Hyperlipidemia Affects Tight Junctions and Pump Function in the Corneal Endothelium.

Area of Science:

• Ophthalmology
• Cardiovascular Biology
• Cell Biology

Background:

• Hyperlipidemia is linked to systemic diseases like atherosclerosis and diabetes.
• The ocular effects of hyperlipidemia, particularly on the cornea, remain largely uncharacterized.

Purpose of the Study:

• To investigate the impact of hyperlipidemia on corneal endothelial cells (CECs) in vivo and in vitro.
• To elucidate the pathological changes and functional consequences of hyperlipidemia in the corneal endothelium.

Main Methods:

• Development of hyperlipidemic murine models using high-fat diets and apolipoprotein E knockout mice.
• In vitro assessment of CECs exposed to hyperlipidemic conditions, including high palmitate levels.
• Microscopic analysis, Oil Red O staining, assessment of tight junctions, Na+-K+-ATPase activity, oxidative stress markers, mitochondrial ultrastructure, and apoptosis.

Main Results:

• Hyperlipidemic mice exhibited lipid droplet accumulation in CECs, reduced cell density, and altered morphology.
• Disruption of endothelial cell junctions, decreased Na+-K+-ATPase function, increased oxidative stress, mitochondrial damage, and apoptosis were observed.
• CEC injury recovery was impaired in hyperlipidemic models, with elevated palmitate in aqueous humor.
• In vitro models confirmed dose-dependent CEC cytotoxicity, morphological changes, reduced pump function, and oxidative stress.

Conclusions:

• Hyperlipidemia induces significant pathological and functional damage to the corneal endothelium.
• Lipid accumulation, oxidative stress, and impaired cellular functions contribute to corneal endothelial dysfunction in hyperlipidemic states.
• These findings highlight a novel link between metabolic dysregulation and ocular surface health, suggesting potential implications for eye diseases.