bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural Basis of Lipid Scrambling and Ion Conduction by TMEM16 Scramblases
Authors: Accardi Alessio , Falzone Maria , Lee Byoung-Cheol , Cheng Xiaolu , Khelashvili George , Weinstein Harel
Published: April 2020

The plasma membrane of eukaryotic cells is asymmetric, with polar and charged lipids sequestered to the inner leaflet when the cell is at rest. Activation of phospholipid scramblases rapidly collapses this asymmetry and externalizes negatively charged phosphatidylserine lipids, activating extracellular signaling networks that control processes such as apoptosis, blood coagulation, membrane fusion and repair. The TMEM16 family is comprised of Ca2+‐dependent Cl− channels and phospholipid scramblases with non‐selective ion channel activity. Structural and functional analyses of TMEM16 scramblases identified a membrane‐exposed hydrophilic groove that serves as a dual translocation pathway for ions and lipids. The mechanisms underlying Ca2+‐dependent gating of TMEM16 scramblases/non‐selective channels, lipid permeation and the emergence of their ion conduction pore remain poorly understood. We used cryo‐electron microscopy to determine the structures of a fungal scramblase/non‐selective channel from Aspergillus fumigatus, afTMEM16, reconstituted in lipid nanodiscs in the presence and absence of Ca2+. These structures reveal that Ca2+ binding induces a global rearrangement of the transmembrane and cytosolic regions, resulting in opening of the lipid permeation pathway by way of rearrangements of TM4 and TM6. The structures of the scramblase/nanodisc complex in the presence and absence of Ca2+ show that the scramblases induce a pronounced distortion of the surrounding membrane: the outer leaflet is bent along the dimer axis of the protein and the membrane is thinned near the opened lipid translocation pathway thereby facilitating transbilayer lipid movement.

Molecular dynamics simulations of a second closely related fungal TMEM16 scramblase, nhTMEM16, revealed that a hydrophobic lock between TM3 and TM4 is essential to maintain the open, lipid‐conductive conformation of the scramblase. MD simulations suggest that disruption of this lock favors the positioning of TM4 giving rise to a Ca2+‐bound conformation that is closed to the membrane and thus non‐conductive for lipids. Indeed, mutations at the TM3/TM4 lock severely impair lipid scrambling. Notably, these mutants retain ion channel activity, indicating that the dual activity scramblase/channel was converted into a channel only protein. The cryoEM structure of a channel‐only mutant reveal a continuous, protein‐delimited pore of sufficient size to allow ion permeation. Our results show that TM6 and TM4 are the gating elements of TMEM16 scramblases where TM6 movement is directly controlled by Ca2+‐binding and TM4 rearrangements are controlled by a hydrophobic lock between TM3 and TM4.

Support or Funding Information

NIGMS 5R01 GM106717
Genome wide analysis of heparan sulfate assembly
Authors: Esko Jeffrey D. , Weiss Ryan J. , Spahn Philipp , Toledo Alejandro Gomez , Chiang Austin W.T. , Kellman Benjamin P. , Li Jing , Benner Christopher , Glass Christoper K. , Gordts Philip L.S.M. , Lewis Nathan E.
Published: April 2020

It is well known that the arrangement and orientation of the sulfated sugar residues in heparan sulfate specify the location of distinct binding sites for protein ligands, and that binding regulates important biological processes including cell proliferation and development. Most of the enzymes involved in glycosaminoglycan biosynthesis have been cloned, purified and studied biochemically, but there is much less information regarding the regulatory mechanisms that control the spatial and temporal expression of heparan sulfate in cells and tissues. We have taken a two‐prong approach towards uncovering these control systems. In one approach, we examined the promoter regions of all genes involved in heparin/heparan sulfate assembly and uncovered a transcription factor binding motif for ZNF263, a C2H2 zinc finger protein. CRISPR‐mediated targeting and siRNA knockdown of ZNF263 in mammalian cell lines and human primary cells led to a dramatic increase in expression of HS3ST1, a key enzyme involved in imparting anticoagulant activity to heparin. Enhanced 3‐O‐sulfation increased binding to antithrombin, which enhanced Factor Xa inhibition. Analysis of transcriptomics data showed an inverse correlation of expression of ZNF263 and HS3ST1 in mast cells and basophils compared to other (non‐heparin producing) immune cells, consistent with its role in regulation of anticoagulant heparin. In a second approach we developed a genome‐wide CRISPR/Cas9‐mediated screen. A lentiviral single guide RNA (sgRNA) library was utilized to knock down gene expression across the entire genome in a human melanoma cell line. High‐throughput screening assays were adapted to identify lentiviral‐encoded sgRNAs that induce resistance to a cytotoxin whose action depends on HSPGs and that reduce binding of HS‐dependent ligands. Top hits from the screens were characterized and categorized based on their predicted gene functions and are currently being individually validated and examined for their involvement in the regulation of HS composition.

