bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Aldh1l2 Knockout on the Metabolic Profile of Mouse Liver
Authors: Sharma Jaspreet , Krupenko Natalia I. , Sumner Susan , Helke Kristi L. , Krupenko Sergey A. 
Published: April 2020

ALDH1L2 (10‐formyltetrahydrofolate dehydrogenase), an enzyme involved in folate metabolism, resides in mitochondria where it converts 10‐formyl‐THF (tetrahydrofolate) to THF and CO2 in a NADP+‐dependent reaction. Though the enzyme could be an important contributor to the NADPH pool in mitochondria, its overall biological significance is not well understood. We have generated mice with a targeted Aldh1l2 knockout and demonstrated that the enzyme is involved in the regulation of lipid metabolism in the liver. Hepatic tissues from 12–14‐weeks‐old Aldh1l2+/+, Aldh1l2+/− and Aldh1l2−/− male mice were profiled to identify metabolite changes and to pinpoint associated pathways. Global metabolomic analysis was performed by Metabolon Inc. (Durham, NC) using Ultrahigh Performance Liquid Chromatography‐Tandem Mass Spectroscopy (UPLC‐MS/MS) for five samples from each group. Levels of 105 metabolites were decreased and levels of 162 metabolites were elevated in the Aldh1l2−/− compared to Aldh1l2+/+ mice. This analysis also found a Aldh1l2 gene‐dosage effect on the liver metabotype. Notably, no effect of the KO on levels of folate was seen. Metabolites that strongly contribute to the differentiation of the Aldh1l2+/+ and Aldh1l2−/− groups are involved in cysteine, glutathione, citric acid and fatty acid metabolism. Also, levels of intermediates in the CoA biosynthesis pathway, as well as levels of CoA itself, were significantly decreased in the livers of knockout mice. Together with the increased levels of several acylcarnitines seen in the KO mice, these findings indicate impaired mitochondrial beta‐oxidation of fatty acids. This conclusion is supported by histological analysis, which revealed accumulation of lipid vesicles in the livers of KO mice. Overall, our study shows that Aldh1l2 is a key regulator of lipid metabolism in the liver.Support or Funding InformationThese studies were supported by the National Institutes of Health grant DK054388 and CA095030( to S.A.K.)
Alternate fatty acid synthesis initiation in Escherichia coli
Authors: Whaley Sarah G. , Rock Charles O. 
Published: April 2020

Fatty acid synthesis is important in both prokaryotes and eukaryotes for formation of functional membranes and dysregulation of the pathway has implications for cell growth and survival. In bacteria, fatty acid production is tightly regulated by the Type II fatty acid synthesis (FASII) pathway. FabH (3‐ketoacyl acyl carrier protein (ACP) synthase III) initiates fatty acid synthesis by condensing acetyl coenzyme A (acetyl‐CoA) with malonyl‐ACP in Escherichia coli. FabH was long thought to be the sole enzyme responsible for initiation of FASII and therefore essential for survival. The observation that fabH deletion strains are viable suggested the existence of an alternate initiation pathway. The yiiD gene was recently identified as essential for initiation of fatty acid synthesis in the absence of FabH in E. coli. The biochemical activity of YiiD is not known.YiiD has an N‐terminal GCN5‐related N‐acetyltransferase (GNAT) domain and a C‐terminal hotdog domain that is annotated as a thioesterase. The full‐length protein, as well as the N‐terminal and C‐terminal domains were purified using an E. coli expression system. Full length YiiD and the C‐terminal hotdog domain are dimers and the N‐terminal GNAT domain is a monomer.YiiD lacks condensing enzyme activity, suggesting that the initiation of FASII by YiiD is occurring through an alternate mechanism. We hypothesized that YiiD is initiating FASII by a transacylase reaction. FabH has acetyl‐CoA:ACP transacetylase activity, however protein extracts from an E. coli fabH deletion strain retain transacetylase activity. Purified YiiD has acetyl‐CoA:ACP transacetylase activity. The N‐terminal GNAT domain was inactive, whereas the C‐terminal domain was 100‐fold more active than intact YiiD. This suggests that the C‐terminal domain has the transacetylase active site and that the N‐terminal domain negatively regulates this activity. These data are consistent with YiiD forming acetyl‐ACP that is used by the elongation condensing enzymes (FabB or FabF) to initiate FASII thus bypassing FabH.Support or Funding InformationNational Institutes of Health Grant GM034496, Cancer Center (CORE) Support Grant CA21765, American and Lebanese Syrian Associated Charities (ALSAC)Proposed model for alternate initiation of fatty acid synthesis by YiiD in E. coliFigure 1
Lending a Helping Hand; Educational Value of a Hand‐Drawn Video Tutorial on Embryonic Underpinnings of Gross Anatomy
Authors: Ryan Megan Victoria , Stratford Jennifer , Lee Lisa 
Published: April 2020

