bluuebunny/crossref_metadata_2025_split huggingface dataset:
OAT3 Mediated Interaction between Steviol Acyl Glucuronide and Probenecid: In Vitro and In Vivo Investigations
Authors: Chow Dandan 
Published: June 2021

Steviol acyl glucuronide (SVAG) is a circulating metabolite formed after the ingestion of rebaudioside A, a naturally occurring sweetner with functional activities. Our previous studies have demonstrated that transporters particularly OAT3 played an important role in renal clearance of SVAG. The present study aimed to investigate the inhibitory effect of probenecid on OAT3 mediated SVAG transport using in vitro and in vivo systems. In the hOAT3 stably transfected HEK293 cell line, probenecid exhibited a dose‐dependent inhibition of SVAG uptake, with an IC50 value of 4.95 μM. In rat kidney slices, the uptake of SVAG was markedly inhibited by probenecid (67.5%), estrone‐3‐sulfate (41.9%), and para‐aminohippurate (PAH, 27.0%), respectively. In rats given an oral dose of 15 mg/kg of rebaudioside A, the Tmax, Cmax and AUC6–8 of SVAG were 6.25 hr, 176 ng/mL and 213.8 ng/mL*hr, respectively. In contrast, an intravenous dose of probenecid (20 mg/kg) led to an increase of Cmax and AUC by 2.15 and 1.71 folds, respectively, while Tmax remained relatively unchanged. Taken together, the inhibition effect on SVAG uptake in the presence of probenecid was mediated via OAT3. As OAT3 is a major uptake transporter in the kidney, the inhibition of OAT3 activity may alter SVAG's renal clearance. It is thus prudent to investigate transporter‐mediated food‐drug interactions and ensure safe and effective use of those products.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Molecular mechanisms of organic cation and anion transport at the blood‐CSF barrier
Authors: Hu Tao , Zha Weibin , Duan Haichuan , Wang Joanne 
Published: June 2021

The blood‐cerebrospinal fluid (CSF) barrier, formed by epithelial cells of the choroid plexus (CP), plays an active role in removing neurotoxins, drugs, and metabolites from the brain. Organic cations and organic anions are known to be transported at the blood‐CSF barrier, but the underlying molecular mechanisms have not been fully understood. The goal of this study is to identify major organic cation and anion transporters expressed in human and mouse CP and to elucidate the functions of these transporters by live tissue imaging using fluorescent probe substrates. For organic cations, real‐time PCR analysis showed a predominant expression of plasma membrane monoamine transporter (PMAT) in both human and mouse CPs. In contrast, organic cation transporters 1–3 (OCT1–3) and the multidrug and toxin extrusion protein 1 and 2 (MATE1/2) are not or minimally expressed. In freshly isolated CP from wildtype mouse, live tissue imaging showed that IDT307, an analog of the organic cation MPP+, was transported into CP epithelial cells at the apical (CSF‐facing) membrane and sensitive to inhibition by the PMAT inhibitor quinine. Once inside CP epithelial cells, IDT307 was highly accumulated in the mitochondria with little efflux at the basolateral (blood‐facing) membrane. IDT307 uptake and intracellular accumulation was greatly attenuated by ~70% in CP tissue from the Pmat knockout mouse. For organic anions, real‐time PCR analysis showed the highest expression of the organic anion transporting polypeptides 1C1 (OATP1C1) and multidrug resistance‐associated protein 1 (MRP1). Organic anion transporter 3 (OAT3/Oat3), MRP4/Mrp4, Oatp1a4/5, OATP1A2 and OATP3A1 also showed significant expression in human or mouse CP. Unlike IDT307, the organic anion fluorescein‐methotrexate (FL‐MTX), which is a reported substrate of OATPs and MRPs, was rapidly taken up at the apical membrane and efficiently excreted into the capillary areas with little intracellular accumulation. Rifampicin, a pan‐inhibitor of OATPs, completely blocked FL‐MTX uptake into the CP tissue whereas MK571, a potent inhibitor of MRP1/4, abolished the basolateral efflux of FL‐MTX, resulting in its high accumulation within the CP epithelial cells. Taken together, our results established that organic cations are transported by PMAT from the CSF and highly accumulated in CP. Larger organic anions are removed from the CSF by OATP (e.g. OATP1C1)‐mediated apical uptake followed by MRP1/4‐mediated basolateral efflux into the blood. Our findings revealed the molecular mechanisms of organic cation and anion transport at the blood‐CSF barrier and suggested important roles of CP transporters in maintaining the homeostasis and normal function of the brain.Support or Funding InformationThis study is supported by National Institutes of Health Grant GM066233.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 α‐Arrestin ARRDC3 Suppresses Breast Carcinoma Invasion by Regulating GPCR Lysosomal Sorting and Signaling
Authors: Arakaki Aleena K. , Pan Wen‐An , Trejo JoAnn 
Published: June 2021

