The Role of Toll-Like Receptors and Nuclear Factor κB p65 Protein in the Pathogenesis of Otitis Media

The role of Toll-like receptor 4 (TLR4) and nuclear factor κB p65 (NF-κB p65) proteins in the pathogenesis of otitis media is explored. In recent years, the incidence of otitis media has been rising globally, becoming a significant threat to human health. More and more studies have found that Toll-like receptor 4 (TLR4), as a member of the Toll-like receptor family, can promote the generation of inflammatory factors and is closely related to the body’s immune response and inflammatory response. Nuclear factor-κB p65 (NF-κB p65) is a nuclear transcription factor that can interact with various cytokines, growth factors, and apoptotic factors, participating in processes such as oxidative stress, apoptosis, and inflammation in the body [1]. This article elaborates on the structure, function, and signaling pathways of TLR4 and NF-κB p65 proteins in the pathogenesis of otitis media, aiming to provide more precise targets and better therapeutic efficacy for the diagnosis and treatment of otitis media. The role of inflammation in disease.

Nuclear Factor kappa B p65 Expression in Mouse Cochlea

Nuclear factor kappa B(NF-κB) is one of the best-characterized transcription factors playing important roles in many cellular responses to a large variety of stimuli,including inflammatory cytokines, phorbol esters, growth factors, and bacterial and viral products. The aim of this study is to demonstrate NF-κB expression in the mouse cochlea and its enhancement in response to lipopolysaccharides(LPS) and kanamycin(KA) treatment. Methods KA treatment consisted of subcutaneous KA injections at 700 mg/kg twice a day with an eight-hour interval between the two injections for 3 or 7 days. For animals in the LPS treatment group, a single dose of 0.3 mg LPS dissolved in 0.2 ml sterile saline were injected into both bullae through the tympanic membrane and kept there for 3 hours. Animals in the control group received subcutaneous saline injection for 7 days. Following immmunohistochemichal processing with rabbit polyclonal anti-NF-κB p65 antibodies, cryosections of the cochlea were examined for expression of NF-κB p65 in various structures in the cochlea. Results NF-κB p65 expression, identified by presence of brown reaction products characteristic of DAB immunohistochemistry, was visible in the spiral ligament, spiral prominence, tectorial membrane(TM), spiral ganglion and nerve fibers. Relatively weak NF-κB p65 expression was also visualized in the organ of Corti. Within the organ of Corti, the inner hair cells(IHC), outer hair cells(OHC), inner pillar cells(IP), outer pillar cells (OP), Deiter’s cells(DC), and Boettcher’s cells exhibited stronger staining than the inner sulcus cells, Hensen’s cells(HC) and Claudius’cells. No NF-κB p65 expression was seen in the nucleus of the IHC and OHC. NF-κB p65 expression was increased in animals exposed to LPS or KA, demonstrating significant differences in the staining between control animals and LPS/KA-treated animals. NF-κB p65 expression was not significantly different between LPS treated and KA treated animals or between 3 and 7 days in KA-treated animals. Conclusion LPS and KA exposure increases expression of NF-κB p65 in the mouse cochlea.

Isoflavone Attenuates the Nuclear Transcription Factor Kappa B (NF-<i>κ</i>B) Activation on MPP⁺-Induced Apoptosis of PC12 Cells

