Ursolic acid promotes apoptosis,autophagy, and chemosensitivity in gemcitabine‐resistant human pancreatic cancer cells

Gemcitabine (GEM) resistance in pancreatic adenocarcinoma mediated by the receptor for advanced glycation end products (RAGE) has been demonstrated. Therefore, investigating the safety and the potential of new auxiliary methods for pancreatic cancer treatment is urgent. Ursolic acid (UA), a natural pentacyclic triterpenoid found in apple peels, rosemary, and thyme, has been reported to have anticancer capacity. This study aimed to reveal the underlying mechanisms of UA in cell death and drug enhancement, especially in GEM‐resistant pancreatic cancer cells. First, GEM‐resistant cells (MIA Paca‐2^GEMR cells) were established by incrementally increasing GEM culture concentrations. UA treatment reduced cell viability through cell cycle arrest and endoplasmic reticulum (ER) stress, resulting in apoptosis and autophagy in a dose‐dependent manner in MIA Paca‐2 and MIA Paca‐2^GEMR cells. High RAGE expression in MIA Paca‐2^GEMR cells was suppressed by UA treatment. Interestingly, knocking down RAGE expression showed similar UA‐induced effects in both cell lines. Remarkably, UA had a drug‐enhancing effect by decreasing cell viability and increasing cell cytotoxicity when combined with GEM treatment. In conclusions, UA triggered ER stress, subsequently regulating apoptosis‐ and autophagy‐related pathways and increasing GEM chemosensitivity in pancreatic cancer cells by inhibiting the expression of RAGE.     

艾炷灸命门穴对衰老模型大鼠脑组织中AGEs、RAGE表达影响

目的:观察艾炷灸命门穴对D-半乳糖致衰老大鼠脑组织中AGEs及其受体RAGE表达的影响,探讨艾炷灸命门穴延缓衰老的作用机制。方法:雄性SD大鼠40只,随机分为空白组10只、模型制备组30只,空白组腹腔注射生理盐水,模型制备组进行腹腔注射D-半乳糖500 mg/kg,每日1次,连续60天,模型制备成功后随机选取20只分为模型对照组、命门穴治疗组,艾炷灸治疗4周。酶联免疫吸附测定法(Elisa)观察各组大鼠脑组织匀浆中AGES、RAGE表达水平,RT-PCR观察RAGE mRNA的表达水平。结果:模型对照组大鼠脑组织中AGES、RAGE及RAGE mRNA表达水平比空白组明显增加(P<0.01);命门穴治疗组脑组织中AGES、RAGE及RAGE mRNA表达水平明显低于模型对照组(P<0.01)。结论:艾炷灸命门穴可以延缓衰老,其机制可能是AGEs的水平下调减少了对蛋白的直接修饰及抑制AGEs与特异性配体RAGE结合而引发一系列的生物学效应而达到延缓衰老的目的。     

Sex-specific association of RAGE and HMGB1 genotype variations with susceptibility to ischemic stroke in Caucasians

BackgroundThe role of genotype variants of HMGB1 and RAGE in susceptibility to acute ischemic stroke remains inconclusive.MethodsCaucasian acute ischemic stroke patients admitted to three hospitals within a large healthcare system in the U.S. between 2009 and 2017 were reviewed. For each stroke case, three age and sex-matched non-stroke patients were identified as controls. Associations of phased-genotype data for RAGE (rs1035798, rs2070600, rs1800624, rs1800625) and HMGB1 (rs1360485, rs1045411, rs3742305, rs2249825, rs1412125) single-nucleotide-polymorphisms (SNPs) and haplotypes with stroke susceptibility were analyzed. The Benjamini-Hochberg procedure was performed.ResultsCollectively, 4,264 patients, 1,066 acute ischemic stroke and 3,198 controls were identified. Genotype distributions were in Hardy-Weinberg equilibrium. None of the SNPs alternate allele frequencies differed from the NCBI SNP database. No differences were found in the genotype distributions when analyzing each SNP and the two most common haplotypes in a covariate adjusted model. In a sex-specific stratification, males harboring the RAGE SNP rs1800625 AG or GG genotype had an independently increased risk for ischemic strokes compared to controls (adjusted OR = 1.27,95%CI 1.03–1.57, p_a = 0.0276). After the Benjamini-Hochberg procedure, a trend towards this association remained (p_BH = 0.1104).ConclusionNo association of RAGE and HMGB1 genotypes variations with risk for overall ischemic stroke or specific stroke subtypes could be observed. Congruent with the literature, a sex-specific role of RAGE SNPs might associate with stroke susceptibility. The functional role of the HMGB1-RAGE axis in this context warrants further exploration.     

