bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endothelial prolyl hydroxylase 2 is necessary for Angiotensin II‐mediated renal fibrosis and reactive oxygen species formation
Authors: Zeng Heng , Zhao Yongzhen , Chen Jian-Xiong 
Published: April 2020

Angiotensin II (Ang‐II) is one of the major contributors to the progression of chronic kidney disease and renal fibrosis. The aim of present study is to investigate the role of endothelial oxygen sensor prolyl hydroxylase‐2 (PHD2) in the Ang‐II‐mediated renal fibrosis and reactive oxygen species (ROS) formation. Wild type (WT) mice and PHD2 endothelial cell‐specific knockout (PHD2ECKO) mice were infused with Ang‐II (1000ng/kg/min) for 28 days. Renal fibrosis, ROS formation, and iron contents were measured by Masson’s trichrome, dihydroethidium, and Prussian blue staining, respectively. In the WT mice, infusion with Ang‐II caused a significant increase in the fibrosis area of kidney. Ang‐II infusion also significantly increased the ROS formation and iron contents. Furthermore, the levels of hypoxia‐inducible factor (HIF)‐1α, HIF‐2α, transforming growth factor‐β1 (TGF‐β1), p47phox and gp91phox, heme oxygenase‐1 (HO‐1), ferroportin, caspase‐3, p53 and the acetylation of p53 (Acetyl‐p53) in both renal cortex and medulla were significantly upregulated after infusion with Ang‐II in WT mice. Interestingly, knockout of PHD2 in endothelium led to a significant suppression of Ang‐II‐induced renal fibrosis, ROS formation and iron accumulation. The expression of HIF‐1α, HIF‐2α, TGF‐β1, p47phox, gp91phox, HO‐1, ferroportin, caspase‐3, p53 and Acetyl‐p53 was also significantly reduced in the PHD2ECKO mice infused with Ang‐II compared with the WT mice infused with Ang‐II. Our study for the first time demonstrates that the endothelial PHD2 is necessary for Ang‐II‐mediated renal fibrosis and injury. Specific knockout of endothelial PHD2 protects the kidney against Ang‐II‐induced fibrosis and ROS formation.Support or Funding InformationThis work was supported by the National Institutes of Health grant 2R01HL102042‐7 and University of Mississippi Medical Center Intramural Research Support Program to J.X. Chen.
The Function of Hepatocellular Uptake Transporters is Affected by Free Cholesterol
Authors: Idowu Jessica Y. , Hagenbuch Bruno 
Published: April 2020

BackgroundWe have previously shown that several transporters located in the basolateral membrane of human hepatocytes e.g. NTCP, OCT1, OATP1B1, and OATP1B3 interact with each other. These interactions are due in part to their co‐localization in detergent resistant membrane domains and impact both function and expression. Understanding how transporter interaction and altered membrane cholesterol content impact the function of these drug uptake transporters has implications regarding pharmacological studies, drug development, and drug‐drug interaction predictions.AimWe wanted to test how both the addition and removal of free cholesterol to and from the plasma membrane alters the function and localization of drug transporters.MethodsThe function of NTCP or OCT1 was measured using HEK293 Flp‐In cells stably expressing either transporter. We treated the cells with methyl‐b‐cyclodextrin (MCD) to remove cholesterol or with a cholesterol‐MCD complex to add cholesterol. Lipid rafts were isolated from HEK293 Flp‐In cells or frozen human liver samples by homogenization in 1% Triton X‐100 and sucrose gradient centrifugation. Gradient fractions were analyzed by western blotting using positive and negative lipid raft markers as well as transporter specific antibodies.ResultsTreatment with MCD stimulated uptake by NTCP while inhibiting uptake by OCT1. Subsequent treatment of the MCD treated cells with the cholesterol‐MCD complex restored function in part for both NTCP and OCT1. Removal and restoration of membrane free cholesterol also impacted the co‐localization of the transporters within the detergent resistant membrane domains. We confirmed the differential localization of transporters in detergent resistant membranes comparing samples of normal and fatty human livers.Summary and ConclusionBoth adding or removing cholesterol alters transport function in a transporter‐dependent way. Furthermore, the localization of transporters in lipid rafts is different in normal and in fatty human livers. These results suggest that drug disposition is affected by fatty liver disease and that some drugs may be cleared faster or slower in patients with increased free cholesterol in the liver, due to NAFLD or NASH.Support or Funding InformationR01GM077336 and P30GM118247
Creation and Curation of an Improved, Custom MALDI‐TOF Edwardsiella Library
Authors: Freese Kaitlin K. , Lawrence Jim , Rogge Matt 
Published: April 2020

