BBR

BBR
  • 文章类型: Journal Article
    鼻咽癌(NPC),主要发现于中国南部地区,是一种以高度转移特性而闻名的恶性肿瘤。由远处转移和疾病复发引起的高死亡率仍然是临床上尚未解决的问题。在临床上,黄连素(BBR)化合物已广泛用于鼻咽癌治疗,以减少转移和疾病复发,并且BBR被记录为具有多种抗NPC作用的主要成分。然而,BBR抑制鼻咽癌生长和转移的机制尚不清楚。在这里,我们表明,BBR有效地抑制了生长,转移,并通过诱导特异性超级增强子(SE)入侵NPC。从机械的角度来看,RNA测序(RNA-seq)结果表明RAS-RAF1-MEK1/2-ERK1/2信号通路,由表皮生长因子受体(EGFR)激活,在BBR诱导的NPC自噬中起重要作用。自噬的阻断显著减弱了BBR介导的NPC细胞生长和转移抑制的作用。值得注意的是,BBR通过转录增加EGFR的表达,和敲除EGFR显著抑制BBR诱导的微管相关蛋白1轻链3(LC3)-II的增加和p62抑制,提示EGFR在BBR诱导的NPC自噬中起关键作用。染色质免疫沉淀测序(ChIP-seq)结果发现,仅在BBR处理的NPC细胞中存在特异性SE。这种SE敲除明显抑制了EGFR和磷酸化EGFR(EGFR-p)的表达,并逆转了BBR对NPC增殖的抑制作用。转移,和入侵。此外,BBR特异性SE可能通过增强EGFR基因转录触发自噬,从而上调RAS-RAF1-MEK1/2-ERK1/2信号通路。此外,体内BBR有效抑制NPC细胞生长和转移,随着LC3和EGFR的增加和p62的减少。总的来说,这项研究确定了一种新的BBR-特殊SE,并建立了一种新的表观遗传范式,BBR调节自噬,抑制增殖,转移,和入侵。它为BBR作为未来NPC治疗中的治疗方案的应用提供了理论基础。
    Nasopharyngeal carcinoma (NPC), primarily found in the southern region of China, is a malignant tumor known for its highly metastatic characteristics. The high mortality rates caused by the distant metastasis and disease recurrence remain unsolved clinical problems. In clinic, the berberine (BBR) compound has widely been in NPC therapy to decrease metastasis and disease recurrence, and BBR was documented as a main component with multiple anti-NPC effects. However, the mechanism by which BBR inhibits the growth and metastasis of nasopharyngeal carcinoma remains elusive. Herein, we show that BBR effectively inhibits the growth, metastasis, and invasion of NPC via inducing a specific super enhancer (SE). From a mechanistic perspective, the RNA sequencing (RNA-seq) results suggest that the RAS-RAF1-MEK1/2-ERK1/2 signaling pathway, activated by the epidermal growth factor receptor (EGFR), plays a significant role in BBR-induced autophagy in NPC. Blockading of autophagy markedly attenuated the effect of BBR-mediated NPC cell growth and metastasis inhibition. Notably, BBR increased the expression of EGFR by transcription, and knockout of EGFR significantly inhibited BBR-induced microtubule associated protein 1 light chain 3 (LC3)-II increase and p62 inhibition, proposing that EGFR plays a pivotal role in BBR-induced autophagy in NPC. Chromatin immunoprecipitation sequencing (ChIP-seq) results found that a specific SE existed only in NPC cells treated with BBR. This SE knockdown markedly repressed the expression of EGFR and phosphorylated EGFR (EGFR-p) and reversed the inhibition of BBR on NPC proliferation, metastasis, and invasion. Furthermore, BBR-specific SE may trigger autophagy by enhancing EGFR gene transcription, thereby upregulating the RAS-RAF1-MEK1/2-ERK1/2 signaling pathway. In addition, in vivo BBR effectively inhibited NPC cells growth and metastasis, following an increase LC3 and EGFR and a decrease p62. Collectively, this study identifies a novel BBR-special SE and established a new epigenetic paradigm, by which BBR regulates autophagy, inhibits proliferation, metastasis, and invasion. It provides a rationale for BBR application as the treatment regime in NPC therapy in future.
