A real-time antibody-dependent cellular phagocytosis assay by live cell imaging.

Antibody-dependent cellular phagocytosis (ADCP) is a cellular process by which antibody-opsonized targets (pathogens or cells) activate the Fc receptors on the surface of phagocytes to induce phagocytosis, resulting in internalization and degradation of pathogens or target cells through phagosome acidification. Besides NK cells-mediated antibody-dependent cellular cytotoxicity (ADCC), tumor-infiltrated monocytes and macrophages can directly kill tumor cells in the presence of tumor antigen-specific antibodies through ADCP, representing another attractive strategy for cancer immunotherapy. Even though several methods have been developed to measure ADCP, an automated and high-throughput quantitative assay should offer highly desirable advantages for drug discovery.

Structural basis of antibody inhibition and chemokine activation of the human CC chemokine receptor 8.

The C-C motif chemokine receptor 8 (CCR8) is a class A G-protein coupled receptor that has emerged as a promising therapeutic target in cancer. Targeting CCR8 with an antibody has appeared to be an attractive therapeutic approach, but the molecular basis for chemokine-mediated activation and antibody-mediated inhibition of CCR8 are not fully elucidated. Here, we obtain an antagonist antibody against human CCR8 and determine structures of CCR8 in complex with either the antibody or the endogenous agonist ligand CCL1.

A case of descending aortic dissection in a patient with unrepaired tetralogy of Fallot and pulmonary atresia.

Unlabelled: The prognosis of tetralogy of Fallot with pulmonary atresia (TOF/PA) is mainly determined by the development of major aorto-pulmonary collateral arteries (MAPCAs) that provide pulmonary blood perfusion. TOF/PA can be managed conservatively until adulthood in patients with adequate, but not excessive perfusion via MAPCAs. To the best of our knowledge, this is the first report of a patient with unrepaired TOF/PA who eventually developed descending aortic dissection (AD), and survived with medical treatment.

Induced Pluripotent Stem Cell-Derived Cardiomyocytes with R1623Q Mutation Associated with Severe Long QT Syndrome in Fetuses and Neonates Recapitulates Pathophysiological Phenotypes.

The R1623Q mutation is one of the most common genetic variants associated with severe congenital long QT syndrome 3 (LQT3) in fetal and neonatal patients. To investigate the properties of the R1623Q mutation, we established an induced pluripotent stem cell (iPSC) cardiomyocyte (CM) model from a patient with LQTS harboring a heterozygous R1623Q mutation. The properties and pharmacological responses of iPSC-CMs were characterized using a multi-electrode array system.

The lysosomal GPCR-like protein GPR137B regulates Rag and mTORC1 localization and activity.

Cell growth is controlled by a lysosomal signalling complex containing Rag small GTPases and mammalian target of rapamycin complex 1 (mTORC1) kinase. Here, we carried out a microscopy-based genome-wide human short interfering RNA screen and discovered a lysosome-localized G protein-coupled receptor (GPCR)-like protein, GPR137B, that interacts with Rag GTPases, increases Rag localization and activity, and thereby regulates mTORC1 translocation and activity. High GPR137B expression can recruit and activate mTORC1 in the absence of amino acids.

Ribonucleoprotein Transfection for CRISPR/Cas9-Mediated Gene Knockout in Primary T Cells.

CRISPR/Cas9 has enabled the rapid and efficient generation of gene knockouts across various cell types of several species. T cells are central players in adaptive immune responses. Gene editing in primary T cells not only represents a valuable research tool, but is also critical for next generation immunotherapies, such as CAR T cells.

Tumor suppressor BAP1 is essential for thymic development and proliferative responses of T lymphocytes.

Loss of function of the nuclear deubiquitinating enzyme BRCA1-associated protein-1 (BAP1) is associated with a wide spectrum of cancers. We report that tamoxifen-induced BAP1 deletion in adult mice resulted in severe thymic atrophy. BAP1 was critical for T cell development at several stages.

Optimized RNP transfection for highly efficient CRISPR/Cas9-mediated gene knockout in primary T cells.

CRISPR (clustered, regularly interspaced, short palindromic repeats)/Cas9 (CRISPR-associated protein 9) has become the tool of choice for generating gene knockouts across a variety of species. The ability for efficient gene editing in primary T cells not only represents a valuable research tool to study gene function but also holds great promise for T cell-based immunotherapies, such as next-generation chimeric antigen receptor (CAR) T cells. Previous attempts to apply CRIPSR/Cas9 for gene editing in primary T cells have resulted in highly variable knockout efficiency and required T cell receptor (TCR) stimulation, thus largely precluding the study of genes involved in T cell activation or differentiation.

