Science Editorial, Oct 16 (EFE).- The skin is the largest organ in the body and its knowledge is key to advancing clinical applications. Now, scientists have managed to create a single-cell and spatial atlas of prenatal human skin that offers a “molecular recipe” to build it and improve transplants for burns or scarring alopecia.
Using single-cell sequencing techniques and other cutting-edge genomic methods, researchers designed this map to understand how the skin, including hair follicles, forms and what goes wrong in the event of disease. In addition, they created a “mini organ” (organoid) to scrutinize the role of immune cells in the repair of this tissue.
The research is published in the journal Nature and is led by experts from the Wellcome Sanger Institute and the University of Newcastle (both in the United Kingdom).
It is part of the Human Cell Atlas (HCA) project, which is mapping all cell types in the human body to transform the understanding of health and disease.
The skin – with an average of two square meters – provides a protective barrier, regulates body temperature and can regenerate itself.
This develops in the sterile environment of the uterus, with all hair follicles formed before birth; After this, a follicular cycle occurs, but new ones are not formed. Before birth, the skin has the unique ability to heal without leaving scars, explains a statement from Wellcome Sanger.
To make this atlas, the scientists used samples of prenatal skin tissue, which they decomposed to observe individual cells in suspension, as well as cells in place within the tissue.
Using advanced genomic techniques, they analyzed individual cells in space and time, and the cellular changes that regulate the development of skin and hair follicles.
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In addition to the atlas and using adult stem cells, the researchers also created a “mini organ” of skin on a plate, known as an organoid, with the capacity to grow hair.
Among others, they found that the organoid model looked more like prenatal skin than adult skin. However, they saw that blood vessels did not form in the skin organoid as well as in prenatal skin.
By adding immune cells known as macrophages to the organoid, they found that they promoted the formation of blood vessels – 3D images were performed to evaluate the formation of blood vessels within the tissue.
These immune cells are known to protect the skin from infections. However, this is the first time that macrophages have been shown to play a key role in the formation of human skin during early development by promoting the growth of blood vessels, the researchers say.
Clues against a type of alopecia
The team also analyzed differences in cell types between prenatal and adult skin. They showed how macrophages play an important role in scar-free skin repair in prenatal skin, which could lead to clinical applications to prevent scar formation after surgery or injury.
The work provides a “molecular recipe” for how human skin is built and how hair follicles form. This knowledge could be used in the creation of new follicles for regenerative medicine, for example for skin transplants in burn victims or with scarring alopecia – characterized by the permanent destruction of hair follicles.
The prenatal human skin atlas will also be used to identify in which cells the genes that cause congenital hair and skin disorders, such as blisters and scaly skin, are activated or expressed.
The researchers discovered that the genes involved in these disorders are expressed in prenatal skin, meaning they originate in the uterus.
Wellcome Sanger’s Elena Winheim summarizes that the atlas provides the first ‘molecular recipe’ for creating human skin and the research uncovers how human hair follicles form before birth.
“This knowledge has amazing clinical potential and could be used in regenerative medicine, offering skin and hair transplants, for example, for burn victims or people with scarring alopecia.”
(c) EFE Agency
