Relationship between Thy‐1 expression and cell‐cycle distribution in human bone marrow hematopoietic progenitors

Abstract

Analysis of the relationship between Thy-1 expression and cell-cycle distribution of hematopoietic stem cells (HSCs) Lin-Thy-1 + fraction, loses Thy-1 expression during 6 days, and re-expresses Thy-1 for an additional 2 days. Cell-cycle analysis demonstrated that this unique subset contains abundant S/G 2 M cells. Thus, Thy-1 expression appears to be an indicator of cell-cycle phase in targeting HSC, which might serve in the cell subset best suited for gene transfer. Am.

Scalable Selection of Hepatocyte- and Hepatocyte Precursor-Like Cells from Culture of Differentiating Transgenically Modified Murine Embryonic Stem Cells

“…The development of hepatocyte‐like cells in adherent cultures in the presence of puromycin was also corroborated by the expression of the specific gene marker of mature hepatocytes Tat [37, 63] and of the gene for the liver‐specific anion transporter LST‐1 [60]. On the other hand, gene and protein expression of progenitor cell markers that, besides hematopoietic and nonhematopoietic bone marrow cells [89, , , , –94], salivary gland [75], neurons [95, 96], and endothelial cells [97], are also typical for hepatoblasts (common progenitors for both hepatocytes and biliary epithelial cells) isolated from fetal liver [40, 74, 76, 77, 98], as well as for hepatic oval (progenitor) cells found in adult liver [70, , –73, 99], suggested the presence of precursor cells in the adherent culture. The profile of the expression of progenitor marker proteins in respect of the colony morphology (center/periphery) is in line with previously published data attributing CD34 and c‐Kit to early hepatocyte precursors [70, 71, 73] and ascribing Thy‐1 and Dlk to advanced differentiated hepatoblasts and fetal hepatocytes [74, 77].…”

Controlling the Balance of Fibroblast Proliferation and Differentiation: Impact of Thy-1

“…Furthermore, human lung fibroblasts derived from patients with hypersensitivity pneumonitis and idiopathic pulmonary fibrosis (IPF) characterized by an increased proliferative capacity are also Thy-1 negative (Ramirez et al, 2011). In contrast, only a Thy-1-positive subset of CD34 + human bone marrow hematopoietic stem cells entered the cell cycle after cytokine stimulation, whereas the Thy-1-negative subset remained quiescent (Takeda et al, 2005). These data suggest different cell type-or contextdependent functions for Thy-1.…”

Reviewing and Updating the Major Molecular Markers for Stem Cells

“…The levels of chimerism of these 2 subset fractions are similar under nonlimiting cell transplantation conditions, but a limiting dilution analysis revealed that HSCs are 5 times more abundant in the Thy-1 + fraction [211]. There are also reports demonstrating the generation of Thy-1 + cells from Thy-1 -cells [211,212]. However, Majeti et al [213] were able to establish a cell hierarchy, where Thy-1 + CD45RA -cells give rise to Thy-1 -CD45RA -cells that are, in turn, upstream of Thy-1 -CD45 + cells.…”

“…A reduction in the number of hematopoietic colonies was observed when an anti-Thy-1 antibody was added to cultures of Thy-1 + cells, suggesting that it may be involved in the development of HSCs [209]. Thy-1 has also been proposed as a cell cycle status indicator based on the observation that only the Thy-1 + fraction enters the S/ G2/M-phases when cells are stimulated by cytokines [212].…”