Fig 2: Effect of crotoxin on the production of MMP-9, MMP-13, cytokines, and chemokines in the 3D collagen gel. Monoculture of human lung fibroblasts MRC-5 and human lung adenocarcinoma cell line A549 incubated with 12.5 nM of CTX for three days; invasion of collagen gel by composite spheroids of MRC-5/A549 at 48 h. After this period, spent media were collected to quantify the volume of MMP-9 (A) and MMP-13 (B) by ELISA. * p < 0.05 compared to the control group. # p < 0.05 compared to the control group. ** p < 0.01 compared to the control group. (n = 6). In (C), cytokine array analysis using composite spheroid invaded gel of at 48 h. The graph indicates the decrease in the growth factors by more than 1.2-folds. A pool of n = 4 was used.

Fig 3: MMP13 serum levels in patients with spinal tuberculosis. MMP13 (A) mRNA and (B) protein levels in the serum of patients with spinal tuberculosis were detected using reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. β-actin was used as a control. *P<0.05 and **P<0.01 vs. the control group. MMP13, matrix metalloproteinase 13.

Fig 4: Astragalin suppressed the mRNA and protein expression of MMPs in TNF-α-induced MH7A cells. MH7A cells were treated with different concentrations of astragalin for 0, 24, 48, and 72 h, and cell viability was measured by CCK-8 assay (A). MH7A cells pretreated for 2 h with various concentrations of astragalin (0, 50, 100, 200 μM), and then exposure to TNF-α (10 ng/ml) for 24 h, the mRNA and protein levels of MMP-1, MMP-3, and MMP-13 were determined using the RT-PCR, ELISA assay, and western blot analysis (B–D). MH7A cells were pretreated with astragalin (200 μM) or not for 2 h, then stimulated with TNF-α for 6 h. Actinomycin D (4 μg/mL) was added to the cells and then mRNA was isolated at time point 0, 2, 4, 6, and 8 h. The levels of MMPs mRNA stability were detected by RT-PCR (E–G). Data are shown as mean ± SEM of three independent experiments. ∗p < 0.05, ∗∗p < 0.01 compared with TNF-α stimulation alone.

Fig 5: Roflumilast reduced IL-18-induced expressions and secretions of MMP-3 and MMP-13 in MH7A FLS. Cells were stimulated with IL-18 (10 ng/mL) in the presence or absence of 5 and 10 μM roflumilast. mRNA of MMP-3 (A) and MMP-13 (B); protein levels of MMP-3 (C) and MMP-13 (D) (####P < 0.0001 vs vehicle group; **P < 0.01, ***P < 0.001 vs IL-18 group).