bluuebunny/crossref_metadata_2025_split huggingface dataset:
vCCI:Chemokine Interactions: Experimental Biochemistry Meets Computational Prediction
Authors: LiWang Patricia , Guan Wenyan , Stark Lauren , Showalter Laura , Colvin Michael 
Published: April 2020

Inflammation plays a major role in many pathologies including asthma, arthritis, atherosclerosis and traumatic brain injury. As such, controlling inflammation is an important goal. While many biological pathways are involved in inflammation, an appealing target is the chemokine pathway. Chemokines are small immune system proteins that mediate chemotaxis of leukocytes bearing cognate chemokine receptors to the site of infection or inflammation. Many viruses have evolved strategies to counter the chemokine system, including the production of chemokine binding proteins. In particular, poxviruses encode vCCI (viral CC chemokine Inhibitor; also called p35), a protein that binds members of the CC class of chemokines. vCCI has been shown to bind many CC chemokines with high affinity and as such vCCI could be a potent tool as part of an anti‐inflammation strategy.The mechanistic details of how vCCI is able to bind dozens of CC chemokines with nanomolar (or sub‐nanomolar) affinity is still being elucidated. Structures of vCCI alone and in complex have revealed a beta sandwich composed of two beta sheets that binds chemokines using one face of the sandwich in conjunction with a long, highly acidic loop after the second beta strand. Experimental work shows that this highly negatively charged loop in vCCI can act as a lid on the bound chemokine and interacts with positive charges on the chemokine.A particularly puzzling vCCI‐chemokine interaction is in the area at the edge of the negatively charged loop in vCCI, where a conserved tyrosine (Y80) is close to K48 of the chemokine. It was hypothesized that mutating Y80 to Ala in vCCI would allow more room for the chemokine to bind, but experimentally the opposite has been shown to be the case: the Y80A variant in vCCI has a greatly decreased ability to bind chemokines.We report a collaborative effort to understand the role of Y80 and the action of the acidic loop in vCCI to bind chemokines. Molecular dynamics simulations suggest that rather than being a hindrance to the function of the loop, the role of Y80 is actually to prop the loop in the “open” conformation so that the chemokine can bind. When Y80 is replaced with Ala in simulations, the loop closes and blocks the chemokine binding site. This intriguing and unexpected hypothesis from in silico work has been tested experimentally using NMR, isothermal titration calorimetry and other biophysical techniques. We therefore report a collaborative set of experiments that includes computation and experimentation to aid in the understanding of the vCCI:chemokine interactionSupport or Funding InformationSupport provided by UC Merced summer graduate funding.
Effect of peroxynitrite scavenger on brain microvascular nitrotyrosination and S‐nitrosylation
Authors: Kolli Lahari , Sakamuri Siva Sankara Vara Prasad , Evans Wesley R. , Sure Venkata N. , Albuck Aaron L. , Mostany Ricardo , Busija David W. , Katakam Prasad V.G. 
Published: April 2020

ObjectivePeroxynitrite, generated from nitric oxide and superoxide, plays a pathological role in both ischemic and neurodegenerative brain injury. Free radical mediated microvascular dysfunction is a key initiator of cerebrovascular and neurological pathologies. Thus, understanding the acute effects of peroxynitrite on brain microvessels will help identify potential therapeutic targets. The objective of the study was to investigate the impact of peroxynitrite scavenger on the nitrotyrosination and S‐nitrosylation of brain microvessels.MethodsBrain microvessels were isolated from the brains of 12‐week‐old female C57bl6 (WT, n= 4) mice by a combination of filtration (40μm – 300μm) and gradient centrifugation. Microvessels were treated with 2.5 μmol/L of peroxynitrite scavenger (FeTMPyP, Fe (III)tetrakis (1‐methyl‐4‐pyridyl) porphyrin pentachlorideporphyrin pentachloride) for 60 minutes at 37°C. Subsequently, western Blots were then performed to detect the nitrotyrosine residues in the protein lysates from microvessels. In addition, we determined the protein S‐nitrosylation in lysates by biotin‐switch method followed by immunoblotting. Nitrotyrosine residue is an indicator of peroxynitrite generation and protein‐S‐nitrosylation is an indirect measure for nitric oxide production.ResultsAcute treatment with FeTMPyP decreased nitrotyrosination of proteins from microvessels (3.16±0.63 vs 19.79±10.82, p=0.03, n=4 mice) in WT mice. In addition, 2.5 μM of FeTMPyP treatment decreased the protein S‐nitrosylation by 40% (p≤0.05).ConclusionsBrain microvessels form peroxynitrite at basal levels. Surprisingly, peroxynitrite inhibition decreases protein S‐nitrosylation in the brain microvessels.Support or Funding InformationSupport: Undergraduate Summer Research Fellowship by American Physiological Society (Albuck); and National Institute of Health: National Institute of General Medical Sciences and National Institute of Neurological Disorders and Stroke (Katakam: R01NS094834) and National Institute on Aging (Mostany: AG047296).
Effect of inhibition of the PI3K‐Akt pathway on the Unfolded Protein Response
Authors: Nguyen Anh , Araujo Kelly , Bhandari Deepali 
Published: April 2020

