细胞外基质（ECM）结构蛋白的交联重构是肝硬化难以逆转的重要因素。在前一个国家自然基金资助下，我们明确了赖氨酸氧化酶家族（LOXs）中LOXL1可介导弹性蛋白交联，抑制后可使肝硬化近50%的ECM交联降解。但如何进一步打破交联促进ECM重构尚不清楚。近期我们还发现与其他家族成员不同，LOX和LOXL1结构高度相似，表达模式一致，且可能有叠加作用。本课题拟以LOX和LOXL1为切入点，首先利用GFAP-ERCre-LOX，LOXL1及LOX/LOXL1条件性敲除小鼠和3D凝胶星状细胞培养模型，探讨二者对ECM交联重构的共同调控作用及对肝硬化逆转的影响。其次利用脂质纳米颗粒传递小干扰RNA特异性靶向肝脏LOX和LOXL1，分析降解ECM交联作用。最后联合免疫共沉淀和质谱技术分析LOX和LOXL1共同作用中参与的关键ECM组分和降解产物等。本课题旨在为干预交联重构逆转肝硬化提供实验依据。

Crosslinked remodeling of extracellular matrix (ECM) structural proteins is an important factor resulting in the irreversibility of liver cirrhosis. Under the support of the previous National Natural Science Foundation of China (“liver fibrosis reversibility regulated by elastin crosslink and degradation through LOXL-1/Fibulin-5 pathway”, 81670539), we preliminary found that lysyl oxidase like-1 (LOXL1) can mediate the crosslinking of ECM elastin, thus acting a crucial role in liver fibrosis or even cirrhosis development and reversion. Our further study found that LOX and LOXL1 share highly conserved carboxyl terminus and amino terminus and have the same expression pattern with enhanced expression only in advanced liver fibrosis, inhibition of LOX or LOXL1 in human hepatic stellate cells (HSCs) has no influence on each other..In this present study we will consider LOX and LOXL1 as entry points, employ GFAP-ERCre-LOX and/or LOXL1 conditional knockout mice, and LOX and/or LOXL1 silence in HSCs and in vitro models silencing LOX and/or LOXL1 endogenously and exogenously to explore their mutual roles in ECM remodeling and liver fibrosis progression or regression. In addition, we will utilize lipid nanoparticles as vehicle delivering specific small interfering RNAs to silence liver LOX and/or LOXL1 and investigate their synergistic effect on anti-fibrosis effects. Then, co-immunoprecipitation coupled with mass spectrometry will be applied to screen key ECM components involved in the process of LOX/LOXL1 mediated ECM remodeling, and further explore their potential mechanisms. Our study aims to provide potential therapeutic targets and experimental evidence for liver fibrosis prevention and treatment.