趋化因子受体CX3CR1对人肝癌细胞7721和HepG2的作用及其机制的研究

目的:探究趋化因子受体CX3CR1(C-X3-C motif chemokine receptor 1,CX3CR1)对人肝癌细胞7721和Hep G2增殖、迁移和侵袭的影响及其机制。方法:采用Q-PCR和Western blot法分别检测人正常肝细胞LO2和两种肝癌细胞(7721和Hep G2)中CX3CR1的基因表达情况(mRNA和蛋白质);以过表达CX3CR1的质粒转染7721细胞,用抑制CX3CR1的干扰RNA转染Hep G2细胞,通过Q-PCR和Western blot法检测CX3CR1的变化;应用MTT和流式细胞实验检测各组细胞的增殖能力;用集落形成实验检测各组细胞的自我更新和增殖能力;借助划痕愈合和Transwell检测各组细胞的迁移和侵袭能力;利用Western blot法检测PI3K/AKT、MAPK/ERK信号通路的激活情况。结果:CX3CR1在7721细胞中mRNA和蛋白质呈低表达趋势,而在Hep G2细胞中则呈高表达趋势;转染过表达CX3CR1质粒后7721细胞中CX3CR1的mRNA和蛋白水平有明显的升高,细胞的增殖、迁移、侵袭能力增强,p-AKT和p-ERK水平升高;转染干扰RNA后Hep G2细胞中的CX3CR1表达水平明显下降,增殖、迁移、侵袭能力减弱,p-AKT和p-ERK水平降低。结论:趋化因子受体CX3CR1可以促进人肝癌细胞增殖、迁移和侵袭能力,该作用可能与PI3K/AKT、MAPK/ERK信号通路激活有关。     

miR-20a靶向CCND1作用PI3K/AKT信号通路抑制皮肤鳞状细胞癌的发展

摘要 目的：探究miR-20a与CCND1蛋白在皮肤鳞状细胞癌（CSCC）中的作用关系,以及其可能涉及的信号通路分子机制。方法：分别收集皮肤鳞状细胞癌患者的皮肤癌组织及其邻近正常皮肤组织,采用qRT-PCR分析组织中miR-20a和CCND1基因表达水平。为探究miR-20a对CSCC细胞的影响,将SCL-1细胞分为对照组（不转染）、miR-NC组（转染miR-NC）和miR-20a mimics组（转染miR-20a mimics）;为探究CCND1与PI3K/AKT信号通路的关系,将SCL-1细胞分为对照组（不转染）、si-NC组（转染si-NC）和si-CCND1组（转染si-CCND1）;为探究miR-20a与CCND1间的作用关系及对CSCC细胞的影响,将SCL-1细胞分为miR-NC组（转染miR-NC）、miR-20a mimics组（转染miR-20a mimics）、mimics+pcDNA组（共转染miR-20a mimics和pcDNA）和mimics+CCND1组（共转染miR-20a mimics和pcDNA-CCND1）。采用Western blot分析p-AKT、AKT、p-PI3K、PI3K和GSK-3β蛋白表达水平;采用MTT检测细胞增殖情况;采用流式细胞术检测细胞凋亡情况;采用Transwell分析细胞迁移和侵袭情况;采用双荧光素酶报告基因检测分析miR-20a与CCND1的靶向关系。结果：CSCC癌组织和SCL-1中miR-20a均低表达,CCND1高表达。与对照组和miR-NC组比较,miR-20a mimics组SCL-1细胞增殖水平以及侵袭和迁移数量均降低（P<0.05）,SCL-1细胞凋亡水平升高（P<0.05）,PI3K和AKT蛋白磷酸化水平降低（P<0.05）。TargetScanHuman数据库分析和双荧光素酶报告基因检测结果显示miR-20a与CCND1存在靶向作用关系。与对照组和si-NC组比较,si-CCND1组SCL-1细胞中CCND1和GSK-3β蛋白表达水平以及PI3K和AKT蛋白磷酸化水平均降低（P<0.01）。与miR-20a mimics组或mimics+pcDNA组比较,mimics+CCND1组SCL-1细胞增殖水平以及侵袭和迁移数量均升高（P<0.05）,SCL-1细胞凋亡水平降低（P<0.05）,PI3K和AKT蛋白磷酸化水平均升高（P<0.05）。结论：过表达miR-20a可能通过靶向抑制CCND1的表达而抑制PI3K/AKT信号通路的激活,从而抑制CSCC细胞的增殖、侵袭和迁移,并促进癌细胞凋亡。     

