bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibiting G protein bg signaling blocks prostate cancer stem cell‐like properties and enhances the efficacy of paclitaxel
Authors: Vaddi Prasanna K. , Paudyal Prakash , Xie Qing , Chen Songhai 
Published: November 2023

Aberrant activation of G protein‐coupled receptors (GPCRs) is implicated in prostate cancer progression. As a treatment strategy, however, targeting GPCR has been challenging because prostate cancer cells overexpress many GPCRs, which have redundant roles in cancer progression. To address this redundancy, we tried to block signaling via a hub through which multiple GPCRs converge — the G‐protein Gβγ subunits. Inhibiting signaling via Gβγ by overexpressing the scavernger, Gαt, or the Gβγ inhibitor, gallein, in several castration‐resistant prostate cancer cell lines (i.e. PC3, DU145 and 22Rv1), impaired cell growth and migration in vitro, and halted tumor growth and metastasis in nude mice. The blockade of Gβγ signaling also diminished prostate cancer stem cell‐like activities, by reducing tumorsphere formation in vitro and tumor formation in a limited dilution assay in nude mice. Furthermore, Gβγ blockade enhanced the sensitivity of prostate cancer cells to paclitaxel treatment, both in vitro and in vivo. Together, our results identify a novel function of Gβγ in regulating prostate cancer stem‐cell‐like activities, and demonstrate that targeting Gβγ signaling is an effective approach in blocking prostate cancer progression and augmenting response to chemotherapy.Support or Funding InformationThis work was supported in part by grants from NIH grant GM094255 (S. Chen) and DOD PCRP breakthrough award PC111628 (S. Chen).
Response Surface Methodology as a Model for Combination Drug Therapy in Human Prostate Cancer Cells
Authors: Oblad Richard , Kenealey Jason 
Published: November 2023

Combining chemotherapeutic drugs to treat malignant tumors has been proven to be effective at preventing drug resistance, tumor regression, and reducing tumor size. Most combinations come from a regimen of treatments that were used in the past, or were devised using synergistic drugs that were identified using the Chou Talalay method. We modeled combination drug therapy in PC‐3 human prostate cancer cells using conventional chemotherapeutics (Mitoxantrone Hydrochloride, Cabazitaxel, and Docetaxel) and natural bioactive compounds (Resveratrol, Piperlongumine, and Flavopiridol). We measured cell viability via the Alamar Blue assay to identify effective concentrations and combinations of drugs. Three drugs were used per combination at varying concentrations. Those points were then used to plot a response surface using the statistical software JMP. The response surface generated provided us with an area of effective combinations which allowed us to differentiate between combinatorial and synergistic combinations. Strong synergistic effects between resveratrol, piperlongumine, cabazitaxel, and flavopiridol were observed, with weaker interactions between the aforementioned drugs and mitoxantrone. Cabazitaxel and docetaxel, both microtubule synthesis inhibitors, showed additive effects when used in combination, but were both effective when used in combination with other drugs. We propose response surface methodology as an effective tool in devising combination treatments based on the response of tumorigenic cell lines.Support or Funding InformationBYU Life Science Startup Grant
Identification of Pharmacogenetic Risk Factors for Zileuton‐Induced Liver Injury Using Diversity Outbred Mice
Authors: Harrill Alison , Gatti Daniel M , Luo Shaoke , Lyn‐cook Lascelles , Churchill Gary 
Published: November 2023

Zileuton is an orally active inhibitor of leukotriene synthesis that is currently used for the maintenance treatment of asthma, although there has been interest in expanding its indications to other inflammatory diseases involving leukotrienes, such as rheumatoid arthritis and inflammatory bowel disease. A limitation for expanding clinical usage is an association with rare (idiosyncratic), but serious liver injury. In this study, we hypothesized that genetic sequence variants could be identified that influence risk of zileuton‐induced hepatotoxicity. Diversity Outbred (DO) mice were used as a surrogate for the human population because they harbor a high degree of genetic diversity and this diversity is well‐randomized throughout the genome, providing an ideal platform for complex trait analysis. In this study, female DO mice were administered zileuton (300 mg/kg, N=400) or vehicle (N=50) and dosed daily for seven days (i.g.). Serum alanine aminotransferase (ALT) was significantly elevated in the zileuton group, with significant interindividual