bluuebunny/crossref_metadata_2025_split huggingface dataset:
Discovery of a lipid deacetylase (AADACL1) as a novel regulator of platelet activation (999.4)
Authors: Holly Stephen , Chang Jae , Li Weiwei , Niessen Sherry , Phillips Ryan , Piatt Raymond , Black Justin , Smith Matthew , Boulaftali Yacine , Weyrich Andrew , Bergmeier Wolfgang , Cravatt Benjamin , Parise Leslie 
Published: June 2021

Hyperactive platelets can trigger thrombotic episodes including myocardial and cerebral infarction, whereas insufficient platelet reactivity can lead to spontaneous bleeding. To better understand these essential vascular processes, we screened human platelets with a carbamate library designed to interrogate the serine hydrolase proteome coupled with competitive activity‐based protein profiling (ABPP) to map the targets of active carbamates. Using this strategy, we identified a novel lipid hydrolase in human platelets named arylacetamide deacetylase‐like 1 (AADACL1) and delineated a critical role for this enzyme in response to multiple agonists, especially collagen. We showed that AADACL1 regulates lipid metabolism, RAP1 and PKC activation, fibrinogen binding, platelet aggregation and thrombus formation in an ex vivo model of collagen‐dependent thrombosis. Preliminary data also suggest that AADACL1 contributes to platelet activation in vivo, since rats injected with a selective AADACL1 inhibitor show reduced platelet aggregation in whole blood. While these data clearly implicate AADACL1 in platelet biology, the physiological role of AADACL1 is currently unknown, so future studies are needed to evaluate the scope of AADACL1 action in the vasculature and determine its value as a potential anti‐thrombotic target.Grant Funding Source: AHA and the NIHLBI
P‐glycoprotein ‐ an ABC Transporter: Toxin Removal to Chemotherapy Interference (LB109)
Authors: Adamson Bennett , Pham Tiffany , Kronenfeld Jason , Reilly Bianca , Crowther Meghan , Fraijo Savanah , Cherrington Emily , Futch Liane , Cherrington Nathan 
Published: June 2021

Cancer claimed 7.6 million lives worldwide in 2013. Despite improvements in chemotherapy, most relapsed cancers become drug resistant due to an ATP‐binding cassette transporter, P‐glycoprotein (P‐gp). P‐gp is a gatekeeper in multiple tissues, controlling exposure to drugs and toxins by pumping them out of the cell. This homodimeric protein of 1,280 amino acids is located on the apical surface and extrudes lipid soluble molecules. Pharmaceutical companies must determine if their drugs are P‐gp substrates before proceeding to clinical trials, as the amount of drug entering the body may vary widely due to P‐gp function. P‐gp may reduce the amount of drugs reaching circulation by transporting drugs back into the digestive tract lumen. Many chemicals act as modulators of P‐gp’s function; for example, the flavonoid naringin in grapefruit juice interacts with P‐gp and may significantly increase the uptake of some statin drugs. The active sites and conformational changes of P‐gp have not been elucidated, as it has been difficult to crystallize P‐gp with its substrates. P‐gp’s complex structure and multiple binding sites allow for interaction with many drug molecules, which enter P‐gp’s binding pocket via pairs of alpha‐helices on opposite sides of P‐gp. The Ironwood Ridge High School SMART team (Students Modeling A Research Topic) modeled P‐gp using 3D printing technology.Grant Funding Source: Supported by a grant from NIH‐SEPA and NIH‐CTSA.
The discovery of a lactone isomerase involved in pectin degradation (LB137)
Authors: Bouvier Jason , Groninger‐Poe Fiona , Vetting Matthew , Almo Steven , Gerlt John 
Published: June 2021

