Macrophage cues for skeleton muscle regeneration
Cells Keep learning
Learning is crucial for both brainy humans and the very building blocks we are made up of – cells. Isn’t it true that because of cell learning about epitopes of antigens, we could defend against viruses? It is also the learning, which helps the skin cells to heal the wound.
The cells keep learning as we humans from the surrounding environment. The way how tumor cells behave is a lot to do with the tumor microenvironment. The regeneration of the injured cells also gets influenced by the wound-derived signals.
There are more comprehensive applications for cues derived
from the microenvironment. Often transparent Zebrafish larva is used as a model system to capture these signals. It is easy to genetically engineer them to express the fluorescent proteins and watch what’s going on there. I stumbled upon an interesting article elucidating the cues from the muscle injury.
Although it is well known that the local stem cells play a crucial role in regeneration, but isolating them and using them for renewal may not work unless we fed them with cues. This study highlighted that local macrophages at the wound site provide signals for stem cells to function.
muscle stem cells regeneration
Isolating and profiling these macrophages at the wound site
revealed that they secrete cytokines that activate the stem cells for
regeneration. Nicotinamide phosphoribosyltransferase (NAMPT) is the cytokine that works through “C-C motif chemokine receptor type 5 (Ccr5)” on muscle stem cells to regenerate.
The therapeutic potential of nicotinamide is validated in the mice model (volumetric muscle loss) for skeletal muscle regeneration. Treatment with a single dose of hrNAMPT at the point of injury led to increased muscle area and decreased fibrotic area at the injury zone.
Read original article: https://www.nature.com/articles/s41586-021-03199-7.pdf