Different endurance exercises modulate NK cell cytotoxic and inhibiting receptors

PURPOSE

Induction of IDO depends on the activation of AhR forming the AhR/IDO axis. Activated AhR can transcribe various target genes including cytotoxic and inhibiting receptors of NK cells. We investigated whether AhR and IDO levels as well as activating (NKG2D) and inhibiting (KIR2DL1) NK cell receptors are influenced by acute exercise and different chronic endurance exercise programs.

METHODS

21 adult breast and prostate cancer patients of the TOP study (NCT02883699) were randomized to intervention programs of 12 weeks of (1) endurance standard training or (2) endurance polarized training after a cardiopulmonary exercise test (CPET). Serum was collected pre-CPET, immediately post-CPET, 1 h post-CPET and after 12 weeks post-intervention. Flow cytometry analysis was performed on autologous serum incubated NK-92 cells for: AhR, IDO, KIR2DL1 and NKG2D. Differences were investigated using analysis-of-variance for acute and analysis-of-covariance for chronic effects.

RESULTS

Acute exercise: IDO levels changed over time with a significant increase from post-CPET to 1 h post-CPET (p = 0.03). KIR2DL1 levels significantly decreased over time (p < 0.01). NKG2D levels remained constant (p = 0.31). Chronic exercise: for both IDO and NKG2D a significant group × time interaction, a significant time effect and a significant difference after 12 weeks of intervention were observed (IDO: all p < 0.01, NKG2D: all p > 0.05).

CONCLUSION

Both acute and chronic endurance training may regulate NK cell function via the AhR/IDO axis. This is clinically relevant, as exercise emerges to be a key player in immune regulation.

Inhibition of neutral sphingomyelinase 2 reduces extracellular vesicle release from neurons, oligodendrocytes, and activated microglial cells following acute brain injury

Extracellular Vesicles (EVs) are implicated in the spread of pathogenic proteinsin a growing number of neurological diseases. Given this, there is rising interest in developing inhibitors of Neutral Sphingomyelinase 2 (nSMase2), an enzyme critical in EV biogenesis. Our group recently discovered phenyl(R)-(1-(3-(3,4-dimethoxyphenyl)-2,6-dimethylimidazo[1,2-b]pyridazin-8-yl)pyrrolidin-3-yl)carbamate (PDDC), the first potent, selective, orally-available, and brain-penetrable nSMase2 inhibitor, capable of dose-dependently reducing EVs release in vitro and in vivo. Herein, using multiplexed Surface Plasmon Resonance imaging (SPRi), we evaluated which brain cell-derived EVs were affected by PDDC following acute brain injury. Mice were fed PDDC-containing chow at doses which gave steady PDDC brain exposures exceeding its nSMase2 IC₅₀. Mice were then administered an intra-striatal IL-1β injection and two hours later plasma and brain were collected. IL-1β injection significantly increased striatal nSMase2 activity which was completely normalized by PDDC. Using SPRi, we found that IL-1β-induced injury selectively increased plasma levels of CD171 + and PLP1 + EVs; this EV increase was normalized by PDDC. In contrast, GLAST1 + EVs were unchanged by IL-1β or PDDC. IL-1β injection selectively increased EVs released from activated versus non-activated microglia, indicated by the CD11b+/IB4 + ratio. The increase in EVs from CD11b + microglia was dramatically attenuated with PDDC. Taken together, our data demonstrate that following acute injury, brain nSMase2 activity is elevated. EVs released from neurons, oligodendrocytes, and activated microglial are increased in plasma and inhibition of nSMase2 with PDDC reduced these IL-1β-induced changes implicating nSMase2 inhibition as a therapeutic target for acute brain injury.

Model studies towards prodrugs of the glutamine antagonist 6-diazo-5-oxo-l-norleucine (DON) containing a diazo precursor

Two distinct diazo precursors, imidazotetrazine and nitrous amide, were explored as promoieties in designing prodrugs of 6-diazo-5-oxo-l-norleucine (DON), a glutamine antagonist. As a model for an imidazotetrazine-based prodrug, we synthesized (S)-2-acetamido-6-(8-carbamoyl-4-oxoimidazo[5,1-d][1,2,3,5]tetrazin-3(4H)-yl)-5-oxohexanoic acid (4) containing the entire scaffold of temozolomide, a precursor of the DNA-methylating agent clinically approved for the treatment of glioblastoma multiforme. For a nitrous amide-based prodrug, we synthesized 2-acetamido-6-(((benzyloxy)carbonyl)(nitroso)amino)-5-oxohexanoic acid (5) containing a N-nitrosocarbamate group, which can be converted to a diazo moiety via a mechanism similar to that of streptozotocin, a clinically approved diazomethane-releasing drug containing an N-nitrosourea group. Preliminary characterization confirmed formation of N-acetyl DON (6), also known as duazomycin A, from compound 4 in a pH-dependent manner while compound 5 did not exhibit sufficient stability to allow further characterization. Taken together, our model studies suggest that further improvements are needed to translate this prodrug approach into glutamine antagonist-based therapy.