Objective: To explore the underlying molecular mechanisms of cellular response to the challenge by 1-methyl-4-phenylpyridinium (MPP+)-induced apoptosis of PC12 cells, an in vitro cell model for Parkinson’s disease, and the effect of NF-κB activation on the protection of Parkinson’s disease by Isoflavone (I). Methods: PC12 cells were used to establish the cell model of Parkinson’s disease, and are divided into five groups: control group;MPP+ group;I (Isoflavone) + MPP+ group;I group;SN-50 + MPP+ group. The content of NF-κB in PC12 cells was determined by immunocytochemistry;The viability of PC12 cells after treated with cell-permeable NF-κB inhibitor SN-50 and cell viability were measured by MTT assay;the expression levels of NF-κB p65 in cytoplasm and nuclear fractions were evaluated by western blot analysis;the mRNA expression of NF-κB p65 was analyzed by in situ hybridization (ISH). Results: Compared with the control group, the protein of NF-κB p65 both in cytoplasm and in nuclei was significantly higher than in I + MPP+ and MPP+ groups;similarly, the mRNA expression level of NF-κB p65 gene was also significantly higher;moreover, the protein expression of NF-κB p65 was much lower in I group (P + group, the protein of NF-κB p65 was significantly lower in I + MPP+ group, the mRNA expression level of NF-κB p65 gene was also significantly lower, and the protein expression level of NF-κB p65 was much lower in I + MPP+ group (P + group (P > 0.05). Conclusion: NF-κB activation is essential to MPP+-induced apoptosis in PC12 cells;but Isoflavone can inhibit the cell damage to some extent to execute its protective function, which may be involved in nigral neurodegeneration in patients with Parkinson’s disease.

Role of nuclear factor kappa B in central nervous system regeneration

Activation of nuclear factor kappa B （NF-κB） is a hallmark of various central nervous system （CNS） pathologies. Neuron-specific inhibition of its transcriptional activator subunit RelA, also referred to as p65, promotes neuronal survival under a range of conditions, i.e., for ischemic or excitotoxic insults. In macro- and microglial cells, post-lesional activation of NF-κB triggers a growth-permissive program which contributes to neural tissue inflammation, scar formation, and the expression of axonal growth inhibitors. Intriguingly, inhibition of such inducible NF-~B in the neuro-glial compartment, i.e., by genetic ablation of RelA or overexpression of a trans- dominant negative mutant of its upstream regulator IκBa, significantly enhances functional recovery and promotes axonal regeneration in the mature CNS. By contrast, depletion of the NF-κB subunit p50, which lacks transcriptional activator function and acts as a transcriptional repressor on its own, causes precocious neuronal loss and exacerbates axonal degeneration in the lesioned brain. Collectively, the data imply that NF-κB orchestrates a multicellular pro- gram in which κB-dependent gene expression establishes a growth-repulsive terrain within the post-lesioned brain that limits structural regeneration of neuronal circuits. Considering these subunit-specific functions, interference with the NF-κB pathway might hold clinical potentials to improve functional restoration following traumatic CNS injury.

核因子-κB p65在小鼠耳蜗中的表达

目的探讨核因子-κB(nuclear factor-kappa B,NF-κB)在耳蜗的表达情况。方法24只小鼠随机平均分为4组,其中2组分别连续3d和7d于皮下注射卡那霉素(kanamycin,KA),一组鼓室注射脂多糖(lipopolysac-charides LPS),另一组皮下注射等量生理盐水7d作为对照,用多克隆兔抗体NF-κB p65免疫组织化学等染色,观察NF-κB p65在小鼠耳蜗的表达。结果NF-κB p65主要定位在耳蜗的螺旋缘、盖膜、血管纹、螺旋韧带、螺旋神经节和神经纤维。整个耳蜗各回均可观察到免疫反应,而螺旋韧带、盖膜、螺旋突、螺旋神经节和神经纤维均可观察到较强的NF-κB p65免疫反应,Corti器的免疫反应比上述结构要弱一些。Corti器的内、外毛细胞,内、外柱细胞,Deiter细胞和Claudious细胞均可观察到NF-κB p65的免疫反应,这些免疫反应在内沟细胞、Hensen细胞和Claudious细胞显示较弱,而在螺旋神经节较强,内、外毛细胞核未见免疫反应。省去一抗的对照染色未观察到NF-κB p65的阳性反应。用脂多糖和卡那霉素处理的小鼠耳蜗NF-κB p65的免疫反应与注射正常生理盐水的小鼠耳蜗有显著性差异,而注射脂多糖和卡那霉素3d和7d NF-κB p65的免疫反应无差异。结论注射脂多糖和卡那霉素可使NF-κB p65在耳蜗的表达增强。

