bluuebunny/crossref_metadata_2025 huggingface dataset:
An Investigation of Anki Flashcards as a Study Tool Among First Year Medical Students Learning Anatomy
Authors: Rana Tanvi , Laoteppitaks Chaiya , Zhang Guiyun , Troutman Gregory , Chandra Shruti
Published: April 2020

Purpose

Anatomy is a challenging course in medical school, in part because of the vast number of facts that must be memorized. Current literature suggests the value of spaced repetition in the learning of factual information, and online tools such as Anki flashcards have been developed to facilitate it. The purpose of this study is to investigate the role of curriculum‐specific Anki flashcards as a study tool for first year medical students learning anatomy.

Methods

A set of Anki flashcards was created for the anatomy thread of Block 1 (back, pectoral, shoulder, vertebral regions) and Block 3A (cardiac & pulmonary regions) of the JeffMD curriculum at Sidney Kimmel Medical College. Upon completion of an initial survey, study volunteers were provided with the curriculum‐specific flashcards. Following the anatomy exam in each block, another survey was administered to gather data regarding participants’ usage and opinions of the flashcards.

Results and Conclusions

148 students completed the initial survey and were provided with the flashcards. Of the 78 students that used the curriculum‐specific flashcards and completed the post‐exam survey in Block 1, 20.5% found them extremely helpful, 29.5% very helpful, 33.3% moderately helpful, 15.4% slightly helpful, and 1.3% not at all helpful. Furthermore, 60.3% believed that the flashcards helped reduce anxiety related to the anatomy, while 18.0% did not believe that they reduced anxiety. Of the 60 students that used the curriculum‐specific flashcards and completed the post‐exam survey in Block 3A, 41.7% found them extremely helpful, 36.7% very helpful, 11.7% moderately helpful, and 10.0% slightly helpful. Moreover, 76.7% believed that the flashcards helped reduce anxiety related to the anatomy, while 15.0% did not believe that they reduced anxiety. These results suggest that spaced repetition of anatomy facts through curriculum‐specific Anki flashcards may have a positive impact on affective learning outcomes among first year medical students.

Support or Funding Information

Sidney Kimmel Medical College at Thomas Jefferson University
Larp6 Regulates Collagen mRNA by Targeted Unwinding of a Conserved Stem‐Loop
Authors: Baggs Eric , Warner Lisa
Published: April 2020

Collagen is the most abundant protein in the human body and a key component of the extracellular matrix. Regulation of collagen production in key to the development of fibroproliferative disorders; everything from scarring to cardiovascular disease. La ribonucleoprotein 6 (Larp6) is an RNA binding protein which has recently been shown to regulate collagen production by binding to a conserved region at the translation start site of collagen mRNA. This interaction appears to be critical to directing RNA to the rough ER for translation initiation. Additionally, LARP6 interaction with a number of molecular chaperones appears to be important for regulating collagen production. We hypothesize that LARP6 utilizes conformational selection in the recognition and discrimination of collagen mRNAs and that tertiary interactions dictate mRNA fate. In vitro RNA chaperone assays, translation assays, RNAi, confocal microscopy, and NMR and SAX structural studies are employed to interrogate these interactions. New information regarding the structures and dynamics that determine the Larp6 interaction with collagen mRNA may inform novel therapeutic targets that can mitigate fibroproliferative disease.

Support or Funding Information

P20GM109095
Role of Heme metabolism in the oxidative state of NO‐receptor soluble guanylyl cyclase (sGC) in aging mouse brain
Authors: Sharina Iraida , Martin Emil , Srinivasan Subhiksha
Published: April 2020

Introduction

Aging is an important risk factor for cardiovascular diseases and neurodegeneration. Heme synthesis and metabolism decline with age. Heme moiety is essential for proper function of the Nitric Oxide receptor soluble guanylyl cyclase (sGC). Evidence suggests the involvement of NO/cGMP signaling in human neurological disorders. sGC also an important role in maintenance of cerebral blood flow, vascular homeostasis and platelet function. NO binds to the ferrous heme moiety of sGC and activates cGMP‐forming activity hundred fold. Therefore, the integrity of reduced sGC heme moiety is essential for proper transduction of NO signal.

Methods and Results

We investigated if the oxidative state and the relative content of sGC heme moiety changes with age in mouse brain tissue. Three groups of animals have been used in our studies: young, 3.5 months old, and mature, 15 months old, and old, 24 months, C57Bl6 mice. sGC‐dependent synthesis of cGMP in protein homogenates from mouse brains in response to sGC regulators was evaluated by quantifying the amount P32‐labeled cGMP using thin layer chromatography. To estimate the changes in the amount of heme‐deficient sGC, protoporphyrin IX (PPIX) was used as a heme‐independent sGC activator. NO‐independent activator BAY 58‐2667, which has a higher affinity for sGC with ferric heme, was used to evaluate the changes in the amount of sGC with oxidized heme. NO donor DEA‐NO was used to evaluate the level of sGC with ferrous heme. For each individual sample the ratios of sGC‐[HemeFe3+] vs sGC‐[HemeFe2+] activities (BAY 58‐2667/DEA‐NO) and heme‐deficient vs sGC‐[HemeFe2+] activities (PPIX/DEA‐NO) were determined. Our analysis demonstrated that the relative amount of heme‐deficient and heme‐oxidized sGC increased in both males and females of older age. Decline in sGC protein expression in oldest animal groups was detected by Western blot analysis. We also investigated if the accumulation of heme‐deficient sGC or sGC with ferric heme in ageing brain correlates with changes in the level of proteins involved in iron and heme metabolism. We found no difference in the level of HSP90 chaperone needed for sGC heme insertion and unchanged level in the iron chaperone PCBP2, which is essential for iron trafficking. The expression of divalent metal ion transporter (DMT1) was also not affected by age. However, we observe a decrease in the expression of Heme Oxygenase 1 (HO1) and Aconitase 2 proteins involved in maintenance of cellular oxidative balance in old animals of both genders.