Pectin, an abundant plant cell wall polymer, is being investigated as a possible raw material for the production of fuel and chemical products. To this end, an understanding of the steps to degrade pectin is useful. Agrobacterium tumefaciens strain C58 can use the primary constituent monomer of pectin, D‐galacturonate, as a sole carbon source and converts it to α‐ketoglutarate through a five step pathway in which the first step is oxidation of D‐galacturonate to D‐galactaro‐1,5‐lactone. We became interested in this pathway because a member of the functionally diverse enolase superfamily, designated Gci, catalyzes the third step in the pathway, and our lab has studied the enolase superfamily for over 20 years. We have identified an enzyme, D‐galactarolactone isomerase (GLI), adjacent to Gci in Agrobacterium’s genome, that catalyzes the second step in the pathway: the isomerization of D‐galactaro‐1,5‐lactone to D‐galactaro‐1,4‐lactone. The uncatalyzed isomerization reaction is “fast” and had been presumed to occur without the need of a catalyst. To characterize the enzyme‐catalyzed isomerization, we used 1H NMR to identify the activity, polarimetry to determine the kinetic constants (kcat = 440 s‐1, kcat/Km = 8.3 x 104 M‐1 s‐1, rate enhancement = 6.8 x 105), x‐ray crystallography to determine its structure, and gene expression analysis to connect the in vitro activity of the enzyme to an in vivo function. GLI is a member of the functionally diverse amidohydrolase superfamily and a homologue of LigI that catalyzes the hydrolysis of 2‐pyrone‐4,6‐dicarboxylate in lignin degradation. GLI’s ability to catalyze lactone isomerization instead of hydrolysis can be explained by the absence of the general basic catalysis used by LigI. This work identified the first example of lactone isomerization in the amidohydrolase superfamily and a missing enzyme in Agrobacterium’s pathway to catabolize pectin.Grant Funding Source: Supported by National Institutes of Health Grants P01GM071790 and U54GM093342 to J.A.G.
Structure‐function analysis of the exoribonuclease domain of arenaviral nucleoproteins in mediating host immune evasion (LB138)
Authors: Ly Hinh , Liang Yuying 
Published: June 2021

Several pathogenic arenaviruses, including Lassa virus, cause hemorrhagic fever (HF) infections that can result in significant morbidity and mortality in humans. A hallmark of severe HF is the high levels of viremia coupled with generalized immune suppression of the hosts, the mechanisms for which are unknown. Recent studies in our laboratory have revealed several potential mechanisms that arenaviruses use to cause virulent infection [McLay, et al., JVI 2013, Jiang, et al., JBC 2013; Kumar, et al., Virol 2012; Wang, et al., JVI 2012; Qi, et al., Nature 2010; Lan, et al., JVI 2009, Arch Virol 2008). A unique feature of lethal Lassa (LASV) arenaviral infection is that it is often associated with a generalized immune suppression of the infected hosts, the exact mechanism of which is unclear but is thought to involve the ability of the viral nucleoprotein (NP) to suppress the induction of type I interferons (IFN). We have recently determined the first crystal structure for LASV NP at 1.80 Angstrom resolution (Qi, et al., Nature 2010), which has unexpectedly revealed its unique mechanisms to suppress interferon‐beta production. Our structurally directed functional assays (using both biochemical and cell‐ and virus‐based assays) have demonstrated that the C‐terminal domain of LASV NP contains exoribonuclease enzymatic activity that is required for suppressing IFN‐beta induction by degrading immune stimulatory RNAs. We have also recently produced evidence to suggest that this is a common mechanism used by all known arenaviruses (Jiang, et al., JBC 2013). Novel insights learned from these studies can be exploited for the development of novel therapeutics and vaccines against deadly HF infections as recently reviewed by us (McLay, et al., Antiviral Research 2012, J Gen Virol 2014).Grant Funding Source: NIH R01 grants AI083409 to Y.L. and AI093580 to H.L.
Acute impairment of early T cell activation following impediment of mitochondrial electron transport (LB166)
Authors: Hwang Inkyu 
Published: June 2021

T cells absorb nanometric membrane vesicles, derived from antigen presenting cells, via dual receptor/ligand interactions of T cell receptor (TCR) with cognate peptide/major histocompatibility complex (MHC) complex plus lymphocyte function‐associated antigen 1 (LFA‐1) with intercellular adhesion molecule 1. Our studies have shown that TCR‐mediated signaling is also critically involved in the vesicle absorption, which is likely for the activation of LFA‐1. In an effort to systematically investigate the signaling process involved in the vesicle absorption process, we exploited chemical biology tools and screened chemical libraries to identify small molecules to interfere with the absorption process. Interestingly, it was found in the course of the study that brief treatments (1 hour) with various mitochondrial antagonists, including complex I, II, III, IV and V inhibitors,, resulted in ubiquitous inhibition of the vesicle absorption at concentrations not compromising viability of T cells. Further studies revealed that the mitochondrial drug treatments caused impairment of specific membrane‐proximal TCR signaling event(s). Thus, the activation of Akt and PLC‐γ1 and entry of extracellular Ca2+ following TCR triggering were severely compromised, while polymerization of monomeric actins immediately monitored upon triggering of TCRs appeared to progress normally even after the treatments. Dynamic F‐actin rearrangement concurring with the vesicle absorption was, however, also found to be impeded by the drug treatments, implying that the inhibition by the drug treatments of downstream signaling events at least in part resulted from the impairment of directional relocation of signaling and cell surface molecules accompanying with actin rearrangement.Grant Funding Source: Supported by Chungnam National University Grant (2013‐1892)
Regulation of mitochondrial functions by SIRT5 and non‐canonical post‐translational modifications (LB172)
Authors: Lombard David , Park Jeongsoon 
Published: June 2021

