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1.  Hematologic outcomes after total splenectomy and partial splenectomy for congenital hemolytic anemia☆☆☆ 
Journal of pediatric surgery  2015;51(1):122-127.
Purpose
The purpose of this study was to define the hematologic response to total splenectomy (TS) or partial splenectomy (PS) in children with hereditary spherocytosis (HS) or sickle cell disease (SCD).
Methods
The Splenectomy in Congenital Hemolytic Anemia (SICHA) consortium registry collected hematologic outcomes of children with CHA undergoing TS or PS to 1 year after surgery. Using random effects mixed modeling, we evaluated the association of operative type with change in hemoglobin, reticulocyte counts, and bilirubin. We also compared laparoscopic to open splenectomy.
Results
The analysis included 130 children, with 62.3% (n = 81) undergoing TS. For children with HS, all hematologic measures improved after TS, including a 4.1 g/dl increase in hemoglobin. Hematologic parameters also improved after PS, although the response was less robust (hemoglobin increase 2.4 g/dl, p < 0.001). For children with SCD, there was no change in hemoglobin. Laparoscopy was not associated with differences in hematologic outcomes compared to open. TS and laparoscopy were associated with shorter length of stay.
Conclusion
Children with HS have an excellent hematologic response after TS or PS, although the hematologic response is more robust following TS. Children with SCD have smaller changes in their hematologic parameters. These data offer guidance to families and clinicians considering TS or PS.
doi:10.1016/j.jpedsurg.2015.10.028
PMCID: PMC5083068  PMID: 26613837
Congenital hemolytic anemia; Splenectomy; Hematologic outcomes; Surgical technique
2.  A novel mouse model for ataxia-telangiectasia with a N-terminal mutation displays a behavioral defect and a low incidence of lymphoma but no increased oxidative burden 
Human Molecular Genetics  2015;24(22):6331-6349.
Ataxia-telangiectasia (A-T) is a rare multi-system disorder caused by mutations in the ATM gene. Significant heterogeneity exists in the underlying genetic mutations and clinical phenotypes. A number of mouse models have been generated that harbor mutations in the distal region of the gene, and a recent study suggests the presence of residual ATM protein in the brain of one such model. These mice recapitulate many of the characteristics of A-T seen in humans, with the notable exception of neurodegeneration. In order to study how an N-terminal mutation affects the disease phenotype, we generated an inducible Atm mutant mouse model (Atmtm1Mmpl/tm1Mmpl, referred to as A-T [M]) predicted to express only the first 62 amino acids of Atm. Cells derived from A-T [M] mutant mice exhibited reduced cellular proliferation and an altered DNA damage response, but surprisingly, showed no evidence of an oxidative imbalance. Examination of the A-T [M] animals revealed an altered immunophenotype consistent with A-T. In contrast to mice harboring C-terminal Atm mutations that disproportionately develop thymic lymphomas, A-T [M] mice developed lymphoma at a similar rate as human A-T patients. Morphological analyses of A-T [M] cerebella revealed no substantial cellular defects, similar to other models of A-T, although mice display behavioral defects consistent with cerebellar dysfunction. Overall, these results suggest that loss of Atm is not necessarily associated with an oxidized phenotype as has been previously proposed and that loss of ATM protein is not sufficient to induce cerebellar degeneration in mice.
doi:10.1093/hmg/ddv342
PMCID: PMC5007607  PMID: 26310626
3.  Serum-free spheroid suspension culture maintains high proliferation and differentiation potentials of mesenchymal stem cells 
Biotechnology progress  2014;30(4):974-983.
There have been many clinical trials recently using ex vivo-expanded human mesenchymal stem cells (MSCs) to treat several indications such as graft-versus-host disease, acute myocardial infarction, Crohn’s disease, and multiple sclerosis. However, the conventional 2-dimensional (2D) culture of MSCs is laborious and limited in scale potential. The large dosage requirement for many of the indications further exacerbates this manufacturing challenge. In contrast, spheroid MSC culture does not require a cell attachment surface and is amenable to large-scale suspension cell culture techniques, such as stirred-tank bioreactors. In this present study, we developed and optimized serum free media for culturing MSC spheroids. We used Design of Experiment (DoE)-based strategies to systematically evaluate media mixtures and a panel of different components. The optimization yielded two prototype media that could allow MSCs to form aggregates and proliferate in both static cultures and dynamic cultures. The expanded MSCs expressed the expected surface markers for mesenchymal cells (CD73, CD90 and CD105). In addition, the expanded cells demonstrated multipotency and differentiated to the osteocyte, chondrocyte and adipocyte lineages, which showed similar or enhanced differentiation levels compared with serum-containing adherent cultures.
doi:10.1002/btpr.1904
PMCID: PMC5081183  PMID: 24616445
Mesenchymal stem cells; spheroid culture; serum free media; differentiation
4.  Concise Review: Process Development Considerations for Cell Therapy 
Stem Cells Translational Medicine  2015;4(10):1155-1163.