variability in response (mean ± SD and range ‐ vehicle: 38 ± 53, 16–71 U/L; zileuton: 48 ± 42, 14–481 U/L; P<0.05). Zileuton treatment‐induced histopathological findings included microvesicular steatosis (37.5%, 150/400 mice), increased mitosis (3.5%, 14/400 mice), and focal and multifocal hepatocellular necrosis (2%, 8/400 mice). Quantitative trait locus mapping of the terminal ALT level revealed a significantly associated gene region on chromosome 3 (log of odds (LOD)=6), with smaller suggestive peaks on chromosomes 5, 11, 13, 16, and 18, suggesting multiple genetic contributors to the toxicity response. Within the Chr 3 support interval lies several promising candidate genes, including: 1) Tpmt (thiopurine methyltransferase) for which genetic variants have been used to select dosages of several drugs known to cause adverse reactions in the clinic, and 2) Ltc4s (leukotriene C4 synthase), for which variant rs730012 is used to predict an increase in asthma exacerbations for patients administered the leukotriene receptor inhibitor drug montelukast. Taken together, our data provide a starting point for identifying the underlying genetic sequence variants that contribute to zileuton‐induced liver injury in susceptible patients. Follow up studies are ongoing to confirm a functional role and human relevance of the candidate pharmacogenetic risk alleles identified in the present study.Support or Funding InformationThis work was supported by the Food and Drug Administration [HHSF223201400183C], Burroughs Wellcome Fund Innovation in Regulatory Sciences Award, Arkansas Biosciences Institute, NIH [Translational Research Institute grant UL1TR000039 and T32 GM106999].
Drug Discovery from Peruvian Medicinal Plants for the Treatment of Psychosis
Authors: Tume Luis , Gallo Carla , Málaga‐Trillo Edward , Poletti Giovanni , Rojas Rosario , Vaisberg Abraham Jaime 
Published: November 2023

BackgroundSchizophrenia is a severe mental disorder that affects approximately 1% of the population. The main symptom is psychosis in which thought and emotions are impaired. Current pharmacological treatments for schizophrenia are partially effective and its long term intake causes side effects. In Peru, native communities since ancient times have considered the psychosis like “madness” and they have treated it using preparations from natural products. The Peruvian traditional medicine is a potential source of drugs because its effectiveness, possible low side effects and they could be acting on different molecular mechanisms compared to the current drugs on the market.AimIn this work, as a part of drug discovery process, we tested compounds‐containing fractions from four ethanolic extracts (EEs) on psychosis animal model, mammalian cells and receptors altered in mental diseases.MethodsWe carried out the separation of compounds‐containing fractions from EEs 1, 2, 3 and 4 based on solubility using medium pressure liquid chromatography. The selection of each fraction was based on thin layer chromatography profile. These fractions were tested in mice treated with MK‐801 (N‐methyl D‐aspartate receptor antagonist) to induce psychosis‐like symptoms. We used the open field test (OFT) to measure the hyperactivity over a period of time and prepulse inhibition (PPI) test to measure the startle response. Cytotoxicity assays were performed in mammalian cells to determine the IC50 using the sulforhodamine B method. Moreover, we determined for the EEs, functional and binding assays on a panel of receptors altered in mental diseases.ResultsFour compounds‐containing fractions (A, B, C and D) were obtained for each EE. In behavioural tests, the fraction A, C and D of EE1, the fraction A and B of EE2 suppressed psychosis‐like symptoms in OFT (p <0.001) and PPI test. Fraction C and D of EE3 only showed an effect on PPI test and all fractions of EE4 were not active neither in the OFT nor in the PPI test. The IC50 for each EE was >0. 01563mg/ml. Finally, functional and binding assays indicates that the four EEs have an effect on serotonin, dopamine, glutamate, adenosine receptors.ConclusionWe obtained potential antipsychotic compounds‐containing fractions as initial stage of drug discovery from four EE of medicinal plants used for the treatment psychotic‐like symptoms. The four EE has an effect on receptors altered in this disease suggesting an effect on signalling pathways altered in psychosis. Therefore, purification and structure elucidation of the active(s) molecule(s) will help us to better understanding of the molecular mechanism by which they are doing their antipsychotic effect.Support or Funding InformationNational Council of science of technology (CONCYTEC) through CIENCIACTIVA and Universidad Peruana Cayetano Heredia.