This study investigates the educational value of incorporating a hand‐drawn embryology video tutorial in an integrated gross anatomy course within a medical curriculum. Due to complex spatial and temporal dimensionalities, embryology is a difficult subject for students to learn, especially in an integrated curriculum with limited contact hours. However, thoughtfully integrated embryology concepts can support students’ understanding of gross anatomy. Short video tutorials can be an effective ancillary learning resource that can ensure content mastery, especially when paired with other pedagogical tools such as drawing.A 10‐minute video tutorial on embryology of the innervation patterns of the skeletal muscle system was created, using a screen capture of hand‐drawn visual aids (Figure
1). In an IRB exempt study (#19‐1749), the first‐year medical students enrolled in an integrated anatomy course were instructed to view the tutorial, then take a quiz on the subject prior to the embryology lecture on the topic. Two days after the lecture, during an active learning session, students completed another quiz on the topic, as well as a survey assessing the perceived usefulness of the video. Significance of the quiz results was assessed using sigma‐restricted parameterization, whereas Tukey Honest Significant Difference and Chi‐Square tests were used to analyze the survey data.The first quiz average was 84% (n=180) and the second quiz score average, completed two days later, was significantly lower at 63.3% (n=166) (
p<0.0001; h2=0.22). Surprisingly, students performed significantly worse on easy (simple recall) versus more difficult (problem‐solving) questions on the second quiz (
p<0.000; h2=0.14). Survey analytics revealed that 89% (n=128) of the participants reported they would like to have more hand‐drawn video tutorials in the future to supplement their learning. 42% (n=60) of the students additionally commented that the real‐time drawing helped them follow along. 86% (n=123) of survey participants stated that learning embryology helped them identify innervation patterns in adult gross anatomy.The study suggests a potential value of the ancillary, hand‐drawn video tutorial on an embryology topic to enhance gross anatomy understanding, at least in the short term. While the significant knowledge decline in the second quiz is alarming, a number of confounds should be considered in its interpretation, such as different level of difficulty in the two quizzes, the quiz taking environments and the time‐allowed, which should be better controlled in the future study.Screenshots of parts of the hand‐drawn video tutorial that was created.Figure 1Screenshots of parts of the hand‐drawn video tutorial that was created.Figure 2
A Pipeline for the Rapid Production and Dissemination of Mouse Intersectional Genetic Alleles for Functional, Molecular, and Anatomical Neural Circuit Mapping. (mouseintersectionalgenetics.org)
Authors: Perdigones Manuel Alejandro Sarrion , Chang Yuan , Venken Koen , Ray Russell S. 
Published: April 2020

