miR-210-3p通过靶向ATG7抑制人膀胱癌细胞J82的自噬和诱导凋亡

目的探索miR-210-3p抑制人膀胱癌细胞J82机制。方法应用定量实时PCR(qRTPCR)检测miR-210-3p及其靶基因自噬相关基因7(autophagy-related gene 7,ATG7)在J82细胞中的表达。为验证miR-210-3p和ATG7之间的生物学关系,进行荧光素酶报告检测。通过体外实验研究miR-210-3p和ATG7在J82细胞中的生物学功能,包括CCK-8法检测细胞增殖情况,hoechst染色检测细胞凋亡,western blot检测细胞自噬。结果 miR-210-3p表达明显下调ATG7表达水平,生物信息学预测和荧光素酶报告实验证明miR-210-3p抑制ATG7是通过直接结合到ATG7 3’-未翻译区域(3’-UTR)。在J82细胞中,miR-210-3p上调可抑制ATG7表达、细胞自噬和细胞增殖,同时诱导细胞凋亡。结论 miR-210-3p通过负调控ATG7抑制细胞增殖和自噬,并促进凋亡,从而促进膀胱癌细胞J82细胞死亡。因此,在膀胱癌中抑制自噬对于开发针对膀胱癌的自噬靶向治疗至关重要。本研究补充了miRNA调控膀胱癌的相关机制。     

白藜芦醇调控miR-34a表达对骨肉瘤MG-63细胞生长、侵袭和自噬的影响

目的:探讨白藜芦醇通过调控微小RNA-34a(miR-34a)表达对骨肉瘤MG-63细胞生长、侵袭和自噬的影响。方法:将骨肉瘤MG-63细胞分为对照组及10、20、40、60和80μmol/L白藜芦醇处理组。采用MTT法、Transwell小室和Western blot实验检测各组骨肉瘤细胞的活力、侵袭能力及自噬蛋白表达;RT-q PCR检测各组骨肉瘤细胞中miR-34a的表达。转染miR-34a模拟物(miR-34a mimic)及阴性对照(miR-34a NC)至骨肉瘤细胞,检测miR-34a mimic和miR-34a NC在白藜芦醇处理后对骨肉瘤细胞活力和侵袭能力的影响,Western blot检测自噬标志蛋白LC3-Ⅰ、LC3-Ⅱ和beclin-1的蛋白表达。结果:与对照组相比,不同浓度的白藜芦醇可抑制肿瘤细胞的活力和侵袭能力,促进自噬(P0.05)。白藜芦醇可上调肿瘤细胞中miR-34a的表达,并具有剂量依赖性(P0.05),同时促使LC3-Ⅱ/LC3-Ⅰ比值升高,beclin-1蛋白表达量上调(P0.05)。miR-34a mimic可增加白藜芦醇对骨肉瘤细胞活力和侵袭能力的抑制,并进一步促进自噬。结论:白藜芦醇可能通过上调miR-34a表达抑制骨肉瘤MG-63细胞生长并促进其自噬。     

