Bright Fluorescent Chemosensor Platforms for Imaging Endogenous Pools of Neuronal Zinc

AbstractA series of new fluorescent Zinpyr (ZP) chemosensors based on the fluorescein platform have been prepared and evaluated for imaging neuronal Zn2+. A systematic synthetic survey of electronegative substitution patterns on a homologous ZP scaffold provides a basis for tuning the fluorescence responses of “off-on” photoinduced electron transfer (PET) probes by controlling fluorophore pKa values and attendant proton-induced interfering fluorescence of the metal-free (apo) probes at physiological pH. We further establish the value of these improved optical tools for interrogating the metalloneurochemistry of Zn2+; the novel ZP3 fluorophore images endogenous stores of Zn2+ in live hippocampal neurons and slices, including the first fluorescence detection of Zn2+ in isolated dentate gyrus cultures. Our findings reveal that careful control of fluorophore pKa can minimize proton-induced fluorescence of the apo probes and that electronegative substitution offers a general strategy for tuning PET chemosensors for cellular studies. In addition to providing improved optical tools for Zn2+ in the neurosciences, these results afford a rational starting point for creating superior fluorescent probes for biological applications

Kinesin family member-18A (KIF18A) is a predictive biomarker of poor benefit from endocrine therapy in early ER+ breast cancer

PURPOSE: Identification of effective and reliable biomarkers that could be used to predict the efficacy of endocrine therapy is of crucial importance to the management of oestrogen receptor positive (ER+) breast cancer (BC). KIF18A, a key regulator of cell cycle, is overexpressed in many human cancers, including BC. In this study, we investigated the role of KIF18A as a biomarker to predict the benefit from endocrine treatment in early ER + BC patients.METHODS: KIF18A expression was assessed at the genomic level using the METABRIC dataset to explore its prognostic and predictive value in ER + BC patients (n = 1506). Predictive significance of KIF18A mRNA was validated using KM-Plot datasets (n = 2061). KIF18A protein expression was assessed using immunohistochemistry in a large annotated series of early-stage ER + BC (n = 1592) with long-term follow-up.RESULTS: High mRNA and protein expression of KIF18A were associated with short recurrence-free survival (RFS), distant-metastasis free survival (DMFS) and BC specific survival (all P  less than 0.05) in ER + BC in patients who received no adjuvant treatment or adjuvant endocrine therapy. In multivariate analysis, high KIF18A expression was an independent prognostic biomarker for poor RFS (P = 0.027) and DMFS (P = 0.028) in patients treated with adjuvant endocrine therapy.Conclusion: KIF18A appears to be a candidate biomarker of a subgroup of ER + BC characterised by poor clinical outcome. High KIF18A expression has prognostic significance to predict poor benefit from endocrine treatment for patients with ER + BC. Therefore, measurement of KIF18A on ER + BC patients prior to treatment could guide clinician decision on benefit from endocrine therapy

Scale setting the M\"obius Domain Wall Fermion on gradient-flowed HISQ action using the omega baryon mass and the gradient-flow scales t0t_0 and w0w_0

We report on a sub-percent scale determination using the omega baryon mass and gradient-flow methods. The calculations are performed on 22 ensembles of $N_f=2+1+1$ highly improved, rooted staggered sea-quark configurations generated by the MILC and CalLat Collaborations. The valence quark action used is M\"obius Domain-Wall fermions solved on these configurations after a gradient-flow smearing is applied with a flowtime of $t_{\rm gf}=1$ in lattice units. The ensembles span four lattice spacings in the range $0.06 \lesssim a \lesssim 0.15$ fm, six pion masses in the range $130 \lesssim m_\pi \lesssim 400$ MeV and multiple lattice volumes. On each ensemble, the gradient-flow scales $t_0/a^2$ and $w_0/a$ and the omega baryon mass $a m_\Omega$ are computed. The dimensionless product of these quantities is then extrapolated to the continuum and infinite volume limits and interpolated to the physical light, strange and charm quark mass point in the isospin limit, resulting in the determination of $\sqrt{t_0}=0.1422(14)$ fm and $w_0 = 0.1709(11)$ fm with all sources of statistical and systematic uncertainty accounted for. The dominant uncertainty in this result is the stochastic uncertainty, providing a clear path for a few-per-mille uncertainty, as recently obtained by the Budapest-Marseille-Wuppertal Collaboration.Comment: v3: Published version; v2: Added determination of t_0 as well as w_0; v1: 13 pages plus appendices. The correlation function data, mass results and analysis code accompanying this publication can be found at this github repository: https://github.com/callat-qcd/project_scale_setting_mdwf_his

Glutamate dehydrogenase (GLUD1) expression in breast cancer

Dysregulated cellular metabolism is regarded as one of the hallmarks of cancer with some tumours utilising the glutamine metabolism pathway for their sustained proliferation and survival. Glutamate dehydrogenase (GLUD1) is a key enzyme in glutaminolysis converting glutamate to α-Ketoglutarate for entry into the TCA cycle. Breast cancer (BC) comprises a heterogeneous group of tumours in terms of molecular biology and clinical behaviour, and we have previously shown that altered glutamine metabolism varies substantially among the different molecular subtypes. We hypothesise that the prognostic value of GLUD1 expression will differ between the BC molecular subtypes and may act as a potential therapeutic target for BC tumours.Methods: GLUD1 was assessed at the DNA, mRNA (n=1,980) and protein (n=1,300) levels in large and well-characterised cohorts and correlated with clinicopathological parameters, molecular subtypes, patient outcome and treatments. Results: There was a correlation between GLUD1 mRNA and GLUD1 protein expression which were highly expressed in low grade Luminal/ER+ BC (

Biological characteristics and clinical outcome of triple negative primary breast cancer in older women - comparison with their younger counterparts.