Sestrin2 Modulates Substrate Metabolism and Prevents Age‐related Intolerance to Ischemia and Reperfusion Injury
Authors: Li Ji , Quan Nanhu , Cates Courtney 
Published: November 2023

A novel stress‐inducible protein, Sestrin2, declines in the heart with aging. AMP‐activated Protein Kinase (AMPK) has emerged as a pertinent stress‐activated kinase shown to have cardioprotective capabilities against myocardial ischemic injury. We identified the interaction between Sestrin2 and AMPK in the ischemic heart. It is hypothesized that the ischemic AMPK activation modulated by Sestrin2‐AMPK complex in the heart is impaired in aging that sensitizes heart to ischemic insults.MethodsC57BL/6 young mice (3–4 months), middle age mice (10–12 months) and aged mice (24–26 months) were subjected to left anterior descending coronary artery occlusion for in vivo regional ischemia. The ex vivo working heart system was used for measuring substrate metabolism. The protein level of Sestrin2 in the hearts were gradually decreased with aging. Intriguingly, ischemic AMPK activation was blunted in the aged hearts as compared with young hearts (p<0.05), the AMPK downstream glucose uptake and the rate of glucose oxidation were significantly impaired in the aged hearts during ischemia and reperfusion (I/R) (p<0.05 vs. young hearts). The myocardial infarction size was larger in the aged hearts (p<0.05 vs. young hearts). The immunoprecipitation with Sestrin2 antibody revealed that cardiac Sestrin2 forms a complex with AMPK and upstream LKB1 during ischemia, intriguingly, the binding affinity between Sestrin2 and AMPK upstream LKB1 is impaired in the aged hearts during ischemia (p<0.05 vs. young hearts). Furthermore, Sestrin2 knock out hearts demonstrate a similar cardiac phenotype and response to ischemic stress as the wild type aged hearts, i.e. impaired ischemic AMPK activation and higher sensitivity to I/R‐induced injury. Adeno‐associated virus (AAV)‐Sestrin2 were delivered into the aged hearts via a coronary delivery approach significantly rescued the protein level of Sestrin2 and the ischemic tolerance of aged hearts. Therefore, Sestrin2 is a scaffold protein that mediates AMPK activation in the ischemic myocardium via an interaction with AMPK upstream LKB1. The decreased Sestrin2 levels in aging lead to a blunted ischemic AMPK activation, alterations in substrate metabolism and an increased sensitivity to ischemic insults.Support or Funding InformationADA 1‐14‐BS‐131, NIHR21AG044820
PET Imaging of Isoproterenol‐Induced Myocardial Injury
Authors: Houson Hailey , Hedrick Andria , Awasthi Vibhudutta 
Published: November 2023

BackgroundClinical assessment of myocardial injury is primarily based on the presence of serum biomarkers and electrocardiogram, with a significant input from perfusion imaging by single photon emission computed tomography (SPECT). Positron emission tomography (PET) is another imaging modality which has the potential to improve diagnostic accuracy by virtue of its high resolution and sensitivity. The objective of this study was to assess isoproteronol‐induced cardiomyopathy by PET using 18F‐fluorodeoxyglucose (FDG) and compare it with conventional SPECT using 99mTc‐Sestamibi (MIBI).MethodsCardiomyopathy was induced in Sprague Dawley rats by injecting high dose of isoproteronol (100 mg/kg, i.p.) on two consecutive days. FDG/PET and MIBI/SPECT were performed before and on the fourth day of isoproteronol administration. FDG (0.1 mCi, 0.2–0.4 mL) and MIBI (2 mCi, 0.5–1 mL) were injected via the tail