MMP9 and ischemic stroke: Moreover, GRb1 reduced the expression levels of proinflammatory factors, attenuated the activity of MMP-9 (Chen et al., 2015), upregulated the expression of γ-aminobutyric acid (GABA) receptors in I/R rats (Chen et al., 2020), protected BBB integrity in ischemic stroke by suppressing neuroinflammation, decreased the production of MMP-9 and NOX4-derived free radicals (Chen et al., 2015), and regulated the probiotic Lac.H and GABA receptor levels (Chen et al., 2020).