Ets-2 is a transcriptional activator that can be modulated by ras-dependent phosphorylation. Evidence is presented indicating that ets-2 can also act as a transcriptional repressor. In the breast cancer cell line MCF-7, exogenous ets-2 repressed the activity of a BRCA1 promoter-luciferase reporter dependent on a conserved ets-2-binding site in this promoter. Conditional overproduction of ets-2 in MCF-7 cells resulted in repression of endogenous BRCA1 mRNA expression. To address the mechanism by which ets-2 could act as a repressor, a biochemical approach was used to identify proteins that interacted with the ets-2 pointed domain. From this analysis, components of the mammalian SWI/ SNF chromatin remodeling complex were found to interact with ets-2. Brg-1, the ATP-hydrolyzing component of the SWI/SNF complex, along with the BAF57/p50 and Ini1 subunits could be co-immunoprecipitated from cells with ets-2. The pointed domain of ets-2 directly interacted in vitro with the C-terminal region of Brg-1 in a phosphorylation-dependent manner. The combination of Brg-1 and ets-2 could repress the BRCA1 promoter reporter in transfection assays. These results support a role for ets-2 as a repressor and indicate that components of the mammalian SNF/SWI complex are required as co-repressors.The ETS family, encompassing approximately 30 vertebrate members, encodes for sequence-specific DNA-binding proteins that are transcriptional activators and repressors (1). The family is defined by a highly conserved DNA binding domain referred to as the ETS domain. However, the DNA-binding properties of these factors are similar and cannot entirely account for the specificity required for the precise activation of target genes that occurs during the diverse biological processes mediated by individual family members. Modification of discrete family members by signal transduction pathways provides an additional mechanism to determine specificity (1).For example, members of the ETS family of transcription factors are important for mediating both transient and persistent changes in gene expression patterns in response to rassignaling pathways (2-4). The ETS family member elk-1 and related factors are directly phosphorylated by mitogen-activated protein kinases (MAPK), 1 a modification required for the activation of immediate early target genes like c-fos (2). Similarly, phosphorylation of the ETS family members ets-1 and ets-2 by ras-dependent pathways leads to persistent expression of target genes including extracellular proteases such as urokinase plasminogen activator (uPA) and stromelysin/MMP-3 (3, 4). Ets-1 and ets-2 are phosphorylated at a conserved residue (threonine 38 and threonine 72, respectively) by the well characterized ras-effector pathway, the Raf/MAPK pathway (4 -7). Additionally, the same residue in ets-2 can also be phosphorylated by another major ras-effector pathway, the phosphatidylinositol 3-kinase/Akt pathway (8).Understanding at the molecular level how phosphorylation modifies the activity of ets-1 and ets-2 will be cri...

BackgroundDaily rhythms in mammals are programmed by a master clock in the suprachiasmatic nucleus (SCN). The SCN contains two main compartments (shell and core), but the role of each region in system-level coordination remains ill defined. Herein, we use a functional assay to investigate how downstream tissues interpret region-specific outputs by using in vivo exposure to long day photoperiods to temporally dissociate the SCN. We then analyze resulting changes in the rhythms of clocks located throughout the brain and body to examine whether they maintain phase synchrony with the SCN shell or core.ResultsNearly all of the 17 tissues examined in the brain and body maintain phase synchrony with the SCN shell, but not the SCN core, which indicates that downstream oscillators are set by cues controlled specifically by the SCN shell. Interestingly, we also found that SCN dissociation diminished the amplitude of rhythms in core clock gene and protein expression in brain tissues by 50–75 %, which suggests that light-driven changes in the functional organization of the SCN markedly influence the strength of rhythms in downstream tissues.ConclusionsOverall, our results reveal that body clocks receive time-of-day cues specifically from the SCN shell, which may be an adaptive design principle that serves to maintain system-level phase relationships in a changing environment. Further, we demonstrate that lighting conditions alter the amplitude of the molecular clock in downstream tissues, which uncovers a new form of plasticity that may contribute to seasonal changes in physiology and behavior.Electronic supplementary materialThe online version of this article (doi:10.1186/s12915-015-0157-x) contains supplementary material, which is available to authorized users.

