Gelatinases Increase in Bleomycin-induced Systemic Sclerosis Mouse Model.

Systemic sclerosis is a fibrotic autoimmune disease in which aberrant remodeling of the extracellular matrix in organs disturbs their functionalities. The aim of this study was to investigate the expression of gelatinases on systemic sclerosis. Consequently, a mouse model of systemic sclerosis was employed and the gelatinolytic activity of gelatinases was evaluated on the fibrotic tissues of this model. Two groups of ten mice were considered in this work: a group of systemic sclerosis model and control group. For the generation of systemic sclerosis model, mice received bleomycin, while the control group was subjected to phosphate buffered saline (PBS) reception. Mice were tested for fibrosis by using trichrome staining, hydroxyproline measurement and α-SMA detection in tissue sections. Additionally, the gelatinolytic activity of matrix metalloproteinase 2 and matrix metalloproteinase 9 were measured using gelatin zymography in lungs and skin tissue homogenates. The obtained results indicated that subcutaneous injection of bleomycin-induced fibrosis in skin and lung tissues of mice. Pro and active forms of matrix methaloproteinase 9 were increased in fibrotic lung tissues (p<0.05 and p<0.01, respectively), while, the gelatinolytic activity of MMP2 was unaffected in these tissues. Additionally, in skin tissues of bleomycin-treated animals, both pro and active forms of MMP9 and MMP2 were increased (p<0.05). Pro and active forms of gelatinases increase differently in skin and lung tissues of bleomycin-induced scleroderma.

Effect of Progesterone on Expression of MMP7 and MMP13 in Lungs of Female Mice.

Gender medicine is a new era of science which focuses on the impact of sex hormones and gender on normal physiology, pathobiology and clinical features of diseases. In this study we investigated the impact of pregnancy doses of progesterone hormone on the expression of a couple of matrix metalloproteinase (MMPs), which are known to be involved in tissue remodeling of lungs in health and disease, namely MMP7 and 13. Pregnancy maintenance dose of progesterone was administered to female BALB/c mice for 21 and 28 days, the control group received PBS for the same days. After removal of the lungs and RNA extraction, quantitative real-time PCR was done using specific primers for MMP7 and MMP13. We found that progesterone can slightly (not significantly) decrease the expression of MMP13 but had no effect on MMP7. Our results shows that progesterone has minimal effect on the expression of matrix metalloproteinase7 and matrix metalloproteinase 13, but it may still have an effect on corresponding tissue inhibitor of matrix metalloproteinases (TIMPs) or other components of the Extracellular matrix  which remains to be elucidated. Also, the effect of progesterone on these MMPs can be further studied in a fibrosis model.