growth factor dependent regulation of skeletal muscle satellite cell proliferation

Definition

Target type: biologicalprocess

Any process that modulates the frequency, rate or extent of satellite cell proliferation; dependent on specific growth factor activity such as fibroblast growth factors and transforming growth factor beta. [GOC:ef, GOC:mtg_muscle, PMID:16607119]

Growth factor-dependent regulation of skeletal muscle satellite cell proliferation is a complex process that plays a crucial role in muscle repair and regeneration. Satellite cells are quiescent, self-renewing stem cells located beneath the basal lamina of muscle fibers. Upon muscle injury, they are activated and undergo a series of events, including proliferation, differentiation, and fusion with damaged muscle fibers to restore muscle mass. Growth factors are key regulators of this process, promoting satellite cell activation, proliferation, and survival. Here's a detailed description:

1. **Activation:** Upon muscle injury, resident macrophages release pro-inflammatory cytokines and growth factors, such as TNF-α and IGF-1, which stimulate satellite cells to exit their quiescent state. This activation involves the expression of genes encoding for cell cycle proteins and growth factor receptors.
2. **Proliferation:** Activated satellite cells proliferate, increasing their numbers to adequately repair the damaged muscle tissue. This proliferation is driven by a complex interplay of various growth factors, including:
* **IGF-1:** Insulin-like growth factor 1 promotes satellite cell proliferation by activating the PI3K/Akt pathway, leading to increased protein synthesis and cell survival.
* **FGF-2:** Fibroblast growth factor 2 acts synergistically with IGF-1 to stimulate satellite cell proliferation and migration.
* **HGF:** Hepatocyte growth factor promotes satellite cell proliferation and differentiation by activating the c-Met receptor, leading to downstream signaling cascades.
* **TGF-β:** Transforming growth factor beta plays a complex role, initially promoting proliferation but later promoting differentiation.
3. **Differentiation:** Proliferating satellite cells differentiate into myoblasts, which express muscle-specific proteins and fuse with each other or with existing muscle fibers to form new muscle tissue. This differentiation process is regulated by various factors, including:
* **Myostatin:** A negative regulator of muscle growth, myostatin inhibits satellite cell proliferation and differentiation.
* **BMPs:** Bone morphogenetic proteins can either promote or inhibit satellite cell differentiation, depending on the specific BMP involved.
* **Wnt signaling:** The Wnt pathway is essential for muscle development and regeneration, promoting both satellite cell proliferation and differentiation.
4. **Fusion:** Differentiated myoblasts fuse with each other and existing muscle fibers, restoring the damaged muscle structure. Fusion requires precise coordination of cell adhesion molecules and cytoskeletal proteins.

The growth factor-dependent regulation of satellite cell proliferation is a highly orchestrated process involving multiple signaling pathways and gene expression changes. Understanding these mechanisms is crucial for developing therapies to enhance muscle regeneration in diseases such as muscular dystrophy and age-related muscle wasting.'
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Proteins (1)

Compounds (3)