bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessing the Activity of Synthetic Opioid AH‐7921 and U‐47700 Analogs in Cloned Human Mu‐Opioid Receptor Expressing Fibrosarcoma HT‐1080 Cells
Authors: Hsu Tom , Mallareddy Jayapal , Yoshida Kayla , Lee Tim , Kemboi Edna , Park Emily , Krstenansky John , Zambon Alexander 
Published: June 2021

While important for their antinociceptive properties in medicine, opioids are commonly abused in America due to easily accessible opiate prescription pain medication. Classic opioids can induce adverse side effects such as gastrointestinal dysfunction and fatal respiratory depression, the latter of which is a key underlying factor contributing to the rising rates of lethality of opioid abuse. New synthetic opioids are emerging on the black market, many of which have not been characterized for structure activity relationships at human mu‐opiate receptors (hOPRM1). The rise of new synthetic opioids complicates the opioid crisis in America as they often escape the traditional illicit drug classifications established by law enforcement and may be more potent and lethal than conventional molecules. In this study, we developed a stable amino terminal HA‐tagged hOPRM1 expressing human fibrosarcoma (HT1080) cell line for determining the pharmacology of a panel of opioids analogs derived from synthetic opioids AH‐7921 and U‐47700. Expression of hOPRM1 was verified by Western blot and immunocytochemistry. Assessing the morphine response in this cell line revealed that morphine EC50 (39.3 nM) was comparable to published findings and were naloxone reversible, thereby validating this cell line. The analogs were assessed for their ability to suppress forskolin‐induced cyclic AMP (cAMP) levels in a hOPRM1‐dependent manner revealing a subset of structurally‐related analogs showing functional activity. The preliminary results found in this study indicate that some of the synthetic opioid analogs are likely to have abuse potential based on their ability to bind to and activate the human OPRM1 receptor.Support or Funding InformationThis project was supported by Award No. 2016‐R2‐CX‐0059, awarded by the National Institute of Justice, Office of Justice Programs, U.S. Department of Justice. The opinions, findings, and conclusions or recommendations expressed in this publication/program/exhibition are those of the author(s) and do not necessarily reflect those of the Department of Justice.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Alpha‐2c Adrenergic Receptor Promotes the Malignant Phenotype of Colon Cancer Cells
Authors: Njeim Rachel , Eid Ali 
Published: June 2021

Cancer remains one of the leading causes of death worldwide, with colorectal cancer (CRC) being the third most common type. Accumulating evidence shows that stress plays a pivotal role in the malignant phenotype of CRC, by promoting hallmarks of CRC including cellular proliferation, migration, invasion, and angiogenesis. During stressful situations, the sympathetic nervous system is activated, causing an elevation in levels of catecholamines, including epinephrine which elicits its effects mainly by activating adrenoceptors. Interestingly, however, the role of alpha2C adrenergic receptor (a2c‐AR) in CRC malignancy remains obscure. Here, we proposed that activation of a2c‐AR potentiates the malignant phenotype of human CRC cells. Treatment of human colon cancer cell lines, SW480 and HT‐29, with increasing concentrations of a2‐AR specific agonist (UK 14,304; 10, 30 or 100 nM) for different time points (24, 48, or 72 hours) did not cause a significant change in proliferation. However, using monolayer scratch assay, a significant increase in migration was observed after treatment with UK 14,304 (100 nM) for 8 and 12 hours in both cell lines. This was further supported by a transwell migration assay where UK 14,304 increased cell migration. Pretreatment with a specific a2c‐AR antagonist (JP 1302; 100 nM) abolished the UK 14,304‐induced cell migration. This increase in migratory capacity was concomitant with increased Rho activation evident by translocation of Rho from cytoplasm to the membrane as well as via a Rhotekin‐binding activation assay. Moreover, treatment with