bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thymoquinone Protects Against Cigarette Smoke Extract‐induced Vascular Dysfunction Through Inhibition of the RhoA/Rho‐Kinase Signaling Pathway
Authors: Moustafa Gamal A. , El-Mahdy Mohamed A. , Ismail Raed S. , Mansour Ahmed M. 
Published: April 2020

BackgroundThere is an ever‐growing focus on the role of natural products in modulating reactive oxygen species (ROS) and RhoA/Rho kinase‐mediated vascular disease. Thymoquinone (TQ), a constituent of the volatile oil derived from Nigella sativa seeds, possesses promising antioxidant and vasodilating properties via its effect on multiple signaling pathways; however, the effect of TQ on the RhoA/Rho‐Kinase pathway remains to be investigated. The aims of the present study were to examine whether TQ protects against CSE‐induced vascular dysfunction and to identify the underlying mechanisms of TQ on CSE‐induced ED in isolated rat aorta.MethodsCigarette smoke extract (CSE)‐exposed rat aortic rings were mounted in a wire myograph and subjected to contraction and relaxation. Quantitative assessment of RhoA activation was determined using G‐LISA RhoA activation assay kit where phosphorylation of myosin light chain‐20, myosin phosphatase‐targeting subunit 1 and protein kinase CPI‐17were determined by western blot analysis in the hole tissue protein extracts.The GSH content of aortic tissues was calculated using HPLC.ResultsTQ protected against CSE‐induced impairment of acetylcholine‐induced endothelium‐dependent relaxation, and decreased CSE‐induced ROS generation and glutathione depletion. Preincubation of aortic rings for 20 min with TQ attenuated the CSE‐enhanced phenylephrine‐induced vascular tension in endothelium‐denuded rings. TQ‐pretreated rings showed a decrease in CSE‐induced RhoA activation and phosphorylation of myosin light chain‐20, myosin phosphatase‐targeting subunit 1 and protein kinase CPI‐17.ConclusionsThese data indicate that TQ inhibited ROS generation‐induced RhoA/Rho kinase pathway activation, protecting against CSE‐induced vascular dysfunction. This study provides mechanistic insight for understanding the molecular basis and efficacy of TQ on vascular disease management.
Investigating the role of RME‐8 as a late onset Parkinson’s Disease marker in SH‐SY5Y neuroblastoma cells
Authors: Strawn Miguel Thomas-Grier , Xhabija Besa 
Published: April 2020

Approximately, 10 million people worldwide live with the progressive, neurological Parkinson’s Disease (PD) experiencing a wide range of symptoms from resting tremors, bradykinesia, rigidity, to postural instability. Recent research has characterized a new mutation in Receptor‐Mediated Endocytosis 8 (RME‐8)/DNAJC13 Asn855Ser conferring a toxic gain‐of‐function resulting in impairment of endosomal transport. Furthermore, in the late‐onset of idiopathic PD, subtle deficits in endosomal receptor‐sorting/recycling are evident through the discover of pathogenic mutations of VPS35, LRRK2, and now DNAJC13/RME‐8.RME‐8 is composed of 2000 amino acids, containing four IWN repeats of unknown functions and a DNAJ binding between the second and third repeat. Through the discovery of genetic screens of Caenorhabditis elegans, RME‐8 mutants exhibited defects in receptor mediated yolk endocytosis in the oocyte and fluid phase endocytosis in the coelomocyte. The continued studies of RME‐8 mutants shows that it is highly conserved. Our laboratory is interested in studying RME‐8 in the context of Parkinson’s and further investigate the effect of RME‐8 N855S in the disease relevant SH‐SY5Y neuroblastoma cell line.
LCZ696 mitigates diabetic‐induced nephropathy through inhibiting oxidative stress, NF‐κB mediated inflammation and glomerulosclerosis in rats
Authors: Belali Osamah , Al-Rejaie Salim 
Published: April 2020