Edwardsiella is a Gram‐negative rod, mannitol‐negative, hydrogen sulfide producing member of the Enterobacteriaceae family. E. tarda was the initial member of the Edwardsiella genus until E. ictaluri, E. hoshinae, E. piscicida, and E. anguillarum were identified as individual species distinct from E. tarda. The five known species of Edwardsiella are genetically and phenotypically similar to one another. We used Matrix‐Assisted Laser Desorption Ionization‐Time of Flight (MALDI‐TOF) mass spectrometry to create a library of spectral entries containing 5 E. tarda, 5E. ictaluri, 4 E. piscicida, and 5 E. anguillarum isolates. Nineteen Mass Spectral Profiles (MSPs) were assembled from 101 E. tarda, 139 E. ictaluri, 123 E. piscicida, and 112 E. anguillarum MALDI‐TOF spectra. This new library, named the UWSP Edwardsiella library, was challenged with the original 19 Edwardsiella isolates. The UWSP Edwardsiella library correctly identified 19 out of 19 isolates. In contrast, currently available commercial libraries identified the same 19 isolates as E. tarda. Scores generated with the current commercial library averaged just over 2.0. The UWSP Edwardsiella Library scores ranged between 2.50 to 2.75. After initial library creation, additional Edwardsiella isolates were obtained and used to challenge the UWSP Edwardsiella library. All 16 of those isolates were correctly identified with identification scores between 2.51 and 2.81. Here we report the creation of a custom Edwardsiella MALDI‐TOF library with improved ability to accurately differentiate and identify individual Edwardsiella species.Support or Funding InformationUWSP Office of Student Creative Activity and Research
Age‐Associated Changes in Cerebrovascular Function and BK Channel Function are Sex‐Specific
Authors: Reed Joseph , Romero Damian , Sriramula Srinivas , Pabbidi Mallikarjuna 
Published: April 2020

Large conductance potassium (BK) channels are known to regulate the myogenic reactivity, yet, it is not clear if aging alters the myogenic reactivity via the BK channel in males and females. Thus we hypothesize that age‐associated changes in BK channel subunits modulate the myogenic reactivity in a sex‐specific manner. We used vascular reactivity, patch‐clamp, and biochemical methods to measure the myogenic reactivity, BK channel function, and expression, respectively, in cerebral vessels of adult and aged male and female Sprague Dawley rats. The results suggest that aging and ovariectomy (OVX) exaggerated the myogenic reactivity of middle cerebral arteries (MCA) in females but attenuated it in males. Aging induced outward eutrophic remodeling in females but inward hypertrophic remodeling in males. Aging decreased total, Kv, BK channel currents, and spontaneous transient outward currents (STOC) in vascular smooth muscle cells isolated from females, but not in males. Aging increased BKα subunit mRNA and protein content both in males and females. However, aging decreased BKβ1 subunit protein and mRNA levels in females only. In males, BKβ1 mRNA is increased, but protein is decreased. Iberiotoxin‐induced MCA constriction is lower in aged females but higher in aged males. OVX decreased, but chronic supplementation of estradiol (OVX+17βE rats) restored BK channel expression and function. BKβ1 mRNA is decreased in cerebral vessels of OVX rats that is consistent with decreased protein content. However, supplementation with 17βE did not increase mRNA, but protein is not decreased suggesting that post‐translational mechanisms contribute to the preservation of the protein. Overall the results suggest that aging and OVX‐associated downregulation of the BKβ1 expression and function in females exaggerates the myogenic reactivity of MCA. However, age‐associated increase in BK channel function in males attenuates the myogenic reactivity of MCA.Support or Funding InformationThis work was supported by, in part, by a grant from the Intramural Research Support Program from UMMC and AHA Scientist Development Grant 13SDG14000006 (M. R. Pabbidi).
‘The Good Place’, Body Donation, and Frida Kahlo: A Perfect Match? A qualitative evaluation of a novel workshop series
Authors: Dueñas Angelique N. , Whiting Demian , Finn Gabrielle M. 
Published: April 2020

