NOX2 deficiency enhances priming and activation of the NLRP3 inflammasome.

BACKGROUND: Nicotinamide adenine dinucleotide phosphate oxidase complex 2 (NOX2) deficiency, or chronic granulomatous disease (CGD), is an inborn error of immunity associated with increased susceptibility to infection and inflammatory manifestations. The pathophysiologic mechanism leading to the increased inflammatory response in CGD remains elusive. OBJECTIVE: We investigated the pathophysiologic mechanisms leading to NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activation in NOX2 deficiency. METHODS: We used NOX2-deficient human primary and CRISPR-engineered macrophages to show that NOX2 deficiency enhances the inflammatory response mainly by modulating the 2 steps of NLRP3 inflammasome activation: its transcriptional priming and its posttranslational triggering. RESULTS: At the transcriptional level, NOX2-deficient phagocytes display increased priming of the NLRP3 inflammasome, as evidenced by increased transcription of NLRP3 and IL-1ß through an IL-1ß-dependent stimulation of the nuclear factor kappa-light-chain enhancer of activated B cells (aka NF-κB) pathway. At the posttranslational level, the absence of NOX2 triggers the NLRP3 inflammasome activation by increased K+ efflux and excessive release of mitochondrial DNA due to mitochondrial damage. Furthermore, NLRP3-driven pyroptosis in NOX2-deficient phagocytes further enhances NLRP3 activation by increasing K+ efflux. CONCLUSION: Our results unveil the role of NOX2 as a repressor of the inflammatory response at both transcriptional and posttranslational levels and pave the way for a more targeted approach to treating CGD patients with inflammatory manifestations.

Dereplication of cytotoxic compounds from different parts of Sophora pachycarpa using an integrated method of HPLC, LC-MS and 1H-NMR techniques.

Sophora pachycarpa Schrenk ex C.A.Mey. is an annual plant belonging to the family Fabaceae. The cytotoxic activities of methanol-dichloromethane extracts (1:1) of different parts of S. pachycarpa were investigated on DU145 (prostate cancer cell line) and MCF-7 (breast cancer cell line) cell lines. The root extract of S. pachycarpa was the only extract that showed significant cytotoxic activity with IC50 values of 39.88 and 16.49 µg/mL on DU145 and MCF-7 cell lines, respectively. The root extract was then subjected to RP-HPLC for further fractionations. Among the isolated fractions from root extract, only one of them had remarkable cytotoxic effects with IC50 value of 26.43 on MCF-7 and 7.54 µg/mL on DU145 cell lines. Further purification led to isolation of a compound with IC50 values of 5.44 and 2.44 µg/mL on MCF-7 and DU145 cell lines, respectively. Based on 1H NMR and 13C NMR spectra, together with LC-MS, the structure of the purified compound was assigned as the flavonostilbene alopecurone A.