bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of beta3 Integrin in Pathological Angiogenesis
Authors: Feng Weiyi , Mahabeleshwar Ganapati H , Phillips David R , Byzova Tatiana V 
Published: June 2021

Background: Angiogenesis depends on the coordinated action of numerous cell types. A key adhesion molecule expressed by most of these cells and having a regulatory function in angiogenesis is αvβ3 integrin. However, the exact role of this integrin in vascular pathologies remains unclear.Method: Using a knock‐in mouse (diYF) characterized by impaired β3 integrin phosphorylation and signaling, the role of β3 integrin in angiogenesis was investigated.Results: Analysis of angiogenesis in wounds and in implanted tumors revealed that the process of neovascularization is impaired in DiYF mice. The key regulatory function in angiogenesis appears to be dependent on the β3 integrin function in recruitment of bone marrow‐derived cells (BMDC) to the sites of neovascularization. BMDC did not directly incorporate into the tumor neovasculature, but were situated in the close proximity of blood vessels and might affect angiogenesis by secretion of key effectors. αvβ3 integrin controls BMDC recruitment and retention at the sites of angiogenesis in vivo. Impaired α3 integrin signaling in CXCR4+BMDC, but not in endothelium, diminishes adhesion and transmigration of CXCR4+cells through endothelial monolayer and their recruitment in angiogenic tissues.Conclusion: β3 integrin controls angiogenesis and angiogenesis‐dependent processes of tumor growth and wound healing by regulating BMDC recruitment to neovasculature.
Frontotemporal dementia associated with a Valosin‐Containing Protein mutation: report of three families
Authors: Spina Salvatore , Van Laar Amber D. , Murrell Jill R. , de Courten‐Myers Gabrielle , Hamilton Ronald L. , Farlow Martin R. , Quinlan John , DeKosky Steven T. , Ghetti Bernardino 
Published: June 2021

Objective: The phenotype of inclusion body myopathy with Paget disease of the bone and frontotemporal dementia (FTD) (IBMPFD), associated with Valosin‐Containing Protein (VCP) mutations is described in 3 families. Methods: Probands were identified on the basis of a pathological diagnosis of frontotemporal lobar degeneration with neuronal intranuclear ubiquitin/TDP‐43‐positive inclusions (FTLD‐U type IV). VCP sequencing was carried out. Clinical data on affected family members were reviewed.Results: Family A: 4 subjects had a myopathy (M): 2 showed also Parkinsonism (P) and FTD. Proband's brain had FTLD‐U type IV and brainstem‐type Lewy body pathology. Muscle displayed neurogenic changes and VCP(+)‐rimmed vacuoles. A VCP R191Q mutation was found in one allele. Family B: 8 subjects developed IBMPFD: FTD was seen in 4, M in 3, P in 2 and primary progressive aphasia (PPA) in one. Proband's brain showed FTLD‐U type IV, hippocampal sclerosis (HS) as well as Lewy neurites in the substantia nigra. A novel VCP T262A mutation was found in one allele. Family C: 2 subjects developed IBMPFD. The proband had FTD while a brother presented M and dementia. Proband's brain had FTLD‐U type IV and HS. A VCP R159C mutation was found in one allele.Conclusions: We identified three new families with IBMPFD associated with VCP mutations. A novel T262A mutation was found. One individual had PPA: a novel finding in IBMPFD. Supported by AG10133
Signal transduction in melanoma transendothelial migration using a tissue‐engineered human blood vessel
Authors: Auger François A. , Fiola Marie‐Christine , Tremblay Pierre‐Luc , Lacroix Dan , Basoni Caroline 
Published: June 2021