Conclusion

Our data indicate that changes in heme homeostasis might contribute to the decline of NO/sGC in brain with aging.
Insight into the Metabolic Machinery of Deep‐Marine Microbes Grown with Light and Heavy Petroleum
Authors: Tejeda-Mora Andres Javier , Maturano Luis Donis , Macias-Contreras Marla I. , Guerrero Abraham , Gonzalez-Sanchez Ricardo , Hernandez-Lopez Edna , Vazquez-Duhalt Rafael , Licea-Navarro Alexei , Moreno-Ulloa Aldo
Published: April 2020

Degradation of hydrocarbons by marine microbes is well studied and specific metabolic routes have been delineated. Deep‐marine sediments (>1000 m) harbor bacterial communities but remain poorly studied compared to those inhabiting shallow waters. While metagenomics studies have evidenced the metabolic potential of microbes from deep‐sea origins, more exploration through novel approaches of their metabolic machinery is warranted. In this study, we profiled the bacterial taxa (16S rRNA amplicon sequencing) and metabolome (Liquid chromatography coupled to high‐resolution mass spectrometry [LC‐HR‐MS]) of microbes from deep‐sea sediments of the Gulf of Mexico cultured with heavy and light petroleum (four distinct types, according to API classification). We utilized a comprehensive chemoinformatic analysis to detect the microbial chemistries using a repertoire of novel chemoinformatic software, and results were integrated with those obtained by the prediction of functional profiles using 16S rRNA data. We noted a better microbial growth in lighter vs. heavier petroleum after 28 days of culturing, wherein the genus Pseudomonas prevailed, to a similar extent, in all conditions. Hydrocarbon‐degradation pathways (e.g., benzoate, naphthalene, and toluene degradation) were represented by predicted functional profiles, but no differences were observed among petroleum types. PCA analysis of metabolic data showed differences among petroleum type. The number of metabolites and chemical diversity were reduced in heavier vs. lighter petroleum. The predominant chemical classes were coumarins and derivatives, prenol lipids, benzene and substituted derivatives (equal to prenol lipids), and prenol lipids for API 7–10, API 16–20, API 35, and API 40, respectively. Also, other chemical classes linked to hydrocarbon‐metabolism were detected. Manual inspection of selected metabolite clusters or groups of structurally‐related metabolites led to the putative identification of aminated, carboxylated, and hydroxylated chemistries linked to microbial metabolism of hydrocarbons. In conclusion, our study provides valuable microbiological and metabolomic information about one of the most understudied ecosystems in the world, the deep‐marine sediments.

Support or Funding Information

This research was funded by the National Council of Science and Technology of México – Mexican Ministry of Energy – Hydrocarbon Trust, project 201441. This is a contribution of the Gulf of México Research Consortium (CIGoM).
Signaling Mechanisms in Cognition
Authors: Doursout Marie-Francoise , Sundaresan Alamelu , Ocampo Jessika Suescun , Schiess Mya. C
Published: April 2020

Signaling in the gastrointestinal tract is of great interest as a contributing factor to the development of cognition. The dysregulation of Gut‐Brain‐Axis (GBA) signaling may be associated with gastrointestinal manifestations preceding impairments in the cognitive and/or memory and learning process, supporting the hypothesis that it starts from the gut and spreads to the brain (
Braak et al. 2013). The overall goal of this project is to identify how the gut signals to the brain via gut‐synthesized molecules in relation to learning and memory. We suggest that α‐synuclein in the gut plays a key role in gut injury in response to lipopolysaccharide (LPS) and alcohol. Its aggregation possibly initiates the spreading of toxicity from the gut to the brain via the vagus nerve. This could cause an increase in hyper‐phosphorylated tau protein and repression of protective BDNF, leading to cognitive impairment. There are several highly innovative aspects of our proposal. Preliminary data showed increased α‐synuclein in LPS/alcohol injury in rodent models. Here, we propose to use a more sophisticated model: Wild Type (WT) and SNCA knockout (KO) mice treated and non‐treated with LPS/alcohol. Specifically, we will assess whether alterations of the intestinal barrier (or leaky guts) enhances damage as well as the increased production of α‐synuclein. The cognitive function test has been successfully performed using the Morris Water Maze (MWM) in murine model (APP‐mice). Since the mechanisms of GBA are still being worked out, the proposed objectives were to assess the time course and thereby threshold of the compromised intestinal barrier capable of influencing brain function, specifically cognitive and memory function in mice challenged with gut injury. Given the intense bidirectional interaction of the gut with the brain influencing neuronal activity, behavior (cognitive and memory), as well as levels of neurotrophic factors and inflammatory processes, the proposed studies may reshape our understanding of the etiology of cognitive and memory functions.
PDE4B2 is Strongly Expressed in Blood Vessels and is Inhibited by Rolipram, Ameliorating Hepatic Ischemia Reperfusion Injury in a Rat Model
Authors: Frimodig Jane , Matheson Paul , Matheson Amy , McClain Craig
Published: April 2020

BACKGROUND

Ischemia reperfusion (IR) injury is caused by the loss and subsequent return of blood flow. It is a limiting factor in the success of liver transplantation. Reperfusion initiates inflammation and recruitment of neutrophils, which are main effectors of liver damage in IR. The Phosphodiesterase‐4 (PDE4) inhibitor rolipram is anti‐inflammatory, since PDEs degrade cAMP, and higher cAMP levels are known to dampen inflammatory signaling. Isoform PDE4B2 is strongly expressed in the brain, in neutrophils and activated monocytes, and in Kupffer cells in the liver. Here we show for the first time that PDE4B2 antibody also stains blood vessel cells in the liver.

