Suppression of Autophagy Dysregulates the Antioxidant Response and Causes Premature Senescence of Melanocytes

YesAutophagy is the central cellular mechanism for delivering organelles and cytoplasm to lysosomes for degradation and recycling of their molecular components. To determine the contribution of autophagy to melanocyte (MC) biology, we inactivated the essential autophagy gene Atg7 specifically in MCs using the Cre-loxP system. This gene deletion efficiently suppressed a key step in autophagy, lipidation of microtubule-associated protein 1 light chain 3 beta (LC3), in MCs and induced slight hypopigmentation of the epidermis in mice. The melanin content of hair was decreased by 10–15% in mice with autophagy-deficient MC as compared with control animals. When cultured in vitro, MCs from mutant and control mice produced equal amounts of melanin per cell. However, Atg7-deficient MCs entered into premature growth arrest and accumulated reactive oxygen species (ROS) damage, ubiquitinated proteins, and the multi-functional adapter protein SQSTM1/p62. Moreover, nuclear factor erythroid 2–related factor 2 (Nrf2)–dependent expression of NAD(P)H dehydrogenase, quinone 1, and glutathione S-transferase Mu 1 was increased, indicating a contribution of autophagy to redox homeostasis in MCs. In summary, the results of our study suggest that Atg7-dependent autophagy is dispensable for melanogenesis but necessary for achieving the full proliferative capacity of MCs

C5b9 Deposition in Glomerular Capillaries Is Associated With Poor Kidney Allograft Survival in Antibody-Mediated Rejection

C4d deposition in peritubular capillaries (PTC) reflects complement activation in antibody-mediated rejection (ABMR) of kidney allograft. However, its association with allograft survival is controversial. We hypothesized that capillary deposition of C5b9—indicative of complement-mediated injury—is a severity marker of ABMR. This pilot study aimed to determine the frequency, location and prognostic impact of these deposits in ABMR. We retrospectively selected patients diagnosed with ABMR in two French transplantation centers from January 2005 to December 2014 and performed C4d and C5b9 staining by immunohistochemistry. Fifty-four patients were included. Median follow-up was 52.5 (34.25–73.5) months. Thirteen patients (24%) had C5b9 deposits along glomerular capillaries (GC). Among these, seven (54%) had a global and diffuse staining pattern. Twelve of the C5b9+ patients also had deposition of C4d in GC and PTC. C4d deposits along GC and PTC were not associated with death-censored allograft survival (p = 0.42 and 0.69, respectively). However, death-censored allograft survival was significantly lower in patients with global and diffuse deposition of C5b9 in GC than those with a segmental pattern or no deposition (median survival after ABMR diagnosis, 6 months, 40.5 months and 44 months, respectively; p = 0.015). Double contour of glomerular basement membrane was diagnosed earlier after transplantation in C5b9+ ABMR than in C5b9– ABMR (median time after transplantation, 28 vs. 85 months; p = 0.058). In conclusion, we identified a new pattern of C5b9+ ABMR, associated with early onset of glomerular basement membrane duplication and poor allograft survival. Complement inhibitors might be a therapeutic option for this subgroup of patients

Expliquer ce qui nous arrive par l’effort ou le manque d’effort est socialement valorisé à l’école : implication pour l’étude de la norme d’internalité en contexte scolaire

International audienc

La valeur sociale des explications causales : norme d'internalité ou conformité à nos présupposés causaux ?

International audienc

Validation expérimentale d'une mesure implicite du préjugé (le test d'associations implicites)

GRENOBLE2/3-BU Droit/Lettres (384212101) / SudocSudocFranceF

“Is that discrimination? I’d better report it!” Self-presentation concerns moderate the prototype effect

International audienc

Interpersonal accuracy in a political context is moderated by the extremity of one's political attitudes

International audienc

Sexism and racism perceptions: It depends on who does it and why

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Mobilisation et réussite des étudiants tutorés en Licence de psychologie

The aim of this exploratory study is to analyse how mentoring affects academic success and dropout rates amongst first year students in psychology. 29.8 % of volunteer students attended at least one monthly group tutoring session out of six. Even though the findings should be interpreted with great care, the study shows that the students who attended these tutoring sessions were more likely to succeed (43 %) and less likely to drop out (40 %) than those who did not participate in the mentorship program (25 % and 59 % respectively). When questioned, learners pinpointed various motivational and academic success factors that are inherent to these tutoring sessions, such as cohesion and support amongst peers, advice offered by the tutors, extreme motivation and encouragement amongst the learners and tutors, revision study groups, and sharing lecture notes. However, it is regrettable that the number of attendees varied session after session