bluuebunny/crossref_metadata_2025_split huggingface dataset:
A context dependent requirement for Fig4 catalytic function in yeast
Authors: Reeves Hannah , Khan Imran , Muñoz-Rivera Alejandra , Habib Alim , Weisman Lois , Strunk Bethany S. 
Published: April 2020

PI lipid phosphatases modulate signaling cascades through localized dephosphorylation of specific phosphoinositides (PI) on subcellular membranes. Additionally, some of these phosphatases regulate cellular processes through lipid phosphatase independent functions. Notably, Fig4, a PI 5‐phosphatase proposed to dephosphorylate PI3,5P2, promotes the synthesis of its substrate independent of its catalytic activity. Fig4 activates its opposing kinase, Fab1, to facilitate dynamic elevation of PI3,5P2 by associating with the Fab1‐Vac14‐Fig4 complex. While Fig4 is critical for development, its catalytic function is not, as catalytically impaired Fig4 rescues neonatal defects in a Fig4 knock‐out mouse. Nevertheless, mice expressing catalytically impaired Fig4 alone display late on‐set neurological abnormalities and reduced life spans indicating that Fig4 catalytic activity is critical for long‐term homeostasis. Strikingly, we show that catalytic impairment of yeast Fig4 is more detrimental to yeast growth on rapamycin and heat stress than total loss of Fig4. Toxicity of catalytically impaired Fig4 can be rescued by co‐expression of wild‐type Fig4 implying that this toxicity results from loss of catalytic function. Moreover, yeast expressing hyperactive Fab1 show similar growth defects on rapamycin and heat stress in the absence of Fig4, which suggests that elevated levels of PI3,5P2 are responsible for this phenotype. These studies provide a new model for investigating the physiological implications of loss of Fig4 catalytic activity.Support or Funding InformationNIH R00 GM120511‐04
Inhibition of Androgen Receptor Decreases Fat Metabolism by Decreasing Carnitine Palmitoyltransferase I Levels in Skeletal Muscles of Trained Mice
Authors: Kim Jisu , Hwang Hyejung , Park Hun-young , Jung Wonsang , Kim Sung-Woo , Lim Kiwon 
Published: April 2020

PurposeAndrogen hormone levels are strongly associated with obesity in adult mammals, especially with advanced age. We investigated androgen receptor inhibition on fat metabolism and long‐chain fatty acid (LCFA) transport proteins in skeletal muscle during exercise.MethodsMale ICR mice were randomly divided into three groups: CON (control), EX (exercise), and EXIN (exercise + androgen receptor inhibition). EX and EXIN groups were trained on a treadmill five times a week. After four weeks, the fat metabolism of each group was measured using open‐circuit calorimetry during one hour of exercise. After the metabolism measurement, the expression levels of LCFA transport proteins (FAT/CD36, CPTI) were analyzed in skeletal muscle.ResultsWeight gain and final body weight were significantly lower in the EX group than in either the CON or EXIN groups. Conversely, food intake was significantly higher in the EX group than it was in the CON and EXIN groups. The total weight (CON; 2.07 ± 0.6, EX; 1.64 ± 0.2, EXIN; 1.95 ± 0.2) of the abdominal adipose tissue were significantly lower in the EX group than in the CON and EXIN groups (P < 0.05). However, there was no different between the CON and EXIN group. Oxygen uptake and fat oxidation during exercise tended to be lower (12%) in the EXIN group than in the EX group. Total fat oxidation in the EXIN group was significantly lower during the initial 20‐min (P < 0.003) and 40‐min (P < 0.041) phases compared to that in the EX group. In addition, the level of FAT/CD36 protein in the EX and EXIN groups was approximately double that in the CON group (P < 0.001, P < 0.001). CPTI expression in the EX group was higher than that in the EX group (P < 0.0069) as well as in the CON group.ConclusionExercise training increases the expression of LCFA transport proteins (FAT/CD36, CPTI). However, blocking androgen receptors decreases the expression of CPTI in the skeletal muscle, which reduces fat metabolism. Thus, reducing sex hormones or suppressing the sensitivity of AR receptors can inhibit energy efficiency and fat metabolism by suppressing CPTI.Support or Funding InformationThis work was supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Korea (NRF‐2015S1A5B5A01016088).
Needs and Opportunities for Ethics and Responsible Conduct of Research (E/RCR) integration in Course‐based Undergraduate Research Experiences: the ENCOUR Fellowship Program
Authors: Diaz-Martinez Laura A. , D'Arcy Christina E. , Olimpo Jeffrey T. 
Published: April 2020

