Glypican-1, phosphacan/receptor protein-tyrosine phosphatase-ζ/β and its ligand, tenascin-C, are expressed by neural stem cells and neural cells derived from embryonic stem cells

Abstract

The heparan sulfate proteoglycan glypican-1, the chondroitin sulfate proteoglycan phosphacan/RPTP (receptor protein-tyrosine phosphatase)-zeta/beta and the extracellular matrix protein tenascin-C were all found to be expressed by neural stem cells and by neural cells derived from them. Expression of proteoglycans and tenascin-C increased after retinoic acid induction of SSEA1-positive ES (embryonic stem) cells to nestin-positive neural stem cells, and after neural differentiation, proteoglycans and tenascin-C are expressed by both neurons and astrocytes, where they surround cell bodies and processes and in certain cases show distinctive expression patterns. With the exception of tenascin-C (whose expression may decrease somewhat), expression levels do not change noticeably during the following 2 weeks in culture. The significant expression, by neural stem cells and neurons and astrocytes derived from them, of two major heparan sulfate and chondroitin sulfate proteoglycans of nervous tissue and of tenascin-C, a high-affinity ligand of phosphacan/RPTP-zeta/beta, indicates that an understanding of their specific functional roles in stem cell neurobiology will be important for the therapeutic application of this new technology in facilitating nervous tissue repair and regeneration.

Keywords: astrocyte; glypican; heparan sulfate; neuron; phosphacan; proteoglycan.

Figure 1. Expression of glypican-1, tenascin-C and phosphacan/RPTP-ζ/β in mouse ES cells (day 0) and on the second and fourth days of retinoic acid treatment during the neural induction period

The green fluorescence in (A–C, D–F and G–J) represents glypican-1, tenascin-C and phosphacan/RPTP-ζ/β respectively. ES cells and neural stem cells are identified in red by their expression of SSEA-1 (A, D, G) and nestin (K, L, M) respectively. β-III tubulin staining (red) is shown in (C) and nuclear staining with TO-PRO-3 is blue.

Figure 2. Expression of glypican-1 by neural cells derived from ES cells

Days after differentiation are indicated on the left, and astrocytes and neurons are identified by their expression of GFAP and β-III tubulin. The green fluorescence indicates the presence of glypican-1.

Figure 3. Expression of phosphacan/RPTP-ζ/β by neural cells derived from ES cells

Days after differentiation are indicated on the left, and astrocytes and neurons are identified by their expression of GFAP and β-III tubulin. The green fluorescence indicates the presence of phosphacan/RPTP-ζ/β.

Figure 4. Expression of tenascin-C by neural cells derived from ES cells

Days after differentiation are indicated on the left, and neurons and astrocytes are identified by their expression of β-III tubulin and GFAP. The green fluorescence indicates the presence of tenascin-C.