vein and the images were acquired 1 h post‐injection. The images were analyzed by drawing region of interest (ROI) around heart tissue. Isoproteronol‐induced myocardial injury was verified at necropsy by tissue staining with tetrazolium chloride (TTC) and plasma cardiac troponin.ResultsIsoproteronol administration resulted in a significant increase in circulating troponin I (p < 0.05) as compared to the basal levels. FDG/PET images showed detectable alterations in cardiac accumulation of FDG and ROI analysis revealed a 75% drop of myocardial FDG uptake after isoproteronol treatment. The uptake of MIBI decreased by 45%, but the images did not show any discernible visual change in perfusion. At necropsy, TTC staining showed remarkable changes in all isoproteronol ‐treated hearts.ConclusionThe results suggest that high‐dose isoproteronol significantly impacts cardiac glucose metabolism without commensurate change in myocardial perfusion. PET imaging of glucose metabolism can be employed as a diagnostic criterion in myocardial injury.Support or Funding InformationFunding: Sandra K and David L Gilliland Chair in Nuclear Pharmacy
Angiotensin (1‐7) Attenuates Angiotensin II‐Induced Cardiac Hypertrophy via a Sirt3‐Dependent Mechanism
Authors: Guo Lirong , Zhong Tiecheng , O'Rourke Stephen T. , Sun Chengwen 
Published: November 2023

The objectives of the current study were to investigate the effect of Ang‐(1‐7) on the development of cardiac hypertrophy, and to identify the intracellular mechanism underlying this action of Ang‐(1‐7). Blood pressure and heart rate were recorded using radiotelemetry before and after chronic subcutaneous infusion of control (PBS), Ang II, Ang‐(1‐7), or Ang II+Ang‐(1‐7) for 4 weeks in normotensive rats. Chronic administration of Ang‐(1‐7) did not affect either basal blood pressure or the Ang II‐induced elevation in blood pressure. However, Ang‐(1‐7) significantly attenuated Ang II‐induced cardiac hypertrophy and perivascular fibrosis in these rats. These effects of Ang‐(1‐7) were confirmed in cultured cardiomyocytes, in which Ang‐(1‐7) significantly attenuated Ang II‐induced increases in cell size. This protective effect of Ang‐(1‐7) was significantly attenuated by pretreatment with A779, a Mas receptor antagonist; Mito‐TEMPO, mitochondria‐targeting superoxide scavenger, as well as blockade of Sirt3, a deacetylation‐acting protein, by viral vector‐mediated overexpression of Sirt3‐shRNA. Western blot analysis demonstrated that treatment with Ang‐(1‐7) dramatically increased Sirt3 expression. In addition, Ang (1‐7) attenuated the Ang II‐induced increase in mitochondrial ROS generation, an effect that was abolished by A779 or Sirt3‐shRNA. Moreover, Ang‐(1‐7) increased FoxO3a deacetylation and SOD2 expression, and these effects were blocked by Sirt3‐shRNA. In summary, the protective effects of Ang‐(1‐7) on Ang II‐induced cardiac hypertrophy and increased ROS production are mediated by elevated SOD2 expression via stimulation of Sirt3‐dependent deacetylation of FoxO3a in cardiomyocytes. Thus, activation of the Ang‐(1‐7)/Sirt3 signaling pathway could be a novel therapeutic strategy in the management of cardiac hypertrophy and associated complications.Support or Funding InformationThis work was supported by Grants from the National Institute of Neurological Disorders and Stroke, National Institutes of Health (NIH, NS55008), American Heart Association (10GRNT3170012), Norman Bethune Program of Jilin University (2015221), and Education Department of Jilin Province (2015498).