髓样细胞表达的触发受体1抑制LPS应激下巨噬细胞的自噬

目的　观察髓样细胞表达的触发受体1（TREM-1）对脂多糖（LPS）应激下巨噬细胞自噬相关基因表达的影响。 方法　观察LPS应激下的巨噬细胞TREM-1蛋白的表达。分别选用TREM-1的激动剂（MAB1187）和TREM-1的拮抗剂（LR12）作用于巨噬细胞,利用qPCR检测巨噬细胞自噬相关基因ATG7、ATG5、ATG12及自噬标志蛋白微管相关蛋白1轻链3（LC3）mRNA的表达;采用Western Blot检测巨噬细胞TREM-1、LC3Ⅱ/Ⅰ、ATG7蛋白的表达;采用免疫荧光检测在LPS应激与TREM-1激活的情况下,巨噬细胞的自噬标志蛋白LC3表达。 结果　LPS（400 ng/mL、1000 ng/mL）应激下巨噬细胞TREM-1蛋白表达明显增加;LPS（1000 ng/mL）作用巨噬细胞24 h,巨噬细胞TREM-1蛋白表达达到峰值。LPS应激的巨噬细胞自噬基因ATG7、ATG5、ATG12及自噬标志分子LC3 mRNA表达均降低;当给予TREM-1拮抗剂后,巨噬细胞的ATG7、ATG5、ATG12、LC3 mRNA表达均升高,而采用TREM-1激动剂后,自噬基因表达被抑制。Western Blot检测结果显示,TREM-1可抑制LPS应激下巨噬细胞LC3 Ⅱ/Ⅰ、ATG7蛋白的表达。免疫荧光检测表明TREM-1激动剂可使巨噬细胞胞内的LC3蛋白表达量减少。 结论　巨噬细胞胞膜上TREM-1激活后,可使巨噬细胞自噬减弱,提示LPS应激下的巨噬细胞TREM-1可能通过抑制巨噬细胞的正常自噬从而发挥炎症放大作用。     

ATG5敲低后抑制人肺癌细胞H1299自噬并增强南蛇藤素诱导的细胞凋亡

目的构建自噬相关基因5(autophagy-related gene 5,ATG5)低表达肺癌细胞株,观察肺癌细胞自噬活性,检测南蛇藤素对肺癌细胞凋亡的影响。方法用ATG5 shRNA技术构建ATG5敲低的人肺癌H1299细胞株作为ATG5敲低组,未敲低ATG5的H1299细胞作为对照组;荧光定量PCR和Western blot检测肺癌细胞中ATG5的表达和自噬标志物微管相关轻链蛋白3(microtubule-associated protein 1A/1B-light chain 3,LC3)及死骨片蛋白1的(sequestosome 1,P62)表达,并转染红色荧光标记的LC3质粒观察LC3斑点聚集情况;经南蛇藤素刺激后,以流式细胞术检测细胞凋亡,最后使用Western blot检测cleaved caspase-3、Bcl-2和Bax等蛋白的表达。结果慢病毒感染组ATG5较对照组mRNA和蛋白表达水平明显降低(P0.05);ATG5敲低后LC3-Ⅱ水平下降,P62水平上升,并且转染后RFP-LC3斑点聚集减少(P0.05)。相比对照组,南蛇藤素明显促进ATG5敲低细胞凋亡(P0.01);ATG5敲低组中促凋亡分子Bax、cleaved caspase-3表达比对照组明显增加(P0.05),抗凋亡蛋白Bcl-2表达减少(P0.05)。结论 ATG5敲低抑制肺癌细胞自噬后,南蛇藤素能够明显增强人肺癌细胞的凋亡,提示抑制肺癌细胞自噬可能为针对性处理肺癌细胞耐药提供新的思路。     

miR-144在SKOV-3细胞中的表达及对Beclin-1的调控作用

目的检测雷帕霉素诱导细胞后4种miRNAs的表达情况,并进一步研究miR-144与Beclin-1基因的靶向调控作用。方法对SKOV-3细胞分别进行雷帕霉素(50μg/L,反应2 h)及3-甲基腺嘌呤(10 nmol/L、反应12 h)处理,RT-q PCR检测各组细胞miR-17、miR-20a、miR-144及miR-155的表达;Western blot检测雷帕霉素组Beclin-1蛋白的表达;双荧光素酶报告系统、Western blot及RT-q PCR,验证miR-144与Beclin-1之间的靶向调控关系。结果与正常对照组相比,雷帕霉素组SKOV-3细胞的miR-17、miR-144及miR-155的表达水平显著上调(P0.05);3-MA组SKOV-3细胞的miR-17、miR-20a及miR-144的表达水平显著下调(P0.05);雷帕霉素组Beclin-1的蛋白表达明显低于正常细胞组(P0.05)。miR-144可靶向作用Beclin-1的3'非翻译区(3'UTR),且抑制其表达;miR-144能明显抑制Beclin-1蛋白及mRNA的表达。结论 miR-144可靶向抑制Beclin-1基因的表达,并参与调控SKOV-3细胞自噬的过程。     

