bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maternal tobacco smoke exposure programs increased lung static compliance in female rat offspring (715.5)
Authors: Sainz Anthony , Wang Yan , Stiers Justin , Zou Chang‐Jiang , German Massiell , Albertine Kurt , Joss‐Moore Lisa 
Published: June 2021

Background: Intrauterine growth restriction (IUGR) increases the risk for postnatal lung disease, in part, through programmed alterations in gene expression patterns. A consequence of altered gene expression programs in the developing lung is changes in lung compliance and resistance. In a rat model of surgically‐induced IUGR (sIUGR), male rat pups have increased compliance and decreased resistance, while female rat pups are unaffected. Maternal tobacco smoke (MTS) exposure also results in IUGR. However, the effects of MTS‐induced IUGR on lung compliance and resistance are unknown.Objective: We hypothesized that MTS exposure alters lung compliance and resistance in rat offspring.Design/Methods: Maternal rats received tobacco smoke exposure from gestational day 11 to term. Pups were delivered at term and cross‐fostered to a control dam until they were weaned at postnatal day 21 (d21). At d21, rats were anesthetized and paralyzed, and closed chest, lung static compliance and lung resistance mechanics were measured using the FlexiVent System.Results: MTS significantly increased lung compliance in female (118 ± 4%, p=0.02), but not male rat offspring. Lung resistance was not affected by MTS in either male or female rat offspring.Conclusion: MTS‐induced IUGR leads to a long‐term increase in lung compliance in female rats. We previously showed that increased compliance in male sIUGR rat pups is accompanied by decreased elastin mRNA variant expression. We therefore speculate that MTS‐induced increased compliance in female rat pups will be accompanied by decreased elastin mRNA variant expression.Grant Funding Source: Supported by the APS STRIDE Fellowship Award
Profound lung remodeling in heart failure, a poorly understood phenomenon with a significant impact (715.6)
Authors: Arkell Alicia , Foster Andrew , Platt Mathew , Dadgar Kayla , Murrant Coral , Simpson Jeremy 
Published: June 2021

Exercise intolerance, characterized by dyspnea and early onset of exertional fatigue, is a chief complaint among patients with heart failure (HF). Limb muscle dysfunction is a known contributor to exercise intolerance, however, this phenomena does not explain dyspnea. Lung remodeling has been reported in end‐stage HF patients which could contribute to dyspnea and exercise intolerance, underscoring the importance and urgent need to better understand its role in HF. Our aim is to characterize the development of lung remodeling and its impact on exercise intolerance in HF. We hypothesize that lung remodeling occurs early in the development of HF, causing exercise‐induced hemoglobin (Hb) desaturation, affecting exercise performance. Methods: Male CD1 mice were subject to either transverse aortic constriction (TAC) or sham surgery. Exercise tolerance and Hb saturation were measured during a graded exercise test. The animals were sacrificed and lungs excised and fixed for histological evaluation. Results: Time to exhaustion was decreased by 40% in TAC. Hb saturation in TAC decreased during exercise while sham remained unchanged (p<0.05). Hb levels were similar between sham and TAC animals. Lung compliance was significantly reduced in 9 week TAC compared to sham (p<0.05), which further declined by 18 weeks (p<0.01). Histological assessment revealed significant remodeling including a 43% increase in fibrosis (p<0.01), marked inflammation and distended alveoli. Conclusions: Lung remodeling plays a significant yet under acknowledged role in exercise intolerance in HF patients. Grant Funding Source: Ontario Thoracic Society
Three conserved domains in the 3’UTR region of αENaC mRNA modulates the stability of the transcript in alveolar epithelial cells (716.1)
Authors: Migneault Francis , Pascariu Mihai , Laperle Jonathan , Dagenais André , Berthiaume Yves 
Published: June 2021

