Biomedical subjects

Stefan Wagner

Publications and source records attributed to Stefan Wagner.

At least 37 records · Page 2Linked to original sources

PubMed2005

Cross-reactivity of mimotopes with a monoclonal antibody against the high molecular weight melanoma-associated antigen (HMW-MAA) does not predict cross-reactive immunogenicity.

The high molecular weight melanoma-associated antigen (HMW-MAA) is highly expressed in advanced primary and metastatic melanoma. An epitope of the core protein of HMW-MAA is recognized by the murine monoclonal antibody (mAb) 225.28S. In this study, we aimed to characterize peptides that antigenically mimicked this epitope and to determine their efficacy as components of an HMW-MAA-based anti-melanoma vaccine. Therefore, we screened a constrained 10 mer phage display peptide library against mAb 225.28S. Selected phage-displayed peptides were then tested for their specificity for the antibody's antigen-binding site. DNA sequences coding for specific peptide ligands were determined. Binding of mAb 225.28S to HMW-MAA was inhibited in a dose-dependent manner by phage-displayed peptides from 51 to 83% and by synthetic peptides from 38 to 87%. Subsequently, the immunogenicity of the five mimotopes with the highest inhibition capacity was examined in rabbits. Immunizations with synthetic mimotopes conjugated to tetanus toxoid resulted in peptide-specific antibodies, but none of the highly antigenic mimotopes induced HMW-MAA cross-reactive antibodies. This report describes an example of disparity between antigenicity and cross-reactive immunogenicity, complicating the selection of potential vaccine candidates.

Animals↗

PubMed2005

Epitope-specific antibody response to Mel-CAM induced by mimotope immunization.

Peptide mimotopes of tumor antigen epitopes have been proposed as components of tumor vaccines. In this study, we determined the immunogenicity of melcam mim1 and melcam mim2, peptide mimics of an epitope of the melanoma cell-adhesion molecule (Mel-CAM). BALB/c mice were vaccinated either with mimotopes or mimotopes coupled to tetanus toxoid (TT). The antibody responses of mice to melcam mim1, melcam mim2, and recombinant Mel-CAM were analyzed by an ELISA and immunoblot analyses. TT-coupled mimotopes led to high titers of IgG mainly of the IgG2a subclass to melcam mim1 and melcam mim2. Immunization with each of the mimotope formulations induced antibodies that cross-reacted with recombinant Mel-CAM. Uncoupled mimotopes induced lymphocyte proliferation and cytokine production in spleen cell cultures indicating that both peptide mimotopes also contained T cell epitopes. TT-coupled mimotopes induced T helper (Th)1 (interleukin (IL)-2, interferon-gamma) and Th2 (IL-4, IL-5) cytokines, whereas uncoupled mimotopes induced a Th1-biased T cell response. Our results suggest that mimotopes potentially represent a novel vaccine approach to induce a tumor antigen-specific humoral and cellular response.

Amino Acid Sequence↗

PubMed2005

Hevea brasiliensis latex allergens: current panel and clinical relevance.

Latex allergy has been studied in detail in Europe and the US over the past two decades, resulting in specific guidelines that succeeded in reducing its incidence in high-risk populations within the medical field. How these developments have affected high-risk populations outside the health care scenario is an important unanswered question. In addition, a second wave of latex allergy may occur in nations that are striving to attain higher economic and technologic standards, including population-dense countries such as China. Therefore, the application of Hevea allergens in novel diagnostic assays and the development of specific latex immunotherapy will provide new opportunities for latex allergy research. In this review, we summarize current knowledge on the immunological properties of the 13 officially accepted Hevea brasiliensis latex allergens.

Adult↗

PubMed2005

Persistent STAT3 activation in colon cancer is associated with enhanced cell proliferation and tumor growth.