BackgroundOne of the most common microvascular complications of diabetes is DN that considered the primary cause of end‐stage renal disease. Recently, combined therapy of angiotensin II receptor antagonist and neprilysin inhibitor are using to attenuate the DN. Thus the present study was designed to investigate the beneficial effects of LCZ696 (LCZ696) therapy on DN‐induced oxidative stress, inflammation and glomerulosclerosis in rats.MethodsA single dose (60 mg/kg/day) of STZ is used to induced type 1 diabetes. The diabetic rats were treated orally with valsartan (31 mg/kg) or LCZ696 (68 mg/kg) for 6 weeks. At end of the treatment period, serum and kidney samples were collected and analyzed. In serum, glucose, insulin, urea, creatinine, TNF‐α, IL‐1β, IL‐6 and IL‐10 levels were estimated. In renal tissues, oxidative stress biomarkers including TBARs, GSH, SOD, CAT, GPx and GST were measured. The levels of TNF‐α, IL‐1β, IL‐6 and NF‐kB levels also estimated in renal tissues. Histological changes were observed in kidney.ResultsDiabetic animals exhibited hyperglycemia and significant elevation in: renal functions, serum and kidney pro‐inflammatory cytokines, NF‐kB, lipid peroxidation, infiltration of leukocytes, mean glomerular volume and glomerulosclerosis with a marked decrease in IL‐10 and antioxidant enzymes. LCZ696 therapy significantly improved renal function and kidney structure and decreased oxidative stress, inflammation and glomerulosclerosis symptoms. Furthermore, valsartan alone had comparable effects against renal oxidative stress, inflammation and glomerulosclerosis.ConclusionTaken together, present data suggest that LCZ696 had therapeutic potential to restrict DN progression through inhibiting oxidative stress, NF‐kB mediated inflammation and glomerulosclerosis.
Pre‐treatment with miR‐182 Antagomir Mitigates Ischemic Brain Damage by Reducing Astrocytes Injury and Inflammation
Authors: Alhadidi Qasim , Xu Lijun , Sun Xiaoyun , Althobaiti Yusuf , Almalki Atiah , Alsaab Hashem , Stary Creed 
Published: April 2020

Ischemic stroke remains a devastating cerebrovascular disease that account for a high proportion of mortality and disability worldwide. MicroRNAs (miRNAs) are a class of small non‐coding RNAs that are responsible for regulation of posttranscriptional gene expression, and growing evidence supports a role for miRNAs in stroke injury and recovery. The current study examined the role of miR‐182 in experimental stroke using both in vitro and in vivo models of ischemic injury. A significant increase in miR‐182 expression was detected in the infarct area of transient middle cerebral artery occlusion (tMCAO) treated mice as well as in primary astrocyte cultures subjected to combined oxygen‐glucose deprivation/reperfusion (OGD/R) injury. In vivo, both stroke volume and neurobehavioral parameters were significantly improved by pretreatment with miR‐182 antagomir. Astrocytes stressed with OGD/R resulted in mitochondrial fragmentation, downregulation of cortactin, an actin binding protein, and reduced levels of connexin 43 expression, a cortactin‐associated protein. Conversely miR‐182 inhibition in astrocyte cultures preserved cortactin expression, and resulted in significantly improved cell viability after OGD/R. In parallel, lipopolysaccharide‐induced nitric‐oxide release in astrocytes was significantly reduced by pretreatment with miR‐182 inhibition. In conclusion, inhibition of ischemia‐induced miR‐182 reduced brain injury in experimental stroke and preserved astrocyte viability after in vitro ischemia, associated with reciprocal alterations in cortactin expression. These findings identify miR‐182 and/or cortactin as potential targets for ischemic stroke therapy.Support or Funding InformationNIH grant NS107445 to Creed M. Stary.
Effect of CO2 on the Expression of Heme Oxygenase‐1 in Vascular Smooth Muscle Cells
Authors: Nakamura Taichi , Sugimoto Naotoshi , Nishimura Naoki , Wada Taizo 
Published: April 2020