Mouse c‐kit+ Cardiac Progenitor Cells Do not Age Gracefully
Authors: Castaldi Alessandra , Dodia Ramsinh Mansinh , Orogo Amabel M. , Najor Rita H. , Gustafsson Asa B. , Brown Joan Heller , Purcell Nicole H. 
Published: November 2023

Although c‐kit+ cardiac progenitor cells (CPCs) are currently used in clinical trials there remain considerable gaps in our understanding of the molecular mechanisms underlying their proliferation and differentiation. Despite the fact that cardiac injury affects mainly the older human population, studies aimed at understanding CPC biology and their ability to contribute to cardiac regeneration have been performed on young animal models. In the present study we asked whether CPCs isolated from young (3 month) and aged (24 month) mice present different characteristics that could account for different outcomes in future CPC‐based therapeutic treatments for cardiac injury. We observed morphological differences and increased senescence as measure by the presence of senescence associated β‐galactosidase and increased p16 mRNA. The aged CPCs proliferated slower than their young counterpart and the expression of the stemness marker LIN28 was extremely low in the lines. We subsequently treated the cells with Dexamethasone (Dex), routinely used to induce cardiac commitment in CPCs, for 7 days and analyzed the expression of cardiac lineage marker genes. While MEF2C, GATA4, GATA6 and PECAM mRNAs were significantly upregulated in response to Dex treatment in young CPCs, their expression was not increased in aged CPCs. Interestingly, Dex treatment of aged CPCs failed to increase mitochondrial biogenesis and expression of the mitochondrial protein Complex III and IV, consistent with a defect in mitochondria complex assembly in the aged CPCs. This study should have an impact on the design of future CPC‐based therapeutic approaches for the treatment of older patients suffering from cardiac injury.Support or Funding InformationThis work was supported by grants from the National Heart, Lung and Blood Institute Grants: HL085577 (JHB, NHP, ÅBG and AC), HL028143 (JHB), HL114949 (NHP), and HL087023 (ÅBG) and by the National Institutes of Health NRSA Predoctoral Fellowship HL123309 (AMO). ÅBG is supported by an AHA Established Investigator Award.
Helium Influences Caveolae Numbers in Left Ventricular Endothelial Cells and Alters Metabolic Profile in Mice
Authors: Warmbrunn Moritz Valerian , Schilling Jan M , Zemljic‐Harpf Alice E , Hollmann Markus W , Roth David M , Patel Hemal H , Weber Nina C 
Published: November 2023

BackgroundMyocardial ischemia and reperfusion (I/R) injury is a major cause of morbidity and mortality. IR injury leads to calcium overload, increased oxidative stress, mitochondrial dysfunction and ultimately apoptosis. Helium, an inert gas, causes cardioprotection potentially through secretion of cellular factors into serum. This study aimed to elucidate the protective potential of helium conditioned serum, the metabolite content of serum, and the impact of helium on endothelial cell ultrastructure. We hypothesized that helium induces the release of circulating factors to mediate conditioning and impacts endothelial cell ultrastructure.Materials and methodsMice were exposed to 70% helium/30% oxygen or 30% oxygen in air. Serum was harvested at 30 min, 4 hrs and 24 hrs after gas exposure (n=7/group). In addition, mice (n=4/group) were prepared and fixed for transmission electron microscopy. High magnification images (11000×) of left ventricular tissue were analyzed for the amount of caveolae in endothelial cells and myocytes. Serum from exposed mice was analyzed for metabolites of primary metabolism and complex lipids by mass spectrometry. Metabolites were