Transcriptome Analysis Reveals That C17 Mycosubtilin Antagonizes Verticillium dahliae by Interfering with Multiple Functional Pathways of Fungi

Mycosubtilin Induces G1 Phase Block and Autophagy in Cervical Cancer HeLa Cells

Cyclic lipopeptides secreted by the probiotic bacterium Bacillus subtilis have attracted much attention due to their antitumor activities and low toxicity. However, the role of Mycosubtilin (Myco) in the prevention and treatment of cervical cancer remains unclear. In the present study, we conducted a systematic evaluation of Myco's anti-cervical cancer effects to identify its molecular mechanism of action using proteomics technology. The results reveal that Myco inhibited the growth of HeLa and SiHa cervical cancer cell lines in a dose-dependent (3-15 µg/mL) and time-dependent (12-48 h) manner and significantly reduced colony formation and migration in HeLa cells, highlighting its potential to suppress tumor spread. Moreover, autophagosome and autolysosome numbers were significantly increased after Myco treatment, and the expression of autophagy-related proteins was significantly modulated, suggesting that autophagy plays a role in its anti-cancer mechanism. Myco treatment also induced G1 phase cell cycle arrest in HeLa cells, as confirmed by proteomics analysis. Myco was shown to induce cell cycle arrest in HeLa cells by regulating the P53 pathway and autophagy-dependent cell death via the PI3K/AKT/mTOR signaling pathway, demonstrating its multidimensional effect on cervical cancer cell growths. Myco treatment significantly inhibited tumor growth in vivo in a nude mouse cervical cancer xenograft model, providing direct evidence of its potential as a therapeutic candidate for cervical cancer. Given its unique anti-cancer mechanism and significant therapeutic efficacy, Myco should be considered a promising therapeutic agent for cervical cancer.

Marine Natural Products as Novel Treatments for Parasitic Diseases

Parasitic diseases including malaria, leishmaniasis, and trypanosomiasis have received significant attention due to their severe health implications, especially in developing countries. Marine natural products from a vast and diverse range of marine organisms such as sponges, corals, molluscs, and algae have been found to produce unique bioactive compounds that exhibit promising potent properties, including antiparasitic, anti-Plasmodial, anti-Leishmanial, and anti-Trypanosomal activities, providing hope for the development of effective treatments. Furthermore, various techniques and methodologies have been used to investigate the mechanisms of these antiparasitic compounds. Continued efforts in the discovery and development of marine natural products hold significant promise for the future of novel treatments against parasitic diseases.

Insights into the antifungal mechanism of Bacillus subtilis cyclic lipopeptide iturin A mediated by potassium ion channel

Fungal infections pose severe and potentially lethal threats to plant, animal, and human health. Ergosterol has served as the primary target for developing antifungal medications. However, many antifungal drugs remain highly toxic to humans due to similarity in cell membrane composition between fungal and animal cells. Iturin A, lipopeptide produced by Bacillus subtilis, efficiently inhibit various fungi, but demonstrated safety in oral administration, indicating the existence of targets different from ergosterol. To pinpoint the exact antifungal target of iturin A, we used homologous recombination to knock out and overexpress erg3, a key gene in ergosterol synthesis. Saccharomyces cerevisiae and Aspergillus carbonarius were transformed using the LiAc/SS-DNNPEG and Agrobacterium-mediated transformation (AMT), respectively. Surprisingly, increasing ergosterol content did not augment antifungal activity. Furthermore, iturin A's antifungal activity against S. cerevisiae was reduced while it pre-incubation with voltage-gated potassium (Kv) channel inhibitor, indicating that Kv activation was responsible for cell death. Iturin A was found to activate the Kv protein, stimulating K+ efflux from cell. In vitro tests confirmed interaction between iturin A and Kv protein. This study highlights Kv as one of the precise targets of iturin A in its antifungal activity, offering a novel target for the development of antifungal medications.

Antifungal metabolites of biocontrol stain LB-1 and their inhibition mechanism against Botrytis cinerea

Introduction

Chaetomium subaffine LB-1 is a novel biocontrol strain that produces non-volatile metabolites that inhibit the growth of Botrytis cinerea. However, the specific metabolites and antimicrobial mechanism of the strain LB-1 remains unclear.

Methods

In this study, the antifungal substances produced by strain LB-1, as well as the underlying mechanism of its inhibitory effect against B. cinerea, were explored using metabolomic and transcriptomic analysis.

Results

The results found that 45 metabolites might be the key antifungal substances, such as ouabain, ferulic acid, chlorogenic acid, spermidine, stachydrine, and stearic acid. The transcriptomic analysis indicated that the inhibition effect of LB-1 on B. cinerea resulted in the upregulation of genes related to adenosine triphosphate (ATP)-binding cassette (ABC) transporters, peroxisome, ER stress, and multiple metabolic pathways, and in downregulation of many genes associated with the synthesis of cell walls/membranes, carbohydrate metabolism, cell cycle, meiosis, and DNA replication.

Discussion

These results suggested that the inhibitory effect of strain LB-1 against B. cinerea might be due to the destroyed cell wall and membrane integrity exerted by antimicrobial substances, which affect cell metabolism and inhibit cell proliferation.

Iturin: A Promising Cyclic Lipopeptide with Diverse Applications

This comprehensive review examines iturin, a cyclic lipopeptide originating from Bacillus subtilis and related bacteria. These compounds are structurally diverse and possess potent inhibitory effects against plant disease-causing bacteria and fungi. Notably, Iturin A exhibits strong antifungal properties and low toxicity, making it valuable for bio-pesticides and mycosis treatment. Emerging research reveals additional capabilities, including anticancer and hemolytic features. Iturin finds applications across industries. In food, iturin as a biosurfactant serves beyond surface tension reduction, enhancing emulsions and texture. Biosurfactants are significant in soil remediation, agriculture, wound healing, and sustainability. They also show promise in Microbial Enhanced Oil Recovery (MEOR) in the petroleum industry. The pharmaceutical and cosmetic industries recognize iturin's diverse properties, such as antibacterial, antifungal, antiviral, anticancer, and anti-obesity effects. Cosmetic applications span emulsification, anti-wrinkle, and antibacterial use. Understanding iturin's structure, synthesis, and applications gains importance as biosurfactant and lipopeptide research advances. This review focuses on emphasizing iturin's structural characteristics, production methods, biological effects, and applications across industries. It probes iturin's antibacterial, antifungal potential, antiviral efficacy, and cancer treatment capabilities. It explores diverse applications in food, petroleum, pharmaceuticals, and cosmetics, considering recent developments, challenges, and prospects.