Serum concentrations of salicylate and naproxen during concurrent therapy in patients with rheumatoid arthritis

Fürst, Daniel E.; Sarkissian, Edmund; Blocka, Kenneth; Cassell, Sidney; Dromgoole, Sydney H.; Harris, Erica; Hirschberg, Joel M.; Josephson, Nathan; Paulus, Harold E.

doi:10.1002/art.1780301011

Cited by 14 publications

(7 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The two drugs that were found to inhibit the HSA-mediated stimulation of heme utilization, salicylic acid and naproxen, did so at concentrations corresponding to therapeutic serum concentrations in patients (44), suggesting that these drugs could be relevant in vivo. However, this range of drug concentrations was inhibitory only when the HSA concentration was kept low; at HSA concentrations closer to serum concentrations, the drug dosage was not sufficient to inhibit heme utilization.…”

Section: Discussionmentioning

confidence: 99%

Human Serum Albumin Facilitates Heme-Iron Utilization by Fungi

Pinsky

Roy

Moshe

et al. 2020

mBio

View full text Add to dashboard Cite

A large portion of biological iron is found in the form of an iron-protoporphyrin IX complex, or heme. In the human host environment, which is exceptionally poor in free iron, heme iron, particularly from hemoglobin, constitutes a major source of iron for invading microbial pathogens. Several fungi were shown to utilize free heme, and Candida albicans, a major opportunistic pathogen, is able both to capture free heme and to extract heme from hemoglobin using a network of extracellular hemophores. Human serum albumin (HSA) is the most abundant host heme-scavenging protein. Tight binding of heme by HSA restricts its toxic chemical reactivity and could diminish its availability as an iron source for pathogenic microbes. We found, however, that rather than inhibiting heme utilization, HSA greatly increases availability of heme as an iron source for C. albicans and other fungi. In contrast, hemopexin, a low-abundance but high-affinity heme-scavenging serum protein, does inhibit heme utilization by C. albicans. However, inhibition by hemopexin is mitigated in the presence of HSA. Utilization of albumin-bound heme requires the same hemophore cascade as that which mediates hemoglobin-iron utilization. Accordingly, we found that the C. albicans hemophores are able to extract heme bound to HSA in vitro. Since many common drugs are known to bind to HSA, we tested whether they could interfere with heme-iron utilization. We show that utilization of albumin-bound heme by C. albicans can be inhibited by the anti-inflammatory drugs naproxen and salicylic acid. IMPORTANCE Heme constitutes a major iron source for microorganisms and particularly for pathogenic microbes; to overcome the iron scarcity in the animal host, many pathogenic bacteria and fungi have developed systems to extract and take up heme from host proteins such as hemoglobin. Microbial heme uptake mechanisms are usually studied using growth media containing free heme or hemoglobin as a sole iron source. However, the animal host contains heme-scavenging proteins that could prevent this uptake. In the human host in particular, the most abundant serum heme-binding protein is albumin. Surprisingly, however, we found that in the case of fungi of the Candida species family, albumin promoted rather than prevented heme utilization. Albumin thus constitutes a human-specific factor that can affect heme-iron utilization and could serve as target for preventing heme-iron utilization by fungal pathogens. As a proof of principle, we identify two drugs that can inhibit albumin-stimulated heme utilization.

show abstract

Section: Discussionmentioning

confidence: 99%

Human Serum Albumin Facilitates Heme-Iron Utilization by Fungi

Pinsky

Roy

Moshe

et al. 2020

mBio

View full text Add to dashboard Cite

show abstract

“…Coverslips with a flawless even FITC-fibronectin coating were transferred to 6-well tissue culture wells and seeded with OvCa429 cells plated at 2.5x10 4 cells/well in serum free medium. After 12 h in culture, cells were treated +/- 10 ng/ml EGF +/- individual drugs (6-MNA, R- or S-naproxen) at 300 μM final concentration which is equivalent to human serum plasma levels at clinically relevant dosages [ 61 , 62 ]; 1:1000 dilution from sterile stock in water. At varying time points (0–24 h) samples were fixed with 3% paraformaldehyde in PBS, permeabilized with 0.1% Triton X-100 and immunostained for Rac, Cdc42, among other markers.…”

