bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increased COX‐2 expression and PGE2 production in pressurized renal medullary interstitial cells
Authors: Norregaard Rikke , Donohue Kaitlin E. , Jensen Anja M. , Roberts Angela L. , Chen Jie , Poppas Dix P. , Felsen Diane , Frøkiær Jørgen 
Published: June 2021

Pressure plays an important role during many physiological processes, and abnormal pressures may induce changes which favour onset and progression of disease in many organs. In vivo, renal medullary interstitial cells (RMIC) are subjected to pressure as a result of ureteral obstruction, which may influence the expression of COX‐2.To further examine this regulation, rats were subjected to unilateral ureteral obstruction (UUO) for 6 and 12h; showed increased COX‐2 mRNA levels in IM, whereas COX‐2 protein expression was increased only after 12hUUO. COX‐1 mRNA and protein level were unchanged. To explore the direct effect of pressure on the expression and activity of COX‐2 cultured RMIC were subjected to pressures of 60 mmHg over time (2‐12 h) using a novel pressure apparatus. QPCR confirmed increased COX‐2 mRNA after 2h. COX‐2 protein expression was increased following 60 mmHg of pressure for 6h. COX‐1 mRNA and protein levels were unchanged. PGE2 excretion from the RMIC was increased, when cells were subjected to pressure of 60 mm Hg for 6h, which was prevented by a selective COX‐2 inhibitor. Importantly, TUNEL and MTT assay studies showed that applying pressure to the RMIC does not affect cell viability, apoptosis, and proliferation.We demonstrated that in vitro application of pressure recapitulates the effects on RMIC found after in vivo UUO. This directly implicates pressure as an important regulator of renal COX‐2.
Identification and characterization of the IRD motif, a novel domain identified in the Ioc3 subunit of the ISW1a chromatin remodeling complex
Authors: Olufemi Lola , Bartholomew Blaine 
Published: June 2021

ISW1 forms two distinct chromatin remodeling complexes in S. cerevisiae, ISW1a and ISW1b. ISW1a is composed of Isw1 and Ioc3 while, ISW1b is comprised of Isw1, Ioc2, and Ioc4. Isw1, functions as the catalytic subunit of the complex. Similar to drosophila ISWI, Isw1 contains HAND, SANT, and SLIDE domains. Ioc2 has an atypical PHD motif that is often found in chromatin associated proteins and Ioc4 has a PWWP motif, a putative DNA binding domain, which is often found in enzymes that function in transcription regulation. Ioc3 has no conserved domains that have been previously characterized in S. cerevisiae; neither does it bear any similarity to proteins which their function has been defined.The aim of this work was to determine the domain architecture of Ioc3 of the ISW1a chromatin remodeling complex. This work explicitly identifies the regions of Ioc3 responsible for maintenance of complex integrity, modulation of directionality during remodeling, and nucleosome spacing. More significantly, the IRD domain (ISW1a‐Regulator of Directionality domain), a novel domain within Ioc3 that has not been previously characterized in S. cerevisiae was identified. The IRD domain was found to be required for the proper regulation of ISW1a remodeling vitro and is a distinguishing feature between the ISW1a and ISW1b complexes.This work was supported by Public Health Service grant GM 70864 from the National Institute of Health.
Accessory subunit of ISW2, Itc1 senses extranucleosomal DNA for regulating nucleosome remodeling
Authors: Prasad Punit , Bartholomew Blaine 
Published: June 2021

