bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular mechanism of Rac1 regulation of endothelial permeability (1095.4)
Authors: Daneshjou Nazila , Komarova Yulia , Sieracki Nathan , Schwartz Martin , Malik Asrar 
Published: June 2021

The RhoGTPase Rac1 plays a critical role in regulating endothelial junctional permeability; however, the causal relationship between Rac1 activity at adherens junctions (AJs) and stability of Vascular Endothelial (VE)‐cadherin adhesion, the main adhesive complex of AJs, is not well understood. Here using photo‐activatable (PA)‐Rac1 and VE‐cadherin‐Dendra2 reporter, we studied Rac1‐mediated VE‐cadherin dynamics. We observed that activation of Rac1 reduced VE‐cadherin dissociation from AJs but had no effect on VE‐cadherin association. The net result of Rac1 activation was to promote steady‐state accumulation of VE‐cadherin at AJs by increasing the affinity of VE‐cadherin homotypic interaction. Inhibition of VE‐cadherin‐mediated adhesion with a peptide that prevents formation of VE‐cadherin‐trans interaction abolished Rac1‐mediated effect on VE‐cadherin kinetics, suggesting that stabilization of trans interaction is required for Rac1 to re‐anneal the AJ barrier. Importantly, Rac1 counterbalanced RhoA activity and decreased the mechanical tension applied to VE‐cadherin adhesion as measured using FRET biosensor. Similar to Rac1 activation, inhibition of Rho kinase (ROCK) at AJs, by un‐caging ROCK inhibitor in UV‐dependent manner, led to accumulation of VE‐cadherin at AJs via stabilization of VE‐cadherin‐trans interaction. Our findings elucidate the important molecular functions of Rac1 in promoting AJ re‐annealing through stabilizing VE‐cadherin‐trans interaction.Grant Funding Source: Supported by AHA 13PRE14670018 and NIH R01 HL045638‐24
The novel Mas agonist, CGEN 856S, promotes Akt/eNOS activation and anti‐proliferation with FOXO1 involvement (1097.3)
Authors: Peluso Antonio , Passos‐Silva Danielle , Etelvino Gisele , Rotman Galit , Santos Robson 
Published: June 2021

Biotechnology advances allowed the discovery of a potential Mas agonist, CGEN 856S, which produces several effects resembling those produced by Angiotensin‐(1‐7). This study evaluated the effect of CGEN 856S on FOXO1 and Akt/eNOS activation, using different cell types. HAEC (Human Aortic Endothelial Cell), A549 and DU145 (human tumoral linages from lungs and prostate, respectively) cell were treated with CGEN 856S with or without previous treatment with A779. The cells were used for immunolocalization of FOXO1, analyzed by confocal microscopy and the nuclear fluorescence intensity was quantified. Mas‐transfected CHO (chinese hamster ovary) cells were stimulated with CGEN 856S. Untransfected CHO cells were used as control and the proteins were used for phospho‐Akt, phospho‐eNOS, phosphor‐FOXO1, Mas and GAPDH detection by western blot. A549 and DU145 cells were also used for cytotoxicity test, being treated with CGEN856S with a combination of PI3 kinase inhibitors, Wortmannin or LY294002, in different concentrations. The results showed a significant nuclear translocation of FOXO1 in HAEC, A549 and DU145 cell types treated with CGEN 856S. The Mas antagonist A779 attenuated to a great extent this effect. The phosphorylation of Akt, eNOS as well as the dephosphorylation of FOXO1 in CHO‐Mas cells treated with CGEN856S was significant. In both DU145 and A549 cells, the combination of the PI3 kinase inhibitors with CGEN 856S was able to potentiate it anti‐proliferative effect. These data suggest that CGEN 856S induces its effects similarly to Ang‐(1‐7), via Mas receptor.Grant Funding Source: Supported by CNPq/MCTI/FAPEMIG #573924/2008‐2
Distinguishing HCO3‐ from CO3= transport by the electrogenic Na/HCO3 cotransporter NBCe1 (SLC4A4) (1098.7)
Authors: Moss Fraser , Lee Seong , Parker Mark , Boron Walter 
Published: June 2021

