OPA1 disease alleles causing dominant optic atrophy have defects in cardiolipin-stimulated GTP hydrolysis and membrane tubulation

The dynamin-related GTPase OPA1 is mutated in autosomal dominant optic atrophy (DOA) (Kjer type), an inherited neuropathy of the retinal ganglion cells. OPA1 is essential for the fusion of the inner mitochondrial membranes, but its mechanism of action remains poorly understood. Here we show that OPA1 has a low basal rate of GTP hydrolysis that is dramatically enhanced by association with liposomes containing negative phospholipids such as cardiolipin. Lipid association triggers assembly of OPA1 into higher order oligomers. In addition, we find that OPA1 can promote the protrusion of lipid tubules from the surface of cardiolipin-containing liposomes. In such lipid protrusions, OPA1 assemblies are observed on the outside of the lipid tubule surface, a protein-membrane topology similar to that of classical dynamins. The membrane tubulation activity of OPA1 is suppressed by GTPγS. OPA1 disease alleles associated with DOA display selective defects in several activities, including cardiolipin association, GTP hydrolysis and membrane tubulation. These findings indicate that interaction of OPA1 with membranes can stimulate higher order assembly, enhance GTP hydrolysis and lead to membrane deformation into tubules

Insights from Multimodal Preclinical Imaging in Immunocompetent Nude Mice

Hydrogels based on gelatin have evolved as promising multifunctional biomaterials. Gelatin is crosslinked with lysine diisocyanate ethyl ester (LDI) and the molar ratio of gelatin and LDI in the starting material mixture determines elastic properties of the resulting hydrogel. In order to investigate the clinical potential of these biopolymers, hydrogels with different ratios of gelatin and diisocyanate (3-fold (G10_LNCO3) and 8-fold (G10_LNCO8) molar excess of isocyanate groups) were subcutaneously implanted in mice (uni- or bilateral implantation). Degradation and biomaterial-tissue- interaction were investigated in vivo (MRI, optical imaging, PET) and ex vivo (autoradiography, histology, serum analysis). Multimodal imaging revealed that the number of covalent net points correlates well with degradation time, which allows for targeted modification of hydrogels based on properties of the tissue to be replaced. Importantly, the degradation time was also dependent on the number of implants per animal. Despite local mechanisms of tissue remodeling no adverse tissue responses could be observed neither locally nor systemically. Finally, this preclinical investigation in immunocompetent mice clearly demonstrated a complete restoration of the original healthy tissue

‘Like Sheep’? Disobedience Among Soviet Tourists Travelling Abroad

Die Einführung des von der UdSSR ausgehenden Auslandstourismus im Zuge der Chruščevschen Tauwetterpolitik bescherte den sowjetischen Autoritäten eine Reihe schwieriger Fragen: Wie ließen sich Bürger finden, die die Sowjetunion im Ausland würdig vertreten würden, wie konnten die Touristen während der Reise unter Kontrolle gehalten werden, und wie konnten Auslandsreisen propagandistisch genutzt werden? Vor dem Hintergrund dieser Fragen betrieben die staatlichen sowjetischen Tourismusorganisationen einen beträchtlichen Aufwand, um Auslandsreisen zu einem kontrollierbaren Element der Kulturdiplomatie zu formen. Der vorliegende Artikel befasst sich in diesem Kontext mit Momenten, in denen die Kontrollmechanismen zeitweilig nicht mehr griffen, etwa wenn Touristen aus den erwarteten Verhaltensmustern ausbrachen oder Mängel in der Reiseorganisation den reibungslosen Ablauf der Auslandsfahrten störten. Derartige Vorfälle waren mehr als nur Unregelmäßigkeiten in einer ansonsten geölten Inszenierungsmaschinerie – sie verwiesen auf strukturelle Probleme des Auslandstourismus, eines wichtigen Elementes der Außendarstellung in Zeiten des Kalten Krieges

OPA1 and cardiolipin team up for mitochondrial fusion

Fusion between the inner membranes of two mitochondria requires the GTPase optic atrophy 1 (OPA1), but the molecular mechanism is poorly understood. A study now shows that fusion of two liposomes can be performed by OPA1 tethered to just one liposome, through an interaction with the phospholipid cardiolipin on the opposing liposome

What is the function of mitochondrial networks? A theoretical assessment of hypotheses and proposal for future research

