Myricetin as a Promising Molecule for the Treatment of Post-Ischemic Brain Neurodegeneration

The available drug therapy for post-ischemic neurodegeneration of the brain is symptomatic. This review provides an evaluation of possible dietary therapy for post-ischemic neurodegeneration with myricetin. The purpose of this review was to provide a comprehensive overview of what scientists have done regarding the benefits of myricetin in post-ischemic neurodegeneration. The data in this article contribute to a better understanding of the potential benefits of myricetin in the treatment of post-ischemic brain neurodegeneration, and inform physicians, scientists and patients, as well as their caregivers, about treatment options. Due to the pleiotropic properties of myricetin, including anti-amyloid, anti-phosphorylation of tau protein, anti-inflammatory, anti-oxidant and autophagous, as well as increasing acetylcholine, myricetin is a promising candidate for treatment after ischemia brain neurodegeneration with full-blown dementia. In this way, it may gain interest as a potential substance for the prophylaxis of the development of post-ischemic brain neurodegeneration. It is a safe substance, commercially available, inexpensive and registered as a pro-health product in the US and Europe. Taken together, the evidence available in the review on the therapeutic potential of myricetin provides helpful insight into the potential clinical utility of myricetin in treating neurodegenerative disorders with full-blown dementia. Therefore, myricetin may be a promising complementary agent in the future against the development of post-ischemic brain neurodegeneration. Indeed, there is a scientific rationale for the use of myricetin in the prevention and treatment of brain neurodegeneration caused by ischemia.     

Effects of Dietary Oat Beta-Glucans on Colon Apoptosis and Autophagy through TLRs and Dectin-1 Signaling Pathways—Crohn’s Disease Model Study

Background: Crohn’s disease (CD) is characterized by chronic inflammation of the gastrointestinal tract with alternating periods of exacerbation and remission. The aim of this study was to determine the time-dependent effects of dietary oat beta-glucans on colon apoptosis and autophagy in the CD rat model. Methods: A total of 150 Sprague–Dawley rats were divided into two main groups: healthy control (H) and a TNBS (2,4,6-trinitrobenzosulfonic acid)-induced colitis (C) group, both including subgroups fed with feed without beta-glucans (βG−) or feed supplemented with low- (βGl) or high-molar-mass oat beta-glucans (βGh) for 3, 7, or 21 days. The expression of autophagy (LC3B) and apoptosis (Caspase-3) markers, as well as Toll-like (TLRs) and Dectin-1 receptors, in the colon epithelial cells, was determined using immunohistochemistry and Western blot. Results: The results showed that in rats with colitis, after 3 days of induction of inflammation, the expression of Caspase-3 and LC3B in intestinal epithelial cells did not change, while that of TLR 4 and Dectin-1 decreased. Beta-glucan supplementation caused an increase in the expression of TLR 5 and Dectin-1 with no changes in the expression of Caspase-3 and LC3B. After 7 days, a high expression of Caspase-3 was observed in the colitis-induced animals without any changes in the expression of LC3B and TLRs, and simultaneously, a decrease in Dectin-1 expression was observed. The consumption of feed with βGl or βGh resulted in a decrease in Caspase-3 expression and an increase in TLR 5 expression in the CβGl group, with no change in the expression of LC3B and TLR 4. After 21 days, the expression of Caspase-3 and TLRs was not changed by colitis, while that of LC3B and Dectin-1 was decreased. Feed supplementation with βGh resulted in an increase in the expression of both Caspase-3 and LC3B, while the consumption of feed with βGh and βGl increased Dectin-1 expression. However, regardless of the type of nutritional intervention, the expression of TLRs did not change after 21 days. Conclusions: Dietary intake of βGl and βGh significantly reduced colitis by time-dependent modification of autophagy and apoptosis, with βGI exhibiting a stronger effect on apoptosis and βGh on autophagy. The mechanism of this action may be based on the activation of TLRs and Dectin-1 receptor and depends on the period of exacerbation or remission of CD.     

