bluuebunny/crossref_metadata_2025_split huggingface dataset:
T4 Factor Involved in Phage‐induced Host mRNA Degradation
Authors: Qi Dan , Otsuka Yuichi , Yonesaki Tetsuro 
Published: June 2021

ObjectiveIdentification and characterization of T4 factor involved in phage‐induced host mRNA degradationResultsBacteriophage T4 causes a shift of gene expression from host Escherichia coli to T4 immediately after infection. In this process, host mRNAs are rapidly degraded, which may facilitate T4 gene expression by providing precursors for transcription and free ribosomes. Recently we found that the rapid degradation of host mRNAs was partially suppressed and a decay intermediate of lpp mRNA was markedly accumulated in Δ(39‐56)6 phage‐infected cells. Since the 4.6‐kb region missing in Δ(39‐56)6 phage contain 8 orfs, we tested the effect of each orf on host mRNA degradation and found that the causal gene is dda.2, a T4 early gene, located immediate downstream of an early promoter. The average number of phages produced in a cell infected with a deletion mutant of dda.2 (Δdda.2) was one‐third, in comparison to that of wild type, indicating that dda.2 is necessary for efficient propagation of T4. On the other hand, over‐expression of Dda.2 was found to be toxic for cells. With the induction of plasmid‐borne dda.2, cell growth was stopped within 30 min, and cell viability was significantly reduced. In addition, amounts of E. coli mRNAs, such as lpp and ompA were considerably reduced. Furthermore, the decay of ompA and lpp mRNAs was accelerated after induction of plasmid‐borne dda.2.Conclusions1. T4 dda.2 is involved in phage‐induced host mRNA degradation, which is thought to be important to facilitate T4 gene expression.2. T4 dda.2 has a significant role in bacterial physiology probably with a modulation in mRNA metabolism.Source of the research support: The ministry of education, culture, sports, science and technology, Japan
An Intrinsically Disordered Low Complexity Domain is Required for U1‐70K Self‐association
Authors: Bishof Isaac , Diner Ian , Seyfried Nicholas 
Published: June 2021

The RNA binding protein U1‐70K aggregates via an unknown mechanism in Alzheimer's disease (AD). Interestingly, AD brain homogenates can induce the aggregation of soluble U1‐70K from control brain or recombinant U1‐70K (rU1‐70K), rendering it detergent‐insoluble. The intrinsically disordered C‐terminus of U1‐70K is necessary for aggregation and harbors two low‐complexity (LC) domains, LC1 and LC2. Similar LC domains have been shown to polymerize into amyloid‐like aggregates in vitro, and the RNA binding proteins TDP‐43 and FUS, which also harbor LC domains, form detergent‐insoluble amyloid‐like aggregates in neurodegenerative disease. Our objective is to determine if the LC domains of U1‐70K are necessary for self‐association. Addressing this question may provide mechanistic insight into the aggregation of U1‐70K in AD. To investigate this question we performed co‐immunoprecipitations of full‐length rU1‐70K and various mutants lacking either the LC1, LC2, or both LC domains. These assays revealed that the LC1 domain (amino acids 231‐308) of rU1‐70K is necessary and sufficient for association with native U1‐70K. Similarly, we utilized bio‐layer interferometry to measure the binding affinity of the LC1 domain with a synthetic peptide corresponding to amino acids 252‐270 of U1‐70K. These data provide evidence for a direct self‐association between regions of the LC1 domain. Finally, by immunocytochemistry we show that rU1‐70K mutants lacking the LC1 domain have an impaired ability to form nuclear granule structures. Together these data indicate that the disordered LC1 domain is necessary for U1‐70K self‐association and subnuclear compartmentalization.Sources of Research Support:NIRG‐12‐242297 (NTS) and T32‐NS007480 (IB)
Hsp90, Hsp60 And HSF‐1 Genes Expression in Muscle, Heart and Brain of Thermally Manipulated Broiler Chicken
Authors: Al‐Zghoul Mohammad 
Published: June 2021