Support or Funding Information

We thank generous support from the National Institutes of Health (R01GM33063 to J.D.E.; R21CA199292 to J.D.E. and N.E.L., R35GM119850 to N.E.L, R21 HD089067 to P.L.S.M.G.), the Fondation Leducq (to C.K.G and P.L.S.M.G.), a fellowship award to R.J.W. (K12HL141956), and generous support from the Novo Nordisk Foundation Center for Biosustainability at the Technical University of Denmark (to N.E.L.).
Leveraging Microfluidics for High‐Throughput Studies of Transcription Factor/DNA Binding
Authors: Fordyce Polly , Aditham Arjun , Horton Connor , DelRosso Nicole , Mokhtari Daniel , Markin Craig
Published: April 2020

Gene expression is regulated primarily by transcription factors (TFs) that bind specific regulatory DNA sequences within the genome, thereby recruiting or repressing the transcriptional machinery to activate or repress transcription, respectively. However, despite decades of research, we remain largely unable to predict TF binding and/or downstream gene expression from regulatory sequence alone. Here, we leverage a microfluidic platform to yield quantitative, high‐throughput measurements of TF‐DNA binding affinities and dissociation rates for hundreds of basic helix‐loop‐helix TF variants interacting with varying DNA sequences. These data establish that sequences outside of known consensus sites can have surprisingly large effects on equilibrium binding and quantitatively map interactions across the TF‐DNA interface. We anticipate that these results will prove broadly useful for computational efforts to predict functional effects of rare mutations in precision medicine and promoter design in synthetic biology.

Support or Funding Information

P.M.F. is a Chan Zuckerberg Investigator and also acknowledges a Sloan Research Fellowship for supporting this work.
Metabolic Modulation of Cardiac Health: The Role of Glucose and Amino Acids
Authors: Tian Rong
Published: April 2020

The heart has high metabolic flexibility in utilizing a variety of substrates for energy production. Reprogramming of cardiac metabolism is recognized as integral to the development of heart failure. In hypertrophied and failing hearts, fatty acid oxidation is reduced and glucose utilization is increased. Recent studies have also identified changes in the catabolism of amino acids and ketone bodies in the failing hearts. Thus, elucidating the functional consequence of the metabolic remodeling could provide mechanistic insights of pathogenesis and therapy of heart failure. While the switch from fatty acids to glucose has been shown ultimately maladaptive for energy supply, the impact of increased glucose reliance on cardiac hypertrophy and remodeling is incompletely understood. Emerging results suggest that changes in glucose and branched chain amino acid metabolism, apart from their contribution to energy production, serve multiple roles in controlling the hypertrophic growth of the heart. A number of studies have evaluated the impact of substrate switch on energy production in the heart by comparing and contrasting the contribution of multiple substrates using bioengineered mouse models. Emerging studies focus on the role of substrate metabolism in signal transduction and biosynthetic function of the cardiomyocytes undergoing hypertrophic growth.
Role of ECM in the Brain‐Gut Connection
Authors: Gomez-Pinilla Fernando , Yang Xia
Published: April 2020

We sought to determine the role of extracellular matrix (ECM) proteoglycans on regulating brain function and cell metabolism. In the first series of studies, we used dietary fructose to perturbate metabolism based on evidence that fructose is a major contributor to the epidemic of diabetes and obesity. Our transcriptomic studies (Meng et al, EBiomed, 157(7), 2016) showed that the gene for the proteoglycan biglycan (Bgn) occupies a central position in a network of genes receptive to the action of fructose in the hypothalamus (main brain center of metabolic control). We pursued studies further and exposed male biglycan knockout mice (Bgn0/−) to fructose for 7 weeks, and results showed that the Bgn0/− gene perturbation compensated for a decrement in learning and memory performance in mice exposed to fructose (Ying et al., BBADIS, 1864(12) 2018). Learning and memory performance was consistent with an attenuation of the action of fructose on hippocampal plasticity markers CREB and BDNF. Bgn siRNA treatment abolished the effects of fructose on CREB and BDNF levels, in conjunction with reducing a fructose‐related increase in Bgn protein. In addition, fructose consumption perturbed the systemic metabolism of glucose and lipids, that were also altered in the Bgn0/ mice. Transcriptomic profiling of hypothalamus, hippocampus, and liver supported the regulatory action of Bgn on key molecular pathways involved in metabolism, immune response, and neuronal plasticity. Overall results underscore the tissue‐specific role of the extracellular matrix in the regulation of metabolism and brain function, and support Bgn as a key modulator of the impact of fructose across body and brain. In separate studies, we found that the gene for the proteoglycan fibromodulin (Fmod) controls a network of genes responsive to the action of brain trauma (EBiomed, 184(16) 2017). The action of Fmod (42–80 KDa) on the brain is poorly understood and rather known for affecting fibrillogenesis, cell adhesion, cytokine activity in the periphery. We found that deletion of Fmod gene mitigated the TBI‐related increase in the pro‐inflammatory marker toll like receptor 4 (TLR4), and attenuated a reduction in cell metabolic markers PGC1alpha and cytochrome oxidase II (COII), in the mouse hypothalamus after TBI. The latter suggests that Fmod deletion can protect against the cell metabolic crisis observed after TBI. In addition, given the regulatory role of the hypothalamus on peripheral metabolism, we sought to determine the effects of Fmod genetic deletion on the homeostasis of lipids in the liver on mice exposed to TBI. Results showed that the deletion of the Fmod gene protected against the action of brain trauma on key lipids and the levels of fatty acid synthase (FAS), a major lipogenic enzyme commonly involved in fatty acid processing. These results suggest a potential effect of Fmod on brain trauma outcome in brain and periphery.

