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Despite advances in the treatment of heart failure in recent years, options for patients are still limited and the disease is associated with considerable morbidity and mortality. Modulating cyclic guanosine monophosphate levels within the natriuretic peptide signaling pathway by inhibiting PDE9A has been associated with beneficial effects in preclinical heart failure models. We herein report the identification of BAY-7081, a potent, selective, and orally bioavailable PDE9A inhibitor with very good aqueous solubility starting from a high-throughput screening hit. Key aspect of the optimization was a switch in metabolism of our lead structures from glucuronidation to oxidation. The switch proved being essential for the identification of compounds with improved pharmacokinetic profiles. By studying a tool compound in a transverse aortic constriction mouse model, we were able to substantiate the relevance of PDE9A inhibition in heart diseases.

Micro-RNAs (miRNAs) are regulators of gene expression and play an important role in physiological homeostasis and disease. In biofluids, miRNAs can be found in protein complexes or in extracellular vesicles (EVs). Altered urinary miRNAs are reported as potential biomarkers for chronic kidney disease (CKD). In this context, we compared established urinary protein biomarkers for kidney injury with urinary miRNA profiles in obese ZSF1 and hypertensive renin transgenic rats. Additionally, the benefit of urinary EV enrichment was investigated in vivo and the potential association of urinary miRNAs with renal fibrosis in vitro. Kidney damage in both rat models was confirmed by histopathology, proteinuria, and increased levels of urinary protein biomarkers. In total, 290 miRNAs were elevated in obese ZSF1 rats compared with lean controls, whereas 38 miRNAs were altered in obese ZSF1 rats during 14–26 weeks of age. These 38 miRNAs correlated better with disease progression than established urinary protein biomarkers. MiRNAs increased in obese ZSF1 rats were associated with renal inflammation, fibrosis, and glomerular injury. Eight miRNAs were also changed in urinary EVs of renin transgenic rats, including one which might play a role in endothelial dysfunction. EV enrichment increased the number and detection level of several miRNAs implicated in renal fibrosis in vitro and in vivo. Our results show the benefit of EV enrichment for miRNA detection and the potential of total urine and urinary EV-associated miRNAs as biomarkers of altered kidney physiology, renal fibrosis and glomerular injury, and disease progression in hypertension and obesity-induced CKD.

Graphical abstract Chronic kidney diseaQueryse (CKD) is associated with oxidative stress which can interrupt the nitric oxide (NO)/soluble guanylyl cyclase (sGC) signaling and decrease cyclic guanosine monophosphate (cGMP) production. Low cGMP concentrations can cause kidney damage and progression of CKD. The novel sGC activator runcaciguat targets the oxidized and heme-free form of sGC, restoring cGMP production under oxidative stress. The purpose of this study is to investigate if runcaciguat could provide an effective treatment for CKD. Runcaciguat was used for the treatment not only in rat CKD models with different etiologies and comorbidities, namely of hypertensive rats, the renin transgenic (RenTG) rat, and angiotensin-supplemented (ANG-SD) rat, but also in rats with diabetic and metabolic CKD, the Zucker diabetic fatty (ZDF) rat. The treatment duration was 2 to 42 weeks and runcaciguat was applied orally in doses from 1 to 10 mg/kg/bid. In these different rat CKD models, runcaciguat significantly reduced proteinuria (urinary protein to creatinine ratio; uPCR). These effects were also significant at doses which did not or only moderately decrease systemic blood pressure. Moreover, runcaciguat significantly decreased kidney injury biomarkers and attenuated morphological kidney damages. In RenTG rats, runcaciguat improved survival rates and markers of heart injury. These data demonstrate that the sGC activator runcaciguat exhibits cardio-renal protection at doses which did not reduce blood pressure and was effective in hypertensive as well as diabetic and metabolic CKD models. These data, therefore, suggest that runcaciguat, with its specific mode of action, represents an efficient treatment approach for CKD and associated CV diseases. Supplementary Information The online version contains supplementary material available at 10.1007/s00210-021-02149-4.

The small-scale impact of submerged vegetation (locally enhanced water transparency) on abiotic / biotic parameters was studied in a shallow (

In shallow aquatic ecosystems, wave-induced water motions affect the whole water column down to the sediment. To estimate the influence of these motions on short-term sedimentation rates (SR) in a shallow wind-exposed lagoon, we used plate traps (PTs) which, in contrast to cylindrical traps (CTs), allow trapped matter to become resuspended. In a series of experiments, we varied distance to the sediments, water depth, incubation time, and studied the SRs of total suspended matter and of suspended organic matter at varying conditions of wave exposure. The coefficient of variation of SRs did not change with incubation time. While SRs were similar on both trap types at very low wave exposure, they decreased with increasing wave exposure on the PTs probably due to instantaneous resuspension. In the CTs, SRs increased with increasing wave exposure. This resulted in about 55 times higher SRs in the CTs than on the PTs at high wave exposure. We conclude that CTs are not suitable to estimate natural SRs in wave-affected waters as they overestimate SRs. Our results indicate that SR obtained by PTs, which were here used for the first time in a wind-exposed, non-tidal ecosystem, are a far better estimate for natural short-term SRs.

