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Background: The overall clinical outcome of inflammatory conditions is the result of the balance between pro-inflammatory and anti-inflammatory mediators. Because nuclear factor kappa B (NF-ĸB) is at the bottom of many inflammatory conditions, methods to evaluate the net effect of inflammation modulators on this master regulator have been conceptualized for years., Methods: Using an ex vivo NF-ĸB reporter cell line-based assay, plasma samples of patients with rheumatoid arthritis (n = 27), psoriasis (n = 15), or severe coronavirus disease-19 (COVID-19) (n = 21) were investigated for NF-ĸB activation compared to plasma samples from 9 healthy volunteers., Results: When separated by C-reactive protein (CRP) threshold levels, samples of patients exhibiting increased CRP levels (≥5 mg/l) activated NF-ĸB more efficiently than samples from patients with levels below 5 mg/l (P = 0.0001) or healthy controls (P = 0.04). Overall, there was a moderate association of CRP levels with NF-ĸB activation (Spearman r = 0.66; p < 0.0001). Plasma from COVID-19 patients activated NF-ĸB more efficiently (mean 2.4-fold compared to untreated reporter cells) than samples from any other condition (healthy controls, 1.8-fold, P = 0.0025; rheumatoid arthritis, 1.7-fold, P < 0.0001; psoriasis, 1.7-fold, P < 0.0001). In contrast, effects of rheumatoid arthritis, psoriasis, or healthy volunteer samples did not differ., Conclusion: This study shows that a NF-ĸB reporter cell line can be used to evaluate the net inflammatory effect of clinical plasma samples. Patients with chronic but stable rheumatoid arthritis or psoriasis do not exhibit increased plasma levels of NF-ĸB-activating compounds as opposed to COVID-19 patients with high inflammatory burden., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Resiquimod (R-848) is an immune response modifier activating toll-like receptor 7 and 8. Its potential to cause pharmacokinetic interactions with concurrently administered drugs is unknown. To study the time course of the effect of resiquimod in LS180 cells as a model for intestinal tissue, luciferase-based reporter gene assays and reverse transcription polymerase chain reaction were used to investigate whether resiquimod affects the activities of nuclear factor kappa B (NF-ĸB), pregnane x receptor (PXR) or the transcription of selected central genes for drug disposition (cytochrome P-450 isozyme 3A4 (CYP3A4), CYP1A1 , UDP-glucuronosyltransferase 1A1 (UGT1A1), ATP-binding cassette transporters ABCC2, ABCB1). Its impact on the activities of organic anion transporting polypeptides 1 or 3 (OATP1B1/3), breast cancer resistance protein (BCRP), P-glycoprotein (P-gp) or CYP3A4 was evaluated using fluorescence- or luminescence-based activity assays. Resiquimod irrelevantly increased NF-ĸB activity after 2 h (1 µM: 1.07-fold, P = 0.0188; 10 µM: 1.09-fold, P = 0.0142), and diminished it after 24 h (1 µM: 0.64-fold, P < 0.0001; 10 µM: 0.68-fold, P < 0.0001) and 30 h (10 µM: 0.68-fold, P = 0.0003). Concurrently, PXR activity after 24 h was marginally increased by 10 µM (1.05-fold, P = 0.0019). Resiquimod did not alter mRNA expression levels, activities of uptake or efflux transporters, or CYP3A4 activity. Given the marginal effects on NF-ĸB, PXR, expression levels of selected PXR target genes, and activities of important drug transporters and CYP3A4 in vitro, resiquimod is not expected to cause major pharmacokinetic drug-drug interactions in vivo. [Display omitted] [ABSTRACT FROM AUTHOR]

Interferon-alpha (IFN-α) is suggested to cause pharmacokinetic drug interactions by lowering expression of drug disposition genes through affecting the activities of nuclear factor kappa B (NF-ĸB) and pregnane X receptor (PXR). The time-resolved impact of IFN-α 2a (1000 U/mL; 5000 U/mL; 2 h to 30 h) on the activities of NF-ĸB and PXR and mRNA expression (5000 U/mL; 24 h, 48 h) of selected drug disposition genes and on cytochrome P450 (CYP3A4) activity in LS180 cells (5000 U/mL; 24 h, 48 h) was evaluated using luciferase-based reporter gene assays, reverse transcription polymerase chain reaction, and luminescence-based CYP3A4 activity assays. The cross-talk between NF-ĸB activation and PXR suppression was evaluated by NF-ĸB blockage (10 µM parthenolide). IFN-α 2a initially (2 h, 6 h) enhanced NF-ĸB activity 2-fold and suppressed PXR activity by 30%. mRNA of CYP3A4 was halved, whereas UGT1A1 was increased (1.35-fold) after 24 h. After 48 h, ABCB1 expression was increased (1.76-fold). CYP3A4 activity remained unchanged after 24 h, but was enhanced after 48 h (1.35-fold). IFN-α 2a demonstrated short-term suppressive effects on PXR activity and CYP3A4 mRNA expression, likely mediated by activated NF-ĸB. Longer exposure enhanced CYP3A4 activity. Clinical trials should evaluate the relevance by investigating the temporal effects of IFN-α on CYP3A4 using a sensitive marker substrate. [ABSTRACT FROM AUTHOR]