ABSTRACT
The CAST-CAPP axion haloscope, operating at CERN inside the CAST dipole magnet, has searched for axions in the 19.74 µeV to 22.47 µeV mass range. The detection concept follows the Sikivie haloscope principle, where Dark Matter axions convert into photons within a resonator immersed in a magnetic field. The CAST-CAPP resonator is an array of four individual rectangular cavities inserted in a strong dipole magnet, phase-matched to maximize the detection sensitivity. Here we report on the data acquired for 4124 h from 2019 to 2021. Each cavity is equipped with a fast frequency tuning mechanism of 10 MHz/ min between 4.774 GHz and 5.434 GHz. In the present work, we exclude axion-photon couplings for virialized galactic axions down to gaγγ = 8 × 10-14 GeV-1 at the 90% confidence level. The here implemented phase-matching technique also allows for future large-scale upgrades.
ABSTRACT
The assessment of the completeness of milk-out in dairy cows is one of the indicators used to evaluate and optimise the milking process. A number of different methods and thresholds are available for this purpose, but procedures and validation of the methods are not always described in detail, and may vary between studies. The objective of this study was to introduce and evaluate a new, precisely defined hand-milking method (DEFINED) and to compare its outcome with two commonly applied methods to assess the completeness of milking: visual scoring of the degree of quarter filling (VISUAL) and quantitative assessment of the number of easy strips (EASYSTRIPS). Each of the three methods was applied in 131 Holstein cows of six dairy herds in northern Germany. The assessment of milk-out was carried out by three experienced but non-regular milkers (evaluators). Each evaluator visited the six herds once during afternoon milking. To avoid any transitions, the interval between visits of two evaluators was at least 2 days. Maximum hand-milking time per cow was set to 60 s. The total strip yield collected in 60 s (SY60) by the application of a strip frequency of 1 Hz was used as a reference for the amount of milk left in the investigated quarter after machine-milking. The three methods were evaluated by analysing their statistical relationship with SY60, and by ranking their suitability for quantitative or qualitative assessment of milk-out. VISUAL and SY60 were not related, indicating that VISUAL was unsuitable for estimating the amount of milk left actually in the udder quarters. The strip yield in 15 s (DEFINED) and SY60 was significantly related, but results varied among evaluators. With regard to EASYSTRIPS, a significant relationship with SY60 was found, but the results were influenced by evaluator and herd. The findings of this study imply that DEFINED allows a rapid and farm-independent quantitative estimate of the post-milking strip yield. Likewise, EASYSTRIPS was meaningful in assessing milk-out of quarters in a given herd, whereas VISUAL allowed neither a quantitative nor a qualitative assessment of post-milking strip yield or milk-out. Thresholds for complete or incomplete milk-out by DEFINED must be lower than those commonly applied in 15 s of post-milking.
Subject(s)
Cattle/physiology , Dairying/methods , Data Collection/methods , Lactation , Animals , Farms , Female , GermanyABSTRACT
Correction to: Histochem Cell Biol (2016).
ABSTRACT
Cattle's relationship with humans is a crucial factor regarding their welfare. In dairy cows, interactions with humans occur regularly during milking. We tested the effect of gentle interactions (stroking, talking in a gentle voice) during milking on avoidance distance and milk composition, yield and flow characteristics as well as behaviour during milking. Over the course of 15 days, an experimenter interacted gently with 14 German Holstein cows for 2 min during morning and evening milkings, totalling 60 min; the experimenter stayed at a similar distance to 12 control cows of the same breed for the same amount of time. There were no significant differences between the groups in behaviour during milking. Over the course of the experimental phase, avoidance distance at the feeding rack decreased significantly in stroked but not in control cows. The treatment did not improve any of the measures of milk composition, yield or flow; on the 1st day of the treatment, milk ejection was impaired in stroked cows, which points towards an effect of the novelty of the treatment. We conclude that gentle interactions during milking improve the relationship between cows and a human. Possible reasons for the absence of an effect on milk characteristics are that cows may not have perceived the interactions as positive or that a ceiling effect occurred due to otherwise optimal milking routines.