早产孕妇血中核因子-κB P65与亚临床绒毛膜羊膜炎的关系

目的:探讨早产孕妇外周血中核因子-κBP65(NF-κB P65)、白细胞介素-8(IL-8)及重金属蛋白酶-9(MMP-9)与亚临床绒毛膜羊膜炎的关系,寻找预测亚临床绒毛膜羊膜炎的最佳指标。方法:采用免疫细胞化学(ICC)方法检测36例早产临产孕妇外周血白细胞中NF-κB P65表达水平,酶联免疫吸附(ELISA)方法检测上述孕妇外周血清中IL-8及MMP-9浓度,胎盘胎膜病理检查有无组织学绒毛膜羊膜炎,并与未足月对照组、足月对照组进行对比。结果:①早产亚临床绒毛膜羊膜炎孕妇NF-κB P65、IL-8及MMP-9均显著高于非绒毛膜羊膜炎孕妇(P<0.05)。②早产临产组内无亚临床绒毛膜羊膜炎者外周血白细胞中NF-κBP65表达水平与未足月对照组、足月对照组比较无显著性差异(P>0.05)。③未足月对照组孕妇外周血白细胞中NF-κBP65表达水平与足月对照组比较无显著性差异(P>0.05)。④根据ROC曲线计算出母血NF-κB P65表达水平为3.50、IL-8浓度34.76ng/ml、MMP-9浓度360.81ng/ml可作为亚临床绒毛膜羊膜炎的诊断阈值。结论:①孕妇血白细胞中NF-κB P65表达水平与感染性早产有关。②孕妇外周血NF-κBP65表达水平可作为预测早产亚临床绒毛膜羊膜炎的指标。

Curcumin suppresses gastric NF-κB activation and macromolecular leakage in Helicobacter pylori-infected rats

AIM:To investigate whether curcumin could attenuate nuclear factor(NF)-κB p65 expression and macromolecular leakage in the gastric mucosa of Helicobacter pylori(H.pylori)-infected rats.METHODS:Twenty-five male Sprague-Dawley rats were equally divided into five groups:control rats(Control),control rats supplemented with 600 mg/kg curcumin,H.pylori-infected rats(Hp),H.pylori-infected rats supplemented with 200 mg/kg curcumin(Hp + curIn H.pylori-infected groups,rats were inoculated with H.pylori suspension twice a day at an interval of 4 h for 3 d.Two weeks later,200 or 600 mg/kg curcumin was given once daily to curcuminsupplemented groups for 7 d.On the day of the experiment,macromolecular leakage in gastric mucosa was examined by intravital fluorescence microscopy.The stomach tissue was removed to examine NF-κB p65 expression in gastric epithelial cells by immunohistochemistry.RESULTS:The expression of NF-κB p65 in gastric epithelial cells and the macromolecular leakage from gastric mucosal microcirculation significantly increased in the Hp group compared with the Control group.The percentages of NF-κB p65 immunoreactive cells in Control and Hp groups were 10.72% ± 2.10% vs 16.02% ± 2.98%,P = 0.004,respectively.The percentages of macromolecular leakage in Control and Hp groups were 10.69% ± 1.43% vs 15.41% ± 2.83%,P = 0.001,respectively.Curcumin supplementation in Hp + cur-CONCLUSION:H.pylori-induced gastric inflammation in rats is associated with increased NF-κB activation and macromolecular leakage which can be reduced by curcumin supplementation.

Protective effect of Jiaweibugan decoction against diabetic peripheral neuropathy

