bluuebunny/crossref_metadata_2025_split huggingface dataset:
Altered Lipid Domains in Pulmonary Arterial Smooth Muscle Facilitate Enhanced Depolarization‐Induced Vasoconstriction following Chronic Hypoxia
Authors: Ahmadian Rosstin , Norton Charles E. , Jernigan Nikki L. , Paffett Michael L. , Naik Jay S. , Walker Benjimen R. , Resta Thomas C. 
Published: April 2020

Chronic hypoxia (CH) augments depolarization‐induced pulmonary vasoconstriction through a myofilament Ca2+ sensitization mechanism involving epidermal growth factor receptor (EGFR) and NADPH oxidase‐dependent Rho kinase activation. Although the mechanism that links CH exposure to activation of this pathway is unknown, previous studies support a role for caveolin‐1 and cholesterol to regulate both EGFR and NADPH oxidase. Furthermore, membrane cholesterol content can influence caveolin‐1 interactions with a variety of proteins. Therefore, we hypothesized that derangement of these lipid domain components contributes to increased depolarization‐induced Ca2+ sensitization and pulmonary vasoconstriction following CH.To test this hypothesis, we examined vasoconstrictor responses to depolarizing concentrations of KCl (30–120 mM) in pressurized, endothelium‐disrupted pulmonary arteries (~150 um diameter) from control and CH (4 wk at 0.5 atm) rats under conditions in which vascular smooth muscle Ca2+ was clamped with ionomycin (3 mM). The effects of altered lipid domains on vasomotor responses were tested utilizing a solution of MβCD and cholesterol (10 mM and 2 mM respectively) to increase cholesterol, and the caveolin‐1 scaffolding domain peptide, AP‐Cav (10 mM). We also assessed the incidence of caveolae using transmission electron microscopy and caveolin‐1 levels by western blotting. Membrane cholesterol content was quantified by filipin (50 mg/ml) fluorescence using confocal microscopy.In agreement with our hypothesis, CH reduced membrane cholesterol content in pulmonary arterial smooth muscle. However, CH was without effect on caveolin‐1 expression or the incidence of caveolae. CH augmented vasoconstrictor sensitivity in response to depolarizing concentrations of KCl as previously described. Both cholesterol repletion and AP‐Cav prevented effects of CH to enhance KCl‐dependent constriction and normalized reactivity between groups. Interestingly, AP‐Cav restored smooth muscle membrane cholesterol in arteries from CH rats to the level of controls, consistent with evidence that caveolin‐1 can regulate cholesterol trafficking to the cell membrane. These results support an effect of AP‐Cav to attenuate KCl‐dependent vasoconstriction following CH by normalizing membrane cholesterol levels. We conclude that alterations in the lipid domains resulting from reduced cholesterol facilitate enhanced depolarization induced pulmonary vasoconstriction following CH.Support or Funding InformationNIH Grants R01 HL132883 and T32 HL007736. AHA Grant 13PRE14580015
Using a Mental Obstacle Course to Engage and Elevate Learning in an Anatomy and Physiology Laboratory
Authors: Marvar Sarah Knight , Hazen Rebecca F. 
Published: April 2020

OBJECTIVEIn order to increase student engagement and learning in a combined anatomy and physiology undergraduate teaching laboratory we designed a type of mental obstacle course. Students completed a series of ‘quests’ designed to increase student learning and develop skills such as critical thinking and analysis. We used this strategy specifically in classes that lacked dynamic student activities and that we felt might otherwise be less engaging and impactful.METHODSIn laboratory classes of 15 students, we designed between 5–8 stations comprised of multistep quests on a specific aspect of the central topic of the laboratory. Students worked in small groups of 2–3, could consult with peers and use outside resources available to them to complete the tasks. The groups of students were required to complete the quests and submit their answers in order to finish the class. Examples of quests that we used were reviewing x‐ray images of various human pathologies of the skeletal system and answering a series of questions about those images including anatomical information, normal physiological processes and apparent pathology of the case. A second example was students were required to create a model of a synovial joint using modeling clay and then annotate the model with information on anatomical features and their functions.RESULTSAs a class we reviewed the tasks and the answers in order to correct any mistakes and student misconceptions. A week later we reviewed the material in quiz form to assess the success of the obstacle course on student understanding. We found that some of the tasks were more successful than others and were occasionally surprised by the results, such as the ability of the students to recall some of the clinical cases from a task.CONCLUSIONSThe quest laboratory set‐up was popular with students and increased their engagement with the material and with each other. Using student feedback and quiz results we plan to improve the design of the tasks and further increase student engagement and understanding.
Effects of Intrathoracic Pressure changes on Diaphragmatic Blood Flow during Mechanical Ventilation
Authors: Horn Andrew Gary , Baumfalk Dryden R. , Schulze Kiana Marie , Colburn Trenton David , Weber Ramona Elaine , Kunkel Olivia Nicole , Bruells Christian S. , Musch Timothy I. , Poole David C. , Behnke Bradley Jon 
Published: April 2020

