Search

There are relatively few articles on the relationship between serum albumin and acute kidney injury (AKI). Therefore, the objective of this research was to study the relationship between serum albumin and AKI in patients who were undergoing surgery for acute type A aortic dissection. Methods: We retrospectively collected data from 624 patients attending a Chinese hospital between January 2015 and June 2017. The target independent variable was serum albumin measured before surgery after hospital admission, and the dependent variable was AKI, defined in accordance with the Kidney Disease Improving Global Outcomes (KDIGO) criteria. Results: The mean age of these 624 selected patients was 48.5 ± 11.1 years, and almost 73.7% were male. A nonlinear association was detected between serum albumin and AKI; the turning point was 32 g/L. The risk of AKI decreased gradually as the serum albumin level increased up to 32 g/L (adjusted OR = 0.87; 95% CI 0.82–0.92; p < 0.001). When the serum albumin level exceeded 32 g/L, the level of serum albumin was not associated with the risk of AKI (OR = 1.01, 95% CI 0.94–1.08; p = 0.769). Conclusions: The findings suggest that preoperative serum albumin below 32 g/L was an independent risk factor for AKI in patients undergoing surgery for acute type A aortic dissection. Trial registration: A retrospective cohort study.

The NRF2-mediated cytoprotective response is central to cellular homoeostasis, and there is increasing interest in developing small-molecule activators of this pathway as therapeutics for diseases involving chronic oxidative stress. The protein KEAP1, which regulates NRF2, is a key point for pharmacological intervention, and we recently described the use of fragment-based drug discovery to develop a tool compound that directly disrupts the protein-protein interaction between NRF2 and KEAP1. We now present the identification of a second, chemically distinct series of KEAP1 inhibitors, which provided an alternative chemotype for lead optimization. Pharmacophoric information from our original fragment screen was used to identify new hit matter through database searching and to evolve this into a new lead with high target affinity and cell-based activity. We highlight how knowledge obtained from fragment-based approaches can be used to focus additional screening campaigns in order to de-risk projects through the rapid identification of novel chemical series.

Pharmacological induction of fetal hemoglobin (HbF) expression is an effective therapeutic strategy for the management of beta-hemoglobinopathies such as sickle cell disease. DNA methyltransferase (DNMT) inhibitors 5-azacytidine (5-aza) and 5-aza-2′-deoxycytidine (decitabine) have been shown to induce fetal hemoglobin expression in both preclinical models and clinical studies, but are not currently approved for the management of hemoglobinopathies. We report here the discovery of a novel class of orally bioavailable DNMT1-selective inhibitors as exemplified by GSK3482364. This molecule potently inhibits the methyltransferase activity of DNMT1, but not DNMT family members DNMT3A or DNMT3B. In contrast with cytidine analog DNMT inhibitors, the DNMT1 inhibitory mechanism of GSK3482364 does not require DNA incorporation and is reversible. In cultured human erythroid progenitor cells (EPCs), GSK3482364 decreased overall DNA methylation resulting in de-repression of the gamma globin genes HBG1 and HBG2 and increased HbF expression. In a transgenic mouse model of sickle cell disease, orally administered GSK3482364 caused significant increases in both HbF levels and in the percentage HbF-expressing erythrocytes, with good overall tolerability. We conclude that in these preclinical models, selective, reversible inhibition of DNMT1 is sufficient for the induction of HbF, and is well-tolerated. We anticipate that GSK3482364 will be a useful tool molecule for the further study of selective DNMT1 inhibition both in vitro and in vivo.