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  • 文章类型: Journal Article
    背景:小檗碱(BBR),黄连的一种异喹啉生物碱,已经发现对各种人类恶性肿瘤有强大的活性,包括乳腺癌.然而,BBR在乳腺癌中的潜在抗肿瘤机制仍然知之甚少。
    方法:将乳腺癌细胞培养并用不同剂量(0、20、40和60μM)的BBR处理48小时。扩散,凋亡,入侵,和迁移使用3-(4,5-二甲基-2-噻唑基)-2,5-二苯基-2H-四唑溴化物(MTT)进行评估,5-乙炔基-2'-脱氧尿苷(EdU),流式细胞术,transwell,和伤口愈合试验。成纤维细胞生长因子7(FGF7),甲基转移酶样3(METTL3),使用实时定量聚合酶链反应(RT-qPCR)和蛋白质印迹测量胰岛素样生长因子2mRNA结合蛋白3(IGF2BP3)的mRNA水平和蛋白质水平。使用甲基化RNA免疫沉淀(MeRIP)-qPCR和RNA免疫沉淀(RIP)测定评估METTL3和FGF7m6A之间的相互作用。使用RIP测定法分析IGF2BP3和FGF7mRNA之间的结合能力。
    结果:BBR治疗阻碍了乳腺癌细胞的增殖,入侵,迁移,诱导细胞凋亡。乳腺癌组织中FGF7表达上调,而其水平在BBR处理的肿瘤细胞中降低。FGF7上调减轻了BBR对乳腺癌细胞恶性行为的抑制。在机制上,METTL3通过m6A-IGF2BP3依赖性机制稳定FGF7mRNA,并自然改善FGF7表达。BBR治疗在体内抑制乳腺癌生长。
    结论:BBR治疗部分通过调节METTL3介导的FGF7mRNA的m6A修饰来阻断乳腺癌细胞的生长和转移,为乳腺癌的治疗提供了一个有希望的治疗靶点。
    BACKGROUND: Berberine (BBR), an isoquinoline alkaloid from Coptidis rhizoma, has been found to have powerful activities against various human malignancies, including breast cancer. However, the underlying antitumor mechanisms of BBR in breast cancer remain poorly understood.
    METHODS: Breast cancer cells were cultured and treated with different doses (0, 20, 40, and 60 μM) of BBR for 48 h. Cell viability, proliferation, apoptosis, invasion, and migration were assessed using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT), 5-ethynyl-2\'-deoxyuridine (EdU), flow cytometry, transwell, and wound healing assays. Fibroblast growth factor 7 (FGF7), methyltransferase-like 3 (METTL3), and insulin-like growth factor-2 mRNA-binding protein 3 (IGF2BP3) mRNA levels and protein levels were measured using real-time quantitative polymerase chain reaction (RT-qPCR) and western blot. Interaction between METTL3 and FGF7 m6A was assessed using methylated RNA immunoprecipitation (MeRIP)-qPCR and RNA immunoprecipitation (RIP) assay. Binding ability between IGF2BP3 and FGF7 mRNA was analyzed using RIP assay.
    RESULTS: BBR treatment hindered breast cancer cell proliferation, invasion, migration, and induced apoptosis. FGF7 expression was upregulated in breast cancer tissues, while its level was reduced in BBR-treated tumor cells. FGF7 upregulation relieved the repression of BBR on breast cancer cell malignant behaviors. In mechanism, METTL3 stabilized FGF7 mRNA through the m6A-IGF2BP3-dependent mechanism and naturally improved FGF7 expression. BBR treatment inhibited breast cancer growth in vivo.