By performing an in vivo screen in Drosophila melanogaster, Scholz, Ehmann, et al. identify Complexin as a functional interaction partner of Bruchpilot. The two proteins mediate a physical attachment of synaptic vesicles to the active zone cytomatrix and promote rapid, sustained synaptic transmission., Information processing by the nervous system depends on neurotransmitter release from synaptic vesicles (SVs) at the presynaptic active zone. Molecular components of the cytomatrix at the active zone (CAZ) regulate the final stages of the SV cycle preceding exocytosis and thereby shape the efficacy and plasticity of synaptic transmission. Part of this regulation is reflected by a physical association of SVs with filamentous CAZ structures via largely unknown protein interactions. The very C-terminal region of Bruchpilot (Brp), a key component of the Drosophila melanogaster CAZ, participates in SV tethering. Here, we identify the conserved SNARE regulator Complexin (Cpx) in an in vivo screen for molecules that link the Brp C terminus to SVs. Brp and Cpx interact genetically and functionally. Both proteins promote SV recruitment to the Drosophila CAZ and counteract short-term synaptic depression. Analyzing SV tethering to active zone ribbons of cpx3 knockout mice supports an evolutionarily conserved role of Cpx upstream of SNARE complex assembly.

Long-term and interannual changes in composition of submerged vegetation, diaspore reservoir and germination were investigated in the lagoon system Westrugensche Boddenkette, Baltic Sea, north-east Germany. Comparison with a survey from 1932, showed vegetation cover is similar to the past, maintaining high cover to depths of 2.8 m despite a period of eutrophication between about 1960 and 1990. Species dominance shifted, however, from small charophytes to larger species like Potamogeton pectinatus. We explain interannual vegetation changes by weather conditions. Such changes were observed in several species, most notably in Chara canescens. This annual species seems to be favoured by extensive winter ice cover. The diaspore reservoir and the germination success of submerged macrophytes do not mirror their frequency in the vegetation, but rather reflect life form strategies. Small oospores, mainly of annual charophytes, represented >97% of all diaspores but very few Chara oospores germinated. The numerous Tolypella oospores probably originated from a discrete period with high abundance during the 1950s and have completely failed to germinate. Angiosperm seeds are larger and less frequent but have higher germination success, especially Ruppia seeds. In conclusion, charophytes are outcompeted by larger angiosperms due to the combined effect of moderate eutrophication and climate change.

Aims Prostaglandin E2 (PGE2) has been shown to mediate anti-ischaemic effects and cardiomyocyte hypertrophy and there is evidence for an involvement of the prostaglandin EP3-receptor subtype. This study focuses on the EP3-mediated hypertrophic action and investigates intracellular signalling pathways of the EP3-receptor subtype in the murine heart. Methods and results Cardiac function was analyzed in vivo by magnetic resonance imaging (MRI) in transgenic (tg) mice with cardio-specific overexpression of the EP3 receptor in comparison with wild-type (wt) mice. Left ventricular (LV) function was determined in isolated perfused hearts subjected to 60 min of zero-flow ischaemia and 45 min of reperfusion. Calcineurin activity and nuclear activity of nuclear factor of activated T-cells (NFAT) were determined by a modified malachite green assay and ELISA, respectively. Extracellular matrix compounds were analyzed by RT–PCR and histology. MRI indicated a significant increase in end-diastolic and end-systolic volume in tg hearts. LV ejection fraction was severely decreased in tg hearts while the relative LV mass was significantly increased. In Langendorff perfused hearts, EP3-receptor overexpression resulted in a marked blunting of the ischaemia-induced increase in LV end-diastolic pressure and creatine kinase release. Analysis of EP3-receptor-mediated signalling revealed significantly increased calcineurin activity and nuclear activity of NFAT in tg hearts. Moreover, elevated mRNA levels of collagen types I and III as well as the collagen-binding proteoglycans biglycan and decorin were detected in tg hearts. Conclusion EP3-receptor-mediated signalling results in a significant anti-ischaemic action and activation of the pro-hypertrophic calcineurin signalling pathway, suggesting the involvement of the EP3 subtype in both PGE2-mediated cardioprotection as well as cardiac hypertrophy.

Background: Cyclooxygenase-2 (COX-2), the inducible isoform of the cyclooxygenases, is upregulated in various inflammatory renal diseases and responsible for prostaglandin formation. As prostaglandins are known to influence cell adhesion processes, we investigated the effect of COX-2 inhibition on the expression of αv integrins, which are also enhanced in renal diseases and control the adherence between the endothelium and the extracellular matrix (ECM) in the glomerulus. Methods: Healthy female Wistar rats and animals with previously induced passive Heymann nephritis (PHN) received either 5 mg/kg body weight/day celecoxib or a placebo. After 28 days, renal cortical mRNA expression of COX-2 and αv integrin subunits was determined. Results: Rats with PHN showed a significant 1.7-fold increase in renal cortical mRNA expression of αv integrin subunits. Treatment with celecoxib increased cortical αv integrin mRNA expression 2.2-fold (p < 0.05) in healthy animals and 4.0-fold (p < 0.05) in rats with PHN, but lowered COX-2 mRNA expression in rats with PHN to 0.8-fold (p < 0.05). An inverse correlation between the expression of COX-2 and αv integrins in rats with PHN was demonstrated. Conclusions: It is suggested that COX-2-derived prostaglandins suppress the expression of αv integrins. This implies a previously unknown role for COX-2 in chronic inflammation in the kidney.

