Matrix metalloproteinase-1 (MMP-1) is a major interstitial collagenase in humans. It degrades collagen molecules at the triple helical domain and regulates extracellular matrix turnover [
1]. In addition, it has been reported to induce human capillary tubular network collapse, leading to regression [
2] and activate transforming growth factor (TGF)-β [
3]. However, the exact mechanism of MMP-1 underlying liver fibrosis and angiogenesis in the early-stage nonalcoholic steatohepatitis (NASH) remains unknown. …