bluuebunny/crossref_metadata_2025_split huggingface dataset:
MET and EGFR signaling pathways play different roles in bile duct ligation (BDL) mice
Authors: Xue Yuhua , Mars Wendy M. , Bowen William , Orr Anne , Stoops John , Michalopoulos George K. 
Published: April 2020

Liver failure is the common ending of most irreversible liver diseases. We have identified that shutdown of both MET and EGFR signaling simultaneously in the murine resting or regenerating liver contributes to this process. In this study, we explore the role of MET and EGFR signaling pathways in biliary injury repair after common bile duct ligation. Mice with combined disruption of MET and EGFR signaling became very ill by 24 hours and died at 1 to 2 days after bile duct ligation. Mice with elimination of EGFR signaling alone showed decreased hepatocyte proliferation, cholangiocyte proliferation, and ductular reaction at 7 days. However, Met knockout mice showed increased proliferation of cholangiocytes and hepatocytes. Mice with elimination MET signaling alone became very ill since 7 days. Furthermore, either Met or EGFR single inhibition mice showed less liver to body ratio at 5 and 7 days time points. We also observed p‐Ezrin (Thr567) is down regulated in the either Met or EGFR deletion mice, while the total Ezrin expression did not change.ConclusionsOur study demonstrates that, in addition to maintaining the baseline liver homeostasis together, MET and EGFR differentially control liver injury response in BDL model, and their combined disruption leads to acute liver failure and early death following severe biliary injury. The receptor tyrosine kinases MET and EGFR appear to play different roles in the biliary injury‐repair responses.
Maternal dexamethasone exposure suppresses placental iron transport through GR‐mediated TFR1 pathway in rats
Authors: Guo Shihui , Yan Kai , Jiang Shuxia , Ni Yingdong , Zhao Ruqian , Ma Wenqiang 
Published: April 2020

Iron is one of the essential trace elements for almost all living organisms, and of course it is especially important for pregnancy and fetal development. However, inappropriately low or high levels of iron during pregnancy are detrimental and contribute to serious and lasting effects on the fetus, such as fetal growth and development disorders, thereby increasing the risk of adulthood. Here we stress pregnant rats by drinking water with 10−7 mol/L dexamethasone, and then explore its effects on iron metabolism of placenta and fetal rats. The results showed that dexamethasone treatment inhibited placental development, down‐regulated the expression of placental iron transporter TFR1, and decreased iron levels in fetal rats. Furthermore, we use a human placental choriocarcinoma cell line (BeWo) as model to explore the pathway linking inhibit of TFR1 under Dex challenge, our results demonstrate that the decrease in TFR1 caused by dexamethasone is alleviated by the addition of dexamethasone inhibitor RU486. Taken together, our results show that dexamethasone downregulate TFR1 expression adjust iron metabolism via GR‐mediated.Support or Funding InformationThis work was supported by grants from the National Key Research and Development Program of China (2016YFD0500502), the National Natural Science Foundation of China (31872439), the Priority Academic Program Development of Jiangsu Higher Education Institutions and the Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control.
Leukocytic Thy‐1 Expression Differs in Kidney Cortex and Medulla in Spontaneously Hypertensive Rats
Authors: Meariman Jacob K. , Sutphen Jane , Denys Ian , Harrison David G. , Kapusta Daniel R. , Gao Juan 
Published: April 2020

Sympathoexcitation and increased inflammation are both involved in mediating hypertension, and decreasing sympathetic nerve activity is vital for reducing inflammation in this disease. However, the mechanism(s) by which the nervous system communicates with the immune system in hypertension is still largely unknown. To examine this interaction in this study, twenty‐week‐old spontaneously hypertensive rats (SHR) underwent renal denervation (RDN) via radiofrequency ablation of the renal artery. After two months, kidneys were harvested and separated into cortex and medulla, and lymphocytes were detected by flow cytometry. RDN significantly decreased CD4+ T cells, CD8+ T cells, and B cells in the renal medulla but had no effect on these immune cells in the cortex. In a separate group of intact SHR, Thy‐1, a reported activator of T cells, was measured in leukocytes isolated from the renal cortex and medulla. Thy‐1 mRNA expression was significantly increased in T cells, non‐T cells, CD45+ cells, and CD45− cells from the leukocytes isolated from the cortex compared to those isolated from the medulla. These findings suggest that Thy‐1 in cortical leukocytes might activate the immune system in the renal cortex independent of the renal nerves. Downregulation of Thy‐1 in the renal cortex could increase the benefit of RDN and decrease renal inflammation in hypertension.Support or Funding InformationNIH NIGMS P30 GM106392
Structural defect leads to human severe (Class I) loss of function in glucose‐6‐phosphate dehydrogenase
Authors: Horikoshi Naoki , Hwang Sunhee , Gati Cornelius , Matsui Tsutomu , Castillo-Orellana Carlos , Garcia Adriana A. , Raub Andrew G , Jabbarpour Fatemeh , Mochly-Rosen Daria , Wakatsuki Soichi , Vöhringer-Martinez Estevan 
Published: April 2020

