Laboratory-grown human embryo model produces blood cells sciences
Scientists have been able to grow embryo-like structures in the laboratory to produce human blood cells, raising new possibilities for regenerative medicine.
The ability to generate blood stem cells in the laboratory may one day make it possible to treat patients who need bone marrow transplants using their own cells.
This advance is the latest in a rapidly advancing field in which embryo models are created from stem cells without the need for eggs or sperm, opening a window into the early stages of human development.
“It was an exciting moment when the blood-red color appeared in the dish, and was visible even with the naked eye,” said Dr. Jitesh Neupane, a researcher at the Gordon Institute at the University of Cambridge and first author of the study.
He and his colleagues use the model system to understand the early developmental stages of heart and blood development.
“This highlights how blood cells form naturally during human embryonic development, providing a potential medical advance for drug screening, studying early blood and immune development, and modeling blood disorders such as leukemia,” Neupane said.
The human stem cells used to grow embryo-like structures can be created from any cell in the body. This means that this approach could also pave the way for the production of blood that is fully compatible with the patient’s body.
Although there are other ways to generate human blood stem cells in the laboratory, they require a mixture of additional proteins, while the new method mimics the natural developmental process in which self-organizing structures lead to the formation of different types of cells.
Professor Azim Sourani from the Gordon Institute, lead author of the study, said: “Although it is still in the early stages, the ability to produce human blood cells in the laboratory represents an important step towards future regenerative therapies – which use the patient’s own cells to repair and regenerate damaged tissue.”
In this latest study, scientists used human stem cells to replicate some of the cells and structures that typically appear in the third and fourth weeks of pregnancy. The model was specifically designed to lack the tissue that forms the placenta and yolk sac in a normal fetus, meaning it did not have the theoretical potential to develop into a fetus and did not develop the tissue that would form the brain.
“This is a simple system,” Neupane said.
The team observed the appearance of 3D embryo-like structures under the microscope. By day two, they have organized themselves into three germ layers—called ectoderm, mesoderm, and endoderm—which are the foundations of the human body plan. By day 8, beating heart cells have formed, the cells that eventually give rise to the heart in a developing human embryo.
By day 13, the team saw red spots of blood appear. Blood stem cells from the model have also been shown to be able to differentiate into different types of blood cells, including oxygen-carrying red blood cells and white blood cells that are essential for the immune system.
The results are published in the journal Cell reports.