Subject(s)
Cattle/physiology , Milk/metabolism , Animals , Dairying , Female , Humans , Lactation , Milk/chemistryABSTRACT
The purinergic receptor P2X7 represents an ATP-gated ionotropic receptor with a selective localization in alveolar epithelial type I cells of the lung. Despite the involvement of the receptor in inflammatory processes of the lung, it is not established whether this receptor plays a specific role in the alveolar epithelial cell biology. There is evidence that P2X7 receptor influences Wnt/ß-catenin signalling pathways in alveolar epithelial cells under conditions of injury. Here, we investigated the expression of GSK-3ß, a potent protein kinase involved in alveolar epithelial barrier functions, and of tight junction molecules occludin, claudin-4 and claudin-18 in wild-type and P2X7-/- mice. Western blot analysis, immunohistochemistry and quantitative real-time RT-PCR revealed a remarkable increase in claudin-18 mRNA and protein in lungs of P2X7-/- mice animals. Furthermore, alveolar epithelial cells from P2X7-/- animals showed decreased levels of GSK-3ß protein and its inactive form GSK-3ß (pS9). Conversely, claudin-18 knockout mice exhibited decreased P2X7 mRNA transcript abundance as measured by mRNA expression microarray and quantitative PCR. Our data are consistent with the hypothesis that P2X7R contributes to alveolar epithelial barrier function through effects on GSK-3ß. Furthermore, these data suggest a potential reciprocal regulation of claudin-18 and P2X7R in the alveolar epithelium.
Subject(s)
Alveolar Epithelial Cells/metabolism , Claudins/metabolism , Glycogen Synthase Kinase 3 beta/metabolism , Lung/cytology , Receptors, Purinergic P2X7/metabolism , Animals , Claudins/deficiency , Mice , Mice, Inbred C57BL , Mice, Knockout , Receptors, Purinergic P2X7/deficiencyABSTRACT
OBJECTIVE: Judicious selection of potential liver transplant candidates and close monitoring of progress are essential to successful outcomes. Pretransplant psychosocial evaluations are the norm, but the relationship between psychosocial (and neurocognitive status) and longer term medical outcomes is understudied. This exploratory study sought to examine the relationship between objective measures of pretransplant psychosocial and neurocognitive status and service utilization, transplant status, and all-cause mortality. METHODS: This retrospective chart review examined outcomes among 108 psychiatric, high-risk liver transplant candidates up to four years following initial evaluation. Predictor variables of outcomes included demographic, medical, neurocognitive, psychological, and mental health treatment variables. RESULTS: Transplant status and neurocognitive functioning were independently associated with all-cause mortality. None of the other variables were associated with outcomes. CONCLUSIONS: Better neurocognitive functioning in high-risk liver transplant candidates may allow for greater involvement in medical care and/or compliance with treatment recommendations. More aggressive assessment and management of neurocognitive dysfunction may improve outcomes. Objective measures identified significant psychopathology typical of liver transplant candidates but were not associated with outcomes; engagement in specialized mental health care may have attenuated this relationship. Further study is needed to better understand the relationship between psychosocial functioning and outcomes.
Subject(s)
Cause of Death , Liver Transplantation/psychology , Mental Disorders/psychology , Adult , Female , Humans , Liver Transplantation/mortality , Male , Mental Disorders/mortality , Middle AgedABSTRACT
The CERN Axion Solar Telescope has finished its search for solar axions with (3)He buffer gas, covering the search range 0.64 eV â² ma â² 1.17 eV. This closes the gap to the cosmological hot dark matter limit and actually overlaps with it. From the absence of excess x rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of gaγ â² 3.3 × 10(-10) GeV(-1) at 95% C.L., with the exact value depending on the pressure setting. Future direct solar axion searches will focus on increasing the sensitivity to smaller values of gaγ, for example by the currently discussed next generation helioscope International AXion Observatory.