Migration and proliferation of medial smooth muscle cells (SMC) in the arterial intima contributes to the development of atherosclerotic plaques and restenotic processes after coronary angioplasty. Prostacyclin (PGI 2 )-mediated stimulation of cyclic adenosine 3′5′-monophosphate (cAMP) signaling is believed to be important for maintaining SMC in a quiescent state. In order to identify new cellular targets of PGI 2 /cAMP action, we have used microarray screening to examine changes in the transcriptional profile in human vascular SMC in response to exposure to the stable PGI 2 mimetic iloprost. We have identified 83 genes with significantly altered expression after iloprost (100 nM) exposure for 6 hr. Fifty-one genes were upregulated, among them stanniocalcin precursor (18.8±2.7), zinc finger transcription factor (7.8±2.0), hyaluronan synthase 2 (6.8±1.8), cyclooxygenase 2 (4.7±0.8), dual specific phosphatase (3.9±0.5) and vascular endothelial growth factor (2.3±0.4). Thirty-two genes were reduced, among them cystein-rich angiogenic protein (−14.9±1.3), monocyte chemotactic protein 1 (−7.4±1.1) and plasminogen activator inhibitor PAI-1 (−4.5±0.5). By means of semi-quantitative RT-PCR, time-courses of gene expression were established. The present study identified genes not hitherto recognized to be targets of PGI 2 action, providing further insight into its cAMP-mediated effects on SMC growth, migration and matrix secretion.

Small RNAs ranging in size between 20 and 30 nucleotides are involved in different types of regulation of gene expression including mRNA degradation, translational repression, and chromatin modification. Here we describe the small RNA profile of Drosophila melanogaster as a function of development. We have cloned and sequenced over 4000 small RNAs, 560 of which have the characteristics of RNase III cleavage products. A nonredundant set of 62 miRNAs was identified. We also isolated 178 repeat-associated small interfering RNAs (rasiRNAs), which are cognate to transposable elements, satellite and microsatellite DNA, and Suppressor of Stellate repeats, suggesting that small RNAs participate in defining chromatin structure. rasiRNAs are most abundant in testes and early embryos, where regulation of transposon activity is critical and dramatic changes in heterochromatin structure occur.

Prostacyclin and its mimetics have repeatedly been shown to act antiatherogenic and to inhibit neointima formation in several animal models of vascular injury. Treatment of human vascular smooth muscle cells with the prostacyclin mimetic iloprost (100 nm) drastically reduces expression of Cyr61, encoding the growth-regulatory cystein-rich angiogenic protein, without affecting the degradation rate of Cyr61 mRNA. Thrombin-induced Cyr61 expression was inhibited completely in the presence of iloprost. It is concluded that vasoprotective actions of prostacyclin in vivo may in part be due to inhibition of expression of the growth regulatory gene Cyr61 at sites of vascular lesions.

Persistent stimulation of the Gs protein-coupled prostacyclin receptor (IP-R) causes its slow desensitization in a variety of cell types, a significant desensitization requiring several hours. To evaluate the role of the human IP-R C-terminus in desensitization and agonist-induced internalization, a C-terminally truncated hIP-receptor was generated. The C-terminal 68 amino acid residues were deleted by introduction of a stop codon for exchange of the original S319 codon (termed D318 mutant). Wild-type (WT) and truncated receptor were expressed in COS1 cells. Pretreatment of cells with the stable prostacyclin mimetic cicaprost (200 nM) desensitized cAMP production via WT and D318 receptors to similar extents. The cAMP response of WT and D318, respectively, was reduced by approximately 50% of maximal cAMP formation after 8 hr of continuous agonist stimulation, indicating significant long-term desensitization. Moreover, agonist-promoted sequestration of WT and D318 C-terminally tagged with green fluorescent protein was demonstrated, indicating that receptor internalization was not prevented by truncation of the C-terminus. These results demonstrated that long-term desensitization and sequestration of hIP-R did not depend on structures located in the hIP-R C-terminus.

Prostaglandin-endoperoxide synthase-2 (PGH-synthase) or cyclooxygenase-2 (COX-2) is inducible by a variety of stimuli, e.g. inflammatory mediators, growth factors and hormones and is believed to be responsible for the majority of inflammatory prostanoid production. Moreover, it has been demonstrated that COX-2 contributes substantially to prostacyclin-synthesis in patients with atherosclerosis. In this study, we demonstrate an up-regulation of COX-2 mRNA, protein and product formation by the prostacyclin-mimetic iloprost in human vascular smooth muscle cells (hSMC). COX-2 mRNA expression was induced transiently between 1 and 6 hr and returned to basal levels after 16 hr of iloprost stimulation. COX-2 protein was induced concomitantly between 3 and 6 hr of iloprost stimulation. This was accompanied by an increase in PGI 2 formation. Forskolin, a direct activator of adenylyl cyclase, and dibutyryl cAMP, a cell-permeable cAMP analogue-induced COX-2 mRNA, suggesting a cAMP-dependent COX-2 expression in hSMC. Iloprost-induced COX-2 protein expression and PGI 2 formation was synergistically elevated by co-stimulation with the phorbolester PMA (phorbol-12-myristate-13-acetate). It is concluded, that the observed up-regulation of COX-2 with subsequent release of newly synthesized PGI 2 and the synergistic effect of iloprost and phorbolester on PGI 2 formation provide a positive feedback of prostaglandins on their own synthesizing enzyme. This might be important for control of hSMC proliferation, migration and differentiation as well as inhibition of platelet aggregation.