DICER activates autophagy and promotes cisplatin resistance in non-small cell lung cancer by binding with let-7i-5p

ObjectiveDrug resistance is the main obstacle in the treatment of non-small cell lung cancer (NSCLC). This study aimed to explore the mechanism of DICER in NSCLC resistance and its downstream signaling pathways.MethodsThe A549 cisplatin (DDP)-resistant strain A549/DDP was established. A549/DDP cells were transfected with DICER- and let-7i-5p-related vectors, and treated with autophagy activator rapamycin. The cell viability and apoptosis were tested by CCK-8 assay and flow cytometry, respectively. The formation of autophagosomes was observed with a transmission electron microscopy. RT-qPCR and Western blot assay were conducted to detect expression levels of DICER, let-7i-5p, autophagy-related proteins, and the PI3K/AKT/mTOR pathway-related proteins. The dual luciferase reporter gene assay was implemented to confirm the targeted binding of DICER and let-7i-5p.ResultsDICER was highly expressed in DDP-resistant NSCLC tissues and cells, and DICER could target and negatively regulate the expression of let-7i-5p. DDP treatment could inhibit the viability and promote cell apoptosis of A549/DDP cells. Downregulation of DICER in A549/DDP cells exhibited a decrease of cell viability, a decreased ratio of LC3-II/LC3-I and autophagosomes, together with an elevation of cell apoptosis rate and the phosphorylation levels of PI3K/AKT/mTOR. Treatment of rapamycin and let-7i-5p inhibitor reversed the effects of downregulated DICER in cell viability, ratio of LC3-II/LC3-I, autophagosomes, cell apoptosis rate and the phosphorylation levels of PI3K/AKT/mTOR in A549/DDP cells.ConclusionOur research suggests that DICER promotes autophagy and DDP resistance in NSCLC through downregulating let-7i-5p, and inhibits the activation of PI3K/AKT/mTOR pathway.     

CircCBFB is a mediator of hepatocellular carcinoma cell autophagy and proliferation through miR-424-5p/ATG14 axis

This study aims to investigate the role of circCBFB in hepatocellular carcinoma (HCC) cell proliferation and autophagy. qRT-PCR and Western blotting analyses quantified the expression levels of circCBFB, miR-424-5p, and ATG14 in HCC tissues and/or HCC cell lines. After transfection with pcDNA3.1-CircCBFB, sh-CircCBFB, miR-424-5p mimic, miR-424-5p inhibitor, pcDNA3.1-ATG14, sh-ATG14, sh-CircCBFB?+?miR-424-5p inhibitor, pcDNA3.1-CircCBFB?+?miR-424-5p mimic, sh-CircCBFB?+?pcDNA3.1-ATG14, or pcDNA3.1-CircCBFB?+?sh-ATG14, the proliferation, cell cycle, and apoptosis of Huh-7 and HCCLM3 cells were detected, respectively, through MTT assay and flow cytometry. Western blotting measured the expression levels of ATG14 and autophagy-related proteins (LC3-ΙΙ/LC3-Ι, Beclin1, and p62). The interactions among circCBFB, miR-424-5p, and ATG14 were identified through RNA fluorescence in situ hybridization and RNA immunoprecipitation. In HCC tissues, circCBFB and ATG14 were highly expressed, and miR-424-5p expression was downregulated. Transfection of pcDNA3.1-CircCBFB, miR-424-5p inhibitor, or pcDNA3.1-ATG14 into HCC cells facilitated HCC cell proliferation and autophagy, while suppressing cell apoptosis, evidenced by elevated cell viability, increased protein levels of autophagosome markers (LC3-ΙΙ/LC3-Ι and Beclin1), repressed apoptosis rate, and suppressed protein level of autophagy receptor p62. miR-424-5p was a target gene of circCBFB, and miR-424-5p negatively mediated ATG14. CircCBFB inhibits miR-424-5p and upregulates ATG14, thus promoting HCC cell proliferation and autophagy.