血浆miR-106b、miR-146a表达水平与癫痫患儿脑电图参数、Th17细胞和凋亡分子的相关性分析

摘要 目的：分析血浆miR-106b、miR-146a表达特点及其与脑电图参数、辅助性T细胞17（Th17）和凋亡分子的相关性以及诊断癫痫的价值。方法：选择2018年1月至2020年10月我院收治的癫痫患儿75例作为癫痫组,检测受试者血浆miR-106b、miR-146a表达,外周血Th17细胞占比、血清B细胞淋巴瘤/白血病-1（Bcl-1）、BCL2-Associated X蛋白（Bax）、Survivin、半胱氨酸天冬酰胺酶（Caspase-3）水平和脑电图参数α、β、 δ、θ波功率。分析miR-106b、miR-146a与Th17细胞占比、Bcl-1、Bax、Survivin、Caspase-3以及α、β、 δ、θ波功率的相关性,受试者工作特征（ROC）曲线分析miR-106b、miR-146a诊断癫痫的价值。结果：癫痫组血浆miR-106b、miR-146a表达、Th17细胞占比、Bax、Caspase-3水平高于对照组（P＜0.05）,α波功率、θ波功率、Bcl-1、Survivin水平低于对照组（P＜0.05）。miR-106b、miR-146a表达与Th17细胞占比、Bax、Caspase-3呈正相关（P＜0.05）,与α波功率、θ波功率、Bcl-1、Survivin呈负相关（P＜0.05）。联合miR-106b和miR-146a诊断癫痫的曲线下面积（AUC）为0.975,高于单独miR-106b和miR-146a诊断的0.884、0.835。结论：癫痫患儿血浆miR-146a、miR-106b表达增高,miR-146a、miR-106b高表达与脑电图异常、Th17细胞功能障碍以及神经细胞凋亡有关,miR-146a、miR-106b有望成为癫痫诊断的新生物学标志物。     

臭椿酮抑制急性骨髓性白血病细胞恶性生物学行为的研究

为了探讨臭椿酮(ailanthone,AIL)对急性骨髓性白血病(acute myelogenous leukemia,AML)细胞恶性生物学行为的影响,用不同浓度(0.2、0.4、0.8、1.6、3.2μmol·L^-1)的AIL处理对数生长期的HL-60细胞,将miR-449a mimic质粒、mimic对照质粒、miR-449a inhibitor质粒、inhibitor对照质粒分别转染至未经任何处理的HL-60细胞,并用1.0μmol·L^-1浓度的AIL处理细胞24 h。采用CCK-8法检测细胞增殖水平,细胞划痕实验检测细胞迁移水平,Transwell小室法检测细胞侵袭水平,Annexin V-FITC/PI双染法检测细胞凋亡水平,qRT-PCR法检测miR-449a mRNA表达水平,Western blot法检测磷脂酰肌醇3-激酶(PI3K)、磷酸化PI3K(p-PI3K)、蛋白激酶B(AKT)、磷酸化AKT(p-AKT)蛋白表达水平。结果显示,AIL干预后HL-60细胞增殖抑制率、凋亡率升高,细胞迁移率及细胞侵袭数降低(P<...     

