-methylenedioxyellagic acid 4'-O-beta-D-glucopyranoside (15), p-hydroxy-benzoic acid (16), guavinoside A (17) and guavinoside B (18). Compounds 2-9 and 14-16 were isolated from this plant for the first time. The ethanol extract showed 61.3% inhibition against the proliferation of colon cancer cell line SW480.

Characterization of the specificities of human blood group H gene-specified alpha 1,2-L-fucosyltransferase toward sulfated/sialylated/fucosylated acceptors: evidence for an inverse relationship between alpha 1,2-L-fucosylation of Gal and alpha 1,6-L-fucosylation of asparagine-linked GlcNAc.

PubMed

Chandrasekaran, E V; Jain, R K; Larsen, R D; Wlasichuk, K; Matta, K L

1996-07-09

The assembly of complex structures bearing the H determinant was examined by characterizing the specificities of a cloned blood group H gene-specified alpha 1,2-L-fucosyltransferase (FT) toward a variety of sulfated, sialylated, or fucosylated Gal beta 1,3/4GlcNAc beta- or Gal beta 1,3GalNAc alpha-based acceptor structures. (a) As compared to the basic type 2, Gal beta 1,4GlcNAc beta-(K(m) = 1.67 mM), the basic type 1 was 137% active (K(m) = 0.83 mM). (b) On C-6 sulfation of Gal, type 1 became 142.1% active and type 2 became 223.0% active (K(m) = 0.45 mM). (c) On C-6 sulfation of GlcNAc, type 2 showed 33.7% activity. (d) On C-3 or C-4 fucosylation of GlcNAc, both types 1 and 2 lost activity. (e) Type 1 showed 70.8% and 5.8% activity, respectively, on C-6 and C-4 O-methylation of GlcNAc. (f) Type 1 retained 18.8% activity on alpha 2,6-sialylation of GlcNAc. (g) Terminal type 1 or 2 of extended chain had lower activity. (h) With Gal in place of GlcNAc in type 1, the activity became 43.2%. (i) Compounds with terminal alpha 1,3-linked Gal were inactive. (j) Gal beta 1,3GalNAc alpha- (the T-hapten) was approximately 0.4-fold as active as Gal beta 1,4GlcNAc beta-. (k) C-6 sulfation of Gal on the T-hapten did not affect the acceptor activity. (l) C-6 sulfation of GalNAc decreased the activity to 70%, whereas on C-6 sulfation of both Gal and GalNAc the T-hapten lost the acceptor ability. (m) C-6 sialylation of GalNAc also led to inactivity. (n) beta 1,6 branching from GalNAc of the T-hapten by a GlcNAc residue or by units such as Gal beta 1, 4GlcNAc-, Gal beta 1,4(Fuc alpha 1,3)GlcNAc-, or 3-sulfoGal beta 1,4GlcNAc- resulted in 111.9%, 282.8%, 48.3%, and 75.3% activities, respectively. (o) The enhancement of enzyme affinity by a sulfo group on C-6 of Gal was demonstrated by an increase (approximately 5-fold) in the K(m) for Gal beta 1,4GlcNAc beta 1,6(Gal beta 1,3)GalNAc alpha-O-Bn in presence of 6-sulfoGal beta 1,- 4GlcNAc beta-O-Me (3.0 mM). (p) Among the two sites in Gal beta 1, 4GlcNAc beta 1,6(Gal beta 1,3) GalNAc alpha-O-Bn, the enzyme had a higher affinity ( > 3-fold) for the Gal linked to GlcNAc. (q) With respect to Gal beta 1,- 3GlcNAc beta-O-Bn (3.0 mM), fetuin triantennary asialo glycopeptide (2.4 mM), bovine IgG diantennary glycopeptide (2.8 mM), asialo Cowper's gland mucin (0.06 mM), and the acrylamide copolymers (0.125 mM each) containing Gal beta 1,3GlcNAc beta-, Gal beta 1,3(6-sulfo)GlcNAc beta-, Gal beta 1,3GalNAc alpha-, Gal beta 1,3Gal beta-, or Gal alpha 1,3Gal beta- units were 153.6%, 43.0%, 6.2%, 52.5%, 94.9%, 14.7%, 23.6%, and 15.6% active, respectively. (r) Fucosylation by alpha 1,2-L-FT of the galactosyl residue which occurs on the antennary structure of the bovine IgG glycopeptide was adversely affected by the presence of an alpha 1,6-L-fucosyl residue located on the distant glucosaminyl residue that is directly attached to the asparagine of the protein backbone. This became evident from the 4-fold activity of alpha 1,2-L-FT toward bovine IgG glycopeptide after approximately 5% removal of alpha 1,6-linked Fuo.

Expression of transforming growth factor-beta1, -beta2 and -beta3 in normal and diseased canine mitral valves.

PubMed

Aupperle, H; März, I; Thielebein, J; Schoon, H-A

2008-01-01

The pathogenesis of chronic valvular disease (CVD) in dogs remains unclear, but activation and proliferation of valvular stromal cells (VSC) and their transdifferentiation into myofibroblast-like cells has been described. These alterations may be influenced by transforming growth factor-beta (TGF-beta), a cytokine involved in extracellular matrix (ECM) regulation and mesenchymal cell differentiation. The present study investigates immunohistochemically the expression of TGF-beta1, -beta2, -beta3 and smooth muscle alpha actin (alpha-SMA) in normal canine mitral valves (MVs) (n=10) and in the valves of dogs with mild (n=7), moderate (n=14) and severe (n=9) CVD. In normal mitral valves there was no expression of alpha-SMA but VSC displayed variable expression of TGF-beta1 (10% of VSC labelled), TGF-beta2 (1-5% labelled) and TGF-beta3 (50% labelled). In mild CVD the affected atrialis contain activated and proliferating alpha-SMA-positive VSC, which strongly expressed TGF-beta1 and -beta3, but only 10% of these cells expressed TGF-beta2. In unaffected areas of the leaflet there was selective increase in expression of TGF-beta1 and -beta3. In advanced CVD the activated subendothelial VSC strongly expressed alpha-SMA, TGF-beta1 and -beta3. Inactive VSC within the centre of the nodules had much less labelling for TGF-beta1 and -beta3. TGF-beta1 labelling was strong within the ECM. These data suggest that TGF-beta plays a role in the pathogenesis of CVD by inducing myofibroblast-like differentiation of VSC and ECM secretion. Changed haemodynamic forces and expression of matrix metalloproteinases (MMPs) may in turn regulate TGF-beta expression.

Functional integrins from normal and glycosylation-deficient baby hamster kidney cells. Terminal processing of asparagine-linked oligosaccharides is not correlated with fibronectin-binding activity.

PubMed

Koyama, T; Hughes, R C

1992-12-25

We have examined the properties of the alpha 5 beta 1 integrin of baby hamster kidney (BHK) cells, a ricin-resistant variant Ric14 lacking N-acetylglucosaminyl transferase I, and hence unable to complete assembly of hybrid- or complex-type N-glycans, and BHK cells treated with 1-deoxymannojirimycin (dMM), an inhibitor of Golgi mannosidases involved in the initial processing of N-glycan precursors. Comparable amounts of alpha 5 beta 1 integrin were isolated from these cells by chromatography of detergent extracts on a fibronectin cell-binding fragment affinity column and elution with EDTA. The alpha 5 beta 1 integrin obtained from normal BHK cells by fibronectin affinity chromatography contained mainly endoglycosidase H-resistant oligosaccharides, whereas in RicR14 cells or dMM-treated BHK cells these were entirely endoglycosidase H-sensitive. Analysis of lactoperoxidase labeled or long term biosynthetically 35S-labeled proteins from cultures of normal or glycosylation deficient cells showed similar steady state levels of alpha 5 beta 1 integrin and expression at the cell surface. Pulse-chase experiments in normal BHK cells showed rapid conversion of the alpha 5 subunit into a mature form containing oligosaccharides resistant to endoglycosidase H and slower maturation of a precursor beta 1 subunit, as in other cell types. In Ric14 cells the precursor beta 1 subunit was found to carry glycans larger than the fully processed Man5GlcNAc2 glycan of the mature subunit, indicating that the bulk precursor pool had not been translocated into the cis-Golgi compartment containing mannosidase I. We conclude that in BHK cells terminal oligosaccharide processing of alpha 5 beta 1 integrin subunits is not required for dimer formation, surface expression, and fibronectin binding, and that expression of the glycosylation defect of Ric14 cells on the alpha 5 beta 1 integrin does not account for the reduced adhesiveness of these cells on fibronectin compared with normal and dMM-treated BHK cells.

Genetics Home Reference: mucolipidosis III alpha/beta

MedlinePlus

... R, Kudo M, Martinelli M, Bosshard NU, Schaffner T, Kornfeld S, Steinmann B. A splicing mutation in the alpha/beta GlcNAc- ... N, Reutter G, Cantz M, Ullrich K, Braulke T. Missense mutations in ... A, Czartoryska B, Groener JE, Ługowska A. Clinical variability in mucolipidosis ...

The influence of surface integrin binding patterns on specific biomaterial-cell interactions

NASA Astrophysics Data System (ADS)

Beranek, Maggi Marie

As the future of biomaterials progresses toward bioactivity, the biomaterial surface must control non-specific protein adsorption and encourage selective protein and cell adsorption. Integrins alphavbeta3, alpha 1beta1, alpha5beta1 and alpha Mbeta2 are expressed on cells involved in endothelialization, inflammation, and intimal hyperplasia. These cellular events play a vital role in biomaterial biocompatibility, especially in the vascular environment. The overall hypothesis of these studies is that biomaterial surfaces exhibit selective integrin binding, which then specifies differential cell binding. To test this hypothesis, four specific aims were developed. The first aim was designed to determine whether metal and polymeric biomaterials exhibit selective integrin binding. The tested materials included 316L stainless steel, nitinol, gold, Elgiloy RTM, poly(D, L-lactide-co-glycolide), polycarbonate urethane and expanded polytetrafluoroethylene. Discrete integrin binding patterns were detected microscopically using integrin specific fluorescent antibodies. Stainless steel exhibited high level integrin alpha1beta 1 and low level integrin alphaMbeta2 binding pattern. This suggests that this metal surface should selectively encourage endothelial cell to inflammatory cell binding. In contrast, gold bound ten times the amount of integrin alphaMbeta2 compared to integrin alpha1beta1, which should encourage inflammatory cell adhesion. The 65/35 poly(D, L-lactide-co-glycolide) was the only polymeric biomaterial tested that had integrin binding levels comparable to metal biomaterials. Based on these observations, a combinational biomaterial with a surface pattern of 65/35 poly(D, L-lactide-co-glycolide) dots on a 316L stainless steel background was created. A pattern of high level integrin alpha1beta1 binding and low level integrin alpha Mbeta2 binding on this combinational surface indicates that this surface should selectively favor endothelial cell binding. In the second aim, the response of surface-bound integrins to flow-related shear stress was examined. Based on fluorescent analysis, total alphavbeta 3, alpha1beta1, and alpha5beta 1 appeared to increase on stainless steel after 90-minute low shear stress exposure, whereas only alpha5beta1 appeared to increase when exposed to high shear. 65/35 poly(D, L-lactide-co-glycolide) exhibited increased total binding of alpha5beta1 and alphaMbeta2, when exposed to either shear stress level. Exposure to either shear stress regimen appeared to increase binding of all integrins on the combinational surface. These responses to shear stress suggest differential integrin binding affinity compared to stainless steel. Using antibodies specific to the integrin subunits, the apparent increase in surface-bound integrins was found to be related to a surface disassociation of alpha and beta subunits. The third aim evaluated human aortic endothelial cells and acute monocytic leukemia cells (THP-1) cell binding to the tested biomaterial surfaces under both static and flow conditions. Both stainless steel and the combinational surface had increased endothelial cell binding compared to monocyte attachment. Pre-incubation of the surface with the specific integrins significantly inhibited human aortic endothelial cell binding. Aim four was designed to investigate the influence of surface bound integrins on human aortic endothelial cell migration under shear stress. If biomaterial surface integrin binding patterns are specific, then pre-bound surface integrins should competitively inhibit binding of cellular integrins to the surface. Cell migration distance on to alphavbeta3, alpha 1beta1, and alpha5beta1 pre-incubated stainless steel was decreased ten-fold, and decreased by three-fold on both 65/35 poly(D, L-lactide-coglycolide) and combinational surfaces compared to the respective bare surfaces. In contrast, migration distance on to alphaMbeta2 pre-coated stainless steel and combinational surface was decreased by only sixty percent and only fifty percent on alphaMbeta2 precoated 65/35 poly(D, L -lactide-co-glycolide). These results suggested that surface binding sites are selective and critical in governing endothelial cell migration. In conclusion, these results support the hypothesis that a surface that encourages specific integrin binding would promote differential cell binding. The novel integrin binding model used in this investigation may be a methodology that can be employed to evaluate potential vascular biomaterials.

Granulocyte-macrophage colony-stimulating factor amplification of interleukin-1beta and tumor necrosis factor alpha production in THP-1 human monocytic cells stimulated with lipopolysaccharide of oral microorganisms.

PubMed

Baqui, A A; Meiller, T F; Chon, J J; Turng, B F; Falkler, W A

1998-05-01

Cytokines, including granulocyte-macrophage colony-stimulating factor (GM-CSF), are used to assist in bone marrow recovery during cancer chemotherapy. Interleukin-1beta (IL-1beta) and tumor necrosis factor alpha (TNF-alpha) play important roles in inflammatory processes, including exacerbation of periodontal diseases, one of the most common complications in patients who undergo this therapy. A human monocyte cell line (THP-1) was utilized to investigate IL-1beta and TNF-alpha production following GM-CSF supplementation with lipopolysaccharide (LPS) from two oral microorganisms, Porphyromonas gingivalis and Fusobacterium nucleatum. LPS of P. gingivalis or F. nucleatum was prepared by a phenol-water extraction method and characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and determination of total protein and endotoxin contents. Resting THP-1 cells were treated with LPS of P. gingivalis or F. nucleatum and/or GM-CSF (50 IU/ml) by using different concentrations for various time periods. Production of IL-1beta and TNF-alpha in THP-1 cells was measured by solid-phase enzyme-linked immunosorbent assay. Reverse transcription (RT)-PCR was used to evaluate the gene expression of resting and treated THP-1 cells. IL-1beta was not detected in untreated THP-1 cells. IL-1beta production was, however, stimulated sharply at 4 h. GM-CSF amplified IL-1beta production in THP-1 cells treated with LPS from both oral anaerobes. No IL-1beta-specific mRNA transcript was detected in untreated THP-1 cells. However, IL-1beta mRNA was detected by RT-PCR 2 h after stimulation of THP-1 cells with LPS from both organisms. GM-CSF did not shorten the IL-1beta transcriptional activation time. GM-CSF plus F. nucleatum or P. gingivalis LPS activated THP-1 cells to produce a 1.6-fold increase in TNF-alpha production at 4 h over LPS stimulation alone. These investigations with the in vitro THP-1 model indicate that there may be an increase in the cellular immune response to oral endotoxin following GM-CSF therapy, as evidenced by production of the tissue-reactive cytokines IL-1beta and TNF-alpha.

[Trofosides A and B and other cytostatic steroid-derived compounds from the Far East starfish Trofodiscus über].

PubMed

Levina, E V; Kalinovskiĭ, A I; Andriiashchenko, P V; Menzorova, N I; Dmitrenok, P S

2007-01-01

Three new polar steroids identified as trofoside A, (20R,24S)-24-O-(3-O-methyl-beta-D-xylopyranosyl)-3beta,6alpha,8,15beta,24-pentahydroxy-5alpha-cholestane, its 22(23)-dehydro derivative (trofoside B), and 15-sulfoxy-(20R,24S)-5alpha-cholestane-3beta,6beta,8,15alpha,24-pentaol sodium salt, were isolated from Trofodiscus uber starfish extracts collected in the Sea of Okhotsk. Two known compounds, trofoside A aglycone, (20R,24S)-3beta,6alpha,8,15beta,24-pentahydroxy-5alpha-cholestane, and triseramide, (20R,24R,25S,22E)-24-methyl-3beta,6alpha,8,15beta-tetrahydroxy-5alpha-cholest-22-en-27-oic acid (2-sulfoethyl)amide sodium salt, were also found. The structures of the isolated polyoxysteroids were established from their spectra. Minimal concentrations causing degradation of unfertilized egg-cells of the sea-urchin Strongylocentrotus intermedius (C(min)) and terminating the cell division at the stage of the first division (C(min) embr.), as well as the concentrations causing 50% immobilization of sperm cells (ImC50) and inhibiting their ability to fertilize egg-cells by 50% (IC50) were determined for the isolated compounds. Of three compounds highly toxic in embryos and sea-urchin sperm cells, the polyol with a sulfo group in the steroid core was the most active; two glycosides with monosaccharide chains located at C3 and C24 atoms were less toxic. Note that all the compounds with the spermiotoxic activities differently affected the embryo development. The positions of monosaccharide residues in the core considerably influence the compound activity. For example, both mono- and double chained glycosides with the monosaccharide fragment at C3 and C24 atoms are active against sea-urchin sperm cells and embryos, whereas the C24 glycosylated trofoside A does not affect embryos and displays a poor spermiotoxicity.

Regulation of HSD17B1 and SRD5A1 in lymphocytes.

PubMed

Zhou, Z; Speiser, P W

1999-11-01

We previously reported lymphocyte expression of genes encoding enzymes required for steroid metabolism; however, only 17beta-HSD and 5alpha-reductase showed significant enzyme activity. We now investigate regulation of lymphocyte expression for genes encoding 17beta-HSD and 5alpha-reductase. Cultured human T and B lymphoid cell lines and peripheral blood mononuclear cells were treated with known regulators of steroidogenic gene expression including forskolin, PMA, ionomycin, various steroids, interleukin (IL)-4, and IL-6. Treatment with 10 or 50 microM forskolin resulted in a 20-60% reduction of expression for HSD17B1 (encoding 17beta-HSD I) in T and B lymphoid cell lines and peripheral blood mononuclear cells, although such a change was not observed in the expression of SRD5A1 (encoding 5alpha-reductase I). No significant changes were found when cells were treated for 24 h with various concentrations of PMA or ionomycin. Incubation with 10(-9) to 10(-7) M androstenedione or estradiol increased expression of HSD17B1, while testosterone decreased the expression of this gene. SRD5A1 expression was increased in the presence of 5alpha-DHT although no consistent changes were observed when the cells were treated with testosterone. Other steroids, including dexamethasone, progesterone, and 6-hydroxypregnanolone, produced no effects on expression of either HSD17B1 or SRD5A1. Treatment with 0.1-10 ng/ml of IL-4 or IL-6 also did not effect significant changes in gene expression. These data implicate the involvement of the cAMP-protein kinase signal transduction pathway in regulating lymphocyte expression of HSD17B1. Furthermore, it appears that lymphocyte HSD17B1 and SRD5A1 are regulated to some extent by specific steroids. Copyright 1999 Academic Press.

Integrin alphaIIb-subunit cytoplasmic domain mutations demonstrate a requirement for tyrosine phosphorylation of beta3-subunits in actin cytoskeletal organization.

PubMed

Yamodo, Innocent H; Blystone, Scott D

2004-01-01

Using truncated or mutated alphaIIb integrin cytoplasmic domains fused to the alphaV extracellular domain and expressed with the beta3 integrin subunit, we demonstrate that the double mutation of proline residues 998 and 999 to alanine (PP998/999AA), previously shown to disturb the C-terminal conformation of the alphaIIb integrin cytoplasmic domain, prevents tyrosine phosphorylation of beta3 integrin induced by Arg-Gly-Asp peptide ligation. This mutation also inhibits integrin mediated actin assembly and cell adhesion to vitronectin. In contrast, progressive truncation of the alphaIIb-subunit cytoplasmic domain did not reproduce these effects. Interestingly, the PP998/999AA mutations of alphaIIb did not affect beta3 tyrosine phosphorylation, cell adhesion, or actin polymerization induced by manganese. Exogenous addition of manganese was sufficient to rescue beta3 phosphorylation, cell adhesion, and actin assembly in cells expressing the PP998/999AA mutation when presented with a vitronectin substrate. Further, induction of the high affinity conformation of this mutant beta3 integrin by incubation with either Arg-Gly-Asp peptide or exogenous manganese was equivalent. These results suggest that the extracellular structure of beta3 integrins in the high affinity conformation is not directly related to the structure of the cytoplasmic face of the integrin. Moreover, the requirement for beta3 phosphorylation is demonstrated without mutation of the beta3 subunit. In support of our previous hypothesis of a role for beta3 phosphorylation in adhesion, these studies demonstrate a strong correlation between beta3 tyrosine phosphorylation and assembly of a cytoskeleton competent to support firm cell adhesion.

Mechanisms of stimulation of interleukin-1 beta and tumor necrosis factor-alpha by Mycobacterium tuberculosis components.

PubMed Central

Zhang, Y; Doerfler, M; Lee, T C; Guillemin, B; Rom, W N

1993-01-01

The granulomatous immune response in tuberculosis is characterized by delayed hypersensitivity and is mediated by various cytokines released by the stimulated mononuclear phagocytes, including tumor necrosis factor-alpha (TNF alpha) and IL-1 beta. We have demonstrated that Mycobacterium tuberculosis cell wall component lipoarabinomannan (LAM), mycobacterial heat shock protein-65 kD, and M. tuberculosis culture filtrate, devoid of LPS as assessed by the Amebocyte Lysate assay, stimulate the production of TNF alpha and IL-1 beta proteins and mRNA from mononuclear phagocytes (THP-1 cells). The effect of LAM on the release of these cytokines was specific, as only LAM stimulation was inhibited by anti-LAM monoclonal antibody. Interestingly, we found that LAM and Gram-negative bacterial cell wall-associated endotoxin LPS may share a similar mechanism in their stimulatory action as demonstrated by inhibition of TNF alpha and IL-1 beta release by monoclonal antibodies to CD14. Anti-CD14 monoclonal antibody MY4 inhibited both TNF alpha and IL-1 beta release with LAM and LPS but no effect was observed with other mycobacterial proteins. An isotype antibody control did not inhibit release of cytokines under the same experimental conditions. M. tuberculosis and its components upregulated IL-1 beta and TNF alpha mRNAs in THP-1 cells. Nuclear run-on assay for IL-1 beta demonstrated that LAM increased the transcription rate. The induction of IL-1 beta was regulated at the transcriptional level, in which these stimuli acted through cis-acting element(s) on the 5' flanking region of the IL-1 beta genomic DNA. M. tuberculosis cell wall component LAM acts similarly to LPS in activating mononuclear phagocyte cytokine TNF alpha and IL-1 beta release through CD14 and synthesis at the transcriptional level; both cytokines are key participants in the host immune response to tuberculosis. Images PMID:7683696

Partial agonist clonidine mediates alpha(2)-AR subtypes specific regulation of cAMP accumulation in adenylyl cyclase II transfected DDT1-MF2 cells.

PubMed

Limon-Boulez, I; Bouet-Alard, R; Gettys, T W; Lanier, S M; Maltier, J P; Legrand, C

2001-02-01

alpha2-Adrenergic receptor (alpha(2)-AR) activation in the pregnant rat myometrium at midterm potentiates beta(2)-AR stimulation of adenylyl cyclase (AC) via Gbetagamma regulation of the type II isoform of adenylyl cyclase. However, at term, alpha(2)-AR activation inhibits beta(2)-AR stimulation of AC. This phenomenon is associated with changes in alpha(2)-AR subtype expression (midterm alpha(2A/D)-AR > alpha(2B)-AR; term alpha(2B) >or =alpha(2A/D)-AR), without any change in ACII mRNA, suggesting that alpha(2A/D)- and alpha(2B)-AR differentially regulate beta(2)-cAMP production. To address this issue, we have stably expressed the same density of alpha(2A/D)- or alpha(2B)-AR with AC II in DDT1-MF2 cells. Clonidine (partial agonist) increased beta(2)-AR-stimulated cAMP production in alpha(2A/D)-AR-ACII transfectants but inhibited it in alpha(2B)-AR-ACII transfectants. In contrast, epinephrine (full agonist) enhanced beta(2)-stimulated ACII in both alpha(2A)- and alpha(2B)-ACII clonal cell lines. 4-Azidoanilido-[alpha-(32)P]GTP-labeling of activated G proteins indicated that, in alpha(2B)-AR transfectants, clonidine activated only Gi(2), whereas epinephrine, the full agonist, effectively coupled to Gi(2) and Gi(3). Thus, partial and full agonists selectively activate G proteins that lead to drug specific effects on effectors. Moreover, these data indicate that Gi(3) activation is required for potentiation of beta(2)-AR stimulation of AC by alpha(2A/D) and alpha(2B)-AR in DDT1-MF2 cells. This may reflect an issue of the amount of Gbetagamma released upon receptor activation and/or betagamma composition of Gi(3) versus Gi(2).

The herpes simplex virus-induced demise of keratinocytes is associated with a dysregulated pattern of p63 expression.

PubMed

Megyeri, Klára; Orosz, László; Kormos, Bernadett; Pásztor, Katalin; Seprényi, György; Ocsovszki, Imre; Mándi, Yvette; Bata-Csörgo, Zsuzsanna; Kemény, Lajos

2009-01-01

p63 plays a pivotal role in the development and maintenance of stratified epithelial tissues. In an effort to gain insight into the pathogenic mechanisms of skin infections caused by HSV-1 and HSV-2, we determined the patterns of p63 expression in primary keratinocytes and in the HaCaT cell line. The levels of DeltaNp63alpha and a 50kDa p73 isoform were decreased, Bax-alpha remained unaffected, while the expressions of the Bax-beta, TAp63gamma and a 44.5kDa p73 isoform were highly increased in both HSV-1-infected HaCaT cells and primary keratinocytes. In contrast, in response to HSV-2 infection the levels of DeltaNp63alpha, a 50kDa p73 isoform and a 44.5kDa p73 protein were decreased, Bax-alpha and TAp63gamma remained unaffected, while the expression of Bax-beta was slightly increased. The knockdown of TAp63 expression enhanced the viability of HSV-1-infected cells. Thus, HSV-1 and HSV-2 modulate the patterns of p63 and Bax expression in a serotype-specific manner. The dysregulated pattern of p63 expression observed in HSV-infected keratinocytes may comprise part of a mechanism by which these viruses perturb the functions of keratinocytes and lead to their demise.

Age-related alterations in IL-1beta, TNF-alpha, and IL-6 concentrations in parotid acinar cells from BALB/c and non-obese diabetic mice.

PubMed

Yamakawa, M; Weinstein, R; Tsuji, T; McBride, J; Wong, D T; Login, G R

2000-08-01

IL-1beta, TNF-alpha, and IL-6 have been implicated in the destruction of parotid gland acinar cells (but not duct cells) in autoimmune sialoadenitis. Here we report the temporal alterations of these cytokines in parotid acinar cells that may lead to this specificity in cell death in the non-obese diabetic (NOD) mouse model for Sjögren's syndrome. Immunohistochemistry on paraffin sections of parotid gland from 5- and 10-week-old BALB/c and NOD mice confirmed the presence of many peri-acinar lymphoid nodules but few T-cells and macrophages between acinar cells. RT-PCR on enzymatically dispersed mouse parotid acinar cells (MPACs) showed no bands for CD3varepsilon, CD20, or F4/80 regardless of mouse strain or age. By ELISA, MPACs from 10-week-old NODs showed a small but highly significant (p<0.003) increase in IL-1beta and a large significant decrease (p<0.008) in IL-6 compared to 5-week-old NODs. Norepinephrine-stimulated amylase release from MPACs was not different regardless of mouse strain or age. These data show that alterations in acinar cell production of IL-1beta and IL-6 in aging NODs precede periductal lymphoid aggregates and acinar cell secretory dysfunction. (J Histochem Cytochem 48:1033-1041,2000)

Cell wall teichoic acids of actinomycetes of three genera of the order actinomycetales.

PubMed

Streshinskaya, G M; Shashkov, A S; Usov, A I; Evtushenko, L I; Naumova, I B

2002-07-01

The structures of cell wall teichoic acids of the members of newly recognized genera of the order Actinomycetales were studied. Planotetraspora mira VKM Ac-2000T contains two types of teichoic acids: 2,3-poly(glycerol phosphate) substituted with alpha-D-Galp at C-1 of glycerol and 1,3-poly(glycerol phosphate) substituted with alpha-L-Rhap at OH-2 of glycerol (60%). Herbidospora cretacea VKM Ac-1997T contains the chains of 1,3-poly(glycerol phosphate) partially substituted with alpha-D-Galp and alpha-D-GalpNAc at C-2 of glycerol. The majority of alpha-D-galactopyranosyl residues are substituted at OH-3 with a sulfate. The aforementioned teichoic acids have not been found in bacteria thus far. Actinocorallia herbida VKM Ac-1994T contains poly(galactosylglycerol phosphate), with the beta-Galp-(1-->2)-Gro-P repeating units being linked via the phosphodiester bonds between the OH-3 of glycerol and OH-6 of galactose. Earlier, this structure was found in the cell wall of Actinomadura madura. The polymer structures were determined by chemical analysis and using 13C-NMR spectroscopy. The results show that teichoic acids are widespread in the order Actinomycetales.

Single-cell transcriptomes identify human islet cell signatures and reveal cell-type–specific expression changes in type 2 diabetes

PubMed Central

Bolisetty, Mohan; Kursawe, Romy; Sun, Lili; Sivakamasundari, V.; Kycia, Ina

2017-01-01

Blood glucose levels are tightly controlled by the coordinated action of at least four cell types constituting pancreatic islets. Changes in the proportion and/or function of these cells are associated with genetic and molecular pathophysiology of monogenic, type 1, and type 2 (T2D) diabetes. Cellular heterogeneity impedes precise understanding of the molecular components of each islet cell type that govern islet (dys)function, particularly the less abundant delta and gamma/pancreatic polypeptide (PP) cells. Here, we report single-cell transcriptomes for 638 cells from nondiabetic (ND) and T2D human islet samples. Analyses of ND single-cell transcriptomes identified distinct alpha, beta, delta, and PP/gamma cell-type signatures. Genes linked to rare and common forms of islet dysfunction and diabetes were expressed in the delta and PP/gamma cell types. Moreover, this study revealed that delta cells specifically express receptors that receive and coordinate systemic cues from the leptin, ghrelin, and dopamine signaling pathways implicating them as integrators of central and peripheral metabolic signals into the pancreatic islet. Finally, single-cell transcriptome profiling revealed genes differentially regulated between T2D and ND alpha, beta, and delta cells that were undetectable in paired whole islet analyses. This study thus identifies fundamental cell-type–specific features of pancreatic islet (dys)function and provides a critical resource for comprehensive understanding of islet biology and diabetes pathogenesis. PMID:27864352

Molecular imaging of alpha v beta3 integrin expression in atherosclerotic plaques with a mimetic of RGD peptide grafted to Gd-DTPA.

PubMed

Burtea, Carmen; Laurent, Sophie; Murariu, Oltea; Rattat, Dirk; Toubeau, Gérard; Verbruggen, Alfons; Vansthertem, David; Vander Elst, Luce; Muller, Robert N

2008-04-01

The integrin alpha v beta3 is highly expressed in atherosclerotic plaques by medial and intimal smooth muscle cells and by endothelial cells of angiogenic microvessels. In this study, we have assessed non-invasive molecular magnetic resonance imaging (MRI) of plaque-associated alpha v beta3 integrin expression on transgenic ApoE-/- mice with a low molecular weight peptidomimetic of Arg-Gly-Asp (mimRGD) grafted to gadolinium diethylenetriaminepentaacetate (Gd-DTPA-g-mimRGD). The analogous compound Eu-DTPA-g-mimRGD was employed for an in vivo competition experiment and to confirm the molecular targeting. The specific interaction of mimRGD conjugated to Gd-DTPA or to 99mTc-DTPA with alpha v beta3 integrin was furthermore confirmed on Jurkat T lymphocytes. The mimRGD was synthesized and conjugated to DTPA. DTPA-g-mimRGD was complexed with GdCl3.6H2O, EuCl3.6H2O, or with [99mTc(CO)3(H2O)3]+. MRI evaluation was performed on a 4.7 T Bruker imaging system. Blood pharmacokinetics of Gd-DTPA-g-mimRGD were assessed in Wistar rats and in c57bl/6j mice. The presence of angiogenic blood vessels and the expression of alpha v beta3 integrin were confirmed in aorta specimens by immunohistochemistry. Gd-DTPA-g-mimRGD produced a strong enhancement of the external structures of the aortic wall and of the more profound layers (possibly tunica media and intima). The aortic lumen seemed to be restrained and distorted. Pre-injection of Eu-DTPA-g-mimRGD diminished the Gd-DTPA-g-mimRGD binding to atherosclerotic plaque and confirmed the specific molecular targeting. A slower blood clearance was observed for Gd-DTPA-g-mimRGD, as indicated by a prolonged elimination half-life and a diminished total clearance. The new compound is potentially useful for the diagnosis of vulnerable atherosclerotic plaques and of other pathologies characterized by alpha v beta3 integrin expression, such as cancer and inflammation. The delayed blood clearance, the significant enhancement of the signal-to-noise ratio, and the low immunogenicity of the mimetic molecule highlight its potential for an industrial and clinical implementation.

Progesterone biotransformation by plant cell suspension cultures.

PubMed Central

Yagen, B; Gallili, G E; Mateles, R I

1978-01-01

Progesterone was converted to 5alpha-pregnane-3alpha-ol-20-one, delta4-pregnene-20alpha-ol-3-one, delta4-pregnene-14alpha-ol-3,20-dione, delta4-pregnene-7beta,14alpha-diol-3,20-dione, and delta4-pregnene-6beta,11alpha-diol-3,20-dione by cell cultures of Lycopersicon esculentum. Cell cultures of Capsicum frutescens (green) metabolized progesterone to delta4-pregnene-20alpha-ol-3-one in very high yield, and Vinca rosea yielded delta4-pregnene-20beta-ol-3-one and delta4-pregnene-14alpha-ol-3,20-dione. A stereospecific reduction of the keto groups and a double bond and stereospecific introduction of hydroxyl groups at the 6, 11, and 14 positions have been observed. The mono- and dihydroxylated progesterones have not previously been reported as metabolic products of progesterone by plant cell systems and represent de novo hydroxylation of a nonglycosylated steroid. PMID:697360

Radiation resistant PIDECα cell using photon intermediate direct energy conversion and a 210Po source.

PubMed

Weaver, Charles L; Schott, Robert J; Prelas, Mark A; Wisniewski, Denis A; Rothenberger, Jason B; Lukosi, Eric D; Oh, Kyuhak

2018-02-01

Radiation damage is a significant concern with both alphavoltaic and betavoltaic cells because their performance degrades, especially with high-energy - (>200keV) beta and alpha particles. Indirect excitation methods, such as the Photon Intermediate Direct Energy Conversion (PIDEC) framework, can protect the transducer from radiation. A nuclear battery using a 90 Sr beta source was constructed by the author's research group, which demonstrated the radiation resistance of a PIDEC cell driven by beta particles (PIDECβ cell). Use of alpha sources to drive nuclear batteries would appear to be much more attractive than beta sources due to higher potential power density. However, they are also subject to higher rates of radiation damage. This paper describes the successful incorporation of alpha particles into the PIDEC framework using the alpha emitter 210 Po to form a PIDECα cell. The PIDECα cell transducer was exposed to alpha particles for over one year without experiencing adverse effects from radiation damage. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mycobacterium leprae-Infected Macrophages Preferentially Primed Regulatory T Cell Responses and Was Associated with Lepromatous Leprosy

PubMed Central

Miranda, Jake W.; Gilson, Danny J.; Song, Zhengyu; Chen, Jia; Shi, Chao; Zhu, Jianyu; Yang, Jun; Jing, Zhichun

2016-01-01

Background The persistence of Mycobacterium leprae (M. leprae) infection is largely dependent on the types of host immune responses being induced. Macrophage, a crucial modulator of innate and adaptive immune responses, could be directly infected by M. leprae. We therefore postulated that M. leprae-infected macrophages might have altered immune functions. Methodology/Principal Findings Here, we treated monocyte-derived macrophages with live or killed M. leprae, and examined their activation status and antigen presentation. We found that macrophages treated with live M. leprae showed committed M2-like function, with decreased interleukin 1 beta (IL-1beta), IL-6, tumor necrosis factor alpha (TNF-alpha) and MHC class II molecule expression and elevated IL-10 and CD163 expression. When incubating with naive T cells, macrophages treated with live M. leprae preferentially primed regulatory T (Treg) cell responses with elevated FoxP3 and IL-10 expression, while interferon gamma (IFN-gamma) expression and CD8+ T cell cytotoxicity were reduced. Chromium release assay also found that live M. leprae-treated macrophages were more resistant to CD8+ T cell-mediated cytotoxicity than sonicated M. leprae-treated monocytes. Ex vivo studies showed that the phenotype and function of monocytes and macrophages had clear differences between L-lep and T-lep patients, consistent with the in vitro findings. Conclusions/Significance Together, our data demonstrate that M. leprae could utilize infected macrophages by two mechanisms: firstly, M. leprae-infected macrophages preferentially primed Treg but not Th1 or cytotoxic T cell responses; secondly, M. leprae-infected macrophages were more effective at evading CD8+ T cell-mediated cytotoxicity. PMID:26751388

Comparison of osteoblast-like cell responses to calcium silicate and tricalcium phosphate ceramics in vitro.

PubMed

Ni, Siyu; Chang, Jiang; Chou, Lee; Zhai, Wanyin

2007-01-01

Calcium silicate ceramics have been proposed as new bone repair biomaterials, since they have proved to be bioactive, degradable, and biocompatible. Beta-tricalcium phosphate ceramic is a well-known degradable material for bone repair. This study compared the effects of CaSiO3 (alpha-, and beta-CaSiO3) and beta-Ca3(PO4)2 (beta-TCP) ceramics on the early stages of rat osteoblast-like cell attachment, proliferation, and differentiation. Osteoblast-like cells were cultured directly on CaSiO3 (alpha-, and beta-CaSiO3) and beta-TCP ceramics. Attachment of a greater number of cells was observed on CaSiO3 (alpha-, and beta-CaSiO3) ceramics compared with beta-TCP ceramics after incubation for 6 h. SEM observations showed an intimate contact between cells and the substrates, significant cells adhesion, and that the cells spread and grew on the surfaces of all the materials. In addition, the proliferation rate and alkaline phosphatase (ALP) activity of the cells on the CaSiO3 (alpha-, and beta-CaSiO3) ceramics were improved when compared with the beta-TCP ceramics. In the presence of CaSiO3, elevated levels of calcium and silicon in the culture medium were observed throughout the 7-day culture period. In conclusion, the results of the present study revealed that CaSiO3 ceramics showed greater ability to support cell attachment, proliferation, and differentiation than beta-TCP ceramic. 2006 Wiley Periodicals, Inc.

Alpha cells secrete acetylcholine as a non-neuronal paracrine signal priming human beta cell function

PubMed Central

Rodriguez-Diaz, Rayner; Dando, Robin; Jacques-Silva, M. Caroline; Fachado, Alberto; Molina, Judith; Abdulreda, Midhat; Ricordi, Camillo; Roper, Stephen D.; Berggren, Per-Olof; Caicedo, Alejandro

2011-01-01

Acetylcholine is a neurotransmitter that plays a major role in the function of the insulin secreting pancreatic beta cell1,2. Parasympathetic innervation of the endocrine pancreas, the islets of Langerhans, has been shown to provide cholinergic input to the beta cell in several species1,3,4, but the role of autonomic innervation in human beta cell function is at present unclear. Here we show that, in contrast to mouse islets, cholinergic innervation of human islets is sparse. Instead, we find that the alpha cells of the human islet provide paracrine cholinergic input to surrounding endocrine cells. Human alpha cells express the vesicular acetylcholine transporter and release acetylcholine when stimulated with kainate or a lowering in glucose concentration. Acetylcholine secretion by alpha cells in turn sensitizes the beta cell response to increases in glucose concentration. Our results demonstrate that in human islets acetylcholine is a paracrine signal that primes the beta cell to respond optimally to subsequent increases in glucose concentration. We anticipate these results to revise models about neural input and cholinergic signaling in the endocrine pancreas. Cholinergic signaling within the islet represents a potential therapeutic target in diabetes5, highlighting the relevance of this advance to future drug development. PMID:21685896

Structural and biological mimicry of protein surface recognition by [alpha/beta]-peptide foldamers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Horne, W. Seth; Johnson, Lisa M.; Ketas, Thomas J.

Unnatural oligomers that can mimic protein surfaces offer a potentially useful strategy for blocking biomedically important protein-protein interactions. Here we evaluate an approach based on combining {alpha}- and {beta}-amino acid residues in the context of a polypeptide sequence from the HIV protein gp41, which represents an excellent testbed because of the wealth of available structural and biological information. We show that {alpha}/{beta}-peptides can mimic structural and functional properties of a critical gp41 subunit. Physical studies in solution, crystallographic data, and results from cell-fusion and virus-infectivity assays collectively indicate that the gp41-mimetic {alpha}/{beta}-peptides effectively block HIV-cell fusion via a mechanism comparablemore » to that of gp41-derived {alpha}-peptides. An optimized {alpha}/{beta}-peptide is far less susceptible to proteolytic degradation than is an analogous {alpha}-peptide. Our findings show how a two-stage design approach, in which sequence-based {alpha} {yields} {beta} replacements are followed by site-specific backbone rigidification, can lead to physical and biological mimicry of a natural biorecognition process.« less

Triterpene glycosides from the tubers of Anemone coronaria.

PubMed

Mimaki, Yoshihiro; Watanabe, Kazuki; Matsuo, Yukiko; Sakagami, Hiroshi

2009-07-01

Six new triterpene glycosides (1-6), together with 11 known ones (7-17), have been isolated from a glycoside-enriched fraction prepared from the tubers of Anemone coronaria L. (Ranunculaceae). On the basis of extensive spectroscopic analysis, including 2D NMR data, and the results of hydrolytic cleavage, the structures of 1-6 were determined to be 3beta-[(O-beta-D-glucopyranosyl-(1-->4)-O-[alpha-L-rhamnopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)oxy]-2beta,23-dihydroxyolean-12-en-28-oic acid (1), 3beta-[(O-beta-D-glucopyranosyl-(1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)-O-[beta-D-glucopyranosyl-(1-->4)]-alpha-L-arabinopyranosyl)oxy]-23-hydroxyolean-12-en-28-oic acid (2), 3beta-[(O-beta-D-glucopyranosyl-(1-->4)-O-[alpha-L-rhamnopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)oxy]-23-hydroxyolean-12-en-28-oic acid O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (3), 3beta-[(O-beta-D-glucopyranosyl-(1-->4)-O-[alpha-L-rhamnopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)oxy]-2beta,23-dihydroxyolean-12-en-28-oic acid O-alpha-L-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (4), 3beta-[(O-beta-D-glucopyranosyl-(1-->4)-O-[alpha-L-rhamnopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)oxy]-2beta-hydroxyolean-12-en-28-oic acid O-alpha-L-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (5), and 3beta-[(O-beta-D-glucopyranosyl-(1-->4)-O-[alpha-L-rhamnopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)oxy]-23-hydroxyolean-18-en-28-oic acid O-alpha-L-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (6), respectively. Furthermore, the isolated compounds were evaluated for their cytotoxic activity against HSC-2 cells.

Distinct symmetry and limited peptide refolding activity of the thermosomes from the acidothermophilic archaea Acidianus tengchongensis S5{sup T}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Li; Hu, Zhong-jun; Luo, Yuan-ming

Recombinant thermosomes from the Acidianus tengchongensis strain S5{sup T} were purified to homogeneity and assembled in vitro into homo-oligomers (rATcpn{alpha} or rATcpn{beta}) and hetero-oligomers (rATcpn{alpha}{beta}). The symmetries of these complexes were determined by electron microscopy and image analysis. The rATcpn{alpha} homo-oligomer was shown to possess 8-fold symmetry while both rATcpn{beta} and rATcpn{alpha}{beta} oligomers adopted 9-fold symmetry. rATcpn{alpha}{beta} oligomers were shown to contain the {alpha} and {beta} subunits in a 1:2 ratio. All of the complexes prevented the irreversible inactivation of yeast alcohol dehydrogenase at 55 {sup o}C and completely prevented the formation of aggregates during thermal inactivation of citrate synthasemore » at 45 {sup o}C. All rATcpn complexes showed trace ATP hydrolysis activity. Furthermore, rATcpn{beta} sequestered fully chemically denatured substrates (GFP and thermophilic malic dehydrogenase) in vitro without refolding them in an ATP-dependent manner. This property is similar to previously reported properties of chaperonins from Sulfolobus tokodaii and Sulfolobus acidocaldarius. These features are consistent with the slow growth rates of these species of archaea in their native environment.« less

The effect of interferon on the receptor sites to rabies virus on mouse neuroblastoma cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Briggs, D.J.

1989-01-01

The binding of rabies virus to mouse neuroblastoma cells (MNA) primed with alpha interferon (IFN-{alpha}), beta interferon (IFN-{beta}), or alpha bungarotoxin (BTX) was examined. A saturable number of receptor sites to rabies virus was calculated by increasing the amount of {sup 3}H-CVS added to a constant number of untreated MNA cells. MNA cells were then exposed to 20 I.U. of IFN-{alpha}, IFN-{beta}, or 1 {mu}g of BTX and assayed to determine if these treatments had an effect on the number of receptor sites to rabies virus. Total amount of {sup 3}H-CVS bound to MNA cells was determined during a threemore » hour incubation period. Cold competition assays using 1,000 fold excess unlabeled CVS were used to determine non-specific binding for each treatment. Specific binding was then calculated by subtracting non-specific binding from the total amount of CVS bound to MNA cells. A similar amount of total viral protein bound to untreated and IFN-{beta}, and BTX treated cells after 180 minutes of incubation. The bound protein varied by only 0.07 {mu}g. However, the amount of specific and non-specific binding varied a great deal between treatments. BTX caused an increase in non-specific and a decrease in specific binding of rabies virus. IFN-{beta} produced variable results in non-specific and specific binding while IFN-{alpha} caused mainly specific binding to occur. The most significant change brought about by IFN-{alpha} was an increase in the rate of viral attachment. At 30 minutes post-infection, IFN-{alpha} treated cells had bound 90% of the total amount of virus bound to untreated cells after 180 minutes. The increased binding rate did not cause a productive infection of rabies virus. No viral production was evident after an incubation period of 48 hours in either IFN-{alpha} or IFN-{beta} treated cells.« less

Expression of cell adhesion molecules in the normal and T3 blocked development of the tadpole's kidney of Bufo arenarum (Amphibian, Anuran, Bufonidae).

PubMed

Izaguirre, M F; García-Sancho, M N; Miranda, L A; Tomas, J; Casco, V H

2008-08-01

Cell adhesion molecules act as signal transducers from the extracellular environment to the cytoskeleton and the nucleus and consequently induce changes in the expression pattern of structural proteins. In this study, we showed the effect of thyroid hormone (TH) inhibition and arrest of metamorphosis on the expression of E-cadherin, beta-and alpha-catenin in the developing kidney of Bufo arenarum. Cell adhesion molecules have selective temporal and spatial expression during development suggesting a specific role in nephrogenesis. In order to study mechanisms controlling the expression of adhesion molecules during renal development, we blocked the B. arenarum metamorphosis with a goitrogenic substance that blocks TH synthesis. E-cadherin expression in the proximal tubules is independent of thyroid control. However, the blockage of TH synthesis causes up-regulation of E-cadherin in the collecting ducts, the distal tubules and the glomeruli. The expression of beta-and alpha-catenin in the collecting ducts, the distal tubules, the glomeruli and the mesonephric mesenchyme is independent of TH. TH blockage causes up-regulation of beta-and alpha-catenin in the proximal tubules. In contrast to E-cadherin, the expression of the desmosomal cadherin desmoglein 1 (Dsg-1) is absent in the control of the larvae kidney during metamorphosis and is expressed in some interstitial cells in the KClO4 treated larvae. According to this work, the Dsg-1 expression is down-regulated by TH. We demonstrated that the expression of E-cadherin, Dsg-1, beta-catenin and alpha-catenin are differentially affected by TH levels, suggesting a hormone-dependent role of these proteins in the B. arenarum renal metamorphosis.

Interleukin 4: signalling mechanisms and control of T cell differentiation.

PubMed

Paul, W E

1997-01-01

Interleukin 4 (IL-4) is a pleiotropic type I cytokine that controls both growth and differentiation among haemopoietic and non-haemopoietic cells. Its receptor is a heterodimer. One chain, the IL-4R alpha chain, binds IL-4 with high affinity and determines the nature of the biochemical signals that are induced. The second chain, gamma c, is required for the induction of such signals. IL-4-mediated growth depends upon activation events that involve phosphorylation of Y497 of IL-4R alpha, leading to the binding and phosphorylation of 4PS/IRS-2 in haemopoietic cells and of IRS-1 in non-haemopoietic cells. By contrast, IL-4-mediated differentiation events depend upon more distal regions of the IL-4R alpha chain that include a series of STAT-6 binding sites. The distinctive roles of these receptor domains was verified by receptor-reconstruction experiments. The 'growth' and 'differentiation' domains of the IL-4R alpha chain, independently expressed as chimeric structures with a truncated version of the IL-2R beta chain, were shown to convey their functions to the hybrid receptor. The critical role of STAT-6 in IL-4-mediated gene activation and differentiation was made clear by the finding that lymphocytes from STAT-6 knockout mice are strikingly deficient in these functions but have retained the capacity to grow, at least partially, in response to IL-4. IL-4 plays a central role in determining the phenotype of naive CD4+ T cells. In the presence of IL-4, newly primed naive T cells develop into IL-4 producers while in its absence they preferentially become gamma-interferon (IFN-gamma) producers. Recently, a specialized subpopulation of T cells, CD4+/NK1.1+ cells, has been shown to produce large amounts of IL-4 upon stimulation. Two examples of mice with deficiencies in these cells are described--beta 2-microglobulin knockout mice and SJL mice. Both show defects in the development of IL-4-producing cells and in the increase in serum IgE in response to stimulation with the polyclonal stimulant anti-IgD. Both sets of mice have major diminutions in the number of CD4+/ NK1.1+ T cells, strongly indicating an important role of these cells in some but not all IgE responses to physiologic stimuli.

Integrin {alpha}{beta}1, {alpha}{sub v}{beta}, {alpha}{sub 6}{beta} effectors p130Cas, Src and talin regulate carcinoma invasion and chemoresistance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sansing, Hope A.; Sarkeshik, Ali; Yates, John R.

2011-03-11

Research highlights: {yields} Proteomics of clustered integrin {alpha}{beta}1, {alpha}{sub v}{beta}, {alpha}{sub 6}{beta} receptors in oral carcinoma. {yields} p130Cas, Dek, Src and talin regulate oral carcinoma invasion. {yields} p130Cas, talin, Src and zyxin regulate oral carcinoma resistance to cisplatin. -- Abstract: Ligand engagement by integrins induces receptor clustering and formation of complexes at the integrin cytoplasmic face that controls cell signaling and cytoskeletal dynamics critical for adhesion-dependent processes. This study searches for a subset of integrin effectors that coordinates both tumor cell invasion and resistance to the chemotherapeutic drug cisplatin in oral carcinomas. Candidate integrin effectors were identified in a proteomicsmore » screen of proteins recruited to clustered integrin {alpha}{beta}1, {alpha}{sub v}{beta} or {alpha}{sub 6}{beta} receptors in oral carcinomas. Proteins with diverse functions including microtubule and actin binding proteins, and factors involved in trafficking, transcription and translation were identified in oral carcinoma integrin complexes. Knockdown of effectors in the oral carcinoma HN12 cells revealed that p130Cas, Dek, Src and talin were required for invasion through Matrigel. Disruption of talin or p130Cas by RNA interference increased resistance to cisplatin, whereas targeting Dek, Src or zyxin reduced HN12 resistance to cisplatin. Analysis of the spreading of HN12 cells on collagen I and laminin I revealed that a decrease in p130Cas or talin expression inhibited spreading on both matrices. Interestingly, a reduction in zyxin expression enhanced spreading on laminin I and inhibited spreading on collagen I. Reduction of Dek, Src, talin or zyxin expression reduced HN12 proliferation by 30%. Proliferation was not affected by a reduction in p130Cas expression. We conclude that p130Cas, Src and talin function in both oral carcinoma invasion and resistance to cisplatin.« less

Molecular study of electron transfer flavoprotein alpha-subunit deficiency in two Japanese children with different phenotypes of glutaric acidemia type II.

PubMed

Purevjav, E; Kimura, M; Takusa, Y; Ohura, T; Tsuchiya, M; Hara, N; Fukao, T; Yamaguchi, S

2002-09-01

Electron transfer flavoprotein is a mitochondrial matrix protein composed of alpha- and beta-subunits (ETF alpha and ETF beta, respectively). This protein transfers electrons between several mitochondrial dehydrogenases and the main respiratory chain via ETF dehydrogenase (ETF-DH). Defects in ETF or ETF-DH cause glutaric acidemias type II (GAII). We investigated the molecular basis of ETF alpha deficiency in two Japanese children with different clinical phenotypes using expression study. Patient 1 had the severe form of GAII, a compound heterozygote of two mutations: 799G to A (alpha G267R) and nonsense 7C to T (alpha R3X). Patient 2 had the mild form and carried two heterozygous mutations: 764G to T (alpha G255V) and 478delG (frameshift). Both patients had one each of missense mutations in one allele; the others were either nonsense or truncated. Restriction enzyme digestion assay using genomic DNAs from 100 healthy Japanese revealed that these mutations were all novel. No signal for ETF alpha was detected by immunoblotting in cases of missense mutants, while wild-type cDNA resulted in expression of ETF alpha protein. Transfection with wild-type ETF alpha cDNA into cultured cells from both patients elevated incorporation of radioisotope-labelled fatty acids. These four mutations were pathogenic for GAII and missense mutations, alpha G255V and alpha G267R were considered anecdotal for mild and severe forms, respectively.

Human Beta Cells Produce and Release Serotonin to Inhibit Glucagon Secretion from Alpha Cells.

PubMed

Almaça, Joana; Molina, Judith; Menegaz, Danusa; Pronin, Alexey N; Tamayo, Alejandro; Slepak, Vladlen; Berggren, Per-Olof; Caicedo, Alejandro

2016-12-20

In the pancreatic islet, serotonin is an autocrine signal increasing beta cell mass during metabolic challenges such as those associated with pregnancy or high-fat diet. It is still unclear whether serotonin is relevant for regular islet physiology and hormone secretion. Here, we show that human beta cells produce and secrete serotonin when stimulated with increases in glucose concentration. Serotonin secretion from beta cells decreases cyclic AMP (cAMP) levels in neighboring alpha cells via 5-HT 1F receptors and inhibits glucagon secretion. Without serotonergic input, alpha cells lose their ability to regulate glucagon secretion in response to changes in glucose concentration, suggesting that diminished serotonergic control of alpha cells can cause glucose blindness and the uncontrolled glucagon secretion associated with diabetes. Supporting this model, pharmacological activation of 5-HT 1F receptors reduces glucagon secretion and has hypoglycemic effects in diabetic mice. Thus, modulation of serotonin signaling in the islet represents a drug intervention opportunity. Published by Elsevier Inc.

Evidence for the opposing roles of different gamma delta T cell subsets in macrophage homeostasis.

PubMed

Tramonti, Daniela; Andrew, Elizabeth M; Rhodes, Kate; Newton, Darren J; Carding, Simon R

2006-07-01

To ensure invading pathogens are eliminated with minimal damage to host tissues it is essential that macrophage activation be tightly regulated. Previously we demonstrated that a subset of gammadelta T cells (Vgamma1(+)) contributes to resolving pathogen-induced immune responses by killing activated macrophages. However, the exaggerated macrophage response seen in infected Vgamma1(+) T cell-deficient mice suggests that gammadelta T cells play a broader role in macrophage homeostasis and other subsets might promote macrophage activation. Using a macrophage:gammadelta T cell co-culture system we have shown that gammadelta T cells increase the activity of macrophages activated in vivo by Listeria monocytogenes infection. In a dose-dependent manner, gammadelta T cells up-regulated production of cytokines (TNF-alpha, IL-6, IL-10) and chemokines (MIP-1alpha, MIP-1beta) by Listeria-elicited macrophages. The ability to increase macrophage cytokine production was prominent among Vgamma4(+) gammadelta T cells. Reciprocally, Vgamma4(+) gammadelta T cells were activated by Listeria-elicited macrophages, resulting in production of the anti-inflammatory cytokine, IL-10. gammadelta T cell adoptive transfer experiments showed that Vgamma4(+) T cells protected TCRdelta(-/-) mice against Listeria-induced liver injury and necrosis. These findings identify distinct and non-overlapping roles for gammadelta T cell subsets in regulating macrophage function during pathogen-induced immune responses.

Expression of alpha-AR subtypes in T lymphocytes and role of the alpha-ARs in mediating modulation of T cell function.

PubMed

Bao, Jing-Yin; Huang, Yan; Wang, Feng; Peng, Yu-Ping; Qiu, Yi-Hua

2007-01-01

Previous work in our laboratory has shown that alpha-adrenoreceptors (alpha-ARs) and beta-ARs exist on lymphocytes from functional profile, and that the receptors mediate the regulation of lymphocyte function by catecholamines. In the present study, we directly examined the expression of alpha-AR subtypes, alpha(1)-AR and alpha(2)-AR mRNAs, in T lymphocytes and explored the roles of the alpha-AR subtypes and intracellular signal transduction mechanisms linked to the receptors in mediating the modulation of T lymphocyte function. T lymphocytes from mesenteric lymph nodes of rats were purified by using a nylon wool column. Reverse transcription polymerase chain reaction was used to detect the expression of alpha(1)-AR and alpha(2)-AR mRNAs in the freshly isolated T cells and the mitogen concanavalin A (Con A)-activated lymphocytes. Colorimetric methylthiazoletetrazolium assay was employed to measure lymphocyte proliferation induced by Con A. Interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) levels in the Con A-stimulated lymphocyte culture supernatants were examined by enzyme-linked immunosorbent assay. T cells expressed both alpha(1)-AR and alpha(2)-AR mRNAs. The expression of both alpha(1)-AR and alpha(2)-AR mRNAs was significantly higher in the Con A-activated lymphocytes than in the resting lymphocytes. Phenylephrine, a selective alpha(1)-AR agonist, had no evident effect on lymphocyte proliferation nor on IFN-gamma and IL-4 production induced by Con A. However, the selective alpha(2)-AR agonist clonidine attenuated Con A-induced lymphocyte proliferation as well as IFN-gamma and IL-4 production. The inhibited lymphocyte proliferation and IFN-gamma and IL-4 production by clonidine were blocked by yohimbine, an alpha(2)-AR antagonist. Either phospholipase C inhibitor U-73122 or protein kinase C inhibitor chelerythrine partially prevented the suppressive effect of clonidine on Con A-stimulated lymphocyte proliferation and IL-4 production. T lymphocytes express both alpha(1)-ARs and alpha(2)-ARs, but only the alpha(2)-ARs participate in the suppressive modulation of lymphocyte proliferation and cytokine production in vitro. The inhibitory effect of alpha(2)-AR stimulation on lymphocyte function is partially mediated via the phospholipase C-protein kinase C pathway. (c) 2008 S. Karger AG, Basel.

IL-9 expression by human eosinophils: regulation by IL-1beta and TNF-alpha.

PubMed

Gounni, A S; Nutku, E; Koussih, L; Aris, F; Louahed, J; Levitt, R C; Nicolaides, N C; Hamid, Q

2000-09-01

IL-9 is a pleiotropic cytokine that exhibits biologic activity on cells of diverse hemopoietic lineage. IL-9 stimulates the proliferation of activated T cells, enhances the production of IgE from B cells, and promotes the proliferation and differentiation of mast cells and hematopoietic progenitors. In this study we evaluated the expression of IL-9 messenger (m)RNA and protein by human peripheral blood eosinophils. We also investigated the role of IL-1beta and TNF-alpha in the release of IL-9 from human peripheral blood eosinophils. RT-PCR, in situ hybridization, and immunocytochemistry were used to investigate the presence of IL-9 mRNA and protein in human peripheral blood eosinophils from asthmatic patients and normal control subjects. Furthermore, biologic assay was used to investigate the release of IL-9 protein from IL-1beta- or TNF-alpha-stimulated eosinophils in vitro. RT-PCR analysis showed the presence of IL-9 mRNA in human peripheral blood eosinophil RNA preparations from subjects with atopic asthma, as well as in the eosinophil-differentiated HL-60 cell line. By using in situ hybridization, a significant difference (P <.01) in IL-9 mRNA expression was detected in human peripheral blood eosinophils freshly isolated from asthmatic subjects compared with those isolated from normal control subjects. Furthermore, the percentage of IL-9 immunoreactive eosinophils from asthmatic patients was increased compared with that found in normal control subjects (P <.01). We also demonstrate that cultured human peripheral blood eosinophils from asthmatic subjects synthesize and release IL-9 protein, which is upregulated on stimulation with TNF-alpha and IL-1beta. Human eosinophils express biologically active IL-9, which suggests that these cells may influence the recruitment and activation of effector cells linked to the pathogenesis of allergic disease. These observations provide further evidence for the role of eosinophils in regulating airway immune responses.

Adenoviral receptor expression of normal bladder and transitional cell carcinoma of the bladder.

PubMed

Buscarini, Maurizio; Quek, Marcus L; Gilliam-Hegarich, Susan; Kasahara, Nori; Bochner, Bernard

2007-01-01

The insertion of absent or underexpressed genes into cancer cells to alter their malignant phenotype is an important potential application of available gene therapy technology. One of the more common viral vector systems that has been extensively studied for this purpose are the replication-deficient adenoviruses (Ad). Adenoviral infection of cells is mediated through a complex pathway, initiated following viral-cell attachment. Adenoviral-cell attachment occurs following interactions with a 46-kDa transmembrane protein with high affinity for both the Coxsackie and adenovirus, designated the CAR (Coxsackie and adenoviral receptor). Additional important cell-viral interactions that occur involve the alpha(v)-based integrins, specifically alpha(v)beta3 and alpha(v)beta5. The purpose of the present study was to determine the extent of expression and localization of the known Ad receptor proteins (CAR, alpha(v)beta3, and alpha(v)beta5) in normal and cancerous human bladders. Frozen tissue samples of normal bladder and invasive transitional cell cancers of the bladder were evaluated. Tissue blocks containing muscle-invasive transitional cell carcinoma (TCC) were obtained following radical cystectomy, which were performed at our institution. Thirty-two invasive transitional cell bladder tumors were evaluated, each with a matched sample of histologically normal-appearing bladder used as a control. Four additional samples of normal bladder were obtained from patients with no evidence of disease of the bladder and served as further controls. Three additional cases of invasive bladder cancer with no matching normal tissue were also evaluated. Identification of the CAR receptor was performed using the anti-CAR mouse monoclonal antibody designated RmBC. The integrins alpha(v)beta3 and alpha(v)beta5 were identified using the mouse monoclonal antibodies designated LM609 and P1F6 respectively. All slides were evaluated by two of the authors (M.B., B.B.) without knowledge of the clinical and pathological data. Normal bladder: Normal bladder mucosa demonstrated a marked positivity for CAR in 29/35 (82.8%) cases. In contrast, normal transitional epithelial cells were uniformly negative when tested for the integrins alpha(v)beta3 and alpha(v)beta5. Subepithelial tissues, specifically the connective tissue components of the lamina propria and deep muscle wall of the bladder, were positive for alpha(v)beta3 and for alpha(v)beta5 in 61 and 75% of samples, respectively. Endothelial cells associated with the various layers throughout the bladder uniformly expressed both integrins and served as a consistent internal control for both antibodies. An almost identical staining pattern of the endothelium was observed using LM609 and P1F6 in all samples tested. Bladder transitional cell carcinoma: CAR immunoreactivity against TCC cells was uniformly decreased compared to normal transitional cells. Nine tumors exhibited a weak positivity for CAR while the remaining samples were negative. In some cases, the absence of CAR positivity was associated with histological evidence of carcinoma in situ. In 6 cases, it led to the identification of small regions of carcinoma in situ that were not noted on primary pathological evaluation. Peritumoral connective tissue expressed both integrins in the majority of cases, similar to the pattern described above for normal bladder. Transitional cell cancers demonstrated a similar pattern of expression of alpha(v)beta5, in which all tumor cells exhibited minimal or no staining. The success of all viral-mediated gene therapy strategies relies on the ability of the vector to efficiently deliver its genetic material to a target cell population. In the current study, we demonstrate that the bladder epithelial layer consistently expresses high levels of CAR. Deeper layers of the epithelium also express CAR, including the basal layer cells. A decrease in the expression of CAR appears as an early event in bladder carcinogenesis. We observed that both alpha(v)beta3 and alpha(v)beta5 are strongly expressed in muscle cells surrounding the neoplastic cells, as well as within the peritumoral connective tissue. In cases of invasive bladder cancer that have lost CAR expression, an adenoviral vector may still be utilized through the less efficient interactions with the integrins. Bladder tumor tissue may be less susceptible to an adenoviral-mediated gene therapy approach in which a significant percentage of tumor cells require transduction. Adenoviral uptake by tumor or peritumoral cells with subsequent gene transfer could be predicted by the level of CAR and alpha(v)-based integrin expression. This would enhance our ability to identify those patients whose tumors would be more susceptible to Ad-mediated gene delivery as part of an antitumor treatment. 2007 S. Karger AG, Basel

Fc gamma RII/III and CD2 expression mark distinct subpopulations of immature CD4-CD8- murine thymocytes: in vivo developmental kinetics and T cell receptor beta chain rearrangement status.

PubMed

Rodewald, H R; Awad, K; Moingeon, P; D'Adamio, L; Rabinowitz, D; Shinkai, Y; Alt, F W; Reinherz, E L

1993-04-01

We have recently identified a dominant wave of CD4-CD8- (double-negative [DN]) thymocytes in early murine fetal development that express low affinity Fc gamma receptors (Fc gamma RII/III) and contain precursors for Ti alpha/beta lineage T cells. Here we show that Fc gamma RII/III is expressed in very immature CD4low single-positive (SP) thymocytes and that Fc gamma RII/III expression is downregulated within the DN subpopulation and before the CD3-CD8low SP stage in T cell receptor (TCR)-alpha/beta lineage-committed thymocytes. DN Fc gamma RII/III+ thymocytes also contain a small fraction of TCR-gamma/delta lineage cells in addition to TCR-alpha/beta progenitors. Fetal day 15.5 DN TCR-alpha/beta lineage progenitors can be subdivided into three major subpopulations as characterized by cell surface expression of Fc gamma RII/III vs. CD2 (Fc gamma RII/III+CD2-, Fc gamma RII/III+CD2+, Fc gamma RII/III-CD2+). Phenotypic analysis during fetal development as well as adoptive transfer of isolated fetal thymocyte subpopulations derived from C57B1/6 (Ly5.1) mice into normal, nonirradiated Ly5.2 congenic recipient mice identifies one early differentiation sequence (Fc gamma RII/III+CD2(-)-->Fc gamma RII/III+CD2(+)-->Fc gamma RII/III-CD2+) that precedes the entry of DN thymocytes into the CD4+CD8+ double-positive (DP) TCRlow/- stage. Unseparated day 15.5 fetal thymocytes develop into DP thymocytes within 2.5 d and remain at the DP stage for > 48 h before being selected into either CD4+ or CD8+ SP thymocytes. In contrast, Fc gamma RII/III+CD2- DN thymocytes follow this same developmental pathway but are delayed by approximately 24 h before entering the DP compartment, while Fc gamma RII/III-CD2+ display accelerated development by approximately 24 h compared with total day 15.5 thymocytes. Fc gamma RII/III-CD2+ are also more developmentally advanced than Fc gamma RII/III+CD2- fetal thymocytes with respect to their TCR beta chain V(D)J rearrangement. At day 15.5 in gestation, beta chain V(D)J rearrangement is mostly, if not entirely, restricted to the Fc gamma RII/III-CD2+ subset of DN fetal thymocytes. Consistent with this analysis in fetal thymocytes, > 90% of adult thymocytes derived from mice carrying a disrupting mutation at the recombination-activating gene 2 locus (RAG-2-/-) on both alleles are developmentally arrested at the DN CD2- stage. In addition, there is a fivefold increase in the relative percentage of thymocytes expressing Fc gamma RII/III in TCR and immunoglobulin gene rearrangement-incompetent homozygous RAG-2-/- mice (15% Fc gamma RII/III+) versus rearrangement-competent heterozygous RAG-2+/- mice (< 3% Fc gamma RII/III+). Thus, Fc gamma RII/III expression defines an early DN stage preceding V beta(D beta)I beta rearrangement, which in turn is followed by surface expression of CD2. Loss of Fc gamma RII/III and acquisition of CD2 expression characterize a late DN stage immediately before the conversion into DP thymocytes.

ASYMMETRIC ABSORPTION PROFILES OF Ly{alpha} AND Ly{beta} IN DAMPED Ly{alpha} SYSTEMS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Hee-Won, E-mail: hwlee@sejong.ac.kr

2013-08-01

Damped Ly{alpha} systems observed in the quasar spectra are characterized by a high neutral hydrogen column density, N{sub HI} > 2 x 10{sup 20} cm{sup -2}. The absorption wing profiles are often fitted using the Voigt function due to the fact that the scattering cross section near the resonant line center is approximately described by the Lorentzian function. Since a hydrogen atom has infinitely many p states that participate in the electric dipole interaction, the cross section starts to deviate from the Lorentzian in an asymmetric way in the line wing regions. We investigate this asymmetry in the absorption linemore » profiles around Ly{alpha} and Ly{beta} as a function of the neutral hydrogen column density N{sub HI}. In terms of {Delta}{lambda} {identical_to} {lambda} - {lambda}{sub {alpha}}, we expand the Kramers-Heisenberg formula around Ly{alpha} to find {sigma}({lambda}) {approx_equal} (0.5f{sub 12}){sup 2}{sigma}{sub T}({Delta}{lambda}/{lambda}{sub {alpha}}){sup -2}[1 + 3.792({Delta}{lambda}/{lambda}{sub {alpha}})], where f{sub 12} and {sigma}{sub T} are the oscillator strength of Ly{alpha} and the Thomson scattering cross section, respectively. In terms of {Delta}{lambda}{sub 2} {identical_to} {lambda} - {lambda}{sub {beta}} in the vicinity of Ly{beta}, the total scattering cross section, given as the sum of cross sections for Rayleigh and Raman scattering, is shown to be {sigma}({lambda}) {approx_equal} {sigma}{sub T}(0.5f{sub 13}){sup 2}(1 + R{sub 0})({Delta}{lambda}{sub 2}/{lambda}{sub {beta}}){sup -2}[1 - 24.68({Delta}{lambda}{sub 2}/{lambda}{sub {beta}})] with f{sub 13} and the factor R{sub 0} = 0.1342 being the oscillator strength for Ly{beta} and the ratio of the Raman cross section to Rayleigh cross section, respectively. A redward asymmetry develops around Ly{alpha}, whereas a blue asymmetry is obtained for Ly{beta}. The absorption center shifts are found to be almost proportional to the neutral hydrogen column density.« less

Genetic control of T cell responsiveness to the Friend murine leukemia virus envelope antigen. Identification of class II loci of the H-2 as immune response genes

PubMed Central

1988-01-01

T cells primed specifically for the envelope glycoprotein of Friend murine leukemia helper virus (F-MuLV) were prepared by immunizing mice with a recombinant vaccinia virus that expressed the entire env gene of F-MuLV. Significant proliferative responses of F-MuLV envelope- specific, H-2a/b T cells were observed when the T cells were stimulated with antigen-pulsed peritoneal exudate cells (PEC) having the b allele at the K, A beta, A alpha, and E beta loci of the H-2. On the other hand, PEC having only the kappa allele at these loci did not induce the envelope-specific T cell proliferation, even when the PEC had the b allele at the E alpha, S, or D loci. F-MuLV envelope-specific proliferation of H-2a/b T cells under the stimulation of antigen- pulsed, H-2a/b PEC was specifically blocked with anti-I-Ab and anti-I- Ek mAbs but not with anti-Kb, anti-Kk, or anti-I-Ak mAbs. Moreover, (B10.MBR x A/WySn)F1 mice that have the b allele only at the K locus but not in I-A subregion were nonresponders to the envelope glycoprotein, and the bm12 mutation at the A beta locus completely abolished the T cell responsiveness to this antigen. These results indicate that proliferative T cells recognize a limited number of epitopes on F-MuLV envelope protein in the context of I-Ab, hybrid I- Ak/b, and/or hybrid I-Ek/b class II MHC molecules but fail to recognize the same envelope protein in the context of I-Ak or I-Ek molecules. This influence of the H-2I region on T cell recognition of the envelope glycoprotein appeared to control in vivo induction of protective immunity against Friend virus complex after immunization with the vaccinia-F-MuLV env vaccine. Thus, these results provide, for the first time, direct evidence for Ir gene-controlled responder/nonresponder phenotypes influencing the immune response to a pathogenic virus of mice. PMID:3141552

Integrins beta 5, beta 3 and alpha v are apically distributed in endometrial epithelium.