AbstractATP‐dependent chromatin remodeling complexes utilize the energy from ATP hydrolysis to bring about changes in the chromatin structure and make DNA accessible to regulatory factors. One such ATP‐dependent chromatin remodeling enzyme from Saccharomyces cerevisiae is ISW2. ISW2, a four subunit complex, consists of Isw2, the catalytic subunit, Itc1, the largest accessory subunit and two histone fold subunits Dpb4 and Dls1. ISW2 complex is well characterized in terms of its function in vivo and in vitro, which makes it a model remodeling enzyme to study biological functions. This work aims at defining the role of Itc1 subunit in nucleosome remodeling by ISW2. Systematic C‐terminal truncations of Itc1 were created with FLAG epitope tag for affinity purification of native complexes. Nucleosome binding affinity was reduced with shortening of the C‐terminus indicating the role of Itc1 in stabilizing the interaction of ISW2 with nucleosomes. Remodeling activity of most of these mutants was unaffected except one which resulted in nucleosome positioning defect. This mutant ISW2 complex was named as DNP (Defect in Nucleosome Position) ISW2. The defect in nucleosome positioning is not due to the loss of complex integrity or change in stoichometry of subunits. Further characterization of DNP ISW2 by site‐directed mapping of nucleosome positions showed that the truncation of the C‐terminus of Itc1 resulted in loss of ability to sense extranucleosomal DNA to effectively remodel nucleosomes.This work was supported by Public Health Service grant GM 70864 from the National Institute of Health
A systematic study of the structural and regulatory features of post‐translational modifications of cellular enzymes: a case study based upon information in PhosphoSitePlus™
Authors: Kornhauser Jon Mark , Skrzypek Elzbieta , Zhang Bin , Murray Beth , Tkachev Sasha , Hornbeck Peter V 
Published: June 2021

PhosphoSitePlus (PSP) is an open resource offering comprehensive information about site‐specific protein modification. PSP aggregates all published sites of protein post‐translational modifications, as well as thousands of newly‐discovered modification sites identified using high‐throughput methods at CST and elsewhere. Data that is manually curated includes upstream events that regulate modifications, and downstream consequences of modifications on the protein and more global cellular processes. The vast amount of information in PSP can be mined to build signaling networks to explore novel features of cellular processes.Of >10,000 proteins curated into PSP, about 1,850 are cellular enzymes with >15,000 known modification sites. We have analyzed information in PSP for patterns and interactions that may provide novel insights into the biology and biochemistry of enzymatic systems. These studies include:1) pathway analysis of regulatory information in PSP;2) potential associations between specific upstream kinases and classes of modified enzymes, protein domains shared between enzymes, or novel sequence motifs;3) identification of sites within motifs or domains that are common to related enzymes; and4) role of modification sites common to sets of enzymes on regulation of downstream processes.www.phosphosite.orgSupported by NIH grants R43GM065768, R44AA014848, and 5R44CA126080
Studies on the role of acid sphingomyelinase and ceramide in the LPS‐induced TNFa secretion by macrophages
Authors: Rozenova Krasimira Aleksandrova , Deevska Gergana , Nikolova‐Karakashian Mariana N 
Published: June 2021

The objective of this study is to decipher the role of ASMase in LPS‐triggered TNFα production. ASMase deficient (ASMase (‐/‐)) and wild‐type (ASMase (+/+)) mice and macrophages were stimulated with LPS and TNFα levels in serum and medium were monitored by ELISA and western blot analysis. The data revealed that ASMase deficiency is linked to increased production of soluble TNFα in response to LPS but does not affect MAP kinases activity or the rate of TNFα mRNA synthesis. These results suggest that ASMase affects post‐transcriptional processing of TNFα.26kDa TNFα precursor (proTNFα), is cleaved to the 17kDa soluble form (sTNFα) by the TNFα converting enzyme (TACE). Substantial portion of the un‐cleaved proTNFα appeared to be rapidly degraded in the endosomes/lysosomes as judged by the increase of proTNFα in the presence of lysomotropic agent ammonium chloride. These data suggest that TACE is a rate‐limiting step in TNFα secretion. Notably, TACE activity is 2‐3 fold greater in ASMase(‐/‐) macrophages as compared to control cells, and it is inhibited by the addition of ceramide. Further studies revealed that the level of TACE mRNA was not affected but ASMase deficiency influences the sub‐cellular distribution of TNFα and TACE.Together, these results suggest that the rate of post‐translational processing of TNFα is important regulator of TNFα secretion and it is modulated by ASMase activity.
Oxidized L‐A‐phosphatidylcholine B‐arachidonoyl‐gamma‐palmitoyl (oxPAPC) induces Increased Synthesis of mRNA and protein expression for IL‐6 in Human Aortic Endothelial Cells
Authors: Dvoracek Lucas A , Kreisberg Jeffrey I , mckinney jordan m , schmid gabrielle , francis Amanda d , francis Amanda d , lee Huey Miin , detrick melinda s , kreisberg robert 
Published: June 2021

