bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soluble epoxide hydrolase contributes to the endothelial dysfunction of peripheral conduit arteries in type 2 diabetic patients
Authors: Duflot Thomas , Remy‐Jouet Isabelle , Morisseau Christophe , Wils Julien , Li Dongyang , Prevost Gaetan , Joannides Robinson , Bellien Jeremy 
Published: June 2021

This study addressed the hypothesis that soluble epoxide hydrolase (sEH), which metabolizes the vasodilator and anti‐inflammatory epoxyeicosatrienoic acids (EETs) to dihydroxyeicosatrienoic acids (DHETs), contributes to conduit artery endothelial dysfunction in type 2 diabetic patients.We measured radial artery endothelium‐dependent flow‐mediated dilatation in 29 patients with well‐controlled type 2 diabetes (HbA1c=6.7±0.6%) and 37 control subjects in response to hand skin heating. We quantified the local plasma concentrations of EETs, DHETs, the NO metabolite nitrite and reactive oxygen species (ROS) at baseline and during heating. The sEH protein expression and activity were measured in peripheral blood mononuclear cells (PBMCs) isolated from patients and controls.Flow‐mediated dilatation was reduced in diabetic patients compared to controls, without change in flow variation and endothelium‐independent dilatation to glyceryl trinitrate. Diabetic patients displayed an elevation in ROS levels and a complete loss of NO release and in EETs production, assessed by the sum of total EETs and DHETs, during the flow stimulation. The conversion of EETs to DHETs (DHET‐to‐EET ratio) was enhanced at baseline and further increased during heating in diabetic patients compared to controls. Moreover, sEH expression and activity were increased in diabetic PBMCs.This study demonstrates that an increased degradation of EETs by sEH contributes with altered NO bioavailability to conduit artery endothelial dysfunction in type 2 diabetic patients. Inhibitors of sEH may be useful to improve endothelial function and thus cardiovascular prognosis in these patients.Support or Funding InformationThis study was funded by a grant from the Fondation de France (2011‐20459) and supported by National Institute of Environmental Health Sciences grant R01‐ES002710.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 Effect of the Dipeptidyl Peptidase‐4 Inhibitor Sitagliptin on Gentamicin Nephrotoxicity in Mice
Authors: Ali Badreldin H. , Suleimani Yousuf M. , Abdelrahman Aly M. , Karaca Turan , Nemmar Abderrahim 
Published: June 2021

This study aimed at investigating the possible ameliorative effects of sitagliptin in mice with gentamicin (GEN) nephrotoxicity. Sitagliptin was given to the animals at an oral dose of 10 mg kg−1 per day for 10 days, and in some of these mice, GEN was injected intraperitoneally at a dose of 100 mg kg−1 per day during the last seven days of the treatment. Nephrotoxicity was evaluated histopathologically by light microscopy and biochemically by measuring several indices in plasma, urine and renal cortex homogenates. GEN treatment induced nephrotoxicity as evidenced by significantly (P<0.0001) increasing the plasma concentrations of urea, creatinine, circulatory cytokines, cystatin C, sclerostin, and TNFα. Treatment with GEN also significantly elevated urinary N‐acetyl‐β‐D glucosaminidase (NAG) concentration (P <0.0001). Moreover, GEN caused significant increase in oxidative stress in the kidneys (P<0.0001). Histopathological examination revealed massive tubular injury, necrosis, infiltration of inflammatory cells and intraluminal hyaline casts in mice treated with GEN. Sitagliptin alone did not significantly affect any of the indices measured. However, concomitant treatment with sitagliptin and GEN significantly mitigated most of the nephrotoxic actions of GEN. Pending further studies, sitagliptin may potentially be useful as a nephroprotectant agent.Support or Funding InformationThis work was financially supported by a grant from SQU, Oman (IG/MED/PHAR/17/1)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Insights into the Structural Determinants of Substrate Binding to Human Cytochromes P450 2C9 and 2C18
Authors: Shah Manish B. 
Published: June 2021

