Project description:The use of carbon labelled PBAT units allowed us to follow biodegradation of all PBAT building blocks. The presented workflow is a novel approach to study the fundamental steps in polymer biodegradation in complex systems.
Project description:We analyzed the transcriptomic differences of cultured mouse spermatocytes (GC2 cells) stably transfected with PHB-targeting shRNA (called PHB KD GC2) from those with a control shRNA (called Ctrl GC2). Furthermore, we also analyzed the difference in the transcriptomes of spermatocytes between Phb conditional knock-out and control mice.
Project description:Prohibitin (PHB) plays a significant role in cancer processes whereas its mechanism in bladder cancer (BC) aggressiveness is not fully understood. This study aimed to investigate the role of PHB in BC aggressiveness. The study employed a range of in vivo and in vitro assays to elucidate the interaction between PHB-NADSYN1 and its underlying function in BC progression. We found that PHB was upregulated in muscle-invasive bladder cancer tissues, and bound to NADSYN1 mRNA in BC tissues more than in adjacent normal tissues. NADSYN1 and PHB were upregulated and positively correlated both in BC tissues and cell lines. We further revealed that deleting NADSYN1 prevented PHB-mediated cell invasiveness of BC in vivo and in vitro. PHB could directly bind to NADSYN1 mRNA, and it was found that the PHB domain was responsible for the PHB-NADSYN1 interaction. Depletion of NADSYN1 expression significantly decreased the protein level of PHB. In addition, Snai2 positively correlated with NADSYN1 and depletion or mutation of Snai2 binding sites inhibited NADSYN1-PHB-mediated BC progression. The study highlights a novel Snai2-NADSYN1-PHB mechanism in BC progression and indicates that PHB and NADSYN1 could serve as a therapeutic target for BC
Project description:Polyhydroxybutyrate (PHB) is a carbon and energy storage polymer, whose accumulation under nutrient imbalances with excess carbon is a widespread phenomenon in bacteria. PhaR is a conserved transcriptional regulator found to be associated to PHB granules in several species. Although its role in modulating PHB storage and metabolism has been extensively studied across the bacterial phylogeny, a comprehensive analysis of the PhaR regulon within the context of its dual role as a metabolic sensor and regulator remains missing. To bridge this gap, we integrated co-expression network analysis with proteome profiling across multiple mutant backgrounds (lack of PhaR (AniA) and/or PHB synthesis) in the free-living state of the PHB-accumulating alphaproteobacterial root nodule symbiont Sinorhizobium meliloti. This analysis was enriched by identifying direct regulatory targets of PhaR through a regulon-centric computational multi-step search for DNA binding site motifs combined with PhaR-DNA binding and promoter-reporter assays. We confirmed that the model of accumulated PHB sequestering PhaR and thereby relieving phasin and PHB depolymerase gene repression to control cellular PHB levels also applies to S. meliloti, and showed that PhaR-mediated regulation also occurs the symbiotic state. A comprehensive picture of the impact of PHB-mediated PhaR titration on cellular functions revealed exopolysaccharide production as well as central carbon metabolism (pdh and bkd), gluconeogenesis (ppdK and pyc), entry into the TCA cycle (gltA), and the initial steps of the Entner-Doudoroff pathway (zwf, pgl and edd) as major regulatory targets, and beyond carbon metabolism several target genes of yet unknown function. Our findings highlight a pivotal role for PhaR in orchestrating carbon metabolism.
Project description:The biodegradable polymer poly-β-hydroxybutyrate (PHB) is a promising carbon source for biological mitigation of nitrogen pollution, a significant problem in aquaculture that physical and chemical methods have not provided a comprehensive solution. Here we investigated the impact of PHB on the zero-water-change largemouth bass culture by 30- and 40-day experiments. PHB loaded into the filter circulation pump at 4g L-1, optimum value determined by the first experiment, significantly reduced the levels of nitrate by 99.65%, nitrite by 95.96%, and total nitrogen by 85.22% compared to the control without PHB. PHB also significantly increased denitrifying bacteria (e.g., Proteobacteria and Fusobacteria) and expression of denitrification genes (e.g., nirK and nirS) in the microbial community, improving growth and health parameters of largemouth bass. While the impact may vary in other culture systems, PHB thus demonstrated its remarkable utility in aquaculture, highlighting ecological assessment and application to larger aquaculture operations as future considerations.