Oxidized L‐A‐phosphatidylcholine B‐arachidonoyl‐gamma‐palmitoyl (oxPAPC) induces Increased Synthesis of mRNA and protein expression for IL‐6 in Human Aortic Endothelial CellsLucas A. Dvoracek1, Jeffrey I. Kreisberg1, Jordan McKinney1, Gabrielle Schmid1, Amanda D. Francis1, Huey Miin Lee, Ph.D.2, Melinda S. Detrick1, and Robert Kreisberg11West Liberty State College, West Liberty, West Virginia 260742West Virginia University, Morgantown, WV 26506‐6330L‐A‐phosphatidylcholine B‐arachidonoyl‐gamma‐palmitoyl (PAPC), a bio‐active component of low density lipoprotein, can become oxidized in the blood. OxPAPC may play a role in triggering an inflammatory reaction at the endothelial cell level. Atherosclerosis, the build‐up of plaque in the vascular wall, may be exacerbated by chronic inflammation initiated by the presence of oxPAPC. In this study, human aortic endothelial cells were treated for 6h with 50μg/mL of PAPC, oxPAPC, or neither. Cellular lysates were collected and treated for mRNA isolation. Transcripts were amplified by RT‐qPCR using primers specific for Interleukin‐6 (IL‐6). Interleukin‐6 has been identified as a potentially sensitive indicator of cardiovascular disease. Data from the RT‐qPCR technique suggests a 23‐fold up‐regulation of IL‐6 mRNA for cells treated with oxPAPC over both PAPC‐treated and No Treatment groups. This publication was made possible by NIH Grant Number 2P20 RR016477 from the IDeA Networks of Biomedical Research Excellence Program of the National Center for Research Resources, WVNASA, and WVEPSCoR SURE
Structural analysis of OmpR a transcription regulator in the mutualistic bacterium, Xenorhabdus nematophila
Authors: Borden W. , Wolff B. , Vogt C. , Jordan P. , Ayesh M. , Brook A. , Day J. , Elewa M. , Flesner G. , Kuriga L. , Lopez H. , Maier B. , Radke J. , Yacoob Z. , Klestinski K. , Vogt D. , Forst Steve 
Published: June 2021

A partnership between Marquette University High School students participating in the MSOE SMART Team (Students Modeling A Research Topic) program and a researcher enabled the team to explore structure and function, and to build a physical model using 3D printing technology, of OmpR. OmpR is a transcription factor necessary for the nutrition gathering strategy of the bacterium Xenorhabdus nematophila. Bacteria absorb food through membrane pores, which change in size to optimize food intake and to protect themselves from toxins.X. nematophila has sensor proteins in the outer membrane. When food touches an outer membrane receptor (EnvZ), the receptor transfers phosphate to OmpR forming OmpR‐P, which can bind to DNA. When nutrients are abundant, OmpR‐P binds to OmpC, a gene promoting formation of a small pore, allowing food yet limiting influx of toxins. When food is scarce, OmpR‐P binds OmpF, a gene promoting formation of a large pore, allowing more food intake and growth of a flagellum enabling movement to a nutrient rich location.The OmpR gene is also responsible for production of antibiotic compounds that combat a broad range of microorganisms. X. nematophila often forms a mutualistic relationship with nematodes. The bacterium‐nematode pair seek to inhabit and eventually kill certain insects, benefiting from the nutrients provided by the insect's corpse.Supported by a grant from NIH‐NCRR‐SEPA
Appropriately glcosylated beta1‐integrin serves as an E‐selectin ligand
Authors: Lin Regina Junhui , Chong Siew‐Meng , Lim Yaw‐Chyn 
Published: June 2021