HeLa细胞中LRP16影响电离辐射诱导的NF-κB核转位

前期研究显示抑制LRP16的表达可以明显增加肿瘤细胞对辐射诱导凋亡的敏感性,但具体机制尚不清楚．大量研究表明,NF-κB信号通路在肿瘤产生辐射抵抗中起着重要的作用. 为研究LRP16影响肿瘤细胞对辐射敏感性的可能机制,首先通过免疫 荧光技术检测电离辐射刺激后不同时间点NF-κB的核转位情况;然后分别过表达和抑制LRP16的表达,采用Western印迹方法检测NF-κB在核蛋白与浆蛋白中的表达情况、 IκB-α总体蛋白水平及磷酸化水平．结果发现,电离辐射后1 h,可见NF-κB明显入核;过表达LRP16可以促进NF-κB入核、提高IκB-α的磷酸化水平、促进IκB-α 的降解;反之,抑制LRP16的表达可以抑制NF-κB入核、降低IκB-α的磷酸化水平、 阻碍IκB-α的降解．上述研究结果表明,在HeLa细胞中LRP16可以影响电离辐射诱导的NF-κB核转位,该研究为LRP16参与肿瘤细胞产生辐射抵抗现象提供一种可能的机制．     

瓜蒂醇提物通过调控Wnt/β-catenin信号通路对肝癌细胞Hep3B恶性生物学行为的影响

该文探讨了瓜蒂醇提物对肝癌细胞Hep3B增殖、迁移、侵袭和凋亡的影响及其分子机制。肝癌细胞Hep3B被分为NC组、不同浓度瓜蒂醇提物(1.0、5.0、10.0、20.0μg/mL)组、LiCl组、20.0μg/mL瓜蒂醇提物+LiCl组。采用CCK-8法检测细胞活性;克隆形成实验检测Hep3B细胞克隆形成数量;流式细胞术检测Hep3B细胞的凋亡情况;蛋白质印迹法检测蛋白表达情况; Transwell检测Hep3B细胞的迁移和侵袭数。不同浓度瓜蒂醇提物处理Hep3B细胞后, Hep3B细胞的活性降低,克隆数量以及迁移侵袭数减少, Hep3B细胞的凋亡率升高, Cleaved-caspase-3表达水平升高, procaspase-3、MMP2、MMP9表达水平降低, Wnt3a、cyclinD1、c-myc、核β-catenin蛋白表达水平降低,APC和质β-catenin蛋白表达水平升高(P<0.05)。Wnt/β-catenin信号通路激活剂LiCl可以逆转瓜蒂醇提物对Hep3B细胞增殖、迁移、侵袭和凋亡的影响。瓜蒂醇提物通过调控Wnt/β-catenin信号通路抑制Hep3B...     

血清miR-26a、miR-130a与老年急性脑梗死患者PI3K/Akt信号通路和预后的关系研究

摘要 目的：研究血清miR-26a、miR-130a与老年急性脑梗死（ACI）患者磷酸酰肌醇3-激酶/蛋白激酶B（PI3K/Akt）信号通路和预后的关系。方法：选取2020年3月-2022年10月我院收治的98例老年ACI患者作为研究组,同期选取60例于本院体检健康的老年人作为对照组。采用实时荧光定量聚合酶链式反应（qRT-PCR）检测血清miR-26a、miR-130a表达水平,蛋白免疫印迹法检测外周血单个核细胞中PI3K、Akt蛋白表达;采用Pearson相关性分析miR-26a、miR-130a表达水平与PI3K、Akt蛋白表达的相关性。患者治疗后行1个月随访,根据改良Rankin量表（mRS）评分分为预后良好组（n=55例,mRS评分≤2分）和预后不良组（n=43例,评分＞2分）。收集患者的一般资料,采用Logistic回归模型分析老年ACI患者预后的影响因素。结果：研究组血清miR-26a表达水平高于对照组,miR-130a表达水平低于对照组（P＜0.05）。研究组PI3K蛋白表达量低于对照组,Akt蛋白表达量高于对照组（P＜0.05）。Pearson相关性分析显示,miR-26a表达水平与PI3K蛋白表达量呈负相关、与Akt蛋白表达量呈正相关,miR-130a表达水平与PI3K蛋白表达量呈正相关、与Akt蛋白表达量呈负相关（P＜0.05）。预后良好组与预后不良组在年龄、房颤占比、入院时美国国立卫生研究院卒中量表（NIHSS）评分、血糖及血清miR-26a、miR-130a表达水平方面比较具有统计学意义（P＜0.05）。Logistic回归分析显示,年龄偏大、入院时NIHSS评分偏高、血糖偏高及血清miR-26a表达水平升高为老年ACI患者预后不良的危险因素,miR-130a表达水平升高为其保护因素（P＜0.05）。结论：老年ACI患者血清miR-26a表达水平升高、miR-130a表达水平下降,与PI3K/Akt信号通路密切相关,是老年ACI患者预后的影响因素。     

