Clinical analysis of selected complement-derived molecules in human adipose tissue

Area of Science:

• Immunology
• Metabolic Research
• Adipose Tissue Biology

Background:

• The complement cascade (CC) and its anaphylatoxins are implicated in obesity and metabolic disorders.
• The biochemical and immunomodulatory profile of human adipose tissue (AT) in this context is not well understood.
• This study investigates CC-derived molecules and adipsin in human AT and their relationship with stromal-derived factor-1 (SDF-1).

Purpose of the Study:

• To quantify levels of CC-derived anaphylatoxins/molecules and adipsin in human subcutaneous and visceral adipose tissue.
• To compare these levels with those found in plasma.
• To explore associations between these molecules, body composition, and metabolic status.

Main Methods:

• Analysis of 70 adipose tissue samples (35 subcutaneous, 35 omental) from patients undergoing surgery.
• Measurement of C3a, C5a, C5b-9/membrane attack complex (MAC), and adipsin in plasma and AT interstitial fluid using ELISA.
• Correlation analysis with body composition, BMI, and adiposity index.

Main Results:

• Significantly lower levels of all examined CC-derived molecules and adipsin were found in AT compared to plasma (P < 0.0000001).
• Subcutaneous AT showed high concentrations of C3a and adipsin.
• Visceral AT depots exhibited high levels of C5b-9/MAC.
• Correlations were observed between these molecules and patient body composition metrics.

Conclusions:

• Human adipose tissue contains significantly lower levels of complement-derived molecules than peripheral blood.
• These complement factors are associated with the metabolic status of individuals.
• Specific associations exist between complement-derived molecules and SDF-1 levels within human AT.