Theoretically, the electrogenic NBCe1 (SLC4A4), could operate by five thermodynamically equivalent mechanisms: (1) 1 Na+ + 2 HCO3‐, (2) 1 Na+ + 1 CO3=, (3) NaCO3‐ ion pair uptake, (4) 1 Na+ + 1 HCO3‐ uptake with 1 H+ extruded, and (5) CO2/HCO3‐‐stimulated extrusion of 2 H+. We obtained current‐voltage (I‐V) relationships from NBCe1 expressing oocytes superfused with out‐of‐equilibrium (OOE) solutions that vary extracellular pH (pHo) from 9.0 to 6.0 at a constant [CO2]o and [HCO3‐]o. Ignoring direct pHo effects on NBCe1, #1 predicts under constant [CO2]o &amp; [HCO3‐]o, Erev will not change. #4 &amp; #5 predict graded decreases in pHo produce steep graded decreases in H+ efflux that manifest as steep graded decreases in slope conductance (GNBC) and inward rectification. #2 &amp; #3 predict pHo decreases will act by lowering [CO3=]o and [NaCO3‐]o, thereby reducing GNBC as predicted by the Michaelis‐Menten equation; the I‐V relationship will remain linear. We find that Erev shifts appropriately for pHo 9.0‐6.0, excluding #1. Importantly, the I‐Vs are linear and exhibit only small GNBC decreases at low pHo, eliminating #4 &amp; #5. In fact ‐‐ based on the experimentally determined Km(CO3=) = 4 μM (constant pHo 7.5 and 5% CO2)‐‐ these GNBC decreases at low pHo, and the increases at high pHo are smaller than expected. In conclusion, the major carbon substrate for NBCe1 must be either CO3= or NaCO3‐ and, extreme pHo paradoxically modulates NBCe1 to minimize changes in transport rate.Grant Funding Source: Supported by NIH DK30344 and NS18400
Age‐related activation of the hepatic unfolded protein response and inflammasome are reduced by trehalose treatment (1115.2)
Authors: Pagliassotti M.J. , LaRocca T.J. , Wei Y. , Wang D. , Hudson W.M. , Zigler M.L. , Seals D.R. 
Published: June 2021

The accumulation of damaged proteins can perturb cellular homeostasis and provoke aging, pathological states and cell death. Quality control systems, such as the unfolded protein response (UPR), inflammasome and autophagy, mitigate the residence time of damaged proteins. In the present study, we have examined the UPR and inflammasome in the liver of young (Y; ~ 5 mo.) and old (O, ~29 mo.) mice (n=8/group) and the ability of trehalose, a compound linked to increased protein stability and autophagy, to counteract aging‐induced effects on these systems. When used, trehalose was provided for 4 wks in the drinking water (n=7/group). Livers from O mice were characterized by activation of the UPR and inflammasome and increased indices of liver injury. Mitofusin‐2 (Mfn‐2), a protein linked to protection against endoplasmic reticulum stress and UPR activation, was reduced in O vs. Y. Trehalose treatment reduced the activation of the UPR and inflammasome, and restored Mfn‐2 in O mice. It has been postulated that a collapse of proteostasis promotes many age‐associated pathologies. Trehalose appears to be an effective intervention to mitigate the activation of quality control systems that respond to disruption of proteostasis in the liver. We postulate that the age‐associated reduction in Mfn‐2 is critical to the activation of the UPR and inflammasome in the liver of old mice.Grant Funding Source: NIH DK072017, AG013038, AG039210
Spontaneous essential hypertension in the non‐human primate Chlorocebus aethiops sabaeus, the African green monkey (1136.16)
Authors: Rhoads Megan , Beierschmitt Amy , Huggins Denise , Collett Jason , Osborn Jeffrey 
Published: June 2021

