Abstract
Runt-related transcription factor 1 (RUNX1) is a well-known master regulator of hematopoietic lineages but its mechanisms of action are still not fully understood. Here, we found that RUNX1 ...localizes on active chromatin together with Far Upstream Binding Protein 1 (FUBP1) in human B-cell precursor lymphoblasts, and that both factors interact in the same transcriptional regulatory complex. RUNX1 and FUBP1 chromatin localization identified c-KIT as a common target gene. We characterized two regulatory regions, at +700 bp and +30 kb within the first intron of c-KIT, bound by both RUNX1 and FUBP1, and that present active histone marks. Based on these regions, we proposed a novel FUBP1 FUSE-like DNA-binding sequence on the +30 kb enhancer. We demonstrated that FUBP1 and RUNX1 cooperate for the regulation of the expression of the oncogene c-KIT. Notably, upregulation of c-KIT expression by FUBP1 and RUNX1 promotes cell proliferation and renders cells more resistant to the c-KIT inhibitor imatinib mesylate, a common therapeutic drug. These results reveal a new mechanism of action of RUNX1 that implicates FUBP1, as a facilitator, to trigger transcriptional regulation of c-KIT and to regulate cell proliferation. Deregulation of this regulatory mechanism may explain some oncogenic function of RUNX1 and FUBP1.
NADPH oxidases are important sources of reactive oxygen species (ROS). Several Nox homologues are present together in the vascular system but whether they exhibit crosstalk at the activity level is ...unknown. To address this, vessel function of knockout mice for the cytosolic Nox organizer proteins p47phox, NoxO1 and a p47phox-NoxO1-double knockout were studied under normal condition and during streptozotocin-induced diabetes.
In the mouse aorta, mRNA expression for NoxO1 was predominant in smooth muscle and endothelial cells, whereas p47phox was markedly expressed in adventitial cells comprising leukocytes and tissue resident macrophages. Knockout of either NoxO1 or p47phox resulted in lower basal blood pressure. Deletion of any of the two subunits also prevented diabetes-induced vascular dysfunction. mRNA expression analysis by MACE (Massive Analysis of cDNA ends) identified substantial gene expression differences between the mouse lines and in response to diabetes. Deletion of p47phox induced inflammatory activation with increased markers of myeloid cells and cytokine and chemokine induction. In contrast, deletion of NoxO1 resulted in an attenuated interferon gamma signature and reduced expression of genes related to antigen presentation. This aspect was also reflected by a reduced number of circulating lymphocytes in NoxO1-/- mice.
ROS production stimulated by NoxO1 and p47phox limit endothelium-dependent relaxation and maintain blood pressure in mice. However, NoxO1 and p47phox cannot substitute each other despite their similar effect on vascular function. Deletion of NoxO1 induced an anti-inflammatory phenotype, whereas p47phox deletion rather elicited a hyper-inflammatory response.
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Peripheral blood leukocytosis and neutrophilia reflect cancer inflammation and have been proposed as prognostic immunological biomarkers in various malignancies. However, previous studies were ...limited by their retrospective nature and small patient numbers. Baseline peripheral blood leukocytes, neutrophils, hemoglobin, platelets, lactate dehydrogenase and carcinoembryonic antigen (CEA) were correlated with clinicopathologic characteristics, and clinical outcome in 1236 patients with rectal cancer treated with 5‐FU‐based preoperative chemoradiotherapy (CRT) alone or with oxaliplatin followed by surgery and adjuvant chemotherapy within the CAO/ARO/AIO‐04 randomized phase 3 trial. Multivariable analyses were performed using Cox regression models. After a median follow‐up of 50 months, baseline leukocytosis remained an independent adverse prognostic factor for disease‐free survival (DFS; HR 1.457; 95% CI 1.163–1.825; p = 0.001), distant metastasis (HR 1.696; 95% CI 1.266–2.273; p < 0.001) and overall survival (OS; HR 1.716; 95% CI 1.264–2.329; p = 0.001) in multivariable analysis. Similar significant findings were observed for neutrophilia and high CEA levels. Conversely, treatment‐induced leukopenia correlated with favorable DFS (p = 0.037), distant metastasis (p = 0.028) and OS (p = 0.012). Intriguingly, addition of oxaliplatin to 5‐FU CRT resulted in a significant DFS improvement only in patients with neutrophilia and leukocytosis (p = 0.028 and p = 0.002). Our findings have important clinical implications and provide high‐level evidence on the adverse prognostic role of leukocytes and neutrophils, and the impact of chemotherapy in the context of these biomarkers. These data could help guide patient stratification and should be further validated within prospective studies.
What's new?
Cancer often causes an inflammatory response, recruiting leukocytes and neutrophils to the tumor site where they hinder anti‐cancer treatments. Here, the authors asked how leukocytosis and neutrophilia affect outcomes in rectal cancer. Unlike previous studies, which have been retrospective, this study examined a large cohort of patients within a phase 3 clinical trial. They found that baseline leukocytosis and neutrophilia independently predicted poor outcomes, including distant metastasis and shorter survival. Treatment‐induced leukopenia, meanwhile, correlated with better outcomes. Adding oxaliplatin to standard chemoradiation improved disease‐free survival only in those patients with leukocytosis & neutrophilia. These findings could lead to improved personalized treatments.