Glutamine Antagonist GA-607 Causes a Dramatic Accumulation of FGAR which can be used to Monitor Target Engagement

BACKGROUND

Metabolomic analyses from our group and others have shown that tumors treated with glutamine antagonists (GA) exhibit robust accumulation of formylglycinamide ribonucleotide (FGAR), an intermediate in the de novo purine synthesis pathway. The increase in FGAR is attributed to the inhibition of the enzyme FGAR amidotransferase (FGAR-AT) that catalyzes the ATP-dependent amidation of FGAR to formylglycinamidine ribonucleotide (FGAM). While perturbation of this pathway resulting from GA therapy has long been recognized, no study has reported systematic quantitation and analyses of FGAR in plasma and tumors.

OBJECTIVE

Herein, we aimed to evaluate the efficacy of our recently discovered tumor-targeted GA prodrug, GA-607 (isopropyl 2-(6-acetamido-2-(adamantane-1-carboxamido)hexanamido)-6-diazo-5-oxohexanoate), and demonstrate its target engagement by quantification of FGAR in plasma and tumors.

METHODS

Efficacy and pharmacokinetics of GA-607 were evaluated in a murine EL4 lymphoma model followed by global tumor metabolomic analysis. Liquid chromatography-mass spectrometry (LC-MS) based methods employing the ion-pair chromatography approach were developed and utilized for quantitative FGAR analyses in plasma and tumors.

RESULTS

GA-607 showed preferential tumor distribution and robust single-agent efficacy in a murine EL4 lymphoma model. While several metabolic pathways were perturbed by GA-607 treatment, FGAR showed the highest increase qualitatively. Using our newly developed sensitive and selective LC-MS method, we showed a robust >80- and >10- fold increase in tumor and plasma FGAR levels, respectively, with GA-607 treatment.

CONCLUSION

These studies describe the importance of FGAR quantification following GA therapy in cancer and underscore its importance as a valuable pharmacodynamic marker in the preclinical and clinical development of GA therapies.

Odderon Exchange from Elastic Scattering Differences between pp and pp[over ¯] Data at 1.96 TeV and from pp Forward Scattering Measurements

We describe an analysis comparing the pp[over ¯] elastic cross section as measured by the D0 Collaboration at a center-of-mass energy of 1.96 TeV to that in pp collisions as measured by the TOTEM Collaboration at 2.76, 7, 8, and 13 TeV using a model-independent approach. The TOTEM cross sections, extrapolated to a center-of-mass energy of sqrt[s]=1.96  TeV, are compared with the D0 measurement in the region of the diffractive minimum and the second maximum of the pp cross section. The two data sets disagree at the 3.4σ level and thus provide evidence for the t-channel exchange of a colorless, C-odd gluonic compound, also known as the odderon. We combine these results with a TOTEM analysis of the same C-odd exchange based on the total cross section and the ratio of the real to imaginary parts of the forward elastic strong interaction scattering amplitude in pp scattering for which the significance is between 3.4σ and 4.6σ. The combined significance is larger than 5σ and is interpreted as the first observation of the exchange of a colorless, C-odd gluonic compound.

Sex Differences in Pulmonary Eicosanoids and Specialized Pro-Resolving Mediators in Response to Ozone Exposure

Ozone (O3) is a criteria air pollutant known to increase the morbidity and mortality of cardiopulmonary diseases. This occurs through a pulmonary inflammatory response characterized by increased recruitment of immune cells into the airspace, pro-inflammatory cytokines, and pro-inflammatory lipid mediators. Recent evidence has demonstrated sex-dependent differences in the O3-induced pulmonary inflammatory response. However, it is unknown if this dimorphic response is evident in pulmonary lipid mediator metabolism. We hypothesized that there are sex-dependent differences in lipid mediator production following acute O3 exposure. Male and female C57BL/6J mice were exposed to 1 part per million O3 for 3 hours and were necropsied at 6 or 24 hours following exposure. Lung lavage was collected for cell differential and total protein analysis, and lung tissue was collected for mRNA analysis, metabololipidomics, and immunohistochemistry. Compared to males, O3-exposed female mice had increases in airspace neutrophilia, neutrophil chemokine mRNA, pro-inflammatory eicosanoids such as prostaglandin E2, and specialized pro-resolving mediators (SPMs) such as resolvin D5 in lung tissue. Likewise, precursor fatty acids (arachidonic and docosahexaenoic acid; DHA) were increased in female lung tissue following O3 exposure compared to males. Experiments with ovariectomized females revealed that loss of ovarian hormones exacerbates pulmonary inflammation and injury. However, eicosanoid and SPM production were not altered by ovariectomy despite depleted pulmonary DHA concentrations. Taken together, these data indicate that O3 drives an increased pulmonary inflammatory and bioactive lipid mediator response in females. Furthermore, ovariectomy increases susceptibility to O3-induced pulmonary inflammation and injury, as well as decreases pulmonary DHA concentrations.

