Developing a Model of Aged Decellularized Muscle Matrix with Advanced Glycation Cross-linking

Volumetric muscle loss (VML) has been found to overwhelm muscle regeneration, resulting in loss of long-term muscle functionality. Decellularized muscle matrices (DMMs) provide an effective environment for muscle regeneration; however, the age of their source has not been adequately explored for clinical translation. Advanced glycation end-products (AGEs) are chemical cross-links that contribute to the aging process by accumulating on collagen fibers, resulting in a stiffening of the collagenous matrix and an increase in inflammation via the receptor for advanced glycation end-products (RAGE). In previous experiments, we found increased levels of AGE-specific cross-links within DMMs in old mice compared to young as proven by ALT-711 treatment. In this study, we developed a model of aged rat DMMs using AGE cross-links and hypothesized that our AGE-DMM model will contain a higher number of collagen cross-links compared to the control. This AGE-DMM model aims to elucidate the effect of AGEs on muscle regeneration when used in vitro or implanted in a volumetric muscle loss model.https://scholarscompass.vcu.edu/uresposters/1424/thumbnail.jp

High yield production of a soluble human interleukin-3 variant from E. coli with wild-type bioactivity and improved radiolabeling properties

Human interleukin-3 (hIL-3) is a polypeptide growth factor that regulates the proliferation, differentiation, survival and function of hematopoietic progenitors and many mature blood cell lineages. Although recombinant hIL-3 is a widely used laboratory reagent in hematology, standard methods for its preparation, including those employed by commercial suppliers, remain arduous owing to a reliance on refolding insoluble protein expressed in E. coli. In addition, wild-type hIL-3 is a poor substrate for radio-iodination, which has been a long-standing hindrance to its use in receptor binding assays. To overcome these problems, we developed a method for expression of hIL-3 in E. coli as a soluble protein, with typical yields of >3mg of purified hIL-3 per litre of shaking microbial culture. Additionally, we introduced a non-native tyrosine residue into our hIL-3 analog, which allowed radio-iodination to high specific activities for receptor binding studies whilst not compromising bioactivity. The method presented herein provides a cost-effective and convenient route to milligram quantities of a hIL-3 analog with wild-type bioactivity that, unlike wild-type hIL‑3, can be efficiently radio-iodinated for receptor binding studies

Desmoglein-2 as a cancer modulator: friend or foe?

Desmoglein-2 (DSG2) is a calcium-binding single pass transmembrane glycoprotein and a member of the large cadherin family. Until recently, DSG2 was thought to only function as a cell adhesion protein embedded within desmosome junctions designed to enable cells to better tolerate mechanical stress. However, additional roles for DSG2 outside of desmosomes are continuing to emerge, particularly in cancer. Herein, we review the current literature on DSG2 in cancer and detail its impact on biological functions such as cell adhesion, proliferation, migration, invasion, intracellular signaling, extracellular vesicle release and vasculogenic mimicry. An increased understanding of the diverse repertoire of the biological functions of DSG2 holds promise to exploit this cell surface protein as a potential prognostic biomarker and/or target for better patient outcomes. This review explores the canonical and non-canonical functions of DSG2, as well as the context-dependent impacts of DSG2 in the realm of cancer

WIYN Open Cluster Study. XXXIX. Abundances in NGC 6253 from HYDRA Spectroscopy of the Li 6708 A Region

