Publications by authors named "Nadejda V Mezentseva"

Bone marrow (BM) has long been considered a potential stem cell source for cardiac repair due to its abundance and accessibility. Although previous investigations have generated cardiomyocytes from BM, yields have been low, and far less than produced from ES or induced pluripotent stem cells (iPSCs). Since differentiation of pluripotent cells is difficult to control, we investigated whether BM cardiac competency could be enhanced without making cells pluripotent.

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Lithium is a commonly used drug for the treatment of bipolar disorder. At high doses, lithium becomes teratogenic, which is a property that has allowed this agent to serve as a useful tool for dissecting molecular pathways that regulate embryogenesis. This study was designed to examine the impact of lithium on heart formation in the developing frog for insights into the molecular regulation of cardiac specification.

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This study examined transgenic mice whose expression of a β-galactosidase (lacZ) reporter is driven by a GATA6 gene enhancer. Previous investigations established that transcription of the transgene was associated with precardiac mesoderm and primary heart tube myocardium, which decreased progressively, so that its expression was no longer observed within ventricular myocardium by midgestation. Expression of this reporter in the adult was investigated for insights into myocyte homeostasis and cardiovascular biology.

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WNT signaling has been shown to influence the development of the heart. Although recent data suggested that canonical WNTs promote the emergence and expansion of cardiac progenitors in the pregastrula embryo, it has long been accepted that once gastrulation begins, canonical WNT signaling needs to be suppressed for cardiac development to proceed. Yet, this latter supposition appears to be odds with the expression of multiple canonical WNTs in the developing heart.

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Ancient metazoan organisms arose from unicellular eukaryotes that had billions of years of genetic evolution behind them. The transcription factor networks present in single-celled ancestors at the origin of the Metazoa (multicellular animals) were already capable of mediating the switching of the unicellular phenotype among alternative states of gene activity in response to environmental conditions. Cell differentiation, therefore, had its roots in phenotypic plasticity, with the ancient regulatory proteins acquiring new targets over time and evolving into the "developmental transcription factors" (DTFs) of the "developmental-genetic toolkit.

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Article Synopsis
  • Limb bud development in chicken embryos starts on day three due to FGF8 from the apical ectodermal ridge, leading to changes in the limb field mesoderm that cause the limbs to bulge out.
  • Heintzelman et al. suggested that the bulging is due to higher liquid-like cohesivity in limb bud tissue compared to flank tissue, with experiments confirming that limb tissues are 1.5- to 2-fold more cohesive.
  • Exposure to FGF8 can increase cohesivity in flank tissue, while the unique response of flank tissue to compression relies on an intact actin cytoskeleton, highlighting the importance of physical properties in tissue morphogenesis.
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Background: Thermogenic brown adipose tissue has never been described in birds or other non-mammalian vertebrates. Brown adipocytes in mammals are distinguished from the more common white fat adipocytes by having numerous small lipid droplets rather than a single large one, elevated numbers of mitochondria, and mitochondrial expression of the nuclear gene UCP1, the uncoupler of oxidative phosphorylation responsible for non-shivering thermogenesis.

Results: We have identified in vitro inductive conditions in which mesenchymal cells isolated from the embryonic chicken limb bud differentiate into avian brown adipocyte-like cells (ABALCs) with the morphological and many of the biochemical properties of terminally differentiated brown adipocytes.

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