BACKGROUND Acute Stanford type A aortic dissection is a lethal disease requiring surgery. Evidence regarding the effects of preoperative creatinine in mortality is limited, and few studies have evaluated the effect of postoperative dialysis treatment on it. METHODS In this cohort study, we continuously recruited 632 surgical patients who were treated for acute type A aortic dissection in our hospital between January 2015 and May 2017. The preoperative level of serum creatinine was measured. All patients were followed up after surgery for 30 days to determine early mortality. RESULTS The 30-day mortality after surgery increased with elevated levels of preoperative serum creatinine. Median (interquartile range) serum creatinine levels in survivors were 9.61 μmol/dL (7.28-12.62 μmol/dL) versus 13.41 μmol/dL (10.28-20.63 μmol/dL) in death (p < 0.01). Adjusted odds ratios for increasing per μmol/dL serum creatinine were 1.09 (95% confidence interval, 1.03-1.15). We also found that the effect of preoperative creatinine on 30-day mortality was diminished by dialysis treatment after surgery. CONCLUSION Preoperative serum creatinine predicts outcome in patients undergoing surgery for Stanford type A aortic dissection, and postoperative dialysis treatment can reduce its hazard.

Hypertrophic cardiomyopathy (HCM) is a complex inherited cardiovascular disease. The present study investigated the long noncoding (lnc)RNA/microRNA (mi)RNA/mRNA expression pattern of patients with HCM and aimed to identify key molecules involved in the development of this condition. An integrated strategy was conducted to identify differentially expressed miRNAs (DEmiRs), differentially expressed lncRNAs (DElncs) and differentially expressed genes (DEGs) based on the {"type":"entrez-geo","attrs":{"text":"GSE36961","term_id":"36961"}}GSE36961 (mRNA), {"type":"entrez-geo","attrs":{"text":"GSE36946","term_id":"36946"}}GSE36946 (miRNA), {"type":"entrez-geo","attrs":{"text":"GSE68316","term_id":"68316"}}GSE68316 (lncRNA/mRNA) and {"type":"entrez-geo","attrs":{"text":"GSE32453","term_id":"32453"}}GSE32453 (mRNA) expression profiles downloaded from the Gene Expression Omnibus datasets. Bioinformatics tools were employed to perform function and pathway enrichment analysis, protein-protein interaction, lncRNA-miRNA-mRNA and hub gene networks. Subsequently, DEGs were used as targets to predict drugs. The results indicated that a total of 2,234 DElncs (1,120 upregulated and 1,114 downregulated), 5 DEmiRs (2 upregulated and 3 downregulated) and 42 DEGs (35 upregulated and 7 downregulated) were identified in 4 microarray profiles. Gene ontology analysis revealed that DEGs were mainly involved in actin filament and stress fiber formation and in calcium ion binding, whereas Kyoto Encyclopedia of Genes and Genomes pathway analysis identified the hypoxia inducible factor-1, transforming growth factor-β and tumor necrosis factor signaling pathways as the main pathways involved in these processes. The hub genes were screened using cytoHubba. A total of 1,086 lncRNA-miRNA-mRNA interactions including 67 lncRNAs, 5 miRNAs and 25 mRNAs were mined in the present study based on prediction websites. Drug prediction indicated that the targeted drugs mainly included angiotensin converting enzyme inhibitors or β-blockers. A comprehensive bioinformatics analysis of the molecular regulatory lncRNA-miRNA-mRNA network was performed and potential therapeutic applications of drugs were predicted in HCM patients. The data may unravel the future molecular mechanism of HCM.

Background Thoracic aortic surgery and cardiopulmonary bypass are both associated with development of postoperative acute kidney injury. In this study, we undertook to investigate the relationship between cardiopulmonary bypass time and postoperative acute kidney injury in patients undergoing thoracic aortic surgery for acute DeBakey Type I aortic dissection. Methods All patients receiving thoracic aortic surgery for acute DeBakey Type I aortic dissection in Beijing Anzhen hospital from December 2015 to April 2017 were included. Cardiopulmonary bypass time was recorded during surgery. Acute kidney injury was defined based on the Kidney Disease Improving Global Outcomes criteria. A total of 115 consecutive patients were eventually analyzed. Results The overall incidence of acute kidney injury was 53.0% (n = 61). The average age was 47.8 ± 10.7 years; 74.8% were male. Mean cardiopulmonary bypass time was 211 ± 56 min. In-hospital mortality was 7.8%. Multivariate logistic regression revealed that cardiopulmonary bypass time was independently associated with the occurrence of postoperative acute kidney injury after adjust confounding factors (odds ratio = 1.171; 95% confidence interval: 1.002–1.368; P = 0.047). Conclusions Cardiopulmonary bypass time is independently associated with an increased hazard of acute kidney injury after thoracic aortic surgery for acute DeBakey Type I aortic dissection. Further understanding of the mechanism of this association is crucial to the design of preventative strategies. Electronic supplementary material The online version of this article (10.1186/s13019-019-0907-x) contains supplementary material, which is available to authorized users.