Protein function is regulated by diverse post‐translational modifications. The mitochondrial sirtuin SIRT5 removes malonyl and succinyl moieties from target lysines. The spectrum of protein substrates subject to these modifications is unknown. We recently reported the first systematic profiling of the mammalian succinylome, identifying 2565 succinylation sites on 779 proteins. Our analysis revealed potential impacts of lysine succinylation on amino acid degradation, the TCA cycle, and fatty acid metabolism. Lysine succinylation was also present on cytosolic and nuclear proteins; indeed, we found that a substantial fraction of SIRT5 was extra‐mitochondrial. SIRT5 repressed biochemical activity of, and cellular respiration through, two protein complexes identified in our analysis, Pyruvate Dehydrogenase Complex (PDC) and Succinate Dehydrogenase (SDH). We will discuss our recent progress on elucidating further the biology of SIRT5 using enzymatic, respiration, and metabolomic flux assays.Grant Funding Source: Supported by NIH awards R01GM101171 and R21CA177925 (D.L.).
Proteomic analysis of hyaluronate‐regulated proteins involved in chondroprotective effect under oxidative stress (LB177)
Authors: Yu Chia‐Jung , Ko Chun‐Jung , Hsieh Chang‐Hsun , Chien Chiang‐Ting , Huang Lien‐Hung , Lee Chien‐Wei , Jiang Ching‐Chuan 
Published: June 2021

Osteoarthritis (OA), the most common type of arthritis, is a degenerative joint disease. Oxidative stress is well known to play important roles in cartilage degradation and pathogenesis of OA. The intra‐articular injection of hyaluronic acid (IAHA) is accepted as an effective clinical therapy for OA, but we do not yet fully understand the mechanisms underlying the effects of HA on OA chondrocytes under oxidative stress. Here, we show for the first time that IAHA significantly reduces the synovial fluid levels of hydrogen peroxide (H2O2) and superoxide (O2−) in patients with knee OA. We also demonstrate that HA suppresses H2O2‐induced cell death in human OA chondrocytes. Proteomic approaches (2‐DE combined with mass spectrometry) allowed us to identify 13 protein spots corresponding to 12 non‐redundant proteins as HA‐regulated proteins in OA chondrocytes under oxidative stress. The expression levels of three putative HA‐regulated proteins (TALDO, ANXA1 and EF2) in control, H2O2‐, HA‐ and HA/H2O2‐treated OA chondrocytes were verified by Western blotting and the results indeed support the notion that HA acts in anti‐oxidation, anti‐apoptosis, and the promotion of cell survival. Our results collectively demonstrate the utility of proteomic approaches and provide new insights into the chondroprotective effects of HA on OA.Grant Funding Source: Supported by National Science Council, R.O.C.
A dietary polyactylene, Gymnasterkoreayne B, induces both intrinsic and extrinsic pathway of apoptosis through the signaling molecules revealed by secretome profiling (LB183)
Authors: Song Dae‐Geun , Kang Kyungsu , Lee Eun Ha , Jung Sang Hoon , Pan Cheol‐Ho , Nho Chu Won 
Published: June 2021