Oxygen free radical damage is regarded as a direct or indirect common pathway associated with diabetic neuropathy and is the main cause of complications in peripheral neuropathies. We speculate that Jiaweibugan decoction has a significant effect in treating diabetic peripheral neuropathy through an anti-oxidative stress pathway. In this study, a diabetic rat model was established by intraperitoneal injection of streptozotocin. Rats were treated with Jiaweibugan decoction via intragastric administration. The levels of malondialdehyde and glutathione, which are indirect indexes of oxidative stress, in serum were determined using a colorimetric method. The expression levels of nuclear factor kappa B p65 mRNA and p38 mitogen-activated protein kinase, which are oxidative stress associated factors, in the dorsal root ganglion of spinal $4-6 segments were evaluated by reverse-transcriptase polymerase chain reaction and immunohistochemistry. Results showed that, Jiaweibugan decoction significantly ameliorated motor nerve conduction velocity in diabetic rats, effectively decreased malondialdehyde levels in serum and the expression of nuclear factor kappa B p65 mRNA and p38 mitogen-activated protein kinase mRNA in the dorsa root ganglion, and increased glutathione levels in serum. Therefore, our experimental findings indicate that Jiaweibugan decoction plays an anti-oxidative stress role in the diabetic peripheral neuropathy process, which has a protective effect on peripheral nerve injury.

Influence of catgut implantation at acupoints on splenic lymphocyte nuclear factor (NF-κB p65) and correlated signaling molecules (β2AR) in rats with experimental colitis

Objective To investigate the mechanisms of catgut implantation at acupoints on ulcerative colitis. Methods Eighteen SD rats were randomly divided into a normal control group （NC）, a model group （MO） and a catgut implantation group （CI） with 6 rats in each group. Animals in group MO and group CI were treated by trinitro-benzene-sulfonic acid （TNBS） to establish model with colitis. No other treatment was given to the rats in group MO, but catgut was implanted at ＂Shàngjùxū＂ （上 巨虚 ST 37）, ＂Tiānshū＂ （天枢 ST 25） and ＂Dàchángshū＂ （大肠俞 BL 25） in the rats in group CI. The symptoms of diarrhea and bloody stool, and changes in histopathology were detected 15 days after the treatment. Expressions of splenic lymphocyte nuclear factor κB p65（NF-κB p65）and correlated signaling molecules（β2AR）were detected by the western blot method. Results Diarrhea and mucus bloody purulent stool were soon controlled, and mucous injures were obviously improved in group CI. The NF-κB p65 value of splenic lymphocytes was signifi cantly increased （P0.01） and expression of β2AR remarkably reduced in group MO （P0.01）, compared with group NC. But, the NF-κB p65 value was significantly decreased （P0.01） and expression of β2AR remarkably increased in group CI （P 0.01） , compared with group MO. Conclusion Catgut implantation at acupoints is obviously effective in treating experimental colitis. Modulation of NF-κB p65 and the correlated signaling molecules β2AR may be involved in the mechanisms.

穴位埋线对溃疡性结肠炎的疗效评价及对NF-κB和5-LOX表达的影响

目的:通过检测结肠黏膜NF-κB p65及5-LOX的表达情况,探讨穴位埋线对溃疡性结肠炎(UC)的治疗效果。方法:选取活动期轻、中度UC患者60例,随机分为三组,即埋线组、拉嗪组和联合组,每组20例,另设20例健康体检者作为对照组,于治疗前后评估临床症状及结肠镜下病变活动性,ELISA法测定血清IL-8和TNF-α血清水平。然后分别运用RT-PCR及免疫组化检测SP法检测结肠黏膜5-LOX和NF-κB p65的mRNA及其蛋白在各组治疗前后的表达情况。结果:治疗后三组临床症状和结肠镜下病变活动性较治疗前有明显改善(P<0.05),且联合组的临床症状和结肠镜下病变活动性与穴位埋线组和美沙拉嗪组相比改善较为明显(P<0.05)。而且治疗后三组的IL-8和TNF-α血清水平明显低于对照组和治疗前。此外治疗前,三组患者结肠黏膜5-LOX和NF-κB p65的mRNA及蛋白表达亦明显高于对照组(P<0.05),治疗6周后,5-LOX和NF-κB p65的mRNA及蛋白表达较治疗前有明显下降(P<0.05)。结论:穴位埋线疗法联合美沙拉嗪治疗活动期轻、中度UC的疗效较好,其机制可能是通过抑制5-LOX和NF-κB p65的表达而起到治疗作用。

