Stromal-Like Cells and Retinal Pigment Epithelium Modulate Choroidal Sprouting Through Galectin-1-Dependent and...

Area of Science:

• Ophthalmology
• Molecular Biology
• Cell Biology

Background:

• Outer retinal function relies on the retinal pigment epithelium (RPE) and choroid.
• Intercellular networks sustaining RPE/choroid are not fully understood.
• Galectin-1 (Gal1) is implicated in angiogenesis and vascular diseases like age-related macular degeneration.

Purpose of the Study:

• Investigate Gal1 expression in the outer retina.
• Determine Gal1's regulatory role in the RPE/choroid under physiological and pathological conditions.

Main Methods:

• Analysis of Gal1 expression in wild-type and Gal1-deficient (Lgals1-/-) mice.
• Assessment of RPE/choroid ultrastructure and gene expression.
• Choroidal explant sprouting assays.
• In vitro studies with stromal-like cells and recombinant Gal1 under hypoxic conditions.

Main Results:

• Gal1 is primarily found in RPE/choroid stromal cells.
• Gal1 deficiency alters RPE/choroid structure and gene expression, reducing choroidal sprouting.
• Recombinant Gal1 promotes choroidal sprouting under hypoxia.
• Stromal-like cells modulate angiogenic gene expression in vitro.
• RPE secretes Gal1 apically in normoxia and basolaterally in hypoxia.

Conclusions:

• Stromal-like cells and RPE are key Gal1 sources in the choroid.
• Gal1 plays distinct roles in maintaining RPE/choroid homeostasis in healthy and pathological states.
• Gal1 influences choroidal angiogenesis and RPE function.