Krüppel-like factor 4, a novel transcription factor regulates microglial activation and subsequent neuroinflammation.
Krüppel-like factor 4, a novel transcription factor regulates microglial activation and subsequent neuroinflammation.
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DOI：
10.1186/1742-2094-7-68
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发表时间：
2010-10-15
影响因子：
9.3
通讯作者：
Basu A
中科院分区：
文献类型：
--
作者：
Kaushik DK;Gupta M;Das S;Basu A
中枢神经系统（CNS）的巨噬细胞小胶质细胞的激活是神经退行性疾病和其他与中枢神经系统感染相关的病理条件下神经炎症的标志。小胶质细胞的激活通常与旁观神经元死亡有关。核因子-κB （NF-κB）是已知与小胶质细胞活化相关的重要转录因子之一，可上调诱导型一氧化氮合酶（iNOS）、环氧合酶-2 （Cox-2）等促炎细胞因子的表达。最近的研究主要集中在锌指转录因子之一kr<s:1> ppel样因子4 （Klf4）在介导炎症中的作用。然而，这些研究仅限于外周系统，其在中枢神经系统中的作用尚不清楚。我们的研究重点是Klf4在介导中枢神经系统炎症中的可能作用。在体外研究中，用500 ng/ml肠沙门氏菌脂多糖（LPS）处理小鼠小胶质细胞BV-2细胞系。用5 mg/kg体重LPS对BALB/c小鼠进行脑组织分离。采用western blotting、实时荧光定量PCR和逆转录聚合酶链反应（rt -PCR）检测Klf4、Cox-2、iNOS和pNF-κB的表达。使用Klf4 mRNA特异性SiRNA敲除Klf4，并通过荧光素酶测定和电迁移位移测定（EMSA）研究Klf4与iNOS启动子元件在体外的相互作用。为了研究两种转录因子之间可能的相互作用，我们进行了Klf4和pNF-κB的共免疫沉淀。LPS刺激使小胶质细胞中Klf4的表达呈时间和剂量依赖关系。敲低Klf4导致促炎细胞因子TNF-α、MCP-1和IL-6水平降低，iNOS和Cox-2表达显著降低。由于Klf4的敲除，NO的产生也减少了。我们发现Klf4可能与pNF-κB相互作用，并且在体外对iNOS和Cox-2启动子活性很重要。这些研究证明了Klf4在小胶质细胞介导细菌内毒素LPS的神经炎症反应中的作用。
Activation of microglia, the resident macrophages of the central nervous system (CNS), is the hallmark of neuroinflammation in neurodegenerative diseases and other pathological conditions associated with CNS infection. The activation of microglia is often associated with bystander neuronal death. Nuclear factor-κB (NF-κB) is one of the important transcription factors known to be associated with microglial activation which upregulates the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (Cox-2) and other pro-inflammatory cytokines. Recent studies have focused on the role of Krüppel-like factor 4 (Klf4), one of the zinc-finger transcription factors, in mediating inflammation. However, these studies were limited to peripheral system and its role in CNS is not understood. Our studies focused on the possible role of Klf4 in mediating CNS inflammation. For in vitro studies, mouse microglial BV-2 cell lines were treated with 500 ng/ml Salmonella enterica lipopolysacchride (LPS). Brain tissues were isolated from BALB/c mice administered with 5 mg/kg body weight of LPS. Expressions of Klf4, Cox-2, iNOS and pNF-κB were evaluated using western blotting, quantitative real time PCR, and reverse transcriptase polymerase chain reactions (RT-PCRs). Klf4 knockdown was carried out using SiRNA specific for Klf4 mRNA and luciferase assays and electromobility shift assay (EMSA) were performed to study the interaction of Klf4 to iNOS promoter elements in vitro. Co-immunoprecipitation of Klf4 and pNF-κB was done in order to study a possible interaction between the two transcription factors. LPS stimulation increased Klf4 expression in microglial cells in a time- and dose-dependent manner. Knockdown of Klf4 resulted in decreased levels of the pro-inflammatory cytokines TNF-α, MCP-1 and IL-6, along with a significant decrease in iNOS and Cox-2 expression. NO production also decreased as a result of Klf4 knockdown. We found that Klf4 can potentially interact with pNF-κB and is important for iNOS and Cox-2 promoter activity in vitro. These studies demonstrate the role of Klf4 in microglia in mediating neuroinflammation in response to the bacterial endotoxin LPS.
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DOI：
10.1152/ajpregu.1996.271.4.r990
发表时间：
1996-10-01
影响因子：
2.8
作者：
Iadecola, C;Zhang, FY
通讯作者：
Zhang, FY
影响因子：
6.2
作者：
Cerciat, M.;Unkila, M.;Arevalo, M. -A.
通讯作者：
Arevalo, M. -A.
影响因子：
15.9
作者：
Kreutzberg, GW
通讯作者：
Kreutzberg, GW
DOI：
10.2165/00129785-200404050-00005
发表时间：
2004-01-01
期刊：
American journal of pharmacogenomics : genomics-related research in drug development and clinical practice
影响因子：
--
作者：
Carson, Monica J;Thrash, J Cameron;Lo, David
通讯作者：
Lo, David
影响因子：
3.7
作者：
Dutta K;Ghosh D;Nazmi A;Kumawat KL;Basu A
通讯作者：
Basu A