The apical transmembrane protein Crumbs is a central regulator of epithelial apical-basal polarity in Drosophila. Loss-of-function mutations in the human homologue of Crumbs, CRB1 (RP12), cause ...recessive retinal dystrophies, including retinitis pigmentosa. Here we show that Crumbs and CRB1 localize to corresponding subdomains of the photoreceptor apical plasma membrane: the stalk of the Drosophila photoreceptor and the inner segment of mammalian photoreceptors. These subdomains support the morphogenesis and orientation of the photosensitive membrane organelles: rhabdomeres and outer segments, respectively. Drosophila Crumbs is required to maintain zonula adherens integrity during the rapid apical membrane expansion that builds the rhabdomere. Crumbs also regulates stalk development by stabilizing the membrane-associated spectrin cytoskeleton, a function mechanistically distinct from its role in epithelial apical-basal polarity. We propose that Crumbs is a central component of a molecular scaffold that controls zonula adherens assembly and defines the stalk as an apical membrane subdomain. Defects in such scaffolds may contribute to human CRB1-related retinal dystrophies.
This work is the second installment of a study that probes the aggregation behavior of asphaltenes by gel permeation chromatography (GPC). In part 1, analysis of GPC aggregate fractions collected ...from the 2017 PetroPhase asphaltene sample by direct infusion revealed an inverse correlation between aggregate size and aromaticity. However, characterization of the largest aggregate fractions by direct infusion was hampered by solvent contaminant peaks and dynamic range limitations due to the extremely low ionization efficiencies of the larger, more aliphatic species that comprise those fractions. Here, we couple the GPC separation with online detection by positive atmospheric pressure photoionization ((+)APPI) 21 T Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to overcome those problems and reveal that the most abundant species that comprise the largest aggregate segment are indeed the most aliphatic. The ability to characterize difficult-to-analyze samples, like asphaltenes, is the first major advantage of online coupling. Another benefit is the increased chromatographic resolution afforded by online coupling, which enables a finer examination in the most aggregated region and reveals a local trend opposed to the global trend. The very first species to elute in the largest aggregates were more condensed polyaromatic compounds, and the larger, more aliphatic species elute shortly thereafter in much greater relative abundance.
Hypertension in the United States Fire Service Khaja, Saeed U; Mathias, Kevin C; Bode, Emilie D ...
International journal of environmental research and public health,
05/2021, Letnik:
18, Številka:
10
Journal Article
Recenzirano
Odprti dostop
Hypertension is a major risk factor for atherosclerotic cardiovascular disease and cardiac remodeling and is associated with an increased risk of sudden cardiac events, the leading cause of ...duty-related death in the fire service. We assessed systemic blood pressures and prevalence of hypertension among US firefighters by decade of life. Medical records of career firefighters (5063 males and 274 females) from four geographically diverse occupational health clinics were assessed. Hypertension was defined as systolic blood pressure ≥130 mmHg or diastolic blood pressure ≥80 mmHg, or taking antihypertensive medication. Results from the firefighter sample were compared to the US general population (2015-2016 and 2017-2018 National Health and Nutrition Examination Surveys). Among the total sample, 69% of firefighters met the criteria for hypertension and 17% were taking antihypertensive medications. Percentages of hypertensive male and female firefighters were 45% and 11% among 20-29 years old, respectively, and increased to 78% and 79% among 50-59 years old, respectively. Compared to the general population, male firefighters had a higher prevalence of hypertension (
< 0.05) across all age groups (11-16% higher). In order to improve firefighter health and protect against sudden incapacitation in this public safety occupational group, increased efforts are necessary to screen for and manage high blood pressure.
This review explores the possibility that central actions of flavanol-rich cocoa-derived products are of benefit in the prevention and treatment of mood disorders. Flavanol-rich cocao-derived ...products have been studied in both neuromolecular and psychological tests. Neuromolecular effects of flavanols in cocoa-derived products include antioxidant, vasodilatory, anticoagulant, and antiinflammatory properties that may serve to counteract depressive brain disorders. Psychological studies in humans have described links between intake of flavanol-rich cocoa-derived products such as dark chocolate and improved mood, while behavioral studies in laboratory animals have reported antidepressant effects of flavanols. It is therefore likely that flavanol-rich cocoa-derived products such as dark chocolate may have beneficial effects as add-on items together with traditional antidepressant regimes.