Current models of essential hypertension have limited comparisons to humans due to differences in posture and periods of activity. The annual cycle of spontaneous hypertension in male Chlorocebus aethiops sabaeus was assessed in an outbred research colony. Using plethysmography, systolic (SBP) and diastolic blood pressures (DBP) of adult male African Green, or vervet, monkeys (n=163) were measured in May/June after ketamine sedation (~10‐15mg/kg). Blood pressure phenotypes were characterized as hypertensive (HT: SBP 蠅 140mmHg) or normotensive (NT: SBP 蠄 120mmHg). SBP and DBP identified 33% (n=53) HT (average SBP 169.04±24.19mmHg) and 41% NT (average SBP 101.32 ±13.28mmHg, n=66) animals. Borderline hypertension (BHT) was identified with an average SBP of 129.09±5.85mmHg (n=44). A randomized group of animals (n=51) were re‐measured in September/October. HT monkeys (n=21) decreased blood pressure from 174.14±27.48mmHg to 128.61±28.48mmHg (p<0.05). SBPs of NT (n=21) and BHT animals (n=9) were unchanged (p>0.05). A third of adult male vervet monkeys in this colony exhibit spontaneous hypertension with unique seasonal variation compared to NT or BHT animals. This model of hypertension in an Old World non‐human primate is highly translational to human essential hypertension and allows for new research directions in a novel genetically similar species.Grant Funding Source: Supported by Behavioural Science Foundation
Beneficial effects of imidazoline compounds in a rat model of type 2 diabetes (1142.1)
Authors: Edwards Lincoln , Manaenko Anatol , Crane Louis , Baziard‐Mouysset Genevieve , Vann Nicholas , Corbin Kathryn , Nunemaker Craig 
Published: June 2021

Therapeutic agents capable of reducing both hyperglycemia and hypertension would prove beneficial to type 2 diabetics. The objective of this study is to highlight the beneficial effects of imidazoline compounds S43126 and moxonidine (mox) in the Zucker diabetic fatty rats (ZDR). Control Zucker lean rats (ZLR) and ZDR were treated with S43126 or mox for 2 weeks, and then plasma glucose and blood pressure were measured. The effect of S43126 on insulin release was measured in mouse islets. Time‐course and dose‐response studies were also carried out in cells, followed by Western blotting. S43126 and mox lowered blood glucose in ZDR by 69% and 52% relative to control, but had no significant effect in ZLR. Both drugs significantly reduce blood pressure in ZDR only. S43126 caused a dose‐dependent insulin release of up to 4 fold, only under conditions of high glucose. Mox did not increase insulin release. Cells treated with mox showed an increased phosphorylation of protein kinase B (PKB) by greater than 3 fold, and this effect could be blocked by efaroxan. Cells overexpressing the imidazoline receptor anti‐sera (IRAS) protein showed greater phosphorylation of PKB compared to control, following mox treatment. These data suggest that imidazoline compounds decrease blood glucose by a mechanism involving insulin release, sensitization, or both. These compounds should be developed as agents to treat diabetics with hypertension.Grant Funding Source: Supported by NIH1R15DK084468‐01 A1
Lipid emulsion rescue therapy blocks AMPK activation and Akt inhibition induced by bupivcaine cardiotoxicity (1154.9)
Authors: Fettiplace Michael , Ripper Richard , Bonini Marcelo , Minshall Richard , Weinberg Guy 
Published: June 2021