There has been a recent shift in focus on emphasizing the overlap of professionalism and ethics (P&E) with anatomy education. There is the sense that topics related to anatomy, such as the relationship between the dead and living, lend well to discussions of philosophy, ethics, professional development, and humanities‐related focus. However, with a general decrease in contact hours for anatomy‐related subjects, a renewed focus on P&E requires innovative teaching methods and interdisciplinary collaboration.With this in mind, a 9‐week workshop series entitled ‘Body and Self’ was designed for first year, undergraduate medical students in a P&E module (course). Designed by an interdisciplinary team, and facilitated by an anatomist, in these workshops, students participated in activities related to topics such as: philosophy, culture, body donation, organ donation, art‐based approaches in medicine, presentation of medicine in lay culture, and medical ethics. The present work evaluates initial student reactions to this novel workshop series, via weekly qualitative survey evaluation. Students also completed an end‐of‐term evaluation of the workshops.Content analysis was completed to code responses and analyze overall student views of these workshops, and how the Body and Self stream was constructively aligned.Preliminary analysis of evaluations indicate that students received most sessions positively, with greater appreciation for topics that students viewed as directly anatomy‐ and medical‐related. The workshops encouraged reflection and growth of professional skills, such as interpersonal skills, personal reflective practice, patient and peer communication. Many students reflected on the “deep thinking” workshop content encouraged, and many viewed sessions as “insightful.” They also responded positively to hearing varied peer perspectives, and considering cultural views on topics such as death, dying, and body donation, as well as the medical ethics surrounding such topics. The majority of negative comments related to the actual structure of the workshop, such as the request for more time. Several students also frequently questioned the link between the workshop content and clinical experiences, and many negative comments correlated with the concept of ‘fixed mindsets.’Initial evaluation of the Body and Self workshops suggest that students react quite positively to ethical discussions surrounding the nature of the body, particularly when these are linked to practical anatomical and clinical presentation. Follow up analysis are planned with consideration of the Kirkpatrick Model of evaluating learning experiences, in order to gauge student learning and possible changes in behavior. However, such a model of workshop, supported by evaluation and feedback, has early indications of being a powerful tool for further embedding anatomical sciences into P&E practice.
Testosterone induces higher carotid body response to hypoxia in older adult male rats
Authors: Kinkead Richard , Janes Tara Adele , Soliz Jorge 
Published: April 2020

Excessive carotid body responsiveness to chemical stimuli contributes to respiratory instability and apneas during sleep. In hypogonadal men, testosterone supplementation increases the risk of sleep‐disordered breathing; however, the site of action is unknown. The present study tested the hypothesis that exposure to elevated levels of testosterone potentiates the carotid body’s response to hypoxia. Because testosterone levels decline with age, we also determined whether these effects are age‐dependent. To do so, carotid bodies were isolated ex vivo from young (70 days old) and aging (185 days old) male Sprague‐Dawley rats. Isolated organs were maintained in oxygenated Tyrode solution (95% O2; 5% CO2) in the presence of testosterone (5 nM) or vehicle (<0.001% DMSO) for 90–120 min. Preparations were then mounted in the recording chamber and a suction electrode was placed on the carotid sinus nerve to record activity (# of impulses/sec). Activity was recorded at rest and during exposure to hypoxia (0% O2, 5% CO2, 95% N2; 15 min). Basal carotid body activity did not differ between age groups; however, the responses to both stimuli were greater in young rats. Testosterone exposure augmented the responses to hypoxia in aging rats only. In vivo experiments performed on anesthetised rats show that testosterone injection (2 mg/kg) 30 min prior hypoxic exposure (12%O2; 20 min) potentiates the hypoxic ventilatory response in an age‐dependent fashion. We conclude that age‐dependent potentiation of the carotid body’s O2 chemosensitivity by testosterone may lead to ventilatory adjustments that exceed the organism’s need. In aging animals, this may predispose to respiratory instability and apnea during sleep.Support or Funding InformationSupported by a discovery grant from the Natural Sciences and Engineering Research Council of Canada (RK). Dr Janes was supported by a scholarship from the Réseau en Recherche Respiratoire du Québec.
The Multi‐Organ Activity of an Lmx1b‐Associated cis‐Regulatory Module Suggests a Global Role in Regulating Lmx1b‐Mediated Development
Authors: Wysong Kenrick E. , Clark Tatianna C. , Pira Charmaine U. , Oberg Kerby C. 
Published: April 2020