PubMed

Aplin, J D; Spanswick, C; Behzad, F; Kimber, S J; Vićovac, L

1996-07-01

Several adhesion molecules have been shown to occur at the surface of endometrial cells. One of these is the integrin alpha v subunit which associates with various beta chains including beta 5. We demonstrate the presence of integrin beta 5 polypeptide in human endometrial epithelial cells throughout the menstrual cycle using immunocytochemistry with monospecific antibodies, and at the mRNA level by thermal amplification from endometrial cDNA. Integrin beta 5 is also found in a population of bone marrow-derived cells. A notable feature of the distribution of the beta 5 subunit in the glandular and luminal epithelium is its apical localization, which may suggest an involvement in implantation. However, no evidence was found for regulated expression of epithelial beta 5. In mouse, the beta 5 subunit is found at both the apical and basal surface of epithelial cells and expression is essentially oestrous cycle-independent. Comparisons are made in both species with the distribution of the alpha v and beta 3 subunits which also localize to the apical epithelium.

Cytokine polymorphism in patients with migraine: some suggestive clues of migraine and inflammation.

PubMed

Yilmaz, Ibrahim Arda; Ozge, Aynur; Erdal, Mehmet Emin; Edgünlü, Tuba Gökdoğan; Cakmak, Sema Erol; Yalin, Osman Ozgür

2010-04-01

There are contrasting results obtained in migraineurs concerning the levels and the role of both pro-inflammatory and anti-inflammatory cytokines. In this study, the association of the occurrence and clinical characteristics of migraine with the polymorphisms of tumor necrosis factor alpha (TNF-alpha) -308 G/A (rs1800629), interleukin-1alpha (IL-1alpha) +4845 G/T (rs17561), IL-1beta+3953 C/T (rs1143634) and interleukin-1 receptor antagonist variable number tandem repeat (IL-1RA VNTR) genes were studied. We also investigated the genetic linkage between these genes. Sixty-seven patients with migraine without aura (MwoA) and 96 unrelated, age- and sex-matched migraine-free, healthy control subjects from the same geographic area were investigated. We observed significant differences in the genotypic distribution of the TNF-alpha-308 G/A and IL-1beta+3953 C/T polymorphism for migraineurs compared with controls (P = 0.004). Frequency of the TNF-alpha-308 GG genotype was higher in the control group than MwoA group (82.1% vs 55.2%). Differences in the distribution of the allele frequencies were also observed, being the TNF-alpha-308 G allele overrepresented in control group and TNF-alpha-308 A allele in MwoA group. In addition, there was a significant increase of the IL-1beta+3953 T allele in MwoA cases compared with controls (P = 0.004). In conclusion, the present results indicate the possible contribution of TNF-alpha and IL-1beta gene polymorphisms to migraine headache generation in MwoA patients.

A cytotoxic and apoptosis-inducing sesquiterpenoid isolated from the aerial parts of Artemisia princeps PAMPANINI (Sajabalssuk).

PubMed

Bang, Myun-Ho; Han, Min-Woo; Song, Myoung-Chong; Cho, Jin-Gyeong; Chung, Hae-Gon; Jeong, Tae-Sook; Lee, Kyung-Tae; Choi, Myung-Sook; Kim, Se-Young; Baek, Nam-In

2008-08-01

Repeated silica gel and octadecyl silica gel (ODS) column chromatography of the aerial parts of Artemisia princeps PAMPANINI (Sajabalssuk) led to the isolation of a new sesquiterpenoid, 3-((S)-2-methylbutyryloxy)-costu-1(10),4(5)-dien-12,6 alpha-olide (2), along with two previously reported sesquiterpenoids: 8 alpha-angeloyloxy-3beta,4 beta-epoxy-6 beta H,7 alpha H,8 beta H-guaia-1(10),11(13)-dien-12,6 alpha-olide (1, carlaolide B) and 3beta,4 beta-epoxy-8 alpha-isobutyryloxy-6 beta H,7 alpha H,8 beta H-guaia-1(10),11(13)-dien-12,6 alpha-olide (3, carlaolide A). The structure of compound 2 was elucidated by spectroscopic data analysis, including one dimensional (1D) and two dimensional (2D) nuclear magnetic resonance (NMR) experiments. Of the isolates, compound 2 exhibited potent cytotoxicity against human cervix adenocarcinoma cells and induced apoptosis.

Immune profiling of plasma and cervical secretions using recycling immunoaffinity chromatography.

PubMed

Castle, Philip E; Phillips, Terry M; Hildesheim, Allan; Herrero, Rolando; Bratti, M Concepcion; Rodríguez, Ana Cecilia; Morera, Lidia Ana; Pfeiffer, Ruth; Hutchinson, Martha L; Pinto, Ligia A; Schiffman, Mark

2003-12-01

Small volumes of cervical secretions have limited measurements of immunity at the cervix, which may be important to studies of human papillomavirus (HPV). We report the use of recycling immunoaffinity chromatography to efficiently study immune profiles in cervical secretions. Frozen pairs of plasma and cervical secretions (collected on ophthalmic sponges) were selected randomly from women with normal cervical cytology (n = 50) participating in a natural history study of HPV in Guanacaste, Costa Rica. Single 25- micro l aliquots of plasma and (diluted) cervical secretions were assayed for interleukin (IL) -1 beta, -2, -4, -6, -8, -10, -12, -13, -15, IFN-alpha, -beta, -gamma, tumor necrosis factor-alpha, -beta, RANTES (regulated on activation normal T-cell express and secreted), MCP-1 (monocyte chemoattractant protein), -2, -3, macrophage inflammatory protein-1 alpha, -1 beta (regulated on activation normal T-cell express and secreted), macrophage colony-stimulating factor, IgG, IgA, and cyclooxygenase 2. All of the specimens were tested as blind replicates, and refrozen plasma was retested 4 months later. To evaluate the reproducibility of the repeat measurements and to examine the correlation between plasma and cervical secretions, we calculated kappa values with 95% confidence intervals among categorized analyte values and Spearman correlation coefficients (rho) among detectable, continuous analyte values. Measurements of all of the analytes in either plasma or cervical secretions were highly reproducible, with all of the kappa > or = 0.78 (70% above 0.90), and all of the rho > or = 0.88 (96% above 0.90). Only IL-1 beta (kappa = 0.60 and rho = 0.82) and IL-6 (kappa = 0.50 and rho = 0.78) levels were strongly correlated between plasma and cervical secretions. IFN-gamma, tumor necrosis factor-beta, RANTES, MCP-1, MCP -2, macrophage inflammatory protein-1 alpha, and macrophage colony-stimulating factor levels were especially poorly correlated between plasma and cervical secretions (kappa < or = 0.25 and rho < or = 0.25). We conclude that recycling immunoaffinity chromatography is a reproducible method of measuring immune profiles from biological specimens, and immune profiles are not well correlated between plasma and cervical secretions, perhaps necessitating cervical collections to study cervix-specific immunity in HPV natural history studies.

Expression of estrogen receptors-alpha and -beta in the pregnant ovine uterine artery endothelial cells in vivo and in vitro.

PubMed

Liao, Wu Xiang; Magness, Ronald R; Chen, Dong-Bao

2005-03-01

Estrogen is recognized to be one of the driving forces in increases in uterine blood flow through both rapid and delayed actions via binding to its receptors, ER alpha and ER beta at the uterine artery (UA) wall, and especially in UA endothelium (UAE). However, information regarding estrogen receptor (ER) expression in UAE is limited. This study was designed to test whether ERs are expressed in UAE in vivo, and if they are, whether these receptors are maintained in cultured UA endothelial cells (UAECs) in vitro. By using immunohistochemical and Western blot analyses, we clearly demonstrated ER alpha and ER beta protein expression in pregnant (Days 120-130) sheep UA and UAE in vivo and as well as cultured UAECs in vitro. Reverse transcription-polymerase chain reaction (RT-PCR) amplified both ER alpha and ER beta mRNAs in UA, UAE, and UAECs. Of interest, a truncated ER beta (ER beta2) variant due to a splicing deletion of exon 5 of the ER beta gene was detected in these cells. Quantitative RT-PCR analysis revealed that ER alpha mRNA levels are approximately 8-fold (P < 0.01) higher than that of ER beta in UAECs, indicating that ER alpha may play a more important role than ER beta in the UAEC responses to estrogen. Fluorescence immunolabeling analysis showed that ER alpha is present in both nuclei and plasma membranes in UAECs, and the latter is also colocalized with caveolin-1. The membrane and nuclear ER alpha presumably participate in rapid and delayed responses, respectively, to estrogen on UAE. Taken together, our data demonstrated that UAE is a direct target of estrogen actions and that the UAEC culture model we established is suitable for dissecting estrogen actions on UAE.

Segregation of two spectrin isoforms: polarized membrane-binding sites direct polarized membrane skeleton assembly.

PubMed

Dubreuil, R R; Maddux, P B; Grushko, T A; MacVicar, G R

1997-10-01

Spectrin isoforms are often segregated within specialized plasma membrane subdomains where they are thought to contribute to the development of cell surface polarity. It was previously shown that ankyrin and beta spectrin are recruited to sites of cell-cell contact in Drosophila S2 cells expressing the homophilic adhesion molecule neuroglian. Here, we show that neuroglian has no apparent effect on a second spectrin isoform (alpha beta H), which is constitutively associated with the plasma membrane in S2 cells. Another membrane marker, the Na,K-ATPase, codistributes with ankyrin and alpha beta spectrin at sites of neuroglian-mediated contact. The distributions of these markers in epithelial cells in vivo are consistent with the order of events observed in S2 cells. Neuroglian, ankyrin, alpha beta spectrin, and the Na,K-ATPase colocalize at the lateral domain of salivary gland cells. In contrast, alpha beta H spectrin is sorted to the apical domain of salivary gland and somatic follicle cells. Thus, the two spectrin isoforms respond independently to positional cues at the cell surface: in one case an apically sorted receptor and in the other case a locally activated cell-cell adhesion molecule. The results support a model in which the membrane skeleton behaves as a transducer of positional information within cells.

Synthesis of plastic scintillation microspheres: alpha/beta discrimination.

PubMed

Santiago, L M; Bagán, H; Tarancón, A; Garcia, J F

2014-11-01

Plastic scintillation microspheres (PSm) have been developed as an alternative for liquid scintillation cocktails due to their ability to avoid the mixed waste, besides other strengths in which the possibility for alpha/beta discrimination is included. The aim of this work was to evaluate the capability of PSm containing two combinations of fluorescence solutes (PPO/POPOP and pT/Bis-MSB) and variable amounts of a second organic solvent (naphthalene) to enhance the alpha/beta discrimination. Two commercial detectors with different Pulse Shape Discrimination performances (Quantulus and Triathler) were used to evaluate the alpha/beta discrimination. An optimal discrimination of alpha/beta particles was reached, with very low misclassification values (2% for beta particles and 0.5% for alpha particles), when PSm containing PPO/POPOP and between 0.6 and 2.0 g of naphthalene were evaluated using Triathler and the appropriate programme for data processing. Copyright © 2014 Elsevier Ltd. All rights reserved.

Hsp105 family proteins suppress staurosporine-induced apoptosis by inhibiting the translocation of Bax to mitochondria in HeLa cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamagishi, Nobuyuki; Ishihara, Keiichi; Saito, Youhei

2006-10-15

Hsp105 (Hsp105{alpha} and Hsp105{beta}), major heat shock proteins in mammalian cells, belong to a subgroup of the HSP70 family, HSP105/110. Previously, we have shown that Hsp105{alpha} has completely different effects on stress-induced apoptosis depending on cell type. However, the molecular mechanisms by which Hsp105{alpha} regulates stress-induced apoptosis are not fully understood. Here, we established HeLa cells that overexpress either Hsp105{alpha} or Hsp105{beta} by removing doxycycline and examined how Hsp105 modifies staurosporine (STS)-induced apoptosis in HeLa cells. Apoptotic features such as the externalization of phosphatidylserine on the plasma membrane and nuclear morphological changes were induced by the treatment with STS, andmore » the STS-induced apoptosis was suppressed by overexpression of Hsp105{alpha} or Hsp105{beta}. In addition, we found that overexpression of Hsp105{alpha} or Hsp105{beta} suppressed the activation of caspase-3 and caspase-9 by preventing the release of cytochrome c from mitochondria. Furthermore, the translocation of Bax to mitochondria, which results in the release of cytochrome c from the mitochondria, was also suppressed by the overexpression of Hsp105{alpha} or Hsp105{beta}. Thus, it is suggested that Hsp105 suppresses the stress-induced apoptosis at its initial step, the translocation of Bax to mitochondria in HeLa cells.« less

Inhibition of dipeptidyl peptidase 4 regulates microvascular endothelial growth induced by inflammatory cytokines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takasawa, Wataru; Ohnuma, Kei; Hatano, Ryo

2010-10-08

Research highlights: {yields} TNF-{alpha} or IL-1{beta} induces EC proliferation with reduction of CD26 expression. {yields} CD26 siRNA or DPP-4 inhibition enhances TNF-{alpha} or IL-1{beta}-induced EC proliferation. {yields} Loss of CD26/DPP-4 enhances aortic sprouting induced by TNF-{alpha} or IL-1{beta}. {yields} Capillary formation induced by TNF-{alpha} or IL-1{beta} is enahced in the CD26{sup -/-} mice. -- Abstract: CD26/DPP-4 is abundantly expressed on capillary of inflamed lesion as well as effector T cells. Recently, CD26/dipeptidyl peptidase 4 (DPP-4) inhibition has been used as a novel oral therapeutic approach for patients with type 2 diabetes. While accumulating data indicate that vascular inflammation is amore » key feature of both micro- and macro-vascular complications in diabetes, the direct role of CD26/DPP-4 in endothelial biology is to be elucidated. We herein showed that proinflammatory cytokines such as tumor necrosis factor or interleukin-1 reduce expression of CD26 on microvascular endothelial cells, and that genetical or pharmacological inhibition of CD26/DPP-4 enhances endothelial growth both in vitro and in vivo. With DPP-4 inhibitors being used widely in the treatment of type 2 diabetes, our data strongly suggest that DPP-4 inhibition plays a pivotal role in endothelial growth and may have a potential role in the recovery of local circulation following diabetic vascular complications.« less

IFN-beta1b augments glucocorticoid-induced suppression of tumor necrosis factor-alpha production by increasing the number of glucocorticoid receptors on a human monocytic cell line.

PubMed

Uitdehaag, B M; Hoekstra, K; Koper, J W; Polman, C H; Dijkstra, C D

2001-03-01

We studied the effect of recombinant interferon-beta1b (IFN-beta1b) on the sensitivity to glucocorticoids (GC) and on the number of GC receptors (GCR) in the human monocytic cell line THP-1. We found that IFN-beta1b augments the suppressive effect that dexamethasone has on the stimulated production of tumor necrosis factor-alpha (TNF-alpha), most likely related to the increased number of GCR observed after exposure to IFN-beta1b. This provides a possible clue to the mechanism of action of IFN-beta in multiple sclerosis.

Alpha-lipoic acid improves subclinical left ventricular dysfunction in asymptomatic patients with type 1 diabetes.

PubMed

Hegazy, Sahar K; Tolba, Osama A; Mostafa, Tarek M; Eid, Manal A; El-Afify, Dalia R

2013-01-01

Oxidative stress plays an important role in the development of diabetic cardiomyopathy. Alpha-lipoic acid (ALA) is a powerful antioxidant that may have a protective role in diabetic cardiac dysfunction. We investigated the possible beneficial effect of alpha-lipoic acid on diabetic left ventricular (LV) dysfunction in children and adolescents with asymptomatic type 1 diabetes (T1D). Thirty T1D patients (aged 10-14) were randomized to receive insulin treatment (n = 15) or insulin plus alpha-lipoic acid 300 mg twice daily (n = 15) for four months. Age and sex matched healthy controls (n = 15) were also included. Patients were evaluated with conventional 2-dimensional echocardiographic examination (2D), pulsed tissue Doppler (PTD), and 2-dimensional longitudinal strain echocardiography (2DS) before and after therapy. Glutathione, malondialdhyde (MDA), nitric oxide (NO), tumor necrosis factor-alpha (TNF-alpha), Fas ligand (Fas-L), matrix metalloproteinase 2 (MMP-2), and troponin-I were determined and correlated to echocardiographic parameters. Diabetic patients had significantly lower levels of glutathione and significantly higher MDA, NO, TNF-alpha, Fas-L, MMP-2, and troponin-I levels than control subjects. The expression of transforming growth factor beta (TGF-beta) mRNA in peripheral blood mononuclear cells was also increased in diabetic patients. Significant correlations of mitral e'/a' ratio and left ventricular global peak systolic strain with glutathione, MDA, NO, TNF-alpha, and Fas-L were observed in diabetic patients. Alpha-lipoic acid significantly increased glutathione level and significantly decreased MDA, NO, TNF-alpha, Fas-L, MMP-2, troponin-I levels, and TGF-beta gene expression. Moreover, alpha-lipoic acid significantly increased mitral e'/a' ratio and left ventricular global peak systolic strain in diabetic patients. These findings suggest that alpha-lipoic acid may have a role in preventing the development of diabetic cardiomyopathy in type 1 diabetes.

T Cell Determinants Incorporating [beta]-Amino Acid Residues Are Protease Resistant and Remain Immunogenic In Vivo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Webb, Andrew I.; Dunstone, Michelle A.; Williamson, Nicholas A.

2010-07-20

A major hurdle in designing successful epitope-based vaccines resides in the delivery, stability, and immunogenicity of the peptide immunogen. The short-lived nature of unmodified peptide-based vaccines in vivo limits their therapeutic application in the immunotherapy of cancers and chronic viral infections as well as their use in generating prophylactic immunity. The incorporation of {beta}-amino acids into peptides decreases proteolysis, yet its potential application in the rational design of T cell mimotopes is poorly understood. To address this, we have replaced each residue of the SIINFEKL epitope individually with the corresponding {beta}-amino acid and examined the resultant efficacy of these mimotopes.more » Some analogs displayed similar MHC binding and superior protease stability compared with the native epitope. Importantly, these analogs were able to generate cross-reactive CTLs in vivo that were capable of lysing tumor cells that expressed the unmodified epitope as a surrogate tumor Ag. Structural analysis of peptides in which anchor residues were substituted with {beta}-amino acids revealed the basis for enhanced MHC binding and retention of immunogenicity observed for these analogs and paves the way for future vaccine design using {beta}-amino acids. We conclude that the rational incorporation of {beta}-amino acids into T cell determinants is a powerful alternative to the traditional homologous substitution of randomly chosen naturally occurring {alpha}-amino acids, and these mimotopes may prove particularly useful for inclusion in epitope-based vaccines.« less

The role of alpha3beta1 integrin in determining the supramolecular organization of laminin-5 in the extracellular matrix of keratinocytes.

PubMed

deHart, Gregory W; Healy, Kevin E; Jones, Jonathan C R

2003-02-01

Analyses of mice with targeted deletions in the genes for alpha3 and beta1 integrin suggest that the alpha3beta1 integrin heterodimer likely determines the organization of the extracellular matrix within the basement membrane of skin. Here we tested this hypothesis using keratinocytes derived from alpha3 integrin-null mice. We have compared the organizational state of laminin-5, a ligand of alpha3beta1 integrin, in the matrix of wild-type keratinocytes with that of laminin-5 in the matrix of alpha3 integrin-null cells. Laminin-5 distributes diffusely in arc structures in the matrix of wild-type mouse keratinocytes, whereas laminin-5 is organized into linear, spike-like arrays by the alpha3 integrin-null cells. The fact that alpha3 integrin-null cells are deficient in their ability to assemble a proper laminin-5 matrix is also shown by their failure to remodel laminin-5 when plated onto surfaces coated with purified laminin-5 protein. In sharp contrast, wild-type keratinocytes organize exogenously added laminin-5 into discrete ring-like organizations. These findings led us next to assess whether differences in laminin-5 organization in the matrix of the wild-type and alpha3 integrin-null cells impact cell behavior. Our results indicate that alpha3 integrin-null cells are more motile than their wild-type counterparts and leave extensive trails of laminin-5 over the surface on which they move. Moreover, HEK 293 cells migrate significantly more on the laminin-5-rich matrix derived from the alpha3 integrin-null cells than on the wild-type keratinocyte laminin-5 matrix. In addition, alpha3 integrin-null cells show low strength of adhesion to surfaces coated with purified laminin-5 compared to wild-type cells although both the wild type and the alpha3 integrin-null keratinocytes adhere equally strongly to laminin-5 that has been organized into arrays by other epithelial cells. These data suggest: (1) that alpha3beta1 integrin plays an important role in determining the incorporation of laminin-5 into its proper higher-order structure within the extracellular matrix of keratinocytes and (2) that the organizational state of laminin-5 has an influence on laminin-5 matrix function. Copyright 2003 Elsevier Science (USA)

Deconfinement and the Hagedorn transition in string theory.

PubMed

Chaudhuri, S

2001-03-05

We introduce a new definition of the thermal partition function in string theory. With this new definition, the thermal partition functions of all of the string theories obey thermal duality relations with self-dual Hagedorn temperature beta(2)(H) = 4pi(2)alpha('). A beta-->beta(2)(H)/beta transformation maps the type I theory into a new string theory (type I) with thermal D p-branes, spatial hypersurfaces supporting a p-dimensional finite temperature non-Abelian Higgs-gauge theory for p< or =9. We demonstrate a continuous phase transition in the behavior of the static heavy quark-antiquark potential for small separations r(2)(*)

Tryptophan W207 in transducin T alpha is the fluorescence sensor of the G protein activation switch and is involved in the effector binding.

PubMed Central

Faurobert, E; Otto-Bruc, A; Chardin, P; Chabre, M

1993-01-01

We have produced a recombinant transducin alpha subunit (rT alpha) in sf9 cells, using a baculovirus system. Deletion of the myristoylation site near the N-terminal increased the solubility and allowed the purification of rT alpha. When reconstituted with excess T beta gamma on retinal membrane, rT alpha displayed functional characteristics of wild-type T alpha vis à vis its coupled receptor, rhodopsin and its effector, cGMP phosphodiesterase (PDE). We further mutated a tryptophan, W207, which is conserved in all G proteins and is suspected to elicit the fluorescence change correlated to their activation upon GDP/GTP exchange or aluminofluoride (AlFx) binding. [W207F]T alpha mutant displayed high affinity receptor binding and underwent a conformational switch upon receptor-catalysed GTP gamma S binding or upon AlFx binding, but this did not elicit any fluorescence change. Thus W207 is the only fluorescence sensor of the switch. Upon the switch the mutant remained unable to activate the PDE. To characterize better its effector-activating interaction we measured the affinity of [W207F]T alpha GDP-AlFx for PDE gamma, the effector subunit that binds most tightly to T alpha. [W207F]T alpha still bound in an activation-dependent way to PDE gamma, but with a 100-fold lower affinity than rT alpha. This suggests that W207 contributes to the G protein effector binding. Images PMID:8223434

Expression of the alpha and beta subunits of Ca2+/calmodulin kinase II in the cerebellum of jaundiced Gunn rats during development: a quantitative light microscopic analysis.

PubMed

Conlee, J W; Shapiro, S M; Churn, S B

2000-04-01

The homozygous (jj) jaundiced Gunn rat model for hyperbilirubinemia displays pronounced cerebellar hypoplasia. To examine the cellular mechanisms involved in bilirubin toxicity, this study focused on the effect of hyperbilirubinemia on calcium/calmodulin-dependent kinase II (CaM kinase II). CaM kinase II is a neuronally enriched enzyme which performs several important functions. Immunohistochemical analysis of alternating serial sections were performed using monoclonal antibodies for the alpha and beta subunits of CaM kinase II. Measurements were made of the total numbers of stained cells in each of the deep cerebellar nuclei and of Purkinje and granule cell densities in cerebellar lobules II, VI, and IX. The beta subunit was present in Purkinje cells and deep cerebellar nuclei of both groups at all ages, but only granule cells which had migrated through the Purkinje cell layer showed staining for beta subunit; external granule cells were completely negative. Many Purkinje cells had degenerated in the older animals, and the percent of granule cells stained for beta subunit was significantly reduced. The alpha subunit was found exclusively in Purkinje cells, although its appearance was delayed in the jaundiced animals. Sulfadimethoxine was administered to some jj rats 24 h or 15 days prior to sacrifice to increase brain bilirubin concentration. Results showed that bilirubin exposure modulated both alpha and beta CaM kinase II subunit expression in selective neuronal populations, but sulfadimethoxine had no acute effect on enzyme immunoreactivity. Thus, developmental expression of the alpha and beta subunits of CaM kinase II was affected by chronic bilirubin exposure during early postnatal development of jaundiced Gunn rats.

Hsp105 reduces the protein aggregation and cytotoxicity by expanded-polyglutamine proteins through the induction of Hsp70

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamagishi, Nobuyuki; Goto, Kazumasa; Nakagawa, Satomi

2010-09-10

Hsp105{alpha} and Hsp105{beta} are major heat shock proteins in mammalian cells and belong to the HSP105/110 family. Hsp105{alpha} is expressed constitutively in the cytoplasm of cells, while Hsp105{beta}, an alternatively spliced form of Hsp105{alpha}, is expressed specifically in the nucleus of cells during mild heat shock. Here, we show that not only Hsp105{beta} but also Hsp105{alpha} accumulated in the nucleus of cells following the expression of enhanced green fluorescent protein with a pathological length polyQ tract (EGFP-polyQ97) and suppressed the intranuclear aggregation of polyQ proteins and apoptosis induced by EGFP-polyQ97. Mutants of Hsp105{alpha} and Hsp105{beta} with changes in the nuclearmore » localization signal sequences, which localized exclusively in the cytoplasm with or without the expression of EGFP-polyQ97, did not suppress the intranuclear aggregation of polyQ proteins and apoptosis induced by EGFP-polyQ97. Furthermore, Hsp70 was induced by the co-expression of Hsp105{alpha} and EGFP-polyQ97, and the knockdown of Hsp70 reduced the inhibitory effect of Hsp105{alpha} and Hsp105{beta} on the intranuclear aggregation of polyQ proteins and apoptosis induced by EGFP-polyQ97. These observations suggested that Hsp105{alpha} and Hsp105{beta} suppressed the expanded polyQ tract-induced protein aggregation and apoptosis through the induction of Hsp70.« less

TNF-alpha, but not IFN-gamma, regulates CCN2 (CTGF), collagen type I, and proliferation in mesangial cells: possible roles in the progression of renal fibrosis.

PubMed

Cooker, Laurinda A; Peterson, Darryl; Rambow, Joann; Riser, Melisa L; Riser, Rebecca E; Najmabadi, Feridoon; Brigstock, David; Riser, Bruce L

2007-07-01

Connective tissue growth factor (CCN2) is a profibrotic factor acting downstream and independently of TGF-beta to mediate renal fibrosis. Although inflammation is often involved in the initiation and/or progression of fibrosis, the role of inflammatory cytokines in regulation of glomerular CCN2 expression, cellular proliferation, and extracellular matrix accumulation is unknown. We studied two such cytokines, TNF-alpha and IFN-gamma, for their effects on cultured mesangial cells in the presence or absence of TGF-beta, as a model for progressive renal fibrosis. Short-term treatment with TNF-alpha, like TGF-beta, significantly increased secreted CCN2 per cell, but unlike TGF-beta inhibited cellular replication. TNF-alpha combined with TGF-beta further increased CCN2 secretion and mRNA levels and reduced proliferation. Surprisingly, however, TNF-alpha treatment decreased baseline collagen type I protein and mRNA levels and largely blocked their stimulation by TGF-beta. Long-term treatment with TGF-beta or TNF-alpha alone no longer increased CCN2 protein levels. However, the combination synergistically increased CCN2. IFN-gamma had no effect on either CCN2 or collagen activity and produced a mild inhibition of TGF-beta-induced collagen only at a high concentration (500 U/ml). In summary, we report a strong positive regulatory role for TNF-alpha, but not IFN-gamma, in CCN2 production and secretion, including that driven by TGF-beta. The stimulation of CCN2 release by TNF-alpha, unlike TGF-beta, is independent of cellular proliferation and not linked to increased collagen type I accumulation. This suggests that the paradigm of TGF-beta-driven CCN2 with subsequent collagen production may be overridden by an as yet undefined inhibitory mechanism acting either directly or indirectly on matrix metabolism.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laouar, A.; Glesne, D.; Huberman, E.

The role of protein kinase C-{beta} (PKC-{beta}) in apoptosis induced by tumor necrosis factor (TNF)-{alpha} and anti-Fas monoclonal antibody (mAb) in the human myeloid HL-60 leukemia cell line was studied by using its variant HL-525, which is deficient in PKC-{beta}. In contrast to the parental HL-60 cells, HL-525 is resistant to TNF-{alpha}-induced apoptosis but sensitive to anti-Fas mAb-induced apoptosis. Both cell types expressed similar levels of the TNF-receptor I, whereas the Fas receptor was detected only in HL-525 cells. Transfecting the HL-525 cells with an expression vector containing PKC-{beta} reestablished their susceptibility to TNF-{alpha}-induced apoptosis. The apoptotic effect of TNF-{alpha}more » in HL-60 and the transfectants was abrogated by fumonisin, an inhibitor of ceramide generation, and by the peptide Ac-YVAD-BoMK, an inhibitor of caspase-1 and -4. Supplementing HL-525 cells with exogenous ceramides bypassed the PKC-{beta} deficiency and induced apoptosis, which was also restrained by the caspase-1 and -4 inhibitor. The apoptotic effect of anti-Fas mAb in HL-525 cells was abrogated by the antioxidants N-acetylcysteine and glutathione and by the peptide z-DEVD-FMK, an inhibitor of caspase-3 and -7. We suggest that TNF-{alpha}-induced apoptosis involves PKC-{beta} and then ceramide and, in turn, caspase-1 and/or -4, whereas anti-Fas mAb-induced apoptosis utilizes reactive oxygen intermediates and, in turn, caspase-3 and/or -7.« less

Cytotoxicity of cardenolides and cardenolide glycosides from Asclepias curassavica.

PubMed

Li, Jun-Zhu; Qing, Chen; Chen, Chang-Xiang; Hao, Xiao-Jiang; Liu, Hai-Yang

2009-04-01

A new cardenolide, 12beta,14beta-dihydroxy-3beta,19-epoxy-3alpha-methoxy-5alpha-card-20(22)-enolide (6), and a new doubly linked cardenolide glycoside, 12beta-hydroxycalotropin (13), together with eleven known compounds, coroglaucigenin (1), 12beta-hydroxycoroglaucigenin (2), calotropagenin (3), desglucouzarin (4), 6'-O-feruloyl-desglucouzarin (5), calotropin (7), uscharidin (8), asclepin (9), 16alpha-hydroxyasclepin (10), 16alpha-acetoxycalotropin (11), and 16alpha-acetoxyasclepin (12), were isolated from the aerial part of ornamental milkweed, Asclepias curassavica and chemically elucidated through spectral analyses. All the isolates were evaluated for their cytotoxic activity against HepG2 and Raji cell lines. The results showed that asclepin (9) had the strongest cytotoxic activity with an IC(50) value of 0.02 microM against the two cancer cell lines and the new compound 13 had significant cytotoxic activity with IC(50) values of 0.69 and 1.46 microM, respectively.

Beta1-integrin and IL-1alpha expression as bystander effect of medium from irradiated cells: the pilot study.

PubMed

Osterreicher, Jan; Skopek, Jirí; Jahns, Juta; Hildebrandt, Guido; Psutka, Jan; Vilasová, Zdenka; Tanner, Judith Maria; Vogt, Jürgen; Butz, Tilman

2003-01-01

Bystander effects have been proposed as a third action pathway of ionising radiation besides direct and indirect effects. The purpose of the study was to investigate whether expression of interleukin-1alpha (IL-1alpha) and beta1-integrin is elevated in bystander cells as a marker for bystander effects in comparison with classical markers such as the clonogenic assay, apoptosis and the presence of micronuclei. The hybrid cell line E.A. hy.926 obtained by fusion of HUVEC cells with the epithelial cell line A 459 was irradiated with 0-5 Gy. Bystander effects were established via medium transfer at 45 min and 4 h after irradiation from irradiated to nonirradiated cell populations. In order to exclude effects of the irradiated medium itself, irradiated medium only was also used for transfer to nonirradiated cells. Then, cells were fixed at 1, 2, 6, and 24 h after irradiation or medium transport and IL-1alpha and beta1-integrin were detected and evaluated. A higher number of beta1-integrin-positive cells was observed in both irradiated and bystander cell populations than in the control group at 1 and 24 h after irradiation with 1 Gy or medium transfer. Significantly higher numbers of IL-1alpha-positive cells were found at 1, 2, and 6 h after irradiation with 1 Gy or medium transfer as well as at 2 and 6 h after irradiation with 5 Gy or medium transfer. Clonogenic survival decreased dependently on the dose in irradiated cells but did not show any significant difference between the bystander cell populations and sham-irradiated cells. The irradiated medium itself did not have any effect. It is concluded that beta1-integrin and IL-1alpha expression may serve as more sensitive markers of post-irradiation responses in bystander cell populations than the classical radiobiological markers. Moreover, overexpression of beta1-integrin and IL-1alpha may induce increased susceptibility to inflammation of bystander cells.

Neoformation of boldenone and related steroids in faeces of veal calves.

PubMed

Pompa, G; Arioli, F; Fracchiolla, M L; Rossi, C A Sgoifo; Bassini, A L; Stella, S; Biondi, P A

2006-02-01

Conflicting findings regarding the boldenone content of bovine faeces suggest it may be synthesized de novo in emitted faeces. We tested this hypothesis by analysing uncontaminated urine, fresh and various forms of dried faeces from 10 calves (not given boldenone) by liquid chromatography/tandem mass spectrometry for 17alpha- and 17beta-boldenone (alpha and beta BOL); 1,4-androstadiene-3,17-dione (ADD); 4-androstene-3,17-dione (AED), testosterone (T) and epitestosterone (ET). Urine contained no alpha BOL, beta BOL or ADD. The analysed substances were variably present in the rectal faeces, and at generally higher levels in faeces scraped from skin or stall floor. In pooled rectal faeces naturally dried for 13 days, alpha BOL, ADD, AED and ET levels were extremely high (much higher than accounted for by increases due to drying), and beta BOL and T were absent. It is concluded that de novo synthesis of alpha BOL and metabolites occurs naturally in bovine faeces and only uncontaminated urine should be analysed for illegal boldenone.

Coordinate regulation of estrogen-mediated fibronectin matrix assembly and epidermal growth factor receptor transactivation by the G protein-coupled receptor, GPR30.

PubMed

Quinn, Jeffrey A; Graeber, C Thomas; Frackelton, A Raymond; Kim, Minsoo; Schwarzbauer, Jean E; Filardo, Edward J

2009-07-01

Estrogen promotes changes in cytoskeletal architecture not easily attributed to the biological action of estrogen receptors, ERalpha and ERbeta. The Gs protein-coupled transmembrane receptor, GPR30, is linked to specific estrogen binding and rapid estrogen-mediated release of heparin-bound epidermal growth factor. Using marker rescue and dominant interfering mutant strategies, we show that estrogen action via GPR30 promotes fibronectin (FN) matrix assembly by human breast cancer cells. Stimulation with 17beta-estradiol or the ER antagonist, ICI 182, 780, results in the recruitment of FN-engaged integrin alpha5beta1 conformers to fibrillar adhesions and the synthesis of FN fibrils. Concurrent with this cellular response, GPR30 promotes the formation of Src-dependent, Shc-integrin alpha5beta1 complexes. Function-blocking antibodies directed against integrin alpha5beta1 or soluble Arg-Gly-Asp peptide fragments derived from FN specifically inhibited GPR30-mediated epidermal growth factor receptor transactivation. Estrogen-mediated FN matrix assembly and epidermal growth factor receptor transactivation were similarly disrupted in integrin beta1-deficient GE11 cells, whereas reintroduction of integrin beta1 into GE11 cells restored these responses. Mutant Shc (317Y/F) blocked GPR30-induced FN matrix assembly and tyrosyl phosphorylation of erbB1. Interestingly, relative to recombinant wild-type Shc, 317Y/F Shc was more readily retained in GPR30-induced integrin alpha5beta1 complexes, yet this mutant did not prevent endogenous Shc-integrin alpha5beta1 complex formation. Our results suggest that GPR30 coordinates estrogen-mediated FN matrix assembly and growth factor release in human breast cancer cells via a Shc-dependent signaling mechanism that activates integrin alpha5beta1.

Type I interferon (IFN-alpha/beta) rescues B-lymphocytes from apoptosis via PI3Kdelta/Akt, Rho-A, NFkappaB and Bcl-2/Bcl(XL).

PubMed

Badr, Gamal; Saad, Heba; Waly, Hanan; Hassan, Khadega; Abdel-Tawab, Hanem; Alhazza, Ibrahim M; Ahmed, Emad A

2010-01-01

Although IFN-alpha was reported to promote the survival of peripheral B-lymphocytes via the PI3-kinase-Akt pathway, the triggered signalling pathways involved in the protection of B cell from apoptosis need to be clarified. Using flow cytometry and western blot analysis, we have found that type 1 IFNs (IFN-alpha/beta) protect human B cells in culture from spontaneous apoptosis and from apoptosis mediated by anti-CD95 agonist, in a dose- and time-dependant manner. IFN-alpha/beta-mediated anti-apoptotic effect on human B cells was totally abrogated by blockade of IFNR1 chain. Our data indicate that PI3Kdelta, Rho-A, NFkappaB and Bcl-2/Bcl(XL) are active downstream of IFN receptors and are the major effectors of IFN-alpha/beta-rescued B cells from apoptosis. Furthermore, immunohistochemical results show marked reduction in numbers of CD20 positive B cell in both spleen and Peyer's patches from mice treated with anti-IFNR1 blocking antibody compared with control group. Moreover, ultrastructural observations of these organs show an obvious increase in apoptotic cells from mice treated with anti-IFNR1 blocking antibody. Our results provide more details about the triggered signalling pathways and the phosphorylation cascade which are involved in the protection of B cell from apoptosis after treatment with IFN-alpha/beta. Copyright 2010 Elsevier Inc. All rights reserved.

Stress-induced facilitation of host response to bacterial challenge in F344 rats is dependent on extracellular heat shock protein 72 and independent of alpha beta T cells.

PubMed

Campisi, Jay; Sharkey, Craig; Johnson, John D; Asea, Alexzander; Maslanik, Thomas; Bernstein-Hanley, Isaac; Fleshner, Monika

2012-11-01

Activation of the in vivo stress response can facilitate antibacterial host defenses. One possible mechanism for this effect is stress-induced release of heat shock protein 72 (Hsp72) into the extracellular environment. Hsp72 is a ubiquitous cellular protein that is up-regulated in response to cellular stress, and modulates various aspects of immune function including macrophage inflammatory/bactericidal responses and T-cell function when found in the extracellular environment. The current study tested the hypothesis that in vivo extracellular Hsp72 (eHsp72) at the site of inflammation contributes to stress-induced restricted development of bacteria, and facilitated recovery from bacteria-induced inflammation, and that this effect is independent of alpha beta (αβ) T cells. Male F344 rats were exposed to either inescapable electrical tail-shocks or no stress, and subcutaneously injected with Escherichia coli (ATCC 15746). The role of eHsp72 was investigated by Hsp72-immunoneutralization at the inflammatory site. The potential contribution of T cells was examined by testing male athymic (rnu/rnu) nude rats lacking mature αβ T cells and heterozygous thymic intact control (rnu/+) rats. The results were that stressor exposure increased plasma concentrations of eHsp72 and facilitated recovery from bacterial inflammation. Immunoneutralization of eHsp72 at the inflammatory site attenuated this effect. Stressor exposure impacted bacterial inflammation and eHsp72 equally in both athymic and intact control rats. These results support the hypothesis that eHsp72 at the site of inflammation, and not αβ T cells, contributes to the effect of stressor exposure on subcutaneous bacterial inflammation.

Langerhans cells beta 2-adrenoceptors: role in migration, cytokine production, Th priming and contact hypersensitivity.

PubMed

Maestroni, Georges J M; Mazzola, Paola

2003-11-01

We showed that norepinephrine (NE) hampers IL-12 and stimulates IL-10 production via adrenoceptors (ARs) in bone marrow-derived dendritic cells (BMDC) influencing their Th priming ability. Others have shown that Langerhans cells (LC) express mRNA for beta1-, beta2- and alpha1(A)-(ARs) and that catecholamines may inhibit the antigen-presenting capability via beta2-ARs. Here, we show that also BMDC express mRNA for beta1-, beta2-, alpha2(A)- and alpha2(C)-ARs. Inhibition of IL-12 is mediated by both beta2- and alpha2(A)-ARs, while stimulation of IL-10 by beta2-ARs only. In addition, LC migration, the contact hypersensitivity response (CHS) and production of IFN-gamma and IL-2 in draining lymph node cells is increased in mice treated topically with the beta2-AR antagonist ICI 118,551 during FITC sensitization. Activation of beta2-ARs in BMDC before adoptive transfer could reduce both migration and CHS response to FITC. Finally, preincubation of BMDC with LPS in presence of the specific beta2-AR agonist salbutamol impaired their chemotactic response to CCL19 and CCL21 and this effect was neutralized by anti-IL-10 mAb. We suggest that the physiological activation of beta2-ARs in DC (LC) results in stimulation of IL-10 which in turn restrains DC (LC) migration influencing antigen presentation and the consequent CHS response.

IFN-{gamma} sensitizes MIN6N8 insulinoma cells to TNF-{alpha}-induced apoptosis by inhibiting NF-{kappa}B-mediated XIAP upregulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Hun Sik; Kim, Sunshin; Lee, Myung-Shik

2005-10-28

Although X-linked inhibitor of apoptosis protein (XIAP) is an important intracellular suppressor of apoptosis in a variety of cell types, its role in cytokine-induced pancreatic {beta}-cell apoptosis remains unclear. Here, we found that: (i) XIAP level was inversely correlated with tumor necrosis factor (TNF)-{alpha}-induced apoptosis in MIN6N8 insulinoma cells; (ii) adenoviral XIAP overexpression abrogated the TNF-{alpha}-induced apoptosis through inhibition of caspase activity; (iii) downregulation of XIAP by antisense oligonucleotide or Smac peptide sensitized MIN6N8 cells to TNF-{alpha}-induced apoptosis; (iv) XIAP expression was induced by TNF-{alpha} through a nuclear factor-{kappa}B (NF-{kappa}B)-dependent pathway, and interferon (IFN)-{gamma} prevented such an induction in amore » manner independent of NF-{kappa}B, which presents a potential mechanism underlying cytotoxic IFN-{gamma}/TNF-{alpha} synergism. Taken together, our results suggest that XIAP is an important modulator of TNF-{alpha}-induced apoptosis of MIN6N8 cells, and XIAP regulation in pancreatic {beta}-cells might play an important role in pancreatic {beta}-cell apoptosis and in the pathogenesis of type 1 diabetes.« less

Radiosensitivity of Prostate Cancer Cell Lines for Irradiation from Beta Particle-emitting Radionuclide ¹⁷⁷Lu Compared to Alpha Particles and Gamma Rays.

PubMed

Elgqvist, Jörgen; Timmermand, Oskar Vilhelmsson; Larsson, Erik; Strand, Sven-Erik

2016-01-01

The purpose of the present study was to investigate the radiosensitivity of the prostate cancer cell lines LNCaP, DU145, and PC3 when irradiated with beta particles emitted from (177)Lu, and to compare the effect with irradiation using alpha particles or gamma rays. Cells were irradiated with beta particles emitted from (177)Lu, alpha particles from (241)Am, or gamma rays from (137)Cs. A non-specific polyclonal antibody was labeled with (177)Lu and used to irradiate cells in suspension with beta particles. A previously described in-house developed alpha-particle irradiator based on a (241)Am source was used to irradiate cells with alpha particles. External gamma-ray irradiation was achieved using a standard (137)Cs irradiator. Cells were irradiated to absorbed doses equal to 0, 0.5, 1, 2, 4, 6, 8, or 10 Gy. The absorbed doses were calculated as mean absorbed doses. For evaluation of cell survival, the tetrazolium-based WST-1 assay was used. After irradiation, WST-1 was added to the cell solutions, incubated, and then measured for level of absorbance at 450 nm, indicating the live and viable cells. LNCaP, DU145, and PC3 cell lines all had similar patterns of survival for the different radiation types. No significant difference in surviving fractions were observed between cells treated with beta-particle and gamma-ray irradiation, represented for example by the surviving fraction values (mean±SD) at 2, 6, and 10 Gy (SF2, SF6, and SF10) for DU145 after beta-particle irradiation: 0.700±0.090, 0.186±0.050 and 0.056±0.010, respectively. A strong radiosensitivity to alpha particles was observed, with SF2 values of 0.048±0.008, 0.018±0.006 and 0.015±0.005 for LNCaP, DU145, and PC3, respectively. The surviving fractions after irradiation using beta particles or gamma rays did not differ significantly at the absorbed dose levels and dose rates used. Irradiation using alpha particles led to a high level of cell killing. The results show that the beta-particle emitter (177)Lu as well as alpha-particles are both good candidates for radionuclide-therapy applications in the treatment of prostate cancer. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Dysregulation of in vitro cytokine production by monocytes during sepsis.

PubMed Central

Munoz, C; Carlet, J; Fitting, C; Misset, B; Blériot, J P; Cavaillon, J M

1991-01-01

The production by monocytes of interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF alpha) in intensive care unit (ICU) patients with sepsis syndrome (n = 23) or noninfectious shock (n = 6) is reported. Plasma cytokines, cell-associated cytokines within freshly isolated monocytes and LPS-induced in vitro cytokine production were assessed at admission and at regular intervals during ICU stay. TNF alpha and IL-6 were the most frequently detected circulating cytokines. Despite the fact that IL-1 alpha is the main cytokine found within monocytes upon in vitro activation of cells from healthy individuals, it was very rarely detected within freshly isolated monocytes from septic patients, and levels of cell-associated IL-1 beta were lower than those of TNF alpha. Cell-associated IL-1 beta and TNF alpha were not correlated with corresponding levels in plasma. Upon LPS stimulation, we observed a profound decrease of in vitro IL-1 alpha production by monocytes in all patients, and of IL-1 beta, IL-6, and TNF alpha in septic patients. This reduced LPS-induced production of cytokines was most pronounced in patients with gram-negative infections. Finally, monocytes from survival patients, but not from nonsurvival ones recovered their capacity to produce normal amounts of cytokines upon LPS stimulation. In conclusion, our data indicate an in vivo activation of circulating monocytes during sepsis as well as in noninfectious shock and suggest that complex regulatory mechanisms can downregulate the production of cytokines by monocytes during severe infections. Images PMID:1939659

Abnormal cytokine production by circulating monocytes and dendritic cells of myeloid origin in ART-treated HIV-1+ patients relates to CD4+ T-cell recovery and HCV co-infection.

PubMed

Almeida, Maria; Cordero, Miguel; Almeida, Julia; Orfao, Alberto

2007-05-01

HIV-1 infection is associated with dysregulation of cytokine production by peripheral blood (PB) monocytes and dendritic cells (DC), but controversial results have been reported. We aimed to analyze the effect of antiretroviral therapy (ART) on the in vitro production of inflammatory cytokines by PB-stimulated monocytes and DC of myeloid origin -CD33(high+ ) myeloid DC (mDC) and CD33(+)/CD14(-/dim+)/CD16(high+) DC- from HIV-1+ patients and its relationship with CD4+ T-cell recovery and co-infection with hepatitis C virus (HCV). In vitro cytokine production was analyzed at the single cell level in 32 HIV-1+ patients, grouped according to the number of CD4+ T-cells/microl in PB (<200 CD4 versus >200 CD4). Patients were tested prior to therapy and at weeks +2, +4, +8, +12 and +52 after ART. Prior to ART, production of IL-6, TNF-alpha and IL-12 by mDC and of IL-8 and IL-12 by CD16+ DC was significantly increased among >200 CD4 patients. After one year of ART, increased production of IL-8 by monocytes, of TNF-alpha by mDC and of IL-1beta, IL-6 and TNF-alpha by CD16+ DC was specifically observed among <200 CD4 HIV-1+ individuals showing a high recovery of PB CD4+ T-cell counts. In turn, we found that the significantly reduced percentage of IL-1beta, IL-6, IL-8 and TNF-alpha-producing monocytes and of IL-6 and IL-8-producing mDC and CD16+ DC, as well as the significantly diminished mean amount of IL-6 produced per monocyte, mDC and CD16+ DC and of IL-12 produced per CD16+ DC observed at week +52 for the >200 CD4 patients, were related to the presence of co-infection with HCV. In summary, HIV-1+ individuals show abnormal production of inflammatory cytokines by PB-stimulated monocytes and DC of myeloid origin even after one year of ART, such abnormalities being associated with the degree of recovery of PB CD4+ T-cell counts in more immunocompromised patients and HCV co-infection in more immunocompetent HIV-1+ individuals.

Subunit assembly of hemoglobin: an important determinant of hematologic phenotype.

PubMed

Bunn, H F

1987-01-01

Hemoglobin's physiologic properties depend on the orderly assembly of its subunits in erythropoietic cells. The biosynthesis of alpha- and beta-globin polypeptide chains is normally balanced. Heme rapidly binds to the globin subunit, either during translation or shortly thereafter. The formation of the alpha beta-dimer is facilitated by electrostatic attraction of a positively charged alpha-subunit to a negatively charged beta-subunit. The alpha beta-dimer dissociates extremely slowly. The difference between the rate of dissociation of alpha beta- and alpha gamma-dimers with increasing pH explains the well-known alkaline resistance of Hb F. Two dimers combine to form the functioning alpha 2 beta 2-tetramer. This model of hemoglobin assembly explains the different levels of positively charged and negatively charged mutant hemoglobins that are encountered in heterozygotes and the effect of alpha-thalassemia and heme deficiency states in modifying the level of the variant hemoglobin as well as Hb A2. Electrostatic interactions also affect the binding of hemoglobin to the cytoplasmic surface of the red cell membrane and may underlie the formation of target cells. Enhanced binding of positively charged variants such as S and C trigger a normally dormant pathway for potassium and water loss. Thus, the positive charge on beta c is responsible for the two major contributors to the pathogenesis of Hb SC disease: increased proportion of Hb S and increased intracellular hemoglobin concentration. It is likely that electrostatic interactions play an important role in the assembly of a number of other multisubunit macromolecules, including membrane receptors, cytoskeletal proteins, and DNA binding proteins.

Glucocorticoids inhibit coordinated translation of. cap alpha. - and. beta. -globin mRNAs in Friend erythroleukemia cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Papaconstantinou, J.; Stewart, J.A.; Rabek, J.P.

The dimethylsulfoxide (Me/sub 2/SO)-mediated induction of hemoglobin synthesis in Friend erythroleukemia cells is inhibited by the glucocorticoids hydrocortisone, dexamethasone, and fluocinolone acetonide; hydrocortisone, at concentrations of 10/sup -5/ to 10/sup -8/ M inhibits by 90-30% and fluocinolone acetonide at concentrations of 10/sup -8/ to 10/sup -11/ M shows a greater than 90% inhibition. At these concentrations the hormones have no effect on cell growth or viability. In this study it has been shown that there is a group of proteins, including the ..cap alpha..- and ..beta..-globins, whose regulation is associated with the induction of Friend erythroleukemia cell differentiation, and thatmore » the expression of these, in addition to ..cap alpha..- and ..beta..-globin, is affected by glucocorticoids. It is concluded that, although the translation of ..cap alpha..- and ..beta..-globin mRNA is a major site of inhibition by glucocorticoids, there is a detectable amount of ..cap alpha..- and ..beta..-globin mRNA translation which results in unequal amounts of globin synthesis and an overall more potent inhibition of hemoglobin formation.« less

Steroids from the leaves of Chinese Melia azedarach and their cytotoxic effects on human cancer cell lines.

PubMed

Wu, Shi-Biao; Ji, Yan-Ping; Zhu, Jing-Jing; Zhao, Yun; Xia, Gang; Hu, Ying-He; Hu, Jin-Feng

2009-09-01

Three new (1-3) and several known (4-6) steroids were isolated from the leaves of Chinese Melia azedarach. The structures of the new compounds were elucidated by means of spectroscopic methods including 2D NMR techniques and mass spectrometry to be (20S)-5,24(28)-ergostadiene-3beta,7alpha,16beta,20-tetrol (1), (20S)-5-ergostene-3beta,7alpha,16beta,20-tetrol (2), and 2alpha,3beta-dihydro-5-pregnen-16-one (3). The cytotoxicities of the isolated compounds against three human cancer cell lines (A549, H460, U251) were evaluated; only compounds 1, 2, and (20S)-5-stigmastene-3beta,7alpha,20-triol (4) were found to show significant cyctotoxic effects with IC(50)s from 12.0 to 30.1 microg/mL.

Independent Causal Contributions of Alpha- and Beta-Band Oscillations during Movement Selection.

PubMed

Brinkman, Loek; Stolk, Arjen; Marshall, Tom R; Esterer, Sophie; Sharp, Poppy; Dijkerman, H Chris; de Lange, Floris P; Toni, Ivan

2016-08-17

To select a movement, specific neuronal populations controlling particular features of that movement need to be activated, whereas other populations are downregulated. The selective (dis)inhibition of cortical sensorimotor populations is governed by rhythmic neural activity in the alpha (8-12 Hz) and beta (15-25 Hz) frequency range. However, it is unclear whether and how these rhythms contribute independently to motor behavior. Building on a recent dissociation of the sensorimotor alpha- and beta-band rhythms, we test the hypothesis that the beta-band rhythm governs the disinhibition of task-relevant neuronal populations, whereas the alpha-band rhythm suppresses neurons that may interfere with task performance. Cortical alpha- and beta-band rhythms were manipulated with transcranial alternating current stimulation (tACS) while human participants selected how to grasp an object. Stimulation was applied at either 10 or 20 Hz and was imposed on the sensorimotor cortex contralaterally or ipsilaterally to the grasping hand. In line with task-induced changes in endogenous spectral power, the effect of the tACS intervention depended on the frequency and site of stimulation. Whereas tACS stimulation generally increased movement selection times, 10 Hz stimulation led to relatively faster selection times when applied to the hemisphere ipsilateral to the grasping hand, compared with other stimulation conditions. These effects occurred selectively when multiple movements were considered. These observations functionally differentiate the causal contribution of alpha- and beta-band oscillations to movement selection. The findings suggest that sensorimotor beta-band rhythms disinhibit task-relevant populations, whereas alpha-band rhythms inhibit neuronal populations that could interfere with movement selection. This study shows dissociable effects of 10 Hz and 20 Hz tACS on the duration of movement selection. These observations have two elements of general relevance. First, the finding that alpha- and beta-band oscillations contribute independently to movement selection provides insight in how oscillations orchestrate motor behavior, which is key to understand movement selection deficits in neurodegenerative disorders. Second, the findings highlight the potential of 10 Hz stimulation as a neurophysiologically grounded intervention to enhance human performance. In particular, this intervention can potentially be exploited to boost rehabilitation after neural damage by targeting the unaffected hemisphere. Copyright © 2016 Brinkman et al.

Differential expression of extracellular matrix molecules and the alpha 6-integrins in the normal and neoplastic prostate.

PubMed Central

Knox, J. D.; Cress, A. E.; Clark, V.; Manriquez, L.; Affinito, K. S.; Dalkin, B. L.; Nagle, R. B.

1994-01-01

The epithelial basal lamina composition and integrin expression profile of normal and neoplastic human prostate was characterized using immunohistochemical analysis of frozen samples. The major components of the basal lamina surrounding normal acini were laminin, type IV collagen, entactin, and type VII collagen with variable amounts of tenascin. The basal lamina of neoplastic acini had a similar composition, except for the loss of type VII collagen, which was observed in all grades of carcinoma. The basal cells of the normal prostate express the alpha 6-, beta 1-, and beta 4-integrin subunits, suggesting that both the alpha 6 beta 1- and alpha 6 beta 4-integrin complexes are formed. In prostate carcinoma there is a complete loss of beta 4 expression and the alpha 6- and beta 1-integrin subunits, which are restricted to the basal and basal lateral surfaces of basal cells, are distributed diffusely throughout the cytoplasmic membrane. The differential expression of type VII collagen and beta 4 are discussed in relationship to their possible role in tumor progression. Images Figure 1 Figure 2 Figure 3 PMID:8030747

Physics-based protein-structure prediction using a hierarchical protocol based on the UNRES force field: assessment in two blind tests.

PubMed

Ołdziej, S; Czaplewski, C; Liwo, A; Chinchio, M; Nanias, M; Vila, J A; Khalili, M; Arnautova, Y A; Jagielska, A; Makowski, M; Schafroth, H D; Kaźmierkiewicz, R; Ripoll, D R; Pillardy, J; Saunders, J A; Kang, Y K; Gibson, K D; Scheraga, H A

2005-05-24

Recent improvements in the protein-structure prediction method developed in our laboratory, based on the thermodynamic hypothesis, are described. The conformational space is searched extensively at the united-residue level by using our physics-based UNRES energy function and the conformational space annealing method of global optimization. The lowest-energy coarse-grained structures are then converted to an all-atom representation and energy-minimized with the ECEPP/3 force field. The procedure was assessed in two recent blind tests of protein-structure prediction. During the first blind test, we predicted large fragments of alpha and alpha+beta proteins [60-70 residues with C(alpha) rms deviation (rmsd) <6 A]. However, for alpha+beta proteins, significant topological errors occurred despite low rmsd values. In the second exercise, we predicted whole structures of five proteins (two alpha and three alpha+beta, with sizes of 53-235 residues) with remarkably good accuracy. In particular, for the genomic target TM0487 (a 102-residue alpha+beta protein from Thermotoga maritima), we predicted the complete, topologically correct structure with 7.3-A C(alpha) rmsd. So far this protein is the largest alpha+beta protein predicted based solely on the amino acid sequence and a physics-based potential-energy function and search procedure. For target T0198, a phosphate transport system regulator PhoU from T. maritima (a 235-residue mainly alpha-helical protein), we predicted the topology of the whole six-helix bundle correctly within 8 A rmsd, except the 32 C-terminal residues, most of which form a beta-hairpin. These and other examples described in this work demonstrate significant progress in physics-based protein-structure prediction.

Streptococcal modulation of cellular invasion via TGF-beta1 signaling.

PubMed

Wang, Beinan; Li, Shaoying; Southern, Peter J; Cleary, Patrick P

2006-02-14

Group A Streptococcus (GAS) and other bacterial pathogens are known to interact with integrins as an initial step in a complex pathway of bacterial ingestion by host cells. Efficient GAS invasion depends on the interaction of bound fibronectin (Fn) with integrins and activation of integrin signaling. TGF-beta1 regulates expression of integrins, Fn, and other extracellular matrix proteins, and positively controls the integrin signaling pathway. Therefore, we postulated that TGF-beta1 levels could influence streptococcal invasion of mammalian cells. Pretreatment of HEp-2 cells with TGF-beta1 increased their capacity to ingest GAS when the bacteria expressed fibronectin-binding proteins (M1 or PrtF1). Western blots revealed significant induction of alpha5 integrin and Fn expression by HEp-2 cells in response to TGF-beta1. Increased ingestion of streptococci by these cells was blocked by a specific inhibitor of the TGF-beta1 receptor I and antibodies directed against alpha5 integrin and Fn, indicating that increased invasion depends on TGF-beta1 up-regulation of both the alpha5 integrin and Fn. The capacity of TGF-beta1 to up-regulate integrin expression and intracellular invasion by GAS was reproduced in primary human tonsil fibroblasts, which could be a source of TGF-beta1 in chronically infected tonsils. The relationship between TGF-beta1 and GAS invasion was strengthened by the observation that TGF-beta1 production was stimulated in GAS-infected primary human tonsil fibroblasts. These findings suggest a mechanism by which GAS induce a cascade of changes in mammalian tissue leading to elevated expression of the alpha5beta1 receptor, enhanced invasion, and increased opportunity for survival and persistence in their human host.

Akt mediates 17beta-estradiol and/or estrogen receptor-alpha inhibition of LPS-induced tumor necresis factor-alpha expression and myocardial cell apoptosis by suppressing the JNK1/2-NFkappaB pathway.

PubMed

Liu, Chung-Jung; Lo, Jeng-Fan; Kuo, Chia-Hua; Chu, Chun-Hsien; Chen, Li-Ming; Tsai, Fuu-Jen; Tsai, Chang-Hai; Tzang, Bor-Show; Kuo, Wei-Wen; Huang, Chih-Yang

2009-09-01

Evidence shows that women have lower tumour necrosis factor-alpha (TNF-alpha) levels and lower incidences of heart dysfunction and sepsis-related morbidity and mortality. To identify the cardioprotective effects and precise cellular/molecular mechanisms behind estrogen and estrogen receptors (ERs), we investigated the effects of 17beta-estradiol (E(2)) and estrogen receptor alpha (ERalpha) on LPS-induced apoptosis by analyzing the activation of survival and death signalling pathways in doxycycline (Dox)-inducible Tet-On/ERalpha H9c2 myocardial cells and ERalpha-transfected primary cardiomyocytes overexpressing ERalpha. We found that LPS challenge activated JNK1/2, and then induced IkappaB degradation, NFkappaB activation, TNF-alpha up-regulation and subsequent myocardial apoptotic responses. In addition, treatments involving E(2), membrane-impermeable BSA-E(2) and/or Dox, which induces ERalpha overexpression, significantly inhibited LPS-induced apoptosis by suppressing LPS-up-regulated JNK1/2 activity, IkappaB degradation, NFkappaB activation and pro-apoptotic proteins (e.g. TNF-alpha, active caspases-8, t-Bid, Bax, released cytochrome c, active caspase-9, active caspase-3) in myocardial cells. However, the cardioprotective properties of E(2), BSA-E(2) and ERalpha overexpression to inhibit LPS-induced apoptosis and promote cell survival were attenuated by applying LY294002 (PI3K inhibitor) and PI3K siRNA. These findings suggest that E(2), BSA-E(2) and ERalpha expression exert their cardioprotective effects by inhibiting JNK1/2-mediated LPS-induced TNF-alpha expression and cardiomyocyte apoptosis through activation of Akt.

The Geonomic Organization of the CD28 Gene. Implications for the Regulation of CD28 mRNA Expression and Heterogeneity

DTIC Science & Technology

1990-07-01

doanrmsialecgtonptcelsvstsrtinrnsoa Partial primary structure of the alpha and beta chains of human tdomn ctmvity nat Nrento 320 ticl levsis.ti tasoa...L. Moretta. and C. MW. Croce. tlon and RNA splicing defects in five cloned j6- thalassaemia genes. 1987. Tp44 molecules Involved In antigen-independent T cell acti- Na t ure 302:59 1.

Cytoskeleton changes following differentiation of N1E-115 neuroblastoma cell line.

PubMed

Oh, J-E; Karlmark Raja, K; Shin, J-H; Pollak, A; Hengstschläger, M; Lubec, G

2006-10-01

No systematic approach to detect expression of differentiation-related elements was published so far. The undifferentiated N1E-115 neuroblastoma cell line was switched into a neuronal phenotype by DMSO treatment and used for proteomic experiments. We used two-dimensional gel electrophoresis followed by unambiguous mass spectrometrical identification of proteins to generate a map of cytoskeleton proteins (CPs), i.e., to search for differentiation-related structures. Alpha-actin, actin-like protein 6A, gamma-tubulin complex component 2, tubulin alpha 3/alpha 7, CLIP associating protein 2, B4 integrin interactor homolog were detectable in the undifferentiated cell line exclusively and neuron-specific CPs drebrin and presynaptic density protein 95, actin-related protein 2/3, alpha and beta-centractin, PDZ-domain actin binding protein, actinin alpha 1, profilin II, ezrin, coactosin-like protein, transgelin 2, myosin light polypeptide 6, tubulin alpha 2, 6 and 7, beta tubulin (94% similar with tubulin beta-2), tubulin beta 3, tubulin tyrosine ligase-like protein 1, lamin B1 and keratin 20 were observed in the differentiated cell line only. We herein identified differentiation-related expressional patterns thus providing new evidence for the role of CPs in the process of neuronal differentiation.

[The modern approach to wound treatment].

PubMed

Komarcević, A

2000-01-01

Wound healing is a complex process involving interactions among a variety of different cell types. The normal wound repair process consists of three phases--inflammation, proliferation, and remodeling that occur in a predictable series of cellular and biochemical events. Wounds are classified according to various criteria: etiology, lasting, morphological characteristics, communications with solid or hollow organs, the degree of contamination. In the last few years many authors use the Color Code Concept, which classifies wounds as red, yellow and black wounds. This paper presents conventional methods of local wound treatment (mechanical cleansing, disinfection with antiseptic solutions, wound debridement--surgical, biological and autolytic; wound closure, topical antibiotic treatment, dressing), as well as general measures (sedation, antitetanous and antibiotic protection, preoperative evaluation and correction of malnutrition, vasoconstriction, hyperglycemia and steroid use, appropriate surgical technique, and postoperative prevention of vasoconstriction through pain relief, warming and adequate volume resuscitation). Growth factors play a role in cell division, migration, differentiation, protein expression, enzyme production and have a potential ability to heal wounds by stimulating angiogenesis and cellular proliferation, affecting the production and the degradation of the extracellular matrix, and by being chemotactic for inflammatory cells and fibroblasts. There are seven major families of growth factors: epidermal growth factor (EGF), transforming growth factor-beta (TGF-beta), insulin-like growth factor (IGF), platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), interleukins (ILs), and colony-stimulating factor (CSF). Acute wounds contain many growth factors that play a crucial role in the initial phases of wound healing. The events of early wound healing reflect a finely balanced environment leading to uncomplicated and rapid wound healing. Chronic wounds, for many reasons, have lost this fine balance. Multiple studies have evaluated the effect that exogenously applied growth factors have on the healing of chronic wounds. In the study conducted by Knighton and colleagues, topical application of mixture of various growth factors (PDGF, TGF-beta, PDAF, PF4, PDEGF) demonstrated increased wound healing over controls. Brown and associates demonstrated a decrease in skin graft donor site healing time of 1 day using topically applied EGF. Herndon and ass. used systemic growth hormone in burned children and reduction in healing time made a significant clinical difference by allowing earlier wound coverage and decreasing the duration of hospitalization. The TGF family of growth factors is believed to be primarily responsible for excessive scar formation, especially the beta 1 and beta 2 isoforms. TGF-beta 3 isoform has recently been described and may have an inhibitory function on scar formation by being a natural antagonist to the TGF-beta 1 and TGF-beta 2 isoforms. Cytokines, especially interferon-alpha (INF-alpha), INF-alpha, and INF-alpha 2b, may also reduce scar formation. These cytokines decrease the proliferation rate of fibroblasts and reduce the rate of collagen and fibronectin synthesis by reducing the production of mRNA. Expression of nitric oxide synthase (NOS) and heat shock proteins (HSP) have an important role in wound healing, as well as trace elements (zinc, copper, manganese). Applications of some drugs (antioxidants--asiaticoside, vitamin E and ascorbic acid; calcium D-pantothenate, exogenous fibronectin; antileprosy drugs--oil of hydnocarpus; alcoholic extract of yeast) accelerate wound healing. Thymic peptide thymosin beta 4 (T beta 4R) topically applicated, increases collagen deposition and angiogenesis and stimulates keratinocyte migration. Thymosin alpha 1 (T alpha 1R), peptide isolated from the thymus, is a potent chemoattractant which accelerates angiogenesis and wound healing. On the contrary, steroid drugs, hemorrhage and denervation of wounds have negative effect on the healing process.

Heterogeneity of cellular proliferation within transitional cell carcinoma: correlation of protein kinase C alpha/betaI expression and activity.

PubMed

Aaltonen, Vesa; Koivunen, Jussi; Laato, Matti; Peltonen, Juha

2006-07-01

A total of 18 histological samples containing both transitional cell carcinoma (TCC) and normal urothelial epithelium were analyzed for protein kinase C (PKC)-alpha and -betaI expression, and for their phosphorylated substrates. The results showed an increased expression of PKC-alpha in 13 out of 18 samples and -betaI in 11 out of 18 TCC samples when compared with normal urothelium. In addition, 11 out of 18 of the TCC tumors displayed heterogeneous expression of the PKC isoenzymes, with different levels of immunosignal in different areas of the tumor. Within the same sample, areas of highest PKC isoenzyme expression also showed highest classical PKC activity, as estimated by immunodetection of phosphorylated forms of PKC substrates. The areas of highest expression of PKC-alpha and/or -betaI isoenzymes showed also the highest number of cells positive for Ki67, an indicator of proliferation. Immunofluorescence and Western blotting demonstrated that in cultured TCC cells, PKC-alpha was located in the cytoplasm, whereas PKC-betaI was located primarily in the nucleus as a 65-kDa fragment and in the cytoplasm as a full-size 79-kDa protein. Our results indicate that increased expression of PKC-alpha and -betaI leads to increased total classical PKC kinase activity and suggest that increased activity of the isoenzymes plays a role in accelerated growth of TCC. Furthermore, these results suggest that even in carcinoma tissue, PKC expression and activity are under strict control.

Tertiary structure in N-linked oligosaccharides.

PubMed

Homans, S W; Dwek, R A; Rademacher, T W

1987-10-06

Distance constraints derived from two-dimensional nuclear Overhauser effect measurements have been used to define the orientation of the Man alpha 1-3Man beta linkage in seven different N-linked oligosaccharides, all containing the common pentasaccharide core Man alpha 1-6(Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4GlcNAc. Conformational invariance of the Man alpha 1-3Man beta linkage was found for those structures bearing substitutions on the Man alpha 1-3Man beta antenna. However, the presence of either a GlcNAc residue in the beta 1-4 linkage to Man beta ("bisecting GlcNAc") or a xylose residue in the beta 1-2 linkage to Man beta of the trimannosyl core was found to generate conformational transitions that were similar. These transitions were accompanied by characteristic chemical shift perturbations of proton resonances in the vicinity of the Man alpha 1-3Man beta linkage. Molecular orbital energy calculations suggest that the conformational transition between the unsubstituted and substituted cores arises from energetic constraints in the vicinity of the Man alpha 1-3Man beta linkage, rather than specific long-range interactions. These data taken together with our previous results on the Man alpha 1-6Man beta linkage [Homans, S. W., Dwek R. A., Boyd, J., Mahmoudian, M., Richards, W. G., & Rademacher, T. W. (1986) Biochemistry 25, 6342] allow us to discuss the consequences of the modulation of oligosaccharide solution conformations.

Estrogen receptor (ER)-beta, but not ER-alpha, is present in thyroid vessels: immunohistochemical evaluations in multinodular goiter and papillary thyroid carcinoma.

PubMed

Ceresini, Graziano; Morganti, Simonetta; Graiani, Virna; Saccani, Maria; Milli, Bruna; Usberti, Elisa; Valenti, Giorgio; Ceda, Gian Paolo; Corcione, Luigi

2006-12-01

Estrogen receptors (ERs) have been demostrated in the vessel structures of several systems. Little is known on the presence of ERs in the thyroid vessels. We immunohistochemically evaluated both ER-alpha and ER-beta immunoreactivity (IR) in both vascular and follicular thyroid cells in tissue samples from 17 cases of multinodular goiter (MNG) and 17 cases of papillary thyroid carcinoma (PTC). ER-alpha IR was undetectable in either tissue examined. In 100% of MNG samples, nuclear ER-beta IR was detected in both endothelial and follicular cells. In PTC samples, endothelial nuclear ER-beta IR was found in 100% of cases, whereas the nuclear staining of follicular cells was found in 83% of cases. The intensity of staining of the endothelial ER-beta IR was comparable between MNG and PTC. However, when follicular cells were considered, a tendency toward a decrease in nuclear staining and a significant increase in cytoplasmic staining were found in PTC lesions as compared to MNG. This study demonstrated that ER-beta, but not ER-alpha, IR is present in the endothelium of thyroid vessels. Furthermore, although data need to be confirmed in larger observations, these results suggest the lack of differences in the pattern of vascular ER-beta IR between MNG and PTC.

