Project description:Candida albicans, a major opportunistic fungal pathogen is frequently found together with Streptococcus mutans in dental biofilms associated with severe childhood tooth-decay, a prevalent pediatric oral disease. Previous studies have demonstrated that S. mutans and C. albicans synergizes virulence of plaque-biofilms in vivo. However, the nature of this bacterial-fungal relationship in this cross-kingdom biofilm remains largely uncharacterized. Using iTRAQ based quantitative proteomics, we found that proteins associated with carbohydrate metabolism such as alpha-1,4 glucan phosphorylase, Hexokinase-2, Isocitrate lyase and malate synthase were significantly upregulated in C. albicans in the mixed-species biofilms (P<0.05). C. albicans proteins associated with growth/morphogenesis such as pH-responsive protein-2, Fma1p and Hsp21 were also induced. Conversely, S. mutans proteins in the tricarboxylic acid cycle such as citrate synthase and in the pentose phosphate pathway such as Ribose-5-phosphate isomerase A as well as proteins associated with sugar transport systems were upregulated indicating enhanced carbohydrate metabolism. Interestingly mixed-species biofilm microenvironment had a lower pH than S. mutans single-species biofilms. This observation was supported by proteomics, wherein proteins associated with lactate and formate assimilation such as Glyoxalase and putative NADPH-dependent methylglyoxal reductase proteins were significantly upregulated in the mixed-species biofilms (P<0.05). Furthermore, we unexpectedly found that S. mutans derived glucosyltransferase B (GtfB), responsible for co-adhesion via glucans, can also contribute to C. albicans growth and carbohydrate metabolism by providing glucose and fructose from sucrose breakdown. These findings demonstrate synergistic bacterial-fungal interactions within mixed-species biofilms and a novel GtfB cross-feeding role. Taken together, quantitative proteomics provides new insights into this virulent cross-kingdom oral biofilm.
Project description:Persicaria chinensis, a well-known traditional Chinese medicinal herb that is both edible and medicinal, has been widely acknowledged for its therapeutic effects, such as anti-inflammatory, antioxidant, and antitumor activities. However, the role of miRNAs from this plant in the cross-kingdom regulation of human diseases has not been investigated. In this study, we analyze the miRNA expression profile of P. chinensis using high-throughput sequencing and identify a total of 673 miRNAs, including 422 novel miRNAs that are unique to this plant and 251 conserved miRNAs. Among the conserved miRNAs, pch-miR319a is found to be the most abundant. Moreover, food-oriented pch-miR319a accumulates in the uterus and tumors and exhibits a rich repertoire of target genes within cancer-related pathways, demonstrating significant cross-kingdom regulatory potential. Utilizing the dual-luciferase reporter gene assay, we demonstrate that pch-miR319a from P. chinensis targets the Itga3 gene, which is associated with cervical cancer progression. Overexpression of pch-miR319a significantly decreases the viability, migration, and induces apoptosis of HeLa cervical cancer cells in vitro. Moreover, in a syngeneic mouse tumor model of cervical cancer, treatment with pch-miR319a effectively inhibits tumor growth and downregulates the expression of ITGA3 and the proliferation marker Ki-67. Our study highlights the potential of pch-miR319a from P. chinensis as a novel therapeutic agent for cervical cancer by targeting ITGA3 and provides new insights into the cross-kingdom regulatory mechanisms of plant miRNAs in human diseases.