OBJECTIVE: To assess changes in energy sensing and cell survival pathways both during bupivacaine‐induced cardiac pharmacotoxicity and during the accelerated recovery caused by lipid‐emulsion.METHODS: Male Sprague‐Dawley rats were anesthetized and instrumented to monitor arterial pressures, carotid flows and to deliver drugs to both jugular veins. Animals were separated into 4‐conditions: no treatment (control), 10mL/kg lipid emulsion (30% Intralipid, Frensius Kabi, Uppsala, Sweden) over 1 minute, 10mg/kg Bupivacaine over 20s, or 10mL/kg Bupivacaine followed 10 seconds later by 10mL/kg lipid emulsion. Animals were sacrificed at four time‐points 0 minutes (for control), 1, 5 &amp; 10 minutes following infusions. Hearts were flash‐frozen and proteins extracted in an anti‐protease, anti‐phosphatase buffer. Following protein quantified for equal loading, the samples were run on a 4‐15% Bis‐Tris gel, transferred to nitrocellulose paper, stained with phosphorylation‐site‐specific antibodies in the AMPK and Akt pathways, exposed to ECL and imaged using light‐sensitive film.RESULTS: Treatment with bupivacaine caused a rapid activation of low energy sensing pathways and deactivation of cell survival pathways including phosphorylation of AMPK, dephosphorylation of Akt, GSK3β &amp; p70‐s6k. Treatment with lipid emulsion reversed this phosphorylation patterns with dephosphorylation of AMPK, and rephosphorylation of Akt, GSK3b and p70‐s6k. Additionally, by 10‐minutes lipid emulsion treatment inactivated Acetyl‐CoA‐carboxylase via phosphorylation.CONCLUSIONS: Bupivacaine toxicity rapidly changes energy modulation and proliferation pathways in the heart. Lipid emulsion treatment reverses these changes and restores cell survival pathways in the context of cardiac pharmacotoxicty. These results imply the importance of energy sensing pathways and energy balance during resuscitation.Grant Funding Source: Supported by American Heart Association Predoctoral Fellowship 13PRE16810063
YAP and TAZ drive matrix stiffness‐dependent fibroblast activation (1180.6)
Authors: Tschumperlin Daniel , Varelas Xaralabos , Liu Fei 
Published: June 2021

Fibroblasts actively respond to changes in extracellular matrix mechanical properties, and positive feedback between matrix stiffness and fibroblast activation may play a pivotal role in fibrosis. Microarray analysis of matrix‐stiffness regulated genes in human lung fibroblasts identified significant overrepresentation of transcriptional targets of YAP (yes‐associated protein) and TAZ (transcriptional coactivator with PDZ‐binding motif), consistent with a prominent role for these factors in fibroblast mechanoresponsiveness. Immunofluorescence imaging demonstrated that YAP and TAZ transitioned from primarily nuclear localization on relatively stiff matrices (25.6 kPa) to cytoplasmic on soft matrices (0.4 kPa). RNAi‐mediated knockdown of YAP/TAZ significantly reduced the cell spreading, focal adhesion length, traction forces, proliferation, pro‐fibrotic gene expression and collagen synthesis observed on stiff matrices, but exerted negligible effects on soft matrices. Conditional overexpression of YAP overcame soft matrix limitations on proliferation, while overexpression of either YAP or TAZ promoted pro‐fibrotic gene expression on both soft and stiff matrices. Taken together, these results support a central role for YAP and TAZ in matrix stiffness‐dependent activation of fibroblasts to a proliferative, contractile and matrix synthetic state implicated in the pathogenesis of fibrosis.Grant Funding Source: Supported by NIH RO1 HL092961
Zinc supplementation improves outcomes associated with traumatic brain injury but does not overcome risks associated with combined ethanol intake (122.4)
Authors: Morris Deborah , Levenson Cathy 
Published: June 2021

