bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gαo Proteins Mediate the Antihyperalgesic and Antidepressant‐like Effects, but not the Convulsive Effects, Produced by Delta Opioid Receptor Activation
Authors: Dripps Isaac , Neubig Richard , Rice Kenner , Jutkiewicz Emily 
Published: November 2023

The delta opioid receptor (DOPr) is a member of the opioid receptor family of G protein‐coupled receptors (GPCRs). Activation of DOPr induces antihyperalgesia and antidepressant‐like effects in animal models. However, some DOPr agonists cause convulsions, hindering their development as therapeutics in humans. Regulator of G protein signaling (RGS) proteins act as negative modulators of GPCR signaling. Our lab has previously demonstrated that RGS4 acts as a negatively modulator of DOPr‐mediated antihyperalgesia and antidepressant‐like effects without impacting convulsions. These findings indicate that the antihyperalgesic and antidepressant‐like effects of DOPr are G protein‐mediated. However, DOPr is known to couple to multiple Gi/o proteins. Therefore, we sought to determine which G protein mediates these behaviors and whether that G protein also plays a role in generating DOPr‐mediated convulsions.To this end, we compared behaviors induced by the DOPr agonist SNC80 in Gαo RGS‐insensitive (RGSi) knock‐in, and Gαo heterozygote knockout mice. DOPr‐mediated antihyperalgesia was evaluated using a CNS‐mediated nitroglycerin‐induced thermal hyperalgesia assay. Antidepressant‐like effects were measured using the forced swim test. The potency of SNC80 to produce antihyperalgesia was significantly increased in the Gαo RGSi mice. SNC80 also produced antidepressant‐like effects in the Gαo RGSi mice with enhanced potency and efficacy. In the Gαo heterozygote knockout mice, SNC80‐induced antihyperalgesia was completely abolished while antidepressant‐like effects in the forced swim test were unaltered. There were no changes in the frequency, duration, or time of onset of SNC80‐induced convulsions in either mouse strain.Taken together, our data demonstrate that DOPr‐mediated antihyperalgesia and antidepressant‐like effects require Gαo. A 50% loss in Gαo was sufficient to abolish the antihyperalgesic, but not the antidepressant‐like effects of DOPr, indicating that DOPr‐mediated antidepressant‐like effects had a lower efficacy requirement than the antihyperalgesic effects. Ostensibly, DOPr‐mediated convulsions are not regulated by Gαo. However, it is possible that the efficacy requirement for convulsions is low enough that they are unaffected by loss of RGS regulation or a 50% reduction in Gαo. DOPr‐mediated convulsions may also be generated by a G protein‐independent signaling mechanism such as the β‐arrestin pathway. Future studies will focus on investigating the efficacy requirements of DOPr‐mediated behaviors and characterizing these behaviors in β‐arrestin2 knockout mice.Support or Funding InformationResearch support was provided by start‐up funds to EMJ.
Peptidomimetics Exhibiting Mu Opioid Receptor (MOPr) Agonist/Delta Opioid Receptor (DOPr) Antagonist Activity as Novel Pain Therapeutics
Authors: Griggs Nicholas , Bender Aaron , Gao Chao , Anand Jessica , Traynor John , Mosberg Henry 
Published: November 2023

Drug discovery and development of opioid ligands has largely favored highly selective agonists/antagonists for a single opioid receptor (OPr); opioid analgesics, such as morphine, are primarily selective for and activate the mu opioid receptor (MOPr). However, evidence suggests an interaction with other OPrs may be beneficial in MOPr‐mediated analgesia. In particular, there is evidence that simultaneous activation of MOPr in the absence, or with inhibition, of the delta opioid receptor (DOPr) can reduce the development of morphine tolerance and dependence. Thus one strategy is to design single compounds, which bind to and concurrently activate MOPr while inhibiting DOPr, as potential therapeutics for the improved clinical management of pain. Here we report on the pharmacological evaluation of a series of compounds with a tetrahydroquinoline (THQ) core and with chemically diverse substituents that alter steric and electronic characteristics of the molecules. The compounds are peptidomimetics based on key elements of opioid peptides vital for activity but that have small molecule‐like features to provide for bioavailability, blood brain barrier permeability, and duration of action in vivo. The peptidomimetics were characterized in vitro by ligand binding to provide affinity (Ki) values and for potency and relative efficacy (EC50, % stimulation compared to standard agonist) using the degree of incorporation of GTPγ35S into G proteins in membranes from cells expressing MOPr or DOPr. Peptidomimetics showing an appropriate profile of similar binding affinity for MOPr and DOPR but acting as MOPr agonists and DOPr antagonists were evaluated for their antinociceptive activity and tolerance liability using the mouse warm water tail withdrawal assay. Certain compounds showed maximal analgesic efficacy that lasted for more than 3 hours as well as a reduction in the development of tolerance. Analysis of in vitro and in vivo data and docking peptidomimetics into the MOPr active and DOPr inactive crystal structures revealed structure‐activity relationships to guide further chemical synthesis and drug development of improved analogues with MOPr agonist/DOPr antagonist activity.Support or Funding InformationFunded by DA‐03910 and the Pharmacological Sciences Training Program (NIGMS‐GM007767)
A biased mu‐opioid receptor positive allosteric modulator that does not alter receptor regulation
Authors: Livingston Kathryn E , Traynor John R 
Published: November 2023