IntroductionAlthough mechanical ventilation (MV) is a life‐saving intervention, prolonged MV can lead to deleterious effects on diaphragm function, such as ventilator‐induced diaphragmatic dysfunction (VIDD) and vascular incompetence. Specifically, prolonged MV elicits time‐dependent reductions in diaphragm blood flow, induces vascular dysfunction, and limits the hyperemic response to contractions associated with weaning. During MV, positive‐end expiratory pressure (PEEP) is used to maintain small airway patency and mitigate alveolar damage; yet increased intrathoracic pressure with high levels of PEEP may impair diaphragm perfusion.PurposeTo test the following hypotheses: 1) Diaphragm blood flow during MV will be less with high vs. low‐peep, and 2) ablation of intrathoracic pressures (via pneumothorax (PTX)) will not alter diaphragm blood flow during MV vs. the low‐peep condition.MethodsFemale Sprague‐Dawley rats (~5 mo) were randomly divided into low PEEP (LP; 1cmH2O, n=7) or high PEEP (HP; 9 cmH2O, n=6) groups during mechanical ventilation. Blood flow, via the fluorescent microsphere technique, was determined during spontaneous breathing (SB) and 10 minutes after intubation and the onset of MV with LP or HP. Thereafter, for a third determination of diaphragm blood flow, the LP group underwent a surgical laparotomy (LAP; to determine effects of intrabdominal pressure on perfusion) and the HP group was subjected to a pneumothorax (PTX), with microsphere infusions occurring 10 minutes after the completion of surgery. Following the final fluorescent microsphere infusion, tissues were harvested for blood flow analysis. The diaphragm was sectioned into costal (ventral, medial, and dorsal) and crural portions to determine diaphragmatic blood flow distribution.ResultsCompared to SB, both LP and HP MV significantly reduced diaphragm medial costal blood flow (LP, 61.9 ± 7.5 vs 43.8 ± 4.9; HP, 46.2 ± 7.7 vs 21.8 ± 3.7 mL/100g/min; P≤0.05). HP MV significantly reduced blood flow to the ventral and medial costal diaphragm compared to LP MV (P≤0.05). In the HP MV+PTX condition, medial and dorsal costal blood flow was significantly increased versus HP MV (P≤0.05). LP MV + LAP did not significantly increase diaphragm blood flow compared to LP MV. Diaphragm perfusion during HP MV+PTX and LP MV were not different (P>0.05).ConclusionThis study demonstrates that HP MV reduces diaphragmatic blood flow to a greater extent than LP MV. Following a PTX in the HP MV condition, diaphragmatic blood flow is not different compared to the LP MV condition, suggesting that the reductions in diaphragmatic blood flow with LP MV are independent of intrathoracic pressure changes, and due likely to diaphragm quiescence.Support or Funding InformationSupported by: NIH HL137156‐01A1
Targeting of the membrane‐anchored Rab GAP (GTPase accelerating protein) Gyp8 to peroxisomes is regulated by the AAA ATPase Msp1
Authors: Nickerson Daniel Patrick , Quinn Monique , Lin Ariel , Mora Adrian , Vuong Chau , Connolly Sean , Delgado Beatriz 
Published: April 2020