In addition to the known behavioral and cognitive impairments, including memory deficits, depression, and anxiety associated with traumatic brain injury (TBI), there is an increased risk for new onset heavy weekly drinking, binge drinking, and alcohol‐related problems. Our previously published work has shown that zinc supplementation robustly reduces behavioral deficits associated with TBI. Our objective was to examine the behavioral and cellular outcomes associated with TBI that are complicated by ethanol consumption, as well as the effect of zinc supplementation on these outcomes. Adult male rats were fed a zinc supplemented (180 ppm) or zinc adequate (30 ppm) diet for 4 weeks followed by a moderately‐severe TBI using controlled cortical impact. After injury, rats were given 3 g/kg of ethanol daily for 7 days via gavage. Ethanol intake exacerbated TBI‐induced anxiety‐like and depression‐like behaviors and significantly impaired the efficacy of zinc supplementation. While ethanol did not worsen learning and memory, ethanol intake prevented zinc supplementation from improving Morris water maze performance. Furthermore, the world’s highest field strength magnet (21.1 Tesla) for in vivo MRI, diffusion mapping, and spectroscopy, is being used to examine the mechanisms by which ethanol prevents the efficacy of zinc after TBI.Grant Funding Source: Supported by U.S. Army MRMC and NIH grant GM081382
Developing research questions and designing studies for your scholarly activities in medical education (14.2)
Authors: Borges Nicole 
Published: June 2021

Attendees will be introduced to medical education research and will learn and apply important concepts regarding designing research studies. Attendees will work to identify their scholarship interests, transform everyday work into scholarship, and develop robust research questions by following strategies and principles.Specific Objectives: At the end of the session, participants will have: 1. Identified their research and scholarship interests 2. Formulated meaningful and feasible questions within those areas
Unraveling the mechanism on how Entamoeba histolytica evokes MUC2 exocytosis (152.3)
Authors: Cornick Steve , Moraeu France , Chadee Kris 
Published: June 2021

MUC2 is the major secreted gel‐forming mucin produced by goblet cells that form the protective mucus blanket covering the colonic epithelium. This mucus barrier confers the first line of innate host defence against invasion by the protozoan parasite Entamoeba histolytica (Eh). During Eh infection, a subset of individuals develop infectious colitis when the parasite degrades and/or deplete mucin stores. In this study we quantified the exocytosis SNARE complex that regulated mucin secretion in vitro in response to Eh using human colonic LS174T goblet cells. Unlike MUC2, SNARE components were not transcriptionally regulated or specifically degraded in response to live Eh. Rather, mucin exocytosis occurred through a protein kinase C and calcium dependent manner. Furthermore, we have characterized the Eh surface virulent factor, cysteine protease 5, as the predominant component that mediated mucin secretion. Interestingly, only viable Eh but not heat‐killed and/or glutaraldehyde fixed Eh evoked mucin exocytosis upon contact with colonic cells. These studies were confirmed using live cell confocal microscopy imaging with fluorescent SNAREs and Eh. Predictably, shRNA silencing of a putative SNARE, SNAP23, markedly decreased mucin exocytosis and rendered the colonic monolayer susceptible to Eh degradation. This work sheds light into the pathogenesis of Eh and the regulatory mechanisms of the host which act to subvert infection.Grant Funding Source: Supported by CIHR and NSERC CREATE HPI
Flipping the neuroanatomy labs: how the production of high quality video and interactive modules changed our approach to teaching (211.3)
Authors: Krebs Claudia , Holman Parker , Bodnar Tamara , Weinberg Joanne , Vogl Wayne 
Published: June 2021

Neuroanatomy is often approached with apprehension, often described as “neurophobia”. The result has been a triage approach by students: memorizing as much information as possible to pass the exam, and relegating a deep understanding of CNS systems as they relate to the clinical reality to clinical experiences.Aware of this reality, we wanted to create content that is accessible and engaging; moreover, we wanted to “flip” the classroom so that students could begin to use class time for knowledge application instead of memorization.The theory behind a flipped classroom approach is to provide resources to the students to prepare with prior to coming to class, and then use the classroom time for the application of this knowledge to clinical cases and in‐depth discussions about CNS systems.We created eight highly produced mini‐documentaries to provide conceptual overviews of key brain systems, and 20 interactive modules for more in‐depth didactic content as well as formative assessment for the students. All of these resources are posted online under a Creative Commons license.A Readiness Assessment Test (RAT) at the beginning of the session gauges student understanding of the material; lab time is then used to address areas of weakness as well as to apply knowledge to clinical cases ‐ a core focus of each lab.Evidence suggests that this approach can make the classroom experience more engaging for both faculty and students.Grant Funding Source: Supported by: UBC Flexible Learning Initiative
Development of No Más Hambre (No More Hunger), an innovative promoter‐driven nutrition education and skill‐building curriculum to reduce the risk of hunger in Mexican‐origin older adults in Texas border colonias (273.3)
Authors: Bustillos Brenda , Sharkey Joseph , Gomez Melissa 
Published: June 2021