转录因子NF-κB在内毒素休克中的作用

目的探讨内毒素休克大鼠组织炎性介质的表达特征及其和核转录因子NFκB(nuclearfactorkappaB)的关系。方法应用免疫组织化学技术检测脂多糖(lippolysaccharice,LPS)内毒素休克大鼠肝肾组织转录因子NFκB、炎性介质ICAM1、VCAM1、iNOS的表达。结果LPS内毒素休克大鼠肝肾组织转录因子NFκBp65,炎性介质ICAM1、VCAM1、iNOS阳性细胞率高于正常对照组;炎性介质ICAM-1、VCAM-1、iNOS阳性细胞率与NF-κBp65阳性细胞率成正相关。用吡咯烷二硫氨基甲酸(pyrrolidinedithiocarbmate,PDTC)抑制转录因子NFκB的内毒素休克大鼠炎性介质ICAM1、VCAM1、iNOS阳性细胞率低于LPS组。结论核转录因子NFκB在LPS引起的大鼠内毒素休克炎性介质的表达中起调节作用。

小续命汤联合超早期针刺督脉对于脑缺血再灌注模型大鼠自噬相关蛋白NF-κB p65的影响

目的:探讨小续命汤联合超早期针刺督脉对于脑缺血再灌注模型大鼠自噬相关蛋白核转录因子-κB p65(NF-κB p65)的影响,研究自噬相关蛋白NF-κB p65与脑保护机制的关系,寻找针刺最佳干预时间点。方法:将152只成年SD雄性大鼠随机分为假手术组、模型组、小续命汤高剂量组(药高组)、小续命汤低剂量组(药低组)、针刺组、小续命汤高剂量+针刺组(针高组)和小续命汤低剂量+针刺(针低组)7组。模型组、药高组、药低组、针刺组根据缺血再灌注30 min,2,4,6 h各分为4个亚组,每组6只。造模成功后,根据Zea Longa的神经功能评分,将符合标准大鼠收入相应组别。假手术组仅做颈动脉剥离;模型组仅造模不做任何治疗;小续命汤高低剂量组按照动物体表面积计算,分别给予60 g·kg-1·d-1和15 g·kg-1·d-1灌胃治疗,针刺治疗采用通督调神针刺。连续治疗14 d后进行神经功能评分;运用蛋白免疫印迹法(Western blot)检测大鼠脑组织中自噬相关蛋白NF-κB p65的表达。结果:与假手术组比较,模型组、药高组、药低组、针刺组、针高组和针低组各时间点神经功能缺损评分显著升高(P<0.01);与模型组比较,药高组、药低组、针刺组、针高组和针低组各时间点神经功能缺损评分显著降低(P<0.01);与假手术组比较,模型组、药高组、药低组、针刺组、针高组和针低组各时间点脑组织中NF-κB p65显著升高(P<0.01);与模型组比较,药高组、药低组、针刺组、针高组和针低组各时间点脑组织中NF-κB p65蛋白表达降低(P<0.05),其中以针高组最为显著(P<0.01)。结论:小续命汤联合超早期针刺督脉可以显著改善脑缺血再灌注模型大鼠神经功能缺损情况;小续命汤联合超早期针刺督脉可以抑制脑缺血再灌注模型大鼠自噬相关蛋白NF-κB p65活性,保护脑功能;小续命汤联合超早期针刺督脉在6 h内各组脑保护效应没有显著差异。

Effect of compound Sophorae Flavescentis Jiechangrongcapsule on expression of NF-κB p65 and STAT6 in theintestinal mucosa of patients with ulcerative colitis