Eukaryotic cells use vesicular transport to build and maintain membrane‐bound organelles housing specific biochemical functions. Rab GTPase signaling proteins (Rabs) are key regulators of vesicular transport, controlling where and when membranes dock and fuse, ensuring lipid and protein cargoes are delivered to appropriate destinations. Rabs depend upon GTPase accelerating proteins (GAPs) to trigger GTP hydrolysis and return the signaling active, GTP‐bound Rab to its inactive, GDP‐bound state. Rab GAPs contribute to the efficiency and fidelity of transport pathways, and defective Rab GAPs are implicated in a variety of human diseases. Rab GAPs tend to be cytosolic proteins that transiently localize at membranes to survey for their client Rab. We report that the yeast Rab GAP Gyp8 is an atypical transmembrane (TM) GAP whose association with peroxisomes is regulated by the AAA ATPase Msp1, a chaperone that functions to remove tail‐anchored proteins from peroxisomes and mitochondria. Computational analysis of Gyp8 predicted a single‐pass TM domain near the carboxy terminus, characteristic of a tail‐anchored protein. Fluoresence microscopy indicated that GFP‐tagged Gyp8 co‐localized with endoplasmic reticulum (ER) and peroxisomal markers in wild type cells. In the absence of peroxisomes, GFP‐Gyp8 redistributed to the ER. Loss of Msp1 chaperone function resulted in mislocalization of GFP‐Gyp8 to mitochondrial membranes. Subcellular fractionation biochemically demonstrated that Gyp8 localized exclusively to a membrane fraction containing peroxisomes. Truncation analyses of Gyp8 indicated that the TM and luminal domains are necessary and sufficient to direct localization to peroxisomes. Growth and viability experiments of cells lacking specific Rab GAPs indicate a peroxisome‐specific carbon utilization defect in cells lacking Gyp8. These data represent the first report in any experimental system of a Rab GAP that localizes to peroxisomes.Support or Funding InformationFunded by grants from the CSUSB Office of Student Research and Associated Students Inc.
A New Player in Glucose Counterregulation: the Glycemic Effects of Neuronostatin through GPR107 and Enhanced Glucagon Secretion
Authors: Grote Stephen , Mahmood Ammar , Samson Willis , Yosten Gina 
Published: April 2020

Regulation of blood glucose is a tightly controlled system with numerous players, woven by both hyperglycemic and hypoglycemic agents that interact in secretion and signaling mechanisms. However, this complex system is deranged in both Type 1 and Type 2 Diabetes, in the response to hyperglycemia (insulin) and hypoglycemia (counterregulatory factors such as glucagon). In treating diabetes with insulin and antidiabetic agents, there is significant risk of hypoglycemia due to improper dosing or inadequate food intake. In addition, repeated bouts of hypoglycemia diminish the counterregulatory response and blunt awareness of symptoms, creating a vicious cycle of unawareness and increasingly severe hypoglycemia. There is great need for better understanding of the players and mechanisms in blood glucose maintenance, and specifically in diabetic hypoglycemia.We recently identified a novel peptide, neuronostatin (NST), encoded in the somatostatin prohormone and found in all somatostatin‐positive tissues. However, the activity of NST is functionally distinct from other prosomatostatin products. Furthermore, it appears the physiologic stimuli of the peptides are different and that the peptides are sequestered in separate secretory vesicles. Our group identified the orphan GPCR, GPR107, as a cognate receptor of NST. Through an interaction with GPR107, NST enhanced glucagon release from isolated islets and immortalized alpha cells. NST also reduced release of insulin in response to high glucose conditions in isolated islets. Based off our findings, we hypothesized that NST is a component of the pancreatic arm of the counterregulatory response. In support of our hypothesis, an infusion of NST substantially increased plasma glucose levels over 30 minutes in male rats, and diminished the insulin response to hyperglycemia in a glucose tolerance test. Additionally, antagonism of the glucagon receptor did not prevent the hyperglycemic effects of NST, suggesting the peptide can act independent of glucagon to increase blood glucose. In insulin‐induced hypoglycemia, NST blunts the drop in blood glucose, further reinforcing the role of NST in counterregulation. The secretion of NST release also appears tied to glucose levels. Fasting blood glucose raised plasma NST levels in rats and humans, and exposure to low glucose stimulated NST release from human islets.Further experiments will confirm the regulatory mechanisms involved in the release of NST, and the importance of its receptor, GPR107. We propose that NST could represent a novel therapeutic target for the treatment and prevention of hypoglycemia in diabetes.Support or Funding InformationThis work was funded by the NIDDK and the Helmsley Charitable Trust.
Impaired bile secretion promotes hepatobiliary injury in Sickle Cell Disease.
Authors: Pradhan-Sundd Tirthadipa , Vats Ravi , Tutuncuoglu Egemen , Singh Sucha 
Published: April 2020