     

长链非编码RNA HULC对肺癌细胞增殖及自噬的调控

目的探讨长链非编码RNA HULC对非小细胞肺癌增殖及其与自噬的关系。方法采用实时定量PCR检测48例肺癌组织以及相应正常肺组织中HULC的表达水平,并检测HULC在肺癌细胞系及正常肺细胞系中的表达情况。通过pcDNA3.1-HULC转染肺癌细胞系A549、95D过表达HULC;采用CCK-8试剂盒检测细胞增殖改变情况;Western blot、免疫荧光检测自噬相关蛋白LC3Ⅱ/Ⅰ、LC3斑点数目变化情况以及自噬相关蛋白Atg7的表达变化。结果HULC在肺癌组织中的表达高于正常肺组织,差异有统计学意义(P<0.05);过表达HULC能促进肺癌细胞增殖,且过表达HULC促进肺癌细胞中LC3-Ⅰ向LC3-Ⅱ的转化和Atg7的表达增加(P<0.05);免疫荧光可见过表达HULC后LC3荧光斑点明显增多。结论肺癌组织中HULC的表达高于正常肺组织,HULC促进肺癌细胞增殖与提高肺癌细胞自噬水平,且与自噬相关蛋白ATG7相关。     

CD147对前列腺癌PC-3细胞自噬的影响

 目的：研究白细胞分化抗原（CD）147在体外对前列腺癌PC-3细胞的自噬作用。方法：通过氨基酸饥饿法建立自噬模型,免疫印迹技术检测CD147的表达。利用RNA干扰CD147表达的细胞系,免疫印迹技术检测自噬蛋白LC3-I和LC3-II的表达;台盼蓝排斥实验检测细胞的死亡情况。结果：在PC-3细胞自噬模型中,随着饥饿诱导时间延长,CD147表达逐渐升高。用RNA干扰技术降低CD147表达后,与阴性对照组比较,在自噬模型中CD147干扰组自噬相关蛋白LC3-II表达增多;并且细胞死亡数量明显增加,阴性对照组细胞死亡率分别为（19.3±3.1）%和（22.3±3.5）%,而在CD147干涉组细胞死亡率为(38.4±3.1)%,差异有统计学意义（P<0.05）。结论：在前列腺癌PC-3细胞中CD147抑制饥饿诱导的自噬,减少自噬性细胞死亡的发生。     

The development of an immunohistochemical method to detect the autophagy-associated protein LC3-II in human tumor xenografts

Autophagy is believed to be an important process during tumorgenesis, and in recent years it has been shown to be modulated in response to a number of conventional anticancer agents. Furthermore, the development of targeted small molecule inhibitors, such as those to the PI3K-AKT-mTOR pathway, has presented a molecular link between the disruption of this signalling cascade and the process of autophagy. The cellular consequence of stimulating or inhibiting autophagy in cancer cells is not completely understood, so it is important that this process be monitored, along with antiproliferative and apoptotic biomarkers, in the preclinical setting. The field of autophagy is still evolving, and there is a constantly changing set of criteria for the assessment of the process in cells, tissues, and organs. The gold standard technique for analyzing autophagy in mammalian cells remains transmission electron microscopy, which has many limitations and is often difficult to perform on in vivo tissue including human tumor xenografts. In order to monitor autophagy in human tumor xenogaft tissue, we have taken the approach to develop an immunohistochemical (IHC) method for the detection of the autophagosome-associated protein, microtubule-associated protein 1 light chain 3 (LC3), in human tumor xenografts. After synthesis, LC3 is cleaved to form LC3-I, and upon induction of autophagy, LC3-I is conjugated to the lipid phosphatidylethanolamine to form LC3-II, which is tightly bound to the membrane of the autophagosome. It is thought that detection of endogenous LC3-II by IHC could be difficult because of the relatively low level of expression of the protein. Here we present the validation of an IHC method to detect LC3 in human tumor xenografts that we believe is able to distinguish LC3-I from LC3-II. It is hoped that this assay can become a useful tool for the detection of autophagy in preclinical xenograft models and determine the effects of anticancer therapies on the autophagic process.     