This review presents an introduction to the process development challenges of cell therapies and describes some of the tools available to address production issues. A summary is provided of what should be considered to efficiently advance a cellular therapy from the research stage through clinical trials and finally toward commercialization.
The development of robust and well-characterized methods of production of cell therapies has become increasingly important as therapies advance through clinical trials toward approval. A successful cell therapy will be a consistent, safe, and effective cell product, regardless of the cell type or application. Process development strategies can be developed to gain efficiency while maintaining or improving safety and quality profiles. This review presents an introduction to the process development challenges of cell therapies and describes some of the tools available to address production issues. This article will provide a summary of what should be considered to efficiently advance a cellular therapy from the research stage through clinical trials and finally toward commercialization. The identification of the basic questions that affect process development is summarized in the target product profile, and considerations for process optimization are discussed. The goal is to identify potential manufacturing concerns early in the process so they may be addressed effectively and thus increase the probability that a therapy will be successful.
Significance
The present study contributes to the field of cell therapy by providing a resource for those transitioning a potential therapy from the research stage to clinical and commercial applications. It provides the necessary steps that, when followed, can result in successful therapies from both a clinical and commercial perspective.
doi:10.5966/sctm.2014-0294
PMCID: PMC4572896  PMID: 26315572
Process development; Mesenchymal stem cells; Cellular therapy; T cell; Pluripotent stem cells
5.  E-cadherin can limit the transforming properties of activating β-catenin mutations 
The EMBO Journal  2015;34(18):2321-2333.
Wnt pathway deregulation is a common characteristic of many cancers. Only colorectal cancer predominantly harbours mutations in APC, whereas other cancer types (hepatocellular carcinoma, solid pseudopapillary tumours of the pancreas) have activating mutations in β-catenin (CTNNB1). We have compared the dynamics and the potency of β-catenin mutations in vivo. Within the murine small intestine (SI), an activating mutation of β-catenin took much longer to achieve Wnt deregulation and acquire a crypt-progenitor cell (CPC) phenotype than Apc or Gsk3 loss. Within the colon, a single activating mutation of β-catenin was unable to drive Wnt deregulation or induce the CPC phenotype. This ability of β-catenin mutation to differentially transform the SI versus the colon correlated with higher expression of E-cadherin and a higher number of E-cadherin:β-catenin complexes at the membrane. Reduction in E-cadherin synergised with an activating mutation of β-catenin resulting in a rapid CPC phenotype within the SI and colon. Thus, there is a threshold of β-catenin that is required to drive transformation, and E-cadherin can act as a buffer to sequester mutated β-catenin.
doi:10.15252/embj.201591739
PMCID: PMC4570519  PMID: 26240067
APC; β-catenin; colorectal cancer; E-cadherin
6.  mTOR Inhibition Improves Anaemia and Reduces Organ Damage in a Murine Model of Sickle Cell Disease 
British journal of haematology  2016;174(3):461-469.
Summary
Mechanistic target of rapamycin (mTOR) has been shown to play an important role in red blood cell physiology, with inhibition of mTOR signalling leading to alterations in erythropoiesis. To determine if mTOR inhibition would improve anaemia in sickle cell disease (SCD), mice with SCD were treated with the dual mTORC1/2 inhibitor, INK128. 1 week after daily oral drug treatment, erythrocyte count, haemoglobin, and haematocrit were all significantly increased while reticulocyte counts were reduced. These parameters remained stable during 3 weeks of treatment. Similar effects were observed following oral treatment with the mTORC1 inhibitor, sirolimus. Sirolimus treatment prolonged the lifespan of sickle cell erythrocytes in circulation, reduced spleen size, and reduced renal and hepatic iron accumulation in SCD mice. Following middle cerebral artery occlusion, stroke size was reduced in SCD mice treated with sirolimus. In conclusion, mTOR inhibition is protective against anaemia and organ damage in a murine model of SCD.
doi:10.1111/bjh.14057
PMCID: PMC4959967  PMID: 27030515
mTOR; anaemia; sickle cell disease; sirolimus; stroke
7.  Improving Underrepresented Minority Student Persistence in STEM 
CBE Life Sciences Education  2016;15(3):es5.
Members of the Joint Working Group on Improving Underrepresented Minorities (URMs) Persistence in Science, Technology, Engineering and Mathematics (STEM), utilizing Kurt Lewin’s planned approach to change, describe five recommendations to increase URM persistence in STEM at the undergraduate level.
Members of the Joint Working Group on Improving Underrepresented Minorities (URMs) Persistence in Science, Technology, Engineering, and Mathematics (STEM)—convened by the National Institute of General Medical Sciences and the Howard Hughes Medical Institute—review current data and propose deliberation about why the academic “pathways” leak more for URM than white or Asian STEM students. They suggest expanding to include a stronger focus on the institutional barriers that need to be removed and the types of interventions that “lift” students’ interests, commitment, and ability to persist in STEM fields. Using Kurt Lewin’s planned approach to change, the committee describes five recommendations to increase URM persistence in STEM at the undergraduate level. These recommendations capitalize on known successes, recognize the need for accountability, and are framed to facilitate greater progress in the future. The impact of these recommendations rests upon enacting the first recommendation: to track successes and failures at the institutional level and collect data that help explain the existing trends.
doi:10.1187/cbe.16-01-0038
PMCID: PMC5008901  PMID: 27543633
8.  The initiator methionine tRNA drives cell migration and invasion leading to increased metastatic potential in melanoma 
Biology Open  2016;5(10):1371-1379.