miR-21通过PTEN/PI3K/AKT信号通路调控胶质瘤细胞的增殖

探讨miR-21对胶质瘤细胞U87中人第10号染色体缺失的磷酸酶及张力蛋白同源的基因/磷脂酰肌醇3激酶/蛋白激酶B(PTEN/PI3K/AKT)信号通路相关影响作用研究。脂质体Lipofectamine~(TM)2000将miR-21 inhibitor和miR-21 NC转入U87细胞中,48 h后,RT-PCR检测miR-21表达,MTT法检测细胞活力,Annexin V/PI流式双染检测细胞凋亡情况,Western blotting检测PTEN/PI3K/AKT激活情况及程序性细胞死亡因子4(PDCD4),Bax及Bcl-2的表达。与miR-21 NC组比较,miR-21 inhibitor组miR-21表达量显著降低,U87细胞活力下降,细胞凋亡率提高,PI3K、Bcl-2及p-AKT表达量下调,PTEN、PDCD4及Bax表达量上调,差异均具有统计学意义(p0.01)。miR-21inhibitor能显著的抑制U87细胞的增殖,与PTEN/PI3K/AKT信号通路有关。     

microRNA-21在食管癌细胞增殖、迁移和凋亡中的作用

本研究检测了40例食管癌组织和40例癌旁组织中的miR-21、PTEN、PI3K和AKT表达,并通过转染miR-21抑制剂来敲低人食管癌细胞系EC9706的miR-21表达,考察了miR-21对食管癌细胞生长的影响。研究发现,食管癌组织中PTEN蛋白的阳性染色评分低于癌旁组织(p<0.05),而PI3K和AKT蛋白的阳性染色评分高于癌旁组织(p<0.05)。miR-21在人食管癌组织中被上调(3.56 vs 1.21,p<0.05)。转染miR-21抑制剂导致PTEN蛋白表达升高,而PI3K和AKT蛋白表达降低(p<0.05)。转染miR-21抑制剂抑制了EC9706细胞的增殖和迁移,但促进了细胞凋亡(p<0.05)。miR-21的上调可通过激活PTEN/PI3K/AKT信号通路来促进食道癌细胞的增殖和迁移,并抑制细胞凋亡。     

MiR-425对血管平滑肌细胞增殖迁移的作用及分子机制

目的探讨miR-425对人主动脉平滑肌细胞增殖迁移的作用及潜在的分子机制。方法实时定量RT-PCR(qRT-PCR)检测人主动脉平滑肌细胞(human aortic smooth muscle cells, HASMCs)中miR-425的表达水平。转染miR-342inhibitor改变HASMCs中内源性miR-425的表达,采用CCK-8法和流式细胞术检测细胞增殖及周期的变化,Transwell检测细胞迁移能力;Western blot检测PTEN、PI3K、p-AKT/AKT、MMP-9的蛋白表达水平。结果血管紧张素Ⅱ(angiotensionⅡ,AngⅡ)可时间及剂量依赖性地促进HASMCs中miR-425的表达。转染miR-425 inhibitor可抑制AngⅡ对HASMCs的促增殖作用,并抑制细胞迁移,同时细胞中PI3K、p-AKT/AKT及MMP-9的蛋白水平显著降低,PTEN水平显著升高。结论沉默miR-425可通过调控PTEN/PI3K/AKT信号通路抑制人主动脉平滑肌细胞的增殖及迁移,提示miR-425可作为血管重构的一个潜在诊疗靶点。     

