Inhibition of nitric oxide-stimulated vasorelaxation by carbon monoxide-releasing molecules.

Carbon monoxide (CO) is a weak soluble guanylyl cyclase stimulator, leading to transient increases in cGMP and vasodilation. The aim of the present work was to measure the effect of CO-releasing molecules (CORMs) on the cGMP/nitric oxide (NO) pathway and to evaluate how selected CORMs affect NO-induced vasorelaxation. METHODS AND RESULTS: Incubation of smooth muscle cells with some but not all of the CORMs caused a minor increase in cGMP levels. Concentration-response curves were bell-shaped, with higher CORMs concentrations producing lower increases in cGMP levels. Although exposure of cells to CORM-2 enhanced cGMP formation, we observed that the compound inhibited NO-stimulated cGMP accumulation in cells and NO-stimulated soluble guanylyl cyclase activity that could be reversed by superoxide anion scavengers. Reactive oxygen species generation from CORMs was confirmed using luminol-induced chemiluminescence and electron spin resonance. Furthermore, we observed that NO is scavenged by CORM-2. When used alone CORM-2 relaxed vessels through a cGMP-mediated pathway but attenuated NO donor-stimulated vasorelaxation. CONCLUSION: We conclude that the CORMs examined have context-dependent effects on vessel tone, as they can directly dilate blood vessels, but also block NO-induced vasorelaxation

Mutant KRAS promotes malignant pleural effusion formation

Malignant pleural effusion (MPE) is the lethal consequence of various human cancers metastatic to the pleural cavity. However, the mechanisms responsible for the development of MPE are still obscure. Here we show that mutant KRAS is important for MPE induction in mice. Pleural disseminated, mutant KRAS bearing tumour cells upregulate and systemically release chemokine ligand 2 (CCL2) into the bloodstream to mobilize myeloid cells from the host bone marrow to the pleural space via the spleen. These cells promote MPE formation, as indicated by splenectomy and splenocyte restoration experiments. In addition, KRAS mutations are frequently detected in human MPE and cell lines isolated thereof, but are often lost during automated analyses, as indicated by manual versus automated examination of Sanger sequencing traces. Finally, the novel KRAS inhibitor deltarasin and a monoclonal antibody directed against CCL2 are equally effective against an experimental mouse model of MPE, a result that holds promise for future efficient therapies against the human condition

GABA antagonists reverse the somatostatin dependent attenuation of rat locomotor activity

Somatostatin infusion in rat ventral pallidum (VP) led to the attenuation of locomotor activity (Marazioti, A., Kastellakis, A., Antoniou, K., Papasava, D., Thermos, K., 2005. Somatostatin receptors in the ventral pallidum/substantia innominata modulate rat locomotor activity. Psychopharmacology 181, 319-326). In the present study, we investigated the putative circuitry involved in somatostatin's actions by examining the involvement of GABAergic neurotransmission in locomotor activity subsequent to somatostatin's infusion into the VP. Male Sprague-Dawley rats, 300-350 g, were used for all experiments. Saline or somatostatin (240 ng/0.5 μl/side) in the absence or presence of bicuculline (GABA-A antagonist; 5 mg/kg/ml, i.p.; 120 ng/side nucleus accumbens (NAc)) or phaclofen (GABA-B antagonist; 10 mg/kg/ml, i.p.; 120 ng/side NAc) were infused bilaterally, and the locomotor activity measured for 60 min using a rectangular activity cage. Somatostatin infused in the VP decreased the locomotor activity of the rat in a statistically significant manner. Bicuculline (i.p., and in the NAc) and phaclofen (only i.p.) reversed SRIF's actions, when administered prior to somatostatin's infusion in the VP. The present study provides further information on somatostatin's involvement in the VP-NAc circuitry, and implicates the GABAergic system in somatostatin's actions in the VP. © 2009 Elsevier Ltd. All rights reserved

"Scar-cinoma": Viewing the fibrotic lung mesenchymal cell in the context of cancer biology.

