iNOS-mediated nitric oxide production and its regulation.

Mitochondria are recognized as one of the most important targets for new drug design in cancer, cardiovascular, and neurological diseases. Currently, the most effective way to deliver drugs specifically to mitochondria is by covalent linking a lipophilic cation such as an alkyltriphenylphosphonium moiety to a pharmacophore of interest. Other delocalized lipophilic cations, such as rhodamine, natural and synthetic mitochondria-targeting peptides, and nanoparticle vehicles, have also been used for mitochondrial delivery of small molecules. Depending on the approach used, and the cell and mitochondrial membrane potentials, more than 1000-fold higher mitochondrial concentration can be achieved. Mitochondrial targeting has been developed to study mitochondrial physiology and dysfunction and the interaction between mitochondria and other subcellular organelles and for treatment of a variety of diseases such as neurodegeneration and cancer. In this Review, we discuss efforts to target small-molecule compounds to mitochondria for probing mitochondria function, as diagnostic tools and potential therapeutics. We describe the physicochemical basis for mitochondrial accumulation of lipophilic cations, synthetic chemistry strategies to target compounds to mitochondria, mitochondrial probes, and sensors, and examples of mitochondrial targeting of bioactive compounds. Finally, we review published attempts to apply mitochondria-targeted agents for the treatment of cancer and neurodegenerative diseases.

/pdf/mitochondria-targeted-triphenylphosphonium-based-compounds-4xqo2evab5.pdf

Mitochondria-Targeted Triphenylphosphonium-Based Compounds: Syntheses, Mechanisms of Action, and Therapeutic and Diagnostic Applications

The pro-inflammatory signalling pathways and cellular mechanisms that initiate the inflammatory response have become increasingly well characterized. However, little is known about the mediators and mechanisms that switch off inflammation. Recent data indicate that the resolution of inflammation is an active process controlled by endogenous mediators that suppress pro-inflammatory gene expression and cell trafficking, as well as induce inflammatory-cell apoptosis and phagocytosis, which are crucial determinants of successful resolution. This review focuses on this emerging area of inflammation research and describes the mediators and mechanisms that are currently stealing the headlines.

Anti-inflammatory lipid mediators and insights into the resolution of inflammation

Treatment of inflammatory diseases today is largely based on interrupting the synthesis or action of mediators that drive the host's response to injury. Non-steroidal anti-inflammatories, steroids and antihistamines, for instance, were developed on this basis. Although such small-molecule inhibitors have provided the main treatment for inflammatory arthropathies and asthma, they are not without their shortcomings. This review offers an alternative approach to the development of novel therapeutics based on the endogenous mediators and mechanisms that switch off acute inflammation and bring about its resolution. It is thought that this strategy will open up new avenues for the future management of inflammation-based diseases.

/pdf/inflammatory-resolution-new-opportunities-for-drug-discovery-20yn0q6qsz.pdf

Inflammatory resolution: new opportunities for drug discovery.

Nitric oxide (NO), generated by the inducible isoform of nitric oxide synthase (iNOS), has been described to have beneficial microbicidal, antiviral, antiparasital, immunomodulatory, and antitumoral effects. However, aberrant iNOS induction at the wrong place or at the wrong time has detrimental consequences and seems to be involved in the pathophysiology of several human diseases. iNOS is primarily regulated at the expression level by transcriptional and post-transcriptional mechanisms. iNOS expression can be induced in many cell types with suitable agents such as bacterial lipopolysaccharides (LPS), cytokines, and other compounds. Pathways resulting in the induction of iNOS expression may vary in different cells or different species. Activation of the transcription factors NF-kappaB and STAT-1alpha, and thereby activation of the iNOS promoter, seems to be an essential step for iNOS induction in most cells. However, at least in the human system, also post-transcriptional mechanism are critically involved in the regulation of iNOS expression. The induction of iNOS can be inhibited by a wide variety of immunomodulatory compounds acting at the transcriptional levels and/or post-transcriptionally.

Regulation of the Expression of Inducible Nitric Oxide Synthase

http://digital.csic.es/bitstream/10261/77814/3/J.%20Biol.%20Chem.-2001-Cernuda-Moroll%c3%b3n-35530-6.pdf

15-Deoxy-Δ12,14-prostaglandin J2Inhibition of NF-κB-DNA Binding through Covalent Modification of the p50 Subunit

https://digital.csic.es/bitstream/10261/167492/1/J.%20Biol.%20Chem.-2003-P%c3%a9rez-Sala-51251-60.pdf

Molecular Basis for the Direct Inhibition of AP-1 DNA Binding by 15-Deoxy-Δ12,14-prostaglandin J2

Molecular basis for the direct inhibition of AP-1 DNA binding by 15-deoxy-Δ12,14-prostaglandin J2. Vol. 278 (2003) 51251-51260