IntroductionThe interactions between selectins and their ligands are important for the extravasation of leukocytes into target tissues.AimTo identify adhesion molecules that mediate E‐ and P‐selectin interactions under defined flow conditions.MethodsThe interactions of NB‐DLB‐1 cells (a lymphoma cell line) with E‐ or P‐selectin were examined in parallel plate flow chamber studies. Putative selectin ligands were identified by function blocking assays, affinity capture and Western blot.ResultsNB‐DLB‐1 cells interact with E‐ and P‐selectin in a shear‐dependent manner under defined flow conditions. Function blocking assays identify PSGL‐1 and CD44 as the major P‐selectin ligands; and L‐selectin and beta1‐integrin as the E‐selectin ligands. Affinity capture using E‐selectin/IgG reveals that the E‐selectin‐binding beta1‐integrin is of the high molecular weight glycoform(s).ConclusionNB‐DLB‐1 cells interactions with E‐ and P‐selectin are mediated by different adhesion molecules. Our data show that L‐selectin and the extensively‐glycosylated form(s) of beta1‐integrin are E‐selectin ligands on NB‐DLB‐1 cells. This novel function of beta1‐integrin implies that in addition to the classical VLA‐4‐VCAM‐1 interactions, appropriately glycosylated beta1‐integrin can bind to E‐selectin.Study funded by ARF, NUS and NMRC, Singapore.
TNFa Antagonizes PDGF‐AB Chemotactic Effects on Mesenchymal Stem Cells (MSC) Migration
Authors: Phua Andy Yong Han , Vijayakumar Praveen , Choolani Mahesh , Chan Jerry , Lim Yaw‐Chyn 
Published: June 2021

MSC are a promising cell source for cellular therapy but often, systemic delivery to target tissues is sub‐optimal. Aim: This study examines the effects of pro‐ and anti‐inflammatory mediators and growth factors on MSC migration in vitro.MethodsThe effects of various chemokines/cytokines, growth factors and lipid mediators (used alone or in combinations) on MSC migration was determined using transwell assays. After 5hr of incubation, the inserts were fixed and stained with Giemsa stain. 21 random fields were digitized at 100x magnification and the mean number of transmigrated cells/field determined.ResultCompared to media control (14±5 cells), MSC migration was significantly increased in the presence of PDGF‐AB (59±21 cells) and IGF‐1 (28±13 cells) whereas SDF‐1, bFGF, SLC, GM‐CSF, VEGF, LTB4 and LXA4 had no detectable chemotactic effect. We found that TNFa significantly inhibited MSC migration (7±2 cells). Furthermore, the addition of TNFa together with PDGF‐AB into the bottom well also significantly inhibited the PDGF‐AB induced migration by 41.3±11.3% (p<0.05 as compared to PDGF‐AB alone).ConclusionTNFa significantly inhibits both baseline and PDGF‐AB induced MSC migration in‐vitro. Our data suggest that the precise composition of the cytokine/chemokine milieu at the injury site will greatly influence MSC recruitment into the tissue.This research is funded by URC NUS.
Development of a substituted phenyldithiolethione as a novel cyclooxygenase inhibitor with minimal gastro‐irritancy
Authors: Jarrott Bevyn , Zanatta Shannon , Williams Spencer John 
Published: June 2021