Lung cancer and pulmonary fibrosis are common, yet distinct, pathological processes that represent urgent unmet medical needs. Striking clinical and mechanistic parallels exist between these distinct disease entities. The goal of this article is to examine lung fibrosis from the perspective of cancer-associated phenotypic hallmarks, to discuss areas of mechanistic overlap and distinction, and to highlight profibrotic mechanisms that contribute to carcinogenesis. Ultimately, we speculate that such comparisons might identify opportunities to leverage our current understanding of the pathobiology of each disease process in order to advance novel therapeutic approaches for both. We anticipate that such "outside the box" concepts could be translated to a more precise and individualised approach to fibrotic diseases of the lung

Engineered versus hybrid cellular vesicles as efficient drug delivery systems: A comparative study with brain targeted vesicles.

Herein we elaborated on methods to load cellular vesicles (CVs) and to incorporate cholesterol (Chol) and PEG lipids in their membrane, for enhancing the potential of such engineered CVs (e-CVs) as drug carriers. Hybrids formed by fusion between PEGylated liposomes (PEG-LIP) and CVs were evaluated as alternatives to e-CV, for the first time. Freeze-thawing cycles (FT) and incubation protocols were tested, and vesicle fusion was monitored by FRET dilution. B16F10, hCMEC/D3, and LLC cells were used for e-CV or hybrid development, and FITC-dextran as a model hydrophilic drug. Results show that dehydration rehydration vesicle (DRV) method is optimal for highest CV loading and integrity, while optimal protocols for Chol/PEG enrichment were identified. FT was found to be more efficient than incubation for hybrid formation. Interestingly, despite their high Chol content, CVs had very low integrity that was not increased by enrichment with Chol, but only after PEG coating; e-CVs demonstrated higher integrity than hybrids. Vesicle uptake by hCMEC cells is in the order: LIP < e-CVs < Hybrids ≤ CVs (verified by confocal microscopy); the higher PEG content of e-CVs is possibly the reason for their reduced cell uptake. While CV and hybrid uptake are highly caveolin-dependent, e-CVs mostly follow clathrin-dependent pathways. In vivo and ex vivo results show that brain accumulation of hybrids is only slightly higher that of CVs, indicating that the surface PEG content of hybrids is not sufficient to prevent uptake by macrophages of the reticuloendothelial system. Taking together with the fact that subjection of CVs to FT cycles reduced their cellular uptake, it is concluded that PEGylated e-CVs are better than hybrids as brain-targeted drug carriers

RAS oncogenes direct metastasis.

RAS genes are cardinal driver oncogenes frequently and differentially mutated across bodily tumors. Their tumorigenic potential has been mainly ascribed to autonomous promotion of tumor cell proliferation and survival. However, recent evidence shows that RAS oncogenes also function to define metastatic tropism. Interestingly, RAS-driven metastasis is mediated by distinct chemokine sets that signal to endothelial and myeloid cells

Prolonged retention of liposomes in the pleural cavity of normal mice and high tumor distribution in mice with malignant pleural effusion, after intrapleural injection.

Background: Intrapleural administration of compounds is a lung targeted, innovative therapeutic strategy for mesothelioma, which can be refined as a route for drug delivery that minimizes the potential for systemic toxicity. However, little is currently known about the retention of liposomal drugs at the site, after such topical administration. Purpose: To evaluate the retention of liposomes in lungs following intrapleural injection, and how this might be modulated by liposome properties and disease progression. Methods: DiR-incorporating liposomes with various lipid compositions and sizes were prepared, characterized (for size distribution and zeta potential) and injected intrapleurally in normal mice and mice with malignant pleural effusion (MPE). DiR retention in pleural cavity was followed by biofluorescence imaging. Results: Experimental results demonstrate that liposome size and PEG-coating, have a significant effect on residence time in the pleural cavity; negative surface charge does not. More than 20% liposomal-DiR is retained 24 d post-injection (in some cases), indicating the high potential towards localized diseases. Ex-vivo liposomal-DiR signal in tumors of MPE mice was similar to signal in liver, suggesting high tumor targeting potential of intrapleurally injected liposomes. Finally, no difference was noticed in liposomal-DiR retention between tumor-inoculated (MPE) and healthy mice, indicating the stability of liposomes in the presence of effusion (in MPE mice). Conclusion: The current study provides novel insights for using liposomes by intrapleural administration for the treatment of lung diseases