Here we describe an effort to build and distribute a community library, based on public input, of more than 100 mouse intersectional genetic alleles to facilitate developmental, anatomical, molecular, and functional characterizations of neural circuit organization in behavior and physiology. Even within narrowly defined cell types, significant diversity is found at multiple levels including genetic and molecular signatures, activity patterns, and synaptic connectivity. Current challenges now center on tools to identify, access, and study cell populations with increasing precision. Intersectional genetics offers exceptionally high resolution to consistently delineate distinct cell types in the embryo and adult mouse for functional, molecular and anatomical studies. Intersectional genetics utilizes a ubiquitously expressed conditional allele that is activated by Cre and Flp site specific recombinases. Upon activation, the intersectional genetic alleles may express any number of Genetically Encodable Effector Molecules (GEEMS), such as channelrhodopsins for neural activity perturbations or an L10‐GFP ribotrap fusion to affinity purify translating mRNAs. The intersectional allele is activated by overlapping expression of both Flp and Cre recombinases in the same cell. Traditionally, these recombinases have been deployed as gene knock‐in or transgenic alleles that are designed to express in a cell or gene specific fashion. The use of two selectors (Cre and Flp) to define a cellular population enables high specificity and modularity in combining any set of Cre, Flp, and intersectional alleles to fit an experiment. The number of Cre and Flp recombinase mouse lines are constantly growing, giving greater access to increasing numbers of cell types. Additionally, these recombinases are the focus of multiple efforts to deploy them in ways that select cells based on other unique properties such as neuronal activity and synaptic connectivity. To make this powerful genetic approach more accessible to as many research laboratories as possible, we are building a production pipeline to create a suite of resources for anyone to easily make their own intersectional mouse line, to produce over 100 targeted ES cell lines that can be developed into mouse lines, as well as 10–15 high demand mouse lines all for public distribution. Priority for the GEEMS to be intersectionally deployed will be based on a public input collected at mouseintersectionalgenetics.org. All plasmids, cell lines, and mouse lines developed under this effort will be distributed without restriction to non‐profit research organizations (Addgene and Mutant Mouse Resource and Research Center; MMRRC).Support or Funding InformationR21OD025327Figure 1
Them1 Binds to Free Fatty Acids and is Allosterically Regulated by Lysophosphatidylcholine to Control Fatty Acyl‐CoA Hydrolysis in Brown Adipose Tissue
Authors: Tillman Matthew C. , Li Yue , Khadka Manoj C. , Imai Norihiro , Adhiyaman Akshitha C. , Juneja Puneet C. , Hagen Susan J. , Cohen David E. , Ortlund Eric A. 
Published: April 2020

Obesity is a global epidemic, greatly increasing in prevalence over the past 30 years. In mammals, brown adipose tissue (BAT) counteracts obesity through thermogenesis: the burning of fat to produce heat. Thioesterase superfamily member 1 (Them1) is a multi‐domain enzyme in brown adipose tissue that slows thermogenesis by converting acyl‐CoA into fatty acids. Additionally, Them1 contains a lipid‐binding StAR‐related lipid transfer (START) domain with an unknown function. We hypothesized that the lipid‐binding START domain controls thermogenesis by either regulating its localization and/or functioning as a lipid sensor to regulate the activity of the enzymatic domains. To test this, we stably transduced brown adipocytes with full‐length and truncated Them1 without the START domain and found the START domain was necessary for proper localization to the lipid droplet, but not necessary for suppression of thermogenesis. Next, we used mass spectrometry, X‐ray crystallography, and microscale thermophoresis to identify long‐chained fatty acids, products of Them1’s enzymatic reaction, and lysophosphatidylcholine (LPC), important signaling lipids implicated in many diseases, bind to the START domain. We tested the impact of these lipids on Them1 enzymatic activity and found that 18:1 LPC inhibited Them1 activity in a START domain dependent manner. We identified LPC as a novel ligand and allosteric regulator of Them1 activity through the START domain. LPC species are elevated in BAT during thermogenesis and enhance the energy expenditure of the tissue; therefore, we postulate that LPC enhances thermogenesis in BAT through binding to the Them1 START domain and inhibiting the enzymatic activity of Them1.Schematic of lysophosphatidylcholine inhibition of Them1 in brown adipocytesFigure 1
Using a “favorite figure” to help students learn challenging pharmacology topics
Authors: Brandl Katharina 
Published: April 2020