HYPOTHESIS

Rolipram is able to protect the liver during IR injury.

METHODS

Male Sprague‐Daley rats were randomized to six groups (n=6–8 per group): 1) sham, 2) sham + rolipram, 3) 40% IR, 4) 40% IR + rolipram, 5) 70% IR, and 6) 70% IR + rolipram. Two levels of severity were attained by clamping either 40% (left lobe) or 70% (left and median lobes) of the rat liver. 1 hour of occlusion was followed by 3 hours of reperfusion. I.V. rolipram (3 mg/kg) was given at the end of the ischemic period. After sacrifice, blood chemistry, histology, and RT PCR were performed. ANOVA was followed by Tukey’s or Bonferroni’s tests. P values < 0.05 were significant. Frozen immunofluorescent histology revealed colocalization of PDE4B2 (short isoform) with CD31, a marker for blood vessels.

RESULTS

Both 40% and 70% IR elevated serum ALT, an indicator of liver damage. Rolipram lowered ALT levels in 40% IR. Histology showed necrosis and increased neutrophil infiltration, which improved with rolipram, in both 40% and 70% IR. Expression of PDE4B2 was elevated in 70% IR, and lowered by rolipram. Correlation analysis revealed that PDE4B2 mRNA increased with increasing ALT, necrosis, and neutrophil count. Both neutrophils and injury markers correlated most strongly with expression of the transcription factors (TFs) activating transcription factor‐3 (ATF3) and interferon regulatory factor‐1 (IRF1). These two genes also correlated positively with PDE4B2 expression. PDE4B2 antibody strongly stained some endothelial and perivascular cells of the liver, indicating that these cells may be playing some kind of role in the protection of rolipram in IR.

CONCLUSION

These data suggest that inhibition of PDE4 reduces IR injury by decreasing neutrophil recruitment, and that IR injury increases with TFs IRF1 and ATF3. Further experiments are needed to determine conclusive effects of this change in TF expression. Histology showed strong staining of PDE4B2 in blood vessels. Mechanisms of PDE4B2 inhibition protection of the liver in blood vessels cells, however, remain to be elucidated. Ultimately, liver injury was decreased by rolipram; therefore, phosphodiesterase‐4 inhibition is a potential therapy for IR injury.

Support or Funding Information

NIH
NMR and Mass Spectroscopy Based Comparison of Blood Metabolites from Dantrolene and SR59230A Treated Arctic Ground Squirrels
Authors: Macander Sophia , Johannsen Michelle , Hunstiger Moriah , Murphy Carl , Thao Shelly , Oliver S. Ryan
Published: April 2020

Arctic ground squirrels (AGS) hibernate during winter, undergoing cycles of torpor, where body temperatures plummet as low as −3°C followed by rapid rewarming to 37°C during interbout arousals (IBA). While IBAs only occur in certain species that experience torpor, they offer a unique model into which one can observe the specific mechanisms responsible for thermogenesis. Rapid rewarming at IBA onset increases AGS body temperature above 15°C through the activation of brown adipose tissue (BAT). Above 15°C, shivering thermogenesis is able to contribute to warming back up to original body temperature. However, the relative contributions of these two thermogenic processes during IBA is not well understood. AGS were treated across periods of coupled torpor cycles, whereby during the second cycle AGS were treated with either carrier (control) or a selected inhibitor. BAT inhibition using SR59230A, a β3‐adrenergic receptor inhibitor, would be expected to strain the rapid heat production. Shivering thermogenesis utilizes calcium cycling and the Ryanodine receptor in skeletal muscles; the use of dantrolene reduces the thermogenic mechanism needed to reach 37°, effectively inhibiting the Ryanodine receptor in muscle. Relative concentrations of blood plasma metabolites were quantified using nuclear magnetic resonance (NMR) to compare whole and polar extracted plasma. The NMR method was compared against full metabolomic analysis performed using liquid chromatography tandem mass spectroscopy (LC MS‐MS). NMR analysis resulted in higher peak resolution quality and increased metabolite identification in polar and lipid extraction samples compared to whole samples, whereas LC MS‐MS provided a greater abundance of metabolites. Overall, total metabolites were significantly reduced during hibernation. Dantrolene treated AGS had alterations in metabolites indicative of increased energy demand. Furthermore, SR treatment resulted in profiles describing decreased beta‐oxidation and generally lower total metabolites compared to Dantrolene. These trends indicate that changes in calcium cycling and BAT stimulation during hibernation can have profound effects on the animals ability to efficiently balance energy usage.

Support or Funding Information

Research reported in this publication was supported by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant number P20GM103395. The content is solely the responsibility of the authors and does not necessarily reflect the official views of the NIH. BLaST is supported by the NIH with the linked awards; TL4GM118992, RL5GM118990, UL1GM118991.
Cardiovascular Responses to Soft Drink Consumption during Mechano‐ and Metaboreceptor Stimulation
Authors: Ji Wenjie , Reed Emma L. , Kueck Paul J. , Bloomfield Adam C. , Zazulak Hannah E. , Chapman Christopher L. , Schlader Zachary J. , Johnson Blair D.
Published: April 2020

Introduction

Acute consumption of a high‐fructose, caffeinated soft drink exacerbates the increase in blood pressure during exercise in the heat. The mechanoreflex and metaboreflex are important contributors to the blood pressure response during exercise. However, the effects of acute soft drink consumption on the mechanoreflex and metaboreflex, independent of heat stress, are currently unknown.