Oxidative stress caused by infection, medication, food, and imbalance of metabolic cycles damages DNA and organelles, which may lead to cancer, blood disorders, and other serious diseases. Glucose‐6‐phosphate dehydrogenase (G6PD) is the rate‐limiting enzyme in the pentose phosphate pathway, which is essential for nucleotide, fatty acid, cholesterol, and hormone synthesis. In addition to those roles, G6PD reduces NADP+ to NADPH, which is crucial for reducing reactive oxygen species. Dysfunction of G6PD increases susceptibility to oxidative stress, especially in erythrocyte due to the lack of mitochondria, which is another source of NADPH. Interestingly, 400 million people worldwide have mutations on the g6pd gene, and the World Health Organization (WHO) has classified more than 160 missense mutations into five classes. The Class I G6PD deficiency is the most severe form; patients have less than 10% enzymatic activity of wild‐type G6PD and suffer from chronic non‐spherocytic hemolytic anemia. Here, we provide a new insight into the loss of activity in G6PD deficiency, based on the structure of the Class I pathogenic mutants of G6PD. We will discuss the structural basis of the Class I mutants of G6PD and its implications to various symptoms in G6PD deficiency.Support or Funding InformationNational Institutes of Health, R01 grant, HD084422; Japan Society for the Promotion of Science KAKENHI, Grant‐in Aid for Research Activity Start‐up, JP19K23713; University of Tsukuba; Stanford University; SLAC National Accelerator Laboratory
The Effect of Habitual Cannabis Smoking on Arterial Stiffness and Vascular Endothelial Function: A Preliminary Analysis
Authors: Cheung Christian P. , Millar Philip J. , Burr Jamie F. 
Published: April 2020

Cannabis ranks globally as the most commonly used recreational drug, and both recreational and medicinal use have recently been legalized in numerous states and countries. The most common means by which cannabis is consumed recreationally is via smoking. Despite its prominent global use, a thorough understanding of the chronic cardiovascular effects of habitual consumption via smoking is lacking. Previous investigations have identified an association between cannabis use and accelerated vascular aging, and rodent models demonstrate impairments in vascular endothelial function following exposure to second‐hand cannabis smoke. Given these findings, it is likely that habitual cannabis smoking by humans results in central artery stiffening and/or decrements in vascular endothelial function; outcomes which are established risk factors for cardiovascular disease. The present work compared the carotid‐femoral pulse wave velocity (cfPWV) and brachial artery reactive hyperemia flow‐mediated dilation (FMD) of habitual cannabis users (CU) and age/anthropometrically matched non‐users (NU). CU were defined by cannabis use a minimum of once per week for ≥3yr. cfPWV was measured using arterial pulse wave tonometry. The FMD protocol included a 1‐minute baseline period, a 5‐minute occlusion of the forearm, and a 3‐minute reperfusion period. FMD is reported as peak change in vessel diameter. CU (n=10, 7M, 3F) and NU (n=10, 6M, 4F) did not differ in age (CU: 21.7±0.4, NU: 21.5±1; p=0.9) nor BMI (CU: 24.2±0.6kg/m2, NU: 23.4±0.4kg/m2, p=0.6). Systolic blood pressure (CU: 111.8±6.8mmHg, NU: 113.3±2.5mmHg, p=0.7), diastolic blood pressure (CU: 68.3±1.4mmHg, NU: 70.3±2.4mmHg, p=0.5), and supine resting heart rate (CU: 65.6±1.8bpm, NU: 66.0±2.8bpm; p=0.9) were similar between groups. Peak FMD (CU: 5.9±0.9%, NU: 6.8±1.1%; p=0.6) was also similar between groups, as was 60 second shear rate area‐under‐curve (CU: 4547±510, NU:4450±572; p=0.9). Peak change in blood velocity (CU: 38.1±3.6cm/s, NU: 36.7±2.0cm/s; p=0.7) and peak change in blood flow (CU: 307±51mL/min, NU: 253±33mL/min; p=0.4) during the FMD test were similar between groups, indicating no differences in microvascular dilatory capacity. cfPWV was higher in CU than in NU (CU: 6.0±0.2m/s, NU: 5.4±0.2m/s; p=0.05). Although no differences in vascular endothelial function were observed in this analysis, an increased sample size will be necessary to confirm these findings. The present data does indicate that habitual cannabis smoking may be associated with increased arterial stiffness.Support or Funding InformationThis work was supported by the Natural Sciences and Engineering Research Council of Canada under Grant 03974.
The Photoreceptor Cells in Retina and Pineal Gland of Amphibian Hoplobatrachus rugulosus
Authors: Liao Meng-Lin , Lin Tzu-Cheun , Chien Chung-Liang 
Published: April 2020