The endoplasmic reticulum (ER) is an organelle in eukaryotic cells that plays a vital role in many important cellular functions including proper folding of secretory and membrane proteins. Any disruption of ER function triggers ER stress leading to activation of an evolutionarily conserved signaling program called the Unfolded Protein Response (UPR). UPR signaling initially aids in re‐establishing normal ER functions and promotes cell viability. However, if the homeostasis is not restored in a timely manner, UPR eventually commits the cells to death. Cancer cells are known to be able to evade ER stress‐induced cell death, which helps them acquire resistance to therapy. Our laboratory has previously shown that Protein kinase B aka Akt is activated in ER stressed cancer cells leading to enhanced cell survival. The goal of this project was to test if Akt activation modulates the outcome of UPR signaling. We treated cells with commercially available inhibitors of the PI3K‐Akt pathway and analyzed changes in the expression and/or post‐translational modification of known UPR signaling proteins by immunoblotting. Our data show that the PI3K‐Akt pathway inactivation differentially regulates the outcome of UPR signaling. Our current experiments are focused on studying the effect of PI3K‐Akt inhibition on viability of multiple cancer cell lines exposed to ER stress.Support or Funding InformationThis project is supported by the NIGMS‐NIH grant #SC2GM121246.
Elucidating the role of antibiotics on PAL release from E.coli
Authors: Jackson Niaya A. , Khokhar Maha , Cheng Susan (Shi) , Gallardo Leslie , Michel Lea V. 
Published: April 2020

Sepsis can result from a systemic bacterial infection, followed by an over‐exuberant immune response, which leads to widespread inflammation. Severe sepsis can result in organ failure and in severe cases, death. Past studies have proposed a role for bacterial Peptidoglycan‐Associated Lipoprotein (Pal) in the pathogenesis of Gram‐negative bacterial sepsis. In this study, we confirmed that Pal is released from Gram‐negative bacteria, Escherichia coli (E. coli), under certain culture conditions, including in the presence of certain antibiotics. Our preliminary results suggest that different antibiotics have differential effects on Pal’s release from E.coli. Since the majority of sepsis patients are administered antibiotics, our findings may be of great significance to the medical field and the sepsis research community.Support or Funding InformationRIT FEAD/DRIG and NIH Bootcamp , RIT LSAMP program, Dr. Michael Pichichero Rochester General Hospital Research Institute
Resident bacteria in the small intestine can shape host drug metabolism through innate lymphoid cell‐derived IL‐22
Authors: Flannigan Kyle L. , Erickson Sarah L. , Johnston Michael J. , Jijon Humberto , Gallo Marco , Hirota Simon A. 
Published: April 2020