MicroRNA-146a and MicroRNA-146b Regulate Human Dendritic Cell Apoptosis and Cytokine Production by Targeting TRAF6 and IRAK1 Proteins

We have previously reported 27 differentially expressed microRNAs (miRNAs) during human monocyte differentiation into immature dendritic cells (imDCs) and mature DCs (mDCs). However, their roles in DC differentiation and function remain largely elusive. Here, we report that microRNA (miR)-146a and miR-146b modulate DC apoptosis and cytokine production. Expression of miR-146a and miR-146b was significantly increased upon monocyte differentiation into imDCs and mDCs. Silencing of miR-146a and/or miR-146b in imDCs and mDCs significantly prevented DC apoptosis, whereas overexpressing miR-146a and/or miR-146b increased DC apoptosis. miR-146a and miR-146b expression in imDCs and mDCs was inversely correlated with TRAF6 and IRAK1 expression. Furthermore, siRNA silencing of TRAF6 and/or IRAK1 in imDCs and mDCs enhanced DC apoptosis. By contrast, lentivirus overexpression of TRAF6 and/or IRAK1 promoted DC survival. Moreover, silencing of miR-146a and miR-146b expression had little effect on DC maturation but enhanced IL-12p70, IL-6, and TNF-α production as well as IFN-γ production by IL-12p70-mediated activation of natural killer cells, whereas miR-146a and miR-146b overexpression in mDCs reduced cytokine production. Silencing of miR-146a and miR-146b in DCs also down-regulated NF-κB inhibitor IκBα and increased Bcl-2 expression. Our results identify a new negative feedback mechanism involving the miR-146a/b-TRAF6/IRAK1-NF-κB axis in promoting DC apoptosis.     

Chikungunya Virus Exploits miR-146a to Regulate NF-κB Pathway in Human Synovial Fibroblasts

Objectives

Chikungunya virus causes chronic infection with manifestations of joint pain. Human synovial fibroblasts get infected with CHIKV and could lead to pro-inflammatory responses. MicroRNAs have potentials to regulate the gene expression of various anti-viral and pro-inflammatory genes. The study aims to investigate the role of miR-146a in modulation of inflammatory responses of human synovial fibroblasts by Chikungunya virus.

Methods

To study the role of miR-146a in CHIKV pathogenesis in human synovial cells and underlying inflammatory manifestations, we performed CHIKV infection in primary human synovial fibroblasts. Western blotting, real-time PCR, luciferase reporter assay, overexpression and knockdown of cellular miR-146a strategies have been employed to validate the role of miR-146a in regulation of pro-inflammatory NF-κB pathway.

Results

CHIKV infection induced the expression of cellular miR-146a, which resulted into down-regulation of TRAF6, IRAK1, IRAK2 and increased replication of CHIKV in human synovial fibroblasts. Exogenous expression of miR-146a in human synovial fibroblasts led to decreased expression of TRAF6, IRAK1, IRAK2 and decreased replication of CHIKV. Inhibition of cellular miR-146a by anti-miR-146a restored the expression levels of TRAF6, IRAK1 and IRAK2. Downregulation of TRAF6, IRAK1 and IRAK2 led to downstream decreased NF-κB activation through negative feedback loop.

Conclusion

This study demonstrated the mechanism of exploitation of cellular miR-146a by CHIKV in modulating the host antiviral immune response in primary human synovial fibroblasts.     

Decrease of miR-146b-5p in monocytes during obesity is associated with loss of the anti-inflammatory but not insulin signaling action of adiponectin

Background

Low adiponectin, a well-recognized antidiabetic adipokine, has been associated with obesity-related inflammation, oxidative stress and insulin resistance. Globular adiponectin is an important regulator of the interleukin-1 receptor-associated kinase (IRAK)/NFκB pathway in monocytes of obese subjects. It protects against inflammation and oxidative stress by inducing IRAK3. microRNA (miR)-146b-5p inhibits NFκB-mediated inflammation by targeted repression of IRAK1 and TNF receptor-associated factor-6 (TRAF6). Therefore, we measured the expression of miR-146b-5p in monocytes of obese subjects. Because it was low we determined the involvement of this miR in the anti-inflammatory, antioxidative and insulin signaling action of globular adiponectin.