Currently used opioid analgesics compete with endogenous opioid peptide ligands by binding to the orthosteric site of the mu opioid receptor (MOPr). Activation of this G protein‐coupled receptor (GPCR) affords analgesia but also causes respiratory depression, sedation, constipation, and euphoria leading to a high addictive liability. Our lab is currently pursuing the idea that positive allosteric modulators of MOPr (mu‐PAMs) may be a way to treat pain with a better therapeutic profile. Such compounds, including the lead ligand BMS‐986122, enhance the affinity, potency, and efficacy of opioid agonists to bind MOPr and activate G protein. On the other hand, BMS‐986122 does not stimulate G protein activation, as measured by [35S]GTPγS binding in the absence of an orthosteric ligand. Here, we sought to determine if BMS‐986122 activates non‐G protein mediated pathways downstream of MOPr and to investigate the long‐term consequences of BMS‐986122 exposure on the regulation of MOPr in vitro using C6 rat glioma cells expressing rat MOPr. The results demonstrate that BMS‐986122 initiates phosphorylation of ERK1/2 in a pertussis‐toxin insensitive manner supporting a G protein‐independent mechanism. BMS‐986122 alone did not cause any long‐term adaptations in MOPr signaling. Moreover, in contrast to its ability to enhance agonist‐mediated activation of G protein, BMS‐986122 failed to enhance agonist‐induced desensitization of MOPr as measured by receptor downregulation, receptor phosphorylation, and loss of receptor‐mediated signaling following long‐term agonist exposure. Development of biased allosteric ligands at GPCRs represents a novel avenue for analgesic drug development. Future work will determine the physiological consequences of this biased PAM in mouse models of pain.Support or Funding InformationFunded by DA039997
Evaluation of Analytical Parameters by Mineralization by Dry Method for Lead Detection in Urine
Authors: Giolo Janaina Aparecida , da Silva Cunha Tiritan Gabrieli , Neves Fernando Tozze Alves 
Published: November 2023

Lead is a metal with no physiological function in the human body, but with harmful effects known since ancient times. Into human body, it is metabolized and complexed to macromolecules, being directly absorbed, distributed in several compartments including blood, soft tissues (kidney, bone marrow, liver and brain), and mainly mineralized tissues (bones and teeth), and it is subsequently excreted, remaining in the body for large periods due to its prolonged half‐life. Both blood and urine may represent suitable samples for analysis, depending of convenience and in accordance with the purpose of the toxicological study performed. For acute poisoning cases, the urine represents the sample choice for screening tests. Among the various methodologies for the toxicological screening tests of metals, the mineralization by the dry process technique is considered the most suitable, especially for lead. In literature, there are few analytical parameters described regarding the sensitivity and specificity of this method. Thus, this study aimed to evaluate the analytical parameters of the mineralization by dry method in urine samples, containing five different concentrations of lead (10; 5,0; 2,5; 1,0 and 0,1 ppm). For the tests, we used blank urine samples contaminated with different forms of lead (nitrate, acetate and chloride) in the concentrations established. The trials were carried out in duplicate by the dry mineralization method with 100 mg (0.1g) of potassium iodide. Our results show that it is possible to verify that this methodology is not specific as to the types of lead compounds tested because all of them had a positive reaction to the test (yellowish color); however, there was lower staining intensity in the lead nitrate. Regarding the sensitivity, it was possible to detect the presence of lead in samples from the concentration of 0.1 ppm in all kinds of compounds analyzed. Thus, we conclude the mineralization method can be considered as a sensitive method, but not so specific regarding the differentiation of lead compound types present in a sample. The formation of the yellowish color in reaction to the potassium iodide makes it specific compared to the other heavy metals.Support or Funding InformationUniversity of Sagrado Coracao (USC), Bauru, Sao Paulo, Brazil.
Organic Cation Transporters in Drug Interactions with Methamphetamine and Metabolites
Authors: Wagner David James , Wang Joanne 
Published: November 2023

