LOC152742通过TLR4信号通路和炎症反应调控结核分枝杆菌对Ⅱ型肺泡上皮细胞的感染

目的 探讨长链非编码RNA(lncRNA)LOC152742对结核分枝杆菌感染的人Ⅱ型肺泡上皮细胞炎症反应和Toll样受体4(TLR4)信号通路的影响。方法 在A549细胞中转染LOC152742 siRNA,实验分为对照（Con）组、感染（H37Rv）组、转染对照（H37Rv+si-NC）组和转染（H37Rv+si-LOC152742）组。RT-PCR分析LOC152742表达水平变化,MTT法分析A549细胞增殖率,流式细胞术检测细胞凋亡情况,蛋白免疫印迹（Western blot）法检测活化的半胱氨酸天冬氨酸蛋白酶-3(cleaved caspase-3)、活化的半胱氨酸天冬氨酸蛋白酶-9(cleaved caspase-9)、TLR4、髓样分化因子（MyD88）蛋白表达,ELISA分析细胞上清中白细胞介素-6(IL-6)、白细胞介素-1β(IL-1β)和肿瘤坏死因子-α(TNF-α)的含量。在H37Rv+si-LOC152742组A549细胞中添加TLR4特异性抑制剂TAK242,检测TAK242对炎症反应的影响。结果 与Con组相比,H37Rv组A549细胞凋亡率、LOC15...     

TLR4介导可溶性尿酸诱导的肾小管上皮细胞自噬流异常

目的:探寻Toll样受体4(TLR4)与可溶性尿酸诱导肾小管上皮细胞HK-2自噬的关系。方法:用可溶性尿酸或/和氯喹(CQ)刺激HK-2细胞,采用Western blot检测LC3-Ⅱ和P62的表达水平,通过透射电子显微镜观察细胞内自噬小体及自噬溶酶体形成。在可溶性尿酸刺激HK-2细胞的基础上加上TLR4抑制剂TAK242后采用RT-qPCR检测TLR4的mRNA表达水平,Western blot检测TLR4、LC3-Ⅱ和P62的蛋白水平,并通过自噬双标腺病毒(mRFP-GFP-LC3)标记观察细胞内自噬流的变化。结果:可溶性尿酸可诱导HK-2细胞LC3-Ⅱ和P62的表达上调,其与CQ共同处理后LC3-Ⅱ及P62的表达进一步增加,透射电子显微镜下观察到自噬小体增多,自噬溶酶体少见,提示自噬流受阻。Western blot结果显示,与正常对照组相比,可溶性尿酸组TLR4、LC3-Ⅱ和P62的蛋白水平增高,而TAK242则抑制可溶性尿酸诱导HK-2细胞的TLR4、LC3-Ⅱ和P62的表达水平。自噬双标腺病毒实验结果显示,可溶性尿酸组与对照组相比,自噬小体显著增多,且自噬溶酶体较少;而与可溶...     

炎症状态下NF-κB-mTOR通路及转录因子RUNX1调控肾小管上皮细胞DC-SIGN表达研究

探讨炎症状态下NF-κB通路、mTOR通路以及转录因子RUNX1对肾小管上皮细胞DC-SIGN表达调控。体外培养肾小管上皮细胞株(HK-2)并经TNF-α刺激,分别给予NF-κB抑制剂(BAY 11-7082)和mTOR抑制剂(Rapamycin)干预。采用免疫印迹试验和实时定量PCR法检测HK-2细胞DC-SIGN表达;免疫印迹试验检测mTOR的磷酸化水平。用上述经TNF-α刺激的HK-2以及建立的肾炎损伤小鼠模型,以实时定量PCR法检测HK-2细胞以及分离的模型鼠肾小管上皮细胞中RUNX1表达。进一步利用HK-2构建过表达RUNX1稳定转染细胞株并经TNF-α刺激,实时定量PCR法检测RUNX1和DC-SIGN表达。结果显示,HK-2经TNF-α刺激模拟炎症状态下,可促进mTOR磷酸化并诱导DC-SIGN表达;NF-κB抑制剂和mTOR抑制剂均能抑制HK-2细胞的DC-SIGN表达,NF-κB抑制剂亦可抑制mTOR的磷酸化。还发现炎症因素刺激下,人和小鼠肾小管上皮细胞体内体外均明显表达RUNX1,且过表达RUNX1的HK-2细胞稳转株显著表达DCSIGN,并在TNF-α刺激下可进一步上调DC-SIGN表达。本研究表明,肾脏微炎症状态下,NF-κB-mTOR通路以及转录因子RUNX1均参与了肾小管上皮细胞DC-SIGN的表达调控。提示此过程中,NF-κB通路作为mTOR上游通路,通过激活后者参与DC-SIGN表达,而转录因子RUNX1可能是启动DC-SIGN表达的关键调控因素。     