ABSTRACT
The cell's repertoire of transfer RNAs (tRNAs) has been linked to cancer. Recently, the level of the initiator methionine tRNA (tRNAiMet) in stromal fibroblasts has been shown to influence extracellular matrix (ECM) secretion to drive tumour growth and angiogenesis. Here we show that increased tRNAiMet within cancer cells does not influence tumour growth, but drives cell migration and invasion via a mechanism that is independent from ECM synthesis and dependent on α5β1 integrin and levels of the translation initiation ternary complex. In vivo and ex vivo migration (but not proliferation) of melanoblasts is significantly enhanced in transgenic mice which express additional copies of the tRNAiMet gene. We show that increased tRNAiMet in melanoma drives migratory, invasive behaviour and metastatic potential without affecting cell proliferation and primary tumour growth, and that expression of RNA polymerase III-associated genes (which drive tRNA expression) are elevated in metastases by comparison with primary tumours. Thus, specific alterations to the cancer cell tRNA repertoire drive a migration/invasion programme that may lead to metastasis.
Summary: This paper demonstrates a functional link between a cancer-associated alteration to the tRNA repertoire and the invasive behaviour of cancer cells by demonstrating that increased tRNAimet can drive invasion and metastasis in melanoma cells.
doi:10.1242/bio.019075
PMCID: PMC5087684  PMID: 27543055
Cell migration; Invasion; tRNA repertoire; RNA polymerase III (Pol III); tRNAiMet; Integrin; Extracellular matrix; Melanoma; Metastasis
9.  Optimization of bioprocess conditions improves production of a CHO cell-derived, bioengineered heparin 
Biotechnology journal  2015;10(7):1067-1081.
Heparin is the most widely used anticoagulant drug in the world today. Heparin is currently produced from animal tissues, primarily porcine intestines. A recent contamination crisis motivated development of a non-animal-derived source of this critical drug. We hypothesized that Chinese hamster ovary (CHO) cells could be metabolically engineered to produce a bioengineered heparin, equivalent to current pharmaceutical heparin. We previously engineered CHO-S® cells to overexpress two exogenous enzymes from the heparin/heparan sulfate biosynthetic pathway, increasing the anticoagulant activity ~100-fold and the heparin/heparan sulfate yield ~10-fold. Here, we explored the effects of bioprocess parameters on the yield and anticoagulant activity of the bioengineered GAGs. Fed-batch shaker-flask studies using a proprietary, chemically-defined feed, resulted in ~two-fold increase in integrated viable cell density and 70% increase in specific productivity, resulting in nearly three-fold increase in product titer. Transferring the process to a stirred-tank bioreactor increased the productivity further, yielding a final product concentration of ~90 µg/mL. Unfortunately, the product composition still differs from pharmaceutical heparin, suggesting that additional metabolic engineering will be required. However, these studies clearly demonstrate bioprocess optimization, in parallel with metabolic engineering refinements, will play a substantial role in developing a bioengineered heparin to replace the current animal-derived drug.
doi:10.1002/biot.201400665
PMCID: PMC4556170  PMID: 26037948
CHO cells; Disaccharide analysis; Fed-batch cultures; Glycosaminoglycans; Metabolic engineering
10.  The Initiator Methionine tRNA Drives Secretion of Type II Collagen from Stromal Fibroblasts to Promote Tumor Growth and Angiogenesis 
Current Biology  2016;26(6):755-765.
Summary
Expression of the initiator methionine tRNA (tRNAiMet) is deregulated in cancer. Despite this fact, it is not currently known how tRNAiMet expression levels influence tumor progression. We have found that tRNAiMet expression is increased in carcinoma-associated fibroblasts, implicating deregulated expression of tRNAiMet in the tumor stroma as a possible contributor to tumor progression. To investigate how elevated stromal tRNAiMet contributes to tumor progression, we generated a mouse expressing additional copies of the tRNAiMet gene (2+tRNAiMet mouse). Growth and vascularization of subcutaneous tumor allografts was enhanced in 2+tRNAiMet mice compared with wild-type littermate controls. Extracellular matrix (ECM) deposited by fibroblasts from 2+tRNAiMet mice supported enhanced endothelial cell and fibroblast migration. SILAC mass spectrometry indicated that elevated expression of tRNAiMet significantly increased synthesis and secretion of certain types of collagen, in particular type II collagen. Suppression of type II collagen opposed the ability of tRNAiMet-overexpressing fibroblasts to deposit pro-migratory ECM. We used the prolyl hydroxylase inhibitor ethyl-3,4-dihydroxybenzoate (DHB) to determine whether collagen synthesis contributes to the tRNAiMet-driven pro-tumorigenic stroma in vivo. DHB had no effect on the growth of syngeneic allografts in wild-type mice but opposed the ability of 2+tRNAiMet mice to support increased angiogenesis and tumor growth. Finally, collagen II expression predicts poor prognosis in high-grade serous ovarian carcinoma. Taken together, these data indicate that increased tRNAiMet levels contribute to tumor progression by enhancing the ability of stromal fibroblasts to synthesize and secrete a type II collagen-rich ECM that supports endothelial cell migration and angiogenesis.