Mitochondria can change their shape from discrete isolated organelles to a large continuous reticulum. The cellular advantages underlying these fused networks are still incompletely understood. In this paper, we describe and compare hypotheses regarding the function of mitochondrial networks. We use mathematical and physical tools both to investigate existing hypotheses and to generate new ones, and we suggest experimental and modelling strategies. Among the novel insights we underline from this work are the possibilities that (i) selective mitophagy is not required for quality control because selective fusion is sufficient; (ii) increased connectivity may have non-linear effects on the diffusion rate of proteins; and (iii) fused networks can act to dampen biochemical fluctuations. We hope to convey to the reader that quantitative approaches can drive advances in the understanding of the physiological advantage of these morphological changes

Oryginalność hieroklesowego porównania Apoloniusza z Tiany z Chrystusem

Sossianus Hierocles, governor of Bithynia and adviser of the emperor Diocletian, at the beginning of the “great persecution” of the Christians published his propagandistic writing under the title The Lover of Truth, in which he drew a comparison between Apollonius of Tyana and Christ. In the apologetic treatise of Eusebius of Caesarea Against Hierocles we find a statement, that this comparison was something new in the hitherto existing attacks of the pagan intellectuals on Christianity and demanded a polemic response from the Christian part. Modern studies regarding the works of Porphyry, famous enemy of the Christians and exponent of the Neo-Platonic philosophy, seem to indicate that even before Hierocles the personage of Apollonius was used in the anti-Christian polemics and was confronted with Christ. The present article try to explain, what the originality of Hierocles’ comparison, testified by Eusebius, consisted in

Polemika Euzebiusza z Cezarei z Sossianusem Hieroklesem na temat porównania Apoloniusza z Tiany i Chrystusa jako reprezentantów kultury pogańskiej i chrześcijańskiej

In the period of the growing importance of Christianity the pagan culture put forward Apollonius of Tyana as its eminent representative and a rival of Christ. At the beginning of the “great persecution” of the Christians Sossianus Hierocles, a high official in the administration of Diocletian, published his anti-Christian tract called The Lover of Truth, in which he drew a formal comparison between Apollonius and Christ. This way he tried to exalt Apollonius and the authors of the stories about him and the followers of the pagan culture. On the other hand he wanted to humiliate Christ and his apostles and all the Christians. Eusebius of Caesarea, the Christian historian, wrote a treatise in answer, in which he submitted the imagine of Apollonius, used by Hierocles in his anti- Christian propaganda, to a critical examination. His historical and philosophical critique reverses the objections of the adversary and shows some elements of pagan culture, represented by Apollonius, which should pass away

Die gespaltene Erinnerung Traudl Junges: eine Analyse der autobiographischen Erzählungen Traudl Junges und deren medialer Inszenierung

Der Beitrag interpretiert die autobiographischen Erzählungen von Hitlers ehemaliger Sekretärin. Traudl Junge (1920-2002) war keineswegs ein Opfer der Geschichte, aber der Preis für ihre gelungene Integration in die Nachkriegsgesellschaft der Bundesrepublik war die Tabuisierung eines Teils ihrer Erinnerungen, die spätestens seit den 1960er Jahren problematisch wurden. Junge konnte eine wohlgeformte Geschichte ihrer selbst erzählen, die aber in ihrer Gegenwartsgesellschaft nicht ohne weiteres kommunizierbar war. Sie konnte sich nachträglich über die historische Rolle Hitlers informieren, aber diese 'dämonisierte Figur' war nur schwer in eine eigene, kohärente biographische Erzählung integrieren. Sie bemühte sich, ihrem Weltwissen als 'Augenzeugin' entsprechende, gesellschaftlich akzeptierte Geschichten zu erzählen, produzierte jedoch vielfach banale Erzählungen (Hitler als Hundeliebhaber) mit problematischem Gehalt. Alle Ungereimtheiten resultierten letztendlich aus dem Bedürfnis, in der bundesrepublikanischen Gesellschaft akzeptiert zu werden, ohne ihre Vergangenheit zu verleugnen. (ICA2

Sprawozdanie z dyskusji panelowej "Wrocławska szkoła historii Kościoła. W 50. rocznicę śmierci ks. prof. Bertolda Altanera 1885-1964" : Katowice, 15 maja 2014 roku

"15 maja 2014 roku w gmachu Wydziału Teologicznego odbyło się kolejne spotkanie w cyklu prezentacji życia i dorobku naukowego wybitnych historyków i patrologów śląskich. Po konferencjach poświęconych ks. dr. Stefanowi Siwcowi i ks. prof. Maksymilianowi Sdralkowi obecna dyskusja panelowa dedykowana była ks. prof. Bertoldowi Altanerowi z okazji przypadającej w tym roku 50. rocznicy jego śmierci." [...] (fragm.