A high fat diet fosters elevated bisretinoids.

Area of Science:

• Ophthalmology
• Metabolic Research
• Cell Biology

Background:

• High dietary fat intake is linked to metabolic issues.
• The impact of high-fat diets (HFD) on photoreceptor cell function and visual cycle adducts is largely unknown.

Purpose of the Study:

• To investigate the effects of an HFD on bisretinoid formation in photoreceptor cells.
• To explore the relationship between HFD, vitamin A transport, and visual cycle chemistry.

Main Methods:

• Mice (C57BL/6J and C57BL/6J^c2j) were fed an HFD or standard diet until 3, 6, or 12 months.
• Bisretinoids were quantified using chromatography.
• In vivo fundus autofluorescence measured bisretinoid levels.
• Retinol-binding protein 4 and vitamin A levels were assessed.
• Phospholipid composition in photoreceptor cells was analyzed.

Main Results:

• HFD-fed mice showed increased bisretinoids and fundus autofluorescence compared to controls.
• Elevated plasma retinol-binding protein 4 and vitamin A were observed in HFD mice.
• Phosphatidylethanolamine, a key reactant for bisretinoids, was increased in HFD mice.
• In contrast, leptin-deficient mice (ob/ob) had elevated retinol-binding protein 4 but not retinal bisretinoids, with reduced photoreceptor viability.

Conclusions:

• High-fat diets accelerate bisretinoid formation in photoreceptor cells, likely due to increased vitamin A delivery and altered phospholipid profiles.
• These findings suggest a link between diet-induced obesity and visual cycle dysfunction.