julilili42/papers huggingface dataset:
Wnt/β‐catenin pathway is activated by thyroid hormone and is required for its hepatomitogenic activity
2012-04-01

Thyroid hormones regulate cell growth, cell differentiation, and metabolic functions via their interaction with the thyroid hormone nuclear receptors (TRs). Recently, it was shown that intestinal epithelial cell proliferation is controlled by triiodothyronine (T3), and that TR‐β directly controls transcription of the β‐catenin gene. However, whether T3 has any effect on the activation of the Wnt pathway and β‐catenin in the liver, is unknown. Here we show by immunohistochemistry that livers from T3‐treated rats exhibited a strong increase in β‐catenin protein with its accumulation in the cytoplasm and an overall increase in the number of β‐catenin‐positive hepatocytes. The increased expression of β‐catenin was associated with increased glutamine synthetase, and an enhancement in nuclear accumulation of cyclin D1, both known targets of β‐catenin. Moreover, while T3 induced hepatocyte proliferation in wt mice, no proliferative response was observed in Ctnnb1 −/− mice. T3 treatment also caused enhanced levels of Cyp2E1 mRNA, another gene known to be up‐regulated by β‐catenin. The increased expression of C yp2E1 was associated with liver injury and mortality induced by a single administration of acetaminophen. Conclusion Our results indicate that T3 induces Ctnnb1 transcription and that high levels of this hormone may be responsible, through activation of β‐catenin, of increased hepatocyte proliferation and an enhanced susceptibility to drug‐induced liver injury. AIRC and PRIN, Italy.
Large Spatial and Temporal Variations in Himalayan Denudation
2012-04-01

Abstract In the last decade growing interest has emerged in quantifying the spatial and temporal variations in mountain building. Until recently, insufficient data have been available to attempt such a task at the scale of large orogens such as the Himalaya. The Himalaya accommodates ongoing convergence between India and Eurasia and is a focal point for studying orogen evolution and hypothesized interactions between tectonics and climate. Here we integrate 1126 published bedrock mineral cooling ages with a transient 1D Monte-Carlo thermal–kinematic erosion model to quantify the denudation histories along ~2700 km of the Himalaya. The model free parameter is a temporally variable denudation rate from 50 Ma to present. Thermophysical material properties and boundary conditions were tuned to individual study areas. Monte-Carlo simulations were conducted to identify the range of denudation histories that can reproduce the observed cooling ages. Results indicate large temporal and spatial variations in denudation and these are resolvable across different tectonic units of the Himalaya. More specifically, across >1000 km of the southern Greater Himalaya denudation rates were highest (~1.5–3 mm/yr) between ~10 and 2 Ma and lower (0.5–2.6 mm/yr) over the last 2 My. These differences are best determined in the NW-Himalaya. In contrast to this, across the ~2500 km length of the northern Greater Himalaya denudation rates vary over length scales of ~300–1700 km. Slower denudation (
The Role of CD 44+ Cells in Human Heart Valve Development
2012-04-01

Background Versican is a structural and function proteoglycan found in the extracellular matrix (ECM) of heart valve leaflets. CD44 is a well‐known cell membrane receptor for binding proteoglycans including versican. In our study, we analyzed the expression of CD44 during the late human fetal valvulogenesis. Methods For gene expression analyses, we used formalin‐fixed paraffin‐embedded (FFPE) human semilunar heart valve leaflets and performed a comparison of four age groups: group I – first trimester; group II – second trimester; group III – 14 to 19 years, group IV – 50 to 55 years. In addition, we analyzed protein expression using immunohistological staining. We employed antibodies for CD44 and versican using FFPE‐aortic heart valve tissues of the different developmental stages. Results We revealed that the transcription of CD44 starts in the first trimester of human fetal development. We also identified that CD44‐positive cells in developing leaflets (first, second and third trimester) are located in a very distinct anatomical site at the junction between vascular wall and leaflet. In contrast, in mature valves, CD44‐positive cells are spread throughout the entire leaflet. Conclusion In this study, we demonstrate that CD44‐positive cells represent a distinct cell population present in developing valve leaflets that is crucial for proper human valve development. Grant Funding Source : Attract 692263 Fraunhofer‐Gesellschaft
Expression and functional significance of Ca2+‐activated Cl‐channels in dendritic cells
2012-04-01