UK 14,304 evoked actin reorganization, an element known to be a prerequisite for cell migration. The induced Rho activation and actin cytoskeletal rearrangement could be mediated by increased oxidative stress since treatment with UK 14,304 increased ROS production. Importantly, ROS is known to induce migration of these cells. Furthermore, adhesion of colon cancer cells to TNF‐alpha‐activated HUVECs was promoted by UK 14,304. This UK14,304‐induced adhesion was followed by a dramatic increase in transendothelial migration of SW480 through HUVECs, clearly indicating that a2c‐AR activation may promote intra‐ or extravasation. Because breaking the endothelial cell barrier requires matrix digestion, we measured the levels of matrix metalloproteinases (MMPs). Importantly, stimulation of a2c‐ARs by UK14,304 increased the production of MMP2 and MMP9, and JP 1302 abolished this UK14,304‐induced production. Taken together, our data suggests that a2c‐AR potentiates the migratory and invasive capacities and hence the malignant phenotype of human colon cancer cells. Therefore, a2c‐AR may represent a novel target in the treatment of CRC.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Deciphering the Role of SLX4IP in Telomere Maintenance Mechanisms
Authors: Whited Tawna , Robinson Nathaniel , Grabowska Magdalena , Schiemann William , Taylor Derek 
Published: June 2021

Telomeres are protective caps found at chromosomal ends that act to prevent attrition of the genome and aberrant activation of DNA repair mechanisms. In somatic cells, telomeric DNA progressively shortens with rounds of replication until a critically short length is reached triggering the cell to undergo senescence to prevent loss of genomic information. However, some cells express telomerase to elongate telomeres and avoid reaching this critical length, thus instilling additional replicative capacity. Notably, 85% of all cancer cells upregulate telomerase and the remaining 15% primarily utilize the alternative lengthening of telomeres (ALT) pathway which relies upon homologous recombination. There is evidence to suggest that cancer cells have the ability to switch to the ALT pathway, should telomerase activity be compromised, but the molecular switch regulating this process is unknown. A recently identified protein, SLX4IP, appears to play a critical role in telomere homeostasis and the telomerase‐to‐‐ALT conversion. In order to identify the basic function of SLX4IP in telomere homeostasis, the interactome of SLX4IP must be interrogated to identify additional proteins involved under specific conditions. For example, identifying differences between the interactomes in telomerase‐positive and ALT‐positive cells will provide insight regarding SLX4IP in telomere maintenance mechanisms. Initially, immunoprecipitation experiments were carried out to identify discrepancies in the proportion of known SLX4IP binding partners among telomerase‐positive and ALT‐positive cell lines. As expected, SLX4IP interacts with TRF2, a telomeric binding protein, and SLX4, an ALT‐associated nuclease scaffold protein, but with varying degrees among the cell types tested. To further dissect the interactome of SLX4IP, wild type SLX4IP, an N‐terminal mutant being interrogated for structural studies, and a C‐terminal mutant which represents a deletion mutant identified in acute lymphoblastic leukemia patients exhibiting poor prognosis were stably overexpressed in telomerase‐positive and ALT‐positive cell lines followed by subsequent immunoprecipitation and proteomic evaluation. This evaluation will provide valuable information as to which regions of SLX4IP are responsible for orchestrating particular interactions in each cell type. With this knowledge, a greater understanding of SLX4IP's role in telomere homeostasis and the telomerase‐to‐ALT conversion can be elucidated.Support or Funding InformationThis work was supported in part by an NIH T32 (GM008803) grant.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
A Hydrogen Sulfide Donor, JK1, Preserves Endothelial Function and Improves Exercise Capacity in Pressure Overload ‐ Induced Heart Failure
Authors: Li Zhen , Carnal Jean , Kang Jianming , Xian Ming , Lefer David J. 