Highlights • Included variables include more comprehensive preoperative findings. • The protocol is designed based on largest single center AD database in China. • This risk scoring system will be verified using internal and external data., Stanford type A aortic dissection is a kind of cardiovascular disease which seriously threatens human life and health. It has the characteristics of rapid onset, rapid progress and high mortality. Surgical treatment is a recognized treatment for type A aortic dissection. There are many disputed places in the actual clinical work about the timing, prognosis and methods of the operation. This study aims to establish an early mortality risk scoring system for acute Stanford A aortic dissection surgery patients. Methods and analysis The structured data of patients with acute type A aortic dissection were collected. The primary outcome is death during hospitalization. Secondary outcomes will include re-operation and related complications. A risk scoring system of patients with acute type A aortic dissection undergoing surgical treatment will be established. Prospective data will be used to validate the risk stratification ability and accuracy of the model in operative risk prediction.

BACKGROUND: Ascending aortic aneurysm is a disease requiring surgical intervention. However, the timing of operation is still controversial. The purpose of this study is to compare the ascending aortic diameter and postoperative outcomes in hospital between patients with simple ascending aortic dissection and patients with simple ascending aortic dilation in China, and to investigate the accuracy of the timing of operation determined by ascending aortic diameter alone. METHODS: We reviewed the data from 2,520 hospitalized patients of aortic aneurysm and aortic dissection who underwent surgical treatment from January 2010 to June 2017 in our hospital. A total of 139 simple ascending aortic dissection and simple ascending aortic aneurysm hospitalized patients excluding Marfan syndrome and heart valve diseases etc. (56 in the aortic dilatation group and 83 in the aortic dissection group) were enrolled. The t-test and univariable analysis were used to compare the differences between two groups. RESULTS: For the aortic diameter, the group of aneurysm has greater ascending aortic diameter and the index of ascending aortic diameter compared with the group of dissection (P

Background Marfan syndrome (MFS) is an inherited connective tissue disease that mainly involves Fibrillin‐1 (FBN1) mutations and aortic manifestations. In this study, we investigated the correlations between the FBN1 genotype–phenotype and aortic events (aortic dissection and aortic aneurysm) in patients with Marfan syndrome. Methods Genotype and phenotype information was evaluated in 180 patients with MFS. DNA sequencing was performed on each patient. According to the clinical manifestation, these patients were split into two groups: the aortic dissection group and the aortic aneurysm group. Aortic wall tissue was obtained from Marfan patients who underwent surgery and was used for staining. Results A total of 180 patients with FBN1 mutations were grouped into four categories: 90 with missense mutations, 32 with splicing mutations, 29 with frameshift mutations, and 29 with nonsense mutations. There was a significantly higher frequency of frameshift and nonsense mutations observed in aortic dissection than in aortic aneurysm (25.58% vs. 4.35%, p = .005; 25.58% vs. 8.70%, p = .033, respectively;), while missense mutations showed a higher frequency in aortic aneurysm than in aortic dissection (69.57% vs. 32.56%, respectively; p, This study increase our understanding of the FBN1 gene mutation spectrum in Chinese patients with MFS. We found that frameshift mutations were more common in patients with aortic dissection and that the aortic wall structure contained fewer elastic fibers and fewer and more disordered smooth muscle cells.