    CONCLUSIONS: BBR treatment blocked breast cancer cell growth and metastasis partly by regulating METTL3-mediated m6A modification of FGF7 mRNA, providing a promising therapeutic target for breast cancer treatment.
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  • 文章类型: Journal Article
    鼻咽癌(NPC)是一种在中国东南部高度流行的恶性肿瘤,其转移仍然是一个尚未解决的临床问题。Ferroptosis,一种非凋亡性细胞死亡,是肿瘤转移的关键途径。小檗碱(BBR),一种植物生物碱,已被探索为潜在的抗NPC转移剂;然而,潜在的机制是未知的。这里,我们表明BBR通过抑制系统Xc-/GSH/GPX4轴驱动的铁凋亡发挥其抗转移作用。本研究首次证明了BBR通过增加活性氧来诱导NPC细胞的铁凋亡。脂质过氧化和细胞Fe2以及铁凋亡抑制剂Ferrostatin-1和甲磺酸去铁胺可挽救BBR诱导的NPC细胞死亡。此外,用透射电镜观察BBR处理的NPC细胞的铁变性特征。机械上,发现系统Xc-(SLC7A11和SLC3A2)和GSH水平在用BBR治疗后被抑制。我们证明了系统Xc-/GSH/GPX4轴是BBR诱导的铁凋亡的关键介质。此外,GPX4是脂质过氧化的关键抑制剂,在蛋白质和mRNA水平上都受到BBR的极大抑制。分子对接结果显示GPX4与BBR之间存在较强的相互作用。值得注意的是,GPX4过表达逆转了BBR诱导的NPC细胞铁凋亡的作用。最后,使用小鼠模型在体内验证BBR介导的NPC转移的抑制。一起来看,我们的数据表明,BBR通过抑制系统Xc-/GSH/GPX4轴诱导NPC细胞的铁凋亡,为BBR抗NPC转移的机制提供了新的见解。
    Nasopharyngeal carcinoma (NPC) is a malignant tumor that is highly prevalent in Southeast China, and its metastasis remains an unresolved clinical problem. Ferroptosis, a type of nonapoptotic cell death, is a critical pathway in tumor metastasis. Berberine (BBR), a plant alkaloid, has been explored as a potential anti-NPC metastatic agent; however, the underlying mechanisms are unknown. Here, we showed that BBR exerted its anti-metastasis role by inhibiting system Xc-/GSH/GPX4 axis-driven ferroptosis. The present study demonstrated for the first time that BBR induced ferroptosis in NPC cells by increasing reactive oxygen species, lipid peroxidation and cellular Fe2+ and that the ferroptosis inhibitors Ferrostatin-1 and Deferoxamine mesylate rescued BBR-induced NPC cell death. Moreover, the ferroptotic characteristics of BBR-treated NPC cells were observed using transmission electron microscopy. Mechanistically, system Xc- (SLC7A11 and SLC3A2) and GSH levels were found to be suppressed after treatment with BBR. We demonstrated that the system Xc-/GSH/GPX4 axis was a critical mediator of BBR-induced ferroptosis. Furthermore, GPX4, a key inhibitor of lipid peroxidation, was greatly suppressed by BBR at both protein and mRNA levels. Molecular docking results showed a strong interaction between GPX4 and BBR. Notably, GPX4 overexpression reversed the effect of BBR-induced ferroptosis in NPC cells. Finally, BBR-mediated inhibition of NPC metastasis was validated in vivo using a mouse model. Taken together, our data suggest that BBR induced ferroptosis of NPC cells via suppressing the system Xc-/GSH/GPX4 axis, provides new insights into the mechanism of BBR anti-NPC metastasis.
