title: Metabolic imaging in multiple time scales.
abstract: We report here a novel combination of time-resolved imaging methods for probing mitochondrial metabolism in multiple time scales at the level of single cells. By exploiting a mitochondrial membrane potential reporter fluorescence we demonstrate the single cell metabolic dynamics in time scales ranging from microseconds to seconds to minutes in response to glucose metabolism and mitochondrial perturbations in real time. Our results show that in comparison with normal human mammary epithelial cells, the breast cancer cells display significant alterations in metabolic responses at all measured time scales by single cell kinetics, fluorescence recovery after photobleaching and by scaling analysis of time-series data obtained from mitochondrial fluorescence fluctuations. Furthermore scaling analysis of time-series data in living cells with distinct mitochondrial dysfunction also revealed significant metabolic differences thereby suggesting the broader applicability (e.g. in mitochondrial myopathies and other metabolic disorders) of the proposed strategies beyond the scope of cancer metabolism. We discuss the scope of these findings in the context of developing portable, real-time metabolic measurement systems that can find applications in preclinical and clinical diagnostics.
authors.affiliation: Metabolic Photonics Laboratory, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Suite D6067, Los Angeles, CA 90048, USA; Department of Surgery, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA; Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA; Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA. Electronic address: Ramanujanv@csmc.edu.
authors.forename: V Krishnan
authors.initials: VK
authors.lastname: Ramanujan
mesh_terms: D057809:HEK293 Cells; D006801:Humans; D007700:Kinetics; D061986:MCF-7 Cells; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000378:metabolism*; D017711:Nonlinear Dynamics; D059010:Single-Cell Analysis / Q000379:methods*; D059008:Time-Lapse Imaging
keywords: Breast cancer; Metabolic imaging; Microscopy; Mitochondria; NDUFS3; Scaling behavior