肾小管上皮细胞转分化及逆转的分子机制

肾小管上皮细胞转分化(EMT)过程广泛存在于胚胎发生和肾纤维化过程中,其调节是一个复杂有序的过程,受多种细胞因子和细胞外基质的调节。促纤维化细胞因子如TGF-β1具有诱导EMT的作用,而抗纤维化细胞因子如骨形成蛋白-7(BMP-7)和肝细胞生长因子(HGF)能抑制纤维化过程。     

Lck对肾小管上皮细胞的IL-12信号传递功能研究

目的 研究lck途径激活后对小鼠肾小管上皮细胞的信号传递功能的影响。方法 应用IL-12、IL-2刺激小管皮细胞,通过原位杂交检测lckmRNA在小管上皮细胞的表达;采用lck抑制剂PP1,阻抑小管上皮细胞,通过原位杂交检测lckmRNA在小管上皮细胞的表达;采用lck抑制剂PP1,阻抑小管上皮细胞的lck激酶,通过免疫印迹和放射自显影方法检测lck对小鼠上皮细胞的信号传递功能的影响。结果 lck激酶激活可调控小管上皮细胞的lck/c-Jun信号传递途径;小管上皮细胞中lck途径激活介导的细胞炎症作用与IL-12的c-Jun表达作用有关。结论 lck在IL-12的信号传递中发挥重要的作用。     

仙茅苷调控miR-1247-3p表达对高糖诱导的肾小管上皮细胞炎症反应的影响北大核心CSCD

目的:探讨仙茅苷对高糖诱导的肾小管上皮细胞炎症反应的影响及分子机制。方法:肾小管上皮细胞HK-2随机分为正常对照组(Con)、高糖组(HG)、HG+仙茅苷低、中、高剂量组、HG+miR-NC组、HG+miR-1247-3p组、HG+仙茅苷+antimiR-NC组、HG+仙茅苷+anti-miR-1247-3p组;ELISA检测TNF-α、IL-6水平;流式细胞术检测细胞凋亡;RT-qPCR检测miR-1247-3p水平。结果:仙茅苷低、中、高剂量处理后,高糖诱导的肾小管上皮细胞培养液中IL-6、TNF-α水平随药物浓度的增加逐渐降低,细胞凋亡率逐渐降低,miR-1247-3p表达水平逐渐升高(P<0.05)。与HG+miR-NC组相比,miR-1247-3p过表达肾小管上皮细胞培养液中IL-6、TNF-α水平降低,细胞凋亡率降低(P<0.05)。下调miR-1247-3p表达可逆转仙茅苷对高糖诱导的肾小管上皮细胞炎症反应作用。结论:仙茅苷通过上调miR-1247-3p表达抑制高糖诱导的肾小管上皮细胞炎症损伤。     

C-反应蛋白诱导人肾小管上皮细胞凋亡

目的:探讨与微炎症状态相应的C-反应蛋白(CRP)水平是否诱导肾小管上皮细胞凋亡。方法:以微炎症状态相应的CRP浓度刺激HK-2细胞。采用AnnexinⅤ-FITC、PI染色和流式细胞术检测凋亡细胞的百分率。采用Hoechst 33258染色观察肾小管上皮细胞凋亡的形态学改变。比色法检测细胞caspase-3活性。Real-time PCR检测促凋亡基因bax、抗凋亡基因bcl-2的mRNA表达。结果:CRP呈剂量和时间依赖性地诱导HK-2细胞凋亡,细胞凋亡在CRP浓度为10 mg/L时达高峰,在20 mg/L时则以晚期凋亡和坏死为主。Hoechst 33258细胞核染色显示CRP作用的HK-2细胞呈现染色质浓缩、碎裂或染色质边集等细胞凋亡的特点。CRP增高细胞caspase-3的酶活性、上调促凋亡基因bax的表达和下调抗凋亡基因bcl-2的表达。结论:CRP轻度增高可诱导肾小管上皮细胞凋亡。     