ObjectiveIn the last two decades medical and pharmacy schools have shifted away from traditional, teacher‐centered curricula using didactic lectures as primary teaching modalities. New curricula offer a variety of teaching modalities including more active learning opportunities, small group teaching and self‐directed learning.Integrating pharmacology instruction into curricula with more active learning opportunities and self‐directed learning can be challenging. Pharmacology is both, a basic science and a clinical science and students are sometimes uncertain what exact drug information (individual compounds versus drug classes) to learn.To help students learn pharmacology in a more self‐directed environment, laminated flashcards containing the most important information about drug classes and individual compounds used to treat a specific disease state were developed. Each card contains also a “favorite figure” in which the mechanism of action of all different drug classes for a specific disease state are shown. This provides a more easily memorized framework that allows students to fit each detailed puzzle piece into a bigger concept.MethodsTen Drug Cards were developed to date and include following drug classes: Antiarrhythmics, Diabetes medications, Antiplatelet and Anticoagulants, Asthma medications, Analgesics, Immunosuppressants, Diuretics, Dyslipidemia Drugs, Drugs used for several Cardiovascular Diseases and Drugs targeting the Autonomic Nervous System. Second Year Pharmacy Students (n=64) of the Skaggs School of Pharmacy and Pharmaceutical Sciences at the University of California, San Diego were provided with these cards. Students were surveyed whether the Drug Cards helped them learn Pharmacology. Students were also questioned how they used the card to learn Pharmacology.ResultsThe survey response rate was 89% (n=57). Ninety‐one percent of the students agreed or strongly agreed that the cards helped them learn pharmacology. Students commented that they used the card as a “great review tool” and a “quick reference guide”. They valued the card as “being handy”, and a “great study aid on the go”. Students also noted that the card helped them to decide what drug information is most essential.ConclusionProviding the students with a framework to study challenging pharmacology topics might help students to grasp the material without loosing the forest for the leaves.Antiarrhythmics Drug Card Front PageFigure 1Antiarrhythmics Drug Card Back PageFigure 2
Soluble claudin to study embryonic development
Authors: Keller Julie Young , Taylor Abigail , Mizrachi Dario Young 
Published: April 2020

The cause and effect relationship between environmental factors, including toxins (naturally occuring) and toxicants (man‐made environmental contaminants), and embryonic development is well‐established. The claudin family of tetra‐spaning transmembrane proteins is essential for tight junction formation and regulation of paracellular transport between epithelial cells. Claudins also play a role in apical‐basal cell polarity, cell adhesion and link the tight junction to the actin cytoskeleton to exert effects on cell shape. The function of claudins in paracellular transport has been extensively studied through loss‐of‐function and gain‐of‐function studies in cell lines and in animal models, however, their role in morphogenesis has been less appreciated. Here we present a protein‐engineering approach to obtain soluble claudin proteins that preserve their function and organization as if they were membrane bound. We demonstrate their ability to influence embryonic development by simply adding these proteins to the environmental milieu of the animal model zebrafish embryos. We discuss their effectiveness in vivo to understand development and be as efficient as other methods that include manipulation of genomic DNA or messenger RNAs.A: Zebrafish embryo 30 hpf, 30 C. Somites from this fish are presented below. B: Zebrafish embryo 30 hpf grown at 20 C. This represents delayed development. C: Zebrafish embryo 30 hpf grown at 30 C. Non‐influential protein. D: Zebrafish embryo 30 hpf grown at 30 C. Somites from this fish is presented below. Embryo treated with soluble claudin protein that targets the skin of the fish. In both D and Somites D it is observable the delayed development.Figure 1
MicroRNAs Contribute to Angiotensin II‐Mediated Regulation of Transmural Electrical Remodeling in the Heart
Authors: Lu Michael Kaiyuan , Gordon Chris , Zuckerman Joan , Brink Peter , Cohen Ira 
Published: April 2020

