What Are Human Pluripotent Stem Cells?
The human body contains hundreds of specialized cell types — from neurons and heart muscle cells to the cells that form the surface of the cornea.
But during the earliest stages of human development, cells have not yet acquired these specialized identities. Some retain a remarkable biological property known as pluripotency.
Pluripotent stem cells can self-renew while maintaining the capacity to generate virtually any cell type in the human body. This combination makes them an extraordinarily powerful tool for studying human biology and developing new approaches to regenerative medicine.
What does “pluripotent” mean?
Stem cells are often classified according to the range of cell types they are capable of producing.
Pluripotent stem cells can generate cells belonging to all three embryonic germ layers — ectoderm, mesoderm and endoderm — which ultimately give rise to the tissues and organs of the body.
Under carefully controlled laboratory conditions, scientists can guide pluripotent stem cells through developmental processes to generate increasingly specialized cell populations.
This process is known as differentiation.
By controlling the signals cells receive during differentiation, researchers can generate many therapeutically relevant cell types, including neurons, cardiomyocytes, pancreatic cells and different cell populations of the eye.
Embryonic stem cells and pluripotent stem cells: what is the difference?
These terms are sometimes used interchangeably, but they do not mean exactly the same thing.
Pluripotent stem cell describes a biological property: the ability of a stem cell to generate essentially all of the specialized cell types of the body.
Human embryonic stem cells (hESCs) are one type of human pluripotent stem cell. They are derived from cells of the early-stage embryo and can be maintained and expanded in the laboratory while retaining their pluripotent state.
But embryonic stem cells are not the only pluripotent stem cells available to researchers.
What are induced pluripotent stem cells?
A major scientific breakthrough demonstrated that mature adult cells could be reprogrammed back into a pluripotent state.
These cells are called induced pluripotent stem cells, or iPSCs.
Rather than originating from an early embryo, iPSCs can be generated by introducing specific reprogramming factors into differentiated cells, such as cells obtained from skin or blood. The resulting cells acquire many of the fundamental properties associated with pluripotent stem cells, including self-renewal and the capacity to differentiate into a broad range of specialized cell types.
Therefore:
Human pluripotent stem cells (hPSCs) is the broad category.
It includes both human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs).
Why are pluripotent stem cells important for regenerative medicine?
Many serious diseases involve the irreversible loss or dysfunction of specialized cells.
Unlike conventional medicines, which often aim to modify the activity of cells that remain in the body, regenerative medicine asks a different question:
Could functional cells be generated and used to replace those that have been lost?
Human pluripotent stem cells provide a potentially renewable starting material from which large numbers of specialized cells can be generated.
However, transforming that biological potential into a medicine is considerably more complex than simply growing stem cells.
Cells must be directed toward the desired identity through carefully controlled differentiation processes. The resulting population must then be characterized for properties such as identity, purity and function, while manufacturing, scalability, cryopreservation, delivery and safety must all be considered as part of therapeutic development.
From pluripotency to specialized ocular cells
The eye contains many highly specialized cell populations, making ophthalmology an important field for regenerative medicine.
Human pluripotent stem cells can be guided through developmental pathways toward different ocular cell identities. This creates opportunities both for studying eye biology and for developing regenerative approaches aimed at replacing cells that have been damaged or lost through disease.
At Corcellys Therapeutics, pluripotent stem cell biology is part of the scientific foundation behind our approach to regenerative therapies for the ocular surface.
Our focus is not simply on the remarkable ability of a pluripotent stem cell to become another cell type, but on the much larger challenge of translating that biology into defined, reproducible and practical cell therapies.
A platform with extraordinary potential
Human pluripotent stem cells have transformed the possibilities of regenerative medicine.
Their value comes from a unique combination: they can be expanded extensively while retaining the capacity to generate specialized human cells.
The challenge — and the opportunity — lies in learning how to control that potential.
From one renewable cellular starting point, it becomes possible to imagine entirely new ways of replacing cells and restoring tissue function.
