Pigment Epithelium-Derived Factor (PEDF) Receptors Are Involved in Survival of Retinal Neurons

The demise of retinal ganglion cells (RGCs) is characteristic of diseases of the retina such as glaucoma and diabetic or ischemic retinopathies. Pigment epithelium-derived factor (PEDF) is a multifunctional secreted protein that mediates neuroprotection and inhibition of angiogenesis in the retina. We have studied expression and regulation of two of several receptors for PEDF, patatin-like phospholipase 2 gene product/PEDF-R and laminin receptor (LR), in serum-starved RGC under normoxia and hypoxia and investigated their involvement in the survival of retinal neuronal cells. We show that PEDF-R and LR are co-expressed in RGC and R28 retinal precursor cells. Expression of both receptors was enhanced in the presence of complex secretions from retinal glial (Müller) cells and upregulated by VEGF and under hypoxic conditions. PEDF-R- and LR-knocked-down cells demonstrated a markedly attenuated expression of anti-apoptotic Bcl-2 family members (Bcl-2, Bcl-xL) and neuroprotective mediators (PEDF, VEGF, BDNF) suggesting that both PEDF-R and LR mediate pro-survival effects of PEDF on RGC. While this study does not provide evidence for a differential survival-promoting influence of either PEDF-R or LR, it nevertheless highlights the importance of both PEDF receptors for the viability of retinal neurons.     

Aspects of reproducibility and stability for partial cure of epoxy matrix resin

Partial cure of thermosets is a promising approach to enhance manufacturing possibilities of reinforced and unreinforced polymers. If partial cure is taken into consideration as a genuine process parameter, novel manufacturing technologies can be developed by exploiting the specific properties of incomplete polymer networks. A main concern in this context is to control the kinetic reaction avoiding inhomogeneous or instable degrees of cure. Based on a combination of numerical simulations and experiments, a methodology is presented that enables a systematic assessment of the reproducibility and stability of partial cure. Special attention is paid to the interaction of thermal boundary conditions and the cure kinetic of thick samples as well as the storability of partially cured resin under different conditions. Guidelines for cure cycle selection, mold design, and storage are derived. The possibility to use complex multistep cure schedules and extended storage periods is demonstrated for an unmodified noninhibited epoxy resin. © 2019 The Authors. Journal of Applied Polymer Science published by Wiley Periodicals Inc. J. Appl. Polym. Sci. 2020 , 137, 48342.     

Kinetic Investigation of Polyurethane Rubber Formation from CO2-Containing Polyols

A novel CO₂ utilization technology allows for the inclusion of CO₂ as carbonate units and double bond moieties to give additional functionality in polyether polyols. This study examines the chain-elongation kinetics of these diols with diisocyanates to polyurethane rubbers by means of thermal analysis. A reaction order of 1 indicates a strong influence of the chains' mobility on the reaction rate. Spectrometry and comparison with non-double-bond polyols reveal that the effect cannot be attributed to a substantial occurrence of side reactions but is rather due to the intertwining of lengthy chains.     

Integrated Approaches Toward High‐Affinity Artificial Protein Binders Obtained via Computationally Simulated Epitopes for Protein Recognition

Widely used diagnostic tools make use of antibodies recognizing targeted molecules, but additional techniques are required in order to alleviate the disadvantages of antibodies. Herein, molecular dynamic calculations are performed for the design of high affinity artificial protein binding surfaces for the recognition of neuron specific enolase (NSE), a known cancer biomarker. Computational simulations are employed to identify particularly stabile secondary structure elements. These epitopes are used for the subsequent molecular imprinting, where surface imprinting approach is applied. The molecular imprints generated with the calculated epitopes of greater stability (Cys‐Ep1) show better binding properties than those of lower stability (Cys‐Ep5). The average binding strength of imprints created with stabile epitopes is found to be around twofold and fourfold higher for the NSE derived peptide and NSE protein, respectively. The recognition of NSE is investigated in a wide concentration range, where high sensitivity (limit of detection (LOD) = 0.5 ng mL^?1) and affinity (dissociation constant (K_d) = 5.3 × 10^?11m ) are achieved using Cys‐Ep1 imprints reflecting the stable structure of the template molecules. This integrated approach employing stability calculations for the identification of stabile epitopes is expected to have a major impact on the future development of high affinity protein capturing binders.     