ABSTRACT
The aim of this experiment was to compare social stress, as measured by social behavior and adrenocortical activity, in young dairy goats during the first week after introduction into a herd of adult goats either during the dry period of the herd (i.e., all goats in the herd being pregnant or dry: PD) or shortly after parturition (i.e., all animals lactating or with their kids: LK). Thirty-two young goats that had had no contact with adult goats from the age of 7 wk were introduced into adult goat groups. Adult goats were kept in 2 groups of 36 animals each. Young goats were introduced (in groups of 4 animals each) into each of these 2 groups either during the PD period (2 repetitions) or during LK (2 repetitions); goats with different rearing experience were balanced over introduction periods. Young goats were more often receivers of agonistic social interactions when introduced during PD than during LK. Irrespective of the period of introduction, young goats had other young goats as neighbors more frequently than expected by chance alone, although this was even more distinct during PD. Cortisol metabolite levels increased markedly from baseline during PD, but not after parturition. Rearing showed an effect only on the nearest neighbors, with mother-reared young goats staying closer together. Our results indicate that young goats experience less social stress when being introduced into a herd of adult dairy goats shortly after parturition and with kids still present rather than during the dry period. Whether this effect is due to the period and lactational stage itself or to the presence of kids needs to be tested in future studies.
Subject(s)
Animals, Newborn/psychology , Dairying/methods , Goats/psychology , Animals , Feces/chemistry , Hydrocortisone/analysis , Parturition/psychology , Social Behavior , Time FactorsABSTRACT
Urokinase-type plasminogen activator receptor (uPAR) regulates pericellular proteolysis by binding the serine proteinase urokinase-type plasminogen activator (uPA) that promotes cell surface activating of plasminogen to plasmin. In addition, uPAR as a glycosylphosphatidylinositol (GPI)-anchored signaling receptor affects cell migration, differentiation, and proliferation. The aim of the present study was to monitor the occurrence and distribution pattern of uPAR in cells of the rat molar tooth germ. By means of immunocytochemistry moderate, uPAR immunoreactivity was detected in epithelial cells of the enamel organ and in ameloblasts and odontoblasts. RT-PCR and Western blotting experiments demonstrated the expression of uPAR in phorbol 12-myristate 13-acetate (PMA)-stimulated dental epithelial cells (HAT-7 cells). A substantial part of uPAR was detected in the detergent-insoluble caveolin-1-containing low-density raft membrane fraction of HAT-7 cells suggesting a partial localization within lipid rafts. However, co-immunoprecipitation experiments showed that uPAR and caveolin-1 do not associate with each other directly. Cell stimulation experiments with PMA indicated that protein kinase C (PKC)-mediated signaling pathways contribute to the expression of uPAR in cells of the enamel organ. The localization of uPAR in membrane rafts provides a basis for further investigations on the role of uPAR-mediated signaling cascades in ameloblasts.
Subject(s)
Epithelial Cells/drug effects , Membrane Microdomains/metabolism , Tetradecanoylphorbol Acetate/analogs & derivatives , Tooth Germ/metabolism , Urokinase-Type Plasminogen Activator/analysis , Animals , Blotting, Western , Cells, Cultured , Epithelial Cells/cytology , Epithelial Cells/metabolism , Female , Immunohistochemistry , Male , Rats , Rats, Wistar , Reverse Transcriptase Polymerase Chain Reaction , Tetradecanoylphorbol Acetate/pharmacology , Tooth Germ/embryology , Urokinase-Type Plasminogen Activator/biosynthesis , Urokinase-Type Plasminogen Activator/geneticsABSTRACT
BACKGROUND: Gastrointestinal endoscopies are increasingly being carried out with sedation. All of the drugs used for sedation are associated with a certain risk of complications. Data currently available on sedation-associated morbidity and mortality rates are limited and in most cases have substantial methodological limitations. The aim of this study was to record severe sedation-associated complications in a large number of gastrointestinal endoscopies. METHODS: Data on severe sedation-associated complications were collected on a multicentre basis from prospectively recorded registries of complications in the participating hospitals (median documentation period 27 months, range 9 - 129 months). RESULTS: Data for 388,404 endoscopies from 15 departments were included in the study. Severe sedation-associated complications occurred in 57 patients (0.01 %). Forty-one percent of the complications and 50 % of all complications with a fatal outcome (10/20 patients) occurred during emergency endoscopies. In addition, it was found that 95 % of the complications and 100 % of all fatal complications affected patients in ASA class ≥ 3. CONCLUSIONS: Including nearly 400,000 endoscopies, this study represents the largest prospective, multicenter record of the complications of sedation worldwide. The analysis shows that sedation is carried out safely in gastrointestinal endoscopy. The morbidity and mortality rates are much lower than previously reported in the literature in similar groups of patients. Risk factors for the occurrence of serious complications include emergency examinations and patients in ASA class ≥ 3.
