bluuebunny/crossref_metadata_2025_split huggingface dataset:
MicroRNA expression profiles in a human induced pluripotent stem cell‐derived model of diabetic cardiomyopathy
Authors: Mishra Manoj K. , Horikoshi Yuichi , Pan Xiaoqing , Liu Pengyuan , Bai Xiaowen , Bosnjak Zeljko J. , Kriegel Alison J. , Liang Mingyu 
Published: June 2021

Diabetic cardiomyopathy (DCM) is a common and important health concern in the rapidly growing population of diabetic patients. At present, no specific drug treatment exists to prevent diabetes‐induced cardiac dysfunction, a complex multifactorial condition that is distinguished by a unique set of metabolic, structural, and molecular changes within the DCM. The advances in disease modeling using human induced pluripotent stem cells (iPSCs) have opened novel paths to study human physiology and disease at the cellular level. Here, we characterized an in vitro cell based model for DCM developed by exposing human induced pluripotent stem cell‐derived cardiomyocytes (iPSC‐CMs) to a diabetic‐like environment (10 mM glucose, 10 nM human‐endothelin‐1, and 1 mM cortisol). The treated cells exhibited metabolic shift (demonstrated by reduced glucose oxidation and increased fatty acid oxidation) and hypertrophy (demonstrated by hypertrophic morphology and increased expression of hypertrophic markers such as BNP, ANP, ACTA1 and MYH7. MicroRNAs (miRNAs) are key factors in controlling complex regulatory networks in cellular functions and disease processes. We performed a small RNA deep sequencing analysis to identify miRNAs associated with this in vitro DCM model. We identified 57 differentially regulated (p<0.05) miRNAs (26 up‐ and 31 down‐regulated) in diabetic CMs compared with control iPSC‐CMs (10 mM mannitol). The differential expression of several miRNAs was verified by real‐time PCR. These findings suggest miRNAs might be involved in this model of DCM. Further investigation will be required to examine functional roles for these miRNAs and identify the mechanisms by which these miRNAs might contribute to the development of DCM.Support or Funding InformationSupported by NIH Grant P01GM066730.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Angiopoietin‐1 Protects 3T3‐L1 Pre‐Adipocytes from Saturated Fatty Acid‐Induced Cell Death
Authors: Son Yura , Paton Chad Michael 
Published: June 2021

Crosstalk between endothelial cells and adipocytes is vital to adipocyte functions, but little is known about the mechanisms or factors controlling the process. Angiogenesis is a critical component linking the endothelium to healthy adipogenesis, yet it is not known if or how it is involved in adipocyte physiology. Therefore, the purpose of this study was to determine the effect of Angiopoietin‐1 (Ang‐1) and ‐2 (Ang‐2) as well as their receptor, Tie‐2, on adipocyte physiology. 3T3‐L1 pre‐ and mature adipocytes were found to express Ang‐1, Ang‐2, and Tie‐2 which decrease upon PUFA‐treatment. Furthermore, 3T3‐L1 cells treated with recombinant Ang‐1 or Ang‐2 increased expression of the anti‐apoptotic gene Bcl‐x and decreased expression of the pro‐apoptotic gene Casp‐8. Next, pre‐adipocytes were treated with saturated fatty acids (SFA) to induce cell stress. SFA‐mediated splicing of X‐box‐binding protein‐1 (Xbp‐1s) was reduced by co‐treatment with Ang‐1 and cell viability was improved in the presence of SFA + Ang‐1. Taken together, these results indicate that Ang‐1 may protect pre‐adipocytes from SFA‐induced apoptosis and ER stress.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Intestinal Axin1 Regulation of Epithelial Functions and Host‐Microbial Interactions in Health and Inflammation
Authors: Garrett Shari , Zhang Yong‐guo , Sun Jun 
Published: June 2021