Hydrogen sulfide has been proposed as an endogenous molecule that inhibits early stages of inflammation. Dithiolethiones can be metabolised to hydrogen sulfide and when coupled to diclofenac produce a compound that is an anti‐inflammatory/analgesic agent without the gastrointestinal toxicity of diclofenac (Wallace 2007).Previous research has shown that compounds containing an antioxidant moiety, 3,5‐di‐tert‐butyl‐4‐hydroxy‐phenyl were cyclooxygenase (COX) inhibitors (Ruiz et al 2003) so we hypothesised that the attachment of a dithiolethione ring onto this antioxidant may give a compound that inhibited COX and also released hydrogen sulfide. We therefore synthesised and tested 5‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl)‐3H‐1,2‐dithiole‐3‐thione and this inhibited purified COX‐1 with an IC50 of 2 µM and COX‐2 with an IC50 of 0.25 µM. After oral administration at a dose of 10 µmol/kg, this compound was anti‐inflammatory in a rat model of inflammation and pain (Complete Freund's adjuvant hind paw model) and had reduced gastrointestinal toxicity in rats (n = 9) when compared to an equivalent dose of diclofenac. Also, in view of the lipid solubility of this compound, it may be centrally acting and neuroprotective in diseases with central inflammatory pathologies.
Synchrotron light source imaging of brain tissue shows changes in iron concentration after chronic implantation of electrodes and electrical stimulation
Authors: Lam Ann , Ma Bonita W. , Nichol Helen , Corcoran Michael E. 
Published: June 2021

PURPOSEVarious metallic electrodes are used in research and clinical applications because of their purported biological compatibility. However, little is known about the effects on surrounding tissue following subsequent stimulation. Using X‐ray fluorescence imaging, we examined metal distribution in the brain after stimulation with three types of electrodes.METHODSBilateral implantation of stainless steel, nickel‐chromium, or platinum‐iridium electrodes into amygdala was used in a rat preparation of epilepsy. Stage 5 seizures were kindled by a once‐daily application of electrical stimulation. Rapid scanning X‐Ray fluorescence and microprobe analysis of brain sections were performed using the imaging beam lines at the Stanford Synchrotron Radiation Lightsource.RESULTSImages showed elevated iron concentrations around the electrode tips in both control and kindled tissue. Concentrations varied according to electrode type and were greater in kindled tissue as compared to yoked controls.CONCLUSIONSChronic implantation of electrodes in the brain results in an increased concentration of iron around the electrode track, which is further increased by stimulation. These findings raise the issue of possible adverse effects from these metal depositions and suggest the need to evaluate the effects of chronic electrical stimulation in clinical settings.Support: NSERC, CIHR
8,9‐Dihydroxyeicosatrienoic acid does not protect the glomerular filtration barrier
Authors: Sharma Mukut , McCarthy Ellen T , Savin Virginia J , Patel Paresh , Shaw Sean , Falck John R , Imig John D 
Published: June 2021

IntroductionFocal segmental glomerulosclerosis (FSGS) leads to end‐stage renal disease. A circulating factor is believed to cause the primary glomerular lesion in FSGS. We have shown that 8,9‐epoxyeicosatrienoic acid (8,9‐EET) protects the glomerular filtration barrier function against the FSGS factor. Presently, we hypothesized that 8,9‐dihydroxyeicosatrienoic acids (8,9‐DiHETrE), vic‐diol of 8,9‐EET produced by soluble (sEH) epoxide hydrolase, is responsible for the observed protective effect of 8,9‐EET.MethodsWe determined the change in glomerular albumin permeability (Palb) in vitro following incubation of rat glomeruli with FSGS‐plasma, FSGS + 8,9‐EET, FSGS + 8,9‐DiHETrE, FSGS + sEH inhibitor AUDA (1‐10 microM) for 15 minutes at 37°C (n=15 in each group). Glomerular sEH protein expression was determined by immunoblotting.ResultsFSGS plasma‐induced increase in Palb (P<0.001 vs. vehicle control) was completely blocked by exogenous 100 nM 8,9‐EET (P<0.001 vs. FSGS) while its metabolite 8,9‐DiHETrE (200 nM) did not cause a significant decrease in Palb (P<0.1 vs. FSGS). AUDA at 1 microM showed a protective effect on Palb against FSGS plasma (P<0.001 vs. FSGS) but 10 microM AUDA did not. Immunoblot analysis showed a relatively weak protein expression of sEH in glomeruli. Summary andConclusions8,9‐EET and AUDA, but not 8,9‐DiHETrE, attenuated the FSGS‐induced increase in Palb. Results suggest that EET metabolism in the glomerulus may be cell‐type specific. We conclude that 8,9‐EET protects against FSGS‐induced glomerular injury and that its vicinal diol 8,9‐DiHETErE does not contribute to the protective effect.
Development of LHRH‐Au@SPIONs for Biomedical Applications
Authors: Mohammad Faruq , Gopalan Balaji , Raghavamenon Achuthan C , Uppu Rao M , Kumar Challa S.S.R. 
Published: June 2021