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  • 文章类型: Journal Article
    多囊卵巢综合征(PCOS)是育龄妇女的内分泌综合征。小檗碱(BBR)是表现出许多与PCOS治疗相关的药理学性质的中草药单体。本研讨旨在剖析BBR对PCOS一细胞模子的影响及根本机制。用二氢睾酮(DHT)处理人卵巢颗粒细胞(KGN)以模拟PCOS细胞模型。circ_0097636,miR-186-5p的RNA表达,通过定量实时聚合酶链反应(qRT-PCR)测定sirtuin3(SIRT3)。蛋白质印迹法检测蛋白质表达。通过CCK-8测定分析细胞活力。通过5-乙炔基-2'-脱氧尿苷(EdU)测定法和流式细胞术测定法研究细胞增殖和凋亡,分别。白细胞介素-6(IL-6)的水平,IL-1β,和肿瘤坏死因子-α(TNF-α)通过酶联免疫吸附测定(ELISA)进行分析。通过铁测定试剂盒评估Fe2+浓度。通过使用商业试剂盒检测活性氧(ROS)水平和丙二醛(MDA)水平来评估氧化应激。miR-186-5p与circ_0097636和SIRT3的关联通过双荧光素酶报告基因测定和RNA下拉测定来鉴定。与对照组相比,PCOS患者和DHT处理的KGN细胞的卵泡液中Circ_0097636表达下调。BBR部分缓解了DHT对细胞增殖的抑制作用,促进了细胞凋亡,炎症,铁性凋亡,和KGN细胞的氧化应激。此外,circ_0097636与miR-186-5p结合,SIRT3在KGN细胞中被鉴定为miR-186-5p的靶基因。BBR治疗通过上调circ_0097636和SIRT3表达和下调miR-186-5p表达来改善DHT诱导的KGN细胞损伤。此外,circ_0097636过表达通过增加SIRT3表达来保护KGN细胞免受DHT诱导的损伤。BBR通过调节circ_0097636/miR-186-5p/SIRT3途径改善DHT诱导的KGN细胞损伤和铁凋亡。
    Polycystic ovarian syndrome (PCOS) is an endocrine syndrome in women of reproductive age. Berberine (BBR) is a Chinese herbal monomer that exhibits many pharmacological properties related to PCOS treatment. This study aims to analyze the effect of BBR on a cell model of PCOS and the underlying mechanism. Human ovarian granulosa (KGN) cells were treated with dihydrotestosterone (DHT) to mimic a PCOS cell model. The RNA expression of circ_0097636, miR-186-5p, and sirtuin3 (SIRT3) was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Protein expression was detected by western blotting. Cell viability was analyzed by CCK-8 assay. Cell proliferation and apoptosis were investigated by 5-ethynyl-2\'-deoxyuridine (EdU) assay and flow cytometry assay, respectively. The levels of interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α (TNF-α) were analyzed by enzyme-linked immunosorbent assays (ELISAs). Fe2+ concentration was assessed by an iron assay kit. Oxidative stress was assessed by detecting reactive oxygen species (ROS) level and malondialdehyde (MDA) level using commercial kits. The association of miR-186-5p with circ_0097636 and SIRT3 was identified by dual-luciferase reporter assay and RNA pull-down assay. Circ_0097636 expression was downregulated in the follicular fluid of PCOS patients and DHT-treated KGN cells when compared with control groups. BBR treatment partially relieved the DHT-induced inhibitory effect on cell proliferation and promoted effects on cell apoptosis, inflammation, ferroptosis, and oxidative stress in KGN cells. Additionally, circ_0097636 bound to miR-186-5p, and SIRT3 was identified as a target gene of miR-186-5p in KGN cells. BBR treatment ameliorated DHT-induced KGN cell injury by upregulating circ_0097636 and SIRT3 expression and downregulating miR-186-5p expression. Moreover, circ_0097636 overexpression protected KGN cells from DHT-induced injury by increasing SIRT3 expression. BBR ameliorated DHT-induced KGN cell injury and ferroptosis by regulating the circ_0097636/miR-186-5p/SIRT3 pathway.
