Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China.
Jiangsu Key Laboratory of Therapeutic Material of Chinese Medicine, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China.
Cell Commun Signal. 2019 Feb 11;17(1):11. doi: 10.1186/s12964-019-0324-8.
Contraction of hepatic stellate cells (HSCs) plays an important role in the pathogenesis of liver fibrosis by regulating sinusoidal blood flow and extracellular matrix remodeling. Here, we investigated how HSC contraction was affected by the natural compound oroxylin A, and elucidated the underlying mechanism.
Cell contraction and glycolysis were examined in cultured human HSCs and mouse liver fibrosis model upon oroxylin A intervention using diversified cellular and molecular assays, as well as genetic approaches.
Oroxylin A limited HSC contraction associated with inhibiting myosin light chain 2 phosphorylation. Oroxylin A blocked aerobic glycolysis in HSCs evidenced by reduction in glucose uptake and consumption and lactate production. Oroxylin A also decreased extracellular acidification rate and inhibited the expression and activity of glycolysis rate-limiting enzymes (hexose kinase 2, phosphofructokinase 1 and pyruvate kinas type M2) in HSCs. Then, we identified that oroxylin A blockade of aerobic glycolysis contributed to inhibition of HSC contraction. Furthermore, oroxylin A inhibited the expression and activity of lactate dehydrogenase-A (LDH-A) in HSCs, which was required for oroxylin A blockade of glycolysis and suppression of contraction. Oral administration of oroxylin A at 40 mg/kg reduced liver injury and fibrosis, and inhibited HSC glycolysis and contraction in mice with carbon tetrachloride-induced hepatic fibrosis. However, adenovirus-mediated overexpression of LDH-A significantly counteracted the oroxylin A's effects in fibrotic mice.
Blockade of aerobic glycolysis by oroxylin A via inhibition of LDH-A reduced HSC contraction and attenuated liver fibrosis, suggesting LDH-A as a promising target for intervention of hepatic fibrosis.
肝星状细胞（HSCs）的收缩在肝纤维化的发病机制中起着重要作用，它可以调节肝窦血流和细胞外基质重塑。在这里，我们研究了天然化合物白杨素 A 如何影响 HSC 的收缩，并阐明了其潜在的机制。
通过多种细胞和分子检测以及遗传方法，研究了白杨素 A 干预培养的人 HSCs 和小鼠肝纤维化模型中 HSC 收缩和糖酵解的情况。
白杨素 A 限制了 HSC 的收缩，同时抑制了肌球蛋白轻链 2 的磷酸化。白杨素 A 通过减少葡萄糖摄取和消耗以及乳酸生成，阻断了 HSCs 的有氧糖酵解。白杨素 A 还降低了细胞外酸化率，并抑制了糖酵解限速酶（己糖激酶 2、磷酸果糖激酶 1 和丙酮酸激酶 M2）在 HSCs 中的表达和活性。然后，我们发现白杨素 A 阻断有氧糖酵解有助于抑制 HSC 收缩。此外，白杨素 A 抑制了 HSCs 中乳酸脱氢酶 A（LDH-A）的表达和活性，这对于白杨素 A 阻断糖酵解和抑制收缩是必需的。40mg/kg 的白杨素 A 口服给药可减轻四氯化碳诱导的肝纤维化小鼠的肝损伤和纤维化，并抑制 HSC 糖酵解和收缩。然而，腺病毒介导的 LDH-A 过表达显著抵消了白杨素 A 在纤维化小鼠中的作用。
白杨素 A 通过抑制 LDH-A 阻断有氧糖酵解，减少 HSC 收缩，减轻肝纤维化，提示 LDH-A 是干预肝纤维化的一个有前途的靶点。