Background — Cyclooxygenase-2 (COX-2) plays a key role in human inflammatory disorders such as vascular inflammation. COX-2 promoter activity is induced by proinflammatory mediators, but the role of cyclic adenosine monophosphate response element (CRE) in promoter stimulation remains unclear. Methods and Results — Transient transfection of a 0.9-kb COX-2 promoter fragment bearing CRE mutation abrogated COX-2 promoter activity induced by proinflammatory mediators in human endothelial cells and fibroblasts. Dual mutations of CRE and an upstream CCAAT/enhancer binding protein (C/EBP) site did not have an additional effect. Binding of CREB-2, ATF-2, USF-2, and c-Jun transactivators to a wild-type and CRE-mutated oligonucleotide was analyzed by a novel DNA-binding assay. CREB-2 and ATF-2 in nuclear extracts of unstimulated endothelial cells bound to CRE, whereas USF-2 and c-Jun or c-Fos bound to non-CRE sites. CREB-2 and c-Fos binding was increased by phorbol 12-myristate 13-acetate but not tumor necrosis factor-α. The binding assay and chromatin immunoprecipitation revealed binding of P300 coactivator to the COX-2 promoter region. Conclusions — CRE plays an obligatory role in COX-2 promoter activation by diverse stimuli. CREB-2 and ATF-2 bound to CRE serve as an anchor for P300 interaction with upstream transactivators and downstream transcription machinery.

Bullous pemphigoid (BP), pemphigoid (herpes) gestationis (PG), cicatricial pemphigoid (CP), and lichen planus pemphigoides (LPP) are autoimmune subepidermal bullous diseases that are characterized by circulating autoantibodies to the transmembrane hemidesmosomal protein BP180/type XVII collagen. Previous studies demonstrated that the majority of patients with BP, PG, and LPP show antibodies to an immunodominant, membrane-proximal non-collagenous domain (NC16A) on the extracellular portion of BP180. By the use of non-overlapping peptides of the NC16A domain, we previously demonstrated that autoantibodies from BP and PG patients mainly react with epitopes clustered within the N-terminus of this immunodominant site of BP180; antibodies from patients with LPP also recognized the C-terminal portion of NC16A. However, some of these results had been obtained indirectly by preadsorption studies. The aim of the present study was to analyze the fine specificity of IgG autoantibodies to NC16A in sera from patients with CP and to compare their reactivity with antibodies from BP, PG, and LPP patients using a series of new overlapping fragments covering the entire NC16A domain. We confirm that BP and PG sera mainly react with N-terminal epitopes of NC16A, whereas sera from patients with LPP also bind to C-terminal portions, of this domain. Interestingly, out of ten patients with CP, the sera of seven reacted with NC16A; within NC16A, these sera bound to both C-terminal fragments and an N-terminal epitope right next to the cell membrane. Our data demonstrate a heterogeneous binding pattern of autoantibodies to BP180 NC16A in patients with CP.

Moxifloxacin is a new broad-spectrum antibacterial agent for treatment of respiratory tract infection of pathogens, including the major pathogens isolated in respiratory tract infections. The pharmacokinetic and pharmacodynamic properties of moxifloxacin are: excellent bioavailability, long half-life, and superior tissue penetration. Consequently, the 90% minimum inhibitory concentration (MIC(90)) values exhibited by moxifloxacin are generally lower than the concentrations of moxifloxacin found in circulation and in pulmonary tissues after a standard 400-mg dose given for up to 30 h. The relationship between moxifloxacin MIC(90) values and clinical response was investigated. The results of 13 clinical trials, performed in 30 countries between 1997 and 1998 and comprising 2618 patients treated with moxifloxacin or a comparator drug, were reviewed. Overall, 94% clinical success and 95% bacterial eradication was observed with moxifloxacin. These results were equivalent or superior to results seen with the comparator drugs. Clinical response rates and bacterial eradication rates with moxifloxacin were not significantly affected by bacterial resistance to other antibiotics (i.e., penicillin, clarithromycin, or amoxicillin). The majority (89%-97%) of the different bacterial strains with MICs for moxifloxacin < or =2 mg/L were successfully eradicated. In conclusion, moxifloxacin has potent in vivo bactericidal activity, and pathogen sensitivity to moxifloxacin is in accordance with US Food and Drug Administration and European suggested breakpoint values.

For the EP 3 subtype of prostaglandin E receptors, different C-terminal splice variants are known, which are coupled to distinct heterotrimeric GTP-binding proteins (G-proteins). To test the hypothesis that the C-terminal domain is essential for the G-protein-coupling specificity of the EP 3 receptor, we exchanged the carboxyl-terminal tail of a porcine G i -coupled EP 3 receptor isoform for the corresponding C-terminal part of a G s -coupled prostaglandin receptor. The porcine EP 3 receptor was truncated at a lysine (K 350 ) residue at the end of the seventh transmembrane region, representing the splicing site of the different EP 3 receptor isoforms. The wild-type C-terminus (37 amino acids) was substituted by the C-terminal tail (89 amino acids) of the human I-type prostaglandin receptor (hIP-R). The G-protein coupling of the resulting chimeric receptor protein was studied in transfected Chinese hamster ovary (CHO) cells. Stimulation of the chimeric receptor protein with the EP 3 receptor-specific agonist M&B 28.767 did not increase adenosine 3′,5′-cyclic monophosphate (cAMP) formation but did reduce the forskolin-stimulated cAMP formation, indicating G i coupling. Furthermore, the chimeric receptor did not show constitutive activity as demonstrated for the C-terminally truncated EP 3 receptor. Thus, coupling specificity of the EP 3 receptor is not exclusively mediated by the carboxyl-terminal tail, and constitutive activity of a C-terminally truncated EP 3 receptor can be suppressed by the hIP-R C-terminus.