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  • 文章类型: Journal Article
    背景:小檗碱(BBR)是一种常用的抗肠道炎症药物,最近发现了它的抗癌活性。BBR可以通过肠道微生物干预和控制恶性结直肠癌(CRC),但其直接分子靶标及相关机制尚不清楚。本研究旨在确定BBR的作用靶点,并从肠道微生物角度剖析其与CRC发生发展的相关机制。
    结果:这里,我们发现BBR抑制几种CRC驱动细菌的生长,尤其是厌氧菌消化链球菌.通过使用生物素结合的BBR衍生物,我们鉴定了蛋白质FtfL(甲酸四氢叶酸连接酶),C1代谢的关键酶,是厌氧菌BBR的分子靶标。BBR表现出强结合亲和力和对FtfL的有效抑制。基于此,我们确定了PaFtfL的晶体结构(P.厌氧菌FtfL)-BBR复合物,并发现BBR不仅可以通过楔入四聚体界面来干扰PaFtfL四聚体的构象灵活性,而且还可以与其底物ATP竞争结合在活性中心内。此外,BBR也可以抑制人肿瘤细胞中FtfL同源蛋白的酶活性。
    结论:总之,我们的研究已经确定FtfL是BBR的直接靶标,并揭示了BBR抗CRC的分子机制。BBR通过靶向FtfLs干扰肠道致病菌,提出了控制CRC发生发展的新手段。
    Berberine (BBR) is a commonly used anti-intestinal inflammation drug, and its anti-cancer activity has been found recently. BBR can intervene and control malignant colorectal cancer (CRC) through intestinal microbes, but the direct molecular target and related mechanism are unclear. This study aimed to identify the target of BBR and dissect related mechanisms against the occurrence and development of CRC from the perspective of intestinal microorganisms.
    Here, we found that BBR inhibits the growth of several CRC-driving bacteria, especially Peptostreptococcus anaerobius. By using a biotin-conjugated BBR derivative, we identified the protein FtfL (formate tetrahydrofolate ligase), a key enzyme in C1 metabolism, is the molecular target of BBR in P. anaerobius. BBR exhibits strong binding affinity and potent inhibition on FtfL. Based on this, we determined the crystal structure of PaFtfL (P. anaerobius FtfL)-BBR complex and found that BBR can not only interfere with the conformational flexibility of PaFtfL tetramer by wedging the tetramer interface but also compete with its substrate ATP for binding within the active center. In addition, the enzymatic activities of FtfL homologous proteins in human tumor cells can also be inhibited by BBR.
    In summary, our study has identified FtfL as a direct target of BBR and uncovered molecular mechanisms involved in the anti-CRC of BBR. BBR interferes with intestinal pathogenic bacteria by targeting FtfLs, suggesting a new means for controlling the occurrence and development of CRC.
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  • 文章类型: Systematic Review
    目的:一些荟萃分析报道补充小檗碱(BBR)可改善血糖参数和炎症标志物,但调查结果仍然不一致。因此,进行了这项研究。
    方法:我们系统地搜索了PubMed,Embase,WebofScience,Scopus,和谷歌学者确定截至2023年4月的相关荟萃分析。
    结果:补充BBR可有效降低空腹血糖(FBG)(ESWMD:-0.77;95%CI:-0.90至-0.63,和ESSMD:-0.65;95%CI:-0.83至-0.47),血红蛋白A1C(HbA1C)(ESWMD:-0.57;95%CI:-0.68至-0.46),胰岛素抵抗的稳态模型评估(HOMA-IR)(ESWMD:-1.04;95%CI:-1.66至-0.42,和ESSMD:-0.71;95%CI:-0.97至-0.46),胰岛素(ESWMD:-1.00;95%CI:-1.70至-0.30,ESSMD:-0.63;95%CI:-0.94至-0.32),白细胞介素(IL)-6(ESSMD:-1.23;95%CI:-1.61至-0.85),肿瘤坏死因子-α(TNF-α)(ESSMD:-1.04;95%CI:-1.28至-0.79),和C反应蛋白(CRP)(ESWMD:-0.62;95%CI:-0.74至-0.50,和ESSMD:-1.70;95%CI:-2.21至-1.19)。
    结论:我们的研究结果表明,补充BBR可以有效改善成人的血糖参数和炎症指标。
    Several meta-analyses reported berberine (BBR) supplementation improves glycemic parameters and inflammatory marker, but findings remain inconsistent. Therefore, this study was conducted.