ABSTRACTThe effect of thermal manipulation (TM) was investigated during embryonic days (ED) 12‐18 on the hatchability, body temperature (Tb) and on thyroid hormones (T3 & T4) and on mRNA levels of heat shock proteins (Hsp90, Hsp60 and HSF‐1) in muscle, heart and brain tissues and during thermal challenge (TC) at days 10 and 28 post‐hatching. One thousand five hundred fertile chicken eggs were randomly allocated into four groups: Control group (37.8°C), TM1 (39°C for 9h), TM2 (39°C for 12h) and TM3 (39°C for 18h). Chicks from each treatment group were then randomly sub‐divided into 2 treatment groups (Naive and TC). At days 10 and 28 of age, chicks in TC groups were subjected to thermal challenge (TC) at 43.0°C for 6h while naïve chicks were kept under regular conditions. Chick's response to TC was evaluated by determination of body temperature (Tb), plasma T3 and T4 levels and mRNA levels of Hsp90, Hsp60 and HSF‐1 in muscle, heart and brain tissues. TM adversely affected chick's hatchability rate. The Tb of TM chicks decreased compared to the control group during the first 2 weeks of age. Interestingly, during TC at days 10 and 28 of age, the Tb of TM chicks was significantly lower than those of the controls. When compared to the control, TM resulted in a significant increase in mRNA levels of Hsp90, Hsp60 and HSF‐1in muscle, heart and brain tissues during embryogenesis and during TC at days 10 and 28 post‐hatching. Results of this study indicated a long‐term enhancement of Hsp90, Hsp60 and HSF‐1 gene expressions associated with improved thermotolerance acquisition in thermally challenged chicks without adversely affecting body performance parameters.
Hypoxia Reduces Mature HERG Channels through Calpain Up‐regulation and Activation
Authors: Lamothe Shawn , Zhang Shetuan 
Published: June 2021

Human ether‐à‐go‐go related gene (hERG) encodes the pore‐forming subunit of the IKr channel, which is important for cardiac repolarization. Loss of function of the hERG channel causes long QT syndrome, a cardiac disorder with high risk of cardiac arrhythmias and sudden death. Patients with medical conditions, such as cardiac ischemia, are associated with prolonged QT intervals and arrhythmias. Since proteases, such as calpain, are upregulated and activated during cardiac ischemia and hypoxia, we investigated the role of calpain in hypoxia‐mediated hERG reduction. We demonstrate that hypoxic (0.5% O2) culture of hERG‐expressing HEK cells and neonatal rat cardiomyocytes led to a significant reduction of mature hERG expression and a concomitant increase in calpain expression. Transfection of hERG‐HEK cells with calpain‐1 reduced mature hERG expression and was accompanied by a significant calpain expression in the cell culture media. Treatment of cells with media from calpain‐1 transfected cells reduced mature hERG channel expression and function. The calpain‐1‐mediated hERG reduction was completely prevented by the membrane‐impermeable calpain inhibitor peptide B27. Replacing the S5‐S6 pore linker of hERG with that of EAG completely eliminated the calpain‐1 and hypoxic culture‐induced hERG reduction. Application of a peptide (BeKm‐1), which binds specifically to hERG's extracellular S5‐pore linker, prevented calpain‐1 and hypoxic culture‐induced hERG reduction. We conclude that hypoxia decreases mature hERG expression by activating calpain, which cleaves the channel protein at the extracellular S5‐S6 pore linker leading to subsequent channel degradation.Supported by the Canadian Institutes of Health Research & the Heart and Stroke Foundation of Ontario
Distinct Roles of Apolipoprotein A1 and Lecithin‐Cholesterol Acyltransferase in Lipopolysaccharide‐Induced Inflammation
Authors: Petropoulou P.I. , Berbée J. , Hatziri A , Karagiannides I. , Kypreos K. 
Published: June 2021