Tumor necrosis factor receptor-1 can function through a G alpha q/11-beta-arrestin-1 signaling complex.

PubMed

Kawamata, Yuji; Imamura, Takeshi; Babendure, Jennie L; Lu, Juu-Chin; Yoshizaki, Takeshi; Olefsky, Jerrold M

2007-09-28

Tumor necrosis factor-alpha (TNFalpha) is a proinflammatory cytokine secreted from macrophages and adipocytes. It is well known that chronic TNFalpha exposure can lead to insulin resistance both in vitro and in vivo and that elevated blood levels of TNFalpha are observed in obese and/or diabetic individuals. TNFalpha has many acute biologic effects, mediated by a complex intracellular signaling pathway. In these studies we have identified new G-protein signaling components to this pathway in 3T3-L1 adipocytes. We found that beta-arrestin-1 is associated with TRAF2 (TNF receptor-associated factor 2), an adaptor protein of TNF receptors, and that TNFalpha acutely stimulates tyrosine phosphorylation of G alpha(q/11) with an increase in G alpha(q/11) activity. Small interfering RNA-mediated knockdown of beta-arrestin-1 inhibits TNFalpha-induced tyrosine phosphorylation of G alpha(q/11) by interruption of Src kinase activation. TNFalpha stimulates lipolysis in 3T3-L1 adipocytes, and beta-arrestin-1 knockdown blocks the effects of TNFalpha to stimulate ERK activation and glycerol release. TNFalpha also led to activation of JNK with increased expression of the proinflammatory gene, monocyte chemoattractant protein-1 and matrix metalloproteinase 3, and beta-arrestin-1 knockdown inhibited both of these effects. Taken together these results reveal novel elements of TNFalpha action; 1) the trimeric G-protein component G alpha(q/11) and the adapter protein beta-arrestin-1 can function as signaling molecules in the TNFalpha action cascade; 2) beta-arrestin-1 can couple TNFalpha stimulation to ERK activation and lipolysis; 3) beta-arrestin-1 and G alpha(q/11) can mediate TNFalpha-induced phosphatidylinositol 3-kinase activation and inflammatory gene expression.

The alpha form of human tryptase is the predominant type present in blood at baseline in normal subjects and is elevated in those with systemic mastocytosis.

PubMed Central

Schwartz, L B; Sakai, K; Bradford, T R; Ren, S; Zweiman, B; Worobec, A S; Metcalfe, D D

1995-01-01

Tryptase, a protease produced by all mast cells, was evaluated as a clinical marker of systemic mastocytosis. Two sandwich immunoassays were evaluated, one which used the mAb G5 for capture, the other which used B12 for capture. The B12 capture assay measured both recombinant alpha- and beta-tryptase, whereas the G5 capture assay measured primarily recombinant beta-tryptase. G5 binds with low affinity to both recombinant alpha-tryptase and tryptase in blood from normal and nonacute mastocytosis subjects, and binds with high affinity to recombinant beta-tryptase, tryptase in serum during anaphylaxis, and tryptase stored in mast cell secretory granules. B12 recognizes all of these forms of tryptase with high affinity. As reported previously, during systemic anaphylaxis in patients without known mastocytosis, the ratio of B12- to G5-measured tryptase was always < 5 and approached unity (Schwartz L.B., T.R. Bradford, C. Rouse, A.-M. Irani, G. Rasp, J.K. Van der Zwan and P.-W.G. Van der Linden, J. Clin. Immunol. 14:190-204). In this report, most mastocytosis patients with systemic disease have B12-measured tryptase levels that are elevated (> 20 ng/ml) and are at least 10-fold greater than the corresponding G5-measured tryptase level. Most of those subjects with B12-measured tryptase levels of < 20 ng/ml had only cutaneous manifestations. The B12 assay for alpha-tryptase and beta-tryptase, particularly when performed in conjunction with the G5 assay for beta-tryptase, provides a more precise measure of mast cell involvement than currently available assessments, a promising potential screening test for systemic mastocytosis and may provide an improved means to follow disease progression and response to therapy. Images PMID:8675637

The alpha form of human tryptase is the predominant type present in blood at baseline in normal subjects and is elevated in those with systemic mastocytosis.

PubMed

Schwartz, L B; Sakai, K; Bradford, T R; Ren, S; Zweiman, B; Worobec, A S; Metcalfe, D D

1995-12-01

Tryptase, a protease produced by all mast cells, was evaluated as a clinical marker of systemic mastocytosis. Two sandwich immunoassays were evaluated, one which used the mAb G5 for capture, the other which used B12 for capture. The B12 capture assay measured both recombinant alpha- and beta-tryptase, whereas the G5 capture assay measured primarily recombinant beta-tryptase. G5 binds with low affinity to both recombinant alpha-tryptase and tryptase in blood from normal and nonacute mastocytosis subjects, and binds with high affinity to recombinant beta-tryptase, tryptase in serum during anaphylaxis, and tryptase stored in mast cell secretory granules. B12 recognizes all of these forms of tryptase with high affinity. As reported previously, during systemic anaphylaxis in patients without known mastocytosis, the ratio of B12- to G5-measured tryptase was always < 5 and approached unity (Schwartz L.B., T.R. Bradford, C. Rouse, A.-M. Irani, G. Rasp, J.K. Van der Zwan and P.-W.G. Van der Linden, J. Clin. Immunol. 14:190-204). In this report, most mastocytosis patients with systemic disease have B12-measured tryptase levels that are elevated (> 20 ng/ml) and are at least 10-fold greater than the corresponding G5-measured tryptase level. Most of those subjects with B12-measured tryptase levels of < 20 ng/ml had only cutaneous manifestations. The B12 assay for alpha-tryptase and beta-tryptase, particularly when performed in conjunction with the G5 assay for beta-tryptase, provides a more precise measure of mast cell involvement than currently available assessments, a promising potential screening test for systemic mastocytosis and may provide an improved means to follow disease progression and response to therapy.

Integrins (alpha7beta1) in muscle function and survival. Disrupted expression in merosin-deficient congenital muscular dystrophy.

PubMed Central

Vachon, P H; Xu, H; Liu, L; Loechel, F; Hayashi, Y; Arahata, K; Reed, J C; Wewer, U M; Engvall, E

1997-01-01

Mutations in genes coding for dystrophin, for alpha, beta, gamma, and delta-sarcoglycans, or for the alpha2 chain of the basement membrane component merosin (laminin-2/4) cause various forms of muscular dystrophy. Analyses of integrins showed an abnormal expression and localization of alpha7beta1 isoforms in myofibers of merosin-deficient human patients and mice, but not in dystrophin-deficient or sarcoglycan-deficient humans and animals. It was shown previously that skeletal muscle fibers require merosin for survival and function (Vachon, P.H., F. Loechel, H. Xu, U.M. Wewer, and E. Engvall. 1996. J. Cell Biol. 134:1483-1497). Correction of merosin deficiency in vitro through cell transfection with the merosin alpha2 chain restored the normal localization of alpha7beta1D integrins as well as myotube survival. Overexpression of the apoptosis-suppressing molecule Bcl-2 also promoted the survival of merosin-deficient myotubes, but did not restore a normal expression of alpha7beta1D integrins. Blocking of beta1 integrins in normal myotubes induced apoptosis and severely reduced their survival. These findings (a) identify alpha7beta1D integrins as the de facto receptors for merosin in skeletal muscle; (b) indicate a merosin dependence for the accurate expression and membrane localization of alpha7beta1D integrins in myofibers; (c) provide a molecular basis for the critical role of merosin in myofiber survival; and (d) add new insights to the pathogenesis of neuromuscular disorders. PMID:9312189

In vivo regulation of gene transcription by alpha- and gamma-Tocopherol in murine T lymphocytes

USDA-ARS?s Scientific Manuscript database

Of the 8 different analogues (alpha-, beta-, gamma-, delta-tocopherols and tocotrienols) designated as vitamin E, alpha-tocopherol (a-T) has been mostly studied, together with gamma-tocopherol (g-T) which is abundant in the US diet. We compared the effect of dietary supplementation with adequate or ...

Mechanism of transfer of LDL-derived free cholesterol to HDL subfractions in human plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miida, T.; Fielding, C.J.; Fielding, P.E.

1990-11-01

The transfer of ({sup 3}H)cholesterol in low-density lipoprotein (LDL) to different high-density lipoprotein (HDL) species in native human plasma was determined by using nondenaturing two-dimensional electrophoresis. Transfer from LDL had a t{sub 1/2} at 37{degree}C of 51 {plus minus} 8 min and an activation energy of 18.0 kCal mol{sup {minus}1}. There was unexpected specificity among HDL species as acceptors of LDL-derived labeled cholesterol. The largest fraction of the major {alpha}-migrating class (HDL{sub 2b}) was the major initial acceptor of LDL-derived cholesterol. Kinetic analysis indicated a rapid secondary transfer from HDL{sub 2b} to smaller {alpha}HDL (particularly HDL{sub 3}) driven enzymatically bymore » the lecithin-cholesterol acyltransferase reaction. Rates of transfer among {alpha}HDL were most rapid from the largest {alpha}HDL fraction (HDL{sub 2b}), suggesting possible protein-mediated facilitation. Simultaneous measurements of the transport of LDL-derived and cell-derived isotopic cholesterol indicated that the former preferably utilized the {alpha}HDL pathyway, with little label in pre-{beta}HDL. The same experiments confirmed earlier data that cell-derived cholesterol is preferentially channeled through pre-{beta}HDL. The authors suggest that the functional heterogeneity of HDL demonstrated here includes the ability to independently process cell- and LDL-derived free cholesterol.« less

[Prevalence survey and molecular characterization of alpha and beta thalassemia in Liuzhou city of Guangxi].

PubMed

Cai, Ren; Li, Liyan; Liang, Xin; Liu, Zhongying; Su, Liu; Li, Wenjun; Zhu, Qiangui; Mo, Qiuhua; Pan, Lizhen; Ouyang, Hong; Huang, Lihua; Xu, Xiangmin

2002-08-01

To investigate the gene frequencies and mutation patterns of alpha thalassemia (alpha-thal) and beta thalassemia (beta-thal) in Liuzhou city of Guangxi Zhuang Autonomous Region. Cluster sampling was used. A total of 1 028 of umbilical blood samples were collected for a prevalence study of alpha-thal and a total of 1 312 healthy young people when receiving pre-marriage consultation were recruited for a beta-thal prevalence survey. Individuals live in city or town area of Liuzhou. A complete blood count as well as hemoglobin electrophoresis analysis were done in all of samples for phenotyping of alpha and beta-thals. Those with Hb Bart's for alpha-thal indicator and those with both microcytosis (MCV < 85 fl) and elevated levels of Hb A(2) (>/=4.0%) for beta-thal were further studied by DNA analysis. PCR-based methodologies were used to characterize the mutation contributions of alpha and beta-thals. All the subjects were tested for the state of carrying beta-thala alleles for evaluating the situation of the compound heterozygotes of alpha-thal with beta-thal. Of 1 028 random samples of umbilical blood screened, 112 of subjects were defined to be the gene carriers of alpha-thal. The alpha-thal carrier rate was as high as 11.19% including 3 compound heterozygotes. Five well-known types of alpha-thal alleles were detected with gene contributions of 37.4% (--(SEA) deletion), 31.3% (-alpha(3.7) deletion), 17.4% (-alpha(4.2) deletion), 12.1% (alpha(CS)alpha mutation), and 0.9% (alpha(QS)alpha mutation), successively. Of the 1 312 adult specimens studied, 89 with beta-thal including 14 of the compound higher Hb F subjects were detected. All of the 89 phenotypic beta-thal carriers had the mutations in the beta-globin gene, making the overall prevalence 6.78%. The commonly seen three mutations, beta CD41 - 42 (-CTTT) frameshift, beta CD17 (T-A) nonsense mutation and beta-28 (A-G) promoter variation were accounted for 90% of the beta-thal alleles in Liuzhou. Of these beta-thal subjects, 16 (accounting for 18%) were found to be the compound heterozygosity for a beta-thal and an alpha-thal with 9 different types of gene defects with a detection rate 1.22%. Data from ecidation of alpha and beta-thal gene frequencies and mutation spectrum in Liuzhou city was useful for genetic counselling and prenatal diagnosis of this disease.

Role of astrocytes in reproduction and neuroprotection.

PubMed

Mahesh, Virendra B; Dhandapani, Krishnan M; Brann, Darrell W

2006-02-26

Hypothalamic astrocytes secrete TGF-beta and 3 alpha,5 alpha-tetrahydro progesterone (3 alpha,5 alpha-THP) in culture. When the astrocyte-conditioned medium (ACM) was incubated with the hypothalamic cell line GT1-7, it resulted in the secretion of GnRH. Immunoneutralization with TGF-beta antibody or ultra-filteration with a 10 kDa cut off filter resulted in attenuation of the GnRH releasing ability of ACM, indicating that TGF-beta was a major factor involved with GnRH release. Treatment with estrogens increases TGF-beta secretion. These observations indicate a significant role of astrocytes in GnRH secretion. Serum-deprivation results in the death of GT1-7 neurons in culture and addition of ACM or TGF-beta to the culture, attenuates cell death. The mechanism of protection from cell death appears to involve phosphorylation of MKK4, JNK, c-Jun(Ser63), and enhancement of AP-1 binding. Co-administration of JNK inhibitors, but not MEK inhibitors attenuated ACM or TGF-beta-induced c-Jun(Ser63) phosphorylation and their neuroprotective effects. These studies suggest that astrocytes can protect neurons, at least in part, by the release of TGF-beta and activation of a c-Jun/AP-1 protective pathway.

Activation of protein kinase C and disruption of endothelial monolayer integrity by sodium arsenite-Potential mechanism in the development of atherosclerosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pereira, Flavia E.; Coffin, J. Douglas; Beall, Howard D.

2007-04-15

Arsenic exposure has been shown to exacerbate atherosclerosis, beginning with activation of the endothelium that lines the vessel wall. Endothelial barrier integrity is maintained by proteins of the adherens junction (AJ) such as vascular endothelial cadherin (VE-cadherin) and {beta}-catenin and their association with the actin cytoskeleton. In the present study, human aortic endothelial cells (HAECs) were exposed to 1, 5 and 10 {mu}M sodium arsenite [As(III)] for 1, 6, 12 and 24 h, and the effects on endothelial barrier integrity were determined. Immunofluorescence studies revealed formation of actin stress fibers and non-uniform VE-cadherin and {beta}-catenin staining at cell-cell junctions thatmore » were concentration- and time-dependent. Intercellular gaps were observed with a measured increase in endothelial permeability. In addition, concentration-dependent increases in tyrosine phosphorylation (PY) of {beta}-catenin and activation of protein kinase C{alpha} (PKC{alpha}) were observed. Inhibition of PKC{alpha} restored VE-cadherin and {beta}-catenin staining at cell-cell junctions and abolished the As(III)-induced formation of actin stress fibers and intercellular gaps. Endothelial permeability and PY of {beta}-catenin were also reduced to basal levels. These results demonstrate that As(III) induces activation of PKC{alpha}, which leads to increased PY of {beta}-catenin downstream of PKC{alpha} activation. Phosphorylation of {beta}-catenin plausibly severs the association of VE-cadherin and {beta}-catenin, which along with formation of actin stress fibers, results in intercellular gap formation and increased endothelial permeability. To the best of our knowledge, this is the first report demonstrating that As(III) causes a loss of endothelial monolayer integrity, which potentially could contribute to the development of atherosclerosis.« less

The effect of TRAIL molecule on cell viability in in vitro beta cell culture.

PubMed

Tekmen, I; Ozyurt, D; Pekçetin, C; Buldan, Z

2007-06-01

Insulin-dependent diabetes mellitus (IDDM) is an organ-specific autoimmune disorder triggered by autoreactive T cells directed to pancreas beta-cell antigens. In this disorder, more than 90% of beta cells are destroyed. Cell death may be mediated via soluble or membrane-bound cell death ligands. One of these ligands may be tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), a member of the TNF-alpha superfamily. In the present study, we examined whether TRAIL had cytotoxic effects on adult rat pancreas beta cell cultures and INS1-E rat insulinoma cell line cultures or not. In this study, cell destruction models were built with TRAIL concentrations of 10, 100 and 1000 ng. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test was used for evaluating cell viability. It was detected that cell cultures with TRAIL added showed no differences statistically when compared with control cultures containing no toxic additions. These results showed that TRAIL did not have significant cytotoxic effects on pancreas beta cell culture and INS-1E rat insulinoma cell line cultures. Detection of the expression of TRAIL receptors and natural apoptosis inhibitor proteins will be favourable to investigate the resistance mechanisms to TRAIL-induced cell death in this cell culture system.

A dynamic alpha-beta inter-subunit agonist signaling complex is a novel feedback mechanism for regulating L-type Ca2+ channel opening.

PubMed

Zhang, Rong; Dzhura, Igor; Grueter, Chad E; Thiel, William; Colbran, Roger J; Anderson, Mark E

2005-09-01

L-type Ca2+ channels are macromolecular protein complexes in neurons and myocytes that open in response to cell membrane depolarization to supply Ca2+ for regulating gene transcription and vesicle secretion and triggering cell contraction. L-type Ca2+ channels include a pore-forming alpha and an auxiliary beta subunit, and alpha subunit openings are regulated by cellular Ca2+ through a mechanism involving the Ca2+-sensing protein calmodulin (CaM) and CaM binding motifs in the alpha subunit cytoplasmic C terminus. Here we show that these CaM binding motifs are "auto-agonists" that increase alpha subunit openings by binding the beta subunit. The CaM binding domains are necessary and sufficient for the alpha subunit C terminus to bind the beta subunit in vitro, and excess CaM blocks this interaction. Addition of CaM binding domains to native cardiac L-type Ca2+ channels in excised cell membrane patches increases openings, and this agonist effect is prevented by excess CaM. Recombinant LTCC openings are also increased by exogenous CaM binding domains by a mechanism requiring the beta subunit, and excess CaM blocks this effect. Thus, the bifunctional ability of the alpha subunit CaM binding motifs to competitively associate with the beta subunit or CaM provides a novel paradigm for feedback control of cellular Ca2+ entry.

PDGF-regulated rab4-dependent recycling of alphavbeta3 integrin from early endosomes is necessary for cell adhesion and spreading.

PubMed

Roberts, M; Barry, S; Woods, A; van der Sluijs, P; Norman, J

2001-09-18

It has been postulated that the regulation of integrin vesicular traffic facilitates cell migration by internalizing integrins at the rear of the cell and transporting them forward within vesicles for exocytosis at the leading edge to form new contacts with the extracellular matrix. The rab family of GTPases control key targeting events in the endo/exocytic pathway; therefore, these GTPases may be involved in the regulation of cell-matrix contact assembly. The endo/exocytic cycle of alphavbeta3 and alpha5beta1 integrins was studied using mouse 3T3 fibroblast cell lines. In serum-starved cells, internalized integrins were transported through rab4-positive, early endosomes and arrived at the rab11-positive, perinuclear recycling compartment approximately 30 min after endocytosis. From the recycling compartment, integrins were recycled to the plasma membrane in a rab11-dependent fashion. Following treatment with PDGF, alphavbeta3 integrin, but not alpha5beta1, was rapidly recycled directly back to the plasma membrane from the early endosomes via a rab4-dependent mechanism without the involvement of rab11. This rapid recycling pathway directed alphavbeta3 to numerous small puncta distributed evenly across the dorsal surface of the cell, and the integrin only became localized into focal complexes at later times following PDGF addition. Interestingly, inhibition of PDGF-stimulated alphavbeta3 recycling using dominant-negative rab4 mutants compromised cell adhesion and spreading on vitronectin (a ligand for alphavbeta3), but adhesion to fibronectin (a ligand for alpha5beta1 and alphavbeta3) was unchanged. We propose that growth factor-regulated, rab4-dependent recycling of alphavbeta3 integrin from early endosomes to the plasma membrane is a critical upstream event in the assembly of cell-matrix contacts.

Deglycosylation of serum vitamin D3-binding protein leads to immunosuppression in cancer patients.

PubMed

Yamamoto, N; Naraparaju, V R; Asbell, S O

1996-06-15

Serum vitamin D3-binding protein (Gc protein) can be converted by beta-galactosidase of B cells and sialidase of T cells to a potent macrophage activating factor, a protein with N-acetylgalactosamine as the remaining sugar moiety. Thus, Gc protein is the precursor of the macrophage activating factor (MAF). Treatment of Gc protein with immobilized beta-galactosidase and sialidase generates an extremely high titered MAF, Gc-MAF. When peripheral blood monocytes/macrophages of 52 patients bearing various types of cancer were incubated with 100 pg/ml of GcMAF, the monocytes/macrophages of all patients were efficiently activated. However, the MAF precursor activity of patient plasma Gc protein was found to be severely reduced in about 25% of this patient population. About 45% of the patients had moderately reduced MAF precursor activities. Loss of the precursor activity was found to be due to deglycosylation of plasma Gc protein by alpha-N-acetylgalactosaminidase detected in the patient's bloodstream. The source of the enzyme appeared to be cancerous cells. Radiation therapy decreased plasma alpha-N-acetylgalactosaminidase activity with concomitant increase of precursor activity. This implies that radiation therapy decreases the number of cancerous cells capable of secreting alpha-N-acetylgalactosaminidase. Both alpha-N-acetylgalactosaminidase activity and MAF precursor activity of Gc protein in patient bloodstream can serve as diagnostic and prognostic indices.

Extrinsic factors regulate partial agonist efficacy of strychnine-sensitive glycine receptors.

PubMed

Farroni, Jeffrey S; McCool, Brian A

2004-08-09

Strychnine-sensitive glycine receptors in many adult forebrain regions consist of alpha2 + beta heteromeric channels. This subunit composition is distinct from the alpha1 + beta channels found throughout the adult spinal cord. Unfortunately, the pharmacology of forebrain alpha2beta receptors are poorly defined compared to 'neonatal' alpha2 homomeric channels or 'spinal' alpha1beta heteromers. In addition, the pharmacologic properties of native alpha2beta glycine receptors have been generally distinct from receptors produced by heterologous expression. To identify subtype-specific pharmacologic tools for the forebrain alpha2beta receptors, it is important to identify a heterologous expression system that closely resembles these native glycine-gated chloride channels. While exploring pharmacological properties of alpha2beta glycine receptors compared to alpha2-homomers, we found that distinct heterologous expression systems appeared to differentially influence partial agonist pharmacology. The beta-amino acid taurine possessed 30-50% efficacy for alpha2-containing receptor isoforms when expressed in HEK 293 cells. However, taurine efficacy was dramatically reduced in L-cell fibroblasts. Similar results were obtained for beta-alanine. The efficacy of these partial agonists was also strongly reduced by the beta subunit. There were no significant differences in apparent strychnine affinity values calculated from concentration-response data between expression systems or subunit combinations. Nor did relative levels of expression correlate with partial agonist efficacy when compared within or between several different expression systems. Finally, disruption of the tubulin cytoskeleton reduced the efficacy of partial agonists in a subunit-dependent, but system-independent, fashion. Our results suggest that different heterologous expression systems can dramatically influence the agonist pharmacology of strychnine-sensitive glycine receptors. In the systems examine here, these effects are independent of both absolute expression level and any system-related alterations in the agonist binding site. We conclude that complex interactions between receptor composition and extrinsic factors may play a significant role in determining strychnine-sensitive glycine receptor partial agonist pharmacology.

Glycosidases in Brachionus plicatilis (Rotifera).

PubMed

Kühle, K; Kleinow, W

1990-01-01

1. Tests for glycosidases were performed in homogenates of Brachionus plicatilis. 2. Hydrolytic activity was detected with the following substrates: (a) with synthetic substrates (NP = 4-nitrophenyl): NP-alpha- and NP-beta-D-glucopyranoside, NP-alpha- and NP-beta-D-galactopyranoside, NP-N-acetyl-beta-D-glucosaminide, NP-N-acetyl-beta-D-galactosaminide, NP-alpha- and NP-beta-D-mannopyranoside and NP-alpha-L-fucopyranoside; (b) with disaccharides: sucrose, maltose, trehalose, isomaltose, cellobiose, gentiobiose and lactose; (c) with polysaccharides: laminarine, carboxymethyl-cellulose, avicel, Micrococcus luteus (for lysozyme) and 4-nitrophenyl-alpha-D-maltoheptaoside (for amylase). 3. The pH dependence of the glycosidase activities was determined. 4. The distribution of enzyme activities within fractions from the homogenate was studied in order to localize them within the cell. 5. Proteins from Brachionus homogenate were separated by SDS-gel electrophoresis and the positions of the following glycosidase activities were detected by assays performed on the gels (estimated molecular weights in parentheses): alpha-glucosidase (250,000); beta-glucosidase (200,000); beta-galactosidase (70,000); N-acetyl-beta-glucosaminidase (60,000).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rouyer-Fessard, P.; Garel, M.C.; Domenget, C.

The soluble pool of alpha hemoglobin chains present in blood or bone marrow cells was measured with a new affinity method using a specific probe, beta A hemoglobin chain labeled with ({sup 3}H)N-ethylmaleimide. This pool of soluble alpha chains was 0.067 {plus minus} 0.017% of hemoglobin in blood of normal adult, 0.11 {plus minus} 0.03% in heterozygous beta thalassemia and ranged from 0.26 to 1.30% in homozygous beta thalassemia intermedia. This elevated pool of soluble alpha chains observed in human beta thalassemia intermedia decreased 33-fold from a value of 10% of total hemoglobin in bone marrow cells to 0.3% inmore » the most dense red blood cells. The amount of insoluble alpha chains was measured by using the polyacrylamide gel electrophoresis in urea and Triton X-100. In beta thalassemia intermedia the amount of insoluble alpha chains was correlated with the decreased spectrin content of red cell membrane and was associated with a decrease in ankyrin and with other abnormalities of the electrophoretic pattern of membrane proteins. The loss and topology of the reactive thiol groups of membrane proteins was determined by using ({sup 3}H)N-ethylmaleimide added to membrane ghosts prior to urea and Triton X-100 electrophoresis. Spectrin and ankyrin were the major proteins with the most important decrease of thiol groups.« less

Compartmentalization of immune responses in human tuberculosis: few CD8+ effector T cells but elevated levels of FoxP3+ regulatory t cells in the granulomatous lesions.

PubMed

Rahman, Sayma; Gudetta, Berhanu; Fink, Joshua; Granath, Anna; Ashenafi, Senait; Aseffa, Abraham; Derbew, Milliard; Svensson, Mattias; Andersson, Jan; Brighenti, Susanna Grundström

2009-06-01

Immune responses were assessed at the single-cell level in lymph nodes from children with tuberculous lymphadenitis. Tuberculosis infection was associated with tissue remodeling of lymph nodes as well as altered cellular composition. Granulomas were significantly enriched with CD68+ macrophages expressing the M. tuberculosis complex-specific protein antigen MPT64 and inducible nitric oxide synthase. There was a significant increase in CD8+ cytolytic T cells surrounding the granuloma; however, CD8+ T cells expressed low levels of the cytolytic and antimicrobial effector molecules perforin and granulysin in the granulomatous lesions. Quantitative real-time mRNA analysis revealed that interferon-gamma, tumor necrosis factor-alpha, and interleukin-17 were not up-regulated in infected lymph nodes, but there was a significant induction of both transforming growth factor-beta and interleukin-13. In addition, granulomas contained an increased number of CD4+FoxP3+ T cells co-expressing the immunoregulatory cytotoxic T-lymphocyte antigen-4 and glucocorticoid-induced tumor necrosis factor receptor molecules. Low numbers of CD8+ T cells in the lesions correlated with high levels of transforming growth factor-beta and FoxP3+ regulatory T cells, suggesting active immunosuppression at the local infection site. Compartmentalization and skewing of the immune response toward a regulatory phenotype may result in an uncoordinated effector T-cell response that reduces granule-mediated killing of M. tuberculosis-infected cells and subsequent disease control.

Phosphatidylinositol 5-phosphate 4-kinase type II beta is required for vitamin D receptor-dependent E-cadherin expression in SW480 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kouchi, Zen, E-mail: zkouchi@toyaku.ac.jp; Fujiwara, Yuki; Yamaguchi, Hideki

2011-05-20

Highlights: {yields} We analyzed Phosphatidylinositol 5-phosphate kinase II{beta} (PIPKII{beta}) function in cancer. {yields} PIPKII{beta} is required for vitamin D receptor-mediated E-cadherin upregulation in SW480. {yields} PIPKII{beta} suppresses cellular motility through E-cadherin induction in SW480 cells. {yields} Nuclear PIP{sub 2} but not plasma membrane-localized PIP{sub 2} mediates E-cadherin upregulation. -- Abstract: Numerous epidemiological data indicate that vitamin D receptor (VDR) signaling induced by its ligand or active metabolite 1{alpha},25-dihydroxyvitamin D{sub 3} (1{alpha},25(OH){sub 2}D{sub 3}) has anti-cancer activity in several colon cancers. 1{alpha},25(OH){sub 2}D{sub 3} induces the epithelial differentiation of SW480 colon cancer cells expressing VDR (SW480-ADH) by upregulating E-cadherin expression; however,more » its precise mechanism remains unknown. We found that phosphatidylinositol-5-phosphate 4-kinase type II beta (PIPKII{beta}) but not PIPKII{alpha} is required for VDR-mediated E-cadherin induction in SW480-ADH cells. The syntenin-2 postsynaptic density protein/disc large/zona occludens (PDZ) domain and pleckstrin homology domain of phospholipase C-delta1 (PLC{delta}1 PHD) possess high affinity for phosphatidylinositol-4,5-bisphosphate (PI(4,5)P{sub 2}) mainly localized to the nucleus and plasma membrane, respectively. The expression of syntenin-2 PDZ but not PLC{delta}1 PHD inhibited 1{alpha},25(OH){sub 2}D{sub 3}-induced E-cadherin upregulation, suggesting that nuclear PI(4,5)P{sub 2} production mediates E-cadherin expression through PIPKII{beta} in a VDR-dependent manner. PIPKII{beta} is also involved in the suppression of the cell motility induced by 1{alpha},25(OH){sub 2}D{sub 3}. These results indicate that PIPKII{beta}-mediated PI(4,5)P{sub 2} signaling is important for E-cadherin upregulation and inhibition of cellular motility induced by VDR activation.« less

Suppression of adenoviral gene expression in the liver: role of innate vs adaptive immunity and their cell lysis mechanisms.

PubMed

Minagawa, Masahiro; Kawamura, Hiroki; Liu, Zhangxu; Govindarajan, Sugantha; Dennert, Gunther

2005-06-01

Injection of adenoviral constructs causes liver infection prompting immunity, which suppress viral gene expression. Innate and adaptive immunity mediate these processes raising the question which pathways are the most prominent. Adenovirus expressing the beta-galactosidase (beta-gal) gene was injected into normal and immunodeficient mice. Elimination of beta-gal-expressing hepatocytes and increases in liver enzymes were assayed. Major histocompatibility complex (MHC) class I densities, perforin channel insertion and apoptosis by Fas and tumor necrosis factor (TNF)-alpha were assayed. At high virus doses, suppression of viral gene expression was as efficient in immunodeficient as in normal mice, while at low doses effects of cytotoxic T lymphocytes (CTL) were demonstrable. Despite CTL priming and elimination of infected hepatocytes no liver injury is detected. Hepatocyte MHC I densities were able to trigger CTL granule exocytosis and perforin lysis in vitro but not in vivo. This is we show is because of decreased sensitivity of hepatocytes from infected mice to perforin and increased sensitivity to Fas and TNF-alpha lysis. Effector cells of the innate immune system are exceedingly effective in suppressing adenoviral gene expression. Perforin-independent pathways, those mediated by TNF-alpha and Fas are very efficient in hepatocytes from virus-infected livers.

Prevalence of -alpha(3.7) and alpha alpha alpha(anti3.7) alleles in sickle cell trait and beta-thalassemia patients in Mexico.

PubMed

Nava, María Paulina; Ibarra, Bertha; Magaña, María Teresa; de la Luz Chávez, María; Perea, F Javier

2006-01-01

The aim of this study was to determine the frequency of alpha-globin gene mutations in three groups of Mexican unrelated individuals. The first two groups were normal and sickle cell trait individuals from the Costa Chica region, a place with a 12.8% frequency of HbS carriers, and the third group comprised of Mexican mestizo patients with beta-thalassemia. We searched for -alpha(3.7) and -alpha(4.2) alpha(+)-thalassemia deletion alleles, as well as the alpha alpha alpha(anti3.7) triplication through long-gap PCR. The alleles -alpha(3.7) and alpha alpha alpha(anti3.7) were found in the heterozygote state only; 19% of the normal subjects had the -alpha(3.7) allele, and 2% showed the alpha alpha alpha(anti3.7) allele. In individuals with the sickle cell trait, 17% had the -alpha(3.7) deletion, and the alpha alpha alpha(anti3.7) triplication was observed in 3% of these individuals. We revealed that 16% of the subjects with beta-thalassemia showed the -alpha(3.7) deletion and 28% the alpha alpha alpha(anti3.7) triplication. The -alpha(4.2) deletion was not detected in any individual. The frequency of the -alpha(3.7) allele was roughly the same in the three groups studied; this can be explained by the fact that the three groups have common genes from Africa and the Mediterranean, where a high prevalence of alpha(+)-thalassemia has been observed. To our knowledge, the frequency of alpha alpha alpha(anti3.7) triplication observed in the Mexican beta-thalassemia patients is the highest reported. As the -alpha(3.7) and alpha alpha alpha(anti3.7) alleles are very common in our selected populations, we believe that there is a need to investigate systematically the alpha-globin gene mutations in all hemoglobinopathies in the Mexican population.

As-Built design specification for PARPLT. [program to produce scatter plots of crop greenness profile parameters

NASA Technical Reports Server (NTRS)

Tompkins, M. A.; Cheng, D. E. (Principal Investigator)

1981-01-01

The design and implementation of the PARPLT program are described. The program produces scatter plots of the greenness profile derived parameters alpha, beta, and t sub o computed by the CLASFYG program (alpha being the approximate greenness rise time; beta, the greenness decay time; and t sub o, the spectral crop emergence date). Statistical information concerning the parameters is also computed.

Thalidomide suppressed IL-1beta while enhancing TNF-alpha and IL-10, when cells in whole blood were stimulated with lipopolysaccharide.

PubMed

Shannon, Edward; Noveck, Robert; Sandoval, Felipe; Kamath, Burde

2008-01-01

Thalidomide is used to treat erythema nodosum leprosum (ENL). The events that precipitate this inflammatory reaction, which may occur in multibacillary leprosy patients, and the mechanism by which thalidomide arrest ENL, are not known. Thalidomide's ability to inhibit tumor necrosis factor alpha (TNF-alpha) in vitro has been proposed as a partial explanation of its effective treatment of ENL. In in vitro assays, thalidomide can enhance or suppress TNF-alpha. This is dependent on the stimulant used to evoke TNF-alpha; the procedure used to isolate the mononuclear cells from blood, and the predominant mononuclear cell type in the culture. To avoid artifacts that may occur during isolation of mononuclear cells from blood, we stimulated normal human blood with LPS and evaluated the effect of thalidomide and dexamethasone on TNF-alpha, and other inflammatory cytokines and biomarkers. Thalidomide suppressed interleukin 1 beta (IL-1beta) (p = 0.007), and it enhanced TNF-alpha (p = 0.007) and interleukin 10 (IL-10) (p = 0.031). Dexamethasone enhanced IL-10 (p = 0.013) and suppressed IL-1beta, TNF-alpha, interleukin 6 (IL-6), and interleukin 8 (IL-8) (p = 0.013). The two drugs did not suppress: C-reactive protein (CRP), Ig-superfamily cell-adhesion molecule 1 (ICAM 1), tumor necrosis factor receptor 1 (TNFR1), tumor necrosis factor receptor 2 (TNFR2), or amyloid A. In vitro and in vivo evidence is accumulating that TNF-alpha is not the primary cytokine targeted by thalidomide in ENL and other inflammatory conditions.

Granulocyte-macrophage and macrophage colony-stimulating factors differentially regulate alpha v integrin expression on cultured human macrophages.

PubMed

De Nichilo, M O; Burns, G F

1993-03-15

The colony-stimulating factors (CSFs) greatly influence mature macrophage function in vitro: macrophage (M)-CSF induces maturation of monocytes and enhances differentiated cell function; granulocyte-macrophage (GM)-CSF stimulates a variety of antimicrobial functions. In vivo M-CSF is thought to promote differentiation, and GM-CSF is thought to potentiate the inflammatory response. One mechanism by which these differential effects may be achieved is through the receptor-mediated interaction of macrophages with their extracellular matrix. Here we show that M-CSF induces specifically the expression of the alpha v beta 5 integrin receptor, whereas GM-CSF rapidly induces mRNA and surface expression of the alpha v beta 3 integrin. The M-CSF-treated cells acquire a flattened epitheloid phenotype, and on vitronectin the alpha v beta 5 is located in adhesion plaques. These cells do not bind collagen or laminin. In contrast, cells treated with GM-CSF adopt an elongated phenotype on a number of substrates, including collagen and laminin, and express alpha v beta 3 at the leading edge of cells on vitronectin. These results suggest that a primary means by which the CSFs exert their individual effects on mature cells may be through regulating integrin expression.

Antidiabetic Property of Symplocos cochinchinensis Is Mediated by Inhibition of Alpha Glucosidase and Enhanced Insulin Sensitivity

PubMed Central

Antu, Kalathookunnel Antony; Riya, Mariam Philip; Mishra, Arvind; Anilkumar, Karunakaran S.; Chandrakanth, Chandrasekharan K.; Tamrakar, Akhilesh K.; Srivastava, Arvind K.; Raghu, K. Gopalan

2014-01-01

The study is designed to find out the biochemical basis of antidiabetic property of Symplocos cochinchinensis (SC), the main ingredient of ‘Nisakathakadi’ an Ayurvedic decoction for diabetes. Since diabetes is a multifactorial disease, ethanolic extract of the bark (SCE) and its fractions (hexane, dichloromethane, ethyl acetate and 90% ethanol) were evaluated by in vitro methods against multiple targets relevant to diabetes such as the alpha glucosidase inhibition, glucose uptake, adipogenic potential, oxidative stress, pancreatic beta cell proliferation, inhibition of protein glycation, protein tyrosine phosphatase-1B (PTP-1B) and dipeptidyl peptidase-IV (DPP-IV). Among the extracts, SCE exhibited comparatively better activity like alpha glucosidase inhibition (IC50 value-82.07±2.10 µg/mL), insulin dependent glucose uptake (3 fold increase) in L6 myotubes, pancreatic beta cell regeneration in RIN-m5F (3.5 fold increase) and reduced triglyceride accumulation (22% decrease) in 3T3L1 cells, protection from hyperglycemia induced generation of reactive oxygen species in HepG2 cells (59.57% decrease) with moderate antiglycation and PTP-1B inhibition. Chemical characterization by HPLC revealed the superiority of SCE over other extracts due to presence and quantity of bioactives (beta-sitosterol, phloretin 2′glucoside, oleanolic acid) in addition to minerals like magnesium, calcium, potassium, sodium, zinc and manganese. So SCE has been subjected to oral sucrose tolerance test to evaluate its antihyperglycemic property in mild diabetic and diabetic animal models. SCE showed significant antihyperglycemic activity in in vivo diabetic models. We conclude that SC mediates the antidiabetic activity mainly via alpha glucosidase inhibition, improved insulin sensitivity, with moderate antiglycation and antioxidant activity. PMID:25184241

Effect of peptide aldehydes with IL-1 beta converting enzyme inhibitory properties on IL-1 alpha and IL-1 beta production in vitro.

PubMed

Németh, K; Patthy, M; Fauszt, I; Széll, E; Székely, J I; Bajusz, S

1995-12-01

Tripeptide and pentapeptide aldehydes as substrate-base inhibitors of cysteine proteases were designed in our laboratory for the inhibition of interleukin-1 beta converting enzyme (ICE), a recently described cysteine protease responsible for the processing of IL-1 beta. The biological effectivity of the peptide aldehydes was studied in THP-1 cells and human whole blood. The released and cell-associated IL-1 alpha and IL-1 beta levels were determined by ELISA from the supernatants and cell lysates, respectively. The total IL-1 like bioactivity was assayed by the D10 G4.1 cell proliferation method. The tripeptide aldehyde (Z-Val-His-Asp-H) and pentapeptide aldehyde (Eoc-Ala-Tyr-Val-Ala-Asp-H) significantly reduced IL-1 beta levels in the supernatants in relatively high concentrations (10-100 microM), but the IL-1 alpha release was unaffected by these peptides. However, a considerable decrease in the cell-associated IL-1 beta and IL-1 alpha levels was observed. N-terminal extension of the tripeptide aldehyde yielded even more potent inhibitors. Amino acid substitution at the P2 position did not cause considerable changes in the inhibitory activity. The peptide aldehydes suppressed the IL-1 beta production in a reversible manner, whereas dexamethasone, a glucocorticoid, had a prolonged inhibitory effect. The inhibitory effect of these peptides and that of dexamethasone appeared to be additive. These findings indicate that these peptide aldehydes might be used as IL-beta inhibitory agents in experimental models in which IL-1 beta is a key mediator or ICE is implicated.

Nicotine induces fibrogenic changes in human liver via nicotinic acetylcholine receptors expressed on hepatic stellate cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soeda, Junpei; Morgan, Maelle; McKee, Chad

Highlights: Black-Right-Pointing-Pointer Cigarette smoke may induce liver fibrosis via nicotine receptors. Black-Right-Pointing-Pointer Nicotine induces proliferation of hepatic stellate cells (HSCs). Black-Right-Pointing-Pointer Nicotine activates hepatic fibrogenic pathways. Black-Right-Pointing-Pointer Nicotine receptor antagonists attenuate HSC proliferation. Black-Right-Pointing-Pointer Nicotinic receptor antagonists may have utility as novel anti-fibrotic agents. -- Abstract: Background and aims: Cigarette smoke (CS) may cause liver fibrosis but possible involved mechanisms are unclear. Among the many chemicals in CS is nicotine - which affects cells through nicotinic acetylcholine receptors (nAChR). We studied the effects of nicotine, and involved pathways, on human primary hepatic stellate cells (hHSCs), the principal fibrogenic cells inmore » the liver. We then determined possible disease relevance by assaying nAChR in liver samples from human non-alcoholic steatohepatitis (NASH). Methods: hHSC were isolated from healthy human livers and nAChR expression analyzed - RT-PCR and Western blotting. Nicotine induction of hHSC proliferation, upregulation of collagen1-{alpha}2 and the pro-fibrogenic cytokine transforming growth factor beta 1 (TGF-{beta}1) was determined along with involved intracellular signaling pathways. nAChR mRNA expression was finally analyzed in whole liver biopsies obtained from patients diagnosed with non-alcoholic steatohepatitis (NASH). Results: hHSCs express muscle type ({alpha}1, {beta}1, delta and epsilon) and neuronal type ({alpha}3, {alpha}6, {alpha}7, {beta}2 and {beta}4) nAChR subunits at the mRNA level. Among these subunits, {alpha}3, {alpha}7, {beta}1 and {epsilon} were predominantly expressed as confirmed by Western blotting. Nicotine induced hHSC proliferation was attenuated by mecamylamine (p < 0.05). Additionally, collagen1-{alpha}2 and TGF-{beta}1 mRNA expression were significantly upregulated by nicotine and inhibited by mecamylamine. {alpha}1 and {alpha}3-nAChR mRNA expression was significantly upregulated in NASH fibrosis compared to normal livers. Conclusion: Nicotine at levels in smokers' blood is pro-fibrogenic, through actions on hHSCs expressed nAChRs. Therefore, CS, via its nicotine content, may worsen liver fibrosis. Moreover, nicotinic receptor antagonists may have utility as novel anti-fibrotic agents.« less

Effect of gel re-organization and tensional forces on alpha2beta1 integrin levels in dermal fibroblasts.

PubMed

Jenkins, G; Redwood, K L; Meadows, L; Green, M R

1999-07-01

Mechanical forces are known to play an important role in regulating cell function in a wide range of biological systems. This is of particular relevance to dermal fibroblast function, given that the skin is known to be held under an intrinsic natural tension. To understand more about the generation of force by dermal fibroblasts and their ability to respond to changes in it, we have studied the role of the beta1 integrin receptors expressed by dermal fibroblasts in their ability to generate tensional forces within a collagen type I matrix and the effect of altered tensional force on integrin expression by dermal fibroblasts. Using a purpose-built culture force monitor, function-blocking antibodies directed towards the beta1 receptors dramatically reduced the tensional forces generated by dermal fibroblasts in a 3D collagen I matrix. However, the specific involvement of alpha1 or alpha2 subunits could not be demonstrated. Analysis of cellular response demonstrated that cells isolated from contracting collagen gels expressed fourfold higher levels of alpha2 mRNA than cells isolated from fully restrained gels. The levels of beta1 messenger RNA were relatively unaffected by reductions in force. Cells exposed to single reductions in force, however, did not exhibit alterations in either alpha1 or beta1 mRNA levels. We propose, therefore that alpha2beta1 integrin receptor levels in dermal fibroblasts are not altered in response to single reductions of gel tension, but do change following a continual change in force and associated matrix re-organization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jiying; Ohno-Matsui, Kyoko, E-mail: k.ohno.oph@tmd.ac.jp; Morita, Ikuo

Highlights: Black-Right-Pointing-Pointer Cholesterol-treated RPE produces more A{beta} than non-treated RPE. Black-Right-Pointing-Pointer Neprilysin expression and activity decreased in cholesterol-treated RPE. Black-Right-Pointing-Pointer {alpha}-Secretase expression and activity decreased in cholesterol-treated RPE. Black-Right-Pointing-Pointer Cholesterol-enriched diet induced subRPE deposits in aged mice. Black-Right-Pointing-Pointer A{beta} were present in cholesterol-enriched-diet-induced subRPE deposits in aged mice. -- Abstract: Subretinally-deposited amyloid {beta} (A{beta}) is a main contributor of developing age-related macular degeneration (AMD). However, the mechanism causing A{beta} deposition in AMD eyes is unknown. Hypercholesterolemia is a significant risk for developing AMD. Thus, we investigated the effects of cholesterol on A{beta} production in retinal pigment epithelial (RPE) cells inmore » vitro and in the mouse retina in vivo. RPE cells isolated from senescent (12-month-old) C57BL/6 mice were treated with 10 {mu}g/ml cholesterol for 48 h. A{beta} amounts in culture supernatants were measured by ELISA. Activity and expression of enzymes and proteins that regulate A{beta} production were examined by activity assay and real time PCR. The retina of mice fed cholesterol-enriched diet was examined by transmission electron microscopy. Cholesterol significantly increased A{beta} production in cultured RPE cells. Activities of A{beta} degradation enzyme; neprilysin (NEP) and anti-amyloidogenic secretase; {alpha}-secretase were significantly decreased in cell lysates of cholesterol-treated RPE cells compared to non-treated cells, but there was no change in the activities of {beta}- or {gamma}-secretase. mRNA levels of NEP and {alpha}-secretase (ADAM10 and ADAM17) were significantly lower in cholesterol-treated RPE cells than non-treated cells. Senescent (12-month-old) mice fed cholesterol-enriched chow developed subRPE deposits containing A{beta}, whereas age-matched mice fed standard rodent chow diet did not. Activities and mRNA levels of NEP and {alpha}-secretase were significantly lower in native RPE cells freshly isolated from cholesterol-enriched chow fed mice compared to standard rodent chow fed mice. These findings suggest that cholesterol enhances subretinal A{beta} accumulation by modulating the activities of enzymes degrading and processing A{beta} in RPE cells in senescent subjects.« less

The group B streptococcal alpha C protein binds alpha1beta1-integrin through a novel KTD motif that promotes internalization of GBS within human epithelial cells.

PubMed

Bolduc, Gilles R; Madoff, Lawrence C

2007-12-01

Group B Streptococcus (GBS) is the leading cause of bacterial pneumonia, sepsis and meningitis among neonates and a cause of morbidity among pregnant women and immunocompromised adults. GBS epithelial cell invasion is associated with expression of alpha C protein (ACP). Loss of ACP expression results in a decrease in GBS internalization and translocation across human cervical epithelial cells (ME180). Soluble ACP and its 170 amino acid N-terminal region (NtACP), but not the repeat protein RR', bind to ME180 cells and reduce internalization of wild-type GBS to levels obtained with an ACP-deficient isogenic mutant. In the current study, ACP colocalized with alpha(1)beta(1)-integrin, resulting in integrin clustering as determined by laser scanning confocal microscopy. NtACP contains two structural domains, D1 and D2. D1 is structurally similar to fibronectin's integrin-binding region (FnIII10). D1's (KT)D146 motif is structurally similar to the FnIII10 (RG)D1495 integrin-binding motif, suggesting that ACP binds alpha(1)beta(1)-integrin via the D1 domain. The (KT)D146A mutation within soluble NtACP reduced its ability to bind alpha(1)beta(1)-integrin and inhibit GBS internalization within ME180 cells. Thus ACP binding to human epithelial cell integrins appears to contribute to GBS internalization within epithelial cells.

A K ATP channel-dependent pathway within alpha cells regulates glucagon release from both rodent and human islets of Langerhans.

PubMed

MacDonald, Patrick E; De Marinis, Yang Zhang; Ramracheya, Reshma; Salehi, Albert; Ma, Xiaosong; Johnson, Paul R V; Cox, Roger; Eliasson, Lena; Rorsman, Patrik

2007-06-01

Glucagon, secreted from pancreatic islet alpha cells, stimulates gluconeogenesis and liver glycogen breakdown. The mechanism regulating glucagon release is debated, and variously attributed to neuronal control, paracrine control by neighbouring beta cells, or to an intrinsic glucose sensing by the alpha cells themselves. We examined hormone secretion and Ca(2+) responses of alpha and beta cells within intact rodent and human islets. Glucose-dependent suppression of glucagon release persisted when paracrine GABA or Zn(2+) signalling was blocked, but was reversed by low concentrations (1-20 muM) of the ATP-sensitive K(+) (KATP) channel opener diazoxide, which had no effect on insulin release or beta cell responses. This effect was prevented by the KATP channel blocker tolbutamide (100 muM). Higher diazoxide concentrations (>/=30 muM) decreased glucagon and insulin secretion, and alpha- and beta-cell Ca(2+) responses, in parallel. In the absence of glucose, tolbutamide at low concentrations (<1 muM) stimulated glucagon secretion, whereas high concentrations (>10 muM) were inhibitory. In the presence of a maximally inhibitory concentration of tolbutamide (0.5 mM), glucose had no additional suppressive effect. Downstream of the KATP channel, inhibition of voltage-gated Na(+) (TTX) and N-type Ca(2+) channels (omega-conotoxin), but not L-type Ca(2+) channels (nifedipine), prevented glucagon secretion. Both the N-type Ca(2+) channels and alpha-cell exocytosis were inactivated at depolarised membrane potentials. Rodent and human glucagon secretion is regulated by an alpha-cell KATP channel-dependent mechanism. We propose that elevated glucose reduces electrical activity and exocytosis via depolarisation-induced inactivation of ion channels involved in action potential firing and secretion.

Characterization of alpha beta and gamma delta T cell subsets expressing IL-17A in ruminants and swine

USDA-ARS?s Scientific Manuscript database

As part of our ongoing program to expand reagents available for research in cattle, we developed a monoclonal antibody (mAb) to bovine IL-17A, a multifunctional cytokine centrally involved in regulating innate and adaptive immune responses. Initial comparative studies demonstrated the mAb recognizes...

Anomalous heat conduction and anomalous diffusion in nonlinear lattices, single walled nanotubes, and billiard gas channels.

PubMed

Li, Baowen; Wang, Jiao; Wang, Lei; Zhang, Gang

2005-03-01

We study anomalous heat conduction and anomalous diffusion in low-dimensional systems ranging from nonlinear lattices, single walled carbon nanotubes, to billiard gas channels. We find that in all discussed systems, the anomalous heat conductivity can be connected with the anomalous diffusion, namely, if energy diffusion is sigma(2)(t)=2Dt(alpha) (01) implies an anomalous heat conduction with a divergent thermal conductivity (beta>0), and more interestingly, a subdiffusion (alpha<1) implies an anomalous heat conduction with a convergent thermal conductivity (beta<0), consequently, the system is a thermal insulator in the thermodynamic limit. Existing numerical data support our theoretical prediction.

The human interleukin-1 alpha gene is located on the long arm of chromosome 2 at band q13.

PubMed

Lafage, M; Maroc, N; Dubreuil, P; de Waal Malefijt, R; Pébusque, M J; Carcassonne, Y; Mannoni, P

1989-01-01

Interleukin-1 alpha (IL-1 alpha) and interleukin-1 beta (IL-1 beta) are two biochemically distinct, but distantly related, polypeptidic cytokines that play a key role in inflammation, immunologic reactions, and tissue repair. Recently, it has been shown that IL-1 alpha is identical to hematopoietin 1, which was described as a hematopoietic growth factor acting on early progenitor cells in synergy with other hematopoietic growth factors. In this report we discuss our use of in situ hybridization on human prometaphase cells with a human IL-1 alpha cDNA probe to localize the human IL-1 alpha gene on the proximal part of the long arm of chromosome 2 at band q13, in the same chromosomal region as the IL-1 beta gene.

Comparative study on cytogenetic damage induced by homo-aza-steroidal esters in human lymphocytes.

PubMed

Mourelatos, D; Papageorgiou, A; Boutis, L; Catsoulacos, P

1995-02-01

The effect of P[N,N-bis(2-chloroethyl)amino]phenylacetate esters of 3 beta-hydroxy-N-methyl-17 alpha-aza-D-homo-5 alpha-androstan-17-one (compound 3) and 3 beta-hydroxy-17 alpha-aza-D-homo-5 alpha-androstane (compound 2) on sister-chromatid exchange (SCE) frequencies and on human lymphocytes proliferation kinetics was studied. The results are compared with those of the P[N,N-bis(2-chloroethyl)amino]phenylacetate esters of 3 beta-hydroxy-17 alpha-aza-D-homo-5 alpha-androstan-17-one (compound 1). All compounds were found to be active in inducing markedly increased SCE rates and cell division delays. A correlation between potency for SCE induction, effectiveness in cell division delay and previously established antitumour activity of these compounds was observed.

Oxygen binding by alpha(Fe2+)2beta(Ni2+)2 hemoglobin crystals.

PubMed Central

Bruno, S.; Bettati, S.; Manfredini, M.; Mozzarelli, A.; Bolognesi, M.; Deriu, D.; Rosano, C.; Tsuneshige, A.; Yonetani, T.; Henry, E. R.

2000-01-01

Oxygen binding by hemoglobin fixed in the T state either by crystallization or by encapsulation in silica gels is apparently noncooperative. However, cooperativity might be masked by different oxygen affinities of alpha and beta subunits. Metal hybrid hemoglobins, where the noniron metal does not bind oxygen, provide the opportunity to determine the oxygen affinities of alpha and beta hemes separately. Previous studies have characterized the oxygen binding by alpha(Ni2+)2beta(Fe2+)2 crystals. Here, we have determined the three-dimensional (3D) structure and oxygen binding of alpha(Fe2+)2beta(Ni2+)2 crystals grown from polyethylene glycol solutions. Polarized absorption spectra were recorded at different oxygen pressures with light polarized parallel either to the b or c crystal axis by single crystal microspectrophotometry. The oxygen pressures at 50% saturation (p50s) are 95 +/- 3 and 87 +/- 4 Torr along the b and c crystal axes, respectively, and the corresponding Hill coefficients are 0.96 +/- 0.06 and 0.90 +/- 0.03. Analysis of the binding curves, taking into account the different projections of the alpha hemes along the optical directions, indicates that the oxygen affinity of alpha1 hemes is 1.3-fold lower than alpha2 hemes. Inspection of the 3D structure suggests that this inequivalence may arise from packing interactions of the Hb tetramer within the monoclinic crystal lattice. A similar inequivalence was found for the beta subunits of alpha(Ni2+)2beta(Fe2+)2 crystals. The average oxygen affinity of the alpha subunits (p50 = 91 Torr) is about 1.2-fold higher than the beta subunits (p50 = 110 Torr). In the absence of cooperativity, this heterogeneity yields an oxygen binding curve of Hb A with a Hill coefficient of 0.999. Since the binding curves of Hb A crystals exhibit a Hill coefficient very close to unity, these findings indicate that oxygen binding by T-state hemoglobin is noncooperative, in keeping with the Monod, Wyman, and Changeux model. PMID:10794410

Analysis of the specificity of sialyltransferases toward mucin core 2, globo, and related structures. identification of the sialylation sequence and the effects of sulfate, fucose, methyl, and fluoro substituents of the carbohydrate chain in the biosynthesis of selectin and siglec ligands, and novel sialylation by cloned alpha2,3(O)sialyltransferase.

PubMed

Chandrasekaran, E V; Xue, Jun; Xia, Jie; Chawda, Ram; Piskorz, Conrad; Locke, Robert D; Neelamegham, Sriram; Matta, Khushi L

2005-11-29

Sialic acids are key determinants in many carbohydrates involved in biological recognition. We studied the acceptor specificities of three cloned sialyltransferases (STs) [alpha2,3(N)ST, alpha2,3(O)ST, and alpha2,6(N)ST] and another alpha2,3(O)ST present in prostate cancer cell LNCaP toward mucin core 2 tetrasaccharide [Galbeta1,4GlcNAcbeta1,6(Galbeta1,3)GalNAcalpha-O-Bn] and Globo [Galbeta1,3GalNAcbeta1,3Galalpha-O-Me] structures containing sialyl, fucosyl, sulfo, methyl, or fluoro substituents by identifying the products by electrospray ionization tandem mass spectral analysis and other biochemical methods. The Globo precursor was an efficient acceptor for both alpha2,3(N)ST and alpha2,3(O)ST, whereas only alpha2,3(O)ST used its deoxy analogue (d-Fucbeta1,3GalNAcbeta1,3-Gal-alpha-O-Me); 2-O-MeGalbeta1,3GlcNAc and 4-OMeGalbeta1,4GlcNAc were specific acceptors for alpha2,3(N)ST. Other major findings of this study include: (i) alpha2,3 sialylation of beta1,3Gal in mucin core 2 can proceed even after alpha1,3 fucosylation of beta1,6-linked LacNAc. (ii) Sialylation of beta1,3Gal must precede the sialylation of beta1,4Gal for favorable biosynthesis of mucin core 2 compounds. (iii) alpha2,3 sialylation of the 6-O-sulfoLacNAc moiety in mucin core 2 (e.g., GlyCAM-1) is facilitated when beta1,3Gal has already been alpha2,3 sialylated. (iv) alpha2,6(N)ST was absolutely specific for the beta1,4Gal in mucin core 2. Either alpha1,3 fucosylation or 6-O-sulfation of the GlcNAc moiety reduced the activity. Sialylation of beta1,3Gal in addition to 6-O-sulfation of GlcNAc moiety abolished the activity. (v) Prior alpha2,3 sialylation or 3-O-sulfation of beta1,3Gal would not affect alpha2,6 sialylation of Galbeta1,4GlcNAc of mucin core 2. (vi) A 3- or 4-fluoro substituent in beta1,4Gal resulted in poor acceptors for the cloned alpha2,6(N)ST and alpha2,3(N)ST, whereas 4-fluoro- or 4-OMe-Galbeta1,3GalNAcalpha was a good acceptor for cloned alpha2,3(O)ST. (vii) 4-O-Methylation of beta1,4Gal abolished the acceptor ability toward alpha2,6(N)ST but increased the acceptor efficiency considerably toward alpha2,3(N)ST. (viii) Just like LNCaPalpha1,2-FT and Gal-3-O-sulfotransferase T2, the cloned alpha2,3(N)ST which modifies terminal Gal in Galbeta1,4GlcNAc also efficiently utilizes the terminal beta1,3Gal in the Globo backbone. Utilization of C-3 blocked compounds such as 3-O-sulfo-Galbeta1,3GalNAcbeta1,3Galalpha-OMe as acceptors by cloned alpha2,3(O)ST and analyses of the resulting products by lectin chromatography and mass spectrometry indicate that alpha2,3(O)ST is capable of attaching NeuAc to another position in C-3-substituted beta1,3Gal.

TNF{alpha} and IL-1{beta} are mediated by both TLR4 and Nod1 pathways in the cultured HAPI cells stimulated by LPS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Wenwen; Zheng, Xuexing; Department of Anesthesiology, University of Miami Miller School of Medicine, Miami, FL 33136

2012-04-20

Highlights: Black-Right-Pointing-Pointer LPS induces proinflammatory cytokine release in HAPI cells. Black-Right-Pointing-Pointer JNK pathway is dependent on TLR4 signaling to release cytokines. Black-Right-Pointing-Pointer NF-{kappa}B pathway is dependent on Nod1 signaling to release cytokines. -- Abstract: A growing body of evidence recently suggests that glial cell activation plays an important role in several neurodegenerative diseases and neuropathic pain. Microglia in the central nervous system express toll-like receptor 4 (TLR4) that is traditionally accepted as the primary receptor of lipopolysaccharide (LPS). LPS activates TLR4 signaling pathways to induce the production of proinflammatory molecules. In the present studies, we verified the LPS signaling pathwaysmore » using cultured highly aggressively proliferating immortalized (HAPI) microglial cells. We found that HAPI cells treated with LPS upregulated the expression of TLR4, phospho-JNK (pJNK) and phospho-NF-{kappa}B (pNF-{kappa}B), TNF{alpha} and IL-1{beta}. Silencing TLR4 with siRNA reduced the expression of pJNK, TNF{alpha} and IL-1{beta}, but not pNF-{kappa}B in the cells. Inhibition of JNK with SP600125 (a JNK inhibitor) decreased the expression of TNF{alpha} and IL-1{beta}. Unexpectedly, we found that inhibition of Nod1 with ML130 significantly reduced the expression of pNF-{kappa}B. Inhibition of NF-{kappa}B also reduced the expression of TNF{alpha} and IL-1{beta}. Nod1 ligand, DAP induced the upregulation of pNF-{kappa}B which was blocked by Nod1 inhibitor. These data indicate that LPS-induced pJNK is TLR4-dependent, and that pNF-{kappa}B is Nod1-dependent in HAPI cells treated with LPS. Either TLR4-JNK or Nod1-NF-{kappa}B pathways is involved in the expression of TNF{alpha} and IL-1{beta}.« less

E-cadherin interactions regulate beta-cell proliferation in islet-like structures.

PubMed

Carvell, Melanie J; Marsh, Phil J; Persaud, Shanta J; Jones, Peter M

2007-01-01

Islet function is dependent on cells within the islet interacting with each other. E-cadherin (ECAD) mediates Ca(2+)-dependent homophilic cell adhesion between b-cells within islets and has been identified as a tumour suppressor. We generated clones of the MIN6 beta-cell line that stably over- (S) and under-express (alphaS) ECAD. Modified expression of ECAD was confirmed by quantitative RT-PCR, immunoblotting and immunocytochemistry. Preproinsulin mRNA, insulin content and basal rates of insulin secretion were higher in S cells compared to aS and control (V) cells. However, stimulated insulin secretory responses were unaffected by ECAD expression levels. ECAD expression did affect proliferation, with enhanced ECAD expression being associated with reduced proliferation and vice versa. Formation of islet-like structures was associated with a significant reduction in proliferation of V and S cells but not alphaS cells. These data suggest that ECAD expression levels do not modulate insulin secretory function but are consistent with a role for ECAD in the regulation of beta-cell proliferation. Copyright (c) 2007 S. Karger AG, Basel.

RACK1 binds to Smad3 to modulate transforming growth factor-beta1-stimulated alpha2(I) collagen transcription in renal tubular epithelial cells.

PubMed

Okano, Kazuhiro; Schnaper, H William; Bomsztyk, Karol; Hayashida, Tomoko

2006-09-08

Although it is clear that transforming growth factor-beta1 (TGF-beta1) is critical for renal fibrogenesis, the complexity of the involved mechanisms is increasingly apparent. TGF-beta1 stimulates phosphorylation of Smad2/3 and activates other signaling molecules as well. The molecular link between these other kinases and Smads is not known. We sought new binding partners for Smad3 in renal cells and identified receptor for activated protein kinase C 1 (RACK1) as a novel binding partner of Smad3. The linker region of Smad3 and the tryptophan-aspartic acid repeat 6 and 7 of RACK1 are sufficient for the association. RACK1 also interacts with Smad3 in the human kidney epithelial cell line, HKC. Silencing RACK1 increases transcriptional activity of TGF-beta1-responsive promoter sequences of the Smad binding element (SBE), p3TP-Lux, and alpha2(I) collagen. Conversely, overexpressed RACK1 negatively modulates alpha2(I) collagen transcriptional activity in TGF-beta1-stimulated cells. RACK1 did not affect phosphorylation of Smad3 at the C terminus or in the linker region. However, RACK1 reduced direct binding of Smad3 to the SBE motif. Mutating a RACK1 tyrosine at residue 246, but not at 228, decreased the inhibitory effect of RACK1 on both alpha2(I) collagen promoter activity and Smad binding to SBE induced by TGF-beta1. These results suggest that RACK1 modulates transcription of alpha2(I) collagen by TGF-beta1 through interference with Smad3 binding to the gene promoter.

Paracrine GABA and insulin regulate pancreatic alpha cell proliferation in a mouse model of type 1 diabetes.

PubMed

Feng, Allen L; Xiang, Yun-Yan; Gui, Le; Kaltsidis, Gesthika; Feng, Qingping; Lu, Wei-Yang

2017-06-01

This study aimed to elucidate the mechanism of increased proliferation of alpha cells in recent-onset type 1 diabetes. Pancreatic beta cells express GAD and produce γ-aminobutyric acid (GABA), which inhibits alpha cell secretion of glucagon. We explored the roles of GABA in alpha cell proliferation in conditions corresponding to type 1 diabetes in a mouse model and in vitro. Type 1 diabetes was induced by injecting the mice with streptozotocin (STZ). Some of the STZ-injected mice were treated with GABA (10 mg/kg daily) for 12 days. Isolated pancreatic islets were treated with STZ or STZ together with GABA for 2 days. The effects of GABA treatment on STZ-induced alpha cell proliferation in vivo and in vitro were assessed. The effect of muscimol, a GABA receptor agonist, on αTC1-6 cell proliferation was also examined. STZ injection substantially decreased levels of GAD, GABA and insulin in pancreatic beta cells 12 h after injection; this was followed by an upsurge of phosphorylated mechanistic target of rapamycin (p-mTOR) in the alpha cells at day 1, and a significant increase in alpha cell mass at day 3. Treating STZ-injected mice with GABA largely restored the immunodetectable levels of insulin and GAD in the beta cells and significantly decreased the number of aldehyde dehydrogenase 1 family, member A3 (ALDH1a3)-positive cells, alpha cell mass and hyperglucagonaemia. STZ treatment also increased alpha cell proliferation in isolated islets, which was reversed by co-treatment with GABA. Muscimol, together with insulin, significantly lowered the level of cytosolic Ca 2+ and p-mTOR, and decreased the proliferation rate of αTC1-6 cells. GABA signalling critically controls the alpha cell population in pancreatic islets. Low intraislet GABA may contribute to alpha cell hyperplasia in early type 1 diabetes.

Alpha-SNAP functions in insulin exocytosis from mature, but not immature secretory granules in pancreatic beta cells.

PubMed

Nakamichi, Y; Nagamatsu, S

1999-06-24

To explore alpha-SNAP function in insulin exocytosis from either immature or mature secretory granules in pancreatic beta cells, we studied the effects of overexpression of adenovirus-mediated wild-type alpha-SNAP and C-terminally deleted alpha-SNAP mutant (1-285) on newly synthesized proinsulin and insulin release by rat islets and MIN6 cells. Rat islets overexpressing alpha-SNAP and mutant alpha-SNAP were pulse-chased. Exocytosis from immature and mature insulin secretory granules was measured as fractional (%) labeled-proinsulin release immediately after the pulse-labeling and percentage labeled-insulin release after a 3-h chase period, respectively. There was no difference in percentage labeled-proinsulin release between the control and alpha-SNAP or mutant alpha-SNAP-overexpressed islets. Although percentage labeled-insulin release after a 3-h chase period was significantly increased in alpha-SNAP-overexpressed islets, it was decreased in mutant alpha-SNAP-overexpressed islets. Thus, the results demonstrated that alpha-SNAP overexpression in rat islets primarily increased exocytosis from mature, but not immature insulin secretory granules. On the other hand, in MIN6 cells, alpha-SNAP overexpression scarcely affected glucose-stimulated insulin release; therefore, we examined the effect of mutant alpha-SNAP overexpression as the dominant-negative inhibitor on the newly synthesized proinsulin/insulin release using the same protocol as in the rat islet experiments. alpha-SNAP mutant (1-285) overexpression in MIN6 cells decreased the percentage labeled insulin release from mature secretory granules, but not percentage labeled proinsulin release from immature secretory granules. Thus, our data demonstrate that alpha-SNAP functions mainly in the mature insulin secretory granules in pancreatic beta cells. Copyright 1999 Academic Press.

Cryptic MCAT enhancer regulation in fibroblasts and smooth muscle cells. Suppression of TEF-1 mediated activation by the single-stranded DNA-binding proteins, Pur alpha, Pur beta, and MSY1.

PubMed

Carlini, Leslie E; Getz, Michael J; Strauch, Arthur R; Kelm, Robert J

2002-03-08

An asymmetric polypurine-polypyrimidine cis-element located in the 5' region of the mouse vascular smooth muscle alpha-actin gene serves as a binding site for multiple proteins with specific affinity for either single- or double-stranded DNA. Here, we test the hypothesis that single-stranded DNA-binding proteins are responsible for preventing a cryptic MCAT enhancer centered within this element from cooperating with a nearby serum response factor-interacting CArG motif to trans-activate the minimal promoter in fibroblasts and smooth muscle cells. DNA binding studies revealed that the core MCAT sequence mediates binding of transcription enhancer factor-1 to the double-stranded polypurine-polypyrimidine element while flanking nucleotides account for interaction of Pur alpha and Pur beta with the purine-rich strand and MSY1 with the complementary pyrimidine-rich strand. Mutations that selectively impaired high affinity single-stranded DNA binding by fibroblast or smooth muscle cell-derived Pur alpha, Pur beta, and MSY1 in vitro, released the cryptic MCAT enhancer from repression in transfected cells. Additional experiments indicated that Pur alpha, Pur beta, and MSY1 also interact specifically, albeit weakly, with double-stranded DNA and with transcription enhancer factor-1. These results are consistent with two plausible models of cryptic MCAT enhancer regulation by Pur alpha, Pur beta, and MSY1 involving either competitive single-stranded DNA binding or masking of MCAT-bound transcription enhancer factor-1.

FcepsilonRI-alpha siRNA inhibits the antigen-induced activation of mast cells.

PubMed

Safaralizadeh, Reza; Soheili, Zahra-Soheila; Deezagi, Abdolkhaleg; Pourpak, Zahra; Samiei, Shahram; Moin, Mostafa

2009-12-01

FcepsilonRI, The high affinity receptor for IgE plays a critical role in triggering the allergic reactions. It is responsible for inducing mast cell degranulation and deliberation of allergy mediators when it is aggregated by allergen and IgE complexes. FcepsilonRI on the mast cells consists of three subunits; alpha chain directly binds IgE, beta chain and dimmer of gamma chains together mediate intracellular signaling. Cross-linking of IgE-bound FcepsilonRI on the surface of mast cells and basophils by the multivalent antigen induces release of chemical mediators. The present in vitro study was designed to investigate the effect of synthetic FcepsilonRI-alpha siRNA on the antigen-induced activation of MC/9 cells. MC/9 cells which are murine mast cells were transfected by FcepsilonRI-alpha siRNA and negative control siRNA. After 6 h, anti-DNP (Dinitrophenyl) IgE was used for the cells sensitization. Then the cells were challenged with Dinitrophenyl-Human Serum Albumin (DNP-HSA) for mast cell degranulation induction before collection of supernatants. The amount of mRNA and protein expression was measured by Real Time PCR and western blot analysis, respectively. Determination of the expression rate of FcepsilonRI-alpha on cell surface was achieved by flow cytometry. ELISA and spectrophotometry methods were used subsequently for measuring the effects of FcepsilonRI-alpha siRNA on antigen-induced histamine and beta-hexosaminidase release. FcepsilonRI-alpha siRNA treated cells showed significant decrease in FcepsilonRI-alpha mRNA and protein expression in comparison to control cells. FcepsilonRI-mediated mast cell release of beta-hexosaminidase and histamine were also inhibited. In this study it was shown that FcepsilonRI-alpha siRNA could suppress FcepsilonRI-alpha expression and inhibited degranulation and histamine release in antigen-stimulated MC/9 cells. In conclusion, knock-down of FcepsilonRI-alpha by siRNA could be a promising method for inhibition of the mast cell-mediated allergic reactions.