The epithelial sodium channel (ENaC) plays an important role in the alveolar epithelium by mediating Na+ reabsorption, an essential process for resolution of pulmonary edema in acute respiratory distress syndrome (ARDS). Several proinflammatory conditions such as TNF‐α leads to a reduction of ENaC expression and activity that contributes to development of ARDS. To study how pro‐inflammatory conditions could modulate αENaC mRNA stability, we developped a Tet‐Off model that allows the specific inhibition of αENaC mRNA expression in presence of doxycycline. Using this model, we found that the half‐life (T1/2) for the transcript was about 1 hr. TNF‐α, a proinflammatory cytokine found in broncho‐alveolar lavage of ARDS patients, decreased T1/2 to 15 min, suggesting that destabilisation of αENaC transcript plays an important role in downregulation of ENaC expression in pro‐inflammatory conditions. The 3’ untranslated region (3’UTR) of a mRNA plays an important role in modulating mRNA stability. αENaC mRNA 3’UTR is very long (~30% of the transcript). Using a bioinformatic approach, we could define three domains (D1, D2, D3) able to form secondary structures that were highly conserved in different species. Alveolar epithelial cells were co‐transfected with 3’UTR deletion mutants inserted in pTRE‐tight vector along with the Tet‐Off vector. Deletion of the distal part of 3’UTR (D3) leaded to stabilization of the transcript with a T1/2 of 2.6 hrs. A longer deletion to remove also D2 showed a T1/2 of 4.6 hrs, while deletion of D1 decreased the half‐life to 0.5 hr. These results showed that the conserved domains have stabilizing (D1) and destabilizing (D2, D3) properties on αENaC mRNA expression. The hairpin structure of these domains could recruit RNA‐binding proteins responsible for modulation of αENaC mRNA stability. Altogether, our results suggest that modulation of αENaC mRNA stability via its 3’UTR could play an important role in regulation of ENaC expression during pro‐inflammatory conditions.Grant Funding Source: Supported by FRSQ, CFC and CIHR.
ENaC activity is decreased in alveolar epithelial cells from protein kinase C‐α knockout mice (716.2)
Authors: Eaton Amity , Bao Hui‐Fang , Yue Qiang , Eaton Douglas 
Published: June 2021

ENaC open probability (Po) requires the association of ENaC with anionic phospholipids like PIP2. Protein kinase C is also alters ENaC activity, but the mechanism is unclear. Recently we showed that PKC can affect ENaC through phosphorylation of myristolyated‐alanine‐rich‐C‐kinase‐substrate protein (MARCKS). MARCKS acts to sequester PIP2 in close proximity to ENaC in the membrane and phosphorylation of MARCKS by protein kinase C (PKC) causes MARCKS to dissociate from the membrane. Without MARCKS in the membrane, PIP2 no longer associates with ENaC and ENaC Po decreases. To test whether PKC‐α influences ENaC activity in the lung, we examined ENaC regulation in a PKCα‐/‐ murine model. Primary cultures of alveolar type II cells were prepared from wild‐type and knockout animals, and were subjected to cell‐attached patch clamp. In PKC‐α KO, ENaC Po was significantly less (0.100 ± 0.0241, n = 18) compared to wildtype SV129 mice (0.200 ± 0.0310, n = 28, p = 0.025). The number of channels per patch (N) also decreased. Evan’s blue assays showed a two‐fold decrease in ENaC‐mediated fluid uptake in the KO mice, while wet‐dry assays also showed a decrease in ENaC activity in the KO animals. To confirm this decrease, a lung from each animal was perfused with biotin and membrane protein pulled down with streptavidin. While total ENaC protein did not change in PKCα‐/‐ mice compared with wildtype, membrane localization of all three ENaC subunits decreased. Using confocal microscopy, we observed an increase in reactive oxygen species (ROS) in the alveolar type II cells of PKCα‐/‐ mice. The increased ROS stimulated PKCδ which phosphorylatyed MARCKS in lieu of PKCα and decreased ENaC in Po in the knockout animals.Grant Funding Source: Supported by NIH
Network of medical school educators for best practices in case‐study Problem Based Learning (719.7)
Authors: Packer C 
Published: June 2021

Medical schools are reforming curriculum to integrate all competencies throughout all years. Interdisciplinary student‐centered case‐study PBL curriculum should result in students: 1. Gaining proficiency and understanding the process in clinical problem solving. 2. Recognizing knowledge gaps, learning to use reliable information, applying new knowledge. 3. Interacting effectively with peers, demonstrating professionalism appropriate to physician/patient interactions. Many schools introduced variations into case‐study content and PBL format and produced numerous assessment tools. Accordingly, the project objective was to form a collaborative network of medical school PBL case‐study teachers to share best strategies in facilitating PBL and develop/revise assessment tools to better address student engagement, learning outcomes, sense of value of PBL. Visits to Indiana University School of Medicine Centers of Medical Education in Terre Haute, Lafayette, Gary, and to University of Louisville and Northern Ontario School of Medicine were conducted. Materials and ideas were also shared electronically. Results include establishment of a collaborative network, sharing best practices and curricular materials, initiation of collaborative projects. An outcome of this work will be a model for other schools who wish to adopt/reform a PBL case study course or curriculum.Grant Funding Source: Supported by an APS Teaching Career Enhancement Award (TCEA).
Brainstem 101: an interactive neuroanatomy application for iOS Platform (720.7)
Authors: Zebarjadi omid , Amirnovin Ramin , Ehrlich Cameron , Puder Barbara 
Published: June 2021

