Expression of MMP-2 and MMP-13 in Bullous Pemphigoid

Objective:To investigate the expression and significance of matrix metalloproteinase-2(MMP-2)and matrix metalloproteinase-13(MMP-13)in bullous pemphigoid(BP)skin lesions.Methods:Immunohistochemical SP method was used to detect the expression of MMP-2 and MMP-13 in 32 BP skin lesions,and compared with 15 normal skin tissues.Results:The expression of MMP-2 in the case group was significantly increased(38.56±10.06)compared to the normal control group(21.20±5.98);the expression of MMP-13 in the case group was significantly augmented(18.62±5.90)compared to the normal control group(11.47±8.484).The expressions of MMP-2 and MMP-13 in the skin lesions of patients with bullous pemphigoid were statistically different from those of normal people(both P<0.05).Compared with the expression of MMP-2 and MMP-13 in bullous pemphigoid,the expression of MMP-2 and MMP-13 was moderately correlated(correlation coefficient was 0.523).Conclusion:The expression of MMP-2 and MMP-13 is significantly increased in bullous pemphigoid skin lesions,suggesting that they may play an important role in the pathogenesis of BP.There is a certain correlation between the expression of MMP-2 and MMP-13,suggesting that the high expression of MMP-13 may play a role in the mechanism that further leads to the high expression of MMP-2.

Madecassoside impedes invasion of rheumatoid fibroblast-like synoviocyte from adjuvant arthritis rats via inhibition of NF-κB-mediated matrix metalloproteinase-13 expression

Fibroblast-like synoviocytes(FLS) play a pivotal role in Rheumatoid arthritis(RA) pathogenesis through aggressive migration and invasion. Madecassoside(Madec), a triterpenoid saponin present in Centella asiatica herbs, has a potent anti-inflammatory effect. In the present study, Madec exerted an obvious therapeutic effect in reversing the histological lesions in adjuvant-induced arthritis(AIA) rats. To recognize the anti-rheumatoid potentials of Madec, we further investigated whether Madec interfered with FLS invasion and metalloproteinase(MMP) expression. In cultures of primary FLS isolated from the AIA rats, Madec(10 and 30 μmol·L–1) was proven to considerably inhibit migration and invasion of FLS induced by interleukin 1β(IL-1β), but exhibiting no obvious effect on cell proliferation. Madec repressed IL-1β-triggered FLS invasion by prohibiting the expression of MMP-13. Additionally, Madec suppressed MMP-13 transcription via inhibiting the MMP-13 promoter-binding activity of NF-κB. Our results further showed that Madec down-regulated the translocation and phosphorylation of NF-κB as demonstrated by Western blotting and immunofluorescence assays. In conclusion, our results suggest that Madec exerts anti-RA activity via inhibiting the NF-κB/MMP-13 pathway.

Structure-based Screening for the Non-zinc-chelating Selective MMP-13 Inhibitors of Natural Products

Matrix metalloproteinase-13(MMP-13) has been considered as a promising therapeutic target for osteoarthritis. In this work, the experimental crystal structures of five MMP-13-ligand complexes are used to build the multiple structure-based pharmacophore model of MMP-13 inhibitors. The reliability of pharmacophore model is validated using a decoy set. The pharmacophore model contains four chemical features: two hydrogen bond acceptor(HBA), one hydrophobic(HY) feature, and one ring aromatic(RA) feature. Particularly, the HY feature is found to orient the MMP-13 inhibitors deep into the S1’ pocket of MMP-13 to produce selective inhibition. By carrying out the screening of pharmacophore model and subsequent molecular docking, the four non-zinc-chelating selective MMP-13 inhibitors of natural products(NP-015973, NP-000814, STOCK1 N-24933, and STOCK1 N-69443) are identified. It is found that the binding modes of MMP-13 with our screened four natural products are very similar to the reported experimental binding mode of MMP-13 with the most active inhibitor(GG12003, IC50: 0.67 n M), and each of them involves the interactions of a ligand with the three amino acid residues Thr226, Lys119, and His201 of MMP-13 receptor. This shows that our modeling results are in good agreement with the relevant experimental results, which strongly supports our screened MMP-13 inhibitors of natural products. These screened natural products may be used as the lead compounds of MMP-13 inhibitors in the future studies of structural modifications.

Iksan526 Rice Callus Extract Induces Dedifferentiation of Rabbit Articular Chondrocytes via ERK1/2 and PI-3K/Akt Pathways

The resveratrol-enriched transgenic rice line Iksan526(IS526),first developed by the Rural Development Administration of Korea using genetic engineering techniques,shows beneficial health effects in mitigating metabolic syndrome and obesity.However,the effects of IS526 on the differentiation of chondrocytes and the underlying mechanism have not been investigated in detail.In this study,the effects and cellular regulatory mechanisms of IS526 on rabbit articular chondrocytes were examined.Following IS526 callus extract treatment,the expression levels of differentiation-related proteins were detected via western blotting,Alcian blue staining and immune-luorescence staining.IS526 decreased the type Ⅱ collagen and proteoglycan levels in dose-and time-dependent manners.We further analyzed the effects of IS526 on skeleton genesis in zebrafish larvae using Alcian blue staining,which showed a reduction in cartilage formation along with increased production of matrix metalloproteinase(MMP)-13.IS526 also increased the phosphorylation of ERK1/2 and p38 kinase but inhibited the phosphorylation of Akt.Pharmacological inhibition of MMP-13 blocked the IS526-induced decrease in type Ⅱ collagen levels.Inhibition of p38 kinase or PI-3K/Akt with SB203580 and LY294002 enhanced the suppression of type Ⅱ collagen,but the blockage of ERK-1/2 by PD98059 rescued IS526-induced dedifferentiation.These results suggested that IS526 regulates type Ⅱ collagen and MMP-13 expression via the ERK1/2 and PI-3K/Akt pathways in rabbit articular chondrocytes.