Objective

We tested the hypothesis that consumption of a high‐fructose, caffeinated soft drink would exacerbate cardiovascular responses to static handgrip (HG) exercise and post exercise muscle ischemia (PEMI) compared to water consumption.

Methods

Eight healthy adults (Age: 26±7 years, 3 females) consumed 500 mL of water (H2O) or soda (Soda, Mountain Dew®) in a randomized, double‐blind study design in a moderate thermal environment (24±1%, 21.7±6% relative humidity). After consuming the assigned beverage, subjects lied on their left side quietly for 20 min and then completed a 10 min baseline (BL) followed by 2 min of static HG at 30% of maximal voluntary contraction followed by 2 min of PEMI. Heart rate (HR, ECG) and mean arterial blood pressure (MAP, finger photoplethysmography) were recorded continuously. Stroke volume (SV) was estimated using Modelflow. Cardiac output (Q) was calculated as HR×SV. Total peripheral resistance (TPR) was calculated as MAP/Q. Data were analyzed as a change from baseline (Δ) to the last 30 s of HG and the last 30 s of PEMI. Data are reported as Δmean±SD.

Results

At BL, there were no differences between Soda and H2O for HR (Soda: 67±9; H2O: 64±8 bpm, P=0.27), MAP (Soda: 79±10; H2O: 83±6 mmHg, P=0.16), or SV (Soda: 101±22; H2O: 95±11 mL, P=0.32). Q was higher with Soda (6.5±1.5 L/min) vs. H2O (5.9±0.8 L/min, P=0.04) and TPR was lower with Soda (12.3±2.5 mmHg/L/min) vs. H2O (14.6±2.1 mmHg/L/min; P=0.02) at BL. During HG, ΔHR (Soda: 15±12; H2O: 13±13bpm, P=0.57), ΔMAP (Soda: 12±13; H2O: 17±7mmHg, P=0.10), ΔSV (Soda: −4±13; H2O: −2±8 mL, P=0.71), ΔQ (Soda: 1.0±1.4; H2O: 1.1±0.9 L/min, P=0.93), and ΔTPR (Soda: −0.1±2.8; H2O: 0.5±2.0 mmHg/L/min, P=0.38) did not differ between drinks. Additionally, there were no differences between drinks during PEMI for ΔHR (Soda: 1±8; H2O: 2±9 bpm, P=0.67), ΔMAP (Soda: 12±13; H2O: 16±11 mmHg, P=0.22), ΔSV (Soda: −1±17; H2O: 4±8 mL, P=0.34), ΔQ (Soda: 0.0±1.1; H2O: 0.4±0.7 L/min, P=0.16), and ΔTPR (Soda: 1.6±2.4; H2O: 1.6±2.9 mmHg/L/min, P=0.98).

Conclusion

These preliminary data indicate that acute consumption of a high‐fructose, caffeinated soft drink does not exacerbate cardiovascular responses to mechanoreflex and metaboreflex stimulation in moderate thermal conditions. Further investigation is warranted to determine if the mechanoreflex and/or the metaboreflex are altered following acute consumption of a high‐fructose, caffeinated soft drink during heat stress.
Sex Differences in Fetal Programming of Blood Pressure and Kidney Gene Expression of Intrauterine Growth Restricted Mouse Model
Authors: Yokota Rodrigo , Maeda Kenji J. , Garrett Michael R. , Intapad Suttira
Published: April 2020

The fetal environment is critical in determining future cardiovascular‐renal function in adulthood. Intrauterine growth restriction (IUGR) results in an unfavorable intrauterine milieu, and can lead to hypertension, renal, and cardiovascular disease of the offspring later in life. However, the underlying mechanisms linking IUGR to cardiovascular and renal afflictions remain unclear. IUGR offspring exhibit impaired kidney development. Furthermore, IUGR reprograms kidney function, resulting in an increase in blood pressure (BP) and susceptibility to kidney injury in the adult. While some renal factors have been postulated, others remain to be elucidated. Here, we have utilized a relevant preclinical mouse model of IUGR induced by reduced uterine perfusion pressure (RUP) to explore the effect of IUGR on renal gene expression patterns as well as sex differences. Pregnant C57bl/6J mice underwent sham or reduced uterine perfusion (RUP) at day 13 of gestation with delivery at full term. IUGR offspring (from RUP dam) had a lower birth weight than control (p<0.05). At 24 weeks of age, control and IUGR mice were subjected to BP measurement. Kidney tissues from control and IUGR mice were isolated and mRNA from these tissues was subjected to microarray analysis to determine differential gene expression. We found that male IUGR offspring had a significantly higher BP compared to male controls (p<0.05). No significant differences in BP were found between female IUGR and female controls, suggesting that sex differences in IUGR programs increased BP in mice. Microarray analysis, at a statistical cutoff of p < 0.05, demonstrates clear sex differences between IUGR and control mice. Of the total number of genetic elements (n = 39,724), 8,356 were significantly different due to IUGR alone, with the majority of these differences occurring in the males (8,319). Network analysis indicated a strong effect on several pathways such as protein processing in the endoplasmic reticulum, oxidative phosphorylation, and mTOR signaling pathways in male IUGR compared to male controls. Interestingly, two pathways (PPAR signaling and AMPK signaling) were significantly altered by IUGR in the female group. In conclusion, there is a clear sex difference in the effect of IUGR on BP and kidney gene expression. The functional implications of these novel factors need to be further investigated.

