MMP2 and aortic aneurysm: Zhu et al. (2022) discovered that older mice lacking CSE show significant enlargement of the aorta and deterioration of elasticity, making them more vulnerable to aortic damage caused by Ang II. Exogenous H2S donor NaHS protected mice from Ang II-stimulated elastin fragmentation and aortic dilation. H2S modifies Sp1 via S-sulfhydration, reducing Sp1 binding to the MMP2 promoter, thereby decreasing MMP2 expression, maintaining elastin levels, and reducing aortic aneurysm pathology (Zhu et al., 2022).