MMP9 and brain ischemia: This metabolic heterogeneity may be driven by multidimensional pathological processes such as mitochondrial oxidative phosphorylation uncoupling caused by cerebral ischemia (Normoyle et al., 2015; Chen et al., 2011; Grasmick et al., 2018), reactive oxygen species (ROS) burst caused by glial activation (Liao et al., 2020), and matrix metalloproteinase (MMP-9)-mediated basement membrane degradation in neurovascular units (Ji et al., 2023), which jointly induce network decompensation of biochemical homeostasis (Au and Makowski, 2018).