Connection between integrins and cell activation in rat adrenal glomerulosa cells: a role for Arg-Gly-Asp peptide in the activation of the p42/p44(mapk) pathway and intracellular calcium.

PubMed

Campbell, Shirley; Otis, Melissa; Côté, Mylène; Gallo-Payet, Nicole; Payet, Marcel Daniel

2003-04-01

Integrins are responsible for adhesion and activation of several intracellular cascades. The present study was aimed at determining whether the interaction between fibronectin and integrins could generate pathways involved in physiological functions of rat adrenal glomerulosa cells. Immunofluorescence studies and adhesion assays showed that fibronectin was the best matrix in promoting the formation of focal adhesion. Binding of glomerulosa cells to fibronectin, but not to collagen I or poly-L-lysine, involved the integrin-binding sequence Arg-Gly-Asp (RGD). Activation of glomerulosa cells with Arg-Gly-Asp-Ser (RGDS) induced an increase in [Ca(2+)](i), whereas fibronectin triggered a release of Ca(2+) from InsP(3)-sensitive Ca(2+) stores. Aldosterone secretion induced by ACTH, angiotensin II, and RGDS and proliferation were improved on fibronectin, compared with poly-L-lysine. The RGDS peptide induced a transient increase in the activity of the p42/p44(mapk), independent of phosphatidylinositol-3 kinase and protein kinase C. Integrins alpha(5) and alpha(V) as well as their fibronectin receptor partners beta(1) and beta(3), were identified. These results suggest that in rat adrenal glomerulosa cells, binding of the alpha(5)beta(1), alpha(v)beta(1), or alpha(v)beta(3) integrins to fibronectin is involved in the generation of two important signaling events, increase in intracellular calcium, and activation of the p42/p44(mapk) cascade, leading to cell proliferation and aldosterone secretion.

BETA (Bitter Electromagnet Testing Apparatus)

NASA Astrophysics Data System (ADS)

Bates, Evan M.; Birmingham, William J.; Rivera, William F.; Romero-Talamas, Carlos A.

2017-10-01

The Bitter Electromagnet Testing Apparatus (BETA) is a 1-Tesla (T) prototype of the 10-T Adjustable Long Pulse High-Field Apparatus (ALPHA). These water-cooled resistive magnets use high DC currents to produce strong uniform magnetic fields. Presented here is the successful completion of the BETA project and experimental results validating analytical magnet designing methods developed at the Dusty Plasma Laboratory (DPL). BETA's final design specifications will be highlighted which include electromagnetic, thermal and stress analyses. The magnet core design will be explained which include: Bitter Arcs, helix starters, and clamping annuli. The final version of the magnet's vessel and cooling system are also presented, as well as the electrical system of BETA, which is composed of a unique solid-state breaker circuit. Experimental results presented will show the operation of BETA at 1 T. The results are compared to both analytical design methods and finite element analysis calculations. We also explore the steady state maximums and theoretical limits of BETA's design. The completion of BETA validates the design and manufacturing techniques that will be used in the succeeding magnet, ALPHA.

Analysis of the T-cell receptor repertoire of human T-cell leukemia virus type 1 (HTLV-1) Tax-specific CD8+ cytotoxic T lymphocytes from patients with HTLV-1-associated disease: evidence for oligoclonal expansion.

PubMed

Utz, U; Banks, D; Jacobson, S; Biddison, W E

1996-02-01

Human T-cell leukemia virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a chronic, progressive neurological disease characterized by marked degeneration of the spinal cord and the presence of antibodies against HTLV-1. Patients with HAM/TSP, but not asymptomatic carriers, show very high precursor frequencies of HTLV-1-specific CD8+ T cells in peripheral blood and cerebrospinal fluid, suggestive of a role of these T cells in the pathogenesis of the disease. In HLA-A2+ HAM/TSP patients, HTLV-1-specific T cells were demonstrated to be directed predominantly against one HTLV-1 epitope, namely, Tax11-19. In the present study, we analyzed HLA-A2-restricted HTLV-1 Tax11-19-specific cytotoxic T cells from three patients with HAM/TSP. An analysis of the T-cell receptor (TCR) repertoire of these cells revealed an absence of restricted variable (V) region usage. Different combinations of TCR V alpha and V beta genes were utilized between, but also within, the individual patients for the recognition of Tax11-19. Sequence analysis of the TCR showed evidence for an oligoclonal expansion of few founder T cells in each patient. Apparent structural motifs were identified for the CDR3 regions of the TCR beta chains. One T-cell clone could be detected within the same patient over a period of 3 years. We suggest that these in vivo clonally expanded T cells might play a role in the pathogenesis of HAM/TSP and provide information on HTLV-1-specific TCR which may elucidate the nature of the T cells that infiltrate the central nervous system in HAM/TSP patients.

Vitamin E and mast cells.

PubMed

Zingg, Jean-Marc

2007-01-01

Mast cells play an important role in the immune system by interacting with B and T cells and by releasing several mediators involved in activating other cells. Hyperreactivity of mast cells and their uncontrolled accumulation in tissues lead to increased release of inflammatory mediators contributing to the pathogenesis of several diseases such as rheumatoid arthritis, atherosclerosis, multiple sclerosis, and allergic disorders such as asthma and allergic rhinitis. Interference with mast cell proliferation, survival, degranulation, and migration by synthetic or natural compounds may represent a preventive strategy for the management of these diseases. Natural vitamin E covers a group of eight analogues-the alpha-, beta-, gamma-, and delta-tocopherols and the alpha-, beta-, gamma-, and delta-tocotrienols, but only alpha-tocopherol is efficiently retained by the liver and distributed to peripheral tissues. Mast cells preferentially locate in the proximity of tissues that interface with the external environment (the epithelial surface of the skin, the gastrointestinal mucosa, and the respiratory system), what may render them accessible to treatments with inefficiently retained natural vitamin E analogues and synthetic derivatives. In addition to scavenging free radicals, the natural vitamin E analogues differently modulate signal transduction and gene expression in several cell lines; in mast cells, protein kinase C, protein phosphatase 2A, and protein kinase B are affected by vitamin E, leading to the modulation of proliferation, apoptosis, secretion, and migration. In this chapter, the possibility that vitamin E can prevent diseases with mast cells involvement by modulating signal transduction and gene expression is evaluated.

Apolipoprotein CIII-induced THP-1 cell adhesion to endothelial cells involves pertussis toxin-sensitive G protein- and protein kinase C alpha-mediated nuclear factor-kappaB activation.

PubMed

Kawakami, Akio; Aikawa, Masanori; Nitta, Noriko; Yoshida, Masayuki; Libby, Peter; Sacks, Frank M

2007-01-01

Plasma apolipoprotein CIII (apoCIII) independently predicts risk for coronary heart disease (CHD). We recently reported that apoCIII directly enhances adhesion of human monocytes to endothelial cells (ECs), and identified the activation of PKC alpha as a necessary upstream event of enhanced monocyte adhesion. This study tested the hypothesis that apoCIII activates PKC alpha in human monocytic THP-1 cells, leading to NF-kappaB activation. Among inhibitors specific to PKC activators, phosphatidylcholine-specific phospholipase C (PC-PLC) inhibitor D609 limited apoCIII-induced PKC alpha activation and THP-1 cell adhesion. ApoCIII increased PC-PLC activity in THP-1 cells, resulting in PKC alpha activation. Pertussis toxin (PTX) inhibited apoCIII-induced PC-PLC activation and subsequent PKC alpha activation, implicating PTX-sensitive G protein pathway. ApoCIII further activated nuclear factor-kappaB (NF-kappaB) through PKC alpha in THP-1 cells and augmented beta1-integrin expression. The NF-kappaB inhibitor peptide SN50 partially inhibited apoCIII-induced beta1-integrin expression and THP-1 cell adhesion. ApoCIII-rich VLDL had similar effects to apoCIII alone. PTX-sensitive G protein pathway participates critically in PKC alpha stimulation in THP-1 cells exposed to apoCIII, activating NF-kappaB, and increasing beta1-integrin. This action causes monocytic cells to adhere to endothelial cells. Furthermore, because leukocyte NF-kappaB activation contributes to inflammatory aspects of atherogenesis, apoCIII may stimulate diverse inflammatory responses through monocyte activation.

Role of {alpha}{sub v}{beta}{sub 5} integrin receptor in endocytosis of crocidolite and its effect on intracellular glutathione levels in human lung epithelial (A549) cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pande, Priyadarshini; Mosleh, Tariq A.; Aust, Ann E.

Crocidolite, containing 27% iron by weight, is the most carcinogenic form of asbestos. Crocidolite fibers are endocytized by {alpha}{sub v}{beta}{sub 5} integrin receptors in rabbit pleural mesothelial cells. We show here that crocidolite fibers are endocytized in human lung epithelial (A549) cells and in primary small airway epithelial (SAEC) cells. Presence of the integrin {alpha}{sub v}{beta}{sub 5} blocking antibody, P1F6, significantly reduced the uptake of crocidolite fibers in A549 cells. Thus, the integrin {alpha}{sub v}{beta}{sub 5} receptor is involved in endocytosis of crocidolite fibers in A549 cells as well. Previously, it has been observed that asbestos fibers lead to changesmore » in the intracellular redox environment, i.e. a marked decrease in intracellular glutathione concentrations and an increase in the extracellular glutathione in A549 cells. In addition, the decrease in intracellular glutathione was found to be largely independent of iron present on the surface of the fiber. A549 cells were treated with crocidolite in the presence of endocytosis inhibitor cytochalasin D. Our data indicate that, upon preventing endocytosis, we were able to reverse the decrease in total intracellular glutathione. The decrease in total intracellular glutathione could also be prevented in the presence of the monoclonal antibody P1F6. Thus, we observed that endocytosis of crocidolite fibers via integrin {alpha}{sub v}{beta}{sub 5} receptor is linked to the marked decrease in total intracellular glutathione in A549 cells.« less

In vivo imaging of tumour angiogenesis in mice with the alpha(v)beta (3) integrin-targeted tracer 99mTc-RAFT-RGD.

PubMed

Sancey, Lucie; Ardisson, Valérie; Riou, Laurent M; Ahmadi, Mitra; Marti-Batlle, Danièle; Boturyn, Didier; Dumy, Pascal; Fagret, Daniel; Ghezzi, Catherine; Vuillez, Jean-Philippe

2007-12-01

The molecular imaging of tumour neoangiogenesis currently represents a major field of research for the diagnostic and treatment strategy of solid tumours. Endothelial cells from tumour neovessels overexpress the alpha(v)beta(3) integrin, which selectively binds to Arg-Gly-Asp (RGD)-containing peptides. We evaluated the potential of the novel radiotracer (99m)Tc-RAFT-RGD for the non-invasive molecular imaging of alpha(v)beta(3) integrin expression in mice models of tumour development. (99m)Tc-RAFT-RGD, (99m)Tc-cRGD (specific control) and (99m)Tc-RAFT-RAD (non-specific control) were injected intravenously to mice bearing B16F0 or TS/A-pc tumours. In vivo whole-body tomographic imaging and post-mortem biodistribution studies were performed 60 min following tracer injection. Adjacent tumour slices were used to compare the localisation of neovessels from immunostaining and the pattern of (99m)Tc-RAFT-RGD uptake from autoradiographic ex vivo imaging. Biodistribution studies indicated that (99m)Tc-RAFT-RGD tumour uptake was significantly higher than that of (99m)Tc-RAFT-RAD in B16F0 (2.4+/-0.5 vs 1.0+/-0.1%ID/g, respectively) and in TS/A-pc tumours (2.7+/-0.8 vs 0.7+/-0.1%ID/g, respectively). Immunohistochemical and autoradiographic studies indicated that (99m)Tc-RAFT-RGD intratumoural uptake preferentially occurred in angiogenic areas. Tomographic imaging allowed tumour visualisation following injection of (99m)Tc-RAFT-RGD and (99m)Tc-cRGD with similar tumour-to-contralateral muscle (T/CM) ratios in B16F0 and in TS/A-pc tumours whereas (99m)Tc-RAFT-RAD T/CM ratios did not allow tumour imaging. In accordance with the higher level of alpha(v)beta(3) integrin expression on TS/A-pc tumours than on B16F0 tumours as determined from western blot and immunoprecipitation analyses, the (99m)Tc-RAFT-RGD T/CM ratio was significantly higher in TS/A-pc than in B16F0 tumours. (99m)Tc-RAFT-RGD allowed the in vivo imaging of alpha(v)beta(3) integrin tumour expression.

Diet-induced obesity in mice reduces the maintenance of influenza-specific CD8+ memory T cells.

PubMed

Karlsson, Erik A; Sheridan, Patricia A; Beck, Melinda A

2010-09-01

Obesity has been associated with increasing the risk for type 2 diabetes and heart disease, but its influence on the immune response to viral infection is understudied. Memory T cells generated during a primary influenza infection are important for protection against subsequent influenza exposures. Previously, we have demonstrated that diet-induced obese (DIO) mice have increased morbidity and mortality following secondary influenza infection compared with lean mice. To determine whether the problem resided in a failure to maintain functional, influenza-specific CD8(+) memory T cells, male DIO and lean mice were infected with influenza X-31. At 84 d postinfection, DIO mice had a 10% reduction in memory T cell numbers. This reduction may have resulted from significantly reduced memory T cell expression of interleukin 2 receptor beta (IL-2R beta, CD122), but not IL-7 receptor alpha (CD127), which are both required for memory cell maintenance. Peripheral leptin resistance in the DIO mice may be a contributing factor to the impairment. Indeed, leptin receptor mRNA expression was significantly reduced in the lungs of obese mice, whereas suppressor of cytokine signaling (Socs)1 and Socs3 mRNA expression were increased. It is imperative to understand how the obese state alters memory T cells, because impairment in maintenance of functional memory responses has important implications for vaccine efficacy in an obese population.

Agglucetin, a tetrameric C-type lectin-like venom protein, regulates endothelial cell survival and promotes angiogenesis by activating integrin {alpha}v{beta}3 signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, W.-J.

2008-05-02

Agglucetin, a platelet glycoprotein (GP)Ib binding protein from Formosan Agkistrodon acutus (A. acutus) venom, could sustain human umbilical vein endothelial cell (HUVEC) proliferation and HUVEC adhering to immobilized agglucetin showed extensive spreading, which was strongly abrogated by integrin antagonists 7E3 and triflavin. Flow cytometric analyses confirmed the expression of GPIb complex on HUVEC is absent and fluorescein isothiocyanate (FITC)-agglucetin binds to HUVEC in a dose-dependent and saturable manner. Furthermore, native agglucetin specifically and dose-dependently inhibited the binding of FITC-23C6, an anti-{alpha}v{beta}3 monoclonal antibody (mAb), but not antibodies against {alpha}2 and {alpha}5, toward HUVEC and purified {alpha}v{beta}3 also bound to immobilizedmore » agglucetin-{beta} in a dose-dependent manner. Moreover, agglucetin exhibited a pro-angiogenic effect in vitro, as well as the focal adhesion kinase (FAK)-associated signaling molecules responsible for HUVEC activation were initiated by agglucetin. In conclusion, agglucetin, acting as a survival factor, promotes endothelial adhesion and angiogenesis by triggering {alpha}v{beta}3 signaling through FAK/phosphatidylinositol 3-kinase (PI3K)/Akt pathway.« less

Polyhydroxy steroids and saponins from China Sea starfish Asterina pectinifera and their biological activities.

PubMed

Peng, Yan; Zheng, Jianxian; Huang, Riming; Wang, Yifei; Xu, Tunhai; Zhou, Xuefeng; Liu, Qiuying; Zeng, Fanli; Ju, Huaiqiang; Yang, Xianwen; Liu, Yonghong

2010-06-01

A new polyhydroxy sterol ester, (25S)-5alpha-cholestane-3beta,6alpha,7alpha,8,15alpha,16beta-hexahydroxyl-26-O-14'Z-eicosenoate (1), together with seven known steroid derivatives (2-8), were isolated from the EtOH extract of the whole body of China Sea starfish Asterina pectinifera. The structure of 1 was determined by using extensive spectra analysis (IR, 1D and 2D NMR, and MS), chemical degradation, and comparison with the known compound (25S)-5alpha-cholestane-3beta,6alpha,7alpha,8,15alpha,16beta,26-heptol (2). All the isolates were evaluated for their antiviral activity against herpes simplex virus type 1 (HSV-1) and their cytotoxicity against human liver carcinoma HepG2 cell line in vitro. Compounds 3-6, and 8 exhibited antiviral activity against HSV-1 virus with the minimal inhibitory concentration (MIC) values of 0.2, 0.05, 0.2, 0.22, and 0.07 microM, respectively. While compounds 4 and 5 exhibited cytotoxicity against HepG2 cells with IC(50) values of 0.2 and 1.6 microM, respectively.

Revisiting the liver in human yellow fever: virus-induced apoptosis in hepatocytes associated with TGF-beta, TNF-alpha and NK cells activity.

PubMed

Quaresma, Juarez A S; Barros, Vera L R S; Pagliari, Carla; Fernandes, Elaine R; Guedes, Fernanda; Takakura, Cleusa F H; Andrade, Heitor F; Vasconcelos, Pedro F C; Duarte, Maria I S

2006-02-05

Flavivirus infection as dengue and yellow fever persists as a terrible menace to pandemics, due to Aedes prevalence in the Americas. Yellow fever is characterized by hepatocyte damage, with steatosis, apoptosis and necrosis, mainly in the midzonal region of the liver, but the injury mechanism has not been studied at the light of recent knowledge, such as the advances in cell death mechanisms, inflammatory response and cytokine cell expression tools. We studied 53 human liver paraffin embedded blocks from patients who died with yellow fever, all with histological demonstration of higher prevalence of apoptosis over necrosis and mild disproportionate inflammatory response. Viral antigens were found most frequently in hepatocytes from the midzonal area than other lobule areas, as detected by specific immunohistochemistry. Infiltrating cell subpopulations showed mainly CD4+ T lymphocytes, with small numbers of CD8+ cytotoxic lymphocytes, CD20+ B lymphocytes, NKT+ cells and S100+ dendritic cells in the sites of inflammation, as compared to normal and leptospirosis liver blocks. Some cells expressed TNF-alpha and IFN-gamma, but a much more intense proportion of TGF-beta expressing cells were found, suggesting both a Th1 and Th3 patterns of immune response in yellow fever. Most affected hepatocyte presented apoptosis markers that appear at the cell death main pathway in this infection. Viral antigens, which production could interfere in hepatocyte biology, could induce the activation of apoptosis cascade, but TGF-beta was also an apoptosis promoter. Our finding supports the key effect of the yellow fever virus in hepatocyte injury, resulting in prevalence of apoptosis over necrosis, aside from a TGF-beta action induced by the inflammatory response.

Cytokine gene expression in skin of susceptible guinea-pig infected with Treponema pallidum.

PubMed Central

Wicher, V; Scarozza, A M; Ramsingh, A I; Wicher, K

1998-01-01

Using a semi-quantitative multiplex reverse transcription-polymerase chain reaction assay, we examined cytokine mRNA expression for interleukin-1alpha (IL-1alpha), IL-2, IL-10, IL-12p40, tumour necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta (TGF-beta) in skin samples obtained from C4-deficient (C4D) guinea-pigs inoculated intradermally with virulent Treponema pallidum (VTP). Controls included unmanipulated animals, guinea-pigs injected with T. pallidum-free rabbit inflammatory testicular fluid (ITF) alone, or mixed with heat-killed organisms (HKTP). The expression of IL-1alpha, IL-12p40, and TNF-alpha mRNA [T helper type 1 (Th1)] remained within the normal range in both infected and control animals throughout the experimental period. However, a significant increase (P<0.05) in IL-10 mRNA (Th2) was found exclusively in the VTP-inoculated animals from 3 to 30 days post-infection. Another unique characteristic of the inflammatory response in infected guinea-pigs was the appearance, between 11 and 30 days post-inoculation, of a substantial number of eosinophils in addition to infiltrating mononuclear cells. The results showed a local Th2 response which is consistent with an inadequate immune response. This is reflected by the lengthy and incomplete clearance of the pathogen from the local site of entry and the chronic infection of distant organs. Images Figure 1 Figure 4 PMID:9824482

All-trans beta-carotene enhances mitogenic responses and ornithine decarboxylase activity of BALB/c 3T3 fibroblast cells induced by tumor promoter and fetal bovine serum but suppresses mutagen-dependent umu C gene expression in Salmonella typhimurium (TA 1535/pSK 1002).

PubMed

Okai, Y; Higashi-Okai, K; Yano, Y; Otani, S

1996-01-19

Although previous epidemiological studies have indicated that beta-carotene is an important agent for the chemical prevention against carcinogenesis, a recent prospective study has strikingly suggested that supplementation with beta-carotene significantly increased the incidence of some types of cancer (The alpha-Tocopherol and beta-Carotene Cancer Prevention Study Group, New Engl. J. Med., 330 (1994) 1031-1035). To analyze the discrepancy of this problem, the authors analyze the effects of beta-carotene on biochemical and biological events associated with carcinogenesis by in vitro experiments. (1) All-trans beta-carotene enhanced the proliferation and DNA synthesis of BALB/c 3T3 cells induced by a tumor promoter, 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and fetal bovine serum, although beta-carotene itself did not show mitogenic activity. (2) All-trans beta-carotene caused a remarkable stimulation for the early induction of ornithine decarboxylase (ODC) activity after the stimulation of TPA and fetal bovine serum. (3) All-trans beta-carotene exhibited significant antimutagenic activity which suppresses umu C gene expression in Salmonella typhimurium (TA 1535/pSK 1002) induced by a typical mutagen, 2-aminoanthracene (2-AA). These experimental results suggest that all-trans beta-carotene might cause beneficial and harmful effects on different phases of carcinogenesis.

Extrinsic factors regulate partial agonist efficacy of strychnine-sensitive glycine receptors

PubMed Central

Farroni, Jeffrey S; McCool, Brian A

2004-01-01

Background Strychnine-sensitive glycine receptors in many adult forebrain regions consist of alpha2 + beta heteromeric channels. This subunit composition is distinct from the alpha1 + beta channels found throughout the adult spinal cord. Unfortunately, the pharmacology of forebrain alpha2beta receptors are poorly defined compared to 'neonatal' alpha2 homomeric channels or 'spinal' alpha1beta heteromers. In addition, the pharmacologic properties of native alpha2beta glycine receptors have been generally distinct from receptors produced by heterologous expression. To identify subtype-specific pharmacologic tools for the forebrain alpha2beta receptors, it is important to identify a heterologous expression system that closely resembles these native glycine-gated chloride channels. Results While exploring pharmacological properties of alpha2beta glycine receptors compared to alpha2-homomers, we found that distinct heterologous expression systems appeared to differentially influence partial agonist pharmacology. The β-amino acid taurine possessed 30–50% efficacy for alpha2-containing receptor isoforms when expressed in HEK 293 cells. However, taurine efficacy was dramatically reduced in L-cell fibroblasts. Similar results were obtained for β-alanine. The efficacy of these partial agonists was also strongly reduced by the beta subunit. There were no significant differences in apparent strychnine affinity values calculated from concentration-response data between expression systems or subunit combinations. Nor did relative levels of expression correlate with partial agonist efficacy when compared within or between several different expression systems. Finally, disruption of the tubulin cytoskeleton reduced the efficacy of partial agonists in a subunit-dependent, but system-independent, fashion. Conclusions Our results suggest that different heterologous expression systems can dramatically influence the agonist pharmacology of strychnine-sensitive glycine receptors. In the systems examine here, these effects are independent of both absolute expression level and any system-related alterations in the agonist binding site. We conclude that complex interactions between receptor composition and extrinsic factors may play a significant role in determining strychnine-sensitive glycine receptor partial agonist pharmacology. PMID:15301692

Effect of heat treatment and enzymatic digestion on the B cell epitopes of cow's milk proteins.

PubMed

Morisawa, Y; Kitamura, A; Ujihara, T; Zushi, N; Kuzume, K; Shimanouchi, Y; Tamura, S; Wakiguchi, H; Saito, H; Matsumoto, K

2009-06-01

Processing milk leads to changes in clinical allergenicity. However, the mechanism by which heat treatment affects the allergenicity of milk proteins is not fully understood. We investigated the effect of heat treatment and enzymatic digestion on the allergenicity of B cell epitopes of milk proteins using a histamine release assay. Human basophils were passively sensitized using sera from 10 patients with allergies to cow's milk. All the patients experienced symptoms immediately after ingesting milk. The human basophils were obtained from umbilical cord blood mononuclear cells after culturing the mononuclear cells for 3-4 weeks in the presence of IL-3. After sensitization with 10% patient sera for 48 h, the cells were stimulated with untreated, heat-treated, or heat-treated and pepsin-and-trypsin-digested beta-lactoglobulin or alpha-casein for 1 h. The histamine concentrations in the supernatants were then measured by radioimmunoassay. Heat treatment alone did not alter the molecular weight of beta-lactoglobulin or alpha-casein. Heat treatment of beta-lactoglobulin significantly increased its susceptibility to enzymatic digestion in a time- and temperature-dependent manner and reduced its ability to induce histamine release from sensitized basophils. Similar findings were not observed for alpha-casein. The combination of heat treatment and enzymatic digestion reduced the abilities of both beta-lactoglobulin and alpha-casein to induce histamine release from passively sensitized basophils. Heat treatment reduced the allergenicity of beta-lactoglobulin by inducing conformational changes and by increasing its susceptibility to enzymatic digestion, both of which disrupted B cell epitopes, whereas heat treatment alone did not alter the allergenicity of alpha-casein.

The effects of interferon-alpha/beta in a model of rat heart transplantation

NASA Technical Reports Server (NTRS)

Slater, A. D.; Klein, J. B.; Sonnenfeld, G.; Ogden, L. L. 2nd; Gray, L. A. Jr

1992-01-01

Interferons have multiple immunologic effects. One such effect is the activation of expression of cell surface antigens. Interferon alpha/beta enhance expression of class I but not class II histocompatibility antigens. Contradictory information has been published regarding the effect of interferon-alpha/beta administration in patients with kidney transplantation. In a model of rat heart transplantation we demonstrated that administration of interferon-alpha/beta accelerated rejection in a dose-dependent fashion in the absence of maintenance cyclosporine. Animals treated with maintenance cyclosporine had evidence of increased rejection at 20 days that was resolved completely at 45 days with cyclosporine alone.

The specificity of induction of alpha-galactosidase from Saccharomyces carlsbergensis.

PubMed

Flórez, I G; Lazo, P S; Ochoa, A G; Gascón, S

1981-04-17

A number of sugars and derivatives have been tested for their ability to induce the synthesis of alpha-galactosidase from Saccharomyces carlsbergensis. Besides galactose and the substrates of the enzyme melibiose, raffinose and stachyose, D-galacturonic acid, L-arabinose, D-tagatose, methyl-alpha-D-galactoside, lactose and isopropyl-beta-D-thiogalactoside were able to act as inducers. Of these, methyl-alpha-D-galactoside, lactose, isopropyl-beta-D-thiogalactoside and L-arabinose have been shown to be gratuitous inducers with which kinetic studies of induction have been carried out. Lactose was the most efficient inducer, giving a maximal differential rate of synthesis of the enzyme of 110 mU/10(7) cells at a concentration of 180 mM, followed by L-arabinose (60 mU/10(7) cells at 40 mM), isopropyl-beta-D-thiogalactoside (43 mU/10(7) cells at 60 mM) and methyl-alpha-D-galactoside (25 mU/10(7) cells at 150 mM). The concentration of inducer required to obtain half-maximal induction was similar for lactose, L-arabinose and isopropyl-beta-D-thiogalactoside and about 5-fold higher for methyl-alpha-D-galactoside. The property of the compounds to act as inducers was compared to their ability to interact with the enzyme and the results discussed in terms of the molecular structures which are recognized by the enzyme and by the induction machinery.

Absence of Fc epsilonRI alpha chain results in upregulation of Fc gammaRIII-dependent mast cell degranulation and anaphylaxis. Evidence of competition between Fc epsilonRI and Fc gammaRIII for limiting amounts of FcR beta and gamma chains.

PubMed Central

Dombrowicz, D; Flamand, V; Miyajima, I; Ravetch, J V; Galli, S J; Kinet, J P

1997-01-01

In mouse mast cells, both Fc epsilonRI and Fc gammaRIII are alpha beta gamma2 tetrameric complexes in which different alpha chains confer IgE or IgG ligand recognition while the signaling FcR beta and gamma chains are identical. We used primarily noninvasive techniques (changes in body temperature, dye extravasation) to assess systemic anaphylactic responses in nonanesthetized wild-type, Fc epsilonRI alpha chain -/- and FcR gamma chain -/- mice. We confirm that systemic anaphylaxis in mice can be mediated largely through IgG1 and Fc gammaRIII and we provide direct evidence that these responses reflect activation of Fc gammaRIII rather than Fc gammaRI. Furthermore, we show that Fc gammaRIII-dependent responses are more intense in normal than in congenic mast cell-deficient KitW/KitW-v mice, indicating that Fc gammaRIII responses have mast cell-dependent and -independent components. Finally, we demonstrate that the upregulation of cell surface expression of Fc gammaRIII seen in Fc epsilonRI alpha chain -/- mice corresponds to an increased association of Fc gammaRIII alpha chains with FcR beta and gamma chains and is associated with enhanced Fc gammaRIII-dependent mast cell degranulation and systemic anaphylactic responses. Therefore, the phenotype of the Fc epsilonRI alpha chain -/- mice suggests that expression of Fc epsilonRI and Fc gammaRIII is limited by availability of the FcR beta and gamma chains and that, in normal mice, changes in the expression of one receptor (Fc epsilonRI) may influence the expression of functional responses dependent on the other (Fc gammaRIII). PMID:9062349

Analysis of thyroid hormone receptor {beta}A mRNA expression in Xenopus laevis tadpoles as a means to detect agonism and antagonism of thyroid hormone action

DOE Office of Scientific and Technical Information (OSTI.GOV)

Opitz, Robert; Lutz, Ilka; Nguyen, Ngoc-Ha

2006-04-01

Amphibian metamorphosis represents a unique biological model to study thyroid hormone (TH) action in vivo. In this study, we examined the utility of thyroid hormone receptors {alpha} (TR{alpha}) and {beta}A (TR{beta}A) mRNA expression patterns in Xenopus laevis tadpoles as molecular markers indicating modulation of TH action. During spontaneous metamorphosis, only moderate changes were evident for TR{alpha} gene expression whereas a marked up-regulation of TR{beta}A mRNA occurred in hind limbs (prometamorphosis), head (late prometamorphosis), and tail tissue (metamorphic climax). Treatment of premetamorphic tadpoles with 1 nM 3,5,3'-triiodothyronine (T3) caused a rapid induction of TR{beta}A mRNA in head and tail tissue withinmore » 6 to 12 h which was maintained for at least 72 h after initiation of T3 treatment. Developmental stage had a strong influence on the responsiveness of tadpole tissues to induce TR{beta}A mRNA during 24 h treatment with thyroxine (0, 1, 5, 10 nM T4) or T3 (0, 1, 5, 10 nM). Premetamorphic tadpoles were highly sensitive in their response to T4 and T3 treatments, whereas sensitivity to TH was decreased in early prometamorphic tadpoles and strongly diminished in late prometamorphic tadpoles. To examine the utility of TR{beta}A gene expression analysis for detection of agonistic and antagonistic effects on T3 action, mRNA expression was assessed in premetamorphic tadpoles after 48 h of treatment with the synthetic agonist GC-1 (0, 10, 50, 250 nM), the synthetic antagonist NH-3 (0, 40, 200, 1000 nM), and binary combinations of NH-3 (0, 40, 200, 1000 nM) and T3 (1 nM). All tested concentrations of GC-1 as well as the highest concentration of NH-3 caused an up-regulation of TR{beta}A expression. Co-treatment with NH-3 and T3 revealed strong antagonistic effects by NH-3 on T3-induced TR{beta}A mRNA up-regulation. Results of this study suggest that TR{beta}A mRNA expression analysis could serve as a sensitive molecular testing approach to study effects of environmental compounds on the thyroid system in X. laevis tadpoles.« less

A Novel Di-Leucine Motif at the N-Terminus of Human Organic Solute Transporter Beta Is Essential for Protein Association and Membrane Localization.

PubMed

Xu, Shuhua; Soroka, Carol J; Sun, An-Qiang; Backos, Donald S; Mennone, Albert; Suchy, Frederick J; Boyer, James L

2016-01-01

The heteromeric membrane protein Organic Solute Transporter alpha/beta is the major bile acid efflux transporter in the intestine. Physical association of its alpha and beta subunits is essential for their polarized basolateral membrane localization and function in the transport of bile acids and other organic solutes. We identified a highly conserved acidic dileucine motif (-EL20L21EE) at the extracellular amino-tail of organic solute transporter beta from multiple species. To characterize the role of this protein interacting domain in the association of the human beta and alpha subunits and in membrane localization of the transporter, Leu20 and Leu21 on the amino-tail of human organic solute transporter beta were replaced with alanines by site-directed mutagenesis. Co-immunoprecipitation study in HEK293 cells demonstrated that substitution of the leucine residues with alanines prevented the interaction of the human beta mutant with the alpha subunit. Membrane biotinylation demonstrated that the LL/AA mutant eliminated membrane expression of both subunits. Computational-based modelling of human organic solute transporter beta suggested that the LL/AA mutation substantially alters both the structure and lipophilicity of the surface, thereby not only affecting the interaction with the alpha subunit but also possibly impacting the capacity of the beta subunit to traffick through the cell and interact with the membrane. In summary, our findings indicate that the dileucine motif in the extracellular N-terminal region of human organic solute transporter beta subunit plays a critical role in the association with the alpha subunit and in its polarized plasma membrane localization.

High beta-palmitate fat controls the intestinal inflammatory response and limits intestinal damage in mucin Muc2 deficient mice.

PubMed

Lu, Peng; Bar-Yoseph, Fabiana; Levi, Liora; Lifshitz, Yael; Witte-Bouma, Janneke; de Bruijn, Adrianus C J M; Korteland-van Male, Anita M; van Goudoever, Johannes B; Renes, Ingrid B

2013-01-01

Palmitic-acid esterified to the sn-1,3 positions of the glycerol backbone (alpha, alpha'-palmitate), the predominant palmitate conformation in regular infant formula fat, is poorly absorbed and might cause abdominal discomfort. In contrast, palmitic-acid esterified to the sn-2 position (beta-palmitate), the main palmitate conformation in human milk fat, is well absorbed. The aim of the present study was to examine the influence of high alpha, alpha'-palmitate fat (HAPF) diet and high beta-palmitate fat (HBPF) diet on colitis development in Muc2 deficient (Muc2(-/-)) mice, a well-described animal model for spontaneous enterocolitis due to the lack of a protective mucus layer. Muc2(-/-) mice received AIN-93G reference diet, HAPF diet or HBPF diet for 5 weeks after weaning. Clinical symptoms, intestinal morphology and inflammation in the distal colon were analyzed. Both HBPF diet and AIN-93G diet limited the extent of intestinal erosions and morphological damage in Muc2(-/-) mice compared with HAPF diet. In addition, the immunosuppressive regulatory T (Treg) cell response as demonstrated by the up-regulation of Foxp3, Tgfb1 and Ebi3 gene expression levels was enhanced by HBPF diet compared with AIN-93G and HAPF diets. HBPF diet also increased the gene expression of Pparg and enzymatic antioxidants (Sod1, Sod3 and Gpx1), genes all reported to be involved in promoting an immunosuppressive Treg cell response and to protect against colitis. This study shows for the first time that HBPF diet limits the intestinal mucosal damage and controls the inflammatory response in Muc2(-/-) mice by inducing an immunosuppressive Treg cell response.

Integrin expression by human osteoblasts cultured on degradable polymeric materials applicable for tissue engineered bone.

PubMed

El-Amin, Saadiq F; Attawia, Mohamed; Lu, Helen H; Shah, Asist K; Chang, Richard; Hickok, Noreen J; Tuan, Rocky S; Laurencin, Cato T

2002-01-01

The use of biodegradable polymers in the field of orthopaedic surgery has gained increased popularity, as surgical pins and screws, and as potential biological scaffolds for repairing cartilage and bone defects. One such group of polymers that has gained considerable attention are the polyesters, poly(lactide-co-glycolide) (PLAGA) and polylactic acid (PLA), because of their minimal tissue inflammatory response, favorable biocompatibility and degradation characteristics. The objective of this study was to evaluate human osteoblastic cell adherence and growth on PLAGA and PLA scaffolds by examining integrin receptor (alpha2, alpha3, alpha4, alpha5, alpha6 and beta1) expression. Primary human osteoblastic cells isolated from trabecular bone adhered efficiently to both PLAGA and PLA, with the rate of adherence on PLAGA comparable to that of control tissue culture polystyrene (TCPS), and significantly higher than on PLA polymers at 3, 6 and 12 h. Human osteoblastic phenotypic expression, alkaline phosphatase (ALP) activity was positive on both degradable matrices, whereas osteocalcin levels were significantly higher on cells grown on PLAGA than on PLA composites. Interestingly, the integrin subunits, alpha2, alpha3, alpha4, alpha5, alpha6 and beta1 were all expressed at higher levels by osteoblasts cultured on PLAGA than those on PLA as analyzed by westerns blots and by flow cytometry. Among the integrins, alpha2, beta5 and beta1 showed the greatest difference in levels between the two surfaces. Thus, both PLA and PLAGA support osteoblastic adhesion and its accompanying engagement of integrin receptor and expression of osteocalcin and ALP. However PLAGA consistently appeared to be a better substrate for osteoblastic cells based on these parameters. This study is one of the first to investigate the ability of primary human osteoblastic cells isolated from trabecular bone to adhere to the biodegradable polymers PLAGA and PLA, and to examine the expression of their key adhesion receptors (integrins) on these substrates.

Functional analysis of alpha5beta1 integrin and lipid rafts in invasion of epithelial cells by Porphyromonas gingivalis using fluorescent beads coated with bacterial membrane vesicles.

PubMed

Tsuda, Kayoko; Furuta, Nobumichi; Inaba, Hiroaki; Kawai, Shinji; Hanada, Kentaro; Yoshimori, Tamotsu; Amano, Atsuo

2008-01-01

Porphyromonas gingivalis, a periodontal pathogen, was previously suggested to exploit alpha5beta1 integrin and lipid rafts to invade host cells. However, it is unknown if the functional roles of these host components are distinct from one another during bacterial invasion. In the present study, we analyzed the mechanisms underlying P. gingivalis invasion, using fluorescent beads coated with bacterial membrane vesicles (MV beads). Cholesterol depletion reagents including methyl-beta-cyclodextrin (MbetaCD) drastically inhibited the entry of MV beads into epithelial cells, while they were less effective on bead adhesion to the cells. Bead entry was also abolished in CHO cells deficient in sphingolipids, components of lipid rafts, whereas adhesion was negligibly influenced. Following MbetaCD treatment, downstream events leading to actin polymerization were abolished; however, alpha5beta1 integrin was recruited to beads attached to the cell surface. Dominant-negative Rho GTPase Rac1 abolished cellular engulfment of the beads, whereas dominant-negative Cdc42 did not. Following cellular interaction with the beads, Rac1 was found to be translocated to the lipid rafts fraction, which was inhibited by MbetaCD. These results suggest that alpha5beta1 integrin, independent of lipid rafts, promotes P. gingivalis adhesion to epithelial cells, while the subsequent uptake process requires lipid raft components for actin organization, with Rho GTPase Rac1.

Characterization of the mucosal cell-mediated immune response in IL-2 knockout mice before and after the onset of colitis.

PubMed Central

McDonald, S A; Palmen, M J; Van Rees, E P; MacDonald, T T

1997-01-01

One of the major advances in the understanding of inflammatory bowel disease has been the observation that mice with immunoregulatory defects, such as interleukin-2 knockout (IL-2 -/-) mice, develop spontaneous gut inflammation. Here we have characterized the immune response in the ileum, caecum and colon of these mice before and after the onset of colitis by examining the cellular infiltrate, the cytokines produced by these cells and the mucosal vascular addressin MAdCAM-1. IL-2 -/- mice developed colitis after 35 days of age and before this the mice were apparently healthy. IL-2 -/- mice aged over 35 days with colitis had large numbers of CD4+, CD8+, alpha beta T-cell receptor (TCR)+ and gamma delta TCR+ T cells, macrophages, dendritic cells and MAdCAM-1+ endothelial cells in the caecum and colon. This was associated with an increase in the number of interferon-gamma (IFN-gamma), IL-1 and tumour necrosis factor-alpha (TNF-alpha) transcripts and a decrease in IL-4 and IL-10 transcripts. Treatment of IL-2 -/- mice with cyclosporin A significantly delayed mortality. Interestingly, IL-2 -/- mice under 35 days, although healthy, did show some subtle immunological signs of preclinical disease. There was a significant increase in the number of macrophages and dendritic cells in the colonic lamina propria and increased mRNA for IL-1 and TNF-alpha. There were also increased numbers of MAdCAM-1+ endothelial cells, but IFN-gamma transcripts were not elevated. These results suggest that T-cell-mediated colitis in IL-2 -/- mice may be secondary to an initial non-specific inflammation. Images Figure 2 Figure 5 PMID:9203968

Curcumin attenuates inflammatory response in IL-1beta-induced human synovial fibroblasts and collagen-induced arthritis in mouse model.

PubMed

Moon, Dong-Oh; Kim, Mun-Ok; Choi, Yung Hyun; Park, Yung-Min; Kim, Gi-Young

2010-05-01

Curcumin, a major component of turmeric, has been shown to exhibit anti-oxidant and anti-inflammatory activities. The present study was performed to determine whether curcumin is efficacious against both collagen-induced arthritis (CIA) in mice and IL-1beta-induced activation in fibroblast-like synoviocytes (FLSs). DBA/1 mice were immunized with bovine type II collagen (CII) and treated with curcumin every other day for 2weeks after the initial immunization. For arthritis, we evaluated the incidence of disease and used an arthritis index based on paw thickness. In vitro proliferation of CII- or concanavalin A-induced splenic T cells was examined using IFN-gamma production. Pro-inflammatory cytokines TNF-alpha and IL-1beta were examined in the mouse ankle joint and serum IgG1 and IgG2a isotypes were analyzed. The expression levels of prostaglandin E(2) (PGE(2)), cyclooxygenase-2 (COX-2), and matrix metalloproteinases (MMPs) in human FLSs were also determined. The results showed that compared with untreated CIA mice, curcumin-treated mice downregulated clinical arthritis score, the proliferation of splenic T cells, expression levels of TNF-alpha and IL-1beta in the ankle joint, and expression levels of IgG2a in serum. Additionally, by altering nuclear factor (NF)-kappaB transcription activity in FLSs, curcumin inhibited PGE(2) production, COX-2 expression, and MMP secretion. These results suggest that curcumin can effectively suppress inflammatory response by inhibiting pro-inflammatory mediators and regulating humoral and cellular immune responses. Copyright 2010 Elsevier B.V. All rights reserved.

Molecular characterization of variant alpha-subunit of electron transfer flavoprotein in three patients with glutaric acidemia type II--and identification of glycine substitution for valine-157 in the sequence of the precursor, producing an unstable mature protein in a patient.

PubMed Central

Indo, Y; Glassberg, R; Yokota, I; Tanaka, K

1991-01-01

In our previous study of eight glutaric acidemia type II (GAII) fibroblast lines by using [35S]methionine labeling and immunoprecipitation, three of them had a defect in the synthesis of the alpha-subunit of electron transfer flavoprotein (alpha-ETF) (Ikeda et al. 1986). In one of them (YH1313) the labeling of the mature alpha-ETF was barely detectable, while that of the precursor (p) was stronger. In another (YH605) no synthesis of immunoreactive p alpha-ETF was detectable. In the third cell line (YH1391) the rate of variant p alpha-ETF synthesis was comparable to normal, but its electrophoretic mobility was slightly faster than normal. In the present study, the northern blot analysis revealed that all three mutant cell lines contained p alpha-ETF mRNA and that their size and amount were comparable to normal. In immunoblot analysis, both alpha- and beta-ETF bands were barely detectable in YH1313 and YH605 but were detectable in YH1391 in amounts comparable to normal. Sequencing of YH1313 p alpha-ETF cDNA via PCR identified a transversion of T-470 to G. We then devised a simple PCR method for the 119-bp section (T-443/G-561) for detecting this mutation. In the upstream primer, A-466 was artificially replaced with C, to introduce a BstNI site into the amplified copies in the presence of G-470 from the variant sequence. The genomic DNA analysis using this method demonstrated that YH1313 was homozygous for T----G-470 transversion. It was not detected either in two other alpha-ETF-deficient GAII or in seven control cell lines. The alpha-ETF cDNA sequence in YH605 was identical to normal. Images Figure 1 Figure 2 Figure 3 Figure 5 PMID:1882842

Suppression of tumorigenicity by plakoglobin: an augmenting effect of N-cadherin.

PubMed

Simcha, I; Geiger, B; Yehuda-Levenberg, S; Salomon, D; Ben-Ze'ev, A

1996-04-01

Plakoglobin is a major component of the submembranal plaque of adherens junctions and desmosomes in mammalian cells. It is closely related to the Drosophila segment polarity gene armadillo which has a role in the transduction of transmembrane signals that regulate cell fate. Like its close homologue beta-catenin, plakoglobin can associate with the product of the tumor suppressor gene APC that is linked to human colon cancer. We have studied the effect of plakoglobin overexpression, and the cooperation between plakoglobin and N-cadherin, on the morphology and tumorigenic ability of cells either lacking, or expressing cadherin and alpha- and beta-catenin. Overexpression of plakoglobin in SV40-transformed 3T3 (SVT2) cells suppressed the tumorigenicity of the cells in syngeneic mice. Transfection with N-cadherin conferred an epithelial phenotype on the cell culture, but had no significant effect on the tumorigenicity of the cells. Cotransfection of plakoglobin and N-cadherin into SVT2 cells, however, was considerably more effective in tumor suppression than plakoglobin overexpression alone. Finally, transfection of plakoglobin into a human renal carcinoma cell line that expresses neither cadherins nor plakoglobin, or alpha-and beta-catenin, resulted in a dose-dependent suppression of tumor formation by these cells in nude mice. Plakoglobin, in these cells, did not exhibit junctional localization and was diffusely distributed in the cytoplasm, with a significant amount of the protein also localized in the nucleus. The results suggest that plakoglobin can efficiently suppress the tumorigenicity of cells in the presence of, or independently of the cadherin-catenin complex.

Effect of proinflammatory cytokines on PIGA- hematopoiesis.

PubMed

Kulkarni, Shashikant; Bessler, Monica

2003-09-01

Blood cells from patients with paroxysmal nocturnal hemoglobinuria lack glycosyl phosphatidylinositol (GPI)-linked proteins, due to a somatic mutation in the X-linked PIGA gene. It is believed that clonal expansion of PIGA- blood cells is due to a survival advantage in the hostile marrow environment of aplastic anemia. Here we investigated the effects of inhibitory cytokines in mice genetically engineered to have blood cells deficient in GPI-linked proteins. The effect of inhibitory cytokines (tumor necrosis factor-alpha [TNF-alpha], interferon-gamma [IFN-gamma], macrophage inflammatory protein-1 alpha [MIP-1alpha], and transforming growth factor-beta1 [TGF-beta1]) was investigated, using clonogenic assays, competitive repopulation, and in vivo induction of proinflammatory cytokines by double-stranded RNA. The expression of Fas on progenitor cells and its up-regulation by inhibitory cytokines were analyzed by flow cytometry. TNF-alpha, IFN-gamma, MIP-1alpha, and TGF-beta1 suppressed colony formation in a dose-dependent fashion that was similar for PIGA+ and PIGA- blood bone marrow cells. Competitive repopulation of bone marrow cells cultured in IFN-gamma and TNF-alpha resulted in a comparable ability of PIGA+ and PIGA- hematopoietic stem cells to reconstitute hematopoiesis. Fas expression was minimal on PIGA+ and PIGA- progenitor cells and was up-regulated to the same extent in response to IFN-gamma and TNF-alpha as assessed by Fas antibody-mediated apoptosis. Similarly, in vivo induction of proinflammatory cytokines by double-stranded RNA had no effect on the proportion of circulating PIGA- blood cells. These results indicate that PIGA+ and PIGA- hematopoietic progenitor cells respond similarly to inhibitory cytokines, suggesting that other factors are responsible for the clonal expansion of paroxysmal nocturnal hemoglobinuria cells.

Translation and assembly of HLA-DR antigens in Xenopus oocytes injected with mRNA from a human B-cell line.

PubMed Central

Long, E O; Gross, N; Wake, C T; Mach, J P; Carrel, S; Accolla, R; Mach, B

1982-01-01

HLA-DR antigens are polymorphic cell surface glycoproteins, expressed primarily in B lymphocytes and macrophages, which are thought to play an important role in the immune response. Two polypeptide chains, alpha and beta, are associated at the cell surface, and a third chain associates with alpha and beta intracellularly. RNA isolated from the human B-cell line Raji was injected in Xenopus laevis oocytes. Immunoprecipitates of translation products with several monoclonal antibodies revealed the presence of HLA-DR antigens similar to those synthesized in Raji cells. One monoclonal antibody was able to bind the beta chain after dissociation of the three polypeptide chains with detergent. The presence of all three chains was confirmed by two-dimensional gel electrophoresis. The glycosylation pattern of the three chains was identical to that observed in vivo, as evidenced in studies using tunicamycin, an inhibitor of N-linked glycosylation. The presence of alpha chains assembled with beta chains in equimolar ratio was further demonstrated by amino-terminal sequencing. An RNA fraction enriched for the three mRNAs, encoding alpha, beta, and intracellular chains, was isolated. This translation-assembly system and the availability of monoclonal antibodies make it possible to assay for mRNA encoding specific molecules among the multiple human Ia-like antigens. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. PMID:6821356

[Application of the polymerase chain reaction (PCR) in the diagnosis of Hb S-beta(+)-thalassemia].

PubMed

Harano, K; Harano, T; Kushida, Y; Ueda, S

1991-08-01

Isoelectric focusing of the hemolysate prepared from a two-year-old American black boy with microcytic hypochromia showed the presence of a high percentage (63.3%) of such Hb variant as Hb S, while the levels of Hb A, Hb F and Hb A2 were 20.0%, 12.7%, and 4.0%, respectively. The ratio of the non-alpha-chain to the alpha-chain of the biosynthesized globin chains was 0.49. The variant was identified as Hb S by amino acid analysis of the abnormal peptide (beta T-1) and digestion of DNA amplified by the polymerase chain reaction with enzyme Eco 81 I. This was further confirmed by DNA sequencing. DNA sequencing of a beta-gene without the beta s-mutation revealed a nucleotide change of T to C in the polyadenylation signal sequence AATAAA 3' to the beta-gene, resulting in beta(+)-thalassemia. These results are consistent with the existence of a beta s-gene and a beta(+)-thalassemia gene in trans.

Involvement of granulysin-producing T cells in the development of superficial microbial folliculitis.

PubMed

Oono, T; Morizane, S; Yamasaki, O; Shirafuji, Y; Huh, W-K; Akiyama, H; Iwatsuki, K

2004-05-01

Granulysin is a recently identified antimicrobial protein expressed on cytotoxic T cells, natural killer (NK) cells and NKT cells. It has been shown that granulysin contributes to the defence mechanisms against mycobacterial infection. Superficial microbial folliculitis is a common skin disease. In a previous report, we showed that, as a first line of defence, alpha-defensin, a human neutrophil peptide, and beta-defensin (human beta-defensin-2) were expressed in infiltrating neutrophils and in lesional epidermal keratinocytes, respectively, in superficial folliculitis. As we also observed many infiltrating lymphocytes in lesional dermis, we hypothesized that infiltrating lymphocytes may possess antimicrobial substances, such as granulysin, and play a role in the defence mechanism as a second line of defence. Seven specimens of superficial microbial folliculitis diagnosed clinically and histologically were examined by means of immunohistochemistry. To identify the phenotype of cells expressing granulysin, confocal laser microscopic examination was performed. A dense lymphoid cell infiltrate was observed in pustules, in the perivascular regions. A large number of these lymphoid cells were positive for granulysin. Phenotypically, cells consisted of CD3+ T cells, CD8+ T cells and UCHL-1+ T cells. CD20+ cells and CD56+ cells were not observed. Microscopic examination with a confocal laser showed that the lymphocytes producing granulysin were CD3+ and CD4+ T cells but not CD8+ T cells. We showed that many granulysin-bearing T cells infiltrated affected follicles and perilesional dermis in superficial microbial folliculitis. However, few granulysin-positive lymphoid cells were observed in sterile pustular lesions. Our observations indicated that adaptive immunity such as granulysin, a lymphocyte-produced antimicrobial protein, may play an important role in the cutaneous defence mechanism.

Prediction of Treatment Outcome in Patients with Obsessive-Compulsive Disorder with Low-Resolution Brain Electromagnetic Tomography: A Prospective EEG Study.

PubMed

Krause, Daniela; Folkerts, Malte; Karch, Susanne; Keeser, Daniel; Chrobok, Agnieszka I; Zaudig, Michael; Hegerl, Ulrich; Juckel, Georg; Pogarell, Oliver

2015-01-01

The issue of predicting treatment response and identifying, in advance, which patient will profit from treating obsessive-compulsive disorder (OCD) seems to be an elusive goal. This prospective study investigated brain electric activity [using Low-Resolution Brain Electromagnetic Tomography (LORETA)] for the purpose of predicting response to treatment. Forty-one unmedicated patients with a DSM-IV diagnosis of OCD were included. A resting 32-channel EEG was obtained from each participant before and after 10 weeks of standardized treatment with sertraline and behavioral therapy. LORETA was used to localize the sources of brain electrical activity. At week 10, patients were divided into responders and non-responders (according to a reduction of symptom severity >50% on the Y-BOCS). LORETA analysis revealed that at baseline responders showed compared to non-responders a significantly lower brain electric activity within the beta 1 (t = 2.86, p < 0.05), 2 (t = 2.81, p < 0.05), and 3 (t = 2.76, p < 0.05) frequency bands and ROI analysis confirmed a reduced activity in alpha 2 (t = 2.06, p < 0.05) in the anterior cingulate cortex (ACC). When baseline LORETA data were compared to follow-up data, the analysis showed in the responder group a significantly lower brain electrical resting activity in the beta 1 (t = 3.17. p < 0.05) and beta 3 (t = 3.11. p < 0.05) frequency bands and equally for the ROI analysis of the orbitofrontal cortex (OFC) in the alpha 2 (t = 2.15. p < 0.05) frequency band. In the group of non-responders the opposite results were found. In addition, a positive correlation between frequency alpha 2 (rho = 0.40, p = 0.010), beta 3 (rho = 0.42, p = 0.006), delta (rho = 0.33, p = 0.038), theta (rho = 0.34, p = 0.031), alpha 1 (rho = 0.38, p = 0.015), and beta1 (rho = 0.34, p = 0.028) of the OFC and the bands delta (rho = 0.33, p = 0.035), alpha 1 (rho = 0.36, p = 0.019), alpha 2 (rho = 0.34, p = 0.031), and beta 3 (rho = 0.38, p = 0.015) of the ACC with a reduction of the Y-BOCS scores was identified. Our results suggest that measuring brain activity with LORETA could be an efficient and applicable technique to prospectively identify treatment responders in OCD.

Prediction of Treatment Outcome in Patients with Obsessive-Compulsive Disorder with Low-Resolution Brain Electromagnetic Tomography: A Prospective EEG Study

PubMed Central

Krause, Daniela; Folkerts, Malte; Karch, Susanne; Keeser, Daniel; Chrobok, Agnieszka I.; Zaudig, Michael; Hegerl, Ulrich; Juckel, Georg; Pogarell, Oliver

2016-01-01

The issue of predicting treatment response and identifying, in advance, which patient will profit from treating obsessive-compulsive disorder (OCD) seems to be an elusive goal. This prospective study investigated brain electric activity [using Low-Resolution Brain Electromagnetic Tomography (LORETA)] for the purpose of predicting response to treatment. Forty-one unmedicated patients with a DSM-IV diagnosis of OCD were included. A resting 32-channel EEG was obtained from each participant before and after 10 weeks of standardized treatment with sertraline and behavioral therapy. LORETA was used to localize the sources of brain electrical activity. At week 10, patients were divided into responders and non-responders (according to a reduction of symptom severity >50% on the Y-BOCS). LORETA analysis revealed that at baseline responders showed compared to non-responders a significantly lower brain electric activity within the beta 1 (t = 2.86, p < 0.05), 2 (t = 2.81, p < 0.05), and 3 (t = 2.76, p < 0.05) frequency bands and ROI analysis confirmed a reduced activity in alpha 2 (t = 2.06, p < 0.05) in the anterior cingulate cortex (ACC). When baseline LORETA data were compared to follow-up data, the analysis showed in the responder group a significantly lower brain electrical resting activity in the beta 1 (t = 3.17. p < 0.05) and beta 3 (t = 3.11. p < 0.05) frequency bands and equally for the ROI analysis of the orbitofrontal cortex (OFC) in the alpha 2 (t = 2.15. p < 0.05) frequency band. In the group of non-responders the opposite results were found. In addition, a positive correlation between frequency alpha 2 (rho = 0.40, p = 0.010), beta 3 (rho = 0.42, p = 0.006), delta (rho = 0.33, p = 0.038), theta (rho = 0.34, p = 0.031), alpha 1 (rho = 0.38, p = 0.015), and beta1 (rho = 0.34, p = 0.028) of the OFC and the bands delta (rho = 0.33, p = 0.035), alpha 1 (rho = 0.36, p = 0.019), alpha 2 (rho = 0.34, p = 0.031), and beta 3 (rho = 0.38, p = 0.015) of the ACC with a reduction of the Y-BOCS scores was identified. Our results suggest that measuring brain activity with LORETA could be an efficient and applicable technique to prospectively identify treatment responders in OCD. PMID:26834658

As-built design specification for PARHIS

NASA Technical Reports Server (NTRS)

Tompkins, M. A. (Principal Investigator)

1981-01-01

The program is part of the CLASFYG package. It produces histograms of the greeness profile derived parameters alpha, beta, t sub o, and chi squared, which are computed by the CLASFYG program. Alpha is the approximate greeness rise time, beta is the approximate greeness decay time, t sub o is the spectral crop emergence date, and chi squared per degree of freedom is the goodness of fit of the actual data to the computed greeness profile. The program also produces statistical information concerning the parameters.

Calcium mobilization elicited by two types of nicotinic acetylcholine receptors in mouse substantia nigra pars compacta.

PubMed

Tsuneki, H; Klink, R; Léna, C; Korn, H; Changeux, J P

2000-07-01

Nicotinic acetylcholine receptors (nAChRs) are expressed in the midbrain ascending dopaminergic system, a target of many addictive drugs. Here we assessed the intracellular Ca2+ level by imaging fura-2-loaded cells in substantia nigra pars compacta in mouse brain slices, and we examined the influence on this level of prolonged exposures to nicotine using mice lacking the nAChR beta2-subunit. In control cells, superfusion with nicotine (10-100 microM) caused a long-lasting rise of intracellular Ca2+ level which depended on extracellular Ca2+. This nicotinic response was almost completely absent in beta2-/- mutant mice, leaving a small residual response to a high concentration (100 microM) of nicotine which was inhibited by the alpha7-subunit-selective antagonist, methyllycaconitine. Conversely, the alpha7-subunit-selective agonist choline (10 mM) caused a methyllycaconitine-sensitive increase in intracellular Ca2+ level both in wild-type and beta2-/- mutant mice. Nicotine-elicited Ca2+ mobilization was reduced by the Na+ channel blocker tetrodotoxin (TTX) and by T-type Ca2+ channel blocking agents, whereas the choline-elicited Ca2+ increase was insensitive to TTX. Neither nicotine nor choline produced Ca2+ increase following inhibition of the release of Ca2+ from intracellular stores by dantrolene. These results demonstrate that in nigral dopaminergic neurons, nicotine can elicit Ca2+ mobilization via activation of two distinct nAChR subtypes: that of beta2-subunit-containing nAChR followed by activation of Na+ channel and T-type Ca2+ channels, and/or activation of alpha7-subunit-containing nAChR. The Ca2+ influx due to nAChR activation is subsequently amplified by the recruitment of intracellular Ca2+ stores. This Ca2+ mobilization may possibly contribute to the long-term effects of nicotine on the dopaminergic system.

Effects of type I/type II interferons and transforming growth factor-beta on B-cell differentiation and proliferation. Definition of costimulation and cytokine requirements for immunoglobulin synthesis and expression.

PubMed

Estes, D M; Tuo, W; Brown, W C; Goin, J

1998-12-01

In this report, we sought to determine the role of selected type I interferons [interferon-alpha (IFN-alpha) and interferon-tau (IFN-tau)], IFN-gamma and transforming growth factor-beta (TGF-beta) in the regulation of bovine antibody responses. B cells were stimulated via CD40 in the presence or absence of B-cell receptor (BCR) cross-linking. IFN-alpha enhanced IgM, IgG2 and IgA responses but did not enhance IgG1 responses. BCR signalling alone was more effective at inducing IgG2 responses with IFN-alpha than dual cross-linking with CD40. Recombinant ovine IFN-tau was less effective at inducing IgG2 responses when compared with IFN-alpha, though IgA responses were similar in magnitude following BCR cross-linking. At higher concentrations, IFN-tau enhanced IgA responses greater than twofold over the levels observed with IFN-alpha. Previous studies have shown that addition of IFN-gamma to BCR or pokeweed mitogen-activated bovine B cells stimulates IgG2 production. However, following CD40 stimulation alone, IFN-gamma was relatively ineffective at stimulating high-rate synthesis of any non-IgM isotype. Dual cross-linking via CD40 and the BCR resulted in decreased synthesis of IgM with a concomitant increase in IgA and similar levels of IgG2 production to those obtained via the BCR alone. We also assessed the effects of endogenous and exogenous TGF-beta on immunoglobulin synthesis by bovine B cells. Exogenous TGF-beta stimulates both IgG2 and IgA production following CD40 and BCR cross-linking in the presence of IL-2. Blocking endogenous TGF-beta did not inhibit the up-regulation of IgG2 or IgA by interferons.

Involvement of both the V2 and V3 regions of the CCR5-tropic human immunodeficiency virus type 1 envelope in reduced sensitivity to macrophage inflammatory protein 1alpha.

PubMed

Maeda, Y; Foda, M; Matsushita, S; Harada, S

2000-02-01

To determine whether C-C chemokines play an important role in the phenotype switch of human immunodeficiency virus (HIV) from CCR5 to CXCR4 usage during the course of an infection in vivo, macrophage inflammatory protein (MIP)-1alpha-resistant variants were isolated from CCR5-tropic (R5) HIV-1 in vitro. The selected variants displayed reduced sensitivities to MIP-1alpha (fourfold) through CCR5-expressing CD4-HeLa/long terminal repeat-beta-galactosidase (MAGI/CCR5) cells. The variants were also resistant to other natural ligands for CCR5, namely, MIP-1beta (>4-fold) and RANTES (regulated upon activation, normal T-cell expressed and secreted) (6-fold). The env sequence analyses revealed that the variants had amino acid substitutions in V2 (valine 166 to methionine) and V3 (serine 303 to glycine), although the same V3 substitution appeared in virus passaged without MIP-1alpha. A single-round replication assay using a luciferase reporter HIV-1 strain pseudotyped with mutant envelopes confirmed that mutations in both V2 and V3 were necessary to confer the reduced sensitivity to MIP-1alpha, MIP-1beta, and RANTES. However, the double mutant did not switch its chemokine receptor usage from CCR5 to CXCR4, indicating the altered recognition of CCR5 by this mutant. These results indicated that V2 combined with the V3 region of the CCR5-tropic HIV-1 envelope modulates the sensitivity of HIV-1 to C-C chemokines without altering the ability to use chemokine receptors.

Mechanisms and regulation of polymorphonuclear leukocyte and eosinophil adherence to human airway epithelial cells.

PubMed

Jagels, M A; Daffern, P J; Zuraw, B L; Hugli, T E

1999-09-01

Polymorphonuclear leukocytes (PMN) and eosinophils (Eos) are important cellular participants in a variety of acute and chronic inflammatory reactions in the airway. Histologic evidence has implicated direct interactions between these two subsets of leukocytes and airway epithelial cells during inflammation. A comprehensive characterization and comparison of physiologic stimuli and adhesion molecule involvement in granulocyte-epithelial-cell interactions done with nontransformed human airway epithelial cells has not been reported. We therefore examined the regulation and biochemical mechanisms governing granulocyte-epithelial-cell adhesion, using either purified PMN or Eos and primary cultures of human bronchial epithelial cells (HBECs). We investigated the involvement of a number of proinflammatory signals associated with allergic and nonallergic airway inflammation, as well as the contribution of several epithelial and leukocyte adhesion molecules, including intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and members of the beta(1), beta(2), and beta(7) integrin families. ICAM-1 was expressed at low levels on cultured HBECs and was markedly upregulated after stimulation with interferon (IFN)-gamma or, to a lesser extent, with tumor necrosis factor (TNF)-alpha or interleukin (IL)-1. VCAM-1 was not present on resting HBECs, and was not upregulated after stimulation with IFN-gamma, IL-1, IL-4, or TNF-alpha. PMN adhesion to HBECs could be induced either through activation of PMN with IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF), or C5a, but not with IL-5 or by preactivation of HBECs with TNF-alpha or IFN-gamma. Blocking antibody studies indicated that PMN-HBEC adherence depended on beta(2) integrins, primarily alpha(M)beta(2) (Mac-1). Adherence of Eos to HBECs could be induced through activation of Eos with IL-5, GM-CSF, or C5a, but not with IL-8 or by prior activation of HBECs with TNF-alpha of IFN-gamma. Maximal adhesion of Eos and PMN required pretreatment of HBECs with either TNF-alpha or IFN-gamma in addition to leukocyte activation. Adherence of Eos to unstimulated HBECs was mediated through both beta(1) and beta(2) integrins, whereas adhesion of Eos to activated HBECs was dominated by beta(2) integrins. Adhesion of both Eos and PMN was inhibited by treatment of HBECs with blocking antibodies to ICAM-1. Differential utilization of beta(1) and beta(2) integrins by Eos, depending on the activation state of the epithelium, is a novel finding and may affect activation and/or recruitment of Eos in airway tissue. Mechanisms of adhesion of HBECs to Eos and PMN, as evidenced by the different responsiveness of the two latter types of cells to IL-8 and IL-5, may account for a prevalence of Eos over PMN in certain airway diseases.

Cytokines and bullous pemphigoid.

PubMed

D'Auria, L; Cordiali Fei, P; Ameglio, F

1999-06-01

This report reviews the data presented in the literature concerning the presence and levels of different cytokines in sera, lesional tissue or blister fluids of patients with bullous pemphigoid. The list of cytokines analysed includes 21 molecules: interleukins (IL)-1 => 8, IL-10 => 13, IL-15, granulocyte-monocyte-colony stimulating factor (GM-CSF), interferon-gamma (IFN-gamma), oncostatin-M (OSM), regulated upon activation normal T cell expressed and presumably secreted (RANTES), transforming growth factor-beta 1 (TGF-beta 1), tumor necrosis factor-alpha (TNF-alpha) and vascular endothelial growth factor (VEGF). Basic information regarding the functions of these cytokines and their possible involvement in the pathogenetic steps of the disease, such as autoantigen expression, autoantibody induction, complement activation, local cell recruitment and stimulation, resident cell activation, release of various effector molecules and tissue damage are also reported. A specific function for each cytokine in bullous pemphigoid induction cannot be still defined, however, the literature attributes a major role to IL-1, IL-4, IL-5, IL-6, IL-8 and IFN-gamma. On the basis of significant (direct or inverse) correlations found between disease intensity and the blister fluid/serum levels, the following cytokines IL-7, IL-15, RANTES, VEGF and TNF-alpha, besides those previously mentioned, may also be involved in this disease.

Antitubercular cassane furanoditerpenoids from the roots of Caesalpinia pulcherrima.

PubMed

Promsawan, Netnapa; Kittakoop, Prasat; Boonphong, Surat; Nongkunsarn, Pakawan

2003-08-01

Activity-guided fractionation of a root extract of Caesalpinia pulcherrima led to the isolation of two cassane-furanoditerpenoids, 6 beta-benzoyl-7 beta-hydroxyvouacapen-5 alpha-ol (1) and 6 beta-cinnamoyl-7beta-hydroxyvouacapen-5 alpha-ol (2). Compound 2 showed strong antitubercular activity with a minimum inhibitory concentration (MIC) of 6.25 microg/mL, whereas the benzoyl analogue (1) was less active (MIC 25 microg/mL). Both compounds expressed moderate cytotoxic activity towards KB (human oral carcinonoid cancer), BC (human breast cancer) and NCl-H187 (small cell lung cancer) cell lines.

Importance of extranuclear estrogen receptor-alpha and membrane G protein-coupled estrogen receptor in pancreatic islet survival.

PubMed

Liu, Suhuan; Le May, Cedric; Wong, Winifred P S; Ward, Robert D; Clegg, Deborah J; Marcelli, Marco; Korach, Kenneth S; Mauvais-Jarvis, Franck

2009-10-01

We showed that 17beta-estradiol (E(2)) favors pancreatic beta-cell survival via the estrogen receptor-alpha (ERalpha) in mice. E(2) activates nuclear estrogen receptors via an estrogen response element (ERE). E(2) also activates nongenomic signals via an extranuclear form of ERalpha and the G protein-coupled estrogen receptor (GPER). We studied the contribution of estrogen receptors to islet survival. We used mice and islets deficient in estrogen receptor-alpha (alphaERKO(-/-)), estrogen receptor-beta (betaERKO(-/-)), estrogen receptor-alpha and estrogen receptor-beta (alphabetaERKO(-/-)), and GPER (GPERKO(-/-)); a mouse lacking ERalpha binding to the ERE; and human islets. These mice and islets were studied in combination with receptor-specific pharmacological probes. We show that ERalpha protection of islet survival is ERE independent and that E(2) favors islet survival through extranuclear and membrane estrogen receptor signaling. We show that ERbeta plays a minor cytoprotective role compared to ERalpha. Accordingly, betaERKO(-/-) mice are mildly predisposed to streptozotocin-induced islet apoptosis. However, combined elimination of ERalpha and ERbeta in mice does not synergize to provoke islet apoptosis. In alphabetaERKO(-/-) mice and their islets, E(2) partially prevents apoptosis suggesting that an alternative pathway compensates for ERalpha/ERbeta deficiency. We find that E(2) protection of islet survival is reproduced by a membrane-impermeant E(2) formulation and a selective GPER agonist. Accordingly, GPERKO(-/-) mice are susceptible to streptozotocin-induced insulin deficiency. E(2) protects beta-cell survival through ERalpha and ERbeta via ERE-independent, extra-nuclear mechanisms, as well as GPER-dependent mechanisms. The present study adds a novel dimension to estrogen biology in beta-cells and identifies GPER as a target to protect islet survival.

alpha1B-Adrenergic receptor phosphorylation and desensitization induced by transforming growth factor-beta.

PubMed Central

Romero-Avila, M Teresa; Flores-Jasso, C Fabián; García-Sáinz, J Adolfo

2002-01-01

Transforming growth factor-beta (TGF-beta) induced alpha(1B)-adrenergic receptor phosphorylation in Rat-1 fibroblasts stably expressing these adrenoceptors. This effect of TGF-beta was rapid, reaching a maximum within 30 min and decreasing thereafter, and concentration-dependent (EC(50) 0.3 pM). The phosphoinositide 3-kinase inhibitors wortmannin and LY294002, and the protein kinase C inhibitors staurosporine, Ro 318220 and bisindolylmaleimide, blocked the effect of this growth factor. alpha(1B)-Adrenergic receptor phosphorylation was associated with desensitization, as indicated by a reduction in the adrenergic-mediated production of [(3)H]inositol phosphates. Phosphorylation of alpha(1B)-adrenergic receptors by TGF-beta was also observed in Cos-1 cells transfected with the receptor. Co-transfection of the dominant-negative mutant of the regulatory subunit of phosphoinositide 3-kinase (Deltap85) inhibited the phosphorylation of alpha(1B)-adrenergic receptors induced by TGF-beta. Our results indicate that activation of TGF-beta receptors induces alpha(1B)-adrenergic receptor phosphorylation and desensitization. The data suggest that phosphoinositide 3-kinase and protein kinase C play key roles in this effect of TGF-beta. PMID:12234252

alpha1B-Adrenergic receptor phosphorylation and desensitization induced by transforming growth factor-beta.