G protein‐coupled receptor (GPCR) signaling regulates cancer cell proliferation, invasion, migration and survival at metastatic sites. However, despite the success and promise of GPCRs as therapeutic targets, there are currently no FDA‐approved drugs targeting GPCRs for cancer. Protease‐activated receptor‐1 (PAR1) is a GPCR that promotes breast cancer progression. PAR1 is overexpressed in breast cancer patient tissue biopsies and in breast carcinoma cell lines, and correlates with increased rates of metastasis and poor prognosis and increased invasion and metastatic potential, respectively. One mechanism that leads to PAR1 aberrant over‐expression is defective lysosomal trafficking. The dysregulation of PAR1 trafficking leads to persistent G protein signaling and promotes breast cancer invasion. However, the mechanisms responsible for aberrant PAR1 trafficking remain unknown. Here we show that arrestin domain containing protein‐3 (ARRDC3), an adaptor protein for E3 ubiquitin ligases, functions as a tumor suppressor by controlling PAR1 trafficking in breast carcinoma cells. We used a tetracyclineinducible pSLIK lentiviral vector to restore expression of ARRDC3 in highly invasive, basal‐like MDA‐MB‐231 cells, which exhibit high PAR1 and low ARRDC3 expression. Re‐expression of ARRDC3 restored agonist‐induced PAR1 degradation, attenuated JNK and Hippo‐YAP signaling, and further inhibited PAR1‐mediated breast carcinoma cell invasion. Our studies suggest a crucial role for ARRDC3 in regulating normal PAR1 lysosomal degradation and signaling, with loss of ARRDC3 resulting in aberrant PAR1 signaling, leading to tumor progression in breast cancer. A better understanding of the mechanisms by which PAR1 contributes to breast cancer progression may lead to new potential therapeutic targets for the treatment or prevention of metastatic breast cancer.Support or Funding InformationFunding for this project was provided by the UCSD Tribal Membership Initiative Graduate Fellowship, UCSD Graduate Training Program in Cellular and Molecular Pharmacology through NIH General Medical Sciences, T32 GM007752 (Aleena Arakaki) and by the National Institute of Health NIGMS R01 GM090689 (JoAnn Trejo).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Acarbose Delays Renal Cancer Progression in Mice: Implications for Obesity‐Induced Immunotherapeutic Failure
Authors: Orlandella Rachael M. , Boi Shannon , Smith Daniel L. , Norian Lyse A. 
Published: June 2021

Obesity is a regarded as a major risk factor for developing renal cell carcinoma (RCC). Advanced‐stage RCC exhibits chemotherapeutic resistance, but is responsive to high‐dose IL‐2 and anti‐PD‐1 immunotherapies. Despite successes in these treatments, response rates remain low (20–30%). Currently, pre‐clinical evaluations of immunotherapeutic strategies typically use lean, young mice and do not account for the presence of patient comorbidities. This may partially explain the underwhelming success in clinical translation. Our laboratory previously demonstrated that a T cell‐based immunotherapy clears orthotopic renal tumors in lean mice, but fails in diet‐induced obese mice. This illustrates the importance of identifying methods to rescue obesity‐induced immunotherapeutic failure in this model. Calorie restriction (CR) delays the onset of chronic diseases, such as obesity and cancer. This attribute has prompted interest in investigating CR and its substitutes as potential cancer therapeutics. Recent murine research shows that diets containing calorie restriction mimetics (CRMs) improve anti‐tumor immunity and chemotherapeutic efficacy. Here we examined acarbose, an α‐glucosidase inhibitor with CRM properties, in a preclinical model of kidney cancer. BALB/c mice were fed an acarbose‐supplemented or control diet following orthotopic tumor challenge with syngeneic Renca renal carcinoma cells. Acarbose reduced endpoint tumor weights (p=0.02) and lung metastases (p=0.03). Flow cytometric analysis at endpoint revealed similar frequencies of splenic and intra‐tumoral CD8 T cells in mice treated with acarbose. These findings suggest that acarbose may exhibit anti‐tumor properties, and indicates a potential treatment opportunity for mice with diet induced obesity. Future experiments will focus on evaluating acarbose in combination with immunotherapy, in lean and obese mice.Support or Funding InformationT32HL105349This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Cardiac autonomic neuropathy as a result of mild hyper‐caloric challenge in absence of signs of diabetes: Modulation by anti‐diabetic drugs
Authors: Bakkar Nour Mounira , Mroueh Ali , Ghali Rana , Al‐Assi Ola , Kaplan Abdullah , Mougharbil Nahed , Eid Ali , Zouein Fouad , El‐Yazbi Ahmed 
Published: June 2021