Transendothelial migration involves major modifications in cell‐cell contact, consequent morphological changes and cytoskeletal reorganization. In this context, GTPases are key modulators in signal transduction leading to cellular modifications. Rap1, a member of the GTPase Ras Family, is implicated in the stability of endothelial adherent junctions. Rap1 is also implicated in integrin‐mediated adhesion of leukocytes to the endothelium, and participate in cadherin‐modulated adhesion. Those mechanisms are poorly understood, so further study is needed to elucidate the steps inherent to this process. We used a tissue‐engineered human blood vessel to analyze the role of Rap1 in the modulation of endothelial junctions. In endothelial cells monocultures, we observed that melanomas increased activated Rap1 and activated Extracellular Signal‐Regulated Kinase (Erk). We further analyzed the distribution of Zonula Occludens‐1 (ZO‐1) in endothelial tight junctions, and we observed a translocation to the nucleus when endothelial cells are stimulated with forskolin, a potent cAMP activator. We have to correlate those activations both with Rap1 signalling pathway and endothelial junctions remodelling. In the future, we will transpose those results using our 3D tissue‐engineered human blood vessels.Financial support is provided by the Canadian Institutes of Health Research.
Dynamics of the polymerase manager protein UmuD: DNA damage tolerance in E. coli
Authors: Koleva Bilyana N. , Ordazzo Michael J. , Fung Amy , Sefcikova Jana , Wales Thomas E. , Engen John R. , Beuning Penny J. 
Published: June 2021

In E. coli, the function of specialized Y family DNA polymerases is regulated by UmuD, a small manager protein, and its cleaved form, UmuD′. The different forms of the UmuD proteins play dramatically different roles in the cellular response to DNA damage: UmuD facilitates a primitive DNA damage checkpoint while UmuD′ enables DNA damage‐dependent mutagenesis. The β processivity clamp, which tethers DNA polymerases to the DNA, confers high processivity on normal DNA polymerases. UmuD is known to bind the β clamp and this may modulate the activity of β. The objective of this study is to understand the conformational dynamics of UmuD to determine its effect on DNA damage tolerance. We constructed a library of single cysteine derivatives of UmuD to facilitate labeling for fluorescence resonance energy transfer (FRET) and electron paramagnetic resonance (EPR) studies. All single cysteine derivatives of UmuD were shown to be active in UV‐induced mutagenesis, and will be labeled. Hydrogen‐deuterium exchange mass spectrometry experiments show that UmuD is flexible, while UmuD′ is slightly less so.This work is supported by a Dreyfus Foundation New Faculty Award and the Northeastern University Office of the Provost.
Role of the conserved distal heme asparagine in coral allene oxide synthase and human catalase
Authors: Gao Benlian , Boeglin William E. , Brash Alan R. 
Published: June 2021

Allene oxide synthase (AOS) metabolizes a specific fatty acid hydroperoxide to an unstable allene epoxide, a biosynthetic precursor of cyclopentanones such as jasmonic acid and marine clavulones. Plant AOS is a cytochrome P450 (CYP74A), whereas coral AOS (cAOS) is structurally related to catalase. The striking similarity of catalase and cAOS revealed by the X‐ray structures opens new questions on the structure‐function of both enzymes. Here we addressed the role of the conserved distal heme Asn in H2O2 breakdown in catalase and in metabolism of the natural hydroperoxide substrate 8R‐HPETE by cAOS. Point mutations were introduced by site directed mutagenesis and the proteins expressed in E. coli. Activities were assayed by UV spectrophotometry and cAOS products were identified by HPLC‐UV. In human catalase, the point mutations N148A, N148S, or N148D reduced Vmax and Km, with little net effect on kcat/Km. In cAOS, the mutations N137A, N137Q, N137S, N137D, and N137H drastically reduced the rate of reaction (to 0.8–4%), yet the mutants all formed the allene oxide as product. This is remarkable because there are many potential heme‐catalyzed transformations of fatty acid hydroperoxides. The distal heme Asn is not essential in either catalase or cAOS. Its conservation throughout evolution may relate to a role in enzyme stabilization and fine‐tuning of catalysis.Supported by NIH grant GM‐074888
Activation of toll‐like receptor‐4 modulates skeletal muscle substrate metabolism in a manner that mimics the metabolic phenotype observed in skeletal muscle of obese humans
Authors: Hulver Matthew W , Frisard Madlyn I. , McMillan Ryan P , Marchand Julie , Wu Yaru , Voelker Kevin 
Published: June 2021