High-dispersion spectra of 89 potential members of the old, super-metal-rich open cluster, NGC 6253, have been obtained with the HYDRA multi-object spectrograph. Based upon radial-velocity measurements alone, 47 stars at the turnoff of the cluster color-magnitude diagram (CMD) and 18 giants are identified as potential members. Five turnoff stars exhibit evidence of binarity while proper-motion data eliminates two of the dwarfs as members. The mean cluster radial velocity from probable single-star members is -29.4 +/- 1.3 km/sec (sd). A discussion of the current estimates for the cluster reddening, derived independently of potential issues with the BV cluster photometry, lead to an adopted reddening of E(B-V) = 0.22 +/- 0.04. From equivalent width analyses of 38 probable single-star members near the CMD turnoff, the weighted average abundances are found to be [Fe/H] = +0.43 +/- 0.01, [Ni/H] = +0.53 +/- 0.02 and [Si/H] = +0.43 (+0.03,-0.04), where the errors refer to the standard errors of the weighted mean. Weak evidence is found for a possible decline in metallicity with increasing luminosity among stars at the turnoff. We discuss the possibility that our turnoff stars have been affected by microscopic diffusion. For 15 probable single-star members among the giants, spectrum synthesis leads to abundances of +0.46 (+0.02,-0.03) for [Fe/H]. While less than half the age of NGC 6791, NGC 6253 is at least as metal-rich and, within the uncertainties, exhibits the same general abundance pattern as that typified by super-metal-rich dwarfs of the galactic bulge.Comment: 5 Tables, 9 figures, 45 page

The Structure of Pre-transitional Protoplanetary Disks I: Radiative Transfer Modeling of the Disk+Cavity in the PDS 70 system

Through detailed radiative transfer modeling, we present a disk+cavity model to simultaneously explain both the SED and Subaru H-band polarized light imaging for the pre-transitional protoplanetary disk PDS 70. Particularly, we are able to match not only the radial dependence, but also the absolute scale, of the surface brightness of the scattered light. Our disk model has a cavity 65 AU in radius, which is heavily depleted of sub-micron-sized dust grains, and a small residual inner disk which produces a weak but still optically thick NIR excess in the SED. To explain the contrast of the cavity edge in the Subaru image, a factor of ~1000 depletion for the sub-micron-sized dust inside the cavity is required. The total dust mass of the disk may be on the order of 1e-4 M_sun, only weakly constrained due to the lack of long wavelength observations and the uncertainties in the dust model. The scale height of the sub-micron-sized dust is ~6 AU at the cavity edge, and the cavity wall is optically thick in the vertical direction at H-band. PDS 70 is not a member of the class of (pre-)transitional disks identified by Dong et al. (2012), whose members only show evidence of the cavity in the millimeter-sized dust but not the sub-micron-sized dust in resolved images. The two classes of (pre-)transitional disks may form through different mechanisms, or they may just be at different evolution stages in the disk clearing process.Comment: 28 pages (single column), 7 figures, 1 table, ApJ accepte

Dual Mechanism of Interleukin-3 Receptor Blockade by an Anti-Cancer Antibody

SummaryInterleukin-3 (IL-3) is an activated T cell product that bridges innate and adaptive immunity and contributes to several immunopathologies. Here, we report the crystal structure of the IL-3 receptor α chain (IL3Rα) in complex with the anti-leukemia antibody CSL362 that reveals the N-terminal domain (NTD), a domain also present in the granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-5, and IL-13 receptors, adopting unique “open” and classical “closed” conformations. Although extensive mutational analyses of the NTD epitope of CSL362 show minor overlap with the IL-3 binding site, CSL362 only inhibits IL-3 binding to the closed conformation, indicating alternative mechanisms for blocking IL-3 signaling. Significantly, whereas “open-like” IL3Rα mutants can simultaneously bind IL-3 and CSL362, CSL362 still prevents the assembly of a higher-order IL-3 receptor-signaling complex. The discovery of open forms of cytokine receptors provides the framework for development of potent antibodies that can achieve a “double hit” cytokine receptor blockade

Impact of Optimized Breastfeeding on the Costs of Necrotizing Enterocolitis in Extremely Low Birthweight Infants

To estimate risk of NEC for ELBW infants as a function of preterm formula and maternal milk (MM) intake and calculate the impact of suboptimal feeding on NEC incidence and costs

Racial/Ethnic Disparities in Inadequate Gestational Weight Gain Differ by Pre-pregnancy Weight