Lmx1b is a LIM homeodomain transcription factor important for normal development of many organ systems including the cerebellum, eyes, limbs, and kidneys. In humans, haploinsufficiency of Lmx1b results in a Nail‐Patella syndrome, a disorder characterized by hypoplastic nails, bone deformities, glaucoma, and even kidney failure in severe cases. Despite its importance in developing these organ systems, the induction and regulation of Lmx1b is poorly understood. Previously using ChIP‐seq analysis, we identified two upstream, highly conserved Lmx1b‐associated regulatory modules (LARM1/2) bound by Lmx1b that were found to be associated with limb‐specific auto‐amplification of Lmx1b expression vital for limb dorsalization. We have subsequently identified another highly conserved region 10 kb upstream to these limb‐specific cis‐regulatory modules (CRMs), although it is not bound by Lmx1b. Yet, due to its active chromatin marks and close proximity to the Lmx1b locus, we hypothesized that this third regulatory module (LARM3) may also play a part in modulating Lmx1b expression. We generated a GFP‐reporter construct containing the isolated LARM3 sequence from mouse genomic DNA to test this hypothesis. To determine limb activity, this LARM3 construct was electoporated into the presumptive limb of Hamilton‐Hamburger stage 14 (HH14) chicken embryos. To determine activity in other organ systems such as the kidney and eye, the LARM3 construct was electroporated into a whole embryo (HH4) and in the presumptive lens placode (HH10), respectively. These embryos were viewed by fluorescent microscopy a few days after transfection to determine enhancer activity. LARM3 was found to be active in the limb mesoderm without a dorsoventral bias, showed punctate activity in the intermediate mesoderm that was consistent with mesonephric development (kidney), and was also active in the presumptive lens placode. The multi‐organ enhancer activity of LARM3 suggests a global role in regulating Lmx1b‐mediated development.Support or Funding InformationFunded in part by the National Organization for Rare Diseases
Crystal structure of the wheat dwarf virus Rep domain
Authors: Litzau Lauren Anne 
Published: April 2020

The wheat dwarf virus Rep domain is an HUH‐endonuclease and is involved in rolling‐circle replication. HUH‐endonucleases, or HUH‐tags, form covalent protein‐ssDNA adducts by coordinating a divalent metal ion to cleave a specific ssDNA sequence and form a phosphotyrosine linkage. This protein‐ssDNA fusion is useful for various biotechnology applications such as cellular imaging, cellular barcoding, DNA‐guided protein localization, and single molecule manipulation of DNA‐tethered proteins. Solving the structure of the Rep domain in complex with DNA could present necessary information regarding HUH‐tag sequence specificity and allow for rational engineering of protein‐DNA interactions. Here, the structure of WDV Rep domain in the apo state was solved with a crystal diffracting to 1.24 Å. While ssDNA soaks were attempted, they proved ineffective. However, the solved structure represents a step towards solving protein‐ssDNA complex.Support or Funding Information1. National Institutes of Health/National Institute of General Medical Sciences (grant No. GM119483); NIH (grant No.242 NIGMS R35‐GM118047)
Formative Assessments Predict Performance and Promote a Positive Learning Environment
Authors: Schneider Brandt , Kaur Gurvinder , Bishop Keith , Gore Megh , Higgins Katie , Vories Bridget , Williams Simon , Lee Vaughan 
Published: April 2020