Nipping disease in the bud: nSMase2 inhibitors as therapeutics in extracellular vesicle-mediated diseases

Extracellular vesicles (EVs) are indispensable mediators of intercellular communication, but they can also assume a nefarious role by ferrying pathological cargo that contributes to neurological, oncological, inflammatory, and infectious diseases. The canonical pathway for generating EVs involves the endosomal sorting complexes required for transport (ESCRT) machinery, but an alternative pathway is induced by the enrichment of lipid membrane ceramides generated by neutral sphingomyelinase 2 (nSMase2). Inhibition of nSMase2 has become an attractive therapeutic strategy for inhibiting EV biogenesis, and a growing number of small-molecule nSMase2 inhibitors have shown promising therapeutic activity in preclinical disease models. This review outlines the function of EVs, their potential role in disease, the discovery and efficacy of nSMase2 inhibitors, and the path to translate these findings into therapeutics.

0556 Sex-Specific Relationship Between Anxiety and Autonomic Nervous System Dysfunction in Obstructive Sleep Apnea

Introduction

Cardiovascular co-morbidities in obstructive sleep apnea (OSA) are hard to treat, perhaps due to autonomic nervous system (ANS) dysfunction. In OSA, intermittent hypoxia and poor tissue oxygen perfusion damage endothelial and nervous tissue, potentially underlying the dysfunction. Moreover, OSA is strongly associated with anxiety, which is independently associated with ANS dysfunction. We assessed sex-specific relationships between anxiety and cardiovascular markers of ANS dysfunction in OSA.

Methods

We studied people diagnosed with OSA and healthy controls. We collected 5 minutes of wakeful resting ECG, continuous non-invasive blood pressure, and respiration data. We calculated heart rate (HR), heart rate variability (HRV; sympathetic-vagal balance related to brainstem ANS output), mean arterial blood pressure (MAP), beat-to-beat MAP variability (BPV; related to peripheral autonomic function) and breathing rate (BR). We analyzed these measures with a multivariate regression model of anxiety symptoms (generalized anxiety disorder; GAD-7 scores), sex, and group (OSA vs. control), age/BMI/AHI covariates, and Bonferroni-corrected post-hoc comparisons (p≤0.05).

Results

We analyzed 64 subjects (32 OSA: AHI [mean±SEM] 24±4events/hour, 12 female, age 52±21years, BMI 33±2kg/m2; 32 control: 19 female, age 46±2; BMI 26±1). We observed significant main effects of anxiety, BMI, AHI, sex on HRV, but only group on BPV; post-hoc comparisons revealed high BPV only in OSA females. Secondary analyses included classifying by anxiety symptoms (GAD-7≥5), showing only OSA females with anxiety had higher BPV. Males showed higher HRV. AHI and anxiety were positively correlated with HRV in OSA males. AHI was negatively correlated with BR in OSA females.

Conclusion

We observed higher anxiety associated with higher BPV in OSA, especially in females. Unexpectedly, BR was lower in OSA females; longer breaths may have led to the greater BPV. Higher HRV in males complicated by OSA severity and anxiety could be related to higher sympathetic tone. The slightly older control group may have influenced the findings. Overall, our findings suggest anxiety in OSA is associated with peripheral and centrally-mediated autonomic dysfunction, but in a sex-specific manner.

Support

National Institutes of Health R56-NR-017435 and RO1-HL-135562.