Support or Funding Information

R01 NS50465, R01 DK104363
Mechanisms of Wnt5a‐Ror Signaling in Development and Disease
Authors: Ho Henry , Konopelski Sara , Susman Michael , Kunz Ryan , Tan Jia , Cohen Michael , Okada Kyoko , Lamb Helen , Choi Shannon , Karuna Edith , Scales Michael , Gygi Steven , Greenberg Michael
Published: April 2020

Wnt5a‐Ror signaling is a conserved developmental pathway that regulates morphogenetic processes during vertebral embryonic development, and dysfunction of the pathway causes a number of human disorders, including Robinow syndrome. The mechanisms of Wnt5a‐Ror signaling remain poorly understood. Using a large‐scale proteomic screen, we identified the E3 ubiquitin ligase Pdzrn3 as a new regulatory target that is degraded upon pathway activation in a beta‐catenin independent, ubiquitin‐proteasome system dependent manner. Using this discovery, we developed a flow cytometry‐based reporter to monitor Pdzrn3 abundance and delineated a signaling cascade involving Frizzled, Dishevelled, Casein kinase 1, and Glycogen synthase kinase 3 that regulates Pdzrn3 degradation. Genetic epistasis analysis suggests that Pdzrn3 resides downstream of Dishevelled and independently of Kif26b, a previously identified Wnt5a‐Ror regulatory target. Further, we discovered that Pdzrn3 degradation requires Wnt5a‐dependent phosphorylation of its C‐terminal LNX3H domain, which is conserved in several Pdzrn3 homologs and likely functions as a novel Wnt5a‐responsive domain. Collectively, this work establishes a new Wnt5a‐Ror signaling cascade involving Pdzrn3 phosphorylation and degradation.

Support or Funding Information

NIH Grant 1R35GM119574
The ESCRT Membrane Scission Machine
Authors: Hurley James , Flower Thomas , Pavlin Mark Remec
Published: April 2020

The ESCRT complexes I, II, and III and the AAA+ ATPase VPS4, catalyze reverse‐topology scission from the inner face of membrane necks in HIV budding, multivesicular endosome biogenesis, cytokinesis, and other pathways. We previously found that VPS4 disassembles model ESCRT‐III filaments by processively unfolding entire ESCRT‐III subunits. Reverse‐topology membrane scission was reconstituted by encapsulating ESCRT‐III and VPS4 in a system allowing membrane nanotubes to be pulled from giant unilamellar vesicles using optical tweezers. In this reconstitution, ESCRT‐III subunits and VPS4 colocalize in puncta on nanotubes throughout the process of membrane scission. Another AAA+ enzyme, spastin, which is best known as a microtubule severing enzyme, is closely related in sequence and structure to VPS4. Spastin associates with the ESCRT‐III subunits CHMP1B and IST1. CHMP1B and IST1 form an unusual ESCRT‐III coat on the outside of membrane tubes and we found that these coats can carry out normal‐topology membrane scission. The roles of VPS4 and spastin in normal topology tube scission by, and disassembly of, CHMP1B‐IST1 complexes will be discussed. ESCRT‐III has long been known to form helical coats and spiral rings on membranes, but the assembly properties of the upstream ESCRTs have been little characterized. We found that ESCRT‐I can assemble into helices with a 12‐fold repeat, and that this helical assembly is important for function.

Support or Funding Information

NIAID, NIH
Filament assembly by the liver phosphofructokinase‐1, the “gatekeeper” of glycolysis
Authors: Webb Bradley , Dosey Anne , Wittmann Torsten , Kollmann Justin , Barber Diane
Published: April 2020

Despite abundant knowledge of the regulation and biochemistry of glycolytic enzymes, we have limited understanding on how they are spatially organized in the cell. Emerging evidence indicates that metabolic enzymes from diverse pathways can assemble into filaments. We show that the liver isoform of glycolytic “gatekeeper” enzyme phosphofructokinase‐1 (PFKL), which catalyzes the step committing glucose to breakdown, forms filaments in vitro and dynamic punctae in cells. Recombinant PFKL, but not platelet or muscle isoforms, assembles into filaments in a concentration‐, substrate‐, and tetramer‐dependent manner. Filaments are apolar and made of stacked tetramers oriented with exposed catalytic sites positioned along the edge of the polymer as determined by negative‐stain electron micrographs. Quantified live‐cell imaging shows PFKL‐EGFP appears as dynamic puncta that are enriched at discrete locations at the plasma membrane. These findings reveal a new behavior of a key glycolytic enzyme with insights on spatial organization and isoform‐specific glucose metabolism in cells.

Support or Funding Information

West Virginia University Start up funds
Characterization of Formate Dehydrogenase of Shewanella amazonensis
Authors: Usman Kabiru , Clarke Thomas , Bowater Richards
Published: April 2020

Background

Members of the family Shewanellacea have the ability to utilise formate as an electron donor for ATP generation under anaerobic respiration. A preliminary study conducted on different strains of Shewanella species shows that the Shewanella amazonensis formate dehydrogenase has a low catalytic activity of formate oxidation, and a high carbon dioxide reductase activity using methyl viologen as an electron acceptor or donor.

