Increased YKL-40 expression in patients with carotid atherosclerosis

Atherosclerosis. 2010 Aug;211(2):589-95. doi: 10.1016/j.atherosclerosis.2010.02.035. Epub 2010 Mar 4.


Objective: We hypothesized a role for the inflammatory protein YKL-40 in atherogenesis and plaque destabilization based on its role in macrophage activation, tissue remodeling, and angiogenesis.

Methods: Serum YKL-40 levels were measured by enzyme immunoassay in 89 patients with carotid atherosclerosis and 20 healthy controls. Carotid expression of YKL-40 was examined by real time RT-PCR in 57 of the patients. Regulation and effect of YKL-40 were examined in THP-1 monocytes.

Results: Our main findings were: (1) serum YKL-40 levels were significantly elevated in patients with carotid atherosclerosis, with particularly high levels in those with symptomatic disease; (2) patients with recent ischemic symptoms (within 2 months) had higher YKL-40 mRNA levels in carotid plaque than other patients; (3) in vitro, the beta-adrenergic receptor agonist isoproterenol, toll-like receptor (TLR) 2 and TLR4 agonists, and in particular releasate from activated platelets significantly increased the expression of YKL-40 in THP-1 monocytes and (4) in vitro, YKL-40 increased matrix metalloproteinase-9 expression and activity in THP-1 monocytes, involving activation of p38 mitogen-activated protein kinase.

Conclusions: Our findings suggest that YKL-40 might be a marker of plaque instability, potentially reflecting macrophage activation and matrix degradation within the atherosclerotic lesion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipokines
  • Adult
  • Aged
  • Aged, 80 and over
  • Carotid Artery Diseases / blood*
  • Case-Control Studies
  • Chitinase-3-Like Protein 1
  • Female
  • Gene Expression Regulation
  • Glycoproteins / biosynthesis*
  • Humans
  • Inflammation
  • Lectins / biosynthesis*
  • Macrophage Activation
  • Macrophages / metabolism
  • Male
  • Matrix Metalloproteinase 9 / metabolism
  • Middle Aged
  • Monocytes / cytology
  • Neovascularization, Pathologic
  • Stroke / pathology
  • Ventricular Remodeling
  • p38 Mitogen-Activated Protein Kinases / metabolism


  • Adipokines
  • CHI3L1 protein, human
  • Chitinase-3-Like Protein 1
  • Glycoproteins
  • Lectins
  • p38 Mitogen-Activated Protein Kinases
  • Matrix Metalloproteinase 9