OBJECTIVES: Pre-pregnancy body mass index (BMI) varies by race/ethnicity and modifies the association between gestational weight gain (GWG) and adverse pregnancy outcomes, which disproportionately affect racial/ethnic minorities. Yet studies investigating whether racial/ethnic disparities in GWG vary by pre-pregnancy BMI are inconsistent, and none studied nationally representative populations. METHODS: Using categorical measures of GWG adequacy based on Institute of Medicine recommendations, we investigated whether associations between race/ethnicity and GWG adequacy were modified by pre-pregnancy BMI [underweight (<18.5kg/m(2)), normal weight (18.5-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)), or obese (≥30.0 kg/m(2)) ] among all births to Black, Hispanic, and White mothers in the 1979 USA National Longitudinal Survey of Youth cohort (n=6849 pregnancies; range=1-10). We used generalized estimating equations, adjusted for marital status, parity, smoking during pregnancy, gestational age, and multiple measures of socioeconomic position. RESULTS: Effect measure modification between race/ethnicity and pre-pregnancy BMI was significant for inadequate GWG (Wald test p-value=0.08). Normal weight Black (Risk Ratio (RR)=1.34, 95% confidence interval (CI): 1.18, 1.52) and Hispanic women (RR=1.33, 95%CI: 1.15, 1.54) and underweight Black women (RR=1.38; 95% CI: 1.07, 1.79) experienced an increased risk of inadequate GWG compared to Whites. Differences in risk of inadequate GWG between minority women, compared to White women, were not significant among overweight and obese women. Effect measure modification between race/ethnicity and pre-pregnancy BMI was not significant for excessive GWG. CONCLUSIONS: The magnitude of racial/ethnic disparities in inadequate GWG appears to vary by pre-pregnancy weight class, which should be considered when designing interventions to close racial/ethnic gaps in healthy GWG

Isozyme-Specific Ligands for O-acetylserine sulfhydrylase, a Novel Antibiotic Target

Conceived and designed the experiments: FS PC BC ES AM. Performed the experiments: FS RS ES PF SR. Analyzed the data: FS BC ES PF GEK PFC AM. Contributed reagents/materials/analysis tools: PC PB GC. Wrote the paper: FS GEK BC AM.The last step of cysteine biosynthesis in bacteria and plants is catalyzed by O-acetylserine sulfhydrylase. In bacteria, two isozymes, O-acetylserine sulfhydrylase-A and O-acetylserine sulfhydrylase-B, have been identified that share similar binding sites, although the respective specific functions are still debated. O-acetylserine sulfhydrylase plays a key role in the adaptation of bacteria to the host environment, in the defense mechanisms to oxidative stress and in antibiotic resistance. Because mammals synthesize cysteine from methionine and lack O-acetylserine sulfhydrylase, the enzyme is a potential target for antimicrobials. With this aim, we first identified potential inhibitors of the two isozymes via a ligand- and structure-based in silico screening of a subset of the ZINC library using FLAP. The binding affinities of the most promising candidates were measured in vitro on purified O-acetylserine sulfhydrylase-A and O-acetylserine sulfhydrylase-B from Salmonella typhimurium by a direct method that exploits the change in the cofactor fluorescence. Two molecules were identified with dissociation constants of 3.7 and 33 µM for O-acetylserine sulfhydrylase-A and O-acetylserine sulfhydrylase-B, respectively. Because GRID analysis of the two isoenzymes indicates the presence of a few common pharmacophoric features, cross binding titrations were carried out. It was found that the best binder for O-acetylserine sulfhydrylase-B exhibits a dissociation constant of 29 µM for O-acetylserine sulfhydrylase-A, thus displaying a limited selectivity, whereas the best binder for O-acetylserine sulfhydrylase-A exhibits a dissociation constant of 50 µM for O-acetylserine sulfhydrylase-B and is thus 8-fold selective towards the former isozyme. Therefore, isoform-specific and isoform-independent ligands allow to either selectively target the isozyme that predominantly supports bacteria during infection and long-term survival or to completely block bacterial cysteine biosynthesis.Yeshttp://www.plosone.org/static/editorial#pee