Obesity is associated with chronic inflammation and the development of type 2 diabetes. Skeletal muscle from obese humans is resistant to insulin and characterized by abnormal substrate metabolism, i.e. increased glycolytic activity, reduced oxidative capacity, and elevated lipid accumulation. Toll‐like receptors (TLRs) are transmembrane receptors that are important in the induction of inflammatory responses. TLRs have been linked to lipid‐induced skeletal muscle insulin resistance and may contribute to reduced oxidative capacity and skeletal muscle lipid accumulation associated with obesity. In the current study, we demonstrate that the TLR4 signaling pathway is up regulated in skeletal muscle of obese humans and regulates substrate metabolism in a manner that reproduces the metabolic phenotype of skeletal muscle observed with obesity. TLR4 gene expression is increased in skeletal muscle of obese humans (p<0.001) and significantly related to BMI (r=0.92, p<0.001) and intramyocellular triglyceride synthesis (r=0.86, p<0.006). In addition, treatment of skeletal muscle cells with Lipopolysaccharide results in a 15% reduction in fatty acid oxidation (p<0.002), a 30% increase in glucose oxidation (p=0.04), and a 33% increase in triglyceride synthesis (p<0.002). These results provide a potential mechanism linking innate immunity with abnormal substrate metabolism associated with obesity.Supported by the American Diabetes Association (Junior Faculty Award, MWH) and the National Institutes of Health (DK078765‐01, MWH).
Metabolic and Genetic Risk Factors Associated With Development Of Complications In Type 2 Diabetes Mellitus (DM)
Authors: Hemimi Neveen Salah El Din , Elwahab Mahmoud M Abd 
Published: June 2021

Background: Glutathione S‐transferases (GSTs) are a family of multifunctional enzymes playing an important role in the cellular detoxification. Therefore, diminished expression of GSTs may result in a reduced body defense against oxidative stress, followed by development of diabetic complications.Aim: To test the hypothesis that the loss of activity of the GSTs enzyme due to deletion polymorphism in GSTT1 and/or GSTM1 may affect the risk of developing complications in DM and to study the other risk factors for complications in DM.Methods: 150 non‐complicated type 2 diabetic patients and 150 complicated type 2 diabetic patients were enrolled in the study. The GSTM1 and GSTT1 genotypes were identified by polymerase chain reaction of peripheral blood DNA samples. Analysis of data was done by using SPSS program.Results: The frequencies of null GSTM1 and GSTT1 genotypes were 53.3% (80/150) and 40% (60/150) respectively in non‐complicated DM group. The frequencies of null GSTM1 and GSTT1 genotype in complicated DM group were 57.3% (86/150) and 58% (87/150) respectively. The null GSTT1 genotype showed statistically significance higher rate in complicated DM compared with non‐complicated DM.Conclusion: Our data provide evidence that diabetics with null GSTT1 genotypes are substantially at higher risk for developing complications.
Mathematical modeling and systems biology approach to study biomaterial composition‐mediated inflammatory signals in endothelial cells
Authors: Shah Miti , Kelso Bret G. , Caplan Michael R. 
Published: June 2021