Colorectal carcinoma (CRC) is a major cause of morbidity and mortality in Western countries. It has so far been molecularly defined mainly by alterations of the Wnt pathway. We show here for the first time that aberrant activities of the signal transducer and activator of transcription STAT3 actively contribute to this malignancy and, thus, are a potential therapeutic target for CRC. Constitutive STAT3 activity was found to be abundant in dedifferentiated cancer cells and infiltrating lymphocytes of CRC samples, but not in non-neoplastic colon epithelium. Cell lines derived from malignant colorectal tumors lost persistent STAT3 activity in culture. However, implantation of colon carcinoma cells into nude mice resulted in restoration of STAT3 activity, suggesting a role of an extracellular stimulus within the tumor microenvironment as a trigger for STAT activation. STAT3 activity in CRC cells triggered through interleukin-6 or through a constitutively active STAT3 mutant promoted cancer cell multiplication, whereas STAT3 inhibition through a dominant-negative variant impaired IL-6-driven proliferation. Blockade of STAT3 activation in CRC-derived xenograft tumors slowed down their development, arguing for a contribution of STAT3 to colorectal tumor growth.

Animals↗

PubMed2004

Excessive sarcoplasmic/endoplasmic reticulum Ca2+-ATPase expression causes increased sarcoplasmic reticulum Ca2+ uptake but decreases myocyte shortening.

BACKGROUND: Increasing sarcoplasmic/endoplasmic reticulum (SR) Ca2+-ATPase (SERCA) uptake activity is a promising therapeutic approach for heart failure. We investigated the effects of different levels of SERCA1a expression on contractility and Ca2+ cycling. We tested whether increased SERCA1a expression levels enhance myocyte contractility in a gene-dose-dependent manner. METHODS AND RESULTS: Rabbit isolated cardiomyocytes were transfected at different multiplicities of infection (MOIs) with adenoviruses encoding SERCA1a (or beta-galactosidase as control). Myocyte relaxation half-time was decreased by 10% (P=0.052) at SERCA1a MOI 10 and by 28% at MOI 50 (P<0.05). Myocyte fractional shortening was increased by 12% at MOI 10 (P<0.05) but surprisingly decreased at MOI 50 (-22%, P<0.05) versus control. SR Ca2+ uptake (in permeabilized myocytes) demonstrated a gene-dose-dependent decrease in K(m) by 29% and 46% and an increase in Vmax by 37% and 72% at MOI 10 and MOI 50, respectively (all P<0.05 versus control). Ca2+ transient amplitude was increased in Ad-SERCA1a-infected myocytes at MOI 10 (by 121%, P<0.05), but at MOI 50, the Ca2+ transient amplitude was not significantly changed. Caffeine-induced Ca2+ transients indicated significantly increased SR Ca2+ content in Ad-SERCA1a-infected cells, by 72% at MOI 10 and by 87% at MOI 50. Mathematical simulations demonstrate that the functional increase in SR Ca2+-ATPase uptake activity at MOI 50 (and increased cytosolic Ca2+ buffering) is sufficient to curtail the Ca2+ transient amplitude and explain the reduced contraction. CONCLUSIONS: Moderate SERCA1a gene transfer and expression improve contractility and Ca(2+) cycling. However, higher SERCA1a expression levels can impair myocyte shortening because of higher SERCA activity and Ca2+ buffering.

Adenoviridae↗

PubMed2004

Synthesis and first in vivo evaluation of new selective high affinity beta1-adrenoceptor radioligands for SPECT based on ICI 89,406.