Gymnasterkoreayne B (GKB) is a natural polyacetylene isolated from Gymnaster koraiensis. The antiproliferative activity of GKB has been reported in various human cancer cells but its mechanism is still unknown. Our objectivity of the study was to investigate the mechanism of the antiproliferative activity of GKB in HCT116 cancer cell and to search any possible candidates that may involve in the cell death signaling. In this study, we confirmed that GKB has induced apoptosis in HCT116 cells, inferentially from the increment of the sub G0/G1 content (%) and the externalization of phosphatidylserine, and the apoptotic morphological changes. We also verified that the antiproliferative activity of GKB was not necroptosis, by the cell death inhibitor assay using z‐VAD‐fmk and necrostatin. In addition, by the mitochondrial membrane potential assay and flow‐cytometric analysis, we elucidated that GKB treatment resulted in ROS accumulation, leading to the activation of both intrinsic and extrinsic apoptotic pathway. To investigate the effect of GKB on the secretome profile, we compared protein levels in the media of GKB‐ or vehicle‐treated HCT116 cells using 1D‐SDS‐PAGE and LC‐MS/MS analysis. Total of 1804 proteins were identified and their expression levels were determined by using spectral counting method. As a result, 70 proteins were down regulated (< 0.5 fold) and 56 proteins were up regulated (> 2.0 fold). Among these, the expression levels of apoptosis‐related proteins, ADAM9, interleukin 18, and serpin B5 were validated by ELISA. In depth analysis regarding the gene ontology of the identified protein suggested that FN1, TGFB1, APP, SERPINE1, HSPD1, SOD1, TXN, and ACTN4 may also act as secretory signaling molecules that trigger GKB‐induced apoptosis. In summary, we have found the mechanism of GKB‐induced apoptosis of HCT116 and we have suggested novel proteins which might be involved in the apoptotic signaling.Grant Funding Source: Supported by Korea Institute of Science and Technology Gangneung Institute intramural research grant (2Z04220)
Differential roles of Sirt1 in HIF‐1a and HIF‐2a mediated hypoxic responses (LB269)
Authors: Yoon Haejin 
Published: June 2021

Hypoxia‐inducible factors 1α and 2α (HIF‐1α and HIF‐2α) determine cancer cell fate under hypoxia. Despite the similarities of their structures, HIF‐1α and HIF‐2α have distinct roles in cancer growth under hypoxia, that is, HIF‐1α induces growth arrest whereas HIF‐2α promotes cell growth. Recently, sirtuin 1 (SIRT1) was reported to fine‐tune cellular responses to hypoxia by deacetylating HIF‐1α and HIF‐2α. Yet, the roles of SIRT1 in HIF‐1α and HIF‐2α functions have been controversial. We here investigated the precise roles of SIRT1 in HIF‐1α and HIF‐2α regulations. Immunological analyses revealed that HIF‐1α K674 and HIF‐2α K741 are acetylated by PCAF and CBP, respectively, but are deacetylated commonly by SIRT1. In the Gal4 reporter systems, SIRT1 was found to repress HIF‐1α activity constantly in ten cancer cell‐lines but to regulate HIF‐2α activity cell type‐dependently. Moreover, SIRT1 determined cell growth under hypoxia depending on HIF‐1α and HIF‐2α. Under hypoxia, SIRT1 promoted proliferation of HepG2 cells, in which SIRT1 differentially regulates HIF‐1α and HIF‐2α. In contrast, such an effect of SIRT1 was not shown in HCT116 cells, in which SIRT1 inactivates both HIF‐1α and HIF‐2α, because conflicting actions of HIF‐1α and HIF‐2α on cell growth may be offset. Our results provide a better understanding of the roles of SIRT1 in HIF‐mediated hypoxic responses and also a basic concept for anticancer strategy targeting SIRT1.Key words: Sirtuin 1; lysine acetylation, hypoxia; hypoxia‐inducible factors; transcriptional activity
Lipoperoxidation in meats cooked in conventional and combined ovens (LB381)
Authors: Chaud Daniela , Razera Érika , Machado Alisson , Abreu Edeli 
Published: June 2021

Introduction: The foods of animal origin have variable amounts of cholesterol in their composition. During thermal processing of these foods a fraction of cholesterol can be oxidized by heat and oxygen, producing cholesterol oxides that are byproducts that are harmful to human health and can express cytotoxic, atherogenic, mutagenic and carcinogenic effects.Objective: To evaluate the formation of cholesterol oxides in meat cooked in conventional and combined ovens.Methods: This cross‐sectional study evaluated the Lipoperoxidation in four types of meat (beef, poultry, fish and pork), which were cooked in conventional and combined ovens, performed in duplicate. The procedures for extraction and analysis followed the TBAR method.Results: The product with higher Lipoperoxidation was the poultry, followed by fish, beef and pork, in both cooking procedures. In all preparations which used the combined oven the formation of cholesterol oxides was higher.Conclusion: The cooking in the combined oven was thermal processing that generated higher Lipoperoxidation in the products analyzed.
Study on the antioxidant effect of Siraegi and Gondeure extracts by in vitro assay system (LB390)
Authors: Kang Myunghwa , Shin Kikyung , Kim Myojung , Song Hyeonhae 
Published: June 2021

