bluuebunny/crossref_metadata_2025_split huggingface dataset:
TG100–115, a PI3 Kinase γ/δ Inhibitor, Reduces Lung Inflammation and Airway Hyperresponsiveness in a Mouse Asthma Model
Authors: Racanelli‐Layton Adrienne Lynn , Eide Lisa , Jarmillo Claudia , Brown Jolene , Dellamary Luis , Martin Michael , Soll Richard , Doukas John 
Published: June 2021

Rationale: The γ and δ isoforms of phosphoinositide 3‐kinase (PI3K) regulate immune/inflammatory responses by multiple cell types including Th2 T cells, mast cells, and eosinophils. We explored whether a dual PI3K γ/δ inhibitor could impact airway hyperresponsiveness (AHR) and inflammation.Methods: Mice were sensitized with ovalbumin (OVA) on Day 0 and boosted on Day 5, followed by inhalation challenges on Days 12–13. TG100–115, a PI3K γ/δ inhibitor (IC50 = 83 and 235 nM, respectively), was delivered by inhalation on Days 11–14 for total daily doses of 100 mg/kg; dexamethasone (DEX) was delivered at 3 mg/kg i.p on Days 8–14. On Day 15, AHR was determined following aerosolized methacholine (MC) challenge, polymorphonuclear (PMN) cell counts were determined from bronchoalveolar lavage fluid (BALF), and lungs were processed for histology.Results: Exposure to aerosolized TG100–115 resulted in sustained compound levels within the lung and airways with minimal plasma exposure. TG100–115 reduced both AHR and PMN accumulation vs. vehicle‐treated animals, to near maximal response of systemic DEX. Histology showed that both treatments reduced inflammation and mucin accumulation to near background levels.Conclusion: An aerosolized PI3K γ/δ inhibitor reduces asthma symptoms in a standard mouse model, and may represent a new anti‐inflammatory therapy for future clinical exploration.
Characterization of soluble epoxide hydrolase (sEH) inhibitors for use in vascular graft stenosis
Authors: Terry Christi M , Morisseau Christophe , Carlson Mary L , Sanders William G , Minami Shoko , Ulu Arzu , Hammock Bruce D , Cheung Alfred K 
Published: June 2021

Vascular grafts often fail due to neointimal hyperplasia development. Vascular smooth muscle cells (SMC) and macrophages are likely key contributors to hyperplasia growth. Anti‐inflammatory epoxyeicosatrienoic acids (EETs) are derived from arachidonate by cytochrome (CYP) P450 enzymes but are catabolized by sEH. Thus, enhanced sEH activity that decreases EETs may contribute to graft hyperplasia.In a pig arteriovenous graft model, we detected a 6‐fold decrease in CYP450 activity and a 4‐fold increase in sEH activity in the venous‐graft anastomatic tissue after graft placement. Consequently, EET levels decreased by 7‐fold. Further, there was intense tissue immunostaining for TNFα and phospho‐IκbEffects of inhibitors of sEH (sEHI) on human aortic SMC and macrophages were investigated. Polytetrafluoroethylene graft material stimulated the release of TNFα from mouse macrophage (RAW) cells. This release was inhibited by sEHI alone or in combination with EETs. sEHI also inhibited LPS‐induced chemotaxis of RAW cells. In SMC, sEHI prevented TNFα‐induced phosphorylation of Iκb, and PDGF‐induced SMC migration to the same extent as imatinib, a PDGF‐receptor antagonist.These results suggest that sEH participates in vascular graft hyperplasia. Thus sEH inhibitors may be useful in preventing graft hyperplasia.
The effect of beta‐glucan pretreatment on TNF production in vivo
Authors: Newsome Courtni Takiyah , LeBlanc Brian , Reichner Jonathan S. 
Published: June 2021

