Inhibiting autophagy promotes collagen degradation by regulating matrix metalloproteinases in pancreatic stellate cells
Inhibiting autophagy promotes collagen degradation by regulating matrix metalloproteinases in pancreatic stellate cells
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DOI：
10.1016/j.lfs.2018.07.049
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发表时间：
2018-09-01
期刊：
影响因子：
6.1
通讯作者：
Zhang, Shu-Kun
中科院分区：
文献类型：
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作者：
Li, Cai-Xia;Cui, Li-Hua;Zhang, Shu-Kun
目的：自噬是一种细胞内代谢过程，通过降解和循环自身成分来维持体内平衡和供应底物。胶原降解的破坏是胰腺纤维化的发病机制之一。在本研究中，我们研究了抑制自噬对PSCs胶原降解的影响。主要方法：大鼠注射二氯化二丁基锡（DBTC）诱导慢性胰腺炎（CP）模型。western blotting检测LC3B的表达。从大鼠胰腺组织中分离出PSCs，实验采用原代PSCs。透射电镜证实了自噬体的存在。LC3B和α - sma免疫荧光检测自噬和活化的PSCs。采用real-time PCR和Western blotting检测自噬抑制3-MA对LC3B、Atg5、Beclin-1以及α - sma、tgf - β 1、ColI、Col III、FN、MMP-2、MMP-13、TIMP-1、TIMP-2表达的影响。同时用ELISA法检测大肠杆菌、Col III和FN的分泌情况。主要发现：大鼠CP模型LC3-II/I比值升高。在PSCs激活过程中观察到自噬体和自噬水平的增加。抑制自噬可下调α - sma、tgf - β 1、FN、ColI、Col III、TIMP-1、TIMP-2的表达，上调MMP-2、MMP-13的表达。意义：本研究证实了PSCs在体内和体外活化过程中自噬水平升高。抑制自噬可阻止PSCs的活化，并通过降低tgf - β 1表达和增加MMPs/TIMPs比值促进细胞外基质（extracellular matrix， ECM）降解来抑制纤维化。
Aims: Autophagy is an intracellular metabolic process that degrades and recycles own constituents to maintain homeostasis and supply substrates. Disruption of collagen degradation is one of the pathogenesis of pancreatic fibrosis. In this study, we investigated the effects of inhibiting autophagy on the collagen degradation of PSCs.Main methods: Rats were injected dibutyltin dichloride (DBTC) to induce chronic pancreatitis (CP) model. The expression of LC3B was measured by western blotting. Rat PSCs were isolated from pancreas tissues, and the experiments used the primary PSCs. Autophagosome was confirmed by transmission electron microscope. Immunofluorescence for LC3B and alpha-SMA were applied to assess autophagy and activated PSCs. The effects of autophagy inhibition of 3-MA on the expressions of LC3B, Atg5, and Beclin-1 were investigated by real-time PCR and Western blotting, as well as the alpha-SMA, TGF-beta 1, ColI, Col III, FN, MMP-2, MMP-13, TIMP-1 and TIMP-2. Meanwhile, the secretion of ColI, Col III and FN were investigated by ELISA.Key findings: The LC3-II/I ratio was increased in rat CP model. Autophagosomes and an increased autophagic level were observed during PSCs activation. Inhibiting autophagy could down-regulate the expressions of alpha-SMA, TGF-beta 1, FN, ColI, Col III, TIMP-1 and TIMP-2, while the expressions of MMP-2 and MMP-13 were increased.Significance: This study confirmed that autophagic level is increased during PSCs activation in vivo and in vitro. Inhibiting autophagy prevents the activation of PSCs, and suppresses fibrosis through promoting extracellular matrix (ECM) degradation by decreasing the expression of TGF-beta 1 and increasing MMPs/TIMPs ratio.