Xenobiotic metabolizing cytochrome P450 (CYP) enzymes constitute the major enzyme family in drug metabolism with increasing importance in pharmacogenetics, and more recently to pharmacogenomics. The highly polymorphic CYP2C9 metabolizes over 15% of clinical drugs that include ibuprofen, diclofenac, warfarin, losartan, tolbutamide, and glimepiride. Whereas CYP2C18 represents the least characterized enzyme with little information regarding substrates, the active site and the overall structure, despite the high sequence identity (more than 80%) with other human CYP2C subfamily of enzymes. Sequence alignment of CYP2C9 and 2C18 revealed interesting differences in amino acid substitutions, which allowed analysis of the active site of two enzymes of the same subfamily with distinct information regarding substrate specificity. A homology model of CYP2C18 created using the most recent crystal structure of CYP2C9‐losartan complex revealed key residue substitutions that significantly reduced the volume of the active site. In particular, the larger side chain substitutions L113, F201, F237 and N365 in CYP2C18 protrude the active site and play an important role in ligand interaction. Molecular docking studies using a diverse range of CYP2C9 substrates demonstrated remarkably altered orientation in the CYP2C18 active site indicative of differences in substrate preference compared to CYP2C9. The results suggest the active site architecture of CYP2C18 may not allow binding of larger or bulkier substrates as seen with other human CYP2C enzymes. Overall, the analysis of amino acid differences in the active site, the access channel and the recently identified potential substrate recognition site at the periphery provide important insights into the role of distinct side chain substitutions among related CYP enzymes.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Cytochromes P450 Involved in Metabolism of Flavonoid Aglycones
Authors: Bojic Mirza , Benkovic Goran , Males Zeljan , Zulj Rajka Truban , Tomic Sinisa 
Published: June 2021

Flavonoids are secondary plant metabolites to which we are exposed through everyday diet (vegetables, fruits, dietary supplements, herbal drugs). They represent a wide class of compounds that have extensively been studied due to beneficial biological effects. As we have evolutionary been exposed to these compounds, human body has developed mechanisms how to excrete these compounds (metabolism, transporters). Objective of this study was to determine cytochromes P450 involved in metabolism of flavonoid aglycones and characterize generated metabolites. Metabolism of 30 flavonoids was assessed using human liver microsomes and recombinant liver cytochrome P450 enzymes. HPLC method coupled with UV detector and MS TOF was used for detection and quantification. Flavonoids could be separated based on retention time even though there are subtle differences in flavonoid structures. Structures of metabolites were elucidated using accurate mass data, retention time and confirmed using flavonoid standards. Flavonoid aglycones are susceptible to hydroxylation and demethylation reactions. The most significant enzyme involved in metabolism of analyzed flavonoids was cytochrome P450 1A2 which is in accordance with previously reported data. Other enzymes involved in metabolism of flavonoid aglycones were cytochromes P450 2D6, 2C19, and 3A4. As data on pharmacokinetics of flavonoids is limited to few well studied flavonoids, understanding metabolism of flavonoids will improve efforts to obtain flavonoid candidates less susceptible to metabolic elimination.Support or Funding InformationThis work was supported by the Croatian Science Foundation under the project UIP‐2014‐09‐5704 (M.B.).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 Chick Chorioallantoic Membrane (CAM) as a Multi‐Purpose Preclinical Model in Oncology
Authors: Hafner Susanne , Zuo Zhi , Rasche Volker , Syrovets Tatiana , Simmet Thomas 
Published: June 2021

The chorioallantoic membrane (CAM) of fertilized chick eggs is a preclinical in vivo model and an alternative or pretest for animal studies in rodents. Although the CAM xenotransplantation model is a reproducible, reliable and efficient model conforming to the 3R principle to reduce mammalian animal experiments, and the United States Food and Drug Administration recommended the CAM for in vivo studies on angiogenesis, the method is not very common so far. Undoubtedly, the CAM assay has its limitations: The experimental window of about 10 days is a limiting factor hampering the establishment of the model in oncology. Here we show the implementation of the CAM model in oncological research on modern diagnostics and therapeutics. Tumor cells were xenotransplanted onto the chorioallantoic membrane, which serves as nutritious natural substrate for their growth and allows the three‐dimensional formation of solid tumors in an in vivo microenvironment. We successfully transplanted cancer cells stably expressing firefly luciferase, e.g. breast and lung cancer cells, and established methods for direct in ovo monitoring after the topical or intravenous administration of diagnostics or therapeutics. Upon administration of doxorubicin, a commonly used chemotherapeutic, the growth of cancer xenografts on the CAM was monitored by bioluminescence imaging using an IVIS in vivo Imaging System after the application of D‐luciferin for up to 3 days after treatment. The obtained results were quantified and validated by immunohistochemical analysis of proliferation and apoptosis (Ki‐67, Tdt) upon tumor tissue extraction. After labelling of compounds with gadolinium (Gd) as a contrast agent, high‐resolution magnetic resonance (MR) imaging at several time‐points enabled the evaluation of the compound's bio‐distribution and accumulation in tumor tissue. To confirm the MR findings, organs were extracted and analyzed for the Gd contents by inductively coupled plasma optical emission spectrometry (ICP‐OES).These methods facilitate the straightforward and non‐invasive assessment of a compound's therapeutic efficacy and biodistribution and therefore possess implications for the development of new pharmacological substances.The studies were conducted in conformance with the FASEB Statement of Principles for the use of Animals in Research and Education.Support or Funding InformationThis work was supported by the Volkswagen Foundation.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
ANTICANCER ACTIVITY OF ANNONA MURICATA EXTRACT ON TRIPLE NEGATIVE BREAST CANCER CELLS AND ISOLATION/CHARCTERIZATION OF ACTIVE COMPOUNDS
Authors: Alshaeri Heba , Alasmari Moudi , Pino‐Figueroa Alejandro 
Published: June 2021