The soluble beta‐glucan preparation PGG‐glucan has been shown to prime antimicrobial functions, including increasing the oxidative burst response, microbicidal activity, and the chemotaxis of leukocytes, without eliciting the production of proinflammatory cytokines. In vitro experiments using primary macrophages and macrophage‐like cell lines have demonstrated that pretreatment with PGG‐glucan can reduce the production of TNF message and protein upon LPS stimulation. The purpose of this study was to examine the effect of PGG‐glucan pretreatment on LPS‐induced TNF protein production in vivo. The hypothesis is that PGG‐glucan pretreatment will result in a reduction of LPS‐induced TNF‐protein levels. To test this hypothesis, CD‐1 mice were pretreated with a single dose of PGG‐glucan 40 hours prior to stimulation with LPS. Following LPS stimulation, serum TNF protein levels were measured by ELISA. Our data suggest that PGG‐glucan pretreatment of mice can attenuate the LPS‐induced TNF production in serum. These results indicate that PGG‐glucan can stimulate cellular immune function while inducing suppression of proinflammatory cytokines in vitro and in vivo. These data and future studies may identify a pharmacological intervention that allows cells of the innate immune system to be primed while not overproducing inflammatory cytokines.Supported by NIHGM66194
Reconstructed Skin by the Self‐Assembly Approach: Is the Stem Cell Niche Present In Vitro?
Authors: Lavoie Amélie , Claudie Paquet , Larouche Danielle , Fugère Claudia , Martel Israel , Fradette Julie , Germain Lucie 
Published: June 2021

Since stem cells are responsible for the continuous generation of the stratified epithelium, their isolation and preservation upon culture in tissue‐engineered skin (TES) is suitable to allow the long‐term regeneration of these tissues after grafting. The objective of the present study is to evaluate the dynamic of stem cells and their division in TES produced by the self‐assembly approach. The slow‐cycling property of stem cells was used to identify them with bromodeoxyuridine (BrDU) in TES produced by the self‐assembly approach. TES cultured at the air‐liquid interface were treated with BrdU for a 7‐day‐pulse period, followed by a 21‐day‐chase period. Epithelial cells of the TES were dissociated by enzymatic digestion and analyzed by flow cytometer or on tissue sections by imunofluorescence with antibodies raised against BrdU and keratin 19 (K19). Analysis revealed that basal cells have retained the nuclei BrdU labelling after the 21‐day‐chase period and most of these label‐retaining cells expressed the K19. This observation was corroborated by FACS analysis. These results suggest TES reconstructed by the self‐assembly approach provide a three‐dimensional environment that allows the preservation of stem cells in vitro and we conclude that it is suitable for grafting.This work was supported by the CIHR. L.G. is the holder of a Canadian research chair on stem cells and tissue engineering from CIHR.
Mammalian pioneer translation initiation complex and mRNA decay
Authors: Maquat Lynne E. , Isken Olaf , Matsuda Daiki , Sato Hanae , Woeller Collynn 
Published: June 2021

Nonsense‐mediated mRNA decay (NMD) is an mRNA surveillance pathway that largely functions to control the quality of gene expression. NMD in mammalian cells generally occurs when translation terminates sufficiently upstream of a splicing generated exon‐exon junction during a pioneer round of translation. The pioneer round utilizes newly synthesized mRNA that is bound by the cap binding protein (CBP) heterodimer CBP80‐CBP20 and, if the mRNA is a product of pre‐mRNA splicing, one or more exon junction complexes (EJCs). Ultimately, the pioneer translation initiation complex is remodeled so that CBP80‐CBP20 is replaced by eukaryotic translation initiation factor (eIF)4E and the EJCs are lost. The eIF4E‐bound translation initiation complex is not detectably targeted for NMD.We will present characterizations of the pioneer translation initiation complex. For example, CBP80 promotes NMD by interacting directly with the Upf1 NMD factor and increasing the interaction between Upf1 and Upf21. We will also discuss mRNP rearrangements that occur when translation terminates in a way that elicits NMD. Comparisons of NMD to Staufen1‐mediated mRNA decay (SMD)2 will also be made. Unlike NMD, SMD functions to conditionally decrease the expression of genes encoding mRNAs that bind Staufen1 downstream of a termination codon3. Considering that the majority of cellular mRNA is bound by eIF4E and only a small fraction is bound by CBP80‐CBP20, our finding that SMD targets mRNA undergoing pioneer and subsequent rounds of translation makes sense1.
Utero exposure to methamphetamine: Risks and adverse outcomes in offspring.
Authors: Chirwa Sanika Samuel 
Published: June 2021