肾小管上皮细胞在肾间质纤维化中的作用

肾小管是连接肾小球与肾间质的枢纽 ,肾小管上皮细胞可通过产生趋化因子、致纤维化细胞因子、表型转化为成纤维 /肌成纤维细胞以及细胞凋亡等方式 ,主动参与肾间质纤维化的发生与发展。干预肾小管上皮细胞的表型转化及凋亡 ,可能会为抗纤维化治疗提供新的思路和手段     

肾小管上皮细胞表达共刺激分子B7-DC并抑制CD4+T细胞活化

目的 探讨肾小管上皮细胞(TECs)表达B7-DC及其对T细胞活化的调节作用.方法 免疫组化检测肾穿刺标本B7-DC表达;流式细胞术分析人及小鼠肾小管上皮细胞B7-DC的表达变化;使用TECs/CD4 T共培养分析TECs表达的B7-DC对CD4 T细胞活化的影响.结果 慢性肾小球肾炎、狼疮性肾炎、小管间质性.肾炎等肾活检组织中发现B7-DC显著表达于肾小管.IFN-γ、TNF-a等炎症因子可诱导体外.肾小管上皮细胞表达137-DC.共培养试验发现阻断B7-DC信号可增强CD4 T细胞分泌细胞因子IFN-γ及IL-2并促进CD4 T细胞表达CD69.结论 肾小管上皮细胞表达B7-DC并可显著下调CD4 T细胞活化,在多种慢性肾脏疾病发展中可能发挥重要作用.     

TLR4/NLRP3炎症复合体介导对比剂诱导的肾小管上皮细胞炎症和损伤

目的:探讨Toll样受体4(TLR4)/Nod样受体蛋白3(NLRP3)炎症复合体是否介导了对比剂(CM)引起的肾小管上皮细胞炎症和损伤。方法:本研究运用碘普罗胺作用于大鼠肾小管上皮细胞NRK-52E建立损伤模型。应用CCK-8法测定细胞存活率;Western blot测定TLR4、NLRP3、凋亡相关斑点样蛋白(ASC)、caspase-1和cleaved caspase-3的蛋白水平;ELISA法检测炎症因子白细胞介素1β(IL-1β)和IL-18的水平;Hoechst 33258核染色法检测凋亡率;JC-1染色法测定线粒体膜电位。用小干扰RNA沉默NLRP3表达。结果:CM可降低NRK-52E细胞的存活率并上调cleaved caspase-3的蛋白水平(P0.05);此外,CM可上调细胞TLR4/NLRP3炎症复合体的表达并促进炎症因子IL-1β和IL-18的分泌(P0.05)。沉默NLRP3可以对抗CM诱导的炎症因子分泌;TLR4抑制剂TAK-242及沉默NLRP3能减轻CM引起的细胞凋亡和线粒体功能损伤。结论:TLR4/NLRP3炎症复合体参与了CM致急性肾损伤的发病机制,并介导了CM诱导的肾小管上皮细胞损伤和炎症。     

HIV-1 infection initiates an inflammatory cascade in human renal tubular epithelial cells

HIV-associated nephropathy (HIVAN) is the most common cause of chronic renal failure in HIV-infected patients. Tubulointerstitial inflammation is a prominent component of the histopathology of HIVAN. The pathogenesis of HIVAN is a result of infection of renal epithelial cells, but the cellular response to this infection remains poorly defined. In these studies, we used oligonucleotide microarrays to identify differentially expressed genes in renal tubular epithelial cells from a patient with HIVAN at three time points after infection with vesicular stomatitis virus-pseudotyped gag/pol-deleted HIV-1. Very few genes were differentially expressed 12 and 24 hours after infection. Three days after infection, however, 47 genes were upregulated by at least 1.8-fold. The most prominent response of these cells to HIV-1 expression was production of proinflammatory mediators, including chemokines, cytokines, and adhesion molecules. Many of the upregulated genes are targets of interleukin 6 and nuclear factor kappa B regulation, suggesting a central role for these proteins in the response of tubular epithelial cells to HIV-1 infection. Analysis of kidneys from HIV-1 transgenic mice revealed upregulation of many of the proinflammatory genes identified in the microarray studies. These studies provide novel insights into the mechanisms by which HIV-1 infection of tubular epithelial cells leads to tubulointerstitial inflammation and progressive renal injury.     

