Induced stem cells (iPS)

Induced stem cells, also known as iPS cells, are a special type of stem cell developed in the laboratory from differentiated adult cells, such as skin or blood cells. These iPS cells have acquired significant importance in medical research and regenerative medicine.

iPS cells are created by genetically reprogramming human embryos.adult cells to bring them back to a state similar to that of embryonic stem cells pluripotent cells. Pluripotent cells have the ability to differentiate into many different cell types, making them extremely valuable for research and therapy.

Induced stem cells generally express specific transcription factors, such as OCT4, SOX2, NANOG, KLF4, and c-MYC. These factors are essential for maintaining the pluripotent state of iPS. They express certain cell surface markers characteristic of pluripotent embryonic stem cells, such as SSEA-3, SSEA-4, TRA-1-60 and TRA-1-81. The expression of these markers can be detected by immunofluorescence or by flow cytometry. Their ability to differentiate into different cell types and form cell derivatives from all three germ layers (ectoderm, mesoderm, endoderm) is an indicator of their pluripotency.

iPS generally show patterns of DNA methylation similar to those of embryonic stem cells, they are induced to differentiate into a specific cell line (for example, heart cells, neurons, blood cells), gene expression can be used as a biomarker to confirm successful differentiation.

Pluripotent iPS cells often have a characteristic morphology, with a ratio of nucleo-cytoplasmic small cell size and a well-defined shape. When grown on culture plates, iPS form compact colonies with sharp edges, which is distinctive compared with differentiated cells.

It is important to note that the biomarkers used may vary depending on the culture, the differentiation and research objectives. Researchers often need to use a combination of these biomarkers to effectively characterise induced stem cells and ensure their quality and safety pluripotency.

iPS cells have a number of potential applications, including

• Disease modelling: iPS cells can be generated from patients with genetic diseases or other conditions. This allows researchers to better understand the progression of these diseases and to test new drugs.

• Thérapie cellulaire : iPS cells can be used to develop cellular therapies. For example, they can be transformed into heart cells to treat heart diseases or in​​​​​​​ nerve cells to treat lesions of the spinal cord.

• Toxicologie et tests de médicaments : iPS cells can be used to assess the toxicity of drugs and chemicals on the human body.​​​​​​​human cells, reducing the need for animal testing.

• Transplantation d'organes : Although some technical challenges remain, iPS cells could eventually be used to generate organs or tissues for​​​​​​​ transplantation, which would solve the problem of organ shortages.

• Recherche fondamentale : iPS cells are also invaluable for studying the processes involved in the development of cell differentiation.