Cardiac autonomic neuropathy (CAN) is an early cardiovascular complication of diabetes occurring before signs of metabolic derangement are evident. The cause of CAN remains elusive and cannot be directly linked to hyperglycemia since pre‐diabetic and metabolic syndrome patients demonstrate signs of cardiac autonomic dysfunction. Recent clinical data report cardioprotective effects of some anti‐diabetic drugs independent of their hypoglycemic action. Significantly, pioglitazone and metformin demonstrated protection in pre‐diabetic patients. Here, we used a rat model receiving limited daily increase in calories from fat (HC diet) to assess whether mild metabolic challenge led to CAN in absence of interfering effects of hyperglycemia, glucose intolerance, or obesity. Compared to controls, rats receiving HC diet for 12 weeks showed reduction in baroreceptor sensitivity and heart rate variability despite lack of change in baseline hemodynamic and cardiovascular structural parameters. Impairment of cardiac autonomic control was accompanied with perivascular adipose inflammation observed as an increased interleukin‐1b (IL‐1b) and tumor necrosis factor‐a (TNF‐a) expression, together with increased cardiac oxidative stress, IL‐1b expression and signaling derangements characteristic of diabetic cardiomyopathy including reduction of AMPK phosphorylation and activation of the TGF‐b/Erk1/2 pathway. At this stage, examination of the brainstem revealed no molecular disorders in support of an early, potentially reversible effect. Two‐week treatment with metformin or pioglitazone rectified the autonomic derangement and corrected the molecular changes in heart and adipose tissue. Switching rats on HC diet to normal chow but not to isocaloric amounts of HC for two weeks reversed CAN. As such, we conclude that adipose inflammation due to increased fat intake might underlie development of CAN and, hence, the beneficial effects of metformin and pioglitazone.Support or Funding InformationSupported by AUB MPP fund #320148.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
VE‐PTP Functions as a Scaffold to Stabilize the AJ and Endothelial Barrier
Authors: Juettner Vanessa , Dan Arkaprava , Leckband Deborah , Komarova Yulia , Malik Asrar 
Published: June 2021

Vascular Endothelial Protein Tyrosine Phosphatase (VE‐PTP) is an endothelial‐specific phosphatase that dephosphorylates multiple proteins including Vascular Endothelial (VE)‐cadherin, the main adhesive protein of adherens junctions (AJ). VE‐PTP‐mediated dephosphorylaiton of VE‐cadherin is required for reassembly of VE‐cadherin junctions and restoration of endothelial barrier function after humoral or mechanical stress. The role of VE‐PTP in regulation of VE‐cadherin adhesion complexes under basal conditions, however, remains unknown. VE‐cadherin establishes adhesion events through trans‐interaction with opposing VE‐cadherin molecules at AJs. In resting endothelial monolayers, VE‐cadherin undergoes continues exchange between junctional and cytosolic pools due to VE‐ cadherin recruitment to and internalization from AJs. Using VE‐cadherin tagged with the photoconvertable protein Dendra2, we have demonstrated that VE‐PTP controls stability of VE‐cadherin junctions in a phosphatase‐independent manner. Overexpression of wild‐type or phosphatase “dead” VE‐PTP mutant similarly decreased the VE‐cadherin internalization rate without having any effect on VE‐cadherin recruitment rate. Consistent with these data, depletion of VE‐PTP increased VE‐cadherin internalization rate from AJs as compared to control cells suggesting that VE‐PTP stabilizes AJs in resting endothelial monolayers. Interestingly, treatment of cells with VE‐PTP phosphatase inhibitor had no effect on VE‐cadherin kinetics, further indicating a specific role of VE‐PTP in regulating stability of AJs independent of Aniopoetin‐1/Tie2 signaling. The phosphatase‐independent role of VE‐PTP was further investigated by elucidating VE‐PTP binding partners through mass spectrometry analysis. We found that VE‐PTP binds to GEF‐H1, a RhoA GEF, and inhibits RhoA activity at AJs. Knockdown of GEF‐H1 reduced both RhoA activity at AJs and tension across VE‐cadherin adhesion in VE‐PTP knockdown cells. These events coincided with restoration of VE‐cadherin kinetics at AJs suggesting that VE‐PTP stabilizes VE‐cadherin junctions via inhibition of RhoA and intracellular tension. Our data, for the first time, describe the scaffold function of VE‐PTP at AJs in the mechanism of AJ stabilization.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Loss of function RGS2 mutations augment vascular contractility ex vivo
Authors: Phan Hoa Thi Nhu , Jackson William , Neubig Richard 
Published: June 2021