牛磺酸治疗通过激活自噬介导对老年大鼠骨量和骨强度的保护作用

目的探讨牛磺酸(NHS)对老年大鼠骨量流失的影响,并探讨可能的机制。方法将30只大鼠随机分为对照组(CON)、模型组(MOD)以及牛磺酸组(NHS),每组10只;其中NHS组大鼠每天接受牛磺酸(2 g/kg)治疗12周;待治疗结束后通过Micro-CT检测、HE染色切片、血清指标、蛋白质印迹观察治疗效果,探讨可能的机制。结果治疗12周后,与MOD组相比,三点弯曲试验、Micro-CT和HE染色切片结果显示NHS组大鼠的骨小梁数量、骨强度和骨密度(bone mineral density,BMD)得到明显改善。NHS组大鼠最大载荷和弹性模量、BMD、TV/BV、Tb.N、Tb.Th和Tb.Sp较OVX组明显改善(P<0.05)。和MOD组比较,NHS治疗后大鼠血清BLAP、P1NP、TRACP-5b和β-CTX水平明显降低,组间差异有统计学意义(P<0.05)。和MOD组比较,NHS组Runx2、BMP2、Beclin-1和LC3Ⅱ/LC3-Ⅰ表达水平明显上调,而P62表达水平显著下调,比较差异有统计学意义(P<0.05)。结论NHS可能通过激活自噬,从而对年龄引起的骨量丢失起到保护作用。     

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...     

乙酰基二肽-1鲸蜡酯的皮肤抗衰老作用及其机制

乙酰基二肽-1鲸蜡酯（acetyl dipeptide-1 cetyl ester,AD-1）是乙酸和十六烷基醇与精氨酸和酪氨酸组成的人工合成肽,具有一定的抗炎和提高皮肤屏障功能的作用,已被用于敏感肌化妆品中。该成分虽然也被用于抗衰老化妆品中,但缺乏公开的系统科学研究。本研究通过评价AD-1的体外抗氧化和抗糖基化作用、建立UVA反复照射真皮原代成纤维细胞的光老化模型,探讨其在光老化细胞中的抗衰老活性。采用MTT法测定AD-1对细胞活力的影响;RT-qPCR法检测AD-1和UVA对衰老相关p21、p53、MMPs、IL6、Col1、Col3以及自噬相关p62、ATG5、ATG7 mRNA表达的影响;Western blot法检测AD-1和UVA对衰老及自噬相关p16、p21、p53、Col1、LC3B、p62蛋白水平的影响;β-半乳糖苷酶染色和MDC染色评价细胞衰老损伤,并通过荧光探针DCFH-DA检测细胞内活性氧水平。实验结果显示,AD-1干预可以减少UVA诱导的细胞损伤和mRNA表达异常,改善p16、p21、p53、Col1、LC3B、p62蛋白水平异常。结果表明,AD-1具有一定的...     

氯化锂通过TGFBI促进角膜基质成纤维细胞增殖和自噬

目的：研究TGFBI和微管相关蛋白轻链3(LC3)在角膜营养不良患者中的表达,及氯化锂(LiCl)通过TGFBI对角膜基质成纤维细胞增殖能力的影响。

方法：用免疫组化和Western-blot方法检测角膜营养不良及正常角膜组织中TGFBI和LC3的表达。实验构建了TGFBI过表达载体并转染角膜基质成纤维细胞,分别以5、10、20、40mmol/L LiCl作用于突变型TGFBI转染的角膜基质成纤维细胞,检测不同时间(0、1、6、12h)后,TGFBI与LC3蛋白表达变化,并用CCK-8法检测细胞增殖活性。

结果：TGFBI和LC3在角膜营养不良患者角膜组织中显著高表达。TGFBI过表达抑制角膜基质成纤维细胞增殖活性(P<0.05)。LiCl抑制突变型TGFBI转染的角膜基质成纤维细胞中TGFBI和LC3蛋白表达,并增强其细胞增殖活性(P<0.05)。