Sporadic reports suggest that babies born to mothers who abuse methamphetamine during pregnancy are predicted to suffer from severe, irreversible brain damage, including reduced intelligence and social skills. These studies are difficult to interpret, however, because of maternal use of other drugs. We have developed and rigorously characterized a guinea pig animal model that can be used to study developmental outcomes such as cognition and behavioral status of subjects exposed to methamphetamine before birth. The animal model allows us to translate our current fundamental examination of the mechanisms underlying memory consolidation to testing how these processes are altered by in utero exposure to drugs of abuse, in particular methamphetamine. This talk will present data we have obtained using this animal model that is beginning to define the consequences of in utero exposure to methamphetamine per se during critical stages of fetal development on intrinsic neural properties, synaptic plasticity and memory persistence as measured by electrophysiological and behavioral paradigms in the offspring. The relevance to methamphetamine use by females of child‐bearing age as a rising major public health concern in terms of the long‐term risk to the offspring will be addressed.Supported by NIH grant MH 57067
A telomerase holoenzyme
Authors: Collins Kathleen 
Published: June 2021

To gain understanding of the physiological mechanisms that direct telomerase biogenesis and regulation, we purified endogenously assembled Tetrahymena telomerase holoenzyme using epitope‐tagged TERT. Together, the results of molecular, genetic and biochemical assays define a holoenzyme complex containing TER, TERT, p75, p65, p45 and p19 subunits. Each subunit has an essential, non‐redundant function in telomerase‐mediated telomere maintenance. Genetic depletion of any subunit results in telomere shortening, but a division of labor among the subunits emerges from a comparison of their impact on telomerase holoenzyme biogenesis. One Tetrahymena telomerase holoenzyme subunit, p65, is an RNP biogenesis factor required for assembly of TER and TERT. Two other subunits, p75 and p45, act to allow telomerase RNP function at telomeres.To understand how telomerase interacts with its telomere substrates, we have characterized substoichiometric interaction partners of Tetrahymena telomerase holoenzyme. New DNA binding proteins have been identified that are crucial for telomerase access to the telomere.
Investigative learning in exercise physiology research: a liberal arts model
Authors: Stavrianeas Stasinos 
Published: June 2021

The preparation of students to enter research, clinical, fitness, or management fields is a critical component of our efforts to promote a healthy lifestyle and curb the prevalence of obesity, diabetes, and cardiovascular disease. We report on the impact of investigative learning on exercise science education in a small, liberal arts college. An NSF award facilitated the acquisition of equipment for assessment of physical fitness and performance. Laboratories were redesigned with emphasis on student‐centered investigative activities. Impact was assessed via student surveys and the number and quality of independent research projects. Surveys revealed that 86% of the students found that the equipment improved their laboratory experience and 65% noted that the availability of equipment influenced their choice of research project; 92% indicated that the laboratories enhanced their understanding of the physiological processes during exercise. All students indicated that the experiences enhanced their confidence in designing and conducting experiments. During the last 2 years 8 student research projects were carried out. The laboratory has become a favorite among the 600 middle and high school students who have visited our facilities. Current science education strategies should be applied in Exercise Science education.Supported by a grant from the NSF‐DUE‐CCLI (0511219).
An Extended Analysis of the Histological Variants of Tau‐Negative FTLD
Authors: Josephs Keith Anthony , Stroh Alex , Amador‐Ortiz Catalina , Graff‐Radford Neill , Dickson Dennis W 
Published: June 2021

