Genetic and serological heterogeneity of the supertypic HLA-B locus specificities Bw4 and Bw6

Gene cloning and sequencing of the HLA-B locus split antigens B38 (B16.1) and B39 (B16.2) allowed localization of their subtypic as well as their public specificities HLA-Bw4 or -Bw6 to the c~-helical region of the c~ 1 domain flanked by the amino acid positions 74-83. Comparison of their amino acid sequences with those of other HLA-B-locus alleles established HLA-Bw6 to be distinguished by Ser at residue 77 and Asn at residue 80. In contrast, HLA-Bw4 is characterized by at least seven different patterns of amino acid exchanges at positions 77 and 80-83. Reactivity patterns of Bw4- or Bw6-specific monoclonal antibodies reveal two alloantigenic epitopes contributing to the HLA-Bw4 or -Bw6 specificity residing next to the region of highest diversity of the cr domain

Lokalisation und Funktion von KDEL-Rezeptoren in Hefe- und Säugerzellen

A/B toxins such as cholera toxin, Pseudomonas exotoxin and yeast killer toxin K28 contain a KDEL-like motif at either subunit which ensures retrograde toxin transport through the secretory pathway of a target cell. Intoxication and host cell entry is initiated by toxin binding to plasma membrane (PM) receptors where the yeast KDEL receptor (KDELR) was recently identified as receptor of K28. Consistent with its function at the cell surface, electron microscopy was performed to support PM co-localization of KDELRs in yeast and mammals. To identify how a major KDELR fraction is retained in the secretory pathway, the C-terminal lysine cluster of KDELRs was confirmed to play an important role for ER retention in yeast and mammalian cells. As KDELRs function as GPCRs in the regulation of vesicle trafficking, a similar signalling function after cargo binding at the cell surface is assumed. To address such novel functions, CRISPR/Cas9-mediated KDELR knock-out (KO) cell lines were generated. While KDELR1-KO inhibited HEK293 cell survival, the generation of KDELR2- and KDELR3-KO cell lines was successful. Characterization of commercial KDELR1-KO HAP1 cells revealed a strong sensitivity under ER stress conditions and an increased secretion of PDI. Additionally, transcriptome analysis showed alterations in the expression of genes whose products are involved in developmental processes, cell adhesion and extracellular matrix functions.A/B-Toxine wie das Cholera-Toxin, Pseudomonas-Exotoxin und das Hefe-Killertoxin K28 enthalten ein KDEL-ähnliches Motiv an einer ihrer Untereinheiten, welches den retrograden Toxintransport durch den Sekretionsweg der Zielzelle ermöglicht. Ihr Eindringen wird durch die Bindung an Plasmamembran (PM)-Rezeptoren initiiert, wobei der KDEL-Rezeptor (KDELR) als PM-Rezeptor von K28 identifiziert werden konnte. Im Zusammenhang mit dieser Funktion an der Zelloberfläche wurde eine Co-Lokalisation des KDELR in der PM von Hefe- und Säugerzellen durch Elektronenmikroskopie bestätigt. Untersuchungen bezüglich der KDELR-Retention im Sekretionsweg konnten eine entscheidende Rolle des C-terminalen Lysin-Clusters in Hefe- und Säugerzellen bestärken. Da KDELRs bei der Regulation von Transportprozessen als GPCRs agieren, kann auch eine ähnliche Signalfunktion nach extrazellulärer Ligandenbindung angenommen werden. Zur Analyse solch neuer Funktionen wurden mittels CRISPR/Cas9-Technologie KDELR-KO Zelllinien hergestellt. Während die Generierung eines KDELR2- und KDELR3-KOs gelang, verhinderte der KDELR1-KO das Überleben von HEK293-Zellen. Die Charakterisierung einer kommerziellen KDELR1-KO HAP1-Zelllinie zeigte eine erhöhte Sensitivität bei ER-Stress sowie eine verstärkte PDI-Sekretion. Zusätzlich konnten mittels Transkriptomanalyse Veränderungen in Entwicklungsprozessen, Zelladhäsion sowie Komponenten der Extrazellulären Matrix nachgewiesen werden

Koordinationschemie -gebundener Cyclopentadienyl-Chalkogeno-Ether

Coordination Chemistry of rr-Bonded Cyclopentadienyl Chalcogeno Ethers, I. - Chelate Complexes of Pentakis(methylthio)cymantrene with Metal Carbonyls [C5(SMe)5]Mn(CO)3 (1) reacts with W(CO)5(THF), Mo(CO)4(C7H8), Cr(CO)3(NCMe)3, and Re(CO)4(-C3H5)/HBF4 to yield the monochelate complexes [[C5(SMe)5]Mn(C0)3][M(CO)4] (M = W: 2; M = Mo: 3) and the dichelate complexes [[C5(SMe)5]Mn(CO)3][M(C0)4]2 (M = W: 4; M = Cr: 5; M = Re BFF4 : 6). The reaction with Mo(CO)3(p-xylene) in THF leads via unstable intermediates, which contain coordinated THF, to a mixture of 3 and [[C5(SMe)5]Mn(CO)3][Mo(CO)4]2 (7). The structures of 3 and 4 in the crystal have been determined by X-ray diffraction methods

