Characterization of LSD1 Expression Within the Murine Eye

Area of Science:

• Ophthalmology
• Molecular Biology
• Epigenetics

Background:

• Lysine-specific demethylase 1 (LSD1) is a key epigenetic regulator involved in neuronal differentiation.
• Understanding the spatial and temporal expression of LSD1 in the retina is crucial for elucidating its role in ocular development and function.

Purpose of the Study:

• To characterize the endogenous expression patterns of LSD1 and its substrates, H3K4me1 and H3K4me2, within the developing and adult murine retina.
• To determine the localization and protein levels of LSD1 and H3K4me1/2 across different developmental stages in the murine eye.

Main Methods:

• Immunofluorescent microscopy was employed on murine eye sections to visualize LSD1, H3K4me1, and H3K4me2.
• Western immunoblotting was utilized to quantify protein levels and confirm localization.
• Analysis spanned across various postnatal developmental time points (P2, P7, P14, P36).

Main Results:

• Retinal LSD1 levels peaked at postnatal day 7 (P7), while its substrates H3K4me1/2 peaked at P2 and P14.
• Protein concentrations decreased to approximately 60% by P36, with LSD1 and H3K4me1/2 initially uniformly expressed in retinal progenitor cells.
• By P36, LSD1 expression varied in the ganglion cell layer and photoreceptors but remained uniform in the inner nuclear layer; H3K4me1/2 expression stayed uniform across layers. LSD1 was also detected in the lens, cornea, and retinal pigment epithelium.

Conclusions:

• The uniform expression of LSD1 in retinal progenitor cells aligns with its known role in neuronal differentiation.
• Varied LSD1 expression in adult photoreceptors, including a ring-like pattern in rod nuclei, suggests unique epigenetic regulation in these cells.
• These findings provide a foundational understanding of endogenous LSD1 expression in the eye, guiding future investigations into its specific roles in ocular structure and cell type development.