PubMed

Romero-Avila, M Teresa; Flores-Jasso, C Fabián; García-Sáinz, J Adolfo

2002-12-01

Transforming growth factor-beta (TGF-beta) induced alpha(1B)-adrenergic receptor phosphorylation in Rat-1 fibroblasts stably expressing these adrenoceptors. This effect of TGF-beta was rapid, reaching a maximum within 30 min and decreasing thereafter, and concentration-dependent (EC(50) 0.3 pM). The phosphoinositide 3-kinase inhibitors wortmannin and LY294002, and the protein kinase C inhibitors staurosporine, Ro 318220 and bisindolylmaleimide, blocked the effect of this growth factor. alpha(1B)-Adrenergic receptor phosphorylation was associated with desensitization, as indicated by a reduction in the adrenergic-mediated production of [(3)H]inositol phosphates. Phosphorylation of alpha(1B)-adrenergic receptors by TGF-beta was also observed in Cos-1 cells transfected with the receptor. Co-transfection of the dominant-negative mutant of the regulatory subunit of phosphoinositide 3-kinase (Deltap85) inhibited the phosphorylation of alpha(1B)-adrenergic receptors induced by TGF-beta. Our results indicate that activation of TGF-beta receptors induces alpha(1B)-adrenergic receptor phosphorylation and desensitization. The data suggest that phosphoinositide 3-kinase and protein kinase C play key roles in this effect of TGF-beta.

Effects of alpha-galactosylceramides on bone marrow cells in vitro and hematopoiesis in vivo.

PubMed

Motoki, K; Morita, M; Kobayashi, E; Uchida, T; Fukushima, H; Koezuka, Y

1996-07-01

We found that AGL-517, an alpha-galactosylceramide (alpha-GalCer), possesses potent radioprotective activities against mice irradiated with 9 Gy of X-ray in contrast to its having no effect on mice irradiated with 10 Gy of X-ray. The result suggested the possibility that alpha-GalCers protect mice from bone marrow death. To examine this possibility, we examined the effects of two kinds of alpha- and beta-GalCers on counts of platelets (PLT) and white blood cells (WBC) in the peripheral blood of normal mice and mice irradiated in a whole body with 5 Gy of X-ray. alpha-GalCers significantly increased the PLT and WBC counts of both mice in comparison with the vehicle-treated group, and their potencies were stronger than those of their beta-types. Furthermore, we evaluated the in vitro bone marrow cell-proliferation stimulatory activities of four kinds of GalCers, and found that alpha-GalCers show stronger stimulatory effects than beta-types. These results demonstrate that the alpha-configuration of GalCers plays an important role in the manifestation of the above-mentioned activities of GalCers. The results also suggest that alpha-GalCers may be useful as hematopoietic stimulators as well as radioprotective agents.

A Combined NMR-Computational Study of the Interaction between Influenza Virus Hemagglutinin and Sialic Derivatives from Human and Avian Receptors on the Surface of Transfected Cells.

PubMed

Vasile, Francesca; Panigada, Maddalena; Siccardi, Antonio; Potenza, Donatella; Tiana, Guido

2018-04-24

The development of small-molecule inhibitors of influenza virus Hemagglutinin could be relevant to the opposition of the diffusion of new pandemic viruses. In this work, we made use of Nuclear Magnetic Resonance (NMR) spectroscopy to study the interaction between two derivatives of sialic acid, Neu5Ac-α-(2,6)-Gal-β-(1⁻4)-GlcNAc and Neu5Ac-α-(2,3)-Gal-β-(1⁻4)-GlcNAc, and hemagglutinin directly expressed on the surface of recombinant human cells. We analyzed the interaction of these trisaccharides with 293T cells transfected with the H5 and H1 variants of hemagglutinin, which thus retain their native trimeric conformation in such a realistic environment. By exploiting the magnetization transfer between the protein and the ligand, we obtained evidence of the binding event, and identified the epitope. We analyzed the conformational features of the glycans with an approach combining NMR spectroscopy and data-driven molecular dynamics simulations, thus obtaining useful information for an efficient drug design.

Development of a new family of conformationally restricted peptides as potent nucleators of beta-turns. Design, synthesis, structure, and biological evaluation of a beta-lactam peptide analogue of melanostatin.

PubMed

Palomo, Claudio; Aizpurua, Jesus M; Benito, Ana; Miranda, José Ignacio; Fratila, Raluca M; Matute, Carlos; Domercq, Maria; Gago, Federico; Martin-Santamaria, Sonsoles; Linden, Anthony

2003-12-31

Novel enantiopure (i)-(beta-lactam)-(Gly)-(i+3) peptide models, defined by the presence of a central alpha-alkyl-alpha-amino-beta-lactam ring placed as the (i+1) residue, have been synthesized in a totally stereocontrolled way by alpha-alkylation of suitable N-[bis(trimethylsilyl)methyl]-beta-lactams. The structural properties of these beta-lactam pseudopeptides have been studied by X-ray crystallography, Molecular Dynamics simulation, and NOESY-restrained NMR simulated annealing techniques, showing a strong tendency to form stable type II or type II' beta-turns either in the solid state or in highly coordinating DMSO solutions. Tetrapeptide models containing syn- or anti-alpha,beta-dialkyl-alpha-amino-beta-lactam rings have also been synthesized and their conformations analyzed, revealing that alpha-alkyl substitution is essential for beta-turn stabilization. A beta-lactam analogue of melanostatin (PLG amide) has also been prepared, characterized as a type-II beta-turn in DMSO-d6 solution, and tested by competitive binding assay as a dopaminergic D2 modulator in rat neuron cultured cells, displaying moderate agonist activity in the micromolar concentration range. On the basis of these results, a novel peptidomimetic design concept, based on the separation of constraint and recognition elements, is proposed.

[Effect of acupuncture-anesthetic composite anesthesia on the incidence of POCD and TNF-alpha, IL-1beta, IL-6 in elderly patients].

PubMed

Lin, Shun-Yan; Yin, Zheng-Lu; Gao, Ju; Zhou, Luo-Jing; Chen, Xin

2014-07-01

To explore the effect of acupuncture-anesthetic composite anesthesia (AACA) on the incidence of postoperative cognitive dysfunction (POCD) and changes of TNF-alpha, IL-1beta, and IL-6 in elderly patients. Totally 83 patients undergoing surgical resection of gastrointestinal tumor were randomly assigned to the simple anesthesia group (A group, 41 cases) and the AACA group (B group, 42 cases). Patients in Group A received endotracheal general anesthesia. Those in Group B were induced by acupuncture anesthesia for 30 min by needling at Baihui (DU20), Neiguan (PC6), Zusanli (ST36). The electro-acupuncture (EA) apparatus was connected after arrival of qi, with the wave pattern of density 2/100 Hz. The stimulus intensity was set by patients' tolerance, with the peak current of 5 mA. Then the endotracheal general anesthesia was performed and the EA lasted till the end of the surgery. The cognitive function of all patients was assessed before operation and at day 3 after operation using mini-mental state examination (MMSE). POCD was confirmed if with one or more decreased stand- ard. The peripheral venous blood was collected before anesthesia induction (TO), immediately at the end of surgery (T1), 24 h after operation (T2), and 48 h after operation (T3), and serum concentrations of IL-1beta, IL-6, and TNF-alpha were correspondingly measured using ELISA. The postoperative anesthesia awakening time was shorter in Group B than in Group A [(20.37 +/- 6.09) min vs (29.24 +/- 7.48) min, P < 0.05]. The remifentanil dose used during the operation was less in Group B than in Group A (P < 0.05). The incidence of POCD at day 3 was lower in Group B than in Group A [10/41 (23.8%) vs 15/42 (36.5%), P < 0.05]. The concentrations of IL-1beta, IL-6, and TNF-alpha at T1-T3 were higher than those at TO in the two groups (P < 0.05). The increment of TNF-alpha and IL-1beta was less in Group B than in Group A (P < 0.05). CONCLUSION AACA could reduce the incidence of POCD and inhibit postoperative release of TNF-alpha, IL-1beta, and IL-6 in elderly patients undergoing colorectal cancer resection.

Depletion of CD8+ cells in human thymic medulla results in selective immune deficiency

PubMed Central

1989-01-01

CD8 molecules expressed on the surface of a subset of T cells participate in the selection of class I MHC antigen-restricted T cells in the thymus, and in MHC-restricted immune responses of mature class I MHC antigen-restricted T cells. Here we describe an immune-deficient patient with lack of CD8+ peripheral blood cells. The patient presented with Pneumocystis carinii pneumonia and was unable to reject an allogeneic skin graft, but had normal primary and secondary antibody responses. Examination of the patient's thymus revealed that the loss of CD8+ cells occurred during intrathymic differentiation: the patient's immature cortical thymocytes included both CD4+ and CD8+ cells while the mature medullary cells expressed the CD4 but not the CD8 protein on their surface. Northern blot and polymerase chain reaction analyses revealed the presence of CD8 alpha and beta mRNA in the patient's thymus but not in the peripheral blood. Both class I MHC antigen expression and the expressed TCR V beta repertoire are normal in this patient. These data are consistent with an impaired selection of CD8+ cells in the patient's thymus and support the role of the CD8 surface protein in thymic selection previously characterized in genetically manipulated and inbred mice. PMID:2511270

Lactococcin G is a potassium ion-conducting, two-component bacteriocin.

PubMed

Moll, G; Ubbink-Kok, T; Hildeng-Hauge, H; Nissen-Meyer, J; Nes, I F; Konings, W N; Driessen, A J

1996-02-01

Lactococcin G is a novel lactococcal bacteriocin whose activity depends on the complementary action of two peptides, termed alpha and beta. Peptide synthesis of the alpha and beta peptides yielded biologically active lactococcin G, which was used in mode-of-action studies on sensitive cells of Lactococcus lactis. Approximately equivalent amounts of both peptides were required for optimal bactericidal effect. No effect was observed with either the alpha or beta peptide in the absence of the complementary peptide. The combination of alpha and beta peptides (lactococcin G) dissipates the membrane potential (delta omega), and as a consequence cells release alpha-aminoisobutyrate, a non-metabolizable alanine analog that is accumulated through a proton motive-force dependent mechanism. In addition, the cellular ATP level is dramatically reduced, which results in a drastic decrease of the ATP-driven glutamate uptake. Lactococcin G does not form a proton-conducting pore, as it has no effect on the transmembrane pH gradient. Dissipation of the membrane potential by uncouplers causes a slow release of potassium (rubidium) ions. However, rapid release of potassium was observed in the presence of lactococcin G. These data suggest that the bactericidal effect of lactococcin G is due to the formation of potassium-selective channels by the alpha and beta peptides in the target bacterial membrane.

Review: Lutheran/B-CAM: a laminin receptor on red blood cells and in various tissues.

PubMed

Kikkawa, Yamato; Miner, Jeffrey H

2005-01-01

The Lutheran blood group glycoprotein (Lu), also known as basal cell adhesion molecule (B-CAM), is a transmembrane receptor with five immunoglobulin-like domains in its extracellular region; it is therefore classified as a member of the immunoglobulin (Ig) gene family. Lu/B-CAM is observed not only on red blood cells, but also on a subset of muscle and epithelial cells in various tissues. Recently, several groups have reported that Lu/B-CAM is a novel receptor for laminin a5. The laminin a5 chain is a component of the laminin-511 (alpha 5 beta 1 gamma 1), -521 (alpha 5 beta 2 gamma 1), and -523 (alpha 5 beta 2 gamma 3) heterotrimers and is expressed throughout the mammalian body. We also have shown that Lu/B-CAM is co-localized with laminin alpha 5 in various tissues. Although the biological role of Lu/B-CAM remains unclear, the specific binding of Lu/B-CAM to laminin alpha 5 suggests that it plays an important role in developmental and physiological processes. It also is necessary to investigate further the interaction between Lu/B-CAM and laminin a5 in pathological processes, including sickle cell disease and cancer.

Promotion of mouse fibroblast collagen gene expression by mast cells stimulated via the Fc epsilon RI. Role for mast cell-derived transforming growth factor beta and tumor necrosis factor alpha

PubMed Central

1994-01-01

Chronic allergic diseases and other disorders associated with mast cell activation can also be associated with tissue fibrosis, but a direct link between mast cell mediator release and fibroblast collagen gene expression has not been established. Using in situ hybridization, we show that the elicitation of an IgE-dependent passive cutaneous anaphylaxis (PCA) reaction in mice results in a transient, but marked augmentation of steady state levels of type alpha-1 (I) collagen mRNA in the dermis. While peak levels of collagen mRNA expression in the skin are observed 16-24 h after mast cell activation, substantial numbers of dermal cells are strongly positive for collagen mRNA at 1 and 2 h after antigen challenge, before circulating inflammatory cells are recruited into the tissues. Furthermore, experiments in mast cell- reconstituted or genetically mast cell-deficient WBB6F1-W/Wv mice demonstrate that the increased expression of collagen mRNA at sites of PCA reactions is entirely mast cell dependent. In vitro studies show that the supernatants of mouse serosal mast cells activated via the Fc epsilon RI markedly increase type alpha-1 (I) collagen mRNA levels in mouse embryonic skin fibroblasts, and also upregulate collagen secretion by these cells. The ability of mast cell supernatants to induce increased steady state levels of collagen mRNA in mouse skin fibroblasts is markedly diminished by absorption with antibodies specific for either of two mast cell-derived cytokines, transforming growth factor beta (TGF-beta 1) or tumor necrosis factor alpha (TNF- alpha), and is eliminated entirely by absorption with antibodies against both cytokines. Taken together, these findings demonstrate that IgE-dependent mouse mast cell activation can induce a transient and marked increase in steady state levels of type alpha-1 (I) collagen mRNA in dermal fibroblasts and that mast cell-derived TGF-beta 1 and TNF-alpha importantly contribute to this effect. PMID:7964480

Effects of preventing O-glycosylation on the secretion of human chorionic gonadotropin in Chinese hamster ovary cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matzuk, M.M.; Krieger, M.; Corless, C.L.

1987-09-01

Human chorionic gonadotropin (hCG) is a member of a family of heterodimeric glycoprotein hormones that have a common ..cap alpha.. subunit but differ in their hormone-specific ..beta..-subunits. The ..beta.. subunit of hCG (hCG..beta..) is unique among the ..beta.. subunits in that it contains four mucin-like O-linked oligosaccharides attached to a carboxyl-terminal extension. To study the effects of O-glycosylation on the secretion and assembly of hCG, expression vectors containing either hCG..beta.. gene alone or together with the hCG..cap alpha.. gene were transfected into a mutant Chinese hamster ovary cell line, 1d1D, which exhibits a reversible defect in O-glycosylation. The results revealmore » that hCG..beta.. can be secreted normally in the absence of its O-linked oligosaccharides. hCG..beta.. devoid of O-linked carbohydrate can also combine efficiently with hCG..cap alpha.. and be secreted as an intact dimer. The authors conclude that in Chinese hamster ovary cells, the hCG..beta.. O-linked chains play no role in the assembly and secretion of hCG. The normal and O-linked oligosaccharide-deficient forms of hCG secreted by these cells should prove useful in examining the role of O-linked chains on the biological function of hCG.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rogers, Z.R.; Powars, D.R.; Williams, W.D.

Of 18 nonblack patients with sickle cell disease, 14 had sickle cell anemia, 2 had hemoglobin SC disease, and 2 had hemoglobin S-{beta}{sup o}-thalassemia. The {beta}{sup s} gene cluster haplotypes that were determined in 7 patients were of African origin and were identified as Central African Republic, Central African Republic minor II, Benin, and Senegal. The haplotype Central African Republic minor II was present on the {beta}{sup o}-thalassemia chromosome in 2 patients. None of 10 patients whose {alpha}-gene status was determined had {alpha}-thalassemia-2. These data strongly support the concept that the {beta}{sup s} gene on chromosome 11 of these individualsmore » is of African origin and that the {alpha}-gene locus on chromosome 16 is of white or native American origin. The clinical severity of the disease in these nonblack patients is appropriate to their haplotype without {alpha}-thalassemia-2 and is comparable with that of black patients. All persons with congenital hemolytic anemia should be examined for the presence of sickle cell disease regardless of physical appearance or ethnic background.« less

Dose-response effects of estrogenic mycotoxins (zearalenone, alpha- and beta-zearalenol) on motility, hyperactivation and the acrosome reaction of stallion sperm

PubMed Central

2011-01-01

Background The aim of this study was to investigate the in vitro effects of the Fusarium fungus-derived mycotoxin, zearalenone and its derivatives alpha-zearalenol and beta-zearalenol on motility parameters and the acrosome reaction of stallion sperm. Since the toxic effects of zearalenone and its derivatives are thought to result from their structural similarity to 17beta-estradiol, 17beta-estradiol was used as a positive control for 'estrogen-like' effects. Methods Stallion spermatozoa were exposed in vitro to zearalenone, alpha-zearalenol, beta-zearalenol or 17beta-estradiol at concentrations ranging from 1 pM - 0.1 mM. After 2 hours exposure, motility parameters were evaluated by computer-assisted analysis, and acrosome integrity was examined by flow cytometry after staining with fluoroscein-conjugated peanut agglutinin. Results Mycotoxins affected sperm parameters only at the highest concentration tested (0.1 mM) after 2 hours exposure. In this respect, all of the compounds reduced the average path velocity, but only alpha-zearalenol reduced percentages of motile and progressively motile sperm. Induction of motility patterns consistent with hyperactivation was stimulated according to the following rank of potency: alpha-zearalenol >17beta-estradiol > zearalenone = beta-zearalenol. The hyperactivity-associated changes observed included reductions in straight-line velocity and linearity of movement, and an increase in the amplitude of lateral head displacement, while curvilinear velocity was unchanged. In addition, whereas alpha- and beta- zearalenol increased the percentages of live acrosome-reacted sperm, zearalenone and 17beta-estradiol had no apparent effect on acrosome status. In short, alpha-zearalenol inhibited normal sperm motility, but stimulated hyperactive motility in the remaining motile cells and simultaneously induced the acrosome reaction. Beta-zearalenol induced the acrosome reaction without altering motility. Conversely, zearalenone and 17beta-estradiol did not induce the acrosome reaction but induced hyperactive motility albeit to a different extent. Conclusions Apparently, the mycotoxin zearalenone has 17beta-estradiol-like estrogenic activity that enables it to induce hyperactivated motility of equine sperm cells, whereas the zearalenol derivatives induce premature completion of the acrosome reaction and thereby adversely affect stallion sperm physiology. The alpha form of zearalenol still possessed the estrogenic ability to induce hyperactivated motility, whereas its beta stereo-isomere had lost this property. PMID:21970729

Constraints upon the spectral indices of relic gravitational waves by LIGO S5

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Y.; Tong, M. L.; Fu, Z. W.

With LIGO having achieved its design sensitivity and the LIGO S5 strain data being available, constraints on the relic gravitational waves (RGWs) become realistic. The analytical spectrum of RGWs generated during inflation depends sensitively on the initial condition, which is generically described by the index {beta}, the running index {alpha}{sub t}, and the tensor-to-scalar ratio r. By the LIGO S5 data of the cross-correlated two detectors, we obtain constraints on the parameters ({beta},{alpha}{sub t},r). As a main result, we have computed the theoretical signal-to-noise ratio of RGWs for various values of ({beta},{alpha}{sub t},r), using the cross-correlation for the given pairmore » of LIGO detectors. The constraints by the indirect bound on the energy density of RGWs by big bang nucleosynthesis and cosmic microwave background have been obtained, which turn out to be still more stringent than LIGO S5.« less

Synthesis and cytotoxic analysis of some disodium 3beta,6beta-dihydroxysterol disulfates.

PubMed

Cui, Jianguo; Wang, Hui; Huang, Yanmin; Xin, Yi; Zhou, Aimin

2009-01-01

Disodium 3beta,6beta-dihydroxy-5alpha-cholestane disulfate (1) was synthesized in 4 steps with a high overall yield from cholesterol. First, cholesterol (4a) was converted to cholest-4-en-3,6-dione (5a) via oxidation with pyridinium chlorochromate (PCC) and then 5a was reduced by NaBH(4) in the presence of NiCl(2) to produce cholest-3beta,6beta-diol (6a). The reaction of 6a with the triethylamine-sulfur trioxide complex generated diammonium 3beta,6beta-dihydroxy-5alpha-cholestane disulfate (7a) and the treatment of 7a by cation exchange resin 732 (sodium form)(Na(+)) yielded the target steroid 1. Disodium 24-ethyl-3beta,6beta-dihydroxycholest-22-ene disulfate (2) and disodium 24-ethyl-3beta,6beta-dihydroxycholestane disulfate (3) were synthesized using a similar method. The cytotoxicity of these compounds against Sk-Hep-1 (human liver carcinoma cell line), H-292 (human lung carcinoma cell line), PC-3 (human prostate carcinoma cell line) and Hey-1B (human ovarian carcinoma cell line) cells was investigated. Our results indicate that presence of a cholesterol-type side chain at position 17 is necessary for their biological activity.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwarz, R.B.; Bach, H.T.; Harms, U.

We used a resonant-ultrasound-spectroscopy technique to measure the three independent elastic constants of PdH{sub x}, PdD{sub x}, and PdT{sub x} single crystals at 300 K. For 0.1x0.62 our PdH{sub x} crystals are two-phase mixtures of coherent {alpha} and {beta} hydride phases. For increasing x in this range, C{sub 44} decreases monotonically whereas C'=12(C11-C12) has a concave parabolic dependence. This difference is because C' is softened by an anelastic relaxation resulting from acoustic-stress-induced changes in the shape of the coherent lenticular-shape precipitates ({beta}-hydride precipitates in {alpha}-hydride matrix and {alpha}-hydride precipitates in {beta}-hydride matrix). In the {beta}-phase C' and C{sub 44} decreasemore » with increasing hydrogen (or deuterium or tritium) content. Furthermore, C' exhibits a strong isotope effect whereas C{sub 44} does not. This effect is attributed to differences in the excitation of optical phonons in Pd-H, Pd-D and Pd-T.« less

Characterization of T cell repertoire changes in acute Kawasaki disease

PubMed Central

1993-01-01

Kawasaki disease (KD) is an acute multisystem vasculitis of unknown etiology that is associated with marked activation of T cells and monocyte/macrophages. Using a quantitative polymerase chain reaction (PCR) technique, we recently found that the acute phase of KD is associated with the expansion of T cells expressing the V beta 2 and V beta 8.1 gene segments. In the present work, we used a newly developed anti-V beta 2 monoclonal antibody (mAb) and studied a new group of KD patients to extend our previous PCR results. Immunofluorescence analysis confirmed that V beta 2-bearing T cells are selectively increased in patients with acute KD. The increase occurred primarily in the CD4 T cell subset. The percentages of V beta 2+ T cells as determined by mAb reactivity and flow cytometry correlated linearly with V beta expression as quantitated by PCR. However, T cells from acute KD patients appeared to express proportionately higher levels of V beta 2 transcripts per cell as compared with healthy controls or convalescent KD patients. Sequence analysis of T cell receptor beta chain genes of V beta 2 and V beta 8.1 expressing T cells from acute KD patients showed extensive junctional region diversity. These data showing polyclonal expansion of V beta 2+ and V beta 8+ T cells in acute KD provide additional insight into the immunopathogenesis of this disease. PMID:8094737

Immune defects in families and patients with xeroderma pigmentosum and trichothiodystrophy.

PubMed Central

Mariani, E; Facchini, A; Honorati, M C; Lalli, E; Berardesca, E; Ghetti, P; Marinoni, S; Nuzzo, F; Astaldi Ricotti, G C; Stefanini, M

1992-01-01

Xeroderma pigmentosum (XP) is a rare autosomal recessive disease characterized by photosensitivity, a high incidence of cancer in sun-exposed portions of the skin and a reduced capacity to repair the u.v.-induced DNA damage. One of the XP mutations (XP-D) has also been identified in patients affected by trichothiodystrophy (TTD), a rare autosomal recessive disease characterized by brittle hair, mental and physical retardation, peculiar face and ichthyosis. However, in these patients there is no evidence of increased skin tumour incidence. Since an impairment of cell-mediated immunity has been proposed as a co-factor in the cancer proneness of XP patients, we investigated the involvement of immune defect(s) in five XP patients, five TTD patients, their parents, and 24 TTD relatives. We evaluated the phenotype of circulating lymphocytes, natural killer (NK) cell lytic activity, target cell binding of NK cells at single cell level and the effect of interferons (IFN) alpha and beta on NK cell activity. The relative proportion of CD3+ and CD4+ circulating lymphocytes was reduced in XP but not in TTD patients. NK cell lytic activity was decreased in XP patients and their mothers, but their fathers showed normal lytic activity. NK activity varied among TTD families: four out of five patients and their relatives presented low NK cell activity, and one family was normal. In TTD family members, NK activity increased after incubation with IFN-alpha or IFN-beta, but never reached normal values. In contrast, in XP patients and their mothers, the defect was almost completely corrected after in vitro incubation with IFN-alpha or IFN-beta. Our study indicates impaired NK lytic activity in the majority of TTD and XP patients and that this defect is present also in members of their families. In addition, XP patients present a low number of circulating T cells. These multiple abnormalities, together with DNA repair defects, could be related to the increased cancer risk in XP patients. PMID:1535035

Radiobiological features of acute myeloblastic leukemia: comparison of self-renewal versus terminally differentiated populations.

PubMed

Cowen, D; Richaud, P; Landriau, S; Lagarde, P; Mahon, F X; Baudet, J J; Belloc, F; Gualde, N; Reiffers, J

1994-12-01

To evaluate the radiosensitivity of self-renewing progenitor cells in acute myeloblastic leukemia (AML), we have compared the radiosensitivity of the cells grown either in methylcellulose alone for 7 days, or first in suspension culture for 7 days before being plated in methylcellulose. Methylcellulose selects for terminal-dividing cells and suspension cultures have been developed because they allow self-renewal to occur: The exponential growth of the progenitors of AML cultured in suspension is due to self-renewal. Cells were harvested from previously untreated leukemic human bone marrows. The myeloblastic lineage of the colonies was assessed by morphological, cytochemical, and immunophenotypic analysis, and by the use of growth factors that did not stimulate the growth of T-lymphocytes. The cell-cycle distribution of the blasts was analyzed by flow cytometry and was comparable for all samples. The irradiation was performed with gamma-photons at a dose-rate of 0.05 Gy/min, similar to the clinical conditions used in our institution for total body irradiation (TBI). The culture methods selected aggressive leukemias. There were large variations of the individual radiosensitivity whatever culture method was used. The progenitor cells capable of self-renewal were more radiosensitive than terminal dividing cells. In two cases, a shoulder was found in the initial part of the cell-survival curves of cells capable of self-renewal. In these two cases, the best fit for the data was the linear quadratic model (survival = e-alpha D-beta D2) with alpha/beta values of 1.49 Gy and 3.12 Gy, respectively. The very low values of alpha/beta suggest a reduced antileukemic effect in case of fractionated TBI, and may lead to more reliable screening methods to determine the most appropriate technique for radiation ablation of bone marrow prior to bone marrow transplantation (BMT).

Dredging Operations Technical Support Program. Mathematical Model of the Consolidation/Desiccation Processes in Dredged Material.

DTIC Science & Technology

1985-07-01

5695 BF(I) - BETA(LDF) * GOTO 7 5700 6 NN - N-i 5705 Ch - CI / (ES(N)-ES(NN)) 5710 AF(I) w ALPHA(N) + CM*(ALPHA(N)-ALPHA(NN)) 5715 DF(I) a BETA(N) 4...1OXP34t4SETTLEMENT DUE TO CONSOLIDATION - PF1O.4) 7845 113 FORMAT(/1OX932HSETTLEMENT DUE TO DESICCATION - PF1O.4) 7850 114 FORNAT(/1OX920HSURFACE

Acetylated flavonoid glycosides potentiating NGF action from Scoparia dulcis.

PubMed

Li, Yushan; Chen, Xigui; Satake, Masayuki; Oshima, Yasukatsu; Ohizumi, Yasushi

2004-04-01

Three new acetylated flavonoid glycosides, 5,6,4'-trihydroxyflavone 7-O-alpha-L-2,3-di-O-acetylrhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (1), apigenin 7-O-alpha-L-3-O-acetylrhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (2), and apigenin 7-O-alpha-L-2,3-di-O-acetylrhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (3), were isolated from Scoparia dulcis together with the known compound eugenyl beta-D-glucopyranoside (4). Their structures were elucidated by spectroscopic analyses. Compounds 2 and 3 showed an enhancing activity of nerve growth factor-mediated neurite outgrowth in PC12D cells.

Inhibitors of sterol synthesis. Synthesis and spectral properties of 3 beta-hydroxy-5 alpha-cholestan-15-one and its 17 beta-epimer and their effects on 3-hydroxy-3-methylglutaryl coenzyme A reductase activity.

PubMed

Siddiqui, A U; Wilson, W K; Parish, E J; Gerst, N; Pinkerton, F D; Schroepfer, G J

1994-10-20

3 beta-Hydroxy-5 alpha-cholestan-15-one (2a) and its 14 beta-epimer 2b were prepared from 3 beta-acetoxy-5 alpha-cholest-8(14)-ene (3). Hydroboration of 3 at 45-50 degrees C gave a mixture of 5 alpha,14 alpha-cholestane-3 beta,15 alpha-diol and 5 alpha,14 beta-cholestane-3 beta,15 beta-diol, which were separated on silica gel as their 3 beta-tert-butyldimethylsilyl ethers 5a and 5b. Oxidation of 5a with pyridinium chlorochromate, followed by desilylation with tetrabutylammonium fluoride gave 2a. Analogous transformations of 5b gave 2b contaminated with 2a. Desilylation of 5b followed by oxidation with pyridinium chlorochromate resulted in a mixture composed mainly of 5 alpha,14 beta-cholestane-3,15-dione and 2b. Successive chromatographic separations on silica gel and reversed phase media gave 2b of high purity. Compound 2a was also prepared by lithium-ammonia reduction of 3 beta-hydroxy-5 alpha-cholest-8(14)-en-15-one (96% yield) and by selective reduction of 5 alpha-cholestane-3,15-dione with lithium tri-tert-butoxyaluminum hydride (90% yield). Isomers 2a and 2b were readily epimerized under acidic or basic conditions or under conditions used for gas chromatographic analysis. The purities of 2a and 2b were measured from nuclear magnetic resonance (NMR) spectra; chromatographic methods gave less reliable estimates of purity. NMR data also showed that ring C of the 14 beta sterols is predominantly in a chair conformation. The effects of 2a and 2b on the levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase have been studied in Chinese hamster ovary cells.

Subcellular distributions of rat CaM kinase phosphatase N and other members of the CaM kinase regulatory system.

PubMed

Kitani, Takako; Okuno, Sachiko; Takeuchi, Masayuki; Fujisawa, Hitoshi

2003-07-01

Ca2+/Calmodulin-dependent protein kinase (CaM kinase) regulatory system is composed of multifunctional CaM kinases such as CaM kinases IV and I, upstream CaM kinases such as CaM kinase kinases alpha and beta, which activate multifunctional CaM kinases, and CaM kinase phosphatases such as CaM kinase phosphatase and CaM kinase phosphatase N, which deactivate the activated multifunctional CaM kinases. To understand the combinations of CaM kinases I and IV, CaM kinase kinases alpha and beta, and CaM kinase phosphatases, the locations of the enzymes in the cell were examined by immunocytochemical studies of cultured cells. The results indicate that CaM kinase I, CaM kinase kinase beta, and CaM kinase phosphatase occur in the cytoplasm and that CaM kinase IV, CaM kinase kinase alpha (and CaM kinase kinase beta in some cell types and tissues), and CaM kinase phosphatase N occur inside the cellular nucleus, suggesting that there are at least two different sets of CaM kinase regulatory systems, one consisting of CaM kinase I, CaM kinase kinase beta, and CaM kinase phosphatase in the cytoplasm and the other consisting of CaM kinase IV, CaM kinase kinase alpha (and CaM kinase kinase beta in some cell types and tissues), and CaM kinase phosphatase N in the nucleus.

Interleukin-2-dependent long-term cultures of low-density lymphocytes allow the proliferation of lymphokine-activated killer cells with natural killer, Ti gamma/delta or TNK phenotype.

PubMed

Testa, U; Care, A; Montesoro, E; Fossati, C; Giannella, G; Masciulli, R; Fagioli, M; Bulgarini, D; Habetswallner, D; Isacchi, G

1990-01-01

We have developed a culture system for "long-term" growth of human lymphokine-activated killer (LAK) cells exhibiting an elevated, wide-spectrum antitumor cytotoxicity. The system allows the exponential growth of monocyte-depleted low-density lymphocytes in the presence of human serum and recombinant human interleukin-2 (10(3) U/ml), alone or in combination with interleukin-1 alpha or beta (both at 10 U/ml). Eighteen cultures were established from 18 normal adult donors. The membrane phenotypes of the final LAK cell population, assessed by a panel of monoclonal antibodies (mAb), consist of three main types: (a) NKH-1+, Ti alpha/beta-, Ti gamma/delta-, and CD3- lymphocytes; (b) NKH-1+, Ti alpha/beta-, Ti gamma/delta+, and CD3+ lymphocytes and (c) NKH-1+, Ti alpha/beta+, Ti gamma/delta- and CD3+ lymphocytes. Northern blot analysis showed that all these cell populations express relatively high levels of perforin RNA, particularly cells exhibiting the first phenotype. This culture system may provide a tool for cellular and molecular studies on the mechanisms of antitumor cytotoxicity, as well as the basis for new adoptive immunotherapy protocols in advanced center.

Arginine supplementation of sickle transgenic mice reduces red cell density and Gardos channel activity.

PubMed

Romero, José R; Suzuka, Sandra M; Nagel, Ronald L; Fabry, Mary E

2002-02-15

Nitric oxide (NO), essential for maintaining vascular tone, is produced from arginine by nitric oxide synthase. Plasma arginine levels are low in sickle cell anemia, and it is reported here that low plasma arginine is also found in our sickle transgenic mouse model that expresses human alpha, human beta(S), and human beta(S-Antilles) and is homozygous for the mouse beta(major) deletion (S+S-Antilles). S+S-Antilles mice were supplemented with a 4-fold increase in arginine that was maintained for several months. Mean corpuscular hemoglobin concentration (MCHC) decreased and the percent high-density red cells was reduced. Deoxy K(+) efflux is characteristic of red cells in sickle cell disease and contributes to the disease process by increasing the MCHC and rendering the cells more susceptible to polymer formation. This flux versus the room air flux was reduced in S+S-Antilles red cells from an average value of 1.6 +/- 0.3 mmol per liter of red cells x minute (FU) in nonsupplemented mice to 0.9 +/- 0.3 FU (n = 4, P < .02, paired t test) in supplemented mice. In room air, V(max) of the Ca(++)-activated K(+) channel (Gardos) was reduced from 4.1 +/- 0.6 FU (off diet) to 2.6 +/- 0.4 FU (n = 7 and 8, P < .04, t test) in arginine-supplemented mice versus clotrimazole. In conclusion, the major mechanism by which arginine supplementation reduces red cell density (MCHC) in S+S-Antilles mice is by inhibiting the Ca(++)-activated K(+) channel.

GTP analogues promote release of the alpha subunit of the guanine nucleotide binding protein, Gi2, from membranes of rat glioma C6 BU1 cells.

PubMed Central

Milligan, G; Mullaney, I; Unson, C G; Marshall, L; Spiegel, A M; McArdle, H

1988-01-01

The major pertussis-toxin-sensitive guanine nucleotide-binding protein of rat glioma C6 BU1 cells corresponded immunologically to Gi2. Antibodies which recognize the alpha subunit of this protein indicated that it has an apparent molecular mass of 40 kDa and a pI of 5.7. Incubation of membranes of these cells with guanosine 5'-[beta gamma-imido]triphosphate, or other analogues of GTP, caused release of this polypeptide from the membrane in a time-dependent manner. Analogues of GDP or of ATP did not mimic this effect. The GTP analogues similarly caused release of the alpha subunit of Gi2 from membranes of C6 cells in which this G-protein had been inactivated by pretreatment with pertussis toxin. The beta subunit was not released from the membrane under any of these conditions, indicating that the release process was a specific response to the dissociation of the G-protein after binding of the GTP analogue. Similar nucleotide profiles for release of the alpha subunits of forms of Gi were noted for membranes of both the neuroblastoma x glioma hybrid cell line NG108-15 and of human platelets. These data provide evidence that: (1) pertussis-toxin-sensitive G-proteins, in native membranes, do indeed dissociate into alpha and beta gamma subunits upon activation; (2) the alpha subunit of 'Gi-like' proteins need not always remain in intimate association with the plasma membrane; and (3) the alpha subunit of Gi2 can still dissociate from the beta/gamma subunits after pertussis-toxin-catalysed ADP-ribosylation. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 8. PMID:3140801

Evidence for a prolonged role of alpha 4 integrin throughout active experimental allergic encephalomyelitis.

PubMed

Keszthelyi, E; Karlik, S; Hyduk, S; Rice, G P; Gordon, G; Yednock, T; Horner, H

1996-10-01

The leukocyte integrin receptor, alpha 4 beta 1, and its endothelial cell ligand, vascular cell adhesion molecule 1, appear to be of critical importance in the leukocyte trafficking that accompanies CNS damage in experimental allergic encephalomyelitis (EAE). In this study, the persistence of the role for alpha 4 beta 1/VCAM-1 in EAE was established by observing antibody-mediated disease reversal up to 1 month following disease onset. Limited treatment with a monoclonal antibody against alpha 4 integrin, GG5/3, resulted in a significant decrease in both clinical and histopathologic signs. This was not observed in isotype control experiments. In the latter phase of progressive disease, widespread demyelination occurred in the animals that did not respond to 6 days of anti-alpha 4 treatment. These results demonstrate an essential role for alpha 4 beta 1 interactions throughout active EAE and illustrate the difference between reversible clinical deficits caused by edema and irreversible deficits associated with demyelination.

Manipulation of two alpha-endo-beta-1,4-glucanase genes, AtCel6 and GmCel7, reduces susceptibility to Heterodera glycines in soybean roots

USDA-ARS?s Scientific Manuscript database

Plant endo-beta-1,4-glucanases (EGases) include cell-wall-modifying enzymes that are involved in nematode-induced growth of syncytia (feeding structures) in nematode-infected roots. EGases in the alpha and beta subfamilies contain signal peptides and are secreted, while those in the gamma subfamily ...

Characterization of alpha(4)beta(1) (CD49d/CD29) on equine leukocytes: potential utility of a potent alpha(4)beta(1) (CD49d/CD29) receptor antagonist in the treatment of equine heaves (recurrent airway obstruction).

PubMed

Treonze, Kelly M; Alves, Kenneth; Fischer, Paul; Hagmann, William K; Hora, Donald; Kulick, Alison; Vakerich, Ken; Smith, Nicholas D; Lingham, Russell B; Maniar, Salony; Reger, Thomas S; Zunic, Jasmine; Munoz, Benito; Prasit, Peppi; Nicholson, Donald; Si, Qian; Judd, Keith; Nicolich, Susan; Kellerhouse, Patricia; Thompson, Donald; Mumford, Richard A

2009-07-15

The purpose of this study was to characterize the alpha(4)beta(1) receptor (CD49d/CD29, very late antigen-4, VLA-4) on circulating equine leukocytes and to evaluate the intrinsic potency of an alpha(4)beta(1) receptor antagonist (Compound B) in the horse. Ultimately, these studies would allow us to determine the suitability of treating recurrent airway obstruction (RAO; heaves) affected horses by blocking the cellular recruitment of lymphocytes and neutrophils into the lung. The data demonstrates the alpha(4)beta(1) integrin is present on horse lymphocytes and neutrophils (fluorescence-assisted cell sorter, FACS) and can bind low molecular weight alpha(4)beta(1) antagonists (Compounds A and B) with high affinity. K(D) values for the binding of Compound A to non-activated alpha(4)beta(1) on isolated horse PBMCs (peripheral blood mononuclear cells) and activated neutrophils were 17 pM and 27 pM, respectively. Compound B was identified as a suitable antagonist for performing a series of in vivo experiments. Compound B was found to possess excellent potency in horse whole blood, possessing IC(50) and IC(90) values of 39 pM and 172 pM, respectively. This represents a 3.9-fold molar excess of drug over the alpha(4)beta(1) concentration in blood. Following oral administration of Compound B (5 mg/kg) to beagle dogs and rhesus monkeys, rapid and sustained alpha(4)beta(1) receptor occupancy (>80%) was achieved and maintained for a period of 24 h. When Compound B was administered intravenously to the horse, by either a slow or rapid infusion at a dose of 0.3 mg/kg, receptor blockade of >80% was observed out to 24 h with a concomitant leukocytosis. We believe that Compound B possesses suitable intrinsic and pharmacological properties to be evaluated clinically in horses affected by RAO.

Novel Humanized mice to test Therapeutics for Human Type 1 Diabetes

DTIC Science & Technology

2014-01-06

performed in non- obese diabetic (NOD) mice, the closest animal model for human T1D, have identified different immune cells involved in pancreatic β-cell...periphery. Each MHC class II chain contributes to the formation of a groove where the peptide is embedded (78). 17 The polygenetic factor underlying...diabetes mellitus in non- obese diabetic mice by transgenes encoding modified I-A beta-chain or normal I-E alpha-chain. Nature 345:727-9 63. Marek

Activins and inhibins: Novel regulators of thymocyte development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Licona-Limon, Paula; Aleman-Muench, German; Chimal-Monroy, Jesus

2009-04-03

Activins and inhibins are members of the transforming growth factor-{beta} superfamily that act on different cell types and regulate a broad range of cellular processes including proliferation, differentiation, and apoptosis. Here, we provide the first evidence that activins and inhibins regulate specific checkpoints during thymocyte development. We demonstrate that both activin A and inhibin A promote the DN3-DN4 transition in vitro, although they differentially control the transition to the DP stage. Whereas activin A induces the accumulation of a CD8{sup +}CD24{sup hi}TCR{beta}{sup lo} intermediate subpopulation, inhibin A promotes the differentiation of DN4 to DP. In addition, both activin A andmore » inhibin A appear to promote CD8{sup +}SP differentiation. Moreover, inhibin {alpha} null mice have delayed in vitro T cell development, showing both a decrease in the DN-DP transition and reduced thymocyte numbers, further supporting a role for inhibins in the control of developmental signals taking place during T cell differentiation in vivo.« less

Effects of 2-deoxy-D-glucose administration on cytokine production in BDF1 mice

NASA Technical Reports Server (NTRS)

Dreau, D.; Morton, D. S.; Foster, M.; Fowler, N.; Sonnenfeld, G.

2000-01-01

Physical exercise and diet changes have been shown to affect immune parameters, and similar effects are also induced by the administration of a nonmetabolizable glucose analog, 2-deoxy-D-glucose (2-DG). The present study was designed to characterize the effects of glucoprivation induced by 2-DG administration on concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and IL-6 in the blood and interferon-gamma (IFN-gamma), IL-2, and IL-4 in vitro production by partially purified T splenocytes in BDF1 mice. Mice (n = 8 per group) were injected intraperitoneally one or three times with 0, 500, 750, or 1000 mg/kg of 2-DG, and blood and spleens were collected 2 h after the last injection. Partially purified T splenocytes were cultured 24 h in the presence of concanavalin A (ConA). A significant increase in the corticosterone levels with the amount of 2-DG injected was observed after one or three injections (p<0.05). The amount of 2-DG injected was associated with an increase in TNF-alpha, IL-1beta, and IL-6 concentrations in the blood of mice after one or three injections of 2-DG (p<0.05). A significant decrease in in vitro proliferation of partially purified splenocytes in the presence of ConA was associated with a decrease in IFN-gamma production in the culture supernatants and an increase in IL-1 receptor expression on the cell surface (p<0.05).

In vivo production of cytokines and beta (C-C) chemokines in human recurrent herpes simplex lesions--do herpes simplex virus-infected keratinocytes contribute to their production?

PubMed

Mikloska, Z; Danis, V A; Adams, S; Lloyd, A R; Adrian, D L; Cunningham, A L

1998-04-01

Recurrent human herpes simplex lesions are infiltrated by macrophages and CD4 and CD8 lymphocytes, which secrete cytokines and chemokines. Vesicle fluid was examined by ELISA for the presence of cytokines and beta (C-C) chemokines. On the first day of the lesion, high concentrations of interleukin (IL)-1beta, and IL-6, moderate concentrations of IL-1alpha and IL-10, and low concentrations of IL-12 and beta chemokines were found; levels of macrophage inflammatory protein (MIP)-1beta were significantly higher than levels of MIP-1alpha and RANTES. At day 3, the concentrations of IL-1beta, IL-6, and MIP-1beta were lower, whereas the levels of IL-10, IL-12, and MIP-1alpha remained similar, and the level of tumor necrosis factor-alpha was now detectable. Herpes simplex virus infection of keratinocytes in vitro stimulated production of beta chemokines followed by IL-12 and then IL-10, IL-1alpha, IL-1beta, and IL-6, indicating a potential role for these events in early recruitment, activation, and interferon-gamma production of CD4 cells in herpetic lesions.

[Effect of Yiguan Decoction on differentiation of bone marrow mesenchymal stem cells into hepatocyte-like cells: an experimental research].

PubMed

Ping, Jian; Chen, Hong-Yun; Yang, Zhou; Yang, Cheng; Xu, Lie-Ming

2014-03-01

To observe the effect of Yiguan Decoction (YGD) on differentiation of bone marrow mesenchymal stem cells (BMSCs) into hepatocyte-like cells in vitro. Rat BMSCs were isolated using whole bone marrow adherent method. The properties of BMSCs were identified by analyzing the expression of surface cytokines by flow cytometry. The third passage cells were differentiated into fat cells to identify their features. BMSCs were incubated with hepatocyte growth factor (HGF) plus fibroblast growth factor 4 (FGF4) or YGD containing serum YGD for 21 days. The mRNA expression of alpha-fetoprotein (alphaAFP), albumin (Alb), and hepatocyte nuclear factor 4alpha (HNF4alpha) were detected by real time PCR. Expression of AFP and cytokeratin 18 (CK18) protein was detected by cell immunofluorescence. Glycogen synthesis was observed using periodic acid-Schiff stain (PAS). CK18, Wnt 3alpha, and alphacatenin protein expressions were detected by Western blot. High expression of CD90, CD29, and CD44, and low expression of CD34 and CD11b were observed in BMSCs isolated by whole bone mar- row adherent method, and numerous lipid droplets were observed in BMSCs using oil red O staining. Both YGD containing serum and growth factor stimulated the expression levels of Alb, AFP, HNF4alpha mRNA and CK18 protein. The down-regulated expression of Wnt 3alpha and beta-catenin could be detected at 21 days after induction. The synthesized glycogen granule could be seen. Down-regulated Wnt 3alpha and beta-catenin expression could also be observed. YGD could induce the differentiation of rat BMSCs into hepatocyte-like cells, which was related to down-regulating Wnt/beta-catenin signal pathway.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiong, J.-P.; Stehle, T.; Zhang, R.

The structural basis for the divalent cation-dependent binding of heterodimeric alpha beta integrins to their ligands, which contain the prototypical Arg-Gly-Asp sequence, is unknown. Interaction with ligands triggers tertiary and quaternary structural rearrangements in integrins that are needed for cell signaling. Here we report the crystal structure of the extracellular segment of integrin alpha Vbeta 3 in complex with a cyclic peptide presenting the Arg-Gly-Asp sequence. The ligand binds at the major interface between the alpha V and beta 3 subunits and makes extensive contacts with both. Both tertiary and quaternary changes are observed in the presence of ligand. Themore » tertiary rearrangements take place in beta A, the ligand-binding domain of beta 3; in the complex, beta A acquires two cations, one of which contacts the ligand Asp directly and the other stabilizes the ligand-binding surface. Ligand binding induces small changes in the orientation of alpha V relative to beta 3.« less

Casein expression in cytotoxic T lymphocytes.

PubMed Central

Grusby, M J; Mitchell, S C; Nabavi, N; Glimcher, L H

1990-01-01

A cDNA that expresses a mRNA restricted to cytotoxic T lymphocytes (CTL) and mammary tissue has been isolated and characterized. The deduced amino acid sequence from this cDNA shows extensive homology with the previously reported amino acid sequence for rat alpha-casein. Indeed, the presence of a six-residue-repeated motif that is specific for rodent alpha-caseins strongly supports the identification of this cDNA as mouse alpha-casein. Northern (RNA) blot analysis of many hematopoietic cell types revealed that this gene is restricted to CTL, being expressed in four of six CTL lines examined. Furthermore, CTL that express this gene were also found to express other members of the casein gene family, such as beta- and kappa-casein. These results suggest that caseins may be important in CTL function, and their potential role in CTL-mediated lysis is discussed. Images PMID:2395885

Purification and characterization of NADP-dependent 7 beta-hydroxysteroid dehydrogenase from Peptostreptococcus productus strain b-52.

PubMed

Masuda, N; Oda, H; Tanaka, H

1983-01-04

An NADP-dependent 7 beta-hydroxysteroid dehydrogenase was purified 11.5-fold over the activity in crude cell extracts prepared from Peptostreptococcus productus strain b-52, by using Sephadex G-200 and DEAE-cellulose column chromatography. 7 beta-Dehydrogenation was the sole transformation of bile acids catalyzed by the partially purified enzyme. The enzyme preparation (spec. act. 2.781 IU per mg protein) had an optimum pH of 9.8. Lineweaver-Burk plots showed a Michaelis constant (Km) value of 0.05 mM for 3 alpha, 7 beta-dihydroxy-5 beta-cholanoic acid whereas higher values were obtained with 3 alpha,7 beta-dihydroxy-5 beta-cholanoyl glycine (0.20 mM), and 3 alpha,7 beta-dihydroxy-5 beta-cholanoyl taurine (0.26 mM). NADP but not NAD could function as an electron acceptor, and had a Km value of 0.30 mM. A molecular weight of 64000 was determined by SDS-polyacrylamide gel electrophoresis. The addition of 0.4 mM of either bile acid to the growth medium suppressed not only cell growth, but also the enzyme yield.

Chimeras of the integrin beta subunit mid-region reveal regions required for heterodimer formation and for activation.

PubMed

Hyland, R H; Douglass, W A; Tan, S M; Law, S K

2001-01-01

A central region of the beta2 integrin subunit, RN (residues D300 to C459), was replaced by the equivalent sequences from beta1 and beta7 to give the chimeras beta2RN1 and beta2RN7. Whilst the former construct failed to form heterodimer at the cell surface with alphaL, the later of these could be expressed together with the alphaL subunit to form a variant LFA-1. Based on recent modelling work, the RN region consists of two parts, one is the C-terminal end of the putative A-domain (RB, residues D300 to A359), and the other the mid-region (BN, residues Y360 to C459). Chimeras exchanging the two component regions were made. Of the four resultant chimeras, only the beta2RB1 chimera failed to support LFA-1 expression. Thus the beta1 specific residues of this region affect the interaction with the alphaL subunit. Whereas the alphaL/beta2RB7 LFA-1 variant is wildtype like with respect to ICAM-1 adhesion, the alphaLbeta2BN1 and alphaLbeta2BN7, as well as the alphaLbeta2RN7, variants are more adhesive than the wildtype. These results suggest that an authentic beta2 mid-region is, in part, required for maintaining the LFA-1 in a resting state.

Proliferation of NS0 cells in protein-free medium: the role of cell-derived proteins, known growth factors and cellular receptors.

PubMed

Spens, Erika; Häggström, Lena

2009-05-20

NS0 cells proliferate without external supply of growth factors in protein-free media. We hypothesize that the cells produce their own factors to support proliferation. Understanding the mechanisms behind this autocrine regulation of proliferation may open for the novel approaches to improve animal cell processes. The following proteins were identified in NS0 conditioned medium (CM): cyclophilin A, cyclophilin B (CypB), cystatin C, D-dopachrome tautomerase, IL-25, isopentenyl-diphosphate delta-isomerase, macrophage migration inhibitory factor (MIF), beta(2)-microglobulin, Niemann pick type C2, secretory leukocyte protease inhibitor, thioredoxin-1, TNF-alpha, tumour protein translationally controlled 1 and ubiquitin. Further, cDNA microarray analysis indicated that the genes for IL-11, TNF receptor 6, TGF-beta receptor 1 and the IFN-gamma receptor were transcribed. CypB, IFN-alpha/beta/gamma, IL-11, IL-25, MIF, TGF-beta and TNF-alpha as well as the known growth factors EGF, IGF-I/II, IL-6, leukaemia inhibitory factor and oncostatin M (OSM) were excluded as involved in autocrine regulation of NS0 cell proliferation. The receptors for TGF-beta, IGF and OSM are however present in NS0 cell membranes since TGF-beta(1) caused cell death, and IGF-I/II and OSM improved cell growth. Even though no ligand was found, the receptor subunit gp130, active in signal transduction of the IL-6 like proteins, was shown to be essential for NS0 cells as demonstrated by siRNA gene silencing.

Two subunits of the 55 K porcine zona pellucida glycoprotein family are immunologically distinct

DOE Office of Scientific and Technical Information (OSTI.GOV)

Subramanian, M.G.; Yurewicz, E.C.; Sacco, A.G.

1986-03-01

The 55K glycoprotein family (ZP3) of the porcine zona pellucida is comprised of two subunits of 46 K and 45 K which can be resolved by endo-..beta..-galactosidase digestion of ZP3 followed by reversed phase HPLC on Vydac C4 resin. Gel electrophoresis revealed that the 46 K component (EBDG..cap alpha..) is approx. 95% pure and the 45 K component (EBGD..beta..) is 100% pure. In the present study, these two subunits were evaluated immunologically by RIA. Under similar reaction protocols (chloramine-T iodination procedure) comparable specific activities were obtained for EBGD..cap alpha.. (33.06 +/- 7.5 ..mu..ci/..mu..gm), EBGD..beta.. (30.45 +/- 1.6) and ZP3 (26.3more » +/- 1.3). Antibody (Ab) titration studies revealed that EBGD..cap alpha.. and ..beta.. are potent immunogens and /sup 125/I-EBGD..cap alpha.. showed minimal cross reactivity to EBGD..beta..-Ab (8% bound at 1:500 dilution), whereas, /sup 125/I-EBGD..beta.. showed a greater degree of cross reactivity to EBGD..cap alpha..-Ab (23% bound at 1:500 dilution). Maximum binding for the two labeled antigens against homologous Abs (1:500) was > 60%. Dose response studies revealed that in the /sup 125/I-EBGD..cap alpha.. vs EBGD..cap alpha.. -Ab system, the 50% intercept was 3.25 +/- 0.32 ng for EBGD..cap alpha.. and 472.43 +/- 30.26 ng for EBGD..beta.. (p < 0.01), whereas, in the /sup 125/I-EBGD..beta.. vs EBGD..beta..-Ab system the 50% intercept was 3.51 +/- 0.58 for EBGD..beta.. and 166.77 +/- 49.20 for EBGD..cap alpha.. (p < 0.01). No significant differences were observed in the slopes of the dose response curves. It is concluded that the two subunits of ZP3 possess distinct immunologic characteristics as evaluated by RIA.« less

Three mouse models of human thalassemia.

PubMed Central

Martinell, J; Whitney, J B; Popp, R A; Russell, L B; Anderson, W F

1981-01-01

Three types of mice with globin gene mutations, called 352HB, 27HB, and Hbath-J, appear to be true animal models of human thalassemia. Expression of the alpha-globin genes in three stocks of mice, each one heterozygous for one of the alpha-globin mutations, was examined at the polypeptide, RNA, and DNA levels. alpha-Globin polypeptide chains, relative to beta-globin chains in heterozygous thalassemic mice, are present at approximately 80% of normal. The ratios of alpha-globin to beta-globin RNA sequences are also 75-80% of normal, exactly reflecting the alpha-globin to beta-globin chain ratios. In the case of mutant 352HB, at least one alpha-globin gene is deleted. Thalassemic mouse erythroid cells appear to compensate partially for the loss of half of their alpha-globin genes. Images PMID:6946454

Manufacture of tumor- and virus-specific T lymphocytes for adoptive cell therapies

PubMed Central

Wang, X; Rivière, I

2015-01-01

Adoptive transfer of tumor-infiltrating lymphocytes (TILs) and genetically engineered T lymphocytes expressing chimeric antigen receptors (CARs) or conventional alpha/beta T-cell receptors (TCRs), collectively termed adoptive cell therapy (ACT), is an emerging novel strategy to treat cancer patients. Application of ACT has been constrained by the ability to isolate and expand functional tumor-reactive T cells. The transition of ACT from a promising experimental regimen to an established standard of care treatment relies largely on the establishment of safe, efficient, robust and cost-effective cell manufacturing protocols. The manufacture of cellular products under current good manufacturing practices (cGMPs) has a critical role in the process. Herein, we review current manufacturing methods for the large-scale production of clinical-grade TILs, virus-specific and genetically modified CAR or TCR transduced T cells in the context of phase I/II clinical trials as well as the regulatory pathway to get these complex personalized cellular products to the clinic. PMID:25721207

Manufacture of tumor- and virus-specific T lymphocytes for adoptive cell therapies.

PubMed

Wang, X; Rivière, I

2015-03-01

Adoptive transfer of tumor-infiltrating lymphocytes (TILs) and genetically engineered T lymphocytes expressing chimeric antigen receptors (CARs) or conventional alpha/beta T-cell receptors (TCRs), collectively termed adoptive cell therapy (ACT), is an emerging novel strategy to treat cancer patients. Application of ACT has been constrained by the ability to isolate and expand functional tumor-reactive T cells. The transition of ACT from a promising experimental regimen to an established standard of care treatment relies largely on the establishment of safe, efficient, robust and cost-effective cell manufacturing protocols. The manufacture of cellular products under current good manufacturing practices (cGMPs) has a critical role in the process. Herein, we review current manufacturing methods for the large-scale production of clinical-grade TILs, virus-specific and genetically modified CAR or TCR transduced T cells in the context of phase I/II clinical trials as well as the regulatory pathway to get these complex personalized cellular products to the clinic.

Modulation of serpin reaction through stabilization of transient intermediate by ligands bound to alpha-helix F.

PubMed

Komissarov, Andrey A; Zhou, Aiwu; Declerck, Paul J

2007-09-07

Mechanism-based inhibition of proteinases by serpins involves enzyme acylation and fast insertion of the reactive center loop (RCL) into the central beta-sheet of the serpin, resulting in mechanical inactivation of the proteinase. We examined the effects of ligands specific to alpha-helix F (alphaHF) of plasminogen activator inhibitor-1 (PAI-1) on the stoichiometry of inhibition (SI) and limiting rate constant (k(lim)) of RCL insertion for reactions with beta-trypsin, tissue-type plasminogen activator (tPA), and urokinase. The somatomedin B domain of vitronectin (SMBD) did not affect SI for any proteinase or k(lim) for tPA but decreased the k(lim) for beta-trypsin. In contrast to SMBD, monoclonal antibodies MA-55F4C12 and MA-33H1F7, the epitopes of which are located at the opposite side of alphaHF, decreased k(lim) and increased SI for every enzyme. These effects were enhanced in the presence of SMBD. RCL insertion for beta-trypsin and tPA is limited by different subsequent steps of PAI-1 mechanism as follows: enzyme acylation and formation of a loop-displaced acyl complex (LDA), respectively. Stabilization of LDA through the disruption of the exosite interactions between PAI-1 and tPA induced an increase in the k(lim) but did not affect the SI. Thus it is unlikely that LDA contributes significantly to the outcome of the serpin reaction. These results demonstrate that the rate of RCL insertion is not necessarily correlated with SI and indicate that an intermediate, different from LDA, which forms during the late steps of PAI-1 mechanism, and could be stabilized by ligands specific to alphaHF, controls bifurcation between the inhibitory and the substrate pathways.

Cycloheximide and actinomycin D delay death and affect bcl-2, bax, and Ice gene expression in astrocytes under in vitro ischemia.

PubMed

Yu, Albert Cheung Hoi; Yung, Hon Wa; Hui, Michael Hung Kit; Lau, Lok Ting; Chen, Xiao Qian; Collins, Richard A

2003-10-15

An in vitro ischemia model was established and the effect of the metabolic inhibitors cycloheximide (CHX) and actinomycin D (ActD) on apoptosis in astrocytes under ischemia studied. CHX decreased by 75% the number of cells dying after 6 hr of ischemia compared with control cultures. TdT-mediated dUTP nick end labelling (TUNEL) staining of comparable cultures was reduced by 40%. ActD decreased cell death by 60% compared with controls. The number of TUNEL-positive cells was reduced by 38%. The nuclear shrinkage in TUNEL-positive astrocytes in control cultures did not occur in ActD-treated astrocytes, indicating that nuclear shrinkage and DNA fragmentation during apoptosis are two unrelated processes. Expression of bcl-2 (alpha and beta), bax, and Ice in astrocytes under similar ischemic conditions, as measured by quantitative reverse transcription-polymerase chain reaction, indicated that ischemia down-regulated bcl-2 (alpha and beta) and bax. Ice was initially down-regulated from 0 to 4 hr, before returning to control levels after 8 hr of ischemia. ActD decreased the expression of these genes. CHX reduced the expression of bcl-2 (alpha and beta) but increased bax and Ice expression. It is hypothesized that the balance of proapoptotic (Bad, Bax) and antiapoptotic (Bcl-2, Bcl-Xl) proteins determines apoptosis. The data suggest that the ratio of Bcl-2/Bad in astrocytes following ActD and CHX treatment does not decrease as much in untreated cells during ischemia. Our data indicate that it is the ratio of Bcl-2 family members that plays a critical role in determining ischemia-induced apoptosis. It is also important to note that ischemia-induced apoptosis involves the regulation of RNA and protein synthesis. Copyright 2003 Wiley-Liss, Inc.

Chromosomal aberrations and delays in cell progression induced by x-rays in Tradescantia clone 02 meristems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geard, C.R.

1983-01-01

In root meristems of Tradescantia clone 02 (developed by Sparrow and his colleagues for mutation studies), X-rays interfere with the progression of cells through the cell cycle and induce chromosomal aberrations in a dose-dependent manner consistent with linear-quadratic kinetics. Sequential mitotic cell accumulations after irradiation indicate that sensitivity to aberration induction is probably greatest in cells from late S to early G2, with chromatid interchanges the most frequent aberration type and all aberrations consistent with initiation from the interaction between two lesions. The ratio of the coefficients in the linear (..cap alpha..) and the quadratic (..beta..) terms (..cap alpha../..beta..) ismore » equal to the dose average of specific energy produced by individual particles in the site where interaction takes place. The ratio ..cap alpha../..beta.. for chromosomal aberrations is similar to that previously found for X-ray-induced mutation in Tradescantia stamen hairs, supporting the proposal that radiation-induced mutational events are due to chromosomal aberrations with interaction distances of about 1..mu..m. Abrahamson and co-workers have noted that both ..cap alpha../..beta.. ratios appear to be related to nuclear target size and are similar for chromosomal and mutational endpoints in the same organism. These findings support this concept; however, it is apparent that any situation which diminishes yield at high doses (e.g., mitotic delay) will probably affect the ..beta.. component. 23 references, 5 figures, 2 tables.« less

Chromosomal aberrations and delays in cell progression induced by x-rays in Tradescantia clone 02 meristems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geard, C.R.

1983-01-01

In root meristems of Tradescantia clone 02 (developed by Sparrow and his colleagues for mutation studies), X-rays interfere with the progression of cells through the cell cycle and induce chromosomal aberrations in a dose-dependent manner consistent with linear-quadratic kinetics. Sequential mitotic cell accumulations after irradiation indicate that sensitivity to aberrration induction is probably greatest in cells from late S to early G2, with chromatid interchanges the most frequent aberration type and all aberrations consistent with intiation from the interaction between two lesions. The ratio of the coefficients in the linear (..cap alpha..) and the quadratic (..beta..) terms (..cap alpha../..beta..) ismore » equal to the dose average of specific energy produced by individual particles in the site where interaction takes place. The ratio ..cap alpha../..beta.. for chromosomal aberrations is similar to that previously found for X-ray-induced mutation in Tradescantia stamen hairs, supporting the proposal that radiation-induced mutational events are due to chromosomal aberrations with interaction distances of about 1 ..mu..m. Abrahmson and co-workers have noted that both ..cap alpha../..beta.. ratios appear to be related to nuclear target size and are similar for chromosomal and mutational endpoints in the same organism. These findings support this concept; however, it is apparent that any situation which diminishes yield at high doses (e.g., mitotic delay) will primarily affect the ..beta.. component, resulting in low assessments of interaction site diameters.« less

Effect of an alpha-blocker (Nicergoline) and of a beta-blocker (Acebutolol) on the in vitro biosynthesis of vascular extracellular matrix.

PubMed

Moczar, M; Robert, A M; Jacotot, B; Robert, L

2001-05-01

The effect of an alpha-blocking agent and of a beta-blocking agent on the biosynthesis of extracellular matrix macromolecules of the arterial wall was investigated. Rabbit aorta explants were cultured up to 48 hours with radioactive proline, lysine or glucosamine. In presence of these drugs, at concentration shown to be effective for the inhibition of platelet-endothelial cell interactions (10(-7) M), the incorporation of 14C proline in total macromolecular proline was higher than in macromolecular hydroxyproline suggesting a relatively higher rate of biosynthesis of non-collagenous proteins as compared to collagens. The alpha-blocking increased the incorporation of 14C proline in collagenous and non-collagenous proteins after 18 hours of incubation. beta-blocking also increased the incorporation of proline in macromolecular proline and hydroxyproline as compared to control cultures. Both increased the incorporation of 3H glucosamine in newly synthesised glycosaminoglycans. beta-blocking increased mainly the neosynthesis of heparan sulphate, alpha-blocking that of hyaluronan. The incorporation of 14C-lysine in crosslinked, insoluble elastin was not modified. These experiments confirm that alpha and beta-blocking agents can influence not only the tonus of aortic smooth muscle cells but also the relative rates of biosynthesis of extracellular matrix macromolecules. This effect should be taken in consideration for the evaluation of the long range effect of alpha and beta-blocking drugs on the vascular wall.

Medicinal flowers. XXVII. New flavanone and chalcone glycosides, arenariumosides I, II, III, and IV, and tumor necrosis factor-alpha inhibitors from everlasting, flowers of Helichrysum arenarium.

PubMed

Morikawa, Toshio; Wang, Li-Bo; Nakamura, Seikou; Ninomiya, Kiyofumi; Yokoyama, Eri; Matsuda, Hisashi; Muraoka, Osamu; Wu, Li-Jun; Yoshikawa, Masayuki

2009-04-01

The methanolic extract from the flowers of Helichrysum arenarium L. MOENCH was found to show inhibitory effect on tumor necrosis factor-alpha (TNF-alpha, 1 ng/ml)-induced cytotoxicity in L929 cells. From the methanolic extract, 50 constituents including four new flavanone and chalcone glycosides named arenariumosides I (1), II (2), III (3), and IV (4) were isolated. The stereostructures of 1-4 were elucidated on the basis of chemical and physicochemical evidence. Among the constituents, naringenin 7-O-beta-D-glucopyranoside (7), apigenin 7-O-beta-D-glucopyranoside (14), apigenin 7-O-gentiobioside (16), and apigenin 7,4'-di-O-beta-D-glucopyranoside (17) significantly inhibited TNF-alpha-induced cytotoxicity in L929 cells at 30 microM.

Strikingly higher interleukin (IL)-1alpha, IL-1beta and soluble interleukin-1 receptor antagonist (sIL-1RA) but similar IL-2, sIL-2R, IL-3, IL-4, IL-6, sIL-6R, IL-10, tumour necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta and interferon IFN-gamma urine levels in healthy females compared to healthy males: protection against urinary tract injury?

PubMed

Sadeghi, M; Daniel, V; Naujokat, C; Weimer, R; Opelz, G

2005-11-01

The aim of this prospective study was to examine gender-related differences of cytokines in the plasma and urine of healthy individuals that might provide a clue concerning the lower rate of chronic renal diseases in females. Soluble interleukin-1 receptor antagonist (sIL-1RA), interleukin (IL)-1alpha, IL-1beta, IL-2, sIL-2R, IL-3, IL-4, IL-6, sIL-6R, IL-10, tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta(2) and interferon (IFN)-gamma were determined using standard enzyme-linked immunosorbent assay (ELISA). Cytokine levels were determined in simultaneously obtained plasma and urine samples of 18 male and 28 female healthy members of our laboratory staff. Urine cytokine levels were studied three times at 1-month intervals. All individuals had a negative urine nitrite test and showed no symptoms of urinary tract infection (UTI). Plasma levels of all studied cytokines were similar in males and females (P = n.s.). However, females had significantly higher urine IL-1alpha (P < 0.0001; P < 0.0001; P < 0.0001) and sIL-1RA (P = 0.0001; P = 0.0003; P = 0.0002) than males at three and higher IL-1beta at one of the three investigations (P = 0.098; P = 0.003; P = 0.073). Urine levels of the other cytokines were similar in males and females. Higher urine levels of IL-1alpha, IL-1beta and sIL-1RA in females may result from stimulation of cells in the urinary tract. Increased sIL-1RA might block T lymphocyte activation. The elevated cytokines may play a role in the protection of the female urinary tract from certain renal diseases, such as pyelonephritis and other inflammatory and sclerotic kidney diseases.

Evolutionarily conserved TCR binding sites, identification of T cells in primary lymphoid tissues, and surprising trans-rearrangements in nurse shark.

PubMed

Criscitiello, Michael F; Ohta, Yuko; Saltis, Mark; McKinney, E Churchill; Flajnik, Martin F

2010-06-15

Cartilaginous fish are the oldest animals that generate RAG-based Ag receptor diversity. We have analyzed the genes and expressed transcripts of the four TCR chains for the first time in a cartilaginous fish, the nurse shark (Ginglymostoma cirratum). Northern blotting found TCR mRNA expression predominantly in lymphoid and mucosal tissues. Southern blotting suggested translocon-type loci encoding all four chains. Based on diversity of V and J segments, the expressed combinatorial diversity for gamma is similar to that of human, alpha and beta may be slightly lower, and delta diversity is the highest of any organism studied to date. Nurse shark TCRdelta have long CDR3 loops compared with the other three chains, creating binding site topologies comparable to those of mammalian TCR in basic paratope structure; additionally, nurse shark TCRdelta CDR3 are more similar to IgH CDR3 in length and heterogeneity than to other TCR chains. Most interestingly, several cDNAs were isolated that contained IgM or IgW V segments rearranged to other gene segments of TCRdelta and alpha. Finally, in situ hybridization experiments demonstrate a conservation of both alpha/beta and gamma/delta T cell localization in the thymus across 450 million years of vertebrate evolution, with gamma/delta TCR expression especially high in the subcapsular region. Collectively, these data make the first cellular identification of TCR-expressing lymphocytes in a cartilaginous fish.

Analysis of the two-peptide bacteriocins lactococcin G and enterocin 1071 by site-directed mutagenesis.

