Study reveals previously unknown ability of the adult brain to repair itself via regenerative astrocytes
核心洞察
Researchers at the University of Zurich identified a specialized population of "regenerative" astrocytes in living mice that rebuild damaged brain tissue after injury or autoimmune disease.
These cells send newly formed nuclei of daughter cells gliding across long distances through astrocyte extensions to repopulate damaged areas and knit the astrocyte network back together.
The findings overturn the long-held assumption that the adult brain cannot fully replace lost astrocytes, such as in neuromyelitis optica spectrum disorder (搜索).
The adult brain can repair itself far better than scientists previously assumed after injuries or certain autoimmune diseases, according to a new study from the University of Zurich (UZH). Using a mouse model, researchers demonstrated that specialized supporting cells repopulate damaged areas of the brain by initially sending only newly formed cell nuclei there, revealing a previously unknown mechanism of brain self-repair.
Glial cells are supporting and nourishing cells in the brain. Star-shaped glial cells called astrocytes are vital to the functioning of neurons: they supply nerve cells with nutrients, help regulate blood flow, and keep brain tissue healthy. It had long been assumed that when astrocytes are lost — as occurs in brain injuries or autoimmune diseases such as the rare neuromyelitis optica spectrum disorder (搜索), in which the body's own antibodies destroy these cells — the adult brain cannot fully replace them.
Regenerative astrocytes rebuild damaged tissue
A new study by co-lead authors Marina Herwerth and Matthias Wyss from the Institute of Pharmacology and Toxicology at the University of Zurich has overturned that assumption. Their research team, headed by Bruno Weber, discovered a specialized group of "regenerative" astrocytes in the brains of living mice that step in on the perimeter of the damaged area of the brain to rebuild the cells.
"The findings of our study reveal a previously unknown ability of the adult brain to repair itself. They point toward new ways of supporting recovery from ailments involving the loss of astrocytes," said Bruno Weber of the University of Zurich.
Only cell nuclei migrate
The researchers used two-photon microscopy to observe the brains of living mice in real time over a period of several weeks, and mapped which genes switch on in which areas of the brain. This approach allowed them to identify the special astrocytes responsible for rebuilding injured tissue. Those cells do not simply divide; they also perform a remarkable feat.
"They send the newly formed nuclei of their daughter cells gliding across long distances to repopulate the damaged area of the brain and knit the astrocyte network back together," Weber explained.
Starting points for targeted regeneration
The discovery of how adult brain cell nuclei migrate through the long star-shaped extensions of astrocytes to injured tissue expands comprehension of how the brain organizes and regenerates itself after certain injuries. If those mechanisms can be selectively activated, that could help to more effectively repair damaged brain tissue, restore astrocyte networks, and thus improve recovery after certain brain disorders.
"We were able to identify numerous genes and signaling pathways that are temporarily activated during repair. They could serve as starting points in the future for influencing post-disease and -injury regeneration processes," Weber stressed.