Highlights
•A mechanistic link between the tRNA repertoire and cancer progression•Selective control of the secretome by levels of the initiator methionine tRNA•A link between the tRNAome and ECM secretion from stromal fibroblasts•A new transgenic model recapitulating a key aspect of the cancer tRNAome
Clarke et al. show that levels of the initiator tRNAiMet are increased in carcinoma-associated fibroblasts. Using a transgenic approach to recapitulate this in vivo and quantitative mass spectrometry to characterize the stromal secretome, they show that elevated tRNAiMet drives production of a type II collagen-rich ECM to drive tumor progression.
doi:10.1016/j.cub.2016.01.045
PMCID: PMC4819511  PMID: 26948875
initiator methionine tRNA (tRNAiMet); extracellular matrix; tumor angiogenesis; secretome; tRNA repertoire; cell migration; tumor stroma
11.  Proceedings of a Sickle Cell Disease Ontology workshop — Towards the first comprehensive ontology for Sickle Cell Disease 
Sickle cell disease (SCD) is a debilitating single gene disorder caused by a single point mutation that results in physical deformation (i.e. sickling) of erythrocytes at reduced oxygen tensions. Up to 75% of SCD in newborns world-wide occurs in sub-Saharan Africa, where neonatal and childhood mortality from sickle cell related complications is high. While SCD research across the globe is tackling the disease on multiple fronts, advances have yet to significantly impact on the health and quality of life of SCD patients, due to lack of coordination of these disparate efforts. Ensuring data across studies is directly comparable through standardization is a necessary step towards realizing this goal. Such a standardization requires the development and implementation of a disease-specific ontology for SCD that is applicable globally. Ontology development is best achieved by bringing together experts in the domain to contribute their knowledge.
The SCD community and H3ABioNet members joined forces at a recent SCD Ontology workshop to develop an ontology covering aspects of SCD under the classes: phenotype, diagnostics, therapeutics, quality of life, disease modifiers and disease stage. The aim of the workshop was for participants to contribute their expertise to development of the structure and contents of the SCD ontology. Here we describe the proceedings of the Sickle Cell Disease Ontology Workshop held in Cape Town South Africa in February 2016 and its outcomes. The objective of the workshop was to bring together experts in SCD from around the world to contribute their expertise to the development of various aspects of the SCD ontology.
doi:10.1016/j.atg.2016.03.005
PMCID: PMC4911424  PMID: 27354937
12.  Paradoxical protection from atherosclerosis and thrombosis in a mouse model of sickle cell disease 
British journal of haematology  2013;162(1):120-129.
Summary
Sickle cell disease (SCD) is associated with vascular complications including premature stroke. The role of atherothrombosis in these vascular complications is unclear. To determine the effect of SCD on atherosclerosis and thrombosis, mice with SCD along with controls were generated by transplantation of bone marrow from mice carrying the homozygous sickle cell mutation (Hbbhβs/hβs) or wild-type mice (Hbb+/+) into C57BL6/J or apolipoprotein E deficient (Apoe−/−) recipient mice. At the time of sacrifice, 23–28 weeks following bone marrow transplantation, anaemia, reticulocytosis, and splenomegaly were present in mice receiving Hbbhβs/hβs bone marrow compared with control mice. Analysis of atherosclerosis involving the aortic root revealed reduced atherosclerotic lesion area with reduced macrophage content and increased collagen content in Apoe−/−, Hbbhβs/hβs mice compared to Apoe−/−, Hbb+/+ mice. In a carotid thrombosis model, the time to thrombosis was prolonged in Hbbhβs/hβs mice compared to Hbb+/+ mice. This apparent protective effect of SCD on atherosclerosis and thrombosis was diminished by inhibition of heme oxygenase-1 (HMOX1) using zinc protoporphyrin IX.
We conclude that SCD in mice is paradoxically protective against atherosclerosis and thrombosis, highlighting the complexity of vascular events in SCD. This protective effect is at least partially mediated by induction of HMOX1.
doi:10.1111/bjh.12342
PMCID: PMC4780334  PMID: 23590132
atherosclerosis; bone marrow transplant; haem oxygenase; thrombosis
13.  Clinical Outcomes of Splenectomy in Children: Report of the Splenectomy in Congenital Hemolytic Anemia (SICHA) Registry 
American journal of hematology  2014;90(3):187-192.
