Lipid-laden cells differentially distributed in the aging brain are functionally active and correspond to distinct...

Area of Science:

• Neuroscience
• Cell Biology
• Aging Research

Background:

• Lipid-laden cells (LLCs) are increasingly recognized in aging tissues.
• Their presence and role in the aging brain remain incompletely understood.

Purpose of the Study:

• To characterize cerebral Oil Red O-positive lipid-laden cells (LLCs) in aging mice.
• To evaluate their distribution, morphology, density, functional activities, and inflammatory phenotype.

Main Methods:

• Histological analysis of brain tissue from aging mice using Oil Red O staining.
• Immunohistochemistry to identify cell markers (PLIN, beclin-1, LC3, β-galactosidase, TNF-α, NeuN, GFAP, Iba-1, S100β).

Main Results:

• Cerebral LLCs were identified in meningeal, cortical, and neurogenic regions, increasing with age.
• LLCs exhibited varying lipid droplet sizes and distributions, with some showing autophagosome markers (beclin-1, LC3) and perilipin (PLIN), indicating lipophagic activity.
• Senescence (β-galactosidase activity) and pro-inflammatory cytokine TNF-α production were observed in cortical LLCs, which also expressed PLIN.

Conclusions:

• Cerebral LLCs display diverse phenotypes in aging mice, including lipophagic and senescent characteristics.
• These cells express pro-inflammatory markers and may contribute to age-associated neuroinflammation.