Milk fat globule membrane protein promotes C₂C₁₂ cell proliferation through the PI3K/Akt signaling pathway

Area of Science:

• Biochemistry
• Cell Biology
• Molecular Biology

Background:

• Milk fat globule membrane (MFGM) protein is recognized for health benefits, including anti-sarcopenia effects.
• The precise molecular mechanisms underlying MFGM protein's benefits, particularly its impact on muscle health, remain largely unelucidated.

Purpose of the Study:

• To investigate the molecular mechanism by which MFGM protein exerts its effects on cell proliferation.
• To identify the specific components and signaling pathways involved in MFGM protein's action.

Main Methods:

• MFGM protein was fractionated, with Fraction 2 showing the most significant impact on C2C12 cell proliferation.
• Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot assays were employed to analyze key signaling molecules.
• Cells were treated with varying concentrations of Fraction 2, with a focus on the PI3K/Akt/mTOR pathway components.

Main Results:

• Fraction 2, predominantly composed of MFG-E8, significantly enhanced C2C12 cell proliferation in a dose-dependent manner.
• MFGM protein upregulated the mRNA expression of mTOR and P70S6K and promoted the phosphorylation of PI3K, Akt, mTOR, and P70S6K.
• Conversely, Fraction 2 inhibited FOXO3a and 4E-BP, indicating a complex regulatory role.

Conclusions:

• MFGM protein, primarily MFG-E8, stimulates C2C12 cell proliferation.
• The PI3K/Akt/mTOR/P70S6K signaling pathway is the key molecular mechanism mediating the proliferative effects of MFGM protein.
• This research clarifies the mechanism of action for MFGM protein, supporting its potential as a therapeutic agent for muscle-related conditions.