Burning fat to keep your stem cells? The role of fatty acid oxidation in various tissue stem cells

Diet suppresses glioblastoma initiation in mice by maintaining quiescence of mutation-bearing neural stem cells

Glioblastoma is thought to originate from neural stem cells (NSCs) of the subventricular zone that acquire genetic alterations. In the adult brain, NSCs are largely quiescent, suggesting that deregulation of quiescence maintenance may be a prerequisite for tumor initiation. Although inactivation of the tumor suppressor p53 is a frequent event in gliomagenesis, whether or how it affects quiescent NSCs (qNSCs) remains unclear. Here, we show that p53 maintains quiescence by inducing fatty-acid oxidation (FAO) and that acute p53 deletion in qNSCs results in their premature activation to a proliferative state. Mechanistically, this occurs through direct transcriptional induction of PPARGC1a, which in turn activates PPARα to upregulate FAO genes. Dietary supplementation with fish oil containing omega-3 fatty acids, natural PPARα ligands, fully restores quiescence of p53-deficient NSCs and delays tumor initiation in a glioblastoma mouse model. Thus, diet can silence glioblastoma driver mutations, with important implications for cancer prevention.

Fatty Acid Transport and Signaling: Mechanisms and Physiological Implications

Long-chain fatty acids (FAs) are components of plasma membranes and an efficient fuel source and also serve as metabolic regulators through FA signaling mediated by membrane FA receptors. Impaired tissue FA uptake has been linked to major complications of obesity, including insulin resistance, cardiovascular disease, and type 2 diabetes. Fatty acid interactions with a membrane receptor and the initiation of signaling can modify pathways related to nutrient uptake and processing, cell proliferation or differentiation, and secretion of bioactive factors. Here, we review the major membrane receptors involved in FA uptake and FA signaling. We focus on two types of membrane receptors for long-chain FAs: CD36 and the G protein-coupled FA receptors FFAR1 and FFAR4. We describe key signaling pathways and metabolic outcomes for CD36, FFAR1, and FFAR4 and highlight the parallels that provide insight into FA regulation of cell function.

Role of Bioactive Compounds in the Regulation of Mitochondrial Dysfunctions in Brain and Age-Related Neurodegenerative Diseases

Mitochondria are multifunctional organelles that participate in a wide range of metabolic processes, including energy production and biomolecule synthesis. The morphology and distribution of intracellular mitochondria change dynamically, reflecting a cell’s metabolic activity. Oxidative stress is defined as a mismatch between the body’s ability to neutralise and eliminate reactive oxygen and nitrogen species (ROS and RNS). A determination of mitochondria failure in increasing oxidative stress, as well as its implications in neurodegenerative illnesses and apoptosis, is a significant developmental process of focus in this review. The neuroprotective effects of bioactive compounds linked to neuronal regulation, as well as related neuronal development abnormalities, will be investigated. In conclusion, the study of secondary components and the use of mitochondrial features in the analysis of various neurodevelopmental diseases has enabled the development of a new class of mitochondrial-targeted pharmaceuticals capable of alleviating neurodegenerative disease states and enabling longevity and healthy ageing for the vast majority of people.

MicroRNAs expressed in neuronal differentiation and their associated pathways: Systematic review and bioinformatics analysis

MicroRNAs (miRNAs) plays an important role in the human brain from the embryonic period to adulthood. In this sense, they influence the development of neural stem cells (NSCs), regulating cellular differentiation and survival. Therefore, due to the importance of better comprehending the regulation of miRNAs in NSCs differentiation and the lack of studies that show the panorama of miRNAs and their signaling pathways studied until now we aimed to systematically review the literature to identify which miRNAs are currently being associated with neuronal differentiation and using bioinformatics analysis to identify their related pathways. A search was carried out in the following databases: Scientific Electronic Library Online (Scielo), National Library of Medicine National Institutes of Health (PubMed), Scopus, Web of Science and Science Direct, using the descriptors "(microRNA [MeSH])" and "(neurogenesis [MeSH])". From the articles found, two independent and previously calibrated reviewers, using the EndNote X7 (Thomson Reuters, New York, NY, US), selected those that concern miRNA in the development of NSCs, based on in vitro studies. After, bioinformatic analysis was performed using the software DIANA Tools, mirPath v.3. Subsequently, data was tabulated, analyzed and interpreted. Among the 106 miRNAs cited by included studies, 55 were up-regulated and 47 were down-regulated. The bioinformatics analysis revealed that among the up-regulated miRNAs there were 24 total and 6 union pathways, and 3 presented a statistically significant difference (p ≤ 0.05). Among the down-regulated miRNAs, 46 total and 13 union pathways were found, with 7 presenting a significant difference (p ≤ 0.05). The miR-125a-5p, miR-423-5p, miR-320 were the most frequently found miRNAs in the pathways determined by bioinformatics. In this study a panel of altered miRNAs in neuronal differentiation was created with their related pathways, which could be a step towards understanding the complex network of miRNAs in neuronal differentiation.