Inhibiting ACSL1-Related Ferroptosis Restrains Murine Coronavirus Infection

Murine hepatitis virus strain A59 (MHV-A59) was shown to induce pyroptosis, apoptosis, and necroptosis of infected cells, especially in the murine macrophages. However, whether ferroptosis, a recently identified form of lytic cell death, was involved in the pathogenicity of MHV-A59 is unknown. We utilized murine macrophages and a C57BL/6 mice intranasal infection model to address this. In primary macrophages, the ferroptosis inhibitor inhibited viral propagation, inflammatory cytokines released, and cell syncytia formed after MHV-A59 infection. In the mouse model, we found that in vivo administration of liproxstatin-1 ameliorated lung inflammation and tissue injuries caused by MHV-A59 infection. To find how MHV-A59 infection influenced the expression of ferroptosis-related genes, we performed RNA-seq in primary macrophages and found that MHV-A59 infection upregulates the expression of the acyl-CoA synthetase long-chain family member 1 (ACSL1), a novel ferroptosis inducer. Using ferroptosis inhibitors and a TLR4 inhibitor, we showed that MHV-A59 resulted in the NF-kB-dependent, TLR4-independent ACSL1 upregulation. Accordingly, ACSL1 inhibitor Triacsin C suppressed MHV-A59-infection-induced syncytia formation and viral propagation in primary macrophages. Collectively, our study indicates that ferroptosis inhibition protects hosts from MHV-A59 infection. Targeting ferroptosis may serve as a potential treatment approach for dealing with hyper-inflammation induced by coronavirus infection.     

长链脂酰辅酶A合成酶1在肝癌中的表达及临床意义

目的探讨长链脂酰辅酶A合成酶1(Long-Chain Acyl-CoA Synthetase 1,ACSL1)在肝细胞癌(hepatocellular carcinoma,HCC)的表达及临床意义。方法收集334例诊断为HCC患者的癌组织与对应癌旁组织;免疫组化分析癌组织与癌旁组织中ACSL1的表达差异,并进一步分析HCC中ACSL1表达与患者临床病理特征的关系及对患者生存的影响;慢病毒转染构建ACSL1过表达的SNU739细胞;MTS、流式细胞术检测ACSL1对SNU739细胞的增殖和凋亡的影响;SeahorseXF24分析仪、乳酸试剂盒探究ACSL1对SNU739细胞能量代谢的影响。结果HCC组织中的ACSL1表达水平显著低于癌旁组织(3.02±2.57 vs 7.60±3.34,t=20.040,P=0.000);HCC中ACSL1的表达水平与患者的年龄有相关性(c2=16.472,P=0.000);ACSL1蛋白表达水平是HCC患者生存的危险因素(HR=1.642,P=0.012);ACSL1可以显著增强SNU739细胞凋亡(t=13.886,P=0.000)、线粒体基础氧耗速率(oxygen consumption rate,OCR)(F=83.429,P=0.001)以及线粒体最大氧耗率(F=859.792,P=0.000)。结论ACSL1在HCC组织中低表达,ACSL1低表达的HCC患者预后更差;ACSL1可作为HCC患者预后的潜在标志物,有助于筛查早期HCC,提高HCC患者生存率。     

PLIN2通过Rab18上调ACSL3表达促进巨噬细胞脂质蓄积

目的]探讨脂滴包被蛋白2(PLIN2)增加巨噬细胞内脂质蓄积的机制。 [方法]将实验分为氧化型低密度脂蛋白(ox-LDL)组、不同PLIN2表达组、不同活性Rab18组,测定高表达和沉默表达PLIN2巨噬细胞中的Rab18和脂酰辅酶A长链合成酶3(ACSL3)蛋白水平,不同活性Rab18的高表达PLIN2巨噬细胞中的PLIN2、Rab18、ACSL3蛋白表达水平。采用Western blot检测蛋白表达水平,采用免疫荧光观察细胞内相关蛋白定位情况,采用油红O染色观察细胞内脂质蓄积情况。 [结果]高表达PLIN2的细胞中Rab18、ACSL3表达水平明显增加(P＜0.05),且PLIN2与Rab18、ACSL3在细胞内存在共定位的现象。转染Rab18显性突变体Q67L质粒(Rab18活性增强)后的PLIN2高表达巨噬细胞中ACSL3表达水平明显升高(P＜0.05),细胞内脂滴的数量也明显增多(P＜0.05)。 [结论]PLIN2可通过Rab18上调ACSL3表达促进巨噬细胞脂质蓄积。