Modulating endothelial adhesion and migration impacts stem cell therapies efficacy

Background: Limited knowledge of stem cell therapies‘ mechanisms of action hampers their sustainable implementation into the clinic. Specifically, the interactions of transplanted stem cells with the host vasculature and its implications for their therapeutic efficacy are not elucidated. We tested whether adhesion receptors and chemokine receptors on stem cells can be functionally modulated, and consequently if such modulation may substantially affect therapeutically relevant stem cell interactions with the host endothelium. Methods: We investigated the effects of cationic molecule polyethylenimine (PEI) treatment with or without nanoparticles on the functions of adhesion receptors and chemokine receptors of human bone marrow-derived Mesenchymal Stem Cells (MSC). Analyses included MSC functions in vitro, as well as homing and therapeutic efficacy in rodent models of central nervous system´s pathologies in vivo. Findings: PEI treatment did not affect viability, immunomodulation or differentiation potential of MSC, but increased the CCR4 expression and functionally blocked their adhesion receptors, thus decreasing their adhesion capacity in vitro. Intravenously applied in a rat model of brain injury, the homing rate of PEI-MSC in the brain was highly increased with decreased numbers of adherent PEI-MSC in the lung vasculature. Moreover, in comparison to untreated MSC, PEI-MSC featured increased tumour directed migration in a mouse glioblastoma model, and superior therapeutic efficacy in a murine model of stroke. Interpretation: Balanced stem cell adhesion and migration in different parts of the vasculature and tissues together with the local microenvironment impacts their therapeutic efficacy. Funding: Robert Bosch Stiftung, IZEPHA grant, EU grant 7 FP Healt

Molecular networks of human muscle adaptation to exercise and age

Physical activity and molecular ageing presumably interact to precipitate musculoskeletal decline in humans with age. Herein, we have delineated molecular networks for these two major components of sarcopenic risk using multiple independent clinical cohorts. We generated genome-wide transcript profiles from individuals (n = 44) who then undertook 20 weeks of supervised resistance-exercise training (RET). Expectedly, our subjects exhibited a marked range of hypertrophic responses (3% to +28%), and when applying Ingenuity Pathway Analysis (IPA) up-stream analysis to ~580 genes that co-varied with gain in lean mass, we identified rapamycin (mTOR) signaling associating with growth (P = 1.4×10−30). Paradoxically, those displaying most hypertrophy exhibited an inhibited mTOR activation signature, including the striking down-regulation of 70 rRNAs. Differential analysis found networks mimicking developmental processes (activated all-trans-retinoic acid (ATRA, Z-score = 4.5; P = 6×10−13) and inhibited aryl-hydrocarbon receptor signaling (AhR, Z-score = −2.3; P = 3×10−7)) with RET. Intriguingly, as ATRA and AhR gene-sets were also a feature of endurance exercise training (EET), they appear to represent “generic” physical activity responsive gene-networks. For age, we found that differential gene-expression methods do not produce consistent molecular differences between young versus old individuals. Instead, utilizing two independent cohorts (n = 45 and n = 52), with a continuum of subject ages (18–78 y), the first reproducible set of age-related transcripts in human muscle was identified. This analysis identified ~500 genes highly enriched in post-transcriptional processes (P = 1×10−6) and with negligible links to the aforementioned generic exercise regulated gene-sets and some overlap with ribosomal genes. The RNA signatures from multiple compounds all targeting serotonin, DNA topoisomerase antagonism, and RXR activation were significantly related to the muscle age-related genes. Finally, a number of specific chromosomal loci, including 1q12 and 13q21, contributed by more than chance to the age-related gene list (P = 0.01–0.005), implying possible epigenetic events. We conclude that human muscle age-related molecular processes appear distinct from the processes regulated by those of physical activity

Comparison of Physical Properties of Untreated and Heat Treated Beech and Hornbeam

Istraživanjem fizikalnih svojstava toplinski obrađene bukovine i grabovine utvrđeno je da je njihova srednja vrijednost manja i signifikantno se razlikuje od srednjih vrijednosti fizikalnih svojstava neobrađene bukovine i grabovine. Srednja vrijednost gustoće u apsolutno suhom stanju toplinski obrađene bukovine manja je za 8,5 % od neobrađene, a za grabovinu je ona manja za 7,5 %. Smanjenje srednjih vrijednosti maksimalnih utezanja toplinski obrađene bukovine i grabovine u odnosu prema neobrađenoj još je veće. Maksimalno radijalno utezanje toplinski obrađene bukovine manje je za 7 %, maksimalno tangencijalno utezanje za 23,5 %, a maksimalno volumno utezanje za 19,3 % od istih fizikalnih svojstava neobrađene bukovine. Toplinski obrađena grabovina ima srednju vrijednost maksimalnoga radijalnog utezanja za 123 %, maksimalnoga tangencijalnog utezanja za 86 % i maksimalnoga volumnog utezanja za 99,5 % manju od istih fizikalnih svojstava neobrađene grabovine. Takvim smanjenjem maksimalnih utezanja u radijalnome i tangencijalnom smjeru toplinskom obradom grabovina postaje znatno prihvatljivija za izradu proizvoda za koje je važna dimenzionalna stabilnost.The investigation of physical properties of heat treated beech wood and hornbeam wood found that their average value is lower and significantly different from average values of physical properties of untreated beech wood and hornbeam wood. The average value of density in absolutely dry condition of heat treated beech wood is smaller by 8.5% from the untreated, and the hornbeam wood is smaller by 7.5%. Reduction of average values of maximum shrinkage of heat treated beech wood and hornbeam wood is even bigger in relation to the untreated wood. Maximum radial shrinkage of heat treated beech wood is smaller by 7%, maximum tangential shrinkage by 23.5% and maximum volumetric shrinkage by 19.3% compared to the same physical properties of untreated beech wood. Heat treated hornbeam wood has an average value of maximum radial shrinkage smaller by 123%, maximum tangential shrinkage by 86% and maximum volume shrinkage by 99.5% compared to the same physical properties of untreated hornbeam wood. With such reduction in the maximum shrinkage in radial and tangential direction using heat treatment, hornbeam becomes particulary suitable for making products where dimensional stability is important

