Target type: biologicalprocess
The orderly movement of a skeletal muscle satellite cell from one site to another. Migration of these cells is a key step in the process of growth and repair of skeletal muscle cells. [GO_REF:0000091, GOC:mr, GOC:TermGenie, PMID:17996437, PMID:19609936]
Skeletal muscle satellite cells (SCs) are quiescent, myogenic stem cells located beneath the basal lamina of muscle fibers. Upon muscle injury, SCs are activated to proliferate and differentiate into myoblasts, which fuse to form new muscle fibers. This process of SC activation and differentiation requires migration of SCs to the site of injury.
SC migration is a complex process involving multiple signaling pathways and cellular interactions. The process can be broadly divided into three main steps:
1. **Activation and detachment:** Upon injury, SCs receive signals from damaged muscle fibers, including factors like transforming growth factor-beta (TGF-β), fibroblast growth factor (FGF), and hepatocyte growth factor (HGF). These factors induce SC activation, causing them to exit quiescence and upregulate expression of genes involved in proliferation and migration. Activated SCs detach from the basal lamina through the action of matrix metalloproteinases (MMPs) and integrin signaling.
2. **Migration:** Once detached, SCs initiate migration towards the injury site. This migration is guided by chemoattractant signals released from damaged muscle fibers and the surrounding microenvironment. These signals include chemokines like stromal cell-derived factor-1 (SDF-1) and growth factors like FGF and HGF. SC migration is facilitated by the cytoskeleton, which undergoes dynamic reorganization to allow for cell movement. SCs can migrate through the extracellular matrix (ECM) by utilizing different mechanisms, including:
* **Chemotaxis:** SCs move in a directed manner towards a chemical gradient.
* **Haptotaxis:** SCs migrate along a substrate gradient.
* **Contact guidance:** SCs follow physical cues in the environment, such as collagen fibers.
3. **Differentiation and fusion:** As SCs migrate towards the injury site, they interact with other cells, including myoblasts and fibroblasts. These interactions contribute to the final differentiation of SCs into myoblasts. The myoblasts then fuse with each other and with pre-existing muscle fibers to form new muscle fibers. This process is regulated by a complex interplay of transcription factors and signaling pathways.
In summary, SC migration is a critical step in muscle regeneration. This process is highly regulated by various signaling pathways, cellular interactions, and environmental cues. Understanding the molecular mechanisms underlying SC migration is crucial for developing therapeutic strategies to promote muscle regeneration and repair in diseases and injuries.'
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Protein | Definition | Taxonomy |
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Transforming protein RhoA | A GTP-binding protein RhoA that is encoded in the genome of human. [PRO:CNA, UniProtKB:P61586] | Homo sapiens (human) |
Compound | Definition | Classes | Roles |
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ccg-203971 |