Mutations in growth hormone gene affect stability of protein structure leading to reduced growth, reproduction, and milk production in crossbred cattle-an insight

The GH has a multifaceted role in growth, reproduction, and milk production. Nonsynonymous mutations identified as L153V were observed from GH1 (L) to GH2 (V) with higher genotypic frequency for GH1 being 0.87. GH2 (V) allele was identified as a rare allele and the population followed Hardy-Weinberg equilibrium. LL homozygote variant had significantly better growth, reproduction, and expected milk production at different ages in crossbred (CB) males. Reports are scanty explaining the molecular mechanism of how individuals with LV genotype were phenotypically inferior to that of wild-type LL. In the present study, it was explored that GH peptide with LV heterozygotes of GH gene, were observed to have reduced structural stability thermodynamically and thus functionally leads to reduced economic traits in CB animals. The fact was first time reported and confirmed through genomic analysis, bioinformatics, and later confirmed through immunohistochemistry. Differential expression analysis of the GH gene with respect to other genes in the hypothalamus-pituitary growth axis of CB cattle was also studied to have a complete insight of the GH gene.

Corrigendum to "Dietary administration of Nexrutine inhibits rat liver tumorigenesis and induces apoptotic cell death in human hepatocellular carcinoma cells". [Toxicol. Rep. 2 (2014) (November) 1-11]

[This corrects the article DOI: 10.1016/j.toxrep.2014.11.006.].

Hydrophilic Small Molecules That Harness Transthyretin To Enhance the Safety and Efficacy of Targeted Chemotherapeutic Agents

The hydrophobicity of many chemotherapeutic agents usually results in their nonselective passive distribution into healthy cells and organs causing collateral toxicity. Ligand-targeted drugs (LTDs) are a promising class of targeted anticancer agents. The hydrophilicity of the targeting ligands in LTDs limits its nonselective passive tissue distribution and toxicity to healthy cells. In addition, the small size of LTDs allows for better tumor penetration, especially in the case of solid tumors. However, the short circulation half-life of LTDs, due to their hydrophilicity and small size, remains a significant challenge for achieving their full therapeutic potential. Therefore, extending the circulation half-life of targeted chemotherapeutic agents while maintaining their hydrophilicity and small size will represent a significant advance toward effective and safe cancer treatment. Here, we present a new approach for enhancing the safety and efficacy of targeted chemotherapeutic agents. By endowing hydrophobic chemotherapeutic agents with a targeting moiety and a hydrophilic small molecule that binds reversibly to the serum protein transthyretin, we generated small hydrophilic drug conjugates that displayed enhanced circulation half-life in rodents and selectivity to cancer cells. To the best of our knowledge, this is the first demonstration of a successful approach that maintains the small size and hydrophilicity of targeted anticancer agents containing hydrophobic payloads while at the same time extending their circulation half-life. This was demonstrated by the superior in vivo efficacy and lower toxicity of our conjugates in xenograft mouse models of metastatic prostate cancer.

Tuning of Magnetic Activity in Spin-Filter Josephson Junctions Towards Spin-Triplet Transport

The study of superconductor-ferromagnet interfaces has generated great interest in the last decades, leading to the observation of spin-aligned triplet supercurrents and 0-π transitions in Josephson junctions where two superconductors are separated by an itinerant ferromagnet. Recently, spin-filter Josephson junctions with ferromagnetic barriers have shown unique transport properties, when compared to standard metallic ferromagnetic junctions, due to the intrinsically nondissipative nature of the tunneling process. Here we present the first extensive characterization of spin polarized Josephson junctions down to 0.3 K, and the first evidence of an incomplete 0-π transition in highly spin polarized tunnel ferromagnetic junctions. Experimental data are consistent with a progressive enhancement of the magnetic activity with the increase of the barrier thickness, as neatly captured by the simplest theoretical approach including a nonuniform exchange field. For very long junctions, unconventional magnetic activity of the barrier points to the presence of spin-triplet correlations.

Enthalpy-Driven Stabilization of Transthyretin by AG10 Mimics a Naturally Occurring Genetic Variant That Protects from Transthyretin Amyloidosis

Transthyretin (TTR) amyloid cardiomyopathy (ATTR-CM) is a fatal disease with no available disease-modifying therapies. While pathogenic TTR mutations (TTRm) destabilize TTR tetramers, the T119M variant stabilizes TTRm and prevents disease. A comparison of potency for leading TTR stabilizers in clinic and structural features important for effective TTR stabilization is lacking. Here, we found that molecular interactions reflected in better binding enthalpy may be critical for development of TTR stabilizers with improved potency and selectivity. Our studies provide mechanistic insights into the unique binding mode of the TTR stabilizer, AG10, which could be attributed to mimicking the stabilizing T119M variant. Because of the lack of animal models for ATTR-CM, we developed an in vivo system in dogs which proved appropriate for assessing the pharmacokinetics-pharmacodynamics profile of TTR stabilizers. In addition to stabilizing TTR, we hypothesize that optimizing the binding enthalpy could have implications for designing therapeutic agents for other amyloid diseases.