bluuebunny/crossref_metadata_2025_split huggingface dataset:
C/EBPα and C/EBPβ mediated genome‐wide combinatorial transcriptional regulatory dynamics during early onset of liver regeneration and chronic alcohol intake (398.6)
Authors: Patra Biswanath , Kuttippurathu Lakshmi , Hoek Jan , Vadigepalli Rajanikanth 
Published: June 2021

The primary objective of this study is to characterize effects of chronic alcohol consumption on genome‐scale transcriptional regulatory network dynamics during the early phase liver regeneration after 70% partial hepatectomy (PHx) at 6h post 2/3rd PHx in the rat. Rats were fed liquid diet containing 36% of total calories derived from ethanol for 5 weeks, controls were pair‐fed an isocaloric liquid diet with carbohydrate replacing ethanol. Genome‐wide binding targets C/EBPα and C/EBPβ were detected by ABI SOLiD sequencing approach and qPCR validation.Our results reveal C/EBPα binding to promoters of metabolic regulator genes, cell cycle inhibitors, glucose transporter, dehydrogenase and reductase family member, RNA metabolic, phosphate metabolic genes, etc. C/EBPβ was detected at the gene promoters of key regulatory pathways such as regulation of cell cycle, regulation of programmed cell death, regulation of cAMP biosynthetic process, positive regulation of RNA metabolic process, MAPK signaling, Insulin signaling, cell adhesion, etc. We performed qPCR validation of a set of genomic loci with increase in C/EBPα and C/EBPβ activity in the ethanol versus control group. We used our PAINT and TRANSFAC bioinformatics software to predict combinatorial regulatory modules containing co‐localized binding sites for C/EBPα and C/EBPβ, on key genes promoter regions. Support: K05 AA017261, and T32 AA007463.
Transdifferentiation of hepatocytes to biliary epithelial cells requires expression of reprogramming factor Oct3/4 (398.8)
Authors: Bhave Vishakha , Bowen William , Donthamsetty Shashikiran , Orr Anne , Michalopoulos George 
Published: June 2021

Transdifferentiation of liver epithelial cells (hepatocytes and biliary cells) into each other provides a rescue mechanism in liver disease under situations where either cell compartment fails to regenerate by itself. The mechanisms underlying such transdifferentiation of terminally differentiated epithelial are not known. Recently we reported that adult rat liver expresses reprogramming factors Oct3/4, Nanog, and KLF4, and their expression is important for hepatocyte proliferation and liver regeneration. To test if reprogramming factor Oct3/4 plays a role in transdifferentiation of hepatocytes to BECs, we used the hepatocyte organoid culture: an in vitro hepatocyte to biliary transdifferentiation model. In this model, primary hepatocytes when plated on collagen coated roller bottles and cultured in presence of HGF, EGF, and dexamethasone, transdifferentiate to form BECs between 6‐8 days in culture. We found that Oct3/4 is upregulated at day 6 in this model as assessed by mRNA and protein levels suggesting its possible involvement in transdifferentiation. When expression of Oct3/4 was blocked in hepatocytes using adenovirus containing Oct shRNA, there was a significant decrease in appearance of biliary cells (compared to controls) as assessed by biliary marker HNF1‐beta, strongly supporting the role of Oct3/4 in transdifferentiation of hepatocyte to biliary epithelial cells. Experiments to investigate mechanisms through which Oct3/4 might regulate transdifferentiation are under way.Grant Funding Source: 1. Pathology Post‐doctoral Research Training grant, 2. Center for chronic diseases of aging grant
Hepatocyte‐like cells derived from mesenchymal stem cells for translational research in the pig (398.9)
Authors: Brückner Sandra , Stock Peggy , Tautenhahn Hans‐Michael , Winkler Sandra , Dollinger Matthias , Christ Bruno 
Published: June 2021