The effect of withdrawal rates on the three-dimensional dendrite growth within the shrouds of single crystal blades during directional solidification was studied by both experiments and numerical simulations. The results showed that at given withdrawal rates, the dendrite pattern within the shrouds comprised three zones: primary dendrite zone, secondary dendrite spread zone, and a higher-order dendrite branched zone. With increasing withdrawal rate, the average primary dendrite arm spacing in the primary dendrite zone and the average secondary dendrite arm spacings in both the secondary dendrite spread zone and the higher-order dendrite branched zone were reduced. Independent of the variation in withdrawal rate, two analogous dendrite growth routes were observed within the shrouds of the employed blade geometry. These routes originated from the primary dendrites in the primary dendrite zone and filled in the shrouds by directly spreading secondary or successively branching higher-order dendrites. Except for a withdrawal rate of 6 mm min−1, these dendrites impinged at the shroud’s highest extremity and could be explained by the simulated moving isotherms. As the withdrawal rate was increased to 2.5 mm min−1, undercooling and contraction stress-related equiaxed grains were observed in the interdendritic region at the lowest shroud extremity. With increasing withdrawal rate, the amount of the defects was increased. Since the defects destroy the integrity of single crystal blades, the solidification condition within the shroud should be controlled to avoid their occurrence. Along the dendrite growth route, an accumulated misorientation of the dendrites was observed. At the same positions, this accumulation increased with increasing withdrawal rate.

Supplemental Digital Content is available in the text, Stanford type A aortic dissection (AD) is a lethal disease requiring surgery. Evidence regarding the prognostic ability of perioperative myocardiac markers on long-term outcome is limited. In this cohort study, we measured perioperative myocardiac markers level in 583 surgical patients with type A AD in our hospital between 2015 and 2017. All patients were followed up after surgery for a median period of 864 days to determine short- and long-term mortality. About one-fifth of patients has a positive preoperative myocardial markers, which was increased significantly after operation. Increase log10 post-creatine kinase MB isoenzyme (CK-MB) (hazard ratio [HR], 4.64; 95% confidence interval [CI] 1.89–11.43; P = .0008), log10 post-TnI (HR, 3.11; 95% CI 1.56–6.21; P = .0013), log10 post-Mb (HR, 3.00; 95% CI 1.40–6.43; P = .0048), log10 pre-CK-MB (HR,1.82; 95% CI 1.03–3.21; P = .0377), and upper tertile of post-CK-MB (HR,1.52; 95% CI 1.05–2.20; P = .0261) were the independent risk factor for 30 days mortality adjusted for potential confounders. None of cardiac markers was significantly associated with long-term outcome independent of other factors. Perioperative myocardiac predicts early outcome in type A AD patients undergoing surgery. Increasing perioperative myocardial markers do not appear to be a predictor for long-term all-cause mortality.

Background The purpose of this study is to identify the risk factors for postoperative severe hypoxemia after surgery for acute type A aortic dissection. Methods This was a single-center retrospective study including 112 consecutive patients undergoing urgent aortic arch surgery for acute type A aortic dissection between December 2016 and April 2017 at Beijing Anzhen Hospital. Results Multivariate logistic regression analysis identified female (OR, 12.978; 95% CI, 3.332 to 50.546; p

Table S1. Characteristics of the study patients at baseline after propensity score matching. (DOC 40 kb)

Table S2. Multivariable analysis to assess the independent impact of CPB time on postoperative AKI in patients with ADTIAD after PSM. (DOC 33 kb)

