@article{BenKraiemSauerNorwigetal.2021, author = {Ben-Kraiem, Adel and Sauer, Reine-Solange and Norwig, Carla and Popp, Maria and Bettenhausen, Anna-Lena and Atalla, Mariam Sobhy and Brack, Alexander and Blum, Robert and Doppler, Kathrin and Rittner, Heike Lydia}, title = {Selective blood-nerve barrier leakiness with claudin-1 and vessel-associated macrophage loss in diabetic polyneuropathy}, series = {Journal of Molecular Medicine}, volume = {99}, journal = {Journal of Molecular Medicine}, number = {9}, doi = {10.1007/s00109-021-02091-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265237}, pages = {1237-1250}, year = {2021}, abstract = {Diabetic polyneuropathy (DPN) is the most common complication in diabetes and can be painful in up to 26\% of all diabetic patients. Peripheral nerves are shielded by the blood-nerve barrier (BNB) consisting of the perineurium and endoneurial vessels. So far, there are conflicting results regarding the role and function of the BNB in the pathophysiology of DPN. In this study, we analyzed the spatiotemporal tight junction protein profile, barrier permeability, and vessel-associated macrophages in Wistar rats with streptozotocin-induced DPN. In these rats, mechanical hypersensitivity developed after 2 weeks and loss of motor function after 8 weeks, while the BNB and the blood-DRG barrier were leakier for small, but not for large molecules after 8 weeks only. The blood-spinal cord barrier remained sealed throughout the observation period. No gross changes in tight junction protein or cytokine expression were observed in all barriers to blood. However, expression of Cldn1 mRNA in perineurium was specifically downregulated in conjunction with weaker vessel-associated macrophage shielding of the BNB. Our results underline the role of specific tight junction proteins and BNB breakdown in DPN maintenance and differentiate DPN from traumatic nerve injury. Targeting claudins and sealing the BNB could stabilize pain and prevent further nerve damage.}, language = {en} } @article{NeuhausSchlundtFehrholzetal.2015, author = {Neuhaus, Winfried and Schlundt, Marian and Fehrholz, Markus and Ehrke, Alexander and Kunzmann, Steffen and Liebner, Stefan and Speer, Christian P. and F{\"o}rster, Carola Y.}, title = {Multiple antenatal dexamethasone treatment alters brain vessel differentiation in newborn mouse pups}, series = {PLoS ONE}, volume = {10}, journal = {PLoS ONE}, number = {8}, doi = {10.1371/journal.pone.0136221}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-148268}, pages = {e0136221}, year = {2015}, abstract = {Antenatal steroid treatment decreases morbidity and mortality in premature infants through the maturation of lung tissue, which enables sufficient breathing performance. However, clinical and animal studies have shown that repeated doses of glucocorticoids such as dexamethasone and betamethasone lead to long-term adverse effects on brain development. Therefore, we established a mouse model for antenatal dexamethasone treatment to investigate the effects of dexamethasone on brain vessel differentiation towards the blood-brain barrier (BBB) phenotype, focusing on molecular marker analysis. The major findings were that in total brains on postnatal day (PN) 4 triple antenatal dexamethasone treatment significantly downregulated the tight junction protein claudin-5, the endothelial marker Pecam-1/CD31, the glucocorticoid receptor, the NR1 subunit of the N-methyl-D-aspartate receptor, and Abc transporters (Abcb1a, Abcg2 Abcc4). Less pronounced effects were found after single antenatal dexamethasone treatment and in PN10 samples. Comparisons of total brain samples with isolated brain endothelial cells together with the stainings for Pecam-1/CD31 and claudin-5 led to the assumption that the morphology of brain vessels is affected by antenatal dexamethasone treatment at PN4. On the mRNA level markers for angiogenesis, the sonic hedgehog and the Wnt pathway were downregulated in PN4 samples, suggesting fundamental changes in brain vascularization and/or differentiation. In conclusion, we provided a first comprehensive molecular basis for the adverse effects of multiple antenatal dexamethasone treatment on brain vessel differentiation.}, language = {en} } @phdthesis{Katschorek2005, author = {Katschorek, Haymo}, title = {Optimierung der Barriereeigenschaften hybridpolymerer Beschichtungssysteme}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-16356}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2005}, abstract = {Quellf{\"a}hige nat{\"u}rliche Schichtsilicate k{\"o}nnen nach vorheriger Modifizierung als nanoskalige Barrieref{\"u}llstoffe f{\"u}r hybridpolymere Beschichtungen eingesetzt werden. Durch Ionenaustausch nach der „Onium-Methode" wurden aus nat{\"u}rlichem Montmorillonit unterschiedlich modifizierte organophile Schichtsilicate hergestellt, die mit thermisch oder strahlenh{\"a}rtenden Barrierelacken vertr{\"a}glich sind. Als Modifizierungsreagenzien kamen neben aliphatischen auch olefinische und alkoxysilylfunktionelle Ammonium-Verbindungen zum Einsatz. Beschichtungen aus den modifizierten Barrierelacken zeigten teilweise deutlich verbesserte Sauerstoffbarriereeigenschaften. Ein signifikanter Einfluß auf die Wasserdampfbarriere war bei diesem F{\"u}llstoffanteil nicht festellbar. Die optische Transparenz der hybridpolymeren Barriereschichten wird auch durch Anteile von bis zu 5 Gew. \% an Schichtsilicat nicht nennenswert beeinflusst. Dies belegen UV-VIS-Spektren.Aufgrund der deutlichen Steigerung der Sauerstoffbarrierewirkung unter Beibehaltung der optischen Transparenz der Beschichtung stellt die Kombination von modifizierten Schichtsilicaten mit hybridpolymeren Barrierelacken daher eine interessante Alternative zu den bisher eingesetzten Barrieresystemen ohne F{\"u}llstoff dar. Der Einfluss von Lacklagerung, Lackkomponenten und H{\"a}rtungsbedingungen im Hinblick auf die Struktur und Sperrwirkung von Hybridpolymerschichten wurde im zweiten Teil dieser Arbeit untersucht. Dabei wurden die Ergebnisse struktureller Untersuchungen durch 29Si, 13C- und 27Al-NMR-Spektroskopie mit Barrieremessungen korreliert. Der letzte Teil der Arbeit befasst sich mit der Optimierung von Migrationsschutzschichten. Hybridpolymere bieten neben einer Barrierewirkung gegen{\"u}ber Gasen und D{\"a}mpfen auch einen wirksamen Schutz gegen die Migration weiterer chemischer Substanzen, wie z.B. Weichmachern. Am Beispiel eines strahlenh{\"a}rtenden hybridpolymeren Lackes wurde {\"u}ber die Formulierung des Lackes eine Korrelation zwischen Migrations- und Sauerstoffbarrierewirkung hergestellt.}, subject = {Metallorganische Polymere}, language = {de} }