BackgroundAxin1 is a scaffold protein in the β‐catenin destruction complex which if disrupted can lead to inflammatory bowel disease or colorectal cancer. Our previous study has demonstrated that Axin1 expression was reduced by pathogenic Salmonella colonization. The physical binding between beta‐catenin and Axin1 was also decreased during bacterial infection. However, the role of Axin1 in modulating intestinal tissue architecture and microbial homeostasis is unknown.MethodsTo explore the novel mechanism of Axin1 in regulating the functions of intestinal epithelia in health and inflammation, we generated a novel Axin1 conditional knockout model in the intestinal epithelial cells (Axin1ΔIEC).ResultsWe found that Axin1ΔIEC mice had less PCNA and β‐catenin compared to the control Axin1 loxp mice, suggesting the reduction of cell proliferation in intestinal epithelial cells without Axin1. Axin1ΔIEC mice exhibit altered goblet cell spatial distribution as well as disordered Paneth cells in the small intestine. Furthermore, in a Salmonella‐colitis model in vivo and cell cultures in vitro, we found bacterial protein AvrA expression modulates the β‐catenin/Axin1 interaction.ConclusionLacking intestinal Axin‐1 led to reduced proliferation and abnormal goblet cells and Paneth cells, suggesting that intestinal epithelial development and differentiation is regulated in an Axin1 dependent manner. Axin1 is involved in regulating the host‐microbial interactions in health and inflammation.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
CREB‐Regulated miR‐27b Is Linked to Hepatic Insulin Resistance by Targeting Insulin/Akt Signaling
Authors: Hsu Shu‐hao , Chen Yen‐Ju 
Published: June 2021

Insulin resistance (IR) is a predisposed condition of type 2 diabetes and commonly leads to fatty liver, in which hepatocytes exhibit excessive lipogenesis and gluconeogenesis. The role of microRNAs (miR) in liver‐associated IR remains largely unknown. Among microRNAs that participate in metabolic signaling, miR‐27b is a critical regulator of lipogenesis in both liver and adipose tissues; however, it is not clear if dysregulation of miR‐27b contributes to IR in liver. To address this question, we established several IR experimental models, including palmitate‐treated mouse AML12 hepatocytes, and dietary‐induced mouse fatty liver; Interestingly, miR‐27b was upregulated in all of these IR models. Furthermore, bioinformatic analysis predicted that miR‐27b targets several genes involved in Akt phosphorylation, including Pdpk1, Pik3ca (P110), Pik3r1 (P85), and Pik3cd. Based on these data, we hypothesize that miR‐27b over‐expression results in defective Akt signaling upon insulin stimulation. Indeed, over‐expression of miR‐27 in human HepaRG liver cells and mouse primary hepatocytes significantly suppressed Akt phosphorylation at both T308 and S473 residues and down‐regulated Pdpk1, Pik3r1 (P85), and Pik3ca (P110) at protein level upon insulin stimulation. Our luciferase reporter assay using 3T3 cells further demonstrated that miR‐27 directly targeted Pdpk1 and Pik3r1 3′UTR. Next, we investigated the mechanism by which miR‐27 is regulated in insulin signaling. Interestingly, we found that insulin significantly reduced miR‐27 expression below 50% of control in both HepaRG and AML12 cells. Further study on the detail mechanisms revealed that miR‐27b expression is positively regulated by cAMP response element‐binding protein (CREB), which is an IR promoter and regulated by insulin. Using HepaRG and AML12 cells, we demonstrated that miR‐27 is significantly down‐regulated by siRNA‐ or metformin‐mediated knockdown of CREB, but up‐regulated by forksolin‐induced activation of CREB. Also, miR‐27b is significantly increased when CREB is up‐regulated in mouse livers by either overnight fasting or high‐fat‐diet feeding, whereas decreased when CREB is down‐regulated in livers of mice treated with metformin. Taken together, our in vitro and in vivo data demonstrated that insulin may negatively regulate miR‐27 by repressing CREB transcriptional activity and the abnormal activation of hepatic CREB in IR animals may cause the aberrant elevation of miR‐27b to further decrease insulin sensitivity.Support or Funding InformationThis project is funded by Ministry of Science and Technology in Taiwan (Project#105‐2628‐B‐002 ‐017‐MY3)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Evaluation of lipoperoxidation processus of HIV‐infected patients
Authors: Rakhmanova Zebiniso P 
Published: June 2021

It is well known, that problem on the nature and direction of changes of activity of enzimes of antiraducal defence at patological occurence of immunoreactivity of organisems, especially at HIV infection, still remains very important at present time and not investigated completely yet.Development of “oxidazing stress” at HIV infections, occured by disfuntion of immune system, can be linked with unsufficient capacity of AOS of infected organisme.We have examened 21 HIV infected paticient from 17 to 43 years of age. HIV infectin was detected by solidfase immunoenzimes analysis in AMI‐HIV‐IFA‐UNIF tests. The intencity of PLO analysis of this group HIV paticients were analysed by methods developped L.I.Andreeva et al., (1988). Determination of SOD has been done on V.T. Mkhitaran, T.E. Badalan and catalase activity was determned on the methods described by M.A.Koroluk (1988)Obtained results showed that amount of MDA content of blood of HIV infected pacients was considerably higher as compared to non‐infected ones. The level of SOD of both infected and non‐infected paticient had no significant difference. Catalase activity was significant higher level in HIV‐infected pacients as compared to non‐infected ones.
The phosphatase laforin crosses evolutionary boundaries and links carbohydrate metabolism to neuronal disease
Authors: Gentry Matthew S. , Dowen Robert H. , Worby Carolyn A. , Mattoo Seema , Ecker Joseph R. , Dixon Jack E. 
Published: June 2021

