Humanity is facing an enormous and growing worldwide threat from the emergence of multi-drug-resistant(MDR)Gram-negative bacteria such as Escherichia coli,Klebsiella pneumoniae,and Acinetobacter baumannii.Polymyxin B ...Humanity is facing an enormous and growing worldwide threat from the emergence of multi-drug-resistant(MDR)Gram-negative bacteria such as Escherichia coli,Klebsiella pneumoniae,and Acinetobacter baumannii.Polymyxin B and E(colistin)constitute the last-line therapies for treating MDR Gram-negative bacteria.Polymyxin is a cationic antibacterial peptide that can destroy the outer membrane of Gram-negative bacteria.With the increasing clinical application of polymyxin,however,there have been many reports of the occurrence of polymyxin-resistant Gram-negative bacteria.This resistance is mainly mediated by the modification or complete loss of lipopolysaccharide(LPS).LPS is also a virulence factor of Gram-negative bacteria,and alterations of LPS may correlate with virulence.Although it is generally believed that the biological costs associated with drug resistance may enable benign susceptible bacteria to overcome resistant bacteria when antibiotic pressure is reduced,some studies have shown that polymyxin-resistant bacteria are associated with higher virulence and greater fitness compared with their susceptible counterparts.To predict the development of polymyxin resis-tance and evaluate interventions for its mitigation,it is important to understand the relative biological cost of polymyxin resistance compared with susceptibility.The impact of polymyxin resistance mecha-nisms on the virulence and fitness of these three Gram-negative bacteria are summarized in this review.展开更多
目的探讨唾液腺腺样囊性癌(SACC)中长链非编码RNA(lncRNA)LINC00970表达与缺氧的关系及其作用。方法低氧(1%O2)诱导48 h后,lncRNA芯片检测SACC-83细胞中缺氧诱导的lncRNA,并用实时荧光定量聚合酶链反应(PCR)验证。使用临床样本分析LINC0...目的探讨唾液腺腺样囊性癌(SACC)中长链非编码RNA(lncRNA)LINC00970表达与缺氧的关系及其作用。方法低氧(1%O2)诱导48 h后,lncRNA芯片检测SACC-83细胞中缺氧诱导的lncRNA,并用实时荧光定量聚合酶链反应(PCR)验证。使用临床样本分析LINC00970在SACC组织中的表达及其与预后的关系。LINC00970敲低质粒转染SACC-LM和SACC-83细胞后,细胞增殖检测(CCK-8)和平板克隆实验检测细胞增殖能力和克隆形成能力,Transwell实验检测细胞侵袭和迁移能力,Western blot检测E-cadherin、Vimentin、Snail和N-cadherin的表达。荧光定量PCR、Western blot和Transwell等实验均重复3次所得均值为该样本测量值,使用SPSS 20.0软件进行统计学分析。SACC组织细胞与正常唾液腺组织中LINC00970相对表达量差异,采用配对t检验分析;比较沉默LINC00970对SACC-83和SACC-LM细胞增殖、克隆形成、侵袭及迁移能力的影响,以及LINC00970沉默对上皮-间充质转化(EMT)相关蛋白的影响,应用独立t检验进行统计学分析。采用Kaplan-Meier法计算LINC00970的表达与SACC患者总生存时间的相关性,并绘制生存曲线。P<0.05为差异有统计学意义。结果lncRNA芯片及实时荧光定量PCR结果显示,LINC00970是SACC-83细胞中在缺氧反应性表达最高的lncRNA(15.13±0.57 vs 1.08±0.06),差异有统计学意义(t=24.56,P<0.001)。临床样本数据分析显示,LINC00970在SACC组织表达显著高于正常唾液腺组织(0.49±0.41 vs 0.08±0.16,t=2.53,P<0.001),且LINC00970高表达患者生存率明显低于LINC00970低表达患者(HR=0.42,P=0.03)。SACC细胞敲低LINC00970后,缺氧促进的侵袭和迁移能力受抑制,且缺氧升高后的间质标志物N-cadherin表达下调,而缺氧诱导降低的上皮标志物E-cadherin恢复上调。结论缺氧可诱导SACC细胞中LINC00970的表达,其高表达与SACC患者的不良预后密切相关,LINC00970可能通过调控EMT从而促进细胞侵袭和迁移。展开更多