The results of cardiac biopsies suggest that myocardial beta1-adrenoceptor (AR) density is reduced in patients with chronic heart failure, while changes in cardiac beta2-ARs vary. A technique for visualization and quantification of beta1-AR populations rather than total beta-AR densities in the human heart would be of great clinical interest. Molecular imaging techniques, either single photon emission computed tomography (SPECT) or positron emission tomography (PET), with appropriate radiopharmaceuticals offer the possibility to assess beta-AR density noninvasively in humans, but to date, neither a SPECT nor a PET-radioligand is clinically established for the selective imaging of cardiac beta1-ARs. The aim of this study was to design a high affinity selective beta1-AR radioligand for the noninvasive in vivo imaging of cardiac beta1-AR density in man using SPECT. Based on the well-known selective beta1-AR antagonist, ICI 89,406, both the racemic iodinated target compound 11a and the (S)-enantiomer 15a were synthesized. Competition studies using the nonselective AR ligand, [(125)I]iodocyanopindolol ([(125)I]ICYP), and ventricular membrane preparations from mice showed that 11a and 15a possess higher beta1-AR affinities (up to 265-fold) and beta1-AR selectivities (up to 245-fold) than ICI 89,406. Encouraged by these results, the radioiodinated counterparts of racemic 11a (11b: (125)I, 11c: (123)I) and (S)-configurated 15a (15b: (125)I, 15c: (123)I) were synthesized. The target compounds were evaluated in rats. Biodistribution and metabolism studies in rats indicated that there is a specific heart uptake of 11b-c and especially 15b-c accompanied by rapid metabolism of the radioligands. Therefore, radioiodinated 11c and 15c appeared to be unpromising SPECT-radioligands for assessing beta1-ARs in vivo in the rat. However, the rat may metabolize beta-AR ligands more rapidly than other species as demonstrated for (S)-[(11)C]CGP 12177, a radioligand structurally related to 11a-c and 15a-c. Therefore further studies in a different animal model will be carried out.

Adrenergic beta-1 Receptor Antagonists↗

PubMed2004

Generation of Peptide mimics of the epitope recognized by trastuzumab on the oncogenic protein Her-2/neu.

Immunizations with the oncogenic protein Her-2/neu elicit Abs exerting diverse biological effects--depending on epitope specificity, tumor growth may be inhibited or enhanced. Trastuzumab (herceptin) is a growth-inhibitory humanized monoclonal anti-Her-2/neu Ab, currently used for passive immunotherapy in the treatment of breast cancer. However, Ab therapies are expensive and have to be repeatedly administered for long periods of time. In contrast, active immunizations produce ongoing immune responses. Therefore, the study aims to generate peptide mimics of the epitope recognized by trastuzumab for vaccine formulation, ensuring the subsequent induction of tumor growth inhibitory Abs. We used the phage display technique to generate epitope mimics, mimotopes, complementing the screening Ab trastuzumab. Five candidate mimotopes were isolated from a constrained 10 mer library. These peptides were specifically recognized by trastuzumab, and showed distinctive mimicry with Her-2/neu in two experimental setups. Subsequently, immunogenicity of a selected mimotope was examined in BALB/c mice. Immunizations with a synthetic mimotope conjugated to tetanus toxoid resulted in Abs recognizing Her-2/neu in a blotted cell lysate as well as on the SK-BR-3 cell surface. Analogous to trastuzumab, the induced Abs caused internalization of the receptor from the cell surface to endosomal vesicles. These results indicate that the selected mimotopes are suitable for formulation of a breast cancer vaccine because the resulting Abs show similar biological features as trastuzumab.

Animals↗

PubMed2004

Scintigraphic imaging of matrix metalloproteinase activity in the arterial wall in vivo.

BACKGROUND: Matrix metalloproteinases (MMPs) are enzymes involved in the proteolytic degradation of extracellular matrix. They play an important role in several disease processes, such as inflammation, cancer, and atherosclerosis. METHODS AND RESULTS: In this study, we have used the broad-spectrum MMP inhibitor CGS 27023A to develop the radioligand [123I]I-HO-CGS 27023A for in vivo imaging of MMP activity. Using this radioligand, we were able to specifically image MMP activity by scintigraphy in vivo in the MMP-rich vascular lesions that develop after carotid artery ligation and cholesterol-rich diet in apolipoprotein E-deficient mice. These results were confirmed by gamma counting of lesional tissue (counts per minute per milligram). CONCLUSIONS: Imaging of MMP activity in vivo is feasible using radiolabeled MMP inhibitors. Additional studies are needed to test the potential of this approach as a novel noninvasive clinical diagnostic tool for the management of human MMP-related diseases.

Animals↗

PubMed2004

In vitro FRAP reveals the ATP-dependent nuclear mobilization of the exon junction complex protein SRm160.

