Saturable leptin transport across the BBB persists in EAE mice

Area of Science:

• Neuroimmunology
• Endocrinology
• Neuroscience

Background:

• Experimental autoimmune encephalomyelitis (EAE) is a mouse model for multiple sclerosis (MS).
• Leptin receptor expression is upregulated in astrocytes within the hippocampus during EAE.
• Elevated serum leptin levels can worsen EAE severity.

Purpose of the Study:

• To investigate the regulation of leptin transport across the blood-brain barrier (BBB) in EAE mice.
• To determine how leptin transport is affected in the brain and spinal cord during different stages of EAE.

Main Methods:

• Utilized (125)I-leptin and (131)I-albumin to measure brain and cervical spinal cord uptake in EAE mice.
• Employed intravenous delivery and in situ brain perfusion techniques.
• Assessed leptin transport via competitive inhibition studies with unlabeled leptin.

Main Results:

• Confirmed the persistence of a saturable leptin transport system across the BBB in EAE mice.
• Demonstrated a time- and region-specific upregulation of leptin transport in the hippocampus and cervical spinal cord during the early stage of EAE.
• Observed increased leptin uptake in these regions, indicating enhanced transport.

Conclusions:

• EAE induces a specific increase in leptin transport across the BBB.
• Enhanced leptin transport and signaling in the brain may contribute to EAE pathogenesis and progression.
• Findings link circulating leptin levels to central nervous system leptin signaling during autoimmune disease.