Course‐based undergraduate research experiences (CUREs) have been shown to enhance students’ development of cognitive and non‐cognitive skills in science, technology, engineering and mathematics (STEM) fields resulting in the proliferation of CURE offerings in college course catalogues. These courses often constitute the initial research experience for undergraduate students in the biological sciences, thereby establishing students’ perceptions of what it is to be a researcher. Though ensuring the integrity of the scientific enterprise through the ethical and responsible conduct of research (E/RCR) is central to the scientific process, documented efforts to integrate E/RCR education in the context of CUREs is lacking. In an effort to address this information gap, we conducted a mixed methods study to evaluate E/RCR implementation efforts within biological sciences CUREs at the national level. Results from these efforts indicate a general awareness from CURE stakeholders of the importance of E/RCR education in CUREs. The majority (65.15%) of individuals surveyed reported having to resolve E/RCR issues within their CUREs and agree that E/RCR education should be included. Although a great majority (96.96%) of respondents reported addressing at least one E/RCR topic in their CUREs, the responses evidenced a lack of planned and intentional integration of E/RCR education into such learning environments. Prominent issues identified by our study participants as barriers for the effective integration of E/RCR education into their CUREs were a perceived lack of time (92% of respondents), resources (85% of respondents), and appropriate training for instructors. Based on these results, the Ethics Network for Course‐based Opportunities in Undergraduate Research (ENCOUR) has developed a fellowship program that aims to serve as a national professional development model for instructors facilitating E/RCR education in biology CUREs. ENCOUR fellows will participate in a year‐long program designed to enhance their E/RCR knowledge and to guide them through the development and assessment of educational resources for effective integration of E/RCR topics into their CUREs.Support or Funding InformationThis work was supported by the National Science Foundation Awards 1727867 and 1919312
Endogenous β‐endorphin Plays a Pivotal Role in Angiotensin II‐mediated Pressor Response
Authors: Badr Safy , Rezq Samar , Hassan Rasha 
Published: April 2020

BackgroundEndorphins are endogenous opioid neuropeptides that are mainly produced from the pituitary gland in response to pain and stress. A number of mediators were reported to stimulate β‐endorphin production including interleukin 1 beta (IL‐1β) and corticotropin‐releasing factor (CRF). Angiotensin II (Ang II) can stimulate β‐endorphin production from anterior pituitary gland, but the exact molecular mechanisms involved in this effect, as well as the role of the released β‐endorphin in Ang II‐mediated pressor response, remain elusive. Our study aimed to fill this knowledge gap.MethodsMale rats (6 per group) were either injected with IL‐1β receptor blocker (IL‐1R antagonist, 100 μg /kg, s.c.), the CRF receptor blocker, astressin (100 μg /kg, Intranasal) or a combination of both prior to Ang II injection (200 μg/kg, ip). Other groups of rats were given naloxone (1.6 mg/kg, s.c.) or telmisartan (10 mg/kg, oral) prior to Ang II injection. Serum and hippocampal β‐endorphin levels, brain IL‐1β and CRF levels were detected. Moreover, markers of oxidative stress including malondialdehyde (MDA) and superoxide dismutase (SOD), the inflammatory marker, C‐reactive protein (CRP) and sympathoexcitation (c‐Fos, L‐glutamate, and phosphorylated MAPK) markers were measured in the hippocampus of different groups.ResultsAng II increased serum and hippocampal β‐endorphin levels by 37.95% and 28.03%, respectively. This response was attenuated when astressin or/and IL‐1R antagonist were given before Ang II injection. Moreover, Ang II induced a pressor response, increased hippocampal IL‐1β (1.4‐fold), CRF (7‐fold), MDA (1.5‐fold) and CRP (3.3‐fold) while deceased SOD (by 31.49%) levels. Also, Ang II injection increased c‐Fos (9.9‐fold), glutamate (3.1‐fold) and phosphorylated‐MAPK (5.6‐fold) levels. The previous effects were abolished when telmisartan was given prior to Ang II injection, while naloxone aggravated Ang II‐mediated pressor response and most of the biochemical changes.ConclusionThese findings suggest that Ang II can induce β‐endorphin release by increasing the levels of both IL‐1β and CRF and that the released endorphin mitigates Ang II‐mediated sympathoexcitatory response. This study reveals new insights on the intermediary role of β‐endorphin in Ang II‐mediated sympathoexcitation and highlights it as a possible target for treating hypertension.
Investigation into the Metabolic Limitations of Alpha Conotoxins as Drugs in the Gastrointestinal Tract
Authors: Gusman Emma , Sandbach Arika , Espiritu Michael 
Published: April 2020