The effects of compound Sophorae Flavescen-tis Jiechangrong capsule(CSFJC)on the expression of nuclear factor-κB p65(NF-κB p65)and signal transducer and activator of transcription 6(STAT6)in the intestinal mucosa of patients with ulcerative colitis and the possible mechanism were investigated.Eighteen patients with ulcerative colitis were randomly divided into a traditional Chinese medicine(TCM)group(n=11)treated by CSFJC and a western medicine(WM)group(n=7)treated by Sulfasalazine tablets.The treatment duration lasted eight weeks.Before and after the treatment,the symptoms and the physical signs were observed,and the routine stool test,the colonoscopy,and pathological examination were performed in the two groups.The expression levels of NF-κB p65 and STAT6 were detected by using immuno-histochemistry.The results showed that the total effective rate of the curative effectiveness in TCM and WM groups was 100%and 71.4%,respectively,and the total effective rate of colonic mucosa lesion in TCM and WM groups was 90.9%and 71.4%,respectively,with the differences being significant(all P<0.05).The total effective rate of syndromes of damp-heat blocking according to the TCM in TCM and WM groups was 90.9%and 71.4%,respectively.After the treatment,the expression of NF-κB p65 and STAT6 in the two groups was decreased,and the decrease of NF-κB p65 and STAT6 expression in TCM group was more significant than in WM group(P<0.05).It was concluded that CSFJC can inhibit the activation and expression of NF-κB p65 and STAT6 in the intestinal mucosa of patients with ulcerative colitis,which is a possible mechanism for CSFJC treating ulcerative colitis.

Expression of STAT6 and NF-κB p65 in the colon mucosa ofpatients with ulcerative colitis

The expression of signal transducer and activator of transcription 6(STAT6)and nuclear factor-κB(NF-κB)in the colonic mucosa of patients with ulcerative colitis(UC)was examined.Real-time polymer-ase chain reaction and immunohistochemistry were used to detect the expression of STAT6 and NF-κB p65 at both mRNA and protein levels in the colonic mucosa of patients with UC and healthy volunteers.The results showed that the expression levels of STAT6 and NFκB p65 in the colonic mucosa of patients with UC were significantly higher than in normal controls at both mRNA and protein levels.These data suggest that STAT6 and NFκB p65 perhaps play an important role in the pathogenesis of UC and underscore the potential value of anti-UC strategies in the clinical management of this disease.

牛大力多糖对LPS诱导的RAW264.7细胞炎性因子释放的影响

目的研究牛大力多糖对脂多糖(LPS)诱导的小鼠巨噬细胞RAW264.7细胞分泌炎症因子的影响,并观察核转录因子-κB p65(NF-κB p65)和抑制性卡巴蛋白-α(IκB-α)表达的变化。方法选用小鼠巨噬细胞RAW264.7,随机分为空白对照组,LPS模型组,牛大力多糖低、中、高剂量组(10,100,1000 ng·m L^(-1)),加药孵育2 h后,再加入10μg·m L^(-1)LPS至培养板中继续培养10 h,ELISA法测定各组细胞炎性因子白细胞介素1(IL-1)、白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)的含量,Western Blot法检测IκB-α蛋白以及NF-κB p65蛋白的表达水平。结果与LPS模型组比较,牛大力多糖高、中、低剂量组均能不同程度地抑制LPS诱导的3种炎性因子IL-1、IL-6、TNF-α的释放(P<0.05,P<0.01),提高IκB-α蛋白表达(P<0.05,P<0.01),降低NF-κB p65蛋白的表达(P<0.05,P<0.01),且牛大力多糖对上述指标的作用强度与剂量呈正相关,各组间比较差异均有统计学意义(P<0.05,P<0.01)。结论牛大力多糖可通过增加IκB-α蛋白和抑制NF-κB p65蛋白的表达,从而降低炎症因子IL-1、IL-6、TNF-α的释放,起到抗炎作用。

Expression and signifi cance of TLR4 and HIF-1α in pancreatic ductal adenocarcinoma

