Sofia Zdunek

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It has been difficult to establish whether we are limited to the heart muscle cells we are born with or if cardiomyocytes are generated also later in life. We have taken advantage of the integration of carbon-14, generated by nuclear bomb tests during the Cold War, into DNA to establish the age of cardiomyocytes in humans. We report that cardiomyocytes(More)
The myelination of axons by oligodendrocytes has been suggested to be modulated by experience, which could mediate neural plasticity by optimizing the performance of the circuitry. We have assessed the dynamics of oligodendrocyte generation and myelination in the human brain. The number of oligodendrocytes in the corpus callosum is established in childhood(More)
The contribution of cell generation to physiological heart growth and maintenance in humans has been difficult to establish and has remained controversial. We report that the full complement of cardiomyocytes is established perinataly and remains stable over the human lifespan, whereas the numbers of both endothelial and mesenchymal cells increase(More)
Signaling proteins driving the proliferation of stem and progenitor cells are often encoded by proto-oncogenes. EphB receptors represent a rare exception; they promote cell proliferation in the intestinal epithelium and function as tumor suppressors by controlling cell migration and inhibiting invasive growth. We show that cell migration and proliferation(More)
Central nervous system injuries are accompanied by scar formation. It has been difficult to delineate the precise role of the scar, as it is made by several different cell types, which may limit the damage but also inhibit axonal regrowth. We show that scarring by neural stem cell-derived astrocytes is required to restrict secondary enlargement of the(More)
Assays to quantify myocardial renewal rely on the accurate identification of cardiomyocyte nuclei. We previously ¹⁴C birth dated human cardiomyocytes based on the nuclear localization of cTroponins T and I. A recent report by Kajstura et al. suggested that cTroponin I is only localized to the nucleus in a senescent subpopulation of cardiomyocytes, implying(More)
Cardiomyocyte Renewal in Humans To the Editor: In a recent review article by Leri, Kajstura, and Anversa1 in Circulation Research, there are several misrepresentations and factual errors in the description of our study on birth dating of heart cells.2 These errors affect their conclusions, and it is thus important to make some clarifications. First, Leri et(More)
It has been unclear whether ischemic stroke induces neurogenesis or neuronal DNA rearrangements in the human neocortex. Using immunohistochemistry; transcriptome, genome and ploidy analyses; and determination of nuclear bomb test–derived 14C concentration in neuronal DNA, we found neither to be the case. A large proportion of cortical neurons displayed DNA(More)
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