Extended liver resection is the only therapeutic option of liver cancer. Yet, the residual liver may not accomplish the regenerative capacity needed, which leads to acute liver failure. Mesenchymal stem cells (MSC) differentiated into hepatocyte‐like cells might provide compensation. Therefore, we characterized porcine MSC from adipose tissue and bone marrow and their hepatocyte differentiation potential for functional liver support in the porcine model.Mesenchymal surface antigens and multi‐lineage differentiation potential of porcine MSC were assessed by flow‐cytometry. Morphology and functional properties were determined during differentiation and compared with primary‐porcine‐hepatocytes.MSC from adipose tissue and bone marrow express the typical mesenchymal markers CD44, CD29, CD90, CD105. MSC displayed differentiation into osteogenic and adipogenic lineage. Glycogen storage was comparable in adipose tissue‐ and bone marrow‐derived cells. Urea synthesis was lower in visceral than in subcutaneous adipose tissue‐derived MSC. Cytochrome P450 activity increased during differentiation and was higher in hepatocyte‐like cells generated from bone marrow as from adipose tissue.The hepatocyte differentiation of porcine adipose tissue‐derived MSC was shown for the very first time. That makes them good preclinical candidates for supportive approaches after liver resection in the pig.
Role of the acetylcholine signaling system in human non‐small cell lung cancers (405.3)
Authors: Brown Kathleen , Lau Jamie , Thornhill Brent , Perry Haley , Stevenson Cathryn , Rollyson William , McNees Christopher , Stover Cody , Dasgupta Piyali 
Published: June 2021

Clinical studies show that smoking correlates to 65% of non‐small cell lung cancer cases (NSCLC) in the United States. Nicotine, the major addictive component of cigarettes, accelerates proliferation of human NSCLCs via nicotinic acetylcholine receptors (nAChRs). However, the molecular pathways underlying the proliferative effects of nicotine are yet to be fully understood. The endogenous ligand for nAChRs in neuronal cells is acetylcholine (ACh). Here we show that human lung adenocarcinomas (LAC) produce ACh and contain all of the cholinergic system proteins, including acetylcholinesterase (AChE), choline acetyltransferase (ChAT), choline transporter 1 (CHT1), vesicular acetylcholine transporter (VAChT) and nAChRs. In addition, human LACs isolated from patients showed robust expression of ChAT and VAChT. Nicotine increased the production of ACh in human LAC cells. BrdU assays revealed that ACh acts as a growth factor for human LACs. Nicotine elevated the expression of VAChT and ChAT while downregulating the level of AChE in human NSCLCs. Our study shows that nicotine‐induced ACh production is one of the mechanisms by which nicotine promotes the proliferation of NSCLCs. Our data raise the possibility that that disruption of cholinergic signaling may have applications in the therapy of NSCLCs.Grant Funding Source: Supported by the Flight Attendant Medical Research Institute YCSA Grant and an NIH R15‐AREA Grant
The use of the iCollaborative’s Pre‐Health Collection online resources to enhance competency development in undergraduate pre‐health and STEM students (530.2)
Authors: Jakubowski Henry , Zapanta Laura , Page Jen 
Published: June 2021

Online educational resources, whether used either in exclusively online courses such as massive open online courses (MOOCS) or more traditional or blended courses as supporting educational resources, must be both high quality and user‐friendly to promote student learning. Characteristics of high quality web resources include common metadata to tag content, balancing expert and community definitions of quality to provide a curated collection of resources, and input from both submitters and users whose comments can evolve the quality of the collection.The Pre‐health Collection, a new addition to MedEdPORTAL’s iCollaborative (an established, free and open access platform provided by the Association of American Medical Colleges that is dedicated to the sharing of innovations that are being developed, implemented and tested within the health education) meets these characteristics. The Pre‐health Collection instructional materials are cataloged by instructional methodology, format type, and student competencies that will be tested in the new MCAT2015 exam and that are also embraced by other organizations such as the American Society for Biochemistry and Molecular Biology and the American Chemical Society. These competencies move past prescribed content to higher order reasoning and inquiry skills articulated by leaders in science education reform. The organization and use of the collection will be presented.
A faculty learning community as a vehicle for change: the effect of iterative course change on student learning and attitudes in introductory biology (530.4)
Authors: Elliott Emily , Coffman C. , Reason R. , Raker J. , Becraft P. , Essner J. , Gangloff E. , Howell S. , Kukday S. , Peterson T. , Sakaguchi D. , Vleck D. , Yin Y. , Powell‐Coffman J. , Ogilvie C. 
Published: June 2021