We present a new in vitro system for characterizing the binding and mobility of enhanced green fluorescent protein (EGFP)-labeled nuclear proteins by fluorescence recovery after photobleaching in digitonin-permeabilized cells. This assay reveals that SRm160, a splicing coactivator and component of the exon junction complex (EJC) involved in RNA export, has an adenosine triphosphate (ATP)-dependent mobility. Endogenous SRm160, lacking the EGFP moiety, could also be released from sites at splicing speckled domains by an ATP-dependent mechanism. A second EJC protein, RNPS1, also has an ATP-dependent mobility, but SRm300, a protein that binds to SRm160 and participates with it in RNA splicing, remains immobile after ATP supplementation. This finding suggests that SRm160-containing RNA export, but not splicing, complexes have an ATP-dependent mobility. We propose that RNA export complexes have an ATP-regulated mechanism for release from binding sites at splicing speckled domains. In vitro fluorescence recovery after photobleaching is a powerful tool for identifying cofactors required for nuclear binding and mobility.

Active Transport, Cell Nucleus↗

PubMed2004

Expression of the B subunit of the heat-labile enterotoxin of Escherichia coli in tobacco mosaic virus-infected Nicotiana benthamiana plants and its characterization as mucosal immunogen and adjuvant.

We have produced biologically active recombinant (r) LTB, the nontoxic B subunit of heat-labile toxin (LT) of Escherichia coli in tobacco mosaic virus (TMV)-infected Nicotiana benthamiana plants. We amplified the LTB encoding sequence with its leader and introduced a hexahistidyl tag and an endoplasmic reticulum retention signal. The resulting product was ligated into a TMV-based plant viral expression vector that was used for the generation of recombinant viral RNA. Eighty-nine percent of N. benthamiana plants inoculated with the recombinant viral RNA were systemically infected as determined by anti-TMV enzyme-linked immunosorbent assay (ELISA) experiments. The rLTB monomer was identified by LT-specific as well as by histidyl-tag-specific immunoblots. rLTB from plant extracts of TMV-infected N. benthamiana leaves was purified to give 75 microg rLTB pentamers per gram fresh plant material and was capable of binding G(M)1 ganglioside. The immunogenicity of the plant-produced rLTB was tested in mice and showed that intranasal application of rLTB (15 microg per mouse) induced LTB-specific IgG1 antibodies. To prove its adjuvanticity, rLTB was intranasally co-administered with the Hevea latex allergen Hev b 3, leading to allergen-specific IgG1 and IgG2a antibody production. The fact that intranasal application of rLTB and Hev b 3 prior to systemic challenge with the allergen enhanced the Th2 responses at the humoral and cellular level indicated that rLTB promoted immune responses that were naturally induced by the antigen/allergen. In conclusion, these results indicate that the plant viral expression system is suitable for the rapid large-scale production of biologically active LTB with strong mucosal adjuvant capacity.

Adjuvants, Immunologic↗

PubMed2004

Synthesis and preliminary biological evaluation of new radioiodinated MMP inhibitors for imaging MMP activity in vivo.

Non-invasive measurement of matrix metalloproteinase (MMP) activity in vivo is a clinical challenge in many disease processes such as inflammation, tumor metastasis and atherosclerosis. Therefore, radioiodinated analogues of the non-peptidyl broad-spectrum MMP inhibitor (MMPI) CGS 27023A 1a were synthesized for non-invasive detection of MMP activity in vivo using single photon emission computed tomography (SPECT). The compounds Br-CGS 27023A 1b and HO-CGS 27023A 1d were synthesized from the amino acid D-valine and used as precursors for radioiodinated derivatives of CGS 27023A and their non-radioactive references I-CGS 27023A 1c and HO-I-CGS 27023A 1e. Radioiodination of the precursors with [(123)I]NaI or [(125)I]NaI produced the no-carrier-added MMP inhibitors [(123)I]I-CGS 27023A 1f, [(125)I]I-CGS 27023A 1g, HO-[(123)I]I-CGS27023A 1h, and HO-[(125)I]I-CGS 27023A 1i. In vitro studies showed that the non-radioactive analogues of the MMP inhibitors exhibited affinities against gelatinase A (MMP-2) and gelatinase B (MMP-9) in the nanomolar range, comparable to the parent compound CGS 27023A. In vivo biodistribution using HO-[(125)I]I-CGS 27023A 1i in CL57 Bl6 mice showed rapid blood and plasma clearance and low retention in normal tissues. The preliminary biological evaluation warrant further studies of these radioiodinated MMP inhibitors as potential new radiotracers for imaging MMP activity in vivo.