A cDNA clone, encoding a complete porcine EP3 receptor, was isolated from a porcine heart cDNA library. The deduced amino acid sequence revealed a protein of 387 amino acid residues with an estimated molecular weight of 43 kD and strongest homology to the human EP3-II receptor (84% identity on protein level). Ligand binding studies with transfected COS-7 cells, expressing the porcine receptor, showed displacement of [3H]PGE1 with the EP3-specific agonist MB 28.767, the EP1/EP3-agonist sulprostone but not with the EP2-specific agonist butaprost. Stimulation of transfected CHO cells with MB 28.767 resulted in inhibition of forskolin-induced cAMP formation, suggesting coupling to an inhibitory G protein. Agonist-induced translocation of the transcription factor NFkappaB into the nucleus of transfected CHO cells was demonstrated by Western blot analysis, indicating that these EP3 receptors modulate NFkappaB-dependent cellular signal transduction. Analysis of the genomic organization identified the major transcription initiation site at about 160 bp upstream of the ATG start codon. The 800-bp 5' flanking region contains a variety of putative cis-acting regulatory elements, including binding sites for AP2, SP1 and MyoD (E-box). The present data will now allow further studies on EP3 receptor-mediated signal transduction and its regulation.

This study describes the molecular cloning and functional characterization of the bovine thromboxane A2 (TP) receptor. Two partial nucleotide sequences coding for the bovine TP receptor were isolated from a bovine genomic and a bovine heart cDNA library. The deduced amino acid sequence suggests a heptahelical protein of 343 amino acids. The receptor protein is homologous with that of human placenta and endothelium at 84.0% and 81.4%, respectively. COS-7 cells were transfected with the bovine TP receptor cDNA, and binding affinities were assessed by radioligand binding studies. Specific displacement of [3H]SQ 29548 was demonstrated in COS-7 cell membranes with the unlabeled TP receptor antagonist SQ 29548 (Kd = 12.6+/-1.1 nM) and the TP receptor agonist U46619 (Kd = 192.1+/-58.9 nM), but not with other prostaglandins (PGD2, PGE1, PGF2alpha), or the PGI2 mimetic cicaprost. Agonist-induced stimulation of adenylyl cyclase in transfected COS-7 cells indicates a linkage to the cAMP signal transduction pathway via coupling to a stimulatory G-protein. Since bovine cells, e.g. vascular smooth muscle cells, are an established model to study the role of eicosanoids in cell signaling, this report on the molecular structure of the bovine TP receptor will allow further studies on receptor regulation.

Abstract The action of prostacyclin, prostaglandin E 1 (PGE 1 ), and their mimetics on myocardial function includes changes in contractility, electrophysiological properties, and protection from injury caused by transient myocardial ischemia. This study was undertaken to investigate the basic properties of myocardial E-type prostaglandin (EP) receptors. Ligand binding studies using an enriched preparation of sarcolemmal membranes prepared from pig hearts revealed a single class of binding sites for [ 3 H]PGE 1 , with a K d of 3.7 nmol/L and a B max of 92 fmol/mg protein. Competition experiments indicated highest affinity for EPs, suggesting an EP receptor. In addition, the EP receptor subtype–selective agonists sulprostone (EP 1 and EP 3 ) and M&B 28.767 (EP 3 ) were active, suggesting the presence of an EP 3 receptor subtype. PGE 1 stimulated sarcolemmal GTPase and inhibited sarcolemmal adenylyl cyclase activity, indicating EP 3 receptor coupling to an inhibitory G protein (G i ). Additional in vivo experiments showed that intracoronary infusion of PGE 1 (1 nmol/min) decreased isoprenaline-stimulated left ventricular contractile activity without altering systemic vascular resistance. This inhibition of β-adrenergic effects is compatible with the known myocardial anti-ischemic action of prostaglandins. Further experiments examined EP 3 receptor density and G-protein coupling in sarcolemma from ischemic and reperfused ischemic myocardium. In anesthetized open-chest minipigs, occlusion of the left anterior descending coronary artery for 60 minutes increased EP 3 receptor density by 50%, whereas receptor affinity was unchanged. This upregulation was prevented by pretreatment with colchicine (2 mg/kg IV), indicating microtubule-dependent receptor externalization. Northern hybridization showed comparable EP 3 receptor mRNA expression in control and ischemic myocardium. The increase of receptor protein was reversed during 60 minutes of reperfusion. G-protein coupling proved to be intact in ischemic and reperfused ischemic myocardial tissue, as shown by preserved GTP-γ-S–induced decrease of [ 3 H]PGE 1 binding. These data demonstrate for the first time that myocardial receptors for PGE 1 belong to the EP 3 subtype. The properties of this receptor include inhibition of adenylyl cyclase and upregulation during regional myocardial ischemia, suggesting an involvement in the anti-ischemic activity of E- and I-type prostaglandins.

The activated leukocyte cell adhesion molecule (ALCAM/CD166) is associated with cell migration and leukocyte invasion into the vessel wall. This study investigates the impact of cholesterol loading on the expression of ALCAM, as compared with P-selectin glycoprotein ligand-1 (PSGL-1), vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) in monocytic U937 cells and human primary monocytes. Cells were enriched with cholesterol by incubation with a cyclodextrin-cholesterol complex. Expression of adhesion molecules and apoptosis was determined by flow cytometry. Migration was quantified by chemotaxis toward serum. Incubation with cholesterol (10-100 μg/ml) for 16 h caused a concentration-dependent increase in apoptosis. Enhanced apoptosis was associated with reduction of ALCAM by >70%. While PSGL-1 was affected similarly, expression of VCAM-1 was markedly increased by cholesterol and ICAM-1 levels were not regulated. The nonselective caspase/apoptosis inhibitor Q-VD-OPh partially prevented cholesterol-modulated alteration of adhesion molecule expression. Migration of cholesterol-rich monocytic cells toward serum was greatly reduced. This effect was partially restored by Q-VD-OPh and was dependent on ALCAM as shown by ALCAM-neutralizing antibodies. In conclusion, cholesterol-induced apoptosis in monocytes is accompanied by reduced expression of ALCAM and attenuated monocyte migration. This may restrain monocytes at cholesterol-rich sites and thereby expedite vascular lesion formation.

