Neutrophil DREAM promotes neutrophil recruitment in vascular inflammation

The interaction between neutrophils and endothelial cells is critical for the pathogenesis of vascular inflammation. However, the regulation of neutrophil adhesive function remains not fully understood. Intravital microscopy demonstrates that neutrophil DREAM promotes neutrophil recruitment to sites of inflammation induced by TNF-α but not MIP-2 or fMLP. We observe that neutrophil DREAM represses expression of A20, a negative regulator of NF-κB activity, and enhances expression of pro-inflammatory molecules and phosphorylation of IκB kinase (IKK) after TNF-α stimulation. Studies using genetic and pharmacologic approaches reveal that DREAM deficiency and IKKβ inhibition significantly diminish the ligand-binding activity of β2 integrins in TNF-α–stimulated neutrophils or neutrophil-like HL-60 cells. Neutrophil DREAM promotes degranulation through IKKβ-mediated SNAP-23 phosphorylation. Using sickle cell disease mice lacking DREAM, we show that hematopoietic DREAM promotes vaso-occlusive events in microvessels following TNF-α challenge. Our study provides evidence that targeting DREAM might be a novel therapeutic strategy to reduce excessive neutrophil recruitment in inflammatory diseases.

Simulated spectra (IR and Raman), NLO, AIM and molecular docking of carisoprodol from DFT approach

The aim of this study to explore the spectroscopic behavior of carisoprodol in terms of simulated spectra (IR and Raman).. The intramolecular H-bond of the molecule has been inspected from the Atoms in Molecule (AIM) approach which infers that there exist partial covalent H-bond in nature. The protein-ligand binding activity of the drug molecule has been analyzed theoretically from the molecular docking approach with the predicted targets in terms of binding energy and conventional H-bond with residue. The molecular docking analysis of the title molecule explores that the binding energy with the protein acetylcholinesterase is more than the protein epoxide hydrolase1. The nonlinear optical (NLO) behavior of title molecule has been scrutinized which motivates that the potent use of the molecule as NLO material. BIBECHANA 18 (2021) 48-57

Chemical Constituents of the Terrestrial Stems of Ephedra sinica and their PPAR-γ Ligand-Binding Activity

Bioassay-guided fractionation of the MeOH extract of Ephedra sinica terrestrial stems, using a PPAR-γ ligand binding assay, resulted in the isolation of 10 compounds, including one new bisabolane-type sesquiterpenoid (10). The structure of the new compound was determined by extensive spectroscopic analysis, including two-dimensional (2D) NMR. Among the isolated compounds, the sitosterol derivatives (1 and 2), flavonoid glucoside (7), and the new sesquiterpenoid (10), showed significant PPAR-γ ligand-binding activity.

Human Cytomegalovirus US28 Ligand Binding Activity Is Required for Latency in CD34+Hematopoietic Progenitor Cells and Humanized NSG Mice

ABSTRACTHuman cytomegalovirus (HCMV) infection of CD34+hematopoietic progenitor cells (CD34+HPCs) provides a critical reservoir of virus in stem cell transplant patients, and viral reactivation remains a significant cause of morbidity and mortality. The HCMV chemokine receptor US28 is implicated in the regulation of viral latency and reactivation. To explore the role of US28 signaling in latency and reactivation, we analyzed protein tyrosine kinase signaling in CD34+HPCs expressing US28. US28-ligand signaling in CD34+HPCs induced changes in key regulators of cellular activation and differentiation.In vitrolatency and reactivation assays utilizing CD34+HPCs indicated that US28 was required for viral reactivation but not latency establishment or maintenance. Similarly, humanized NSG mice (huNSG) infected with TB40E-GFP-US28stop failed to reactivate upon treatment with granulocyte-colony-stimulating factor, but viral genome levels were maintained. Interestingly, HCMV-mediated changes in hematopoiesis during latencyin vivoandin vitrowas also dependent upon US28, as US28 directly promoted differentiation toward the myeloid lineage. To determine whether US28 constitutive activity and/or ligand-binding activity were required for latency and reactivation, we infected both huNSG mice and CD34+HPCsin vitrowith HCMV TB40E-GFP containing the US28-R129A mutation (no CA) or Y16F mutation (no ligand binding). TB40E-GFP-US28-R129A was maintained during latency and exhibited normal reactivation kinetics. In contrast, TB40E-GFP-US28-Y16F exhibited high levels of viral genome during latency and reactivation, indicating that the virus did not establish latency. These data indicate that US28 is necessary for viral reactivation and ligand binding activity is required for viral latency, highlighting the complex role of US28 during HCMV latency and reactivation.IMPORTANCEHuman cytomegalovirus (HCMV) can establish latency following infection of CD34+hematopoietic progenitor cells (HPCs), and reactivation from latency is a significant cause of viral disease and accelerated graft failure in bone marrow and solid-organ transplant patients. The precise molecular mechanisms of HCMV infection in HPCs are not well defined; however, select viral gene products are known to regulate aspects of latency and reactivation. The HCMV-encoded chemokine receptor US28, which binds multiple CC chemokines as well as CX3CR1, is expressed both during latent and lytic phases of the virus life cycle and plays a role in latency and reactivation. However, the specific timing of US28 expression and the role of ligand binding in these processes are not well defined. In this report, we determined that US28 is required for reactivation but not for maintaining latency. However, when present during latency, US28 ligand binding activity is critical to maintaining the virus in a quiescent state. We attribute the regulation of both latency and reactivation to the role of US28 in promoting myeloid lineage cell differentiation. These data highlight the dynamic and multifunctional nature of US28 during HCMV latency and reactivation.