Objectives

The aim of this research was to characterize formate dehydrogenase of Shewanella amazonensis and to investigate its possible use as a biocatalyst for the reduction of CO2 to formate. The growth phenotypes of Shewanella amazonensis was compared to Shewanella oneidensis on formate under aerobic and anaerobic conditions, and the catalytic properties of the formate dehydrogenase from Shewanella amazonensis were investigated further to better understand the preliminary data.

Methods

Shewanella amazonensis and Shewanella oneidensis cells were grown aerobically in LB media supplemented with formate. Minimal media supplemented with formate and fumarate was used to study the ability of the strains to utilize formate and fumarate. Methyl viologen was used to study formate oxidation and carbon dioxide reduction using minimal media under anaerobic condition.

Results

Anaerobic growth on Minimal media supplemented with formate and fumarate suggested that the Shewanella amazonensis growth rate was lower than the growth rate of Shewanella oneidensis. Kinetic assays suggest a lower Vmax was responsible for the observed kinetic differences.
OmpA Porin of Salmonella enterica serovar Enteritidis Possesses Aamyloid‐Forming Properties
Authors: Belousov Mikhail V. , Kosolapova Anastasiia O. , Antonets Kirill S. , Nizhnikov Anton A.
Published: April 2020

The major focus of Salmonella enterica studies is the molecular determinants of the virulence and host‐specificity. Important virulence factors shared by the majority of pathogenic gram‐negative bacteria are the outer membrane proteins (OMP), many of which belong to the porins – beta barrel proteins serving as passive membrane pores. One of the most studied in terms of pathogenesis is the OmpA porin family. The proteins of the OmpA family are involved in the important virulence‐ and pathogenesis‐related processes including adhesion, penetration and damage of host tissues, as well as avoiding the immune response. Proteins of this family are highly conserved. For instance, the amino acid sequence similarity of OmpA proteins of Escherichia coli and S. enterica serovar Enteritidis is 94%. Considering ability of the E. coli OmpA porin to form amyloid‐like aggregates, we have produced recombinant OmpA protein from S. enterica serovar Enteritidis in vitro and have analyzed its amyloid properties. We have determined the typical fibrillary morphology of the obtained OmpA aggregates using transmission electron microscopy and have demonstrated that these aggregates exhibit yellow‐green birefringence being stained with amyloid‐specific dye Congo Red. We have also found that OmpA protein fused with YFP aggregates in yeast Saccharomyces cerevisiae while OmpA fibrils secreted in vivo at the surface of bacterial cells in the Curli‐Dependent Amyloid Generator system demonstrate properties typical for amyloids including unbranched morphology and birefringence upon binding with Congo Red. Taken together, these results suggest that the S. enterica serovar Enteritidis OmpA porin has amyloid‐forming properties.

Support or Funding Information

This work was supported by the Russian Science Foundation (Grant No 19‐76‐00026).
Impact of an aspartame‐containing diet soft drink on postprandial metabolism
Authors: Pearson Regis C. , Green Edward S. , Olenick Alyssa A. , Jenkins Nathan T.
Published: April 2020

Objective

Non‐nutritive sweeteners (NNS) are widely used to lower daily caloric intake. However, controversy exists concerning possible metabolic effects of NNS. We hypothesized that Diet Coke, containing aspartame, differentially affects postprandial metabolism compared to a sugar‐sweetened beverage (Coke), but not water when co‐ingested with a mixed meal.

Methods

Six healthy lean (26±1% body fat) males aged 20–26 yrs completed three separate tests consisting of a mixed meal (0.4g fat, 0.8g carbohydrates, and 0.3g protein/kg FFM) with the addition of 20oz of Coca‐Cola (CC: 787±49kcal), Diet Coke (NNS: 547±49kcal), or water (CON: 547±49kcal). Resting metabolic rate was measured via indirect calorimetry and blood samples were obtained immediately before, 5, 10 and 30 min, and 1, 2 and 3 hours after meal and beverage ingestion.

Results

There was a significant main effect of treatment on fat oxidation rate, with post hoc analysis indicating differences between effect between CC and CON (P < 0.001), and CC and NNS (P = 0.012). For all measures of fat oxidation, including total fat oxidized, area under the fat oxidation curve (AUC), and total postprandial fat oxidized, NNS and CON were significantly higher compared to CC (P < 0.05). Additionally, there was a significant main effect of treatment on the rate of carbohydrate oxidation, with post hoc testing indicating differences between CC and CON (P < 0.001), and CC and NNS (P = 0.023). All measures of carbohydrate oxidation, including total carbohydrate oxidized, carbohydrate oxidation AUC, and total postprandial carbohydrate oxidized were significantly lower during NNS and CON treatments compared to CC (P < 0.05), with no differences between NNS and CON. There were no significant differences among treatments in glucose concentrations.

Conclusion

Diet Coke does not impact postprandial metabolism, whereas Coca‐Cola suppresses fat oxidation and increases carbohydrate oxidation compared to Diet Coke and water.