MicroRNA-30a调控Beclin-1对缺氧复氧乳鼠心肌细胞的保护效应

目的: 观察microRNA-30a(miR-30a)在原代心肌细胞缺氧复氧中的作用,探讨miR-30a保护缺血再灌注心肌的分子机制。方法: 重组构建慢病毒miR-30a表达载体(LV-GFP-miR-30a)感染原代乳鼠心肌细胞,构建缺氧复氧损伤模型。实验分为正常培养组、单纯缺氧复氧组、LV-GFP加缺氧复氧组、LV-miR-30a-GFP加缺氧复氧组和3-甲基腺嘌呤(3-MA)加缺氧复氧组。Real-time PCR检测缺氧复氧和慢病毒感染对miR-30a的表达影响,Western blotting检测LC3和Beclin-1蛋白表达变化,TUNEL和PI染色检测缺氧复氧后心肌细胞死亡情况。结果: (1)缺氧复氧后心肌miR-30a表达水平下调(P<0.05);(2)慢病毒miR-30a表达载体高效感染后心肌细胞miR-30a表达水平上调(P<0.05),心肌过表达miR-30a下调Beclin-1蛋白表达(P<0.05);(3)心肌过表达miR-30a抑制缺氧复氧后Beclin-1表达(P<0.05);3-MA处理减少缺氧复氧后心肌Beclin-1表达,减少缺氧复氧后LC3-Ⅰ转化为LC3-Ⅱ(P<0.05);(4)过表达miR-30a和3-MA处理减少缺氧复氧后心肌细胞凋亡(P<0.05)。结论: 心肌细胞过表达miR-30a显著下调Beclin-1;抑制自噬可以减少缺氧复氧后心肌细胞死亡。     

Autophagy in Niemann-Pick C disease is dependent upon Beclin-1 and responsive to lipid trafficking defects

Niemann-Pick C (NPC) disease is an autosomal recessive lipid storage disorder characterized by a disruption of sphingolipid and cholesterol trafficking that produces cognitive impairment, ataxia and death, often in childhood. Most cases are caused by loss of function mutations in the Npc1 gene, which encodes a protein that localizes to late endosomes and functions in lipid sorting and vesicle trafficking. Here, we demonstrate that NPC1-deficient primary human fibroblasts, like npc1(-/-) mice fibroblasts, showed increased autophagy as evidenced by elevated LC3-II levels, numerous autophagic vacuoles and enhanced degradation of long-lived proteins. Autophagy because of NPC1 deficiency was associated with increased expression of Beclin-1 rather than activation of the Akt-mTOR-p70 S6K signaling pathway, and siRNA knockdown of Beclin-1 decreased long-lived protein degradation. Induction of cholesterol trafficking defects in wild-type fibroblasts by treatment with U18666A increased Beclin-1 and LC3-II expression, whereas treatment of NPC1-deficient fibroblasts with sphingolipid-lowering compound NB-DGJ failed to alter the expression of either Beclin-1 or LC3-II. Primary fibroblasts from patients with two other sphingolipid storage diseases, NPC2 deficiency and Sandhoff disease, characterized by sphingolipid trafficking defects also showed elevation in Beclin-1 and LC3-II levels. In contrast, Gaucher disease fibroblasts, which traffic sphingolipids normally, showed wild-type levels of Beclin-1 and LC3-II. Our data define a critical role for Beclin-1 in the activation of autophagy because of NPC1 deficiency, and reveal an unexpected role for lipid trafficking in the regulation of this pathway in patients with several sphingolipid storage diseases.     

