Objective
Factors and mechanisms that activate macrophages in atherosclerotic plaques are incompletely understood. We examined the capacity of heparanase to activate macrophages.
Results/Methods
Highly purified heparanase was added to mouse peritoneal macrophages (MPM) and macrophage-like J774 cells and the levels of TNFα, MMP-9, IL-1, and MCP-1 were evaluated by ELISA. Gene expression was determined by RT-PCR. Cells collected from Toll like receptor (TLR)-2 and -4 knockout mice (KO) were evaluated similarly. Heparanase levels in the plasma of patients with acute myocardial infarction (MI), stable angina (SA), and healthy subjects were determined by ELISA. Immunohistochemistry was applied to detect the expression of heparanase in control specimens and specimens of patients with SA or acute MI. Addition or over expression of heparanase variants resulted in marked increase in TNFα, MMP-9, IL-1 and MCP-1 levels. MPM harvested from TLR-2 or TLR-4 knockout mice were not activated by heparanase. Plasma heparanase level was higher in patients with acute MI, compared to patients with SA and healthy subjects. Pathologic coronary specimens obtained from vulnerable plaques showed increased heparanase staining compared to specimens of stable plaque and controls.
Conclusion
Heparanase activates macrophages, resulting in marked induction of cytokine expression associated with plaque progression towards vulnerability.
Sarcoidosis is a systemic granulomatous disease of unknown etiology that involves many organs and has different clinical manifestation. We reviewed the clinical manifestations of sarcoid liver disease. Liver involvement in sarcoidosis can be serious and life-threatening, independent of its lung and other organ involvement.
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