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:Cellular metabolism and chromatin landscape both contribute to cell fate determination. However, their interplay remains poorly understood. Here we show that Prohibitin (PHB), an evolutionarily conserved protein, involves in a histone variant H3.3 chaperon HIRA complex-dependent epigenetic and metabolic circuitry to maintain the identity of human embryonic stem cells (hESCs). We found that silencing of PHB triggers hESC differentiation with concomitant enhancements of histone 3 (H3) lysine (K) methyl modifications as a result of the reduced production of α-ketoglutarate (α-KG), a metabolite required for activities of many dioxygenase and in turn chromatin structure1,2. Mechanistically, PHB acts as a functional member of the HIRA complex3,4. Resembling PHB deficiency, loss of HIRA in hESCs leads to massive differentiation and aberrant histone modifications, although it was previously found not to disrupt the self-renewal in mouse ESCs (mESCs)5. Genome-wide H3.3 ChIP- sequence analyses indicate that reduction of H3.3 deposition caused by PHB knock down is extremely similar to that induced by HIRA knock down. Specifically, silencing either HIRA or PHB leads to repressive chromatin characters at promoters of pluripotency genes and isocitrate dehydrogenases (IDHs), the enzyme responsible for α-KG production, but active chromatin features at promoters of developmental genes, paralleling to transcript levels of these genes. Our results identify PHB as an essential factor not only for hESC self-renewal but also for the proper function of the HIRA complex, linking the HIRA complex-dependent H3.3 deposition to the production of a critical metabolite required for shaping chromatin structure, and demonstrating the importance of the interplay between epigenetic state and metabolic regulation in cell fate determination. Examination of H3.3 deposition in NT, PHB, and HIRA siRNA treated hESCs respectively.
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.