Support or Funding Information

R.C.P. was support by the University of Georgia Graduate School Georgia Research Education Award Traineeship Follows Program
Age‐Dependent Decrease in PI3K p110 gamma
Authors: Askvig Jason , Ihry Victoria , Weidner Emily , Irmen Riley , Bexell Sydney
Published: April 2020

We previously demonstrated that the hypothalamic supraoptic nucleus (SON) undergoes a robust axonal sprouting response following unilateral transection of the hypothalamo‐neurohypophysial tract in a young, 35‐day‐old rat. However, no collateral sprouting occurs following axotomy in a 125‐day‐old rat. Our lab has in vitro evidence demonstrating the role of CNTF (ciliary neurotrophic factor) in promoting process outgrowth via PI3K signaling. Thus, we compared the protein levels of the PI3K catalytic and regulatory subunits in the SON between 35‐ and 125‐day rats. We found less protein of the catalytic domain, PI3K p110γ, in the 125‐day rat SON; however, we did not observe changes in the other three catalytic domains nor the regulatory domains that we analyzed. Dual fluorescent studies demonstrated that all PI3K catalytic and regulatory subunits analyzed are localized to astrocytes and neurons in the SON. These data suggest that the lack of PI3K p110γ found in the 125‐day rat SON may prevent the collateral sprouting response from occurring, but future studies need to be performed to confirm this hypothesis.

Support or Funding Information

This material is based upon work supported by the National Science Foundation under Grant No. 1643998
Prevalence of Neuropsychiatric Disorders in Patients With Systemic Lupus Erythematosus (SLE).
Authors: Punnam Anurag Reddy , Khan Zainab Haider , Nayakanti Abraham , lambo jonathan
Published: April 2020

BACKGROUND

Neuropsychiatric systemic lupus erythematosus (NPSLE) is a serious and well‐known complication of systemic lupus erythematosus (SLE). There are few studies on the population‐based estimates of the prevalence of NPSLE and its manifestations. Reliable prevalence estimates are needed to quantify the burden of the disease and to direct the attention of policy makers to magnitude of suffering associated with SLE. We aimed to quantify the prevalence of NPSLE in different population settings.

METHODS

We searched PubMed from January 2009 to June 2019 to identify studies relevant to this review. Databases searches combined terms from three themes: all age groups/general population, psychosis, neuropsychiatric impairment, mental disorders and delusions; and SLE, lupus, and systemic lupus erythematosus. Terms were searched as both keywords (title/abstract words) and subject headings as appropriate. We also searched original papers relevant to this review from the retrieved articles. For case classification and case ascertainment, NPSLE was classified according to the American College of Rheumatology guidelines.

RESULT

We excluded 79 from the initial 105 articles from the screening of titles and abstracts. The remaining 26 full text articles were reviewed and 9 were included in the review. The major neuropsychiatric comorbidities that were observed from the studies were major depression, headaches, seizures and cerebrovascular diseases. The prevalence estimates of neuropsychiatric disorders in NPSLE patients were as follows: major depression in patients (17%–52%) headaches (38.8%–60%), seizures (26.4%–63%), and cerebrovascular diseases (26%–38.8%). The overall prevalence estimates of NPSLE varies from 11% to 60% of all SLE patients.

CONCLUSION

This study confirms that the burden of neuropsychiatric manifestations of SLE, including major depression, seizures, cerebrovascular disease is high. Further studies are needed to elucidate the pathogenesis of neurological involvement in patients with SLE and to address the risk factors for NPSLE.

Support or Funding Information

American Association for Anatomists
ERa suppresses liver cancer EMT and amoeboid movement by targeting Ga12
Authors: Yun Jessica , Kim Sang Geon
Published: April 2020

Several reports demonstrate the association of certain cancer progression and estrogen receptor alpha (ERa) expression. Due to poor prognosis and high relapse, hepatocellular carcinoma (HCC) is the second most common cancer worldwide. Moreover, aggressiveness and mortality of HCC is more frequent in men than women. Ga12 gep oncogene plays a critical role in promoting epithelial‐mesenchymal transition (EMT), a well‐established mechanism for tumor invasion. We previously showed that Ga12 is overly expressed in HCC patients. Here, we report an inverse correlation of ERa and Ga12 expression in HCC, which may contribute to the cancer metastasis and patient mortality. ERa transcriptionally inhibited Ga12 expression in a cancer cell model. In addition, tumor cells can take another modes of movement, characterized as amoeboid movement. Both EMT and amoeboid movement are necessary for an efficient metastasis of cancer cell. Since ROCK is one of the main downstream molecules of the Ga12 pathway and is known to activate amoeboid motility, we hypothesized whether ERa may affect amoeboid phenotype by modulating Ga12 signaling pathway, and found that ERa activation inhibited amoeboidal cell migration/invasion in conjunction with Ga12 repression. Moreover, we found microRNA‐141 and ‐200a as functional molecules affected downstream from the ERa‐Ga12 pathway, and their targeting of PTP4A1. Together, our results show that the ERa‐Ga12 pathway may play a role in targeting EMT and amoeboid movement plasticity of liver cancer, which may account for the gender disparity in HCC incidence and malignant progression.