Background. Continued debates exist regarding the optimal temperature during hypothermic circulatory arrest in aortic arch repair for patients with type A aortic dissection. This study seeks to examine whether the use of moderate hypothermic circulatory arrest in a pig model provides comparable vital organ protection outcomes to the use of deep hypothermic circulatory arrest. Methods. Thirteen pigs were randomly assigned to 30 minutes of hypothermic circulatory arrest without cerebral perfusion at 15°C (n = 5), 25°C (n = 5), and a control group (n = 3). The changes in standard laboratory tests and capacity for protection against apoptosis in different vital organs were monitored with different temperatures of hypothermic circulatory arrest management in pig model to determine which temperature was optimal for hypothermic circulatory arrest. Results. There were no significant differences in the capacity for protection against apoptosis in vital organs between 2 groups (p > 0.05, respectively). Compared with the moderate hypothermic circulatory arrest group, the deep hypothermic circulatory arrest group had no significant advantages in terms of the biologic parameters of any other organs (p > 0.05). Conclusions. Compared with deep hypothermic circulatory arrest, moderate hypothermic circulatory arrest is a moderate technique that has similar advantages with regard to the levels of biomarkers of injury and capacity for protection against apoptosis in vital organs.

Nrf2, a master regulator of the phase II gene response to stress, is kept at low concentrations in the cell through binding to Keap1, an adaptor protein for the Cul3 ubiquitin ligase complex. To identify Nrf2 activators, two separate time-resolved fluorescence resonance energy transfer (TR-FRET) assays were developed to monitor the binding of Nrf2-Keap1 and Cul3-Keap1, respectively. The triterpenoid, 1-[2-cyano-3-,12-dioxooleana-1,9(11)-dien-28-oyl] imidazole (CDDO-Im) and its analogs, exhibited approximately 100-fold better potency in the Cul3-Keap1 assay than in the Nrf2-Keap1 assay, and this difference was more profound at 37 °C than at room temperature in the Nrf2-Keap1 assay, but this phenomenon was not observed in the Cul3-Keap1 assay. A full diversity screen of approximately 2,200,000 GSK compounds was run with the Cul3-Keap1 TR-FRET assay and multiple chemical series were identified and characterized.

Abnormal accumulation of β-catenin protein, a key transcriptional activator required for Wnt signaling, is the hallmark of many tumor types, including colon cancer. In normal cells, β-catenin protein level is tightly controlled by a multiprotein complex through the proteosome pathway. Mutations in the components of the β-catenin degradation complex, such as adenomatous polyposis coli (APC) and Axin, lead to β-catenin stabilization and the constitutive activation of target genes. Since the signal transduction of Wnt/β-catenin is mainly mediated by protein-protein interactions, this pathway has been particularly refractory to conventional target-based small-molecule screening. Here we designed a cellular high-content imaging assay to detect β-catenin protein through immunofluorescent staining in the SW480 colon cancer cell line, which has elevated β-catenin endogenously. We demonstrate that the assay is robust and specific to screen a focused biologically diverse chemical library set against known targets that play diverse cellular functions. We identified a number of hits that reduce β-catenin levels without causing cell death. These hits may serve as tools to understand the dynamics of β-catenin degradation. This study demonstrates that detecting cell-based β-catenin protein stability is a viable approach to identifying novel mechanisms of β-catenin regulation as well as small molecules of therapeutic potential.

Beta-hemoglobinopathies such as sickle cell disease represent a major global unmet medical need. De-repression of fetal hemoglobin in erythrocytes is a clinically validated approach for the management of sickle cell disease, but the only FDA-approved medicine for this purpose has limitations to its use. We conducted a phenotypic screen in human erythroid progenitor cells to identify molecules with the ability to de-repress fetal hemoglobin, which resulted in the identification of the benzoxaborole-containing hit compound 1. This compound was found to have modest cellular potency and lead-like pharmacokinetics, but no identifiable SAR to enable optimization. Systematic deconstruction of a closely related analog of 1 revealed the fragment-like carboxylic acid 12, which was then optimized to provide tetrazole 31, which had approximately 100-fold improved cellular potency compared to 1, high levels of oral exposure in rats, and excellent solubility.

