bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of ABCG2 Inhibitors as a New Combination Therapy to Improve Outcome in AML
Authors: Allcock Alice , Fukuda Yu , Lin Wenwei , Chen Taosheng , Schuetz John D. 
Published: November 2023

Acute myeloid leukemia (AML) arises secondary to lesions that disrupt normal myelopoiesis. Despite recent advances in chemotherapy, the 5‐year survival rate is poor (~50%) due to relapse and/or refractory disease. The primary treatment regimen for AML relies upon the antineoplastic, mitoxantrone. An ATP‐binding cassette (ABC) transporter, ABCG2, exports multiple cytotoxic chemotherapeutics, including mitoxantrone, from cancer cells producing strong resistance. In AML, ABCG2 is expressed at higher levels in samples from relapse patients, and high ABCG2 levels are associated with poor survival in multiple AML cohorts. Currently available ABCG2 inhibitors are not suitable due to neurotoxicity, low specificity, or possess a high IC50 that is not clinically achievable. Therefore, we hypothesized that identification of chemotherapeutics that target pathways activated in AML, (e.g. Wnt or tyrosine kinase) but also inhibit ABCG2 function would have clinical impact when combined with a chemotherapy that includes mitoxantrone. To this end, we developed a high throughput screening assay that assessed ABCG2's ability to export a specific fluorescent substrate, pheophorbide a (PhA) from mouse embryonic fibroblasts (MEFs) which were engineered to express human ABCG2. We validated the assay using a previously reported ABCG2 inhibitor, lapatinib (tyrosine kinase inhibitor, TKI), as a control. Subsequently, using a single concentration of 10 μM, a library of ~12,000 bioactive compounds including FDA‐approved drugs was assessed for their ability to block the export of PhA. Compounds producing >80% inhibition, compared to lapatinib, were further subjected to a secondary dose responsive analysis. Chemotherapeutic agents displaying activity were further validated for their specificity and activity in wild‐type MEFs, MEFs lacking Abcg2(KO) or KO‐MEFs harboring human ABCG2. These compounds were evaluated for their ability to enhance the cytotoxicity of mitoxantrone in MEFs and AML cell lines. Several TKIs have been shown to inhibit ABCG2, but at high concentrations (>10 μM). We identified a TKI that inhibits ABCG2 with an IC50 < 1 μM, but was previously unknown. We also identified a Wnt pathway antagonist that potently inhibits ABCG2. In summary, these potent ABCG2 inhibitors we identified have a selective advantage in killing AML cells because their dual actions will disrupt a vital pathway in AML, but also increase the cytotoxicity of mitoxantrone, an approach that is likely to reduce relapse and increase durable remissions.Support or Funding InformationThis work was supported by NIH and by the ALSAC.
Impact of ABCB1 genetic polymorphisms on the interactions between novel dipyranone derivatives and P‐glycoprotein
Authors: Wang Yen‐Hsiang , Chen Chien‐Yu , Liu Nai‐Yu , Chang Chih‐Shiang , Hung Chin‐Chuan 
Published: November 2023

Multidrug resistance (MDR) is one of the major obstacle in cancer treatment and over‐expression of P‐glycoprotein (P‐gp) is highly related to this issue. Genetic polymorphisms in P‐gp may influence clinical treatment outcomes. Therefore, this study aims to evaluate the effect of novel dipyranone derivatives on wild‐ and variant‐types human P‐gp efflux function and investigate underlying kinetic and molecular mechanisms.Recombinant P‐gp‐expressing HEK293 cell lines were established with the common polymorphisms in human ABCB1 gene. Real‐time RT‐PCR was performed to confirm the mRNA expression. Influence of dipyranone derivatives on P‐gp function was evaluated by calcein‐AM uptake assay, rhodamine 123 efflux assay and doxorubicin efflux assay. MDR1 shift assay and ATPase assay were conducted to evaluate the interaction between P‐gp and dipyranone derivatives.Among the tested compounds, compound A, B and C were the top three P‐gp inhibitors after primary screening. SRB assay showed that all of these three compounds had no cytotoxicity effect. However, wild‐type P‐gp mRNA expressions were reduced after treating compound B and C. Calcein‐AM uptake assay, rhodamine 123 efflux assay and doxorubicin efflux assay indicated that these three compounds significantly inhibited P‐gp efflux function. For rhodamine 123 efflux, compound A competitive inhibited wild‐type P‐gp, while compound B and C uncompetitive inhibited wild‐type P‐gp. In doxorubicin efflux, compound A and B modulated wild‐type P‐gp through uncompetitive inhibition, and compound C inhibited wild‐type P‐gp by competitive inhibition. Moreover, the common variants on ABCB1 gene would affect the P‐gp inhibition effect and interaction kinetics of compound B. Based on the results of MDR1 shift assay, these three compounds were not the substrates of P‐gp. However, compound A, B, and C influenced the P‐gp ATPase function and may interact with other P‐gp substrates as indicated by the ATPase assays.This study characterized the novel dipyranone derivatives, compound A, B and C as potential P‐gp inhibitors. The inhibition potency were affected by the common polymorphism haplotypes in ABCB1 gene, which implied that genotypes may take into consideration for further in vivo studies.
Study of Jadomycin Pharmacokinetics in Balb/C Mice
Authors: Relja Nicholas , Hall Steven R. , Sleno Lekha , Bennett Leah , MacLeod Jeanna , Martinez‐Farina Camilo F. , Jakeman David L. , Goralski Kerry B. 
Published: November 2023