AIM:To investigate the expression of toll-like receptor(TLR) 4,nuclear factor-κB(NF-κB) p65 and hypoxiainducible transcription factor 1α(HIF-1α) in pancreatic ductal adenocarcinoma and their clinical significance.METHODS:The mRNA of TLR4 and HIF-1α were investigated by real-time polymerase chain reaction in 30 cases of pancreatic ductal adenocarcinoma and its adjacent tissues,and expression of TLR4,NF-κB p65 and HIF-1α protein were detected by immunohistochemistry in 65 cases of pancreatic ductal adenocarcinoma tissues and 38 cases of corresponding adjacent tissues.The relationship between TLR4 or HIF-1α and pathologic features,as well as the association between TLR4 and HIF-1α,were also analyzed.Kaplan-Meier method was used to assess the impact of expression of TLR4 and HIF-1α on survival of patients with pancreatic cancer.RESULTS:The relative quantif ication of TLR4 and HIF-1α mRNA in tumor tissues was 0.81±0.10 and 0.87±0.11,respectively,signif icantly higher than that in adjacent tissues(0.81±0.10 vs 0.70±0.16,P=0.002;0.87±0.11 vs 0.68±0.13,P=0.000).The protein expression of TLR4,NF-κB p65 and HIF-1α in tumor tissues was 69.20%,66.15% and 70.80%,respectively,being signif icantly higher than that in adjacent normal tissues(69.20% vs 39.50%,P=0.003;66.15% vs 31.58%,P=0.001;70.80% vs 36.80%,P=0.001).There was no signif icant correlation between TLR4 or HIF-1α expression and the age,gender,tumor location,the degree of tumor differentiation in the patients(P>0.05).However,there was signif icant correlation between the expression of TLR4 or HIF-1α and tumor size,lymph node metastasis,venous invasion and clinical staging(P<0.05).The expression of TLR4 and HIF-1α had a signif icant impact on survival of patients with pancreatic adenocarcinoma.CONCLUSION:TLR4,NF-κB p65 and HIF-1α are overexpressed in pancreatic adenocarcinoma,TLR4 may be partly involved in up-regulating HIF-1α,and both synergestically promote development of pancreatic adenocarcinoma.

Losartan reduced connexin43 expression in left ventricular myocardium of spontaneously hypertensive rats

Objective:To assess the effect of angiotensin II type 1(AT1)receptor antagonist losartan on myocardium con- nexin43(Cx43)gap junction(GJ)expression in spontaneously hypertensive rats(SHRs)and investigate possible mechanisms. Methods:Sixteen 9-week-old male SHRs and 8 age-matched male Wistar-Kyoto(WKY)rats were included in this study.SHRs were randomly divided into two groups to receive losartan at 30 mg/(kg·d)by oral gavage once daily for 8 weeks(SHR-L)or vehicle(0.9%saline)to act as controls(SHR-V);WKY rats receiving vehicle for 8 weeks served as normotensive controls.At the end of the experiment,rats were sacrificed and the hearts were removed.Expressions of Cx43 and nuclear factor-kappaB p65 (NF-κB p65)proteins in all three groups were observed and further investigations on the effect of angiotensin II type 1 receptor antagonist losartan(30 mg/(kg·d),8 weeks)on Cx43 expression were conducted with Western blot and immunohistochemistry. NF-κB p65 protein in nuclear extracts was determined by Western blot.Results:Left ventricular(LV)hypertrophy was prominent in SHRs,Cx43 and NF-κB p65 protein expressions were obviously upregulated and Cx43 distribution was dispersed over the cell surface.Treatment with losarton reduced the over-expressions of Cx43 and NF-κB p65 in LV myocardium.The distribution of Cx43 gap junction also became much regular and confined to intercalated disk after losartan treatment.Conclu- sion:Cx43 level was upregulated in LV myocardium of SHR during early stage of hypertrophy.Angiotensin II type 1 receptor antagonist losartan prevented Cx43 gap junction remodeling in hypertrophied left ventricles,possibly through the NF-κB pathway.

Cardioprotective effect of erythropoietin on sepsisinduced myocardial injury in rats