Animals↗

PubMed2003

Inhibition of tumor cell growth by antibodies induced after vaccination with peptides derived from the extracellular domain of Her-2/neu.

The anti Her-2/neu monoclonal antibody Trastuzumab has strong inhibiting effects on tumor growth in vitro and in vivo and is therefore used for immunotherapy in breast cancer patients. Due to necessity of frequent applications, however, cost intensiveness of Trastuzumab treatment and its limited duration of affectivity, an active immunization inducing a perhaps preventive and long-term immunity to Her-2/neu remains a desirable goal. We attempted to induce anti Her-2/neu antibodies by peptide vaccination and to test their efficacy in inhibiting tumor cell growth in vitro. By computer aided analyses, 7 putative B cell epitopes of Her-2/neu were defined and synthesized. These peptide epitopes were coupled to tetanus toxoid and used for immunization in BALB/c mice. Among these peptides, immunizations with 2 single peptides or a combination of 2 peptides induced anti-peptide antibody levels, primarily of the IgG1 isotype. These antibodies were also directed against the native Her-2/neu antigen, as shown in precipitation assays and ELISA with cell lysates of the Her-2/neu overexpressing breast cancer cell line SK-BR-3. Isolated IgG fractions from immune sera incubated with SK-BR-3 cells led to a moderate inhibition of the tumor cell growth in vitro, as well as to complement dependent cell lyses comparable to that achieved by incubation with Trastuzumab. Moreover, peptide immunization in rabbits generated anti-Her 2-neu IgG that, in contrast to mouse sera, were able to mediate a 31-46% lysis of SK-BR-3 cells in ADCC experiments. We conclude from our data that immunization with Her-2/neu peptides successfully induced humoral immune response with anti-tumor activity in an animal model.

Amino Acid Sequence↗

PubMed2003

Na(+)-Ca(2+) exchanger overexpression predisposes to reactive oxygen species-induced injury.

OBJECTIVE: In heart failure (HF), the generation of reactive oxygen species (ROS) is enhanced. It was shown that failing cardiac myocytes are more susceptible to ROS-induced damage, possibly due to increased expression of the sarcolemmal Na-Ca exchanger (NCX). METHODS: We investigated the consequences of increased expression levels of NCX in adult rabbit ventricular cardiomyocytes (via adenovirus-mediated gene transfer, Ad-NCX1-GFP) with respect to tolerance towards ROS. After 48-h incubation, cells were monitored for morphological changes on an inverted microscope. ROS were generated via hydrogen peroxide (H(2)O(2)) (100 micromol/l) and Fe(3+)/nitrilotriacetate (Fe(3+)/NTA, 100/200 micromol/l) for 4 min and cell morphology was followed over 30 min. [Na(+)](i) and [Ca(2+)](i) in native cells were measured using SBFI-AM and Indo1-AM, respectively. RESULTS: In native myocytes, exposure to ROS induced hypercontracture. This was accompanied by a 1.3-fold increase in diastolic Indo1 fluorescence ratio (P<0.05). Overexpression of NCX significantly enhanced development of hypercontracture. After 15 min, the percentage of cells that had undergone hypercontracture (F(hyper)) was 85+/-4% vs. only 44+/-10% in control cells (P<0.05). Inhibition of NCX-mediated Ca(2+) entry with KB-R7943 (5 micromol/l) reduced F(hyper) to 33+/-11% (P<0.05). [Na(+)](i) was increased 2.9-fold 1 min prior to hypercontracture (P<0.05). CONCLUSIONS: ROS-induced hypercontracture is due to Ca(2+) entry via NCX which could be triggered by a concomitant substantial increase in [Na(+)](i). Elevated NCX levels predispose to ROS-induced injury, a mechanism likely contributing to myocyte dysfunction and death in heart failure.

Adenoviridae↗

PubMed2003

Design of new beta1-selective adrenoceptor ligands as potential radioligands for in vivo imaging.

