Sheng-Hua Wu

Anti-Cancerous Effect of Inonotus taiwanensis Polysaccharide Extract on Human Acute Monocytic Leukemia Cells through ROS-Independent Intrinsic Mitochondrial Pathway

Acute leukemia is one of the commonly diagnosed neoplasms and causes human death. However, the treatment for acute leukemia is not yet satisfactory. Studies have shown that mushroom-derived polysaccharides display low toxicity and have been used clinically for cancer therapy. Therefore, we set out to evaluate the anti-cancerous efficacy of a water-soluble polysaccharide extract from Inonotus taiwanensis (WSPIS) on human acute monocytic leukemia THP-1 and U937 cell lines in vitro. Under our experimental conditions, WSPIS elicited dose-dependent growth retardation and induced apoptotic cell death. Further analysis showed that WSPIS-induced apoptosis was associated with a mitochondrial apoptotic pathway, such as the disruption of mitochondrial membrane potential (MMP), followed by the activation of caspase-9, caspase-3, and PARP (poly(ADP-ribose) polymerase) cleavage. However, a broad caspase inhibitor, Z-VAD.fmk, could not prevent WSPIS-induced apoptosis. These data imply that mechanism(s) other than caspase might be involved. Thus, the involvement of endonuclease G (endoG), a mediator arbitrating caspase-independent oligonucleosomal DNA fragmentation, was examined. Western blotting demonstrated that WSPIS could elicit nuclear translocation of endoG. MMP disruption after WSPIS treatment was accompanied by intracellular reactive oxygen species (ROS) generation. However, pretreatment with N-acetyl-l-cysteine (NAC) could not attenuate WSPIS-induced apoptosis. In addition, our data also show that WSPIS could inhibit autophagy. Activation of autophagy by rapamycin decreased WSPIS-induced apoptosis and cell death. Taken together, our findings suggest that cell cycle arrest, endonuclease G-mediated apoptosis, and autophagy inhibition contribute to the anti-cancerous effect of WSPIS on human acute monocytic leukemia cells.

Taxonomy and phylogeny of Lopharia s.s., Dendrodontia, Dentocorticium and Fuscocerrena (Basidiomycota, Polyporales)

Abstract Eleven taxa of Lopharia s.s., Dendrodontia, Dentocorticium and Fuscocerrena in Polyporales are included in the phylogenetic analyses of nuc rDNA ITS1-5.8S-ITS2 (ITS), D1-D2 domains of nuc 28S rDNA (28S) and RNA polymerase II second-largest subunit (rpb2) sequences. New species Lopharia resupinata and L. sinensis are described and illustrated. Lopharia resupinata, from south-eastern China, is closely related to L. ayresii, and L. sinensis, from northern China, is related to L. cinerascens and L. mirabilis. Lopharia mirabilis specimens from temperate to tropical areas with varied hymenophore configurations all cluster together in a fully supported clade. Dendrodontia and Fuscocerrena are shown to be synonyms of Dentocorticium, which is phylogenetically related to Lopharia. Four new combinations, Dentocorticium bicolor, D. hyphopaxillosum, D. portoricense and D. taiwanianum, are proposed. Revised generic descriptions of Lopharia and Dentocorticium are provided with keys to the six accepted species in each genus. A list of all names in Lopharia and Dentocorticium are presented with their current taxonomic status. Type specimens of Dentocorticium brasiliense and D. irregulare were examined and determined to be later synonyms of Punctularia subhepatica and Diplomitoporus daedaleiformis, respectively.

Hyphoderma pinicola sp. nov. of H. setigerum complex (Basidiomycota) from Yunnan, China

BackgroudHyphoderma setigerum (Fr.) Donk is a white-rot wood-decaying corticoid fungal species. It occurs worldwide from tropical to temperate regions. However, taxonomic studies in recent decades showed that H. setigerum is a species complex with four separate species, before this study.ResultsHyphoderma pinicola sp. nov. was collected on dead wood of Pinus yunnanensis Franch. in the temperate montane belt at 2200–2400 m altitudes, in Yunnan Province of China. Within the H. setigerum complex this new taxon is distinguished by having 2-sterigmate basidia, long basidiospores, and nearly naked septocystidia. A description and illustrations of this new species are provided, along with a key to five species of the H. setigerum complex. Phylogenetic reconstruction based on 5.8S-ITS2 sequences indicated that H. pinicola belongs to the H. setigerum complex and has a separate position within the clade including H. subsetigerum and H. setigerum s.s. Bayesian inference of phylogeny based on two datasets, ITS and 28S nuclear ribosomal DNA sequences, confirmed the independent status of H. pinicola.ConclusionMorphological and phylogenetic studies showed that H. pinicola represents a fifth species of H. setigerum complex.