Embolic tubular epithelial cells in percutaneous renal biopsies

Four percutaneous renal biopsies with intravascular embolic tubular epithelial cells are presented. This unusual finding is presumably the result of the needle biopsy procedure and can be a puzzling and misleading artifact. It is postulated that dislodged tubular epithelial cells are pushed forward into or pulled back into punctured intrarenal arteries and subsequently transported to distant glomeruli.     

白细胞介素—12信号转导参与小鼠肾小管上皮细胞炎性损伤

为观察白细胞介素-12（IL-12）在小鼠肾小管上皮细胞（TEC）炎症损伤的信号传递,以培养的正常小鼠TEC作为空白对照组,狼疮肾炎（LN）TEC作为实验组,以IL-12（10μg/L)刺激5min,利用放射自显影检测发现正常对照及LN组lck活性增强,后者更明显,应用lck抑制剂PP1后其活性消失。再以等浓度IL-12刺激TEC15min,采用免疫印迹观察到LN组P38磷酸化强于正常对照组,应用PP1或P38抑制剂SB203580则不发生P38磷酸化。给予IL-12刺激时发现LN组c-Jun基因表达水平强于正常对照组,应用PP1或SB203580后则未有c-Jun基因表达,提示IL-12可通过lck/P38/c-Jun信号途径参与对狼疮小鼠TEC的炎症损伤。     

Toll-like receptors TLR2 and TLR4 initiate the innate immune response of the renal tubular epithelium to bacterial products

Renal tubular epithelial cells (TECs) respond diffusely to local infection, with the release of multiple cytokines, chemokines and other factors that are thought to orchestrate the cellular constituents of the innate immune response. We have investigated whether the Toll-like receptors TLR4 and TLR2, which are present on tubular epithelium and potentially detect a range of bacterial components, co-ordinate this inflammatory response acting through nuclear factor-kappa B (NF-kappaB). Primary cultures of TECs were grown from C57BL/6, C3H/HeN, C3H/HeJ, TLR2 and TLR4 knock-out mice. Cell monolayers were stimulated with lipopolysaccharide (LPS) and synthetic TLR2 and 4 agonists. The innate immune response was quantified by measurement of the cytokines tumour necrosis factor (TNF)-alpha and KC (IL-8 homologue) in cell supernatants by enzyme-linked immunosorbent assay. Cultured TECs grown from healthy mice produced the cytokines TNF-alpha and KC in response to stimulation by LPS and synthetic TLR2 and TLR4 agonists. Cells lacking the respective TLRs had a reduced response to stimulation. The TLR2- and TLR4-mediated response to stimulation was dependent on NF-kappaB signalling, as shown by curcumin pretreatment of TECs. Finally, apical stimulation of these TLRs elicited basal surface secretion of TNF-alpha and KC (as well as the reverse), consistent with the biological response in vivo. Our data highlight the potential importance of TLR-dependent mechanisms co-ordinating the innate immune response to upper urinary tract infection.     

Fingerprinting of the TLR4-induced acute inflammatory response

Intensive scientific efforts in the past decades have helped shed light into the pathogenesis of endotoxin-induced inflammation. We have used multiplexing bead-based assays to characterize the responses in two models of in vivo LPS challenge. C57BL/6 mice were either injected intraperitoneally (endotoxemia) or intratracheally (acute lung injury; ALI) with lipopolysaccharide (LPS). The time courses (1 h–24 h) of the following 20 inflammatory mediators in plasma or broncho-alveolar lavages were simultaneously analyzed: IL-1α, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-9, IL-12(p40), IL-13, Eotaxin (CCL11), G-CSF, GM-CSF, IFN-γ, KC (CXCL1), MCP-1 (CCL2), MIP-1α (CCL3), MIP-1β (CCL4), RANTES (CCL5) and TNF-α. While significant inductions of all mediators were found, substantial differences in their absolute concentrations, time points of maximal concentrations and clearances were observed. There were also notable variations in the patterns of several cytokines/chemokines when samples from endotoxemia and LPS-ALI were compared. These data may be helpful in defining analytic strategies including selection of optimal time points for studying the host immune response to endotoxin.     