Students learn concepts and skills more efficiently when they actively engage with content, and introductory biology courses nationwide are shifting towards student‐centered classes. However, incorporating student‐centered learning into a large‐enrollment course presents unique challenges. Here we describe a Faculty Learning Community (FLC) where faculty instructors collaborate to transform a large enrollment introductory biology course from a traditional lecture format into a student‐centered course. Activities and strategies are incorporated and improved over time as faculty discuss successes and new approaches, allowing the FLC to optimize activities and build up a resource pool. We evaluate the effect of this iterative change on the classroom environment, student learning, and student attitudes utilizing a pre‐ and ‐post survey design. Preliminary results suggest that student content learning is increasing over time. Further, certain types of activities may be particularly effective at improving learning. Longitudinal data from three semesters of the course will be used to explore 1) how iterative change affects student learning, 2) which approaches are most effective, 3) how to target difficult concepts and 4) how different student populations are impacted by the changes. Results will provide a template for other institutions seeking to incorporate similar course improvements.Grant Funding Source: Supported by HHMI “Engage to Excel” grant at Iowa State University
A discrepancy in the improvement of critical thinking skills exists between ESL and non‐ESL students after content‐based instruction and peer discussion (531.19)
Authors: Hryciw Deanne , Burder Ronan , Tangalakis Kathy 
Published: June 2021

In students with English as a second language (ESL), language instruction based on relevant discipline specific content can be used to assist students to achieve better learning outcomes. However, a limitation is that it may not develop higher order critical thinking skills. Here we describe a pilot study that uses a peer discussion activity in addition to content‐based instruction, to enhance critical thinking skills in both ESL and non‐ESL Biomedical Science undergraduate students.Students were provided with a protocol for the analysis of a scientific manuscript. Then, they participated in a peer discussion following a Socratic format. Students wrote evaluative pieces to summarize the manuscript’s topics before and after the discussion.Using a Bloom’s taxonomy score to rank the students evaluative pieces, only 20% of ESL students improved their critical thinking score, compared to 42% of non‐ESL students. Despite this, survey data demonstrated that all students agreed that the peer discussion improved their understanding of the content in the manuscript and enhanced their ability to review scientific literature. Importantly, ESL students believed that the discussion made them feel positive about their ability to read scientific literature. Thus, further development of specific tools for enhancing critical thinking in the ESL student group is warranted.
The FUTURE Program: ensuring that underserved populations become the scientific and civic leaders of tomorrow (531.24)
Authors: Roberts Rebecca 
Published: June 2021

The Center for Science and the Common Good (CSCG) at Ursinus College provides a framework for all Ursinus science majors to think, speak, and write about the impact of science on the common good. One target group of the CSCG is the FUTURE Students (Fellowships in the Ursinus Transition to the Undergraduate Research Experience), members of underserved populations in science who are given research opportunities early and often to ensure that they can become scientific and civic leaders. We include underrepresented minorities (URMs), women, first‐generation college students, and disabled students in this program. Students in the program enter a research experience at an early point, participate in a team‐taught course titled “Science and Mathematics in Society”, continue research in subsequent years, and are closely mentored by a faculty member and an upper class FUTURE Mentor. FUTURE students are encouraged to become FUTURE Mentors and to participate fully in the CSCG. The CSCG was founded in 2012 through an HHMI grant following a successful pilot FUTURE cohort in 2010. The program has had a positive impact on students, making them more resolute in their career choice, giving them confidence in their ability to communicate and make connections with faculty members, and increasing their awareness of the role of science in the common good.Grant Funding Source: Supported by the Center for Science and the Common Good with support from HHMI
Medical gross anatomy: conversion of a traditional discipline‐based course to a briefer and more clinically focused foundational module in a revamped preclinical curriculum (532.1)
Authors: Davies David , Malak Sharp , Jensen Joseph , Akhter Noor , Beneš Helen , Childs Gwen , Daniel Joseph , Hayes Helen , Kandavalli Naveen , Phelan Kevin , Stanley Laura , Syed Mohsin 
Published: June 2021

