Scientific Resources

Alzheimer's disease (AD) is emerging as a synaptopathology driven by metaplasticity. Indeed,reminiscent of metaplasticity,oligomeric forms of the amyloid-beta$ peptide (oAbeta$) prevent induction of long-term potentiation (LTP) via the prior activation of GluN2B-containing NMDA receptors (NMDARs). However,the downstream Ca2+-dependent signaling molecules that mediate aberrant metaplasticity are unknown. In this study,we show that oAbeta$ promotes the activation of Ca2+/calmodulin-dependent kinase II (CaMKII) via GluN2B-containing NMDARs. Importantly,we find that CaMKII inhibition rescues both the LTP impairment and the dendritic spine loss mediated by oAbeta$. Mechanistically resembling metaplasticity,oAbeta$ prevents subsequent rounds of plasticity from inducing CaMKII T286 autophosphorylation,as well as the associated anchoring and accumulation of synaptic AMPA receptors (AMPARs). Finally,prolonged oAbeta$ treatment-induced CaMKII misactivation leads to dendritic spine loss via the destabilization of surface AMPARs. Thus,our study demonstrates that oAbeta$ engages synaptic metaplasticity via aberrant CaMKII activation. View Publication

Functional evaluation assays using human induced pluripotent stem cell (hiPSC)-derived neurons can predict the convulsion toxicity of new drugs and the neurological effects of antiepileptic drugs. However,differences in responsiveness depending on convulsant type and antiepileptic drugs,and an evaluation index capable of comparing in vitro responses with in vivo responses are not well known. We observed the difference in synchronized burst patterns in the epileptiform activities induced by pentylentetrazole (PTZ) and 4-aminopryridine (4-AP) with different action mechanisms using multi-electrode arrays (MEAs); we also observed that 100 µM of the antiepileptic drug phenytoin suppressed epileptiform activities induced by PTZ,but increased those induced by 4-AP. To compare in vitro results with in vivo convulsive responses,frequency analysis of below 250 Hz,excluding the spike component,was performed. The in vivo convulsive firing enhancement of the high gamma$ wave and beta$ wave component were observed remarkably in in vitro hiPSC-derived neurons with astrocytes in co-culture. MEA measurement of hiPSC-derived neurons in co-culture with astrocytes and our analysis methods,including frequency analysis,appear effective for predicting convulsion toxicity,side effects,and their mechanism of action as well as the comparison of convulsions induced in vivo. View Publication

Chronic myelomonocytic leukemia (CMML) is a clinically heterogeneous neoplasm in which JAK2 inhibition has demonstrated reductions in inflammatory cytokines and promising clinical activity. We hypothesize that annotation of inflammatory cytokines may uncover mutation-independent cytokine subsets associated with novel CMML prognostic features. A Luminex cytokine profiling assay was utilized to profile cryopreserved peripheral blood plasma from 215 CMML cases from three academic centers,along with center-specific,age-matched plasma controls. Significant differences were observed between CMML patients and healthy controls in 23 out of 45 cytokines including increased cytokine levels in IL-8,IP-10,IL-1RA,TNF-alpha$,IL-6,MCP-1/CCL2,hepatocyte growth factor (HGF),M-CSF,VEGF,IL-4,and IL-2RA. Cytokine associations were identified with clinical and genetic features,and Euclidian cluster analysis identified three distinct cluster groups associated with important clinical and genetic features in CMML. CMML patients with decreased IL-10 expression had a poor overall survival when compared to CMML patients with elevated expression of IL-10 (P = 0.017),even when adjusted for ASXL1 mutation and other prognostic features. Incorporating IL-10 with the Mayo Molecular Model statistically improved the prognostic ability of the model. These established cytokines,such as IL-10,as prognostically relevant and represent the first comprehensive study exploring the clinical implications of the CMML inflammatory state. View Publication

Abnormal signaling pathways mediated by N-methyl-d-aspartate receptors (NMDARs) have been implicated in the pathogenesis of various CNS disorders and have been long considered as promising points of therapeutic intervention. However,few efforts have been previously described concerning evaluation of therapeutic modulators of NMDARs and their downstream pathways in human neurons with endogenous expression of NMDARs. In the present study,we assessed expression,functionality,and subunit composition of endogenous NMDARs in human induced pluripotent stem cell (hiPSC)-derived cortical neurons (iCell Neurons and iCell GlutaNeurons). We initially confirmed the expected pharmacological response of iCell Neurons and iCell GlutaNeurons to NMDA by patch-clamp recordings. Subsequent pharmacological interrogation using GluN2 subunit-selective antagonists revealed the predominance of GluN2B in both iCell Neurons and iCell GlutaNeurons. This observation was also supported by qRT-PCR and Western blot analyses of GluN2 subunit expression as well as pharmacological experiments using positive allosteric modulators with distinct GluN2 subunit selectivity. We conclude that iCell Neurons and iCell GlutaNeurons express functional GluN2B-containing NMDARs and could serve as a valuable system for development and validation of GluN2B-modulating pharmaceutical agents. View Publication

