PFKFB3-Meditated Glycolysis via the Reactive Oxygen Species-Hypoxic Inducible Factor 1α Axis Contributes to Inflammation and Proliferation of Staphylococcus aureus in Epithelial Cells.

Mastitis caused by antibiotic-resistant strains of Staphylococcus aureus is a significant concern in the livestock industry due to the economic losses it incurs. Regulating immunometabolism has emerged as a promising approach for preventing bacterial inflammation. To investigate the possibility of alleviating inflammation caused by S aureus infection by regulating host glycolysis, we subjected the murine mammary epithelial cell line (EpH4-Ev) to S aureus challenge. Our study revealed that S aureus can colonize EpH4-Ev cells and promote inflammation through hypoxic inducible factor 1α (HIF1α)-driven glycolysis. Notably, the activation of HIF1α was found to be dependent on the production of reactive oxygen species (ROS). By inhibiting PFKFB3, a key regulator in the host glycolytic pathway, we successfully modulated HIF1α-triggered metabolic reprogramming by reducing ROS production in S aureus-induced mastitis. Our findings suggest that there is a high potential for the development of novel anti-inflammatory therapies that safely inhibit the glycolytic rate-limiting enzyme PFKFB3.

Dynamic variation of Paris polyphylla root-associated microbiome assembly with planting years.

MAIN CONCLUSION: P. polyphylla selectively enriches beneficial microorganisms to help their growth. Paris polyphylla (P. polyphylla) is an important perennial plant for Chinese traditional medicine. Uncovering the interaction between P. polyphylla and the related microorganisms would help to utilize and cultivate P. polyphylla. However, studies focusing on P. polyphylla and related microbes are scarce, especially on the assembly mechanisms and dynamics of the P. polyphylla microbiome. High-throughput sequencing of the 16S rRNA genes was implemented to investigate the diversity, community assembly process and molecular ecological network of the bacterial communities in three root compartments (bulk soil, rhizosphere, and root endosphere) across three years. Our results demonstrated that the composition and assembly process of the microbial community in different compartments varied greatly and were strongly affected by planting years. Bacterial diversity was reduced from bulk soils to rhizosphere soils to root endosphere and varied over time. Microorganisms benefit to plants was selectively enriched in P. polyphylla roots as was its core microbiome, including Pseudomonas, Rhizobium, Steroidobacter, Sphingobium and Agrobacterium. The network's complexity and the proportion of stochasticity in the community assembly process increased. Besides, nitrogen metabolism, carbon metabolism, phosphonate and phosphinate metabolism genes in bulk soils increased over time. These findings suggest that P. polyphylla exerts a selective effect to enrich the beneficial microorganisms and proves the sequential increasing selection pressure with P. polyphylla growth. Our work adds to the understanding of the dynamic processes of plant-associated microbial community assembly, guides the selection and application timing of P. polyphylla-associated microbial inoculants and is vital for sustainable agriculture.

Root Endophytes and Ginkgo biloba Are Likely to Share and Compensate Secondary Metabolic Processes, and Potentially Exchange Genetic Information by LTR-RTs.

Ginkgo biloba is a pharmaceutical resource for terpenes and flavonoids. However, few insights discussed endophytes' role in Ginkgo, and whether genetic exchange happens between Ginkgo and endophytes remains unclear. Herein, functional gene profiles and repetitive sequences were analyzed to focus on these issues. A total of 25 endophyte strains were isolated from the Ginkgo root and distributed in 16 genera of 6 phyla. Significant morphological diversities lead to the diversity in the COG functional classification. KEGG mapping revealed that endophytic bacteria and fungi potentially synthesize chalcone, while endophytic fungi might also promote flavonoid derivatization. Both bacteria and fungi may facilitate the lignin synthesis. Aspergillus sp. Gbtc_1 exhibited the feasibility of regulating alcohols to lignans. Although Ginkgo and the endophytes have not observed the critical levopimaradiene synthase in ginkgolides synthesis, the upstream pathways of terpenoid precursors are likely intact. The MVK genes in Ginkgo may have alternative non-homologous copies or be compensated by endophytes in long-term symbiosis. Cellulomonas sp. Gbtc_1 became the only bacteria to harbor both MEP and MVA pathways. Endophytes may perform the mutual transformation of IPP and DMAPP in the root. Ginkgo and bacteria may lead to the synthesis and derivatization of the carotenoid pathway. The isoquinoline alkaloid biosynthesis seemed lost in the Ginkgo root community, but L-dopa is more probably converted into dopamine as an essential signal-transduction substance. So, endophytes may participate in the secondary metabolism of the Ginkgo in a shared or complementary manner. Moreover, a few endophytic sequences predicted as Ty3/Gypsy and Ty1/Copia superfamilies exhibited extremely high similarity to those of Ginkgo. CDSs in such endophytic LTR-RT sequences were also highly homologous to one Ginkgo CDS. Therefore, LTR-RTs may be a rare unit flowing between the Ginkgo host and endophytes to exchange genetic information. Collectively, this research effectively expanded the insight on the symbiotic relationship between the Ginkgo host and the endophytes in the root.