Support or Funding Information

Dr. Intapad was supported by funding from the AHA 16SDG27770041, ASN Kidney Research Career Development grant, and grant P20GM109036 K. J. Maeda was supported by National Institutes of Health Grants T32HL‐105324 and 20PRE352000021. Dr. Garrett was supported by P20GM‐103476, P20GM‐104357 and P20GM‐121334
Microtubule Arrangement and FKBP51 Localization is Altered in BMPR2‐Deficient Pulmonary Artery Endothelial Cells Isolated from a Rat Model of PAH
Authors: Hamilton Caleb L. , Snyder Emily A. , West Brittanee A. , Vasauskas Audrey A.
Published: April 2020

Pulmonary arterial hypertension (PAH) is an incurable vasoconstrictive pathology of which there are limited palliative treatments. The hallmarks of PAH include vascular smooth muscle cell proliferation and endothelial dysfunction in the small pulmonary arteries. Endothelial cytoskeletal defects have been implicated in BMPR2‐associated PAH, and BMPR2‐silencing alters cytoskeletal arrangement in pulmonary artery endothelial cells (PAECs). Indeed, targeting cytoskeletal proteins, particularly microtubules, may be a novel approach to PAH treatment as microtubule disruption has been efficacious in the treatment of other inflammatory and proliferative diseases. FK506‐binding protein 51 (FKBP51), a peptidyl‐prolyl isomerase member of the immunophilin family, is a known regulator of the glucocorticoid receptor and its expression is upregulated upon glucocorticoid receptor activation. Furthermore, FKBP51 is a binding partner to Hsp90 and stabilizes microtubules in PAECs. Here, we show microtubule disruption and altered FKBP51 distribution in PAECs from a rat model of PAH. PAECs isolated from the Sugen/hypoxia rat model of PAH (PAH PAECs) or normoxic control cells were gifted from the University of South Alabama. The PAH PAECs have lower BMPR2 gene expression than normoxic controls, as shown by real‐time PCR. These cells also demonstrate decreased BMPR2 signaling compared to normoxic control PAECs, as demonstrated by lower ID‐1 expression levels upon BMP4 or BMP6 stimulation. Immunocytochemistry studies of α‐tubulin indicate microtubule disorganization in PAH PAECs, as compared to the normoxic control PAECs, which demonstrate normal perinuclear distribution of interphase microtubules. Immunocytochemical staining of FKBP51, using a novel antibody developed by our laboratory, reveals a microtubule‐like distribution of FKBP51 in normoxic control PAECs. Upon treatment with the synthetic glucocorticoid dexamethasone (DEX), FKBP51 is predominantly observed in the nucleus of normoxic control PAECs, with reduced cytosolic organization and distribution. PAH PAECs, however, showed diffuse cytoplasmic staining of FKBP51, with no change in distribution upon DEX treatment. Western blot analysis of PAEC nuclear fractions also demonstrated greater protein levels of FKBP51 upon DEX treatment, compared to DEX‐treated PAH PAECs. Taken together, these data indicate that microtubule rearrangement is evident in BMPR2‐deficient PAH PAECs, and FKBP51 dysregulation may play a role in cytoskeletal abnormalities as well as the disruption of metabolic homeostasis in these cells.

Support or Funding Information

Supported by NIH1R15HL137135‐01A1
Characterization of a putative antibiotic producing microbe from the plastics‐here
Authors: Pinkowski Dakota , Louks John , Simmons Rachel Elizabeth
Published: April 2020

In this study we are identifying an unknown, putative antibiotic producing bacterium found on a piece of submerged coastal plastic. We isolated genomic DNA, amplified hypervariable regions of 16S rRNA and used Oxford Nanopore sequencing to characterize this species. Through this process we have identified this bacterium as Phaeobacter inhibens. Further characterization of this sample based on a partially complete genome will be discussed as well as potential antibacterial properties that could prove useful for future research and medicinal purposes.

Support or Funding Information

This project is supported by the NSF‐HSI grant #1832545, and from NU internal grants. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
Bio‐lethal effect of BAPCs‐dsRNA formulations for genetics‐based pest management
Authors: de Melo Barros Sheila , Van Ekert Evelien , Whitaker Susan K. , Avila L. Adriana , Stewart William , Gillian Jason , Aulisa Lorenzo , Tomich John M.
Published: April 2020

The use of RNA interference (RNAi) or double‐stranded RNA (dsRNA)‐mediated gene silencing has become one of the most promising tools on the field of pest management. One of the barriers for RNAi efficiency, however, has being the fact that it needs to be rapidly taken up by cells before being degraded by nucleases. In this context, the nanoscale delivery system formed by Branched Amphiphilic Peptides Capsules (BAPCs™) are proposed as a solution for a safer and more efficient cellular uptake of lethal dsRNA constructs. BAPCs can be synthesized in a varied diameters ranging from 10 to 500 nm. BAPCs act as cationic nucleation centers for nucleic acids, generating peptide‐DNA or dsRNA complexes that are readily taken up by eukaryotic cells, escape late endosomes, and lead to the release of the surface‐bound nucleic acids that alter protein expression. Recently, we described the use of BAPCs for suppressing the translation of genes transcripts related to the unfolded protein response (UPR) in Tribolium castaneum and Acyrthosiphon pisum, which led to a premature death with a 50% increase in lethality when compared to dsRNA alone. For this study, BAPCs were combined with 3 different concentrations of a dsRNA supplied by GreenLight Biosciences™. The test sequence contained ~600 bp. Its lethal bio‐efficacy was compared to the dsRNA by itself on Colorado potato beetle. The tests using unformulated dsRNA at 0.00005, 0.0001 and 0.001, mg/mL exhibited a lethal effect of 10%, 30% and 50% lethality after 8 days by contrast of 30%, 60% and 90% of BAPCs‐dsRNA formulations, followed by approximately 40% reduction on leaf consumption in comparison to the unformulated material. The present results have shown that BAPCs‐dsRNA formulations offer a considerable increase in lethality bio‐efficacy over unformulated dsRNA indicating an additive effect in dsRNA delivery over using dsRNA by itself.

