Project description:Receptor-interacting protein kinase 1 (RIP1)-mediated necroptosis plays a vital role in various diseases, but the involvement of RIP1 and its functional mechanism in osteoarthritis pathogenesis remains largely unknown. To identify molecular targets of RIP1 in chondrocytes, RNA sequencing was performed in chondrocytes treated with adenovirus expressing RIP1 or vector control. We found that 9857 genes were differentially expressed in chondrocytes after RIP1 overexpression. GO analysis indicated that DNA replication, chromosome segregation and regulation of cell cycle process were upregulated, while terms including cartilage development, skeletal system development, extracellular matrix organization, skeletal system morphogenesis, chondrocyte differentiation, collagen fibril organization and limb development were downregulated. Pathway analysis revealed that IL-17 signaling pathway, cell cycle, DNA replication, proteasome, TNF signaling pathway, cellular senescence and p53 signaling pathway were significantly upregulated by RIP1, meanwhile, ECM-receptor interaction, other glycan degradation and glycosaminoglycan degradation were downregulated. These results underscore the importance of RIP1 in OA by perturbing a series of essential events during disease progression such like cell cycle regulation, chondrocyte differentiation, inflammation and ECM remodeling.
Project description:In order to identify mRNA and sRNAs associated with the RNA-binding protein Hfq in Serratia marcescens strain Db10, Hfq-bound RNA was immunoprecipitated from a strain encoding an Hfq-3FLAG fusion protein at the normal location and sequenced, in parallel with the wild type strain (no fusion) as negative control. Additionally global transcriptional start site mapping was performed on total RNA, with or without TEX treatment, isolated from wild type Serratia marcescens. The data was used to identify regions of mRNA and sRNAs associated with Hfq in this organism. Associated work in Serratia marcescens Db10, an opportunistic bacterial pathogen, has shown that Hfq is essential for virulence in several models and exerts a wide-ranging impact on the transcriptome and, particularly, genes encoding virulence factors.
Project description:We report the application of transcriptome sequencing technology for high-throughput profiling of Serratia marcescens for producing prodigiosin. By obtaining over 163 million bases of sequence from Serratia marcescens genome DNA, we generated transcriptome -state maps of Serratia marcescens 12h cells, 24h cells, and 36h cells at 30C and 37C,respectively. We explored the mechanism of S. marcescens response temperature regulation at the transcription level through transcriptome sequencing technology. We found that the pig gene cluster at low temperature would favor at the transcriptional level, however, higher temperature resulting in instability and loss of enzyme activity. Numerous amino acid metabolic pathways involved in prodigiosin biosynthesis in S. marcescens responded to temperature changes, and metabolic fluxes were directed towards prodigiosin biosynthesis. At the same time, quorum sensing, two-component regulatory system and sRNA were stimulated by temperature to regulate PG biosynthesis and involve strain virulence and exclusive genes. Moreover, inhibition factors was the one reason for S. marcescens incapable synthesis of prodigiosin at 37C. This study laid a good foundation for understanding the biological functions of prodigiosin, improving the temperature tolerance of industrial strains, and excavating temperature-sensitive regulatory elements.
Project description:Mycobacterium tuberculosis is exposed to a variety of stresses during a chronic infection, as the immune system simultaneously produces bactericidal compounds and starves the pathogen for essential nutrients. The intramembrane protease, Rip1, plays an important role in the adaptation to these stresses, at least partially by the cleavage of membrane bound transcriptional regulators. Although Rip1 is known to be critical for surviving copper intoxication and nitric oxide exposure, these stresses do not fully account the regulatory protein’s essentiality during infection. In this work, we demonstrate that Rip1 is also necessary for growth in low iron and zinc conditions, similar to those imposed by the immune system. Using a newly generated library of sigma factor mutants, we show that the known regulatory target of Rip1, SigL, shares this defect. Transcriptional profiling under iron limiting conditions supported the coordinated activity of Rip1 and SigL and demonstrated that the loss of these proteins produces an exaggerated iron starvation response. These observations demonstrate that Rip1 coordinates several aspects of metal homeostasis and suggest that a Rip1- and SigL-dependent pathway is involved in the adaptation to the iron deficient environments encountered during infection.
Project description:In order to identify changes in the global mRNA transcriptome caused by deletion of the RNA-binding protein Hfq in Serratia marcescens, total mRNA was isolated from wild type Serratia marcescens Db10 and an otherwise isogenic strain carrying an in-frame deletion of the hfq gene (SMDB11_4482) and analysed by RNAseq. Four independent biological replicates were sequenced for each strain using the Illumina HiSeq platform. The data was used to identify the nature and extent of changes in transcript level between the two strains and to inform on the role of Hfq in virulence of Serratia marcescens, an opportunist bacterial pathogen.