In general, the failing human heart is characterized by a selective reduction in beta(1)-adrenoceptors (beta(1)-ARs) without change in beta(2)-AR density. Medical imaging techniques, either single photon emission computed tomography (SPECT) or positron emission tomography (PET) with appropriate radioligands, offer the possibility of assessing beta-adrenoceptor density non-invasively in humans. To date, neither a SPECT nor a PET radioligand is available for the selective imaging of cardiac beta(1)-ARs. The aim of this study was to develop potential high affinity beta(1)-selective AR radioligands for the non-invasive in vivo imaging of the beta(1)-AR density in the human heart using SPECT or PET. A variety of racemic N-aryl-N'-[2-[3-aryloxy-2-hydroxy-propylamino]-ethyl]-urea derivatives and chain-elongated analogues, related to the established beta(1)-AR antagonist, ICI 89,406 8i, were synthesized. Competition studies using the non-selective AR ligand, [(125)I]iodocyanopindolol ([(125)I]ICYP), and ventricular membrane preparations of wild-type mice revealed nine ligands with higher beta(1)-AR affinities (up to 76-fold) and beta(1)-AR selectivities (up to 139-fold) than 8i. Mostly, these ligands possess a 2-substituted phenoxy group and a 4-substituted phenyl residue in contrast to the lead compound 8i. The non-radioactive counterparts of the desired SPECT- and PET-radiotracers were synthesized as reference compounds [e.g., 8f, 8g, 8h and 8l as the non-radioactive analogues of the radioiodinated SPECT radioligands, 8e and 8h as the non-radioactive compounds of C-11 labelled PET-tracers (C-11 in the methoxy group)]. The established library of high affinity beta(1)-selective AR antagonists was screened for chemical precursors for the radiosynthesis of the mentioned radioligands. Furthermore, the library consists of some comparison compounds that are unsubstituted, allyl- and alkyl-substituted or chain-elongated (e.g., 8a, 8j, 8o and 8r-t). Future steps will include radiolabelling and pharmacokinetic evaluation of the beta(1)-selective target compounds, which could be applied as sympathetic innervation agents for in vivo investigations and diagnostics in patients suffering from cardiac diseases like heart failure and ventricular arrhythmias.

Adrenergic beta-1 Receptor Antagonists↗

PubMed2003

Effects of adenovirus-mediated sorcin overexpression on excitation-contraction coupling in isolated rabbit cardiomyocytes.

To evaluate the effect of sorcin on cardiac excitation-contraction coupling, adult rabbit ventricular myocytes were transfected with a recombinant adenovirus coding for human sorcin (Ad-sorcin). A beta-galactosidase adenovirus (Ad-LacZ) was used as a control. Fractional shortening in response to 1-Hz field stimulation (at 37 degrees C) was significantly reduced in Ad-sorcin-transfected myocytes compared with control myocytes (2.10+/-0.05% [n=311] versus 2.42+/-0.06% [n=312], respectively; P<0.001). Action potential duration (at 20 degrees C) was significantly less in the Ad-sorcin group (458+/-22 ms, n=11) compared with the control group (520+/-19 ms, n=10; P<0.05). In voltage-clamped, fura 2-loaded myocytes (20 degrees C), a reduced peak-systolic and end-diastolic [Ca2+]i was observed after Ad-sorcin transfection. L-type Ca2+ current amplitude and time course were unaffected. Caffeine-induced Ca2+ release from the sarcoplasmic reticulum (SR) and the accompanying inward Na+-Ca2+ exchanger (NCX) current revealed a significantly lower SR Ca2+ content and faster Ca2+-extrusion kinetics in Ad-sorcin-transfected cells. Higher NCX activity after Ad-sorcin transfection was confirmed by measuring the NCX current-voltage relationship. beta-Escin-permeabilized rabbit cardiomyocytes were used to study the effects of sorcin overexpression on Ca2+ sparks imaged with fluo 3 at 145 to 160 nmol/L [Ca2+] using a confocal microscope. Under these conditions, caffeine-mediated SR Ca2+ release was not different between the two groups. Spontaneous spark frequency, duration, width, and amplitude were lower in sorcin-overexpressing myocytes. In summary, sorcin overexpression in rabbit cardiomyocytes decreased Ca2+-transient amplitude predominantly by lowering SR Ca2+ content via increased NCX activity. The effect of sorcin overexpression on Ca2+ sparks indicates an effect on the ryanodine receptor that may also influence excitation-contraction coupling.