A hallmark of Lafora disease (LD), a fatal neurodegenerative disease, is the accumulation of insoluble carbohydrates called Lafora bodies (LBs). LD is caused by mutations in the gene encoding the phosphatase laforin, which reportedly exists solely in vertebrates.We utilized a novel bioinformatics screen to identify laforin orthologs in five protists, Toxoplasma gondii, Eimeria tenella, Tetrahymena thermophila, Paramecium tetraurelia, and Cyanidioschyzon merolae. Strikingly, laforin is absent in all invertebrate organisms, and only exists in vertebrates and these five protists. These protists all evolved from a progenitor red‐alga and all synthesize an insoluble carbohydrate, whose composition closely resembles LBs. Furthermore, we show that Kingdom Plantae, which lacks laforin, possesses a protein with laforin‐like properties called SEX4. Mutations in the Arabidopsis SEX4 gene results in a starch excess phenotype. We demonstrate that human laforin fully complements the sex4 phenotype, and establish laforin and SEX4 as functional equivalents.Thus, despite the broad evolutionary diversity between vertebrates, plants and protists, laforin and SEX4 conduct a heretofore overlooked conserved function: they regulate the metabolism of “insoluble glycogen”, starch and floridean starch. Finally, we show that this family of phosphatases dephosphorylates insoluble carbohydrates, providing a molecular explanation for the etiology of LD.
“ROLE OF THE BETA‐ADRENERGIC RECEPTORS IN THE CARDIAC RESPONSE TO BETA‐BLOCKER THERAPY”
Authors: Anim Brandon N. , Mohapatra Bhagyalaxmi , Vatta Matteo , Murray Debra , Weinstock George , Gibbs Richard 
Published: June 2021

Arrhythmias are electrical abnormalities leading to irregular heart rhythms. The central nervous system releases endogenous catecholamines, which bind to adrenergic receptors on the heart and may increase the risk of arrhythmias.Patients with arrhythmias treated with â‐blocker therapy result in a significant reduction in the incidence of cardiac events, however, not all patients respond to â‐blocker therapy and the molecular basis is poorly understood in children. Previous studies in adults with heart failure identified S49G and G389R single nucleotide polymorphisms (SNPs) in â‐1ADR associated with the refractoriness using â‐blocker therapy.We sought to investigate whether these SNPs affect â‐blocker therapy in children with arrhythmias. We setup a pilot study to test non‐responsive subjects, responsive individuals, patients with heart diseases without arrhythmias and general control subjects. Polymerase chain reactions were followed by direct DNA sequencing covering the coding sequence of both ADRB1/2 genes. The preliminary screening process identified the S49G and G389R SNPs in the ADBR1, while a novel ADBR2 variant was also identified. We will need to expand the patient cohorts to reach statistical significance. Finding â‐1/2ADR variants in subjects with arrhythmias will greatly help understand the role these receptors play in unsuccessful responsiveness to â‐blocker therapy.
NMR structure and dynamics of the NADH nicotinamide ring bound to dihydrodipicolinate reductase
Authors: Ge Xia , Sem Daniel S. 
Published: June 2021