The ability of the intestinal microbiota to influence drug metabolism has been recognized, however the mechanisms through which this occurs remain relatively unexplored. Recent work in germ‐free mice has demonstrated that conventionalization with specific pathogen free (SPF) microbiota influences the expression of cytochrome P450 (CYP) enzymes in the liver and small intestine (SI), two important sites for drug metabolism. Given that CYP enzymes, including CYP3A11 in mice, account for roughly 75% of total drug metabolism, we sought to investigate the role of specific gut‐residing microbes in shaping the expression and activity of these enzymes. Utilizing PCR arrays, we found that colonization of SPF mice with the immunomodulatory bacteria segmented filamentous bacteria (SFB) altered the expression of various CYP enzymes in the SI (but not liver), with Cyp3a11 being one of the most downregulated genes. Further analysis showed that SFB‐induced IL‐22 production by type 3 innate lymphoid cells (ILC3) correlated with reduced SI Cyp3a11 expression. Additionally, SFB colonization had no effect on the expression of Cyp3a11 in the SI of IL‐22−/− mice or RAG1−/− mice in which ILCs were depleted with anti‐Thy1 antibody. Both SFB colonization and administration of IL‐23, to activate IL‐22 from ILC3, increased the ability of the CYP3A11‐metabolized drug glibenclamide to decrease basal blood glucose levels when administered orally. In mouse SI enteroid cultures, IL‐22 dose‐dependently reduced the expression of Cyp3a11 and decreased the ability of SI enteroids to metabolize CYP3A11 specific substrates, effects that were blocked by the STAT3 inhibitor Stattic. Finally, when applied to human ileal organoids, IL‐22 induced robust changes in the transcriptome, with substantial effects on drug metabolism pathways centred around CYP3A. Our data suggest that specific gut‐resident microbes can influence the expression and activity of the drug metabolizing enzyme CYP3A11. This involves the production of IL‐22 by small intestinal ILC3, which down regulates CYP3A11 in the SI epithelium. These findings provide an understanding of how the intestinal microbiota modulates host drug metabolism, and how microbiota‐immune cell crosstalk may influence the efficacy and toxicity of various drugs.Support or Funding InformationAlberta Innovates, Canadian Association of Gastroenterology, Canadian Institute of Health Research
Evaluating a High‐throughput method of Shearing DNA Using a Bead Mill for ChIP
Authors: Easparro Brandon 
Published: April 2020

Chromatin Immunoprecipitation (ChIP) is key to understanding DNA‐protein interactions. This includes the mapping transcriptional factors and histone modifiers. Recent advancements have shown a transition from ChIP‐chip experiments to ChIP‐seq experiments, partly due to a reduction in materials cost, an increase in genomic coverage, as well as a reduction in required starting material. However, preparation of the chromatin is still prepared by either shearing cross‐linked chromatin by sonication or native chromatin micrococcal nuclease digestion. These options require longer incubation times and lower throughput, resulting in overall longer preparation. Bead milling provides an alternative of shearing DNA through the use of high impact beads. Through the use of specific beads, DNA shearing is achievable. Here we report the comparison of bead milling to ultrasonic shearing of DNA extracted from HEK cells for ChIP analysis.Support or Funding InformationOmni International, Inc935 Cobb Place BlvdKennesaw Ga 30144
Dietary unsaturated fatty acid metabolites modulate life span and health span of C. elegans
Authors: Lee Kin Sing Stephen , Alan Jamie , Kessler Benjamin , Dattmore Devon , Zhang Fan , Sarparastzardroudi Morteza 
Published: April 2020

Dietary unsaturated fatty acids are essential to physiology in different organisms. However, their mechanism remains largely unknown. Recent studies showed that the downstream metabolites play a critical role in inflammation, blood pressure regulation, pain perception, carcinogenesis, wound healing, and tissue and neural repair. However, their role in lifespan and healthspan in mammals remain largely unknown. To study the role and associated mechanism on the effect of unsaturated fatty acid metabolites on lifespan and healthspan in organism, we use C. elegans as a model organism because of the following reasons: 1) It is genetically close to humans; 2) the genome is known; 3) genetic modification is relatively easy; 4) imaging C. elegans is relatively easy, and more importantly, 5) part of the unsaturated fatty acid metabolism is conserved between humans and C. elegans. In this presentation, we will present the effect of cytochrome P450 metabolites on lifespan and healthspan on C. elegans and will discuss the potential mechanism behind such effects.Support or Funding InformationThis work was supported by the National Institute of Environmental Health Sciences (NIEHS) R00 ES024806. This work was also supported by National Science Foundation DMS‐1761320.
Intestinal epithelial cell‐specific deletion of Hif1a affects the hepatic energy metabolism in cholestasis induced liver injury
Authors: Luo Beibei , Xiang Dao , Cao Wei , Huang Xiaoqian , Wu Die , Chen Peijie 
Published: April 2020