Methods

miR-146b-5p expression in monocytes of obese subjects was determined by qRT-PCR. The effect of miR-146b-5p silencing on molecular markers of inflammation, oxidative stress and insulin signaling and the association with globular adiponectin was assessed in human THP-1 monocytes.

Results

miR-146b-5p was downregulated in monocytes of obese persons. Low globular adiponectin decreased miR-146b-5p and IRAK3 in THP-1 monocytes, associated with increased mitochondrial reactive oxygen species (ROS). Intracellular ROS and insulin receptor substrate-1 (IRS1) protein were unchanged. Silencing of miR-146b-5p with an antisense inhibitor resulted in increased expression of IRAK1 and TRAF6 leading to more NFκB p65 DNA binding activity and TNFα. As a response IRAK3 and IRS1 protein increased. Mitochondrial and intracellular ROS production did not increase despite more inflammation. In addition, exposure of miR-146b-5p-depleted THP-1 monocytes to high levels of globular adiponectin resulted in an increased production of TNFα and intracellular ROS. Still, they did not lose their potential to increase IRAK3 and IRS1 protein and to decrease mitochondrial ROS.

Conclusion

miR-146b-5p, decreased in monocytes during obesity, is a major mediator of the anti-inflammatory action of globular adiponectin. It appears not to be involved in insulin signaling possibly by protective response of IRAK3 and lack of mitochondrial ROS production.     

miR-146a regulates inflammatory cytokine production in Porphyromonas gingivalis lipopolysaccharide-stimulated B cells by targeting IRAK1 but not TRAF6

It has been suggested that microRNAs (miRs) are involved in the immune regulation of periodontitis. However, it is unclear whether and how miRs regulate the function of B cells in the context of periodontitis. This study is to explore the role of miR-146a on the inflammatory cytokine production of B cells challenged by Porphyromonas gingivalis (P. gingivalis) lipopolysaccharide (LPS). Primary B cells were harvested from mouse spleen. Quantitative real-time polymerase chain reaction (qPCR), enzyme-linked immunosorbent assay (ELISA) were used to detect the expression of inflammatory cytokines in B cells in the presence or absence of P. gingivalis LPS and/or miR-146a. Bioinformatics, luciferase reporter assay and overexpression assay were used to explore the binding target of miR-146a. Our results showed that miR-146a level in B cells was elevated by P. gingivalis LPS stimulation, and the mRNA expressions of interleukin (IL)-1β, 6 and 10, and IL-1 receptor associated kinase-1 (IRAK1), but not TNF receptor associated factor 6 (TRAF6), were also upregulated. The expression levels of IL-1β, 6, 10 and IRAK1 were reduced in the presence of miR-146a mimic, but were elevated by the addition of miR-146a inhibitor. MiR-146a could bind with IRAK1 3′ untranslated region (UTR) but not TRAF6 3′-UTR. Overexpression of IRAK1 reversed the inhibitory effects of miR-146a on IL-1β, 6 and 10. In summary, miR-146a inhibits inflammatory cytokine production in B cells through directly targeting IRAK1, suggesting a regulatory role of miR-146a in B cell-mediated periodontal inflammation.     

miR-146a Enhances the Oncogenicity of Oral Carcinoma by Concomitant Targeting of the IRAK1, TRAF6 and NUMB Genes