Atonal homolog 1 (Atoh1) is a basic helix-loop-helix 9 (bHLH) transcription factor acting downstream of Notch and is required for the differentiation of sensory hair cells in the inner ear and the specification of secretory cells during the intestinal crypt cell regeneration. Motivated by the observations that the upregulation of Atoh1 gene expression, through genetic manipulation or pharmacological inhibition of Notch signaling (e.g. γ-secretase inhibitors, GSIs), induces ectopic hair cell growth in the cochlea of the inner ear and partially restores hearing after injuries in experimental models, we decided to identify small molecule modulators of the Notch-Atoh1 pathway, which could potentially regenerate hair cells. However, the lack of cellular models of the inner ear has precluded the screening and characterization of such modulators. Here we report using a colon cancer cell line LS-174T, which displays Notch inhibition-dependent Atoh1 expression as a surrogate cellular model to screen for inducers of Atoh1 expression. We designed an Atoh1 promoter-driven luciferase assay to screen a target-annotated library of ~6000 compounds. We further developed a medium throughput, real-time quantitative RT-PCR assay measuring the endogenous Atoh1 gene expression to confirm the hits and eliminate false positives from the reporter-based screen. This strategy allowed us to successfully recover GSIs of known chemotypes. This LS-174T cell-based assay directly measures Atoh1 gene expression induced through Notch-Hes1 inhibition, and therefore offers an opportunity to identify novel cellular modulators along the Notch-Atoh1 pathway.

Background: Thoracic aortic surgery and obesity are both associated with risk of acute kidney injury (AKI). We hypothesized that the risk of postoperative AKI increases when the body mass index (BMI) increases in patients undergoing aortic total arch surgery for Type A acute aortic dissection (AAD). Methods: We conducted a population-based cohort study in Beijing anzhen hospital from December 2015 to April 2017. All AAD patients receiving aortic total arch surgery were included. BMI was calculated on the basis of height and weight recorded on the day of hospital admission preoperatively. AKI was defined by the Kidney Disease Improving Global Outcomes criteria. Findings: We included 115 consecutive in this timeframe. The overall incidence of AKI was 53·0% (n=61). Mean age was 47·8±10·7 years; 25·2% were women. Mean BMI was 26·2±3·9kg/m2. In-hospital mortality was significantly higher in the AKI group (13·11% vs 1·85%; P=0·025). Multivariate logistic regression revealed that BMI was independently associated with the development of postoperative AKI after adjust other confounding factors (odds ratio [OR], 1·22; 95% confidence interval [CI], 1·07-1·39; P =0·004). Interpretation: Body mass index is independently associated with an increased risk of acute kidney injury after aortic total arch surgery. Further understanding of the molecular basis of this association is critical to the design of preventative strategies. Funding Statement: This study was supported by National Key R&D Program of China（2017YFC1308000）and the Beijing Lab for Cardiovascular Precision Medicine, Beijing, China. PXM2017_014226_000037. Declaration of Interests: The authors have declared that no conflicts of interest exist. Ethics Approval Statement: This study was approved by the human research and development committees of the Beijing Anzhen Hospital and was adhered to the rules of the Declaration of Helsinki and principles of Good Clinical Practice. Individual consent was waived for the retrospective study.

Luciferase reporter gene assays have long been used for drug discovery due to their high sensitivity and robust signal. A dual reporter gene system contains a gene of interest and a control gene to monitor non-specific effects on gene expression. In our dual luciferase reporter gene system, a synthetic promoter of γ-globin gene was constructed immediately upstream of the firefly luciferase gene, followed downstream by a synthetic β-globin gene promoter in front of the Renilla luciferase gene. A stable cell line with the dual reporter gene was cloned and used for all assay development and HTS work. Due to the low activity of the control Renilla luciferase, only the firefly luciferase activity was further optimized for HTS. Several critical factors, such as cell density, serum concentration, and miniaturization, were optimized using tool compounds to achieve maximum robustness and sensitivity. Using the optimized reporter assay, the HTS campaign was successfully completed and approximately 1000 hits were identified. In this chapter, we also describe strategies to triage hits that non-specifically interfere with firefly luciferase.