Stress granules aid cell survival in response to environmental stressors by acting as sites of translational repression. We report an unanticipated link between stress granules and the ...serine/threonine kinase RSK2. In stressed breast cells, endogenous RSK2 colocalizes in granules with TIA-1 and poly(A)-binding protein 1, and the sequestration of RSK2 and TIA-1 exhibits codependency. The RSK2 N-terminal kinase domain controls the direct interaction with the prion-related domain of TIA-1. Silencing RSK2 decreases cell survival in response to stress. Mitogen releases RSK2 from the stress granules and permits its nuclear import via a nucleocytoplasmic shuttling sequence in the C-terminal domain. Nuclear accumulation is dependent on TIA-1. Surprisingly, nuclear localization of RSK2 is sufficient to enhance proliferation through induction of cyclin D1, in the absence of other active signaling pathways. Hence, RSK2 is a pivotal factor linking the stress response to survival and proliferation.
Tensions between constructions of nature and culture are increasingly relevant in the twenty-first century as natural environments near large population centres come under increasing pressure from ...developers. The western face of the Mount Lofty Ranges, South Australia, is a historically significant cultural landscape where, following European colonisation, landscape use transitioned between 'cultural' and 'natural' according to local economies and changing public perceptions. Historical and archaeological evidence for the evolution of this landscape illustrate the dichotomies between these changing landscape values and growing public appreciation of the aesthetic qualities of this 'green' backdrop to the city of Adelaide. During the 1960s and 1970s the South Australian Parliament passed legislation creating a Hills Face Zone to protect this region from urban development. This paper presents evidence why, fifty years later, this model for landscape management is increasingly relevant as world population growth and urban sprawl extend into natural environments.
The C-terminal segment of the human insulin receptor α-chain (designated αCT) is critical to insulin binding as has been previously demonstrated by alanine scanning mutagenesis and ...photo-cross-linking. To date no information regarding the structure of this segment within the receptor has been available. We employ here the technique of thermal-factor sharpening to enhance the interpretability of the electron-density maps associated with the earlier crystal structure of the human insulin receptor ectodomain. The αCT segment is now resolved as being engaged with the central β-sheet of the first leucine-rich repeat (L1) domain of the receptor. The segment is α-helical in conformation and extends 11 residues N-terminal of the classical αCT segment boundary originally defined by peptide mapping. This tandem structural element (αCT-L1) thus defines the intact primary insulin-binding surface of the apo-receptor. The structure, together with isothermal titration calorimetry data of mutant αCT peptides binding to an insulin minireceptor, leads to the conclusion that putative "insulin-mimetic" peptides in the literature act at least in part as mimics of the αCT segment as well as of insulin. Photo-cross-linking by novel bifunctional insulin derivatives demonstrates that the interaction of insulin with the αCT segment and the L1 domain occurs in trans, i.e., these components of the primary binding site are contributed by alternate α-chains within the insulin receptor homodimer. The tandem structural element defines a new target for the design of insulin agonists for the treatment of diabetes mellitus.