Subject(s)
Drug-Related Side Effects and Adverse Reactions/mortality , Endoscopy, Gastrointestinal/mortality , Hypnotics and Sedatives/therapeutic use , Registries , Adult , Aged , Female , Germany/epidemiology , Humans , Incidence , Male , Middle Aged , Patient Safety , Prospective Studies , Risk Factors , Survival RateABSTRACT
BACKGROUND: The influence of the bisphosphonate zoledronic acid (ZA) on prostate cancer (PC) growth, adhesion and invasive behavior was investigated. METHODS: PC-3, DU-145 and LNCaP cells were treated with ZA, and tumor-cell growth was then investigated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Furthermore, tumor-cell adhesion to vascular endothelium or to immobilized extracellular matrix proteins, as well as migratory properties of the cells, was evaluated. Integrin ß subtypes, integrin-dependent signaling, as well as cell-cycle regulating proteins, were analyzed by western blots. RESULTS: ZA dose-dependently reduced tumor-cell growth but did not impair tumor-endothelium and tumor-matrix interaction. However, ZA significantly inhibited tumor migration and invasive activity. Cyclin E was reduced by ZA in LNCaP and DU-145, and p21 was elevated in LNCaP cells. p27 was upregulated in all tumor cell lines, compared with the controls. ZA elevated ß1-integrin in PC-3 and diminished ß4-integrin in PC-3 and DU-145 cells. CONCLUSIONS: ZA inhibits PC growth and motility but does not influence the mechanical contact between tumor cells and the vascular wall.
Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Cell Adhesion/drug effects , Cell Movement/drug effects , Diphosphonates/pharmacology , Imidazoles/pharmacology , Prostatic Neoplasms/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Humans , Male , Prostatic Neoplasms/pathology , Signal Transduction/drug effects , Zoledronic AcidABSTRACT
The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using (3)He as a buffer gas. At T=1.8 K this allows for larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with (4)He. With about 1 h of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.39 eVâ²m(a)â²0.64 eV. From the absence of excess x rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g(aγ)â²2.3×10(-10) GeV(-1) at 95% C.L., the exact value depending on the pressure setting. Kim-Shifman-Vainshtein-Zakharov axions are excluded at the upper end of our mass range, the first time ever for any solar axion search. In the future we will extend our search to m(a)â²1.15 eV, comfortably overlapping with cosmological hot dark matter bounds.
ABSTRACT
It has recently been shown in epithelial cells that the ATP-gated ion channel P2X7R is in part, associated with caveolae and colocalized with caveolin-1. In the present study of the mouse heart, we show for the first time, using immunohistochemistry and cryoimmunoelectron microscopy, that P2X7R is expressed in atrial cardiomyocytes and in cardiac microvascular endothelial cells, but not in the ventricle cardiomyocytes. Furthermore, biochemical data indicate the presence of two forms of P2X7R, the classical glycosylated 80 kDa isoform and a protein with the molecular weight of 56 kDa, in both cardiomyocytes and endothelial cells of the mouse heart. The functionality of both proteins in heart cells is still unclear. In cardiac tissue homogenates derived from caveolin-1 deficient mice (cav-1(-/-)), an increase of the P2Xrx7 mRNA and P2X7R protein (80 kDa) was found, particularly in atrial samples. In addition, P2rx7(-/-) mice showed enhanced protein levels of caveolin-1 in their atrial tissues. Although the details of cellular mechanisms that underlie the relationship between caveolin-1 and P2X7R in atrial cardiomyocytes and the electrophysiological consequences of the increased P2X7R expression in atrial cells of cav-1(-/-) mice remain to be elucidated, the cardiomyopathy detectable in cav-1(-/-) mice is possibly related to a disturbed crosstalk between P2X7R and caveolin-1 in different heart cell populations.