Methamphetamine (Meth) is the second most commonly abused illicit drug with marijuana being the first. High levels of Meth abuse are reported in individuals receiving treatment for HIV and hepatitis who may be receiving multiple drugs for treatment. Organic cation transporters (OCTs) and multidrug and toxin extrusion transporters (MATEs) are known to be involved in tissue distribution and elimination of a number of these antiretrovirals including lamivudine and zalcitabine. Meth and its main metabolites (amphetamine and p‐hydroxyMeth) are organic cations but their potential effects and drug interaction potential with the OCTs and MATEs are poorly understood. The goal of this study is to determine if Meth and metabolites inhibit renal and hepatic OCTs and MATEs, which may lead to clinically significant drug‐drug interactions with antiretroviral drugs in Meth users. The inhibitory effects of Meth and metabolites are determined using uptake assays in cell lines stably expressing human OCT and MATE transporters and the drug interaction potential is assessed by comparing IC50 values with reported Meth/metabolite concentrations in drug abusers. Meth inhibited hOCT1, hOCT2, hOCT3, hMATE1, and hMATE2k at clinically relevant drug concentrations with the greatest potencies against hOCT1 (IC50 = 21 ± 8.8 μM) and hOCT2 (IC50 = 17 ± 6.8 μM). Amphetamine showed a similar inhibition potency and pattern towards these transporters. p‐hydroxyMeth is a more potent inhibitor of hOCT3, exhibiting approximately 8‐fold greater potency than Meth but was approximately 5‐fold less potent toward hOCT2. Based on the reported blood concentrations of Meth and metabolites in illicit users and the FDA guidance on transporter‐mediated DDIs, our studies suggest potential in vivo drug interactions of Meth with drug substrates of the OCTs and MATEs. This information can be considered when prescribing medications to suspected or known abusers of methamphetamine to mitigate the risk of increased toxicity or reduced therapeutic efficacy.Support or Funding InformationThis study was supported by NIH grants P01DA032507 and T32GM07750.
Tamoxifen affects PLCg1 expression in ER+ breast cancer cells
Authors: Vergne Ralphdy , Ortiz Carmen , Godoy Lenin , Matta Jaime 
Published: November 2023

Phospholipase C gamma 1 (PLCg1) can be found in the cytoplasm and in the nucleus of the cells and is involved in signal transduction pathways and proliferation. Previous data from our lab shows that PLCg1 expression in breast cancer cells is higher in comparison to non‐tumorigenic cells. Also, oxidative stress‐induced PLCg1 activation enhances cell survival. Many anticancer drugs can cause oxidative stress as a side effect, such as tamoxifen. Tamoxifen is currently used for the treatment of both early and advanced estrogen receptor positive (ER+) breast cancer in pre‐ and post‐menopausal women. In addition, patients using tamoxifen have a higher probability to develop oxidative stress by consequence of the drug. Our aim is to compare and analyze PLCg1 expression in an ER+ breast cancer cell line (MCF‐7) under the effect of tamoxifen. Our hypothesis is that there will be a high expression of PLCg1 in cells treated with tamoxifen in comparison to untreated cells. To achieve this, we cultured MCF‐7 cells using complete media without phenol red and 4μM tamoxifen. After 24hrs, cells were lysed and protein and RNA were extracted. To determine PLCg1 expression we used a Taqman gene expression assay using GAPDH as housekeeping gene. Our results shows that PLCg1 expression was two times higher in MCF‐7 cells treated with tamoxifen compared to untreated cells at 24 hrs. However, this effect was not statistically significant. This preliminary data indicates that the PLCg1 expression might be involved in ER modulation. Currently, we are developing an MCF‐7 cell line resistant to tamoxifen to further study the changes in PLCg1 protein and gene expression upon acquired resistance.Support or Funding InformationThis work was supported by the UPR‐PRISE Program Grant #R25GM096955 and NIGMS‐NIH grants R25GM082406 (CO), and 9SC1CA182846‐04. We also acknowledge the support of the Molecular and Genomics Core at Ponce Health Sciences University (NIMHD Grant MD007579).
In vitro Basis for Cell Line‐Dependent Interaction between Sorafenib and Dasatinib in Human Non‐Small Cell Lung Carcinoma Cell Lines
Authors: Zhou Qingyu , Choksi Riya , Guo Xiaofang 
Published: November 2023

