Lipids and membrane-associated proteins in autophagy

Autophagy is essential for the maintenance of cellular homeostasis and its dysfunction has been linked to various diseases. Autophagy is a membrane driven process and tightly regulated by membrane-associated proteins. Here, we summarized membrane lipid composition, and membrane-associated proteins relevant to autophagy from a spatiotemporal perspective. In particular, we focused on three important membrane remodeling processes in autophagy, lipid transfer for phagophore elongation, membrane scission for phagophore closure, and autophagosome-lysosome membrane fusion. We discussed the significance of the discoveries in this field and possible avenues to follow for future studies. Finally, we summarized the membrane-associated biochemical techniques and assays used to study membrane properties, with a discussion of their applications in autophagy.

Autoerotismo, narcisismo e a função integradora da ilusão / Auto eroticism, narcissism, and the integrative function of illusion / Autoerotismo, narcisismo y la función integradora de la ilusión / Autoérotisme, narcissisme et la fonction intégratrice de l'illusion

O presente estudo sustenta o papel fundamental da ilusão no processo de integração do Eu (nova ação psíquica). Para tanto, questiona a possibilidade de a própria divisão (cisão) do Eu ser a manifestação de uma estrutura primária, não patológica, presente no desenvolvimento normal desde o autoerotismo, que busca a integração, em diferentes níveis, por meio da ilusão. Além disso, analisa a presença do fenômeno da ilusão em conceitos fundamentais da psicanálise, concluindo com uma leitura de Freud em que ele nos adverte não propriamente em relação aos perigos da ilusão, mas sim ao perigo de submissão a uma ilusão externa em vez de construir o próprio sistema ilusório (simbólico).

This paper supports the fundamental role of illusion in the process of ego integration (new psychic action). To that end, the author wonders about the possibility of the splitting of the Ego itself being a manifestation of a primary structure, which is not pathological, and which exists in normal development since the auto eroticism. This primary structure seeks integration, at different levels, through illusion. Furthermore, this author analyzes the presence of the phenomenon of illusion in fundamental psychoanalytic concepts. The conclusion of this paper brings a reading of Freud in which he advises us not exactly about the dangers of illusion, but about the danger of submission to an external illusion instead of building one's own illusory system (symbolic system).

El presente trabajo sostiene el papel fundamental de la ilusión en el proceso de la integración del Yo (nueva acción psíquica). Para esto, cuestiona la posibilidad de que la propia división (escisión) del Yo sea la manifestación de una estructura primaria, no patológica, presente en el desarrollo normal desde el autoerotismo, que busca la integración en distintos niveles a través de la ilusión. Además, analiza la presencia del fenómeno de la ilusión en conceptos fundamentales del psicoanálisis, concluyendo con una lectura de Freud en la que él nos advierte no exactamente en relación a los peligros de la ilusión, pero sí sobre el riesgo de sumisión a una ilusión externa en lugar de construir el propio sistema ilusorio (simbólico).

Cette étude soutient le rôle fondamental de l'illusion dans le processus d'intégration du Moi (nouvelle action psychique). Pour ce faire, il questionne la possibilité de la division (la scission) du Moi être la manifestation d'une structure primaire, non pathologique, présente au développement normal dès l'autoérotisme, laquelle cherche l'intégration dans des niveaux différents, au moyen de l'illusion. En plus, il analyse la présence du phénomène de l'illusion dans des concepts fondamentaux de la psychanalyse, en concluant par une lecture de Freud où celui-ci nous avertit, pas exactement sur les dangers de l'illusion mais, en effet, sur le danger de se soumettre à une illusion externe, au lieu de construire le propre système illusoire (symbolique).

