Visceral fat-based
metabolic syndrome has a strong impact on atherosclerotic
cardiovascular disease (CVD), clustering diabetes,
dyslipidemia,
hypertension,
hyperuricemia, and
non-alcoholic fatty liver disease (
NAFLD).
Adiponectin, a
protein specifically secreted by adipocytes, circulates abundantly in the human bloodstream, but its concentration decreases under pathological conditions such as visceral fat accumulation. Extensive clinical evidence has demonstrated that
hypoadiponectinemia is associated with the development of CVD and chronic organ diseases. Although several binding partners of
adiponectin, such as AdipoR1/2, have been identified, how
adiponectin exerts its multiple beneficial effects on various organs remains to be fully elucidated. Recent progress in
adiponectin research has revealed that
adiponectin accumulates on cardiovascular tissues by binding to a unique
glycosylphosphatidylinositol-anchored
T-cadherin. The
adiponectin/
T-cadherin complex enhances exosome biogenesis and secretion, which may contribute to the maintenance of cellular homeostasis and tissue regeneration, particularly in the vasculature.
Xanthine oxidoreductase (XOR) is a rate-limiting
enzyme that catabolizes
hypoxanthine and
xanthine to
uric acid. XOR produces
reactive oxygen species in the reaction process, suggesting that XOR is involved in the pathological mechanism underlying CVD progression. Recent findings from clinical and laboratory studies have shown strong positive correlations between plasma XOR activity and liver
enzymes. Furthermore, especially in
NAFLD conditions, excessive hepatic XOR leaked into the bloodstream accelerates
purine catabolism in the circulation, using
hypoxanthine secreted from vascular endothelial cells and adipocytes, which can promote
vascular remodeling. In this review, we focused on the cardiovascular significance of adipose-derived
adiponectin and liver-derived XOR in the development of CVD associated with
metabolic syndrome.