The rockefeller university

The elevation of cancer antigen 125 (CA125) levels in the serum of asymptomatic patients precedes the radiologic detection of high-grade serous ovarian cancer by at least 2 mo and the final clinical diagnosis by 5 mo. PET imaging of CA125 expression by ovarian cancer cells may enhance the evaluation of the extent of disease and provide a roadmap to surgery as well as detect recurrence and metastases. Methods: Zr-89-labeled mAb-B43.13 was synthesized to target CA125 and evaluated via PET imaging and biodistribution studies in mice bearing OVCAR3 human ovarian adenocarcinoma xenografts. Ex vivo analysis of tumors and lymph nodes was performed via autoradiography, histopathology, and immunohistochemistry. Results: PET imaging using Zr-89-DFO-mAb-B43.13 (DFO is desferrioxamine) clearly delineated CA125-positive OVCAR3 xenografts as early as 24 h after the administration of the radioimmunoconjugate. Biodistribution studies revealed accretion of Zr-89-DFO-mAb-B43.13 in the OVCAR3 tumors, ultimately reaching 22.3 +/- 6.3 percentage injected dose per gram (%ID/g) at 72 h after injection. Most interestingly, activity concentrations greater than 50 %ID/g were observed in the ipsilateral lymph nodes of the xenograft-bearing mice. Histopathologic analysis of the immuno-PET positive lymph nodes revealed the presence of grossly metastasized ovarian cancer cells within the lymphoid tissues. In control experiments, only low-level, non-specific uptake of 89Zr-labeled isotype IgG was observed in OVCAR3 tumors; similarly, low-activity concentrations of Zr-89-DFO-mAb-B43.13 accumulated in CA125-negative SKOV3 tumors. Conclusion: Immuno-PET with Zr-89-labeled mAb-B43.13 is a potential strategy for the noninvasive delineation of extent of disease and may add value in treatment planning and treatment monitoring of high-grade serous ovarian cancer.

The bacterial CRISPR/Cas9 system allows sequence-specific gene editing in many organisms and holds promise as a tool to generate models of human diseases, for example, in human pluripotent stem cells(1,2). CRISPR/Cas9 introduces targeted double-stranded breaks (DSBs) with high efficiency, which are typically repaired by non-homologous end-joining (NHEJ) resulting in nonspecific insertions, deletions or other mutations (indels)(2). DSBs may also be repaired by homology-directed repair (HDR)(1,2) using a DNA repair template, such as an introduced single-stranded oligo DNA nucleotide (ssODN), allowing knock-in of specific mutations(3). Although CRISPR/Cas9 is used extensively to engineer gene knockouts through NHEJ, editing by HDR remains inefficient(3-8) and can be corrupted by additional indels(9), preventing its widespread use for modelling genetic disorders through introducing disease-associated mutations. Furthermore, targeted mutational knock-in at single alleles to model diseases caused by heterozygous mutations has not been reported. Here we describe a CRISPR/Cas9-based genome-editing framework that allows selective introduction of mono-and bi-allelic sequence changes with high efficiency and accuracy. We show that HDR accuracy is increased dramatically by incorporating silent CRISPR/Casblocking mutations along with pathogenic mutations, and establish a method termed 'CORRECT' for scarless genome editing. By characterizing and exploiting a stereotyped inverse relationship between a mutation's incorporation rate and its distance to the DSB, we achieve predictable control of zygosity. Homozygous introduction requires a guide RNA targeting close to the intended mutation, whereas heterozygous introduction can be accomplished by distance-dependent suboptimal mutation incorporation or by use of mixed repair templates. Using this approach, we generated human induced pluripotent stem cells with heterozygous and homozygous dominant early onset Alzheimer's disease-causing mutations in amyloid precursor protein (APP(Swe))(10) and presenilin 1 (PSEN1M146V)(11) and derived cortical neurons, which displayed genotype-dependent disease-associated phenotypes. Our findings enable efficient introduction of specific sequence changes with CRISPR/Cas9, facilitating study of human disease.

Background: Transforming growth factor-beta 1 (TGF-beta 1) has been implicated in the pathogenesis of aortic valve stenosis (AS). There is, however, little direct evidence for a role of active TGF-beta 1 in AS due to the sensitivity of current assays. We searched for evidence of plasma TGF-beta 1 activation by assaying Smad2/3 phosphorylation in circulating leukocytes and platelet-leukocyte aggregates (PLAs) in a mouse model of AS (Reversa). Methods: Echocardiography was used to measure AS and cardiac function. Intracellular phospho-flow cytometry in combination with optical fluorescence microscopy was used to detect PLAs and p-Smad2/3 levels. Results: Reversa mice on a western diet developed AS, had significantly increased numbers of PLAs and more intense staining for p-Smad2/3 in both PLAs and single leukocytes (all p < 0.05). p-Smad2/3 staining was more intense in PLAs than in single leukocytes in both diet groups (p < 0.05) and correlated with plasma total TGF-beta 1 levels (r = 0.38, p = 0.05 for PLAs and r = 0.37, p = 0.06 for single leukocytes) and reductions in ejection fraction (r = 0.42, p = 0.03 for PLAs and r = 037, p = 0.06 for single leukocytes). Conclusions: p-Smad2/3 staining is more intense in leukocytes of hypercholesterolemic mice that developed AS, suggesting increased circulating active TGF-beta 1 levels. Leukocyte p-Smad2/3 may be a valuable surrogate indicator of circulating active TGF-beta 1. (C) 2016 Elsevier Inc All rights reserved.