MicroRNAs are short non-coding RNAs that regulate gene expression and are crucial to tumorigenesis. Oral squamous cell carcinoma (OSCC) is a prevalent malignancy worldwide. Up-regulation of miR-146 has been identified in OSCC tissues. However, the roles of miR-146 in carcinogenesis are controversial as it is suppressive in many other malignancies. The present study investigated the pathogenic implications of miR-146a in oral carcinogenesis. Microdissected OSCC exhibits higher levels of miR-146a expression than matched adjacent mucosal cells. The plasma miR-146a levels of patients are significantly higher than those of control subjects; these levels decrease drastically after tumor resection. miR-146a levels in tumors and in patients’ plasma can be used to classify OSCC and non-disease status (sensitivity: >0.72). Exogenous miR-146a expression is significantly increased in vitro oncogenic phenotypes as well as during xenograft tumorigenesis and OSCC metastasis. The plasma miR-146a levels of these mice parallel the xenograft tumor burdens of the mice. A miR-146a blocker abrogates the growth of xenograft tumors. miR-146a oncogenic activity is associated with down-regulation of IRAK1, TRAF6 and NUMB expression. Furthermore, miR-146a directly targets the 3′UTR of NUMB and a region within the NUMB coding sequence when suppressing NUMB expression. Exogenous NUMB expression attenuates OSCC oncogenicity. Double knockdown of IRAK1 and TRAF6, and of TRAF6 and NUMB, enhance the oncogenic phenotypes of OSCC cells. Oncogenic enhancement modulated by miR-146a expression is attenuated by exogenous IRAK1 or NUMB expression. This study shows that miR-146a expression contributes to oral carcinogenesis by targeting the IRAK1, TRAF6 and NUMB genes.     

Retracted: MicroRNA-99b suppresses human cervical cancer cell activity by inhibiting the PI3K/AKT/mTOR signaling pathway

Cervical cancer is common cancer among women with high morbidity. MicroRNAs (miRs) are involved in the progression and development of cervical cancer. This study aimed to explore the effect of miR-99b-5p (miR-99b) on invasion and migration in cervical cancer through the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mechanistic target of rapamycin (mTOR) signaling pathway. The microarray-based analysis was used to screen out differentially expressed miRNAs. Expression of miR-99b, PI3K, AKT, mTOR, and ribosomal protein S6 kinase (p70S6K) was determined in both cervical cancer tissues and paracancerous tissues. Next, alteration of miR-99b expression in cervical cancer was conducted to evaluate levels of PI3K, AKT, mTOR, p70S6K matrix metallopeptidase 2, epithelial cell adhesion molecule, and intercellular adhesion molecule 1, as well as the effect of miR-99b on cell proliferation, invasion, migration, cell cycle distribution, and apoptosis. The results demonstrated that miR-99b expression was decreased and levels of PI3K, AKT, mTOR, and p70S6K were elevated in cervical cancer tissues. More important, overexpressed miR-99b repressed the PI3K/AKT/mTOR signaling pathway, inhibited cell proliferation, invasion, and migration, blocked cell cycle entry, and promoted apoptosis in cervical cancer. These results indicate that miR-99b attenuates the migration and invasion of human cervical cancer cells through downregulation of the PI3K/AKT/mTOR signaling pathway, which provides a therapeutic approach for cervical cancer treatment.     

miR-146a Ameliorates Liver Ischemia/Reperfusion Injury by Suppressing IRAK1 and TRAF6

A critical role of the Toll-like receptor(TLR) and its downstream molecules, including IL-1 receptor-associated kinase 1(IRAK1) and tumor necrosis factor receptor– associated factor 6(TRAF6), in the pathogenesis of liver ischemia/reperfusion (I/R) injury has been documented. Recently a microRNA, miR-146a, was identified as a potent negative regulator of the TLR signaling pathway. In this study, we investigated the role of miR-146a to attenuate TLR signaling and liver I/R injury in vivo and in vitro. miR-146a was decreased in mice Kupffer cells following hepatic I/R, whereas IRAK1 and TRAF6 increased. Overexpression of miR-146a directly decreased IRAK1 and TRAF6 expression and attenuated the release of proinflammatory cytokines through the inactivation of NF-κB P65 in hypoxia/reoxygenation (H/R)-induced macrophages, RAW264.7 cells. Knockdown experiments demonstrated that IRAK1 and TRAF6 are two potential targets for reducing the release of proinflammatory cytokines. Moreover, co-culture assays indicated that miR-146a decreases the apoptosis of hepatocytes after H/R. In vivo administration of Ago-miR-146a, a stable version of miR-146a in vivo, protected against liver injury in mice after I/R via inactivation of the TLR signaling pathway. We conclude that miR-146a ameliorates liver ischemia/reperfusion injury in vivo and hypoxia/reoxygenation injury in vitro by directly suppressing IRAK1 and TRAF6.     