Extracellular HMGB1 as a therapeutic target in inflammatory diseases

Introduction: High-mobility group box 1 (HMGB1) is a ubiquitous nuclear protein that promotes inflammation when released extracellularly after cellular activation, stress, damage or death. HMGB1 operates as one of the most intriguing molecules in inflammatory disorders via recently elucidated signal and molecular transport mechanisms. Treatments based on antagonists specifically targeting extracellular HMGB1 have generated encouraging results in a wide number of experimental models of infectious and sterile inflammation. Clinical studies are still to come.

Areas covered: We here summarize recent advances regarding pathways for extracellular HMGB1 release, receptor usage, and functional consequences of post-translational modifications. The review also addresses results of preclinical HMGB1-targeted therapy studies in multiple inflammatory conditions and outlines the current status of emerging clinical HMGB1-specific antagonists.

Expert opinion: Blocking excessive amounts of extracellular HMGB1, particularly the disulfide isoform, offers an attractive clinical opportunity to ameliorate systemic inflammatory diseases. Therapeutic interventions to regulate intracellular HMGB1 biology must still await a deeper understanding of intracellular HMGB1 functions. Future work is needed to create more robust assays to evaluate functional bioactivity of HMGB1 antagonists. Forthcoming clinical studies would also greatly benefit from a development of antibody-based assays to quantify HMGB1 redox isoforms, presently assessed by mass spectrometry methods.     

RAGE and CCR7 mediate the transmigration of Zika-infected monocytes through the blood-brain barrier

Details of the “Trojan Horse” mechanism by which Zika virus (ZIKV) crosses the blood-brain barrier (BBB) remain unclear. However, the migration of ZIKV-infected monocytes to the brain is thought to be dependent on both pattern-recognition and chemokine receptors. In this study, we investigated whether the migration of ZIKV-infected MonoMac-1 (MM-1) cells through the BBB is dependent on chemokine receptor 7 (CCR7) and receptor for advanced glycation end (RAGE); we also determined whether high mobility group box protein 1 (HMGB1) could facilitate the permeabilization of endothelial cells. We demonstrated that ZIKV infects MM-1 cells, leading to milieu accumulation of HMGB1. Our results suggest that HMGB1 is involved in the dysregulation of primary human brain microvascular endothelial cell junction markers. Our results also indicate that the migration of ZIKV-infected monocytes is dependent on chemokine ligand 19 (CCL19), the natural ligand of CCR7, in conditions recapitulating inflammation. RAGE-dependent migration of ZIKV-infected cells declined during transmigration assays in the presence of RAGE receptor antagonist FPS-ZM1. Understanding the molecular role of monocyte trafficking during ZIKV infections could facilitate the development of new therapeutic strategies to prevent the deleterious consequences of ZIKV neuroinfection.     