Recently, the mathematical formalism of the Dyson boson mapping has been extended to a system of 3n fermions, leading to the boson–fermion and the baryon mapping. In the present paper, the case of a restriction to a subset of three‐fermion quantum numbers, the collective indices, is discussed. A theory is developed for the representation of fermionic states and operators in a truncated ideal space where only collective boson–fermion pairs or collective ideal baryons are allowed. An exact reproduction of physical properties is proved to be possible provided that the original fermionic problem can be solved in a subspace where all three‐fermion subsystems carry collective indices. Examples of simple applications are presented in the two subsequent papers of this series.

The formalism derived for the boson–fermion and the baryon mapping in Paper I of this series is applied to the single‐orbit quark shell model developed by Petry and co‐workers for the description of nuclear properties. The multiquark space is reduced to the collective subspace of multinucleon states. A collective representation of states and operators in terms of bosons and ideal fermions or in terms of ideal baryons, respectively, is constructed. The results of the original model in the multinucleon space are exactly reproduced. Finally, the two transformations are compared with a related mapping technique recently published by Pittel, Engel, Dukelsky, and Ring.

The theory developed in Paper I of this series is applied to the general case of a system consisting of colorfree quark triplets, whose quantum numbers are chosen as collective trifermion indices. The appropriate mapping technique to be used here is the baryon mapping. It is demonstrated that the original multiquark states can be exactly represented by states of colorfree ideal baryons. Besides, collective extended images are derived for a class of fermionic operators leaving the collective fermion space invariant.

The generalized Dyson boson mapping is extended to multifermion systems containing three‐particle substructures as occurring in nuclear matter. Two different approaches are described. The first one leads to a mapping involving equal numbers of bosons and fermions, where each boson, as usual, represents a fermion pair. The second possibility consists of the introduction of new kinds of fermions carrying the quantum numbers of the original three‐fermion subsystems. Both transformations are nonunitary.

Background— The generation of prostaglandin E 2 (PGE 2 ) is significantly increased in acute myocardial ischemia and reperfusion. PGE 2 , in addition to other prostaglandins, protects the reperfused ischemic myocardium. It has been hypothesized that this cardioprotection is mediated by E-type prostaglandin receptors of the G i -coupled EP 3 subtype. Methods and Results— We tested this hypothesis by generating transgenic (tg) mice with cardiospecific overexpression of the EP 3 receptor. According to ligand binding, a 40-fold overexpression of the EP 3 receptor was achieved in membranes prepared from tg hearts compared with wild-type (wt) littermates. In isolated cardiomyocytes from tg mice, the forskolin-induced rise in cAMP was markedly attenuated, indicating coupling of the overexpressed EP 3 receptor to inhibitory G proteins (G i ) with constitutive receptor activity. There was no evidence for EP 3 receptor coupling to G q -mediated protein kinase C signaling. Isolated hearts from tg and wt mice were subjected to 60 minutes of no-flow ischemia and 45 minutes of reperfusion. In tg hearts, ischemic contracture was markedly delayed compared with wt hearts, and the ischemia-induced increase in left ventricular end-diastolic pressure was reduced by 55%. Creatine kinase and lactate dehydrogenase release was significantly decreased by 85% and 73%, respectively, compared with wt hearts. Conclusions— Constitutive prostaglandin EP 3 receptor signaling exerts a protective effect on cardiomyocytes, which is probably G i mediated and results in a remarkable attenuation of myocardial injury during ischemia and reperfusion. Cardioprotective actions of E-type prostaglandins may be mediated by this receptor subtype.

There is concern that cyclooxygenase (COX)-2 inhibitors may promote atherothrombosis by inhibiting vascular formation of prostacyclin (PGI 2 ) and an increased thrombotic risk of COX-2 inhibitors has been reported. It is widely accepted that the prothrombotic effects of COX-2 inhibitors can be explained by the removal of platelet-inhibitory PGI 2 . Using microarray chip technology, we have previously demonstrated that thrombomodulin (TM) mRNA is upregulated in cultured human coronary artery smooth muscle cells by the stable prostacyclin mimetic iloprost. This study is the first to demonstrate a stimulation of the expression of functionally active thrombomodulin in human smooth muscle cells by prostaglandins, endogenously formed via the COX-2 pathway. Because TM is an important inhibitor of blood coagulation, these findings provide a novel platelet-independent mechanism to explain the prothrombotic effects of COX-2 inhibitors. The full text of this article is available online at http://circres.ahajournals.org.

SummaryThere are two principal cyclooxygenase isoforms referred to as COX-1 and COX-2. Recently, COX-3 has been identified. We have demonstrated the expression of COX-2 in platelets from patients after coronary artery bypass grafting (CABG). Careful biochemical analysis revealed that, when compared to recombinant COX-2, platelet COX-2 had a slightly higher electrophoretic mobility. Two COX-2 sequences (∼1.8 kb, ∼1.7 kb) were cloned from platelet mRNA. The ∼1.7 kb sequence, designated COX-2a, differed from the human COX-2 sequence only in a deletion from position +458 to +567. Similar to the human COX-3, there is a frame shift in the COX-2a sequence resulting in a TAA stop codon at position +490. Thus, the expression of a COX-2a protein corresponding to the 67 kDa COX-2 protein is not clear. However, the marked shifting from COX-2 to COX-2a in platelets from some patients after CABG is a striking finding.