Hoplobatrachus rugulosus, commonly referred to as tiger‐skinned frog, is to be chosen the animal model in this study. It has been found that both chicken α‐internexin and zebrafish inaa (an ortholog of mammalian α‐internexin) were developmentally distributed not only in photoreceptors of retina but also in the photoreceptor‐like cells of the pineal gland from our previous studies. However, from an evolutionary point of view, there is still lack of evidence to illustrate the temporal and spatial distribution of frog α‐internexin protein in the developing pineal gland. According to other studies about Xenopus laevis, the animal model that is usually used for amphibian developmental research, the mRNA sequence which encodes Xenopus α‐internexin had been identified as “xefiltin”. Although H. rugulosus is not the same species with X. laevis, both of them are classified in the same order. The aims of this study is to characterize the expression pattern of α‐internexin‐like proteins, internexin neuronal intermediate filament protein alpha S homeolog (ina.S) and low molecular weight neuronal intermediate filament S homeolog (nif.S) which might be expressed in the developing retina and the pineal gland of the tiger‐skinned frog. Thus, the specific antibodies were generated to detect the frog α‐internexin‐like proteins and to confirm the distribution of these proteins in the developing frog retina as well as the pineal gland by western blot and immunohistochemistry. Furthermore, the markers applied to detect the photoreceptor cell in the retina and the pineal gland are recoverin and XAP1, both of them are reported to be specific to photoreceptors. Based on the distribution patterns in frog retina, immunopositive staining of anti‐nif.S could be observed in the outer segment of photoreceptors, but anti‐ina.S could only be found in retinal neurons. In the pineal gland, both photoreceptor markers, recoverin and XAP1, could be detected. The α‐internexin‐like protein, ina.S and nif.S, could be detected only in a few photoreceptor‐like cells at the early stage of the frog pineal gland. In summary, the distribution patterns of photoreceptor cells in retina and in pineal gland of developing tiger‐skinned frogs has been characterized in this study. It can be concluded that XAP1 could be a good marker to identify the photoreceptor cells in the developing pineal gland of frogs.Support or Funding InformationGrant SponsorMinistry of Science and Technology, Taiwan; Grant Number: MOST 108‐2312‐B‐002‐030‐MY2.
Role of Carbonic Anhydrase in the Regulation of Na‐H exchanger‐1 in Experimental Colitis
Authors: Khan Islam 
Published: April 2020

A role of carbonic anhydrase (CA) was investigated in the regulation of Na–H exchanger‐1 (NHE‐1) in experimental colitis. Trinitrobenzenesulphonic acid (TNBS) was administered intra‐rectally to induce colitis in rats, and the animals were sacrificed on day 6 post TNBS. The isoforms CA‐I and CA‐II were the abundant isoforms in the colon but expressed as minor ones in the ileum. Both CA isoforms, on co‐immunoprecipitation and confocal microscopy, appeared to be colocalized with the NHE‐1 isoform in the colon. Importantly, inflammation reduced the expression of these proteins in the colon, but not in the ileum. The reduction in the level of co‐immunoprecipitated CA isoforms was more pronounced as compared to their level of expression in the inflamed tissue. Ex‐vivo treatment of uninflamed colonic strips by TNF‐α reduced the expression of CA isoforms. The binding site of the CA‐II isoform was identified in a peptide (83 aa) selected from the NHE‐1 C‐terminus. However, the CA‐I isoform did not bind with the same peptide. Since the tissues used in this study expressed inflammatory markers, the present data suggest that the uncoupling of CA and NHE‐1 is due to inflammation. This uncoupling would lead to a reduction in the NHE‐1 activity and an accumulation of H+ intracellularly, which together cause acidosis and necrosis in the inflamed colon in the present model.Support or Funding InformationResearch Sector, Kuwait University, Kuwait (Grant # MB03/15)
Blood Brain Barrier Permeability and Brain Capillary Endothelial Cell Tight Junctions in the Dahl S Model of Spontaneous Superimposed Preeclampsia
Authors: Maeda Kenji J. , Hoskins Glenn A. , Bidwell Gene L. , Garrett Michael R. , Sasser Jennifer M. 
Published: April 2020