    We systematically searched PubMed, Embase, Web of Science, Scopus, and Google Scholar to identify the relevant meta-analyses up to April 2023.
    BBR supplementation was effective in reducing fasting blood glucose (FBG) (ESWMD: -0.77; 95% CI: -0.90 to -0.63, and ESSMD: -0.65; 95% CI: -0.83 to -0.47), hemoglobin A1C (HbA1C) (ESWMD: -0.57; 95% CI: -0.68 to -0.46), homeostasis model assessment for insulin resistance (HOMA-IR) (ESWMD: -1.04; 95% CI: -1.66 to -0.42, and ESSMD: -0.71; 95% CI: -0.97 to -0.46), insulin (ESWMD: -1.00; 95% CI: -1.70 to -0.30, and ESSMD: -0.63; 95% CI: -0.94 to -0.32), interleukin (IL)-6 (ESSMD: -1.23; 95% CI: -1.61 to -0.85), tumor necrosis factor-α (TNF-α) (ESSMD: -1.04; 95% CI: -1.28 to -0.79), and C-reactive protein (CRP) (ESWMD: -0.62; 95% CI: -0.74 to -0.50, and ESSMD: -1.70; 95% CI: -2.21 to -1.19).
    The finding of our umbrella showed that the supplementation of BBR could be effective in improving glycemic parameters and inflammatory marker in adults.
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  • 文章类型: Journal Article
    小檗碱(BBR),黄连中的一种主要生物碱,和(-)-表没食子儿茶素-3-没食子酸酯(EGCG),绿茶中的主要儿茶素,是两种常见的植物化学物质,具有许多健康益处,包括抗菌功效。然而,有限的生物利用度限制了它们的应用。先进的共组装技术,以形成纳米复合纳米粒子精确控制的形态,电荷,和纳米材料的功能。这里,我们报道了一种简单的一步法制备新型纳米复合BBR-EGCG纳米颗粒(BBR-EGCGNPs)。相对于游离BBR和一线抗生素,这些BBR-EGCGNP在体外和体内表现出改善的生物相容性和更大的抗菌作用(即,苄青霉素钾和环丙沙星)。此外,当与EGCG联合使用时,我们证明了对BBR的协同杀菌作用。我们还评估了BBR的抗菌活性以及在MRSA感染的伤口中与EGCG的可能协同作用。金黄色葡萄球菌和MRSA之间的协同作用的潜在机制也通过ATP测定进行了探索,纳米粒子和细菌之间的相互作用,and,然后,转录分析。此外,我们对金黄色葡萄球菌和MRSA的实验证实了BBR-EGCGNP的生物膜清除作用。更重要的是,毒性分析表明,BBR-EGCGNPs对小鼠主要器官没有毒性作用。最后,我们提出了一种制造BBR-EGCG组合的绿色方法,这可能为不使用抗生素治疗MRSA感染提供替代方法。
    Berberine (BBR), a major alkaloid in Coptis chinensis, and (-)-epigallocatechin-3-gallate (EGCG), a major catechin in green tea, are two common phytochemicals with numerous health benefits, including antibacterial efficacy. However, the limited bioavailability restricts their application. Advancement in the co-assembly technology to form nanocomposite nanoparticles precisely controls the morphology, electrical charge, and functionalities of the nanomaterials. Here, we have reported a simple one-step method for preparing a novel nanocomposite BBR-EGCG nanoparticles (BBR-EGCG NPs). These BBR-EGCG NPs exhibit improved biocompatibility and greater antibacterial effects both in vitro and in vivo relative to free-BBR and first-line antibiotics (i.e., benzylpenicillin potassium and ciprofloxacin). Furthermore, we demonstrated a synergistic bactericidal effect for BBR when combined with EGCG. We also evaluated the antibacterial activity of BBR and the possible synergism with EGCG in MRSA-infected wounds. A potential mechanism for synergism between S. aureus and MRSA was also explored through ATP determination, the interaction between nanoparticles and bacteria, and, then, transcription analysis. Furthermore, our experiments on S. aureus and MRSA confirmed the biofilm-scavenging effect of BBR-EGCG NPs. More importantly, toxicity analysis revealed that the BBR-EGCG NPs had no toxic effects on the major organs of mice. Finally, we proposed a green method for the fabrication of BBR-EGCG combinations, which may provide an alternative approach to treating infections with MRSA without using antibiotics.