Understanding of intracellular signaling in response to biomaterials is crucial for rational design of bioactive materials that elicit desired cellular behavior. To understand correlation of signaling to recruitment of inflammation by endothelial cells, human umbilical vein endothelial cells (HUVECs) were cultured on substrates prepared by adsorbing nine different extracellular matrix components to tissue culture plates in addition to a non‐adsorbed plate. Activation of kinases (ERK1/2, JNK‐1, Akt and IKK) was quantified by high‐throughput kinase assays for HUVECs exposed to these surfaces for various times. Principal component analysis (PCA), a well‐known matrix analysis technique, indicates that principal component 1 (PC1), captured the most information, is positively correlated to JNK activity, gelatin, polystyrene and negatively to chondroitin sulfate. PC2 correlated positively to ERK1/2 activity, vitronectin and negatively to Akt activity, chondroitin sulfate and heparin sulfate. PC3 correlated mostly with IKK activity, and PC3 is high for matrigel and laminin but low for vitronectin and heparan sulfate. Correlating these observations with ICAM‐1/E‐selectin expression and leukocyte adhesion will provide further insight into biomaterial composition‐mediated inflammatory signals in endothelial cells.Source of research support: K22 DE014846 (NIDCR), R21 EB004386 (NIBIB)
Site‐directed mutagenesis of bovine deoxyhypusine hydroxylase at the hinge loop area
Authors: Murtaugh Megan L , Wang Yinglu , Smith Joshua L , Soustek Meghan S , Appidi Vidya , Huang Jenq‐Kuen , Wen Lisa 
Published: June 2021

Deoxyhypusine hydroxylase (DOHH) is the second of the two enzymes that catalyze the maturation of eukaryotic initiation factor 5A (eIF5A). It has been well established that hypusinated eIF5A is essential for eukaryotic cell proliferation and survival and that posttranslational modifications of eIF5A could be a suitable target for anticancer therapy.We have recently cloned bovine DOHH cDNA. The deduced amino acid sequence shared 88% identity with human DOHH. The dual function of human DOHH has been reported: the Fe containing holoenzyme exhibited hydroxylase activity while the apoenzyme showed molecular chaperone activity (Kang et al., The FASEB Journal. 2007;21:lb122). The structure transition between the holoenzyme and the apoenzyme is believed to take place around the variable hinge loop area. In this work, we prepare three amino acid substitution mutants at the loop area: P143S (Pro at the position 143 to Ser), D148A (Asp at 148 to Ala), and E154V (Glu at 154 to Val) of the bovine DOHH. The mutant DNA has been created by site‐directed mutagenesis using PCR primed with mutagenic primers followed by overlap extension. The mutant DNA is subcloned into pGEX‐2T, overexpressed, and characterized. We will compare the hydroxylase and chaperone activities of the mutant proteins to the wild‐type DOHH.Supported by grants from National Institutes of Health 1R15 GM60266‐01A1 and the University Research Council at WIU.
PKA‐RSK1 Interaction Modulates RSK1 Activity and Cellular Apoptosis
Authors: Chaturvedi Deepti , Cohen Michael S. , Taunton Jack , Patel Tarun B. 
Published: June 2021

Cyclic AMP dependent protein kinase (PKA) and ribosomal S6 kinase 1 (RSK1) share several cellular proteins as substrates. Previously, we showed novel interactions between RSK1 and the subunits of the PKA (Chaturvedi et al., Mol. Cell. Biol. 2006, Vol. 26, 4586–4600) that regulate the activity of PKA and cellular distribution of RSK1 as well as phosphorylation of RSK1 substrates. Using small inhibitory RNA (siRNA) against subunits of PKA (RI and PKAc) we have examined the role of PKA‐RSK1 interactions in regulation of RSK1 activity and apoptosis. In mouse lung fibroblast (B82L) cells, silencing of the RI subunit of PKA increases the phosphorylation of RSK1 whereas, silencing of PKAc results in decrease in phosphorylation of RSK1 in response to EGF. These changes in phosphorylation status of RSK1 are accompanied by the changes in kinase activity of the enzyme. Further, silencing of either the regulatory or catalytic subunit of PKA decreases the nuclear accumulation of active RSK1 and increases its cytosolic content in response to EGF. These changes in subcellular redistribution of active RSK1 were accompanied by decreased cellular proliferation and increased phosphorylation of its cytosolic substrate BAD with a resultant increase in the anti‐apoptotic actions of EGF. Our data also show that silencing of RI subunit increases the activity of PKA with a resultant increase in phosphorylation of PKA substrates including BAD (at Ser 155) and thus contributing in the protection of cells against apoptosis under basal conditions. Thus, we conclude that RSK1 interactions with the subunits of PKA play an important role in the regulation of RSK1 activity and its subsequent biological actions.Supported by NIH grants GM 079226
Alpha‐melanocyte stimulating hormone (α‐MSH) induction of Treg cell differentiation
Authors: Taylor Andrew W. , Li Dayu 
Published: June 2021