The outcomes of children with congenital hemolytic anemia (CHA) undergoing total splenectomy (TS) or partial splenectomy (PS) remain unclear. In this study, we collected data from 100 children with CHA who underwent TS or PS from 2005–2013 at 16 sites in the Splenectomy in Congenital Hemolytic Anemia (SICHA) consortium using a patient registry. We analyzed demographics and baseline clinical status, operative details, and outcomes at 4, 24, and 52 weeks after surgery. Results were summarized as hematologic outcomes, short-term adverse events (AEs) (≤ 30 days after surgery), and long-term AEs (31–365 days after surgery). For children with hereditary spherocytosis, after surgery there was an increase in hemoglobin (baseline 10.1 ± 1.8 gm/dl, 52 week 12.8 ± 1.6 gm/dl; mean ± SD), decrease in reticulocyte and bilirubin as well as control of symptoms. Children with sickle cell disease had control of clinical symptoms after surgery, but had no change in hematologic parameters. There was an 11% rate of short-term AEs and 11% rate of long-term AEs. As we accumulate more subjects and longer follow-up, use of a patient registry should enhance our capacity for clinical trials and engage all stakeholders in the decision-making process.
doi:10.1002/ajh.23888
PMCID: PMC4333061  PMID: 25382665
Congenital hemolytic anemia; hereditary spherocytosis; sickle cell disease; partial splenectomy; splenectomy
14.  Potent Antiviral Activities of the Direct-Acting Antivirals ABT-493 and ABT-530 with Three-Day Monotherapy for Hepatitis C Virus Genotype 1 Infection 
ABT-493 is a hepatitis C virus (HCV) nonstructural (NS) protein 3/4A protease inhibitor, and ABT-530 is an HCV NS5A inhibitor. These direct-acting antivirals (DAAs) demonstrated potent antiviral activity against major HCV genotypes and high barriers to resistance in vitro. In this open-label dose-ranging trial, antiviral activity and safety were assessed during 3 days of monotherapy with ABT-493 or ABT-530 in treatment-naive adults with HCV genotype 1 infection, with or without compensated cirrhosis. The presence of baseline resistance-associated variants (RAVs) was also evaluated. The mean maximal decreases in HCV RNA levels from baseline were approximately 4 log10 IU/ml for all ABT-493 doses ranging from 100 mg to 700 mg and for ABT-530 doses of ≥40 mg. There were no meaningful differences in viral load declines for patients with versus without compensated cirrhosis. Twenty-four (50%) of the baseline samples from patients treated with ABT-493 had RAVs to NS3/4A protease inhibitors. Among 40 patients treated with ABT-530, 6 (15%) carried baseline RAVs to NS5A inhibitors. Viral load declines in patients with single baseline NS5A RAVs were similar to those in patients without RAVs. One patient harbored baseline RAVs at 3 NS5A positions and appeared to have a slightly less robust viral load decline on day 3 of monotherapy. No serious or grade 3 (severe) or higher adverse events and no clinically relevant laboratory abnormalities were observed with either compound. ABT-493 and ABT-530 demonstrated potent antiviral activity and acceptable safety during 3-day monotherapy in patients with HCV genotype 1 infection, with or without compensated cirrhosis. Based on these results, phase II studies assessing the combination of these DAAs for the treatment of chronic HCV infection in patients with or without compensated cirrhosis have been initiated. (This study has been registered at ClinicalTrials.gov under registration no. NCT01995071.)
doi:10.1128/AAC.02264-15
PMCID: PMC4775945  PMID: 26711747
15.  Intravital FRAP Imaging using an E-cadherin-GFP Mouse Reveals Disease- and Drug-Dependent Dynamic Regulation of Cell-Cell Junctions in Live Tissue 
Cell Reports  2015;14(1):152-167.
Summary
E-cadherin-mediated cell-cell junctions play a prominent role in maintaining the epithelial architecture. The disruption or deregulation of these adhesions in cancer can lead to the collapse of tumor epithelia that precedes invasion and subsequent metastasis. Here we generated an E-cadherin-GFP mouse that enables intravital photobleaching and quantification of E-cadherin mobility in live tissue without affecting normal biology. We demonstrate the broad applications of this mouse by examining E-cadherin regulation in multiple tissues, including mammary, brain, liver, and kidney tissue, while specifically monitoring E-cadherin mobility during disease progression in the pancreas. We assess E-cadherin stability in native pancreatic tissue upon genetic manipulation involving Kras and p53 or in response to anti-invasive drug treatment and gain insights into the dynamic remodeling of E-cadherin during in situ cancer progression. FRAP in the E-cadherin-GFP mouse, therefore, promises to be a valuable tool to fundamentally expand our understanding of E-cadherin-mediated events in native microenvironments.