Previous studies in our lab have shown increases in brain water content and Evan’s Blue extravasation in the brains of pregnant Dahl salt‐sensitive (Dahl S) rats compared to Sprague Dawley (SD) rats. The goal of this study was to test the hypothesis that pregnant Dahl S rats display increased blood brain barrier (BBB) permeability and disruption of brain capillary endothelial cell tight junctions.Female (20 week old) Dahl S and SD virgin and pregnant rats were used. Female rats were mated with males of the same strain, and gestational day 1 (G1) of pregnancy was defined by the detection of sperm histologically from a vaginal swab. On G20, rats were perfused with a 1.0% paraformaldehyde/2.0% glutaraldehyde solution and brains were collected for electron microscopy. Transmission electron microscopic images were used to assess the following parameters of brain capillaries: basement membrane status (% dissolved), basement membrane thickness, vesicle formation, tight junction status (% open), luminal membrane protrusions, and vessel diameter. In a separate group, rats were perfused with 5mg/kg of 3kDa Texas Red dextran (1 hour circulation) followed by 5mg/kg injection of 500kDa FITC (3 minute circulation) on G20, brains were collected, and 5μm sections from the posterior cortex were used for confocal microscopy. A ratio of extra‐:intra‐vascular Texas Red mean intensity values was determined to portray a percentage of Texas Red extravasation. All image analyses were conducted blindly.Dahl S pregnant rats showed significant differences in basement membrane status (23% increase of dissolution) and vesicle formation (11±1 vs. 4±1) compared to SD pregnant rats (p < 0.01, 2way ANOVA for multiple comparisons – Tukey post‐hoc). Significant differences were observed in tight junction status among the groups (% open: SD Virgin = 3.03, SD Pregnant = 11.77, Dahl S Virgin = 11.77, Dahl S Pregnant = 26.47, p = 0.04, Fisher’s Exact Test of Independence). No statistical differences were found for measurements of basement membrane thickness, luminal membrane protrusions, or vessel diameter. Dahl S pregnant rats displayed a 17% increase in Texas Red extravasation compared to Dahl S virgin rats (p = 0.01, unpaired t‐test with Welch’s correction).Our results indicate that pregnant Dahl S rats display increases in BBB permeability to low molecular weight fluorescent dextran and increased disruption of brain capillary endothelial cell tight junctions as well as decreased basement membrane integrity. In addition, the increase in vesicle formation may suggest increases in BBB permeability as it relates to transcellular transport across the BBB.Support or Funding InformationKJM was supported by 5T32HL105324‐10 and 20PRE352000021. Work was supported by 1R01HL137673 to MRG and R01HL134711 to JMS.
Microvascular Pachymeningeal Lymphatic Structures: Association with Blood Vessels and Cranial Bones
Authors: Glinskii Olga , Huxley Virginia , Xie Leike , Bunyak Filiz , Palaniappan Kannappan , Glinsky Vladislav 
Published: April 2020

The role of cranial dura mater microvascular networks, as means for maintaining brain fluid movement and balance, and as the source of significant initiators and/or contributors to neurological disorders, has been underappreciated until recently. These networks consist of both blood and lymphatic vessels. The goal of this study was to uncover microvascular pachymeningeal lymphatic structures that are not associated with venous sinuses and investigate their interrelationship with the blood microvascular networks and cranial bones. Using markers specific for blood and lymphatic endothelia, we demonstrate the existence of the complex non‐sinus‐associated lymphatic microvasculature. We show the interrelationship and possible connections between lymphatic vessels and dural blood vessels. Furthermore, we unveil vascular connections between dural microvascular networks and cranial bone marrow sinusoids. Our novel findings reveal the presence of lymphatic‐like structures that exist on their own and/or in close proximity to microvessels. Of particular interest are sub‐sets of vascular complexes with dual (lymphatic and blood) vessel identity representing a unique microenvironment within the cranial dura. The close association of the systemic blood circulation and meningeal lymphatics achieved in these complexes could facilitate fluid exchange between the two compartments and constitute an alternative route for CSF drainage.Support or Funding InformationThis work was supported in parts by the NIH National Institute of Neurological Disorders and Stroke (R01NS110915), the NIH National Cancer Institute (R01 CA160461), and the U.S. Army Research Laboratory project W911NF‐18‐2‐0285.
Intestinal lncRNA H19 and miRNA‐675 expression Influenced by Metal Transporter ZIP14
Authors: Jimenez Felix R. , Ruggiero Courtney H. , Cousins Robert J. 
Published: April 2020