Published: June 2021

Background and HypothesisHydrogen sulfide (H2S) protects against heart failure by ameliorating oxidative stress, improving mitochondrial function, and attenuating apoptosis. At present there is a lack of data demonstrating the protective actions of H2S in the late stages of heart failure. And the effects of H2S on exercise intolerance, the clinical hallmark of heart failure, has not been evaluated in preclinical models. In current study, we tested the efficacy of delayed therapy with a novel H2S donor, JK1, on cardiac function, endothelial function, and exercise capacity in a murine model of pressure overload‐induced heart failure.MethodsMale C57/BL6J mice at 10 weeks (wks) of age were subjected to transverse aortic constriction (TAC) for 18 weeks. JK1 (200 μg/kg/d, n=20) or the H2S deficient control compound (200 μg/kg/d, n=18) was administered via i.p. injection twice per day starting at 10 wks post TAC, in which time all mice had EF lower than 45%. Echocardiography was performed at baseline and tri‐weekly to assess LV structure and function. LV hemodynamics, cardiac fibrosis, vascular reactivity (isolated thoracic aorta), and exercise capacity were measured at the endpoint, 18 wks post TAC.ResultsDelayed treatment with JK1 initiated at 10 wks post TAC reduced LV dilation (p < 0.01) and attenuated eccentric hypertrophy (p < 0.01). However, no significant difference was noted in LV ejection fraction and cardiac fibrosis. JK1 treated mice displayed lower LV end‐diastolic pressure (LVEDP 17.8 ± 1.8 mmHg vs. 22.9 ± 1.23 mmHg, p < 0.05) and improved relaxation time constant (Tau 8 ± 0.27 ms vs. 10.05 ± 0.58 ms, p < 0.01). In addition, aortic vasorelaxation in response to acetylcholine treatment was markedly improved in mice received JK1 treatment (Max. Relaxation 51.8 ± 4.2% vs. 31.5 ± 3.6%, p < 0.01). More importantly, mice received JK1 treatment exhibited improved exercise capacity (Distance 312 ± 13.4 m vs. 89 ± 6.3 m, p < 0.05) as compared to those received control.ConclusionThese results demonstrate that delayed administration of a novel H2S donor, JK1, improves exercise capacity in severe heart failure following TAC. JK1 treatment initiated at 10 weeks post TAC did not improve systolic function or reduce cardiac fibrosis, suggesting that the beneficial effects of 10‐wks‐delayed H2S therapy in pressure overload heart failure are a result of the improved vascular function and LV hemodynamics.Support or Funding Information
AMP‐activated protein kinase activation by traditional herbal medicines and their active compounds ameliorates oxidative stress as mediated with liver kinase B1 and farnesoid X receptor
Authors: Baek Su Youn , Lee Eun Hye , Kim Young Woo 
Published: June 2021

BackgroundOxidative stress is a disorder in the oxidant‐antioxidant balance potentially leading to cellular damage in human. In the liver, oxidative stress stimulated by iron accumulation can induce a variety of chronic liver diseases, including liver fibrosis, cirrhosis and cancer. Oxidative stress resulting from iron accumulation may induce the release of arachidonic acid, and excessive amounts of arachidonic acid can cause high levels of cellular and mitochondrial ROS that reduce the functioning of mitochondrial respiration in the liver.MethodsThis study was designed to examine the effects of traditional herbal medicines and their active compounds against severe oxidative stress and mitochondrial impairment and its cellular mechanisms of action in vivo and in vitro.ResultsIn cell experiments, the medicinal herbs such as Fructus Ligustri lucidi and Glycyrrihiza Radix effectively protected hepatocyte from arachidonic acid + iron‐induced oxidative stress and apoptosis, as indicated by depletion of glutathione, formation of reactive oxygen species, increases in mitochondrial membrane permeability and altered expression of apoptosis‐related proteins, all of which are similar with aminoimidazole‐carboxamide ribonucletide treatment, as a positive control. In mice, The administration of the drug candidates also protected against oxidative stress and liver injury induced by carbon tetrachloride injection, as indicated by decreases in histological liver damage and serum alanine amino transferase level. Moreover, active compounds from the herbs also induced the activation of AMP‐activated protein kinase, which was mediated by its upstream kinase liver kinase B1 and farnesoid X receptor.ConclusionsOur results confirmed that beneficial herbs have the ability to protect hepatocytes and liver against oxidative injury through regulation of the AMP‐activated protein kinase signaling pathway. This work was supported by the National Research Foundation of Korea grant funded by the Korea government [MSIP] (No. 2017R1D1A3B03027847) and (2015K1A3A1A59069800). All authors disclose no conflict of interests.Support or Funding InformationThis work was supported by the National Research Foundation of Korea grant funded by the Korea government [MSIP] (No. 2017R1D1A3B03027847) and (2015K1A3A1A59069800). All authors disclose no conflict of interests.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Activation of Endothelial Nitric Oxide Production by the Sigma Receptor Agonist Afobazole
Authors: Motawe Zeinab Y. , Katnik Christopher P. , Trujillo Andrea N. , Cuevas Javier , Breslin Jerome W. 