Simultaneous quantification of ten constituents of Xanthoceras sorbifolia Bunge using UHPLC-MS methods and evaluation of their radical scavenging, DNA scission protective, and α-glucosidase inhibitory activities / 中国天然药物

The present study was designed to investigate the bioactive constituents of Xanthoceras sorbifolia in terms of amounts and their antioxidant, DNA scission protection, and α-glucosidase inhibitory activities. Simultaneous quantification of 10 X. sorbifolia constituents was carried out by a newly established ultra-high performance liquid chromatography-quadrupole mass spectrometry method (UHPLC-MS). The antioxidant activities were evaluated by measuring DPPH radical scavenging and DNA scission protective activities. The α-glucosidase inhibitory activities were investigated by using an assay with α-glucosidase from Bacillus Stearothermophilus and disaccharidases from mouse intestine. We found that the wood of X. sorbifolia was rich in phenolic compounds with the contents of catechin, epicatechin, myricetin, and dihydromyricetin being 0.12-0.19, 1.94-2.16, 0.77-0.91, and 6.76-7.89 mg·g(-1), respectively. The four constituents strongly scavenged DPPH radicals (with EC50 being 4.2, 3.8 and 5.7 μg·mL(-1), respectively) and remarkably protected peroxyl radical-induced DNA strand scission (92.10%, 94.66%, 75.44% and 89.95% of protection, respectively, at a concentration of 10 μmol·L(-1)). A dimeric flavan 3-ol, epigallocatechin-(4β→8, 2β→O-7)-epicatechin potently inhibited α-glucosidase with an IC50 value being as low as 1.2 μg·mL(-1). The established UHPLC-MS method could serve as a quality control tool for X. sorbifolia. In conclusion, the high contents of antioxidant and α-glucosidase inhibitory constituents in X. sorbifolia support its use as complementation of other therapeutic agents for metabolic disorders, such as diabetes and hypertension.

Inactivation of Tor proteins affects the dynamics of endocytic proteins in early stage of endocytosis.

Tor2 is an activator of the Rom2/Rho1 pathway that regulates α-factor internalization. Since the recruitment of endocytic proteins such as actin-binding proteins and the amphiphysins precedes the internalization of α-factor, we hypothesized that loss of Tor function leads to an alteration in the dynamics of the endocytic proteins. We report here that endocytic proteins, Abp1 and Rvs167, are less recruited to endocytic sites not only in tor2 but also tor1 mutants. Furthermore, we found that the endocytic proteins Rvs167 and Sjl2 are completely mistargeted to the cytoplasm in tor1Δtor2ts double mutant cells. We also demonstrate here that the efficiency of endocytic internalization or scission in all tor mutants was drastically decreased. In agreement with the Sjl2 mislocalization, we found that in tor1Δtor2ts double mutant cells, as well as other tor mutant cells, the overall PIP2 level was dramatically increased. Finally, the cell wall chitin content in tor2ts and tor1Δtor2ts mutant cells was also significantly increased. Taken together, both functional Tor proteins, Tor1 and Tor2, are essentially required for proper endocytic protein dynamics at the early stage of endocytosis.

Cysteine rich cyanopeptide β2 from Spirulina fussiformis exhibits plasmid DNA pBR322 scission prevention and cellular antioxidant activity.

Isolation of three different active peptides from C-phycocyanin (C-pc) β chain of S. fussiformis and their biological properties are reported. Phycocyanin peptide β fraction 2 (cyanopeptide β 2) facilitated both antioxidant and plasmid DNA strand scission prevention activity due to higher cysteine moieties in the isolated peptide. The peptide significantly scavenged the free radicals like 1-1,-diphenyl-2-picryl hydrazyl and ferric reducing ability of plasma, increased the absorbance values in reducing power and also showed the higher trolox equivalent antioxidant capacity values in total reactive antioxidant potentials assay. Cyanopeptide β 2 also inhibited reactive oxygen species induced DNA pBR322 damage in dose dependent manner along with free radical scavenging properties suggesting the role in the DNA integrity which is also evident by DNA binding activity of peptide. In addition, the generation of reactive oxygen species (ROS) was dose dependent (10 and 20 ng/ml) and significantly quenched by cyanopeptide β2 in human fibroblast cell line TIG 3-20. In vitro cell scratch injury assay demonstrated the capacity of cyanopeptide β2 in cell migration in to wounded area suggesting fibroblast proliferation and migration. The results suggest that cyanopeptide β2 can be a free radical scavenger and effective peptide for future biomedical applications like wound healing, atherosclerosis, cell redox potential and hypoxia.