categorized by physiologic pathways and multivariate analysis was used to determine interaction between helium and recover time.ResultsEndothelial cell caveolae number was increased at 30 min and 24 hrs post exposure in the helium group by 39% (p < 0.01, C: 3.5 ± 0.2, n=83 images; He: 4.8 ± 0.3 caveolae/mm, n=67 as mean ± SEM) and 18% (p < 0.05, C: 4.3 ± 0.3, n=72; He: 5.3 ± 0.3 caveolae/mm, n=61), respectively. No differences were observed in myocyte caveolae formation. Interaction of time and drug showed a trend for oxidative phosphorylation (p= 0.097) and galactose metabolism pathway (p= 0.0798). An overall drug effect between the different time points was observed for biotin metabolism (p < 0.05). The metabolites of the two pathways, valine/leucine/isoleucine and pantothenate/CoA biosynthesis showed a trend towards a drug effect (p=0.053; p=0.057 respectively). Three pathways were significantly changed in the 4 hrs group and in the 24 hrs group biosynthesis of unsaturated fatty acids was influenced. In addition three cardioprotective ceramides were significantly upregulated by helium (p < 0.05).ConclusionHelium exposure altered endothelial cell ultrastructure by inducing the formation of caveolae and induced secretion of factors resulting in different metabolic profiles of primary metabolism and complex lipids. Such changes in cell ultrastructure and metabolite secretion may be key to the conditioning effects induced by helium.
Potent Blood Pressure Lowering Effect of Optogenetic Stimulation of ‘Angiotensin‐sensitive’ Neurons within the Nodose Ganglion
Authors: da Silva Souza Gean Domingos B , Bruce Erin B. , Hiller Helmut , Smeltzer Michael D. , Tan Yalun , Brandi Igor Viana , Sumners Colin , Raizada Mohan K , Krause Eric G. , de Kloet Annette D 
Published: November 2023

Neurons within the nodose ganglion (NG) convey baroreceptor status to the brain and their stimulation is known to reduce blood pressure and heart rate; however, whether a distinct population of angiotensin‐sensitive neurons within the NG mediate these effects is not clear. Here, we use neuroanatomical and optogenetic techniques to test the hypothesis that angiotensin type 1‐a receptor (AT1a)‐expressing neurons within the NG influence hemodynamic responses in male mice. Initial neuroanatomical studies revealed that AT1a‐containing neurons are localized to the NG and uncovered a dense localization of terminals arising from AT1a neurons to the intermediate nucleus of the solitary tract, consistent with their localization to the vagal afferent neurons of the NG. To examine the functional relevance of these distinct angiotensin sensitive neurons, the Cre/Lox system was then used to generate male mice expressing channelrhodopsin‐2 and yellow fluorescent protein (eYFP) specifically in AT1a‐expressing neurons. These mice (n=6) were catheterized into the left carotid artery and the left NG was identified and isolated from adjacent tissues in order to optogenetically stimulate AT1a‐containing neurons within the area. Consistent with our hypothesis, photo‐activation (473nm blue light;1, 15 or 30Hz; 1 min) of these AT1a‐expressing neurons led to significant decreases in mean arterial pressure (MAP, Δ= −16±3, −36±4 and −44±7 mmHg) and heart rate (HR, Δ= −13±7, −104±44 and −163±59 bpm) in AT1a‐ChR2‐eYFP mice but not in control mice subjected to the same stimulation parameters. Collectively, our results demonstrate that activation of AT1a‐expressing neurons in NG effectively reduces MAP and HR in mice, suggesting that AT1a in the NG might play an important role in cardiovascular equilibrium.Support or Funding InformationNational Heart, Lung, and Blood Institute Grant HL122494 (EGK), HL125805 (ADdK), HL‐033610 (CS and MKR)