miR-296-5p 靶向 PLK1 调控 PI3K/ AKT 通路诱导骨肉瘤细胞中的自噬并抑制上皮-间质转化

目的 探讨 miR-296-5p 靶向 PLK1 对骨肉瘤 (osteosarcoma, OS) 细胞自噬及抑制上皮-间质转化 (EMT) 的作用机制。 方法 qRT-PCR 检测 miR-296-5p 在 OS 细胞中的表达。 采用生物信息学分析预测 miR-296-5p 的靶基因, 验证 miR-296-5p 对靶基因 PLK1 的直接靶向调控; 细胞转染构建 miR-296-5p 过表达 和干扰细胞, CCK-8、 克隆形成、 Transwell 小室、 流式、 蛋白免疫印迹实验检测 miR-296-5p 的不同表达对 U2OS 细胞中 PTBP1 表达水平及细胞增殖、 侵袭、 凋亡、 自噬及 EMT 的影响。 结果 与对照组比较, miR-296-5p 在 OS 中表达降低, 而 PLK1 则升高 (P< 0. 05); 与 miR-NC 组比较, mimic 组的克隆形成率、 侵袭 细胞数目及 PTBP1、 p62、 N-cadherin、 Vimentin、 p-PI3K/ PI3K、 p-AKT/ AKT 水平降低, 细胞凋亡率、 Beclin-1、 LC3-Ⅱ/ Ⅰ、 E-cadherin 水平升高 (P< 0. 05); 与 PLK1 组比较, PLK1 + mimic 组的克隆形成率、 侵袭 细胞数目及 PTBP1、 p62、 N-cadherin、 Vimentin、 p-PI3K/ PI3K、 p-AKT/ AKT 水平降低, 细胞凋亡率、 Beclin-1、 LC3-Ⅱ/ Ⅰ、 E-cadherin 水平升高 (P< 0. 05)。 结论 miR-296-5p 可能能够靶向 PLK1 调控 PI3K/ AKT 通路诱导 OS 细胞中的自噬并抑制 EMT。     

Induction of autophagy enhances porcine reproductive and respiratory syndrome virus replication

Autophagy is an evolutionarily conserved lysosome-dependent degradation pathway that acts in the maintenance of cellular homeostasis and plays important functions in viral replication and pathogenesis. In this study, we investigated the role of autophagy in the replication of porcine reproductive and respiratory syndrome virus (PRRSV), an agent that has caused devastating losses in the international swine industry since the late 1980s. Using protein quantification and microscopy, we observed that PRRSV infection results in LC3-I/II conversion, an increased accumulation of punctate GFP-LC3-expressing cells, and a higher number of autophagosome-like double-membrane vesicles in the cytoplasm of host cells. Inhibition of autophagy using 3-methyladenine (3-MA) or small interfering RNAs targeting ATG7 and Beclin-1 led to a significant reduction in PRRSV titers and protein expression. Conversely, induction of autophagy by rapamycin resulted in increased viral replication. These results demonstrate that PRRSV infection induces autophagy which, in turn, enhances viral replication efficiency.     

Atorvastatin induces autophagy in MDA-MB-231 breast cancer cells

This article explores the effects of atorvastatin on cultured breast cancer cells. Our experiment demonstrated that atorvastatin triggered autophagy and inhibited proliferation in breast cancer cells. A CCK8 assay indicated that atorvastatin can inhibit the activity of MDA-MB-231 breast cancer cells. Western blotting results showed that atorvastatin increased the conversion of light chain 3 (LC3)-I to LC3-phosphatidylethanolamine conjugate (LC3-II). Confocal microscopy was used to reveal the appearance of a punctate structure in the cytoplasm, and electron microscopy was used to reveal the formation of double-membrane autophagosome. In conclusion, our study showed that atorvastatin may affect MDA-MB-231 breast cancer cells by inducing autophagy.     

