Single-nucleus transcriptomics reveals sepsis-related neurovascular dysfunction in the human hippocampus

Area of Science:

• Neuroscience
• Immunology
• Genomics

Background:

• Sepsis is a significant cause of long-term cognitive impairment.
• The cellular mechanisms behind sepsis-related hippocampal damage are not well understood.

Purpose of the Study:

• To investigate the transcriptional changes in neurovascular cells within the human hippocampus during sepsis.
• To identify specific cell populations and molecular pathways affected by sepsis in the brain.

Main Methods:

• Single-nucleus RNA sequencing was performed on human hippocampal tissues from sepsis patients and controls.
• Transcriptional profiles of various cell types, including astrocytes, microglia, endothelial, and mural cells, were analyzed.

Main Results:

• Sepsis induced significant alterations in 21 cell populations, marked by astrocyte and microglia polarization.
• Astrocytes showed mixed A1/A2 gene expression, while microglia displayed inflammatory (M1-like) or hypo-responsive states.
• Evidence of blood-brain barrier disruption, oxidative stress, and increased astrocyte-microglia communication was observed.

Conclusions:

• A coordinated glial and vascular response to sepsis involves altered cell communication and polarization.
• These changes likely contribute to blood-brain barrier dysfunction, neuroinflammation, and cognitive deficits in sepsis survivors.
• Targeting glial-vascular interactions and cell polarization presents potential therapeutic strategies for post-sepsis neurological issues.