Kallistatin attenuates endothelial senescence by modulating Let-7g-mediated miR-34a-SIRT1-eNOS pathway.

Area of Science:

• Vascular Biology
• Cellular Senescence
• Molecular Mechanisms

Background:

• Endothelial senescence contributes to vascular dysfunction and aging.
• Kallistatin is a plasma protein with known protective roles against vascular injury.

Purpose of the Study:

• To investigate the role and mechanism of kallistatin in endothelial senescence.
• To elucidate kallistatin's effects on oxidative stress and inflammation in endothelial cells.

Main Methods:

• Human endothelial cells treated with H2O2 and kallistatin.
• Analysis of senescence markers (β-galactosidase, p16INK4a), oxidative stress markers (superoxide, NADPH oxidase), inflammatory markers (VCAM-1, ICAM-1, IL-6, miR-34a), and antioxidant enzymes (eNOS, SIRT1, catalase, SOD-2).
• Experiments using endothelium-specific kallistatin knockout mice and Let-7g inhibitors.

Main Results:

• Kallistatin inhibited H2O2-induced endothelial senescence, oxidative stress, and inflammation.
• Kallistatin upregulated antioxidant enzymes (eNOS, SIRT1, catalase, SOD-2) and downregulated pro-senescence/inflammatory factors (miR-34a).
• Kallistatin's effects were mediated by the SIRT1-eNOS pathway and Let-7g upregulation, which inhibited miR-34a.

Conclusions:

• Endogenous kallistatin protects against endothelial senescence via the Let-7g-mediated miR-34a-SIRT1-eNOS pathway.
• Kallistatin exhibits anti-senescence, anti-oxidant, and anti-inflammatory properties in endothelial cells.
• Kallistatin represents a potential therapeutic target for age-related vascular diseases.