Profiling Temporal Changes of the Pineal Transcriptomes at Single Cell Level Upon Neonatal HIBD.

Area of Science:

• Neuroscience
• Developmental Biology
• Chronobiology

Background:

• Neonatal hypoxic-ischemic brain damage (HIBD) is linked to circadian rhythm disorders.
• Pineal gland dysfunction, including cyst formation, is associated with HIBD-induced circadian problems.
• The precise mechanisms of pineal gland involvement in HIBD remain unclear.

Purpose of the Study:

• To molecularly characterize pineal gland cell responses to neonatal HIBD at a single-cell level.
• To identify specific cell types and pathways affected by HIBD in the pineal gland.
• To explore potential therapeutic strategies for HIBD-associated circadian dysfunction.

Main Methods:

• Single-cell RNA sequencing (10x Genomics) was performed on pineal glands at 24 and 72 hours post-neonatal HIBD.
• Bioinformatic analysis was used to identify distinct pineal cell types and their transcriptomic changes.
• Molecular pathways, including pyroptosis, were investigated in affected cells.

Main Results:

• Pinealocytes showed a subtype conversion (β to α) post-HIBD.
• Astrocytes exhibited differential responses, with reactive markers upregulated.
• Microglia were activated and showed a reduction in number, with pyroptosis occurring via the NLRP3-Caspase-1-GSDMD pathway.

Conclusions:

• Neonatal HIBD induces significant temporal molecular and cellular changes in the pineal gland.
• Pineal gland microglia pyroptosis is a key finding, presenting a novel mechanism.
• Targeting pineal gland pyroptosis may offer a therapeutic avenue for improving circadian rhythm disorders in HIBD neonates.