Nitric Oxide Regulates Immune Cell Bioenergetic: A Mechanism to Understand Immunomodulatory Functions of Nitric Oxide-Releasing Anti-Inflammatory Drugs

Abstract The 2-(acetyloxy)benzoic acid 3-(nitrooxymethyl)phenyl ester (NCX-4016) is a NO-releasing derivative of aspirin. In this study, we provide evidence that NCX-4016 delivered to PMBC-derived T lymphocytes and monocytes causes a transitory inhibition of cell respiration and ≈50% reduction of cellular ATP, which translates in a time-reversible inhibition of cell proliferation and IL-2, IL-4, IL-5, and IFN-γ secretion. Exposure of lymphocytes and monocytes to aspirin, 2-(acetyloxy)benzoic acid 3-(hydroxymethyl)phenyl ester (NCX-4017), a non-NO-releasing analog of NCX-4016, and cyclooxygenase inhibitors, reduced PG formation, but has no effect on cytokine/chemokine release. In contrast, delivering NO with (z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl)amino] diazen-1-ium-1,2 diolate (DETA-NO) reproduced most of the metabolic and anti-cytokine activities of NCX-4016. Scavenging NO with hemoglobin or adding selective substrates of complex II, III, and IV of the mitochondrial respiratory chain reverses NCX-4016′ inhibitory activities. Exposure to DETA-NO and NCX-4016 enhances glucose uptake, glycolytic rate, and lactate generation in CD3/CD28-costimulated lymphocytes, while reduced citric acid cycle intermediates. These effects were not reproduced by selective and nonselective cyclooxygenase 2 inhibitors. In summary, we demonstrated that exposure of lymphocytes to NCX-4016 causes a metabolic hypoxia that inhibits lymphocyte reactivity to costimulatory molecules, providing a potential counteregulatory mechanism to control activated immune system

New histone deacetylase inhibitors as potential therapeutic tools for advanced prostate carcinoma

The anti-epileptic drug valproic acid is also under trial as an anti-cancer agent due to its histone deacetylase (HDAC) inhibitory properties. However, the effects of valproic acid (VPA) are limited and concentrations required for exerting anti-neoplastic effects in vitro may not be reached in tumour patients. In this study, we tested in vitro and in vivo effects of two VPA-derivatives (ACS2, ACS33) on pre-clinical prostate cancer models. PC3 and DU-145 prostate tumour cell lines were treated with various concentrations of ACS2 or ACS33 to perform in vitro cell proliferation 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays and to evaluate tumour cell adhesion to endothelial cell monolayers. Analysis of acetylated histones H3 and H4 protein expression was performed by western blotting. In vivo tumour growth was conducted in subcutaneous xenograft mouse models. Tumour sections were assessed by immunohistochemistry for histone H3 acetylation and proliferation. ACS2 and ACS33 significantly up-regulated histone H3 and H4 acetylation in prostate cancer cell lines. In micromolar concentrations both compounds exerted growth arrest in PC3 and DU-145 cells and prevented tumour cell attachment to endothelium. In vivo, ACS33 inhibited the growth of PC3 in subcutaneous xenografts. Immunohistochemistry and western blotting confirmed increased histone H3 acetylation and reduced proliferation. ACS2 and ACS33 represent novel VPA derivatives with superior anti-tumoural activities, compared to the mother compound. This investigation lends support to the clinical testing of ACS2 or ACS33 for the treatment of prostate cancer

ACS6, a Hydrogen sulfide-donating derivative of sildenafil, inhibits homocysteine-induced apoptosis by preservation of mitochondrial function