Luciferase reporter gene assays have long been used for drug discovery due to their high sensitivity and robust signal. A dual reporter gene system contains a gene of interest and a control gene to monitor non-specific effects on gene expression. In our dual luciferase reporter gene system, a synthetic promoter of γ-globin gene was constructed immediately upstream of the firefly luciferase gene, followed downstream by a synthetic β-globin gene promoter in front of the Renilla luciferase gene. A stable cell line with the dual reporter gene was cloned and used for all assay development and HTS work. Due to the low activity of the control Renilla luciferase, only the firefly luciferase activity was further optimized for HTS. Several critical factors, such as cell density, serum concentration, and miniaturization, were optimized using tool compounds to achieve maximum robustness and sensitivity. Using the optimized reporter assay, the HTS campaign was successfully completed and approximately 1000 hits were identified. In this chapter, we also describe strategies to triage hits that non-specifically interfere with firefly luciferase.

DNA-encoded small-molecule library technology has recently emerged as a new paradigm for identifying ligands against drug targets. To date, this technology has been used with soluble protein targets that are produced and used in a purified state. Here, we describe a cell-based method for identifying small-molecule ligands from DNA-encoded libraries against integral membrane protein targets. We use this method to identify novel, potent, and specific inhibitors of NK3, a member of the tachykinin family of G-protein coupled receptors (GPCRs). The method is simple and broadly applicable to other GPCRs and integral membrane proteins. We have extended the application of DNA-encoded library technology to membrane-associated targets and demonstrate the feasibility of selecting DNA-tagged, small-molecule ligands from complex combinatorial libraries against targets in a heterogeneous milieu, such as the surface of a cell.

Virtual screening of the corporate compound collection yielded compound 1 as a subtype selective muscarinic M1 receptor agonist hit. Initial optimization of the N-capping group of the central piperidine ring resulted in compounds 2 and 3 with significantly improved potency and selectivity. Subsequent optimization of substituents on the phenyl ring of the benzimidazolone moiety led to the discovery of novel muscarinic M1 receptor agonists 4 and 5 with excellent potency, general and subtype selectivity, and pharmacokinetic (PK) properties including good central nervous system (CNS) penetration and oral bioavailability. Compound 5 showed robust in vivo activities in animal models of cognition enhancement. The combination of high potency, excellent selectivity, and good PK properties makes compounds 4 and 5 valuable tool compounds for investigating and validating potential therapeutic benefits resulting from selective M1 activation.

Further optimization of the biaryl amide series via extensively exploring structure–activity relationships resulted in potent and subtype selective M1 agonists exemplified by compounds 9a and 9j with good rat PK properties including CNS penetration. Synthesis, structure–activity relationships, subtype selectivity for M1 over M2–5, and DMPK properties of these novel compounds are described.

Clinical evaluation of tachykinin NK(3) receptor antagonists has provided support for the therapeutic utility of this target in schizophrenia. However, these studies have not been entirely conclusive, possibly because of the pharmacokinetic limitations of these molecules. In the search for tachykinin NK(3) receptor antagonists with improved properties, we have discovered GSK172981 and GSK256471. Both compounds demonstrated high affinity for recombinant human (pK(i) values 7.7 and 8.9, respectively) and native guinea pig (pK(i) values 7.8 and 8.4, respectively) tachykinin NK(3) receptors. In vitro functional evaluations revealed GSK172981 to be a competitive antagonist (pA(2)=7.2) at cloned human tachykinin NK(3) receptor whereas GSK256471 diminished the neurokinin B-induced E(max) response, indicative of non-surmountable antagonist pharmacology (pA(2)=9.2). GSK172981 also exhibited a competitive profile in antagonizing neurokinin B-stimulated neuronal activity recorded from the guinea pig medial habenula slices (apparent pK(B)=8.1), whilst GSK256471 abolished the agonist-induced response. Central nervous system penetration by GSK172981 and GSK256471 was indicated by dose-dependent ex vivo tachykinin NK(3) receptor occupancy in medial prefrontal cortex (ED(50) values of 0.8 and 0.9 mg/kg, i.p., respectively) and the dose-dependent attenuation of agonist-induced "wet dog shake" behaviours in guinea pigs. Finally, in vivo microdialysis studies demonstrated that acute GSK172981 (30 mg/kg, i.p.) and GSK256471 (1mg/kg, i.p.) attenuated haloperidol-induced increases in extracellular dopamine in the guinea pig nucleus accumbens. Taken together, these in vitro and in vivo characterisations of the tachykinin NK(3) receptor antagonists GSK172981 and GSK256471 support their potential utility in the treatment of schizophrenia.