AimWe studied lipopolysaccharide (LPS)‐induced inflammation under conditions of Apoa1‐ or Lcat‐ deficiency.MethodsRAW 264.7 macrophages, whole blood and peritoneal macrophages from C57BL/6 (WT), Lcat‐deficient (Lcat‐/‐) and Apoa1‐deficient (Apoa1‐/‐) mice were challenged with LPS and plasma TNFα was measured. WT, Lcat‐/‐ and Apoa1‐/‐ mice were challenged intravenously with LPS and plasma cytokines were monitored. WT, Lcat‐/‐ and Apoa1‐/‐ leukocytes were phenotyped using FACS.ResultsSerum and HDL from Lcat‐/‐ and Apoa1‐/‐ mice display reduced capacity to attenuate the LPS‐induced TNFα response, in vitro. Blood from Lcat‐/‐ and Apoa1‐/‐ mice show an increased TNFα response when stimulated with LPS ex vivo, with more pronounced effect for Lcat‐/‐ blood. Lcat‐/‐ and Apoa1‐/‐ mice show a markedly enhanced and prolonged LPS‐induced inflammatory response in vivo. LCAT‐deficiency is associated with leukocytosis, increased CD11b+/Ly‐6Cmed monocyte and CD4+ lymphocyte levels, but low CD11b+/Ly‐6Chi monocyte levels and CD11b expression. Similarly, peritoneal macrophages from Lcat‐/‐ mice show reduced LPS‐induced TΝFα response. In contrast, APOA1 deficiency is associated with decreased leukocyte, CD11b+/Ly‐6Clo/med/hi monocyte and CD4+, CD8+ lymphocyte levels.ConclusionsLCAT deficiency renders leukocytes less responsive to LPS, but increases their number in circulation, while APOA1 deficiency results in fewer but more responsive leukocytes.
Lipin‐1 Links Lipid Signaling with Inflammation
Authors: Balboa María , Meana Clara , Lordén Gema , Balsinde Jesús 
Published: June 2021

Lipins are Mg2+‐dependent phosphatidic acid phosphatases involved in the de novo synthesis of phospholipids and triglycerides. Although they regulate cellular levels of important signaling lipids, little is known about the role of lipins in the immune response. Using lipin‐1‐deficient animals, we show in this work that this phosphatase acts as a proinflammatory modulator during TLR signaling and also in the developmentof in vivo inflammatory processes. After stimulation with lipopolysaccharide (LPS), lipin‐1 deficient macrophages had a decreased production of DAG, activation of MAPKs and phosphorylation of the AP‐1 transcription factor c‐jun. Consequently, the generation of cytokines like IL‐6, IL12, IL23, or proteins like iNOS and COX‐2 was reduced. In the same line, responses to Salmonella were diminished, although no differences in phagocytosis rates were found. During the development of chemically‐induced colitis these animals exhibited reduced inflammatory responses and were protected against tissue damage and disease severity. These effects correlated with a lower generation of gut pathogenic factors like IL‐17 and IFNg and increased production of the gut protective factor TGFa. These findings demonstrate an unanticipated role for lipin‐1 as a mediator of inflammatory‐based pathological states and support a critical link between lipid signaling and inflammatory responses.Supported by Grant SAF2013‐48201‐R from the Spanish Ministry of Economy and Competitiveness.
Spatiotemporal Activation of Yeast Lipin Pah1 and Phospholipid Remodelling during Lipid Droplet Formation
Authors: Barbosa Antonio , Sembongi Hiroshi , Han Gil‐Soo , Su Wen‐Min , Carman George , Siniossoglou Symeon 
Published: June 2021