BackgroundJadomycins are natural product molecules derived from the soil bacteria Streptomyces venezuelae; jadomycins maintain their cytotoxicity in multidrug resistant (MDR) human and mouse breast cancer cell lines that overexpress ATP‐binding cassette (ABC) transporters. While effective in in vitro assays, jadomycins have not been studied in animal models.ObjectiveTo conduct the first in animal pharmacokinetic and safety studies of jadomycins B, S, and F in male and female Balb/C mice.MethodsJadomycins were administered intraperitoneally (IP) to male and female Balb/C mice at a 6mg/kg dose. In one group of mice (n = 5) up to four repeated saphenous vein blood samples (40 mL) were obtained after 15, 30, 60, and 90 minutes with terminal blood collection occurring at 120 minutes in order to characterize absorption and distribution phases. In a second group of mice saphenous vein blood samples were obtained at 2, 4, 6, 8 and 10 hours to characterize terminal elimination. Liver, kidney, lung and brains were collected after 2 hours and then at 8 or 10 hours (males and females respectively) to characterize jadomycin distribution to these tissues. Serum and tissue samples underwent extraction and jadomycin concentrations were then determined by mass spectrometry.ResultsThe concentration versus time profiles of jadomycins B, S and F were similar. They were absorbed rapidly after IP injection with peak concentrations in the 1–10 mM range observed after 15 minutes. This was followed by a rapid distribution phase (t1/2a = 20 – 40 min) and a slower terminal elimination (t1/2b = 1.5 – 2 hours). Jadomycins accumulated in the liver > kidney > lung and were not detectable in the brain. No metabolites were detected and no acute toxicity responses were observed.ConclusionsThese 1st in vivo studies of jadomycins reveal that jadomycins are safe at a 6 mg/kg IP dose and achieve concentrations in mouse serum that are above the IC50s (1–4 μM) for human and mouse breast cancer cells in vitro. Our results indicate that jadomycins are rapidly eliminated as unchanged drug and that two to three times daily dosing will be required for future tumor studies.Support or Funding InformationCancer Research Training Program (CRTP) through Beatrice Hunter Cancer Research Institute, Canadian Breast Cancer Foundation Atlantic (CBCF), Nova Scotia Health Research Foundation (NSHRF), and Dalhousie University
Endothelial cell‐specific deletion of a single Nanog allele demonstrates its crucial role in the microenvironment of adult tissues
Authors: Baruah Jugajyoti , Wary Kishore 
Published: November 2023

RationaleAlthough Nanog is a known regulator of pluripotency, the functional significance of low level expression of Nanog in endothelial cells (ECs) remains incompletely understood.Methods and resultsWe have created ROSAmT/mG::Nanogfl/+::Cdh5CreERT2 genetically engineered mouse model (GEMM) system. Administration of tamoxifen (TAM) to these adult mice induced EC‐specific loss of single Nanog allele. GFP lineage tracing combined with high‐resolution microscopy revealed GFP‐positive ECs in the microenvironment of adult tissues. Knockout (KO) or knockdown of single Nanog allele in ECs decreased expression of VEGFR2 and hTERT upon Wnt3a stimulation, suggesting a close relationship between Nanog and hTERT. In a chromatin immunoprecipitation (ChIP) assay, we identified Nanog binding sites on the promoter/enhancer region of the human hTERT in ECs. Elevated expression of Nanog increased hTERT‐promoter luciferase activity in ECs. Conversely, in Wnt3a stimulated ECs, Nanog‐depletion decreased hTERT protein which modulates EC proliferation. Importantly, re‐expression of hTERT in Nanog‐depleted ECs partially restored proliferation and angiogenesis.SummaryThese novel findings establish a key role for low level expression of Nanog in the regulation of EC homeostasis that is independent from its recognized function as a regulator of pluripotency.Support or Funding InformationStudies were supported by the National Institute of Health (HL079356), American Heart Association (GRNT25710129) and by the University of Illinois at Chicago Center for Clinical and Translation Science Award (UL1RR029879) to K.K.W. J.B was supported by AHA pre‐doctoral fellowship mid‐west affiliate (15PRE22760004) and UIC‐CCTS‐PECTS fellowship (#1UL1TR002003).
Pharmacological inhibition of endothelial HDAC6 provides protection against atherogenesis through upregulation of cystathionine gamma‐lyase derived hydrogen sulfide
Authors: Leucker Thorsten Martin , Kim Jae Hyung , Nomura Yohei , Bhatta Anil , Wang Victor , Pandey Deepesh 
Published: November 2023