Hepatic crisis is an emergent complication affecting sickle cell disease (SCD) patients, however, the molecular mechanism of sickle cell hepatobiliary crisis remains poorly understood. Here, we use intravital imaging to show that sinusoidal ischemia occurs in the liver of transgenic‐humanized SCD mice under basal condition. SCD mice manifested progressive hepatomegaly, liver injury and hyperbilirubinemia. RNA‐sequence analysis identified dysregulation of genes encoding proteins responsible for fibrosis, bile acid synthesis, bile transport and cholesterol metabolism in the SCD mice liver. Immunohistochemical analysis confirmed inflammation, fibrosis and increased ductular reaction in SCD mice. Intravital imaging also revealed impaired bile secretion into the bile canaliculi, which was associated with loss of apical bile transporters and bile acid biosynthetic enzymes, hepatic bile accumulation, and activation of Farnesoid X receptor (FXR) and small heterodimer partner (Shp) in SCD mice liver. These findings are the first to identify that impaired bile acid synthesis and misexpression of bile transporters promote intrahepatic bile accumulation and impaired bile secretion, leading to hepatobiliary injury of SCD. Improved understanding of these processes could potentially benefit the development of new therapies to treat sickle cell hepatic crisis.Support or Funding InformationTP‐S is funded by PLRC pilot and feasibility award and Community Liver Alliance Pilot Grant award.
Dynamic resistance training attenuate cardiac and renal oxidative stress profile in spontaneously hypertensive male rats
Authors: Shecaira Tânia Plens , de Araujo Amanda Aparecida , Mesquita Frederico , Allioni Gabriela Abrahão , Paixão Camila , da Silva Dias Danielle , Stoyell-Conti Felipe Fernandes , Bernardes Nathalia , De Angelis Kátia 
Published: April 2020

Cardiovascular diseases are the leading cause of death in the world. Hypertension and physical inactivity being the main risk factors for its development and oxidative stress is largely related to the pathogenesis and maintenance of hypertension. In addition, the literature is scarce regarding the benefits of resistance training. Therefore, this study aims to evaluate the effects of dynamic resistance training (DRT) on oxidative stress of spontaneously hypertensive rats (SHR). For this, 16 young SHR were divided into 2 groups (n = 8): SM ‐ sedentary males and TM ‐ trained males. They were submitted to the maximum effort test and trained for 8 weeks, and the SM group remained sedentary during the same period. Oxidative stress analyzes were performed on cardiac and renal tissue. As a result, the TM group increased physical capacity compared to the SM group (TM: 737±39.4 vs. SM: 476±50.3 g) and there was no difference in body weight (p=0.97). There was a reduction in lipoperoxidation only in cardiac tissue (TM: 6985±521 vs. SM: 9211±683 cps/mg protein), as well as protein oxidation (TM: 4.91±0.23 vs MS: 6.12±0.23 nmol/mg protein). Hydrogen peroxide was reduced only in renal tissue (TM: 6.83±1.78 vs. SM: 35.54±4.64 nmoles H2O2/g of tissue). There was no difference in the antioxidant enzyme catalase (p>0.05) but there was an increase in superoxide dismutase in both tissues (Heart: TM: 25.38±1.43 vs. SM: 20.08±1.53 USOD/mg protein; Kidney: TM: 7.71±0.22 VS. SM: 7.00±0.16 USOD/mg protein). In addition, the TM group increased the oxidized‐reduced glutathione ratio in cardiac tissue (TM: 11.32±0.47 vs. SM: 8.63±0.32). Thus, we can conclude that moderate‐intensity DRT was able to reduce oxidative stress, reducing target organ damage and increasing antioxidant defenses in a hypertension model. These findings, coupled with the well‐described benefits of aerobic exercise training, may contribute to a reduced risk of cardiovascular events.Support or Funding InformationFAPESP: 2015/10329‐5, CAPES.
Characterizing Donor‐Specific T Cells in Islet Transplant Recipients Using scRNA‐seq
Authors: Trende Reed Fearing , Ramachandran Sabarinathan , Hering Bernhard , Matson Anders 
Published: April 2020

Organ transplants remain an effective treatment of various end‐stage diseases. Induction of tolerance has remained the elusive goal of transplant community to overcome the mortality and morbidity associated with chronic immunosuppression for long term function of the transplanted organs. We have developed a tolerogenic protocol using apoptotic donor leukocytes (ADLs) that circumvents the need for immunosuppressants and have established the efficacy of ADLs for islet transplants in macaques with diabetes. However, the mechanism by which ADLs induce tolerance has not been fully elucidated. Single‐cell RNA‐sequencing (scRNA‐seq) has proven to be a powerful tool for precisely tracking changes to specific cell types and cell developmental trajectories. Flow sorting using fluorochrome‐labelled MHC class II tetramers was used to isolate donor‐specific T cells from macaques that did and did not receive ADLs prior to an islet transplant, and scRNA‐seq on the 10X Genomics platform was used to characterize these cells. Transcription profiling, TCR fingerprinting and functional clustering of the scRNA‐seq data was used to describe how treatment with ADLs altered specific T cell subtypes, as well as how they develop and interconvert between subtypes. Additionally, combining scRNA‐seq data with the macaques’ clinical outcomes will enable identification of biomarkers that can alert physicians to the fate of the transplanted islets (tolerance or rejection). The results of this project enable a better understanding of the fundamental molecular mechanisms of tolerance induced by ADLs, and further validation studies of the identified biomarkers could greatly aid the physicians’ ability to non‐invasively monitor transplant recipients.Support or Funding InformationFunding from Diabetes Research Wellness Foundation
Effects of Increased Hemoglobin Oxygen Affinity on Cerebrovascular Reserve Capacity in Sickle Cell Disease
Authors: Courelli Vasiliki , Kusmanov Madi , Munoz Carlos , Cabrales Pedro 
Published: April 2020

