TY - JOUR
T1 - Nucleostemin rejuvenates cardiac progenitor cells and antagonizes myocardial aging
AU - Hariharan, Nirmala
AU - Quijada, Pearl
AU - Mohsin, Sadia
AU - Joyo, Anya
AU - Samse, Kaitlen
AU - Monsanto, Megan
AU - De La Torre, Andrea
AU - Avitabile, Daniele
AU - Ormachea, Lucia
AU - McGregor, Michael J.
AU - Tsai, Emily J.
AU - Sussman, Mark A.
PY - 2015/1/1
Y1 - 2015/1/1
N2 - Background: Functional decline in stem cell-mediated regeneration contributes to aging associated with cellular senescence in c-kit+ cardiac progenitor cells (CPCs). Clinical implementation of CPC-based therapy in elderly patients would benefit tremendously from understanding molecular characteristics of senescence to antagonize aging. Nucleostemin (NS) is a nucleolar protein regulating stem cell proliferation and pluripotency. Objectives: This study sought to demonstrate that NS preserves characteristics associated with "stemness" in CPCs and antagonizes myocardial senescence and aging. Methods: CPCs isolated from human fetal (fetal human cardiac progenitor cell [FhCPC]) and adult failing (adult human cardiac progenitor cell [AhCPC]) hearts, as well as young (young cardiac progenitor cell [YCPC]) and old mice (old cardiac progenitor cell [OCPC]), were studied for senescence characteristics and NS expression. Heterozygous knockout mice with 1 functional allele of NS (NS+/-) were used to demonstrate that NS preserves myocardial structure and function and slows characteristics of aging. Results: NS expression is decreased in AhCPCs relative to FhCPCs, correlating with lowered proliferation potential and shortened telomere length. AhCPC characteristics resemble those of OCPCs, which have a phenotype induced by NS silencing, resulting in cell flattening, senescence, multinucleated cells, decreased S-phase progression, diminished expression of stemness markers, and up-regulation of p53 and p16. CPC senescence resulting from NS loss is partially p53 dependent and is rescued by concurrent silencing of p53. Mechanistically, NS induction correlates with Pim-1 kinase-mediated stabilization of c-Myc. Engineering OCPCs and AhCPCs to overexpress NS decreases senescent and multinucleated cells, restores morphology, and antagonizes senescence, thereby preserving phenotypic properties of "stemness." Early cardiac aging with a decline in cardiac function, an increase in senescence markers p53 and p16, telomere attrition, and accompanied CPC exhaustion is evident in NS+/- mice. Conclusions: Youthful properties and antagonism of senescence in CPCs and the myocardium are consistent with a role for NS downstream from Pim-1 signaling that enhances cardiac regeneration.
AB - Background: Functional decline in stem cell-mediated regeneration contributes to aging associated with cellular senescence in c-kit+ cardiac progenitor cells (CPCs). Clinical implementation of CPC-based therapy in elderly patients would benefit tremendously from understanding molecular characteristics of senescence to antagonize aging. Nucleostemin (NS) is a nucleolar protein regulating stem cell proliferation and pluripotency. Objectives: This study sought to demonstrate that NS preserves characteristics associated with "stemness" in CPCs and antagonizes myocardial senescence and aging. Methods: CPCs isolated from human fetal (fetal human cardiac progenitor cell [FhCPC]) and adult failing (adult human cardiac progenitor cell [AhCPC]) hearts, as well as young (young cardiac progenitor cell [YCPC]) and old mice (old cardiac progenitor cell [OCPC]), were studied for senescence characteristics and NS expression. Heterozygous knockout mice with 1 functional allele of NS (NS+/-) were used to demonstrate that NS preserves myocardial structure and function and slows characteristics of aging. Results: NS expression is decreased in AhCPCs relative to FhCPCs, correlating with lowered proliferation potential and shortened telomere length. AhCPC characteristics resemble those of OCPCs, which have a phenotype induced by NS silencing, resulting in cell flattening, senescence, multinucleated cells, decreased S-phase progression, diminished expression of stemness markers, and up-regulation of p53 and p16. CPC senescence resulting from NS loss is partially p53 dependent and is rescued by concurrent silencing of p53. Mechanistically, NS induction correlates with Pim-1 kinase-mediated stabilization of c-Myc. Engineering OCPCs and AhCPCs to overexpress NS decreases senescent and multinucleated cells, restores morphology, and antagonizes senescence, thereby preserving phenotypic properties of "stemness." Early cardiac aging with a decline in cardiac function, an increase in senescence markers p53 and p16, telomere attrition, and accompanied CPC exhaustion is evident in NS+/- mice. Conclusions: Youthful properties and antagonism of senescence in CPCs and the myocardium are consistent with a role for NS downstream from Pim-1 signaling that enhances cardiac regeneration.
KW - Aging
KW - Senescence
KW - Signal transduction
UR - http://www.scopus.com/inward/record.url?scp=84922600175&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84922600175&partnerID=8YFLogxK
U2 - 10.1016/j.jacc.2014.09.086
DO - 10.1016/j.jacc.2014.09.086
M3 - Article
C2 - 25593054
AN - SCOPUS:84922600175
VL - 65
SP - 133
EP - 147
JO - Journal of the American College of Cardiology
JF - Journal of the American College of Cardiology
SN - 0735-1097
IS - 2
ER -