The TRAF3 adaptor protein drives proliferation of anaplastic large cell lymphoma cells by regulating multiple signaling pathways

T cells devoid of tumor necrosis factor receptor associated factor-3 (Traf3) exhibit decreased proliferation, sensitivity to apoptosis, and an improper response to antigen challenge. We therefore hypothesized that TRAF3 is critical to the growth of malignant T cells. By suppressing TRAF3 protein in different cancerous T cells, we found that anaplastic large cell lymphoma (ALCL) cells require TRAF3 for proliferation. Since reducing TRAF3 results in aberrant activation of the noncanonical nuclear factor-κB (NF-κB) pathway, we prevented noncanonical NF-κB signaling by suppressing RelB together with TRAF3. This revealed that TRAF3 regulates proliferation independent of the noncanonical NF-κB pathway. However, suppression of NF-κB-inducing kinase (NIK) along with TRAF3 showed that high levels of NIK have a partial role in blocking cell cycle progression. Further investigation into the mechanism by which TRAF3 regulates cell division demonstrated that TRAF3 is essential for continued PI3K/AKT and JAK/STAT signaling. In addition, we found that while NIK is dispensable for controlling JAK/STAT activity, NIK is critical to regulating the PI3K/AKT pathway. Analysis of the phosphatase and tensin homolog (PTEN) showed that NIK modulates PI3K/AKT signaling by altering the localization of PTEN. Together our findings implicate TRAF3 as a positive regulator of the PI3K/AKT and JAK/STAT pathways and reveal a novel function for NIK in controlling PI3K/AKT activity. These results provide further insight into the role of TRAF3 and NIK in T cell malignancies and indicate that TRAF3 differentially governs the growth of B and T cell cancers.     

Thymosin β4 Up-regulation of MicroRNA-146a Promotes Oligodendrocyte Differentiation and Suppression of the Toll-like Proinflammatory Pathway

Thymosin β4 (Tβ4), a G-actin-sequestering peptide, improves neurological outcome in rat models of neurological injury. Tissue inflammation results from neurological injury, and regulation of the inflammatory response is vital for neurological recovery. The innate immune response system, which includes the Toll-like receptor (TLR) proinflammatory signaling pathway, regulates tissue injury. We hypothesized that Tβ4 regulates the TLR proinflammatory signaling pathway. Because oligodendrogenesis plays an important role in neurological recovery, we employed an in vitro primary rat embryonic cell model of oligodendrocyte progenitor cells (OPCs) and a mouse N20.1 OPC cell line to measure the effects of Tβ4 on the TLR pathway. Cells were grown in the presence of Tβ4, ranging from 25 to 100 ng/ml (RegeneRx Biopharmaceuticals Inc., Rockville, MD), for 4 days. Quantitative real-time PCR data demonstrated that Tβ4 treatment increased expression of microRNA-146a (miR-146a), a negative regulator the TLR signaling pathway, in these two cell models. Western blot analysis showed that Tβ4 treatment suppressed expression of IL-1 receptor-associated kinase 1 (IRAK1) and tumor necrosis factor receptor-associated factor 6 (TRAF6), two proinflammatory cytokines of the TLR signaling pathway. Transfection of miR-146a into both primary rat embryonic OPCs and mouse N20.1 OPCs treated with Tβ4 demonstrated an amplification of myelin basic protein (MBP) expression and differentiation of OPC into mature MBP-expressing oligodendrocytes. Transfection of anti-miR-146a nucleotides reversed the inhibitory effect of Tβ4 on IRAK1 and TRAF6 and decreased expression of MBP. These data suggest that Tβ4 suppresses the TLR proinflammatory pathway by up-regulating miR-146a.