title: Bioorthogonal chemical imaging of metabolic activities in live mammalian hippocampal tissues with stimulated Raman scattering.
abstract: Brain is an immensely complex system displaying dynamic and heterogeneous metabolic activities. Visualizing cellular metabolism of nucleic acids, proteins, and lipids in brain with chemical specificity has been a long-standing challenge. Recent development in metabolic labeling of small biomolecules allows the study of these metabolisms at the global level. However, these techniques generally require nonphysiological sample preparation for either destructive mass spectrometry imaging or secondary labeling with relatively bulky fluorescent labels. In this study, we have demonstrated bioorthogonal chemical imaging of DNA, RNA, protein and lipid metabolism in live rat brain hippocampal tissues by coupling stimulated Raman scattering microscopy with integrated deuterium and alkyne labeling. Heterogeneous metabolic incorporations for different molecular species and neurogenesis with newly-incorporated DNA were observed in the dentate gyrus of hippocampus at the single cell level. We further applied this platform to study metabolic responses to traumatic brain injury in hippocampal slice cultures, and observed marked upregulation of protein and lipid metabolism particularly in the hilus region of the hippocampus within days of mechanical injury. Thus, our method paves the way for the study of complex metabolic profiles in live brain tissue under both physiological and pathological conditions with single-cell resolution and minimal perturbation.
authors.affiliation: Department of Chemistry, Columbia University, New York, New York, USA.
authors.forename: Fanghao
authors.initials: F
authors.lastname: Hu
authors.affiliation: Department of Biomedical Engineering, Columbia University, New York, New York, USA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Lamprecht
authors.affiliation: Department of Chemistry, Columbia University, New York, New York, USA.
authors.forename: Lu
authors.initials: L
authors.lastname: Wei
authors.affiliation: Department of Biomedical Engineering, Columbia University, New York, New York, USA.
authors.forename: Barclay
authors.initials: B
authors.lastname: Morrison
authors.affiliation: Department of Chemistry, Columbia University, New York, New York, USA.|Kavli Institute for Brain Science, Columbia University, New York, New York, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Min
mesh_terms: D065767:Activation, Metabolic; D000480:Alkynes / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000503:physiopathology; D000070642:Brain Injuries, Traumatic / Q000503:physiopathology; D002794:Choline / Q000378:metabolism; D003903:Deuterium / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D006624:Hippocampus / Q000000981:diagnostic imaging* / Q000378:metabolism; D050356:Lipid Metabolism; D013058:Mass Spectrometry; D008853:Microscopy; D009696:Nucleic Acids / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D051381:Rats; D013059:Spectrum Analysis, Raman
chemical_list: D000480:Alkynes; D005227:Fatty Acids; D009696:Nucleic Acids; D010743:Phospholipids; D003903:Deuterium; D002794:Choline