The functions of dendritic cells (DCs), professional antigen presenting cells linking innate and adaptive immunity, are under regulation of Ca 2+ . Ca 2+ entry is sensitive to the membrane potential and may depend on Cl − channel activity. The present study employed whole‐cell patch clamp experiments on mouse bone marrow‐derived DCs to identify expression and regulation of Cl − channels. Outwardly rectifying Cl − currents were activated by elevation of cytosolic Ca 2+ triggered either by ionomycin in the presence of extracellular Ca 2+ or by inositol‐triphosphate‐induced Ca 2+ release from intracellular stores. Most importantly, Ca 2+ ‐activated Cl − channels (CaCCs) were activated by the chemokine CCL21, which induces DC migration to the lymph nodes. The currents were inhibited by Cl − channel and CaCC blockers: tannic, digallic and niflumic acids and AO1. According to Fura2 fluorescence, the CaCC blockers blunted the store operated Ca 2+ entry following depletion of intracellular Ca 2+ stores with thapsigargin or upon stimulation with CCL21. The CaCC blockers further inhibited spontaneous, and chemokine‐ (CXCL12, CCL21)‐induced migration and secretion of interleukin‐2 (IL‐2) and IL‐6. According to RT‐PCR and Western blot data, Anoctamin 6 is expressed and can contribute to CaCCs in DCs. Our data identify Ca 2+ ‐activated Cl − channels in mouse DCs as major players in Ca 2+ homeostasis and Ca 2+ ‐regulated DC functions.
The NHE3 interacting PDZ protein NHERF2 determines the lipid raft association of the apical Na+/H+ exchanger NHE3 in murine small intestine
2012-04-01

Background Intestinal NHE3 is scaffolded and differentially regulated by Na + /H + Exchanger Regulatory Factor (NHERF) PDZ‐adaptors. NHE3 partially resides in lipid rafts of the Brush Border Membrane (BBM). Aim To investigate if there is a cross talk between NHERFs and membrane rafts, specifically if NHERFs associate differentially with the raft and non‐raft fraction of NHE3, and whether they influence the function and distribution of NHE3 in these microdomains. Methods and Results Murine BBM was detergent‐solubilised and lipid rafts isolated by density gradient floatation. NHE3 was partially, NHERF2 strongly and NHERF1 weakly raft‐associated, and NHERF3 exclusively in the non‐raft fraction. In absence of NHERF2, raft‐associated NHE3 was strongly decreased. Increasing the membrane sphingomyelin/ceramide ratio, increased NHE3‐dependent small intestinal fluid absorption in vivo, as well as overall NHE3 in the lipid rafts, suggesting a positive correlation between NHE3 function and raft association. Conclusions In murine small intestinal BBM, NHE3 differentially associates with the different NHERFs in the raft and non‐raft fraction. NHE3 raft‐association is NHERF2‐dependent. NHE3 and NHERF raft‐association and function are modulated by changes in the lipidic environment. This suggests that PDZ‐scaffolding proteins are involved in the retention of membrane proteins within lipid raft platforms.
K + homeostasis is maintained with knockdown of big‐conductance K + channel in principal cells of connecting tubule/collecting duct
2012-04-01

Big‐conductance K + (BK) channels are expressed in principal cells (PC) and intercalated cells of the kidney and contribute to K + homeostasis and flow‐induced K + secretion. To define the role of BK channels in PC, we generated mice with conditionally inactivated BK channels in PC of the connecting tubule/collecting duct (AQP2:Cre; BK loxloxCre ). Cre negative BK loxlox mice served as controls (Con). On standard diet (Teklad 7001), Plasma Na + (Con vs BK loxloxCre : 150±0.4 vs 150±0.4 mmol/l), K + (4.4±0.1 vs 4.3±0.1 mmol/l), pH (7.4±0.04 vs 7.4±0.04), and hematocrit (49±0.4 vs 50±0.5 %) were not different between genotypes. Systolic blood pressure and heart rate, determined by tail cuff, were comparable between genotypes (Con: 113±2 mmHg and 623±16 min −1 , BK loxloxCre : 116±2 mmHg and 647±13 min −1 ). Spontaneous urine collections showed similar urine osmolality in Con and BK loxloxCre (2041±87 vs 1950±85 mmol/kg). However, urinary K + /Na + ratio was significantly higher in BK loxloxCre vs Con (1.49±0.07 vs. 1.17±0.07, P&lt;0.05 ) due to lower urinary Na + /creatinine (crea) in BK loxloxCre vs Con (21.7±1.3 vs. 25.4±1.1, mmol/mmol P&lt;0.05 ), while urinary K + /crea was not different (31.9±1.8 vs 29.6±1.6 mmol/mmol). Our data indicate that under control diet conditional knockdown of BK channels in PC of the connecting tubule/collecting duct reduces Na + excretion while K + homeostasis is maintained.
Electrospun Proteoglycan Matrices for Tracheal Tissue Engineering
2012-04-01

