Adiponectin complexes in human cerebrospinal fluid: distinct complex distribution from serum.

Area of Science:

• Endocrinology
• Neuroscience
• Metabolic Research

Background:

• Adiponectin is an adipocyte-secreted hormone regulating energy homeostasis.
• Its presence and complex forms in human cerebrospinal fluid (CSF) remain unclear.
• Adiponectin exists in serum as distinct functional complexes (e.g., trimers, hexamers).

Purpose of the Study:

• To determine if adiponectin is present in human CSF.
• To investigate the specific adiponectin complexes found in CSF compared to serum.
• To examine potential sex-related differences in CSF adiponectin distribution.

Main Methods:

• Analysis of matched serum and CSF samples from 22 human subjects (11 men, 11 women).
• Quantification of total adiponectin and its oligomeric complexes (hexameric, trimeric, and high-molecular-weight forms).
• Comparison of adiponectin levels and complex distribution between sexes.

Main Results:

• Adiponectin is present in human CSF at approximately 0.1% of serum concentration.
• CSF contains only trimeric and low-molecular-mass hexameric adiponectin complexes, unlike serum.
• A bias towards the trimeric form was observed in CSF.
• Male subjects exhibited a higher CSF:serum ratio of total adiponectin and slightly higher trimer levels.

Conclusions:

• The trimeric form of adiponectin is the predominant oligomer in human CSF.
• Adiponectin crosses the blood-brain barrier, with specific oligomers being selectively transported or processed.
• Sex influences the distribution of adiponectin and its complexes in the central nervous system.