The current development of NMR methods facilitates the study of the mechanism by which enzymes catalyze reactions. The focus of this study is the dynamics and geometry of cofactor NAD(H) upon its binding to a dehydrogenase. To facilitate NMR analysis, the NAD(H) carboxamide was labeled with 15N (15N‐CA). CPMG relaxation dispersion measurements for free [15N‐CA]‐NAD+ showed millisecond timescale conformation exchange, consistent with previous report of exchange between open/closed conformations. Interestingly, in the complex of E. coli dihydrodipicolinate reductase (DHPR) and [15N‐CA]‐NADH, the relaxation dispersion curve also indicated conformational exchange; upon addition of the DHPR substrate analog pyridine 2,6‐dicarboxylate, the exchanged is no longer observed, indicating restricted motion induced by substrate binding.Survey of 288 X‐ray structures of bound NAD+ and we found that ∼10% of NAD+ carboxamide bonds are in a reversed orientation. We studied the carboxamide of NAD+ bound to DHPR with 15N filtered transferred NOEs and found that it bound with DHPR in the orientation with its C=O pointed in the direction of H− transfer, which is consistent with its X‐ray structure. This 15N‐carboxamide group of NAD(P)(H) permits determination of carboxamide geometry, as a complement to crystal structure analysis which often lacks resolution to determine this.
The polymerase activity of a mycobacterial galactofuranosyltransferase suggests a novel mechanism for template‐independent processive polymerization
Authors: May John F , Splain Rebecca A , Brotschi Christine , Kiessling Laura L 
Published: June 2021

Galactofuranose residues form the structurally crucial galactan polysaccharide in the cell‐wall core of Mycobacterium tuberculosis, the causative agent of tuberculosis. Elucidating galactan biogenesis will help efforts to fight drug‐resistant tuberculosis by providing new therapeutic targets. The mycobacterial galactofuranosyltransferase GlfT is thought to polymerize the galactan, but it is unknown whether GlfT has polymerase activity. Since galactan is built upon a lipid‐linked acceptor, we tested whether the lipid portion of the acceptor influences the activity of GlfT. We found that GlfT processively elongated synthetic acceptors that contained long lipids to produce polysaccharides as long as the naturally occurring galactan. We also found that the degree of polymerization by GlfT depended on acceptor substrate concentration. Our results suggest that GlfT, a template‐independent polymerase, uses a novel mechanism to attain processive polymerization and to control polymeric length.This research was supported by the National Institutes of Health (AI063596); JFM was supported by an National Science Foundation Graduate Research Fellowship.
Spatiotemporal patterning of T cell signaling as an important regulator of T cell activation at the systems level
Authors: Wuelfing Christoph , Singleton Kentner L. , Roybal Kole T. , Sun Yi 
Published: June 2021

Spatiotemporal patterning of various individual proteins in T cell activation, i.e. the formation of an immunological synapse, is well described. However, a comprehensive analysis of multiple proteins in the same system is still lacking, yet critical: Spatiotemporal patterning governs interaction probabilities. Two proteins enriched at the same time and location are more likely to interact than ones with distinct patterns. To thus understand how spatiotemporal patterning guides signaling interactions, we determined the patterning of 25 elements of T cell activation, mostly signaling intermediates, in the activation of the same primary T cells by professional APCs. Spatiotemporal pattering was highly diverse: No two elements of T cell activation showed the same patterns. This diversity is critical in allowing control of spatiotemporal patterning to be a powerful regulator of T cell signaling. We also determined the patterning of key receptors/signaling intermediates using T cells with different TCRs. Here, TCR patterning controlled patterning and efficiency of T cell signaling. Spatiotemporal pattering thus is an important regulator of T cell signaling at the systems level.Supported by the NIH.
Characterization of a novel basic‐rich signaling motif found in the CD3 ε subunit of the T cell receptor
Authors: DeFord‐Watts Laura M. , Albanesi Joseph P. , Murphy Tara , van Oers Nicolai S. C. 
Published: June 2021

The T cell receptor (TCR) complex consists of the ligand‐binding α/β heterodimer as well as four associated signaling chains (CD3 γ, δ, ε, and ζ). Each of the CD3 subunits contains one or more copies of a signaling motif termed an immunoreceptor tyrosine‐based activation motif (ITAM). Phosphorylation of tyrosine residues within the ITAMs is critical for TCR‐mediated signaling events. We recently identified an additional signaling motif in the cytoplasmic tail of CD3 ε that we termed the basic‐rich stretch (BRS). Biochemical studies revealed that the BRS could complex the serine/threonine kinase G protein‐coupled receptor kinase 2 (GRK2). Interactions between the BRS and GRK2 likely contribute to TCR cross‐talk with G protein‐coupled receptors, such as CXCR4. To address the role of the BRS in T cell functions, we generated several murine CD3 ε transgenic lines bearing distinct mutations in the BRS. Preliminary results indicate that select modifications of the BRS can dramatically attenuate T cell development and/or alter phosphoprotein induction. Our findings suggest that in addition to its ITAM, CD3 ε contains a second signaling motif (the BRS) that is critical for T cell functions.[Work was supported by grants from NIAID 5T32AI005284 and AI042953]
Dendritic cell subset‐specific expression of glucocorticoid receptor translational isoforms
Authors: Cao Yun , Lu Nick Z. 
Published: June 2021

