bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aging photoreceptors: light, stress and transcription
Authors: Weake Vikki M. 
Published: June 2021

Aging is associated with functional decline of neurons and increased incidence of both neurodegenerative and ocular disease. Photoreceptor neurons in Drosophila melanogaster provide a powerful model for studying the molecular changes involved in functional senescence of neurons since decreased visual behavior precedes retinal degeneration. Flies show decreased phototaxis by day 40 without any significant retinal degeneration. We have identified gene expression changes that correlate with this functional decline in visual behavior during aging. By profiling the nuclear transcriptome of genetically‐labeled photoreceptors over a 40 day time course, we identified increased expression of genes involved in stress and DNA damage response, and decreased expression of genes required for neuronal function. These age‐regulated genes share specific sequence motifs and genomic features suggesting that both transcription factors and epigenetic mechanisms contribute to these expression changes. In addition, we have identified age‐regulated splicing events in photoreceptors, and shown that these differentially spliced genes are enriched for visual function and phototransduction. Indeed, proper splicing is necessary for visual behavior in young flies because photoreceptor‐specific RNAi against multiple splicing factors reduces phototaxis. To identify the environmental factors that drive the age‐related changes in gene expression and splicing, we have developed a blue light stress model that induces oxidative stress and eventual retinal degeneration. Using this light stress model, we have shown that there is a strong correlation between the gene expression changes in photoreceptors that are induced by light and during aging. However, there are also some significant differences suggesting that there are other factors that are involved in the age‐related gene expression changes. Current research focuses on identifying the transcription factors and epigenetic regulators that contribute to age‐related changes in gene expression and visual behavior.Support or Funding InformationThe authors thank the Ralph W. and Grace M. Showalter Research Trust, National Institutes of Health R01EY024905 to VW, Purdue University Center for Cancer Research (American Cancer Society Institutional Research Grant, IRG #58‐006‐53; NIH P30 CA023168), and shared Instrumentation Grant, NCRR 1 S10 RR023734‐01A1 for funding to support this work.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Targeted Proteomics‐Driven Computational Modeling of Macrophage Microbial Sensing Pathways
Authors: Nita‐Lazar Aleksandra , Manes Nathan P. , Mann Jessica M. , Kaplan Pauline , Meier‐Schellersheim Martin , Fraser Iain D. C. , Germain Ronald N. 
Published: June 2021

Toll‐like receptor (TLR) signaling in macrophages is essential for generating effective innate immune responses. Quantitative differences dependent on the dose and timing of the stimulus critically affect cell function and involve proteins that are not components of widely shared transduction pathways. These features make mathematical modeling an important approach to a better understanding of how these signaling networks function in time and space.To model the TLR signaling networks, we are using selected reaction monitoring (SRM) to measure the absolute abundance of TLR pathway proteins, with the resulting values used as pathway model parameters. RNA‐seq was performed to identify expressed transcripts, and shotgun mass spectrometry was used to identify proteotypic peptides. SRM assays for the canonical TLR signaling pathway and related proteins and phosphoproteins have been successfully developed. SRM with heavy‐labeled internal peptide standards was used to quantify protein and phosphorylated protein molecule numbers per cell in both untreated and LPS‐stimulated macrophages. A preliminary model of the TLR pathway has been developed using Simmune and the resulting estimated protein abundance values.Support or Funding InformationThis research was supported by the Intramural Research Program of the National Institute of Allergy and Infectious Diseases, NIH.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Rad5 Prevents the Accumulation of ssDNA Gaps at Stressed DNA Replication Forks
Authors: Brown Grant W. , Gallo David W. , Kim Simon , Zhang Zhaolei , Branzei Dana 
Published: June 2021