人肾小管上皮细胞necroptosis模型的构建

 目的：以体外培养的人肾小管上皮细胞（HK-2细胞）为靶细胞,构建肾小管上皮细胞凋亡样坏死（necroptosis）的模型。方法：采用肿瘤坏死因子 α (tumor nercosis factor α, TNF-α)诱导细胞凋亡,同时采用抗霉素A (antimycin A)耗竭ATP,构建肾小管上皮细胞凋亡的模型,并以caspase-8抑制剂苄氧羰酰-缬氨酰-丙氨酰-天冬氨酰-氟甲基酮(benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone, zVAD-fmk) 阻断凋亡,用necroptosis的特异性抑制剂necrostatin-1（Nec-1）阻断necroptosis,观察细胞在不同的处理下形态学的变化,同时检测细胞存活率及标志物微管相关蛋白1轻链3-Ⅱ（microtubule-associated protein 1 light chain 3-Ⅱ,LC3-Ⅱ）的表达。结果：（1）在TNF-α+zVAD- fmk+antimycin A处理1 h时细胞及细胞器膨胀,电镜下细胞膜碎裂,线粒体变圆、肿胀,嵴逐渐模糊,胞浆中出现大量自噬小体,而Nec-1预处理后细胞的坏死程度较对照组明显改善。（2）在TNF-α+zVAD-fmk+antimycin A 1 h实验组,Nec-1预处理后细胞的存活率显著增加（P<0.05）。（3）TNF-α+zVAD-fmk+antimycin A干预1 h实验组在Nec-1预处理后LC3-Ⅱ的表达量明显下降（P<0.05）。结论：凋亡环境中阻断凋亡可以诱导肾小管上皮细胞necroptosis,抑制剂Nec-1能特异性阻断肾小管上皮细胞发生坏死。     

Identification and regulation of reticulon 4B (Nogo-B) in renal tubular epithelial cells

Nogo-B is a member of the reticulon family of proteins that has been implicated in diverse forms of vascular injury. Although Nogo-B is expressed in renal tissues, its localization and function in the kidney have not been examined. Here, we report that Nogo-B is expressed specifically in the epithelial cells of the distal nephron segments in the murine kidney. After unilateral ureteral obstruction (UUO) and ischemia/reperfusion, Nogo-B gene and protein levels increased dramatically in the kidney. This increase was driven in part by injury-induced de novo expression in proximal tubules. Examination of Nogo-B immunostaining in human biopsy specimens from patients with acute tubular necrosis showed similar increases in Nogo-B in cortical tubules. Mice genetically deficient in Nogo-A/B were indistinguishable from wild-type (WT) mice based on histological appearance and serum analyses. After UUO, there was a significant delay in recruitment of macrophages to the kidney in the Nogo-A/B-deficient mice. However, measurements of fibrosis, inflammatory gene expression, and histological damage were not significantly different from WT mice. Thus, Nogo-B is highly expressed in murine kidneys in response to experimental injuries and may serve as a marker of diverse forms of renal injury in tissues from mice and humans. Furthermore, Nogo-B may regulate macrophage recruitment after UUO, although it does not greatly affect the degree of tissue injury or fibrosis in this model.     

Apoptosis of tubular epithelial cells in rats with chronic renal failure

Tubular injury leading to tubular atrophy and tubular loss is one of the characteristic features of chronic renal failure. To reveal the mechanism of tubular atrophy in chronic renal failure, the involvement of apoptosis was studied byin situ nick end labeling of biotinylated deoxyuridine by terminal deoxy nucleotidyl transferase (TUNEL) as well as by electron microscopy. TUNEL-positive cells and heterophagosomes containing apoptotic body-like structures having nuclear fragments with condensed chromatin were observed in the renal tubular epithelium 8 weeks after nephrectomy. It has become apparent from our study that atrophy of the tubules in chronic renal failure results, to some extent, from cell deletion by apoptosis.