Mexican‐origin older adults who live along the Texas‐Mexico border experience high rates of poverty, food insecurity and hunger, and health disparities. Among this hard‐to‐reach population, promotoras de salud (community health workers) serve as a cultural bridge, provide outreach, and are recognized as respected health advocates and peer health educators. The purpose of this study was to design, develop, and pilot test curricula and instructional materials that provide promotoras with knowledge and skill‐building training to target seniors at risk for hunger through tailored and culturally appropriate education and skill building on food acquisition and preparation using community food resources. 95 Mexican‐origin seniors from four Texas border areas and 25 promotoras participated in focus groups to determine educational and skill needs. Emergent themes included desire for home‐based nutrition education and guidance regarding food acquisition and food preparation, given limited resources. No Más Hambre (No More Hunger) consists of seven modules of instruction that engage and empower promotoras to deliver evidence‐based education and skills. This Spanish‐language curriculum was developed and delivered by employing Adult Learning Theory and applying strategies and techniques such as interactive instructional modules and case‐based discussions to guide resource‐dependent education. The curriculum includes strategies to overcome barriers to food insecurity and encourages seniors to engage in collaborative networks to locate resources within the community. Pre‐ and post‐tests comparisons were assessed for each module. This project constitutes a major new effort to enhance nutrition knowledge and skills among Mexican‐origin older adults and to effectively apply the science of human nutrition to meet the needs of this vulnerable and food insecure population.Grant Funding Source: Supported by AARP Foundation and CDC's PRC Healthy Aging Research Network
The SDF‐1/CXCR4 axis utilizes mTOR signal transduction to promote angiogenesis (278.8)
Authors: Ziegler Mary , Hughes Christopher 
Published: June 2021

Pathological angiogenesis, which occurs during chronic inflammation or tumor growth, results when positive and negative angiogenic regulators are disrupted. The chemokine stromal‐cell derived factor‐1 (SDF‐1) and its receptor CXCR4 promote endothelial cell (EC) migration and tube formation. PI3K is a key downstream regulator of CXCR4‐mediated chemotaxis and mammalian target of rapamycin (mTOR) is at the center of PI3K‐mediated signal transduction. We have hypothesized that the SDF‐1/CXCR4/mTOR signaling axis contributes to the molecular mechanism of angiogenesis. This study illustrates that SDF‐1 stimulation activates mTOR signal transduction in EC grown in monolayer cell culture. The pharmacological inhibition of CXCR4 or mTOR blocks sprouting in an in vitro 3D angiogenesis model, and also abolishes EC migration in a 3D angiogenic invasion assay. Specific inhibition of mTOR complex 1 or mTOR complex 2 (mTORC2) reveals that SDF‐1‐induced angiogenesis occurs via mTORC2 signal transduction. An analysis of targets downstream of mTOR indicates that 6‐phosphofructo‐2‐kinase (PFKFB3), which is a key regulator of glycolysis, is downregulated in EC in which mTORC2 is inhibited. Taken together these data indicate that the SDF‐1/CXCR4 axis activates angiogenesis by utilizing an mTORC2 signal transduction pathway. In addition, these data present a potential link between mTORC2, metabolism and angiogenesis, which deserves further exploration.Grant Funding Source: The project described was supported by Grant Number T32CA009054 from the National Cancer Institute.