Cellular Senescence Is Associated With Human Retinal Microaneurysm Formation During Aging

Area of Science:

• Ophthalmology
• Gerontology
• Cell Biology

Background:

• Microaneurysms are observed in healthy aging human retinas.
• The underlying age-related mechanisms for microaneurysm formation remain unclear.
• Cellular senescence is a key feature of aging and age-related diseases.

Purpose of the Study:

• To investigate the role of cellular senescence in the formation of microaneurysms in aging human retinas.
• To analyze cellular senescence in the retinas of aging humans and a progeric mouse model.

Main Methods:

• Retinal tissues from human donors and Bmi1-deficient mice were analyzed.
• Techniques included immunohistochemistry, senescence-associated β-galactosidase assay, Sudan black B staining, and electron microscopy.
• Senescence markers (p16, p53, p21), apoptosis, and endothelial cell changes were assessed.

Main Results:

• Neurons and blood vessels in aging human retinas exhibited cellular senescence.
• Senescence markers and apoptosis were present in human microaneurysms.
• A progeric mouse model showed retinal vascular aging and increased microaneurysms, with p21 overexpression.

Conclusions:

• Cellular senescence is identified as a contributing factor in the pathogenesis of retinal microaneurysms in old age.
• The findings suggest potential mechanisms involving endothelial cell apoptosis and anoikis.
• This study links aging processes to retinal vascular pathologies.