Sickle cell disease (SCD) is associated with a high incidence of ischemic stroke. SCD is characterized by hemolytic anemia, resulting in limited oxygen (O2) delivery to tissues, increased nitric oxide (NO) scavenging, and impaired cerebrovascular hemodynamics. Cerebral blood flow (CBF) is a key metric in determining proper O2 delivery to cerebral tissue. CBF is tightly regulated to maintain constancy of cerebral perfusion by both local mechanisms and autonomic control. Independent from cerebral autoregulation, the influence of the partial arterial carbon dioxide (PaCO2) tension on CBFis known as the cerebrovascular CO2 responsiveness and reflects the vasodilatory capacity of the cerebral vasculature or cerebrovascular reserve capacity. Since cerebrovascular CO2 responsiveness is oxygen dependent and has been related to an increased stroke risk in microvascular diseases such as SCD. This study determines the effects of changes in hemoglobin O2 affinity in cerebrovascular CO2 responsiveness in SCD. CBF was measured using a laser Doppler probe placed over the cortex. The Hb O2 affinity was manipulated via intravenous administration of 5‐hydroxymethyl‐2‐furfural (5HMF), to decrease the Hb‐O2 affinity of homozygous Townes transgenic SCD mice form 32 mmHg to 16 mmHg. To estimate the cerebrovascular reserve capacity animals were challenged with hypercapnia (5% CO2/21% O2 over 20 minutes) for three cycles. Animals with increased Hb O2 affinity showed increased cerebrovascular reserve capacity compared to animals with normal Hb O2 affinity. In conclusion, increasing Hb‐O2 affinity of sickle cell mice protects cerebrovascular CO2 responsiveness, suggesting a increased cerebrovascular reserve capacity which might protect from stroke in SCD.Support or Funding InformationThis work was supported by the NIH Heart Lung and Blood Institute under Grants T32‐HL105373, R01‐HL126945, and the DOD DMRDP under Grant W81XWH‐18‐1‐0059
Anatomical Sciences Educational Outreach: A tool for boosting science education.
Authors: Mbagwu Smart I. , Okafor Izuchukwu A. , Eze Chinyere E. , Anokwulu Osmond 
Published: April 2020

There is an increasing loss of interest in sciences amongst secondary school and university students despite the growing need for scientists. In order to address this, science advocacy at early childhood and post primary education is undoubtedly imminent for the identification and grooming of the next generation of scientists. This may often require the introduction of special non‐curricular based programs for students at different levels. Considering this, we initiated an anatomical sciences‐inspired educational outreach project tagged “Science Advocacy Program for Youngsters” (SAPFY) for school children in public and private primary and secondary schools in Nnewi, Anambra State, Nigeria. The program was aimed at promoting basic science education by providing suplementary practical‐based skills in science education, enhancing science teaching and learning skills and inspiring science careers through exposure to scientific research and career opportunities especially in the areas of anatomical sciences. The program held over a 3‐day period at the Department of Anatomy, Nnamdi Azikiwe University, Nnewi Campus, Nigeria with a total of 200 participants comprised of primary and secondary school students, teachers and facilitators. The program was organized in four sessions to include introductory lessons on science, anatomy and careers in anatomical sciences. The other sessions involved hands‐on activities, career‐guide interactive sessions and guided tour of the Anatomy museum. Pre‐event assessment of the participants perception about science was performed, while post‐event evaluation to observe the impact of the outreach on the attitude of the participants towards science and their overall perception about the event was performed using feedback forms. We observed a general positivity towards science by the participants and significant outcome of the impact of the event on their attitude towards science. The participants described the event to be educative, inspiring, interactive, expository, fun and innovative. The impact of the outreach programme revealed positive outcomes indicating that the outreach can create a support system capable of providing recommendable modalities for a seamless learning experience for science‐based topicsSupport or Funding InformationAmerican Association for Anatomy