Suchergebnisse

Enhancing the phagocytosis of immune cells with medicines provides benefits to the physiological balance by removing foreign pathogens and apoptotic cells. The fungal immunomodulatory protein (FIP) possessing various immunopotentiation functions may be a good candidate for such drugs. However, the effect and mechanism of FIP on the phagocytic activity is limitedly investigated. Therefore, the present study determined effects of Cordyceps militaris immunomodulatory protein (CMIMP), a novel FIP reported to induce cytokines secretion, on the phagocytosis using three different types of models, including microsphere, Escherichia Coli and Candida albicans. CMIMP not only significantly improved the phagocytic ability (p < ; 0.05), but also enhanced the bactericidal activity (p < ; 0.05). Meanwhile, the cell size, especially the cytoplasm size, was markedly increased by CMIMP (p < ; 0.01), accompanied by an increase in the F-actin expression (p < ; 0.001). Further experiments displayed that CMIMP-induced phagocytosis, cell size and F-actin expression were alleviated by the specific inhibitor of TLR4 (p < ; 0.05). Similar results were observed in the treatment with the inhibitor of the NF-κB pathway (p < ; 0.05). In conclusion, it could be speculated that CMIMP promoted the phagocytic ability of macrophages through increasing F-actin expression and cell size in a TLR4-NF-κB pathway dependent way.

Cordyceps militaris, a valuable edible and medicinal fungus, has attracted increasing attention because of its various bioactive ingredients. However, the biosynthetic pathway of C. militaris carotenoids is still unknown due to lack of transcriptome information. To uncover genes related to the biosynthesis of C. militaris carotenoids, the transcriptomes of mycelia CM10_D cultured under dark conditions and mycelia CM10_L cultured under light exposure conditions were sequenced. Compared with mycelia CM10_D, 866 up-regulated genes and 856 down-regulated genes were found in mycelia CM10_L. Gene ontology (GO) analysis of differentially expressed genes (DEGs) indicated that DEGs were mainly classified into the "metabolic process," "membrane," and "catalytic activity" terms. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of DEGs suggested that DEGs were mainly enriched in "metabolic pathways," "MAPK signaling pathway-yeast," and "biosynthesis of secondary metabolites." In addition, the carotenoid content of the Cmtns gene deletion mutant (ΔCmtns) was significantly lower than that of the wild-type C. militaris CM10, while the carotenoid content of the complementary strain (ΔCmtns-c) of the Cmtns gene was not significantly different from that of C. militaris CM10, suggesting that the Cmtns gene significantly affected the biosynthesis of carotenoids in C. militaris. These results potentially pave the way for revealing the biosynthetic pathway of carotenoids and improving carotenoids production in C. militaris.

Cordyceps militaris fruiting bodies contain a variety of bioactive components that are beneficial to the human body. However, the low yield of fruiting bodies and the low carotenoid content in C. militaris have seriously hindered the development of the C. militaris industry. To elucidate the developmental mechanism of the fruiting bodies of C. militaris and the biosynthesis mechanism of carotenoids, the function of the flavohemoprotein-like Cmfhp gene of C. militaris was identified for the first time. The Cmfhp gene was knocked out by the split-marker method, and the targeted gene deletion mutant ΔCmfhp was obtained. An increased nitric oxide (NO) content, no fruiting body production, decreased carotenoid content, and reduced conidial production were found in the mutant ΔCmfhp. These characteristics were restored when the Cmfhp gene expression cassette was complemented into the ΔCmfhp strain by the Agrobacterium tumefaciens-mediated transformation method. Nonetheless, the Cmfhp gene had no significant effect on the mycelial growth rate of C. militaris. These results indicated that the Cmfhp gene regulated the biosynthesis of NO and carotenoids, the development of fruiting bodies, and the formation of conidia. These findings potentially pave the way to reveal the developmental mechanism of fruiting bodies and the biosynthesis mechanism of carotenoids in C. militaris.