ABSTRACT
nioma endothelial cells.
ABSTRACT
The action mechanism of matrix metalloproteinases-2 (MMP-2) and tissue inhibitor of metalloproteinases-2 (TIMP-2) in the genesis, development and degeneration of haemangioma was in-vestigated by detecting their expression in the tissue of haemangioma in different phases by using the immunohistochemistry. Fifty paraffin-embedded specimens of skin capillary haemangioma were col-lected, which were documented in the Department of Pathology, Renmin Hospital of Wuhan University from 2000 to 2006. All samples were stained by regular HE method, and proliferative cell nuclear anti-gen (PCNA) was tested by immunohistochemical S-P method, The samples were classified according to the Mulliken criteria and the expression pattern of PCNA. Immunohistochemical S-P method was ap-plied to detect the expression of MMP-2 and TIMP-2 in proliferative and degenerative phases of cuta-neous capillary haemangioma, and in normal skin tissues. In combination with the detection of the ex-pression of factor Ⅷ-related antigen, it was verified that in haemangioma tissues, the cells expressing MMP-2 and TIMP-2 were vascular endothelial cells. The MMP-2 and TIMP-2 expression was quantita-tively analyzed by image analysis system (HPIAS-1000), and one-way ANOVA(107) and SNK(q) test were done to analyze average absorbance (A) and positive area rate of immunohistochemically positive particles by using SPSS11.5. The results showed: (1) Among 50 samples of haemangioma, there were 26 proliferative haemangiomas, and 24 degenerative haemangiomas, respectively; (2) The expression of MMP-2 was weak in normal vascular endothelial cells, cytoplasm of connective tissues and extracellu-lar matrix around blood vessels. The expression of MMP-2 in proliferative group was significantly higher than in degenerative group and control group (normal skin) (P<0.05), but there was no statisti-cally significant difference between the latter two groups; (3) TIMP-2 was highly expressed in normal tissues, degenerative vascular endothelial cells, cytoplasm of connective tissues and extracellular matrix around blood vessels. The expression level of TIMP-2 in proliferative phase was significantly lower than in degenerative phase (P<0.05), and the expression of TIMP-2 in proliferative phase was signifi-cantly different from that in degenerative phase and normal tissues (P<0.05). It was concluded that in proliferative phase of haemangioma, MMP-2 may promote over-proliferation of endothelial cells of haemangioma, and in degenerative phase, TIMP-2 can inhibit the proliferation of endothelial cells of haemangioma. The two substances play important roles in the genesis, development and degeneration of haemangiomas.
ABSTRACT
Mouse blastocysts were exposed to doses of 0,1 and 10μmol/L retinoic acid (RA) for 24h and the cytotoxic effect of RA on the mouse blastocysts in vitro was observed. FITC-labeled terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL-FITC) assay was employed to stain apoptotic cells and immunohistochemical S-P staining method was used to detect the expression of Fas protein in mouse blastocysts in vitro. The results showed that RA could induce apoptosis and increase the expression of Fas proteins of trophectoderm (TE) and inner cell mass (ICM) cells in blastocysts. Compared with the findings for the control blastocysts, exposure to RA (10μmol/L) resulted in a more significant apoptosis and higher expression level of Fas proteins (P<0.01). It was concluded that RA could induce apoptosis, which may result in a significant reduction in the average number of total cells and the trophectoderm/inner cell mass in blastocysts and an increased expression of Fas protein, suggesting that RA had a cytotoxic effect on the growth and development of early embryos in mice.