skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Assessment of DNA synthesis in Islet-1{sup +} cells in the adult murine heart

Abstract

Highlights: • Islet-1 was expressed in the adult heart. • Islet-1-positive cells did not proliferate in the adult heart. • Sinoatrial node cells did not proliferate in the adult heart. - Abstract: Rationale: Islet-1 positive (Islet-1{sup +}) cardiac progenitor cells give rise to the right ventricle, atria and outflow tract during murine cardiac development. In the adult heart Islet-1 expression is limited to parasympathetic neurons, few cardiomyocytes, smooth muscle cells, within the proximal aorta and pulmonary artery and sinoatrial node cells. Its role in these cells is unknown. Here we tested the hypothesis that Islet-1{sup +} cells retain proliferative activity and may therefore play a role in regenerating specialized regions in the heart. Methods and results: DNA synthesis was analyzed by the incorporation of tritiated thymidine ({sup 3}H-thymidine) in Isl-1-nLacZ mice, a transgenic model with an insertion of a nuclear beta-galactosidase in the Islet-1 locus. Mice received daily injections of {sup 3}H-thymidine for 5 days. DNA synthesis was visualized throughout the heart by dipping autoradiography of cryosections. Colocalization of an nLacZ-signal and silver grains would indicate DNA synthesis in Islet-1{sup +} cells. Whereas Islet{sup −} non-myocyte nuclei were regularly marked by accumulation of silver grains, colocalization with nLacZ-signals was notmore » detected in >25,000 cells analyzed. Conclusions: Islet-1{sup +} cells are quiescent in the adult heart, suggesting that, under normal conditions, even pacemaking cells do not proliferate at higher rates than normal cardiac myocytes.« less

Authors:
; ; ; ;
Publication Date:
OSTI Identifier:
22416882
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biochemical and Biophysical Research Communications; Journal Volume: 456; Journal Issue: 1; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; ADULTS; AORTA; ATRIA; AUTORADIOGRAPHY; CELL CYCLE; DNA; GALACTOSIDASE; HEART; MICE; MUSCLES; NERVE CELLS; REGENERATION; SILVER; SYNTHESIS; THYMIDINE; TRITIUM