Background: The hydrogen sulfide-releasing sildenafil, ACS6, has been demonstrated to inhibit superoxide formation through donating hydrogen sulfide (H2S). We have found that H2S antagonizes homocysteine-induced oxidative stress and neurotoxicity. The aim of the present study is to explore the protection of ACS6 against homocysteine-triggered cytotoxicity and apoptosis and the molecular mechanisms underlying in PC12 cells. Methods: Cell viability was determined by Cell Counting Kit-8 assay. Cell apoptosis was observed using the chromatin dye Hoechst 33258 and analyzed by Flow Cytometry after propidium iodide staining. Mitochondrial membrane potential was monitored using the fluorescent dye Rh123. Intracellular reactive oxygen species were determined by oxidative conversion of cell permeable 2\u2019,7\u2019-dichlorfluorescein-diacetate to fluorescent 2\u2019,7\u2019- dichlorfluorescein. The expression of cleaved caspase-3 and bcl-2 and the accumulation of cytosolic cytochrome c were analyzed by Western blot. Results: We show that ACS6 protects PC12 cells against cytotoxicity and apoptosis induced by homocysteine and blocks homocysteine-triggered cytochrome c release and caspase-3 activation. ACS6 treatment results in not only prevention of homocysteine-caused mitochondrial membrane potential (\u394\u3c8) loss and reactive oxygen species (ROS) overproduction but also reversal of Bcl-2 down-expression. Conclusions: These results indicate that ACS6 protects PC12 cells against homocysteine-induced cytotoxicity and apoptosis by preservation of mitochondrial function though inhibiting both loss of \u394\u3c8 and accumulation of ROS as well as modulating the expression of Bcl-2. Our study provides evidence both for a neuroprotective effect of ACS6 and for further evaluation of ACS6 as novel neuroprotectants for Alzheimer\u2019s disease associated with homocysteine

Gastric tolerability and prolonged prostaglandin inhibition in the brain with a nitric oxide-releasing flurbiprofen derivative (NCX 2216, [3-[4-(2-fluoro-a-methyl[1,1-biphenyl]-4-acetyloxy)-3-methoxyphenyl]-2-propenoic acid 4-nitrooxybutyl

ABSTRACT NCX-2216 [3-[4-(2-fluoro-␣-methyl-[1,1Ј-biphenyl]-4-acetyloxy)-3-methoxyphenyl]-2-propenoic acid 4-nitrooxy butyl ester] is an NO-releasing flurbiprofen derivative that also contains a ferulic acid (antioxidant) moiety. NCX-2216 has been shown to be effective in reducing ␤-amyloid deposition in a transgenic mouse model of Alzheimer's disease. The tolerability of this compound in the stomach and its ability to suppress prostaglandin synthesis in the brain are not known. The purpose of this study was to assess the contribution of nitric oxide (NO) and ferulic acid to the pharmacological properties of NCX-2216 versus flurbiprofen; thus, we compared their gastric tolerability and suppression of prostaglandin synthesis, peripherally and centrally. Oral flurbiprofen produced extensive gastric damage and suppressed gastric prostaglandin synthesis. In contrast, while suppressing prostaglandin production, equimolar doses of NCX-2216 did not cause detectable gastric injury. The NO-releasing moiety of NCX-2216 (but not the ferulic acid moiety) was crucial for the gastric safety of this compound. NCX-2216 substantially inhibited prostanoid synthesis despite not being detectable in plasma and despite producing only low amounts of flurbiprofen in plasma and in the brain. Inhibition of brain prostaglandin synthesis by NCX-2216 (22 mg/ kg) persisted for a much longer period of time (up to 48 h) than was seen with flurbiprofen (Յ12 h). These results demonstrate that a single administration of NCX-2216 can produce prolonged suppression of brain prostaglandin synthesis without causing gastric injury. It is likely that an active metabolite of NCX-2216 contributes to the suppression of cyclooxygenase activity. NCX-2216 may represent an attractive alternative to conventional nonsteroidal anti-inflammatory drugs for long-term treatment of a variety of inflammatory disorders, especially those occurring in the central nervous system

NEW ANTICANCER COMPOUNDS

The present invention relates to new polysulfurated compounds containing 2 or more sulphur atoms belonging to the class of organic thiosulfonates, or dithiole-thione derivatives cyclic or linear, or trithiocarbonates for the use alone or in combination with other anticancer treatments for the treatment and/or prevention of cancer and inflammatory diseases