BackgroundPhosphorylated peptides presented by MHC molecules represent a new class of neoantigens expressed on cancer cells and recognized by CD8 T-cells. These peptides are promising targets for ...cancer immunotherapy. Previous work identified an HLA-A*0201-restricted phosphopeptide from insulin receptor substrate 2 (pIRS2) as one such target. The purpose of this study was to characterize a second phosphopeptide, from breast cancer antiestrogen resistance 3 (BCAR3), and to evaluate safety and immunogenicity of a novel immunotherapic vaccine comprising either or both of these phosphorylated peptides.MethodsPhosphorylated BCAR3 protein was evaluated in melanoma and breast cancer cell lines by Western blot, and recognition by T-cells specific for HLA-A*0201-restricted phosphorylated BCAR3 peptide (pBCAR3126-134) was determined by 51Cr release assay and intracellular cytokine staining. Human tumor explants were also evaluated by mass spectrometry for presentation of pIRS2 and pBCAR3 peptides. For the clinical trial, participants with resected stage IIA–IV melanoma were vaccinated 6 times over 12 weeks with one or both peptides in incomplete Freund’s adjuvant and Hiltonol (poly-ICLC). Adverse events (AEs) were coded based on National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) V.4.03, with provision for early study termination if dose-limiting toxicity (DLT) rates exceeded 33%. The enrollment target was 12 participants evaluable for immune response to each peptide. T-cell responses were assessed by interferon-γ ELISpot assay.ResultspBCAR3 peptides were immunogenic in vivo in mice, and in vitro in normal human donors, and T-cells specific for pBCAR3126-134 controlled outgrowth of a tumor xenograft. The pIRS21097-1105 peptide was identified by mass spectrometry from human hepatocellular carcinoma tumors. In the clinical trial, 15 participants were enrolled. All had grade 1 or 2 treatment-related AEs, but there were no grade 3–4 AEs, DLTs or deaths on study. T-cell responses were induced to the pIRS21097-1105 peptide in 5/12 patients (42%, 90% CI 18% to 68%) and to the pBCAR3126-134 peptide in 2/12 patients (17%, 90% CI 3% to 44%).ConclusionThis study supports the safety and immunogenicity of vaccines containing the cancer-associated phosphopeptides pBCAR3126-134 and pIRS21097-1105, and the data support continued development of immune therapy targeting phosphopeptides. Future studies will define ways to further enhance the magnitude and durability of phosphopeptide-specific immune responses.Trial registration numberNCT01846143
Non-obstructive azoospermia (NOA) is the most severe form of male infertility and typically incurable. Defining the genetic basis of NOA has proven challenging, and the most advanced classification ...of NOA subforms is not based on genetics, but simple description of testis histology. In this study, we exome-sequenced over 1000 clinically diagnosed NOA cases and identified a plausible recessive Mendelian cause in 20%. We find further support for 21 genes in a 2-stage burden test with 2072 cases and 11,587 fertile controls. The disrupted genes are primarily on the autosomes, enriched for undescribed human "knockouts", and, for the most part, have yet to be linked to a Mendelian trait. Integration with single-cell RNA sequencing data shows that azoospermia genes can be grouped into molecular subforms with synchronized expression patterns, and analogs of these subforms exist in mice. This analysis framework identifies groups of genes with known roles in spermatogenesis but also reveals unrecognized subforms, such as a set of genes expressed across mitotic divisions of differentiating spermatogonia. Our findings highlight NOA as an understudied Mendelian disorder and provide a conceptual structure for organizing the complex genetics of male infertility, which may provide a rational basis for disease classification.
Protein biochemistry protocols typically include disulfide bond reducing agents to guard against unwanted thiol oxidation and protein aggregation. Commonly used disulfide bond reducing agents include ...dithiothreitol, β-mercaptoethanol, glutathione, and the tris(alkyl)phosphine compounds tris(2-carboxyethyl)phosphine (TCEP) and tris(3-hydroxypropyl)phosphine (THPP). While studying the catalytic activity of the NAD(P)H-dependent enzyme Δ1-pyrroline-5-carboxylate reductase, we unexpectedly observed a rapid non-enzymatic chemical reaction between NAD+ and the reducing agents TCEP and THPP. The product of the reaction exhibits a maximum ultraviolet absorbance peak at 334 nm and forms with an apparent association rate constant of 231–491 M–1 s–1. The reaction is reversible, and nuclear magnetic resonance characterization (1H, 13C, and 31P) of the product revealed a covalent adduct between the phosphorus of the tris(alkyl)phosphine reducing agent and the C4 atom of the nicotinamide ring of NAD+. We also report a 1.45 Å resolution crystal structure of short-chain dehydrogenase/reductase with the NADP+–TCEP reaction product bound in the cofactor binding site, which shows that the adduct can potentially inhibit enzymes. These findings serve to caution researchers when using TCEP or THPP in experimental protocols with NAD(P)+. Because NAD(P)+-dependent oxidoreductases are widespread in nature, our results may be broadly relevant.
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