Runx2通过抑制细胞巨自噬以诱导C2C12细胞向成骨细胞分化

 目的：探讨细胞巨自噬与Runx2诱导C2C12细胞成骨分化的关系。方法： 在强力霉素(doxycycline, Dox)诱导Runx2表达的细胞系C2C12/Runx2Dox中进行研究。Dox (10 mg/L) 处理0 d、1 d、3 d及6 d后,real-time qPCR检测LC3b、Beclin-1、p62和LAMP-2表达情况,Western blotting分析LC3-I/LC3-II比值。设置不同的3-甲基腺嘌呤(3-methyladenine, 3-MA)或雷帕霉素(rapamycin, Rap)浓度,Dox处理14 d后分析碱性磷酸酶(alkaline phosphatase,ALP)活性。用3-MA (5 mmol/L)或Rap (10 μmol/L)与Dox共同处理1 d、3 d及6 d后检测ALP及骨钙素 (osteocalcin,OC)表达情况。结果： (1) C2C12细胞向成骨分化时,LC3b 与Beclin-1显著下调,p62与LAMP-2无明显变化;(2) LC3-I向LC3-II转换的过程被抑制;(3) 3-MA (5 mmol/L)可增强ALP 活性,而Rap(10 μmol/L)则抑制其活性;(4) 3-MA可上调ALP及OC表达,Rap则下调二者表达。结论： Runx2通过下调LC3和Beclin-1、抑制LC3-I向LC3-II转换的方式阻碍自噬体形成,以诱导C2C12细胞分化为成骨细胞。     

miR-210 调控Mex3B 蛋白对肺癌细胞侵袭和增殖的影响

目的:探讨miR-210 和Mex3B 蛋白对肺癌细胞侵袭和增殖能力的影响。方法:运用qPCR 检测miR-210 在正常肺组织和癌旁组织中的表达情况;运用qPCR 检测Mex3B 在肺癌组织、癌旁组织中的表达;qPCR 检测miR-210 在不同肺癌细胞株中(A549、H1299、H1650 和H358)的表达水平;双荧光素酶报告基因系统检测miR-210 对Mex3B 转录的影响;细胞活性实验检测miR-210 的表达对肺癌细胞活性的影响;平板克隆实验检测miR-210 的表达对肺癌细胞A549 的增殖能力的影响;Transwell 侵袭实验检测miR-210 的表达对肺癌细胞株A549 的侵袭能力的影响。结果:和癌旁组织比较,miR-210 在肺癌组织中表达明显增高,和癌旁组织比较,Mex3B 在肺癌中表达较低,双荧光素酶报告基因系统检测结果显示,miR-210 可以直接调控Mex3B 的转录活性,抑制miR-210 的表达活性后,A549 肺癌细胞的细胞活性受到一定的抑制;抑制miR-210 后,肺癌细胞株A549 的侵袭和增殖能力明显降低。结论:miR-210 可以靶向调控肺癌细胞的侵袭和增殖能力。     

程序化细胞死亡因子5对缺氧/复氧诱导的心肌细胞凋亡和自噬的影响及机制

目的:探讨程序化细胞死亡因子5(PDCD5)对缺氧/复氧(H/R)诱导的心肌细胞凋亡和自噬的影响及其作用机制。方法:以H9c2心肌细胞系为研究对象,建立H/R损伤模型,采用RNA干扰方法抑制PDCD5的表达,MTT法检测心肌细胞的存活率,TUNEL显色法检测细胞凋亡率,RT-qPCR和Western blot法分别检测mRNA和蛋白的表达水平。结果:H/R损伤的H9c2心肌细胞中,PDCD5表达水平升高,同时细胞的存活率降低,细胞凋亡率和自噬水平增加,而PDCD5沉默能够增加细胞存活率,同时减少细胞凋亡率,促进Bax表达且抑制抑Bcl-2、LC3-Ⅱ/LC3-Ⅰ及自噬相关蛋白beclin-1的表达。此外,沉默PDCD5可通过降低p-P65的蛋白水平抑制NF-κB通路。结论:沉默PDCD5通过阻断NF-κB信号通路而抑制H/R损伤诱导的心肌细胞凋亡和自噬,从而保护心肌细胞。     