Subject(s)
Caveolin 1/deficiency , Heart Atria/cytology , Myocytes, Cardiac/metabolism , Receptors, Purinergic P2/biosynthesis , Receptors, Purinergic P2/genetics , Animals , Blotting, Western , Female , Immunohistochemistry , Mice , RNA, Messenger/genetics , Receptors, Purinergic P2X7 , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
UNLABELLED: Heparin-induced thrombocytopenia (HIT II) in childhood is rare. Suspected HIT II requires immediate diagnostic and therapeutic measures in order to avoid potentially life threatening complications. Heparin must be stopped immediately. We report on a 6-year old boy who required cardiac surgery due to tetralogy of Fallot. To our knowledge he had been exposed to heparin for the first time during cardiac catheterization on the day before surgery. Preoperatively, platelet count was normal. Postoperatively (3 days after heparin exposure), he developed pulmonary and renal failure and required inotropic cardiac support and dialysis. He also developed progressive (severe) thrombocytopenia under heparin therapy on day 2-3 postoperatively. The dialysis filter required daily exchanges due to clotting despite increasing heparin doses. The first ELISA for HIT on postop day 4 was negative. 3 days later a repeated test was positive. Von Willebrand factor antigen and D-dimers were markedly increased. The patient was immediately switched to lepirudin and subsequently stabilized slowly. No major systemic thrombosis occurred. After lepirudin treatment for 6 weeks the patient was fully recovered and HIT II-testing was negative again. CONCLUSION: In children with progressive thrombocytopenia in the setting of heparin exposure and signs of major or micro thrombosis HIT II must be ruled out. Even if a first early test turns out negative repeated testing should be performed. Lepirudin anticoagulation is effective and should be monitored correctly. Platelet transfusion should be avoided in HITII.
Subject(s)
Anticoagulants/therapeutic use , Heparin/adverse effects , Tetralogy of Fallot/surgery , Thrombocytopenia/chemically induced , Thrombocytopenia/drug therapy , Child , Hirudins , Humans , Male , Postoperative Period , Recombinant Proteins/therapeutic use , Treatment OutcomeABSTRACT
P2X(4) and P2X(7) receptors are abundantly expressed in alveolar epithelial cells, and are thought to play a role in regulating fluid haemostasis. Here, we analyzed the expression and localization of the P2X(4)R, and characterized the interaction between Cav-1 and both P2X(4)R and P2X(7)R in the mouse alveolar epithelial cell line E10. Using the biotinylation assay, we found that only glycosylated P2X(4)R is exposed at the cell surface. Triton X-100 solubility experiments and sucrose gradient centrifugation revealed that P2X(4)R was partially localized in Cav-1 rich membrane fractions. Cholesterol depletion with Mbeta-CD displaced Cav-1 and P2X(4)R from the low-density to the high-density fractions. Suppression of Cav-1 protein expression using short hairpin RNAs resulted in a large reduction in P2X(4)R levels. Double immunofluorescence showed that P2X(4)R and Cav-1 partially colocalize in vitro. Using the GST pull-down assay, we showed that Cav-1 interacts in vitro with both P2X(4)R and P2X(7)R. Co-immunoprecipitation experiments confirmed the interaction between P2X(7)R and Cav-1. ATP stimulation increased the level of P2X(4)R in the lipid raft/caveolae fraction, whereas Cav-1 content remained constant. Our results support recent evidence that P2X receptors are present in both raft and non-raft compartments of the plasma membrane and thus exhibit variable ATP sensitivity.