ObjectivesCarbon dioxide is one of the factors that affect the constriction and dilatation of smooth muscle cells. However, the effects of CO2 on smooth vascular cell homeostasis are unclear. The heme oxygenase‐1(HO‐1) enzyme is involved in heme metabolism, and this protein helps protect cells against oxidative stress. This study aimed to clarify the role of CO2 in regulating HO‐1 expression and elucidate its cytoprotective mechanisms in vascular smooth muscle cells.MethodsA7r5 rat smooth muscle cells were maintained in Dulbecco’s modified Eagle’s medium, supplemented with 10% fetal bovine serum, at 37°C in a 5% CO2 incubator. The cells were exposed to 20% CO2 for 24 h and 48 h. The expression of HO‐1 was subsequently evaluated by real time PCR, and cell viability was analyzed 24 h after treatment with hydrogen peroxide (H2O2; 100μM).ResultsThe expression levels of HO‐1 were significantly reduced in the vascular smooth muscle cells following exposure to 20% CO2. Exposure to 20% CO2 for 24 h and 48 h facilitated H2O2‐induced cell death in the vascular smooth muscle cells.ConclusionsThese results suggested that exposure to CO2 may attenuate cytoprotection against oxidative stress via the downregulation of HO‐1 expression in vascular smooth muscle cells.Support or Funding InformationKakenhi 16K10064, 17H01963
A Novel Three‐Dimensional Drawing Activity to Learn the Dural Venous Sinuses
Authors: Shaia Jacqueline K. , Elzie Carrie 
Published: April 2020

BackgroundThe use of drawing as a pedagogical tool in anatomy has been shown to be effective at increasing knowledge and engaging students. Creating three‐dimensional drawings or models can be especially beneficial as students struggle to translate two‐dimensional images into three‐dimensional structures in order to comprehend the dynamic aspects of functional anatomy.ObjectiveWe developed a three‐dimensional drawing activity of the dural venous sinuses to increase student knowledge of anatomical structures and improve their understanding of the spatial orientation and drainage system.MethodsStudents were given a pre‐test, a lecture, put in pairs, given markers and white swim caps, asked to draw the sinuses on their partner with anatomical accuracy, and completed a post‐test. All pre and post‐tests were evaluated using a T‐test. Effectiveness of the activity was gauged using a modified Likert Scale and was evaluated based on mean and median values.ResultsResults from the post‐test revealed a significant increase in knowledge related to structure identification and drainage (p = 0.017). Further, students found drawing to be an effective way to learn anatomical structures and strongly agreed that translating a two‐dimensional picture into a three‐dimensional drawing improved understanding of anatomical orientation.ConclusionOverall, this was a quick, effective activity utilizing three‐dimensional drawing to solidify the understanding of the dural venous sinuses. This educational tool required minimal time, direction and supplies, making it an ideal intervention for both small groups and large lab settings in any anatomy or neuroanatomy course.
Identification and Characterization of the Regulation of N‐Methyl‐D‐Aspartate Receptor by the Protein Tyrosine Phosphatase Ptpmeg
Authors: Robertson Quayd , Hill Carlin , Hoss Grace , Murcia Luis , Ree Brandy 
Published: April 2020