Nitric oxide (NO) synthesis is a late event during differentiation of mouse embryonic stem cells (mESC) and occurs after release from serum and leukemia inhibitory factor (LIF). Here we show that ...after release from pluripotency, a subpopulation of mESC, kept in the naive state by 2i/LIF, expresses endothelial nitric oxide synthase (eNOS) and endogenously synthesizes NO. This eNOS/NO-positive subpopulation (ESNO+) expresses mesendodermal markers and is more efficient in the generation of cardiovascular precursors than eNOS/NO-negative cells. Mechanistically, production of endogenous NO triggers rapid Hdac2 S-nitrosylation, which reduces association of Hdac2 with the transcriptional repression factor Zeb1, allowing mesendodermal gene expression. In conclusion, our results suggest that the interaction between Zeb1, Hdac2, and eNOS is required for early mesendodermal differentiation of naive mESC.
Stem cell persistence into adulthood requires self-renewal from early developmental stages. In the developing mouse brain, only apical progenitors located at the ventricle are self-renewing, whereas ...basal progenitors gradually deplete. However, nothing is known about the mechanisms regulating the fundamental difference between these progenitors. Here we show that the conditional deletion of the small Rho-GTPase cdc42 at different stages of neurogenesis in mouse telencephalon results in an immediate increase in basal mitoses. Whereas cdc42-deficient progenitors have normal cell cycle length, orientation of cell division and basement membrane contact, the apical location of the Par complex and adherens junctions are gradually lost, leading to an increasing failure of apically directed interkinetic nuclear migration. These cells then undergo mitoses at basal positions and acquire the fate of basal progenitors. Thus, cdc42 has a crucial role at the apical pole of progenitors, thereby regulating the position of mitoses and cell fate.
The immense molecular diversity of neurons challenges our ability to understand the genetic and cellular etiology of neuropsychiatric disorders. Leveraging knowledge from neurobiology may help parse ...the genetic complexity: identifying genes important for a circuit that mediates a particular symptom of a disease may help identify polymorphisms that contribute to risk for the disease as a whole. The serotonergic system has long been suspected in disorders that have symptoms of repetitive behaviors and resistance to change, including autism. We generated a bacTRAP mouse line to permit translational profiling of serotonergic neurons. From this, we identified several thousand serotonergic-cell expressed transcripts, of which 174 were highly enriched, including all known markers of these cells. Analysis of common variants near the corresponding genes in the AGRE collection implicated the RNA binding protein CELF6 in autism risk. Screening for rare variants in CELF6 identified an inherited premature stop codon in one of the probands. Subsequent disruption of Celf6 in mice resulted in animals exhibiting resistance to change and decreased ultrasonic vocalization as well as abnormal levels of serotonin in the brain. This work provides a reproducible and accurate method to profile serotonergic neurons under a variety of conditions and suggests a novel paradigm for gaining information on the etiology of psychiatric disorders.
We propose a kinetic Monte Carlo (kMC) model for simulating the movement of platinum particles on supports, based on atom-by-atom diffusion on the surface of the particle. The proposed model was able ...to reproduce equilibrium cluster shapes predicted using Wulff-construction. The diffusivity of platinum particles was simulated both purely based on random motion and assisted using an external field that causes a drift velocity. The overall particle diffusivity increases with temperature; however, the extracted activation barrier appears to be temperature independent. In addition, this barrier was found to increase with particle size, as well as, with the adhesion between the particle and the support.
Mice produce ultrasonic vocalizations (USVs) in a variety of social situations, and USVs have been leveraged to study many neurological diseases including verbal dyspraxia, depression, autism and ...stuttering. Pups produce isolation calls, a common USV, spontaneously when they are isolated from their mother during the first 2 weeks of life. Several genetic manipulations affect (and often reduce) pup isolation calls in mice. To facilitate the use of this assay as a means of testing whether significant functional differences in genotypes exist instead of contextual differences, we test the variability inherent in many commons measures of mouse vocalizations. Here we use biological consistency as a way of determining which are reproducible in mouse pup vocalizations. We present a comprehensive analysis of the normal variability of these vocalizations in groups of mice, individual mice and different strains of mice. To control for maturation effects, we recorded pup isolation calls in the same group of C57BL/6J 5 days old mice twice, with 1 h of rest in between recordings. In almost all cases, the group averages between the first and second recordings were the same. We also found that there were high correlations in some parameters in individual mice across recording while others were not well correlated. These findings could be replicated for the majority of features in a separate group of C57BL/6J mice and a group of 129/SvEvBrd-C57BL/6J mice. The averages of these mouse USV features are highly consistent and represent a robust assay to test the effects of genetic and other interventions in the experimental setting.
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