Decorin (DCN) is a proteoglycan (PG) present in the extracellular matrix (ECM) of many tissues, including the trachea. Electrospinning is a suitable method for three‐dimensional (3D) scaffold fabrication to mimic the ECM's fibrous structure. In this study, we generated electrospun DCN‐polymer hybrids to obtain scaffolds that allow human tracheal cell (hTC) seeding. Methods DCN containing scaffolds were fabricated and characterized using scanning electron microscopy, contact angle measurements and dynamic mechanical analyses. Immunofluorescence (IF) staining was performed to detect DCN within the scaffold. For cell‐matrix interaction studies, we seeded primary hTCs and confirmed their phenotype by using immunocytochemistry. Results Analyses of the 3D substrates revealed a fibrous scaffold with a random fiber orientation. An average fiber diameter of 0.42 ± 0.20 μm and a pore size of 14.4 ± 6.4 μm2 was determined. Antibody staining for DCN showed the PG randomly distributed throughout the entire scaffold. After cell seeding, IF staining with an antibody against FOXJ1 revealed that ciliated hTCs adhered and proliferated on the scaffolds. Conclusion Here, we showed the successful electrospinning of PGs in combination with polymers to generate a fibrous scaffold with features of the natural ECM. Our data suggest that these substrates are excellent for applications in regenerative medicine. Grant Funding Source : Fraunhofer‐Gesellschaft (Attract 692263 to K.S.‐L)
Age and nutritional status influence peripheral immune cell phenotypes in healthy men in rural Pakistan
2012-04-01

Immune status is influenced by age and malnutrition. How these factors interact in developing countries and whether age‐associated differences are similar to those determined in industrialized countries is unclear, and were therefore, investigated in this study. Peripheral blood immune cell phenotypes were analyzed by polychromatic flow cytometry in young and elderly subjects. Data on anthropometrics and diet were collected through interviews. Plasma samples were analyzed for common clinical chemistry variables. As a group, elderly had a significantly lower CD4:CD8 ratio, a lower percentage of CD8+ naïve T cells and significantly higher late‐differentiated memory cells. These results were broadly similar to those in industrialized countries. Subjects in 4 BMI categories revealed an influence of nutritional status on immune parameters. This was greater within the young group, and unlike age, affected the CD4 subset more profoundly than the CD8 subset. No age‐ or nutrition‐associated differences were seen in B or NK cells. CD8+ cells as a percentage of CD3+ T cells were positively associated with plasma CRP levels but not other factors. We conclude that immune profiles in younger and older men in a developing country seem broadly similar to the more extensively‐documented state reported in industrialized countries, despite the marked societal, nutritional and many other differences. The study was funded by the German Academic Exchange Program (DAAD), and EU FP7 contract 259679 “IDEAL”....... Grant Funding Source : ASN
Changes in cell hydration and amino acid efflux related to chronically higher water intake in healthy young men
2012-04-01

Cell hydration is integral to endocrine, immune, neural, cardiovascular, gastrointestinal, muscle, and skeletal function. Acute cell dehydration is associated with a wide variety of adverse outcomes under extreme conditions and in critical illness. Biomarkers of chronic cell hydration are needed to test for longer‐term effects under daily life conditions. In vitro, cells adapt to chronic cell dehydration by increasing protein breakdown to increase intracellular concentrations and counter the osmotic gradient. Once adapted, cells overswell if exposed to hypoosmotic conditions, and release accumulated amino acids. In vivo, in chronically stressed animals, hypoosmotic amino acid efflux is measurable in urine. This study explored for changes in cell hydration and urinary amino acid excretion in 5 healthy men (20–25y) with habitually low total water intake (&lt;2L/d) who increased water intake to 3.5L/d over 4 wks by drinking water. Each week, urine was collected after a 750ml bolus of drinking water. Higher water intake was associated with increased urine volume, decreased urine ADH and osmolality, a downward shift in the distribution of red cell deformability over the osmolality range, and altered post‐bolus urinary amino acid excretion. More work is needed on amino acid efflux as a possible biomarker of chronic cell hydration. Funded by Danone Research, NIH #UL1 RR024131 &amp; #5UL1RR024131‐05, and RAS #A106017.
Abstract 1698: ERG protein expression and genomic rearrangement status in primary and metastatic prostate cancer - A comparative study of two monoclonal antibodies
2012-04-01