African trypanosomes are mammalian pathogens that must regularly change their protein coat to survive in the host bloodstream. Chronic trypanosome infections are potentiated by their ability to access a deep genomic repertoire of Variant Surface Glycoprotein (VSG) genes and switch from the expression of one VSG to another. Switching VSG expression is largely based in DNA recombination events that result in chromosome translocations between an acceptor site, which houses the actively transcribed VSG, and a donor gene, drawn from an archive of more than 2,000 silent VSGs. One element implicated in these duplicative gene conversion events is a DNA repeat of approximately 70 bp that is found in long regions within each BES and short iterations proximal to VSGs within the silent archive. Early observations showing that 70-bp repeats can be recombination boundaries during VSG switching led to the prediction that VSG-proximal 70-bp repeats provide recombinatorial homology. Yet, this long held assumption had not been tested and no specific function for the conserved 70-bp repeats had been demonstrated. In the present study, the 70-bp repeats were genetically manipulated under conditions that induce gene conversion. In this manner, we demonstrated that 70-bp repeats promote access to archival VSGs. Synthetic repeat DNA sequences were then employed to identify the length, sequence, and directionality of repeat regions required for this activity. In addition, manipulation of the 70-bp repeats allowed us to observe a link between VSG switching and the cell cycle that had not been appreciated. Together these data provide definitive support for the long-standing hypothesis that 70-bp repeats provide recombinatorial homology during switching. Yet, the fact that silent archival VSGs are selected under these conditions suggests the 70-bp repeats also direct DNA pairing and recombination machinery away from the closest homologs (silent BESs) and toward the rest of the archive.

AimClarifying whether multiple introductions of a species remain relatively isolated or merge and interbreed is essential for understanding the dynamics of invasion processes. Multiple introductions from different sources can result in a mixture of genetically distinct populations, increasing the total genetic diversity. This mixing can resolve the genetic paradox', whereby in spite of the relatively small numbers of introduced individuals, the augmented diversity due to this mixing increases adaptability and the ability of the species to spread in new environments. Here, we aim to assess whether the expansion of a successful invader, the Eastern grey squirrel, was partly driven by the merger of multiple introductions and the effects of such a merger on diversity. LocationUK, Ireland. MethodsWe analysed the genetic variation at 12 microsatellite loci of 381 individuals sampled from one historical and 14 modern populations of grey squirrels. ResultsOur data revealed that current UK population structure resembles a mosaic, with minimal interpopulation mixing and each element reflecting the genetic make-up of historic introductions. The genetic diversity of each examined population was lower than a US population or a historical UK population. Numbers of releases in a county did not correlate with county-level genetic diversity. Inbreeding coefficients remain high, and effective population sizes remain small. Main conclusionsOur results support the conclusion that rapid and large-scale expansion in this species in the UK was not driven by a genetic mixing of multiple introduced populations with a single expansion front, but was promoted by repeated translocations of small propagules. Our results have implications for the management of grey squirrels and other invasive species and also demonstrate how invaders can overcome the genetic paradox, if spread is facilitated by human-mediated dispersal.

Estrogens affect dopamine transmission in the striatum, increasing dopamine availability, maintaining D2 receptor density, and reducing the availability of the dopamine transporter. Some of these effects of estrogens are rapid, suggesting that they are mediated by membrane associated receptors. Recently our group demonstrated that there is extra-nuclear labeling for ER alpha, ER beta, and GPER1 in the striatum, but that ER alpha and GPER1 are not localized to dopaminergic neurons in this region. GABAergic neurons are the most common type of neuron in the striatum, and changes in GABA transmission affect dopamine transmission. Thus, to determine whether ER alpha or GPER1 are localized to GABAergic neurons, we double labeled the striatum with antibodies for ER alpha or GPER1 and GABA and examined them using electron microscopy. Ultrastructural analysis revealed that ER alpha and GPER1 are localized exclusively to extranuclear sites in the striatum, and 35% of the dendrites and axon terminals labeled for these receptors contain GABA immunoreactivity. Binding at membrane-associated ER alpha and GPER1 could account for rapid estrogen-induced decreases in GABA transmission in the striatum, which, in turn, could affect dopamine transmission in this region. (C) 2016 Elsevier Ireland Ltd. All rights reserved.

Multidirectional interactions between the nervous and immune systems have been documented in homeostasis and pathologies ranging from multiple sclerosis to autism, and from leukemia to acute and chronic inflammation. Recent studies have addressed this crosstalk using cell-specific targeting, novel sequencing, imaging, and analytical tools, shedding light on unappreciated mechanisms of neuro-immune regulation. This Review focuses on neuro-immune interactions at barrier surfaces-mostly the gut, but also including the skin and the airways, areas densely populated by neurons and immune cells that constantly sense and adapt to tissue-specific environmental challenges.

Diversity in cytoskeleton organization and function may be achieved through variations in primary sequence of tubulin isotypes. Recently, isotype functional diversity has been linked to a "tubulin code" in which the C-terminal tail, a region of substantial sequence divergence between isotypes, specifies interactions with microtubule-associated proteins. However, it is not known whether residue changes in this region alter microtubule dynamic instability. Here, we examine recombinant tubulin with human beta isotype IIB and characterize polymerization dynamics. Microtubules with beta IIB have catastrophe frequencies approximately threefold lower than those with isotype beta III, a suppression similar to that achieved by regulatory proteins. Further, we generate chimeric beta tubulins with native tail sequences swapped between isotypes. These chimeras have catastrophe frequencies similar to that of the corresponding full-length construct with the same core sequence. Together, our data indicate that residue changes within the conserved beta tubulin core are largely responsible for the observed isotype-specific changes in dynamic instability parameters and tune tubulin's polymerization properties across a wide range.