Cell death in neurodegenerative diseases such as Alzheimer’s or after traumatic brain injury is associated with over stimulation of the N‐methyl‐D‐aspartate receptor (NMDAR). NMDAR is a glutamate‐gated Ca2+ channel that normally plays an important role in memory formation, but whose hyperactivation in pathological conditions leads to cell death. The NMDA receptor is a known target of tyrosine phosphorylation in mammals and Drosophila. Ptpmeg, a protein tyrosine phosphatase found in Drosophila, is highly expressed in the brain. Here it is responsible for the proper formation and maintenance of axonal projections in the mushroom body, the center for olfactory learning and memory. Ptpmeg has two vertebrate homologs, PTPN3 and PTPN4. Like the Drosophila counterpart, PTPN4 is expressed in neurons. PTPN4 physically associates with a subunit of the NMDAR, NMDAR2B, in both cultured cells and in the brain. Because PTPN4 is expressed in the neurons where it associates with a protein known to play a role in neuron death, NMDAR, this leads to potential implications of PTPN4 having a role in neuron death, and thus neurodegenerative diseases. However, analysis of the molecular and phenotypic impact of this interaction is lacking. Drosophila are a convenient and inexpensive way to address this knowledge gap. Our initial findings revealed that Ptpmeg physically interacts with dNR1 in neural tissue. We subsequently confirmed that a loss of Ptpmeg results in a statistically significant increase in the phosphorylated form of the dNR1 subunit of NMDAR. Of note, absence of Ptpmeg produced a defect in programmed cell death in non‐neural tissue. Collectively, these data suggest a role for Ptpmeg in governing NMDAR activity associated with neuronal death during neurodegeneration.Support or Funding InformationArkansas College of Osteopathic Medicine
Extracellular Matrix Remodeling with Ageing Associates with Cardiac Functional and Structural Changes in a Sex‐Specific Manner
Authors: de Castro Brás Lisandra , Grilo Gabriel A. , Shaver Patti R. , Stoffel Hamilton J. , Morrow Caleb Anthony , Johnson Octavious T. , Iyer Rugmani Padmanabhan 
Published: April 2020

Age‐related remodeling of the heart causes structural and functional changes in the left ventricle (LV) that are associated with a high index of morbidities and mortality worldwide. Some cardiac pathologies in the elderly population vary between genders revealing that cardiac remodeling during aging may be sex‐dependent. Herein, we analyzed the effects of cardiac aging in male and female C57Bl/6 mice in four age groups, 3, 6, 12, and 18 month old (n=6–12 animals/sex/age), to elucidate which age‐related characteristics of LV remodeling are sex‐specific. We focused particularly in parameters associated with age‐dependent remodeling of the LV extracellular matrix (ECM) that are involved in collagen metabolism. LV function and anatomical structure were assessed both by conventional echocardiography and strain analysis. We then measured ECM proteins that directly affect LV contractility and remodeling. All data were analyzed across ages and between sexes and were directly linked to LV functional changes. Echocardiography confirmed an age‐dependent decrease in chamber volumes and LV internal diameters, indicative of concentric remodeling. As in humans, animals displayed preserved ejection fraction with age. Notably, changes to chamber dimensions and volumes were temporally distinct between sexes. Complementary to the traditional echocardiography, speckle tracking echocardiography (STE) revealed that circumferential strain rate declined in 18 month old females, compared to younger animals, but not in males, suggesting STE as an earlier indicator for changes in cardiac function between sexes. Age‐dependent collagen deposition and expression in the endocardium did not differ between sexes; however, other factors involved in collagen metabolism were sex‐specific. Specifically, while decorin, osteopontin, Cthrc1, and Ddr1 expression were age‐dependent but sex‐independent, periostin, lysyl oxidase, and Mrc2 displayed age‐dependent and sex‐specific differences. Moreover, our data also suggest that with age males and females have distinct TGFβ signaling pathways. Overall, our results give evidence of sex‐specific molecular changes during physiological cardiac remodeling that associate with age‐dependent structural and functional dysfunction. These data highlight the importance of including sex‐differences analysis when studying cardiac aging.Support or Funding InformationWe acknowledge funding support from the East Carolina University and the American Heart Association [grant numbers 18AIREA33960311 and 19PRE34450066].
Obesity‐associated Hypoxia Contributes to Aberrant Methylation of Genes Implicated in Inflammation and vascular Function
Authors: Ali Mohamed M. , Naquiallah Dina , Hassan Chandra , Masrur Mario , Bianco Francesco M. , Frederick Patrice , Cristoforo Giulianotti , Gangemi Antonio , Phillips Shane A. , Mahmoud Abeer M. 
Published: April 2020