Support or Funding Information

This work was financially supported by the Bio & Medical Technology Development Program of the NRF funded by the Korean government, MSIP (2015M3A9B6074045).
Transcriptome Analysis of Mice Treated with Anti‐miR‐144
Authors: Iloabuchi Vivian , Laws Tyler , Link Jenny , Vallim Thomas , Tarling Elizabeth
Published: April 2020

Heart disease is a leading cause of death each year in the United States. In this study, we investigated the regulation of reverse cholesterol transport, a process shown to attenuate heart disease. Our lab has previously shown that mice treated with anti‐miR‐144 for 4 weeks increased ABCA1, which is involved in increased levels of high‐density lipoprotein and less fat in the heart. We hypothesized that long‐term treatment with anti‐miR‐144 would reveal other key genes in reverse cholesterol transport. Mice were placed on high fat, high cholesterol diet for 16 weeks, and treated with either saline, control anti‐miRNA, or anti‐miR‐144. Liver tissues were collected and processed for RNA sequencing. Using differential gene expression analysis, we found very few differences in gene expression among the treatment groups. When we did a comparison between the control‐treated mice and the anti‐miR‐144‐treated mice there was only one gene called MerTK that showed significant changes in gene expression. When we did a comparison between anti‐miR‐144‐treated mice and PBS‐treated mice, there were five genes that were shown to be differentially expressed which were Rgs3, Cd300lf, Fabp5, Dmac2l, and Slc1a3. Rgs3 and Slc1a3 showed higher expression in the PBS‐treated mice and the Cd300lf, Fabp5, Dmac2l showed higher expression in the anti‐miR‐144‐treated mice. As a reference, we did a comparison between the control‐treated mice and PBS‐treated mice and found that Cd300lf and the Fabp5 were also significantly expressed; this means that the changes for the two genes may not be due to anti‐miR‐144 treatment. Overall, we think that long‐term treatment of anti‐miR‐144 suppressed acute effects at the mRNA transcript level.

Support or Funding Information

UCLA, Bruins‐in‐Genomics Summer Program. Fisk University
Age‐related Effects of Feeder Space Availability on Blood Physiological Variables of Broilers Grown to Heavy Weights (> 3 kg)
Authors: Olanrewaju Hammed A , Purswell Joseph L , Collier Stephanie D , Branton Scott L
Published: April 2020

Demand for and consumption of poultry meat has increased dramatically, and is expected to continue in the future due to the relative price‐competitiveness as compared to other meat products. Consumer concern about rapid growth and increased production efficiency is perceived to negatively impact the well‐being of the animal. Hematological analyses including changes in acid‐base balance provide a thorough evaluation of the health status of individuals; and changes are the indicators of internal organ health and systemic homeostasis in both domestic animals and human beings. This study investigated the effects of feeder space availability on blood physiological variables of broilers grown to heavy weights (> 3.0 kg). A total of 1440 1‐d‐old chicks (straight‐run) were obtained from a commercial hatchery. Chicks were equally and randomly allocated to 32 pens based on feeder space treatment assigned. Treatments were four different feeder space allocations: 2.30 (Single feeder), 2.30, 4.60, and 6.90 cm/bird. In order to maintain uniform bird:feeder floor space except for the single feeder, three feeders were installed in each pen. Blood samples (3 ml) were collected from the brachial wing vein of 3 birds per pen on d 27 and 55, which were then analyzed immediately for whole blood physiological variables. The remaining blood samples were centrifuged to collect plasma that was used for corticosterone analysis. Results show there was no effect of feeder space on most of the selected physiological variables, but age had significant effects on most of the examined variables. However, all observed changes were within physiological ranges. Plasma corticosterone was not affected by feeder space and age, indicating absence of physiological stress. The results are in broad agreement with those reported in the literature and contribute to our knowledge of blood physiological and homeostatic variation in developing broilers. In conclusion, expanding feeder allowance does not enhance the welfare of broilers grown to heavy weights.
Addressing and Overcoming Difficulties for Students with Color Vision Differences or Deficits (Color Blindness) in Educational Instruction and Assessment
Authors: Henry Nancy , Stephenson Connor M. , Clough Rich , Shea Sandra
Published: April 2020

Approximately 8% of males and 0.4% of females in the United States have color vision differences that result in inabilities to discern red or green based colors. Color Vision Difference or Deficit (CVD) is often an X‐linked genetic disorder related to absent or altered functioning of certain cones in the retina. Individuals with the most prevalent forms of CVD (deuteranomaly and protanomaly) have been classified as red‐green color blind and have difficulty distinguishing between colors of reds, greens, browns, oranges, and purples. Individuals with CVD are often challenged by commonly used teaching and testing materials that rely on descriptions and discriminations based on color. Examples of problems encountered by learners include: labeled structures in textbooks, PowerPoint© presentations, and exams wherein labels are made in colors that are indiscernible to students with CVD. Additional difficulties are often evident in histology curricula where tissue specimens are most frequently stained with Hematoxylin & Eosin. Eosinophilic structures (that stain red or pink) such as collagen, muscle, mitochondria, and blood cells are very difficult to distinguish or may seem almost imperceptible to students with CVD.

Although there is a high prevalence of CVD in the United States, many educators are not aware of the challenges individuals with CVD encounter when color‐based teaching and testing materials are used. There are currently several computer‐based CVD simulator tools that allow educators and learners to upload images to simulate specific perceptual difficulties for individuals with CVD. These programs combined with extensive feedback and input from learners with CVD were used to identify problem areas in teaching and assessment of students with color vision differences. Methods were developed to help CVD individuals succeed in the histology and anatomy curricula, as well as in other academic disciplines. These inexpensive, simple, and easily applied methods include: ensuring the differentiation and descriptions of structures are not based solely on color; outlining specific tissue borders in colors with high contrast (not red or green); using textured backgrounds; and avoiding the use of red, green, or color‐coded labels. Additionally, procedures utilizing gray‐scale and modified‐color images have been employed in other curricula. These approaches have increased awareness of CVD among faculty and have fostered the development of strategies to ensure fairness, parity, and accessibility in histology, anatomy, and other programs.