MicroRNAs (miRNAs) represent a new class of noncoding RNAs encoded in the genomes of plants, invertebrates, and vertebrates. MicroRNAs regulate translation and stability of target mRNAs based on (partial) sequence complementarity. Although the number of newly identified miRNAs is still increasing, target mRNAs of animal miRNAs remain to be identified. Here we describe 31 novel miRNAs that were identified by cloning from mouse tissues and the human Saos-2 cell line. Fifty-three percent of all known mouse and human miRNAs have homologs in Fugu rubripes (pufferfish) or Danio rerio (zebrafish), of which almost half also have a homolog in Caenorhabditis elegans or Drosophila melanogaster. Because of the recurring identification of already known miRNAs and the unavoidable background of ribosomal RNA breakdown products, it is believed that not many more miRNAs may be identified by cloning. A comprehensive collection of miRNAs is important for assisting bioinformatics target mRNA identification and comprehensive genome annotation.

Migration of vascular smooth cells from the media to the intima essentially contributes to neointima formation after percutaneous transluminal angioplasty and stent implantation. The stable prostacyclin mimetic iloprost has been shown to inhibit neointima formation in experimental restenosis, but it is currently unknown whether this may be caused by an antimigratory effect. Hence, the present study analyses (i) the influence of G(s)-coupled prostacyclin (IP) receptors on cell migration and (ii) verifies whether EP(3) receptors with opposite (i.e., G(i)) coupling may conversely stimulate cell migration. In a modified Boyden chamber model, it was shown that iloprost dose-dependently inhibits the migration of primary human arterial smooth muscle cells, which constitutively express the IP receptor. On the other hand, human arterial smooth muscle cell migration was stimulated by the EP(3) receptor agonist M&B 28.767. To independently study the effects of these receptors, IP or EP(3) receptors were stably overexpressed in chinese hamster ovary cells (CHO-IP and CHO-EP(3)). Chemotaxis of CHO cells transfected with G(s)-coupled IP receptors was concentration-dependently inhibited by iloprost (2-100 nM), while there was no effect of iloprost on mock-transfected CHO. By contrast, CHO-cells that overexpressed EP(3) receptors showed a significant, concentration dependent (1-100 nM) increase of cell migration in presence of the selective EP(3) agonist M&B 28.767. It is concluded that the prostacyclin mimetic iloprost inhibits vascular cell migration, which probably depends on a G(s)-mediated increase of intracellular cAMP. EP(3) receptors conversely stimulate CHO migration.

Background: Nitric oxide (NO) is an important mediator of inflammatory processes, including macrophage-mediated cellular host defense, and is found to be increased in peritonitis. The ability of human mononuclear cells to contribute to the NO production by expression of active inducible NO synthase (iNOS) is still discussed controversely. Aims: This study was designed to investigate the influence of prostacyclin receptor (IP receptor) activation on iNOS expression and NO formation in human peripheral blood monocytes. Method and Results: Using reverse transcriptase-polymerase chain reaction, we demonstrated that human monocytes express high levels of IP receptor mRNA. Stimulation of monocytes with the IP receptor selective agonist cicaprost (100 nM) significantly induced cellular cyclic adenosine monophosphate formation, indicating functional coupling of the receptor to Gs. Treatment of cells with lipopolysaccharide (LPS)/interferon gamma (IFN-γ) further enhanced the IP receptor mRNA expression 2.7 ± 0.1-fold above basal levels (n = 6). Analysis of iNOS expression revealed barely detectable mRNA levels in unstimulated monocytes which were increased 3.75 ± 0.3-fold (n = 5) after costimulation with 1 µg/ml LPS and 250 U/ml INF-γ for 16 h. Further increases of iNOS mRNA expression (9.4 ± 0.9-fold above basal, n = 5) were obtained, if the monocytes were costimulated with 1 µg/ml LPS, 250 U/ml INF-γ, and 100 nM cicaprost for 16 h. Measurement of the NO generation correlated with the polymerase chain reaction data: treatment of cells with 1 µg/ml LPS plus 250 U/ml INF-γ increased the NO2 production to 2.6 µM, being above the basal level of 2.0 µM, as determined in the cell culture medium. Additional treatment with 100 nM cicaprost further significantly increased the NO2 production to 3.43 µM. Conclusions: An IP receptor mediated increase in cyclic adenosine monophosphate formation plays an important role in enhancing LPS/IFN-γ-induced iNOS expression in human monocytes/macrophages and may, therefore, contribute to the increased production of NO during peritonitis.

MicroRNAs (miRNAs) are a new class of noncoding RNAs, which are encoded as short inverted repeats in the genomes of invertebrates and vertebrates [1, 2]. It is believed that miRNAs are modulators of target mRNA translation and stability, although most target mRNAs remain to be identified. Here we describe the identification of 34 novel miRNAs by tissue-specific cloning of approximately 21-nucleotide RNAs from mouse. Almost all identified miRNAs are conserved in the human genome and are also frequently found in nonmammalian vertebrate genomes, such as pufferfish. In heart, liver, or brain, it is found that a single, tissue-specifically expressed miRNA dominates the population of expressed miRNAs and suggests a role for these miRNAs in tissue specification or cell lineage decisions. Finally, a miRNA was identified that appears to be the fruitfly and mammalian ortholog of C. elegans lin-4 stRNA.