Brainstem101, is an innovative computer application that combines art and neuroanatomy ‐‐ brainstem structures, functionalities and clinical highlights‐‐ together to create an interactive learning module for medical students and professionals. The Application features an atlas of human brainstem that presents 9 horizontal Cross‐Sections (CSx) along with an index of structures. Selection of a CSx will provide a list of its structures, while selection from the index displays the structure in CSx(s) where present. Each CSx can be viewed individually in the “Profile Page”, where one can select a structure and read about functions and clinical relevance. The application allows user interaction not only by tapping to select the structures of a CSx, but also by allowing the user to put any CSx onto a “Draw Pad” where he can take notes/collaborate by writing on top of the diagram.Another major feature is the “Clinical Page”; this component provides a list of syndromes to choose from, with a detailed description of the syndromes' features (and structural origins) and artfully displays the physical manifestations of that syndrome on a human model. The associated vascular compromise is outlined on a 3D brainstem model.Other features include “Quiz Mode”, radiology imaging, search function, and supplemental schematics.Grant Funding Source: none
Use of heart rate monitors to assess student engagement in lecture (721.25)
Authors: Darnell Diana , Krieg Paul 
Published: June 2021

Some years ago, Bligh carried out a series of classroom lecture studies showing that student heart rates decreased over the course of a 50‐minute lecture (Bligh 1972, 1998, 2000). The decline in heart rate was interpreted as a measure of decreasing arousal, which is one component of engagement. In addition, Bligh reported a single event where a question from a student resulted in elevation of heart rate in observers. It appears that these studies are unique in using a physiological readout as a measure of student engagement or attention in the classroom. We plan to repeat and extend this study using current technology in interactive lecture, allowing more students to participate, more data to be collected, and additional analysis of the impact of interruptions and activities.We propose that lightweight heart rate monitors with wireless connectivity (Mio Alpha; resembling fat wrist watches), may be used to measure student engagement in the classroom setting. In preliminary studies using seven monitors worn by medical student volunteers, we have replicated Bligh's observations and observed, 1) a decrease in average heart rate between across a 50‐minute lecture class, and 2) a temporary increase in heart rate in response to student questions. In addition, we have observed that brief pair‐share sessions (an interactive learning method) resulted in elevated average heart rate. Results will be presented from analysis of heart rate data from more than 20 lecture classes. The long‐term objective is to use heart rate to assess the relative effectiveness of different interactive and non‐interactive teaching methods to increase student engagement.Bligh DA. What’s the Use of Lectures? Jossey‐Bass Publishers, SF (2000). Or Intellect Books (1998). Originally published in 1972.Grant Funding Source: Supported by UA AMES Education grant
Turning selfish proteins into programmable genome editors (733.2)
Authors: Richter Jazmine , Shen Betty , Lambert Abbie , Stoddard Barry , Kaiser Brett 
Published: June 2021

Though no suitable methods for genome editing yet exist, the most promising approaches utilize targeted nucleases and take advantage of a cell’s natural repair processes that either disrupts the cleaved sequence or repairs it using a donor DNA template. LAGLIDADG Homing Endonucleases (LHE’s) are naturally occurring selfish proteins with two key features ideal for genome editing: recognition of a long DNA target site (~22 bp) and double‐stranded cleaving activity. Originally thought to be impossible to engineer due to their size and complexity, recent approaches based on experimentally determined structural models to direct the bioengineering process have proven successful. The aim of my research project was to solve the three dimensional structures of various LHE’s using x‐ray crystallography. Using E. coli‐expressed proteins, I solved the structures of two LHE’s (I‐GpeMI and I‐CpaMI) bound to their target DNA. With these structures we are able to identify DNA‐interacting amino acids and focus our engineering efforts of the enzyme scaffolds towards new DNA target sites.Grant Funding Source: Murdock Trust
Encapsulation of biological stains for drug delivery imaging and microscopy in dentin tubules (733.6)
Authors: Lau Michael , Haseeb Ridwan , Montagner Francisco , Rodrigues Danieli 
Published: June 2021