Project description:<p>Wheat is a major staple crop grown across the globe. Fusarium crown rot (FCR) of wheat, caused by Fusarium pseudograminearum, is a destructive soil-borne disease that lacks effective sustainable control measures. Here, we assembled a cross-kingdom synthetic microbial community (SMC) comprising Trichoderma harzianum T19, Bacillus subtilis BS-Z15, and four other Bacillus strains, and evaluated its biocontrol efficacy against FCR under non-sterile soil conditions. The SMC treatment significantly suppressed FCR, reducing the disease severity index by approximately 70%. Wheat growth and yield were simultaneously enhanced: SMC inoculation nearly doubled plant biomass (with fresh and dry weights ~100% higher) and increased thousand-kernel weight by ~14% compared to the controls. In the rhizosphere, SMC improved soil health by elevating soil organic matter and nitrogen levels by over 50%, while mitigating pathogen-induced nutrient imbalances (excess available P and K) and boosting nutrient-cycling enzyme activities. Amplicon sequencing revealed that SMC suppressed pathogenic Fusarium in the rhizosphere and enriched beneficial microbes, including antagonistic fungi (Trichoderma, Chaetomium) and plant growth-promoting bacteria (Pseudomonas, Paenibacillus). Co-occurrence network analysis showed that SMC treatment restructured the rhizosphere microbial network with higher connectivity, stability, and a prevalence of positive cooperative interactions under F. pseudograminearum stress. Defense-related metabolites, such as epi-jasmonic acid, allantoin, Nβ-acetyltryptamine, and dihydrodaidzein, accumulated to higher levels with SMC, consistent with KEGG enrichment in pathways related to amino acid biosynthesis, carbon metabolism, signal transduction, and plant defense. These findings demonstrate that the cross-kingdom SMC modulates soil nutrients, microbial community structure, and rhizosphere metabolites to synergistically promote wheat growth and enhance resistance to FCR.</p>
Project description:Fungal-bacterial interactions generate unique biofilms that cause many infections in humans. Candida albicans interact with Streptococcus mutans in dental biofilms associated with severe childhood tooth-decay, a prevalent pediatric oral disease. Current modalities are ineffective and primarily based on antimicrobial monotherapies despite the polymicrobial nature of the infection. Here, we show that the combination of clinically used topical antifungal fluconazole with povidone iodine (PI) can completely suppress C. albicans carriage and mixed-biofilm formation without increasing bacterial killing activity in vivo. We unexpectedly found that the inclusion of PI enhanced fluconazole efficacy by potently disrupting the assembly of a protective bacterial exopolysaccharide (EPS) matrix through inhibition of α-glucan synthesis by S. mutans exoenzyme (GtfB) bound on the fungal surface. Further analyses revealed that the EPS produced in situ directly bind and sequester fluconazole, reducing uptake and intracellular transportation of the drug. Conversely, inhibition of GtfB activity by PI, enzymatic degradation of the α-glucan matrix or co-culturing with gtfB-defective S. mutans re-established antifungal susceptibility. Hence, topical antifungal has limitations in mixed oral biofilms due to enhanced C. albicans tolerance to fluconazole afforded by the shielding effect of bacterial-derived EPS. The data provide new insights for treatment of C. albicans in cross-kingdom biofilms, indicating that EPS inhibitors may be required for enhanced killing efficacy and optimal anti-biofilm activity.
Project description:Fungi are ubiquitous in the environment and, like bacteria, are an integral part of the gut microbiome. However, unlike bacteria, fungal species that can stably colonize the murine gut and model commensal behavior remain elusive. Here, we show that Kazachstania pintolopesii, a dominant fungus found in pet store mice from geographically distinct regions, stably colonized laboratory mice. K. pintolopesii outcompeted other fungi and maintained stable colonization independent of gut bacteria. We find that K. pintolopesii does not induce a typical antifungal response in murine hosts locally in the gut or upon systemic challenge. Accordingly, K. pintolopesii colonization did not afford protection against systemic fungal infection by Candida albicans. Instead, K.pintolopessii colonization increased type 2 immune responses in the intestine and protected mice against helminth infection.
Project description:Extracellular vesicles (EVs), released by both eukaryotic and prokaryotic cells, have emerged as key mediators of cell-to-cell communication. Recent advances highlight their crucial role in cross-kingdom communication, bridging the microbial world with human biology. Here, we investigated the molecular mechanisms underlying EV-mediated bidirectional communication within the gastrointestinal ecosystem. Using a model that includes human colon cells and both Gram-positive and Gram-negative gut bacteria, we reveal an intricate exchange of information between these kingdoms. Our analysis uncovered highly specific responses of host cells to bacterial EVs (BEVs) and BEV-RNA cargo, including uptake rates by human cells, impact on human cell viability, and alterations in their transcriptomic landscape. In parallel, we discovered that host-derived EVs and miR-192-5p are internalized by gut bacteria, leading to changes in their growth pattern. These findings highlight the precision with which EVs and their RNA cargo mediate interkingdom communication. Our results underscore the importance of tailored, context-specific analyses for understanding the scope of EV-mediated interactions in complex biological systems.
Project description:Extracellular vesicles (EVs), released by both eukaryotic and prokaryotic cells, have emerged as key mediators of cell-to-cell communication. Recent advances highlight their crucial role in cross-kingdom communication, bridging the microbial world with human biology. Here, we investigated the molecular mechanisms underlying EV-mediated bidirectional communication within the gastrointestinal ecosystem. Using a model that includes human colon cells and both Gram-positive and Gram-negative gut bacteria, we reveal an intricate exchange of information between these kingdoms. Our analysis uncovered highly specific responses of host cells to bacterial EVs (BEVs) and BEV-RNA cargo, including uptake rates by human cells, impact on human cell viability, and alterations in their transcriptomic landscape. In parallel, we discovered that host-derived EVs and miR-192-5p are internalized by gut bacteria, leading to changes in their growth pattern. These findings highlight the precision with which EVs and their RNA cargo mediate interkingdom communication. Our results underscore the importance of tailored, context-specific analyses for understanding the scope of EV-mediated interactions in complex biological systems.