Lipid droplets (LD) are central players in several biological functions but many aspects of LD biology are far from being understood. LD expansion requires the synthesis of the neutral lipids triacylglycerol (TAG) and steryl‐esters. In this work, we used the yeast Saccharomyces cerevisiae to unveil the regulation of enzymes involved in TAG formation, which requires Pah1‐driven synthesis of diacylglycerol and an acyl‐CoA donor. In yeast, LD biogenesis is induced in stationary phase.Pah1 lacks a transmembrane domain, suggesting recruitment onto membranes under specific conditions. We observed recruitment of Pah1 to a domain of the nuclear envelope before the translocation to lipid droplets. This recruitment is independent of the glucose repression machinery but can be mimicked by physiological cues that govern entry into stationary phase, providing a mechanism for Pah1 activation.We have shown that phospholipases B and the transacylase Lro1 generate, from phospholipids, the majority of the fatty acids required for TAG synthesis in stationary phase. Under these conditions, Pah1 and the phospholipase associated with LD are in contact with the ER. The conversion of phospholipids into storage lipids prevents aberrant expansion of membranes in stationary phase.Our data show a nutrient‐dependent recruitment of Pah1 to specific membranes and a rewiring of lipid metabolism towards storage at the expense of phospholipids.Work supported by grants from the Medical Research Council and the National Institutes of Health.
Role of Cardiac mir‐208a in Nebivolol‐Mediated Signaling
Authors: Mahmood Abuzar , Gul Rukhsana , Luck Christian , Pulakat Lakshmi 
Published: June 2021

The myomiR miR‐208a is implicated in cardiac hypertrophy, fibrosis, induction of obesity, and up‐regulation of β‐myosin heavy chain (β‐MHC) and GATA binding protein 4 (GATA4) expression. Nebivolol (Neb), a 3rd generation β1 adrenergic receptor blocker, suppresses cardiac hypertrophy and fibrosis. We reported that Neb treatment attenuated weight gain in obese, leptin resistant rats and suppressed Mammalian Target of Rapmycin Complex 1 (mTORC1) (PMID: 22969779). This study tested the hypothesis that Neb regulates miR‐208a and its effectors (β‐MHC, GATA4) in cardiomyocytes via mTORC1. Treatment of mouse atrial cardiomyocyte HL‐1 cells with Neb (1μM: 12 hrs) significantly suppressed β‐MHC and GATA4 as determined by immunostaining with anti‐β‐MHC and anti‐GATA4 antibodies and nuclear stain DAPI (n=3 experiments; analysis of > 40 cells for each group; P<0.05). Neb also attenuated increases in miR‐208a expression in HL‐1 cells induced by treatment with Angiotensin II (Ang II: 100nM: 12 hrs) as determined by real‐time RT‐PCR (P<0.05; n=5). Losartan (1μM), an AT1R blocker, and Rapamycin (10nM), an mTORC1 blocker, attenuated Ang II‐induced miR‐208a expression, but AT2R blocker PD123319(1μM), NADPH oxidase inhibitor apocynin (500μM) or Phospholipase C inhibitor U73122 (10μM) did not. Rap and Neb also suppressed Ang II‐induced phosphorylation (p) of mTOR (pSer2448), S6K1 (pThr389) and RPS6 (pSer235/236) (P<0.05).ConclusionNeb suppresses miR‐208a and its effectors in cardiomyocytes by inhibiting mTORC1. Such suppression of cardiac miR‐208a may underlie Neb‐induced body weight loss in leptin resistant rats.Research support: LSME, UM‐Columbia (LP) and NIH 1R01HL118376‐01(LP)
Evaluation of the Antimicrobial Activities from Secondary Metabolites in Plant Families (Boraginaceae, Fabaceae, Lamiaceae, and Lauraceae)
Authors: Compean Kassandra , Ynalvez Ruby 
Published: June 2021