Dendritic cells (DC) play important roles in both innate and adaptive immunity. Mature DC, but not immature DC, are killed by the potent anti‐inflammatory agents glucocorticoids, the mechanisms of which are unclear. We reported that GR translational isoforms mediate distinct glucocorticoid sensitivity in bone cells. Here we determined the role of these novel GR isoforms in glucocorticoid sensitivity in DC. Bone marrow derived immature DC are resistant to glucocorticoid killing while mature DC induced by lipopolysaccharide and other toll‐like receptor ligands are killed by glucocorticoids. Immature DC contain the GR‐D isoform, the same isoform that mediates glucocorticoid resistance in bone cells. In contrast, mature DC express the GR‐A, ‐B, and ‐C isoforms, enabling glucocorticoid killing. Selective GR translational isoforms also suppressed maturation stage‐specific DC functions, e.g., antigen uptake in immature DC and cytokine secretion in mature DC. The GR mRNA level is similar between immature and mature DC, indicating that translational mechanisms may be involved in the differential expression of GR isoforms in subsets of DC. These observations may provide a basis for designing GR isoform‐selective glucocorticoids with improved anti‐inflammatory efficacy and reduced side effects.Supported by divisional fund of Allergy‐Immunology, Northwestern University.
Designer glycopeptides for cytotoxic T cell‐based elimination of carcinomas
Authors: Franco Alessandra , Sidney John , Sette Alessandro , Maewal Ajesh 
Published: June 2021

Our laboratory has elucidated the immunochemical requirements for recognition of tumor associated carbohydrate antigens (TACA) by mouse and human CD8+ cytotoxic T cells. These results proved that TcRs accommodate small TACA as the Thomsen Freidenreich antigen (TF) and its monomer Tn, conventionally presented to T cells in the context of peptides linked to MHC molecules.TF‐ and Tn‐containing glycopeptides with high affinity for class I MHC molecules were capable of priming Th‐independent primary and memory TACA‐specific CTL responses in vivo in mice and normal human donors. These CTL could kill a variety of TACA‐expressing tumors in vitro.We are currently performing pre‐clinical studies with a variety of Tn‐containing glycopeptides derived from the MUC1 glycoprotein (MUC1 contains Tn and TF), aiming at the prevention/treatment of carcinomas. These glycopeptides contain the “PDTR” fragment of the variable number of tandem repeat (VNTR) domains of MUC1. “PDTR”‐containing glycopeptides bind with very high affinity A2 class I MHC molecules since have been designed to incorporate primary and secondary anchor residues for optimal binding.
Consumption of the slow digesting starch waxy maize leads to blunted and sustained carbohydrate utilization but does not influence energy expenditure or appetite
Authors: Sands Amanda L. , Leidy Heather J. , Hamaker Bruce R. , Maguire Paul , Campbell Wayne W. 
Published: June 2021

Background: The postprandial metabolic and appetitive responses of waxy maize, a slow‐digesting carbohydrate (CHO), are undocumented in humans and were examined in this study.Methods: 12 young, physically fit men and women (age: 23 ± 1 y; BMI: 22.2 ± 0.7 kg/m2; physical activity: 556 ± 120 min/wk) consumed, on separate testing days, 50 g of available CHO as either fast‐digesting maltodextrin (M) or waxy‐maize starch (WM). Plasma glucose and insulin concentrations, whole body energy expenditure and appetite (hunger, fullness, and desire to eat) were measured over 4 h.Results: Compared to M, WM led to lower postprandial glucose (1082 ± 151 vs. 2186 ± 262 mg/dL•240 min; p<0.001) and insulin (833 ±164 vs. 1628 ± 165 uU/mL•240 min; p<0.005) area under the curve during the 4 h period. These differences were driven by the blunted glucose response during the first hour (p<0.001) and the blunted insulin response during the first two hours (p<0.005) in WM. CHO utilization was lower after 1 h but higher after 4 h following WM vs. M. Composite CHO utilization over the entire 4 h period was not different between WM and M. No differences in energy expenditure or appetite were observed between WM vs. M.Conclusion: These results support that waxy maize provides sustained glucose availability in young, physically fit adults.Support: US Army, Natick Soldier RDECOM, Combat Feeding Directorate; Ingestive Behavior Res. Ctr., Purdue University