Dietary vitamin A supplementation prevents early obesogenic diet-induced microbiota, neuronal and cognitive alterations
INTERNATIONAL JOURNAL OF OBESITY
Authors: Biyong, Essi F.; Alfos, Serge; Dumetz, Fabien; Helbling, Jean-Christophe; Aubert, Agnes; Brossaud, Julie; Foury, Aline; Moisan, Marie-Pierre; Lay, Sophie; Richard, Emmanuel; Patterson, Elaine; Murphy, Kiera; Rea, Kieran; Stanton, Catherine; Schellekens, Harriet; Cryan, John F.; Capuron, Lucile; Pallet, Veronique; Ferreira, Guillaume
Abstract
Background Early consumption of obesogenic diets, rich in saturated fat and added sugar, is associated with a plethora of biological dysfunctions, at both peripheral and brain levels. Obesity is also linked to decreased vitamin A bioavailability, an essential molecule for brain plasticity and memory function. Methods Here we investigated in mice whether dietary vitamin A supplementation (VAS) could prevent some of the metabolic, microbiota, neuronal and cognitive alterations induced by obesogenic, high-fat and high-sugar diet (HFSD) exposure from weaning to adulthood, i.e. covering periadolescent period. Results As expected, VAS was effective in enhancing peripheral vitamin A levels as well as hippocampal retinoic acid levels, the active metabolite of vitamin A, regardless of the diet. VAS attenuated HFSD-induced excessive weight gain, without affecting metabolic changes, and prevented alterations of gut microbiota alpha-diversity. In HFSD-fed mice, VAS prevented recognition memory deficits but had no effect on aversive memory enhancement. Interestingly, VAS alleviated both HFSD-induced higher neuronal activation and lower glucocorticoid receptor phosphorylation in the hippocampus after training. Conclusion Dietary VAS was protective against the deleterious effects of early obesogenic diet consumption on hippocampal function, possibly through modulation of the gut-brain axis.
All-transretinoic acid in non-promyelocytic acute myeloid leukemia: driver lesion dependent effects on leukemic stem cells
CELL CYCLE
Authors: Nguyen, Chi H.; Grandits, Alexander M.; Purton, Louise E.; Sill, Heinz; Wieser, Rotraud
Abstract
Acute myeloid leukemia (AML) is an aggressive, often fatal hematopoietic malignancy.All-transretinoic acid (atRA), one of the first molecularly targeted drugs in oncology, has greatly improved the outcome of a subtype of AML, acute promyelocytic leukemia (APL). In contrast, atRA has so far provided little therapeutic benefit in the much larger group of patients with non-APL AML. Attempts to identify genetically or molecularly defined subgroups of patients that may respond to atRA have not yielded consistent results. Since AML is a stem cell-driven disease, understanding the effectiveness of atRA may require an appreciation of its impact on AML stem cells. Recent studies reported that atRA decreased stemness of AML with anFLT3-ITD mutation, yet increased it inAML1-ETOdriven orEVI1-overexpressing AML. This review summarizes the role of atRA in normal hematopoiesis and in AML, focusing on its impact on AML stem cells.