Bone marrow mesenchymal stem cell-derived exosomes inhibit chondrocyte apoptosis and the expression of MMPs by regulating Drp1-mediated mitophagy

Osteoarthritis (OA) is a joint degenerative disease commonly seen in the elderly. Bone marrow mesenchymal stem cell-exosomes (BMSC-exosomes) are closely associated with the progression of OA. Here, we investigated whether BMSC-exosomes can affect OA development by regulating mitophagy. Primary rat chondrocytes were treated with advanced glycation end products (AGEs) to induce cell damage. The results of flow cytometry showed that AGEs treatment significantly promoted apoptosis of chondrocytes. AGEs treatment also enhanced the expression of matrix metalloproteinases (MMPs), MMP-3 and MMP-13, and dynamin-related protein 1 (Drp1) in chondrocytes. To investigate the impact of BMSC-exosomes on chondrocytes, chondrocytes were treated with BMSC-exosomes. AGEs-mediated increase of apoptosis and up-regulation of MMP-3, MMP-13, and Drp1 in chondrocytes were abrogated by BMSC-exosomes. Western blot analysis of autophagy-related proteins and Mito-Keima assay revealed that BMSC-exosome treatment elevated the expression of autophagy-related proteins, LC3-II/LC3-I and Beclin-1, and promoted mitophagy in the AGEs-treated chondrocytes. Moreover, Drp1 overexpression repressed the expression of LC3-II/LC3-I and Beclin-1, and enhanced apoptosis and the expression of MMP-3 and MMP-13 in AGEs-treated chondrocytes. BMSC-exosomes reversed the impact of Drp1 overexpression on AGEs-treated chondrocytes. In conclusion, this work demonstrates that BMSC-exosomes inhibit chondrocyte apoptosis and the expression of MMPs, which attributes to regulate Drp1-mediated mitophagy. Thus, BMSC-exosomes may be a potential treatment for OA.     

miR-142-3p 靶向ATG4c 调控RAW264.7 巨噬细胞自噬

目的:研究miR-142-3p 对自噬相关基因ATG4c 的靶向调控作用,探究miR-142-3p 影响RAW264.7 细胞自噬途径的作用机制。方法:生物信息学软件分析miR-142-3p 的靶基因为ATG4c,构建pMIR-Report-ATG4c 和pMIR-Report-ATG4c mut 重组质粒,双荧光素酶报告系统、qRT-PCR、Western blot 验证miR-142-3p 与ATG4c 的靶向作用;将做不同处理的RAW264.7 细胞分为4 组:正常细胞作为对照、50 ng/ ml 雷帕霉素作用2 h、EBSS 饥饿作用12 h、10 nmol/ L 的3-甲基腺嘌呤(3-MA)作用12 h 后,实时荧光定量PCR(qRT-PCR)检测miR-142-3p 不同干预组中的相对表达情况;将miR-142-3p mimics、miR- 142-3p inhibitor 及miR-142-3p control 分别转染到RAW264.7 细胞中,检测miR-142-3p 和LC3域的相对表达。结果:双荧光素酶报告系统、qRT-PCR、Western blot 验证miR-142-3p 通过靶向作用于ATG4c 的3忆-UTR 抑制其表达;与对照组相比,雷帕霉素和饥饿处理的RAW264.7 细胞miR-142-3p 明显上调,而3-MA 处理组miR-142-3p 明显下调;与miR-142-3p control 组相比,转染miR-142-3p mimics 组中LC3域蛋白表达显著下调,而miR-142-3p inhibitor 组中表达显著上调。结论:miR-142-3p 通过靶向调控自噬相关基因ATG4c,参与RAW264.7 小鼠巨噬细胞自噬的调控。