Internalisation of neutrophils extracellular traps by macrophages aggravate rheumatoid arthritis via Rab5a.

OBJECTIVES: Although elevated levels of neutrophil extracellular traps (NETs) have been reported in patients with rheumatoid arthritis (RA), the role of NETs in RA and the relationship between NETs and macrophages in the pathogenesis of RA requires further research. Here, we sought to determine the role of NETs in RA pathogenesis and reveal the potential mechanism. METHODS: Neutrophil elastase (NE) and myeloperoxidase (MPO)-DNA were measured in human serum and synovium. NETs inhibitor GSK484 was used to examine whether NETs involved with RA progression. We stimulated macrophages with NETs and detected internalisation-related proteins to investigate whether NETs entry into macrophages and induced inflammatory cytokines secretion through internalisation. To reveal mechanisms mediating NETs-induced inflammation aggravation, we silenced GTPases involved in internalisation and inflammatory pathways in vivo and in vitro and detected downstream inflammatory pathways. RESULTS: Serum and synovium from patients with RA showed a significant increase in NE and MPO, which positively correlated to disease activity. Inhibiting NETs formation alleviated the collagen-induced arthritis severity. In vitro, NETs are internalised by macrophages and located in early endosomes. Rab 5a was identified as the key mediator of the NETs internalisation and inflammatory cytokines secretion. Rab 5a knockout mice exhibited arthritis alleviation. Moreover, we found that NE contained in NETs activated the Rab5a-nuclear factor kappa B (NF-κB) signal pathway and promoted the inflammatory cytokines secretion in macrophages. CONCLUSIONS: This study demonstrated that NETs-induced macrophages inflammation to aggravate RA in Rab 5a dependent manner. Mechanically, Rab5a mediated internalisation of NETs by macrophages and NE contained in NETs promoted macrophages inflammatory cytokines secretion through NF-κB-light-chain-enhancer of activated B cells signal pathway. Therapeutic targeting Rab 5a or NE might extend novel strategies to minimise inflammation in RA.

Identification of metabolites from edible mushroom Morchella sextelata and their biological evaluation.

To identify bioactive metabolites from the fruiting body of Morchella sextelata, fourteen metabolites (1-14) including one undescribed morchesexten A (1) were isolated. Their structures including absolute configurations were assigned on the basis of spectroscopic data and quantum chemical computational methods. Furthermore, the anti-inflammatory and antioxidant activities of the isolated compounds were evaluated. Compounds 10-12 showed inhibitory effects on nitric oxide (NO) production with IC50 values of 15.2 ± 2.7, 10.2 ± 1.9 and 35.3 ± 10.5 µM, respectively. Compounds 7 and 9 exhibited strong antioxidant effect with IC50 values of 6.7 ± 0.4 and 7.3 ± 0.8 µM compared with Vit C (IC50 15.4 ± 0.2 µM).

Aspertaichunol A, an Immunomodulatory Polyketide with an Uncommon Scaffold from the Insect-Derived Endophytic Aspergillus taichungensis SMU01.

Aspertaichunol A (1), a polyketide with a novel scaffold, was isolated from the medicinal insect (Periplaneta americana)-derived endophytic Aspergillus taichungensis SMU01. Its structure was assigned on the basis of spectroscopic data and quantum chemical computational methods. Notably, 1 possesses an uncommon tricyclo[6.2.0.02,6]decane motif and an unusual bridgehead double bond (anti-Bredt system). A plausible biosynthetic pathway, involving a key intramolecular [2+2] cycloaddition and a reductive cyclization, is postulated. Finally, the immunomodulatory activity of 1 at 20 nM was evaluated by promoting Th9 cell differentiation from naive CD4+CD62L+ T cells.

Glycoside constituents with various antioxidant effects from fresh Cynomorium songaricum.

Cynomorium songaricum Rupr. (CSR), an edible and medicinal material, is widely cultivated in desert regions of Eastern and Western Asia, Europe, and North Africa. Ten glycoside constituents 1-10 including one new songaricumone A (1) were isolated from the fresh C. songaricum. Their structures were elucidated by comprehensive NMR data analysis. Further, various antioxidant effects of isolated compounds (1-3 and 5-10) were comprehensively and comparatively investigated. In conclusion, it is obvious that different glycosides vary significantly toward different sources of free radicals, which are attributed to different aglycones and substituted positions of sugar unit in structures.