Support or Funding Information

This project is a result of a collaboration between GreenLight Biosciences&[trade], Inc. and Phoreus Biotechnology, Inc.
Comparison of Autoregulation Index during Sit‐To‐Stand in Young Healthy Individuals across Races
Authors: Liu Jie , Favre Michelle , Iring Stephanie , Le Cao Thuy Tien , Serrador Jorge
Published: April 2020

Cerebral autoregulation is an important mechanism to protect the brain by maintaining the brain perfusion over varying blood pressures. The cerebral blood flow velocity response to Sit‐To‐ Stand maneuver has been widely used to assess dynamic cerebral autoregulation. Previous work has demonstrated sex differences in autoregulation; however, little is known about the impact of race. Potential racial differences in cerebral autoregulation may contribute to different incidences of cerebrovascular events between different races. Therefore, the purpose of this study was to compare the Autoregulatory index between four different racial groups. We enrolled 55 young healthy subjects (aged 18~35 years) with four racial groups, i.e. White/Caucasian (Age 27±5; n=11; 5 Males), Black/African American (Age 28±6; n=8; 4 Males), Latino (Age 28±6; n=6; 2 Males), and Asian (Age 27±3; n=30; 15 Males). The transcranial Doppler was used to continuously record the cerebral blood flow velocity at middle cerebral artery during 3 repeated sit‐to‐stand maneuvers, with simultaneous measurements of blood pressure, heart rate, and end‐tidal CO2 (ETCO2). There was no difference in demographic variables across groups except for BMI (24±4, 26±4, 27±5, and 23±3; kg/m2, P=0.043). Similarly, there were no differences in baseline cerebral blood flow velocity, blood pressure or heart rate with the exception of ETCO2 (35±3, 40±4, 35±3, and 38±3 mmHg, P=0.003). We found no differences between groups in the physiological response during sit‐to‐stand. Similarly, autoregulatory index was similar across all racial groups (3.6±2.4, 3.9±1.2, 3.3±2.6, and 3.6±1.5, P=0.948). These data suggest that cerebral autoregulation is similar in young healthy individuals across different races. However, these findings must be interpreted with caution due to the small number of participants in the various racial groups. Future studies are warranted to include larger sample size, older subjects and also to consider sex differences within each race.

Support or Funding Information

Supported by the Funding from Rutgers University and U.S. Department of Defense.
Calf Circumference Is Associated with Malnutrition in Elderly Patients on Hemodialysis
Authors: Rodrigues Renata Gomes , Dalboni Maria Aparecida , Moyses Rosa Maria Affonso , Elias Rosilene Motta
Published: April 2020

Background and objectives

Chronic kidney disease (CKD) is considered a world health problem and is associated with a high mortality rate, particularly among elderly patients. With the aging population, there has been an increase in elderly patients starting hemodialysis. Elderly patients are subject to a high burden of comorbidities and the risk of falls and fractures is a concern since it can lead to hospitalization and death. Falls occur as a consequence of clinical pathologies and are aggravated by hemodialysis‐associated hypotension. Sarcopenia, defined as the loss of muscle mass and strength that occurs with aging is commonly seen in these patients. Measurement of calf circumference (CC) is an easy and not expensive tool to assess muscle mass. The objective of this study was to test the association between CC, a marker of sarcopenia, and the risk of falls and fractures in elderly patients on hemodialysis.

Methods

This is a cross‐sectional study that included clinically stable patients ≥ 65 years, on maintenance hemodialysis. The same observer measured the calf circumference in the non‐dominant leg. Clinical and biochemical data were collected from the charts.

Results

Preliminary results of 96 patients (age 73 ± 6 years, % mean) showed a CC of 32.7 ±3.5 and 31.5 ± 4.6 cm in men and women, respectively, p=0,143). History of falls was found in 20 patients (40.6% with low CC vs. 36.8% with normal CC, p=0.789). Patients with low CC according to gender presented lower body mass index (p=0.0001) and had lower weight gain between dialysis sessions (p=0.008). They did not differ from patients with normal CC according to age, gender, race, blood pressure, serum albumin, and presence of comorbidities such as hypertension, diabetes, and congestive heart failure.

Conclusions

Although the measurement of CC did not predict falls in elderly patients on hemodialysis, it did identify patients with low body mass index, which is probably related to sarcopenia. Further studies are necessary to definitely conclude the lack of association between CC and falls.
Myocardial Oxygen Saturation Measured by Photoacoustic EKV Imaging
Authors: Hackfort Bryan T. , Chalise Upendra , Daseke Michael J. , Lindsey Merry L.
Published: April 2020

Cardiac remodeling following myocardial infarction (MI) leads to structural and vascular changes in the myocardium. To better understand the mechanisms involved, we used photoacoustic ECG‐gated Kilohertz Visualization imaging (PA EKV) to measure oxygen saturation in the myocardium. Photoacoustic imaging is a noninvasive imaging technique that uses near‐infrared laser light to optically excite molecules in vivo. Oxygenated hemoglobin absorbs laser light at a different wavelength (850nm) from non‐oxygenated hemoglobin (750nm) which allows for the detection of the relative oxygen saturation (sO2) of a tissue and the amount of hemoglobin present (HbT). In this study, photoacoustic imaging was combined with EKV imaging for continuous measurement of sO2 and HbT throughout the contraction cycle.