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  • 文章类型: Journal Article
    2016年,Google提出了基于瓶颈带宽和往返传播时间(BBR)的拥塞控制算法。BBR拥塞控制算法实时测量网络瓶颈带宽和最小延迟以计算带宽延迟乘积(BDP),然后调整传输速率以最大化吞吐量和最小化延迟。然而,相关研究表明,BBR仍然存在RTT不公平、高丢包率,和深度缓冲性能下降。本文以其最突出的RTT公平性问题作为优化研究的起点。用流体模型描述BBR拥塞控制中的数据传输过程,提出了一种基于起搏增益的公平性优化策略。三角函数,反比例函数,和伽马校正函数进行分析和选择,构建起搏增益模型,形成三个不同的调整函数,用于自适应调整传输速率。仿真和实际实验表明,3种优化算法显著提高了原BBR算法的公平性和网络传输性能。特别是,采用伽玛校正函数作为增益模型的优化算法具有最佳的稳定性。
    In 2016, Google proposed a congestion control algorithm based on bottleneck bandwidth and round-trip propagation time (BBR). The BBR congestion control algorithm measures the network bottleneck bandwidth and minimum delay in real-time to calculate the bandwidth delay product (BDP) and then adjusts the transmission rate to maximize throughput and minimize latency. However, relevant research reveals that BBR still has issues such as RTT unfairness, high packet loss rate, and deep buffer performance degradation. This article focuses on its most prominent RTT fairness issue as a starting point for optimization research. Using fluid models to describe the data transmission process in BBR congestion control, a fairness optimization strategy based on pacing gain is proposed. Triangular functions, inverse proportional functions, and gamma correction functions are analyzed and selected to construct the pacing gain model, forming three different adjustment functions for adaptive adjustment of the transmission rate. Simulation and real experiments show that the three optimization algorithms significantly improve the fairness and network transmission performance of the original BBR algorithm. In particular, the optimization algorithm that employs the gamma correction function as the gain model exhibits the best stability.