Endothelial cystathionine gamma‐lyase (CSE) molecular mechanisms that control CSE gene expression in vascular endothelium during cardiovascular diseases are unclear. In this study, isolated murine aortic rings exposed to OxLDL (50mg/ml) for 24 hours exhibited impaired endothelial‐dependent vascular relaxation but were protected by adenoviral‐mediated increases in CSE expression. Cultured human aortic endothelial cells (HAECs) that were exposed to OxLDL and intact aortas from atherogenic ApoE knockout mice fed a high‐fat diet for 12 weeks both exhibited reduced CSE mRNA and protein expression. Utilizing class‐specific inhibitors of histone deacetylases (HDACs) class‐specific inhibitors and HDAC6 specific small molecule inhibitor and siRNA, we identified HDAC6 to be a critical regulator of endothelial CSE expression in response to injury stimulus such as OxLDL. HDAC6 mRNA and protein expression were both upregulated in OxLDL exposed HAECs. The reduced endothelial CSE expression/activity with OxLDL was reversed by an HDAC6 inhibitor, tubacin (10mM), and by HDAC6 siRNA (30nM). Further, OxLDL significantly impaired endothelial‐dependent vascular relaxation in mouse aortic rings and reduced CSE expression. The deleterious effect of OxLDL was significantly improved by adenoviral‐mediated overexpression of CSE in murine aortas and by inhibition of HDAC6 with tubacin. Our findings show that HDAC6 is a critical regulator of CSE expression in the vascular endothelium, and strategies to inhibit HDAC6 activity may improve endothelial function and prevent/reverse the development of atherosclerosis.Support or Funding InformationThis work was supported by American Heart Association Scientist Development Grant to D. Pandey (16SDG27340010), 2017 StAAR award from Department of Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine to D. Pandey and National Institutes of Health‐National Heart, Lung, and Blood Institute training grant T32‐HL007227‐40 to T. Leucker.
Protection of Endothelial Function from Homocysteine‐induced Injury by Endothelial Nitric Oxide Synthase Enhancer in Human Internal Mammary Artery
Authors: Hou Hai‐Tao , Yang Qin , Wang Jun , Wang Zheng‐Qing , Chen Tie‐Nan , Liu Zhi‐Gang , Liu Xiao‐Cheng , He Guo‐Wei 
Published: November 2023