Objective: To determine if subcortical, brainstem and cerebellar lesion pattern characteristics of the different types of tau‐negative frontotemporal lobar degeneration (FTLD) would be similar to neocortical and hippocampal patterns [Type 1 has neuronal cytoplasmic inclusions (NCI) and dystrophic neurites (DN), type 2 mainly DN, and type 3 mainly NCI (Mackenzie et al., 2006)].Design/Methods: We analyzed 40 cases of tau‐negative FTLD from Mayo Clinic, Florida. For each case, 12 standardized sections covering 16 different brain regions or nuclei were sampled including neocortex, hippocampus, subcortical grey, brainstem and cerebellum. TDP‐43 immunohistochemistry was performed and abnormal immunoreactivity semiquantitated.Results: Thirty‐six cases were classified into one of the three types. For subcortical grey and brainstem regions, we did not see predominance of DN in type 2, and the density of NCI and DN were similar in type 3. Type 2 cases had significantly more NCI in basal ganglia compared to the other types (p<0.05). We found a trend that fine DN in hippocampal CA1 region was more frequent in type 1 compared to type 2 and 3 (p=0.07). A novel finding was that NCI were Pick body‐like in type 2 but granular‐like in type 3.Conclusion: This study extends the patterns of pathology previously described in the three variants of tau‐negative FTLD and shows how subcortical areas are affected by TDP‐43.
TDP‐43 Neuronal Cytoplasmic Inclusions in the Amygdala of Patients with Advanced Alzheimer Disease
Authors: Hu William T , Parisi Joseph E , Josephs Keith A , Dickson Dennis W 
Published: June 2021

TAR DNA binding protein‐43 (TDP‐43)‐immunoreactive neuronal cytoplasmic inclusions (NCIs), characteristically associated with frontotemporal lobar degenerations (FTLD‐U and FTLD‐MND), have been found in the hippocampal dentate granule cells of about 20% of cases with advanced Alzheimer disease (AD). The extent and distribution of TDP‐43 pathology in brain regions other than hippocampus in AD is not known, especially in AD cases without hippocampal NCIs.Sections of hippocampus, amygdala, neocortex, and medulla from patients with clinical dementia and pathologic features of AD were analyzed for the presence of TDP‐43‐immunoreactive NCIs.22 cases of advanced AD (Braak Stage V‐VI) without hippocampal NCIs and 23 cases of advanced AD with hippocampal NCIs were included. 6 hippocampal‐negative cases (27%) had TDP‐43 positive NCIs in the amygdala. All 23 cases of hippocampal‐positive cases had numerous TDP‐43 NCIs in the amygdala, with decreasing density of NCIs in the other brain regions.In summary, TDP‐43 immunoreactive NCIs are found predominantly in the medial temporal structures in advanced AD, and the amygdala appears to be the area most vulnerable.
Structural characterization of histone‐binding PHD fingers
Authors: Kutateladze Tatiana G , Champagne Karen , Pena Pedro , Hom Robert , Musselman Catherine , Hung Tiffany , Gozani Or 
Published: June 2021

Post‐translational histone modifications and protein modules that bind these epigenetic marks are essential components of the chromatin remodeling and gene expression machinery. The PHD (plant homeodomain) finger is found in many chromatin‐associated complexes and transcription factors, however the biological function of this domain remains unclear. Recently, it was found that a subset of PHD fingers recognizes histone H3 tri‐methylated at lysine 4 (H3K4me3). In this study we aimed to characterize the determinants of the PHD finger's binding specificity toward modified and unmodified histone tails using X‐ray crystallography, NMR and fluorescence spectroscopic approaches. Here we report the crystal structures of ING1, ING4 and ING5 in complex with histone peptides, and identify residues important for the specific histone interactions. The histone binding sites were also mapped by resonance perturbation analysis and mutagenesis, and binding affinities were measured using tryptophan fluorescence. Together our results provide novel insights into the molecular mechanisms underlying the activity of the histone‐binding PHD fingers, and impart a greater understanding on how the histone code is read.Supported by NIH (GM071424 and CA113472 to TGK).
The histone H3 variant CENP‐A localizes to sites of DNA repair induced by laser microirradiation of living cells
Authors: Zeitlin Sam G. , Baker Norman M , Wang Jean JY , Berns Michael W , Cleveland Don W 
Published: June 2021