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  • 文章类型: Journal Article
    线粒体功能障碍被认为是阿尔茨海默病(AD)的早期事件。D-核糖是一种存在于细胞中的天然单糖,尤其是在线粒体中,并可能导致认知功能障碍。然而,原因尚不清楚。小檗碱(BBR)是一种能靶向线粒体的异喹啉类生物碱,在AD治疗中具有很大的应用前景。PINK1的甲基化增强了阿尔茨海默病病理学的负担。本研究探讨BBR和D-核糖在与DNA甲基化相关的AD线粒体自噬和认知功能中的作用。APP/PS1小鼠和N2a细胞用D-核糖处理,BBR,和线粒体自噬抑制剂Mdivi-1观察它们对线粒体形态的影响,线粒体自噬,神经元组织学,AD病理学,动物行为,和PINK1甲基化。结果表明,D-核糖诱导线粒体功能障碍,线粒体自噬损伤,和认知障碍。然而,BBR抑制PINK1启动子甲基化可以逆转D-核糖引起的上述效应,改善线粒体功能,通过PINK1-Parkin通路恢复线粒体自噬,从而减少认知缺陷和AD病理负担。该实验为D-核糖在认知障碍中的作用机制提供了新的思路,并揭示了BBR用于AD治疗的新见解。
    Mitochondrial dysfunction is considered an early event of Alzheimer disease (AD). D-ribose is a natural monosaccharide that exists in cells, especially in mitochondria, and can lead to cognitive dysfunction. However, the reason for this is unclear. Berberine (BBR) is an isoquinoline alkaloid that can target mitochondria and has great prospect in the treatment of AD. The methylation of PINK1 reinforces the burden of Alzheimer\'s pathology. This study explores the role of BBR and D-ribose in the mitophagy and cognitive function of AD related to DNA methylation. APP/PS1 mice and N2a cells were treated with D-ribose, BBR, and mitophagy inhibitor Mdivi-1 to observe their effects on mitochondrial morphology, mitophagy, neuron histology, AD pathology, animal behavior, and PINK1 methylation. The results showed that D-ribose induced mitochondrial dysfunction, mitophagy damage, and cognitive impairment. However, BBR inhibition of PINK1 promoter methylation can reverse the above effects caused by D-ribose, improve mitochondrial function, and restore mitophagy through the PINK1-Parkin pathway, thus reducing cognitive deficits and the burden of AD pathology. This experiment puts a new light on the mechanism of action of D-ribose in cognitive impairment and reveals new insights in the use of BBR for AD treatment.
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  • 文章类型: Journal Article
    目前,用于可靠传输的计算机网络传输层的最广泛使用的协议是传输控制协议(TCP)。然而,TCP存在一些问题,例如高握手延迟,线头(HOL)阻塞,等等。为了解决这些问题,Google提出了快速用户数据报协议Internet连接(QUIC)协议,支持0-1往返时间(RTT)握手,用户模式下的拥塞控制算法配置。到目前为止,QUIC协议已与传统的拥塞控制算法集成,在许多场景中效率不高。为了解决这个问题,我们提出了一种基于深度强化学习(DRL)的有效拥塞控制机制,即,QUIC的近端带宽延迟快速优化(PBQ),它将传统的瓶颈带宽和往返传播时间(BBR)与近端策略优化(PPO)相结合。在PBQ中,PPO代理输出拥塞窗口(CWnd)并根据网络状态进行自我改进,并且BBR指定客户的起搏速率。然后,我们将提出的PBQ应用于QUIC,并形成QUIC的新版本,即,PBQ增强的QUIC。实验结果表明,与现有流行版本的QUIC相比,所提出的PBQ增强的QUIC在吞吐量和RTT方面都具有更好的性能。如QUIC与立方和QUIC与BBR。
    Currently, the most widely used protocol for the transportation layer of computer networks for reliable transportation is the Transmission Control Protocol (TCP). However, TCP has some problems such as high handshake delay, head-of-line (HOL) blocking, and so on. To solve these problems, Google proposed the Quick User Datagram Protocol Internet Connection (QUIC) protocol, which supports 0-1 round-trip time (RTT) handshake, a congestion control algorithm configuration in user mode. So far, the QUIC protocol has been integrated with traditional congestion control algorithms, which are not efficient in numerous scenarios. To solve this problem, we propose an efficient congestion control mechanism on the basis of deep reinforcement learning (DRL), i.e., proximal bandwidth-delay quick optimization (PBQ) for QUIC, which combines traditional bottleneck bandwidth and round-trip propagation time (BBR) with proximal policy optimization (PPO). In PBQ, the PPO agent outputs the congestion window (CWnd) and improves itself according to network state, and the BBR specifies the pacing rate of the client. Then, we apply the presented PBQ to QUIC and form a new version of QUIC, i.e., PBQ-enhanced QUIC. The experimental results show that the proposed PBQ-enhanced QUIC achieves much better performance in both throughput and RTT than existing popular versions of QUIC, such as QUIC with Cubic and QUIC with BBR.
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