Background: Bronchoscopic thermal vapor ablation (BTVA) reduces lung volumes in emphysema patients by inducing a localized inflammatory response (LIR) leading to a healing process of fibrosis, but may also increase symptoms. Objectives: We sought to evaluate whether the clinical manifestation of LIR correlated with patient outcome. Methods: Respiratory adverse events and inflammatory markers were analyzed from a multicenter trial of BTVA in patients with upper-lobe-predominant emphysema. End points including changes in forced expiratory flow (FEV₁), lobar volume, St. George's Respiratory Questionnaire (SGRQ), modified Medical Research Council (mMRC) and 6-minute-walk distance (6-MWD) were analyzed according to the presence or absence of a respiratory adverse event requiring treatment with an antibiotic or steroid. Results: Forty-four patients received BTVA. Increases of inflammatory markers were observed with a peak between the second and fourth week. Eighteen respiratory adverse events occurred in 16 patients within 30 days of BTVA, requiring antibiotics and/or steroids. These patients had significantly greater lobar volume reduction (65.3 vs. 33.4%, p = 0.007) and a change in residual volume at 12 months (-933 vs. 13 ml, p < 0.001) associated with a greater improvement of exercise capacity and health-related quality of life than patients without respiratory adverse events. Conclusion: Patients with more prominent respiratory symptoms in the first 30 days following BTVA experience greater efficacy. The clinical manifestations of the LIR are predictive of long-term clinical benefits.

Rationale and Objectives With employment of both multi-detector computed tomography (MDCT) and endobronchial procedures in multi-center studies, effects of timing of endobronchial procedures on quantitative imaging (Q-MDCT) metrics is a question of increasing importance. Materials and Methods Six subjects were studied via MDCT at baseline, immediately following and at 4hrs and 24hrs post-BAL (right middle lobe (RML) and lingula). Through quantitative image analysis, non-air, or ‘tissue’ volume (TV) in each lung and lobe was recorded. Change in TV from baseline was used to infer retention and re-distribution of lavage fluid. Results Bronchoscopist reported unrecovered BAL volume correlated well with Q-MDCT for whole lung measures, but less well with individual lobes indicating redistribution. TV in all lobes except the RLL differed significantly (p<.05) from baseline immediately post lavage. At 24hrs, all lobes except the LLL (small 1% mean difference at 24hrs.) returned to baseline. Conclusions These findings suggest fluid movement, effecting Q-MDCT metrics, between lobes and between lungs before eventual resolution, and preclude protocols involving the lavage of one lung and imaging of the other to avoid interactions. We demonstrate that Q-MDCT is sensitive to lavage fluid retention and re-distribution, and endobronchial procedures should not precede Q-MDCT imaging by less than 24hrs.

Light improves cognitive function in humans; however, the neurobiological mechanisms underlying positive effects of light remain unclear. One obstacle is that most rodent models have employed lighting conditions that cause cognitive deficits rather than improvements. Here we have developed a mouse model where light improves cognitive function, which provides insight into mechanisms underlying positive effects of light. To increase light exposure without eliminating daily rhythms, we exposed mice to either a standard photoperiod or a long day photoperiod. Long days enhanced long-term recognition memory, and this effect was abolished by loss of the photopigment melanopsin. Further, long days markedly altered hippocampal clock function and elevated transcription of Insulin-like Growth Factor2 (Igf2). Up-regulation of Igf2 occurred in tandem with suppression of its transcriptional repressor Wilm’s tumor1. Consistent with molecular de-repression of Igf2, IGF2 expression was increased in the hippocampus before and after memory training. Lastly, long days occluded IGF2-induced improvements in recognition memory. Collectively, these results suggest that light changes hippocampal clock function to alter memory, highlighting novel mechanisms that may contribute to the positive effects of light. Furthermore, this study provides insight into how the circadian clock can regulate hippocampus-dependent learning by controlling molecular processes required for memory consolidation.