No abstract

We previously identified a novel family of genes, BRINP1, 2, and 3, that are predominantly and widely expressed in both the central nervous system (CNS) and peripheral nervous system (PNS). In the present study, we analyzed the expression pattern of three BRINP genes during differentiation of mouse embryonic stem (ES) cell-derived neural stem cells (NSCs) and their effects on the cell-cycle regulation of NSCs. While there was no significant expression of any BRINP-mRNA expressed in mouse ES cells, BRINP 1 and 2-mRNAs was expressed at high levels in the ES cell-derived neural stem cells. Upon differentiation into neuronal cells in the presence of retinoic acid and BDNF, all three types of BRINP-mRNA were induced with a similar time course peaking at day three of treatment. Upon differentiation into astroglial cells in the presence of serum, BRINP1-mRNA was slightly up-regulated, while BRINP2- and BRINP3-mRNAs were almost abolished in the astrocytes. While 69.2, 26.1, and 7.7% of cells in a population of NSCs in the exponentially growing phase were in the G1, S and G2 phases, respectively, over-expression of any one of the three BRINP genes completely abolished cells in the G2 phase and significantly reduced the cells in S phase to 11.8-13.8%. Based on these results, the physiological roles of induced BRINP genes in the cell-cycle suppression of terminally differentiated post-mitotic neurons are discussed.

Alterations in the structure of cell surface glycoforms occurring during the stages of stem cell differentiation remain unclear. We describe a rapid glycoblotting-based cellular glycomics method for quantitatively evaluating changes in glycoform expression and structure during neuronal differentiation of murine induced pluripotent stem cells (iPSCs) and embryonic stem cells (ESCs). Our results show that changes in the expression of cellular N-glycans are comparable during the differentiation of iPSCs and ESCs. The expression of bisect-type N-glycans was significantly up-regulated in neurons that differentiated from both iPSCs and ESCs. From a glycobiological standpoint, iPSCs are an alternative neural cell source in addition to ESCs.

As articular cartilages have rarely healed by themselves because of their characteristics of avascularity and low cell density, surgical intervention is ideal for patients with cartilaginous injuries. Because of structural characteristics of the cartilage tissue, a three‐dimensional culture of stem cells in biomaterials is a favorable system on cartilage tissue engineering. Induced pluripotent stem cells (iPSCs) are a new cell source in cartilage tissue engineering for its characteristics of self‐renewal capability and pluripotency. However, the optimal cultivation condition for chondrogenesis of iPSCs is still unknown. Here we show that a novel chondrogenic differentiation method of iPSCs using the combination of three‐dimensional cultivation in ultra‐purified alginate gel (UPAL gel) and multi‐step differentiation via mesenchymal stem cell‐like cells (iPS‐MSCs) could efficiently and specifically differentiate iPSCs into chondrocytes. The iPS‐MSCs in UPAL gel culture sequentially enhanced the expression of chondrogenic marker without the upregulation of that of osteogenic and adipogenic marker and histologically showed homogeneous chondrogenic extracellular matrix formation. Our results suggest that the pluripotency of iPSCs can be controlled when iPSCs are differentiated into iPS‐MSCs before embedding in UPAL gel. These results lead to the establishment of an efficient three‐dimensional system to engineer artificial cartilage tissue from iPSCs for cartilage regeneration. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1086–1093, 2019.