BackgroundRecent clinical trials have demonstrated a better‐than‐average therapeutic outcome of the multi‐kinase inhibitor sorafenib in patients with chemorefractory non‐small cell lung carcinomas (NSCLCs) as well as the inevitable treatment failure due to the reduced tumor sensitivity to sorafenib over time. In search of strategies to overcome the acquired sorafenib resistance, we evaluated the feasibility of combining sorafenib with dasatinib for the treatment of NSCLCs with different sensitivity to sorafenib.MethodsThe sorafenib and dasatinib combination was evaluated in A549, H358 and H1915 human NSCLC cell lines. The effect of sorafenib and dasatinib alone and in combination on tumor cell growth was determined by the MTT assay using fixed molar concentration ratio design, inhibitory sigmoid Emax model and combination index (CI) theorem. Western blot analysis of changes in targeted signaling pathways were performed to assess sorafenib and dasatinib interactions.ResultsCombination of sorafenib with dasatinib inhibited the in vitro growth of A549, H358 and H1915 cells in an additive or synergistic fashion based on the CI values as defined by Chou and Talalay (mean CI = 0.99, 1.04 and 0.28 for A549, H358 and H1915, respectively). The improved in‐vitro sorafenib cytotoxicity by the combination in those NSCLC cells was associated with the increased inhibition of the AKT/GSK3 and MEK/ERK/p90RSK pathways.ConclusionsSorafenib and dasatinib exhibited increased cytotoxicity in NSCLC cell lines when used in combination. Given that the H1915 cell line was originally developed from a brain metastasis from a primary lung carcinoma, future studies are warranted for further assessment of the beneficial therapeutic effect of sorafenib and dasatinib combination in an in vivo orthotopic model of lung cancer metastasis to brain.Support or Funding InformationThis work is supported by the University of South Florida College of Pharmacy start‐up fund and Internal Seed Grant (2012–2013) to Q.Z.
Radiofrequency Renal Denervation Improves Left Ventricular Function and Hemodynamics Through Modulation of Natriuretic Plasma Peptides in the Setting of Heart Failure
Authors: Polhemus David J , Gao Juan , Scarborough Amy , Trivedi Rishi , Bradley Jessica , Goodchild Traci , Smart Frank , Kapusta Daniel R , Lefer David 
Published: November 2023

BackgroundOveractivity of the sympathetic nervous system plays a critical role in the pathogenesis of heart failure. We investigated the effects of renal sympathetic nerve denervation (RDN) on left ventricular (LV) function and vasoactive natriuretic peptide levels in a rodent model of ischemic heart failure.MethodsSpontaneously hypertensive rats (SHR) were subjected to 45 min of coronary artery ligation and reperfusion for 12 weeks. At 4 weeks post‐reperfusion, SHR underwent either bilateral radiofrequency RDN (n=9) or sham RDN (n=8) procedure. Every 2 weeks, transthoracic echocardiogram was performed using Vevo 2100 (Visualsonics). LV function was analyzed from EKV™ (ECG‐Gated Kilohertz Visualization) generated M‐mode long‐axis images. 12 weeks following reperfusion, plasma brain natriuretic peptide‐32 (BNP) and atrial natriuretic peptide (ANP) were quantified using ELISA technique.ResultsRDN preserved LV ejection fraction (49.4 ± 2.6 vs. 32.1 ± 2.6%, p < 0.05) and LV stroke volume (318 ± 24.5 vs. 215 ± 17.8 μl, p < 0.05) at 12 weeks compared to sham. Heart weight/tibia length was also markedly reduced in the RDN group (41 ± 2.4 vs. 49 ± 1.2 mg/mm, p < 0.05). Despite reduced cardiac enlargement, Plasma BNP levels (377.7 ± 12.0 vs. 166.6 ± 37.3 pg/ml, p < 0.05) and ANP levels (297.0 ± 25.7 vs. 57.0 ± 12.4, p < 0.05) were significantly elevated in the RDN treated group compared to sham.ConclusionRadiofrequency RDN improved LV function, reduced remodeling and significantly increased circulating cardioprotective natriuretic peptides. We conclude that RDN exerts beneficial effects in preventing and treating heart failure following coronary ischemia and reperfusion; in part via increasing circulating cardiprotective natriuretic peptides.Support or Funding InformationP30GM106392 to DK
Ontogeny Influences Pharmacological‐Induced L‐Type Ca2+ Dependent Contractility of Pulmonary Arteries in Sheep
Authors: Wolfe Craig , Brunelle Alexander , Longo Lawrence , Wilson Sean M 
Published: November 2023