Published: June 2021

Afobazole is a sigma‐1 receptor agonist that has been shown to enhance survival in a rat mid‐cerebral artery occlusion stroke model. The mechanism has been previously attributed to an inhibition of ischemia‐induced calcium dysregulation that lowers glial cell loss and infarct volume. A recently published finding is that afobazole can stimulate nitric oxide (NO) production from lymphatic endothelial cells. In the current study, we investigated the ability of afobazole to relax arterioles from the brain and potential interactions between the sigma‐1 receptor and endothelial NO synthase (eNOS). Parenchymal arterioles were isolated from brains of Sprague‐Dawley rats and mounted onto glass micropipettes in a 37 °C bath containing albumin‐physiological salt solution. Afobazole was applied to the bath at concentrations of 50, 100, 150, 200, and 250 μM. The ability of afobazole to elicit NO production from cultured human brain microvascular endothelial cells (HBMEC) was assessed using 4‐Amino‐5‐Methylamino‐2′,7′‐Difluorofluorescein Diacetate (DAF‐FM) loading and fluorescence microscopy. Phosphorylation of eNOS on Ser‐1177 in the absence or presence of afobazole was evaluated by Western blotting. Lastly, intracellular localization of eNOS and the sigma‐1 receptor were evaluated by immunofluorescence and laser confocal microscopy. The results show that 200 and 250 μM afobazole elicited significant dilation of parenchymal arterioles. Afobazole also elicited elevated NO production from HBMEC in association with elevated phosphorylation of eNOS on Ser‐177. Lastly, eNOS and the sigma‐1 receptor were found partially colocalized in what appears to be the Golgi complex in confocal image stacks of HBMEC. This study shows for the first time a novel mechanism by which afobazole can relax brain arterioles via eNOS‐mediated NO production. This mechanism is likely associated with previously reported improvements of outcomes following stroke induced brain injury.Support or Funding InformationSupported by NIH grant R01GM120774.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Hyperglycemia Enhances Constriction of Retinal Venules to Endothelin‐1 via Activation of the Reverse‐Mode Sodium‐Calcium Exchanger
Authors: Chen Yen‐Lin , Xu Wenjuan , Rosa Robert H. , Kuo Lih , Hein Travis W. 
Published: June 2021

The ocular level of vasoconstrictor endothelin‐1 (ET‐1) is elevated in diabetic retinopathy, which is associated with hyperglycemia and increased retinal vascular fluid filtration, a process heavily influenced by postcapillary pressure and venous constriction. However, the impact and mechanistic action of ET‐1 on venular vasomotor activity in the retina remain unclear. We addressed these issues by examining the contributions of ET‐1 receptor subtypes, extracellular calcium, and reverse‐mode sodium‐calcium exchanger (NCX) to ET‐1‐induced constriction of retinal venules during exposure to euglycemia and hyperglycemia. Retinal venules (<150 μm maximum diameter) were isolated from streptozocin‐induced diabetic pigs (2‐wk; chronic hyperglycemia: 456 ± 26 mg/dl) or age‐matched control pigs (euglycemia: 98 ± 3 mg/dl) and then cannulated and pressurized to 5 cmH2O for vasoreactivity study. For acute hyperglycemia study, vessels from euglycemic pigs were exposed intraluminally to high glucose (25 mM ≈ 450 mg/dl) for 2 hr, and normal glucose (5 mM ≈ 90 mg/dl) served as the control. Porcine retinal venules developed stable basal tone (constricted to about 90% of maximum diameter) and constricted to ET‐1 in a concentration‐dependent manner. This vasoconstriction was significantly increased after exposure to acute or chronic hyperglycemia and was abolished in the presence of ETA receptor antagonist BQ123 or extravascular calcium‐free solution, but not ETB receptor antagonist BQ788. The reverse‐mode NCX inhibitors SEA0400 and KB‐R7943 prevented the enhanced constriction of retinal venules to ET‐1 during chronic hyperglycemia, but they did not alter the ET‐1‐induced