Subject(s)
Caveolin 1/metabolism , Epithelial Cells/metabolism , Lung/cytology , Pulmonary Alveoli/cytology , Receptors, Purinergic P2/metabolism , Adenosine Triphosphate/pharmacology , Animals , Caveolae/drug effects , Caveolae/metabolism , Cell Line , Cholesterol/deficiency , Down-Regulation/drug effects , Epithelial Cells/cytology , Epithelial Cells/drug effects , Glycosylation/drug effects , Membrane Microdomains/metabolism , Mice , Protein Binding/drug effects , Protein Processing, Post-Translational/drug effects , Protein Transport/drug effects , Pulmonary Alveoli/metabolism , RNA, Small Interfering/metabolism , Receptors, Purinergic P2X4 , Receptors, Purinergic P2X7 , beta-Cyclodextrins/pharmacologyABSTRACT
In tooth development matrix metalloproteinases (MMPs) are under the control of several regulatory mechanisms including the upregulation of expression by inducers and downregulation by inhibitors. The aim of the present study was to monitor the occurrence and distribution pattern of the extracellular matrix metalloproteinase inducer (EMMPRIN), the metalloproteinases MMP-2 and MT1-MMP and caveolin-1 during the cap and bell stage of rat molar tooth germs by means of immunocytochemistry. Strong EMMPRIN immunoreactivity was detected on the cell membranes of ameloblasts and cells of the stratum intermedium in the bell stage of the enamel organ. Differentiating odontoblasts exhibited intense EMMPRIN immunoreactivity, especially at their distal ends. Caveolin-1 immunoreactivity was evident in cells of the internal enamel epithelium and in ameloblasts. Double immunofluorescence studies revealed a focal co-localization between caveolin-1 and EMMPRIN in ameloblastic cells. Finally, western blotting experiments demonstrated the expression of EMMPRIN and caveolin-1 in dental epithelial cells (HAT-7 cells). A substantial part of EMMPRIN was detected in the detergent-insoluble caveolin-1-containing low-density raft membrane fraction of HAT-7 cells suggesting a partial localization within lipid rafts. The differentiation-dependent co-expression of MMPs with EMMPRIN in the enamel organ and in odontoblasts indicates that EMMPRIN takes part in the induction of proteolytic enzymes in the rat tooth germ. The localization of EMMPRIN in membrane rafts provides a basis for further investigations on the role of caveolin-1 in EMMPRIN-mediated signal transduction cascades in ameloblasts.
Subject(s)
Basigin/analysis , Caveolin 1/biosynthesis , Epithelial Cells/metabolism , Matrix Metalloproteinases/biosynthesis , Membrane Microdomains/metabolism , Tooth Germ/chemistry , Animals , Basigin/biosynthesis , Blotting, Western , Caveolin 1/analysis , Caveolin 1/metabolism , Cell Differentiation/physiology , Cell Line , Cells, Cultured , Electrophoresis, Polyacrylamide Gel , Epithelial Cells/cytology , Epithelial Cells/ultrastructure , Female , Immunohistochemistry , Male , Matrix Metalloproteinases/metabolism , Membrane Microdomains/ultrastructure , Rats , Rats, Wistar , Tooth Germ/cytology , Tooth Germ/ultrastructureABSTRACT
The P2X7 receptor has recently been described as a marker for lung alveolar epithelial type I cells. Here, we demonstrate both the expression of P2X7 protein and its partition into lipid rafts in the mouse lung alveolar epithelial cell line E10. A significant degree of colocalization was observed between P2X7 and the raft marker protein Caveolin-1; also, P2X7 protein was associated with caveolae. A marked reduction in P2X7 immunoreactivity was observed in lung sections prepared from Caveolin-1-knockout mice, indicating that Caveolin-1 expression was required for full expression of P2X7 protein. Indeed, suppression of Caveolin-1 protein expression in E10 cells using short hairpin RNAs resulted in a large reduction in P2X7 protein expression. Our data demonstrate a potential interaction between P2X7 protein and Caveolin-1 in lipid rafts, and provide a basis for further functional and biochemical studies to probe the physiologic significance of this interaction.