The cyclopentenone prostaglandin and PPARgamma agonist 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) displays anti-inflammatory effects in several experimental models. Direct modification of protein thiols is arising as an important mechanism of cyclopentenone prostaglandin action. However, little is known about the extent or specificity of this process. Mesangial cells (MC) play a key role in glomerulonephritis. In this work, we have studied the selectivity of protein modification by 15d-PGJ(2) in MC, and the correlation with the modulation of several proinflammatory genes. MC incubation with biotinylated 15d-PGJ(2) results in the labeling of a distinct set of proteins as evidenced by two-dimensional electrophoresis. 15d-PGJ(2) binds to nuclear and cytosolic targets as detected by fluorescence microscopy and subcellular fractionation. The pattern of biotinylated 15d-PGJ(2)-modified polypeptides is readily distinguishable from that of total protein staining or labeling with biotinylated iodoacetamide. 15d-PGJ(2) addition requires the double bond in the cyclopentane ring. 9,10-Dihydro-15d-PGJ(2), a 15d-PGJ(2) analog that shows the same potency as peroxisome proliferator-activated receptor (PPAR) agonist in MC but lacks the cyclopentenone moiety, displays reduced ability to modify proteins and to block 15d-PGJ(2) binding. Micromolar concentrations of 15d-PGJ(2) inhibit cytokine-elicited levels of inducible nitricoxide synthase, cyclooxygenase-2, and intercellular adhesion molecule-1 in MC. In contrast, 9,10-dihydro-15d-PGJ(2) does not reproduce this inhibition. 15d-PGJ(2) effect is not blocked by the PPARgamma antagonist 2-chloro-5-nitro-N-phenylbenzamide (GW9662). Moreover, compounds possessing an alpha,beta-unsaturated carbonyl group, like 2-cyclopenten-1-one and 2-cyclohexen-1-one, reduce pro-inflammatory gene expression. These observations indicate that covalent modification of cellular thiols by 15d-PGJ(2) is a selective process that plays an important role in the inhibition of MC responses to pro-inflammatory stimuli.

/pdf/protein-thiol-modification-by-15-deoxy-delta12-14-3qjwiy8q2n.pdf

Protein thiol modification by 15-deoxy-Delta12,14-prostaglandin J2 addition in mesangial cells: role in the inhibition of pro-inflammatory genes.

The cyclopentenone prostaglandin and PPARγ agonist 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) displays anti-inflammatory effects in several experimental models. Direct modification of protein thiols is arising as an important mechanism of cyclopentenone prostaglandin action. However, little is known about the extent or specificity of this process. Mesangial cells (MC) play a key role in glomerulonephritis. In this work, we have studied the selectivity of protein modification by 15d-PGJ2 in MC, and the correlation with the modulation of several proinflammatory genes. MC incubation with biotinylated 15d-PGJ2 results in the labeling of a distinct set of proteins as evidenced by two-dimensional electrophoresis. 15d-PGJ2 binds to nuclear and cytosolic targets as detected by fluorescence microscopy and subcellular fractionation. The pattern of biotinylated 15d-PGJ2-modified polypeptides is readily distinguishable from that of total protein staining or labeling with biotinylated iodoacetamide. 15d-PGJ2 addition requires the double bond in the cyclopentane ring. 9,10-Dihydro-15d-PGJ2, a 15d-PGJ2 analog that shows the same potency as peroxisome proliferator-activated receptor (PPAR) agonist in MC but lacks the cyclopentenone moiety, displays reduced ability to modify proteins and to block 15d-PGJ2 binding. Micromolar concentrations of 15d-PGJ2 inhibit cytokine-elicited levels of inducible nitricoxide synthase, cyclooxygenase-2, and intercellular adhesion molecule-1 in MC. In contrast, 9,10-dihydro-15d-PGJ2 does not reproduce this inhibition. 15d-PGJ2 effect is not blocked by the PPARγ antagonist 2-chloro-5-nitro-N-phenylbenzamide (GW9662). Moreover, compounds possessing an α,β-unsaturated carbonyl group, like 2-cyclopenten-1-one and 2-cyclohexen-1-one, reduce pro-inflammatory gene expression. These observations indicate that covalent modification of cellular thiols by 15d-PGJ2 is a selective process that plays an important role in the inhibition of MC responses to pro-inflammatory stimuli.

Eva Cernuda-Morollón

Papers

15-Deoxy-Δ12,14-prostaglandin J2Inhibition of NF-κB-DNA Binding through Covalent Modification of the p50 Subunit

Molecular Basis for the Direct Inhibition of AP-1 DNA Binding by 15-Deoxy-Δ12,14-prostaglandin J2

Molecular basis for the direct inhibition of AP-1 DNA binding by 15-deoxy-Δ12,14-prostaglandin J2. Vol. 278 (2003) 51251-51260

Protein thiol modification by 15-deoxy-Delta12,14-prostaglandin J2 addition in mesangial cells: role in the inhibition of pro-inflammatory genes.

in mesangial cells: role in the inhibition of pro-inflammatory genes*