In S. cerevisiae Rad5 is a component of the post‐replication repair pathway (PRR) and possesses both E3‐ubiquitin ligase and DNA helicase activity. We recently found that Rad5 forms sub‐nuclear foci after treatment with hydroxyurea (HU). Previous studies indicate that Rad5‐dependent poly‐ubiquitination of PCNA is required for error‐free bypass of MMS‐ or UV‐induced DNA lesions but there is little insight into the role of Rad5 in response to HU‐induced replication stress, where base lesions are likely absent. Here we define the function of Rad5 during HU‐induced replication stress. Rad5 foci form predominantly during S phase of the cell cycle and are induced by both chemical and genetic replication stress, suggesting that Rad5 foci correspond to Rad5 action at stressed DNA replication forks. Using chromatin immunoprecipitation followed by deep sequencing (ChIP‐seq) we show that Rad5 is recruited and retained at HU‐stressed forks, and that recruitment depends on mono‐ubiquitination of PCNA. To reveal the function of Rad5 at stressed‐forks we monitored cell cycle progression of WT and rad5 null cells recovering from HU‐induced replication stress. In this scenario rad5 null cells delay in G2/M with an activated DNA damage checkpoint, chromatin bridges, and increased RPA foci, indicating the presence of ssDNA. The ssDNA that accumulates in rad5Δ is not a product of incomplete replication at specific loci, and is not the result of abnormal recombination. In fact, deletion of the anti‐recombinase gene SRS2 rescues the accumulation of chromatin bridges in rad5Δ, suggesting that activating homologous recombination during S phase can compensate for rad5 deficiency during replication stress. We use a modified version of DNA combing to show the presence of ssDNA gaps directly, and to show that these accumulate in rad5Δ. Taken together, our results indicate that Rad5 prevents accumulation of ssDNA and allows for non‐recombinogenic recovery from replication stress.Support or Funding InformationFunded by the Canadian Cancer Society Research Institute and the Natural Sciences and Engineering Research Council of CanadaThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Myeloid‐specific Glut1 Ablation Attenuates Mammary Gland Inflammation and Claudin‐low Breast Cancer Progression
Authors: Fuller Ashley M. , Cozzo Alyssa J. , Freemerman Alex J. , Ezzell J. Ashley , Galanko Joseph A. , Troester Melissa A. , Hursting Stephen D. , Makowski Liza 
Published: June 2021

Obesity is a strong risk and progression factor for triple‐negative breast cancer (TNBC), a class of tumors comprised of the basal‐like and claudin‐low (CLBC) molecular subtypes. Macrophage infiltration and chronic inflammation are features of both obese adipose and TNBC microenvironments, and may thus underlie observed associations between obesity and TNBC. We have previously shown that the glucose transporter, GLUT1 (Slc2a1), is a critical mediator of macrophage glucose metabolism and associated pro‐inflammatory responsiveness. Thus, the goal of this study was to evaluate the effect of myeloid lineage Glut1 loss on mammary gland inflammation and obesity‐associated TNBC progression. Lean and obese myeloid‐specific Glut1 knockout mice were orthotopically injected with syngeneic M‐Wnt cells, a model of CLBC that recapitulates genomic and molecular features of human tumors. M‐Wnt tumor growth was impeded in lean Glut1M−/− compared to Glut1MFl/Fl mice; however, a similar protective effect of myeloid Glut1 loss was not observed in obese animals. Among lean mice, no significant genotype‐driven differences in markers of tumor proliferation, apoptosis, angiogenesis, or desmoplasia were observed. However, tumors from lean Glut1M−/− compared to lean Glut1MFl/Fl animals exhibited reduced concentrations of inflammatory mediators, including MCP‐1, TNFα, IL‐1β, and IL‐10, which paralleled in vitro findings in GLUT1‐deficient compared to control macrophages. No change in total myeloid cell or macrophage content was detected in the mammary gland microenvironment. However, mammary tissue macrophages (MTMs) of both lean and obese Glut1M−/−, but not Glut1MFl/Fl, mice were skewed toward an anti‐inflammatory phenotype with reduced iNOS (Nos2) expression, and were associated with reduced expression of pro‐inflammatory and growth‐supportive factors in the mammary gland. Taken together, these results indicate that myeloid Glut1 regulates inflammation and MTM immunophenotypes in both lean and obese models, but attenuates tumor progression only in the lean setting. Changes unique to lean Glut1M−/− tumors may be used to guide development of intervention and treatment strategies for obesity‐associated TNBCs.Support or Funding InformationThis work was supported by the National Cancer Institute (CA197627) and a UNC University Cancer Research Fund (UCRF)‐UNC LCCC Tier 2 Development Grant to LM and SDH. The UNC Nutrition Obesity Research Center (NORC) is funded by the National Institutes of Health (DK056350). AMF and AJC received support from the UNC Integrated Vascular Biology program (NHLBI HL069768) and the UNC Royster Society of Fellows during the course of this work. AMF was also supported by NCI CA179715 to MT.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Biotin deficiency induces Th1 and Th17 mediated inflammatory response in CD4+T lymphocytes via activation of mTOR signaling pathway
Authors: Elahi Asif , Sabui Subrata , Agrawal Anshu , Said Hamid M. 
Published: June 2021