Citation Formats

Weinberger, Florian, E-mail: f.weinberger@uke.de, Mehrkens, Dennis, E-mail: dennis.mehrkens@uk-koeln.de, Starbatty, Jutta, E-mail: starbatty@uke.uni-hamburg.de, Nicol, Philipp, E-mail: Philipp.Nicol@gmx.de, and Eschenhagen, Thomas, E-mail: t.eschenhagen@uke.de. Assessment of DNA synthesis in Islet-1{sup +} cells in the adult murine heart. United States: N. p., 2015. Web. doi:10.1016/J.BBRC.2014.11.074.
Weinberger, Florian, E-mail: f.weinberger@uke.de, Mehrkens, Dennis, E-mail: dennis.mehrkens@uk-koeln.de, Starbatty, Jutta, E-mail: starbatty@uke.uni-hamburg.de, Nicol, Philipp, E-mail: Philipp.Nicol@gmx.de, & Eschenhagen, Thomas, E-mail: t.eschenhagen@uke.de. Assessment of DNA synthesis in Islet-1{sup +} cells in the adult murine heart. United States. doi:10.1016/J.BBRC.2014.11.074.
Weinberger, Florian, E-mail: f.weinberger@uke.de, Mehrkens, Dennis, E-mail: dennis.mehrkens@uk-koeln.de, Starbatty, Jutta, E-mail: starbatty@uke.uni-hamburg.de, Nicol, Philipp, E-mail: Philipp.Nicol@gmx.de, and Eschenhagen, Thomas, E-mail: t.eschenhagen@uke.de. Fri . "Assessment of DNA synthesis in Islet-1{sup +} cells in the adult murine heart". United States. doi:10.1016/J.BBRC.2014.11.074.
@article{osti_22416882,
title = {Assessment of DNA synthesis in Islet-1{sup +} cells in the adult murine heart},
author = {Weinberger, Florian, E-mail: f.weinberger@uke.de and Mehrkens, Dennis, E-mail: dennis.mehrkens@uk-koeln.de and Starbatty, Jutta, E-mail: starbatty@uke.uni-hamburg.de and Nicol, Philipp, E-mail: Philipp.Nicol@gmx.de and Eschenhagen, Thomas, E-mail: t.eschenhagen@uke.de},
abstractNote = {Highlights: • Islet-1 was expressed in the adult heart. • Islet-1-positive cells did not proliferate in the adult heart. • Sinoatrial node cells did not proliferate in the adult heart. - Abstract: Rationale: Islet-1 positive (Islet-1{sup +}) cardiac progenitor cells give rise to the right ventricle, atria and outflow tract during murine cardiac development. In the adult heart Islet-1 expression is limited to parasympathetic neurons, few cardiomyocytes, smooth muscle cells, within the proximal aorta and pulmonary artery and sinoatrial node cells. Its role in these cells is unknown. Here we tested the hypothesis that Islet-1{sup +} cells retain proliferative activity and may therefore play a role in regenerating specialized regions in the heart. Methods and results: DNA synthesis was analyzed by the incorporation of tritiated thymidine ({sup 3}H-thymidine) in Isl-1-nLacZ mice, a transgenic model with an insertion of a nuclear beta-galactosidase in the Islet-1 locus. Mice received daily injections of {sup 3}H-thymidine for 5 days. DNA synthesis was visualized throughout the heart by dipping autoradiography of cryosections. Colocalization of an nLacZ-signal and silver grains would indicate DNA synthesis in Islet-1{sup +} cells. Whereas Islet{sup −} non-myocyte nuclei were regularly marked by accumulation of silver grains, colocalization with nLacZ-signals was not detected in >25,000 cells analyzed. Conclusions: Islet-1{sup +} cells are quiescent in the adult heart, suggesting that, under normal conditions, even pacemaking cells do not proliferate at higher rates than normal cardiac myocytes.},
doi = {10.1016/J.BBRC.2014.11.074},
journal = {Biochemical and Biophysical Research Communications},
number = 1,
volume = 456,
place = {United States},
year = {Fri Jan 02 00:00:00 EST 2015},
month = {Fri Jan 02 00:00:00 EST 2015}
}
  • Suspensions rich in pancreatic {beta} cells were transfected by means of electroporation or by using the liposome technique with DNA constructs coding for the {beta} chain of platelet-derived growth factor (PDGF) and the PDGF {alpha} and {beta} receptors to induce a mitotic response in this slowly replicating cell type. Transfection with the B-chain construct induced synthesis of the PDGF B-chain homodimer (PDGF-BB) as assessed by the presence of {sup 125}I-labeled PDGF-BB competing activity in the conditioned medium of the transfected islet cells. Moreover, islet cells transfected with the PDGF {beta}-receptor construct exhibited increased immunofluorescence staining with a PDGF {beta}-receptor antibody.more » These cells also displayed increased {sup 125}I-labeled PDGF-BB binding compared with control transfected cells. The {beta} cells exhibited elevated levels of ({sup 3}H)inositol trisphosphate after transfection with the B-chain and {beta}-receptor constructs, indicating activation of phospholipase C. Islet cells transfected with the different receptor constructs exhibited different patterns of tyrosine phosphorylation upon ligand activation. The results demonstrate that pancreatic islet cells can be stimulated to increase DNA synthesis by transfection with the PDGF {beta}-receptor gene, whereas cotransfection with the {alpha}-receptor gene may attenuate the growth response.« less