基金supported by the National Key Research and Development Program of China (2017YFC1600100 and2017YFC1200203)the National Natural Science Foundation of China (81702040)the National Science Foundation of Zhejiang Province,China (LY20H190002)
文摘Humanity is facing an enormous and growing worldwide threat from the emergence of multi-drug-resistant(MDR)Gram-negative bacteria such as Escherichia coli,Klebsiella pneumoniae,and Acinetobacter baumannii.Polymyxin B and E(colistin)constitute the last-line therapies for treating MDR Gram-negative bacteria.Polymyxin is a cationic antibacterial peptide that can destroy the outer membrane of Gram-negative bacteria.With the increasing clinical application of polymyxin,however,there have been many reports of the occurrence of polymyxin-resistant Gram-negative bacteria.This resistance is mainly mediated by the modification or complete loss of lipopolysaccharide(LPS).LPS is also a virulence factor of Gram-negative bacteria,and alterations of LPS may correlate with virulence.Although it is generally believed that the biological costs associated with drug resistance may enable benign susceptible bacteria to overcome resistant bacteria when antibiotic pressure is reduced,some studies have shown that polymyxin-resistant bacteria are associated with higher virulence and greater fitness compared with their susceptible counterparts.To predict the development of polymyxin resis-tance and evaluate interventions for its mitigation,it is important to understand the relative biological cost of polymyxin resistance compared with susceptibility.The impact of polymyxin resistance mecha-nisms on the virulence and fitness of these three Gram-negative bacteria are summarized in this review.
文摘目的探讨唾液腺腺样囊性癌(SACC)中长链非编码RNA(lncRNA)LINC00970表达与缺氧的关系及其作用。方法低氧(1%O2)诱导48 h后,lncRNA芯片检测SACC-83细胞中缺氧诱导的lncRNA,并用实时荧光定量聚合酶链反应(PCR)验证。使用临床样本分析LINC00970在SACC组织中的表达及其与预后的关系。LINC00970敲低质粒转染SACC-LM和SACC-83细胞后,细胞增殖检测(CCK-8)和平板克隆实验检测细胞增殖能力和克隆形成能力,Transwell实验检测细胞侵袭和迁移能力,Western blot检测E-cadherin、Vimentin、Snail和N-cadherin的表达。荧光定量PCR、Western blot和Transwell等实验均重复3次所得均值为该样本测量值,使用SPSS 20.0软件进行统计学分析。SACC组织细胞与正常唾液腺组织中LINC00970相对表达量差异,采用配对t检验分析;比较沉默LINC00970对SACC-83和SACC-LM细胞增殖、克隆形成、侵袭及迁移能力的影响,以及LINC00970沉默对上皮-间充质转化(EMT)相关蛋白的影响,应用独立t检验进行统计学分析。采用Kaplan-Meier法计算LINC00970的表达与SACC患者总生存时间的相关性,并绘制生存曲线。P<0.05为差异有统计学意义。结果lncRNA芯片及实时荧光定量PCR结果显示,LINC00970是SACC-83细胞中在缺氧反应性表达最高的lncRNA(15.13±0.57 vs 1.08±0.06),差异有统计学意义(t=24.56,P<0.001)。临床样本数据分析显示,LINC00970在SACC组织表达显著高于正常唾液腺组织(0.49±0.41 vs 0.08±0.16,t=2.53,P<0.001),且LINC00970高表达患者生存率明显低于LINC00970低表达患者(HR=0.42,P=0.03)。SACC细胞敲低LINC00970后,缺氧促进的侵袭和迁移能力受抑制,且缺氧升高后的间质标志物N-cadherin表达下调,而缺氧诱导降低的上皮标志物E-cadherin恢复上调。结论缺氧可诱导SACC细胞中LINC00970的表达,其高表达与SACC患者的不良预后密切相关,LINC00970可能通过调控EMT从而促进细胞侵袭和迁移。
