title: Multi-isotope imaging mass spectrometry quantifies stem cell division and metabolism.
abstract: Mass spectrometry with stable isotope labels has been seminal in discovering the dynamic state of living matter, but is limited to bulk tissues or cells. We developed multi-isotope imaging mass spectrometry (MIMS) that allowed us to view and measure stable isotope incorporation with submicrometre resolution. Here we apply MIMS to diverse organisms, including Drosophila, mice and humans. We test the 'immortal strand hypothesis', which predicts that during asymmetric stem cell division chromosomes containing older template DNA are segregated to the daughter destined to remain a stem cell, thus insuring lifetime genetic stability. After labelling mice with (15)N-thymidine from gestation until post-natal week 8, we find no (15)N label retention by dividing small intestinal crypt cells after a four-week chase. In adult mice administered (15)N-thymidine pulse-chase, we find that proliferating crypt cells dilute the (15)N label, consistent with random strand segregation. We demonstrate the broad utility of MIMS with proof-of-principle studies of lipid turnover in Drosophila and translation to the human haematopoietic system. These studies show that MIMS provides high-resolution quantification of stable isotope labels that cannot be obtained using other techniques and that is broadly applicable to biological and medical research.
authors.affiliation: Department of Medicine, Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Steinhauser
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Bailey
authors.forename: Samuel E
authors.initials: SE
authors.lastname: Senyo
authors.forename: Christelle
authors.initials: C
authors.lastname: Guillermier
authors.forename: Todd S
authors.initials: TS
authors.lastname: Perlstein
authors.forename: Alex P
authors.initials: AP
authors.lastname: Gould
authors.forename: Richard T
authors.initials: RT
authors.lastname: Lee
authors.forename: Claude P
authors.initials: CP
authors.lastname: Lechene
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002455:Cell Division; D004247:DNA / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology; D020895:Enterocytes / Q000166:cytology; D005347:Fibroblasts / Q000166:cytology; D006801:Humans; D007421:Intestine, Small / Q000166:cytology; D007553:Isotope Labeling; D007554:Isotopes; D007962:Leukocytes / Q000166:cytology; D050356:Lipid Metabolism; D038041:Lymphopoiesis; D013058:Mass Spectrometry / Q000379:methods*; D051379:Mice; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism* / Q000473:pathology; D013698:Templates, Genetic; D013936:Thymidine / Q000378:metabolism
chemical_list: D007554:Isotopes; D004247:DNA; D013936:Thymidine