CMR detects decreased myocardial deformation in asymptomatic patients at risk for heart failure

Aims: The main management strategy of heart failure with preserved ejection fraction (HFpEF) is prevention since HFpEF is associated with many cardiovascular (CV) risk factors, especially since HFpEF is linked to a high risk for both mortality and recurrent heart failure (HF) hospitalizations. Therefore, there is a need for new tools to identify patients with a high risk profile early. Regional strain assessment by CMR seems to be superior in describing deformation impairment in HF. The MyoHealth score is a promising tool to identify cardiac changes early. Methods and results: Heart failure patients irrespective of LVEF and asymptomatic controls were recruited, and CMR based measures were obtained. For this analysis the asymptomatic control group (n = 19) was divided into asymptomatic subjects without CV co-morbidities or evidence of cardiac abnormalities and (n = 12) and asymptomatic subjects with CV co-morbidities or evidence of cardiac abnormalities (n = 7) as well as patients with HFpEF (n = 19). We performed CMR scans at rest and during a stress test using isometric handgrip exercise (HG). Assessing the MyoHealth score at rest revealed preserved regional strain in 85 +/- 9% of LV segments in controls, 73 +/- 11% in at Risk subjects and 73 +/- 8% in HFpEF patients. During stress the MyoHealth score was 84 +/- 7% in controls, 83 +/- 7 in at risk subjects and 74 +/- 11 in HFpEF patients. Conclusion: In summary, we show for the first time that asymptomatic subjects with increased CV risk present with HFpEF like impaired myocardial deformation at rest, while they show results like controls under HG stress. The potential of preventive treatment in this group of patients merits further investigation in future

Fine-mapping and identification of candidate causal genes for tail length in the Merinolandschaf breed

Docking the tails of lambs in long-tailed sheep breeds is a common practice worldwide. But this practice is associated with pain. Breeding for a shorter tail could offer an alternative. Therefore, this study aimed to analyze the natural tail length variation in the Merinolandschaf and to identify causal alleles for the short tail phenotype segregating within long-tailed breeds. We used SNP-based association analysis and haplotype-based mapping in 362 genotyped (Illumina OvineSNP50) and phenotyped Merinolandschaf lambs. Genome-wide significant regions were capture sequenced in 48 lambs and comparatively analyzed in various long and short-tailed sheep breeds and wild sheep subspecies. Here we show a SNP located in the first exon of HOXB13 and a SINE element located in the promotor of HOXB13 as promising candidates. These results enable more precise breeding towards shorter tails, improve animal welfare by amplification of ancestral alleles and contribute to a better understanding of differential embryonic development

Effects of the glucagon-like peptide-1 receptor agonist liraglutide in juvenile transgenic pigs modeling a pre-diabetic condition

Background: The glucagon-like peptide-1 receptor (GLP1R) agonist liraglutide improves glycemic control and reduces body weight of adult type 2 diabetic patients. However, efficacy and safety of liraglutide in adolescents has not been systematically investigated. Furthermore, possible pro-proliferative effects of GLP1R agonists on the endocrine and exocrine pancreas need to be further evaluated. We studied effects of liraglutide in adolescent pigs expressing a dominant-negative glucose-dependent insulinotropic polypeptide receptor (GIPRdn) in the beta-cells, leading to a pre-diabetic condition including disturbed glucose tolerance, reduced insulin secretion and progressive reduction of functional beta-cell mass. Methods: Two-month-old GIPRdn transgenic pigs were treated daily with liraglutide (0.6-1.2 mg per day) or placebo for 90 days. Glucose homeostasis was evaluated prior to and at the end of the treatment period by performing mixed meal and intravenous glucose tolerance tests (MMGTT and IVGTT). Finally animals were subjected to necropsy and quantitative-stereological analyses were performed for evaluation of alpha-and beta-cell mass, beta-cell proliferation as well as acinus-cell proliferation. Results: MMGTT at the end of the study revealed 23% smaller area under the curve (AUC) for glucose, a 36% smaller AUC insulin, and improved insulin sensitivity, while IVGTT showed a 15% smaller AUC glucose but unchanged AUC insulin in liraglutide-vs. placebo-treated animals. Liraglutide led to marked reductions in body weight gain (-31%) and food intake (-30%) compared to placebo treatment, associated with reduced phosphorylation of insulin receptor beta (INSRB)/insulin-like growth factor-1 receptor beta (IGF1RB) and protein kinase B (AKT) in skeletal muscle. Absolute alpha-and beta-cell mass was reduced in liraglutide-treated animals, but alpha-and beta-cell mass-to-body weight ratios were unchanged. Liraglutide neither stimulated beta-cell proliferation in the endocrine pancreas nor acinus-cell proliferation in the exocrine pancreas, excluding both beneficial and detrimental effects on the pig pancreas. Conclusions: Although plasma liraglutide levels of adolescent transgenic pigs treated in our study were higher compared to human trials, pro-proliferative effects on the endocrine or exocrine pancreas or other liraglutide-related side-effects were not observed