Here we report ongoing work to replace discipline‐based courses with foundational and system‐based modules in a new curriculum. As part of this effort, a new Human Structure module was designed to teach clinically relevant anatomy as a basis for subsequent courses. Multiple steps were employed to achieve these goals. Specifically, course duration was decreased from 19 to 8 weeks, instructional time was trimmed 25% (168 hrs to 125 hrs), scheduled lab sessions were cut 40% (45 labs to 27 labs), and embryological topics were moved to other modules. Clinical lectures were increased 57% (7 hrs to 11 hrs): 11 radiologists and surgeons contributed lectures, led case discussions, and/or worked in the dissection laboratory. Five clinical case studies and four histology lectures were also added. Three outcomes gauge the effects of these changes. On a customized NBME final exam, students achieved a mean score of 87.6% ± 7.4 (STD, n = 172). Students evaluated the course with an online survey as 4.44 ± 0.85 (Likert Scale, 5 = outstanding). Similarly, student evaluations of 19 instructors yielded a mean score of 4.38 ± 0.78. Informal faculty assessment indicated that student participation, performance, and morale were equivalent to that in the traditional gross anatomy course.Grant Funding Source: Supported by: UAMS Dept. of Neurobiology and Developmental Sciences.
Auto‐regulatory interactions between NFI occupancy and ETV1 direct the timing of gene expression in late maturing neurons (539.10)
Authors: Ding Baojin , Cave John , Kilpatrick Daniel 
Published: June 2021

Developmental timing mechanisms play an essential role in nervous system development, and their disruption during synapse maturation is implicated in neurodevelopmental disorders. To examine how the timing of gene expression related to synapse formation is regulated during neuronal maturation, we used cerebellar tissues from gene knockout mouse and lentiviral transduction of mouse cerebellar granule neuron (CGN) cultures together with microarray, qRT‐PCR, and chromatin immunoprecipitation assays. We found that Nuclear Factor One (NFI) regulates the temporal expression of genes required for dendrite and synapse formation via its delayed binding to their promoters in developing CGNs. Further, a second transcription factor, ETV1, directly binds to and is required for the NFI occupancy and expression of numerous NFI‐dependent genes in vitro and in vivo. ETV1 binds to and activates the Etv1 gene itself, and this auto‐regulatory loop is induced prior to the activation of downstream target genes. We propose that ETV1 activates NFI temporal occupancy of late‐expressed genes in a stepwise manner by initial positive feedback up‐regulation of the Etv1 gene followed by activation of downstream late genes as ETV1 expression increases. Sequential transcription factor auto‐regulation and subsequent binding to downstream promoters provides a developmental timing mechanism for dendrite/synapse gene expression.Grant Funding Source: Supported by PHS grant NS063047 to DLK
A novel cytoplasmic tail fqqi motif mediates internalization and intracellular trafficking of guanylyl‐cyclase/natriuretic peptide receptor‐A (539.4)
Authors: Mani Indra , Tripathi Satyabha , Pandey Kailash 
Published: June 2021

Cardiac hormone, atrial natriuretic peptide (ANP) modulates blood pressure and blood volume by activation of guanylyl cyclase/natriuretic peptide receptor‐A (GC‐A/NPRA), which produces the second messenger cGMP. The aim of the present study was to examine the role of small sequence motifs in the internalization and intracellular trafficking pathway of NPRA by immunofluorescence confocal microscopy. A chimeric protein of enhanced green fluorescence protein (eGFP) and NPRA (eGFP‐NPRA) was used to study the NPRA trafficking in the intact mouse mesangial cells (MMCs). We have identified a FQQI (Phe790, Gln791, Gln792 and Ile793) motif in the cytoplasmic tail of NPRA sequence and mutated with alanine residues (FQQI/AQQA) and cells were transiently transfected with both constructs. In the ANP‐treated cells, colocalization of wild‐type eGFP‐NPRA with pan‐Cadherin, a plasma membrane marker, indicated that internalization of receptor accounted for 59.2%, 70.0%, 71.8%, and 77.4% at 5, 10, 15, and 30 min, respectively of total fluorescence intensity compared with untreated cells. Colocalization of eGFP‐NPRA with early endosome antigen‐1 (EEA‐1) marker was maximum at 5 min (64.5%), and gradually decreased at 30 min (24.4%). However, the mutation of FQQI/AQQA decreased the receptor internalization by 45% (P< 0.001) and the receptor colocalization into endosome by 58% (P<0.001), respectively, compared with wild type receptor. Our, study suggest that a novel FQQI motif in the cytoplasmic tail mediates the internalization and intracellular trafficking of NPRA, which plays critical roles in hypertension and cardiovascular homeostasis.Grant Funding Source: Supported by the NIH grant (HL57531)
Subcellular gravin localization regulates PKA compartmentalization and PKA‐dependent signaling (539.7)
Authors: Schott Micah , Maliske Ben , Thompson Gonowolo Faith , Grove Bryon 
Published: June 2021