The hypoxia‐inducible factor (HIF) and its prolyl hydroxylases (PHDs) are pivotal in the transcriptional response to oxygen flux. Our previous study found that exercise elevates in vivo HIF‐1α expression in the small intestine and liver. Hepatic HIF‐1α and PHD2 signaling pathways are involved in exercise‐induced protection against cholestasis. Bile acids are synthesized from cholesterol and further metabolized by the intestinal microbiota. The integrity of intestinal barrier and the function intestinal epithelial cell (IEC) are regulated by HIF‐1α. Therefore, we hypothesized that intestinal HIF‐1α and PHD2 are engaged in the hepatic energy metabolism in response to cholestasis. The noninvasive bioluminescence imaging was applied to monitor HIF‐1α expression in ROSA26 ODD‐Luc/+ mouse model (ODD‐Luc) that ubiquitously expresses a bioluminescent reporter consisting of firefly luciferase fused to a region of HIF‐1α. We found that in vivo HIF‐1α markedly increases in the small intestine of DDC fed ODD‐Luc mice. Next, the Villin Cre mediated, IEC‐specific deletion of Hif1a (Hif1aVKO) and IEC‐specific deletion of Phd2 (Phd2VKO) mice were generated. We fed Hif1aVKO, Phd2VKO and wild‐type (Hif1afl/fl and Phd2fl/fl) mice (male, 8‐week, n=6–8 per group) with normal chow or 3.5‐diethoxycarbonyl‐1.4‐dihydrocollidine (DDC) for 4 weeks, to induce cholestasis with biliary obstruction and bile duct injury. The liver structure was detected by H&E staining. Bile acid profile was analyzed by high performance liquid chromatography. Expression levels of bile acid metabolism related genes were determined using PCR array. The body weight, liver weight, albumin, alanine aminotransferase, aspartate aminotransferase, total bilirubin, triglycerides, total cholesterol, LDL cholesterol, and HDL cholesterol levels were also measured. All animal experiments were performed in compliance with and approved by the university ethical review board. The data was shown that DDC fed mice were suffered from cholestasis including biliary obstruction and bile duct injury with no group differences. The cholestasis induced symptoms in body weight reduction and liver injury related makers in DDC‐Hif1aVKO were severer. In Hif1aVKO, bile acid synthesisgenes related genes expression were increased. IEC Hif1a deletion affected bile acid profile in liver. The levels of taurocholic acid sodium salt hydrate, glycocholic acid hydrate synthetic and taurodeoxycholic acid sodium salt monohydrate were higher in Hif1aVKO (p<0.05), compared to Hif1afl/fl. Taken together, these results demonstrated that intestinal HIF‐1α signaling is involved in the hepatic energy metabolism in cholestasis induced liver injury.Support or Funding InformationThe National Natural Science Foundation of China (31701040, 31801003 and 31471135), Shanghai Sailing Program (17YF1418000) and Chenguang Program (16CG57).
Prebiotic effects of Jerusalem artichoke prevent hepatic steatosis in young rats submitted to a Western diet
Authors: St-Pierre David H , Lupien-Meilleur Joseph , Ou Ya , Lilya Melbouci , Auclair Nickolas , Marette André , Emile Levy , Denis Roy 
Published: April 2020

The gut microbiota is a key mediator of metabolic functions. Alterations in its microbial ecology are closely associated to obesity and ensuing disorders. The present study was designed to investigate the beneficial effects of whole Jerusalem artichoke powder (JA; enriched in inulin prebiotic fibers) in a rodent model of diet‐induced obesity. Young rats (3 weeks old) were submitted to: 1) a Western diet (WD); 2) a WD supplemented with whole JA powder (10 %); or 3) a conventional CHOW diet for 8 weeks. Body weight, food consumption, fecal energy content and glucose disposal were measured. Muscle, liver and fat pads were weighted, intra‐organ fat accumulation was analysed in liver and muscles, and triglycerides and cholesterol levels were quantified in plasma. Fecal short chain fatty acid (SCFA) production and metataxonomic analysis were also performed. As expected, body weight, fat accumulation (intra‐organ and fat pads), plasma triglycerides and cholesterol concentrations were higher (p<0.05) in WD‐fed rats vs. CHOW‐fed rats. Energy intake and fecal energy excretion were not different in WD vs. JA animals. On the other hand, plasma triglyceride levels and intra‐organ fat accumulation were significantly reduced in JA‐supplemented rats. SCFA profiles were modified and the microbial production of propionate was increased in feces of the JA group (p <0.05). Such an upregulation of propionate synthesis was associated to potent changes in gut microbial ecology. Metataxonomic analysis showed that the treatment with JA significantly increased numbers of organisms from the Verrucomicrobiales and Bifidobacteriales orders. Therefore, the present results highlight the promising prebiotic potential of JA. This further supports the importance to consider JA for food‐based interventions against obesity and the onset of metabolic disorders.Support or Funding InformationCMDO, NSERC, FRQS
The role of calcium regulation in the expression of PERK protein induced by sorafenib in hepatoma cells
Authors: Li Fu-Jian , Liu Ze-feng , Yang Zhou-fan , Liang Yong-han , Zhang Guo 
Published: April 2020