Increased Micronucleus Induction in 170Tm-irradiated Nanogold-labeled SCL II-cells

Photoelectric absorption of photons with energies slightly above the K shell binding energy of an appropriate element can result in the emission of a shower of lowenergy Auger-electrons. It is well known that those electrons released by Augerelectron-emitting radionuclides located in the immediate vicinity of the DNA cause high-LET-type damage and induce an enhanced relative biological effectiveness when compared to low-LET radiation. Therefore, an enhanced biological effectiveness is expected after photon activation as well. To proof if photoelectric absorptionleads to an increased cellular radiotoxicity we investigated in SCL II-cells whether photon activation of intracellular located nano-sized gold particles is feasibleto enhance cyto- and genotoxic effects in vitro. SCL II-cells were transfected with colloidal nano-sized gold particles (40 nm) and gold-labeled DNA-triplexforming-oligonucleotides (TFO) and irradiated with a suitable 170Tm source (micro seeds). Genotoxicity was assessed using the Micronucleus-Assay and cytotoxicity was investigated using the Colony-Forming-Assay. Preliminary results indicate that Nanogold-labeled SCL II-cells show a 2-fold increase in micronucleus formation when compared to irradiated non-labeled cells. Non-irradiated NanogoldlabeledSCL II-cells showed the same background level of micronucleated cells as non-labeled SCLII-cells. The mitotic activity was neither disturbed by the goldlabeling nor the transfection procedure. Cytotoxic effects are less prominent but still need further investigation. Photon activation might be a promising approach to increase the biological effectiveness of low-LET-radiation and might be of great value for new brachytherapy strategies.This work is financially supported by STEP Pockau Gmb

Chronic co-administration of the cannabinoid receptor agonist WIN55,212-2 during puberty or adulthood reverses 3,4 methylenedioxymetamphetamine (MDMA)-induced deficits in recognition memory but not in effort-based decision making.

Cannabis and 3,4 methylenedioxymetamphetamine (MDMA, "ecstasy") are the most frequently combined illegal drugs among young adults in western societies. This study examined the effects of chronic co-administration of the cannabinoid receptor agonist WIN 55,212-2 (WIN) and MDMA on working memory and effort-based decision making in rats. Treatment consisted of MDMA (7.5 mg/kg), WIN (1.2 mg/kg), a combination of these substances (MDMA + WIN) or vehicle over a period of 25 days during puberty (PD40-65) or adulthood (PD80-105). Ten days after the last treatment, WIN reversed MDMA-induced working memory deficits in the object recognition test in animals treated during adulthood or puberty, but had no influence on impairment of adult rats in the effort-based T-maze task. No differences were observed between groups of pubertally treated rats in the decision making task. During a subsequent acute drug challenge MDMA and MDMA + WIN decreased high reward choices in both age groups, indicating MDMA-induced cost-aversive choice. Differential long-term interactions on the neuronal level in the hippocampus and MDMA-induced disturbances in cortico-limbic connections are suggested

Stimulators of the soluble guanylyl cyclase: promising functional insights from rare coding atherosclerosis-related GUCY1A3 variants

Stimulators of the soluble guanylyl cyclase (sGC) are emerging therapeutic agents in cardiovascular diseases. Genetic alterations of the GUCY1A3 gene, which encodes the alpha(1) subunit of the sGC, are associated with coronary artery disease. Studies investigating sGC stimulators in subjects with CAD and carrying risk-related variants in sGC are, however, lacking. Here, we functionally investigate the impact of coding GUCY1A3 variants on sGC activity and the therapeutic potential of sGC stimulators in vitro. In addition to a known loss-of-function variant, eight coding variants in GUCY1A3 were cloned and expressed in HEK 293 cells. Protein levels and dimerization capability with the beta(1) subunit were analysed by immunoblotting and co-immunoprecipitation, respectively. All alpha(1) variants found in MI patients dimerized with the beta(1) subunit. Protein levels were reduced by 72 % in one variant (p < 0.01). Enzymatic activity was analysed using cGMP radioimmunoassay after stimulation with a nitric oxide (NO) donor. Five variants displayed decreased cGMP production upon NO stimulation (p < 0.001). The addition of the sGC stimulator BAY 41-2272 increased cGMP formation in all of these variants (p < 0.01). Except for the variant leading to decreased protein level, cGMP amounts reached the wildtype NO-induced level after addition of BAY 41-2272. In conclusion, rare coding variants in GUCY1A3 lead to reduced cGMP formation which can be rescued by a sGC stimulator in vitro. These results might therefore represent the starting point for discovery of novel treatment strategies for patients at risk with coding GUCY1A3 variants