Section: Methodsmentioning

confidence: 99%

Novel Activities of Select NSAID R-Enantiomers against Rac1 and Cdc42 GTPases

et al. 2015

View full text Add to dashboard Cite

Rho family GTPases (including Rac, Rho and Cdc42) collectively control cell proliferation, adhesion and migration and are of interest as functional therapeutic targets in numerous epithelial cancers. Based on high throughput screening of the Prestwick Chemical Library® and cheminformatics we identified the R-enantiomers of two approved drugs (naproxen and ketorolac) as inhibitors of Rac1 and Cdc42. The corresponding S-enantiomers are considered the active component in racemic drug formulations, acting as non-steroidal anti-inflammatory drugs (NSAIDs) with selective activity against cyclooxygenases. Here, we show that the S-enantiomers of naproxen and ketorolac are inactive against the GTPases. Additionally, more than twenty other NSAIDs lacked inhibitory action against the GTPases, establishing the selectivity of the two identified NSAIDs. R-naproxen was first identified as a lead compound and tested in parallel with its S-enantiomer and the non-chiral 6-methoxy-naphthalene acetic acid (active metabolite of nabumetone, another NSAID) as a structural series. Cheminformatics-based substructure analyses—using the rotationally constrained carboxylate in R-naproxen—led to identification of racemic [R/S] ketorolac as a suitable FDA-approved candidate. Cell based measurement of GTPase activity (in animal and human cell lines) demonstrated that the R-enantiomers specifically inhibit epidermal growth factor stimulated Rac1 and Cdc42 activation. The GTPase inhibitory effects of the R-enantiomers in cells largely mimic those of established Rac1 (NSC23766) and Cdc42 (CID2950007/ML141) specific inhibitors. Docking predicts that rotational constraints position the carboxylate moieties of the R-enantiomers to preferentially coordinate the magnesium ion, thereby destabilizing nucleotide binding to Rac1 and Cdc42. The S-enantiomers can be docked but are less favorably positioned in proximity to the magnesium. R-naproxen and R-ketorolac have potential for rapid translation and efficacy in the treatment of several epithelial cancer types on account of established human toxicity profiles and novel activities against Rho-family GTPases.

show abstract

“…Before assessing whether the NSAID, sodium salicylate, would potentiate the heat shock response and protect motor neurons from different stresses, preliminary experi-ments were conducted to evaluate the concentrations of sodium salicylate tolerated by motor neurons in dissociated spinal cord cultures. Cultures were exposed to 0.5, 1, 2, and 5 mM, concentrations that encompass the therapeutic range of serum concentrations (0.9-1.9 mM) used in rheumatoid arthritic patients (Pollet et al 1985;Furst et al 1987). Motor neurons were microinjected with the dextran-fluorescein marker, treated with sodium salicylate the subsequent day, and counted over 10 days.…”

Section: Dose-response Of Motor Neurons To Sodium Salicylatementioning

confidence: 99%

Nonsteroidal anti-inflammatory drugs differentially affect the heat shock response in cultured spinal cord cells

2005

View full text Add to dashboard Cite

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to amplify the heat shock response in cell lines by increasing the binding of heat shock transcription factor-1 to heat shock elements within heat shock gene promoters. Because overexpression of the inducible heat shock protein 70 (Hsp70) was neuroprotective in a culture model of motor neuron disease, this study investigated whether NSAIDs induce Hsp70 and confer cytoprotection in motor neurons of dissociated spinal cord cultures exposed to various stresses. Two NSAIDs, sodium salicylate and niflumic acid, lowered the temperature threshold for induction of Hsp70 in glia but failed to do so in motor neurons. At concentrations that increased Hsp70 in heat shocked glial cells, sodium salicylate failed to delay death of motor neurons exposed to hyperthermia, paraquat-mediated oxidative stress, and glutamate excitotoxicity. Neither sodium salicylate nor the cyclooxygenase-2 inhibitor, niflumic acid, protected motor neurons from the toxicity of mutated Cu/Zn-superoxide dismutase (SOD-1) linked to a familial form of the motor neuron disease, amyotrophic lateral sclerosis. Thus, treatment with 2 types of NSAIDs failed to overcome the high threshold for the activation of heat shock response in motor neurons.

show abstract

Serum concentrations of salicylate and naproxen during concurrent therapy in patients with rheumatoid arthritis

Cited by 14 publications

References 13 publications

Human Serum Albumin Facilitates Heme-Iron Utilization by Fungi

Human Serum Albumin Facilitates Heme-Iron Utilization by Fungi

Novel Activities of Select NSAID R-Enantiomers against Rac1 and Cdc42 GTPases

Nonsteroidal anti-inflammatory drugs differentially affect the heat shock response in cultured spinal cord cells

Contact Info

Product

Resources

About