[Effects of PPAR-gamma agonist rosiglitazone on MMP-9 and TIMP-1 expression of monocyte-derived macrophages isolated from patients with acute coronary syndrome].

OBJECTIVE: Coronary arterial plaque rupture and secondary thrombosis are the major pathogenesis of acute coronary syndrome (ACS). Metalloprotease (MMPs) secreted by monocyte/macrophage was the main predisposing factor of the plaque rupture and peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is involved in a variety of inflammatory cytokine gene transcriptional regulations. We explored the possible role of PPAR-gamma in the regulation of MMP-9 and TIMP-1 expressed by peripheral monocyte-derived macrophages (MDMs) from patients with ACS. METHODS: Peripheral blood mononuclear cells were isolated from 48 patients with ACS and 28 healthy controls and stimulated by macrophage colony-stimulating factor (0.1 microg/ml for 24 hours) to form MDMs. MDMs were then incubated under various concentrations of rosiglitazone (0, 1, 10, 20 micromol/L) for 48 hours. The concentrations of MMP-9 and TIMP-1 in the supernatant were measured by enzyme linked immunosorbent assay, and the mRNA expression of PPAR-gamma, MMP-9 by RT-PCR and nuclear factor-kappaB P65 (NF-kappaB P65) expression by immunohistochemistry. RESULTS: PPAR-gamma mRNA expression was significantly lower while NF-kappaB P65 and MMP-9 expression as well as MMP-9 and TIMP-1 concentrations in supernatant were significantly higher in ACS group than those in control group (all P < 0.05). After rosiglitazone intervention, PPAR-gamma mRNA expression was significantly upregulated in both ACS and control groups in a dose-dependent manner. Both the MMP-9 concentration in the supernatant and MMP-9 mRNA expression were reduced post intervention with rosiglitazone in both groups. The TIMP-1 mRNA expression and concentration in supernatant were not affected by rosiglitazone in both groups. Rosiglitazone induced significant downregulation of NF-kappaB P65 expression in both groups. CONCLUSION: Rosiglitazone intervention may downregulate MMP-9 expression by upregulating PPAR-gamma expression, and by downregulating NF-kappaB expression in MDMs isolated from patients with ACS.

[Discovery of anatase in atmospheric inhalable particles and its significance].

Laser Raman microprobe (LRM) is a reliable technique for phase identification to analyze the molecular composition and microstructure on 1 microm2 area of samples, and therefore, it is well-suited for identifying the mineral phases of single fine particles. In the present paper, we utilized LRM to identify the mineral phases of the single inhalable particles (PM10) from samples in Beijing City and compared the Raman microscopic spectra of samples with the standard spectra of mineral and inorganic material of Renishaw's database. Then we confirmed, for the first time, that the mineral phase of Ti-rich particles in the environmental atmosphere is the anatase TiO2, whose Raman spectrum has a strong O-Ti-O band at 638 cm(-1) and two medium O-Ti-O bands at 398 and 517 cm(-1) respectively. Thus it ensures the existence of TiO2 particles in PM10. Anatase is an important photocatalyst which can speed up the heterogeneous reaction between mineral particles, especially the calcium carbonates, when carried by these particles. Furthermore, the crystal structure of anatase, relative humidity of environment and the surface pH value can significantly influence the photocatalysis of anatase in atmosphere.