补阳还五汤对肺纤维化中HMGB1-RAGE信号通路的调控作用

目的:观察肺纤维化中诱导免疫损伤和异常修复的高迁移率族蛋白Box-1(high mobility group Box-1 protein,HMGB1)及晚期糖基化终产物受体(receptor of advanced glycation end-product,RAGE)的表达,及补阳还五汤对HMGB1-RAGE信号通路的调控作用。方法:144只SD大鼠随机分为6组,分别为正常组,博莱霉素(BLM)模型组,补阳还五汤低、中、高剂量组(6.83,13.66,27.32 g·kg~(-1)),阳性药组(强的松,4.2 mg·kg~(-1)),动物实验采用博莱霉素气管注入法复制肺纤维化模型后,分别给予补阳还五汤高、中、低剂量和强的松灌胃,于造模后第7,14,28天分批提取样本。采用逆转录-聚合酶链式反应(RTPCR)法检测肺组织中的HMGB1,RAGE mRNA的表达;采用蛋白质免疫印记法(Western blot)检测HMGB1,α-平滑肌肌动蛋白(alpha-smooth muscle action,α-SMA)的表达。细胞实验采用含药血清药理学的实验方法,以5%,10%,15%,20%的补阳还五汤含药血清和空白血清来干预HMGB1诱导刺激的人肺成纤维细胞(HFL1),采用Western blot法检测α-SMA蛋白的表达。结果:动物实验中,与正常组比较,模型组在第28天显著上调HMGB1 mRNA(P0.01),在第7天和第14天显著上调RAGE mRNA(P0.01),在各时间点显著上调HMGB1,α-SMA(P0.01);与BLM模型组比较,补阳还五汤高剂量组在第14天和第28天显著下调HMGB1 mRNA(P0.01),在第7天和第14天显著下调RAGE mRNA(P0.01),在各时间点显著下调HMGB1和α-SMA蛋白(P0.01)。细胞实验中,与空白组比较,20%空白血清预培养加HMGB1组显著升高α-SMA蛋白(P0.01);与20%空白血清预培养加HMGB1组比较,不同剂量的补阳还五汤含药血清显著下调细胞中α-SMA蛋白(P0.01)。结论:补阳还五汤可抑制HMGB1在大鼠肺组织中和人肺成纤维细胞中所引起的RAGE,α-SMA的表达增加。提示补阳还五汤可能通过阻断HMGB1/RAGE信号通路,减少肌成纤维细胞生成,对肺纤维化的发生发展起到防治作用。     

补肾活血方对高糖高脂诱导损伤的小鼠脑微血管内皮细胞内质网应激和RAGE/LRP-1蛋白表达的影响

目的:在细胞水平探索补肾活血方对高糖高脂诱导的小鼠脑微血管内皮细胞(BEND3细胞)损伤的改善作用,并探究补肾活血方对高糖高脂导致的内质网应激和转运Aβ相关受体蛋白的作用。方法:采用高糖高脂(25mmol/L葡萄糖,200μmol/L棕榈酸)刺激BEND3细胞,用CCK-8法筛选合适的补肾方(BS)、活血方(HX)、补肾活血方(BSHX)的最佳用药浓度;应用免疫蛋白印迹法检测BS、HX、BSHX最佳用药浓度对葡萄糖调节蛋白78(GRP78)、磷酸化真核起始因子2α(p-eIF2α)、活性转录因子4(ATF4)、核因子κB(NF-κB)抗体以及脑内与转运β淀粉样蛋白相关的晚期糖基化终产物受体(RAGE)和低密度脂蛋白受体相关蛋白-1(LRP-1)的表达情况。结果:CCK-8检测细胞活力,最终选定补肾方100mg/L、活血方20mg/L和补肾活血方120mg/L;与正常对照组比较,高糖高脂刺激BEND3细胞后,GRP78、p-eIF2α、ATF4、NF-κB、RAGE表达显著增加(P<0.01),LRP-1表达下降(P<0.01);药物干预后,GRP78、p-eIF2α、ATF4、NF-κB、RAGE蛋白下调,BSHX组LRP-1表达显著上调(P<0.05,P<0.01);且以BSHX组最为明显。结论:补肾方、活血方、补肾活血方对高糖高脂诱导的BEND3细胞损伤均有改善作用,但以补肾活血方疗效最为突出,且对高糖高脂导致的内质网应激和转运β淀粉样蛋白受体的蛋白表达具有调节作用。     