Biotin (vitamin B7) is essential for normal human health due to its involvement, as a cofactor, in a variety of critical cellular metabolic reactions. Previous studies have shown that biotin deficiency enhances inflammation, and that certain chronic inflammatory diseases (like inflammatory bowel diseases) are associated with biotin deficiency. However, the mechanisms that mediate the association between biotin status and inflammation are not well understood. Here, we examined the effect of biotin deficiency on human CD4+ T cell responses to determine their role in biotin deficiency associated inflammation. Our investigations revealed that anti‐CD3/CD28 stimulated human CD4+ T cells cultured in biotin deficient media secreted significantly enhanced levels of pro‐inflammatory cytokines, IFN‐γ, TNF‐α, and IL‐17. Expression of the transcription factors, T‐bet and RORγt, was increased along with a decrease in Foxp3 expression in biotin deficient CD4+ T cells. The percentage of T regulatory cells was also decreased under biotin deficient condition. Further investigations indicated that the enhanced inflammatory response was not a consequence of increased T‐cell differentiation towards Th1 and Th17 or increased proliferation. Instead deficiency of biotin enhanced the production of IFN‐γ from already differentiated cells. Moreover, the results indicated that the increased inflammatory response was due to enhanced activation of the mTOR signaling pathway in biotin deficient CD4+ T cells. Similar increase in T‐bet, RORγt and decrease in Foxp3 transcription factors was also observed in inguinal lymph nodes of mice fed with biotin deficient diet relative to pair‐fed controls. Further, the level of IFN‐γ, IL‐17 cytokines and the expression of mTOR were found to be increased significantly in CD4+T cells isolated from inguinal lymph node of diet induced biotin deficient mice. These findings revealed that biotin deficiency leads to the upregulation of IFN‐γ secreting Th1 and IL‐17 secreting Th‐17 cells via activation of mTOR signaling pathway which may contribute to inflammation associated with biotin deficiencySupport or Funding InformationThis study supported by grants from the DVA and the NIH (DK58057, DK56061 and AA 018071)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Role of the Creatine Kinase Energy System in Intestinal Inflammation
Authors: Lanis Jordi M. , Colgan Sean P. 
Published: June 2021

Inflammatory bowel disease (IBD) is a chronic inflammation of the intestine affecting more than 1 million people in the United States. Intestinal epithelia facilitate nutrient transport as well as protect against luminal bacteria and disruption of the intestinal epithelial barrier is a hallmark of IBD. The regulation of intestinal epithelial barrier is made possible by junctional complexes including tight junctions and adherens junctions that are supported by the actin cytoskeleton. Maintenance of the actin cytoskeleton is an energy demanding process and intestinal epithelial cells shuttle energy to the locations of the cellular junctions through the creatine energy circuit. Within the cell, creatine and its associated enzyme creatine kinase (CK) facilitate the shuttling of high energy phosphates in the form of phosphocreatine between sites of ATP generation. Previous work in our lab has shown that CK contributes to apical junction assembly in vitro and that supplementation of creatine in murine colitis models has a protective effect. Further studies have shown that mice lacking the brain and mitochondrial isoforms of CK have worse outcomes in a DSS model of colitis. In addition to impaired barrier function, this may be due in part to exacerbated intestinal bleeding observed in these mice. To that end, we measured platelet counts and aggregation and found that platelet counts are lower in CK double knockout mice compared to wild‐type mice. The platelets from the knockout mice also showed a hyporesponsive phenotype in a collagen adhesion assay. Together, these results provide evidence that the CK energy circuit is essential in maintaining intestinal epithelial barrier function as well as supporting proper platelet function.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Inhibition of FPR2 Impaired Leukocyte Get‐in Signal and Triggers Non‐Resolving Inflammation in Heart Failure
Authors: Kain Vasundhara , Wright Griffin M. , Halade Ganesh V. 
Published: June 2021

Non‐resolving inflammation is a prominent trigger for heart failure (HF)‐related morbidity and mortality following myocardial infarction (MI). Post‐MI activated leukocyte expressed formyl peptide receptor 2 (FPR2) belongs to the essential for inflammation‐resolution mechanisms. However, the role of FPR2 in leukocyte kinetics in acute HF is incompletely understood. Here, we aimed to determine whether pharmacological inhibition of FPR2 would impair leukocyte trafficking to the site of cardiac injury using WRW4 (FPR2 antagonist). For this, male C57BL/6 (8 to 12 week) mice were subjected to acute HF using permanent coronary artery ligation. FPR2 inhibitor WRW4 (1μg/kg/day; subcutaneous) was injected 3 hours post‐MI and saline‐injected‐mice served as MI‐control. Inhibition of FPR2 impaired leukocyte trafficking (“get‐in” signal) that altered post‐MI immune responsive clearance in the infarcted LV and spleen. Leukocyte kinetics, measured using flow cytometry, showed there was an overall decrease in CD45+/CD11b+; 23.3±2% in WRW4‐injected mice when compared with MI‐control (49.1±2%) in the LV. FPR2 inhibitor, WRW4, decreased FPR2 in the LV and spleen tissue, and mice displayed increase F4/80+/Ly6Chi macrophages (14.8±2%) compared to the MI‐control group (10±1%) in LV, this is indicative of amplified proinflammatory profile. Inhibition of WRW4 primes immature neutrophil infiltration Ly6Gint and intensifies the Ccl2 (all p<0.05) expression compared to MI‐control in the infarcted LV post‐MI. WRW4 increased transcripts of pro‐inflammatory markers TNF‐α and IL‐1β, with a decrease in expression of Arg‐1 (p<0.05) in the infarcted LV compared to MI‐controls is suggestive of non‐resolving or immune suppressive inflammation. In summary, FPR2 inhibition using WRW4 altered leukocyte get‐in signal leading to the onset of frustrated resolution signaling in acute HF post‐MI.Support or Funding InformationHL132989 to GVH and 16POST31000008 to VKThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Regulation of Cardiomyocyte Cohesion and Gap Junctions via Desmosomal Adhesion
Authors: Schinner Camilla , Erber Bernd M. , Waschke Jens 
Published: June 2021