ObjectiveRegulator of G protein signaling 2 (RGS2) plays a significant role in alleviating vascular contraction and promoting vascular relaxation due to its GTPase accelerating protein activity toward Gαq. Through a cell‐based Ca2+ mobilization assay, we identified 4 loss‐of‐function (LOF) mutations (Q2L, D40Y, R44H and R188H) out of 16 rare, missense mutations in RGS2 selected from various human exome sequencing projects. This study is to investigate whether these LOF RGS2 mutations disrupt the protein function in regulating vascular contractility.Approach and resultWe confirmed that RGS2‐deficient mice expressed a hypertensive phenotype by telemetric femoral artery blood pressure measurement in conscious mice (WT SBP 120 ± 3 vs RGS2−/−SBP 128 ± 2 mmHg, p<0.01). Isolated mesenteric arteries from RGS2−/− mice showed higher contractile response to 10 nM angiotensin II (AngII) stimulation in pressure myograph while isolated aortic rings from those animals generated more tension upon phenylephrine (PE) stimulation (Emax 238 mg vs 68 mg, p = 0.01) compared to aortic rings from RGS2+/+ mice. Reintroduction of wild‐type RGS2‐GFP plasmids into RGS2−/− mesenteric arteries by reversible permeabilization suppressed the vasoconstrictor response to 50 nM AngII (RGS2 WT plasmid −4% vs pcDNA control −35% of basal diameter, p = 0.01). Transfection with RGS2 LOF mutation plasmidss did not suppress Ang II constriction compared to those expressing WT‐RGS2 (Q2L −20%, D40Y, R44H and R188H −30% of basal diameter, p < 0.05).ConclusionsThis study is the first to investigate the function of human mutant RGS2 in resistance arteries in a near physiological condition. It demonstrates that RGS2 attenuates vasoconstriction in the mesenteric arteries and that RGS2 mutations disrupt this effect. Although these mutations are rare, knowledge about their function may provide insights into pathophysiology and treatment.Support or Funding InformationThis work was supported by the American Heart Association predoctoral fellowship [15PRE24680004] to H.P).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Enhanced Arterial Medial Calcification in Mice with Smooth Muscle‐Specific Deletion of Lysosomal Acid Ceramidase.
Authors: Bhat Owais M. , Yuan Xinxu , Zhang Yang , Boini Krishna , Lohner Hannah , Li Pin‐Lan 
Published: June 2021

Arterial medial calcification (AMC) is associated with transition of arterial smooth muscle cells (SMCs) to osteogenic phenotype. These arterial SMCs secrete matrix vesicles or exosomes to form the first nidus for mineralization. However, the mechanisms mediating exosome excretion in SMCs remain poorly understood. Whether SMC‐specific lysosomal Asah1 gene (acid ceramidase (AC) gene code in mice) expression and associated lysosomal ceramide signaling are required for osteogenic phenotype change and exosome excretion are unknown. In the present study, we used Asah1fl/fl/SMcre mice with SMC‐specific deletion of lysosomal AC and Smpd1trg/SMcre with SMC‐specific overexpression of acid sphingomyelinase (ASM) gene (mouse gene code: Smpd1) to demonstrate the role of lysosomal ceramide signaling pathway in AMC. Using high dose of vitamin D (500,000 IU/kg/day) to induce AMC, Asah1fl/fl/SMcre mice were found to have increased expression of RUNX2 and osteopontin, but downregulation of SM22‐α (SMC marker) with decreased ratio of α‐SMA vs. vimentin in coronary and aortic media compared to their littermates (Asah1fl/fl/WT and WT/WT mice). Asah1fl/fl/SMcre mice also had augmented AnX2 and ALP expression (exosome markers) and reduced co‐localization of lysosome marker (LAMP‐1) with multivesicular body marker (VPS16) in both coronary and aortic media. Morphological examinations confirmed that severe AMC occurred in both aorta and coronary arteries in Asah1fl/fl/SMcre, but not in their littermates. In Smpd1trg/SMcre mice, similar biochemical and morphological changes were found to Asah1fl/fl/SMcre mice. These data indicate that lysosomal AC in SMC plays a critical role in osteogenic phenotype change, exosome release and mineral deposition in the mouse model of AMC and that lysosomal ceramide signaling pathway may control exosome excretion and osteogenic phenotype transition in SMCs that determine the development of AMC.Support or Funding Information(Supported by NIH grants HL057244, HL075316 and HL122937).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 Colonic Inflammation on Morphine Induced Antinociceptive Tolerance
Authors: Komla Essie , Dewey William L. , Akbarali Hamid I. 
Published: June 2021

