The loss of limbs in humans is generally considered irreversible, but some animals—such as worms, fish, and amphibians—have the ability to regenerate lost body parts. A group of researchers from Texas A&M University conducted an experiment on mice and discovered that mammals have partially retained the capacity to initiate bone tissue restoration.
When tissue is injured, a blood clot first forms in the body, then immune cells clean the wound, and fibroblasts create a dense network of collagen and fibronectin. This allows the injury to be quickly sealed, but the result is the formation of scar tissue rather than new tissue.
However, in animals with full regenerative abilities, this process involves the formation of a blastema—a cellular structure from which a new limb grows. The study authors note that even if scientists manage to slightly reduce scar formation in humans, it would already bring tangible benefits.
The researchers applied the protein FGF2 to the amputated toes of mice. This allowed the formation of tissue similar to a blastema, although it was unable to develop into fully functional structures. Later, they added BMP2, which can stimulate bone tissue growth, after which fragments of bone, ligaments, and tendons began to take shape.
The authors of the experiment conclude that complete limb regeneration is currently impossible, but the results of the tests prove that mammals have partially retained regenerative mechanisms.
About the Author
