RESUMO
Lipid droplets (LDs) are dynamic lipid storage organelles. They are tightly linked to metabolism and can exert protective functions, making them important players in health and disease. Most LD studies in vivo rely on staining methods, providing only a snapshot. We therefore developed a LD-reporter mouse by labelling the endogenous LD coat protein perilipin 2 (PLIN2) with tdTomato, enabling staining-free fluorescent LD visualisation in living and fixed tissues and cells. Here we validate this model under standard and high-fat diet conditions and demonstrate that LDs are highly abundant in various cell types in the healthy brain, including neurons, astrocytes, ependymal cells, neural stem/progenitor cells and microglia. Furthermore, we also show that LDs are abundant during brain development and can be visualized using live imaging of embryonic slices. Taken together, our tdTom-Plin2 mouse serves as a novel tool to study LDs and their dynamics under both physiological and diseased conditions in all tissues expressing Plin2.
Assuntos
Encéfalo , Gotículas Lipídicas , Perilipina-2 , Animais , Perilipina-2/metabolismo , Perilipina-2/genética , Gotículas Lipídicas/metabolismo , Encéfalo/metabolismo , Camundongos , Neurônios/metabolismo , Técnicas de Introdução de Genes , Camundongos Transgênicos , Feminino , Proteínas Luminescentes/metabolismo , Proteínas Luminescentes/genética , Masculino , Astrócitos/metabolismo , Dieta Hiperlipídica , Camundongos Endogâmicos C57BL , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/citologia , Microglia/metabolismoRESUMO
The induction of cellular reprogramming via expression of the transcription factors Oct4, Sox2, Klf4 and c-Myc (OSKM) can drive dedifferentiation of somatic cells and ameliorate age-associated phenotypes in multiple tissues and organs. However, the benefits of long-term in vivo reprogramming are limited by detrimental side-effects. Here, using complementary genetic approaches, we demonstrated that continuous induction of the reprogramming factors in vivo leads to hepatic and intestinal dysfunction resulting in decreased body weight and contributing to premature death (within 1 week). By generating a transgenic reprogrammable mouse strain, avoiding OSKM expression in both liver and intestine, we reduced the early lethality and adverse effects associated with in vivo reprogramming and induced a decrease in organismal biological age. This reprogramming mouse strain, which allows longer-term continuous induction of OSKM with attenuated toxicity, can help better understand rejuvenation, regeneration and toxicity during in vivo reprogramming.
