Unipotent stem cells

Unipotent stem cells are a type of stem cell that is even more specialised than multipotent stem cells. Unlike pluripotent and multipotent stem cells, which have the capacity to differentiate into several cell types, unipotent stem cells have extremely limited differentiation potential and can only develop into a single specialised cell type. They are generally associated with the specific regeneration of a type of tissue or organ. For example, in the female reproductive system, oocytes (eggs) are produced from unipotent germline stem cells in the ovaries. These cells can only differentiate into oocytes, which is a very specific and unipotent differentiation.

As a general rule, unipotent stem cells are less common than multipotent or pluripotent stem cells, and their role is often very specific in the regeneration and renewal of particular tissues. They are not as versatile as other types of stem cells, but they play a crucial role in preserving and maintaining bodily functions by regenerating essential specialised cells.

Since unipotent stem cells have a differentiation potential limited to a single cell type, specific biomarkers can be used to identify and characterise these cells;

Specific gene expression : Unipotent stem cells can express specific genes associated with their limited differentiation potential. For example, in the case of oocytes produced from germline stem cells unipotent ovaries, the expression of genes linked to oocyte formation would be a biomarker.​​​​ of RNA sequencing to analyse the profiles of gene expression of unipotent stem cells.

Proteins specific to differentiation : Proteins specifically expressed during the differentiation of unipotent stem cells into their target cell type can be used as biomarkers. These proteins may include transcription factors and the cell surface markers.

Cell surface markers : Surface markers specific to the target cell can be used to identify unipotent stem cells and differentiated cells. For example, in the case of unipotent stem cells producing blood cells, surface markers specific to red blood cells, white blood cells or platelets could be used.

Specific regulatory mechanisms : Certain mechanisms regulating gene expression or cell signalling specific to unipotent differentiation can be considered as biomarkers. Cell signalling pathways, such as Wnt, Notch, or TGF-β, can be specifically activated or deactivated during unipotent differentiation. Detection of these activations can be used as biomarkers.

Cellular localisation : The specific localisation of unipotent stem cells in tissues can be a biomarker. For example, the presence of unipotent stem cells in specific niches in tissues can be used to identify them. For example, in the case of haematopoietic stem cells, the CD34 is often used as a marker, so the histological staining can be used to identify unipotent stem cells on the basis of their morphology and location in the tissue. In addition to molecular biomarkers, unipotent stem cells can be characterised by their specific functions in functional tests, such as their ability to differentiate into specific cells in cell cultures.

In vitro differentiation capacity :The ability of a unipotent stem cell to differentiate into a single cell type by​​​​​​​ in vitro culture can be used as a biomarker. The use of fluorescent proteins such as GFP (green fluorescent protein) or fluorescent dyes can be used to visually monitor cell differentiation in real time. The​​​​​​​ DNA sequencing or the​​​​​​​ RNA can be used to assess differentiation in vitro by monitoring changes in the​​​​​​​ transcriptome or the​​​​​​​ methyloma over time.