Encapsulation of Biological Stains for Drug Delivery Imaging and Microscopy in Dentin Tubules
Michael Lau1, Ridwan Haseeb1, Francisco Montagner2, Danieli Rodrigues1: 1Department of Bioengineering, University of Texas at Dallas, Richardson, TX; 2Department of Conservative Dentistry, Federal University of Rio Grande do Sul, Brazil; Introduction: Bacteria are able to remain into dentin after the root canal disinfection. Drug penetration into the tubules can be a key component for infection control. This study uses the synthesis of poly(ethylene glycol)‐block‐poly(L‐lactide) PEG/PLA encapsulated biological stain particles to characterize the penetration depth of drug delivery systems with Confocal Laser Scanning Microscopy (CLSM).Methodology: Encapsulation of the biological stain was done with an oil‐water emulsion‐evaporation technique. The PEG/PLA copolymer and the stain were dissolved in the oil phase while the surfactant was dissolved in water. The oil phase and water phase was combined and emulsified then stirred. The particles were centrifuged, washed, and lyophilized. Characterizing the particle size and fluorescence was done with CLSM (VK‐X200 Keyence Laser Scanning Microscope).Results: The microscopy has shown particle formation in the 0.3‐1.0 m range, which depended on the method of emulsification: homogenizing or sonication. CLSM revealed that the particles fluoresce under light with 525‐605 nm wavelengths.Conclusion: The encapsulation technique effectively encapsulated the biological stain to penetrate the dentin tubules. With particle size similar to dentin morphology, the encapsulated stain proliferation into the dentin tubules will model dentin penetration of drug delivery systems of similar size.
Three distinct pathways for double‐strand break formation at palindromic repeats in yeast (735.10)
Authors: Sheng Ziwei , Saini Natalie , Haber James , Lobachev Kirill 
Published: June 2021

Palindromic DNA sequences capable of forming cruciform and hairpin structures are strong hot‐spots for chromosomal rearrangements in a variety of organisms including humans. Previously, we demonstrated that palindromes induce chromosomal instability by triggering double‐strand breaks (DSBs) in yeast. In this study, we uncovered three mechanisms for DSB formation at palindromic loci.In E. coli and S. pombe, the SbcCD and Rad23‐Rad50‐Nbs1 complex were implicated in metabolism of palindrome during replication. On the other hand, the S. cerevisiae homolog Mre11/Rad50/Xrs2 (MRX) complex does not induce DSBs at the Alu quasi‐palindrome. We found that the perfect palindromes, compared to quasi‐palindrome, create a more prominent replication barrier and at the same time, are subject to MRX attack. Mus81‐Mms4 generates breakage in mrx mutants at palindromes formed by two URA3 genes but not at other perfect palindromes. The fact that hairpin‐capped DSB formation is not eliminated in mrx or Δmus81 mutant implies the existence of an alternative pathway for chromosomal breakage at palindromic loci. We developed a system that allows creating a quasi‐palindrome in a controllable manner throughout the cell cycle. The advantage of this system is that the pre‐existing population of DSBs is absent therefore allowing the visualization of DSBs in each cell cycle stage. Surprisingly, we found that, break formation is tightly regulated and occurs mainly in the G2 stage. We are using this system to examine the roles of cell cycle kinases and the other known structure‐specific nucleases in the generation of hairpin‐capped breaks.
Sumoylation of the transcription factor Nrf2 (739.3)
Authors: Walters Treniqka , Arinze Ifeanyi 
Published: June 2021