Graphical Abstract
Highlights
•The E-cadherin-GFP mouse allows in situ quantification of E-cadherin mobility•We monitored E-cadherin mobility during tissue homeostasis and disease development•Invasive pancreatic cancer driven by mutant Kras/p53 increases E-cadherin mobility•Dasatinib treatment reverts E-cadherin mobility and reinforces tumor cell junctions
Erami et al. generate an E-cadherin-GFP mouse to demonstrate real-time quantification of E-cadherin mobility using intravital photobleaching in a range of tissue types. They show that changes in E-cadherin mobility correlate with changes in cell junction integrity and invasiveness while demonstrating applications of the mouse for future drug discovery studies.
doi:10.1016/j.celrep.2015.12.020
PMCID: PMC4709331  PMID: 26725115
intravital imaging; FRAP; E-cadherin; Src-kinase; pancreatic cancer; invasion and metastasis; cell adhesion and migration; Kras; p53
16.  Boundaries can steer active Janus spheres 
Nature Communications  2015;6:8999.
The advent of autonomous self-propulsion has instigated research towards making colloidal machines that can deliver mechanical work in the form of transport, and other functions such as sensing and cleaning. While much progress has been made in the last 10 years on various mechanisms to generate self-propulsion, the ability to steer self-propelled colloidal devices has so far been much more limited. A critical barrier in increasing the impact of such motors is in directing their motion against the Brownian rotation, which randomizes particle orientations. In this context, here we report directed motion of a specific class of catalytic motors when moving in close proximity to solid surfaces. This is achieved through active quenching of their Brownian rotation by constraining it in a rotational well, caused not by equilibrium, but by hydrodynamic effects. We demonstrate how combining these geometric constraints can be utilized to steer these active colloids along arbitrary trajectories.
Self-propelled colloidal particles can be potentially used to transport cargoes at the microscale, but it is challenging to prevent randomization of their motion by Brownian rotations. Here, Das et al. quench these rotations by solid walls, which guide in-plane swimming without the need for external fields.
doi:10.1038/ncomms9999
PMCID: PMC4686856  PMID: 26627125
17.  Abnormal pulmonary function and associated risk factors in children and adolescents with sickle cell anemia 
Obstructive and restrictive pulmonary changes develop in children with sickle cell disease, but reports conflict as to the type of change that predominates. We prospectively performed spirometry, plethysmography and lung diffusing capacity in 146 children aged 7–20 years with hemoglobin SS or Sβ0-thalassemia. Nineteen percent of the patients had obstructive physiology as defined according to guidelines of the American Thoracic Society. In addition, 9% had restrictive physiology and 11% had abnormal but not categorized physiology. Increasing age, patient- or family-reported history of asthma or wheezing, and higher lactate dehydrogenase concentration were independent predictors of obstruction as reflected in lower FEV1/FVC. In conclusion, abnormal pulmonary function, most often obstructive, is common in children with hemoglobin SS and Sβ0-thalassemia. Full pulmonary function testing should be performed in children with hemoglobin SS or Sβ0 thalassemia, especially with history of asthma or wheezing and accentuated elevations in hemolytic markers.
doi:10.1097/MPH.0000000000000011
PMCID: PMC4681275  PMID: 24309610
sickle cell anemia; pulmonary function tests; obstructive pulmonary function; lactate dehydrogenase; reticulocyte count
18.  Minimizing the Risk of Preoperative Brain Injury in Neonates with Aortic Arch Obstruction 
The Journal of pediatrics  2014;165(6):1116-1122.e3.
Objective
To determine whether prenatal diagnosis lowers the risk of preoperative brain injury by assessing differences in the incidence of preoperative brain injury across centers.
Study design
From 2 prospective cohorts of newborns with complex congenital heart disease studied by preoperative cerebral magnetic resonance imaging, one cohort from the University Medical Center Utrecht (UMCU) and a combined cohort from the University of California San Francisco (UCSF) and University of British Columbia (UBC), patients with aortic arch obstruction were selected and their imaging and clinical course reviewed.
Results
Birth characteristics were comparable between UMCU (n = 33) and UCSF/UBC (n = 54). Patients had a hypoplastic aortic arch with either coarctation/interruption or hypoplastic left heart syndrome. In subjects with prenatal diagnosis, there was a significant difference in the prevalence of white matter injury (WMI) between centers (11 of 22 [50%] at UMCU vs 4 of 30 [13%] at UCSF/UBC; P < .01). Prenatal diagnosis was protective for WMI at UCSF/UBC (13% prenatal diagnoses vs 50% postnatal diagnoses; P < .01), but not at UMCU (50% vs 46%, respectively; P > .99). Differences in clinical practice between prenatally diagnosed subjects at UMCU vs UCSF/UBC included older age at surgery, less time spent in the intensive care unit, greater use of diuretics, less use of total parenteral nutrition (P < .01), and a greater incidence of infections (P = .01). In patients diagnosed postnatally, the prevalence of WMI was similar in the 2 centers (46%at UMCU vs 50% at UCSF/UBC; P > .99). Stroke prevalence was similar in the 2 centers regardless of prenatal diagnosis (prenatal diagnosis: 4.5% at Utrecht vs 6.7% at UCSF/UBC, P = .75; postnatal diagnosis: 9.1% vs 13%, respectively, P > .99).