Activation of somatostatin receptors in the globus pallidus increases rat locomotor activity and dopamine release in the striatum

Rationale: Somatostatin and its receptors have been localized in brain nuclei implicated in motor control, such as the striatum, nucleus accumbens, ventral pallidum, and globus pallidus (GP). Objectives: The objective of this study was to investigate the role of somatostatin receptors (sst 1,2,4) in the GP on dopamine (DA)-mediated behaviors, such as locomotor activity, and to examine the GP-striatum circuitry by correlating the effect of somatostatin in the GP with the release of DA in the striatum. Materials and methods: Animals received saline, somatostatin (60, 120, 240 ng/0.5 μl per side) or the following selective ligands: L-797,591 (sst 1 analog, 60, 120, 240 ng/0.5 μl per side), L-779,976 (sst 2 analog, 120, 240, 480 ng/0.5 μl per side), L-803,087 (sst 4 analog; 120, 240, 480 ng/0.5 μl per side), L-796,778 (sst 3 analog, 240 ng/0.5 μl per side), SRA-880 (sst1 selective antagonist + somatostatin, 120 ng/0.5 μl per side), CYN154806 (sst2 selective antagonist + somatostatin, 120 ng/0.5 μl per side) bilaterally in the GP of the rat. Locomotor activity was measured for 60 min. The effect of somatostatin, administered intrapallidally, on the extracellular concentrations of DA, 3,4-dihydroxyphenylacetic acid, and homovanillic acid in the striatum was also studied in the behaving rat using in vivo microdialysis methodology. Results: Somatostatin increased the locomotor activity of the rat in a dose-dependent manner. This effect was mediated by activation of the sst1, sst2, and sst4 receptors. Selective sst agonists increased locomotor activity in a statistical significant manner, while selective sst1 and sst2 antagonists reversed the somatostatin-mediated locomotor activity to control levels. DA levels increased in the striatum after intrapallidal infusion of somatostatin (240 ng/side). Conclusions: These data provide behavioral and neurochemical evidence of the functional role of somatostatin receptors in the GP-striatum circuitry. © 2008 Springer-Verlag

Carbon Footprint of the University of Patras in Greece: Evaluating Environmental Culture and Campus’ Energy Management towards 2030

Climate change has already had observable effects due to greenhouse gases (GHG) produced by human activities. Over the years, this becomes more evident as the concentration of GHG released in the atmosphere is concerningly increased as does the earth’s average temperature too. Hence, all countries and many independent organizations are taking actions to reduce the Global Warming phenomenon by setting targets for carbon dioxide emissions. The energy sector is proved to play the most important role in emissions reduction. Greece’s target for this sector is very ambitious in total transformation of energy mixture in the forthcoming years. Universities are also contributing to GHG emissions through their operations and members’ activities. Energy management at the University of Patras in Greece has already started since 2019 by installing energy meters going from manual calculations to an online system. The reliable records and accurate calculations proved as a very important action and a starting point for performing detailed analysis. In this study, there was an effort to calculate the CO2 emissions of the University of Patras using the Carbon Campus Calculator. The results showed that the students commuting is the main source of GHG emissions at the University of Patras and the purchased electricity comes next. These two factors together comprise 60.2% of the total emissions and priority should be given to reducing their footprint. Specific targets were set up for 2030 in compliance with the National Plan for Energy and Climate of Greece. Moreover, an Action Plan managing carbon and energy more efficiently and creating a strong environmental culture among the community is proposed. In the future, the university’s management team should act proactively in every change at Patras University. An assessment on the environmental impact should take place before any decision making. If necessary, extra actions should be defined in order not to deviate from the targets and new standards set