PubMed

Oppegård, Camilla; Fimland, Gunnar; Thorbaek, Lisbeth; Nissen-Meyer, Jon

2007-05-01

The two peptides (Lcn-alpha and Lcn-beta) of the two-peptide bacteriocin lactococcin G (Lcn) were changed by stepwise site-directed mutagenesis into the corresponding peptides (Ent-alpha and Ent-beta) of the two-peptide bacteriocin enterocin 1071 (Ent), and the potencies and specificities of the various hybrid constructs were determined. Both Lcn and, to a lesser extent, Ent were active against all the tested lactococcal strains, but only Ent was active against the tested enterococcal strains. The two bacteriocins thus differed in their relative potencies to various target cells, despite their sequence similarities. The hybrid combination Lcn-alpha+Ent-beta had low potency against all strains tested, indicating that these two peptides do not interact optimally. The reciprocal hybrid combination (i.e., Ent-alpha+Lcn-beta), in contrast, was highly potent, indicating that these two peptides may form a functional antimicrobial unit. In fact, this hybrid combination (Ent-alpha+Lcn-beta) was more potent against lactococcal strains than wild-type Ent was (i.e., Ent-alpha+Ent-beta), but it was inactive against enterococcal strains (in contrast to Ent but similar to Lcn). The observation that Ent-alpha is more active against lactococci in combination with Lcn-beta and more active against enterococci in combination with Ent-beta suggests that the beta peptide is an important determinant of target cell specificity. Especially the N-terminal residues of the beta peptide seem to be important for specificity, since Ent-alpha combined with an Ent-beta variant with Ent-to-Lcn mutations at positions 1 to 4, 7, 9, and 10 was >150-fold less active against enterococcal strains but one to four times more active against lactococcal strains than Ent-alpha+Ent-beta. Moreover, Ent-to-Lcn single-residue mutations in the region spanning residues 1 to 7 in Ent-beta had a more detrimental effect on the activity against enterococci than on that against lactococcal strains. Of the single-residue mutations made in the N-terminal region of the alpha peptide, the Ent-to-Lcn mutations N8Q and P12R in Ent-alpha influenced specificity, as follows: the N8Q mutation had no effect on activity against tested enterococcal strains but increased the activity 2- to 4-fold against the tested lactococcal strains, and the P12R mutation reduced the activity >150-fold and only approximately 2-fold against enterococcal and lactococcal strains, respectively. Changing residues in the C-terminal half/part of the Lcn peptides (residues 20 to 39 and 25 to 35 in Lcn-alpha and Lcn-beta, respectively) to those found in the corresponding Ent peptides did not have a marked effect on the activity, but there was an approximately 10-fold or greater reduction in the activity upon also introducing Lcn-to-Ent mutations in the mid-region (residues 8 to 19 and 9 to 24 in Lcn-alpha and Lcn-beta, respectively). Interestingly, the Lcn-to-Ent F19L+G20A mutation in an Lcn-Ent-beta hybrid peptide was more detrimental when the altered peptide was combined with Lcn-alpha (>10-fold reduction) than when it was combined with Ent-alpha ( approximately 2-fold reduction), suggesting that residues 19 and 20 (which are part of a GXXXG motif) in the beta peptide may be involved in a specific interaction with the cognate alpha peptide. It is also noteworthy that the K2P and A7P mutations in Lcn-beta reduced the activity only approximately 2-fold, suggesting that the first seven residues in the beta peptides do not form an alpha-helix.

Dexamethasone inhibits high glucose-, TNF-alpha-, and IL-1beta-induced secretion of inflammatory and angiogenic mediators from retinal microvascular pericytes.

PubMed

Nehmé, Alissar; Edelman, Jeffrey

2008-05-01

To characterize the effects of dexamethasone in human retinal pericytes (HRMPs), monocytes (THP-1), and retinal endothelial cells (HRECs) treated with high glucose, TNF-alpha, or IL-1beta. HRMP and HREC phenotypes were verified by growth factor stimulation of intracellular calcium-ion mobilization. Glucocorticoid receptor phosphorylation was assessed with an anti-phospho-Ser(211) glucocorticoid receptor antibody. Secretion of 89 inflammatory and angiogenic proteins were compared in cells incubated with (1) normal (5 mM) or high (25 mM) D-glucose and (2) control medium, TNF-alpha (10 ng/mL), or IL-1beta (10 ng/mL), with or without dexamethasone (1 nM to 1 microM). The proteins were compared by using multianalyte profile testing. HRMPs and HRECs expressed functional PDGFB-R and VEGFR-2, respectively. Dexamethasone induction of glucocorticoid receptor phosphorylation was dose-dependent in all cell types. High glucose increased secretion of inflammatory mediators in HRMPs, but not in HRECs. Dexamethasone dose dependently inhibited secretion of these mediators in HRMPs. For all cells, TNF-alpha and IL-1beta induced a fivefold or more increase in inflammatory and angiogenic mediators; HRMPs secreted the greatest number and level of mediators. Dexamethasone dose dependently inhibited the secretion of multiple proteins from HRMPs and THP-1 cells, but not from HRECs (IC(50) 2 nM to 1 microM). High glucose, TNF-alpha, and IL-1beta induced an inflammatory phenotype in HRMPs, characterized by hypersecretion of inflammatory and angiogenic mediators. Dexamethasone at various potencies blocked hypersecretion of several proteins. Pericytes may be a key therapeutic target in retinal inflammatory diseases, including diabetic retinopathy. Inhibition of pathologic mediators may depend on delivering high levels ( approximately 1 microM) of glucocorticoid to the retina.

Substance P enhances proliferation and paracrine potential of adipose-derived stem cells in vitro.

PubMed

Kim, Suna; Piao, Jiyuan; Son, Youngsook; Hong, Hyun Sook

2017-03-25

Stem cells have tremendous promise to treat intractable diseases. Notably, adipose-derived stem cells (ADSCs) are actively being investigated because of ease of sampling and high repopulation capacity in vitro. ADSCs can exert a therapeutic effect through differentiation and paracrine potential, and these actions have been proven in many diseases, including cutaneous and inflammatory diseases. Transplantation of ADSCs necessitates therapeutic quantities and thus, long term ex vivo culture of ADSCs. However, this procedure can impair the activity of ADSCs and provoke cellular senescence, leading to low efficacy in vivo. Accordingly, strategies to restore cellular activity and inhibit senescence of stem cells during ex vivo culture are needed for stem cell-based therapies. This study evaluated a potential supplementary role of Substance P (SP) in ADSC ex vivo culture. After confirming that the ADSC cell cycle was damaged by passage 6 (p6), ADSCs at p6 were cultured with SP, and their proliferation rates, cumulative cell numbers, cytokine profiles, and impact on T/endothelial cells were assessed. Long-term culture weakened proliferation ability and secretion of the cytokines, transforming growth factor-beta 1 (TGF-beta1), vascular endothelial growth factor (VEGF), and stromal cell derived factor-1 alpha (SDF-1alpha) in ADSCs. However, SP treatment reduced the population doubling time (PDT), enabling gain of a sufficient number of ADSCs at early passages. In addition, SP restored cytokine secretion, enhancing the ADSC-mediated paracrine effect on T cell and human umbilical vein endothelial cells (HUVECs). Taken together, these results suggest that SP can retain the therapeutic effect of ADSCs by elevating their proliferative and paracrine potential in ex vivo culture. Copyright © 2017 Elsevier Inc. All rights reserved.

Lymphotoxin-beta receptor signaling regulates hepatic stellate cell function and wound healing in a murine model of chronic liver injury.

PubMed

Ruddell, Richard G; Knight, Belinda; Tirnitz-Parker, Janina E E; Akhurst, Barbara; Summerville, Lesa; Subramaniam, V Nathan; Olynyk, John K; Ramm, Grant A

2009-01-01

Lymphotoxin-beta (LTbeta) is a proinflammatory cytokine and a member of the tumor necrosis factor (TNF) superfamily known for its role in mediating lymph node development and homeostasis. Our recent studies suggest a role for LTbeta in mediating the pathogenesis of human chronic liver disease. We hypothesize that LTbeta co-ordinates the wound healing response in liver injury via direct effects on hepatic stellate cells. This study used the choline-deficient, ethionine-supplemented (CDE) dietary model of chronic liver injury, which induces inflammation, liver progenitor cell proliferation, and portal fibrosis, to assess (1) the cellular expression of LTbeta, and (2) the role of LTbeta receptor (LTbetaR) in mediating wound healing, in LTbetaR(-/-) versus wild-type mice. In addition, primary isolates of hepatic stellate cells were treated with LTbetaR-ligands LTbeta and LTbeta-related inducible ligand competing for glycoprotein D binding to herpesvirus entry mediator on T cells (LIGHT), and mediators of hepatic stellate cell function and fibrogenesis were assessed. LTbeta was localized to progenitor cells immediately adjacent to activated hepatic stellate cells in the periportal region of the liver in wild-type mice fed the CDE diet. LTbetaR(-/-) mice fed the CDE diet showed significantly reduced fibrosis and a dysregulated immune response. LTbetaR was demonstrated on isolated hepatic stellate cells, which when stimulated by LTbeta and LIGHT, activated the nuclear factor kappa B (NF-kappaB) signaling pathway. Neither LTbeta nor LIGHT had any effect on alpha-smooth muscle actin, tissue inhibitor of metalloproteinase 1, transforming growth factor beta, or procollagen alpha(1)(I) expression; however, leukocyte recruitment-associated factors intercellular adhesion molecule 1 and regulated upon activation T cells expressed and secreted (RANTES) were markedly up-regulated. RANTES caused the chemotaxis of a liver progenitor cell line expressing CCR5. This study suggests that LTbetaR on hepatic stellate cells may be involved in paracrine signaling with nearby LTbeta-expressing liver progenitor cells mediating recruitment of progenitor cells, hepatic stellate cells, and leukocytes required for wound healing and regeneration during chronic liver injury.

Structural characterisation of galactoglucomannan secreted by suspension-cultured cells of Nicotiana plumbaginifolia.

PubMed

Sims, I M; Craik, D J; Bacic, A

1997-08-25

Galactoglucomannan (GGM) from cultures of Nicotiana plumbaginifolia has Man:Glc:Gal:Ara:Xyl in 1.0:1.1:1.0:0.1:0.04 ratio. Linkage analysis contained 4- and 4,6-Manp, 4-Glcp, terminal Galp and 2-Galp, small amounts and terminal Arap and terminal Xylp, and approximately 0.03 mol acetyl per mol of glucosyl residue. Treatment with alpha- and beta-D-galactosidases showed that the majority of the side-chains were either single Galp-alpha-(1-->residues or the disaccharide Galp-beta-(1-->2)-Galp-alpha-(1-->linked to O-6 of the 4-Manp residues of the glucomannan backbone. Analysis of the oligosaccharides generated by endo-(1-->4)-beta-mannanase digestion confirmed that the GGM comprises a backbone of predominantly alternating-->4)-D-Manp-beta-(1-->and-->4)-D-Glcp-beta-(1-->branch ed at O-6 of 65% of the 4-Manp residues. The major oligosaccharide identified was D-Glcp-beta-(1-->4)-[D-Galp-beta-(1-->2)-D-Galp-alpha-(1-->6)]-D-Man p-beta-(1-->4)-D-Glcp-beta-(1-->4)-[D-Galp-alpha-(1-->6)]-D-Manp -beta-(1-->(27%), and most of the other oligosaccharides produced in significant quantities were based on this structure.

Histochemistry of glycoconjugates in the skin of the bovine muzzle, with special reference to glandular structures.

PubMed

Meyer, W; Tsukise, A

1989-01-01

The distribution of glycoconjugates in the muzzle of young adult Holstein cows has been studied by means of selected light-microscopic histochemical methods, including lectin histochemistry. In the skin layers, strong reactions were confined to intercellular substances in between the cells of the vital epidermis, exhibiting neutral glycoconjugates mainly with alpha-D-galactosyl and N-acetyl-D-galactosaminyl residues. In the nasolabial glands, distinctly positive staining for neutral glycoproteins with various saccharide residues (alpha-D-galactose, alpha-N-acetylgalactosamine, D-galactose-beta(1----3)D-N-acetylgalactosamine, beta-D-galactose), and for smaller amounts of acidic glycoconjugates, was found in the secretory cells and the luminal secretion. The cells of the excretory duct system showed weak to moderate reactions (alpha-D-galactose, beta-D-galactose), only the collecting ducts reacted positively for acidic glycoproteins with sialyl residues. The results obtained are discussed in view of muzzle function, with special reference to the salivary nature of the secretion of bovine nasolabial glands.

Transforming growth factor-beta inhibits human antigen-specific CD4+ T cell proliferation without modulating the cytokine response.

PubMed

Tiemessen, Machteld M; Kunzmann, Steffen; Schmidt-Weber, Carsten B; Garssen, Johan; Bruijnzeel-Koomen, Carla A F M; Knol, Edward F; van Hoffen, Els

2003-12-01

Transforming growth factor (TGF)-beta has been demonstrated to play a key role in the regulation of the immune response, mainly by its suppressive function towards cells of the immune system. In humans, the effect of TGF-beta on antigen-specific established memory T cells has not been investigated yet. In this study antigen-specific CD4(+) T cell clones (TCC) were used to determine the effect of TGF-beta on antigen-specific proliferation, the activation status of the T cells and their cytokine production. This study demonstrates that TGF-beta is an adequate suppressor of antigen-specific T cell proliferation, by reducing the cell-cycle rate rather than induction of apoptosis. Addition of TGF-beta resulted in increased CD69 expression and decreased CD25 expression on T cells, indicating that TGF-beta is able to modulate the activation status of in vivo differentiated T cells. On the contrary, the antigen-specific cytokine production was not affected by TGF-beta. Although TGF-beta was suppressive towards the majority of the T cells, insensitivity of a few TCC towards TGF-beta was also observed. This could not be correlated to differential expression of TGF-beta signaling molecules such as Smad3, Smad7, SARA (Smad anchor for receptor activation) and Hgs (hepatocyte growth factor-regulated tyrosine kinase substrate). In summary, TGF-beta has a pronounced inhibitory effect on antigen-specific T cell proliferation without modulating their cytokine production.

Probing conformational changes in the I-like domain and the cysteine-rich repeat of human beta 3 integrins following disulfide bond disruption by cysteine mutations: identification of cysteine 598 involved in alphaIIbbeta3 activation.

PubMed

Chen, P; Melchior, C; Brons, N H; Schlegel, N; Caen, J; Kieffer, N

2001-10-19

We have investigated receptor function and epitope expression of recombinant alpha(IIb)beta(3) mutated at Cys(177) or Cys(273) in the I-like domain as well as Cys(598), located in the fourth repeat of the membrane-proximal cysteine-rich region and mutated in a Glanzmann's thrombasthenia type II patient. The beta(3) mutants beta(3)C177A, beta(3)C273A, and beta(3)C598Y exhibited a decreased electrophoretic mobility in SDS-polyacrylamide gel electrophoresis under nonreducing conditions, confirming the disruption of the respective disulfide loops. Despite reduced surface expression, the alpha(IIb)beta(3)C177A, alpha(IIb)beta(3)C273A, and alpha(IIb)beta(3)C598Y receptors mediated cell adhesion to immobilized fibrinogen and translocated into focal adhesion plaques. The beta(3)C598Y mutation, but not the beta(3)C177A or beta(3)C273A mutations, induced spontaneous binding of the ligand mimetic monoclonal antibody PAC-1, while the beta(3)C177A and beta(3)C273A mutants exhibited reduced complex stability in the absence of Ca(2+). Epitope mapping of function-blocking monoclonal antibodies (mAbs) allowed the identification of two distinct subgroups; mAbs A2A9, pl2-46, 10E5, and P256 did not interact with alpha(IIb)beta(3)C273A and bound only weakly to alpha(IIb)beta(3)C177A, while mAbs AP2, LM609 and 7E3 bound normally to mutant alpha(IIb)beta(3)C273A, but interacted only weakly with mutant alpha(IIb)beta(3)C177A. Furthermore, a cryptic epitope recognized by mAb 4D10G3 and not exposed on wild type alpha(IIb)beta(3) became accessible only on mutant alpha(IIb)beta(3)C177A and was mapped to the 60-kDa chymotrypsin fragment of beta(3). Finally, the ligand-induced binding site (LIBS) epitopes AP5, D3, LIBS1, and LIBS2 were spontaneously expressed on all three mutants independent of RGDS or dithiothreitol treatment. Our results provide evidence that disruption of a single cysteine disulfide bond in the cysteine-rich repeat domain, but not in the I-like domain, activates integrin alpha(IIb)beta(3). In contrast, disruption of each of the disulfide bonds in the two long insertions of the I-like domain predicted to be in close contact with the alpha subunit beta-propeller domain affect the stability of the alpha(IIb)beta(3) heterodimer and inhibit complex-specific mAb binding without affecting the RGD binding capacity of the metal ion-dependent adhesion site-like domain.

A Jurkat 76 based triple parameter reporter system to evaluate TCR functions and adoptive T cell strategies.

PubMed

Rosskopf, Sandra; Leitner, Judith; Paster, Wolfgang; Morton, Laura T; Hagedoorn, Renate S; Steinberger, Peter; Heemskerk, Mirjam H M

2018-04-03

Adoptive T cell therapy using TCR transgenic autologous T cells has shown great potential for the treatment of tumor patients. Thorough characterization of genetically reprogrammed T cells is necessary to optimize treatment success. Here, we describe the generation of triple parameter reporter T cells based on the Jurkat 76 T cell line for the evaluation of TCR and chimeric antigen receptor functions as well as adoptive T cell strategies. This Jurkat subline is devoid of endogenous TCR alpha and TCR beta chains, thereby circumventing the problem of TCR miss-pairing and unexpected specificities. The resultant reporter cells allow simultaneous determination of the activity of the transcription factors NF-κB, NFAT and AP-1 that play key roles in T cell activation. Human TCRs directed against tumor and virus antigens were introduced and reporter responses were determined using tumor cell lines endogenously expressing the antigens of interest or via addition of antigenic peptides. Finally, we demonstrate that coexpression of adhesion molecules like CD2 and CD226 as well as CD28 chimeric receptors represents an effective strategy to augment the response of TCR-transgenic reporters to cells presenting cognate antigens.

a Combined Molecular Dynamics and NMR Spectroscopic Protocol for the Conformational Analysis of Oligosaccharides.

NASA Astrophysics Data System (ADS)

Varma, Vikram

A combined experimental and theoretical protocol for the conformational analysis of oligosaccharides is presented. Three disaccharides, methyl alpha - scD-mannopyranosyl-(1 to 3)-alpha- scD-mannopyranoside, methyl beta- scD-galactopyranosyl-(1 to 4)-beta- scD-glucopyranoside, and propyl beta- scD-2-acetamido -2-deoxy glucopyranosyl-(1 to 3)- alpha- scL-rhamnopyranoside, are used to evaluate a protocol for conformational analysis that makes use of molecular dynamics calculations with the CHARMM force field. Dynamics trajectories computed in vacuo and in water are used to calculate time-averaged NMR parameters such as spin-lattice relaxation times (T_1 ), Nuclear Overhauser Enhancements (NOE), and heteronuclear spin-spin coupling constants (^3J _{rm CH}). The calculated NMR parameters are then compared to experimental values and used to evaluate the computational procedure. The energetically accessible conformations are effectively sampled by the simulations. The method has been extended to the conformational analysis of higher-order oligosaccharides corresponding to the cell-wall polysaccharide of the Streptococcus Group A, and the Shigella flexneri Y O-antigen. The Streptococcus Group A cell-wall polysaccharide is comprised of a backbone of rhamnopyranosyl units connected by alternating alpha- scL-(1 to 3) and alpha- scL -(1 to 2) linkages, to which are attached N-acetyl-beta- scD-glucosamine ( beta- scD-GlcpNAc) residues at the 3 positions of the rhamnose backbone.rm A&rm B^'qquad A^'& rm Bqquad Acr[{-alpha}{-}L{-}Rha {it p}{-}(1to2){-alpha }{-}L{-}Rha{it p} {-}(1to3){-alpha}{ -}L{-}Rha{it p}-(1to2) -alpha-L-Rha{it p}{-}(1 to3){-alpha}{-}L{- }Rha{it p}{-}cr&uparrow(1 to3)&uparrow(1to3)crbeta {-}D{-}&rm Glc{it p }NAcqquadbeta{-}D{-}& rm Glc{it p}NAccr&rm C ^'&rm C] A branched trisaccharide (A^' -(C)B), a tetrasaccharide (A^' -(C)B-A), a pentasaccharide (C^' -B^'-A ^'-(C)B), and two hexasaccharides (C^'-B^ '-A^' -(C)B-A) and (A-(C^')B ^'-A^' -(C)B), have been chosen for study. The Shigella flexneri Y O-antigen is a linear polysaccharide that is composed of rhamnose units linked alpha- scL-(1 to 3) and alpha- scL-(1 to 2), interspersed by N-acetyl-beta - scD-glucosamine (beta- scD -GlcpNAc) to form a periodic repeating unit ABCD. &rm A&rm B&rm C&rm Dcr [{-alpha}{-}L {-}Rha{it p}-(1to2){ -alpha}{-}L{-}Rha{it p}{-}(1to3){-alpha} {-}L{-}Rha{it p}{ -}(1to3){-}beta{-}D {-}Glc{it p}NAc{-}(1 to2){-}]_{it n}A heptasaccharide corresponding to the fragment (ABCDA^'B ^'C^' ) of the Shigella flexneri Y polysaccharide has been investigated. The conformational properties of all of the oligosaccharides have been studied using molecular dynamics simulations. Interproton distances derived from ROESY spectra are used to determine the starting conformations of the oligosaccharides used in the dynamics calculations, and dynamics simulations are computed with proton pairs constrained to the ROESY -derived distances, as well as with the constraints removed. These dynamics trajectories are used to calculate ROESY buildup curves with CROSREL, a program that treats cross relaxation by means of a full matrix relaxation approach. The calculated buildup curves compare favorably with the experimental buildup curves. The study demonstrates that molecular dynamics, in conjunction with NMR spectroscopy, can be a useful tool in the understanding of the conformational behavior of oligosaccharides in solution. The results provide a model for antigen topology that can be used to infer some of the critical features of antibody-antigen interactions.

Fibronectin-mediation cell adhesion is required for induction of 92-kDa type IV collagenase/gelatinase (MMP-9) gene expression during macrophage differentiation : the signaling role of protein kinase C-{beta}.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, B.; Laouar, A.; Huberman, E.

1998-05-08

Induction of the 92-kDa gelatinase (MMP-9) gene expression is associated with macrophage differentiation. In this study, we explored the regulatory mechanisms underlying this differentiation-associated MMP-9 gene expression in human HL-60 myeloid leukemia cells and human peripheral blood monocytes. Phorbol 12-myristate 13-acetate (PMA) markedly induced MMP-9 gene expression in HL-60 cells; the induction closely paralleled the timing and extent of PMA-induced cell adhesion and spreading, a hallmark of macrophage differentiation. Similarly, treatment with PMA or macrophage-colony stimulating factor stimulated adherence and spreading of blood monocytes with a concurrent 7- or 5-fold increase in MMP-9 production, respectively. In protein kinase C (PKC)-betamore » -deficient HL-60 variant cells (HL-525), PMA failed to induce cell adhesion and MMP-9 gene expression. Transfecting HL-525 cells with a PKC-beta expression plasmid restored PKC-beta levels and PMA inducibility of cell adhesion and spreading as well as MMP-9 gene expression. Induction of cell adhesion and MMP-9 gene expression in HL-60 cells and blood monocytes was strongly inhibited by neutralizing monoclonal antibodies to fibronectin (FN) and its receptor {alpha}5{beta}1 integrin. HL-525 cells, which constitutively display high levels of surface {alpha}5{beta}1 integrin, adhered and spread on immobilized FN with concomitant induction of MMP-9 gene expression. Cytochalasins B and D were each a potent inhibitor of MMP-9 production. Our results suggest that {alpha}5{beta}1 integrin-mediated interaction of immature hematopoietic cells with FN plays a critical role in modulating matrix-degrading activities during macrophage differentiation.« less

Blockade of rat alpha3beta4 nicotinic receptor function by methadone, its metabolites, and structural analogs.

PubMed

Xiao, Y; Smith, R D; Caruso, F S; Kellar, K J

2001-10-01

The opioid agonist properties of (+/-)-methadone are ascribed almost entirely to the (-)-methadone enantiomer. To extend our knowledge of the pharmacological actions of methadone at ligand-gated ion channels, we investigated the effects of the two enantiomers of methadone and its metabolites R-(+)-2-ethyl-1,5-dimethyl-3,3-diphenylpyrrolinium perchlorate (EDDP) and R-(+)-2-ethyl-5-methyl-3,3-diphenyl-1-pyrroline hydrochloride (EMDP), as well as structural analogs of methadone, including (-)-alpha-acetylmethadol hydrochloride (LAAM) and (+)-alpha-propoxyphene, on rat alpha3beta4 neuronal nicotinic acetylcholine receptors (nAChRs) stably expressed in a human embryonic kidney 293 cell line, designated KXalpha3beta4R2. (+/-)-methadone inhibited nicotine-stimulated 86Rb+ efflux from the cells in a concentration-dependent manner with an IC50 value of 1.9 +/- 0.2 microM, indicating that it is a potent nAChR antagonist. The (-)- and (+)-enantiomers of methadone have similar inhibitory potencies on nicotine-stimulated 86Rb+ efflux, with IC50 values of approximately 2 microM. EDDP, the major metabolite of methadone, is even more potent, with an IC50 value of approximately 0.5 microM, making it one of the most potent nicotinic receptor blockers reported. In the presence of (+/-)-methadone, EDDP, or LAAM, the maximum nicotine-stimulated 86Rb+ efflux was markedly decreased, but the EC50 value for nicotine stimulation was altered only slightly, if at all, indicating that these compounds block alpha3beta4 nicotinic receptor function by a noncompetitive mechanism. Consistent with a noncompetitive mechanism, (+/-)-methadone, its metabolites, and structural analogs have very low affinity for nicotinic receptor agonist binding sites in membrane homogenates from KXalpha3beta4R2 cells. We conclude that both enantiomers of methadone and its metabolites as well as LAAM and (+)-alpha-propoxyphene are potent noncompetitive antagonists of alpha3beta4 nAChRs.

[IL-1beta, IL-10, INF-gamma, TNF-alpha, S100beta, AMA-M2 and cell immune response in stroke].

PubMed

Sergeeva, S P; Erofeeva, L M; Gul'tiaev, M M

2011-01-01

Clinical data showed a role for stress, inflammatory, innate immune and adaptive immune mechanisms is stroke. Absolute and relative count of lymphocytes decrease, CD3 HLA DR+ and immunoregulatory balance (CD4+/CD8+) increase, concentration of IL-1beta, INF-gamma, TNF-alpha, S100beta, AMA-M2 increase, IL-10 decrease were detected in peripheral blood of 25 patients with stroke. It is explained that the products of brain cell stroke destruction (AMA-M2) play in autoimmune stroke progress mechanisms the same role as neurospecific proteins as S100beta. It is concluded that both stereotype and autoimmune mechanisms are involved in the development of stroke.

Induction of T helper 3 regulatory cells by dendritic cells infected with porcine reproductive and respiratory syndrome virus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silva-Campa, Erika; Flores-Mendoza, Lilian; Resendiz, Monica

2009-05-10

Delayed development of virus-specific immune response has been observed in pigs infected with the porcine reproductive and respiratory syndrome virus (PRRSV). Several studies support the hypothesis that the PRRSV is capable of modulating porcine immune system, but the mechanisms involved are yet to be defined. In this study, we evaluated the induction of T regulatory cells by PRRSV-infected dendritic cells (DCs). Our results showed that PRRSV-infected DCs significantly increased Foxp3{sup +}CD25{sup +} T cells, an effect that was reversible by IFN-alpha treatment, and this outcome was reproducible using two distinct PRRSV strains. Analysis of the expressed cytokines suggested that themore » induction of Foxp3{sup +}CD25{sup +} T cells is dependent on TGF-beta but not IL-10. In addition, a significant up-regulation of Foxp3 mRNA, but not TBX21 or GATA3, was detected. Importantly, our results showed that the induced Foxp3{sup +}CD25{sup +} T cells were able to suppress the proliferation of PHA-stimulated PBMCs. The T cells induced by the PRRSV-infected DCs fit the Foxp3{sup +}CD25{sup +} T helper 3 (Th3) regulatory cell phenotype described in the literature. The induction of this cell phenotype depended, at least in part, on PRRSV viability because IFN-alpha treatment or virus inactivation reversed these effects. In conclusion, this data supports the hypothesis that the PRRSV succeeds to establish and replicate in porcine cells early post-infection, in part, by inducing Th3 regulatory cells as a mechanism of modulating the porcine immune system.« less

Deglycosylation of serum vitamin D3-binding protein by alpha-N-acetylgalactosaminidase detected in the plasma of patients with systemic lupus erythematosus.

PubMed

Yamamoto, N; Naraparaju, V R; Moore, M; Brent, L H

1997-03-01

A serum glycoprotein, Gc protein (vitamin D3-binding protein), can be converted by beta-galactosidase of B cells and sialidase of T cells to a potent macrophage-activating factor (MAF), a protein with N-acetylgalactosamine as the remaining sugar moiety. Thus, Gc protein is the precursor for MAF. Treatment of Gc protein with immobilized beta-galactosidase and sialidase generates a remarkably high titered macrophage-activating factor (GcMAF). When peripheral blood monocytes/ macrophages (designated macrophages) of 33 systemic lupus erythematosus patients were incubated with GcMAF (100 pg/ml), the macrophages of all patients were activated as determined by superoxide generation. However, the precursor activity of patient plasma Gc protein was lost or reduced in these patients. Loss of the precursor activity was the result of deglycosylation of plasma Gc protein by alpha-N-acetylgalactosaminidase activity found in the patient plasma. Levels of plasma alpha-N-acetylgalactosaminidase activity in individual patients had an inverse correlation with the MAF precursor activity of their plasma Gc protein. Deglycosylated Gc protein cannot be converted to macro-phage-activating factor. The resulting defect in macro-phage activation may lead to an inability to clear pathogenic immune complexes. Thus, elevated plasma alpha-N-acetylgalactosaminidase activity resulting in the loss of MAF precursor activity and reduced macro-phage activity may play a role in the pathogenesis of systemic lupus erythematosus.

Cholesterol depletion by methyl-beta-cyclodextrin enhances myoblast fusion and induces the formation of myotubes with disorganized nuclei.

PubMed

Mermelstein, Cláudia S; Portilho, Débora M; Medeiros, Rommel B; Matos, Aline R; Einicker-Lamas, Marcelo; Tortelote, Giovane G; Vieyra, Adalberto; Costa, Manoel L

2005-02-01

The formation of a skeletal muscle fiber begins with the withdrawal of committed mononucleated precursors from the cell cycle. These myoblasts elongate while aligning with each other, guided by recognition between their membranes. This step is followed by cell fusion and the formation of long striated multinucleated myotubes. We used methyl-beta-cyclodextrin (MCD) in primary cultured chick skeletal muscle cells to deplete membrane cholesterol and investigate its role during myogenesis. MCD promoted a significant increase in the expression of troponin T, enhanced myoblast fusion, and induced the formation of large multinucleated myotubes with nuclei being clustered centrally and not aligned at the cell periphery. MCD myotubes were striated, as indicated by sarcomeric alpha-actinin staining, and microtubule and desmin filament distribution was not altered. Pre-fusion MCD-treated myoblasts formed large aggregates, with cadherin and beta-catenin being accumulated in cell adhesion contacts. We also found that the membrane microdomain marker GM1 was not present as clusters in the membrane of MCD-treated myoblasts. Our data demonstrate that cholesterol is involved in the early steps of skeletal muscle differentiation.

Analysis of molecular assemblies by flow cytometry: determinants of Gi1 and by binding

NASA Astrophysics Data System (ADS)

Sarvazyan, Noune A.; Neubig, Richard R.

1998-05-01

We report here a novel application of flow cytometry for the quantitative analysis of the high affinity interaction between membrane proteins both in detergent solutions and when reconstituted into lipid vesicles. The approach is further advanced to permit the analysis of binding to expressed protein complexes in native cell membranes. The G protein heterotrimer signal transduction function links the extracellularly activated transmembrane receptors and intracellular effectors. Upon activation, (alpha) and (beta) (gamma) subunits of G protein undergo a dissociation/association cycle on the cell membrane interface. The binding parameters of solubilized G protein (alpha) and (beta) (gamma) subunits have been defined but little is known quantitatively about their interactions in the membrane. Using a novel flow cytometry approach, the binding of low nanomolar concentrations of fluorescein-labeled G(alpha) i1 (F- (alpha) ) to (beta) (gamma) both in detergent solution and in a lipid environment was quantitatively compared. Unlabeled (beta) $gama reconstituted in biotinylated phospholipid vesicles bound F-(alpha) tightly (Kd 6 - 12 nM) while the affinity for biotinylated-(beta) (gamma) in Lubrol was even higher (Kd of 2.9 nM). The application of this approach to proteins expressed in native cell membranes will advance our understanding of G protein function in context of receptor and effector interaction. More generally, this approach can be applied to study the interaction of any fluorescently labeled protein with a membrane protein which can be expressed in Sf9 plasma membranes.

Regulation of the human SLC25A20 expression by peroxisome proliferator-activated receptor alpha in human hepatoblastoma cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tachibana, Keisuke, E-mail: nya@phs.osaka-u.ac.jp; Takeuchi, Kentaro; Inada, Hirohiko

2009-11-20

Solute carrier family 25, member 20 (SLC25A20) is a key molecule that transfers acylcarnitine esters in exchange for free carnitine across the mitochondrial membrane in the mitochondrial {beta}-oxidation. The peroxisome proliferator-activated receptor alpha (PPAR{alpha}) is a ligand-activated transcription factor that plays an important role in the regulation of {beta}-oxidation. We previously established tetracycline-regulated human cell line that can be induced to express PPAR{alpha} and found that PPAR{alpha} induces the SLC25A20 expression. In this study, we analyzed the promoter region of the human slc25a20 gene and showed that PPAR{alpha} regulates the expression of human SLC25A20 via the peroxisome proliferator responsive element.

Decreased agonist sensitivity of human GABA(A) receptors by an amino acid variant, isoleucine to valine, in the alpha1 subunit.

PubMed

Westh-Hansen, S E; Rasmussen, P B; Hastrup, S; Nabekura, J; Noguchi, K; Akaike, N; Witt, M R; Nielsen, M

1997-06-25

Recombinant human GABA(A) receptors were investigated in vitro by coexpression of cDNAs coding for alpha1, beta2, and gamma2 subunits in the baculovirus/Sf-9 insect cell system. We report that a single amino acid exchange (isoleucine 121 to valine 121) in the N-terminal, extracellular part of the alpha1 subunit induces a marked decrease in agonist GABA(A) receptor ligand sensitivity. The potency of muscimol and GABA to inhibit the binding of the GABA(A) receptor antagonist [3H]SR 95531 (2-(3-carboxypropyl)-3-amino-6-(4-methoxyphenyl)pyridazinium bromide) was higher in receptor complexes of alpha1(ile 121) beta2gamma2 than in those of alpha1(val 121) beta2gamma2 (IC50 values were 32-fold and 26-fold lower for muscimol and GABA, respectively). The apparent affinity of the GABA(A) receptor antagonist bicuculline methiodide to inhibit the binding of [3H]SR 95531 did not differ between the two receptor complex variants. Electrophysiological measurements of GABA induced whole-cell Cl- currents showed a ten-fold decrease in the GABA(A) receptor sensitivity of alpha1 (val 121) beta2gamma2 as compared to alpha1(ile 121) beta2gamma2 receptor complexes. Thus, a relatively small change in the primary structure of the alpha1 subunit leads to a decrease selective for GABA(A) receptor sensitivity to agonist ligands, since no changes were observed in a GABA(A) receptor antagonist affinity and benzodiazepine receptor binding.

Receptor protection studies comparing recombinant and native nicotinic receptors: Evidence for a subpopulation of mecamylamine-sensitive native alpha3beta4* nicotinic receptors.

PubMed

Free, R Benjamin; Kaser, Daniel J; Boyd, R Thomas; McKay, Dennis B

2006-01-09

Studies involving receptor protection have been used to define the functional involvement of specific receptor subtypes in tissues expressing multiple receptor subtypes. Previous functional studies from our laboratory demonstrate the feasibility of this approach when applied to neuronal tissues expressing multiple nicotinic acetylcholine receptors (nAChRs). In the current studies, the ability of a variety of nAChR agonists and antagonists to protect native and recombinant alpha3beta4 nAChRs from alkylation were investigated using nAChR binding techniques. Alkylation of native alpha3beta4* nAChRs from membrane preparations of bovine adrenal chromaffin cells resulted in a complete loss of specific [(3)H]epibatidine binding. This loss of binding to native nAChRs was preventable by pretreatment with the agonists, carbachol or nicotine. The partial agonist, cytisine, produced partial protection. Several nAChR antagonists were also tested for their ability to protect. Hexamethonium and decamethonium were without protective activity while mecamylamine and tubocurarine were partially effective. Addition protection studies were performed on recombinant alpha3beta4 nAChRs. As with native alpha3beta4* nAChRs, alkylation produced a complete loss of specific [(3)H]epibatidine binding to recombinant alpha3beta4 nAChRs which was preventable by pretreatment with nicotine. However, unlike native alpha3beta4* nAChRs, cytisine and mecamylamine, provide no protection for alkylation. These results highlight the differences between native alpha3beta4* nAChRs and recombinant alpha3beta4 nAChRs and support the use of protection assays to characterize native nAChR subpopulations.

Characteristic cytokine generation patterns in cancer cells and infiltrating lymphocytes in oral squamous cell carcinomas and the influence of chemoradiation combined with immunotherapy on these patterns.

PubMed

Yamamoto, Tetsuya; Kimura, Tsuyoshi; Ueta, Eisaku; Tatemoto, Yukihiro; Osaki, Tokio

2003-01-01

Cytokines produced by tumor cells and tumor-infiltrating lymphocytes (TIL) appear to regulate tumor cell growth and the cytotoxic activity of TIL. The objectives of the present study were to investigate cytokine generation patterns in tumor cells and TIL and to examine the influence of cancer therapy on this cytokine production and the cytotoxic activity of TIL. We determined the levels of cytokines produced by tumor cells and TIL in vitro and measured the cytotoxic activity of TIL against Daudi cells in patients with oral squamous cell carcinoma (OSC) before and 1 week after the start of concomitant chemo-radio-immunotherapy. Before the therapy, OSC cells generated higher levels of granulocyte-macrophage colony-stimulating factor, tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta (TGF-beta) than did oral keratinocytes isolated from the noninflamed gingivae of healthy individuals, but both kinds of cells generated similar levels of interleukin (IL)-1beta and IL-6. Compared with peripheral blood mononuclear cells (PBMC) of the patients, TIL produced higher levels of IL-1beta, IL-6, IL-10, TNF-alpha and TGF-beta, whereas their production of IL-12 and interferon-gamma (IFN-gamma) was only slightly higher than that in PBMC. After 1 week of therapy, the cytokine production by OSC cells had largely decreased, while the production of TNF-alpha, IFN-gamma, TGF-beta and IL-12 by TIL had increased greatly, although other cytokine levels were almost constant during the investigations. The cytotoxic activity of TIL was higher than that of PBMC before the therapy, and this activity was strongly increased by 1 week of therapy. These results suggest that the cytokine productivities of TIL and tumor cells differ from those of PBMC and normal keratinocytes, respectively, and that chemo-radio-immunotherapy modulates in situ cytokine generation, which is advantageous for inhibition of tumor cell growth and activation of TIL. Copyright 2003 S. Karger AG, Basel

Metabolic Stress and Compromised Identity of Pancreatic Beta Cells

PubMed Central

Swisa, Avital; Glaser, Benjamin; Dor, Yuval

2017-01-01

Beta cell failure is a central feature of type 2 diabetes (T2D), but the molecular underpinnings of the process remain only partly understood. It has been suggested that beta cell failure in T2D involves massive cell death. Other studies ascribe beta cell failure to cell exhaustion, due to chronic oxidative or endoplasmic reticulum stress leading to cellular dysfunction. More recently it was proposed that beta cells in T2D may lose their differentiated identity, possibly even gaining features of other islet cell types. The loss of beta cell identity appears to be driven by glucotoxicity inhibiting the activity of key beta cell transcription factors including Pdx1, Nkx6.1, MafA and Pax6, thereby silencing beta cell genes and derepressing alternative islet cell genes. The loss of beta cell identity is at least partly reversible upon normalization of glycemia, with implications for the reversibility of T2D, although it is not known if beta cell failure reaches eventually a point of no return. In this review we discuss current evidence for metabolism-driven compromised beta cell identity, key knowledge gaps and opportunities for utility in the treatment of T2D. PMID:28270834

Metabolic Stress and Compromised Identity of Pancreatic Beta Cells.

PubMed

Swisa, Avital; Glaser, Benjamin; Dor, Yuval

2017-01-01

Beta cell failure is a central feature of type 2 diabetes (T2D), but the molecular underpinnings of the process remain only partly understood. It has been suggested that beta cell failure in T2D involves massive cell death. Other studies ascribe beta cell failure to cell exhaustion, due to chronic oxidative or endoplasmic reticulum stress leading to cellular dysfunction. More recently it was proposed that beta cells in T2D may lose their differentiated identity, possibly even gaining features of other islet cell types. The loss of beta cell identity appears to be driven by glucotoxicity inhibiting the activity of key beta cell transcription factors including Pdx1, Nkx6.1, MafA and Pax6, thereby silencing beta cell genes and derepressing alternative islet cell genes. The loss of beta cell identity is at least partly reversible upon normalization of glycemia, with implications for the reversibility of T2D, although it is not known if beta cell failure reaches eventually a point of no return. In this review we discuss current evidence for metabolism-driven compromised beta cell identity, key knowledge gaps and opportunities for utility in the treatment of T2D.

Controlling aggregation propensity in A53T mutant of alpha-synuclein causing Parkinson's disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Sonu; Sarkar, Anita; Sundar, Durai, E-mail: sundar@dbeb.iitd.ac.in

2009-09-18

Understanding {alpha}-synuclein in terms of fibrillization, aggregation, solubility and stability is fundamental in Parkinson's disease (PD). The three familial mutations, namely, A30P, E46K and A53T cause PD because the hydrophobic regions in {alpha}-synuclein acquire {beta}-sheet configuration, and have a propensity to fibrillize and form amyloids that cause cytotoxicity and neurodegeneration. On simulating the native form and mutants (A30P, E46K and A53T) of {alpha}-synuclein in water solvent, clear deviations are observed in comparison to the all-helical 1XQ8 PDB structure. We have identified two crucial residues, {sup 40}Val and {sup 74}Val, which play key roles in {beta}-sheet aggregation in the hydrophobic regionsmore » 36-41 and 68-78, respectively, leading to fibrillization and amyloidosis in familial (A53T) PD. We have also identified V40D{sub V}74D, a double mutant of A53T (the most amyloidogenic mutant). The simultaneous introduction of these two mutations in A53T nearly ends its aggregation propensity, increases its solubility and positively enhances its thermodynamic stability.« less

Tumor necrosis factor (cachectin) is an endogenous pyrogen and induces production of interleukin 1.

PubMed

Dinarello, C A; Cannon, J G; Wolff, S M; Bernheim, H A; Beutler, B; Cerami, A; Figari, I S; Palladino, M A; O'Connor, J V

1986-06-01

Recombinant human tumor necrosis factor (rTNF alpha) injected intravenously into rabbits produces a rapid-onset, monophasic fever indistinguishable from the fever produced by rIL-1. On a weight basis (1 microgram/kg) rTNF alpha and rIL-1 produce the same amount of fever and induce comparable levels of PGE2 in rabbit hypothalamic cells in vitro; like IL-1, TNF fever is blocked by drugs that inhibit cyclooxygenase. At higher doses (10 micrograms/kg) rTNF alpha produces biphasic fevers. The first fever reaches peak elevation 45-55 min after bolus injection and likely represents a direct action on the thermoregulatory center. During the second fever peak (3 h later), a circulating endogenous pyrogen can be shown present using passive transfer of plasma into fresh rabbits. This likely represents the in vivo induction of IL-1. In vitro, rTNF alpha induces the release of IL-1 activity from human mononuclear cells with maximal production observed at 50-100 ng/ml of rTNF alpha. In addition, rTNF alpha and rIFN-gamma have a synergistic effect on IL-1 production. The biological activity of rTNF alpha could be distinguished from IL-1 in three ways: the monophasic pyrogenic activity of rIL-1 was destroyed at 70 degrees C, whereas rTNF alpha remained active; anti-IL-1 neutralized IL-1 but did recognize rTNF alpha or natural cachectin nor neutralize its cytotoxic effect; and unlike IL-1, rTNF alpha was not active in the mitogen-stimulated T cell proliferation assay. The possibility that endotoxin was responsible for rTNF alpha fever and/or the induction of IL-1 was ruled-out in several studies: rTNF alpha produced fever in the endotoxin-resistant C3H/HeJ mice; the IL-1-inducing property of rTNF alpha was destroyed either by heat (70 degrees C) or trypsinization, and was unaffected by polymyxin B; pyrogenic tolerance to daily injections of rTNF alpha did not occur; levels of endotoxin, as determined in the Limulus amebocyte lysate, were below the minimum rabbit pyrogen dose; and these levels of endotoxin were confirmed by gas chromatography/mass spectrometry analysis for the presence of beta-hydroxymyristic acid. Although rTNF alpha is not active in T cell proliferation assays, it may mimic IL-1 in a T cell assay, since high concentrations of rTNF alpha induced IL-1 from epithelial or macrophagic cells in the thymocyte preparations. These studies show that TNF (cachectin) is another endogenous pyrogen which, like IL-1 and IFN-alpha, directly stimulate hypothalamic PGE2 synthesis. In addition, rTNF alpha is an endogenous inducer of IL-1.(ABSTRACT TRUNCATED AT 400 WORDS)

Characterization of rat leydig cell gonadotropin receptor structure by affinity cross-linking

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Q.Y.; Hwang, J.; Menon, K.M.J.

1986-05-01

The gonadotropin receptor from rat leydig cell has been characterized with respect to binding kinetics and physiological regulation. The present study was intended to examine the structure of the receptor. Leydig cell suspension was prepared by either collagenase digestion or by mechanical disruption of the testis. The cells were incubated with /sup 125/I-hCG and the unreacted hCG was removed by centrifugation. The /sup 125/I-hCG was then covalently linked to the cell surface receptor using cleavable (dithiobis (succinimidyl propionate)) and non-cleavable (disuccinimidyl suberate) cross-linking reagents. The extracted cross-linked membrane proteins were resolved on SDS-polyacrylamide gels under reducing and non-reducing conditions andmore » subjected to autoradiographic analysis. Under non-reducing conditions, two labeled species with M/sub r/ = 87,000 and 120,000 were detected. However, only one labeled band was detected under reducing conditions with M/sub r/ = 64,000. The binding of /sup 125/I-hCG to the receptor was inhibited by hCG and LH, but not by a number of peptides and proteins. The data suggest that hCG receptor in leydig cell is an oligomeric complex consisting of four subunits, ..cap alpha cap alpha beta gamma... The ..beta.. and ..gamma.. subunits are each linked to an ..cap alpha.. subunit through disulfide linkage and the hormone binds to each ..cap alpha.. subunit. The two dimers formed (..cap alpha beta cap alpha gamma..) are associated by noncovalent interactions.« less

Anode materials for lithium ion batteries

DOEpatents

Abouimrane, Ali; Amine, Khalil

2015-06-09

A composite material has general Formula (1-x)J-(x)Q wherein: J is a metal carbon alloy of formula Sn.sub.zSi.sub.z'Met.sub.wMet'.sub.w'C.sub.t; Q is a metal oxide of formula A.sub..gamma.M.sub..alpha.M'.sub..alpha.'O.sub..beta.; A is Li, Na, or K; M, M', Met, and Met' are individually Ge, Mo, Al, Ga, As, Sb, Te, Ti, Ta, Zr, Ca, Mg, Sr, Ba, Li, Na, K, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Rt, Ru or Cd; 0

Loss of tumorigenic potential by human lung tumor cells in the presence of antisense RNA specific to the ectopically synthesized alpha subunit of human chorionic gonadotropin.

PubMed

Rivera, R T; Pasion, S G; Wong, D T; Fei, Y B; Biswas, D K

1989-06-01

A clonal strain of human lung tumor cells in culture (ChaGo), derived from a bronchogenic carcinoma, synthesizes and secretes large amounts of alpha (alpha) and a comparatively lower level of beta (beta) subunit of the glycoprotein hormone, human chorionic gonadotropin (HCG). ChaGo cells lost their characteristic anchorage-independent growth phenotype in the presence of anti-alpha-HCG antibody. The effect of the antibody was partially reversed by addition of alpha-HCG to the culture medium. ChaGo cells were transfected with an expression vector (pRSV-anti-alpha-HCG), that directs synthesis of RNA complementary to alpha-HCG mRNA. The transfectants produced alpha-HCG antisense RNA which was associated with the reduced level of alpha-HCG. Transfectants also displayed several altered phenotypic properties, including altered morphology, less mitosis, reduced growth rate, loss of anchorage-independent growth, and loss of tumorigenicity in nude mice. Treatment of transfectants with 8,bromo-cAMP resulted in increased accumulation of alpha-HCG mRNA, no change in the level of alpha-HCG antisense RNA, release of the inhibition of [3H]thymidine incorporation, and restoration of anchorage-independent growth phenotype. The overexpression of c-myc, observed in ChaGo cells, was unaffected by the reduced level of alpha-HCG. These results suggest that ectopic synthesis of the alpha subunit of HCG plays a functional role in the transformation of these human lung cells.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amirshahrokhi, K.; Dehpour, A.R.; Hadjati, J.

Type 1 diabetes is an autoimmune disease characterized by inflammation of pancreatic islets and destruction of {beta} cells by the immune system. Opioids have been shown to modulate a number of immune functions, including T helper 1 (Th1) and T helper 2 (Th2) cytokines. The immunosuppressive effect of long-term administration of opioids has been demonstrated both in animal models and humans. The aim of this study was to determine the effect of methadone, a {mu}-opioid receptor agonist, on type 1 diabetes. Administration of multiple low doses of streptozotocin (STZ) (MLDS) (40mg/kg intraperitoneally for 5 consecutive days) to mice resulted inmore » autoimmune diabetes. Mice were treated with methadone (10mg/kg/day subcutaneously) for 24days. Blood glucose, insulin and pancreatic cytokine levels were measured. Chronic methadone treatment significantly reduced hyperglycemia and incidence of diabetes, and restored pancreatic insulin secretion in the MLDS model. The protective effect of methadone can be overcome by pretreatment with naltrexone, an opioid receptor antagonist. Also, methadone treatment decreased the proinflammatory Th1 cytokines [interleukin (IL)-1{beta}, tumor necrosis factor-{alpha} and interferon-{gamma}] and increased anti-inflammatory Th2 cytokines (IL-4 and IL-10). Histopathological observations indicated that STZ-mediated destruction of {beta} cells was attenuated by methadone treatment. It seems that methadone as an opioid agonist may have a protective effect against destruction of {beta} cells and insulitis in the MLDS model of type 1 diabetes.« less

Role of phosphoinositide 3-kinase regulatory isoforms in development and actin rearrangement.

PubMed

Brachmann, Saskia M; Yballe, Claudine M; Innocenti, Metello; Deane, Jonathan A; Fruman, David A; Thomas, Sheila M; Cantley, Lewis C

2005-04-01

Class Ia phosphoinositide 3-kinases (PI3Ks) are heterodimers of p110 catalytic and p85 regulatory subunits that mediate a variety of cellular responses to growth and differentiation factors. Although embryonic development is not impaired in mice lacking all isoforms of the p85alpha gene (p85alpha-/- p55alpha-/- p50alpha-/-) or in mice lacking the p85beta gene (p85beta-/-) (D. A. Fruman, F. Mauvais-Jarvis, D. A. Pollard, C. M. Yballe, D. Brazil, R. T. Bronson, C. R. Kahn, and L. C. Cantley, Nat Genet. 26:379-382, 2000; K. Ueki, C. M. Yballe, S. M. Brachmann, D. Vicent, J. M. Watt, C. R. Kahn, and L. C. Cantley, Proc. Natl. Acad. Sci. USA 99:419-424, 2002), we show here that loss of both genes results in lethality at embryonic day 12.5 (E12.5). The phenotypes of these embryos, including subepidermal blebs flanking the neural tube at E8 and bleeding into the blebs during the turning process, are similar to defects observed in platelet-derived growth factor receptor alpha null (PDGFRalpha-/-) mice (P. Soriano, Development 124:2691-2700, 1997), suggesting that PI3K is an essential mediator of PDGFRalpha signaling at this developmental stage. p85alpha-/- p55alpha+/+ p50alpha+/+ p85beta-/- mice had similar but less severe defects, indicating that p85alpha and p85beta have a critical and redundant function in development. Mouse embryo fibroblasts deficient in all p85alpha and p85beta gene products (p85alpha-/- p55alpha-/- p50alpha-/- p85beta-/-) are defective in PDGF-induced membrane ruffling. Overexpression of the Rac-specific GDP-GTP exchange factor Vav2 or reintroduction of p85alpha or p85beta rescues the membrane ruffling defect. Surprisingly, reintroduction of p50alpha also restored PDGF-dependent membrane ruffling. These results indicate that class Ia PI3K is critical for PDGF-dependent actin rearrangement but that the SH3 domain and the Rho/Rac/Cdc42-interacting domain of p85, which lacks p50alpha, are not required for this response.

Interaction with glycosaminoglycans is required for cyclophilin B to trigger integrin-mediated adhesion of peripheral blood T lymphocytes to extracellular matrix.

PubMed

Allain, Fabrice; Vanpouille, Christophe; Carpentier, Mathieu; Slomianny, Marie-Christine; Durieux, Sandrine; Spik, Geneviève

2002-03-05

Cyclophilins A and B (CyPA and CyPB) are cyclosporin A-binding proteins that are involved in inflammatory events. We have reported that CyPB interacts with two types of cell-surface-binding sites. The first site corresponds to a functional receptor and requires interaction with the central core of CyPB. This region is highly conserved in cyclophilins, suggesting that CyPA and CyPB might share biological activities mediated by interaction with this receptor. The second site is identified with glycosaminoglycans (GAGs), the binding region located in the N terminus of CyPB. The difference in the N-terminal extensions of CyPA and CyPB suggests that a unique interaction with GAGs might account for selective activity of CyPB. To explore this hypothesis, we analyzed the lymphocyte responses triggered by CyPA, CyPB, and CyPB(KKK-), a mutant unable to interact with GAGs. The three ligands seemed capable enough to elicit calcium signal and chemotaxis by binding to the same signaling receptor. In contrast, only CyPB enhanced firm adhesion of T cells to the extracellular matrix. This activity depended on the interactions with GAGs and signaling receptor. CyPB-mediated adhesion required CD147 presumably because it was a costimulatory molecule and was related to an activation of alpha4beta1 and alpha4beta7 integrins. Finally, we showed that CyPB was capable mainly to enhance T cell adhesion of the CD4+CD45RO+ subset. The present data indicate that CyPB rather than CyPA is a proinflammatory factor for T lymphocytes and highlight the crucial role of CyPB-GAG interaction in the chemokine-like activity of this protein.

Involvement of central, but not placental corticotropin releasing hormone (CRH) in heat stress induced immunosuppression during pregnancy.

PubMed

Nakamura, H; Nagase, H; Ogino, K; Hatta, K; Matsuzaki, I

2001-03-01

To clarify whether corticotropin releasing hormone (CRH) and beta-endorphin (betaEP) system mediate maternal immunosuppression in pregnant rats exposed to heat through central or placental pathway, we examined the effects of intravenous (iv) (100 or 500 microg) or intracerebroventricular (icv) (5 microg) administration of CRH receptor antagonist alpha-helical CRH (9-41) on splenic natural killer cell activity (NKCA) as well as betaEP in blood, pituitary lobes, and placenta in pregnant rats at 15 to 16 days gestation. Two-way ANOVA revealed that heat reduced NKCA and elevated blood and pituitary betaEP but did not change placental betaEP. Iv administered 500 microg and icv administered alpha-helical CRH reversed the reduced NKCA and the elevated pituitary betaEP, while iv administration of 100 microg alpha-helical CRH did not. The increased blood betaEP was reversed by iv 100 and 500 microg alpha-helical CRH and icv administration. Both iv and icv administrations reduced placental betaEP independent of heat exposure. Thus, the response of placental betaEP to iv administration of alpha-helical CRH seemed to be stronger than that of pituitary betaEP. These results indicate that alpha-helical CRH which acts on pituitary betaEP antagonizes heat-induced immunosuppression during pregnancy, suggesting that immunosuppression produced by heat stress during pregnancy is mediated by the central CRH system. The placental CRH-betaEP system seems unlikely to be involved in the immunosuppression. Physiologic roles of placental CRH and opioid system should be clarified by future in vitro experiments using placenta specimen including placental immunocyte.

Dexamethasone antagonizes IL-4 and IL-10-induced release of IL-1RA by monocytes but augments IL-4-, IL-10-, and TGF-beta-induced suppression of TNF-alpha release.

PubMed

Joyce, D A; Steer, J H; Kloda, A

1996-07-01

The activities of monocyte-derived tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 beta are potentially modified by IL-1RA and soluble receptors for TNF (sTNF-R), which are themselves monocyte products. IL-4, IL-10, TGF-beta, and glucocorticoids (GC) all suppress the lipopolysaccharide (LPS)-stimulated release of TNF-alpha and IL-1beta but vary in their effects on IL-1RA and sTNF-R. This raises the prospect of interactions between the cytokines and glucocorticoids, which may be antagonistic or additive on IL-1 and TNF activity. We, therefore, studied the interactions of the GC dexamethasone (Dex) with IL-4, IL-10, and transforming growth factor (TGF)-beta on the release of TNF-alpha and IL-1RA by human monocytes and the monocytic THP-1 cell line. Low concentration of Dex (10(-8)-10(-7)M) acted additively with low concentrations of IL-4 (0.01-1 ng/ml), IL-10 (0.01-0.1 U/ml), or TGF-beta (0.01-1 ng/ml) to profoundly suppress LPS-stimulated release of TNF-alpha by whole blood and, to a lesser degree, THP-1 cells. Dex also suppressed spontaneous release of IL-1RA from PBMC and THP-1 cells, whereas IL-4 and IL-10, but not TGF-beta, stimulated release. Dex antagonized the enhanced release in IL-4 and IL-10-stimulated cultures. The capacity to stimulate release of IL-1RA may contribute to the anti-inflammatory potential of IL-4 and IL-10 in monocyte/macrophage-mediated disease. GC, therefore, do not uniquely enhance the suppressive functions of IL-4 and IL-10 on monokine activity. The therapeutic benefit of combinations of GC and IL-4, IL-10 or TGF-beta in disease may depend on the roles of the individual monokines and antagonists in pathogenesis.

Unsaturated free fatty acids increase benzodiazepine receptor agonist binding depending on the subunit composition of the GABAA receptor complex.

PubMed

Witt, M R; Westh-Hansen, S E; Rasmussen, P B; Hastrup, S; Nielsen, M

1996-11-01

It has been shown previously that unsaturated free fatty acids (FFAs) strongly enhance the binding of agonist benzodiazepine receptor ligands and GABAA receptor ligands in the CNS in vitro. To investigate the selectivity of this effect, recombinant human GABAA/benzodiazepine receptor complexes formed by different subunit compositions (alpha x beta y gamma 2, x = 1, 2, 3, and 5; y = 1, 2, and 3) were expressed using the baculovirus-transfected Sf9 insect cell system. At 10(-4) M, unsaturated FFAs, particularly arachidonic (20:4) and docosahexaenoic (22:6) acids, strongly stimulated (> 200% of control values) the binding of [3H]flunitrazepam ([3H]FNM) to the alpha 3 beta 2 gamma 2 receptor combination in whole cell preparations. No effect or small increases in levels of unsaturated FFAs on [3H]FNM binding to alpha 1 beta x gamma 2 and alpha 2 beta x gamma 2 receptor combinations were observed, and weak effects (130% of control values) were detected using the alpha 5 beta 2 gamma 2 receptor combination. The saturated FFAs, stearic and palmitic acids, were without effect on [3H]FNM binding to any combination of receptor complexes. The hydroxylated unsaturated FFAs, ricinoleic and ricinelaidic acids, were shown to decrease the binding of [3H]FNM only if an alpha 1 beta 2 gamma 2 receptor combination was used. Given the heterogeneity of the GABAA/ benzodiazepine receptor subunit distribution in the CNS, the effects of FFAs on the benzodiazepine receptor can be assumed to vary at both cellular and regional levels.

Resolution of the discrepancy between Balmer alpha emission rates, the solar Lyman beta flux, and models of geocoronal hydrogen concentration

NASA Technical Reports Server (NTRS)

Levasseur, A.-C.; Meier, R. R.; Tinsley, B. A.

1976-01-01

New satellite Balmer alpha measurements and solar Lyman beta flux and line profile measurements, together with new measurements of the zodiacal light intensity used in correcting both ground and satellite Balmer alpha measurements for the effects of the Fraunhofer line in the zodiacal light, have been used in a reevaluation of the long-standing discrepancy between ground-based Balmer alpha emission rates and other geocoronal hydrogen parameters. The solar Lyman beta line center flux is found to be (4.1 plus or minus 1.3) billion photons per sq cm per sec per angstrom at S(10.7) equals 110 and, together with a current hydrogen model which has 92,000 atoms per cu cm at 650 km for T(inf) equals 950 K, gives good agreement between calculated Balmer alpha emission rates and the ground-based and satellite measurements.

Modulation of adhesion-dependent cAMP signaling by echistatin and alendronate

NASA Technical Reports Server (NTRS)

Fong, J. H.; Ingber, D. E.

1996-01-01

We measured intracellular cAMP levels in cells during attachment and spreading on different extracellular matrix (ECM) proteins. Increases in cAMP were observed within minutes when cells attached to fibronectin, vitronectin, and a synthetic RGD-containing fibronectin peptide (Petite 2000), but not when they adhered to another integrin alpha nu beta 3 ligand, echistatin. Because echistatin also inhibits bone resorption, we measured the effects of adding another osteoporosis inhibitor, alendronate, in this system. Alendronate inhibited the cAMP increase induced by ligands that primarily utilize integrin alpha nu beta 3 (vitronectin, Peptite 2000), but not by fibronectin which can also use integrin alpha 5 beta 1. These results show that cell adhesion to ECM can increase intracellular cAPM levels and raise the possibility that inhibitors of osteoporosis may act, in part, by preventing activation of this pathway by integrins.

Inhibitors of sterol synthesis. Chemical syntheses and spectral properties of 26-oxygenated derivatives of 3 beta-hydroxy-5 alpha-cholest-8(14)-en-15-one and their effects on 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in CHO-K1 cells.

PubMed

Siddiqui, A U; Wilson, W K; Ruecker, K E; Pinkerton, F D; Schroepfer, G J

1992-11-01

26-Oxygenated derivatives of delta 8(14)-15-ketosterols have been synthesized from (25R)-3 beta,26-diacetoxy-5 alpha-cholest-8(14)-en-15-one (IX) as part of a program to prepare potential metabolites and analogs of 3 beta-hydroxy-5 alpha-cholest-8(14)-en-15-one (I), a potent regulator of cholesterol metabolism. Partial hydrolysis of IX gave a mixture, from which the 3 beta,26-diol II and the 26-acetate (XI) and 3 beta-acetate (X) monoesters were isolated. Mitsunobu reaction of XI followed by hydrolysis gave (25R)-3 alpha,26-dihydroxy-5 alpha-cholest-8(14)-en-15-one (VI). Oxidation of XI with pyridinium chlorochromate followed by hydrolysis of the acetate gave (25R)-26-hydroxy-5 alpha-cholest-8(14)-ene-3,15-dione (VII). Oxidation of X with Jones reagent followed by hydrolysis of the acetate gave (25R)-3 beta-hydroxy-15-keto-5 alpha-cholest-8(14)-en-26-oic acid (IVa). Jones oxidation of II gave (25R)-3,15-diketo-5 alpha-cholest-8(14)-en-26-oic acid (VII). 1H and 13C nuclear magnetic resonance assignments and analyses of mass spectral fragmentation data are presented for each of the new compounds and their derivatives. The 3,15-diketone VII was found to be highly active in lowering the levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in CHO-K1 cells, with a potency comparable to that of I. In contrast, 3 alpha,26-diol VI was less potent than I or VII. The two carboxylic acid analogs IVa and VIII were considerably less potent than VI in lowering the levels of HMG-CoA reductase activity.

Differential usage of T-cell receptor V beta gene families by CD4+ and CD8+ T cells in patients with CD8hi common variable immunodeficiency: evidence of a post-thymic effect.

PubMed Central

Duchmann, R; Jaffe, J; Ehrhardt, R; Alling, D W; Strober, W

1996-01-01

In this study, we report that differences between T-cell receptor (TCR) V beta gene family usage in CD4+ and CD8+ T cells are significantly greater in a subgroup of patients with common variable immunodeficiency (CVI) and high levels of activated CD8+ T cells (CD8hi CVI) than in controls (P < 0.001). In CD8hi CVI patients, such differences were also significantly greater for V beta 12 than for other V beta families. As the causes of the differential usage of V beta gene families by CD4+ and CD8+ T cells are under investigation, it was interesting that the combined differences between V beta gene family usage in the CD4+ and CD8+ T-cell subpopulations as a whole were significantly lower than the combined differences between individual V beta gene family usage in either CD4+ or CD8+ T-cell subpopulations (P < 0.001 in both control and CD8hi CVI patients). Further, the pattern of V beta gene family usage in CD4+ T cells was remarkably similar to that in CD8+ T cells in both groups. These data strongly suggest that differences in V beta gene family usage arising from coselection by major histocompatibility complex (MHC) class I versus MHC class II restriction elements do not fundamentally distort 'basic' V beta gene family usage patterns. They also support the concept that differences in CD4+ and CD8+ T-cell V beta gene family usage, which were increased in CD8hi CVI, can arise from high-affinity interactions between disease-associated antigens or superantigens and T cells in the post-thymic T-cell compartment. Images Figure 6 PMID:8666443

Constitutive activation of NF-kappa B and secretion of interleukin-8 induced by the G protein-coupled receptor of Kaposi's sarcoma-associated herpesvirus involve G alpha(13) and RhoA.

PubMed

Shepard, L W; Yang, M; Xie, P; Browning, D D; Voyno-Yasenetskaya, T; Kozasa, T; Ye, R D

2001-12-07

The Kaposi's sarcoma herpesvirus (KSHV) open reading frame 74 encodes a G protein-coupled receptor (GPCR) for chemokines. Exogenous expression of this constitutively active GPCR leads to cell transformation and vascular overgrowth characteristic of Kaposi's sarcoma. We show here that expression of KSHV-GPCR in transfected cells results in constitutive transactivation of nuclear factor kappa B (NF-kappa B) and secretion of interleukin-8, and this response involves activation of G alpha(13) and RhoA. The induced expression of a NF-kappa B luciferase reporter was partially reduced by pertussis toxin and the G beta gamma scavenger transducin, and enhanced by co-expression of G alpha(13) and to a lesser extent, G alpha(q). These results indicate coupling of KSHV-GPCR to multiple G proteins for NF-kappa B activation. Expression of KSHV-GPCR led to stress fiber formation in NIH 3T3 cells. To examine the involvement of the G alpha(13)-RhoA pathway in KSHV-GPCR-mediated NF-kappa B activation, HeLa cells were transfected with KSHV-GPCR alone and in combination with the regulator of G protein signaling (RGS) from p115RhoGEF or a dominant negative RhoA(T19N). Both constructs, as well as the C3 exoenzyme from Clostritium botulinum, partially reduced NF-kappa B activation by KSHV-GPCR, and by a constitutively active G alpha(13)(Q226L). KSHV-GPCR-induced NF-kappa B activation is accompanied by increased secretion of IL-8, a function mimicked by the activated G alpha(13) but not by an activated G alpha(q)(Q209L). These results suggest coupling of KSHV-GPCR to the G alpha(13)-RhoA pathway in addition to other G proteins.

Uncoupling between CD1d upregulation induced by retinoic acid and conduritol-B-epoxide and iNKT cell responsiveness.

PubMed

Balreira, Andrea; Cavallari, Marco; Sá Miranda, Maria Clara; Arosa, Fernando A

2010-06-01

Gaucher disease (GD) is associated with upregulation of CD1d and MHC-class II expression by monocytes. While the physiological impact of CD1d upregulation remains uncertain, it has been proposed that MHC-class II upregulation is associated with inflammation. Hereby, we show that the decrease in MHC-class II expression seen in GD patients under therapy correlates positively with chitotriosidase activity, a marker of inflamed macrophages. We also show that retinoic acid (RA) and the beta-glucocerebrosidase inhibitor conduritol-B-epoxide (CBE) lead to upregulation of CD1d expression by THP-1 cells, which correlated with an increase in mRNA expression. In vitro co-culture experiments showed that RA treated THP-1 cells were more stimulatory for CD4(+) than for CD8(+) T cells, as determined by CFSE loss, in comparison to untreated THP-1 cells. Interestingly, even though addition of exogenous isoglobotrihexosylceramide (iGb3), a physiological CD1d ligand, augmented the percentage of dividing CD4(+) T cells, we could not detect a significant expansion of CD4(+)Valpha24(+) invariant Natural Killer T (iNKT) cells. In contrast, addition of alpha-galactosylceramide (alpha-GC) induced expansion of Valpha24(+) iNKT cells as determined by using alpha-GC-loaded human CD1d dimers. These results strengthen the existence of a cross-talk between monocyte lipid accumulation, inflammation and changes in cell surface CD1d and MHC-class II in monocytes, which may result in inappropriate recognition events by immune cells and perpetuate chronic inflammation. Copyright 2009 Elsevier GmbH. All rights reserved.

Aldo-keto reductase family 1 B10 protein detoxifies dietary and lipid-derived alpha, beta-unsaturated carbonyls at physiological levels.

PubMed

Zhong, Linlin; Liu, Ziwen; Yan, Ruilan; Johnson, Stephen; Zhao, Yupei; Fang, Xiubin; Cao, Deliang

2009-09-18

Alpha, beta-unsaturated carbonyls are highly reactive mutagens and carcinogens to which humans are exposed on a daily basis. This study demonstrates that aldo-keto reductase family 1 member B10 (AKR1B10) is a critical protein in detoxifying dietary and lipid-derived unsaturated carbonyls. Purified AKR1B10 recombinant protein efficiently catalyzed the reduction to less toxic alcohol forms of crotonaldehyde at 0.90 microM, 4-hydroxynonenal (HNE) at 0.10 microM, trans-2-hexanal at 0.10 microM, and trans-2,4-hexadienal at 0.05 microM, the concentrations at or lower than physiological exposures. Ectopically expressed AKR1B10 in 293T cells eliminated immediately HNE at 1 (subtoxic) or 5 microM (toxic) by converting to 1,4-dihydroxynonene, protecting the cells from HNE toxicity. AKR1B10 protein also showed strong enzymatic activity toward glutathione-conjugated carbonyls. Taken together, our study results suggest that AKR1B10 specifically expressed in the intestine is physiologically important in protecting the host cell against dietary and lipid-derived cytotoxic carbonyls.

Aldo-keto reductase family 1 B10 protein detoxifies dietary and lipid-derived alpha, beta-unsaturated carbonyls at physiological levels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong, Linlin; Department of Neurobiology and Anatomy, China Medical University, Shenyang 110001; Liu, Ziwen

2009-09-18

Alpha, beta-unsaturated carbonyls are highly reactive mutagens and carcinogens to which humans are exposed on a daily basis. This study demonstrates that aldo-keto reductase family 1 member B10 (AKR1B10) is a critical protein in detoxifying dietary and lipid-derived unsaturated carbonyls. Purified AKR1B10 recombinant protein efficiently catalyzed the reduction to less toxic alcohol forms of crotonaldehyde at 0.90 {mu}M, 4-hydroxynonenal (HNE) at 0.10 {mu}M, trans-2-hexanal at 0.10 {mu}M, and trans-2,4-hexadienal at 0.05 {mu}M, the concentrations at or lower than physiological exposures. Ectopically expressed AKR1B10 in 293T cells eliminated immediately HNE at 1 (subtoxic) or 5 {mu}M (toxic) by converting to 1,4-dihydroxynonene,more » protecting the cells from HNE toxicity. AKR1B10 protein also showed strong enzymatic activity toward glutathione-conjugated carbonyls. Taken together, our study results suggest that AKR1B10 specifically expressed in the intestine is physiologically important in protecting the host cell against dietary and lipid-derived cytotoxic carbonyls.« less

Possible Role of Non-Muscle Alpha-Actinins in Muscle Cell Mechanosensitivity

PubMed Central

Ogneva, Irina V.; Biryukov, Nikolay S.; Leinsoo, Toomas A.; Larina, Irina M.