Progressive Atrial Conduction Defects Associated With Bone Malformation Caused by a Connexin-45 Mutation.

Background: Inherited cardiac conduction disease is a rare bradyarrhythmia associated with mutations in various genes that affect action potential propagation. It is often characterized by isolated conduction disturbance of the His-Purkinje system, but it is rarely described as a syndromic form.

Objectives: The authors sought to identify the genetic defect in families with a novel bradyarrhythmia syndrome associated with bone malformation.

Connexin45 contributes to global cardiovascular development by establishing myocardial impulse propagation.

Among gap junction-encoding genes, the loss of connexin (Cx) 45 most profoundly obstructs embryogenesis through an endocardial cushion defect and conduction block. However, the interdependence of these defects is not known, and the details of conduction block have not been elucidated. Here, we examined mouse embryos with a region-specific deletion of Cx45 in the myocardium (CA-Cre; Cx45(flox/flox)) or endothelium (Tie2-Cre; Cx45(flox/flox)).

Systematic Discovery of Human Gene Function and Principles of Modular Organization through Phylogenetic Profiling.

Functional links between genes can be predicted using phylogenetic profiling, by correlating the appearance and loss of homologs in subsets of species. However, effective genome-wide phylogenetic profiling has been hindered by the large fraction of human genes related to each other through historical duplication events. Here, we overcame this challenge by automatically profiling over 30,000 groups of homologous human genes (orthogroups) representing the entire protein-coding genome across 177 eukaryotic species (hOP profiles).

Gap junctional regulation of pressure, fluid force, and electrical fields in the epigenetics of cardiac morphogenesis and remodeling.

Epigenetic factors of pressure load, fluid force, and electrical fields that occur during cardiac contraction affect cardiac development, morphology, function, and pathogenesis. These factors are orchestrated by intercellular communication mediated by gap junctions, which synchronize action potentials and second messengers. Misregulation of the gap junction protein connexin (Cx) alters cardiogenesis, and can be a pathogenic factor causing cardiac conduction disturbance, fatal arrhythmia, and cardiac remodeling in disease states such as hypertension and ischemia.

A polarized Ca2+, diacylglycerol and STIM1 signalling system regulates directed cell migration.

Ca(2+) signals control cell migration by regulating forward movement and cell adhesion. However, it is not well understood how Ca(2+)-regulatory proteins and second messengers are spatially organized in migrating cells. Here we show that receptor tyrosine kinase and phospholipase C signalling are restricted to the front of migrating endothelial leader cells, triggering local Ca(2+) pulses, local depletion of Ca(2+) in the endoplasmic reticulum and local activation of STIM1, supporting pulsatile front retraction and adhesion.

A connexin40 mutation associated with a malignant variant of progressive familial heart block type I.

Background: Progressive familial heart block type I (PFHBI) is a hereditary arrhythmia characterized by progressive conduction disturbances in the His-Purkinje system. PFHBI has been linked to genes such as SCN5A that influence cardiac excitability but not to genes that influence cell-to-cell communication. Our goal was to explore whether nucleotide substitutions in genes coding for connexin proteins would associate with clinical cases of PFHBI and if so, to establish a genotype-cell phenotype correlation for that mutation.

A crucial role of activin A-mediated growth hormone suppression in mouse and human heart failure.

Infusion of bone marrow-derived mononuclear cells (BMMNC) has been reported to ameliorate cardiac dysfunction after acute myocardial infarction. In this study, we investigated whether infusion of BMMNC is also effective for non-ischemic heart failure model mice and the underlying mechanisms. Intravenous infusion of BMMNC showed transient cardioprotective effects on animal models with dilated cardiomyopathy (DCM) without their engraftment in heart, suggesting that BMMNC infusion improves cardiac function via humoral factors rather than their differentiation into cardiomyocytes.

SKAP associates with kinetochores and promotes the metaphase-to-anaphase transition.

The spindle assembly checkpoint (SAC) controls the anaphase onset by preventing premature chromosome segregation until bipolar microtubule (MT) attachment and inter-kinetochore tension are fully established for every kinetochore pair. Once the SAC is off, activation of the Anaphase-Promoting Complex/Cyclosome, a ubiquitin ligase, leads to the degradation of securin and cyclin B, the activation of separase and the initiation of anaphase. We report here the identification and characterization of a G(2)-induced gene, SKAP, as a regulator for the anaphase onset.

Plk1 and Aurora A regulate the depolymerase activity and the cellular localization of Kif2a.

The microtubule depolymerase Kif2a controls spindle assembly and dynamics and is essential for chromosome congression and segregation. Through a proteomic analysis, we identified Kif2a as a target for regulation by the Polo-like kinase Plk1. Plk1 interacts with Kif2a, but only in mitosis, in a manner dependent on its kinase activity.