Alpha‐MSH is a potent anti‐inflammatory neuropeptide. We previously reported our discovery that mouse CD4+ T cells primed to function as Th1 cells are suppressed in their expected Th1 functionality when treated with α‐MSH as they were restimulated through their T cell receptor (Tcr). Also, we discovered that the re‐stimulated α‐MSH‐treated primed CD4+ T cells are now TGF‐β‐producing CD25+ Treg cells. We asked whether these α‐MSH‐induced Treg cells express markers and FoxP3 in common with other characterized Treg cells. In addition, we examined the possibility that α‐MSH expands the natural CD25+ Treg cells in the primed CD4+ T cell population. The α‐MSH‐treated Tcr‐stimulated primed CD25+ CD4+ T cells had high expression of CD44 and CTLA‐4, and low expression of CD62L and GITR. The FoxP3 mRNA levels in the CD4+ T cells were 2‐fold enhanced by α‐MSH‐treatment with a parallel decline in high CD127 expression. The depletion of CD25+ cells from the primed CD4+ T cell population before restimulation prevented activation of Th1 cell functionality, but did not change α‐MSH‐induced TGF‐β production. Therefore, α‐MSH‐induces Treg cells that are found in the CD25+ CD4+ T cell population that are not derived from natural CD25+ CD4+ Treg cells. The results suggest that α‐MSH is a potential Treg cell differentiation factor with implications on α‐MSH activity at the resolution of immune responses and in immune homeostasis.Work supported by PHS grant EY10752
Calcineurin Deficiency Decreases Inflammatory Lesions in TGFbeta1‐deficient Mice
Authors: Bommireddy Ramireddy , Bueno Orlando F. , Martin Jennifer , Ormsby Ilona , Chen Dora , Molkentin Jeffery D. , Boivin Gregory P. , Babcock George F. , Doetschman Thomas 
Published: June 2021

Tgfb1 knockout mice develop severe autoimmune inflammatory lesions and die within 3 wks after birth. Since the calcineurin inhibitor FK506 inhibits the hyperresponsiveness of Tgfb1−/− thymocytes, and since calcineurin Aβ‐deficient (Cnab−/−)T cells are hyporesponsive to stimulation, we have generated Tgfb1−/− Cnab−/− mice (double knockout mice) to address whether CnAβ deficiency prevents T‐cell activation and inflammation in Tgfb1−/− mice. Here we show that in Tgfb1−/− Cnab−/− mice inflammation is reduced relative to that in Tgfb1−/− mice. Both CD4+ and CD8+ T cells in double knockout (DKO) mice are activated. To our surprise, we have found that T cells undergo spontaneous activation in Cnab KO mice. Further analysis of Cnab KO mice revealed that Foxp3 expression is down regulated and total Treg cell numbers are reduced suggesting that CnAβ could regulate T‐cell activation through generation of Treg cells. These data also suggest a dual role for CnAβ in T‐cell activation and regulation.Grant support: This study was supported by NIH AI067903 and CA84291 to TD, and by a grant from Shriners of North America to GFB.
IL‐22 directly induces keratinocyte hyperplasia, up‐regulates anti‐microbial peptide and pro‐inflammatory cytokine gene expression in mouse skin
Authors: Napierata Lee , Liang Spencer , Mason Larry , Cai Jie , Collins Mary , Nickerson‐Nutter Cheryl , Fouser Lynette , Young Debbie , Ma Hak‐Ling Margery 
Published: June 2021