AimThis study aimed to determine whether calcium signal participates in the sorafenib induced ER stress process and has an impact on the action of sorafenib for the hepatoma.MethodsLiver cancer HepG2 cell lines were maintained in DMEM with 10% fetal bovine serum and subcultured in plates or dishes at different densities for the following designed studies. HepG2 cells were basically treated with different doses of sorafenib (5–200 μM) for different time (0–48h) in the present or absent of trans‐Ned‐19 (a NAADP inhibitor, 100μM ) . The intracellular calcium signal was simultaneously recorded by confocal microscopy, and the expression level of PERK and caspase3 protein was detected by westernblot in HepG2 cells. The cell growth and apoptosis in these cells were analyzed by flow cytometry as well.ResultsConfocal microscopy showed that sorafenib (20–200 μM) induced substantial calcium release in HepG2 cells in a concentration‐dependent manner. Compared with the sorafenib intervention alone, trans‐Ned‐19 significantly attenuated sorafenib‐induced intracellular calcium elevation. Meanwhile, westernbolt assay showed that sorafenib time‐dependently but doses‐independently induced an increment in PERK expression in HepG2 cells. However, in the present of trans‐Ned‐19 was found to significantly enhance this sorafenib‐induced PERK and caspase3 levels, as well as apoptosis rate of HepG2 cells (P<0.05). For further treatment with trans‐Ned‐19 for 24 h, microscopic observation showed that trans‐Ned‐19 significantly inhibited cell growth and caused abnormal cell morphology changes compared with the sorafenib alone group.ConclusionOur preliminary data showed that NAADP‐mediated intracellular calcium release was importantly involved in sorafenib‐induced perk protein expression and cell apoptosis. Blocking NAADP‐mediated calcium channels can significantly enhance the efficacy of sorafenib in the hepatoma cells, suggesting that the combination of NAADP analogues and sorafenib might be a potential strategy in the treatment of liver cancer.Support or Funding InformationSupport or Funding InformationSupported by NSFC Grants 81360077, 81860654, 30630145, 81172260 and GXNSFC Grants 2015GXNSFDA139022 to Guo Zhang
Implications of Systemic Hematocrit on the Radial Distribution of Red Cells in Arterioles
Authors: Johnson Paul C. , Yalcın Ozlem , Jani Vivek P. , Intaglietta Marcos , Cabrales Pedro 
Published: April 2020

It is well‐established that the tube hemacocrit (HctT) in blood vessels and glass tubes with an internal diameter less than 200‐microns is significantly lower than feed or discharge Hct (the Fahraeus Effect). Microscopic imaging of the flow stream reveals a decrease in Hct in the vicinity of the wall (the plasma layer, PL) but the mechanism of the effect is unclear. To address this question, we recorded high speed videos (3000 fps) of blood flow in 35‐micron diameter arterioles of the rat cremaster muscle at systemic Hct (HctS) levels of 20% to 72%. We found that the PL is an annulus bordering the wall that occupies 12% to 50% of the flow stream cross section, and that it is inversely related to HctS. In addition, results indicate that the Hct in the core region of the flow stream is not significantly different from HctS. The position of the PL coincides with the region of maximal shear stress in the flow stream, which may strip away the red cell monolayer adjacent to the wall, creating the PL while the monolayer moves toward the faster‐flowing center of the flow stream. In conclusion, while volumetric flow is related to the cross section of the flow stream, the PL is related to the circumference, thus reducing HctT as radius decreases.Support or Funding InformationThis work was supported by the NIH Heart Lung and Blood Institute under Grants R01HL126945 and R01HL138116.