  • Isolated adult rat heart cells incubated with 5 microM Mn in a medium with 1 mM Ca showed a rapid phase of Mn binding plus a slow phase of Mn uptake. The rapid phase was extracellular binding, as judged by its temperature-insensitive removal by ethylene glycol bis(beta-aminoethyl ether) N, N'-tetraacetic acid. The slow linear phase represented cellular uptake, as judged by its release with digitonin plus the ionophore A23187. Isoproterenol increased the linear rate of Mn uptake and induced spontaneous beating activity in some cells. Both effects were inhibited by nitrendipine. Electrical stimulation of the cells in suspension increased themore » linear rate of cellular Mn uptake. The increase was potentiated by isoproterenol, and inhibited by nitrendipine or verapamil. Stimulation-dependent Mn uptake (per milligram protein) was greater for cells from 5- to 6-week-old rats than for 8- to 9-month-old female retired breeder rats, in the presence of isoproterenol. Ryanodine increased the stimulation-dependent Mn uptake in the presence of isoproterenol, but not in its absence. We conclude: (i) that cellular uptake of /sup 54/Mn is a good probe of Ca channel function; (ii) that isoproterenol promotes Mn influx by the channel in isolated heart cells; (iii) that cells from young rats (5-6 weeks) have a higher beta-adrenergically induced Ca channel activity than cells from mature rats (8-9 months); and (iv) that ryanodine promotes Ca channel activity (perhaps indirectly) in the presence of isoproterenol.« less
  • Whole-cell DNA preparations isolated from SC-1 cells chronically infected with N- or B-tropic murine leukemia viruses (MuLV) were tested for infectious activity in an Fv-1/sup n/ (NIH-3T3) and two Fv-1/sup b/ (C57BL/6 and SV-A31) cell cultures. Efficiency of transfection for all DNAs was better in the NIH-3T3 cells than in C57BL/6 or SV-A31 cells; and an (N-tropic MuLV)SC-1 cell DNA preparation was slightly more infectious than a (B-tropic MuLV)SC-1 cell DNA preparation in all three cell cultures, regardless of their Fv-1 geonotypes. Progeny viruses from the transfection showed N- or B-tropism corresponding to that of the parent viruses produced bymore » the infected SC-I cells that were used for the DNA preparation. DNA dose-response studies in NIH-3T3 cells revealed a one-hit mechanism for both the (B-tropic MuLV)SC-1 cell DNA and the (N-tropic MuLV)SC-1 cell DNA preparation. These results demonstrate that, in contrast to virion infection, transfection of N- and B-tropic MuLV with DNA preparations from chronically infected cells is not affected by the Fv-1 gene.« less
  • Diabetes mellitus results from an absolute or relative deficiency of insulin producing pancreatic beta-cells. The adult human beta-cell's turnover rate remains unknown. We employed novel techniques to examine adult human islet beta-cell turnover and longevity in vivo. Subjects enrolled in NIH clinical trials received thymidine analogues [iododeoxyuridine (IdU) or bromodeoxyuridine (BrdU)] 8-days to 4-years prior to death. Archival autopsy samples from ten patients (aged 17-74 years) were employed to assess beta-cell turnover by scoring nuclear analog labeling within insulin staining cells. Human adult beta-cell longevity was determined by estimating the cells genomic DNA integration of atmospheric carbon-14 ({sup 14}C). DNAmore » was purified from pancreatic islets isolated from cadaveric donors; whole islet prep DNA was obtained from a 15 year old donor, and purified beta-cell DNA was obtained from two donors (age 48 and 80 years). {sup 14}C levels were then determined using accelerator mass spectrometry (AMS). Cellular 'birth date' was determined by comparing the subject's DNA {sup 14}C content relative to a well-established {sup 14}C atmospheric prevalence curve. In the two subjects less than age 20 years, 1-2% of the beta-cell nuclei co-stained for BrdU/IdU. No beta-cell nuclei co-stained in the eight patients more than 30 years old. Consistent with the BrdU/IdU turnover data, beta-cell DNA {sup 14}C content indicated the cells 'birth date' occurred within the subject's first 30 years of life. Under typical circumstances, adult human beta-cells and their cellular precursors are established by young adulthood.« less
  • Studies were designed to determine whether AET and cysteamine would alter DNA synthesis in mammalian hemic cells. in vivo studies were performed on young male Swiss mice injected with tritiated thymidine, and in vitro studies were made with bone marrow from either hybrid or Swiss mice. In the in vitro studies a one-hour exposure to tritiated thymidine was allowed. It was shown that AET administered to mice, at times and concentrations compatible with its use as a radioprotective agent both in vitro and in vivo leads to a marked inhibition of DNA synthesis. Cysteamine also inhibited bone-marrow DNA synthesis inmore » vitro. (H.M.G.)« less