Hydrogen sulfide and sodium nitroprusside compete to activate/deactivate MMPs in bone tissue homogenates

Figures & data

Figure 1 MMP activity with H₂S.

Notes: MMP activity decreases with increasing H₂S concentration. A significant decrease starts at 16 μM and continues to decrease at 24, 32, and 40 μM with a constant slope.
Abbreviations: MMP, matrix metalloproteinase; H₂S, hydrogen sulfide.

Figure 2 MMP activity with NO.

Notes: MMP activity increases with increasing NO concentration that begins at 1 μM and increases exponentially with each μM added. A trend line is added that shows this exponential increase.
Abbreviations: MMP, matrix metalloproteinase; NO, nitric acid; NaNO, sodium nitroprusside.

Figure 3 H₂S competes to activate/deactivate MMP activity.

Notes: With 40 μM of H₂S added to the solution, MMP activity is turned off. However, as sodium nitroprusside is added, there is an exponential increase in MMP activity.
Abbreviations: MMP, matrix metalloproteinase; NO, nitric acid; H₂S, hydrogen sulfide.

Figure 4 Conversion of latent MMP to active MMP.

Notes: MMP accepts NO, and combines with superoxide to form peroxynitrite that cleaves latent MMP into active MMP. MMP/NO/TIMP proceeds to oxidized TIMP and active MMP.
Abbreviations: MMP, matrix metalloproteinase; NO, nitric acid; NaNO, sodium nitroprusside; H₂S, hydrogen sulfide; TIMP, tissue inhibitor of metalloproteinases.

Figure 5 Balance of MMP activation with H₂S and NO.

Notes: H₂S inhibits conversion of latent MMP to active MMP as well as destruction of the collagen helix caused by oxidative stress. NO promotes oxidative stress by combining with superoxide and forming peroxynitrite, thereby encouraging conversion of latent MMP to active MMP and destruction of the collagen helix.
Abbreviations: MMP, matrix metalloproteinase; NO, nitric acid; H₂S, hydrogen sulfide.