We and others have shown that K+‐depolarization induced pulmonary arterial (PA) contraction is due to the combined activation of L‐type Ca2+ channels (CaL) and Rho kinase (ROK). In fetal sheep we demonstrated that CaL inhibition with nifedipine (NIF) reduced 125 mM K+‐mediated contraction up to about one‐half, with ROK contributing the remainder, and that the relationship between these two pathways was preserved following antenatal chronic hypoxia (CH). To better define the relationship between these pathways and the impact of antenatal CH, we tested the hypothesis that direct activation of CaL would elicit a NIF sensitive contraction and this contraction would be similar in arteries from fetus or adult. This was examined using wire‐myography approaches on small diameter PA isolated from late gestation fetal (~140 days) or adult sheep. Our results show that direct activation of CaL with 1 mM FPL 64176 (FPL) elicited a contraction that was similar to the maximum K+‐induced depolarization (TKmax) in fetus but was reduced in adults. The contraction due to 1 mM Bay K 8644 (BayK) was reduced relative to High K in both fetus and adult. In fetal and adult PA 10 mM NIF reduced FPL and BayK, but not High K‐induced contraction back to baseline. These data illustrate that there are subtle differences between FPL and BayK induced, NIF‐sensitive CaL‐dependent contraction with ontogeny and that direct CaL activation causes PA constriction in a distinct way compared to K+‐depolarization.Support or Funding InformationSupport from NIH
Western Medicine vs. Oriental Medicine in Hypertension Therapy: Case Study
Authors: Tulp Orien L , Chow Tin , Konyk Carla M , Einstein George P 
Published: November 2023

BackgroundHypertension [HTN] is a key risk factor for cardiovascular morbidity and mortality and is a leading cause of end‐stage renal disease; approximately 7.1 million deaths per year may be directly attributed to poor control of blood pressure. Advances in the diagnosis and treatment of HTN have had a major impact on management of this chronic disease. To determine the comparative effectiveness of conventional Western treatment vs drug free Oriental Therapy [OT] for HTN, we reviewed the data from two independent studies.Methods and ResearchThe prevention and therapy include multi variables that cause or contribute to the development of HTN. The research review is based on a review of the diagnosis and therapy of Western and Oriental medicine. The patients were administered the ARB Sartan [SR] in the EU and Amlodipine [AD] in USA. For patients in China the Chinese oriental medicine of Wu Cao Si Wu Tang formula was administered. For the treatment of high blood pressure [HTN] with this protocol, 21 were men and 9 women, age range 30–67 years old, with mean systolic pressure [SBP] of 160 mmHg or above, and the mean diastolic pressure [DBP] of 95 mmHg upon admission to the study.ResultsThe patients used SR in EU and AD in USA stabilized the systolic and diastolic blood pressure effectively, however with frequent side effects. The Chinese formula resulted in an equally effective outcome, defined as resulting SBP of 141 mmHg or less and DBP of 90 or less with normalization of BP and disappearance of symptoms of HTN, similar to that which was observed on the altiplano where abundant daily exercise and traditional Bolivian diet contributed to a healthy lifestyle [Tulp, 1994].ConclusionThe therapy by SR in EU and AD in USA to stabilize the blood pressure was equally effective to OT. Common side effects of SR included blurred vision, that was reported to be disruptive for driving and reading by patients. The AD side effects, which can be potentially life‐threatening, included hives, swelling of the throat, and difficulty breathing. In contrast, the Wu Cao Si Wu Tang formula is effective and no side effects were observed and appears to be a worthy alternative to present day conventional Western approaches for the treatment of HTN.Support or Funding InformationSupported by Institutional Resources of USAT and the Einstein Medical Institute