At Texas Tech University Health Sciences Center School of Medicine, our curriculum begins with a rigorous and fast‐paced Clinically Oriented Anatomy course. Over the past four years, we have increased and improved the use of formative quizzes and exams to promote higher learning and performance outcomes, clarify examination expectations, and reduce student stress. Prior to starting our curriculum students are offered the opportunity to take a 25 question comprehensive formative pre‐test that previews examination content and USMLE vignette style questions. In the past year, we found that 93% of the incoming class utilized this voluntary resource. An average score of 23% on this pre‐test is consistent with a lack of familiarity of incoming students with human anatomy. To evaluate the effectiveness of our curriculum to bridge this informational gap, we provide students with two formative assessments (practice practical and practice written exam) prior to each summative exam. Computer based laboratory practice exams use digital images of prosected cadavers while didactic exams encompass a range of first, second and third order questions. Post‐assessment question/answer rationales provide students with immediate feedback to help identify areas of strength and weakness. Using this formative assessment approach, we have investigated the ability of formative assessments to predict exam performance and identify “at risk” students early in the course (i.e. after taking the first formative practice exam). Analysis of formative assessment data revealed a strong correlation with graded exam performance (p values ranging from 0.01–0.001 and r values from 0.44–0.70). Furthermore, overall graded summative exams correlate strongly with NBME performance (p = 0.001 and r = 0.92). Indicative of a successful educational experience, students scored an average of 233% higher on the repeat post‐course formative exam. Furthermore, the student’s perception of these formative assessments is very favorable and increases each year. In the past year, we had significantly fewer “at risk” students, and NBME performance was a record high. Thus, we find that formative assessments improve the educational experience, boost exam performance, and reduce student stress.Support or Funding Information(Sponsored by the Department of Medical Education at the TTUHSC SOM.)This study is approved by TTUHSC‐QIRB (approval#17008)
Human Intestinal AIEC Strains Alter the Mucosal Microbiome and Establish a Niche for AIEC and Non‐AIEC Strains in Il10−/− Mice
Authors: Bleich Rachel , Barlogio Cassandra , Franks Adrienne , Zarmer Sandra , Broberg Christopher , Bulik-Sullivan Emily , Dogan Belgin , Simpson Kenneth , Carroll Ian , Gharaibeh Raad , Arthur Janelle 
Published: April 2020

Inflammatory bowel disease (IBD) affects over one million people in the United States and costs billions of dollars in direct medical expenses annually. This chronic inflammatory condition, which includes Crohn’s disease, currently has no medical cure. Additionally, patients with IBD are at a greater risk of developing inflammation‐associated colorectal cancer (I‐CRC). IBD and I‐CRC are associated with an increase of mucosally‐adhered bacteria, particularly Adherent‐Invasive Escherichia coli (AIEC). This proximity to the host can promote host‐directed pro‐inflammatory and pro‐carcinogenic activities by AIEC and co‐colonizing microbes. The overall aim of the project is to assess how colonization with Crohn’s‐associated clinicalE. coli strains alters the mucosal microbial community in the inflamed and non‐inflamed intestine.To this end, we have developed a polymicrobial colonization strategy that uses a novel barcoding technology to easily distinguish genetically similar, but functionally distinct sub‐strains of E. coli in a complex community. We have developed this strategy using a collection of well‐characterized clinical AIEC and non‐AIEC strains isolated from the intestinal mucosa of IBD and healthy patients. These strains are administered to formerly germ‐free mice (either inflammation susceptible Il10−/− or resistant WT) also with a murine fecal microbial transplant (FMT) to simulate physiologically‐relevant conditions. Our in vivo modeling has revealed that colonization with a pool of clinical isolates in the presence of the FMT enhances inflammation and promotes higher levels of E. coli colonizing the mucosa in inflammation‐susceptible mice. Importantly, colonization with these strains very significantly alters the composition of the mucosal microbiome, assessed by 16S rRNA sequencing, in inflamed but not uninflamed mice, including expansion of a co‐occuring pro‐inflammatory taxon and contraction of multiple protective species. These data suggest that colonization of the chronically inflamed with high levels of E. coli influence host health through both host‐microbe and microbe‐microbe interactions.Support or Funding InformationSupported by K01 award to JCA and the SPIRE NIH IRACDA program.