Triple negative breast cancer (TNBC) cells are a subtype of breast cancer that lack of estrogen receptors (ERs), progesterone receptors (PRs) and human epidermal growth factor receptor 2 (HER2). This type of breast cancer has poor prognosis and accounts for 15–20% of newly diagnosed breast cancer (BC) cases. Annona muricata is a tropical plant and has been used as a folk medicine to treat several diseases such as malaria, inflammation, diabetes and recently it was known to have anticancer activity on various cancer types. However, the underlying molecular mechanisms remain to be explored. The purpose of this study was to investigate the anti‐proliferative activity and mechanism of action of Annona muricata ethyl acetate (AMEA) extract and one active fraction on BT‐20 TNBC cells.The AMEA showed significant decrease on BT‐20 cell viability as determined by the MTS assay. Furthermore, the AMEA was subjected to preparative thin layer chromatography (TLC) and eight fractions were obtained. From the 8 fractions only fraction 4 (F4) showed significant reduction in cell viability by the MTS assay. Immunoblotting analysis revealed that AMEA and F4 produced anti‐proliferative effect via inhibiting the EGFR phosphorylation and the phosphorylation of its downstream signaling proteins including AKT and MAPK. These effects were accompanied with down‐regulation of cyclin D1 production resulting in cell cycle arrest at G1/S phase. Furthermore, NF‐κB was measured due to its involvement in the progression of cancer that overexpress EGFR as reported in several studies. It was found that AMEA and F4 decreased significantly NF‐κB p65 protein expression in the nuclear fraction, therefore, inhibiting its activation and preventing the induction of cell survival. Our data indicated that neither AMEA nor F4 had significant effect on apoptosis biomarkers when tested on Bcl‐2, Bax, cytochrome c and caspase 3/7 activities. Taken together, these findings provide a scientific basis for the molecular mechanism of action of Annona muricata extract and its active fraction F4 in the treatment of TNBC. It has been demonstrated the anti‐proliferative effect via EGFR‐mediated signaling pathways which includes AKT/MAPK/NF‐κB pathways and cyclin D1 inhibition. Further studies are required to demonstrate the applications of this natural product in breast cancer therapy.Support or Funding InformationThis work was funded by MCPHS UniversityThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
KV7.2–7.5 Channel‐Activation Contributes to Bladder Relaxation Induced by Oxybutynin or Mirabegron
Authors: Dalsgaard Thomas , Strøbæk Dorte , Christophersen Palle 
Published: June 2021

