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Medeiros Parks posted an update 8 hours, 7 minutes ago
pylori.Combinatorial action of transcription factors (TFs) with partially overlapping expression is a widespread strategy to generate novel gene-expression patterns and, thus, cellular diversity. Known mechanisms underlying combinatorial activity require co-expression of TFs within the same cell. find more Here, we describe the mechanism by which two TFs that are never co-expressed generate a new, intersectional expression pattern in C. elegans embryos lineage-specific priming of a gene by a transiently expressed TF generates a unique intersection with a second TF acting on the same gene four cell divisions later; the second TF is expressed in multiple cells but only activates transcription in those where priming occurred. Early induction of active transcription is necessary and sufficient to establish a competent state, maintained by broadly expressed regulators in the absence of the initial trigger. We uncover additional cells diversified through this mechanism. Our findings define a mechanism for combinatorial TF activity with important implications for generation of cell-type diversity.Urothelial carcinoma (UC) is the predominant form of bladder cancer. Significant molecular heterogeneity caused by diverse molecular alterations brings about large variations in the response to treatment in UC. An improved understanding of the genetic mechanisms underlying the development and progression of UC is essential. Through deep analysis of next-generation sequencing data of 99 UC patients, we found that 18% of cases had recurrent somatic mutations in zinc finger protein gene zinc finger protein 83 (ZNF83). ZNF83 mutations were correlated with poor prognosis of UC. We also found a hotspot mutation, p.E293V, in the evolutionarily well-conserved region of ZNF83. ZNF83-E293V increased tumor growth and reduced the apoptosis of UC cells compared to wild-type ZNF83 both in vitro and in mice xenografted tumors. ZNF83-E293V activated nuclear factor κB (NF-κB) more potently than did the wild-type protein owing to its decreased transcriptional repression for S100A8. The NF-κB inhibitors could pharmacologically block the tumor growth in mice engrafted with ZNF83-E293V-transfected UC cells. These findings provide a mechanistic insight and a potential therapeutic strategy for UC, which established a foundation for using the ZNF83-E293V mutation as a predictive biomarker of therapeutic response from NF-κB inhibitors.While drug resistance mutations provide the gold standard proof for drug target engagement, target deconvolution of inhibitors identified from a phenotypic screen remains challenging. Genetic screening for functional in-frame drug resistance mutations by tiling CRISPR-Cas nucleases across protein coding sequences is a method for identifying a drug’s target and binding site. However, the applicability of this approach is constrained by the availability of nuclease target sites across genetic regions that mediate drug resistance upon mutation. In this study, we show that an enhanced AsCas12a variant (enAsCas12a), which harbors an expanded targeting range, facilitates screening for drug resistance mutations with increased activity and resolution in regions that are not accessible to other CRISPR nucleases, including the prototypical SpCas9. Utilizing enAsCas12a, we uncover new drug resistance mutations against inhibitors of NAMPT and KIF11. These findings demonstrate that enAsCas12a is a promising new addition to the CRISPR screening toolbox and allows targeting sites not readily accessible to SpCas9.Zika virus (ZIKV) infection can lead to neurological complications and fetal defects, and it has attracted global public health concerns. Effective treatment for ZIKV infection remains elusive, and a preventative vaccine is not yet available. Therapeutics for fetuses need to overcome placenta barriers to reach the fetuses and require higher safety standards. In the present study, we engineered mammalian extracellular vesicles (EVs) to deliver a host restriction factor, interferon-induced transmembrane protein 3 (IFITM3), for the treatment of ZIKV infection. Our results demonstrated that the IFITM3-containing EVs (IFITM3-Exos) suppressed ZIKV viremia by a 2-log reduction in pregnant mice. Moreover, the engineered EVs effectively delivered IFITM3 protein across the placental barrier and suppressed ZIKV in the fetuses with significant reduction of viremia in key fetal organs as measured by quantitative real-time PCR. Mechanistic study showed that IFITM3 was delivered to late endosomes/lysosomes where it inhibited viral entry into the host cells. Our study demonstrated that EVs could act as a cross-placenta drug delivery vehicle to the fetus, and IFITM3, an endogenous restriction factor, is a potential treatment for ZIKV infection during pregnancy.Ferroptosis is primarily caused by intracellular iron catalytic activity and lipid peroxidation. The potential interplay between ferroptosis and apoptosis remains poorly understood. Here, we show that the expression of a nuclear long non-coding RNA (lncRNA), LINC00618, is reduced in human leukemia and strongly increased by vincristine (VCR) treatment. Furthermore, LINC00618 promotes apoptosis by increasing the levels of BCL2-Associated X (BAX) and cleavage of caspase-3. LINC00618 also accelerates ferroptosis by increasing the levels of lipid reactive oxygen species (ROS) and iron, two surrogate markers of ferroptosis, and decreasing the expression of solute carrier family 7 member 11 (SLC7A11). Interestingly, VCR-induced ferroptosis and apoptosis are promoted by LINC00618, and LINC00618 accelerates ferroptosis in a manner dependent upon apoptosis. LINC00618 attenuates the expression of lymphoid-specific helicase (LSH), and LSH enhances the transcription of SLC7A11 after the recruitment to the promoter regions of SLC7A11, further inhibiting ferroptosis. Knowledge of these mechanisms demonstrates that lncRNAs related to ferroptosis and apoptosis are critical to leukemogenesis and chemotherapy.
To compare the outcomes of Boston keratoprosthesis (KPro) type I implantation between patients who are legally blind versus sighted in the contralateral eye.
Single centre retrospective comparative case series.
Patients who underwent Boston KPro type I implantation between 2008 and 2017.
Single-center retrospective comparative case series. Patients were divided into 2 groups based on the preoperative best-corrected visual acuity (BCVA) in the contralateral eye group I (>20/200) and group II (20/200).
Postoperative BCVA, device retention, and complications.
Group I (56 eyes) and group II (53 eyes) had similar demographics, median preoperative BCVA (hand movements) in the operated eye, and median duration of postoperative follow-up (76.92 vs 85.6 months, respectively). Final postoperative BCVA of the operated eye was statistically better in group I compared with group II (20/400 and hand movements, respectively, p = 0.03). There was no statistical significance in device retention mean survival time.