IL‐22 is a member of the IL‐10 family of cytokines that signals through the class II cytokine receptor heterodimer IL‐22R/IL‐10R2. It is secreted by activated CD4+ T cells and NK cells and has been shown to regulate keratinocyte hyperplasia and differentiation in vitro. Since the IL‐22 receptor is expressed on a variety of epithelial tissues, the IL‐22/IL‐22R pathway is believed to have effects on epithelial cells. The fact that IL‐23 induced ear swelling is significantly decreased in IL‐22 deficient mice when compared with the control mice further highlights the role of IL‐22 in dermal inflammation and acanthosis.To directly examine the role of IL‐22 in vivo, IL‐22 or saline was injected into the ears of wild type Balb/c mice every other day for two weeks. RNA from the mouse ears was prepared for quantitative RT‐PCR analysis two weeks after the first injection. At the end of the two weeks, IL‐22 induced keratinocyte hyperplasia in the mouse ear, as well as increased defensin β1, S100A8 and S100A9 transcripts. IL‐22 also significantly induced IL‐1α gene expression with a trend towards increased IL‐6 and TNFα transcripts. These results further confirmed that IL‐22 directly induces pro‐inflammatory gene expression and proliferation of keratinocytes that may lead to the recruitment of immune cells and contribute to the development of skin inflammation in vivo.
Titanium increases CCR4 expression and promotes expression of inflammatory cytokines in human T cells
Authors: Sutanto Michael , Chan Erwin , Mhawi Amir , Filgueira Luis 
Published: June 2021

Titanium is increasingly used for implanted bio‐medical devices, including bone fracture treatment and joint replacement therapies. Bio‐corrosion of implants and accumulation of titanium in immune cells, lymph nodes and spleen has been reported. Inflammatory reactions against titanium implants have been reported in up to 15% of cases. However, little is known about the effect of titanium on immune cells. The aim of this study was to investigate the effect of Ti(IV) ions (1 to100μM) on human T‐lymphocytes, freshly isolated from buffy coats or peripheral venous blood of healthy individuals (n=10). No toxic effect was detected in viability assays for the applied titanium concentrations. Using energy filtered transmission electron microscopy, uptake and accumulation of titanium in T‐lymphocytes was documented. Titanium induced cell proliferation (BrdU incorporation assays) in a concentration dependent manner in 40% of the tested individuals. Cytokine measurement in the culture supernatants revealed increased IL‐6 and TNFα production at 12.5μM titanium concentration. Measurement of surface marker expression with flow cytometry showed increased expression of CD3, CD4, CD45 and the chemokine receptor CCR4.This study indicates that titanium affects human T‐lymphocytes by enhancing their inflammatory properties.
Aging impairs plasmacytoid dendritic cell function in response to TLR9 activation
Authors: Stout‐Delgado Heather , Tesar Bethany M , Goldstein Daniel R 
Published: June 2021

Plasmacytoid dendritic cells are innate sensors that produce IFNα in response to type A unmethylated CpG sequences or viral infections. However, the impact of aging on plasmacytoid dendritic cell function is unknown. Determining how aging alters the function of these cells may explain why older people are more susceptible to viral infections. Hence, we examined the effect of aging on plasmacytoid dendritic cell function in response to TLR9 stimulation with either type A CpG or herpes simplex virus type 2. We found that aged murine plasmacytoid dendritic cells produced lower levels of IFNα but preserved IL‐12p40 production after TLR9 activation as compared to young plasmacytoid dendritic cells. Transfer of young plasmacytoid dendritic cells into aged hosts recovered IFNα production and led to control of viremia during herpes simplex viral infection. We found that aged plasmacytoid dendritic cells manifested decreased gene expression of several signal adaptors, including interferon regulatory factor 7, which are critical for IFNα production during Toll‐like receptor activation. In sum, aging impairs the type 1 IFN‐signaling pathway in plasmacytoid dendritic cells, which may explain the increased susceptibility of older people to certain viral infections.This work was supported in part by NIH grants AG028082 and AG026772 to DRG. HWSD is supported by NIH grant T32AG019134. WEW is supported by NIH grant 5T32HL007778.