ObjectiveHomocysteine (Hcy) is a sulfur‐containing amino acid formed during the metabolism of methionine. Hcy is an independent risk factor for endothelial dysfunction in cardiovascular diseases and atherosclerosis in the general population. We hypothesized that the eNOS transcription enhancer AVE3085 might improve the endothelial function altered by Hcy in the human internal mammary artery (IMA).MethodsCumulative concentration‐relaxation curves to acetylcholine (−10 to −4.5 log mol/L) were established in IMAs (n=28) from patients undergoing coronary artery bypass grafting in the precontraction induced by U46619 (−8 log mol/L) in the absence or presence of Hcy (100 μmol/L) with/without AVE3085 (30 μmol/L) in vitro in a myograph. Quantitative real‐time reverse transcription–polymerase chain reactions (RT‐qPCR) and enzyme‐linked immunosorbent assay (ELISA) were used to quantify the mRNA and protein levels of eNOS.ResultsMaximal relaxation induced by acetylcholine was significantly attenuated by Hcy in human IMA. Co‐incubation with AVE3085 protected endothelium from the impairment of Hcy. Exposure to Hcy for 24 h downregulated eNOS protein expression (P<0.05) whereas it upregulated the expression of eNOS at the mRNA level (P<0.05). The presence of AVE3085 in addition to Hcy significantly increased the eNOS protein (P<0.05) and slightly decreased the mRNA level.ConclusionsHcy caused endothelial dysfunction through the modulation of NO production associated with a downregulation of eNOS in human IMA. AVE3085 prevents endothelial dysfunction, which is attributed to upregulation of eNOS expression. These findings provide new insights into the protection of the endothelium of the coronary artery bypass grafting conduits and the possible improvement of the long‐term patency of the grafts. Therefore, the present study may have strong clinical implications regarding the long‐term results of coronary artery surgery.Supported by National Natural Science Foundation of China (81641017), Zhejiang Provincial Natural Science Foundation (LY15H020008), Hangzhou Science and Technology Projects (20140633B12), & Tianjin Binhai Key Platform for Creative Research Program (2012‐BH110004), Binhai New Area Health Bureau (2016BWKZ003, 2016BWKY007, 2012BWKZ008)Support or Funding InformationThis study was supported by National Natural Science Foundation of China (81641017), Zhejiang Provincial Natural Science Foundation (LY15H020008), Hangzhou Science and Technology Projects (20140633B12), & Tianjin Binhai Key Platform for Creative Research Program (2012‐BH110004), Binhai New Area Health Bureau (2016BWKZ003, 2016BWKY007, 2012BWKZ008)
Pharmacological Profile of BIA 10‐2474, a Novel FAAH Inhibitor, in the Rat
Authors: Bonifacio Maria‐Joao , Aires Cátia , Loureiro Ana Isabel , Moser Paul , Soares‐da‐Silva Patrício 
Published: November 2023

BIA 10‐2474 (3‐(1‐(cyclohexyl (methyl)carbamoyl)‐1H‐imidazol‐4‐yl)pyridine 1‐oxide) is a novel fatty acid amide hydrolase (FAAH) inhibitor. In this study, the pharmacodynamic effects of BIA 10‐2474 in the rat were evaluated as well as its interaction with FAAH.The interaction of the compound with the enzyme was evaluated by determining the potency of the compound in inhibiting rat brain FAAH in vitro at various pre‐incubation periods. The IC50 for BIA 10‐2474 decreased with pre‐incubation time, from 1134 (745; 1726) nM with no pre‐incubation to 400 (265, 488) nM with 1 h pre‐incubation, suggesting a time‐dependent interaction with the enzyme.The pharmacodynamic effects of BIA 10‐2474 in Wistar rat were explored by evaluating hepatic and brain FAAH activity and levels of fatty acid amides in the brain. BIA 10‐2474, at 0.1 mg/kg, completely abolished hepatic FAAH activity in the first 8 hours post‐administration, with the enzyme slowly recovering activity and reaching 79 % control values after 6 days. The ED50 determined at 1 h was 5 (4; 7) μg/kg. In the brain, the effect of BIA 10‐2474 was less marked at 1 h with an ED50 of 96 (36; 255) μg/kg. At a dose of 0.1 mg/kg the maximum inhibition of brain FAAH (92 % inhibition) was achieved at 8 h post‐administration with the enzyme slowly recovering activity and reaching 73 % control levels after 6 days.A PK/PD study in the rat using 10 mg/kg BIA 10‐2474 showed that anandamide (AEA), palmitoeylethanolamide (PEA) and oleoylethanolamide (OEA) levels peaked at 4 h (respectively 75.10±14.2 pmol/g, 4.8±0.5 nmol/g and 2.1±0.2 nmol/g) and slowly declined up to 24 h. The Cmax of BIA 10‐2474 was achieved at 1 h both in plasma (4266±352 ng/ml) and brain (840±51) and, at 8 h levels were almost undetectable in brain and had decreased to 278±60 ng/ml in plasma.In conclusion, these data show that BIA 10‐2474 acts as a time‐dependent FAAH inhibitor, with a potent inhibitory effect upon FAAH and prolonged action in vivo and modulates brain AEA, PEA and OEA levels.
Long Term Treatment with Empagliflozin Attenuates Renal Damage in Obese Zucker Rat
Authors: Ginjupalli Gautam kumar , Manne Nandini D. P. K , Rice Kevin M , Blough Eric R 
Published: November 2023

