Effect of alternan versus chitosan on the biological properties of human mesenchymal stem cells.

Alternan, an α-1,3- and α-1,6-linked glucan, is a polysaccharide that is produced by bacteria. Although the structure of alternan used in this study, an α-1,3- and α-1,6-linked glucan (hereafter referred to as alternan), has been comprehensively characterized, its function on cell biology, especially relative to cell growth and differentiation, has not been fully elucidated. In this study, we set forth to compare the effect of alternan versus chitosan on the biological properties of human mesenchymal stem cells (MSCs). The effect of chitosan on MSC differentiation has already been well characterized. The treated cells were determined for cell proliferation and differentiation capacity compared to untreated cells. The result showed that treatment by alternan or chitosan increased cell proliferation, as demonstrated by increased cell number and scratched regions that were fully restored in less time than it took to fully restore controls. Further investigation found that alternan and chitosan activates the toll-like receptor (TLR) pathway suggesting that these cells may be prone to differentiation. In agreement with this result, an increase in deposited calcium was observed in alternan- or chitosan-treated cells after osteogenic differentiation induction. However, adipogenic differentiation was significantly inhibited in the presence of chitosan, but no change was observed in alternan treatment. Taken together, these results demonstrate biological effects of alternan on human MSCs. Moreover, these novel roles of alternan may have important beneficial medical applications and may provide a basis from which stem cell therapies can be developed in the future.

Generation of human induced pluripotent stem cell line carrying SCN5AC2204>T Brugada mutation (MUSli009-A-1) introduced by CRISPR/Cas9-mediated genome editing.

Human induced pluripotent stem cells (hiPSCs) derived from dermal fibroblasts having wild type (WT) SCN5A were engineered by CRISPR/Cas9-mediated genome editing to harbor a specific point mutation (C2204>T) in SCN5A, which results in a substitution of the WT alanine by valine at codon 735 (A735V). The established MUSli009-A-1 hiPSC line has a homozygous C2204>T mutation on exon 14 of SCN5A that was confirmed by DNA sequencing analysis. The cells exhibited normal karyotype, expressed pluripotent markers and retained its capability to differentiate into three germ layers. The cardiomyocytes derived from this line would be a useful model for investigating cardiac channelopathy.

The Hippo pathway regulates human megakaryocytic differentiation.

The Hippo pathway is involved in several biological processes in both flies and mammals. Recent studies have shown that the Hippo pathway regulates Drosophila's haematopoiesis; however, understanding of its role in mammalian haematopoiesis is still limited. In flies, deletion of the Hippo component gene, Warts, affects crystal cell differentiation. We explored the role of the Hippo pathway in human haematopoiesis focusing on megakaryopoiesis. To investigate the role of LATS1/2 (a mammalian homolog of Warts) in human megakaryoblastic cell differentiation and platelet formation, megakaryoblastic cell (MEG-01) line was used as a model to gain insight into mechanism of the Hippo pathway in mammalian megakaryopoiesis. Effect of LATS1/2 on megakaryoblastic cell differentiation and platelet production were determined by functional changes. We found that depletion of LATS1/2 resulted in an increase of CD41+ megakaryocytes with impaired platelet biogenesis. Our study shows that the Hippo signalling pathway plays a crucial role in human megakaryoblastic cell differentiation and thrombopoiesis.