IntroductionObesity is a major risk factor for cardiovascular disease. We previously demonstrated an impaired vascular function in obese adults (OB). We now hypothesize a role of obesity‐associated hypoxia in disturbing the methylation/expression of genes involved in inflammation/vascular function. We also propose a mediating role of the hypoxia‐inducible factor, HIF1α and the DNA hydroxymethylase, TET1.MethodsWe obtained subcutaneous and visceral adipose tissue (AT) biopsies from bariatric patients (n=60; age: 36±7 yrs; BMI: 50.7±8.7 kg/m2) and non‐obese (NOB) adults having elective surgeries (n=30; age: 36±2 yrs; BMI: 25.8±1 kg/m2). AT‐isolated arterioles were tested for vasoreactivity in response to pressure gradients of Δ10‐Δ100 cmH2O. Arteriolar nitric oxide (NO) and reactive oxygen species (ROS) were measured. Protein expression of HIF1α and TET1 and methylation/expression of leptin, IL1β, IL6, IL8, IL17, CXCL5, TNF‐α, and IFNγ were measured in the AT.ResultsFlow‐induced dilation (FID) was 40–50% higher in NOB than OB adults across all pressure gradients (p<0.05). NO production was higher, and ROS generation was lower in OB arterioles compared to NOB. HIF1α and TET1 proteins were 2–4‐fold higher in OB compared to NOB adults and correlated negatively with arteriolar FID, NO, and brachial artery FID (r=0.82, 0.64, 0.91, respectively; p<0.001) and positively with ROS (r=−0.71, p<0.01). Global hydroxymethylation and adipocytokine promoter hypomethylation and increased expression were observed in OB compared to NOB.ConclusionOur results suggest that vascular dysfunction in OB adults may be attributed to aberrant DNA methylation and increased expression of adipocytokines. This conclusion was also supported by invitro mechanistic studies.Support or Funding InformationThis research was funded by the National Heart, Lung, and Blood Institute (NHLBI), grants K99HL140049 and 4 R00 HL140049‐03 (AM) and HL095701 (S.P.)
Confirmation of Allosteric Switches in Human Sirtuin 1 Using a Sirtuin Activating Compound
Authors: Nguyen Thi-Tina N. , Amaya Carina Araceli , Huynh Angelina , Lustig Brooke , Wang Ningkun 
Published: April 2020

Sirtuin 1 (SIRT1) is a protein deacetylase that requires cosubstrate NAD+ for its enzymatic function. A favorable target for drug development, SIRT1 is involved in stress response, metabolism, and age‐related diseases. Sirtuin activating compounds (STACs) are molecules that bind to a domain in SIRT1’s N‐terminus called the SBD (STAC Binding Domain), and change SIRT1 activity. In particular, resveratrol, an allosteric modulator of SIRT1, is one of the best‐studied STACs and is used in our experiment. This change in SIRT1 activity is due to allostery— a phenomenon where a modulator binds distal to the active site of an enzyme. Presently, the mechanism of how the N‐terminus interacts with the catalytic core to change enzyme activity is poorly understood. We hypothesized that SIRT1 contains an allosteric switch within the STAC binding domain that is the key to allosteric regulation of SIRT1. The allosteric switch is postulated to be a region of multiple residues that undergo a change in secondary structure upon allosteric interactions. The objective of this study is to predict and confirm a novel allosteric switch region in human SIRT1 (hSIRT1) using enzymatic assays with resveratrol and various peptide substrates. Using computational methods, SIRT1 residues 186–189 (TFVQ) and 190–193 (QHLM) were found to be highly ordered and thus predicted to be possible switch regions within the SBD. Mutating all four residues to serines would increase the disorder propensity of this region, which is expected to abolish the switch‐like behavior. To test this, we have cloned and purified these two serine mutations of SIRT1: SIRT1(186–189S) and SIRT1(190–193S). We performed enzyme‐coupled assays in triplicates to measure the steady‐state kinetics of these mutants to test for allosteric response to resveratrol and to ensure that they remained catalytically active. We obtained the Michaelis‐Menten parameters for the wildtype SIRT1 and the two mutated SIRT1 constructs, using Ac‐p53W as the peptide substrate. Wildtype SIRT1 showed an increase in catalytic efficiency after the addition of resveratrol. For both mutated constructs, the catalytic efficiency after adding resveratrol decreased, mostly due to an increase in KM, which is the opposite of what happens with wildtype SIRT1. This suggests that the mutations affected the allosteric network. Identifying an allosteric switch will provide insight on the mechanism of STACs with the wildtype enzyme, adding valuable information on allosteric regulation and the potential of developing drugs for age‐related diseases, stress responses, and metabolism.Support or Funding InformationSJSU Undergraduate Research Grant, California State University Program for Education and Research in Biotechnology Travel Grant Award, and NIH Grant 1SC2GM122000.
Intestinal alkaline phosphatase is a diagnostic biomarker for necrotizing enterocolitis in preterm infants
Authors: Buckley Rebecca , Heath Maya , Gerber Zeromeh , Davis Porcha , Linneman Laura , Gong Qingqing , Barkemeyer Brian , Fang Zhide , Good Misty , Penn Duna , Kim Sunyoung 
Published: April 2020