The muscarinic receptor antagonist, Oxybutynin (Ox), and the β3‐receptor agonist, mirabegron (Mb), are used in the treatment of overactive bladder syndrome (OAB). However, the exact downstream mechanisms by which Ox and Mb opposes the enhanced contractility in OAB is unknown. The KCNQ genes encode five Kv7 K+ channel subunits (KV7.1–Kv7.5). Of these, KV7.2–KV7.5 channels have been proposed to be involved in regulation of smooth muscle tone, i.e. the contractile state of the bladder. In this study, we investigated the involvement of KV7.2–KV7.5 channels in Ox‐ and Mb‐induced relaxation of the bladder. Furthermore, the direct effect of KV7.2–KV7.5 channel‐activation on bladder relaxation was determined. Patch clamp recordings from HEK cells expressing KV7.1–KV7.5 channels were used to determine the relative potency of five different activators; ICA‐27243, ML213, NS15370, Retigabine, and SciFluor, on the KV7.2–KV7.5 channels. Bladder strips from rats mounted in organ baths and contracted with electrical field stimulation were used to investigate the functional effects of inhibiting and activating KV7.2–KV7.5 channels. This study found that inhibiting KV7 channels with XE991 markedly reduced Ox‐ and Mb‐induced relaxation of bladder strips. Furthermore, bladder strip EC50 values corresponded well with HEK cell EC50 values for both KV7.2–3 and Kv7.4 channels, and arranged the five activators with the most potent first accordingly: NS15370>ML213=SciFluor>Retigabine>ICA‐27243. In conclusion, this study showed that KV7.2–KV7.5 channels are probably involved in the therapeutic relaxation of the bladder induced by Ox and Mb in OAB patients. In addition, direct pharmacological activation of KV7.2–KV7.5 channels induced a potent relaxation of the bladder, suggesting that KV7.2–KV7.5 channel activators may be a new target for treating OAB ‐ either as standalone treatment or as enhancers of the effect of currently available treatment options.Support or Funding InformationThis study was funded by the Innovation Fund Denmark.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Regional Haemodynamic responses to Adenosine A2A‐Receptor Agonists in Conscious Freely Moving Rats
Authors: Cooper Samantha Louise , March Julie , Hill Stephen , Woolard Jeanette 
Published: June 2021

Endogenous adenosine acts as a local mediator in the cardiovascular system to protect against the influences of stress (including ischaemia and reperfusion injury). In highly metabolic tissues, such as skeletal muscle and the coronary circulation, adenosine A1 and A2 receptors help to mediate arteriolar vasodilatation [1]. The present study compared the effects of adenosine or specific A2A agonists on regional haemodynamics in the presence or absence of an A2A‐specific antagonist (SCH58261). As described previously [2], rats were instrumented with miniature pulsed Doppler flow probes (for assessment of regional haemodynamics) sutured around the renal and mesenteric arteries, and the descending abdominal aorta. Animals were also instrumented with intra‐arterial and intra‐venous catheters for measurement of heart rate (HR) and mean arterial pressure (MAP), and drug administration, respectively. Studies were conducted in conscious, freely‐moving rats. All procedures were carried out with approval of the University of Nottingham Animal Welfare Ethical Review Board, under Home Office Project and Personal License Authority. All compounds were prepared in a propylene glycol (PEG) ‐ based buffer (5% PEG, 2% Tween, 0.9% saline) or saline. Agonists were evaluated in the presence or absence of SCH58261 or vehicle (0.1 or 1.0 mg/kg; given as a bolus of 0.1 ml). For example, CGS21680 was administered as 3 min infusions of 0.1, 0.3 and 1 μg/kg/min administered over a total of 9 min at an infusion rate of 0.1ml/min, at least 10 min following the bolus injection of SCH58261 or vehicle. CGS21680 produced tachycardic and depressor effects, which were associated with renal and hindlimb vasodilatations. There was little effect in the mesenteric vascular bed. Responses were antagonised by SCH58261 at 1.0 mg/kg. Responses to adenosine and other modulators of adenosine receptors (e.g. VCP746) will also be presented.Support or Funding InformationWe thank the British Heart Foundation for financial support.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Interleukin 6 plus High Salt Increases Systolic Blood Pressure
Authors: Hecht Gillian Grace , Moyer Hayley Catherine , Krishnamurthy Ashwini , van Elst Henrieke , Hoover Robert S. , Wynne Brandi Michele 
Published: June 2021