Triple negative (ER, PgR and HER2 negative) breast cancers (TNBCs) are often considered as a poor prognostic phenotype. There is dearth of evidence showing the prevalence and biological behaviour of TNBCs in older women. This study aimed to analyse their biological characteristics in comparison with a well characterised younger series from a single centre with long term clinical follow-up. Over 37 years (1973–2010), 1,758 older (≥70 years) women with early operable

DNA damage response markers are differentially expressed in BRCA-mutated breast cancers

Cells have stringent DNA repair pathways that are specific for each different set of DNA lesions which is accomplished through the integration of complex array of proteins. However, BRCA-mutated breast cancer (BC) has defective DNA repair mechanisms. This study aims to investigate differential expression of a large panel of DNA repair markers to characterise DNA repair mechanisms in BRCA-associated tumours compared to sporadic tumours in an attempt to characterise these tumours in routine practice. Immunohistochemistry and tissue microarray technology were applied to a cohort of clinically annotated series of sporadic (n = 1849), BRCA1-mutated (n = 48), and BRCA2-mutated (n = 27) BC. The following DNA damage response (DDR) markers are used; BRCA1, BRCA2, RAD51, Ku70/Ku80, BARD, PARP1 (cleaved), PARP1 (non-cleaved), and P53 in addition to basal cytokeratins, ER, PR, and HER2. A significant proportion of BRCA1 tumours were positive for PARP1 (non-cleaved), and negative for BARD1 and RAD51 compared with sporadic BC. BRCA2 tumours were significantly positive for PARP1 (non-cleaved) compared with sporadic tumours. RAD51 was significantly higher in BRCA1 compared with BRCA2 tumours (p = 0.005). When BRCA1/2 BCs were compared to triple-negative (TN) sporadic tumours of the studied DDR proteins, BARD1 (p < 0.001), PARP1 (non-cleaved) (p < 0.001), and P53 (p = 0.002) remained significantly different in BRCA1/2 tumours compared with TN BC. DNA repair markers showed differential expression in BRCA-mutated tumours, with a substantial degree of disruption of DNA repair pathways in sporadic BC especially TN BC. DNA double-strand break (DSB) repair is assisted by PARP1 expression in BRCA-mutated tumours, whereas the loss of DSB repair via RAD51 is predominant in BRCA1 rather than BRCA2 BC

Broad Balmer Wings in BA Hyper/Supergiants Distorted by Diffuse Interstellar Bands: Five Examples in the 30 Doradus Region from the VLT-FLAMES Tarantula Survey

Extremely broad emission wings at Hβ and Hα have been found in VLT-FLAMES Tarantula Survey data for five very luminous BA supergiants in or near 30 Doradus in the Large Magellanic Cloud. The profiles of both lines are extremely asymmetrical, which we have found to be caused by very broad diffuse interstellar bands (DIBs) in the longward wing of Hβ and the shortward wing of Hα. These DIBs are well known to interstellar but not to many stellar specialists, so that the asymmetries may be mistaken for intrinsic features. The broad emission wings are generally ascribed to electron scattering, although we note difficulties for that interpretation in some objects. Such profiles are known in some Galactic hyper/supergiants and are also seen in both active and quiescent Luminous Blue Variables (LBVs). No prior or current LBV activity is known in these 30 Dor stars, although a generic relationship to LBVs is not excluded; subject to further observational and theoretical investigation, it is possible that these very luminous supergiants are approaching the LBV stage for the first time. Their locations in the HRD and presumed evolutionary tracks are consistent with that possibility. The available evidence for spectroscopic variations of these objects is reviewed, while recent photometric monitoring does not reveal variability. A search for circumstellar nebulae has been conducted, with an indeterminate result for one of them

Spectrum and Morphology of the Two Brightest Milagro Sources in the Cygnus Region: MGRO J2019+37 and MGRO J2031+41

The Cygnus region is a very bright and complex portion of the TeV sky, host to unidentified sources and a diffuse excess with respect to conventional cosmic-ray propagation models. Two of the brightest TeV sources, MGRO J2019+37 and MGRO J2031+41, are analyzed using Milagro data with a new technique, and their emission is tested under two different spectral assumptions: a power law and a power law with an exponential cutoff. The new analysis technique is based on an energy estimator that uses the fraction of photomultiplier tubes in the observatory that detect the extensive air shower. The photon spectrum is measured in the range 1 to 200 TeV using the last 3 years of Milagro data (2005-2008), with the detector in its final configuration. MGRO J2019+37 is detected with a significance of 12.3 standard deviations ($\sigma$), and is better fit by a power law with an exponential cutoff than by a simple power law, with a probability $>98$% (F-test). The best-fitting parameters for the power law with exponential cutoff model are a normalization at 10 TeV of $7^{+5}_{-2}\times10^{-10}$ $\mathrm{s^{-1}\: m^{-2}\: TeV^{-1}}$, a spectral index of $2.0^{+0.5}_{-1.0}$ and a cutoff energy of $29^{+50}_{-16}$ TeV. MGRO J2031+41 is detected with a significance of 7.3$\sigma$, with no evidence of a cutoff. The best-fitting parameters for a power law are a normalization of $2.4^{+0.6}_{-0.5}\times10^{-10}$ $\mathrm{s^{-1}\: m^{-2}\: TeV^{-1}}$ and a spectral index of $3.08^{+0.19}_{-0.17}$. The overall flux is subject to an $\sim$30% systematic uncertainty. The systematic uncertainty on the power law indices is $\sim$0.1. A comparison with previous results from TeV J2032+4130, MGRO J2031+41 and MGRO J2019+37 is also presented.Comment: 11 pages, 10 figure