No abstract

SUMMARYThe aim of this study was to assess the synovial fluid (SF) neurotransmitter excitatory amino acid (EAA) levels, including glutamate (Glu) and aspartate (Asp), in the context of SF levels of other amino acids, TNF-a and chemokines from patients with active arthropathies . The SF was collected from patients with active rheumatoid arthritis (RA), gout, or osteoarthritis (OA). The SF samples were analysed for levels of neurotransmitters glutamate and aspartate, tumour necrosis factor-alpha (TNF-a ), R egulated upon Activation N ormally T-cell E xpressed and S ecreted (RANTES), macrophage inhibitory factor-1 alpha (MIP-1 a ) and interleukin 8 (IL-8). SF WBC counts were also determined. Correlations between SF EAA, TNF-a and chemokines were determined by the Pearson product-moment correlation. Primary cultures derived from SF from active RA and gout patients were incubated with added L -glutamate, to assess if exposure to Glu could increase TNF-a levels. There were significant elevations in SF EAA, SF TNF-a and SF RANTES in RA patients compared to gout or OA patients. Significant correlations between SF EAA and SF RANTES, MIP-1 a and IL-8 levels were seen, and SF EAA and SF TNF-a or SF WBC levels approached significance. Addition of exogenous neurotransmitter glutamate significantly increased TNF-a levels in primary cell cultures derived from RA and gout patients. The SF neurotransmitter EAA levels significantly correlated to selected SF chemokine levels, in clinically active RA, gout and OA patients, independent of disease. Added Glu resulted in significantly increased TNF-a levels in primary synovial cell cultures. These data expand the relationship of SF neurotransmitter EAA levels to SF cytokines and chemokines in patients with clinically active arthritis, and suggest that neurotransmitters Glu and Asp contribute to peripheral inflammatory processes.

Background: Most commercial TNF␣ inhibitors are biomacromolecules. Results: A lead compound named C87 was identified using computer-aided drug design and could attenuate murine acute hepatitis. Conclusion: C87 was one of the first effective small-molecule inhibitors of TNF␣ identified to date. Significance: The study highlights the effectiveness of combining virtual screening with functional assays for developing novel small-molecule TNF␣ inhibitors.

The process of initiation of host invasion and survival of some foliar phytopathogenic fungi in the absence of external nutrients on host leaf surfaces remains obscure. Here, we demonstrate that gluconeogenesis plays an important role in the process and nutrient-starvation adaptation before the pathogen host invasion. Deletion of phosphoenolpyruvate carboxykinase gene BcPCK1 in gluconeogenesis in Botrytis cinerea, the causative agent of grey mould, resulted in the failure of the ΔBcpck1 mutant conidia to germinate on hard and hydrophobic surface and penetrate host cells in the absence of glucose, reduction in conidiation and slow conidium germination in a nutrient-rich medium. The wild-type and ΔBcpck1 conidia germinate similarly in the presence of glucose (higher concentration) as the sole carbon source. Conidial glucose-content should reach a threshold level to initiate germination and host penetration. Infection structure formation by the mutants displayed a glucose-dependent fashion, which corresponded to the mutant virulence reduction. Exogenous glucose or complementation of BcPCK1 completely rescued all the developmental and virulence defects of the mutants. Our findings demonstrate that BcPCK1 plays a crucial role in B. cinerea pathogenic growth and virulence, and provide new insights into gluconeogenesis mediating pathogenesis of plant fungal pathogens via initiation of conidial germination and host penetration.