Activation of the local renin angiotensin system (RAS) by Angiotensin II (Ang II) in the heart induces electrical remodeling, including inhibition of transient outward potassium current Ito, prolongation of the action potential, and increased contractility. Moreover, the long‐term, persistent action of Ang II causes cardiac hypertrophy and heart failure (anatomic remodeling). The transmural gradient of multiple ionic currents, including Ito, is involved in Ang II‐mediated electrical remodeling. Differential expression of miRNAs may play a critical role in the signaling cascade for Ang II‐induced electrical remodeling. To investigate this hypothesis, a detailed analysis of potential miRNAs involved in Ang II‐mediated modulation was undertaken using miRNA microarray analysis of endocardium and epicardium tissue from the left ventricle of a Sprague‐Dawley rat. The left ventricular tissue samples were treated with either Ang II (2mM) or Losartan (2mM) to further screen for differences in miRNA expression between EPI and ENDO. Although forty‐nine miRNAs were expressed in a significant gradient between EPI and ENDO, only miR‐385‐5p and miR‐301a‐3p were found to exhibit similar expression patterns as Ito when modulated by Ang II. Taken together, these data suggest that miR‐382‐5p and miR‐301a‐3p could contribute to Ang II‐mediated transmural electrical remodeling and may provide a potential target for the study of heart failure mechanisms and therapeutic application.Expression of miR‐382‐5p and miR‐301a‐3p in EPI and ENDO.A. Left: miR‐382‐5p is upregulated in EPI compared to ENDO. Middle: miR‐382‐5p is upregulated in EPI compared to EPI with Ang II. Right: miR‐382‐5p is downregulated in ENDO compared to ENDO with Losartan.B. Left: miR‐301a‐3p is downregulated in EPI compared to ENDO. Middle: miR‐301a‐3p is downregulated in EPI compared to EPI with Ang II. Right: miR‐301a‐3p is upregulated in ENDO compared to ENDO with Losartan.Figure 1Schematic diagram of Ang II‐mediated anatomic and electrical remodeling in the heart. The transmural distribution of Ang II causes the transmural gradient of ionic currents including Ito, Ip, ICaL and ICaTL (electrical remodeling). Under long term imbalances between volume load and maximum contractile strength, the heart undergoes hypertrophy and heart failure (anatomic remodeling). We hypothesize that miR‐382‐5p and miR‐301a‐3p contribute to Ang‐II mediated remodeling of the heart.Figure 2
mTOR Inhibitor rapamycin can reverses the combination antiretroviral therapy induced central nervous system disorder
Authors: Chennakesavan Karthick 
Published: April 2020

BackgroundAccumulating evidences indicate that the combined antiretroviral therapy (cART) has dramatically increased the life expectancy of HIV infected individuals. However, existing HIV population on cART show several complications including liver or pancreas damage, cardiovascular diseases and central nervous system disorders. Unexpectedly the prevalence of HIV+ associated neurotoxicity is on the rise. Hence, the current study is undertaken to determining the potential therapeutic effects of rapamycin against anti‐retroviral therapy induced neuronal dysfunction.ObjectiveThis study is aimed at exploring the therapeutic potential of rapamycin on cART induced central nervous system disorder.MethodologyPrimary midbrain neuronal cells (PMNC) were treated with antiretroviral drugs like Ritonavir (protease inhibitor) and Abacavir (reverse transcriptase inhibitor) in the combined form.ResultsAfter 24 hours treatment, immunoblot analysis shows that there is upregulation of autophagy marker proteins LC3 II, P62 levels in cART treated primary midbrain neuronal cells compared to control cells. Similarly, cART treated cells shows upregulation of endoplasmic reticulum (ER) resident proteins expression with mitochondrial dysfunction. These results are suggesting that neuronal cells treated with cART have dysregulated autophagy, higher ER stress and mitochondrial dysfunction. The beneficial effects of rapamycin are well described; though, it is unknown whether rapamycin ameliorates the harmful effects of cART‐induced toxicity in neuronal cells. Hence, in this study, we intend to investigate the effects of rapamycin on PMNC treated with cART. Our results indicate that rapamycin treatment ameliorates the autophagy dysfunction as well as, it normalizes the mitochondrial function and reduces the ER stress.ConclusionThis study shows that rapamycin have a good potential in reversing cART‐induced autophagy and mitochondrial dysfunction in primary midbrain neuronal cells.Schematic representation of therapetic effects of rapamycinFigure 1