Subject(s)
Caveolin 1/metabolism , Epithelial Cells/metabolism , Membrane Microdomains/metabolism , Pulmonary Alveoli/metabolism , Receptors, Purinergic P2/metabolism , Respiratory Mucosa/metabolism , Animals , Cell Line , Cryoelectron Microscopy , Lung/cytology , Lung/metabolism , Membrane Microdomains/ultrastructure , Mice , Pulmonary Alveoli/cytology , Receptors, Purinergic P2X7 , Respiratory Mucosa/cytologyABSTRACT
Immunohistochemical and in vitro studies indicate that caveolin-1, which occurs abundantly in alveolar epithelial type I cells and microvascular endothelial cells of the lung, is selectively downregulated in the alveolar epithelium following exposure to bleomycin. Bleomycin is also known to enhance the expression levels of metalloproteinases and of the metalloproteinase inducer CD147/EMMPRIN in lung cells. Experimental in vitro data has showed that MMP-inducing activity of CD147 is under the control of caveolin-1. We studied the effects of bleomycin on the expression of caveolin-1, CD147 and metalloproteinases using an alveolar epithelial rat cell line R3/1 with properties of both alveolar type I and type II cells and explanted rat lung slices. In parallel, retrospective samples of bleomycin-induced fibrosis in rats and mice as well as samples of wild type and caveolin-1 knockout animals were included for immunohistochemical comparison with in vitro data. Here we report that treatment with bleomycin downregulates caveolin-1 and increases CD147 and MMP-2 and -9 expression/activity in R3/1 cells using RT-PCR, Western blot analysis, MMP-2 activity assay and immunocytochemistry. Immunofluorescence double labeling revealed that caveolin-1 and CD147 were not colocalized in vitro. The in vitro findings were confirmed through immunohistochemical studies of the proteins in paraffin embedded precision-cut rat lung slices and in fibrotic rat lung tissues. The caveolin-1-negative hyperplastic ATII cells exhibited enhanced immunoreactivity for CD147 and MMP-2. Caveolin-1-negative ATI cells of fibrotic samples were mostly CD147 negative. There were no differences in the pulmonary expression of CD147 between the normal and caveolin-1 deficient animals. The results demonstrate that bleomycin-induced lung injury is associated with an increase in CD147 expression and MMP activity, particularly in alveolar epithelial cells. In addition, our data exclude any functional interaction between CD147 and alveolar epithelial caveolin-1.
Subject(s)
Basigin/physiology , Caveolin 1/physiology , Pulmonary Fibrosis/physiopathology , Animals , Bleomycin , Cell Line , Down-Regulation , Matrix Metalloproteinase 2/biosynthesis , Matrix Metalloproteinase 9/biosynthesis , Pulmonary Fibrosis/chemically induced , Rats , Rats, Wistar , Up-RegulationABSTRACT
Two alveolar epithelial cell lines R3/1 and L2 were screened by immunocytochemical and RT-PCR analysis of epithelial and mesenchymal/contractile marker proteins. R3/1 and L2 cells were tested for their sensitivity to bleomycin (BLM), an anticancer drug, which is proposed to induce changes in lung cell differentiation. Both epithelial cell lines exhibited a mixed phenotype consisting of epithelial (E-cadherin, aquaporin-5 and cytokeratin 8) and myofibroblast-like (vimentin, alpha-SMA and caveolin-3) properties suggesting that the cell lines are arrested in vitro at a certain developmental stage during epithelial-mesenchymal transition (EMT). BLM treatment of R3/1 cells resulted in a partial reversal of this process modifying the cells in an epithelial direction, e.g., upregulation of E-cadherin, aquaporin-5 and other lung epithelial antigens at the mRNA and protein level. L2 cells showed similar alterations following BLM exposure.Immunohistochemical investigation of lung tissue from two different animal models of BLM-induced fibrosis (mouse and rat), revealed no signs of EMT, e.g., myofibroblastic differentiation of alveolar epithelial cells in situ. Immunohistological analysis of tissue samples of the rat model showed a heterogeneous population of myofibroblasts (alpha-SMA+/caveolin-3+, alpha-SMA-/caveolin-3+, and alpha-SMA+/caveolin-3-). These results suggest that BLM, on one hand, induces fibrosis and on the other hand possibly suppresses EMT during fibrogenesis.