A series of N-arylpiperazine camphor sulfonamides was discovered as novel CXCR3 antagonists. The synthesis, structure–activity relationships, and optimization of the initial hit that resulted in the identification of potent and selective CXCR3 antagonists are described.

The high affinity interleukin-2 receptor is composed of three cell surface subunits, IL-2Ralpha, IL-2Rbeta, and IL-2Rgamma. Functional forms of the IL-2 receptor exist, however, that enlist only two of the three subunits. On activated T-cells, the alpha- and beta-subunits combine as a preformed heterodimer (the pseudo-high affinity receptor) that serves to capture IL-2. On a subpopulation of natural killer cells, the beta- and gamma-subunits interact in a ligand-dependent manner to form the intermediate affinity receptor site. Previously, we have demonstrated the feasibility of employing coiled-coil molecular recognition for the solution assembly of a heteromeric IL-2 receptor complex. In that study, although the receptor was functional, the coiled-coil complex was a trimer rather than the desired heterodimer. We have now redesigned the hydrophobic heptad sequences of the coiled-coils to generate soluble forms of both the pseudo-high affinity and the intermediate affinity heterodimeric IL-2 receptors. The properties of these complexes were examined and their relevance to the physiological IL-2 receptor mechanism is discussed.

Background and purpose: M1 muscarinic ACh receptors (mAChRs) represent an attractive drug target for the treatment of cognitive deficits associated with diseases such as Alzheimer's disease and schizophrenia. However, the discovery of subtype-selective mAChR agonists has been hampered by the high degree of conservation of the orthosteric ACh-binding site among mAChR subtypes. The advent of functional screening assays has enabled the identification of agonists such as AC-42 (4-n-butyl-1-[4-(2-methylphenyl)-4-oxo-1-butyl]-piperidine), which bind to an allosteric site and selectively activate the M1 mAChR subtype. However, studies with this compound have been limited to recombinantly expressed mAChRs. Experimental approach: In this study, we have compared the pharmacological profile of AC-42 and a close structural analogue, 77-LH-28-1 (1-[3-(4-butyl-1-piperidinyl)propyl]-3,4-dihydro-2(1H)-quinolinone) at human recombinant, and rat native, mAChRs by calcium mobilization, inositol phosphate accumulation and both in vitro and in vivo electrophysiology. Key results: Calcium mobilization and inositol phosphate accumulation assays revealed that both AC-42 and 77-LH-28-1 display high selectivity to activate the M1 mAChR over other mAChR subtypes. Furthermore, 77-LH-28-1, but not AC-42, acted as an agonist at rat hippocampal M1 receptors, as demonstrated by its ability to increase cell firing and initiate gamma frequency network oscillations. Finally, 77-LH-28-1 stimulated cell firing in the rat hippocampus in vivo following subcutaneous administration. Conclusions and implications: These data suggest that 77-LH-28-1 is a potent, selective, bioavailable and brain-penetrant agonist at the M1 mAChR and therefore that it represents a better tool than AC-42, with which to study the pharmacology of the M1 mAChR. British Journal of Pharmacology (2008) 154, 1104–1115; doi:10.1038/bjp.2008.152; published online 5 May 2008

A series of 2-aminomethyl piperidines has been discovered as novel urotensin-II receptor antagonists. The synthesis, initial structure-activity relationships, and optimization of the initial hit that resulted in the identification of potent, cross-species active, and functional urotensin-II receptor antagonists such as 1a and 11a are described.