结论：LiCl可以促进角膜基质成纤维细胞增殖活性和自噬,其作用机制与下调TGFBI和LC3的表达有关。     

Autophagy: a new mechanism for regulating VEGF and PEDF expression in retinal pigment epithelium cells

AIM: To investigate the regulation of vascular endothelial growth factors (VEGF) and pigment epithelium-derived factor (PEDF) expression by autophagy in retinal pigment epithelium (RPE) cells on exposure to hypoxia. METHODS: ARPE-19, an RPE cell line, was treated as following: the control group was kept in a normoxic incubator; the hypoxia group was incubated in a hypoxic incubator with 1% O2/5% CO2/94% N2 for 24h; the hypoxia + 3-methyladenine (3-MA) group was pretreated with 10 mmol/L 3-MA for 1h and then in the hypoxic incubator for 24h; and the hypoxia + chloroquine (CQ) group was pretreated with 50 μmol/L CQ for 1h and then in the hypoxic incubator for 24h. The morphology and ultrastructure of the cells was observed by an inverted microscope or a transmission electronic microscope (TEM). Western blot was performed to assay the expression of autophagy-associated markers, including microtubule associated protein 1 light chain 3 B (LC3B), Beclin-1, Atg5 and p62. The concentration of VEGF and PEDF in the culture supernatant was determined by ELISA, and the ratio of VEGF/PEDF was calculated. RESULTS: There were no obvious differences in cell morphology among different groups and autolysosomes could be observed in the cytoplasm in all groups. Compared to the control cells, the LC3B-II/I ratio and levels of Beclin-1 and Atg5 were significantly increased and p62 level was significantly decreased in the hypoxia group. With the increase of VEGF and decrease of PEDF concentration, the VEGF/PEDF ratio was significantly increased in the hypoxia group compared to the control cells. The LC3B-II/I ratio was significantly reduced by 3-MA treatment and increased by CQ treatment. The expressions of Beclin-1 and Atg5 were significantly reduced by 3-MA or CQ treatment, while expression of p62 was increased in the 3-MA or CQ treated cells. The concentration of VEGF was significantly decreased and PEDF increased, thereby the VEGF/PEDF ratio was decreased in the hypoxia + 3-MA group and hypoxia + CQ group compared with that in the hypoxia group. CONCLUSION: Hypoxia leads to elevated autophagy in RPE cells, and expression of VEGF and PEDF might be regulated by autophagy on exposure to hypoxia to further participate in regulating the formation of retinal neovascularization.     

人参皂苷Rb1在Aβ损伤的PC12细胞中激活线粒体自噬的机制研究＊

目的 基于Aβ损伤的PC12模型，观察人参皂苷Rb1对线粒体自噬的调节作用。方法 用Aβ损伤PC12细胞建立体外AD模型，采用人参皂苷Rb1进行干预后，利用透射电镜观察自噬情况，Western blot检测LC3Ⅱ/Ⅰ、p62、PINK1、parkin、NDP52和OPTN蛋白的表达，荧光实时定量PCR检测LC3、p62、PINK1、parkin、NDP52、OPTN mRNA水平。结果 人参皂苷Rb1高剂量促进细胞中自噬小体包裹受损线粒体，升高LC3Ⅱ/Ⅰ比值（P < 0.05），减少p62蛋白水平（P < 0.05）；同时，人参皂苷Rb1显著增加了PINK1蛋白表达（P < 0.01），同时减少OPTN及NDP52蛋白水平（P < 0.05）；此外，人参皂苷Rb1高剂量组parkin、OPTN mRNA表达显著上调（P < 0.01），低剂量组PINK1、NDP52 mRNA表达也显著上调（P < 0.05）。结论 人参皂苷Rb1神经保护作用与调节线粒体自噬相关，通过激活PINK1/parkin通路促进线粒体自噬而改善体外AD模型损伤情况。     

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.