Adenoviridae↗

PubMed2003

The spatial targeting and nuclear matrix binding domains of SRm160.

The Ser-Arg (SR)-related protein SRm160 is a coactivator of pre-mRNA splicing. It bridges splicing factors located at the 5' splice site, branch site, and 3' splice site. Recently, SRm160 has also been shown to be involved in mRNA export as part of an exon-junction complex. SRm160 is highly concentrated in splicing speckles but is also present in long branched intranuclear tracks connecting splicing speckles with sites at the nuclear lamina. In this study we identified domains of SRm160 important for spatial targeting within the nucleus and for binding to the nuclear matrix. Using a series of FLAG- and enhanced GFP-conjugated deletion mutants we found two contiguous sequences that independently target SRm160 to nuclear matrix sites at splicing speckled domains: amino acids 300-350 and 351-688. Constructs containing amino acids 300-350 were also targeted to sites peripheral to speckled domains where most mRNA originate subsequent to splicing. Sequences from the N-terminal domain localized proteins to the nuclear lamina near sites where mRNA leaves the nucleus.

Antigens, Nuclear↗

PubMed2002

Gender differences in acute myocardial infarction in the era of reperfusion (the MITRA registry).

There is conflicting information about gender differences in presentation, treatment, and outcome after acute ST elevation myocardial infarction (STEMI) in the era of thrombolytic therapy and primary percutaneous coronary intervention. From June 1994 to January 1997, we enrolled 6,067 consecutive patients with STEMI admitted to 54 hospitals in southwest Germany in the Maximal Individual TheRapy of Acute myocardial infarction (MITRA), a community-based registry. Women were 9 years older than men, more often had hypertension, diabetes mellitus, and congestive heart failure, and had a history of previous myocardial infarction less often. Women had a longer prehospital delay (45 minutes), had anterior wall infarction more often (odds ratio [OR] 1.21; 95% confidence interval [CI] 1.08 to 1.36), and received reperfusion therapy less often (OR 0.83; 95% CI 0.74 to 0.94). The percentage of patients who were eligible for thrombolysis and received no reperfusion was higher in women (OR 1.7; 95% CI 1.56 to 1.89). Women had recurrent angina (OR 1.45; 95% CI 1.23 to 1.71) and congestive heart failure (OR 1.26; 95% CI 1.01 to 1.56) more often. There was a trend toward a higher hospital mortality in women (age-adjusted OR 1.16, 95% CI 0.99 to 1.35; multivariate OR 1.21, 95% CI 0.96 to 1.51), but there was no gender difference in long-term mortality after multivariate analysis (age-adjusted OR 0.95, 95% CI 0.78 to 1.15; multivariate OR 0.93, 95% CI 0.72 to 1.19). Thus, women with STEMI receive reperfusion therapy less often than men. They experience recurrent angina and congestive heart failure more often during their hospital stay. The age-adjusted long-term mortality is not different between men and women, but there is a trend for a higher short-term mortality in women.

Aged↗

PubMed2002

Induction of protein translation by ADAR1 within living cell nuclei is not dependent on RNA editing.

Translation of mRNA is usually cytoplasmic. We report that the RNA editing enzyme ADAR1, which catalyzes the deamination of adenosine to inosine in double-stranded RNA substrates, induces translation within the nucleus, possibly at the surface of the nucleolus. This activity does not depend on RNA editing. Two regions within ADAR1 are defined that act independently of each other to induce translation: the first includes the double-stranded RNA binding domains (DRBMs) of ADAR1 while the second maps to the C-terminal portion of the catalytic domain. Point mutations within each domain are identified that reduce nuclear translation; those in the DRBM region are also known to diminish RNA binding. This report adds to the growing functionality ascribed to the nucleus.

3T3 Cells↗