For several decades, there has been an increased interest in the antimicrobial activities of different extracts obtained from traditional medicinal plants. There are more than 20,000 species of plants used in traditional medicines. Drugs can be derived from natural products, which are usually secondary metabolites and their derivatives. The increased prevalence of antibiotic‐resistant bacteria emerging from the extensive use of antibiotics may render the current antimicrobial agents insufficient to control at least some bacterial infections. Therefore, the search for new antimicrobial agents is an important line of research.The objective of this study was to determine the antimicrobial activities of plant extracts from Sassafras albidum, Ehretia anacua, Melissa officinalis, Eysenhardtia texana, and Melissa odorata. The ethanol and aqueous extracts were prepared for each of the five plant species and tested against Staphylococcus aureus and Pseudomonas aeruginosa. To test the antimicrobial activity, the disk diffusion method was performed using streptomycin as a positive control. Zone of inhibitions were measured using a vernier caliper. Results showed an antimicrobial potential for the Ehretia anacua (family: Boraginaceae) ethanol extract against Staphylococcus aureus; therefore, it was tested for more antibacterial and antifungal activities, using acetone, ethanol, and diethyl ether extracts. Ehretia anacua was also subjected to qualitative and quantitative phytochemical analysis to determine the exact constituents exhibiting these biological activities.
Pathogenetic Pathways of Aberrant O‐glycosylation of IgA1 in an Autoimmune Disease, IgA Nephropathy
Authors: Novak Jan , Takahashi Kazuo , Suzuki Hitoshi , Yamada Koshi , Reily Colin , Stewart Tyler , Ueda Hiroyuki , Hall Stacy , Moldoveanu Zina , Raska Milan , Julian Bruce , Renfrow Mathew 
Published: June 2021

IgA nephropathy (IgAN), a frequent cause of end‐stage renal disease, is an autoimmune disease wherein immune complexes consisting of IgA1 with galactose‐deficient O‐glycans (Gd‐IgA1; autoantigen) and anti‐glycan autoantibodies deposit in the glomeruli and induce renal injury. Serum IgA1 has 3‐6 clustered core 1 O‐glycans, some of which may be deficient in galactose. Patients with IgAN usually have elevated serum levels of Gd‐IgA1. The mechanisms involved in production of Gd‐IgA1 are not fully understood.Using IgA1‐producing cell lines, we have analyzed the heterogeneity of IgA1 O‐glycosylation and the corresponding biosynthetic pathways. IgA1 secreted by cells from IgAN patients vs. healthy controls had more O‐glycans and more galactose‐deficient sites. These changes were associated with differential expression/activity of key glycosyltransferases, elevated for an initiating enzyme GalNAc‐transferase 14 and for GalNAc‐specific sialyltransferase (ST6GalNAc‐II) and, conversely, decreased for the galactosyltransferase (C1GalT1) and C1GalT1‐associated chaperone Cosmc. These findings were confirmed by siRNA knock‐down.Expression of these enzymes can be affected by cytokines that further enhance the enzyme imbalance, resulting in increased Gd‐IgA1 production.In summary, Gd‐IgA1, the key autoantigen in IgAN, is produced by IgA1‐secreting cells due to dysregulation of multiple key enzymes. These findings thus provide insight into possible targets for future disease‐specific therapy.Supported by NIH grants DK078244, DK082753, GM098539 and by a gift from IGA Nephropathy Foundation of America.
Endothelial Deficiency of the Extracellular Matrix Protein CCN1 Alters Developmental and Pathological Angiogenesis
Authors: Chaqour Brahim , Krupska Izabela , Yan Lulu , Lau Lester , Grant Maria , Chintala Hemabindu 
Published: June 2021

CCN1 is a secreted cysteine‐rich and integrin‐binding matricellular protein required for proper cardiovascular development. However, our understanding of the cellular origins and activities of this molecule is incomplete. Here, we show that CCN1 is predominantly expressed in angiogenic endothelial cells (ECs) at the leading front of actively growing vessels in the mouse retina. Endothelial deletion of CCN1 in mice using a Cre/Lox system is associated with EC hyperplasia and formation of dense retinal vascular networks lacking the normal hierarchical arrangement of arterioles, capillaries and venules. CCN1 is a product of an immediate‐early gene that is transcriptionally induced in ECs in response to stimulation by vascular endothelial growth factor (VEGF). We found that CCN1 activity is integrated with VEGF receptor 2 (VEGF‐R2) activation and downstream signaling pathways required for tubular network formation. CCN1 increased the expression of and association between Src homology 2 domain–containing protein tyrosine phosphatase‐1 (SHP‐1) and VEGF‐R2 which leads to rapid dephosphorylation of VEGF‐R2 tyrosine preventing EC hyperproliferation.Concordantly, ectopic expression of CCN1 prevents the exuberant ischemia‐induced retinal neovascularization in an oxygen‐induced retinopathy model by altering the balance of activation of VEGF‐R2 and SHP‐1. These data highlight novel functions of CCN1 as a naturally optimized molecule fine controlling key processes in physiological angiogenesis and safeguarding against aberrant angiogenic responses.Supported by NEI‐NIH grant EY022091‐01
Association of IDH1 Gene R132H Mutation and Increased Tumor HIF1‐α and Serum VEGF Levels in Primary Glioblastoma Multiforme
Authors: Aydin Hikmet , Yalaza Cem , Ak Handan , Cagli Mehmet , Ozgiray Erkin , Atay Sevcan 
Published: June 2021

