title: Crosstalk between circadian rhythmicity, mitochondrial dynamics and macrophage bactericidal activity.
abstract: Biological functions show rhythmic fluctuations with 24-hr periodicity regulated by circadian proteins encoded by the so-called 'clock' genes. The absence or deregulation of circadian proteins in mice leads to metabolic disorders and in vitro models have shown that the synthesis of pro-inflammatory cytokines by macrophages follows a circadian rhythm so showing a link between circadian rhythmicity, metabolism and immunity. Recent evidence reveals that mitochondrial shape, position and size, collectively referred to as mitochondrial dynamics, are related to both cell metabolism and immune function. However, studies addressing the simultaneous crosstalk between circadian rhythm, mitochondrial dynamics and cell immune function are scarce. Here, by using an in vitro model of synchronized murine peritoneal macrophages, we present evidence that the mitochondrial dynamics and the mitochondrial membrane potential (∆ψm ) follow a circadian rhythmic pattern. In addition, it is shown that the fusion of mitochondria along with high ∆ψm , indicative of high mitochondrial activity, precede the highest phagocytic and bactericidal activity of macrophages on Salmonella typhimurium. Taken together, our results suggest a timely coordination between circadian rhythmicity, mitochondrial dynamics, and the bactericidal capacity of macrophages.
authors.affiliation: Laboratorio de Inmunorregulación, Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, México D.F, México.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Oliva-Ramírez
authors.forename: María Maximina B
authors.initials: MM
authors.lastname: Moreno-Altamirano
authors.forename: Benjamín
authors.initials: B
authors.lastname: Pineda-Olvera
authors.forename: Patricia
authors.initials: P
authors.lastname: Cauich-Sánchez
authors.forename: F Javier
authors.initials: FJ
authors.lastname: Sánchez-García
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002940:Circadian Rhythm / Q000502:physiology*; D004705:Endocytosis / Q000276:immunology; D008264:Macrophages / Q000276:immunology* / Q000382:microbiology*; D017737:Macrophages, Peritoneal / Q000276:immunology / Q000382:microbiology; D053078:Membrane Potential, Mitochondrial; D051379:Mice; D063154:Mitochondrial Dynamics / Q000502:physiology*; D010587:Phagocytosis / Q000276:immunology; D012486:Salmonella typhimurium / Q000276:immunology
keywords: bactericidal activity; circadian rhythmicity; macrophages; mitochondrial dynamics