O-linked N-acetylglucosamine in differentiation and gene expression of mouse and human pluripotent stem cells

Peptide posttranslational modifications have been shown to regulate multiple aspects of cell signalling, thereby influencing cellular functions. The addition of O-linked Nacetylglucosamine to serine or threonine residues (O-GlcNAcylation) of proteins has only recently been characterized and its overall role in cell signalling remains elusive to date. Recent studies suggest an essential role of O-GlcNAcylation on the viability and pluripotency of mouse and human embryonic stem (ES) cells. Here we show that increased levels of O-GlcNAcylation in response to specific inhibition of O-GlcNAc hydrolase (Oga) hinder mouse ES cell differentiation. In addition to these findings, I could also demonstrate that increased O-GlcNAcylation leads to expression of a gene set normally epigenetically repressed in mouse ES cells and associated with a subpopulation resembling cells in the 2-cell-stage embryo. I also extended our lab's investigations to human induced pluripotent stem (iPS) cells. While mesendodermal differentiation remains unaffected by high O-GlcNAc levels, neural differentiation is severely disrupted in these cells. Human iPS cells with elevated O-GlcNAcylation are unable to commit to the ectodermal lineage and fail to organize in neural tube-like structures, so-called neural rosettes. Following these observations we performed mRNA sequencing analysis on human iPS cells with high O-GlcNAc levels and found gene expression to be significantly altered. Genes affected by increased O-GlcNAcylation include modulators of key neural developmental processes, for example components of the bone morphogenic protein signalling cascade.

Name dc:type.qualificationname

Doctor of Philosophy

Level dc:type.qualificationlevel

Doctoral Thesis

Grantor dc:publisher.institution

University of Dundee

Year dc:date.issued

2016

Author dc:creator

• Domke, Tanja Carolina Elisabeth

Advisor dc:contributor.advisor

• Stavridis, Marios

Language dc:language

eng

Identifier

oai:discovery.dundee.ac.uk:studenttheses/e84ff9a1-a4ab-41d0-828c-60a191b42c69

OAI identifier oai:identifier

oai:discovery.dundee.ac.uk:studenttheses/e84ff9a1-a4ab-41d0-828c-60a191b42c69