Glioblastoma multiforme (GBM) is the most common form of primary brain tumors. Although mutations in isocitrate dehydrogenase‐1 (IDH1) have been identified in a number of cancers, their role in tumor development has not been fully elucidated. In this preliminary study we aimed to investigate the association between IDH1 mutations, tumor tissue HIF‐1 alpha and serum VEGF levels in patients with primary GBM.32 patients (mean age, years: 58 ± 14.0) diagnosed with primary glioblastoma multiforme were screened for IDH1 mutations (R132H, R132S, R132C and R132L) by direct sequencing. Serum VEGF and tumor tissue HIF1‐alpha levels were measured by ELISA. Associations between categoric variables were determined using chi‐square tests. Differences between two groups were compared with t test for continuous variables. Two patients were heterozygous for R132H mutation (6%). Tumor HIF1‐alpha and serum VEGF levels were found to be significantly increased in IDH1‐mutated tumor tissues.

Wild Type IDH1 (n=30)
Mutant IDH1 (n=2)
p

Serum VEGF (ng/ml)
0.189 ± 0.08
0.309 ± 0.016
0.0454

Tumor HIF1‐α (ng/ml)
0.710 ± 0.835
5.058 ± 3.75
&lt; 0.0001

Our preliminary results suggest that mutated IDH1 may contributes to carcinogenesis via induction of HIF‐1 alpha pathway in primary GBM.
LOXL2 Expression in HCT116 Cells under Normoxia is Regulated by ROS and HIF Signaling
Authors: Okkelman Irina , Dmitriev Ruslan , Zhdanov Alexander , Papkovsky Dmitri 
Published: June 2021

HIF1α is well known for its role in induction of metastasis leading to cancer progression.LOXL2 and LOX can induce epithelial‐to‐mesenchymal transition (EMT) of tumor cells and turn them into more aggressive phenotype. Recent findings show that LOX expression can be activated by both hypoxia and reactive oxygen species (ROS) via HIF1 pathway, suggesting complex regulation of LOX in EMT in vivo. To address this, we studied the mechanism of regulation of LOXL2 gene expression in human colon cancer HCT116 cells with impaired mitochrondrial respiration (SCO2‐/‐ mutant).q‐PCR showed that under normoxic conditions (21% O2) expression of LOXL2 gene in SCO2‐/‐ cells, which have increased ROS production, is 8 times higher than in wild type. Culturing of SCO2‐/‐ cells for 1 week with ROS scavenger N‐acetylcysteine (NAC) or inhibitor of HIF‐α signaling FM19G11 under normoxia led to twofold decrease in LOXL2 expression, suggesting direct involvement of ROS/HIF1 axis in LOXL2 gene expression in this cell line. However, we saw no statistical difference in LOXL2 expression in SCO2‐/‐ cells treated with NAC under the hypoxic conditions (3% O2), confirming that ROS levels are decreased in hypoxia and are less involved in regulation of LOXL2. At the same time treatment of SCO2‐/‐ cells with FM19G11 led to twofold decrease in expression of LOXL2, thus demonstrating the active role of HIF pathway. Altogether these data demonstrate that different pathways can be involved in HIF1 dependent expression of LOXL2 under hypoxia and oxidative stress. This mechanism can play important role in vivo in cancer progression mediated by LOXs.Supported by SFI.