RCS1, a substrate of APC/C, controls the metaphase to anaphase transition.

The anaphase-promoting complex/cyclosome (APC/C) controls the onset of anaphase by targeting securin for destruction. We report here the identification and characterization of a substrate of APC/C, RCS1, as a mitotic regulator that controls the metaphase-to-anaphase transition. We showed that the levels of RCS1 fluctuate in the cell cycle, peaking in mitosis and dropping drastically as cells exit into G(1).

Bora and the kinase Aurora a cooperatively activate the kinase Plk1 and control mitotic entry.

A central question in the study of cell proliferation is, what controls cell-cycle transitions? Although the accumulation of mitotic cyclins drives the transition from the G2 phase to the M phase in embryonic cells, the trigger for mitotic entry in somatic cells remains unknown. We report that the synergistic action of Bora and the kinase Aurora A (Aur-A) controls the G2-M transition. Bora accumulates in the G2 phase and promotes Aur-A-mediated activation of Polo-like kinase 1 (Plk1), leading to the activation of cyclin-dependent kinase 1 and mitotic entry.

Reduced hydrophobic interaction of polystyrene surfaces by spontaneous segregation of block copolymers with oligo (ethylene glycol) methyl ether methacrylate blocks: force measurements in water using atomic force microscope with hydrophobic probes.

Reduction of hydrophobic interaction in water is important in biological interfaces. In our previous work, we have found that poly(styrene- b-triethylene glycol methyl ether methacrylate) (PS-PME3MA) segregates the PME3MA block to the surface in hydrophobic environment, such as in air or in a vacuum, and shows remarkable resistance against adsorption or adhesion of proteins, platelets, and cells in water. In this paper, we report that atomic force microscopy (AFM) with hydrophobic probes can directly monitor the reduced hydrophobic interaction of the PS surfaces modified by poly(styrene- b-origoethylene glycol methyl ether methacrylate) (PS-PME NMA), where N is the number of ethylene glycol units.

DDA3 recruits microtubule depolymerase Kif2a to spindle poles and controls spindle dynamics and mitotic chromosome movement.

Dynamic turnover of the spindle is a driving force for chromosome congression and segregation in mitosis. Through a functional genomic analysis, we identify DDA3 as a previously unknown regulator of spindle dynamics that is essential for mitotic progression. DDA3 depletion results in a high frequency of unaligned chromosomes, a substantial reduction in tension across sister kinetochores at metaphase, and a decrease in the velocity of chromosome segregation at anaphase.

Plk1- and beta-TrCP-dependent degradation of Bora controls mitotic progression.

Through a convergence of functional genomic and proteomic studies, we identify Bora as a previously unknown cell cycle protein that interacts with the Plk1 kinase and the SCF-beta-TrCP ubiquitin ligase. We show that the Bora protein peaks in G2 and is degraded by proteasomes in mitosis. Proteolysis of Bora requires the Plk1 kinase activity and is mediated by SCF-beta-TrCP.

CKAP2 is a spindle-associated protein degraded by APC/C-Cdh1 during mitotic exit.

We reported here an efficient and generally applicable genomic analysis that uses transcriptional profiling to identify candidate substrates of regulatory enzymes, such as kinases and ubiquitin ligases. We applied this strategy to the anaphase-promoting complex/cyclosome (APC/C), a ubiquitin ligase that controls sister chromatid separation and exit from mitosis. We found that a microtubule-associated protein, CKAP2, is a substrate of APC/C and demonstrated that ubiquitination and degradation of CKAP2 in vitro require a KEN-box and is mediated by Cdh1, an activator of APC/C.

Effect of charge substitutions at residue his-142 on voltage gating of connexin43 channels.

Previous studies indicate that the carboxyl terminal of connexin43 (Cx43CT) is involved in fast transjunctional voltage gating. Separate studies support the notion of an intramolecular association between Cx43CT and a region of the cytoplasmic loop (amino acids 119-144; referred to as "L2"). Structural analysis of L2 shows two alpha-helical domains, each with a histidine residue in its sequence (H126 and H142).

Cep55, a microtubule-bundling protein, associates with centralspindlin to control the midbody integrity and cell abscission during cytokinesis.

We report here an efficient functional genomic analysis by combining information on the gene expression profiling, cellular localization, and loss-of-function studies. Through this analysis, we identified Cep55 as a regulator required for the completion of cytokinesis. We found that Cep55 localizes to the mitotic spindle during prometaphase and metaphase and to the spindle midzone and the midbody during anaphase and cytokinesis.