2014-01-01

The main hypothesis suggested that changes in the external mechanical load would lead to different deformations of the submembranous cytoskeleton and, as a result, dissociation of different proteins from its structure (induced by increased/decreased mechanical stress). The study subjects were fibers of the soleus muscle and cardiomyocytes of Wistar rats. Changes in external mechanical conditions were reconstructed by means of antiorthostatic suspension of the animals by their tails for 6, 12, 18, 24 and 72 hours. Transversal stiffness was measured by atomic force microscopy imaging; beta-, gamma-actin, alpha-actinin 1 and alpha-actinin 4 levels in membranous and cytoplasmic fractions were quantified by Western blot analysis; expression rates of the corresponding genes were studied using RT-PCR. Results: In 6 hours, alpha-actinin 1 and alpha-actinin 4 levels decreased in the membranous fraction of proteins of cardiomyocytes and soleus muscle fibers, respectively, but increased in the cytoplasmic fraction of the abovementioned cells. After 6–12 hours of suspension, the expression rates of beta-, gamma-actin, alpha-actinin 1 and alpha-actinin 4 were elevated in the soleus muscle fibers, but the alpha-actinin 1 expression rate returned to the reference level in 72 hours. After 18–24 hours, the expression rates of beta-actin and alpha-actinin 4 increased in cardiomyocytes, while the alpha-actinin 1 expression rate decreased in soleus muscle fibers. After 12 hours, the beta- and gamma-actin content dropped in the membranous fraction and increased in the cytoplasmic protein fractions from both cardiomyocytes and soleus muscle fibers. The stiffness of both cell types decreased after the same period of time. Further, during the unloading period the concentration of nonmuscle actin and different isoforms of alpha-actinins increased in the membranous fraction from cardiomyocytes. At the same time, the concentration of the abovementioned proteins decreased in the soleus muscle fibers. PMID:24780915

{alpha}-Lipoic acid exhibits anti-amyloidogenicity for {beta}-amyloid fibrils in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ono, Kenjiro; Hirohata, Mie; Yamada, Masahito

2006-03-24

Inhibition of the formation of {beta}-amyloid fibrils (fA{beta}), as well as the destabilization of preformed fA{beta} in the CNS would be attractive therapeutic targets for the treatment of Alzheimer's disease (AD). Using fluorescence spectroscopic analysis with thioflavin T and electron microscopic studies, we examined the effects of {alpha}-lipoic acid (LA) and the metabolic product of LA, dihydrolipoic acid (DHLA), on the formation, extension, and destabilization of fA{beta} at pH 7.5 at 37 {sup o}C in vitro. LA and DHLA dose-dependently inhibited fA{beta} formation from amyloid {beta}-protein, as well as their extension. Moreover, they destabilized preformed fA{beta}s. LA and DHLA couldmore » be key molecules for the development of therapeutics for AD.« less

On the composition of the preimmune repertoire of T cells specific for Peptide-major histocompatibility complex ligands.

PubMed

Jenkins, Marc K; Chu, H Hamlet; McLachlan, James B; Moon, James J

2010-01-01

Millions of T cells are produced in the thymus, each expressing a unique alpha/beta T cell receptor (TCR) capable of binding to a foreign peptide in the binding groove of a host major histocompatibility complex (MHC) molecule. T cell-mediated immunity to infection is due to the proliferation and differentiation of rare clones in the preimmune repertoire that by chance express TCRs specific for peptide-MHC (pMHC) ligands derived from the microorganism. Here we review recent findings that have altered our understanding of how the preimmune repertoire is established. Recent structural studies indicate that a germline-encoded tendency of TCRs to bind MHC molecules contributes to the MHC bias of T cell repertoires. It has also become clear that the preimmune repertoire contains functionally heterogeneous subsets including recent thymic emigrants, mature naive phenotype cells, memory phenotype cells, and natural regulatory T cells. In addition, sensitive new detection methods have revealed that the repertoire of naive phenotype T cells consists of distinct pMHC-specific populations that consistently vary in size in different individuals. The implications of these new findings for the clonal selection theory, self-tolerance, and immunodominance are discussed.

Phenotypic differences between oral and skin fibroblasts in wound contraction and growth factor expression.

PubMed

Shannon, Diane B; McKeown, Scott T W; Lundy, Fionnuala T; Irwin, Chris R

2006-01-01

Wounds of the oral mucosa heal in an accelerated fashion with reduced scarring compared with cutaneous wounds. The differences in healing outcome between oral mucosa and skin could be because of phenotypic differences between the respective fibroblast populations. This study compared paired mucosal and dermal fibroblasts in terms of collagen gel contraction, alpha-smooth muscle actin expression (alpha-SMA), and production of the epithelial growth factors: keratinocyte growth factor (KGF) and hepatocyte growth factor/scatter factor (HGF). The effects of transforming growth factor -beta1 and -beta3 on each parameter were also determined. Gel contraction in floating collagen lattices was determined over a 7-day period. alpha-SMA expression by fibroblasts was determined by Western blotting. KGF and HGF expression were determined by an enzyme-linked immunosorbent assay. Oral fibroblasts induced accelerated collagen gel contraction, yet surprisingly expressed lower levels of alpha-SMA. Oral cells also produced significantly greater levels of both KGF and HGF than their dermal counterparts. Transforming growth factor-beta1 and -beta3, over the concentration range of 0.1-10 ng/mL, had similar effects on cell function, stimulating both gel contraction and alpha-SMA production, but inhibiting KGF and HGF production by both cell types. These data indicate phenotypic differences between oral and dermal fibroblasts that may well contribute to the differences in healing outcome between these two tissues.

Power dependence of reflectivity of metallic films.

PubMed

Yeh, Y C; Stafsudd, O M

1976-01-01

The reflectivity of vacuum-deposited gold films on quartz glass substrates was studied as a function of 10.6-microm radiation power density. A simple linear model of the temperature dependence of the absorptivity of the gold film is developed. This temperature dependence is coupled with a three-dimensional heat flow analysis and fits the experimental data well. The absorptivity alpha is written as alpha(0)(1 + betaT) and the values of alpha(0) and beta are determined, respectively, as (0.88 +/- 0.01) x 10(-2) and 12 x 10(-4)/ degrees C.

Delayed polymorphonuclear leukocyte infiltration is an important component of Thalassophryne maculosa venom pathogenesis.

PubMed

Pareja-Santos, Alessandra; Oliveira Souza, Valdênia Maria; Bruni, Fernanda M; Sosa-Rosales, Josefina Ines; Lopes-Ferreira, Mônica; Lima, Carla

2008-07-01

Thalassophryne maculosa fish envenomation is characterized by severe pain, dizziness, fever, edema and necrosis. Here, the dynamic of cellular influx, activation status of phagocytic cells, and inflammatory modulator production in the acute inflammatory response to T. maculosa venom was studied using an experimental model. Leukocyte counting was performed (2 h to 21 days) after venom injection in BALB/c mice footpads. Our results showed an uncommon leukocyte migration kinetic after venom injection, with early mononuclear cell recruitment followed by elevated and delayed neutrophil influx. The pattern of chemokine expression is consistent with the delay in neutrophil recruitment to the footpad: T. maculosa venom stimulated an early production of IL-1beta, IL-6, and MCP-1, but was unable to induce an effective early TNF-alpha and KC release. Complementary to these observations, we detected a marked increase in soluble KC and TNF-alpha in footpad at 7 days post-venom injection when a prominent influx of neutrophils was also detected. In addition, we demonstrated that bone marrow-derived macrophages and dendritic cells were strongly stimulated by the venom, showing up-regulated ability to capture FITC-dextran. Thus, the reduced levels of KC and TNF-alpha in footpad of mice concomitant with a defective accumulation of neutrophils at earlier times provide an important clue to uncovering the mechanism by which T. maculosa venom regulates neutrophil movement.

Beta-alanine/alpha-ketoglutarate aminotransferase for 3-hydroxypropionic acid production

DOEpatents

Jessen, Holly Jean [Chanhassen, MN; Liao, Hans H [Eden Prairie, MN; Gort, Steven John [Apple Valley, MN; Selifonova, Olga V [Plymouth, MN

2011-10-04

The present disclosure provides novel beta-alanine/alpha ketoglutarate aminotransferase nucleic acid and protein sequences having increased biological activity. Also provided are cells containing such enzymes, as well as methods of their use, for example to produce malonyl semialdehyde and downstream products thereof, such as 3-hydroxypropionic acid and derivatives thereof.

Beta-alanine/alpha-ketoglutarate aminotransferase for 3-hydroxypropionic acid production

DOEpatents

Jessen, Holly Jean; Liao, Hans H; Gort, Steven John; Selifonova, Olga V

2014-11-18

The present disclosure provides novel beta-alanine/alpha ketoglutarate aminotransferase nucleic acid and protein sequences having increased biological activity. Also provided are cells containing such enzymes, as well as methods of their use, for example to produce malonyl semialdehyde and downstream products thereof, such as 3-hydroxypropionic acid and derivatives thereof.

Fluid shear-induced mechanical signaling in MC3T3-E1 osteoblasts requires cytoskeleton-integrin interactions

NASA Technical Reports Server (NTRS)

Pavalko, F. M.; Chen, N. X.; Turner, C. H.; Burr, D. B.; Atkinson, S.; Hsieh, Y. F.; Qiu, J.; Duncan, R. L.

1998-01-01

Mechanical stimulation of bone induces new bone formation in vivo and increases the metabolic activity and gene expression of osteoblasts in culture. We investigated the role of the actin cytoskeleton and actin-membrane interactions in the transmission of mechanical signals leading to altered gene expression in cultured MC3T3-E1 osteoblasts. Application of fluid shear to osteoblasts caused reorganization of actin filaments into contractile stress fibers and involved recruitment of beta1-integrins and alpha-actinin to focal adhesions. Fluid shear also increased expression of two proteins linked to mechanotransduction in vivo, cyclooxygenase-2 (COX-2) and the early response gene product c-fos. Inhibition of actin stress fiber development by treatment of cells with cytochalasin D, by expression of a dominant negative form of the small GTPase Rho, or by microinjection into cells of a proteolytic fragment of alpha-actinin that inhibits alpha-actinin-mediated anchoring of actin filaments to integrins at the plasma membrane each blocked fluid-shear-induced gene expression in osteoblasts. We conclude that fluid shear-induced mechanical signaling in osteoblasts leads to increased expression of COX-2 and c-Fos through a mechanism that involves reorganization of the actin cytoskeleton. Thus Rho-mediated stress fiber formation and the alpha-actinin-dependent anchorage of stress fibers to integrins in focal adhesions may promote fluid shear-induced metabolic changes in bone cells.

Beta-lactam antibiotics modulate T-cell functions and gene expression via covalent binding to cellular albumin.

PubMed

Mor, Felix; Cohen, Irun R

2013-02-19

Recent work has suggested that beta-lactam antibiotics might directly affect eukaryotic cellular functions. Here, we studied the effects of commonly used beta-lactam antibiotics on rodent and human T cells in vitro and in vivo on T-cell-mediated experimental autoimmune diseases. We now report that experimental autoimmune encephalomyelitis and adjuvant arthritis were significantly more severe in rats treated with cefuroxime and other beta-lactams. T cells appeared to mediate the effect: an anti-myelin basic protein T-cell line treated with cefuroxime or penicillin was more encephalitogenic in adoptive transfer experiments. The beta-lactam ampicillin, in contrast to cefuroxime and penicillin, did not enhance encephalomyelitis, but did inhibit the autoimmune diabetes developing spontaneously in nonobese diabetic mice. Gene expression analysis of human peripheral blood T cells showed that numerous genes associated with T helper 2 (Th2) and T regulatory (Treg) differentiation were down-regulated in T cells stimulated in the presence of cefuroxime; these genes were up-regulated in the presence of ampicillin. The T-cell protein that covalently bound beta-lactam antibiotics was found to be albumin. Human and rodent T cells expressed albumin mRNA and protein, and penicillin-modified albumin was taken up by rat T cells, leading to enhanced encephalitogenicity. Thus, beta-lactam antibiotics in wide clinical use have marked effects on T-cell behavior; beta-lactam antibiotics can function as immunomodulators, apparently through covalent binding to albumin.

Nicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone induce cyclooxygenase-2 activity in human gastric cancer cells: Involvement of nicotinic acetylcholine receptor (nAChR) and {beta}-adrenergic receptor signaling pathways

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shin, Vivian Yvonne; Jin, H.C.; Ng, Enders K.O.

Induction of cyclooxygenase-2 (COX-2) associates with cigarette smoke exposure in many malignancies. Nicotine and its derivative, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), are the two important components in cigarette smoke that contributes to cancer development. However, the molecular mechanism(s) by which nicotine or NNK promotes gastric carcinogenesis remains largely unknown. We found that nicotine and NNK significantly enhanced cell proliferation in AGS cells that expressed both alpha7 nicotinic acetylcholine receptor ({alpha}7 nAChR) and {beta}-adrenergic receptors. Treatment of cells with {alpha}-bungarotoxin ({alpha}-BTX, {alpha}7nAChR antagonist) or propranolol ({beta}-adrenergic receptor antagonist) blocked NNK-induced COX-2/PGE{sub 2} and cell proliferation, while nicotine-mediated cell growth and COX-2/PGE{sub 2} induction canmore » only be suppressed by propranolol, but not {alpha}-BTX. Moreover, in contrast to the dependence of growth promoting effect of nicotine on Erk activation, inhibitor of p38 mitogen-activated protein kinase (MAPK) repressed NNK-induced COX-2 upregulation and resulted in suppression of cell growth. In addition, nicotine and NNK mediated COX-2 induction via different receptors to modulate several G1/S transition regulatory proteins and promote gastric cancer cell growth. Selective COX-2 inhibitor (SC-236) caused G1 arrest and abrogated nicotine/NNK-induced cell proliferation. Aberrant expression of cyclin D1 and other G1 regulatory proteins are reversed by blockade of COX-2. These results pointed to the importance of adrenergic and nicotinic receptors in gastric tumor growth through MAPK/COX-2 activation, which may perhaps provide a chemoprevention strategy for cigarette smoke-related gastric carcinogenesis.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamashita, T.; Fujino, T.; Masaki, N.

The structural parameters of ..cap alpha..- and ..beta..-CdUO/sub 4/ crystals are determined by x-ray powder diffraction technique. ..cap alpha..-CdUO/sub 4/ is rhombohedral and cell parameters are a = 6.233(3) A and ..cap alpha.. = 36.12(5)/sup 0/. ..beta..-CdUO/sub 4/ crystallizes in a C-centered orthorhombic cell with a = 7.023(4), b = 6.849(3), c = 3.514(2) A. The space groups are R3m for ..cap alpha..-CdUO/sub 4/ and Cmmm for ..beta..-CdUO/sub 4/. ..cap alpha..-CdUO/sub 4/: 1U in (000), 1Cd in (1/2 1/2 1/2), 2O(1) in +-(uuu), 2O(2) in +-(vvv); u = 0.113, v= 0.350, Z = 1. ..beta..-CdUO/sub 4/: 2U in (000; 1/2more » 1/2 0), 2Cd in (1/2 0 1/2; 0 1/2 1/2), 40(1) in (0, +-y, 0; 1/2, 1/2 +-y, 0), 4O(2) in (+-x, 0, 1/2; 1/2 +-x, 1/2, 1/2); x = 0.159, y = 0.278, Z = 2. ..beta..-CdUO/sub 4/ contains collinear uranyl UO/sub 2//sup 2 +/ groups with a U-O(1) distance of 1.91 A, located either along or parallel to the c axis whereas the U-O(1) bond length in ..cap alpha..-CdUO/sub 4/ is 1.98 A which is longer than the usual uranyl bond length.« less

Changes in proteasome structure and function caused by HAMLET in tumor cells.

PubMed

Gustafsson, Lotta; Aits, Sonja; Onnerfjord, Patrik; Trulsson, Maria; Storm, Petter; Svanborg, Catharina

2009-01-01

Proteasomes control the level of endogenous unfolded proteins by degrading them in the proteolytic core. Insufficient degradation due to altered protein structure or proteasome inhibition may trigger cell death. This study examined the proteasome response to HAMLET, a partially unfolded protein-lipid complex, which is internalized by tumor cells and triggers cell death. HAMLET bound directly to isolated 20S proteasomes in vitro and in tumor cells significant co-localization of HAMLET and 20S proteasomes was detected by confocal microscopy. This interaction was confirmed by co-immunoprecipitation from extracts of HAMLET-treated tumor cells. HAMLET resisted in vitro degradation by proteasomal enzymes and degradation by intact 20S proteasomes was slow compared to fatty acid-free, partially unfolded alpha-lactalbumin. After a brief activation, HAMLET inhibited proteasome activity in vitro and in parallel a change in proteasome structure occurred, with modifications of catalytic (beta1 and beta5) and structural subunits (alpha2, alpha3, alpha6 and beta3). Proteasome inhibition was confirmed in extracts from HAMLET-treated cells and there were indications of proteasome fragmentation in HAMLET-treated cells. The results suggest that internalized HAMLET is targeted to 20S proteasomes, that the complex resists degradation, inhibits proteasome activity and perturbs proteasome structure. We speculate that perturbations of proteasome structure might contribute to the cytotoxic effects of unfolded protein complexes that invade host cells.

Modeling the survival of Salmonella spp. in chorizos.

PubMed

Hajmeer, M; Basheer, I; Hew, C; Cliver, D O

2006-03-01

The survival of Salmonella spp. in chorizos has been studied under the effect of storage conditions; namely temperature (T=6, 25, 30 degrees C), air inflow velocity (F=0, 28.4 m/min), and initial water activity (a(w0)=0.85, 0.90, 0.93, 0.95, 0.97). The pH was held at 5.0. A total of 20 survival curves were experimentally obtained at various combinations of operating conditions. The chorizos were stored under four conditions: in the refrigerator (Ref: T=6 degrees C, F=0 m/min), at room temperature (RT: T=25 degrees C, F=0 m/min), in the hood (Hd: T=25 degrees C, F=28.4 m/min), and in the incubator (Inc: T=30 degrees C, F=0 m/min). Semi-logarithmic plots of counts vs. time revealed nonlinear trends for all the survival curves, indicating that the first-order kinetics model (exponential distribution function) was not suitable. The Weibull cumulative distribution function, for which the exponential function is only a special case, was selected and used to model the survival curves. The Weibull model was fitted to the 20 curves and the model parameters (alpha and beta) were determined. The fitted survival curves agreed with the experimental data with R(2)=0.951, 0.969, 0.908, and 0.871 for the Ref, RT, Hd, and Inc curves, respectively. Regression models relating alpha and beta to T, F, and a(w0) resulted in R(2) values of 0.975 for alpha and 0.988 for beta. The alpha and beta models can be used to generate a survival curve for Salmonella in chorizos for a given set of operating conditions. Additionally, alpha and beta can be used to determine the times needed to reduce the count by 1 or 2 logs t(1D) and t(2D). It is concluded that the Weibull cumulative distribution function offers a powerful model for describing microbial survival data. A comparison with the pathogen modeling program (PMP) revealed that the survival kinetics of Salmonella spp. in chorizos could not be adequately predicted using PMP which underestimated the t(1D) and t(2D). The mean of the Weibull probability density function correlated strongly with t(1D) and t(2D), and can serve as an alternative to the D-values normally used with first-order kinetic models. Parametric studies were conducted and sensitivity of survival to operating conditions was evaluated and discussed in the paper. The models derived herein provide a means for the development of a reliable risk assessment system for controlling Salmonella spp. in chorizos.

Targeted drug delivery and enhanced intracellular release using functionalized liposomes

NASA Astrophysics Data System (ADS)

Garg, Ashish

The ability to target cancer cells using an appropriate drug delivery system can significantly reduce the associated side effects from cancer therapies and can help in improving the overall quality of life, post cancer survival. Integrin alpha5beta1 is expressed on several types of cancer cells, including colon cancer and plays an important role in tumor growth and metastasis. Thus, the ability to target the integrin alpha 5beta1 using an appropriate drug delivery nano-vector can significantly help in inhibiting tumor growth and reducing tumor metastasis. The work in this thesis focuses on designing and optimizing, functionalized stealth liposomes (liposomes covered with polyethylene glycol (PEG)) that specifically target the integrin alpha5beta1. The PEG provides a steric barrier allowing the liposomes to circulate in the blood for longer duration and the functionalizing moiety, PR_b peptide specifically recognizes and binds to integrin alpha5beta1 expressing cells. The work demonstrates that by optimizing the amount of PEG and PR_b on the liposomal interface, nano-vectors can be engineered that bind to CT26.WT colon cancer cells in a specific manner and internalize through alpha 5beta1-mediated endocytosis. To further improve the efficacy of the system, PR_b functionalized pH-sensitive stealth liposomes that exhibit triggered release under mild acidic conditions present in endocytotic vesicles were designed. The study showed that PR_b functionalized pH-sensitive stealth liposomes, undergo destabilization under mildly acidic conditions and incorporation of the PR_b peptide does not significantly affect the pH-sensitivity of the liposomes. PR_b functionalized pH-sensitive stealth liposomes bind to CT26.WT colon carcinoma cells that express integrin alpha5beta 1, undergo cellular internalization, and release their load intracellularly in a short period of time as compared to other formulations. PR_b-targeted pH-sensitive stealth liposomes encapsulating 5-fluorouracil (5-FU) show significantly higher cytotoxicity than the PR_b-targeted inert stealth liposomes and the non-targeted stealth liposomes (both pH-sensitive and inert). The studies demonstrated that optimized PR_b functionalized pH sensitive liposomes have the potential to deliver a payload, such as chemotherapeutic agents, directly to colon cancer cells in an efficient and specific manner.

Cytokines released from blood monocytes and expressed in mucocutaneous lesions of patients with paracoccidioidomycosis evaluated before and during trimethoprim-sulfamethoxazole treatment.

PubMed

Parise-Fortes, M R; Marques, S A; Soares, A M V C; Kurokawa, C S; Marques, M E A; Peracoli, M T S

2006-04-01

Mucocutaneous lesions in paracoccidioidomycosis are granulomatous and result from tissue responses to Paracoccidioides brasiliensis, the aetiological agent. In this study we investigate the expression of tumour necrosis factor (TNF)-alpha, interleukin (IL)-10 and transforming growth factor (TGF)-beta1 by immunohistochemistry in skin and mucosa lesions from patients with the chronic form of paracoccidioidomycosis, evaluated before and at day 20 of trimethoprim-sulfamethoxazole treatment. Cytokine production by peripheral blood monocytes was also studied by enzyme immunoassay. Intense immunostaining for TNF-alpha was detected in mononuclear cells that infiltrated granulomas in all skin and mucosa lesions before treatment simultaneously with low IL-10 granular deposits in these cells. At day 20 of treatment, there was reduced TNF-alpha and IL-10 deposition. Immunoreactive TGF-beta1 was observed diffusely in the dermis and generally in the cytoplasm of macrophages and giant cells, before treatment, and as increased TGF-beta1 deposits in the fibrosis area at day 20 of treatment. Peripheral blood monocytes from patients with paracoccidioidomycosis, evaluated before treatment, produced high endogenous levels of TNF-alpha, TGF-beta1 and IL-10 in relation to healthy controls. Lipopolysaccharide-stimulated monocytes from patients secreted lower levels of TNF-alpha in both periods of evaluation while no impairment in capacity of IL-10 and TGF-beta production was observed. Trimethoprim-sulfamethoxazole therapy was effective in decreasing fungal load in the lesions, allowing patient immune response to control the infection leading to the healing of the lesions.

Localization of Alpha-Keratin and Beta-Keratin (Corneous Beta Protein) in the Epithelium on the Ventral Surface of the Lingual Apex and Its Lingual Nail in the Domestic Goose (Anser Anser f. domestica) by Using Immunohistochemistry and Raman Microspectroscopy Analysis.

PubMed

Skieresz-Szewczyk, Kinga; Jackowiak, Hanna; Buchwald, Tomasz; Szybowicz, Mirosław

2017-08-01

The epithelium of the ventral surface of the apex of the tongue in most birds is specified by the presence of the special superficial layer called lingual nail. The aim of the present study is to determine the localization of the alpha-keratin and beta-keratin (corneous beta protein) in this special epithelium in the domestic goose by using immunohistochemistry staining and the Raman spectroscopy analysis. Due to lack of commercially available antibodies to detect beta-keratin (corneous beta protein), the Raman spectroscopy was used as a specific tool to detect and describe the secondary structure of proteins. The immunohistochemical (IHC) detections reveal the presence of alpha-keratin in all layers of the epithelium, but significant differences in the distribution of the alpha-keratin in the epithelial layers appear. The staining reaction is stronger from the basal layer to the upper zone of the intermediate layer. The unique result is weak staining for the alpha-keratin in the lingual nail. Applications of the Raman spectroscopy as a complementary method not only confirmed results of IHC staining for alpha-keratin, but showed that this technique could be used to demonstrate the presence of beta-keratin (corneous beta protein). Functionally, the localization of alpha-keratin in the epithelium of the ventral surface of the lingual apex provides a proper scaffold for epithelial cells and promotes structural integrity, whereas the presence of beta-keratin (corneous beta protein) in the lingual nail, described also as exoskeleton of the ventral surface of the apex, endures mechanical stress. Anat Rec, 300:1361-1368, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Structural and molecular characterization of the prefoldin beta subunit from Thermococcus strain KS-1.

PubMed

Kida, Hiroshi; Sugano, Yuri; Iizuka, Ryo; Fujihashi, Masahiro; Yohda, Masafumi; Miki, Kunio

2008-11-14

Prefoldin (PFD) is a heterohexameric molecular chaperone that is found in eukaryotic cytosol and archaea. PFD is composed of alpha and beta subunits and forms a "jellyfish-like" structure. PFD binds and stabilizes nascent polypeptide chains and transfers them to group II chaperonins for completion of their folding. Recently, the whole genome of Thermococcus kodakaraensis KOD1 was reported and shown to contain the genes of two alpha and two beta subunits of PFD. The genome of Thermococcus strain KS-1 also possesses two sets of alpha (alpha1 and alpha2) and beta subunits (beta1 and beta2) of PFD (TsPFD). However, the functions and roles of each of these PFD subunits have not been investigated in detail. Here, we report the crystal structure of the TsPFD beta1 subunit at 1.9 A resolution and its functional analysis. TsPFD beta1 subunits form a tetramer with four coiled-coil tentacles resembling the jellyfish-like structure of heterohexameric PFD. The beta hairpin linkers of beta1 subunits assemble to form a beta barrel "body" around a central fourfold axis. Size-exclusion chromatography and multi-angle light-scattering analyses show that the beta1 subunits form a tetramer at pH 8.0 and a dimer of tetramers at pH 6.8. The tetrameric beta1 subunits can protect against aggregation of relatively small proteins, insulin or lysozyme. The structural and biochemical analyses imply that PFD beta1 subunits act as molecular chaperones in living cells of some archaea.

Control of the synthesis and subcellular targeting of the two GDH genes products in leaves and stems of Nicotiana plumbaginifolia and Arabidopsis thaliana.

PubMed

Fontaine, Jean-Xavier; Saladino, Francesca; Agrimonti, Caterina; Bedu, Magali; Tercé-Laforgue, Thérèse; Tétu, Thierry; Hirel, Bertrand; Restivo, Francesco M; Dubois, Frédéric

2006-03-01

Although the physiological role of the enzyme glutamate dehydrogenase which catalyses in vitro the reversible amination of 2-oxoglutarate to glutamate remains to be elucidated, it is now well established that in higher plants the enzyme preferentially occurs in the mitochondria of phloem companion cells. The Nicotiana plumbaginifolia and Arabidopis thaliana enzyme is encoded by two distinct genes encoding either an alpha- or a beta-subunit. Using antisense plants and mutants impaired in the expression of either of the two genes, we showed that in leaves and stems both the alpha- and beta-subunits are targeted to the mitochondria of the companion cells. In addition, we found in both species that there is a compensatory mechanism up-regulating the expression of the alpha-subunit in the stems when the expression of the beta-subunit is impaired in the leaves, and of the beta-subunit in the leaves when the expression of the alpha-subunit is impaired in the stems. When one of the two genes encoding glutamate dehydrogenase is ectopically expressed, the corresponding protein is targeted to the mitochondria of both leaf and stem parenchyma cells and its production is increased in the companion cells. These results are discussed in relation to the possible signalling and/or physiological function of the enzyme which appears to be coordinated in leaves and stems.

Targeting Alpha5 Beta1 Integrin to Prevent Metastatic Breast Cancer Cell Invasion: PhScN Target Site Definition and Plasma Stability

DTIC Science & Technology

2015-11-01

systemic therapy to prevent breast cancer bone colony progression. Figure 6. Colocalization of Ac-PhscNGGK-Bio with DiI in lung– extravasated SUM149PT cells...breast cancer progression that are ultimately fatal. Hence, prevention of extravasation which leads to colony formation would increase life...1 Award Number: W81XWH-12-1-0097 TITLE: “Targeting Alpha5 Beta1 Integrin to Prevent Metastatic Breast Cancer Cell Invasion: PhScN Target Site

Early application of Met-RANTES ameliorates chronic allograft nephropathy.

PubMed

Song, Erwei; Zou, Hequn; Yao, Yousheng; Proudfoot, Amanda; Antus, Balazs; Liu, Shanying; Jens, Lutz; Heemann, Uwe

2002-02-01

Initial insults to kidney allografts, characterized by infiltration of mononuclear inflammatory cells, contribute to chronic allograft nephropathy. Chemokines such as RANTES (regulated upon activation, normal T cell expressed) are thought to be responsible for the recruitment and activation of infiltrating cells. The present study investigated whether early application of Met-RANTES, a chemokine receptor antagonist that blocks the effects of RANTES, can protect renal allografts from long-term deterioration. Fisher (F344) rat kidneys were orthotopically transplanted into Lewis recipients and treated with cyclosporine A (1.5 mg/kg/day) for the first 10 days following transplantation, together with either Met-RANTES at 40 microg/day, 200 microg/day or vehicle for the first 7 days. Animals were harvested at 2 and 28 weeks after transplantation for histologic, immunohistologic and molecular analysis. Met-RANTES treatment reduced the infiltration of lymphocytes and macrophages in allografts at 2 weeks after transplantation, accompanied by decreased mRNA expression of interleukin (IL)-2, IL-1beta, tumor necrosis factor-alpha (TNF-alpha) and RANTES. At post-transplantation week 28, Met-RANTES treatment at high and low doses reduced urinary protein excretion and significantly ameliorated glomerulosclerosis, interstitial fibrosis, tubular atrophy, intimal proliferation of graft arteries and mononuclear cell infiltration. However, creatinine clearance was not influenced by Met-RANTES. Furthermore, Met-RANTES suppressed the mRNA expression of transforming growth factor-beta (TGF-beta) and platelet-derived growth factor-B (PDGF-B). Blockade of chemokine receptors by Met-RANTES diminishes early infiltration and activation of mononuclear cells in the grafts, and thus reduces the pace of chronic allograft nephropathy.

Search for long lived heaviest nuclei beyond the valley of stability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chowdhury, P. Roy; Samanta, C.; Physics Department, Virginia Commonwealth University, Richmond, Virginia 23284-2000

2008-04-15

The existence of long lived superheavy nuclei (SHN) is controlled mainly by spontaneous fission and {alpha}-decay processes. According to microscopic nuclear theory, spherical shell effects at Z=114, 120, 126 and N=184 provide the extra stability to such SHN to have long enough lifetime to be observed. To investigate whether the so-called 'stability island' could really exist around the above Z, N values, the {alpha}-decay half-lives along with the spontaneous fission and {beta}-decay half-lives of such nuclei are studied. The {alpha}-decay half-lives of SHN with Z=102-120 are calculated in a quantum tunneling model with DDM3Y effective nuclear interaction using Q{sub {alpha}}more » values from three different mass formulas prescribed by Koura-Uno-Tachibana-Yamada (KUTY), Myers-Swiatecki (MS), and Muntian-Hofmann-Patyk-Sobiczewski (MMM). Calculation of spontaneous fission (SF) half-lives for the same SHN are carried out using a phenomenological formula and compared with SF half-lives predicted by Smolanczuk et al. A possible source of discrepancy between the calculated {alpha}-decay half-lives of some nuclei and the experimental data of GSI, JINR-FLNR, RIKEN, is discussed. In the region of Z=106-108 with N{approx}160-164, the {beta}-stable SHN {sub 106}{sup 268}Sg{sub 162} is predicted to have highest {alpha}-decay half-life (T{sub {alpha}}{approx}3.2 h) using Q{sub {alpha}} value from MMM. Interestingly, it is much greater than the recently measured T{sub {alpha}} ({approx}22 s) of deformed doubly magic {sub 108}{sup 270}Hs{sub 162} nucleus. A few fission-survived long-lived SHN which are either {beta}-stable or having large {beta}-decay half-lives are predicted to exist near {sup 294}110{sub 184}, {sup 293}110{sub 183}, {sup 296}112{sub 184}, and {sup 298}114{sub 184}. These nuclei might decay predominantly through {alpha}-particle emission.« less

Increased neuronal beta-amyloid precursor protein expression in human temporal lobe epilepsy: association with interleukin-1 alpha immunoreactivity.

PubMed

Sheng, J G; Boop, F A; Mrak, R E; Griffin, W S

1994-11-01

Levels of immunoreactive beta-amyloid precursor protein and interleukin-1 alpha were found to be elevated in surgically resected human temporal lobe tissue from patients with intractable epilepsy compared with postmortem tissue from neurologically unaffected patients (controls). In tissue from epileptics, the levels of the 135-kDa beta-amyloid precursor protein isoform were elevated to fourfold (p < 0.05) those of controls and those of the 130-kDa isoform to threefold (p < 0.05), whereas those of the 120-kDa isoform (p > 0.05) were not different from control values. beta-Amyloid precursor protein-immunoreactive neurons were 16 times more numerous, and their cytoplasm and proximal processes were more intensely immunoreactive in tissue sections from epileptics than controls (133 +/- 12 vs. 8 +/- 3/mm2; p < 0.001). However, neither beta-amyloid precursor protein-immunoreactive dystrophic neurites nor beta-amyloid deposits were found in this tissue. Interleukin-1 alpha-immunoreactive cells (microglia) were three times more numerous in epileptics than in controls (80 +/- 8 vs. 25 +/- 5/mm2; p < 0.001), and these cells were often found adjacent to beta-amyloid precursor protein-immunoreactive neuronal cell bodies. Our findings, together with functions established in vitro for interleukin-1, suggest that increased expression of this protein contributes to the increased levels of beta-amyloid precursor protein in epileptics, thus indicating a potential role for both of these proteins in the neuronal dysfunctions, e.g., hyperexcitability, characteristic of epilepsy.

Characterization of the retina in the alpha7 nicotinic acetylcholine receptor knockout mouse

NASA Astrophysics Data System (ADS)

Smith, Marci L.

Acetylcholine receptors (AChRs) are involved in visual processing and are expressed by inner retinal neurons in all species studied to date (Keyser et al., 2000; Dmitrieva et al., 2007; Liu et al., 2009), but their distribution in the mouse retina remains unknown. Reductions in alpha7 nicotinic AChRs (nAChRs) are thought to contribute to memory and visual deficits observed in Alzheimer's and schizophrenia (Coyle et al., 1983; Nordberg et al., 1999; Leonard et al., 2006). However, the alpha7 nAChR knockout (KO) mouse has a mild phenotype (Paylor et al., 1998; Fernandes et al., 2006; Young et al., 2007; Origlia et al., 2012). The purpose of this study was to determine the expression of AChRs in wildtype (WT) mouse retina and to assess whether up-regulation of other AChRs in the alpha7 nAChR KO retina may explain the minimal deficits described in the KO mouse. Reverse-transcriptase PCR (RT-PCR) showed that mRNA transcripts for alpha2-7, alpha 9, alpha10, beta2-4 nAChR subunits and m1-m5 muscarinic AChR (mAChR) subtypes were present in WT murine retina. Western blot analysis confirmed the presence of alpha3-5, alpha9, and m1-m5 AChR proteins and immunohistochemical analysis demonstrated nAChR and mAChR proteins expressed by subsets of bipolar, amacrine and ganglion cells. This is the first reported expression of alpha9 and alpha10 nAChR transcripts and alpha9 nAChR proteins in the retina of any species. Quantitative RT-PCR (qPCR) showed changes in AChR transcript expression in the alpha7 nAChR KO mouse retina relative to WT. Within whole retina alpha2, alpha9, alpha10, beta4, m1 and m4 AChR transcripts were up-regulated, while alpha5 nAChR transcripts were down-regulated. However, cell populations showed subtle differences; m4 mAChR transcripts were up-regulated in the ganglion cell layer and outer portion of the inner nuclear layer (oINL),while beta4 nAChR transcript up-regulation was limited to the oINL. Surprisingly, alpha2, alpha9, beta4, m2 and m4 transcripts were down-regulated in the inner portion of the INL. These results indicate that compensation is mediated by differential regulation of more than one receptor type and changes in mRNA expression vary between cell populations.

Human brucellosis is characterized by an intense Th1 profile associated with a defective monocyte function.

PubMed

Rodríguez-Zapata, Manuel; Matías, Marlene J; Prieto, Alfredo; Jonde, Marco A; Monserrat, Jorge; Sánchez, Lorenzo; Reyes, Eduardo; De la Hera, Antonio; Alvarez-Mon, Melchor

2010-07-01

In animal models, a defective Th1 response appears to be critical in the pathogenesis of brucellosis, but the Th1 response in human brucellosis patients remains partially undefined. Peripheral blood from 24 brucellosis patients was studied before and 45 days after antibiotherapy. Twenty-four sex- and age-matched healthy donors were analyzed in parallel. Significantly increased levels of interleukin 1beta (IL-1beta), IL-2, IL-4, IL-6, IL-12p40, gamma interferon (IFN-gamma), and tumor necrosis factor alpha (TNF-alpha), but not of IL-10, in serum and/or significantly increased percentages of samples with detectable levels of these cytokines, measured by enzyme-linked immunosorbent assays (ELISA), were found for untreated brucellosis patients, but these levels were reduced and/or normalized after treatment. Flow cytometry studies showed that the intracytoplasmic expression of IFN-gamma, IL-2, and TNF-alpha, but not that of IL-4, by phorbol myristate-activated CD4(+) CD3(+) and CD8(+) CD3(+) T lymphocytes was significantly increased in untreated brucellosis patients and was also partially normalized after antibiotherapy. The percentage of phagocytic cells, the mean phagocytic activity per cell, and the phagocytic indices for monocytes at baseline were defective and had only partially reverted at follow-up. T lymphocytes from untreated brucellosis patients are activated in vivo and show Th1 cytokine production polarization, with strikingly high serum IFN-gamma levels. In spite of this Th1 environment, we found deficient effector phagocytic activity in peripheral blood monocytes.

Noradrenaline inhibits lipopolysaccharide-induced tumor necrosis factor and interleukin 6 production in human whole blood.

PubMed Central

van der Poll, T; Jansen, J; Endert, E; Sauerwein, H P; van Deventer, S J

1994-01-01

Sepsis and lipopolysaccharide (LPS) trigger the systemic release of both cytokines and catecholamines. Cytokines are known to be capable of eliciting a stress hormone response in vivo. The present study sought insight into the effect of noradrenaline on LPS-induced release of tumor necrosis factor alpha (TNF) and interleukin 6 (IL-6) in human whole blood. Whole blood was incubated with LPS for 4 h at 37 degrees C in the presence and absence of noradrenaline and/or specific alpha and beta antagonists and agonists. Noradrenaline caused a dose-dependent inhibition of LPS-induced TNF and IL-6 production. This effect could be completely prevented by addition of the specific beta 1, antagonist metoprolol, while it was not affected by the alpha antagonist phentolamine. Specific beta-adrenergic stimulation by isoprenaline mimicked the inhibiting effect of noradrenaline on LPS-evoked cytokine production, whereas alpha-adrenergic stimulation by phenylephrine had no effect. Fluorescence-activated cell sorter analysis demonstrated that beta-adrenergic stimulation had no effect on LPS binding to and internalization into mononuclear cells or on the expression of CD14, the major receptor for LPS on mononuclear cells. In acute sepsis, enhanced release of noradrenaline may be part of a negative feedback mechanism meant to inhibit ongoing TNF and IL-6 production. PMID:8168970

Granulocyte colony-stimulating-factor-induced psoriasiform dermatitis resembles psoriasis with regard to abnormal cytokine expression and epidermal activation.

PubMed

Mössner, R; Beckmann, I; Hallermann, C; Neumann, C; Reich, K

2004-06-01

Psoriasis is a chronic inflammatory skin disorder characterized by accumulation of Th1-type T cells and neutrophils, regenerative keratinocyte proliferation and differentiation, and enhanced epidermal production of antimicrobial peptides. The underlying cause is unknown, but there are some similarities with the immunologic defense program against bacteria. Development of psoriasiform skin lesions has been reported after administration of granulocyte colony-stimulating factor (G-CSF), a cytokine induced in monocytes by bacterial antigens. To further investigate the relation between this type of cytokine-induced dermatitis and psoriasis, we analyzed the cutaneous cytokine profile [tumor necrosis factor-alpha (TNF-alpha), interferon-gamma, transforming growth factor-beta1 (TGF-beta1), interleukin-10 (IL-10), IL-12p35 and p40, and IL-8] and expression of markers of epidermal activation [Ki-67, cytokeratin-16, major histocompatibility complex (MHC) class II, intercellular adhesion molecule-1 (ICAM-1)] in a patient who developed G-CSF-induced psoriasiform dermatitis by using quantitative real-time reverse transcriptase-polymerase chain reaction and immunohistology. The histologic picture resembled psoriasis with regard to epidermal hyperparakeratosis and the accumulation of lymphocytes in the upper corium. CD8(+) T cells were found to infiltrate the epidermis which was associated with an aberrant expression of Ki-67, cytokeratin-16, MHC class II, and ICAM-1 on adjacent keratinocytes. As compared to normal skin (n = 7), there was an increased expression of TNF-alpha, IL-12p40, and IL-8, a decreased expression of TGF-beta1, and a lack of IL-10, similar to the findings in active psoriasis (n = 8). Therefore, G-CSF may cause a lymphocytic dermatitis that, similar to psoriasis, is characterized by a pro-inflammatory Th1-type cytokine milieu and an epidermal phenotype indicative of aberrant maturation and acquisition of non-professional immune functions.

Effects of estradiol, estrogen receptor subtype-selective agonists and genistein on glucose metabolism in leptin resistant female Zucker diabetic fatty (ZDF) rats.

PubMed

Weigt, Carmen; Hertrampf, Torsten; Flenker, Ulrich; Hülsemann, Frank; Kurnaz, Pinar; Fritzemeier, Karl Heinrich; Diel, Patrick

2015-11-01

The leptin resistant Zucker diabetic fatty (ZDF) rats are hyperphagic and become obese, but whereas the males develop type 2 diabetes mellitus (T2DM), the females remain euglycaemic. As estrogen deficiency is known to increase the risk of developing T2DM, we evaluated the role of ER subtypes alpha and beta in the development of glucose tolerance in leptin resistant ovariectomized (OVX) ZDF rats. At least six rats per group were treated with either vehicle (OVX), 17β-estradiol (E2), ER subtype-selective agonists (Alpha and Beta), or genistein (Gen) for 17 weeks. At the end of the treatment period a glucose tolerance assay was performed and the metabolic flux of (13)C-glucose for the E2 group was investigated. OVX ZDF rats treated with E2, Alpha, Beta, and Gen tolerated the glucose significantly better than untreated controls. E2 treatment increased absorbance/flux of (13)C-glucose to metabolic relevant tissues such liver, adipose tissue, gastrocnemius, and soleus muscle. Moreover, whereas Alpha treatment markedly increased mRNA expression of GLUT4 in gastrocnemius muscle, Beta treatment resulted in the largest fiber sizes of the soleus muscle. Treatment with Gen increased both the mRNA expression of GLUT 4 and the fiber sizes in the skeletal muscle. In addition, E2 and Alpha treatment decreased food intake and body weight gain. In summary, estrogen-improved glucose absorption is mediated via different molecular mechanisms: while activation of ER alpha seems to stimulate muscular GLUT4 functionality, activation of ER beta results in a hypertrophy of muscle fibers. In addition, selective activation of ER alpha decreased food intake and body weight gain. Our data further indicate that ER subtype-selective agonists and genistein improve systemic glucose tolerance also in the absence of a functional leptin signaling pathway. Copyright © 2015 Elsevier Ltd. All rights reserved.

Tumor evasion of the immune system by converting CD4+CD25- T cells into CD4+CD25+ T regulatory cells: role of tumor-derived TGF-beta.

PubMed

Liu, Victoria C; Wong, Larry Y; Jang, Thomas; Shah, Ali H; Park, Irwin; Yang, Ximing; Zhang, Qiang; Lonning, Scott; Teicher, Beverly A; Lee, Chung

2007-03-01

CD4+CD25+ T regulatory (T(reg)) cells were initially described for their ability to suppress autoimmune diseases in animal models. An emerging interest is the potential role of T(reg) cells in cancer development and progression because they have been shown to suppress antitumor immunity. In this study, CD4+CD25- T cells cultured in conditioned medium (CM) derived from tumor cells, RENCA or TRAMP-C2, possess similar characteristics as those of naturally occurring T(reg) cells, including expression of Foxp3, a crucial transcription factor of T(reg) cells, production of low levels of IL-2, high levels of IL-10 and TGF-beta, and the ability to suppress CD4+CD25- T cell proliferation. Further investigation revealed a critical role of tumor-derived TGF-beta in converting CD4+CD25- T cells into T(reg) cells because a neutralizing Ab against TGF-beta, 1D11, completely abrogated the induction of T(reg) cells. CM from a nontumorigenic cell line, NRP-152, or irradiated tumor cells did not convert CD4+CD25- T cells to T(reg) cells because they produce low levels of TGF-beta in CM. Finally, we observed a reduced tumor burden in animals receiving 1D11. The reduction in tumor burden correlated with a decrease in tumor-derived TGF-beta. Treatment of 1D11 also reduced the conversion of CD4+ T cells into T(reg) cells and subsequent T(reg) cell-mediated suppression of antitumor immunity. In summary, we have demonstrated that tumor cells directly convert CD4+CD25- T cells to T(reg) cells through production of high levels of TGF-beta, suggesting a possible mechanism through which tumor cells evade the immune system.

Spotlight on agalsidase beta in Fabry disease.

PubMed

Keating, Gillian M; Simpson, Dene

2007-01-01

Agalsidase beta (Fabrazyme) is a recombinant human alpha-galactosidase A enzyme approved for intravenous use in the treatment of Fabry disease. Fabry disease is a progressive, multisystemic, potentially life-threatening disorder caused by a deficiency of alpha-galactosidase A. This deficiency results in accumulation of glycosphingolipids, particularly globotriaosylceramide (GL-3), in the lysosomes of various tissues. This accumulation is the underlying driver of disease progression. Agalsidase beta provides an exogenous source of alpha-galactosidase A. Intravenous agalsidase beta is effective and well tolerated in patients with Fabry disease. In a phase III trial, agalsidase beta was shown to clear GL-3 from various target cells and, in a subsequent extension of this trial, prevent GL-3 reaccumulation. In a post-approval trial, agalsidase beta was shown to provide significant clinical benefit by reducing the risk of a major clinical event. Thus, agalsidase beta represents an important advance in the treatment of Fabry disease, and agalsidase beta therapy should be strongly considered in patients with Fabry disease who are suitable candidates.

Agalsidase Beta: a review of its use in the management of Fabry disease.

PubMed

Keating, Gillian M; Simpson, Dene

2007-01-01

Agalsidase beta (Fabrazyme) is a recombinant human alpha-galactosidase A enzyme approved for intravenous use in the treatment of Fabry disease. Fabry disease is a progressive, multisystemic, potentially life threatening disorder caused by a deficiency of alpha-galactosidase A. This deficiency results in accumulation of glycosphingolipids, particularly globotriaosylceramide (GL-3), in the lysosomes of various tissues. This accumulation is the underlying driver of disease progression. Agalsidase beta provides an exogenous source of alpha-galactosidase A.Intravenous agalsidase beta is effective and well tolerated in patients with Fabry disease. In a phase III trial, agalsidase beta was shown to clear GL-3 from various target cells and, in a subsequent extension of this trial, prevent GL-3 reaccumulation. In a post-approval trial, agalsidase beta was shown to provide significant clinical benefit by reducing the risk of a major clinical event. Thus, agalsidase beta represents an important advance in the treatment of Fabry disease, and agalsidase beta therapy should be strongly considered in patients with Fabry disease who are suitable candidates.

Two cofactors and cytoplasmic chaperonin are required for the folding of alpha- and beta-tubulin.

PubMed Central

Gao, Y; Vainberg, I E; Chow, R L; Cowan, N J

1993-01-01

Though the chaperonins that mediate folding in prokaryotes, mitochondria, and chloroplasts have been relatively well characterized, the folding of proteins in the eukaryotic cytosol is much less well understood. We recently identified a cytoplasmic chaperonin as an 800-kDa multisubunit toroid which forms a binary complex with unfolded actin; the correctly folded polypeptide is released upon incubation with Mg-ATP (Y. Gao, J. O. Thomas, R. L. Chow, G.-H. Lee, and N. J. Cowan, Cell 69:1043-1050, 1992). Here we show that the same chaperonin also forms a binary complex with unfolded alpha- or beta-tubulin; however, there is no detectable release of the correctly folded product, irrespective of the concentration of added Mg-ATP and Mg-GTP or the presence of added carrier tubulin heterodimers with which newly folded alpha- or beta-tubulin polypeptides might exchange. Rather, two additional protein cofactors are required for the generation of properly folded alpha- or beta-tubulin, which is then competent for exchange into preexisting alpha/beta-tubulin heterodimers. We show that actin and tubulins compete efficiently with one another for association with cytoplasmic chaperonin complexes. These data imply that actin and alpha- and beta-tubulin interact with the same site(s) on chaperonin complexes. Images PMID:8096061

Mutation analysis of 12 genes in Chinese families with congenital cataracts

PubMed Central

Sun, Wenmin; Xiao, Xueshan; Li, Shiqiang; Guo, Xiangming

2011-01-01

Purpose To identify mutations in 12 genes in Chinese families with congenital cataracts. Methods Twenty five families with congenital cataracts involved in this study. The coding exons and adjacent intronic regions of 12 genes were analyzed by cycle sequencing, including the alpha A crystallin (CRYAA), alpha B crystallin (CRYAB), beta A1 crystallin (CRYBA1), beta A4 crystallin (CRYBA4), beta B1 crystallin (CRYBB1), beta B2 crystallin (CRYBB2), beta B3 crystallin (CRYBB3), gamma C crystallin (CRYGC), gamma D crystallin (CRYGD), gamma S crystallin (CRYGS), alpha 3 gap junction protein (GJA3), and alpha 8 gap junction protein (GJA8) genes. Novel variants were further evaluated in 96 normal controls. Results Nine mutations were identified in 10 of the 25 families (40%), including 5 novel (c.350_352delGCT in CRYAA, c.205C>T in CRYAB, c.106G>C in CRYGD, c.77A>G in CRYGS, c.1143_1165del23 in GJA3) and 4 known (c.292G>A in CRYAA; c.215+1G>A and c.272_274delGAG in CRYBA1, and c.176C>T in GJA3). All novel mutations were predicted to be pathogenic and were not present in 96 controls. Conclusions Mutations in the 12 genes encoding crystallins and connexins were responsible for 40% Chinese families with congenital cataracts. Our results enriched our knowledge on the molecular basis of congenital cataracts in Chinese population. PMID:21866213

Probing transmembrane mechanical coupling and cytomechanics using magnetic twisting cytometry

NASA Technical Reports Server (NTRS)

Wang, N.; Ingber, D. E.

1995-01-01

We recently developed a magnetic twisting cytometry technique that allows us to apply controlled mechanical stresses to specific cell surface receptors using ligand-coated ferromagnetic microbeads and to simultaneously measure the mechanical response in living cells. Using this technique, we have previously shown the following: (i) beta 1 integrin receptors mediate mechanical force transfer across the cell surface and to the cytoskeleton, whereas other transmembrane receptors (e.g., scavenger receptors) do not; (ii) cytoskeletal stiffness increases in direct proportion to the level of stress applied to integrins; and (iii) the slope of this linear stiffening response differs depending on the shape of the cell. We now show that different integrins (beta 1, alpha V beta 3, alpha V, alpha 5, alpha 2) and other transmembrane receptors (scavenger receptor, platelet endothelial cell adhesion molecule) differ in their ability to mediate force transfer across the cell surface. In addition, the linear stiffening behavior previously observed in endothelial cells was found to be shared by other cell types. Finally, we demonstrate that dynamic changes in cell shape that occur during both cell spreading and retraction are accompanied by coordinate changes in cytoskeletal stiffness. Taken together, these results suggest that the magnetic twisting cytometry technique may be a powerful and versatile tool for studies analyzing the molecular basis of transmembrane mechanical coupling to the cytoskeleton as well as dynamic relations between changes in cytoskeletal structure and alterations in cell form and function.

Molecular role of TGF-beta, secreted from a new type of CD4+ suppressor T cell, NY4.2, in the prevention of autoimmune IDDM in NOD mice.

PubMed

Han, H S; Jun, H S; Utsugi, T; Yoon, J W

1997-06-01

A new type of CD4+ T cell clone (NY4.2) isolated from pancreatic islet-infiltrated lymphocytes of acutely diabetic non-obese diabetic (NOD) mice prevents the development of insulin-dependent diabetes mellitus (IDDM) in NOD mice, as well as the recurrence of autoimmune diabetes in syngeneic islet-transplanted NOD mice. It has been demonstrated that the cytokine TGF-beta, secreted from the cells of this clone, is the substance which prevents autoimmune IDDM. This investigation was initiated to determine the molecular role TGF-beta plays in the prevention of autoimmune IDDM by determining its effect on IL-2-induced signal transduction in Con A-activated NOD mouse splenocytes and HT-2 cells. First, we determined whether TGF-beta, secreted from NY4.2 T cells, inhibits IL-2-dependent T cell proliferation in HT-2 cells (IL-2-dependent T cell line) and NOD splenocytes. We found that TGF-beta suppresses IL-2-dependent T cell proliferation. Second, we determined whether TGF-beta inhibits the activation of Janus kinases (JAKs), as well as signal transducers and activators of transcription (STAT) proteins, involved in an IL-2-induced signalling pathway that normally leads to the proliferation of T cells. We found that TGF-beta inhibited tyrosine phosphorylation of JAK1, JAK3, STAT3 and STAT5 in Con A blasts from NOD splenocytes and HT-2 cells. Third, we examined whether TGF-beta inhibits the cooperation between STAT proteins and mitogen-activated protein kinase (MAPK), especially extracellular signal-regulated kinase 2 (ERK2). We found that TGF-beta inhibited the association of STAT3 and STAT5 with ERK2 in Con A blasts from NOD splenocytes and HT-2 cells. On the basis of these observations, we conclude that TGF-beta may interfere with signal transduction via inhibition of the IL-2-induced JAK/STAT pathway and inhibition of the association of STAT proteins with ERK2 in T cells from NOD splenocytes, resulting in the inhibition of IL-2-dependent T cell proliferation. TGF-beta-mediated suppression of T cell activation may be responsible for the prevention of effector T cell-mediated autoimmune IDDM in NOD mice by TGF-beta-producing CD4+ suppressor T cells.

Transforming growth factor beta induced FoxP3+ regulatory T cells suppress Th1 mediated experimental colitis.

PubMed

Fantini, M C; Becker, C; Tubbe, I; Nikolaev, A; Lehr, H A; Galle, P; Neurath, M F

2006-05-01

The imbalance between effector and regulatory T cells plays a central role in the pathogenesis of inflammatory bowel diseases. In addition to the thymus, CD4+CD25+ regulatory T cells can be induced in the periphery from a population of CD25- T cells by treatment with transforming growth factor beta (TGF-beta). Here, we analysed the in vivo function of TGF-beta induced regulatory T (Ti-Treg) cells in experimental colitis. Ti-Treg cells were generated in cell culture in the presence or absence of TGF-beta and tested for their regulatory potential in experimental colitis using the CD4+CD62L+ T cell transfer model. Ti-Treg cells significantly suppressed Th1 mediated colitis on CD4+CD62L+ T cell transfer in vivo, as shown by high resolution endoscopy, histology, immunohistochemistry, and cytokine analysis. Further analysis of in vivo and in vitro expanded Ti-Treg cells showed that exogenous interleukin 2 (IL-2) was crucial for survival and expansion of these cells. Our data suggest that regulatory Ti-Treg cells expand by TGF-beta and exogenous IL-2 derived from effector T cells at the site of inflammation. In addition to Tr1 and thymic CD4+CD25+ T cells, peripheral Ti-Treg cells emerge as a class of regulatory T cells with therapeutic potential in T cell mediated chronic intestinal inflammation.

Electromotive force measurements on cells involving beta-alumina solid electrolyte

NASA Technical Reports Server (NTRS)

Choudhury, N. S.

1973-01-01

Open-circuit emf measurements have been made to demonstrate that a two-phase, polycrystalline mixture of beta-alumina and alpha-alumina could be used as a solid electrolyte in galvanic cells with reversible electrodes fixing oxygen or aluminum chemical potentials. These measurements indicate that such a two-phase solid electrolyte may be used to monitor oxygen chemical potentials as low as that corresponding to Al and Al2O3 coexistence (potentials of about 10 to the minus 47th power atm at 1000 K). The activity of Na2O in beta-alumina in coexistence with alpha-alumina was also determined by emf measurements.

Towards atomic scale engineering of rare-earth-doped SiAlON ceramics through aberration-corrected scanning transmission electron microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yurdakul, Hilmi; Idrobo Tapia, Juan C; Pennycook, Stephen J

2011-01-01

Direct visualization of rare earths in {alpha}- and {beta}-SiAlON unit-cells is performed through Z-contrast imaging technique in an aberration-corrected scanning transmission electron microscope. The preferential occupation of Yb and Ce atoms in different interstitial locations of {beta}-SiAlON lattice is demonstrated, yielding higher solubility for Yb than Ce. The triangular-like host sites in {alpha}-SiAlON unit cell accommodate more Ce atoms than hexagonal sites in {beta}-SiAlON. We think that our results will be applicable as guidelines for many kinds of rare-earth-doped materials.

Developmental programming of polycystic ovary syndrome (PCOS): prenatal androgens establish pancreatic islet α/β cell ratio and subsequent insulin secretion.

PubMed

Ramaswamy, S; Grace, C; Mattei, A A; Siemienowicz, K; Brownlee, W; MacCallum, J; McNeilly, A S; Duncan, W C; Rae, M T

2016-06-06

Exogenous androgenic steroids applied to pregnant sheep programmes a PCOS-like phenotype in female offspring. Via ultrasound guidance we applied steroids directly to ovine fetuses at d62 and d82 of gestation, and examined fetal (day 90 gestation) and postnatal (11 months old) pancreatic structure and function. Of three classes of steroid agonists applied (androgen - Testosterone propionate (TP), estrogen - Diethystilbesterol (DES) and glucocorticoid - Dexamethasone (DEX)), only androgens (TP) caused altered pancreatic development. Beta cell numbers were significantly elevated in prenatally androgenised female fetuses (P = 0.03) (to approximately the higher numbers found in male fetuses), whereas alpha cell counts were unaffected, precipitating decreased alpha:beta cell ratios in the developing fetal pancreas (P = 0.001), sustained into adolescence (P = 0.0004). In adolescence basal insulin secretion was significantly higher in female offspring from androgen-excess pregnancies (P = 0.045), and an exaggerated, hyperinsulinaemic response to glucose challenge (P = 0.0007) observed, whereas prenatal DES or DEX treatment had no effects upon insulin secretion. Postnatal insulin secretion correlated with beta cell numbers (P = 0.03). We conclude that the pancreas is a primary locus of androgenic stimulation during development, giving rise to postnatal offspring whose pancreas secreted excess insulin due to excess beta cells in the presence of a normal number of alpha cells.

Developmental programming of polycystic ovary syndrome (PCOS): prenatal androgens establish pancreatic islet α/β cell ratio and subsequent insulin secretion

PubMed Central

Ramaswamy, S.; Grace, C.; Mattei, A. A.; Siemienowicz, K.; Brownlee, W.; MacCallum, J.; McNeilly, A. S.; Duncan, W. C.; Rae, M. T.

2016-01-01

Exogenous androgenic steroids applied to pregnant sheep programmes a PCOS-like phenotype in female offspring. Via ultrasound guidance we applied steroids directly to ovine fetuses at d62 and d82 of gestation, and examined fetal (day 90 gestation) and postnatal (11 months old) pancreatic structure and function. Of three classes of steroid agonists applied (androgen - Testosterone propionate (TP), estrogen - Diethystilbesterol (DES) and glucocorticoid - Dexamethasone (DEX)), only androgens (TP) caused altered pancreatic development. Beta cell numbers were significantly elevated in prenatally androgenised female fetuses (P = 0.03) (to approximately the higher numbers found in male fetuses), whereas alpha cell counts were unaffected, precipitating decreased alpha:beta cell ratios in the developing fetal pancreas (P = 0.001), sustained into adolescence (P = 0.0004). In adolescence basal insulin secretion was significantly higher in female offspring from androgen-excess pregnancies (P = 0.045), and an exaggerated, hyperinsulinaemic response to glucose challenge (P = 0.0007) observed, whereas prenatal DES or DEX treatment had no effects upon insulin secretion. Postnatal insulin secretion correlated with beta cell numbers (P = 0.03). We conclude that the pancreas is a primary locus of androgenic stimulation during development, giving rise to postnatal offspring whose pancreas secreted excess insulin due to excess beta cells in the presence of a normal number of alpha cells. PMID:27265420

The characteristics of the (alpha V371C)3(beta R337C)3 gamma double mutant subcomplex of the TF1-ATPase indicate that the catalytic site at the alpha TP-beta TP interface with bound MgADP in crystal structures of MF1 represents a catalytic site containing inhibitory MgADP.

PubMed

Bandyopadhyay, Sanjay; Muneyuki, Eiro; Allison, William S

2005-02-22

In the MF(1) crystal structure with the MgADP-fluoroaluminate complex bound to two catalytic sites [Menz, R. I., Walker, J. E., and Leslie, A. G. W. (2001) Cell 106, 331-341], the guanidinium of betaR(337) is within 2.9 A of the alpha-oxygen of alphaS(370) and 3.7 A of a methyl group of alphaV(371) at the alpha(E)-beta(HC) interface. To examine the functional role of this contact, the (alphaV(371)C)(3)(betaR(337)C)(3)gamma subcomplex of the TF(1)-ATPase was prepared and characterized. Steady state ATPase activity of the reduced double-mutant is 30% of that of the wild type. Inactivation of the double mutant containing empty catalytic sites or MgADP bound to one catalytic site with CuCl(2) cross-linked two alpha-beta pairs, whereas a single alpha-beta pair cross-linked when at least two catalytic sites contained MgADP. The reduced double mutant hydrolyzed substoichiometric ATP 100-fold more rapidly than the enzyme containing two cross-linked alpha-beta pairs. Addition of AlCl(3) and NaF to the reduced double mutant after incubation with stoichiometric MgADP or 200 microM MgADP irreversibly inactivated the steady state ATPase activity with rate constants of 1.5 x10(-2) and 4.1 x 10(-2) min(-1), respectively. In contrast, addition of AlCl(3) and NaF to the cross-linked enzyme after incubation with stoichiometric or 200 microM MgADP irreversibly inactivated ATPase activity with a common rate constant of approximately 10(-4) min(-1). Correlation of these results with crystal structures of MF(1) suggests that the catalytic site at the alpha(TP)-beta(TP) interface is loaded first upon addition of nucleotides to nucleotide-depleted F(1)-ATPases and that the catalytic site at the alpha(TP)-beta(TP) interface with bound MgADP in crystal structures represents a catalytic site containing inhibitory MgADP.

Transforming growth factor-beta controls T helper type 1 cell development through regulation of natural killer cell interferon-gamma.

PubMed

Laouar, Yasmina; Sutterwala, Fayyaz S; Gorelik, Leonid; Flavell, Richard A

2005-06-01

Interferon-gamma and interleukin 12 produced by the innate arm of the immune system are important regulators of T helper type 1 (T(H)1) cell development, but signals that negatively regulate their expression remain controversial. Here we show that transforming growth factor-beta (TGF-beta) controlled T(H)1 differentiation through the regulation of interferon-gamma produced by natural killer (NK) cells. Blockade of TGF-beta signaling in NK cells caused the accumulation of a large pool of NK cells secreting copious interferon-gamma, responsible for T(H)1 differentiation and protection from leishmania infection. In contrast, blockade of TGF-beta signaling in dendritic cells did not affect dendritic cell homeostasis or interleukin 12 production, thus indicating a previously undescribed demarcation of the function of TGF-beta in NK cells versus dendritic cells.

Predominant Improvement of Alpha Cell Function after Steroid Therapy in a Patient with Autoimmune Pancreatitis: Case Report.

PubMed

Takeshima, Ken; Ariyasu, Hiroyuki; Iwakura, Hiroshi; Kawai, Shintaro; Uraki, Shinsuke; Inaba, Hidefumi; Furuta, Machi; Warigaya, Kenji; Murata, Shin-Ichi; Akamizu, Takashi

2018-06-01

Autoimmune pancreatitis (AIP) is a subset of inflammatory pancreatic disease, responsive to corticosteroid therapy. It is prone to being affected by diabetes mellitus, but the effectiveness of steroid therapy on pancreatic endocrine function is still controversial. We present a case of AIP, focusing on pancreatic endocrine function after steroid therapy. The patient was referred to our hospital with exacerbation of diabetic control and pancreatic swelling. By admission, the insulin secretory capacity was severely impaired. The patient was diagnosed with AIP and treated with prednisolone, resulting in marked improvement of the pancreatic swelling. Glycemic control worsened transiently after initiation of steroid therapy, but insulin requirements decreased along with tapering prednisolone dosage. Pancreatic cytology showed that the acinar structure had been destroyed, and the islets had disappeared. Insulin and glucagon immunostaining revealed slightly scattered alpha and beta cells within the fibrotic stroma. The patient notably showed improved pancreatic alpha cell function predominantly after steroid therapy, despite partial improvement of beta cell function. An imbalance between alpha and beta cell function may contribute to insufficient diabetic control in some patients with AIP. The pancreatic endocrine function test in combination with pancreatic cytology could be helpful when considering the treatment strategy for diabetic control in patients with AIP.

Decursin and PDBu: two PKC activators distinctively acting in the megakaryocytic differentiation of K562 human erythroleukemia cells.

PubMed

Kim, Hyeon Ho; Ahn, Kyung Seop; Han, Hogyu; Choung, Se Young; Choi, Sang-Yun; Kim, Ik-Hwan

2005-12-01

Protein kinase C (PKC) plays an important role in the proliferation and differentiation of various cell types including normal and leukemic hematopoietic cells. Phorbol 12,13-dibutyrate (PDBu) induces the megakaryocytic differentiation of K562 human erythroleukemia cells through PKC activation. Decursin, a pyranocoumarin from Angelica gigas, exhibits the cytotoxic effects on various human cancer cell lines and in vitro PKC activation. We report here the differences between two PKC activators, tumor-suppressing decursin and tumor-promoting PDBu, in their actions on the megakaryocytic differentiation of K562 cells. First of all, decursin inhibited PDBu-induced bleb formation in K562 cells. Decursin also inhibited the PDBu-induced megakaryocytic differentiation of K562 cells that is characterized by an increase in substrate adhesion, the secretion of granulocyte/macrophage colony stimulating factor (GM-CSF) and interleukin-6 (IL-6), and the surface expression of integrin beta3. The binding of PDBu to PKC was competitively inhibited by decursin. Decursin induced the more rapid down-regulation of PKC alpha and betaII isozymes than that induced by PDBu in K562 cells. Unlike PDBu, decursin promoted the translocation of PKC alpha and betaII to the nuclear membrane. Decursin-induced faster down-regulation and nuclear translocation of PKC alpha and betaII were not affected by the presence of PDBu. All these results indicate that decursin and phorbol ester are PKC activators distinctively acting in megakaryocytic differentiation and PKC modulation in K562 leukemia cells.

The environmental chemical tributyltin chloride (TBT) shows both estrogenic and adipogenic activities in mice which might depend on the exposure dose

DOE Office of Scientific and Technical Information (OSTI.GOV)

Penza, M.; Jeremic, M.; Marrazzo, E.

2011-08-15

Exposure during early development to chemicals with hormonal action may be associated with weight gain during adulthood because of altered body homeostasis. It is known that organotins affect adipose mass when exposure occurs during fetal development, although no knowledge of effects are available for exposures after birth. Here we show that the environmental organotin tributyltin chloride (TBT) exerts adipogenic action when peripubertal and sexually mature mice are exposed to the chemical. The duration and extent of these effects depend on the sex and on the dose of the compound, and the effects are relevant at doses close to the estimatedmore » human intake (0.5 {mu}g/kg). At higher doses (50-500 {mu}g/kg), TBT also activated estrogen receptors (ERs) in adipose cells in vitro and in vivo, based on results from acute and longitudinal studies in ERE/luciferase reporter mice. In 3T3-L1 cells (which have no ERs), transiently transfected with the ERE-dependent reporter plus or minus ER{alpha} or ER{beta}, TBT (in a dose range of 1-100 nM) directly targets each ER subtype in a receptor-specific manner through a direct mechanism mediated by ER{alpha} in undifferentiated preadipocytic cells and by ER{beta} in differentiating adipocytes. The ER antagonist ICI-182,780 inhibits this effect. In summary, the results of this work suggest that TBT is adipogenic at all ages and in both sexes and that it might be an ER activator in fat cells. These findings might help to resolve the apparent paradox of an adipogenic chemical being also an estrogen receptor activator by showing that the two apparently opposite actions are separated by the different doses to which the organism is exposed. - Research Highlights: > The environmental organotin tributyltin chloride shows dose-dependent estrogenic and adipogenic activities in mice. > The duration and extent of these effects depend on the sex and the dose of the compound. > The estrogenic and adipogenic effects of TBT occur at doses closed to the estimated human intake. > TBT activates the estrogen receptors (ER{alpha} and ER{beta}) in 3T3-L1 cells at nM concentrations.« less

L-beta-ODAP alters mitochondrial Ca2+ handling as an early event in excitotoxicity.

PubMed

Van Moorhem, Marijke; Decrock, Elke; Coussee, Evelyne; Faes, Liesbeth; De Vuyst, Elke; Vranckx, Katleen; De Bock, Marijke; Wang, Nan; D'Herde, Katharina; Lambein, Fernand; Callewaert, Geert; Leybaert, Luc

2010-03-01

The neurotoxin beta-N-oxalyl-L-alpha,beta-diaminopropionic acid (L-beta-ODAP) is an L-glutamate analogue at alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)/kainate receptors in neurons and therefore acts as an excitotoxic substance. Chronic exposure to L-beta-ODAP present in Lathyrus sativus L. (L. sativus) seeds is proposed as the cause of the neurodegenerative disease neurolathyrism, but the mechanism of its action has not been conclusively identified. A key factor in excitotoxic neuronal cell death is a disturbance of the intracellular Ca2+ homeostasis, including changes in the capacity of intracellular Ca2+ stores like the endoplasmic reticulum (ER) or mitochondria. In this study, aequorin and other Ca2+ indicators were used in N2a neuroblastoma cells to investigate alterations of cellular Ca2+ handling after 24 h exposure to L-beta-ODAP. Our data demonstrate increased mitochondrial Ca2+ loading and hyperpolarization of the mitochondrial membrane potential (Psi(m)), which was specific for L-beta-ODAP and not observed with L-glutamate. We conclude that L-beta-ODAP disturbs the ER-mitochondrial Ca2+ signaling axis and thereby renders the cells more vulnerable to its excitotoxic effects that ultimately will lead to cell death. 2010 Elsevier Ltd. All rights reserved.

Identification of a repeated domain within mammalian alpha-synemin that interacts directly with talin.