Imaging was done on C57Bl/6J mice (F, 4–5 months of age) to measure baseline sO2 levels in the anterior and posterior myocardium. An MI was induced by ligation of the left anterior descending coronary artery. Mice were imaged at days 1, 7, and 14 after MI to measure changes in myocardial sO2. All data presented here are from diastole of the long axis orientation and similar results were obtained from short axis measurements. Oxygen saturation on the anterior myocardial wall decreased from 74.7% pre‐MI to 19.9% 1 day after MI (p<0.0001). Oxygen saturation showed recovery at 7 (54.9%, p=0.023) and 14 (49.9%, p=0.007) days post infarct, yet remained significantly reduced from pre‐MI levels. Oxygen saturation was lower on the posterior myocardium (57.2%) compared to the anterior myocardium but did not change following MI.

Our results demonstrate oxygen saturation begins to recover 7 days after MI as the heart adapts to ligation and neoangiogenesis is stimulated. This study validates the use of PA EKV for the measurement of oxygen saturation in the infarcted myocardium.

Support or Funding Information

We acknowledge funding from National Institutes of Health under Award Numbers HL075360, HL129823, and HL137319, and from the Biomedical Laboratory Research and Development Service of the Veterans Affairs Office of Research and Development under Award Numbers 5I01BX000505. The UNMC Ultrasound Core is supported by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institution of Health under grant P30 GM127200.
What is the Functional Role of Organelle Zinc finger 1 in the Plant C‐to‐U RNA Editing Complex?
Authors: Jimenez-Salinas Alfredo , Cortez Carlos Rodrigo , Hayes Michael Lloyd
Published: April 2020

Higher plants utilize protein
complexes to precisely edit hundreds of RNA transcripts in organelles. The mechanistic model of RNA editing involves a C‐to‐U deamination reaction facilitated through the interaction of the RNA with a protein complex. Complex models have been proposed, but the minimal “editosome” capable of catalyzing C‐to‐U changes and the functions of many of the protein components have not been revealed. This research focuses on describing the functional role of one critical protein component belonging to the RAN binding protein 2 type zinc fingers protein family, Organelle Zinc finger 1 (OZ1). Zinc finger proteins have been associated with RNA binding; though RNA binding and site recognition in editosomes is known to occur via PPR proteins, OZ1 may be interacting with a scaffold RNA sequence. Recombinant OZ1 from Arabidopsis thaliana was used to analyze zinc coordination and RNA binding of this zinc finger protein. Spectrophotometric analysis of OZ1 after immobilized metal affinity chromatography (IMAC) suggests nucleic acid association. ICP‐MS and ESI‐MS analysis of a truncated variant of OZ1, only the sequence containing its two zinc finger domains (OZ1zf), suggests that OZ1 is coordinating only one zinc ion instead of the proposed two. Computational analysis of OZ1 dependent sites in Brachypodium distachyon returned a potential motif conserved among OZ1‐dependent editing sites. Electrophoretic mobility shift assays (EMSAs) are used to test RNA binding and the motif. Understanding this protein will bring us a step closer to manipulating this precise editing machine for use in biotechnology and may be used for purposes of crop improvement.

Support or Funding Information

Funding for this work was provided by NIH SCORE SC2 ID: SC2 GM122718 awarded to Dr. Michael L. Hayes and the NIH MBRS‐RISE R25 GM 061331‐17 grant in support of Alfredo Jimenez‐Salinas.
Comparison of intrinsic chemosensitivity of acutely dissociated medullary serotonergic and retrotrapezoid nucleus neurons
Authors: Wu Yuanming , Bravo Eduardo , Richerson George Bradley
Published: April 2020

Objective

Serotonergic neurons of the medullary raphe and Phox2b expressing neurons of the retrotrapezoid nucleus (RTN) are both putative respiratory chemoreceptors. Here we compare their intrinsic response to acidosis using patch clamp recordings after acute dissociation in vitro.

Methods

The midline medulla and rostral ventrolateral medulla were dissected from mice (>P10) that expressed fluorescent reporters: 1) Phox2b‐Cre::Floxed‐tdTomato:ChAT‐GFP for RTN, and; 2) ePet‐EYFP for 5‐HT. Cells were treated with papain, mechanically dissociated, plated on CELLocate coverslips and allowed to adhere for a variable period before recordings were made. RTN neurons were identified as those that expressed tdTomato but not GFP. In some cases, immunohistochemistry was used to ensure that RTN neurons did not express tyrosine hydroxylase. Patch clamp recordings were made with standard methods previously used to study chemosensitivity of these neurons in culture and slices. Neurons were considered “chemosensitive” if they increased their firing rate by more than 20% in response to a decrease in pH from 7.4 to 7.2 (due to an increase in PCO2 from 5% to 9%, balance O2). Neurons were chosen for recordings only if they were isolated from other neurons. In some cases a lack of synaptic connections was verified with immunohistochemistry for MAP2 using confocal microscopy. The methods used to dissociate and record 5‐HT and RTN neurons were identical.

