Inhibition of Metalloproteinases Extends Longevity and Function of In Vitro Human iPSC-Derived Skeletal Muscle

Area of Science:

• Cell Biology
• Biotechnology
• Biomaterials Science

Background:

• In vitro culture longevity is crucial for disease modeling and drug testing, especially with contractile cells like skeletal muscle.
• Cell detachment due to dynamic cell behavior, such as forceful contractions, limits long-term studies.
• Extracellular matrix (ECM) degradation by enzymes is a key factor in cell detachment.

Purpose of the Study:

• To investigate if regulating ECM dynamics can prolong the attachment of human induced pluripotent stem cell (iPSC)-derived skeletal muscle (SKM) cultures.
• To determine the effect of inhibiting matrix metalloproteinases (MMPs) on SKM culture longevity.
• To assess the functional impact of modulating ECM dynamics on myotube performance.

Main Methods:

• Utilized human iPSC-derived skeletal muscle (SKM) cultures.
• Administered MMP inhibitors (tempol, doxycycline) and an MMP inducer (PMA).
• Assessed cell attachment duration, myofiber function (fatigue index, fidelity), and MMP activity via gel zymography.

Main Results:

• SKM cultures treated with MMP inhibitors remained adhered for up to 80 days.
• Inhibitor-treated cells showed a reduced fatigue index, while PMA-treated cells detached prematurely and had increased fatigue.
• Gel zymography confirmed MMP inhibition and induction, correlating with observed cell behavior.

Conclusions:

• Regulating ECM dynamics by inhibiting MMPs effectively maximizes in vitro myotube longevity.
• This strategy provides a valuable tool for long-term disease modeling and chronic therapeutic effect evaluation.
• The findings support the hypothesis that controlling ECM turnover is key to sustained in vitro cell culture.