Discovery of fibroblast growth factor 2-derived peptides for enhancing mice skeletal muscle satellite cell proliferation.

Skeletal muscle satellite cells (SCs) are essential for muscle regeneration. Their proliferation and differentiation are influenced by fibroblast growth factor (FGF)-2. In this study, we screened for FGF-2-derived peptides that promote SC proliferation.

Detection of muscle stem cell-derived myonuclei in murine overloaded muscles.

Muscle satellite cells (MuSCs) supply nuclei to existing myofibers in response to mechanical loading. This myonuclear accretion is critical for efficient muscle hypertrophy. Herein, we present protocols for the detection of MuSC-derived new myonuclei in loaded mouse muscle, including procedures for EdU injection to stain myonuclei, followed by surgery and skeletal muscle fixation.

Relayed signaling between mesenchymal progenitors and muscle stem cells ensures adaptive stem cell response to increased mechanical load.

Adaptation to mechanical load, leading to enhanced force and power output, is a characteristic feature of skeletal muscle. Formation of new myonuclei required for efficient muscle hypertrophy relies on prior activation and proliferation of muscle stem cells (MuSCs). However, the mechanisms controlling MuSC expansion under conditions of increased load are not fully understood.

Exercise/Resistance Training and Muscle Stem Cells.

Skeletal muscle has attracted attention as endocrine organ, because exercise-dependent cytokines called myokines/exerkines are released from skeletal muscle and are involved in systemic functions. While, local mechanical loading to skeletal muscle by exercise or resistance training alters myofiber type and size and myonuclear number. Skeletal muscle-resident stem cells, known as muscle satellite cells (MuSCs), are responsible for the increased number of myonuclei.

Dlk1 regulates quiescence in calcitonin receptor-mutant muscle stem cells.

Muscle stem cells, also called muscle satellite cells (MuSCs), are responsible for skeletal muscle regeneration and are sustained in an undifferentiated and quiescent state under steady conditions. The calcitonin receptor (CalcR)-protein kinase A (PKA)-Yes-associated protein 1 (Yap1) axis is one pathway that maintains quiescence in MuSCs. Although CalcR signaling in MuSCs has been identified, the critical CalcR signaling targets are incompletely understood.

Site-specific HNK-1 epitope on alternatively spliced fibronectin type-III repeats in tenascin-C promotes neurite outgrowth of hippocampal neurons through contactin-1.

The human natural killer-1 (HNK-1) carbohydrate epitope, composed of a unique sulfated trisaccharide (HSO3-3GlcAβ1-3Galβ1-4GlcNAc-R), is highly expressed during brain development and regulates higher brain function. However, it remains unclear which glycoprotein carries the HNK-1 epitope in the embryonic brain and the functional role it plays. Here, we showed that one of the major HNK-1 carrier proteins in the embryonic brain is tenascin-C (TNC), an extracellular matrix protein that regulates neurite outgrowth by interacting with the GPI-anchored protein contactin-1 (CNTN).