ABSTRACT
Objective: To establish a real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) method for examining the expression of sialic acid-binding immunoglobulin-like lectin-one (Siglec-1)gene in the peripheral blood mononuclear cells (PBMCs) in patients with coronary heart disease (CHD),so as to explore the relationship between Siglec-1 mRNA expression and the development/progression of CHD. Methods: Based on the fluorescent SYBR Green method, a real-time quantitative RT-PCR was set up. The expression of Siglec-1 gene in the PBMCs of 57 patients with CHD and 38 healthy controls were measured by ABI PRISM 7000 Sequence Detection Systems. The blood lipid levels were determined in all the subjects by routine biochemical examination. Results: The mean Siglec-1 mRNA copy was significantly higher in the CHD group than that in the healthy control group (mean 3.23 folds, ranging 1.28-8.11 folds, P < 0.01). The expression in the acute myocardial infarction group,stable angina and unstable angina group were 3.32(1.38-7.97),2.56(0.88-7.42),and 3.35(1.25-8.96) folds that of the control group,respectively. No significant difference was observed in the normalized Siglec-1 mRNA copy number between CHD group with normal level of serum lipids and abnormal level of serum lipids. Conclusion: A real-time quantitative RT-PCR method for detecting the expression of Siglec-1 gene in PBMCs has been successfully established. The expression of Siglec-1 is dramatically increased in PBMCs in CHD patients.
ABSTRACT
Objective:To explore the role of sialic acid-binding immunoglobulin-like lectin-one (Siglec-1) in oxidized lowdensity lipoprotein (ox-LDL)-induced atherosclerotic inflammation. Methods: Ox-LDL was prepared by oxidization of native LDL ;different concentrations of ox-LDL were used to treat U937 cells for 48 h. Cells and supernatants were collected. The expression of Siglec-1 protein and mRNA was examined by flow cytometry (FCM) and real-time quantitative RT-PCR, respectively. The levels of MIP-1α, MCP-I and IL-8 in the supernatants were determined by ELISA. Results: Stimulation with ox-LDL significantly increased Siglec-1 protein and mRNA in U937 cells compared with the control group ( P < 0. 01). Meanwhile, the levels of MIP-Iα, MCP-I and IL-8 in the supernatants were also significantly increased in a concentration-dependent manner compared with those in the control group(P<0. 01). Conclusion: The proatherogenic effect of ox-LDL may be partly through up-regulating Siglec-1 expression in macrophages and enhancing the expression of inflammatory cytokines and chemokines. The activated macrophages recruit more macrophages and lymphocytes to the site of atherosclerotic plaques and exacerbate the inflammatory responses.
ABSTRACT
Primary biliary cirrhosis (PBC) is an autoimmune disease with unknown causes. Most PBC patients have abnormal lipid metabolism characterized by hypercholesterolemia. Paradoxically, clinical observations and pre-experimental studies showed that the risk of hyperlipidemia associated cardiovascular event and the mortality of PBC patients were not increased. In this review we summarize the possible reasons and the underlying mechanisms.