Peptides isolated from cone snails, known as conotoxins, have potential in treating neuropathic pain. Peptides often lack efficacy as drugs due to poor pharmacokinetic profiles despite displaying high potency and selectivity. Conotoxins present significant sequence diversity, but little information exists about their pharmacokinetic properties. We hypothesize that this diversity will correlate with dynamic pharmacokinetic profiles, with some peptides exhibiting increased stability. In this study, we aimed to gain a basic understanding of the stability of the conotoxins α‐IMI and α‐GI in the stomach and intestines. Both have different primary sequences despite serving as antagonists of the acetylcholine receptor, which is a potential target in cancer, chemotherapy‐induced allodynia and possibly pain associated with Crohn’s disease. In order to study these peptides, novel mass spectrometry (LC‐MS/MS) methods were developed incorporating multiple reaction monitoring scans for each peptide in simulated gastric and intestinal fluids. The quantitation range of our method was 0.5–5 μg/mL, which is 20 times more sensitive than traditional methods. To compare gastrointestinal metabolic stability, each peptide was incubated in simulated gastric fluid and intestinal fluid and their stability was measured using our LC‐MS/MS method at times ranging from 0–90 minutes. Both peptides displayed a high amount of stability in gastric fluid, as no significant loss of either peptide was determined after 90 minutes. In intestinal fluid IMI degraded rapidly (t1/2= ~6 minutes), whereas α‐GI displayed far more stability in the same environment (t1/2= ~257 minutes). α‐GI incorporates a prominent helix in its structure which is likely responsible for its increased stabilization in comparison to IMI. Considering the differences in the metabolic stability of these peptides, further study of conotoxin sequences may result in the identification of stable molecular scaffolds. In the future, we plan to pinpoint what particular features are responsible for metabolic stability or susceptibility across more conotoxins, such as differences in sequence, structure and rigidity and plan to use this information to produce analogs with increased stability within the gastrointestinal tract.Support or Funding InformationSource of Research Support: This work was supported by the Pacific University Research Incentive Grant Program and an ASPET Summer Undergraduate Research Fellowship (SURF) award at Pacific University.
Spinal trigeminal subnucleus pars muralis: An interface for apneic reflex
Authors: Perez Amalia Callado , Kleinfeld David , Deschênes Martin 
Published: April 2020

Noxious stimulation of the nasal cavity elicits protective reflexes for the upper respiratory tract, including sneezing, mucus secretion, apnea and cardiovascular reflexes. Yet, no studies have shown the full circuit responsible for the apneic response upon noxious stimulation of the nasal mucosa. Here, we show that injection of cholera toxin beta subunit into the nasal mucosa leads to terminal labeling in the transition zone between the interpolaris and caudalis subnuclei of the trigeminal sensory complex, i.e. subnucleus muralis (SpVm). We also provide physiological evidence that ammonia vapor delivered into the nasal cavity induces an apneic reaction and activates some SpVm cells. Subnucleus muralis cells also respond to mechanical stimulation of the narial pad and the nasal mucosa. Yet, none of the muralis cells responded to vibrissa deflection. Electrolytic lesion of SpVm or unilateral transection of the anterior ethmoidal nerve prevent apnea induced by ammonia delivery to the nasal epithelium, demonstrating their crucial role in the apneic reflex. We also found direct projections from SpVm to the respiratory centers, particularly the preBötzinger complex (preBötC). Inhibition of inspiratory preBötC cells and increased firing of expiratory preBötC cells are associated with ammonia‐induced apnea.Anatomical and physiological data presented here support the hypothesis that nasal induced apnea may be mediated by direct projections from nasal innervated Subnucleus muralis neurons to the PreBötC complex.
Control of Vasoconstriction by Myoendothelial Ca2+ Signaling Through Gap Junctions
Authors: Saavedra Andrea , Espinoza Hilda , Burboa Pia , Figueroa Xavier 
Published: April 2020