The conserved centromere protein A (CENP‐A) is most similar to histone H3, with a unique N‐terminal tail. CENP‐A is known to be essential for recruitment of other kinetochore proteins to mediate attachment of mitotic spindle microtubules to chromosomes. Recently, we reported that DNA damaging mechanisms influence CENP‐A binding to DNA in vitro. We now report that CENP‐A localizes to sites of DNA damage induced by a laser in interphase nuclei of living cells, along with known DNA repair markers such as 53BP1, phosphorylated H2AX, Nbs1 and Chk2. CENP‐A tagged with GFP rapidly localizes to sites of damage, while other tagged histones such as H3 and H2B do not.These observations suggest that CENP‐A may function in DNA repair as part of a non‐nucleosomal complex, in addition to its known function in kinetochore formation.SGZ was supported by the California Institute of Regenerative Medicine
The deubiquitinating enzyme ataxin‐3 edits K63‐linkages in mixed linkage ubiquitin chains
Authors: Winborn Brett J , Travis Sue M , Todi Sokol V , Xu Ping , Peng Junmin , Cohen Robert E , Paulson Henry L 
Published: June 2021

The importance of differentially linked ubiquitin chains in physiological processes is emerging. The canonical lysine 48‐linked chain (K48‐Ub) primarily signals for proteasomal degradation while other chains, such as those linked at K63 (K63‐Ub), function in myriad pathways. This complexity is regulated by a diverse set of ubiquitin ligases and deubiquitinating enzymes (DUB). One such DUB is the neurodegenerative disease protein, ataxin‐3. Ataxin‐3 contains a N‐terminal catalytic Josephin domain and a C‐terminal ubiquitin binding region with 3 ubiquitin interacting motifs (UIMs) flanking a polyglutamine tract. The tract is expanded in persons with Spinocerebellar Ataxia Type 3.We report that ataxin‐3 has novel ubiquitin protease activity, editing K63‐linkages in topologically complex ubiquitin chains. Ataxin‐3 binds both K48‐ and K63‐Ub, yet preferentially cleaves K63‐linkages. Proteolysis of K63‐Ub is restricted to longer chains containing at least 5 ubiquitin moieties. Intriguingly, however, ataxin‐3 readily cleaves K63‐linkages in shorter chains containing a mixture of K48‐ and K63‐linkages. The UIMs appear to gate or orient specific linkages for cleavage by the Josephin domain, since UIM mutations eliminate ataxin‐3's K63‐linkage specificity. Our results establish ataxin‐3 as the first reported, mixed linkage ubiquitin‐editing enzyme.Funding: R01 NS038712 (HLP)
Interactions of cytosolic phospholipase A2 with pyrrophenone, ca2+ and phospholipids studied using deuterium exchange mass spectrometry
Authors: Burke John E , Hsu Howard , Deems Raymond , Woods Virgil , Dennis Edward A 
Published: June 2021