Support or Funding Information

This work was supported by Southern Illinois University School of Medicine.
Epithelial‐mesenchymal transition (EMT) drives mesothelial fusion during avian chorioallantoic membrane (CAM) formation
Authors: Sheng Guojun
Published: April 2020

Chorioallantoic membrane (CAM) is formed through fusion of the chorion and allantois in amniote early development. The CAM mediates oxygen and calcium uptake in birds and gives rise to fetal part of the placenta in mammals. Molecular mechanism regulating CAM fusion is poorly understood. We carried out cellular and molecular analyses of CAM fusion between E3.5 and E4.5 of chicken development. we show that CAM fusion is preceded by a brief period of contact between chorionic and allantoic mesothelia (two mesoderm‐derived epithelial structures) followed by their EMT and subsequent integration. We identified molecular (EMT‐related and non‐EMT‐related) markers specific to each tissue layer during CAM fusion. We will also discuss our data on canonical (SNAI1 and ZEB2) and non‐canonical (WT1) EMT‐associated transcription factors in driving mesothelial EMT. We propose that avain CAM fusion is a new model for studying mesothelial cell EMT, which is known to play important physiological (e.g., placenta formation) and pathological (e.g., mesothelioma and ovarian cancer) roles in the human.

Support or Funding Information

IRCMS, Takeda Science Foundation, JSPS
Knowledge is Both a Source Of and a Barrier to Innovation
Authors: Carlile Paul
Published: April 2020

Learning approaches have been dominated by a “transfer” view of knowledge that assumes that knowledge needs to be transferred from an expert to a novice. This has led to a focus on decimating and memorizing facts or WHAT knowledge. With this emphasis, HOW that knowledge is created and WHY is useful is seldom examined. To fully develop a new skill or perspective you have to comprehend the WHAT, HOW and the WHY of it. In this talk I will provide a relational framework to think about how learning happens outside of a traditional classroom setting to provide guidance on how we can improve the learning space or interface between an expert and a novice. So improving learning by adding to a transfer space a translation space and then a transformation space.
Therapeutic Extracellular Vesicles from Mesenchymal Stromal Cells: Can they help us restore lung development and evade BPD?
Authors: Kourembanas Stella
Published: April 2020

There is currently no single effective therapy for either the prevention or treatment of bronchopulmonary dysplasia (BPD), whose incidence is on the rise. Therefore, the need for new tools to treat and reduce risks of further complications associated with extreme preterm birth is urgent. Therapies based on transplantation of mesenchymal stromal cells (MSCs) have shown effectiveness in preclinical models, and promise in recent Phase 1 clinical trials of preterm infants at high risk for BPD. Our studies over the past decade have established that the main therapeutic vector of MSCs is present in their secretome, and is comprised by Extracellular Vesicles (EV), including exosomes. These vectors are small (less than 150nm), lipid bilayer‐enclosed structures secreted by almost all cells. Their varied origin, biogenesis and molecular composition implicate them in diverse and pivotal physiological roles, the most intriguing of which is an effective method of cell‐to‐cell communication dubbed the ‘New Endocrinology’. Consequently, MSC exosomes/small EVs (termed MEx) represent promising novel reagents for therapeutic applications. Work from our group has shown that MEx can restore lung function in rodent experimental models of BPD. MEx treatment suppresses lung inflammation and lung emphysema and restores normal lung development when administered either prenatally to a high risk pregnancy (i.e., preeclampsia or chorioamnionitis), or postnatally, to neonatal mice exposed to hyperoxia‐induced lung injury. Importantly, MEx modulate both innate and adaptive immunity through their effect on lung monocyte/macrophage phenotypes and thymic T cell development as well as promoting bone marrow ‐ derived myeloid cells to adopt a non‐classical signature. Our observations support the hypothesis that reprogrammed monocytes, of bone marrow origin, mediate the protective effects of MEx therapy on the lung and other organs. MEx thus provide a novel platform for therapeutic intervention in the perinatal period to treat tissue injury associated with inflammatory insults and to restore lung development to a physiologic path.

Support or Funding Information

Supported in part by NIH grants R01HL146128; United Therapeutics Research Grant; and Charles H. Hood Foundation Major Grants Initiative
Exploiting Cell‐Instructive Nanocomposites for Tissue Engineering, Bio‐printing and Therapeutics Applications
Authors: Paul Arghya
Published: April 2020

Considerable effort has recently been directed towards the development of hydrogels for tissue engineering and printing complex tissues in 3D, as they can mimic the physical, chemical, and biological properties of most biological tissues. Dr. Paul, in his talk, will highlight the immense potential various bioactive nanomaterials (e.g. mineral based nanoparticles), biopolymers (e.g. DNA, gelatin) and their nanocomposites to develop advanced multifunctional hydrogels for additive manufacturing and therapeutic delivery applications, as well as to effectively control stem cell fate in a 3D microenvironment.