In resistance arteries, smooth muscle cells (SMCs) and endothelial cells (ECs) are communicated through gap junctions (i.e. myoendothelial gap junctions), which provide a signaling pathway for control of vasomotor tone. In this context, the Ca2+ signaling associated to smooth muscle contraction might also be transmitted via myoendothelial gap junctions and activate a regulatory feedback mechanism (myoendothelial feedback) by the production of endothelium‐dependent vasodilators. It is thought that IP3 is the main Ca2+‐related signaling transmitted from smooth muscle cells to endothelial cells, but the direct contribution of Ca2+ to the myoendothelial feedback is not clear. We investigated the temporal pattern of vasoconstriction in mesenteric resistance arteries, and their temporal relationship with the increase of Ca2+ in SMC and EC. We used intact mesenteric resistance arteries of Sprague dawley male rats (≤ 10 mm in length) to measure the vasoconstriction and changes in [Ca2+]i of smooth muscle cells and endothelial cells observed in response to phenylephrine (PE) or KCl using the fluorescent indicators of Ca2+, Fluo‐4 and X‐Rhod‐1.Changes in [Ca2+]i were also evaluated in primary cultures of mesenteric endothelial cells. All procedures were approved by the local Bioethical Committee (ID:180806005). The vasoconstriction induced by PE and KCl was not only associated with an increase of [Ca2+]i in smooth muscle cells, but also in endothelial cells, which was prevented by the blockade of L‐type voltage‐dependent Ca2+ channels with 10 μM nifedipine or the inhibition of gap junctions with 50 μM 18‐b‐Glycyrrhetenic acid. Although the stimulation with PE or KCl did not evoke an increment of [Ca2+]i in primary cultures of endothelial cells, the response induced by these vasoconstrictors was larger after blocking nitric oxide (NO) production with NG‐nitro‐L‐arginine (100 μM). These results suggest that the direct diffusion of Ca2+ contributes to the NO‐mediated component of the myoendothelial feedback.Support or Funding InformationConicyt 21171840
Evaluating the Dose Dependent Response to DTT Treatment Resulting in HSF Activation in Drosophila cells
Authors: Shirk Austin , Choi Annette , Hrizo Stacy , Buckley Martin 
Published: April 2020

Proteins drive many of the biological processes in cells. To do this, they fold into complex 3D structures that are integral for their functionality. Notably, various environmental and chemical stressors can disrupt protein folding and thus disable the functions of proteins, threatening the livelihood of cells. To mitigate this stress, organisms initiate the highly‐conserved heat shock stress response. In eukaryotes, the master heat shock activator heat shock factor (HSF) is rapidly recruited to the Hsp70 heat shock protein genes and triggers the recruitment of additional co‐activator proteins that facilitate gene expression. This leads to the production of heat shock proteins that function as molecular chaperones to promote refolding of proteins, prevent aggregation and increase protein degradation pathways. Notably, activation of the heat shock response pathway, can be visualized by measuring GFP‐tagged HSF binding to the heat shock protein genes in living Drosophila salivary gland nuclei. Our lab is currently using this technique to identify novel compounds that induce the heat shock response pathway. Our pioneering experiments have shown that diamide and hydrogen peroxide, two chemicals known to cause protein misfolding and activation of the heat shock response pathway, trigger the recruitment of GFP‐HSF to the Hsp70 loci in living salivary gland cells to a similar level as HS stress. In addition, to our surprise, high levels of Dithiothreitol (DTT, 100 mM), a chemical known to cause protein misfolding and activation of the unfolded protein response pathway (UPR), results in the recruitment of GFP‐HSF to the Hsp70 gene loci. Here we describe experiments to further explore a possible dose dependent activation of HSF by DTT.Support or Funding InformationStudent Faculty Research Grant for Slippery Rock University
Catalytic Characterization of Human Malate Dehydrogenase 1 (MDH1)
Authors: Huynh Ngoc H. , Hoang An , Sohl Christal D. 
Published: April 2020