Cyclooxygenase-2 (COX-2), the inducible isoform of the cyclooxygenases, is upregulated in various inflammatory renal diseases and responsible for prostaglandin formation. As prostaglandins are known to influence cell adhesion processes, we investigated the effect of COX-2 inhibition on the expression of alpha(v) integrins, which are also enhanced in renal diseases and control the adherence between the endothelium and the extracellular matrix (ECM) in the glomerulus.Healthy female Wistar rats and animals with previously induced passive Heymann nephritis (PHN) received either 5 mg/kg body weight/day celecoxib or a placebo. After 28 days, renal cortical mRNA expression of COX-2 and alpha(v) integrin subunits was determined.Rats with PHN showed a significant 1.7-fold increase in renal cortical mRNA expression of alpha(v) integrin subunits. Treatment with celecoxib increased cortical alpha(v) integrin mRNA expression 2.2-fold (p0.05) in healthy animals and 4.0-fold (p0.05) in rats with PHN, but lowered COX-2 mRNA expression in rats with PHN to 0.8-fold (p0.05). An inverse correlation between the expression of COX-2 and alpha(v) integrins in rats with PHN was demonstrated.It is suggested that COX-2-derived prostaglandins suppress the expression of alpha(v) integrins. This implies a previously unknown role for COX-2 in chronic inflammation in the kidney.

Protection of the myocardium from ischemic injury by prostacyclins and PGE1 has been repeatedly reported. Part of the antiischemic effects may be mediated by cardiac sarcolemmal EP3-receptors which have been characterized earlier in this laboratory by ligand binding studies. Of particular notice is the presence of multiple EP3 isoforms, e. g. in mouse, cattle and man which are generated by differential splicing. Here we describe the cloning and subtype characterization of the porcine EP3-receptor. We obtained two different isoforms of the receptor by screening a porcine heart cDNA library. The predicted receptor proteins consisted of 395 and 387 amino acids, respectively, with differences only in the C-terminal part of the protein. Several overlapping genomic clones were obtained from a porcine genomic library. Sequence comparison of the cDNA with the genomic DNA indicated that an intron was located in the region corresponding to the sixth transmembrane domain of the receptor protein. This position exactly matches the corresponding intron in the human TXA2-, the human PGD2- and the mouse PGE-receptor (EP1-subtype). In further experiments, we expressed the porcine EP3-receptor in COS-7 cells and performed ligand-binding-studies. In addition the expression of the porcine EP3-receptor mRNA in different tissues was demonstrated by RT-PCR.

The "silent" allele at the immunoglobulin heavy-chain locus in the pre-B-lymphocyte line 18-81 contains a correctly assembled gene. However, an amber termination codon within the variable-region gene segment prematurely terminates translation into complete heavy chain. Revertants that do produce heavy chain are generated at a high rate, which is termed hypermutation. By DNA sequencing of subclones, we have confirmed that whenever mu chain is produced by the usually silent allele, a true reversion is found in the DNA. Mutations are not confined to the position of the amber termination codon but are also found at other sites in and near the variable-region gene segment.

Several strains, which according to their cell wall type and morphology belong to the genus Actinomadura, differ markedly from already recognized species. They are considered to be new taxa: A. libanotica, A. ferruginea, and A. spiralis. Their descriptions and illustrations are presented.

Thirty-nine isolates and additional reference strains of methanotrophic bacteria were studied with respect to mol % G + C of their DNA and the type of intracytoplasmatic membranes. The results on the whole confirm the former classification scheme of Whittenbury et al. (1970). However, problematic groups such as “Methylocystis” and “Methylobacter” are in need of additional taxonomic studies.

We have analyzed 210 lambda-producing hybridomas derived from lipopolysaccharide-stimulated spleen cells from a single kappa-suppressed mouse. All were classified as lambda 1, lambda 2 or lambda 3 with the exception of four unusual lines. Two of these were due to V lambda 2 J lambda 1 and the other two to V lambda 2 J lambda 3 rearrangements. The lines were clonally independent since the point of VJ recombination in each one was different. Southern blot analysis of the V lambda 2 C lambda 1-producing lines showed no evidence for an inversion. Under the assumption of a simple deletion model of rearrangement these findings place the V lambda 2 cluster upstream of the V lambda 1 cluster oriented in the same direction.

Phosphorylation of the human prostacyclin (PGI2) receptor (hIP-R) by diacylglycerol-regulated protein kinase C (PKC) has been reported to be responsible for its rapid desensitization in HEK293 cells. In this study we demonstrate, that human fibroblasts reveal a much slower hIP-R desensitization kinetics, which was neither affected by stimulation nor inhibition of PKC by either phorbol 12-myristate-13-acetate or GF-109203X suggesting a different cellular mechanism. Although agonist-promoted sequestration of a C-terminally green fluorescent protein-tagged hIP-R was demonstrated, it did not account for the long-term desensitization. Concanavalin A did not abolish, but accelerated receptor desensitization kinetics. Resensitization of hIP-R involved receptor recycling and/or de novo synthesis of receptor protein, depending on the duration of prior desensitization. This is the first study investigating the mechanisms of hIP-R desensitization in intact human cells naturally expressing hIP-R. Our data suggest, that a hitherto unknown mechanism of hIP-R long-term desensitization, which is independent of receptor phosphorylation by conventional and novel type PKC isoforms or endocytosis, is a key event in regulating the cellular responsiveness to PGI2.