constriction of retinal venules during acute or chronic euglycemia. Furthermore, the mRNA levels of ETA receptors, ETB receptors, and NCX isoforms (NCX1, NCX2, and NCX3) in retinal venules were not influenced by chronic hyperglycemia. In conclusion, ET‐1 elicits ETA receptor‐dependent constriction of porcine retinal venules related to extracellular calcium entry. Although the calcium entry mode of NCX does not appear to contribute to venular constriction to ET‐1 during euglycemia, hyperglycemia enhances this vasoconstriction by activating the reverse‐mode NCX independent of changes in NCX and ET‐1 receptor mRNA expression levels. The ability of hyperglycemia to augment venular constriction to ET‐1 may elevate postcapillary pressure and promote retinal tissue edema during diabetic retinopathy. Blockade of reverse‐mode NCX in retinal venules may provide a new therapeutic strategy to mitigate this pathologic process.Support or Funding InformationNIH Grants R01EY023335 and R01EY024624, Kruse Chair Endowment Fund, and Retina Research FoundationThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Association between Cerebrovascular Reactivity and Intravascular Cellular Activation in Postmenopausal Women Following Use of Menopausal Hormone Treatments
Authors: Pearson Andrew G. , Jayachandran Muthuvel , Lahr Brian D. , Joyner Michael J. , Miller Virginia M. , Barnes Jill N. 
Published: June 2021

Cerebrovascular reactivity to hypercapnia, an estimate of microvascular responses in the brain, is increased during menopausal hormone treatment (MHT) in postmenopausal women. It is unclear whether this effect of MHT continues beyond the treatment period. We hypothesized that prior MHT use would not affect cerebrovascular reactivity 3 years after treatment. In addition, we have previously shown that cerebrovascular reactivity is associated with vascular activation in postmenopausal women with elevated cardiovascular risk. We hypothesized that cerebrovascular reactivity is not associated with markers of intravascular cellular activation in postmenopausal women with low cardiovascular risk who are within 10 years of menopause. Cerebrovascular reactivity to hypercapnia was measured in 58 postmenopausal women from the Kronos Early Estrogen Prevention Study at Mayo Clinic 3 years after the cessation of MHT [oral conjugated equine estrogen (oCEE), n=15; transdermal 17β‐estradiol (tE2, n=22); or placebo (PLA, n=23)]. Cerebrovascular reactivity was estimated from the middle cerebral artery flow velocity (MCAv) response to hypercapnia. Mean arterial blood pressure (MAP) was measured continuously throughout the protocol. Fasting blood was analyzed for a set of 14 activation markers of platelet and endothelial cells, inflammation and thrombogenicity. Principal components (PC) analysis was used to reduce these measures to fewer dimensions on which the associations of intravascular cellular activation with cerebrovascular reactivity could be based. Women were 60±3 years of age with a body mass index of 28±4 Kg/m2. MAP (99±14 mmHg in PLA, 97±7 mmHg in tE2, 98±9 mmHg in oCEE; p>0.90) and MCAv (60±14 cm/s in PLA, 68±20 cm/s in tE2, 71±18cm/s in oCEE; p>0.16) did not differ among groups. Cerebrovascular reactivity did not differ among women based on previous MHT randomization (1.2±0.7 cm/s/mmHg in PLA, 1.4±1.0 cm/s/mmHg in tE2 and 1.7±1.0 cm/s/mmHg in oCEE; p>0.17). The 14 markers of intravascular cellular activation were reduced to five PC that did not differ based on prior MHT assignment. There was no overall association of cellular activation PC with cerebrovascular reactivity. Effects of MHT on cerebral microvascular reactivity do not extend beyond the time of menopausal hormone treatment. Intravascular cellular activation does not alter cerebrovascular reactivity to hypercapnia in postmenopausal women with low cardiovascular risk profiles 3 years after the cessation of MHT.Support or Funding InformationNIH grant P50 AG44170This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.