Results

45% of 5‐HT neurons (n=84) were chemosensitive, with a mean increase in firing rate by 135%+/−115% (mean+/−SD). 38% of these neurons increased firing rate by more than 50% (i.e. to 150% of baseline firing rate. In contrast, only 29% of RTN neurons (n=21) increased their firing rate by more than 20%, and none of them increased their firing rate by more than 50%. Chemosensitive RTN neurons increased firing rate by a mean of 29%+/−8%. The mean firing rate of chemosensitive 5‐HT neurons was 1.1+/−0.6 Hz at pH 7.4 and 2.15+/−0.9 Hz at pH 7.2 (n=38; p<0.0001). The mean firing rate of chemosensitive RTN neurons was 3.3+/−2.3 Hz at pH 7.4 and 4.3+/−2.8 Hz at pH 7.2 (n=6; p<0.05). Recordings were performed in a separate cohort of 5‐HT neurons using a change in CO2 from 5% to 9% in 21% O2 (balance N2) and their response was not different than in 95% O2.

Conclusions

5‐HT neurons had a high degree of intrinsic (cell‐autonomous) chemosensitivity to small changes in pH that was similar to that reported for these neurons in acute brain slices and in cell culture. Intrinsic chemosensitivity of RTN neurons was uncommon. When present it was small, similar to that previously reported in a small percentage of neurons in the neocortex, hippocampus and cerebellum. RTN neurons may play a more important role either as “emergency chemoreceptors” (i.e. responding to very large pH changes) or as relays from other chemoreceptors than as pH sensors themselves.

Support or Funding Information

NIH U01 NS090414
Hypoxia Targeting Nanoparticles for Immunogenic Cell Death of Triple Negative Breast Cancer
Authors: Bhise Ketki , Sau Samaresh , Rauf Mohd Ahmar , Alzhrani Rami , Iyer Arun
Published: April 2020

Triple Negative Breast Cancer (TNBC) accounts for 10–20% mortality amongs all breast carcinoma cases. There is no targeted therapy approved for TNBC owing to absence of major biomarkers: estrogen, progesterone and Her‐2. Advanced stage TNBC tumors present themselves with a hypoxic, vascularized drug‐resistant core, which is rich in cancer stem cells and tumor‐associated growth factors. Earlier reports from our lab have identified the role of hypoxia biomarker, carbonic anhydrase IX (CAIX) in tumor proliferation and metastasis. Based on this, we have developed a CAIX‐targeted prodrug of Doxorubicin (CAIX‐Dox). Further, we have encapsulated the prodrug in long circulating, serum albumin binding lipid nanoparticles (abbreviated CAIX‐Dox‐NP) that can selectively deliver Dox to the hypoxic regions of the tumor, thus reducing Dox‐associated toxicity. CAIX‐Dox‐NP were synthesized using high pressure homogenization for achieving nanosized particles with a narrow polydispersity index. Nanoparticles with size ~200 nm and CAIX‐Dox loading of 13–19% were obtained, which were stable over 48 h at 10% serum and for over 3 months at refrigerated conditions. CAIX‐Dox‐NP were optimized based on lipid composition and ratio of aqueous to organic phases. CAIX‐Dox exhibited a sustained release pattern at physiological and mildly acidic conditions in vitro. Recent studies have shown that immunogenic cell death (ICD) plays an important role in resurrecting CD8+ T cells mediated tumor killing. ICD inducers like Dox, when presented as hypoxia targeting prodrug in the form of CAIX‐Dox, has the ability to penetrate deep into the tumor tissues, including hypoxic regions, killing epithelial cells as well as tumor promoting T cells. CAIX‐Dox has shown killing of syngeneic 4T1 TNBC cells via ICD pathway as demonstrated by Western blot analysis through upregulation of ICD markers like HMGB1, calreticulin and induction of early phase apoptosis on treatment over 72 h, by a factor greater than 3‐fold as compared to control. Thus far, CAIX‐Dox portend to be a new avenue for the treating TNBC, warranting further investigations.
Chemotherapeutic drugs negatively affect myoblast proliferation and myotube anabolism by reducing rDNA transcription
Authors: Guo Bin , Belcher Daniel J. , Nader Gustavo A.
Published: April 2020

Cancer cachexia negatively affects quality of life and contributes to increased morbidity and mortality in a wide variety of cancer types. Emerging evidence suggests that, in addition to tumor derived factors, chemotherapeutic drugs may also play a role in muscle wasting. The goal of this study was to determine the cellular mechanisms underpinning skeletal muscle depletion by chemotherapy drugs. Treatment of myoblasts or myotubes with Paclitaxel (PTX) or Doxorubicin (DXR) reduced cell viability in a dose dependent manner with myoblasts displaying more susceptibility than myotubes regardless of the drug. At non‐lethal doses, PTX or DXR induced significant reductions in myoblast proliferation (47%, p<0.01 and 43%, p<0.05 respectively). In myoblasts, PTX and DXR caused a reduction in rDNA transcription of 24% (p<0.0001) and 19% (p<0.0005) relative to control and a concomitant reduction in rRNA of 16% (p<0.0001) and 18% (p<0.0001), respectively. In myotubes, PTX or DXR reduced rDNA transcription by 21% (p<0.0001) and 30% (p<0.0001) compared to control, and consequently rRNA was 20% (p<0.01) and 17% (p<0.05) lower after the respective drug treatments. The reduction in rRNA reduced translational capacity in myotubes as evidenced by lower global protein synthesis of 52% (p<0.001) and 47% (p<0.001) following exposure to PTX or DXR. These results indicate that chemotherapeutic agents may affect muscle mass by impairing the ability of myogenic cells to proliferate, and by reducing the capacity for protein synthesis in myofibers via a reduction in rDNA transcription.

Support or Funding Information

Supported by NIH grant AR073385