Necrotizing enterocolitis (NEC) in preterm infants is an often fatal, gastrointestinal emergency. There is a need for a robust NEC biomarker that can be adopted in pathology labs and that is not confounded by sepsis. Use of such a NC biomarker could improve bedside management, lower morbidity and mortality, and permit patient selection in clinical trials for therapeutic candidates. We evaluated if aberrant intestinal alkaline phosphatase (iAP) biochemistry in infant stool is a molecular biomarker for necrotizing enterocolitis and not correlated to sepsis in the absence of NEC. There were 136 premature infants enrolled in three hospitals in this observational and prospective study. Median birthweight (IQR) was 1050 g (790‐350 g) and median gestational age was 28.4 weeks (26‐0.9 wks). Twenty‐five infants were diagnosed with severe NEC, 19 were suspected of having NEC, and 91 were non‐NEC infants. Twenty‐six patients were diagnosed with late‐onset sepsis and 14 had other non‐GI infections. Infant stool samples were collected between 24–40+ weeks postconceptual age (PCA). Enrolled infants were subject to abdominal radiography at physician and hospital site discretion. Enzyme activity and relative abundance of iAP were measured using fluorometric detection and immunoassays, respectively. Post‐measurement, biochemical data were evaluated against clinical entries from infants’ hospital stay. Fecal iAP content was 99±19, 123±41, and 5±3 (median±SE) for severe, suspected, and non‐NEC samples, respectively. Enzyme activity was 183±108, 355±180, and 613±218 kU/g (median±SE) for severe, suspected, and non‐NEC samples, respectively. ROC area under the curve (AUC) values were 0.96, 0.97, 0.54, and 0.58 for relative iAP content measurements at time of severe NEC, suspected NEC, sepsis, and other non‐GI infections; AUC values for iAP activity were 0.60, 0.76, 0.52 and 0.57, respectively. High amounts of iAP protein in stool and low iAP enzyme activity are reliable and specific biomarkers for NEC: iAP biochemistry uniquely has clinical utility in distinguishing NEC from sepsis.Support or Funding InformationThis work was supported by the National Institutes of Health (R41HD095779 to RB and SK; R01GM097350 to SK; K08DK101608, R03DK111473 and R01DK118568 to MG), National Science Foundation (IIP‐1713220 and IIP‐1547932 to RB and SK); March of Dimes (5‐FY17‐79 to MG), Louisiana Board of Regents (LEQSF‐RD‐D‐07 to SK), LSU LIFT2 (HSCNO‐2017‐LIFT‐006 to SK), Children’s Discovery Institute of Washington University and St. Louis Children’s Hospital (MG), Department of Pediatrics at Washington University School of Medicine, St. Louis (MG), LSU School of Medicine (BB, SK, and MH), and LSU Health Foundation (MH, ZG, and SK).