Conclusion
Prenatal diagnosis can be protective for WMI, but this protection may be dependent on specific clinical management practices that differ across centers.
doi:10.1016/j.jpeds.2014.08.066
PMCID: PMC4624274  PMID: 25306190
19.  E-cadherin can limit the transforming properties of activating β-catenin mutations 
The EMBO Journal  2015;34(18):2321-2333.
Wnt pathway deregulation is a common characteristic of many cancers. Only colorectal cancer predominantly harbours mutations in APC, whereas other cancer types (hepatocellular carcinoma, solid pseudopapillary tumours of the pancreas) have activating mutations in β-catenin (CTNNB1). We have compared the dynamics and the potency of β-catenin mutations in vivo. Within the murine small intestine (SI), an activating mutation of β-catenin took much longer to achieve Wnt deregulation and acquire a crypt-progenitor cell (CPC) phenotype than Apc or Gsk3 loss. Within the colon, a single activating mutation of β-catenin was unable to drive Wnt deregulation or induce the CPC phenotype. This ability of β-catenin mutation to differentially transform the SI versus the colon correlated with higher expression of E-cadherin and a higher number of E-cadherin:β-catenin complexes at the membrane. Reduction in E-cadherin synergised with an activating mutation of β-catenin resulting in a rapid CPC phenotype within the SI and colon. Thus, there is a threshold of β-catenin that is required to drive transformation, and E-cadherin can act as a buffer to sequester mutated β-catenin.
doi:10.15252/embj.201591739
PMCID: PMC4570519  PMID: 26240067
APC; β-catenin; colorectal cancer; E-cadherin
20.  Next-Generation Psychiatric Assessment: Using Smartphone Sensors to Monitor Behavior and Mental Health 
Objective
Optimal mental health care is dependent upon sensitive and early detection of mental health problems. The current study introduces a state-of-the-art method for remote behavioral monitoring that transports assessment out of the clinic and into the environments in which individuals negotiate their daily lives. The objective of this study was examine whether the information captured with multi-modal smartphone sensors can serve as behavioral markers for one’s mental health. We hypothesized that: a) unobtrusively collected smartphone sensor data would be associated with individuals’ daily levels of stress, and b) sensor data would be associated with changes in depression, stress, and subjective loneliness over time.
Methods
A total of 47 young adults (age range: 19–30 y.o.) were recruited for the study. Individuals were enrolled as a single cohort and participated in the study over a 10-week period. Participants were provided with smartphones embedded with a range of sensors and software that enabled continuous tracking of their geospatial activity (using GPS and WiFi), kinesthetic activity (using multi-axial accelerometers), sleep duration (modeled using device use data, accelerometer inferences, ambient sound features, and ambient light levels), and time spent proximal to human speech (i.e., speech duration using microphone and speech detection algorithms). Participants completed daily ratings of stress, as well as pre/post measures of depression (Patient Health Questionnaire-9), stress (Perceived Stress Scale), and loneliness (Revised UCLA Loneliness Scale).
Results
Mixed-effects linear modeling showed that sensor-derived geospatial activity (p<.05), sleep duration (p<.05), and variability in geospatial activity (p<.05), were associated with daily stress levels. Penalized functional regression showed associations between changes in depression and sensor-derived speech duration (p<.05), geospatial activity (p<.05), and sleep duration (p<.05). Changes in loneliness were associated with sensor-derived kinesthetic activity (p<.01).
Conclusions and implications for practice
Smartphones can be harnessed as instruments for unobtrusive monitoring of several behavioral indicators of mental health. Creative leveraging of smartphone sensing will create novel opportunities for close-to-invisible psychiatric assessment at a scale and efficiency that far exceed what is currently feasible with existing assessment technologies.
doi:10.1037/prj0000130
PMCID: PMC4564327  PMID: 25844912
21.  A caveolin-dependent and PI3K/AKT-independent role of PTEN in β-catenin transcriptional activity 
Nature Communications  2015;6:8093.
Loss of the tumour suppressor PTEN is frequent in human melanoma, results in MAPK activation, suppresses senescence and mediates metastatic behaviour. How PTEN loss mediates these effects is unknown. Here we show that loss of PTEN in epithelial and melanocytic cell lines induces the nuclear localization and transcriptional activation of β-catenin independent of the PI3K–AKT–GSK3β axis. The absence of PTEN leads to caveolin-1 (CAV1)-dependent β-catenin transcriptional modulation in vitro, cooperates with NRASQ61K to initiate melanomagenesis in vivo and induces efficient metastasis formation associated with E-cadherin internalization. The CAV1-β–catenin axis is mediated by a feedback loop in which β-catenin represses transcription of miR-199a-5p and miR-203, which suppress the levels of CAV1 mRNA in melanoma cells. These data reveal a mechanism by which loss of PTEN increases CAV1-mediated dissociation of β-catenin from membranous E-cadherin, which may promote senescence bypass and metastasis.