Zinc has been shown to influence intestinal barrier function. To function properly, zinc must be placed at specific sites of action in cells. Previously, we demonstrated that the zinc transporter Zip14 (Slc39a14) is highly expressed in the small intestine and is localized to the basolateral membrane of enterocytes. Ablation of Zip14 in mice produces a phenotype that includes increased intestinal permeability and metabolic endotoxemia. To investigate the mechanism involved, we performed genome‐wide examination of gene expression in the small intestine from WT and Zip14 KO mice using Illumina RNA sequencing. This RNAseq analysis revealed that among 1079 long non‐coding (lnc) RNAs profiled, 36 annotated lncRNAs were identified as overexpressed in intestines of Zip14 KO mice. H19 RNA was the most highly overexpressed lncRNA. Read densities of other selected lncRNAs demonstrated specificity in the differential expression of H19 in the intestine of the KO mice. Upon confirmation using qPCR, we found that H19 was significantly up‐regulated in intestines of the Zip14 KO mice. Up‐regulation of miR‐675‐5p, a microRNA derived from H19, was also demonstrated. Intestinal epithelial cells (IEC) isolated by a chelation method revealed high expression of intestinal alkaline phosphatase and Zip14 mRNAs, indicative of substantial enterocyte‐enrichment. Expression of H19, but not miR‐675‐5p, was localized to the isolated IECs. Markedly enhanced expression of H19 was detected in IECs from the Zip14 KO mice compared to WT mice. The increased H19 expression in Zip14 KO mice was limited to IECs and skeletal muscle of the six tissues examined. IECs were also isolated from intestine‐specific Zip14 KO (I‐KO) mice. The up‐regulation of H19 was observed in IECs from the I‐KO mice compared to those from flox/flox controls, but miR‐675‐5p expression was not different between cells from the two genotypes. These data suggest that intestinal H19 is produced by IECs and is up‐regulated with Zip14 ablation. H19 overexpression suggests it is involved in a molecular defect in intestinal function of Zip14, perhaps including intestinal barrier dysfunction.Support or Funding InformationNIH Grant R01 DK 094244
The Role of The DNA Damage Checkpoint in The Relocalization of CAG Trinucleotide Repeats to The Nuclear Pore Complex During S‐phase
Authors: Johnson Matthew , Whalen Jenna , Freudenreich Catherine 
Published: April 2020

The instability of CAG trinucleotide repeats has been known to cause neurodegenerative diseases including Huntington’s disease and myotonic muscular dystrophy. Moreover, CAG trinucleotide repeats are capable of forming lesion inducing hairpin structures during the replication of DNA during S‐phase. These lesions must be repaired in order for DNA to be faithfully replicated and properly segregated during mitotic division. Failure to correct these lesions may result in deleterious mutations at these sequences. The DNA damage checkpoint elicits the first response to damage including double stranded breaks and collapsed replication forks resulting from CAG hairpin stalling. Notably, these collapsed forks are relocalized from the center of the nucleus to the nuclear pore complex (NPC) for repair. It is hypothesized that the DNA damage checkpoint plays a role in signaling relocalization of these lesions to the NPC during S‐phase.To test this hypothesis, a GFP based zoning assay system was designed to assess CAG repeat relocalization to the NPC in several gene backgrounds defective in the DNA damage checkpoint response. These zoning assays have indicated that the DNA damage checkpoint does indeed play a role in the relocalization of CAG repeats during S‐phase. Several mutants tested also displayed abnormal nuclear arrangement. This research demonstrates that the DNA damage checkpoint is necessary for the relocalization of CAG tracts to the NPC which is known to be necessary for repair of persistent DNA lesions. Further studies will determine the mechanisms by which the checkpoint is involved in this relocalization and why abnormal nuclear arrangement is sometimes seen in mutants that are unable to elicit a proper checkpoint response.Support or Funding InformationAll support and funding is provided through the Tufts University Biology Department and specifically the Freudenreich Lab.