MicroRNAs are known to play an important role in modulating gene expression in various diseases including cancers and cardiovascular disorders, but only a few of them are associated with the pathology of aflatoxin B₁ (AFB₁), a potent mycotoxin. Here, we discovered a novel regulatory network between AFB₁, miR-33a and β-catenin in human carcinoma cells. The level of miR-33a was up-regulated in hepatocellular carcinoma (HCC) cells treated with AFB₁, while in the same cells causing the decrease in β-catenin expression when treated at their IC₅₀ values. miR-33a, specifically miR-33a-5p, was demonstrated to down-regulate the expression of β-catenin, affect the β-catenin pathway, and inhibit cell growth. Also, by employing a luciferase assay, we found that miR-33a down-regulated β-catenin by directly binding to the 3’-UTR of β-catenin. These results suggested that AFB₁ might down-regulate β-catenin by up-regulating miR-33a. This understanding opens new lines of thought in the potential role of miR-33a in the clinical therapy of cancer.

Light is an essential environmental factor for Sparassis latifolia primordia formation, but the molecular mechanism is still unclear. In this study, differential expression profiling of light-induced primordia formation (LIPF) was established by integrating the assay for transposase accessible chromatin by sequencing (ATAC-seq) and RNA-seq technology. The integrated results from the ATAC-seq and RNA-seq showed 13 down-regulated genes and 17 up-regulated genes in both the L vs. D and P vs. D groups, for both methods. According to the gene ontology (GO) annotation of these differentially expressed genes (DEGs), the top three biological process categories were cysteine biosynthetic process via cystathionine, vitamin B6 catabolic, and glycine metabolic; the top three molecular function categories were 5-methyltetrahydropteroyltriglutamate-homocysteine S-methyltransferase activity, glycine binding, and pyridoxal phosphate binding; cellular component categories were significantly enriched in the glycine cleavage complex. The KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis revealed that these genes were associated with vitamin B6 metabolism; selenocompound metabolism; cysteine and methionine metabolism; glycine, serine, and threonine metabolism; and glyoxylate and dicarboxylate metabolism pathways. The expression of most of the DEGs was validated by qRT-PCR. To the best of our knowledge, this study is the first integrative analysis of ATAC-seq and RNA-seq for macro-fungi. These results provided a new perspective on the understanding of key pathways and hub genes in LIPF in S. latifolia. It will be helpful in understanding the primary environmental response, and provides new information to the existing models of primordia formation in edible and medicinal fungi.

We recently proposed, and successfully applied, a novel and efficient technique—ultrasonic-circulating extraction (UCE) integrating superfine pulverization—to extract and prepare antioxidant crude polysaccharides other natural active substances from Ganoderma lucidum. The aim of this study was to evaluate the antioxidant and hepatoprotective activities and active ingredients in the powder from UCE (UCEP) through comparison with powder from hot water extraction (HWEP). The DPPH radical, ABTS radical, superoxide anion, total antioxidant activity, and ferric-reducing antioxidant power assay results showed that the UCEP exhibited stronger (P < 0.01) in vitro antioxidant activity than the HWEP. The hepatoprotective activity of the extracts was evaluated against CCl₄-induced oxidative damage in the liver. Measurements of reduced glutathione, superoxide dismutase, and malondialdehyde in rat liver; measurements of alanine transaminase, aspartate transaminase, and lactate dehydrogenase in rat blood; and Western blotting for antioxidant proteins of transforming growth factor-β₁, heme-oxygenase 1, and glutathione per-oxidase showed that the UCEP had antioxidant activity in vivo either similar to or slightly stronger than (P < 0.1) the HWEP. Further analysis of the active ingredients revealed that the UCEP and HWEP have similar mean yield and total triterpenoid content, but the former has significantly higher (P < 0.05) mean yield and total polysaccharide content than the latter. Our results suggest that the UCEP displays stronger antioxidant activities because of the larger amount of total polysaccharides; the UCEP may be able to be used as an antioxidant and liver protectant.

Sparassis latifolia is a valuable edible mushroom cultivated in China. In 2018, our research group reported an incomplete and low-quality genome of S. latifolia obtained by Illumina HiSeq 2500 sequencing. These limitations in the available genome have constrained genetic and genomic studies in this mushroom resource. Herein, an updated draft genome sequence of S. latifolia was generated by Oxford Nanopore sequencing and the high-through chromosome conformation capture (Hi-C) technique. A total of 8.24 Gb of Oxford Nanopore long reads representing ∼198.08X coverage of the S. latifolia genome were generated. Subsequently, a high-quality genome of 41.41 Mb, with scaffold and contig N50 sizes of 3.31 and 1.51 Mb, respectively, was assembled. Hi-C scaffolding of the genome resulted in 12 pseudochromosomes containing 93.56% of the bases in the assembled genome. Genome annotation further revealed that 17.47% of the genome was composed of repetitive sequences. In addition, 13,103 protein-coding genes were predicted, among which 98.72% were functionally annotated. BUSCO assay results further revealed that there were 92.07% complete BUSCOs. The improved chromosome-scale assembly and genome features described here will aid further molecular elucidation of various traits, breeding of S. latifolia, and evolutionary studies with related taxa.