Objectives gamma$delta$ T cells,a non-conventional innate lymphocyte subset containing cells that can be activated by lipids and phosphoantigens,are abnormally regulated in systemic sclerosis (SSc). To further evaluate the significance of this dysregulation,we compared how exposure to an autoantigenic lipid,cardiolipin (CL),during co-stimulation with an amino-bisphosphonate (zoledronate,zol),affects the activation and cytokine production of SSc and healthy control (HC) gamma$delta$ T cells. Methods Expression of CD25 on Vgamma$9+,Vdelta$1+,and total CD3+ T cells in cultured peripheral blood mononuclear cells (PBMCs),their binding of CD1d tetramers,and the effect of monoclonal antibody (mAb) blockade of CD1d were monitored by flow cytometry after 4 days of in vitro culture. Intracellular production of IFNgamma$ and IL-4 was assessed after overnight culture. Results Percentages of CD25+ among CD3+ and Vdelta$1+ T cells were elevated significantly in short-term cultured SSc PBMC compared to HC. In SSc but not HC,CL and zol,respectively,suppressed {\%}CD25+ Vgamma$9+ and Vdelta$1+ T cells but,when combined,CL + zol significantly activated both subsets in HC and partially reversed inhibition by the individual reagents in SSc. Importantly,Vdelta$1+ T cells in both SSc and HC were highly reactive with lipid presenting CD1d tetramers,and a CD1d-blocking mAb decreased CL-induced enhancement of {\%}SSc CD25+ Vdelta$1+ T cells in the presence of zol. {\%}IFNgamma$+ cells among Vgamma$9+ T cells of SSc was lower than HC cultured in medium,CL,zol,or CL + zol,whereas {\%}IFNgamma$+ Vdelta$1+ T cells was lower only in the presence of CL or CL + zol. {\%}IL-4+ T cells were similar in SSc and HC in all conditions,with the exception of being increased in SSc Vgamma$9+ T cells in the presence of CL. Conclusion Abnormal functional responses of gamma$delta$ T cell subsets to stimulation by CL and phosphoantigens in SSc may contribute to fibrosis and immunosuppression,characteristics of this disease. View Publication

Nonsense mutations are present in 10{\%} of patients with CF,produce a premature termination codon in CFTR mRNA causing early termination of translation,and lead to lack of CFTR function. There are no currently available animal models which contain a nonsense mutation in the endogenous Cftr locus that can be utilized to test nonsense mutation therapies. In this study,we create a CF mouse model carrying the G542X nonsense mutation in Cftr using CRISPR/Cas9 gene editing. The G542X mouse model has reduced Cftr mRNA levels,demonstrates absence of CFTR function,and displays characteristic manifestations of CF mice such as reduced growth and intestinal obstruction. Importantly,CFTR restoration is observed in G542X intestinal organoids treated with G418,an aminoglycoside with translational readthrough capabilities. The G542X mouse model provides an invaluable resource for the identification of potential therapies of CF nonsense mutations as well as the assessment of in vivo effectiveness of these potential therapies targeting nonsense mutations. View Publication

$\beta$-hemoglobinopathies such as sickle cell disease (SCD) and $\beta$-thalassemia result from mutations in the adult HBB ($\beta$-globin) gene. Reactivating the developmentally silenced fetal HBG1 and HBG2 ($\gamma$-globin) genes is a therapeutic goal for treating SCD and $\beta$-thalassemia 1 . Some forms of hereditary persistence of fetal hemoglobin (HPFH),a rare benign condition in which individuals express the $\gamma$-globin gene throughout adulthood,are caused by point mutations in the $\gamma$-globin gene promoter at regions residing {\~{}}115 and 200 bp upstream of the transcription start site. We found that the major fetal globin gene repressors BCL11A and ZBTB7A (also known as LRF) directly bound to the sites at -115 and -200 bp,respectively. Furthermore,introduction of naturally occurring HPFH-associated mutations into erythroid cells by CRISPR-Cas9 disrupted repressor binding and raised $\gamma$-globin gene expression. These findings clarify how these HPFH-associated mutations operate and demonstrate that BCL11A and ZBTB7A are major direct repressors of the fetal globin gene. View Publication

Hematotoxicity is a significant issue for drug safety and can result from direct cytotoxicity toward circulating mature blood cell types as well as targeting of immature blood-forming stem cells/progenitor cells in the bone marrow. In vitro models for understanding and investigating the hematotoxicity potential of new test items/drugs are critical in early preclinical drug development. The traditional method,colony forming unit (CFU) assay,is commonly used and has been validated as a method for hematotoxicity screening. The CFU assay has multiple limitations for its application in investigative work. In this paper,we describe a detailed protocol for a liquid-culture,microplate-based in vitro hematotoxicity assay to evaluate lineage-specific (myeloid,erythroid,and megakaryocytic) hematotoxicity at different stages of differentiation. This assay has multiple advantages over the traditional CFU assay,including being suitable for high-throughput screening and flexible enough to allow inclusion of additional endpoints for mechanistic studies. Therefore,it is an extremely useful tool for scientists in pharmaceutical discovery and development. {\textcopyright} 2018 by John Wiley & Sons,Inc. View Publication