The mechanism by which PTEN mutation is melanomagenic is complicated by different PTEN functions in different cellular locations. Here, the authors identify an alternative to membrane PI3K–AKT signalling, a caveolin-1-dependent PTEN pathway that induces nuclear localization and activation of β-catenin.
doi:10.1038/ncomms9093
PMCID: PMC4560817  PMID: 26307673
22.  Melanoma tumor growth is accelerated in a mouse model of sickle cell disease 
Background
The effect of sickle cell disease (SCD) on tumor growth is unknown. Sickled red blood cells may form aggregates within the microvasculature of hypoxic tumors and reduce blood flow leading to impairment of tumor growth. However, there is a paucity of data related to tumor growth in SCD.
Methods
To investigate the effect of SCD on tumor growth in a melanoma model, we generated SCD and control mice using bone marrow transplantation and inoculated the chest wall with B16-F10 melanoma cells. Tumor growth was monitored and angiogenesis was studied in vivo and in vitro.
Results
From day 1 to 21, tumor growth rate was nearly identical between SCD and WT mice, however from day 22 to day 29 tumor growth was accelerated in SCD mice compared to WT mice. Disparity in tumor size was confirmed at autopsy with an approximate 2-fold increase in tumor weights from SCD mice. Tumors from SCD mice showed increased vascularity and elevated levels of heme oxygenase-1 (HO-1). HO-1 inhibition with zinc protoporphyrin (ZnPP) blocked the angiogenic and tumor growth response to SCD in vivo and the response to hemin in vitro.
Conclusions
Growth of melanoma tumors is potentiated in a mouse model of SCD. Therapies targeting angiogenesis or HO-1 may be useful in SCD patients with malignant tumors.
doi:10.1186/s40164-015-0014-1
PMCID: PMC4496890  PMID: 26161296
Sickle cell disease; Melanoma; Angiogenesis; Heme oxygenase-1
23.  Reimagining the Pipeline: Advancing STEM Diversity, Persistence, and Success 
Bioscience  2014;64(7):612-618.
Achieving trainee diversity in science, technology, engineering, and mathematics is rapidly becoming a challenge faced by many nations. Success in this area ensures the availability of a workforce capable of engaging in scientific practices that will promote increased production capacity and creativity and will preserve global scientific competitiveness. The near-term vision of achieving this goal is within reach and will capitalize on the growing numbers of underrepresented minority groups in the population. Although many nations have had remarkable histories as leaders in science and technology, few have simultaneously struggled with the challenge of meeting the educational and training needs of underrepresented groups. In this article, we share strategies for building the agency of the scientific community to achieve greater diversity by highlighting four key action areas: (1) aligning institutional culture and climate; (2) building interinstitutional partnerships; (3) building and sustaining critical mass; and (4) ensuring, rewarding, and maximizing faculty involvement.
doi:10.1093/biosci/biu076
PMCID: PMC4282132  PMID: 25561747
diversity; retention; STEM education; training; workforce
24.  Reimagining the Pipeline: Advancing STEM Diversity, Persistence, and Success 
Bioscience  2014;64(7):612-618.
Achieving trainee diversity in science, technology, engineering, and mathematics is rapidly becoming a challenge faced by many nations. Success in this area ensures the availability of a workforce capable of engaging in scientific practices that will promote increased production capacity and creativity and will preserve global scientific competitiveness. The near-term vision of achieving this goal is within reach and will capitalize on the growing numbers of underrepresented minority groups in the population. Although many nations have had remarkable histories as leaders in science and technology, few have simultaneously struggled with the challenge of meeting the educational and training needs of underrepresented groups. In this article, we share strategies for building the agency of the scientific community to achieve greater diversity by highlighting four key action areas: (1) aligning institutional culture and climate; (2) building interinstitutional partnerships; (3) building and sustaining critical mass; and (4) ensuring, rewarding, and maximizing faculty involvement.
doi:10.1093/biosci/biu076
PMCID: PMC4282132  PMID: 25561747
diversity; retention; STEM education; training; workforce
25.  Differences in the clinical and genotypic presentation of sickle cell disease around the world 
Summary
Sickle cell disease (SCD), caused by a mutation in the β-globin gene HBB, is widely distributed in malaria endemic regions. Cardiopulmonary complications are major causes of morbidity and mortality. Hemoglobin SS (Hb SS) represents a large proportion of SCD in the Americas, United Kingdom, and certain regions of Africa while higher proportions of hemoglobin SC are observed in Burkina Faso and hemoglobin Sβ-thalassemia in Greece and India. Coinheritance of α-thalassemia and persistence of hemoglobin F production are observed in highest frequency in certain regions of India and the Middle East. As confirmed in the PUSH and Walk-PHaSST studies, Hb SS, absence of co-inheriting alpha-thalassemia, and low hemoglobin F levels tend to be associated with more hemolysis, lower hemoglobin oxygen saturations, greater proportions of elevated tricuspid regurgitant jet velocity and brain natriuretic peptide, and increased left ventricular mass index. Identification of additional genetic modifiers will improve prediction of cardiopulmonary complications in SCD.
doi:10.1016/j.prrv.2013.11.003
PMCID: PMC3944316  PMID: 24361300
Sickle Cell Disease; Echocardiogram; Pulmonary Function Test; Hemoglobin F; Alpha thalassemia

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