During recent years, Super Paramagnetic Iron Oxide nano particles (SPIONs) have been raised a great deal of interest because of their use in a number of bio‐medical applications such as targeted drug delivery, sensitive diagnostic tools, contrast agents for Magnetic Resonance Imaging (MRI), protein purification studies and lab‐on‐a‐chip devices. We have been interested in the development of ligand bound SPIONs as contrast agents for MRI of breast tumors and their metastases (Leuschner et al., Breast Cancer Res. Treat. 99, 163‐176, 2006). The Luteinizing‐Hormone Releasing Hormone (LHRH) has been found to be an excellent targeting agent for breast tumors and their metastases and hence LHRH‐SPIONs have been shown to enhance the contrast efficiency in MRI. In order to modulate magnetic properties of SPIONs through gold coating, we have synthesized gold coated SPIONs and established an approach to bind LHRH to gold surface through cysteamine linkage as shown below.We have characterized the LHRH‐Au@SPIONs using TEM, X‐ray absorption spectroscopy and SQUID magnetometer. These particles are currently being evaluated for their cytotoxicity and inflammatory cytokine release using cell‐based assay systems. In addition to the toxicity results, investigations from their targeting ability in vitro using breast cancer cells followed by their MRI contrast efficiency will be presented.
Mice expressing ouabain‐sensitive α1 Na,K‐ATPase have increased susceptibility to pressure overload‐induced cardiac hypertrophy
Authors: Wansapura Arshani N , Lasko Valerie , Lingrel Jerry B , Lorenz John N 
Published: June 2021

Endogenous cardiotonic steroids (CS) are elevated in a variety of cardiovascular disease states, but their (patho)physiological role is not well understood. In addition to their conventional role as Na,K‐ATPase inhibitors, studies suggest that CS binding to the Na+ pump may activate signaling pathways that induce cardiac growth, implicating a role in the development of cardiac hypertrophy. In the present study, we hypothesized that the hypertrophic response to pressure overload would be aggravated in mutant mice with a ouabain‐sensitive α1 Na,K‐ATPase subunit (αNKA). We performed transverse aortic constriction (TAC) surgery in α1‐resistant/α2‐resistant (α1R/R α2R/R), α1‐sensitive/α2‐resistant (α1S/Sα2R/R), and α1‐resistant/α2‐sensitive mice (α1R/Rα2S/S, wild type) to induce pressure‐overload left ventricular (LV) hypertrophy. At 4 weeks, echocardio‐graphy revealed a pronounced increase in LV mass and wall thickness in the α1S/Sα2R/R mice. Terminal analyses of histology and function demonstrated extensive perivascular and replacement fibrosis and significantly depressed LV systolic function in α1S/Sα2R/R mice compared to α1R/Rα2S/S, α1R/Rα2R/R and sham‐operated mice. These data reveal that mice expressing a ouabain‐sensitive α1NKA subunit have a dramatically enhanced susceptibility to pressure overload‐induced cardiac hypertrophy.(NIH grants DK57552 & HL28573)