Opioids are one of the most widely prescribed classes of drugs for the treatment of moderate to severe pain. Opioids are prescribed for abdominal pain, a major symptom associated with Crohn's Disease. Recent studies have reported that continued opioid use in patients with Crohn's Disease is associated with increased mortality rate, duration and severity of disease, as well as infection. However, it is not clear if this association is causal. We have previously demonstrated that chronic use of morphine, in addition to the development of antinociceptive tolerance, also causes the disruption of the intestinal barrier function resulting in bacterial translocation from the gut lumen into the peritoneal organs, thus inducing an inflammatory response in the colon. Therefore, we tested if inflammation in the colon, as in Crohn's disease, affects the rate of antinociceptive tolerance development to morphine. To test this hypothesis, we induced colonic inflammation in Swiss Webster male mice using 2,4,6‐trinitro‐benzene sulfonic acid (TNBS) or vehicle intrarectally and then surgically implanted 25 mg, 50 mg (2 × 25 mg), or 75 mg slow release morphine pellets or placebo pellets subcutaneously on the dorsum. Tail immersion assay was performed on day 3, 4, and 5 post treatment and colons were extracted from the animals to measure mRNA expression of Interleukin 1 beta (IL‐1β) and tumor necrosis factor alpha (TNF‐α) by real‐time polymerase chain reaction (RT‐PCR). A morphine (10 mg/kg) challenge was used to test for the development of antinociceptive tolerance at various times in morphine pelleted with (n= 7) or without TNBS (n= 5). In TNBS + morphine pelleted mice, tolerance developed by day 5 in 25 mg morphine pelleted mice, by day 4 in 50 mg (2 × 25 mg) morphine pelleted mice, and as early as day 2 in 75 mg morphine pelleted mice. In the absence of TNBS‐induced inflammation, tolerance to morphine did not develop to either 25 mg or 50 mg morphine pellets up to day 5, and at day 4 in 75 mg morphine pellets. Furthermore, IL‐1β production was significantly increased in the morphine and placebo pelleted treated animals with TNBS from day 1 compared to the vehicle treated groups. In summary, chronic morphine administration in the presence of colonic inflammation leads to an increased rate and extent of antinociceptive tolerance development.Support or Funding InformationAgency: NIDA Agency Number: 5R01DA036975‐04This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
SML0417 from Saussurea lappa ameliorates asthma features in murine allergic asthma model
Authors: Nam So‐Yeon , Lee Bo‐Kyung , Kang Saeromi , Park Soo‐Jin , Im Dong‐Soon 
Published: June 2021

BackgroundThe root of Saussurea lappa has traditionally been used as an ingredient in the treatment of asthma, rheumatism, abdominal pain, anorexia, nausea, and other conditions. Extracts of Saussurea lappa were reported to alleviate house dust mite‐induced atopic‐like dermatitis in Nc/Nga mice, and sesquiterpene lactones were isolated.METHODSTo elucidate whether SML0417, a sesquiterpene lactone has beneficial effects on allergic asthma, anti‐asthma effects were studied using female Balb/c mice and rat RBL‐2H3 mast cells. Antigen‐induced degranulation was measured in vitro by measuring β‐hexosaminidase activity. A murine ovalbumin‐induced allergic asthma model was used to test the in vivo efficacy of SML0417.RESULTSAntigen‐induced degranulation was inhibited by SML0417. Sensitization and challenge of ovalbumin induced allergic asthma responses. Histologic studies showed administration of SML0417 reduced inflammatory signs and mucin production in lungs. Administration of SML0417 decreased numbers of inflammatory cells, especially eosinophils, and reduced the expression and secretion of Th2 cytokines, including IL‐4 and IL‐13, in lung tissues and bronchoalveolar lavage fluid.CONCLUSIONThe present findings provide evidence that SML0417 has a potential therapeutic use in allergic asthma.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.