Support or Funding Information

AP acknowledges the funding and support from Canada Research Chairs Program of the Natural Sciences and Engineering Research Council (NSERC) of Canada.
Retrieval and Integration: Making Histology Physiological
Authors: Ettarh Rajunor
Published: April 2020

Integration of teaching and of learning is a central goal in medical education. Some of the main challenges towards achieving this goal include fostering interdisciplinary connections as well as the applicability of material taught and learned to clinical practice. Integration of histology with histopathology or physiology has been described in various curricula models and with different formats including lecture, small group, case‐based or problem‐based. The challenge of integration of multiple knowledge streams in medical education draws parallels with a similar challenge within the healthcare informatics scientific community: how to achieve and deliver semantic integration of heterogeneous textual medical knowledge coming from healthcare information. The development of retrieval practice and tools for measuring effectiveness of retrieval have historically been associated with knowledge: retrieval has a complex role in testing, encoding of information, accessibility of knowledge and retention. Several models have been described for measuring the effectiveness of retrieval of information. Placing the challenge of integration within the context of retrieval of knowledge gained in two subject domains ‐ histology and physiology ‐ requires innovation in teaching, learning, and assessment. Many of the approaches for integration in the teaching and learning histology and physiology draw on established methods of teaching and learning in medical education. To enhance retrieval and integration in histology and physiology, innovative strategies need to be explored that address the (a) development of proper links between retrieval practice and integration of these two disciplines (b) identification and selection of appropriate retrieval methods and tools that map properly to the integration of knowledge in histology and physiology as well as their application in clinical or professional practice.
Cranial Nerve Development, Distribution, and Function
Authors: Mosconi Tony
Published: April 2020

Human evolution has produced a prodigious brain and fashioned an elaborate mechanism of convolution and gyrification to fit the neural tissue inside a rigid boney chamber. Critical systems, from olfaction and vision, to control of muscles for articulated speech, have been concentrated in the head, through a set of cranial nerves and their nuclei, located mainly in the brainstem. This presentation will trace the development, describe the distribution, and explore the functions of those cranial nerves.

Early in development, dorsal and ventral columns emerge in the gray matter of the neural tube. Dorsally, the alar plate differentiates into sensory regions in both the spinal cord (dorsal horns) and the brainstem (sensory nuclei). The ventral portion of the neural tube, the basal plate, is the source of motor structures including the spinal cord ventral horn and brainstem motor nuclei. Bilaterally, a longitudinal furrow in the wall of the central canal, the sulcus limitans, divides the alar and basal plates and establishes the spatial segregation of motor and sensory neuronal systems. As the embryo elongates it differentiates into a five‐vesicle structure that is the progenitor of forebrain cerebral hemispheres and diencephalon, and brainstem midbrain, pons, and medulla.

With the formation of the five‐vesicle embryo, the lumen of the central canal begins to elaborate rostrally to form the ventricular system. The lateral ventricles expand within the core of the cerebral hemispheres, and the third ventricle opens on the midline with the diencephalon forming its walls. The cerebral aqueduct is the ventricular correlate of the midbrain, connecting the third and fourth ventricles. The fourth ventricle is roughly pyramidal, tapering upward as it receives the cerebral aqueduct, being broadest at the pons‐medulla junction, and tapering again caudally to become continuous with the central canal of the spinal cord. The sulcus limitans persists in the walls of the fourth ventricle, separating alar plate derivative sensory nuclei dorsolaterally from the basal plate‐derived motor nuclei ventromedially. This effectively establishes the layout of brainstem cranial nerve nuclei. Functionally related nuclear columns are distributed throughout the rostro‐caudal length of the brainstem in consistent relative locations.

Cranial nerves (CN) I (olfactory) and II (optic) are the only cranial nerves that have no brainstem nuclei, and their circuity is in the forebrain. Nuclei of CN III, the oculomotor nerve, and CN IV, the trochlear nerve occupy the midbrain. Cranial nerves V (trigeminal), VI (abducens) and the motor nucleus of CN VII (facial motor) are found in the pons, and CNn VIII (vestibulocochlear), IX (glossopharyngeal), X (vagus), XI (accessory), and XII (hypoglossal) develop in the medulla. Extensive cephalization of the brain and cranial nerves has shaped our facial morphology. The functions of the cranial nerves are well known, and predictable and diagnostic deficits appear after injuries.
The Role of Spatial Abilities in Medicine: Implications for Selection and Training
Authors: Hegarty Mary
Published: April 2020

The ability to represent and process spatial information is central to many aspects of medicine, including learning anatomy, performing surgery, and using medical imagery technologies. Consistent with this view, there is evidence that task performance in a variety of medical specialties is correlated with spatial abilities. In this talk, I will take a broad view of spatial abilities, which includes both small‐scale and large‐scale spatial abilities and the ability to understand and use spatial representations. I will review research on how these abilities are related to the development of expertise in medical specialties such as surgery and dentistry. This research raises questions of whether individual differences in medical performance are best viewed in terms of an ability model or a skill model of individual differences. It suggests that spatial abilities are most important at the early stages of skill acquisition and in non‐routine situations whereas more routine spatial skills become less dependent on spatial abilities with training.