Cytokines and immune cells are implicated in the development of hypertension (HTN), and clinically, interleukin 6 (IL‐6) is independently correlated with HTN. HTN is also characterized by increased sodium (Na+) reabsorption along the aldosterone‐sensitive distal nephron (ASDN), as well as increased expression and/or activity of Na+ transport proteins, such as the sodium chloride cotransporter (NCC) and the epithelial sodium channel (ENaC). We have previously shown that IL‐6 can activate the mineralocorticoid receptor (MR) in vitro, and intrarenal IL‐6 perfusion significantly increases expression of total and phosphorylated (T53)‐NCC, and ENaC α/γ subunits in vivo. Here, we hypothesize that IL‐6 increases Na+ reabsorption, leading to HTN. To determine whether IL‐6 increases blood pressure (BP), mice (C57Bl6) were implanted with miniosmotic pumps and tail cuff plethysmography used to measure systolic BP during IL‐6 infusion (16 ng/hr, 0.01% BSA in saline) or sham surgery. Mice were fed normal chow (NC) or high salt (HS) food. Mice with systemic IL‐6 infusion (3 days) plus HS diet had significantly increased BP as compared to HS alone (129±6 mmHg vs. 110±5 mmHg, n=4, *p<0.05) with no increases in proteinuria (7 days). No changes in BP was observed in mice treated with IL‐6 and fed NC.To investigate whether intra‐renal IL‐6 activates NCC via the MR, in vivo, jugular catheters were attached to a miniosmotic pump and inserted under the renal capsule. Mice were infused with IL‐6 (16 ng/hr, 0.1% BSA in saline; 3 days) or vehicle. Mice were sacrificed, tissues removed and then cryosectioned for immunofluorescence (IF) studies. We observed a significant increase in phosphor(T53)‐NCC expression (291±12 mean pixel intensity, MPI) vs. vehicle (236±9; p<0.01, n=3). Mice were then given the MR antagonist (spironolactone, [0.6 mg/day] in peanut butter); we observed a significant reduction in the IL‐6‐mediated increase in phosphor(T53)‐NCC expression (210±12 MPI; p<0.001, n=3).Our data suggest that IL‐6 infusion plus HS increases systolic BP, beginning on day 3, without significant renal damage on day 7. Although we observed a significant increase in IL‐6‐mediated MR‐dependent phosphor(T53)‐NCC expression, our metabolic cage data suggest that pressure natriuresis may be occurring by day 3. Together, these data suggest a novel role for cytokines and high salt in the development of HTN.Support or Funding InformationEmory SIRE to GGH and BMW; ASPET SURF to GGH; Emory University SUPERR 5R25DK101390‐05 to HCM; NIDDK085097 and VA MERIT I01BX002322 to RSH and 2T32DK7656‐2 to BMWThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
HEMODYNAMIC EFFECTS OF Gq/11‐SPECIFIC CYCLIC DEPSIPEPTIDE INHIBITOR LIGANDS IN NORMOTENSIVE AND HYPERTENSIVE MICE
Authors: Edwards Alethia J. , Meleka Matthew M. , Dahlen Shelby A. , Osei‐Owusu Patrick 
Published: June 2021

Augmented vasoconstriction is a hallmark of hypertension and is mediated partly by hyper‐stimulation of G protein‐coupled receptors (GPCRs) and downstream signaling components. Although GPCR blockade is a key component of current anti‐hypertensive strategies, whether hypertension is better managed by directly targeting G proteins has not been thoroughly investigated. Here, we tested whether inhibiting Gq/11 proteins in vivo or ex vivo using cyclic depsipeptides, YM‐254890 (YM), FR‐900359 (FR) and WU‐07047 (WU) is sufficient to reduce vasoconstriction and reverse hypertension in mice. FR, YM and WU markedly reduced vasoconstriction evoked with Gq/11‐coupled GPCRs. YM and WU but not FR inhibited vasoconstriction through G protein‐dependent and independent pathways by blocking L‐type calcium channel‐mediated Ca2+ influx. Acute subcutaneous injection of FR and YM (0.3 mg/kg, s.c.) in normotensive and hypertension mice elicited marked hypotension, which was more severe and long lasting (FRt1/2 □ 12 hr vs. YMt1/2 □ 4 hr) after the injection of FR relative to YM. In DOCA‐salt hypertension mice, chronic injection of FR (0.3 mg/kg, s.c., daily for seven days) reversed hypertension (vehicle SBP: 149 ± 5 vs. FR SBP: 117 ± 7 mmHg). Incubation of cells with YM or FR caused cellular redistribution of Gq from the plasma membrane. Our results together support the hypothesis that increased vascular Gq/11 activity is involved in the pathogenesis of hypertension, and that direct systemic blockade of Gq/11 can reverse hypertension. The findings provide clear evidence for targeting Gq/11 in the cardiovascular system as an effective therapy for treating hypertension.Support or Funding InformationThis study is supported by grants from Pennsylvania Department of Health (CURE), Margaret Q. Landenberger Foundation, American Heart Association (16SDG27260276) and NIH (HL139754) to P. Osei‐Owusu.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.