PubMed

Sun, Ning; Critchley, David R; Paulin, Denise; Li, Zhenlin; Robson, Richard M

2008-05-01

The type VI intermediate filament (IF) protein synemin is a unique member of the IF protein superfamily. Synemin associates with the major type III IF protein desmin forming heteropolymeric intermediate filaments (IFs) within developed mammalian striated muscle cells. These IFs encircle and link all adjacent myofibrils together at their Z-lines, as well as link the Z-lines of the peripheral layer of cellular myofibrils to the costameres located periodically along and subjacent to the sarcolemma. Costameres are multi-protein assemblies enriched in the cytoskeletal proteins vinculin, alpha-actinin, and talin. We report herein a direct interaction of human alpha-synemin with the cytoskeletal protein talin by protein-protein interaction assays. The 312 amino acid insert (SNTIII) present only within alpha-synemin binds to the rod domain of talin in vitro and co-localizes with talin at focal adhesion sites within mammalian muscle cells. Confocal microscopy studies showed that synemin co-localizes with talin within the costameres of human skeletal muscle cells. Analysis of the primary sequences of human alpha- and beta-synemins revealed that SNTIII is composed of seven tandem repeats, each containing a specific Ser/Thr-X-Arg-His/Gln (S/T-X-R-H/Q) motif. Our results suggest human alpha-synemin plays an essential role in linking the heteropolymeric IFs to adherens-type junctions, such as the costameres within mammalian striated muscle cells, via its interaction with talin, thereby helping provide mechanical integration for the muscle cell cytoskeleton.

Targeting Alpha5 Beta1 Integrin to Prevent Metastatic Breast Cancer Cell Invasion: PhScN Target Site Definition and Plasma Stability

DTIC Science & Technology

2015-11-01

increased PhScN potency as a result of preventing endoproteolytic degradation. Finally, the in vivo lung extravasation and colonization data, as well as...successful colonization are late stages in breast cancer progression that are ultimately fatal. Hence, prevention of extravasation which leads to colony...Award Number: TITLE: “Targeting Alpha5 Beta1 Integrin to Prevent Metastatic Breast Cancer Cell Invasion: PhScN Target Site Definition and Plasma

Opposing actions of Arx and Pax4 in endocrine pancreas development.

PubMed

Collombat, Patrick; Mansouri, Ahmed; Hecksher-Sorensen, Jacob; Serup, Palle; Krull, Jens; Gradwohl, Gerard; Gruss, Peter

2003-10-15

Genes encoding homeodomain-containing proteins potentially involved in endocrine pancreas development were isolated by combined in silico and nested-PCR approaches. One such transcription factor, Arx, exhibits Ngn3-dependent expression throughout endocrine pancreas development in alpha, beta-precursor, and delta cells. We have used gene targeting in mouse embryonic stem cells to generate Arx loss-of-function mice. Arx-deficient animals are born at the expected Mendelian frequency, but develop early-onset hypoglycemia, dehydration, and weakness, and die 2 d after birth. Immunohistological analysis of pancreas from Arx mutants reveals an early-onset loss of mature endocrine alpha cells with a concomitant increase in beta-and delta-cell numbers, whereas islet morphology remains intact. Our study indicates a requirement of Arx for alpha-cell fate acquisition and a repressive action on beta-and delta-cell destiny, which is exactly the opposite of the action of Pax4 in endocrine commitment. Using multiplex reverse transcriptase PCR (RT-PCR), we demonstrate an accumulation of Pax4 and Arx transcripts in Arx and Pax4 mutant mice, respectively. We propose that the antagonistic functions of Arx and Pax4 for proper islet cell specification are related to the pancreatic levels of the respective transcripts.

High P-T phase transitions and P-V-T equation of state of hafnium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hrubiak, Rostislav; Drozd, Vadym; Karbasi, Ali

2016-07-29

We measured the volume of hafnium at several pressures up to 67 GPa and at temperatures between 300 to 780 K using a resistively heated diamond anvil cell with synchrotron x-ray diffraction at the Advanced Photon Source. The measured data allows us to determine the P-V-T equation of state of hafnium. The previously described [Xia et al., Phys. Rev. B 42, 6736-6738 (1990)] phase transition from hcp ({alpha}) to simple hexagonal ({omega}) phase at 38 GPa at room temperature was not observed even up to 51 GPa. The {omega} phase was only observed at elevated temperatures. Our measurements have alsomore » improved the experimental constraint on the high P-T phase boundary between the {omega} phase and high pressure bcc ({beta}) phase of hafnium. Isothermal room temperature bulk modulus and its pressure derivative for the {alpha}-phase of hafnium were measured to be B{sub 0} = 112.9{+-}0.5 GPa and B{sub 0}'=3.29{+-}0.05, respectively. P-V-T data for the {alpha}-phase of hafnium was used to obtain a fit to a thermodynamic P-V-T equation of state based on model by Brosh et al. [CALPHAD 31, 173-185 (2007)].« less

Chemokines, macrophage inflammatory protein-2 and stromal cell-derived factor-1{alpha}, suppress amyloid {beta}-induced neurotoxicity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raman, Dayanidhi; Milatovic, Snjezana-Zaja; Milatovic, Dejan

2011-11-15

Alzheimer's disease (AD) is characterized by a progressive cognitive decline and accumulation of neurotoxic oligomeric peptides amyloid-{beta} (A{beta}). Although the molecular events are not entirely known, it has become evident that inflammation, environmental and other risk factors may play a causal, disruptive and/or protective role in the development of AD. The present study investigated the ability of the chemokines, macrophage inflammatory protein-2 (MIP-2) and stromal cell-derived factor-1{alpha} (SDF-1{alpha}), the respective ligands for chemokine receptors CXCR2 and CXCR4, to suppress A{beta}-induced neurotoxicity in vitro and in vivo. Pretreatment with MIP-2 or SDF-1{alpha} significantly protected neurons from A{beta}-induced dendritic regression and apoptosismore » in vitro through activation of Akt, ERK1/2 and maintenance of metalloproteinase ADAM17 especially with SDF-1{alpha}. Intra-cerebroventricular (ICV) injection of A{beta} led to reduction in dendritic length and spine density of pyramidal neurons in the CA1 area of the hippocampus and increased oxidative damage 24 h following the exposure. The A{beta}-induced morphometric changes of neurons and increase in biomarkers of oxidative damage, F{sub 2}-isoprostanes, were significantly inhibited by pretreatment with the chemokines MIP-2 or SDF-1{alpha}. Additionally, MIP-2 or SDF-1{alpha} was able to suppress the aberrant mislocalization of p21-activated kinase (PAK), one of the proteins involved in the maintenance of dendritic spines. Furthermore, MIP-2 also protected neurons against A{beta} neurotoxicity in CXCR2-/- mice, potentially through observed up regulation of CXCR1 mRNA. Understanding the neuroprotective potential of chemokines is crucial in defining the role for their employment during the early stages of neurodegeneration. -- Research highlights: Black-Right-Pointing-Pointer Neuroprotective ability of the chemokines MIP2 and CXCL12 against A{beta} toxicity. Black-Right-Pointing-Pointer MIP-2 or CXCL12 prevented dendritic regression and apoptosis in vitro. Black-Right-Pointing-Pointer Neuroprotection through activation of Akt, ERK1/2 and maintenance of ADAM17. Black-Right-Pointing-Pointer Neuroprotection of hippocampal pyramidal neurons in vivo by MIP-2 or CXCL12. Black-Right-Pointing-Pointer MIP-2 or CXCL12 prevent elevation of F2-Isoprostanes against A{beta} treatment.« less

beta2-Agonist modulates epithelial gene expression involved in the T- and B-cell chemotaxis and induces airway sensitization in human isolated bronchi.

PubMed

Faisy, Christophe; Pinto, Francisco M; Blouquit-Laye, Sabine; Danel, Claire; Naline, Emmanuel; Buenestado, Amparo; Grassin Delyle, Stanislas; Burgel, Pierre-Régis; Chapelier, Alain; Advenier, Charles; Candenas, Maria-Luz; Devillier, Philippe

2010-02-01

Regular use of beta(2)-adrenoceptor agonists may enhance non-specific airway responsiveness and inflammation. In earlier experimental studies, we showed that prolonged in vitro fenoterol exposure induced airway sensitization via perturbed epithelial regulation of bronchoconstriction. The aim of the present work was to examine the involvement of inflammatory mediator genes and proinflammatory cells and to investigate the role of the bronchial epithelium in these untoward effects. Bronchial tissues were surgically removed from 17 ex-smokers. Bronchial rings and primary cultures of bronchial epithelial cells were incubated with 0.1microM fenoterol for 15h. Levels of mRNA-expression were analyzed using a real-time quantitative reverse transcription-polymerase chain reaction array. Bronchial rings were contracted with endothelin-1 and immune cell infiltration was assessed by immunohistochemistry. Compared to paired controls, fenoterol up-regulated the mRNAs of cytokines/proteins implicated in the recruitment of T and B cells or the activation and proliferation of bronchial epithelial cells (CCL20/MIP-3alpha, FOXA2, PPAR-gamma) in isolated bronchi and in cultured epithelial cells. Fenoterol exposure significantly enhanced CD8(+)-T and differentiated CD138(+)-B-cells infiltration into the bronchi, especially the subepithelial area. Increase in CD8 or CD138 labeling-intensity strongly correlated with rise in maximal contraction to endothelin-1 induced by fenoterol exposure. In summary, our results show that fenoterol modulates the T and B cells chemotaxis possibly via the epithelial chemokine secretion in isolated bronchi from ex-smokers. They also suggest that the infiltration of resident T and B cells into the subepithelial area is associated with an increase in airway responsiveness due to fenoterol exposure. Copyright 2009 Elsevier Ltd. All rights reserved.

Functional characterization of the beta-adrenergic receptor subtypes expressed by CA1 pyramidal cells in the rat hippocampus.

PubMed

Hillman, Kristin L; Doze, Van A; Porter, James E

2005-08-01

Recent studies have demonstrated that activation of the beta-adrenergic receptor (AR) using the selective beta-AR agonist isoproterenol (ISO) facilitates pyramidal cell long-term potentiation in the cornu ammonis 1 (CA1) region of the rat hippocampus. We have previously analyzed beta-AR genomic expression patterns of 17 CA1 pyramidal cells using single cell reverse transcription-polymerase chain reaction, demonstrating that all samples expressed the beta2-AR transcript, with four of the 17 cells additionally expressing mRNA for the beta1-AR subtype. However, it has not been determined which beta-AR subtypes are functionally expressed in CA1 for these same pyramidal neurons. Using cell-attached recordings, we tested the ability of ISO to increase pyramidal cell action potential (AP) frequency in the presence of subtype-selective beta-AR antagonists. ICI-118,551 [(+/-)-1-[2,3-(dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanol] and butoxamine [alpha-[1-(t-butylamino)ethyl]-2,5-dimethoxybenzyl alcohol) hydrochloride], agents that selectively block the beta2-AR, produced significant parallel rightward shifts in the concentration-response curves for ISO. From these curves, apparent equilibrium dissociation constant (K(b)) values of 0.3 nM for ICI-118,551 and 355 nM for butoxamine were calculated using Schild regression analysis. Conversely, effective concentrations of the selective beta1-AR antagonists CGP 20712A [(+/-)-2-hydroxy-5-[2-([2-hydroxy-3-(4-[1-methyl-4-(trifluoromethyl)-1H-imidazol-2-yl]phenoxy)propyl]amino)ethoxy]-benzamide methanesulfonate] and atenolol [4-[2'-hydroxy-3'-(isopropyl-amino)propoxy]phenylacetamide] did not significantly affect the pyramidal cell response to ISO. However, at higher concentrations, atenolol significantly decreased the potency for ISO-mediated AP frequencies. From these curves, an apparent atenolol K(b) value of 3162 nM was calculated. This pharmacological profile for subtype-selective beta-AR antagonists indicates that beta2-AR activation is mediating the increased AP frequency. Knowledge of functional AR expression in CA1 pyramidal neurons will aid future long-term potentiation studies by allowing selective manipulation of specific beta-AR subtypes.

[Chemical constituents from Neo-Taraxacum siphonathum].

PubMed

Shi, Shuyun; Zhou, Honghao; Zhang, Yuping; Huang, Kelong; Liu, Suqin

2009-04-01

To study the chemical constituents from the antioxidant fraction of Neo-Taraxacum siphonathum. Various chromatographic techniques were used to isolate and purify the constituents. The structures were elucidated on the basis of chemical evidence and spectral analysis. Ten compounds were isolated and identified from Neo-T. siphonathum, caffeic acid (1), chlorogenic acid (2), quercetin (3), luteolin (4), quercetin-3-O-beta-D-glucopyranoside (5), quercetin-3-O-alpha-D-arabinofuranoside (6), quercetin-3-O-alpha-D-arabinopyranoside (7), luteolin-7-O-beta-D-glucopyranoside (8), beta-sitosterol (9) and daucosterol (10). Compounds 1-10 were isolated from this plant for the first time.

Defective insulin secretion in hepatocyte nuclear factor 1alpha-deficient mice.

PubMed Central

Pontoglio, M; Sreenan, S; Roe, M; Pugh, W; Ostrega, D; Doyen, A; Pick, A J; Baldwin, A; Velho, G; Froguel, P; Levisetti, M; Bonner-Weir, S; Bell, G I; Yaniv, M; Polonsky, K S

1998-01-01

Mutations in the gene for the transcription factor hepatocyte nuclear factor (HNF) 1alpha cause maturity-onset diabetes of the young (MODY) 3, a form of diabetes that results from defects in insulin secretion. Since the nature of these defects has not been defined, we compared insulin secretory function in heterozygous [HNF-1alpha (+/-)] or homozygous [HNF-1alpha (-/-)] mice with null mutations in the HNF-1alpha gene with their wild-type littermates [HNF-1alpha (+/+)]. Blood glucose concentrations were similar in HNF-1alpha (+/+) and (+/-) mice (7.8+/-0.2 and 7.9+/-0.3 mM), but were significantly higher in the HNF-1alpha (-/-) mice (13.1+/-0.7 mM, P < 0.001). Insulin secretory responses to glucose and arginine in the perfused pancreas and perifused islets from HNF-1alpha (-/-) mice were < 15% of the values in the other two groups and were associated with similar reductions in intracellular Ca2+ responses. These defects were not due to a decrease in glucokinase or insulin gene transcription. beta cell mass adjusted for body weight was not reduced in the (-/-) animals, although pancreatic insulin content adjusted for pancreas weight was slightly lower (0.06+/-0.01 vs. 0.10+/-0.01 microg/mg, P < 0.01) than in the (+/+) animals. In summary, a null mutation in the HNF-1alpha gene in homozygous mice leads to diabetes due to alterations in the pathways that regulate beta cell responses to secretagogues including glucose and arginine. These results provide further evidence in support of a key role for HNF-1alpha in the maintenance of normal beta cell function. PMID:9593777

Selective destruction of mouse islet beta cells by human T lymphocytes in a newly-established humanized type 1 diabetic model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Yong, E-mail: yongzhao@uic.edu; Guo, Chengshan; Hwang, David

2010-09-03

Research highlights: {yields} Establish a human immune-mediated type 1 diabetic model in NOD-scid IL2r{gamma}{sup null} mice. {yields} Using the irradiated diabetic NOD mouse spleen mononuclear cells as trigger. {yields} The islet {beta} cells were selectively destroyed by infiltrated human T cells. {yields} The model can facilitate translational research to find a cure for type 1 diabetes. -- Abstract: Type 1 diabetes (T1D) is caused by a T cell-mediated autoimmune response that leads to the loss of insulin-producing {beta} cells. The optimal preclinical testing of promising therapies would be aided by a humanized immune-mediated T1D model. We develop this model inmore » NOD-scid IL2r{gamma}{sup null} mice. The selective destruction of pancreatic islet {beta} cells was mediated by human T lymphocytes after an initial trigger was supplied by the injection of irradiated spleen mononuclear cells (SMC) from diabetic nonobese diabetic (NOD) mice. This resulted in severe insulitis, a marked loss of total {beta}-cell mass, and other related phenotypes of T1D. The migration of human T cells to pancreatic islets was controlled by the {beta} cell-produced highly conserved chemokine stromal cell-derived factor 1 (SDF-1) and its receptor C-X-C chemokine receptor (CXCR) 4, as demonstrated by in vivo blocking experiments using antibody to CXCR4. The specificity of humanized T cell-mediated immune responses against islet {beta} cells was generated by the local inflammatory microenvironment in pancreatic islets including human CD4{sup +} T cell infiltration and clonal expansion, and the mouse islet {beta}-cell-derived CD1d-mediated human iNKT activation. The selective destruction of mouse islet {beta} cells by a human T cell-mediated immune response in this humanized T1D model can mimic those observed in T1D patients. This model can provide a valuable tool for translational research into T1D.« less

Heterocellular interaction enhances recruitment of {alpha} and {beta}-catenins and ZO-2 into functional gap-junction complexes and induces gap junction-dependant differentiation of mammary epithelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Talhouk, Rabih S.; Mroue, Rana; Mokalled, Mayssa

2008-11-01

Gap junctions (GJ) are required for mammary epithelial differentiation. Using epithelial (SCp2) and myoepithelial-like (SCg6) mouse-derived mammary cells, the role of heterocellular interaction in assembly of GJ complexes and functional differentiation ({beta}-casein expression) was evaluated. Heterocellular interaction is critical for {beta}-casein expression, independent of exogenous basement membrane or cell anchoring substrata. Functional differentiation of SCp2, co-cultured with SCg6, is more sensitive to GJ inhibition relative to homocellular SCp2 cultures differentiated by exogenous basement membrane. Connexin (Cx)32 and Cx43 levels were not regulated across culture conditions; however, GJ functionality was enhanced under differentiation-permissive conditions. Immunoprecipitation studies demonstrated association of junctional complexmore » components ({alpha}-catenin, {beta}-catenin and ZO-2) with Cx32 and Cx43, in differentiation conditions, and additionally with Cx30 in heterocellular cultures. Although {beta}-catenin did not shuttle between cadherin and GJ complexes, increased association between connexins and {beta}-catenin in heterocellular cultures was observed. This was concomitant with reduced nuclear {beta}-catenin, suggesting that differentiation in heterocellular cultures involves sequestration of {beta}-catenin in GJ complexes.« less

Normal T lymphocytes can express two different T cell receptor beta chains: implications for the mechanism of allelic exclusion

PubMed Central

1995-01-01

We have examined the extent of allelic exclusion at the T cell receptor (TCR) beta locus using monoclonal antibodies specific for V beta products. A small proportion (approximately 1%) of human peripheral blood T cells express two V beta as determined by flow cytometric analysis, isolation of representative clones, and sequencing of the corresponding V beta chains. Dual beta T cells are present in both the CD45R0+ and CD45R0- subset. These results indicate that dual beta expression is compatible with both central and peripheral selection. They also suggest that the substantial degree of TCR beta allelic exclusion is dependent only on asynchronous rearrangements at the beta locus, whereas the role of the pre-TCR is limited to signaling the presence of at least one functional beta protein. PMID:7699339

Incretin Receptor Null Mice Reveal Key Role of GLP-1 but Not GIP in Pancreatic Beta Cell Adaptation to Pregnancy

PubMed Central

Moffett, R. Charlotte; Vasu, Srividya; Thorens, Bernard; Drucker, Daniel J.; Flatt, Peter R.

2014-01-01

Islet adaptations to pregnancy were explored in C57BL6/J mice lacking functional receptors for glucagon-like peptide 1 (GLP-1) and gastric inhibitory polypeptide (GIP). Pregnant wild type mice and GIPRKO mice exhibited marked increases in islet and beta cell area, numbers of medium/large sized islets, with positive effects on Ki67/Tunel ratio favouring beta cell growth and enhanced pancreatic insulin content. Alpha cell area and glucagon content were unchanged but prohormone convertases PC2 and PC1/3 together with significant amounts of GLP-1 and GIP were detected in alpha cells. Knockout of GLP-1R abolished these islet adaptations and paradoxically decreased pancreatic insulin, GLP-1 and GIP. This was associated with abolition of normal pregnancy-induced increases in plasma GIP, L-cell numbers, and intestinal GIP and GLP-1 stores. These data indicate that GLP-1 but not GIP is a key mediator of beta cell mass expansion and related adaptations in pregnancy, triggered in part by generation of intra-islet GLP-1. PMID:24927416

The effects of alpha tocopherol supplementation on monocyte function. Decreased lipid oxidation, interleukin 1 beta secretion, and monocyte adhesion to endothelium.

PubMed Central

Devaraj, S; Li, D; Jialal, I

1996-01-01

Low levels of alpha tocopherol are related to a higher incidence of cardiovascular disease and increased intake appears to afford protection against cardiovascular disease. In addition to decreasing LDL oxidation, alpha tocopherol may exert intracellular effects on cells crucial in atherogenesis, such as monocytes. Hence, the aim of this study was to test the effect of alpha tocopherol supplementation on monocyte function relevant to atherogenesis. Monocyte function was assessed in 21 healthy subjects at baseline, after 8 wk of supplementation with d-alpha tocopherol (1,200 IU/d) and after a 6-wk washout phase. The release of reactive oxygen species (superoxide anion, hydrogen peroxide), lipid oxidation, release of the potentially atherogenic cytokine, interleukin 1 beta, and monocyte-endothelial adhesion were studied in the resting state and after activation of the monocytes with lipopolysaccharide at 0, 8, and 14 wk. There was a 2.5-fold increase in plasma lipid-standardized and monocyte alpha tocopherol levels in the supplemented phase. After alpha tocopherol supplementation, there were significant decreases in release of reactive oxygen species, lipid oxidation, IL-1 beta secretion, and monocyte-endothelial cell adhesion, both in resting and activated cells compared with baseline and washout phases. Studies with the protein kinase C inhibitor, Calphostin C, suggest that the inhibition of reactive oxygen species release and lipid oxidation is due to an inhibition of protein kinase C activity by alpha tocopherol. Thus, this study provides novel evidence for an intracellular effect of alpha tocopherol in monocytes that is antiatherogenic. PMID:8698868

Developmental regulation by cytokines of bone marrow-derived dendritic cells and epidermal Langerhans cells.

PubMed

Yamaguchi, Y

1998-01-01

Dendritic cells (DC) are specialized antigen-presenting cells involved in T cell-mediated immune responses. Differentiation and functional maturation of the DC are now known to be regulated by various cytokines, including TGF-beta1. The experiments of this study examined the effect of other cytokines, such as IL-4, IL-10 and IL-6, on the differentiation and maturation of bone marrow (BM)-derived DC (BM-DC) and epidermal Langerhans cells (LC). When IL-6 or IL-10 was added to cultures of BM cells in the presence of GM-CSF, both cytokines, as in the case of TGF-beta1, suppressed the maturation of DC in terms of the expression of adhesion and costimulatory molecules and T cell-stimulating activity. In contrast, IL-4 was not suppressive but rather supportive for the differentiation of DC. However, these suppressive cytokines hardly counteracted the maturation-inducing activity of TNF-alpha when added to cultures of immature DC. In addition, they appeared to block the overmaturation of DC, which is characterized by a loss of MHC class II molecules. Regarding LC maturation in epidermal cell cultures, IL-6 and IL-10 were inhibitory for the expression of CD86 and CD80 in a dose-dependent fashion. Unlike BM-DC, LC maturation was slightly enhanced by TGF-beta1. The protein antigen-presentation by LC to Th1 clone was not affected by IL-6, but slightly reduced by IL-10. These results suggest that each cytokine contributes to regulate the differentiation and maturation of DC at a different developmental stage.

Calmodulin-dependent gating of Ca(v)1.2 calcium channels in the absence of Ca(v)beta subunits.

PubMed

Ravindran, Arippa; Lao, Qi Zong; Harry, Jo Beth; Abrahimi, Parwiz; Kobrinsky, Evgeny; Soldatov, Nikolai M

2008-06-10

It is generally accepted that to generate calcium currents in response to depolarization, Ca(v)1.2 calcium channels require association of the pore-forming alpha(1C) subunit with accessory Ca(v)beta and alpha(2)delta subunits. A single calmodulin (CaM) molecule is tethered to the C-terminal alpha(1C)-LA/IQ region and mediates Ca2+-dependent inactivation of the channel. Ca(v)beta subunits are stably associated with the alpha(1C)-interaction domain site of the cytoplasmic linker between internal repeats I and II and also interact dynamically, in a Ca2+-dependent manner, with the alpha(1C)-IQ region. Here, we describe a surprising discovery that coexpression of exogenous CaM (CaM(ex)) with alpha(1C)/alpha(2)delta in COS1 cells in the absence of Ca(v)beta subunits stimulates the plasma membrane targeting of alpha(1C), facilitates calcium channel gating, and supports Ca2+-dependent inactivation. Neither real-time PCR with primers complementary to monkey Ca(v)beta subunits nor coimmunoprecipitation analysis with exogenous alpha(1C) revealed an induction of endogenous Ca(v)beta subunits that could be linked to the effect of CaM(ex). Coexpression of a calcium-insensitive CaM mutant CaM(1234) also facilitated gating of Ca(v)beta-free Ca(v)1.2 channels but did not support Ca2+-dependent inactivation. Our results show there is a functional matchup between CaM(ex) and Ca(v)beta subunits that, in the absence of Ca(v)beta, renders Ca2+ channel gating facilitated by CaM molecules other than the one tethered to LA/IQ to support Ca2+-dependent inactivation. Thus, coexpression of CaM(ex) creates conditions when the channel gating, voltage- and Ca2+-dependent inactivation, and plasma-membrane targeting occur in the absence of Ca(v)beta. We suggest that CaM(ex) affects specific Ca(v)beta-free conformations of the channel that are not available to endogenous CaM.

T-cell receptor variable genes and genetic susceptibility to celiac disease: an association and linkage study.

PubMed

Roschmann, E; Wienker, T F; Gerok, W; Volk, B A

1993-12-01

Genetic susceptibility of celiac disease is primarily associated with a particular combination of and HLA-DQA1/DQB1 gene; however, this does not fully account for the genetic predisposition. Therefore, the aim of this study was to examine whether T-cell receptor (TCR) genes may be susceptibility genes in celiac disease. HLA class II typing was performed by polymerase chain reaction amplification in combination with sequence-specific oligonucleotide hybridization. TCR alpha (TCRA), TCR gamma (TCRG), and TCR beta (TCRB) loci were investigated by restriction fragment length polymorphism analysis. Allelic frequencies of TCRA, TCRG, and TCRB variable genes were compared between patients with celiac disease (n = 53) and control patients (n = 67), and relative risk (RR) estimates were calculated. The RR was 1.67 for allele C1 at TCRA1, 3.35 for allele D2 at TCRA2, 1.66 for allele B2 at TCRG, and 1.35 for allele B at TCRB, showing no significant association. Additionally, linkage analysis was performed in 23 families. The logarithm of odd scores for celiac disease vs. the TCR variable genes at TCRA, TCRG, and TCRB showed no significant linkage. These data suggest that the analyzed TCR variable gene segments V alpha 1.2, V gamma 11, and V beta 8 do not play a major role in susceptibility to celiac disease.

Integrin distributions in renal cell carcinomas of various grades of malignancy.

PubMed Central

Korhonen, M.; Laitinen, L.; Ylänne, J.; Koukoulis, G. K.; Quaranta, V.; Juusela, H.; Gould, V. E.; Virtanen, I.

1992-01-01

We studied 41 renal cell carcinomas, classified according to histologic grades G1 through G3, by indirect immunofluorescence microscopy using a panel of monoclonal antibodies (MAb) against various integrin subunits, and the basement membrane (BM) components laminin and collagen type IV. Selected cases also were immunostained using the avidin-biotin-complex method. The alpha 3 and beta 1 integrin subunits were detected in tumor cells of all the carcinomas. All G1 carcinomas, like normal tubular epithelial cells, expressed the alpha 6 subunit, whereas it was lacking in 20% and 40% of G2 and G3 carcinomas, respectively. Furthermore, when alpha 6 was expressed, a lack of basally polarized organization of the subunit, coupled with disorganization of the BM components, correlated with histologic grade. Another feature that appeared to characterize the more anaplastic tumors was their high level (80%) of the alpha v subunit expression as compared with its absence in the G1 carcinomas. Stromal myofibroblasts, identified by double-labeling with anti-myosin, were often characterized by the expression of the alpha 1, alpha 3, alpha 5 and beta 1 subunits. These results indicate that changes in integrin expression in renal cell carcinomas may be correlated with their degree of histologic malignancy. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:1443050

Catfish (Clarias batrachus) serum lectin recognizes polyvalent Tn [alpha-D-GalpNAc1-Ser/Thr], Talpha [beta-D-Galp-(1-->3)-alpha-D-GalpNAc1-Ser/Thr], and II [beta-D-Galp(1-->4)-beta-D-GlcpNAc1-] mammalian glycotopes.

PubMed

Singha, Biswajit; Adhya, Mausumi; Chatterjee, Bishnu P

2008-09-22

A new calcium dependent GalNAc/Gal specific lectin was isolated from the serum of Indian catfish, Clarias batrachus and designated as C. batrachus lectin (CBL). It is a disulfide-linked homodecameric lectin of 74.65kDa subunits and the oligomeric form is essential for its activity. Binding specificity of CBL was investigated by enzyme-linked lectin-sorbent assay using a series of simple sugars, polysaccharides, and glycoproteins. GalNAc was more potent inhibitor than Gal; and alpha glycosides of both were more inhibitory than their beta counterparts. CBL showed maximum affinity for human tumor-associated Tn-antigens (GalNAcalpha1-Ser/Thr) at the molecular level and was 3.5 times higher than GalNAc. CBL interacted strongly with polyvalent Tn and Talpha (Galbeta1,3GalNAcalpha1-) as well as multivalent-II (Galbeta1,4GlcNAcbeta1-) antigens containing glycoproteins and intensity of inhibition was 10(3)-10(5) times more than monovalent ones. The overall specificity of CBL lies in the order of polyvalent Tn, Talpha and II>monovalent Tn > or = Me-alphaGalNAc>monovalent Talpha> Me-betaGalNAc>Me-alphaGal>monovalent T>GalNAc>monovalent F>monovalent II>Me-betaGal>Gal.

Development of a homogeneous pulse shape discriminating flow-cell radiation detection system

NASA Astrophysics Data System (ADS)

Hastie, K. H.; DeVol, T. A.; Fjeld, R. A.

1999-02-01

A homogeneous flow-cell radiation detection system which utilizes coincidence counting and pulse shape discrimination circuitry was assembled and tested with five commercially available liquid scintillation cocktails. Two of the cocktails, Ultima Flo (Packard) and Mono Flow 5 (National Diagnostics) have low viscosities and are intended for flow applications; and three of the cocktails, Optiphase HiSafe 3 (Wallac), Ultima Gold AB (Packard), and Ready Safe (Beckman), have higher viscosities and are intended for static applications. The low viscosity cocktails were modified with 1-methylnaphthalene to increase their capability for alpha/beta pulse shape discrimination. The sample loading and pulse shape discriminator setting were optimized to give the lowest minimum detectable concentration for alpha radiation in a 30 s count time. Of the higher viscosity cocktails, Optiphase HiSafe 3 had the lowest minimum detectable activities for alpha and beta radiation, 0.2 and 0.4 Bq/ml for 233U and 90Sr/ 90Y, respectively, for a 30 s count time. The sample loading was 70% and the corresponding alpha/beta spillover was 5.5%. Of the low viscosity cocktails, Mono Flow 5 modified with 2.5% (by volume) 1-methylnaphthalene resulted in the lowest minimum detectable activities for alpha and beta radiation; 0.3 and 0.5 Bq/ml for 233U and 90Sr/ 90Y, respectively, for a 30 s count time. The sample loading was 50%, and the corresponding alpha/beta spillover was 16.6%. HiSafe 3 at a 10% sample loading was used to evaluate the system under simulated flow conditions.

Regional localization of the human integrin {beta}{sub 6} gene (ITGB6) to chromosome 2q24-q31

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernandez-Ruiz, E.; Sanchez-Madrid, F.

The heterodimer {alpha}{sub v}{beta}{sub 6} acts as a fibronectin receptor for human carcinoma cells. The authors report here the regional localization of the {beta}{sub 6} gene to 2q24-q31 by fluorescence in situ hybridization coupled with GTG-banding. This gene is located close to the region to which genes coding for the {alpha} subunits of the integrins VLA-4 and vitronectin receptor (ITGA4 and ITGAV, respectively) have been previously mapped (2q31-q32). These data suggest a proximal position of the integrin {beta}{sub 6} locus (ITGB6) on this integrin gene cluster. Futhermore, double-labeling in situ hybridization experiments performed with {alpha}{sub 4} and {alpha}{sub v} probesmore » indicated a telomeric position of ITGAV with respect to ITGA4. 22 refs., 2 figs.« less

Dendritic cell immunization route determines CD8+ T cell trafficking to inflamed skin: role for tissue microenvironment and dendritic cells in establishment of T cell-homing subsets.

PubMed

Dudda, Jan C; Simon, Jan C; Martin, Stefan

2004-01-15

The effector/memory T cell pool branches in homing subsets selectively trafficking to organs such as gut or skin. Little is known about the critical factors in the generation of skin-homing CD8+ T cells, although they are crucial effectors in skin-restricted immune responses such as contact hypersensitivity and melanoma defense. In this study, we show that intracutaneous, but not i.v. injection of bone marrow-derived dendritic cells induced skin-homing CD8+ T cells with up-regulated E-selectin ligand expression and effector function in contact hypersensitivity. The skin-homing potential and E-selectin ligand expression remained stable in memory phase without further Ag contact. In contrast, i.p. injection induced T cells expressing the gut-homing integrin alpha(4)beta(7). Although differential expression of these adhesion molecules was strictly associated with the immunization route, the postulated skin-homing marker CCR4 was transiently up-regulated in all conditions. Interestingly, dendritic cells from different tissues effectively induced the corresponding homing markers on T cells in vitro. Our results suggest a crucial role for the tissue microenvironment and dendritic cells in the instruction of T cells for tissue-selective homing and demonstrate that Langerhans cells are specialized to target T cells to inflamed skin.

Structure of a Trypanosoma Brucei Alpha/Beta--Hydrolase Fold Protein With Unknown Function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Merritt, E.A.; Holmes, M.; Buckner, F.S.

2009-05-26

The structure of a structural genomics target protein, Tbru020260AAA from Trypanosoma brucei, has been determined to a resolution of 2.2 {angstrom} using multiple-wavelength anomalous diffraction at the Se K edge. This protein belongs to Pfam sequence family PF08538 and is only distantly related to previously studied members of the {alpha}/{beta}-hydrolase fold family. Structural superposition onto representative {alpha}/{beta}-hydrolase fold proteins of known function indicates that a possible catalytic nucleophile, Ser116 in the T. brucei protein, lies at the expected location. However, the present structure and by extension the other trypanosomatid members of this sequence family have neither sequence nor structural similaritymore » at the location of other active-site residues typical for proteins with this fold. Together with the presence of an additional domain between strands {beta}6 and {beta}7 that is conserved in trypanosomatid genomes, this suggests that the function of these homologs has diverged from other members of the fold family.« less

15 beta-hydroxysteroids (Part IV). Steroids of the human perinatal period: the synthesis of 3 alpha,15 beta,17 alpha-trihydroxy-5 alpha-pregnan-20-one and its A/B-ring configurational isomers.

PubMed

Reeder, A Y; Joannou, G E

1995-12-01

In recent years several 15 beta-hydroxysteroids have emerged pathognomonic of adrenal disorders in human neonates of which 3 alpha,15 beta,17 alpha-trihydroxy-5 beta-pregnan-20-one (2) was the first to be identified in the urine of newborn infants affected with congenital adrenal hyperplasia. In this investigation we report the synthesis of the three remaining 3 xi,5 xi-isomers, namely 3 alpha,15 beta,17 alpha-trihydroxy-5 alpha-pregnan-20-one (3), 3 beta,15 beta,17 alpha-trihydroxy-5 alpha-pregnan-20-one (7) and 3 beta,15 beta,17 alpha-trihydroxy-5 beta-pregnan-20-one (8) for their definitive identification in pathological conditions in human neonates. 3 beta,15 beta-Diacetoxy-17 alpha-hydroxy-5-pregnen-20-one (11), a product of chemical synthesis was converted to the isomeric 3 and 7, while conversion of 15 beta,17 alpha-dihydroxy-4-pregnen-3,20-dione (4), a product of microbiological transformation, resulted in the preparation of 8. In brief, selective acetate hydrolysis of 11 gave 15 beta-acetoxy-3 beta,17 alpha-dihydroxy-5-pregnen-20-one (12) which on catalytic hydrogenation gave 15 beta-acetoxy-3 beta,17 alpha-dihydroxy-5 alpha-pregnan-20-one (13) a common intermediate for the synthesis of the 3 beta(and alpha),5 alpha-isomers. Hydrolysis of the 15 beta-acetate gave 7, whereas oxidation with pyridinium chlorochromate gave 15 beta-acetoxy-17 alpha-hydroxy-5 alpha-pregnan-3,20-dione (14) which on reduction with L-Selectride and hydrolysis of the 15 beta-acetate gave 3. Finally, hydrogenation of 4 gave 15 beta, 17 alpha-dihydroxy-5 beta-pregnan-3,20-dione (10) which on reduction with L-Selectride gave 8.

Confirmatory analysis of 17beta-boldenone, 17alpha-boldenone and androsta-1,4-diene-3,17-dione in bovine urine by liquid chromatography-tandem mass spectrometry.

PubMed

Draisci, Rosa; Palleschi, Luca; Ferretti, Emanuele; Lucentini, Luca; delli Quadri, Fernanda

2003-06-15

A sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS-MS) method for confirmatory analysis of 17beta-boldenone (17beta-BOL), 17alpha-boldenone (17alpha-BOL) and androsta-1,4-diene-3,17-dione (ADD) in bovine urine was developed. [2H(2)]17beta-Testosterone (17beta-T-d(2)) was used as the internal standard. Sample preparation involved enzymatic hydrolysis and purification on a C(18) solid-phase extraction column. Chromatographic separation of the analytes was obtained using an RP-C(18) HPLC column. LC-MS-MS detection was carried out with an atmospheric pressure chemical ionisation (APCI) source equipped with a heated nebulizer (HN) interface operating in the positive ion mode. For unambiguous hormone confirmation, three analyte precursor-product ion combinations were monitored during multiple-reaction monitoring (MRM) LC-MS-MS analysis. Overall recovery (%), repeatability (relative standard deviations, RSD, %) and within-laboratory reproducibility (RSD, %) ranged from 92.2 to 97.7%, from 6.50 to 2.94% and from 13.50 to 5.04%, respectively, for all analytes. The limit of quantification in bovine urine was 0.20 ng ml(-1) for 17beta-BOL and ADD and 0.50 ng ml(-1) for 17alpha-BOL. The validated method was successfully applied for determination of 17beta-BOL, 17alpha-BOL and ADD in a large number of bovine urine samples collected within the national Official Residue Control Program.

Genetic ablation of the alpha 6-integrin subunit in Tie1Cre mice enhances tumour angiogenesis.

PubMed

Germain, Mitchel; De Arcangelis, Adèle; Robinson, Stephen D; Baker, Marianne; Tavora, Bernardo; D'Amico, Gabriela; Silva, Rita; Kostourou, Vassiliki; Reynolds, Louise E; Watson, Alan; Jones, J Louise; Georges-Labouesse, Elisabeth; Hodivala-Dilke, Kairbaan

2010-02-01

Laminins are expressed highly in blood vessel basement membranes and have been implicated in angiogenesis. alpha6beta1- and alpha6beta4-integrins are major receptors for laminins in endothelial cells, but the precise role of endothelial alpha6-integrin in tumour angiogenesis is not clear. We show that blood vessels in human invasive ductal carcinoma of the breast have decreased expression of the alpha6-integrin-subunit when compared with normal breast tissue. These data suggest that a decrease in alpha6-integrin-subunit expression in endothelial cells is associated with tumour angiogenesis. To test whether the loss of the endothelial alpha6-integrin subunit affects tumour growth and angiogenesis, we generated alpha6fl/fl-Tie1Cre+ mice and showed that endothelial deletion of alpha6-integrin is sufficient to enhance tumour size and tumour angiogenesis in both murine B16F0 melanoma and Lewis cell lung carcinoma. Mechanistically, endothelial alpha6-integrin deficiency elevated significantly VEGF-mediated angiogenesis both in vivo and ex vivo. In particular, alpha6-integrin-deficient endothelial cells displayed increased levels of VEGF-receptor 2 (VEGFR2) and VEGF-mediated downstream ERK1/2 activation. By developing the first endothelial-specific alpha6-knockout mice, we show that the expression of the alpha6-integrin subunit in endothelial cells acts as a negative regulator of angiogenesis both in vivo and ex vivo. Copyright 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The effects of topically applied glycolic acid and salicylic acid on ultraviolet radiation-induced erythema, DNA damage and sunburn cell formation in human skin.

PubMed

Kornhauser, Andrija; Wei, Rong-Rong; Yamaguchi, Yuji; Coelho, Sergio G; Kaidbey, Kays; Barton, Curtis; Takahashi, Kaoruko; Beer, Janusz Z; Miller, Sharon A; Hearing, Vincent J

2009-07-01

alpha-Hydroxy acids (alphaHAs) are reported to reduce signs of aging in the skin and are widely used cosmetic ingredients. Several studies suggest that alphaHA can increase the sensitivity of skin to ultraviolet radiation. More recently, beta-hydroxy acids (betaHAs), or combinations of alphaHA and betaHA have also been incorporated into antiaging skin care products. Concerns have also arisen about increased sensitivity to ultraviolet radiation following use of skin care products containing beta-HA. To determine whether topical treatment with glycolic acid, a representative alphaHA, or with salicylic acid, a betaHA, modifies the short-term effects of solar simulated radiation (SSR) in human skin. Fourteen subjects participated in this study. Three of the four test sites on the mid-back of each subject were treated daily Monday-Friday, for a total of 3.5 weeks, with glycolic acid (10%), salicylic acid (2%), or vehicle (control). The fourth site received no treatment. After the last treatment, each site was exposed to SSR, and shave biopsies from all four sites were obtained. The endpoints evaluated in this study were erythema (assessed visually and instrumentally), DNA damage and sunburn cell formation. Treatment with glycolic acid resulted in increased sensitivity of human skin to SSR, measured as an increase in erythema, DNA damage and sunburn cell formation. Salicylic acid did not produce significant changes in any of these biomarkers. Short-term topical application of glycolic acid in a cosmetic formulation increased the sensitivity of human skin to SSR, while a comparable treatment with salicylic acid did not.

The effects of thalidomide on the stimulation of NF-kappaB activity and TNF-alpha production by lipopolysaccharide in a human colonic epithelial cell line.

PubMed

Kim, You Sun; Kim, Joo Sung; Jung, Hyun Chae; Song, In Sung

2004-04-30

The immunomodulatory and anti-inflammatory effects of thalidomide are associated with inhibition of TNF-alpha levels. However, the mechanism by which thalidomide reduces TNF-alpha production remains elusive. NF-kappaB is known to play a central role in regulating inflammatory responses in patients with inflammatory bowel disease (IBD). We tested whether thalidomide acts through inhibiting NF-kappaB activity. HT-29 cells were stimulated with LPS (1 microg/ml) alone, or after pretreatment with thalidomide (100 microg/ml), and NF-kappaB activity was determined by gel mobility shift assays. RT-PCR was used to measure expression of the proinflammatory cytokine genes TNF-alpha, IL-1beta and IL-8. The level of TNF-alpha mRNA was also analyzed by real-time quantitative RT-PCR, and TNF-alpha protein was measured by ELISA. Thalidomide pretreatment did not affect NF-kappaB activity in HT-29 cells stimulated with LPS but production of TNF-alpha was depressed. Thalidomide was found to accelerate the degradation of TNF-alpha mRNA, but had little effect on IL-1beta or IL-8. These observations suggest that the immunomodulatory effect of thalidomide in colonic epithelial cells is associated with inhibition of TNF-alpha. However, it does not act by inhibiting NF-kappaB but rather by inducing degradation of TNF-alpha mRNA.

Pregnancy Specific Glycoprotein 23 binds to CD151 and Induces the Secretion of IL-10 and TGF-beta1 in Murine Macrophages

DTIC Science & Technology

2007-07-11

levels of trophoblast-specific beta-1-globulin (SP1) and alpha -1- fetoprotein (AFP) in pregnant women with rheumatoid arthritis]. Cesk Gynekol, 1991...transforming growth factor-beta TNF-": tumor necrosis factor- alpha TXA: thromboxane A2 uNK: uterine natural killer cell 1 PART ONE...specific glycoprotein, pregnancy-associated plasma protein A, "- fetoprotein , as well as an array of cytokines, including IL-6, and TGF-! [95

Molecular mechanism of emotional stress-induced and catecholamine-induced heart attack.

PubMed

Ueyama, Takashi; Senba, Emiko; Kasamatsu, Ken; Hano, Takuzo; Yamamoto, Katsuhiro; Nishio, Ichiro; Tsuruo, Yoshihiro; Yoshida, Ken-ichi

2003-01-01

Emotional or physical stress triggers 'tako-tsubo' cardiomyopathy or 'transient left ventricular apical ballooning', but the pathogenesis is unclear. In response to the immobilization stress of rats, a useful model of emotional stress, rapid activation of p44/p42 mitogen-activated protein kinase was observed in the heart, followed by a transient upregulation of immediate early genes in the smooth muscle cells of coronary arteries, the endothelial cells and the myocardium. Heat shock protein 70 was induced in the aortic and coronary arterial smooth muscle cells and in the myocardium. Natriuretic peptide genes were also upregulated in the myocardium. Sequential gene expression can be considered as an adaptive response to emotional stress. Blocking of both alpha-adrenoceptors and beta-adrenoceptors eliminated the upregulation of immediate early genes induced by stress, while alpha-agonists and beta-agonists upregulated immediate early genes in the perfused heart. Activation of alpha-adrenoceptors and beta-adrenoceptors is the primary trigger of emotional stress-induced molecular changes in the heart.

Function of the two Xenopus smad4s in early frog development.

PubMed

Chang, Chenbei; Brivanlou, Ali H; Harland, Richard M

2006-10-13

Signals from the transforming growth factor beta family members are transmitted in the cell through specific receptor-activated Smads and a common partner Smad4. Two Smad4 genes (alpha and beta/10, or smad4 and smad4.2) have been isolated from Xenopus, and conflicting data are reported for Smad4beta/10 actions in mesodermal and neural induction. To further understand the functions of the Smad4s in early frog development, we analyzed their activities in detail. We report that Smad10 is a mutant form of Smad4beta that harbors a missense mutation of a conserved arginine to histidine in the MH1 domain. The mutation results in enhanced association of Smad10 with the nuclear transcription corepressor Ski and leads to its neural inducing activity through inhibition of bone morphogenetic protein (BMP) signaling. In contrast to Smad10, both Smad4alpha and Smad4beta enhanced BMP signals in ectodermal explants. Using antisense morpholino oligonucleotides (MOs) to knockdown endogenous Smad4 protein levels, we discovered that Smad4beta was required for both activin- and BMP-mediated mesodermal induction in animal caps, whereas Smad4alpha affected only the BMP signals. Neither Smad4 was involved directly in neural induction. Expression of Smad4beta-MO in early frog embryos resulted in reduction of mesodermal markers and defects in axial structures, which were rescued by either Smad4alpha or Smad4beta. Smad4alpha-MO induced only minor deficiency at late stages. As Smad4beta, but not Smad4alpha, is expressed at high levels maternally and during early gastrulation, our data suggest that although Smad4alpha and Smad4beta may have similar activities, they are differentially utilized during frog embryogenesis, with only Smad4beta being essential for mesoderm induction.

Rapid activation of ERK1/2 and AKT in human breast cancer cells by cadmium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu Zhiwei; Yu Xinyuan; Shaikh, Zahir A.

2008-05-01

Cadmium (Cd), an endocrine disruptor, can induce a variety of signaling events including the activation of ERK1/2 and AKT. In this study, the involvement of estrogen receptors (ER) in these events was evaluated in three human breast caner cell lines, MCF-7, MDA-MB-231, and SK-BR-3. The Cd-induced signal activation patterns in the three cell lines mimicked those exhibited in response to 17{beta}-estradiol. Specifically, treatment of MCF-7 cells, that express ER{alpha}, ER{beta} and GPR30, to 0.5-10 {mu}M Cd for only 2.5 min resulted in transient phosphorylation of ERK1/2. Cd also triggered a gradual increase and sustained activation of AKT during the 60more » min treatment period. In SK-BR-3 cells, that express only GPR30, Cd also caused a transient activation of ERK1/2, but not of AKT. In contrast, in MDA-MB-231 cells, that express only ER{beta}, Cd was unable to cause rapid activation of either ERK1/2 or AKT. A transient phosphorylation of ER{alpha} was also observed within 2.5 min of Cd exposure in the MCF-7 cells. While the estrogen receptor antagonist, ICI 182,780, did not prevent the effect of Cd on these signals, specific siRNA against hER{alpha} significantly reduced Cd-induced activation of ERK1/2 and completely blocked the activation of AKT. It is concluded that Cd, like estradiol, can cause rapid activation of ERK1/2 and AKT and that these signaling events are mediated by possible interaction with membrane ER{alpha} and GPR30, but not ER{beta}.« less

Enhancement of fruit shelf life by suppressing N-glycan processing enzymes.

PubMed

Meli, Vijaykumar S; Ghosh, Sumit; Prabha, T N; Chakraborty, Niranjan; Chakraborty, Subhra; Datta, Asis

2010-02-09

In a globalized economy, the control of fruit ripening is of strategic importance because excessive softening limits shelf life. Efforts have been made to reduce fruit softening in transgenic tomato through the suppression of genes encoding cell wall-degrading proteins. However, these have met with very limited success. N-glycans are reported to play an important role during fruit ripening, although the role of any particular enzyme is yet unknown. We have identified and targeted two ripening-specific N-glycoprotein modifying enzymes, alpha-mannosidase (alpha-Man) and beta-D-N-acetylhexosaminidase (beta-Hex). We show that their suppression enhances fruit shelf life, owing to the reduced rate of softening. Analysis of transgenic tomatoes revealed approximately 2.5- and approximately 2-fold firmer fruits in the alpha-Man and beta-Hex RNAi lines, respectively, and approximately 30 days of enhanced shelf life. Overexpression of alpha-Man or beta-Hex resulted in excessive fruit softening. Expression of alpha-Man and beta-Hex is induced by the ripening hormone ethylene and is modulated by a regulator of ripening, rin (ripening inhibitor). Furthermore, transcriptomic comparative studies demonstrate the down-regulation of cell wall degradation- and ripening-related genes in RNAi fruits. It is evident from these results that N-glycan processing is involved in ripening-associated fruit softening. Genetic manipulation of N-glycan processing can be of strategic importance to enhance fruit shelf life, without any negative effect on phenotype, including yield.

Limitations of commonly used internal controls for real-time RT-PCR analysis of renal epithelial-mesenchymal cell transition.

PubMed

Elberg, Gerard; Elberg, Dorit; Logan, Charlotte J; Chen, Lijuan; Turman, Martin A

2006-01-01

Progressive renal fibrotic disease is accompanied by the massive accumulation of myofibroblasts as defined by alpha smooth muscle actin (alphaSMA) expression. We quantitated gene expression using real-time RT-PCR analysis during conversion of primary cultured human renal tubular cells (RTC) to myofibroblasts after treatment with transforming growth factor-beta1 (TGF-beta1). We report herein the limitations of commonly used reference genes for mRNA quantitation. We determined the expression of alphaSMA and megakaryoblastic leukemia-1 (MKL1), a transcriptional regulator of alphaSMA, by quantitative real-time PCR using three common internal controls, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), cyclophilin A and 18S rRNA. Expression of GAPDH mRNA and cyclophilin A mRNA, and to a lesser extent, 18S rRNA levels varied over time in culture and with exposure to TGF-beta1. Thus, depending on which reference gene was used, TGF-beta1 appeared to have different effects on expression of MKL1 and alphaSMA. RTC converting to myofibroblasts in primary culture is a valuable system to study renal fibrosis in humans. However, variability in expression of reference genes with TGF-beta1 treatment illustrates the need to validate mRNA quantitation with multiple reference genes to provide accurate interpretation of fibrosis studies in the absence of a universal internal standard for mRNA expression. 2006 S. Karger AG, Basel.

Substance P enhances proliferation and paracrine potential of adipose-derived stem cells in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Suna; Piao, Jiyuan; Son, Youngsook

Stem cells have tremendous promise to treat intractable diseases. Notably, adipose-derived stem cells (ADSCs) are actively being investigated because of ease of sampling and high repopulation capacity in vitro. ADSCs can exert a therapeutic effect through differentiation and paracrine potential, and these actions have been proven in many diseases, including cutaneous and inflammatory diseases. Transplantation of ADSCs necessitates therapeutic quantities and thus, long term ex vivo culture of ADSCs. However, this procedure can impair the activity of ADSCs and provoke cellular senescence, leading to low efficacy in vivo. Accordingly, strategies to restore cellular activity and inhibit senescence of stem cells during ex vivo culturemore » are needed for stem cell-based therapies. This study evaluated a potential supplementary role of Substance P (SP) in ADSC ex vivo culture. After confirming that the ADSC cell cycle was damaged by passage 6 (p6), ADSCs at p6 were cultured with SP, and their proliferation rates, cumulative cell numbers, cytokine profiles, and impact on T/endothelial cells were assessed. Long-term culture weakened proliferation ability and secretion of the cytokines, transforming growth factor-beta 1 (TGF-beta1), vascular endothelial growth factor (VEGF), and stromal cell derived factor-1 alpha (SDF-1alpha) in ADSCs. However, SP treatment reduced the population doubling time (PDT), enabling gain of a sufficient number of ADSCs at early passages. In addition, SP restored cytokine secretion, enhancing the ADSC-mediated paracrine effect on T cell and human umbilical vein endothelial cells (HUVECs). Taken together, these results suggest that SP can retain the therapeutic effect of ADSCs by elevating their proliferative and paracrine potential in ex vivo culture. - Highlights: • Long-term culture of ADSCs leads to cell senescence. • Paracrine potential of ADSC decreases as passage number increases. • SP enhances the weakened proliferation capacity of ADSCs. • SP stimulates cytokine secretion from ADSC with impaired paracrine potential.« less

alpha 4 beta 2 subunit combination specific pharmacology of neuronal nicotinic acetylcholine receptors in N1E-115 neuroblastoma cells.

PubMed

Zwart, R; Abraham, D; Oortgiesen, M; Vijverberg, H P

1994-08-22

Pharmacological characteristics of native neuronal nicotinic acetylcholine receptor-mediated ion currents in mouse N1E-115 neuroblastoma cells have been investigated by superfusion of voltage clamped cells with known concentrations of the agonists acetylcholine, nicotine and cytisine, and the antagonists alpha-bungarotoxin and neuronal bungarotoxin. The sensitivity of the nicotinic acetylcholine receptor for agonists followed the agonist potency rank-order: nicotine approximately acetylcholine > cytisine. The EC50 values of acetylcholine and nicotine are 78 microM and 76 microM, respectively. Equal concentrations of acetylcholine and nicotine induce inward currents with approximately the same peak amplitude whereas cytisine induces much smaller inward currents. Acetylcholine-induced currents are unaffected by high concentrations of alpha-bungarotoxin. Conversely, at 10 and 90 nM neuronal bungarotoxin reduces the amplitude of the 1 mM acetylcholine-induced inward current to 47% and 11% of control values, respectively. Both the agonist potency rank-order and the differential sensitivity to snake toxins of nicotinic receptors in N1E-115 cells are consistent with the known pharmacological profile of alpha 4 beta 2 nicotinic receptors expressed in Xenopus oocytes and distinct from those of all other nicotinic acetylcholine receptors of known functional subunit compositions. All data indicate that the native nicotinic acetylcholine receptor in N1E-115 cells is an assembly of alpha 4 and beta 2 subunits, the putative major subtype of nicotinic acetylcholine receptor in the brain.

Single-hit mechanism of tumour cell killing by radiation.

PubMed

Chapman, J D

2003-02-01

To review the relative importance of the single-hit mechanism of radiation killing for tumour response to 1.8-2.0 Gy day(-1) fractions and to low dose-rate brachytherapy. Tumour cell killing by ionizing radiation is well described by the linear-quadratic equation that contains two independent components distinguished by dose kinetics. Analyses of tumour cell survival curves that contain six or more dose points usually provide good estimates of the alpha- and beta-inactivation coefficients. Superior estimates of tumour cell intrinsic radiosensitivity are obtained when synchronized populations are employed. The characteristics of single-hit inactivation of tumour cells are reviewed and compared with the characteristics of beta-inactivation. Potential molecular targets associated with single-hit inactivation are discussed along with strategies for potentiating cell killing by this mechanism. The single-hit mechanism of tumour cell killing shows no dependence on dose-rate and, consequently, no evidence of sublethal damage repair. It is uniquely potentiated by high linear-energy-transfer radiation, exhibits a smaller oxygen enhancement ratio and exhibits a larger indirect effect by hydroxyl radicals than the beta-mechanism. alpha-inactivation coefficients vary slightly throughout interphase but mitotic cells exhibit extremely high alpha-coefficients in the range of those observed for lymphocytes and some repair-deficient cells. Evidence is accumulating to suggest that chromatin in compacted form could be a radiation-hypersensitive target associated with single-hit radiation killing. Analyses of tumour cell survival curves demonstrate that it is the single-hit mechanism (alpha) that determines the majority of cell killing after doses of 2Gy and that this mechanism is highly variable between tumour cell lines. The characteristics of single-hit inactivation are qualitatively and quantitatively distinct from those of beta-inactivation. Compacted chromatin in tumour cells should be further investigated as a radiation-hypersensitive target that could be modulated for therapeutic advantage.

Soluble antigens from group B streptococci induce cytokine production in human blood cultures.

PubMed Central

von Hunolstein, C; Totolian, A; Alfarone, G; Mancuso, G; Cusumano, V; Teti, G; Orefici, G

1997-01-01

Group B streptococcal antigens stimulated tumor necrosis factor alpha (TNF-alpha), interleukin-1 (IL-1), and IL-6 production in human blood cultures in a concentration- and time-dependent fashion. The minimal concentrations of type-specific polysaccharides, lipoteichoic acid, and group-specific polysaccharide required to produce these effects were, respectively, 0.01, 1, and 10 microg/ml. Cell separation experiments indicated that monocytes were the cell type mainly responsible for cytokine production. Time course studies indicated that TNF-alpha was released before the other cytokines. TNF-alpha, however, did not appear to directly induce IL-1beta, as shown by blockade experiments with anti-TNF-alpha antibodies. IL-6 levels were moderately but significantly decreased by anti-TNF-alpha. These data indicate that several products from group B streptococci are able to directly stimulate human monocytes to release TNF-alpha, IL-1beta, and IL-6. These findings may be clinically relevant, since proinflammatory cytokines can mediate pathophysiologic changes during sepsis. PMID:9317001

GABAA receptor subunit gene expression in human prefrontal cortex: comparison of schizophrenics and controls

NASA Technical Reports Server (NTRS)

Akbarian, S.; Huntsman, M. M.; Kim, J. J.; Tafazzoli, A.; Potkin, S. G.; Bunney, W. E. Jr; Jones, E. G.; Bloom, F. E. (Principal Investigator)

1995-01-01

The prefrontal cortex of schizophrenics is hypoactive and displays changes related to inhibitory, GABAergic neurons, and GABAergic synapses. These changes include decreased levels of glutamic acid decarboxylase (GAD), the enzyme for GABA synthesis, upregulation of muscimol binding, and downregulation of benzodiazepine binding to GABAA receptors. Studies in the visual cortex of nonhuman primates have demonstrated that gene expression for GAD and for several GABAA receptor subunit polypeptides is under control of neuronal activity, raising the possibility that similar mechanisms in the hypoactive prefrontal cortex of schizophrenics may explain the abnormalities in GAD and in GABAA receptor regulation. In the present study, which is the first of its type on human cerebral cortex, levels of mRNAs for six GABAA receptor subunits (alpha 1, alpha 2, alpha 5, beta 1, beta 2, gamma 2) and their laminar expression patterns were analyzed in the prefrontal cortex of schizophrenics and matched controls, using in situ hybridization histochemistry and densitometry. Three types of laminar expression pattern were observed: mRNAs for the alpha 1, beta 2, and gamma 2 subunits, which are the predominant receptor subunits expressed in the mature cortex, were expressed at comparatively high levels by cells of all six cortical layers, but most intensely by cells in lower layer III and layer IV. mRNAs for the alpha 2, alpha 5, and beta 1 subunits were expressed at lower levels; alpha 2 and beta 1 were expressed predominantly by cells in layers II, III, and IV; alpha 5 was expressed predominantly in layers IV, V, and VI. There were no significant changes in overall mRNA levels for any of the receptor subunits in the prefrontal cortex of schizophrenics, and the laminar expression pattern of all six receptor subunit mRNAs did not differ between schizophrenics and controls. Because gene expression for GABAA receptor subunits is not consistently altered in the prefrontal cortex of schizophrenics, the previously reported upregulation of muscimol binding sites and downregulation of benzodiazepine binding sites in the prefrontal and adjacent cingulate cortex of schizophrenics are possibly due to posttranscriptional modifications of mRNAs and their translated polypeptides.

The bioactive effects of casein proteins on enteroendocrine cell health, proliferation and incretin hormone secretion.

PubMed

Gillespie, Anna L; Green, Brian D

2016-11-15

Previous studies suggest that casein exerts various anti-diabetic effects. However, it is not known which casein proteins are bioactive, nor their effects on enteroendocrine cells. This study evaluated the effects of intact whole casein, intact individual proteins (alpha, beta and kappa casein) and hydrolysates on an enteroendocrine cell line. High content analysis accurately monitored changes in cell health and intracellular glucagon-like peptide-1 (GLP-1) content. Cheese ripening duration and GLP-1 secretory responses were also considered. Beta casein significantly stimulated enteroendocrine cell proliferation and all caseins were potent GLP-1 secretagogues (except kappa casein). Interestingly the GLP-1 secretory activity was almost always lost or significantly reduced upon hydrolysis with proteolytic enzymes. Only pepsin-derived beta casein hydrolysates had significantly increased potency compared with the intact protein, but this was diminished with prolonged hydrolysis. In conclusion casein proteins are not detrimental to enteroendocrine cells, and alpha and beta casein are particularly beneficial stimulating proliferation and GLP-1 secretion. Copyright © 2016 Elsevier Ltd. All rights reserved.

Expression of interferon-gamma and tumour necrosis factor-alpha messenger RNA does not correlate with protection in guinea pigs challenged with virulent Mycobacterium tuberculosis by the respiratory route.

PubMed

Jeevan, Amminikutty; Bonilla, Diana Lucia; McMurray, David Neil

2009-09-01

Cytokine messenger RNA (mRNA) expression was investigated in the spleen and lung digest cells of bacillus Calmette-Guérin (BCG)-vaccinated and non-vaccinated guinea pigs following low-dose, pulmonary exposure to virulent Mycobacterium tuberculosis. After purified protein derivative (PPD) stimulation, the levels of lung cell interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha) and spleen cell interleukin-12 (IL-12) p40 mRNAs were significantly increased in the non-vaccinated M. tuberculosis-infected guinea pigs compared to the BCG-vaccinated guinea pigs. In contrast, the expression of anti-inflammatory transforming growth factor-beta and IL-10 mRNAs was significantly enhanced in the spleens of BCG-vaccinated animals. Despite the presence of protective cytokine mRNA expression, the non-vaccinated guinea pigs had significantly higher lung and spleen bacterial burdens. In contrast, BCG-vaccinated guinea pigs controlled the bacterial multiplication in their lungs and spleens, indicating that both protective as well as anti-inflammatory cytokine responses are associated with a reduction in bacteria. In addition, lung digest cells from non-vaccinated guinea pigs contained a significantly higher percentage of neutrophils, CD3(+) and CD8(+) T cells, while the percentage of macrophages was increased in the BCG-vaccinated animals. Total and purified lung digest T cells co-cultured with lung macrophages (LMøs) proliferated poorly after PPD stimulation in both non-vaccinated and BCG-vaccinated animals while robust proliferation to PPD was observed when T cells were co-cultured with peritoneal macrophages (PMøs). Macrophages within the lung compartment appear to regulate the response of T cells irrespective of the vaccination status in guinea pigs. Taken together, our results suggest that type I cytokine mRNA expression is not associated with vaccine-induced protection in the low-dose guinea pig model of tuberculosis.

Inflammatory parameters in Caco-2 cells: effect of stimuli nature, concentration, combination and cell differentiation.

PubMed

Van De Walle, Jacqueline; Hendrickx, Aurélie; Romier, Béatrice; Larondelle, Yvan; Schneider, Yves-Jacques

2010-08-01

Enterocytes regulate gut maintenance and defence by secreting and responding to inflammatory mediators and by modulating the intestinal epithelial permeability. In order to develop an in vitro model of the acute phase of intestinal inflammation, Caco-2 cells were exposed to the inflammatory mediators IL-1beta, TNF-alpha, IFN-gamma and LPS, and the importance of several experimental parameters, i.e. cell differentiation, stimulus nature, concentration and combination on the inflammatory response was assessed by measuring the production of IL-6, IL-8, PGE-2 and NO and by evaluating the monolayer permeability. A maximal increase in IL-8, IL-6 and PGE-2 production and monolayer permeability was observed when using the cytokines simultaneously at their highest level, but this relied mainly on IL-1beta. The effects of TNF-alpha on IL-8 and IL-6 or NO production were stronger upon combination with IL-1beta or IFN-gamma, respectively, whereas cells were unaffected by the presence of LPS. Although NO production, induced by IFN-gamma-containing combinations, was observed only in differentiated cells, general inflammatory response was higher in proliferating cells. The use of a mixture of IL-1beta, TNF-alpha and IFN-gamma thus accurately mimics intestinal inflammatory processes, but cell differentiation and stimuli combination are important parameters to take into account for in vitro studies on intestinal inflammation. Copyright (c) 2010. Published by Elsevier Ltd.

Lactose carrier protein of Escherichia coli. Transport and binding of 2'-(N-dansyl)aminoethyl beta-D-thiogalactopyranoside and p-nitrophenyl alpha-d-galactopyranoside.

PubMed

Overath, P; Teather, R M; Simoni, R D; Aichele, G; Wilhelm, U

1979-01-09

The elevated level of lactose carrier protein present in cytoplasmic membranes derived from Escherichia coli strain T31RT, which carries the Y gene of the lac operon on a plasmid vector (Teather, R. M., et al. (1978) Mol. Gen. Genet. 159, 239--248), has allowed the detection of a complex between the carrier and the fluorescent substrate 2'-(N-dansyl)-aminoethyl beta-D-thiogalactopyranoside (Dns2-S-Gal). Binding is accompanied by a 50-nm blue shift in the emission maximum of the dansyl residue. The complex (dissociation constant, KD = 30 micron) rapidly dissociates upon addition of competing substrates such as beta-D-galactopyranosyl 1-thio-beta-D-galactopyranoside or upon reaction with the thiol reagent p-chloromercuribenzenesulfonate. Binding of both Dns2-S-Gal and p-nitrophenyl alpha-D-galactopyranoside (alpha-NPG) occurs spontaneously in the absence of an electrochemical potential gradient across the membrane. Comparison of equilibrium binding experiments using Dns2-S-Gal or alpha-NPG and differential labeling of the carrier with radioactive amino acids shows that the carrier binds 1 mol of substrate per mol of polypeptide (molecular weight 30 000). In addition to specific binding to the lactose carrier, Dns2-S-gal binds unspecifically to lipid vesicles or membranes, as described by a partition coefficient, K = 60, resulting in a 25-nm blue shift in the emission maximum of the dansyl group. Both Dns2-S-Gal and alpha-NPG are not only bound by the lactose carrier but also transported across the membrane by this transport protein in cells and membrane vesicles. The fluorescence changes observed with dansylated galactosides in membrane vesicles in the presence of an electrochemical gradient (Schuldiner et al. (1975) J. Biol. Chem. 250, 1361--1370)) are interpreted as an increase in unspecific binding after translocation.

Improvement of macrophage dysfunction by administration of anti-transforming growth factor-beta antibody in EL4-bearing hosts.

PubMed

Maeda, H; Tsuru, S; Shiraishi, A

1994-11-01

An experimental therapy for improvement of macrophage dysfunction caused by transforming growth factor-beta (TGF-beta) was tried in EL4 tumor-bearing mice. TGF-beta was detected in cell-free ascitic fluid from EL4-bearers, but not in that from normal mice, by western blot analysis. The ascites also showed growth-suppressive activity against Mv1Lu cells, and the suppressive activity was potentiated by transient acidification. To investigate whether the functions of peritoneal macrophages were suppressed in EL4-bearers, the abilities to produce nitric oxide and tumor necrosis factor-alpha (TNF-alpha) upon lipopolysaccharide (LPS) stimulation were measured. Both abilities of macrophages in EL4-bearing mice were suppressed remarkably on day 9, and decreased further by day 14, compared with non-tumor-bearing controls. TGF-beta activity was abrogated by administration of anti-TGF-beta antibody to EL4-bearing mice. While a large amount of TGF-beta was detected in ascitic fluid from control EL4-bearers, little TGF-beta was detectable in ascites from EL4-bearers given anti-TGF-beta antibody. Furthermore, while control macrophages exhibited little or no production of nitric oxide and TNF-alpha on LPS stimulation in vitro, macrophages from EL4-bearers administered with anti-TGF-beta antibody showed the same ability as normal macrophages. These results clearly indicate that TGF-beta contributes to macrophage dysfunction and that the administration of specific antibody for TGF-beta reverses macrophage dysfunction in EL4-bearing hosts.

Immunolocalization of bone-resorptive cytokines in rat pulp and periapical lesions following surgical pulp exposure.

PubMed

Tani-Ishii, N; Wang, C Y; Stashenko, P

1995-08-01

The bone-resorptive cytokines interleukin 1 (IL-1) and tumor necrosis factor (TNF) have been implicated in the pathogenesis of many chronic inflammatory diseases, including pulpitis and apical periodontitis.To further elucidate their role in these disorders, we have identified cells that express IL-1 alpha and TNF alpha in infected pulps and in developing rat periapical lesions after surgical pulp exposure. As detected by immunohistochemistry, IL-1 alpha- and TNF alpha-positive cells were present as early as 2 days after pulp exposure in both the pulp and periapical region. The numbers of cytokine-expressing cells increased up to day 4 in the pulp and up to day 30 in the periapex. In contrast, cells expressing IL-1 beta and TNF beta, the homologous forms of these mediators, were not found in pulp or periapical lesions during this period. Cells expressing IL-1 alpha and TNF alpha were identified primarily as macrophages and fibroblasts, with occasional staining of polymorphonuclear leukocytes. Osteoblasts and osteoclasts were also positive, whereas lymphocytes were negative. In general, cytokine-expressing cells were located proximal to abscesses and the root apex. These findings demonstrate that cells that express bone-resorptive cytokines IL-1 alpha and TNF alpha are present immediately after pulp exposure in this model, which supports the hypothesis that these mediators play a key role in pulpal and periapical pathogenesis, including the concomitant bone destruction. They also indicate that both resident connective tissue cells as well as infiltrating cells express bone-resorptive cytokines in response to infection in these lesions.

Modulation of fat-soluble vitamin concentrations and blood mononuclear leukocyte populations in milk replacer-fed calves by dietary vitamin A and beta-carotene.

PubMed

Nonnecke, B J; Horst, R L; Waters, W R; Dubeski, P; Harp, J A

1999-12-01

Dairy calves (n = 18), separated from dams at birth, were fed 1 L of pooled-colostrum. For the remaining 7 wk of the study, they were fed one of three diets consisting of either a custom-formulated milk replacer without vitamin A (controls), or supplemented with retinyl palmitate (equivalent to 32,000 IU of vitamin A/d) or with beta-carotene (equivalent to 20,000 IU of vitamin A/d). Plasma retinol, beta-carotene, and RRR-alpha-tocopherol concentrations were lowest at birth, and increased substantially from birth to 1 wk postpartum in all groups, a probable consequence of ingestion of colostrum. From 1 to 7 wk of age, retinol concentrations were greatest in retinyl palmitate-supplemented calves, intermediate in beta-carotene-supplemented calves and lowest in control calves. At 2, 3, 5, 6, and 7 wk, RRR-alpha-tocopherol concentrations were lower in retinyl palmitate-supplemented calves than in control calves. A negative correlation between plasma retinol and vitamin E concentrations existed from wk 2 to 7, suggesting vitamin A influences the absorption and distribution of RRR-alpha-tocopherol. Supplemental retinyl palmitate, but not beta-carotene, was associated with a reduction in the percentage of blood mononuclear leukocytes expressing CD2, CD4, and CD8-T cell antigens and interleukin-2 receptors. By wk 7, leukocyte populations from retinyl palmitate-supplemented calves were more similar to those from adult cattle than those from control calves, suggesting that supplemental vitamin A, as retinyl palmitate, affects the maturation of the neonatal immune system. Differences in the composition of blood mononuclear leukocyte populations may represent changes in immune competency.