In vivo recovery effect of silibinin treatment on streptozotocin-induced diabetic mice is associated with the modulations of sirt-1 expression and autophagy in pancreatic β-cell

Improper adjustments of autophagy and silent information regulator 1 (Sirt-1) expression were reported to be closely associated with metabolic disorders. In this study, we examined the roles of Sirt-1 and autophagy in streptozotocin-induced diabetes mellitus, assessed the relationship between autophagy and Sirt-1, and investigated the protective mechanism of silibinin. Diabetes was induced in 6-week-old mice by intravenous injection of streptozotocin (150 mg/kg/day, for 2 weeks). In the treatment groups, silibinin (50 mg/kg/day, intramuscular injection, for 8 weeks) or inhibitors (50 mg/kg/day, subcutaneous injection, for 8 weeks) were given. Diabetic control animals received vehicle for the same time. Compared with diabetic controls, silibinin or autophagy inhibitor, 3-methyladenine, treated mice showed decreased levels of glycosylated hemoglobin A1C (P < 0.01), serum triglyceride (P < 0.01), cholesterol (P < 0.01), blood glucose (P < 0.05), autophagy (P < 0.05), and apoptosis ratio (P < 0.05) of pancreatic β-cells. Systemic administration of silibinin reversed streptozotocin-induced downregulation of Sirt-1 expression. Sirt-1 may play a role in regulating the physiological level of autophagy and is associated with loss of pancreatic β-cells and metabolic biochemical disorders. Through promoting Sirt-1 expression and recovering autophagy physiologically, silibinin may reverse hyperglycemia and repair damaged pancreatic β-cells.     

补阳还五汤通过AMPK/mTOR/ULK1信号通路调控自噬减轻大鼠脑缺血/再灌注损伤

目的探讨补阳还五汤抗大鼠脑缺血/再灌注损伤的AMPK/mTOR/ULK1自噬信号通路机制。方法用改良线栓法建造大鼠左侧脑缺血模型,各组大鼠每24 h给药1次,共3次。再灌注72 h后观察大鼠神经损伤情况和脑梗死体积改变;尼氏染色法和TUNEL染色法观察神经细胞形态、数量以及凋亡情况;Western blot检测自噬蛋白和AMPK/mTOR/ULK1自噬信号通路相关蛋白表达情况。结果补阳还五汤改善大鼠神经功能缺陷,减少脑梗死体积和神经细胞凋亡,减轻脑组织病理损伤;抑制AMPK磷酸化活化,解除AMPK对下游mTOR和ULK1的抑制,促进二者磷酸化激活,抑制细胞自噬。AMPK激动剂Metformin提高细胞自噬水平,同时逆转了补阳还五汤抗大鼠脑缺血/再灌注损伤作用。结论补阳还五汤介导AMPK/mTOR/ULK1自噬信号通路对脑缺血/再灌注损伤大鼠发挥神经保护作用。     

雷帕霉素诱导细胞自噬在衰老相关疾病中的作用

哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,m TOR)是衰老和衰老相关疾病的一个关键调节因子。雷帕霉素(rapamycin,RAPA)可通过抑制m TOR通路,诱导和促进细胞自噬的发生。细胞自噬是维持细胞内稳态的主要方式与途径,通过降解多余的、受损的及衰老的蛋白与细胞器,为细胞重建、再生和修复提供必需原料。早老症(hutchinson-gilford progeria syndrome,HGPS)患者细胞中伴随早老蛋白(progerin)的异常聚集;此外,诸如亨廷顿病、帕金森病、阿尔茨海默病等神经退行性疾病细胞内同样出现异常蛋白质的聚集,而这些异常蛋白的清除正依赖于细胞的自噬作用。由此可见,雷帕霉素是潜在的抗衰老、治疗早老症及衰老相关疾病的重要药物。该文主要阐述雷帕霉素促进细胞自噬方面的功能及在HGPS、神经退行性疾病方面的应用。     

肿瘤多药耐药与自噬的研究进展

肿瘤多药耐药（multidrug resistance,MDR）对肿瘤的药物治疗的疗效有严重的影响。多药耐药拥有十分复杂的发生发展的机制。通过讨论自噬与药物抗肿瘤时的相互影响,旨在阐明自噬与肿瘤细胞多药耐药的关系,为今后抗肿瘤药物治疗的临床应用提供新的思路。     

细胞自噬与肿瘤治疗

综述细胞自噬及其与肿瘤的关系以及相关抗肿瘤治疗靶点和药物研究方面的最新进展。细胞自噬是一种广泛存在于真核生物中的细胞程序性死亡机制,其可通过降解受损细胞器和大分子来维持细胞内稳态,并实现细胞内成分的循环利用。近年来发现细胞自噬在肿瘤发生发展过程中起着重要作用,从而成为肿瘤治疗的研究热点。     

Triptolide induced cell death through apoptosis and autophagy in murine leukemia WEHI‐3 cells in vitro and promoting immune responses in WEHI‐3 generated leukemia mice in vivo