The transcription factor Nrf2 induces transcription by binding to the antioxidant response element(s) in target gene promoters, enabling oxidatively stressed cells to mount a response to oxidative stress in order to restore redox homeostasis. To act as a transcription factor, Nrf2 must be separated from its inhibitory protein Keap1. Post‐translational modifications (PTMs) that mediate separation of Nrf2 from Keap1 have been extensively studied but PTMs that impact its biology after this separation are just beginning to emerge. Using in vitro sumoylation assay and other methods, we demonstrated that Nrf2 is a SUMO‐targeted protein [Malloy et al. (2013) JBC 288, 14569‐14583]. Here, we have used three SUMO site‐predicting algorithms (SeeSUMO, SUMOsp and SUMOplot) to locate putative SUMO‐binding sites in mouse Nrf2. Three of the fifteen putative sumoylation sites identified by these algorithms have high probability scores on all three prediction algorithms. Using site‐directed mutagenesis, Co‐IP, and in vitro sumoylation assays, we investigated which of these sites is/are authentic for SUMO conjugation. We also assessed whether sumoylating Nrf2 impacts its transcriptional activity.Grant Funding Source: Supported by NIH grants SC1CA143985, 5T32 GM07628‐34 and CTSA award No.UL1TR000445 from the NCATS.
Profiling the O‐GlcNAcylation of the kinome using kinase microarrary (739.8)
Authors: Han Guanghui , Neiswinger Johnathan , Hardiville Stephan , Sakabe Kaoru , Zhu Heng , Hart Gerald 
Published: June 2021

Mutations and dysregulation of kinases play causal roles in human disease development, signaling, and metabolism. Understanding the function of kinases is of an outstanding interest for biomarker discovery and also necessary for the development of agonists and antagonists for the use in disease therapy. O‐linked beta‐N‐acetylglucosamine (O‐GlcNAcylation) is a post‐translational modification known to regulate different aspects of a proteins function including localization, activity, and stability. Like phosphorylation, O‐GlcNAcylation, which modifies serine and threonine residues on nuclear and cytoplasmic proteins, is a ubiquitous, reversible process that regulates numerous cellular processes. Recent evidence indicates that site‐specific crosstalk between O‐GlcNAcylation and phosphorylation and the O‐GlcNAcylation of kinases play an important role in regulating cell signaling. Hence, it is very important to investigate the O‐GlcNAcylation of the kinome. Previously, we identified 42 kinases that are substrates for O‐GlcNAcylation using an in vitro OGT assay with [H3] radiolabel on a functional kinase array. However, using [H3] has serve senstitive limiations suggesting a more sensitive approach is needed to probe large libraries of proteins. Herein, using a novel kinase microarray coupled with an in vitro OGT labeling assay with immuno fluorophore detection technique, we report a simple, yet sensitive, strategy by which this method can be used to profile the entire kinome for O‐GlcNAcylated proteins.Grant Funding Source: NIH R01CA42486, R01DK61671; N01‐HV‐00240; P01HL107153, R24DK084949
ARE‐mediated posttranscriptional regulation of human IL‐3 in T cells (749.1)
Authors: Gonzalez Pablo , Hernandez Marimar , Gonzalez‐Feliciano Jose , Gonzalez Carlos 
Published: June 2021

Interleukin‐3 (IL‐3) is a lymphokine that supports a broad range of hematopoietic cells and is involved in the body’s inflammatory response. Aberrant expression of this lymphokine is implicated in chronic inflammation and several types of cancer. IL‐3 is a member of a class of transiently expressed mRNAs that harbor Adenosine/Uridine‐Rich Elements (ARE) in their 3’‐Untranslated Regions (3’‐UTR). Previous results from our laboratory suggest a regulatory role for the IL‐3 AREs. We identified four different ARE clusters within the IL‐3 3’‐UTR. To understand the role of these sequences in translational regulation, we conducted site‐directed mutagenesis to interrupt each ARE cluster. Firefly luciferase reporters harboring different mutations in the ARE clusters were transfected into HeLa and Jurkat cell lines. The luciferase chimeras lacking the IL‐3 ARE region showed an increase in luciferase activity, suggesting a loss of translational repression. The chimeric reporter with a mutated ARE3 cluster, which is a nonamer class ARE, appears to be mainly responsible for the 3’‐UTR exerted repression. We also investigated the possible role of the 3’‐UTR in the interaction between the IL‐3 mRNA and ribosomes via polysome profile analysis. These results showed a reduced ribosomal interaction in chimeras harboring the IL‐3 3’‐UTR, suggesting that the ARE can inhibit the translational capability of the IL‐3 transcript.Grant Funding Source: Supported by U54 CA96297, PR‐LSAMP, UPR‐MSC and RISE 2R25GM61151