Profiling TRA-1-81 antigen distribution on a human embryonic stem cell

Abstract

Human embryonic stem (hES) cells hold great promise in regenerative medicine. Although hES cells have unlimited self-renewal potential, they tend to differentiate spontaneously in culture. TRA-1-81 is a biomarker of undifferentiated hES cells. Quantitative characterization of TRA-1-81 expression level in a single cell helps capture the "turn-on" signal and understand the mechanism of early differentiation. Here we report on our examination of TRA-1-81 distribution and association on a hES cell membrane using an atomic force microscope (AFM). Our results suggest that aggregated distribution of TRA-1-81 antigen is characteristic for undifferentiated hES cells. We also evaluated the TRA-1-81 expression level at ~17800 epitopes and ~700 epitopes per cell on an undifferentiated cell and a spontaneously differentiated cell, respectively. The method in this study can be adapted in examining other surface proteins on various cell types, thus providing a general tool for investigating protein distribution and association at the single cell level.

Nanostructure and β1-integrin distribution analysis of pig's spermatogonial stem cell by atomic force microscopy

“…It may be used to obtain ultrastructural details of biological samples with high resolution and measure the force within and between single biomolecules (Hu et al, 2008;Kienberger et al, 2006;Lee et al, 2007;Pranav et al, 2008;Qiu et al, 2008;Vincent et al, 2009;Yersin et al, 2007). As such, we obtained the nanostructure of SSCs by AFM and β1-integrin antibody functionalized AFM tip was used to detect complementary receptors on cellular surface to map the distribution of β1-integrin at nanometer level, these results provide a new insight into the nano-biology of β1-integrin expression on SSCs membrane.…”

Adapting collagen/CNT matrix in directing hESC differentiation

“…Our previous studies on the spontaneous differentiation of hESCs used a high serum concentration with DMEM media in the presence of non-essential amino acids without additional growth factors [12]. When gelatin or matrigel were used as a matrix, the medium allowed rapid spontaneous differentiation into all three lineages with no specification.…”

A microfluidic method for the selection of undifferentiated human embryonic stem cells and in situ analysis

“…Pluripotent hESCs have the potential to become any type of cell in our body, but all pluripotent cells may not have the same expression level of the various stem-cell markers (Stewart et al 2006). For example, Qiu et al (2008) demonstrated that expression of Tra-1-81 receptors varies significantly even among stem cells from the same line (Qiu et al 2008). Future experiments to determine expression level of receptors on the surface could help determine whether this as a potential source of the difference in capture efficiency.…”

“…Although undifferentiated hESC markers are well characterized, it is also clear that there exists significant heterogeneity between hESC lines and even within pluripotent hESC populations from the same line with respect to the levels of expressed proteins (Gu et al 2010;Mantel et al 2007;Qiu et al 2008;Stewart et al 2006). Pluripotent hESCs have the potential to become any type of cell in our body, but all pluripotent cells may not have the same expression level of the various stem-cell markers (Stewart et al 2006).…”

“…Selected cell capture with anti-Tra-1-81 vs. anti-SSEA-4-functionalized channels Both Tra-1-81 and SSEA-4 are expressed in hESCs(DraperDraper et al 2002;Qiu et al 2008;Zhao et al …”