加味参芪寿胎汤治疗早期先兆流产合并亚临床甲减的临床疗效及其对外周血中HMGB1、RAGE细胞因子的影响

目的:探究加味参芪寿胎汤联合优甲乐治疗治疗早期先兆流产合并亚临床甲减的临床疗效及其对外周血中高迁移率族蛋白B1(High Mobility Group Box 1 Protein,HMGB1)、晚期糖基化终末产物受体(Receptor for Advanced Glycationend Product,RAGE)的影响。方法:选取2015年3月到2016年3月收治患早期先兆流产合并亚临床甲减及符合本研究标准的患者78例作为观察对象,按照随机数字表法分为观察组和对照组,每组39例。观察组给予加味参芪寿胎汤联合优甲乐治疗,对照组给予黄体酮注射液及优甲乐治疗。观察2组患者治疗前后血清β-人绒毛膜促性腺激素、雌二醇、孕酮、促甲状腺激素及外周血HMGB1及RAGE水平变化。结果:治疗后观察组HMGB1、RAGE阳性反应率优于对照组,差异有统计学意义(P0.05),观察组总有效率为84.62%优于对照组69.23%,组间比较,差异有统计学意义(P0.05),治疗后观察组血清β-人绒毛膜促性腺激素(β-human Chorionic Gonadotrophin,β-HCG)、雌二醇(Estradiol2,E2)、孕酮(Progesterone,P)及促甲状腺激素(Thyroid Stimulating Hormone,TSH)指数优于对照组,差异有统计学意义(P0.05)。结论:加味参芪寿胎汤联合优甲乐治疗早期先兆流产合并亚临床甲减具有显著临床效果,可帮助患者改善临床症状,维持患者黄体,恢复正常妊娠水平,降低促甲状腺激素分泌,改善甲状腺功能,降低外周血中HMGB1、RAGE细胞因子指数,帮助机体内该炎性介质因子的分泌,增强机体免疫能力,充分调节机体内体液和细胞免疫,促使机体免疫状态相对平稳。     

Amphoterin as an extracellular regulator of cell motility: from discovery to disease

Amphoterin is a ubiquitous and highly conserved protein previously considered solely as a chromatin-associated, nuclear molecule. Amphoterin is released into the extracellular space by various cell types, and plays an important role in the regulation of cell migration, differentiation, tumorigenesis and inflammation. This paper reviews recent research on the mechanistic background underlying the biology of secreted amphoterin, with an emphasis on the role of amphoterin as an autocrine/paracrine regulator of cell migration.     

SA2RAGE: a new sequence for fast B1+ -mapping

At high magnetic field strengths (≥ 3T), the radiofrequency wavelength used in MRI is of the same order of magnitude of (or smaller than) the typical sample size, making transmit magnetic field (B1+) inhomogeneities more prominent. Methods such as radiofrequency-shimming and transmit SENSE have been proposed to mitigate these undesirable effects. A prerequisite for such approaches is an accurate and rapid characterization of the B1+ field in the organ of interest. In this work, a new phase-sensitive three-dimensional B1+-mapping technique is introduced that allows the acquisition of a 64 × 64 × 8 B1+-map in ≈ 20 s, yielding an accurate mapping of the relative B1+ with a 10-fold dynamic range (0.2-2 times the nominal B1+). Moreover, the predominant use of low flip angle excitations in the presented sequence minimizes specific absorption rate, which is an important asset for in vivo B1+-shimming procedures at high magnetic fields. The proposed methodology was validated in phantom experiments and demonstrated good results in phantom and human B1+-shimming using an 8-channel transmit-receive array.