Scaffold proteins play a critical role in cellular homeostasis by positioning signaling molecules in proximity to downstream effectors. However, some scaffold proteins do not assemble static enzyme complexes, but form dynamic signalosomes that traffic to different subcellular compartments in response to stimuli. Gravin (AKAP12) ‐ a multivalent scaffold linked to cell cycle progression, cellular migration, β2‐adrenergic receptor regulation, and hippocampal learning and memory ‐ anchors PKA and other enzymes to the plasma membrane but is redistributed to the cytosol after [Ca2+]i elevation. We postulate that gravin redistribution represents a novel mechanism for cross‐talk between Ca2+‐dependent and cAMP‐dependent signaling pathways. To assess this, we measured the impact of gravin localization on compartmentalized PKA activity using the PKA FRET biosensor AKAR3. Expression of gravin in cells lacking endogenous gravin caused an increase in forskolin‐dependent PKA activity in AKAR3 constructs targeted to the plasma membrane when compared to control cells lacking gravin or expressing a gravin construct lacking the PKA‐binding domain. Expression of a gravin mutant with reduced membrane localization showed no increase in membrane PKA activity compared to control cells lacking gravin. Interestingly, gravin expression caused a decrease in forskolin‐dependent PKA activity in cytosolic AKAR3 constructs compared to control cells lacking gravin. These results confirm that gravin localization regulates PKA signaling and support the hypothesis that gravin mediates cross‐talk between Ca2+ and cAMP‐dependent signaling in functions such as in cell cycle progression, cellular migration, β2‐adrenergic receptor regulation, and hippocampal learning and memory. Based on these results, dynamics in scaffold protein localization likely represents an important paradigm for the regulation of cellular signaling networks.Grant Funding Source: NIH P30GM103329
Structure/function studies on the allosteric mechanism of Rad51 recombinase (549.8)
Authors: Morrical Scott , Mandigo Torrey , Silva Michelle , Maher Robyn , Villanueva Nicolas , Eckenroth Brian , Zahn Karl , Nguyen Xinh‐Xinh , Averill April 
Published: June 2021

Eukaryotic Rad51 recombinase plays a central role in maintaining genome stability by promoting homology‐directed repair of DNA double‐strand breaks and stalled replication forks. Rad51 forms presynaptic filaments on single‐stranded DNA, which activates the ATPase, homologous pairing, and DNA strand exchange activities of the enzyme. Structure/function studies of yeast Rad51 reveal that coordination between the ATP and DNA binding sites is mediated by residues at the protomer‐protomer interface and in DNA binding loops L1 and L2. Conserved interface residues Phe‐187 and His‐352 play central roles in sensing the ATP‐bound state of Rad51‐ssDNA filaments and inducing conformational changes in the filament that are necessary for DNA strand exchange. An F187A mutant is proficient in ssDNA‐dependent ATPase activity but deficient in DNA strand exchange, suggesting an inability to couple ATP binding to the homology search function of Rad51. Mutations at the His‐352 locus affect ssDNA‐binding affinity and catalytic turnover. An H352Y mutant catalyzes a single round of DNA strand exchange and subsequently fails due to a nucleotide exchange defect. Meanwhile, new X‐ray crystallographic structures reveal previously unseen details of the DNA and ATP binding surfaces of Rad51. The structures indicate that conserved aromatic residue Phe‐290 is important for stabilizing a conformation of L1 that allows optimal contacts between conserved Arg‐293 and DNA. Results of this work will facilitate modeling of the structural transitions that occur in Rad51 filaments during recombination.Grant Funding Source: NIH grant no. P02 CA098993