The mouse trachea is thought to contain two distinct stem cell compartments that contribute to airway repair-basal cells in the surface airway epithelium (SAE) and an unknown submucosal gland (SMG) cell type. Whether a lineage relationship exists between these two stem cell compartments remains unclear. Using lineage tracing of glandular myoepithelial cells (MECs),we demonstrate that MECs can give rise to seven cell types of the SAE and SMGs following severe airway injury. MECs progressively adopted a basal cell phenotype on the SAE and established lasting progenitors capable of further regeneration following reinjury. MECs activate Wnt-regulated transcription factors (Lef-1/TCF7) following injury and Lef-1 induction in cultured MECs promoted transition to a basal cell phenotype. Surprisingly,dose-dependent MEC conditional activation of Lef-1 in vivo promoted self-limited airway regeneration in the absence of injury. Thus,modulating the Lef-1 transcriptional program in MEC-derived progenitors may have regenerative medicine applications for lung diseases. View Publication

The complete resolution of inflammation requires the uptake of apoptotic polymorphonuclear cells (PMN) by local macrophages (efferocytosis) and the consequent reprogramming of the engulfing phagocytes to reparative and pro-resolving phenotypes. The tyrosine kinase receptors TYRO3,AXL,and MERTK (collectively named TAM) are fundamental mediators in regulating inflammatory responses and efferocytosis. Protein S (PROS1) is a ligand for all TAM receptors that mediates various aspects of their activity. However,the involvement of PROS1 in the resolution of inflammation is incompletely understood. Here,we report the upregulation of Pros1 in macrophages during the resolution of inflammation. Selective knockout of Pros1 in the myeloid lineage significantly downregulated macrophage pro-resolving properties. Hence,Pros1-deficient macrophages engulfed fewer apoptotic PMN remnants in vivo,and exogenous PROS1 rescued impaired efferocytosis ex vivo. Moreover,Pros1-deficient peritoneal macrophages secreted higher levels of the pro-inflammatory mediators TNF$\alpha$ and CCL3,while they secreted lower levels of the reparative/anti-inflammatory IL-10 following exposure to lipopolysaccharide in comparison to their WT counterparts. Moreover,Pros1-deficient macrophages expressed less of the anti-inflammatory/pro-resolving enzymes arginase-1 and 12/15-lipoxygenase and produced less of the specialized pro-resolving mediator resolvin D1. Altogether,our results suggest that macrophage-derived PROS1 is an important effector molecule in regulating the efferocytosis,maturation,and reprogramming of resolution phase macrophages,and imply that PROS1 could provide a new therapeutic target for inflammatory and fibrotic disorders. View Publication

Pluripotent stem cell-derived cardiomyocyte grafts can remuscularize substantial amounts of infarcted myocardium and beat in synchrony with the heart,but in some settings cause ventricular arrhythmias. It is unknown whether human cardiomyocytes can restore cardiac function in a physiologically relevant large animal model. Here we show that transplantation of ∼750 million cryopreserved human embryonic stem cell-derived cardiomyocytes (hESC-CMs) enhances cardiac function in macaque monkeys with large myocardial infarctions. One month after hESC-CM transplantation,global left ventricular ejection fraction improved 10.6 ± 0.9{\%} vs. 2.5 ± 0.8{\%} in controls,and by 3 months there was an additional 12.4{\%} improvement in treated vs. a 3.5{\%} decline in controls. Grafts averaged 11.6{\%} of infarct size,formed electromechanical junctions with the host heart,and by 3 months contained ∼99{\%} ventricular myocytes. A subset of animals experienced graft-associated ventricular arrhythmias,shown by electrical mapping to originate from a point-source acting as an ectopic pacemaker. Our data demonstrate that remuscularization of the infarcted macaque heart with human myocardium provides durable improvement in left ventricular function. View Publication

Nonhuman primate (NHP) models are more predictive than rodent models for developing induced pluripotent stem cell (iPSC)-based cell therapy,but robust and reproducible NHP iPSC-cardiomyocyte differentiation protocols are lacking for cardiomyopathies research. We developed a method to differentiate integration-free rhesus macaque iPSCs (RhiPSCs) into cardiomyocytes with {\textgreater}85{\%} purity in 10 days,using fully chemically defined conditions. To enable visualization of intracellular calcium flux in beating cardiomyocytes,we used CRISPR/Cas9 to stably knock-in genetically encoded calcium indicators at the rhesus AAVS1 safe harbor locus. Rhesus cardiomyocytes derived by our stepwise differentiation method express signature cardiac markers and show normal electrochemical coupling. They are responsive to cardiorelevant drugs and can be successfully engrafted in a mouse myocardial infarction model. Our approach provides a powerful tool for generation of NHP iPSC-derived cardiomyocytes amenable to utilization in basic research and preclinical studies,including in vivo tissue regeneration models and drug screening. View Publication