Mutations in desmosomal proteins such as desmoglein‐2, desmoplakin or plakoglobin can induce arrhythmogenic cardiomyopathy, a disease leading to arrhythmia and sudden cardiac death. Previous data demonstrated adrenergic signaling to be important to regulate desmosomal cohesion in cardiomyocytes. Here, we investigated how signaling pathways including adrenergic signaling, PKC and SERCA regulate desmosomal adhesion and how desmosomal adhesion controls gap junctions in cardiomyocytes. As revealed by dissociation and immunostaining experiments in cardiomyocytes, activation of PKC by PMA or adrenergic signaling increased cell cohesion and desmoglein‐2 and desmoplakin localization at cell junctions whereas Trp‐treatment to inhibit cadherin binding or inhibition of SERCA pump by thapsigargin reduced cardiomyocyte cohesion. Cohesion was rescued by both cAMP elevation or PMA. In parallel to increased cohesion elevated phosphorylation of the gap junctions component connexin‐43 was revealed by Western blotting and immunostaining. Using a multi‐electrode array, disruption of cell cohesion by Trp impaired conduction of excitation comparable to the connexin inhibitor carbenoxolone. Elevation of cAMP levels was effective to increase conduction velocity and to improve arrhythmia under baseline conditions as well as after Trp treatment. Immunoprecipitation revealed connexin‐43 to interact with desmoglein‐2 and β1‐adrenergic receptor. Weakened cell cohesion by Trp or siRNA‐mediated depletion of desmoglein‐2 or plakoglobin were sufficient to block signaling via the β1‐adrenergic receptor. Moreover, depletion of desmosomal proteins increased arrhythmia and reduced conduction velocity, both of which was rescued by cAMP elevation. These data demonstrate gap junction and desmosomal proteins to form a complex with the β1‐adrenergic receptor. The function of this complex was regulated by cell cohesion, adrenergic and PKC signaling or inhibition of SERCA. These results support the identification of new targets to treat arrhythmogenic cardiomyopathy.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Uremic toxins are conditional danger‐ or homeostasis‐ associated molecular patterns, which are highly selective increase rather than purely passive accumulation, in chronic kidney disease and coronary arteria disease
Authors: Sun Yu , Lu Yifan , Nanayakkara Gayani , Li Yafeng , Fu Hangfei , Johnson Candice , Shao Ying , Yang William Y. , Wang Hong , Li Rongshan , Yang Xiaofeng 
Published: June 2021

Cardiovascular morbidity and mortality in patients with advanced CKD are 10‐ to 30‐ folds greater than that in the general population. In the U.S. and worldwide, the incidence of CKD is increasing, and atherosclerosis‐ related CVD is a major cause of mortality in these patients. We performed novel metabolomics/gene database mining, where we identified protein‐bound uremic toxin (UT) receptors as well as the enzymes for UT generation, and analyzed their gene expression changes in chronic kidney disease (CKD), vascular and metabolic diseases. We made the following findings: 1) In CKD, UTs represent a very small fraction of the total human serum small‐molecule metabolome, roughly 1/80th; 2) The serum concentrations of some UTs are increased not only in CKD but in other diseases; 3) Protein‐bound UTs either induce or suppress the expression of pro‐inflammatory molecules; 4) The expression of UT genes is significantly modulated in the tubules of CKD patients, and adipose tissue of coronary artery disease (CAD) patients, compared with those of metabolic syndrome and type 2 diabetes patients; 5) The expression of UT genes is upregulated by caspase‐1 and TNF‐α pathways, more than toll‐like receptors (TLRs), IL‐1β and IFN‐g pathways; and 6) The expression of UT genes is inhibited by regulatory T cells. Our results have demonstrated that UTs are highly selectively accumulated, and serve as danger signal‐associated molecular patterns (DAMPs) and homeostasis‐associated molecular patterns (HAMPs) that modulate inflammation. In addition, our results show that some UT genes are upregulated in CKD and CAD, presumably via caspase‐1/inflammatory cytokine pathways, rather than by purely passive accumulation.Support or Funding InformationThis work is partially supported by NIH grants to Drs. XF. Yang, H. Wang.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.