To elucidate the functionality of Siraegi and Gondeure, their were extracted by solvent and their were investigated in in vitro system for antioxidant effect. Gondeure were boiling for two hours. Half of their were freezed and half of their were dried under 50 ℃. 3 g of each sample was added to 80% ethanol 60 mL and extracted by sonification during 4hour at 40 ℃.The extracts were diluted to a concentration 2000 ppm, 1000 ppm, 500 ppm, 250 ppm, 100 ppm with 80% ethanol . Hydrogen radical scavenging activity of Siraegi extracts were 52.19 ± 0.2253mg/ml in freezed Siraegi, and 30.29 ± 0.1860mg/ml in Gondeur. Phenolic acid compounds were 1.52 ± 0.0013mg/ml in freezed Siraegi, and 1.28 ± 0.0092mg/ml in hot air dried Siraegi. The reducing power was 2.12 ± 0.0148mg/ml in hot air dried Gondeure, the lowest in freezed Siraegi. Antioxidant capacity of Gondeure than the siraegi was good. Pre‐processing the activity of freeze‐dried samples than samples dried at 50 ℃ showed good activity.Grant Funding Source: No
Evaluation of the anticancer activity of methionine methylsulfonium chloride: the involvement of SAPK/JNK activation (LB393)
Authors: Kim Gun‐Hee 
Published: June 2021

The aim of the present study was to investigate the anticancer activity and mechanism of action of methanol extract from Artemisia princeps var. orientalis (APME). First, the antiproliferative activity of APME against T47D cells was at various concentrations (5‐200 μg/mL) and treatment times (24‐72 h) determined by MTT assay. APME significantly inhibited cell proliferation in a dose‐dependent manner, regardless of treatment times. Under the same condition, cytotoxicity (LDH release) of APME was only appeared at 72 h. In addition, treatment with the IC50 concentration of APME for 24 h caused cell cycle arrest and apoptosis. APME arrested cells in both G1 and G2/M phases of the cell cycle, a response that was related to the induction of CDK1, cyclin B, p21Cip1 expression, and repression of CDK2 and cyclin A. The induction of p21Cip1 by APME caused activation of p53 and modulation of its downstream targets Bcl‐2 and Bax. Subsequently, caspase‐8 and ‐9 were cleaved in cells treated with APME. Activation of these caspases in turn led to increased activation of caspase‐3. The results of this study suggest that APME produce anticancer effects in T47D cells through cell cycle arrest associated with the induction of p21Cip1 and apoptosis mediated by p53 and caspase‐depedent pathways.Grant Funding Source: This work was supported by Priority Research Centers Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education, Science and Technology(KNF‐2009‐0094017).
Increased capacity for glycogen turnover in the rat ventromedial hypothalamus (VMH) following hypoglycemia (LB449)
Authors: Mun Jonathan , Rhodes Justin , Beverly Lee 
Published: June 2021

Recurrent hypoglycemia impairs the ability of the VMH to initiate a counterregulatory response and contributes to hypoglycemia‐associated autonomic failure (HAAF). We hypothesize that mobilization of VMH glycogen during and following hypoglycemia interferes with local glucose sensing and that genes associated with increased glycogen turnover will be upregulated after single and recurrent episodes of hypoglycemia. VMH were dissected from rats (N=23) 6 h after a single episode of insulin‐induced hypoglycemia (IIH) (acute), 24 h after the third of 3 recurrent episodes of IIH (recurrent), and saline‐treated euglycemia (control). RNA was extracted for RNA sequencing and real time‐PCR (RT‐PCR) analysis for glucose metabolism genes. One‐way ANOVA identified genes with statistically significant expression changes between treatments, principal component (PC) analysis of significantly different genes separated data points by treatment group, and genes significantly correlated with the PCs were identified. Glycogen synthase, phosphorylase kinase, glycogen phosphorylase, and UDP‐glucose pyrophosphorylase were significantly increased after acute hypoglycemia compared to control in the RT‐PCR analysis. Glycogen phosphorylase was upregulated in the acute treatment groups from both RNAseq and RT‐PCR compared to control and showed sustained elevation in the recurrent treatment from RT‐PCR analysis. These data provide evidence supporting the hypothesis that glycogen metabolism contributes to impaired glucose counterregulation and identify genes that are associated with novel hypotheses for future exploration. Supported by DK082609Grant Funding Source: DK082609