Empagliflozin, a known sodium‐glucose cotransporter type 2 (SGLT2) inhibitor is currently prescribed as an antihyperglycemic drug in adult Type 2 diabetic patients. Empagliflozin reduces hyperglycemia by promoting urinary excretion of glucose through inhibition of SGLT2 in proximal renal tubules. Data from the three year Empa‐Reg‐Outcome clinical study demonstrated that empagliflozin treatment was associated with improvements in blood glucose levels, decreased A1C, improved kidney function and significantly lower rates of CV death, all‐cause mortality and hospitalization for heart failure. In an effort to better understand the mechanistic basis of these findings, we investigated the long term effects of empagliflozin on kidney function in the diabetic Obese Zucker animal model. Obese Zucker rats were randomly assigned to one of four different groups; lean control, lean treated, obese control, and obese treated. The treated animals received empagliflozin (10 mg/kg body weight) for 25 weeks. Preliminary results suggest that treatment was associated with significant reductions in blood glucose and in the urinary levels of NGAL and Cystatin C. Consistent with these data, histological examination of renal sections from the obese control and treated animals demonstrated that empagliflozin treatment attenuated the loss of brush border, proximal tubule dilatation and glomerular sclerosis. Taken together, our findings suggest that the long term use of empagliflozin in the diabetic Obese Zucker rats is associated with improvements in glucose tolerance, attenuation of renal damage and improved kidney function.Support or Funding InformationThe study was funded by Boehringer Ingelheim to Eric R. Blough
Resveratrol‐Mediated Repression of a Liver Cancer Cell Line
Authors: Zhang Baochun , Lakshmanan Jaganathan , Motameni Amirreza , Harbrecht Brian G 
Published: November 2023

Among the polyphenols, resveratrol (trans‐3,5,4′‐trihydroxystilbene) is a natural product with potential for the treatment of several diseases, including cancer. The aim of present study was to investigate the ability of resveratrol (RES) to inhibit HepG2 liver cancer cell growth, and examined the underlying mechanisms.HepG2 cells were cultured in MEM with 5% FBS, the cells were treated with vehicle, 50 micro Molar, or 100 micro Molar of RES for 48 hours. Cell viability measured by MTT ((3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) stain were decreased approximately 26% and 32% respectively among the cells treated with RES. To understand whether RES – induced cell death and/or cell proliferation contributed the loss of cell viability, Bromodeoxyuridine (BrDU) and apoptosis gene screen assay were performed. HepG2 cells treated with 50 micro Molar and 100 micro Molar RES exhibited a marked decrease in BrDU incorporation rate (18% and 5%); indicating that suppressed cell proliferation played a major role of the effects of RES on HepG2 cell viability. Multi‐Target apoptosis paths scan showed that 100 micro Molar RES induced a significantly increase of both phosphorylated‐ and total‐p53 protein level. Meanwhile, no significant changes were observed on level of dephosphorylated and total Bad, cleaved caspase 3, and cleaved PARP on cells treated with RES.In this study, we found that RES induced inhibition of HepG2 cell viability by suppressing their proliferation. Increased phosphorylation of p53 may contribute the effect of RES and may trigger apoptosis at long time. Thus, these findings suggest that RES has potential as a candidate agent against human liver cancer.
A Rat Model of Ischemic Enteritis: Pathogenic Importance of Enterobacteria, iNOS/NO, and COX‐2/PGE2
Authors: Takeuchi Koji , Komatsu Yoshino , Kotani Tohru 
Published: November 2023

We investigated the roles of prostaglandins (PGs), nitric oxide (NO) and enterobacteria in a model of ischemic enteritis. Under ether anesthesia, ischemic enteritis was induced in 18 h‐fasted rats by a stenosis in the superior mesenteric artery (SMA) that was produced by placing a needle (23 guage) on the vessel, ligating both the vessel and needle, and then removing a needle from the ligature. After operation, the animals were fed normally and killed 3 days after surgery. Various drugs were given once daily for 2 days after the operation. Stenosis of the SMA produced hemorrhagic enteritis on the anti‐mesenteric side of the small intestine. The occurrence of enteritis was accompanied by enterobacterial invasion and the upregulated expression of iNOS/NO as well as COX‐2/PGE2 in the mucosa. The enteritis was prevented by ampicillin, L‐NAME or aminoguanidine, while aggravated by indomethacin, rofecoxib or an EP4 antagonist. The deleterious effect of indomethacin was antagonized by the co‐administration of PGE2 or an EP4 agonist. These results suggest that enterobacteria played a major pathogenic role in this model of ischemic enteritis, and also that iNOS/NO was deleterious in the pathogenesis of these lesions, while COX‐2/PGE2 prevented the development of ischemic enteritis by activating EP4 receptors.Support or Funding Informationnone