Abstract Introduction and Objective: Overexpression of the ERG protein is highly prevalent in prostate cancer (PCa) and most commonly results from gene fusions involving the ERG gene. Recently, an N-terminal epitope targeted mouse and a C-terminal epitope targeted rabbit monoclonal anti-ERG antibody have been introduced for the detection of the ERG protein. Independent studies reported that immunohistochemical (IHC) stains with both monoclonal anti-ERG antibodies (ERG-MAbs) highly correlate with the underlying ERG gene rearrangement status. However, a comparative study of both antibodies has not been provided so far. Here, we are the first to compare the mouse ERG-MAb to the rabbit ERG-MAb for their concordance on the same PCa cohort. Furthermore, we assessed if the ERG protein expression is conserved in lymph node and distant PCa metastases, of which a subset underwent decalcification. Methods: We evaluated tissue microarrays of 278 specimens containing 265 localized PCa, 29 lymph node, 30 distant metastases, and 13 normal prostatic tissues. We correlated the ERG protein expression with the ERG rearrangement status using an ERG break-apart fluorescence in-situ hybridization (FISH) assay and IHC of both ERG antibodies. Results: ERG protein expression and ERG rearrangement status were highly concordant regardless of whether the mouse or rabbit ERG-MAb was used (97.8% versus 98.6%, respectively). Of interest, both ERG antibodies reliably detected the ERG expression in lymph node and distant PCa metastases, of which a subset underwent decalcification. If an ERG protein expression was present in localized PCa, we observed the same pattern in the corresponding lymph node metastases. Conclusions: This is the first study to comprehensively compare the two available ERG-MAbs. By demonstrating a broad applicability of IHC to study ERG protein expression using either antibody, this study adds an important step towards a facilitated routine clinical application. Further, we demonstrate that the clonal nature of the ERG rearrangement is not restricted to the genomic level, but proceeds in the proteome. Together, our results simplify future efforts to further elucidate the biological role of ERG in PCa. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1698. doi:1538-7445.AM2012-1698
Evaluation of a new, large field of view, small animal PET/MR system
2012-04-01

Ziel/Aim: Combined PET/MR imaging is an evolving field in small animal as well as human medical imaging. Our group successfully constructed a second generation small animal PET-insert, which allows for large field of view PET/ MR imaging. Here we present technical details about the new PET-insert as well as an evaluation of its PET and MR performance. Methodik/Methods: The new PET-insert uses a total of 16 circularly arranged, copper shielded, detector cassettes. Each cassette consists of 3 avalanche photodiode (APD) arrays, each attached to a 15x15 LSO crystal block (single crystal size 1.5x1.5x10mm). The PET-insert is air cooled via vortex tubes and a temperature feedback system to an operating temperature of 15°C. The PETinsert is mounted inside a 7T small animal MR system. The total PET/MR field of view with installed whole body MR coils is ca. 72x70mm, allowing for whole body mouse as well as rat imaging. The PET spatial resolution was evaluated for different reconstruction algorithms, using a glass capillary tube, filled with 1MBq of F-18-FDG solution. Furthermore the sensitivity of the PET-insert was measured via a small glass sphere filled with 340kBq of F-18 in an energy window of 350keV-650keV. On the MR side the signal to noise ratio (SNR) as well as image homogeneity was measured for different MR sequences (n=18). In vivo images of a rat heart were also obtained. Ergebnisse/Results: The PET spatial resolution for an OSEM reconstruction (16 iterations) was found to be (2.22±0.06)mm without an MR sequence running, and (2.19±0.05)mm with an EPI MR sequence applied. The sensitivity at the center FOV of the PET insert was (3.19±0.22)% without and (3.1±0.08)% with the MR sequence. Neither spatial resolution nor sensitivity of the PET changed significantly when an MR EPI sequence was applied. The MR SNR with the PET insert varied, depending on the used MR sequence, between 25 for turbospinecho and 8 for flash sequences. Only for the TSE sequence a small, but significant (p&lt;0.05) drop of the SNR (without PET: 24.9±0.3 with PET: 24.4±0.3) on the order of 2% was observed. The other sequences showed no significant influence of the PET on the MR performance. In vivo images of a rat heart revealed, that gated acquisitions of PET and MR data were simultaneously possible with this setup. The high quality images allowed identification of the heart ventricles. Schlussfolgerungen/Conclusions: Our data clearly shows that the next generation of small animal PET/MR systems is able to perform on par with stand alone solutions. Small fluctuations of the SNR with the PET insert installed are in the range of the typical experimental variability for small animal studies. The in vivo imaging data reveals the huge potential of this technique in preclinical and clinical research.
Enhanced Ca 2+ entry and Na + /Ca 2+ exchanger activity in dendritic cells from AMP‐activated protein kinase‐deficient mice
2012-04-02