Lung cancer is the leading cause of cancer death. Non‐small cell lung cancer (NSCLC) makes up 85% of all types of lung cancer, and includes squamous cancer, adenocarcinomas, and large cell cancer. Malate dehydrogenase (MDH) exists as two forms, MDH1 (cytosolic) and MDH2 (mitochondrial). Both forms are elevated in tumor cells, but only high expression of MDH1 is associated with poor prognosis. Patients with amplified MDH1 have a 50% reduction rate of survival. MDH1 appears to support proliferation of tumor cells by fueling glycolysis with the regeneration of nicotinamide adenine dinucleotide (NAD+). However, studies of the kinetics of human MDH1 is limited. Our goal is to characterize the catalytic features and regulation of MDH1. We hypothesized that MDH1 activity is inhibited in the presence of reactive oxygen species (ROS). Human MDH1 was expressed heterogenously from Escherichia coli and purified using immobilized cobalt affinity chromatography. The enzyme catalytic activity was determined in the optimal conditions of salt, pH, temperature, and buffer. In the assay, MDH1 activity was calculated from the oxidation rate of NADH to NAD+ at 340 nm using a spectrophotometer after incubating MDH1 with oxaloacetate and NADH under steady‐state conditions. To test our hypothesis under oxidative environment, we repeated this assay using oxidized glutathione. The enzyme activity was 6‐fold lower than that measured in reducing conditions. In the absence of the enzyme, oxidized glutathione does not convert NADH to NAD+, which implied the enzyme’s conformation was affected and hence the observed loss in enzyme activity. In the future, we will employ site‐directed mutagenesis to gain an insight whether our observed inhibition was due to the sensitivity of cysteine residues to oxidation.Support or Funding InformationThis work was funded by a Research Scholar Grant, RSG‐19‐075‐01‐TBE, from the American Cancer Society (C.D.S.), National Institutes of Health R00 CA187594 (C.D.S.), U54CA132384 (SDSU) & U54CA132379 (UC San Diego), MARC 5T34GM008303 (SDSU), and IMSD 5R25GM058906 (SDSU), as well as the California Metabolic Research Foundation (SDSU).
Epigallocatechin‐3‐gallate inhibits tumor angiogenesis via endoglin/Smad1 pathway in human umbilical vein endothelium cells
Authors: Sheu Ming-Jyh , Chen Chiao-Yun 
Published: April 2020

Endoglin, a transforming growth factor‐β (TGF‐β) co‐receptor, is highly expressed in endothelial cells and various solid tumors, including lung cancer. It may be involved in endothelial cell (EC) differentiation, migration, and proliferation. TRC105, an endoglin‐neutralizing antibody, increased VEGF signaling in ECs. Besides, anti‐VEGF treatment increased the endoglin level. Therefore, we hypothesized that a combination of both endoglin and VEGF inhibitors may increase and maintain anti‐angiogenetic activity in human umbilical vein endothelial cells (HUVECs). Structures of all 2000 compounds from the TCM database were used for screening to find the potential compounds. Discovery Studio (version 4.5) was used for the virtual screen of various compounds targeting the endoglin. Among them, epigallocatechin‐3‐gallate (EGCG) showed its possibility to bind with endoglin. The sulforhodamine B (SRB) and western blotting assay were used to determine the cell density and measurement of the cellular protein content. Our results showed that EGCG demonstrated the strongest binding affinity to endoglin, and inhibited the endogin protein expression in HUVECs. The main contribution of the study indicated that EGCG significantly decreased the semaxanib‐induced overexpression of endoglin. Therefore, a combination treatment including EGCG will probably solve the drug resistance to anti‐VEGF treatments.Support or Funding InformationChina Medical Universityand Asia University (CMU106‐ASIA‐14) and Show Chwan Memorial Hospital, Changhua, Taiwan (RD107042)
Usual and Unexpected Variations in the Veins of the Posterior Abdomen: A Case Study
Authors: Stewart Ian F. 
Published: April 2020

Two venous system components comprise the drainage of the posterior abdominal cavity. One component drains blood from the visceral derivatives of the urogenital ridge (e.g., kidneys, gonads) directly to the inferior vena cava (IVC). The other venous system collects blood from the body wall and drains into the azygos system through the subcostal vein, ascending lumbar vein, and lower posterior intercostal veins. Veins, and especially the azygos system, are notoriously variable. Much of this variability arises from the complex embryological development of the caval venous system in the thoracic and abdominopelvic cavities; but the formation of venous anastomoses representing multiple routes of drainage from a single region also contribute to the variability of veins.During routine dissection of the abdomen of a male cadaver (Caucasian, 67 years), the right testicular vein demonstrated multiple anatomical variations. An anomalous vein arising from several small tributaries at the lateral end of the 11th and 12th ribs was discovered during the dissection. This vein crossed the posterior abdominal wall inferomedially to drain into the right testicular vein. Further exploratory dissection revealed direct communication between the anomalous vein and the right 11th posterior intercostal vein, which could be traced from the origination of the anomalous vein to the connection with the azygos vein at the appropriate vertebral level. The anomalous vein represents an unusual route for collateral venous circulation between the azygos system and the caval system in the abdomen via the right 11th posterior intercostal vein. Additionally, the right testicular vein drained into the right renal vein instead of directly draining into the IVC. No other notable variations were observed in the abdominal vasculature. The left testicular vein, left renal vein, left posterior intercostal veins, and left subcostal vein all demonstrated typical merging patterns. Accompanying renal, testicular, and posterior intercostal arteries on the right side also appeared to have normal branching patterns.