In vivo 19F MR inflammation imaging after myocardial infarction in a large animal model at 3 T

Magnetic Resonance Materials in Physics, Biology and Medicine - Fluorine-19 (19F) MRI with intravenously applied perfluorocarbons allows the in vivo monitoring of infiltrating immune cells as...     

13C-NMR-Spektren von 2-Bromcholest-5-en-3-onen

¹³C-N.M.R. Spectroscopic Investigation of 2-Bromo-cholest-5-en-3-ones The ¹³C-n.m.r. spectra of the 2-epimeric 2-bromocholest-5-en-3-ones have been measured and the substituent effects are determined. The substituent effects of 2-Br and Δ⁵ double bond follow the rules known from literature.     

Nα-Acetyl-aminosäure-methylamide als Modellverbindungen zur Interpretation der 13C-NMR-Spektren geschützter Peptide

N^α-Acetyl-methylamides of Amino Acids as Model Compounds for Interpretation of ¹³C-NMR-Spectra of Protected Peptides N^α-Acetyl-methylamides of differents amino acids have been synthesized as model compounds for amino acid residues in peptides, and ¹³C-n.m.r. spectra have been measured. The three derivatives of peptides Boc-Glu(OBzl)-Arg(H⁺)-Gly-Phe-Phe-Tyr(Bzl)-Thr(Bzl)-Pro-Lys(Z)- Ala-OBzl (B 21–30). Boc-Leu-Tyr(Bzl)-Leu-Val-Cys(SEt)-Gly-OH (B 15–20) and Boc-Ser(Bzl)-His(Trt)-Leu-Val-Glu(OBzl)-Ala-OH (B 9–14) used for the synthesis of insulin B chain are an illustration for the fact that chemical shifts of characteristic amino acid carbon atoms obtained by corresponding model compounds, allow a simple and correct interpretation of peptide derivative spectra.     

Patient-Specific iPSC-Derived Neural Differentiated and Hepatocyte-like Cells,Carrying the Compound Heterozygous Mutation p.V1023Sfs*15/p.G992R,Present the “Variant” Biochemical Phenotype of Niemann-Pick Type C1 Disease

Niemann–Pick disease type C1 (NP-C1) is a rare lysosomal storage disorder caused by autosomal recessive mutations in the NPC1 gene. Patients display a wide spectrum on the clinical as well as on the molecular level, wherein a so-called “variant” biochemical phenotype can be observed. Here, we report an in vitro analysis of fibroblasts obtained from an NP-C1 patient carrying the undescribed compound heterozygous mutation p.V1023Sfs*15/p.G992R. Since NP-C1 is a neurovisceral disease and the patient suffers from severe neurological as well as hepatic symptoms, we extended our study to neural differentiated and hepatocyte-like cells derived from patient-specific induced pluripotent stem cells. We detected slightly increased intracellular cholesterol levels compared to the control cell line in fibroblasts, neural differentiated and hepatocyte-like cells, suggesting a “variant” biochemical phenotype. Furthermore, the total NPC1 protein, as well as post-ER glycoforms of the NPC1 protein, tended to be reduced. In addition, colocalization analysis revealed a mild reduction of the NPC1 protein in the lysosomes. The patient was diagnosed with NP-C1 at the age of 34 years, after an initial misdiagnosis of schizophrenia. After years of mild and unspecific symptoms, such as difficulties in coordination and concentration, symptoms progressed and the patient finally presented with ataxia, dysarthria, dysphagia, vertical supranuclear gaze palsy, and hepatosplenomegaly. Genetic testing finally pointed towards an NP-C1 diagnosis, revealing the so-far undescribed compound heterozygous mutation p.V1023Sfs*15/p.G992R in the NPC1 gene. In light of these findings, this case provides support for the p.G992R mutation being causative for a “variant” biochemical phenotype leading to an adult-onset type of NP-C1 disease.