ABSTRACT In dendritic cells (DCs), chemotactic chemokines, such as CXCL12, rapidly increase cytosolic Ca 2+ concentrations ([Ca 2+ ] i ) by triggering Ca 2+ release from intracellular stores followed by store‐operated Ca 2+ (SOC) entry. Increase of [Ca 2+ ] i is blunted and terminated by Ca 2+ extrusion, accomplished by K + independent Na + /Ca 2+ exchangers (NCXs) and K + ‐dependent Na + /Ca 2+ exchangers (NCKXs). Increased [Ca 2+ ] i activates energy‐sensing AMP‐activated protein kinase (AMPK), which suppresses proinflammatory responses of DCs and macrophages. The present study explored whether AMPK participates in the regulation of DC [Ca 2+ ] i and migration. DCs were isolated from AMPKα1‐deficient ( ampk –/– ) mice and, as control, from their wild‐type ( ampk +/+ ) littermates. AMPKα1, Orai1‐2, STIM1‐2, and mitochondrial calcium uniporter protein expression was determined by Western blotting, [Ca 2+ ] i by Fura‐2 fluorescence, SOC entry by inhibition of endosomal Ca 2+ ATPase with thapsigargin (1 μM), Na + /Ca 2+ exchanger activity from increase of [Ca 2+ ] i , and respective whole‐cell current in patch clamp following removal of extracellular Na + . Migration was quantified utilizing transwell chambers. AMPKα1 protein is expressed in ampk +/+ DCs but not in ampk –/– DCs. CXCL12 (300 ng/ml)‐induced increase of [Ca 2+ ] i , SOC entry, Orai 1 protein abundance, NCX, and NCKX were all significantly higher in ampk –/– DCs than in ampk +/+ DCs. NCX and NCKX currents were similarly increased in ampk –/– DCs. Moreover, CXCL12 (50 ng/ml)‐induced DC migration was enhanced in ampk –/– DCs. AMPK thus inhibits SOC entry, Na + /Ca 2+ exchangers, and migration of DCs.—Nurbaeva, M. K., Schmid, E., Szteyn, K., Yang, W., Viollet, B., Shumilina, E., Lang, F. Enhanced Ca 2+ entry and Na + /Ca2 + exchanger activity in dendritic cells from AMP‐activated protein kinase‐deficient mice. FASEB J. 26, 3049–3058 (2012). www.fasebj.org
A Novel Marker of Human Endometrial Mesenchymal Stem-Like Cells
2012-04-03

Coexpression of CD140b (PDGFRβ) and CD146 has been used to isolate endometrial mesenchymal stem-like cells (eMSCs), which have a perivascular location. This study aims to evaluate a single marker for purifying eMSCs. Using an antibody panel with novel specificities, we screened human endometrial tissues and stromal cell suspensions by flow cytometry and immunohistochemistry to identify perivascular markers. Sorted subpopulations were examined for colony-forming unit (CFU), self-renewal, and differentiation assays for mesenchymal stem cell (MSC) function. We also transplanted sorted eMSCs under the kidney capsule of superimmunodeficient NSG mice. Magnetic bead selection was compared with flow cytometry sorting (flow sorting) using CFU assay. One novel marker (W5C5) was particularly effective in selecting eMSCs. W5C5 + cells comprise 4.2 ± 0.6% ( n = 34) of endometrial stromal cells and reside predominantly in a perivascular location in both basal and functional layers of endometrium. The clonogenicity of W5C5 + cells is significantly greater than W5C5 - and unselected cells. W5C5 + cells differentiated into adipocytes, osteocytes, chondrocytes, myocytes, and endothelial cells. W5C5 + cells produce endometrial stromal-like tissue in vivo. In terms of clonogenicity, magnetic bead-selected W5C5 + cells gave rise to significantly higher CFU numbers compared to flow-sorted W5C5 + cells. This study identified W5C5 as a single marker capable of purifying eMSCs possessing MSC properties and reconstituting endometrial stromal tissues in vivo. W5C5 enriches eMSCs to high purity and provides a simple protocol for their prospective isolation using magnetic bead selection rather than flow sorting. W5C5 selection may provide an alternate, readily available autologous source of MSC, obtainable with minimal morbidity using an office endometrial biopsy procedure for future cell-based therapies.