Related Experiment Video

Updated: Aug 27, 2025

Multicolor Flow Cytometry-based Quantification of Mitochondria and Lysosomes in T Cells
06:22

Multicolor Flow Cytometry-based Quantification of Mitochondria and Lysosomes in T Cells

Published on: January 9, 2019

13.1K

mTORC1 Mediates the Processes of Lysine Regulating Satellite Cells Proliferation, Apoptosis, and Autophagy

Mengqi Liu1,2,3,4, Zhengkai Yue1, Bin Zhang1

  • 1Department of Animal Science and Technology, Shandong Agricultural University, Tai'an 271018, China.

Metabolites
|September 23, 2022
PubMed

Insights

Lysine is vital for muscle growth. This study reveals that lysine enhances skeletal muscle satellite cell proliferation and survival by activating the mTORC1 pathway, crucial for protein synthesis.

Area of Science:

  • Muscle physiology and molecular biology
  • Cellular signaling pathways
  • Nutritional biochemistry

Background:

  • Lysine (Lys) is an essential amino acid critical for skeletal muscle growth and protein synthesis in mammals.
  • The precise regulatory mechanisms governing Lys-dependent skeletal muscle development remain largely unelucidated.
  • Understanding the interplay between lysine and key signaling pathways like mTORC1 is crucial for muscle health.

Purpose of the Study:

  • To investigate the potential cross-talk between mammalian targets of rapamycin complex 1 (mTORC1) and lysine in regulating muscle satellite cell (SC) proliferation.
  • To elucidate the role of lysine in modulating SCs' viability, protein synthesis, cell cycling, autophagy, and apoptosis.
  • To determine the involvement of the mTORC1 signaling pathway in mediating lysine's effects on SCs.

Main Methods:

  • Muscle satellite cells (SCs) were treated with lysine-supplemented or lysine-deficient media.
  • Pharmacological modulators of mTORC1, rapamycin (inhibitor) and MHY1485 (activator), were applied to SCs.
  • Assessed SCs viability, protein synthesis, cell cycling, autophagy, and apoptosis under various conditions.

Main Results:

  • Lysine deprivation significantly impaired SCs viability, protein synthesis, and cell cycling, while increasing autophagy and apoptosis, accompanied by mTORC1 pathway inhibition.
  • Restoring lysine levels effectively reversed these detrimental effects.
  • Modulating the mTORC1 pathway (activation during lysine deficiency or inhibition during lysine sufficiency) significantly altered the impact of lysine on SCs.

Conclusions:

  • Lysine plays a significant role in promoting SCs proliferation and survival.
  • Lysine exerts its beneficial effects by inhibiting SCs apoptosis and autophagy, primarily through the mTORC1 signaling pathway.
  • This study highlights the critical link between lysine availability, mTORC1 signaling, and skeletal muscle development.
Keywords:
apoptosisautophagylysinemTORC1 signaling pathwayproliferationsatellite cells

More Related Videos

In Situ Immunofluorescent Staining of Autophagy in Muscle Stem Cells08:35

In Situ Immunofluorescent Staining of Autophagy in Muscle Stem Cells

Published on: June 12, 2017

10.3K
Exploring the Regulation of Lipid Droplet Catabolism through Lipophagy07:20

Exploring the Regulation of Lipid Droplet Catabolism through Lipophagy

Published on: January 31, 2025

621

Related Concept Videos

mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
3.9K
PI3K/mTOR/AKT Signaling Pathway01:22

PI3K/mTOR/AKT Signaling Pathway

The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a...
3.8K
Satellite Stem Cells and Muscular Dystrophy01:21

Satellite Stem Cells and Muscular Dystrophy

Satellite stem cells or myosatellite cells are quiescent stem cells that Alexander Mauro first identified in 1961. These cells are located between the sarcolemma, the plasma membrane of muscle fibers, and the basal lamina, the connective tissue sheath covering it. These mononucleated cells are activated in response to muscle injury, can transform into myoblasts, and may form or repair muscle fibers. Myosatellite cells can provide additional myonuclei for muscle regeneration or return to a...
2.0K
Autophagic Cell Death01:18

Autophagic Cell Death

Christian de Duve discovered “autophagy,” a process in which cellular components are engulfed by membrane-bound organelles called autophagosomes. The autophagosomes then fuse with lysosomes to digest the enclosed contents. Autophagy is generally activated in cells to prevent cell death. However, cell death is triggered when the damage is beyond repair.
Autophagy and Apoptosis
Autophagy can activate apoptosis. In normal conditions, the autophagy activating protein Beclin-1 and...
3.5K
Mesenchymal Stem Cells01:19

Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) are adult stem cells that can differentiate into most connective tissue cell types, except for hematopoietic cells, depending upon the source of MSCs. For example, bone-marrow-derived MSCs (BM-MSCs) can differentiate into osteocytes, hepatocytes, and pancreatic and neuronal cells. MSCs can be isolated from various sources such as bone marrow, placenta, adipose tissue, teeth, and Wharton’s jelly, a gelatinous substance in the umbilical cord. The ease of their...
4.9K
Regulation of the Unfolded Protein Response01:31

Regulation of the Unfolded Protein Response

Inositol-requiring kinase one or IRE1 is the most conserved eukaryotic unfolded protein response (UPR) receptor. It is a type I transmembrane protein kinase receptor with a distinctive site-specific RNase activity. As the binding mechanics of the misfolded proteins with the N-terminal domain of IRE-1 are unclear, three binding models — direct, indirect, and allosteric -- are proposed for receptor activation. Nevertheless, it is known that once a misfolded protein associates with IRE1, it...
2.5K