Parksdecker8301
Iron is essential for all bacteria. In most bacteria, intracellular iron homeostasis is tightly regulated by the ferric uptake regulator Fur. However, how Fur activates the iron-uptake system during iron deficiency is not fully elucidated. In this study, we found that YdiV, the flagella gene inhibitor, is involved in iron homeostasis in Escherichia coli. Iron deficiency triggers overexpression of YdiV. High levels of YdiV then transforms Fur into a novel form which does not bind DNA in a peptidyl-prolyl cis-trans isomerase SlyD dependent manner. Thus, the cooperation of YdiV, SlyD and Fur activates the gene expression of iron-uptake systems under conditions of iron deficiency. Bacterial invasion assays also demonstrated that both ydiV and slyD are necessary for the survival and growth of uropathogenic E. coli in bladder epithelial cells. This reveals a mechanism where YdiV not only represses flagella expression to make E. coli invisible to the host immune system, but it also promotes iron acquisition to help E. coli overcome host nutritional immunity.The brain is a functional unit made up of multi-level connected elements showing a pattern of synchronized activity that varies in different states. The wake-sleep cycle is a major variation of brain functional condition that is ultimately regulated by subcortical arousal- and sleep-promoting cell groups. We analyzed the evolution of functional MRI signal in the whole cortex and in a deep region including most sleep- and wake-regulating subcortical nuclei at loss of consciousness induced by the hypnotic agent propofol. Optimal data were obtained in 21 of the 30 healthy participants examined. A dynamic analysis of functional MRI time courses on a time-scale of seconds was conducted to characterize consciousness transition, and functional connectivity maps were generated to detail the anatomy of structures showing different dynamics. Inside the magnet, loss of consciousness was marked by the participants ceasing to move their hands. We observed activity synchronization after loss of consciousness within both the cerebral cortex and subcortical structures. However, the evolution of functional MRI signal was dissociated, showing a transient reduction of global cortico-subcortical coupling that was restored during the unconscious state. find more An exception to cortico-subcortical decoupling was a brain network related to self-awareness (i.e., the default mode network) that remained connected to subcortical brain structures. Propofol-induced unconsciousness is thus characterized by an initial, transitory dissociated synchronization at the largest scale of brain activity. Such cortico-subcortical decoupling and subsequent re-coupling may allow the brain to detach from waking activity and reorganize into a functionally distinct state.
Our previous studies have indicated that miR-198 reduces cellular methylguanine DNA methyltransferase (MGMT) levels to enhance temozolomide sensitivity. Transforming growth factor beta 1 (TGF-β1) switches off miR-198 expression by repressing K-homology splicing regulatory protein (KSRP) expression in epidermal keratinocytes. However, the underlying role of TGF-β1 in temozolomide resistance has remained unknown.
The distribution of KSRP was detected by Western blotting and immunofluorescence. Microarray analysis was used to compare the levels of long non-coding RNAs (lncRNAs) between TGF-β1-treated and untreated cells. RNA immunoprecipitation was performed to verify the relationship between RNAs and KSRP. Flow cytometry and orthotopic and subcutaneous xenograft tumor models were used to determine the function of TGF-β1 in temozolomide resistance.
Overexpression of TGF-β1 contributed to temozolomide resistance in MGMT-promoter hypomethylated glioblastoma cells in vitro and in vivo. TGF-β1 treatment reduceide resistance. Furthermore, our findings suggest that a novel combination of temozolomide with a TGF-β inhibitor may serve as an effective therapy for glioblastomas.Stable protein complexes, including those formed with RNA, are major building blocks of every living cell. Escherichia coli has been the leading bacterial organism with respect to global protein-protein networks. Yet, there has been no global census of RNA/protein complexes in this model species of microbiology. Here, we performed Grad-seq to establish an RNA/protein complexome, reconstructing sedimentation profiles in a glycerol gradient for ∼85% of all E. coli transcripts and ∼49% of the proteins. These include the majority of small noncoding RNAs (sRNAs) detectable in this bacterium as well as the general sRNA-binding proteins, CsrA, Hfq and ProQ. In presenting use cases for utilization of these RNA and protein maps, we show that a stable association of RyeG with 30S ribosomes gives this seemingly noncoding RNA of prophage origin away as an mRNA of a toxic small protein. Similarly, we show that the broadly conserved uncharacterized protein YggL is a 50S subunit factor in assembled 70S ribosomes. Overall, this study crucially extends our knowledge about the cellular interactome of the primary model bacterium E. coli through providing global RNA/protein complexome information and should facilitate functional discovery in this and related species.
The specific characteristics of pediatric and adolescent differentiated thyroid cancer (DTC) is the more frequent occurrence of distant metastasis (DM) compared with adult DTC.
To investigate the clinical outcomes of DM in this population and analyze risk factors related to DM.
Medical records of 171 patients with DTC < 19 years old, who underwent initial surgery between 1979 and 2014 were retrospectively reviewed.
Clinical responses to radioiodine (RAI) therapy evaluated by the American Thyroid Association (ATA) guidelines for adult DTC and Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Risk factors related to distant-metastasis-free survival (DMFS).
DM was observed in 29 patients, and all were lung metastases. The pattern of lung metastasis was classified into 3 categories macronodular, micronodular, and no apparent nodule (detected only by RAI scintigraphy). Patients with excellent responses according to the ATA guideline criteria or complete remission of the RECIST criteria were most frequently observed in those with no apparent nodule.