Triptolide, a traditional Chinese medicine, obtained from Tripterygium wilfordii Hook F, has anti‐inflammatory, antiproliferative, and proapoptotic properties. We investigated the potential efficacy of triptolide on murine leukemia by measuring the triptolide‐induced cytotoxicity in murine leukemia WEHI‐3 cells in vitro. Results indicated that triptolide induced cell morphological changes and induced cytotoxic effects through G0/G1 phase arrest, induction of apoptosis. Flow cytometric assays showed that triptolide increased the production of reactive oxygen species, Ca²⁺ release and mitochondrial membrane potential (ΔΨ_m), and activations of caspase‐8, ‐9, and ‐3. Triptolide increased protein levels of Fas, Fas‐L, Bax, cytochrome c, caspase‐9, Endo G, Apaf‐1, PARP, caspase‐3 but reduced levels of AIF, ATF6α, ATF6β, and GRP78 in WEHI‐3 cells. Triptolide stimulated autophagy based on an increase in acidic vacuoles, monodansylcadaverine staining for LC‐3 expression and increased protein levels of ATG 5, ATG 7, and ATG 12. The in vitro data suggest that the cytotoxic effects of triptolide may involve cross‐talk between cross‐interaction of apoptosis and autophagy. Normal BALB/c mice were i.p. injected with WEHI‐3 cells to generate leukemia and were oral treatment with triptolide at 0, 0.02, and 0.2 mg/kg for 3 weeks then animals were weighted and blood, liver, spleen samples were collected. Results indicated that triptolide did not significantly affect the weights of animal body, spleen and liver of leukemia mice, however, triptolide significant increased the cell populations of T cells (CD3), B cells (CD19), monocytes (CD11b), and macrophage (Mac‐3). Furthermore, triptolide increased the phagocytosis of macrophage from peripheral blood mononuclear cells (PBMC) but not effects from peritoneum. Triptolide promoted T and B cell proliferation at 0.02 and 0.2 mg/kg treatment when cells were pretreated with Con A and LPS stimulation, respectively; however, triptolide did not significant affect NK cell activities in vivo. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 550–568, 2017.     

Shh信号通路变化对小鼠胚胎腭突间充质细胞自噬的影响

目的：探讨地塞米松（dexamethasone,DEX）及平滑激动剂（smoothened agonist,SAG）干预下小鼠胚胎腭突间充质细胞Shh信号通路改变后,小鼠胚胎腭突间充质细胞自噬状态的变化。方法：体外培养胚胎14.5 d的C57BL/6J小鼠胚胎腭突间充质细胞,根据干预方式分为4组：对照组、地塞米松组（DEX组）、地塞米松+SAG组（DEX+SAG组）、单独SAG干预组（SAG组）。通过透射电镜观察各组细胞自噬体或自噬溶酶体的数量,Western blot检测各组Shh、Ptch1、Smo、Gli3A/R、Cyclin D1及自噬标志物LC3Ⅱ/Ⅰ和P62、Beclin-1的表达情况。结果：电镜结果显示,对照组和DEX组中自噬体/自噬溶酶体的数量无明显差异,而SAG干预后可观察到大量自噬体/自噬溶酶体。Western blot结果显示,与对照组相比,P62、Ptch1、Smo、Gli3A/R、CyclinD1在DEX组中明显降低（P<0.05）,LC3Ⅱ/Ⅰ、Beclin1表达无明显变化（P>0.05）;DEX+SAG组及SAG组中Ptch1、Smo、Gli3...     

电针对脑缺血再灌注大鼠自噬相关蛋白LC3-Ⅱ、Bec-lin1表达的影响

目的 观察电针对脑缺血再灌注损伤大鼠神经功能的改善程度及自噬相关蛋白LC3-Ⅱ、Beclin1表达的影响.方法 根据随机数字表法,将72只雄性SD大鼠随机分为对照组、模型组和电针组,每组24只.采用Longa线栓法建立改良的急性局灶性脑缺血再灌注大鼠模型,并在缺血1h后进行再灌注.参照改良的Zea Longa 8级神经...     

自噬在类风湿关节炎中的作用及中药干预研究进展

类风湿关节炎(RA)目前临床上多使用糖皮质激素或免疫抑制剂进行治疗,但长期使用具有明显的毒副作用,且免疫抑制剂价格昂贵,一定程度限制其广泛的应用。中药治疗RA历史悠久,且毒副作用小,但其具体作用机制不甚明确。自噬的过程是细胞自身在受到外界的刺激,通过细胞内信号转导,触发的一系列细胞维持内环境稳定的一种主动的生物学过程,其异常参与多种疾病的发生。目前研究表明自噬异常与RA的发生发展过程关系密切,可以干预RA血管翳生成、滑膜炎症和骨破坏等关键病理环节,从而影响RA的进展和预后。近年来很多研究发现中药复方及其活性成分可以通过调节自噬过程,发挥治疗RA的作用。本文对中药调控自噬进而干预RA的相关文献进行调研,以期为中药治疗RA重要作用机制、新药开发及临床治疗提供新思路。     

探讨中医“既病防变”理论与自噬在宫颈癌前病变防治中的微观联系

以既病防变的宏观治病思路深入剖析,探讨其与自噬可能存在微观联系。认为自噬作为一种自我保护性的细胞死亡,对维持细胞及机体内环境稳态具有重要作用。近年来发现自噬水平的高低影响着宫颈癌前病变的发生发展,具有双向调节作用。中医既病防变理论包含了早期治疗及防止传变两层含义,抓住宫颈癌前病变这一黄金期进行调控的思路,与中医"既病防变"理论不谋而合,从中医微观辨证角度探讨,自噬机制与人之"正气"相类,自噬维持的稳态即"阴平阳秘"状态,既病防变理论原则下需要早期扶正制邪及平衡阴阳,防止疾病传变,当下中医药对细胞自噬的调节作用已有一定的实验论证,但证据不够充分,其中的调控机制仍亟待研究。