Phospholipase A2 (PLA2) catalyzes hydrolysis of the sn‐2 fatty acyl bond of phospholipids (PL), liberating free fatty acid and lysophospholipid. We are studying the)mechanism of activation, and membrane binding of the cytosolic GIVA PLA2. This enzyme liberates arachidonic acid from phospholipids, which is a precursor formany inflammatory mediators.We have used hydrogen‐deuterium exchange mass spectrometry (DXMS) to study this enzyme. The rate of exchange of each amide proton is directly proportional to the accessibility to bulk solvent. Measurements of exchange rates have been used to characterize changes in solvent accessibility that result from protein/lipid binding interactions, and conformational changes.Group IVA cPLA2's interactions with inhibitors and phospholipid were studied using DXMS. We used pyrrophenone, a potent inhibitor of GIVA PLA2, to probe the changes in conformation upon binding in the active site. Large amide exchange rate changes were seen upon inhibitor binding. We propose that these changes can be explained by the opening of the lid region with inhibitor bound. Large changes were also seen upon calcium‐mediated lipid binding, mainly in the C2 domain. We propose the protein inserting into the lipid membrane causes these changes. These studies show that DXMS is an excellent technique for probing enzyme interfacial activation. This work was supported by NIHGM20,501
Enhanced phosphorylation of FOXO and GSK‐3 by organo‐vanadium complexes: potential role in insulino‐mimesis
Authors: Vardatsikos George , Mehdi Mohamad Z , Srivastava Ashok K 
Published: June 2021

Several organo‐vanadium complexes (OVCs) have been shown to exert multiple insulino‐mimetic effects in rodent models of diabetes. We have shown that Bis(maltolato) OxoVanadium(IV) (BMOV) activates several components of the insulin signaling pathway such as phosphatidyl inositol‐3 kinase (PI3‐K) and protein kinase B (PKB). Forkhead Box Proteins (FOXO) and Glycogen Synthase Kinase‐3 (GSK‐3), downstream substrates of PKB, are thought to contribute to insulin‐induced gene expression of key gluconeogenic enzymes such as phosphoenolpyruvate carboxykinase (PEPCK) and glucose‐6‐phosphatase (G6Pase). OVCs are known to modulate the expression of PEPCK and G6Pase, hence in the present studies we investigated BMOV‐induced FOXO and GSK‐3 regulation. Treatment of Chinese hamster ovary cells overexpressing human insulin receptor (CHO‐HIR) enhanced FOXO and GSK‐3 phosphorylation. Wortmannin, a PI3‐K inhibitor, decreased FOXO and GSK‐3 phosphorylation induced by both insulin and OVCs, as did AG1024, an inhibitor of IR/IGF‐1R‐PTK activity. In summary, these data demonstrate that OVCs potently enhance the phosphorylation of FOXO and GSK‐3 via IGF‐1R‐PTK/PI3K‐dependent pathways, suggesting that OVCs may contribute towards the insulino‐mimetic effects of BMOV by transcription regulation of gluconeogenic enzymes.(Supported by grants from Canadian Institutes of Health Research).
Myc upregulates anti‐apoptotic protein, Survivin via a transcriptional activation
Authors: Li Hui , Wei Yun , Tan Yun , Wu Xinxing 
Published: June 2021

The Myc has been characterized to be a key regulator of cell growth, proliferation, differentiation, and apoptosis for years. Myc is essential for embryonic development and dysregulation of Myc is observed in most of human cancers. Survivin, a member of the IAP family, inhibits activation of downstream effectors of apoptosis, caspase‐3 and ‐7, in cells exposed to apoptotic stimuli. An elevated survivin is also observed in human cancers. In this study, we found that knockdown of Myc expression with siRNA duplexes dramatically decreased the level of survivin in HeLa (a cervical cancer cell line) and MCF‐7 (a breast cancer cell line). RT‐PCR analysis demonstrated that the decease was due to reduction of survivin transcription in siRNA treated cells. In the other hand, overexpression of Myc led an increase of both survivin mRNA and protein. Finally, Our luciferase reporter assays confirmed that Myc was able to induce the survivin promoter in both cancer and normal cells. Further mutagenesis data suggested that Myc upregulated survivin transcription through a non‐canonical E‐box site (CACGCG) and Sp1 sites at the promoter. Thus, survivin is a Myc target and may contribute some functions of Myc in cancer cells. They both are potential targets for cancer therapy.This work was supported by grants from the National Natural Science Foundation of China (No. 30500465) and China Hubei Natural Science Foundation.