BACKGROUND:Sepsis-induced myocardial injury is one of the major predictors of morbidity and mortality of sepsis.The cytoprotective function of erythropoietin(EPO) has been discovered and extensively studied.However,the cardioprotective effects of EPO on sepsis-induced myocardial injury in the rat sepsis model has not been reported.METHODS:The rat models of sepsis were produced by cecal ligation and perforation(CLP)surgery.Rats were randomly(random number) assigned to one of three groups(n=8 for each group):sham group,CLP group and EPO group(1000 lU/kg erythropoietin).Arterial blood was withdrawn at3,6,12,and 24 hours after CLP.cTnl,BNP,CK-MB,LDH,AST,TNF-a,IL-6,IL-10,and CRP were tested by the ELISA assay.Changes of hemodynamic parameters were recorded at 3,6,12,24 hours after the surgery.Histological diagnosis was made by hematoxylin and eosin.Flow cytometry was performed to examine cell apoptosis,myocardium mitochondrial inner membrane potential,and NF-κB(p65).Survival rate at 7 days after CLP was recorded.RESULTS:In the CLP group,myocardial enzyme index and inflammatory index increased at3,6,12 and 24 hours after CLP compared with the sham group,and EPO significantly blocked the increase.Compared with the CLP group,EPO significantly improved LVSP,LV +dpldt_(max) LV-dp/dt_(min),and decreased LVEDP at different time.EPO blocked the reduction of mitochondrial transmembrane potential,suppressed the cardiomyocyte apoptosis,inhibited the activation of NF-κB,and reduced the production of proinflmmatory cytokines.No difference in the survival rate at 7 days was observed between the CLP group and the EPO group.CONCLUSION:Exogenous EPO has cardioprotective effects on sepsis-induced myocardial injury.

An enriched environment reduces hippocampal inflammatory response and improves cognitive function in a mouse model of stroke

An enriched environment is used as a behavio ral intervention therapy that applies sensory,motor,and social stimulation,and has been used in basic and clinical research of va rious neurological diseases.In this study,we established mouse models of photothrombotic stroke and,24 hours later,raised them in a standard,enriched,or isolated environment for 4 weeks.Compared with the mice raised in a standard environment,the cognitive function of mice raised in an enriched environment was better and the pathological damage in the hippocampal CA1 region was remarkably alleviated.Furthermore,protein expression levels of tumor necrosis factor receptor-associated factor 6,nuclear factorκB p65,interleukin-6,and tumor necrosis factorα,and the mRNA expression level of tumor necrosis factor receptor-associated factor 6 were greatly lower,while the expression level of miR-146a-5p was higher.Compared with the mice raised in a standard environment,changes in these indices in mice raised in an isolated environment were opposite to mice raised in an enriched environment.These findings suggest that different living environments affect the hippocampal inflammatory response and cognitive function in a mouse model of stro ke.An enriched environment can improve cognitive function following stroke through up-regulation of miR-146a-5p expression and a reduction in the inflammatory response.

桑叶水提物对db/db糖尿病小鼠肾脏的保护作用及其机制

目的:观察桑叶水提物(MLE)对db/db糖尿病小鼠肾脏的保护作用,并探讨其机制。方法:24只雄性C57BLKS/JGpt-Leprdb/Leprdb(db/db)小鼠按空腹血糖(FBG)值随机分为模型组、二甲双胍组、桑叶水提物低剂量(MLE-L)组和桑叶水提物高剂量(MLE-H)组,每组6只;另设6只C57BLKS/JGpt同窝野生型(m/m)小鼠作为正常组。各给药组小鼠灌胃相应药物,正常组和模型组小鼠均给予等体积去离子水,每日灌胃1次,连续给药8周。测定小鼠体质量、双侧肾脏绝对重量、FBG,并进行口服葡萄糖耐量实验(OGTT),苏木素-伊红染色、过碘酸雪夫染色观察肾脏组织病理变化,检测血清肌酐(SCr)、血清尿素氮(BUN)含量,酶联免疫吸附测定法检测血清肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)和尿微量白蛋白(U-mAlb)含量,蛋白免疫印迹法(Western blot)检测肾组织Toll样受体4(TLR4)、髓样分化因子88(MyD88)、核转录因子-κB p65(NF-κB p65)蛋白表达水平。结果:与正常组比较,模型组小鼠体质量、肾脏绝对重量、FBG、OGTT曲线下面积(AUC)显著升高(P<0.01),SCr、BUN、U-mAlb含量显著升高(P<0.01),血清TNF-α、IL-6含量显著升高(P<0.01),肾组织出现肾小球基底膜增厚,炎性细胞浸润明显,肾组织TLR4、MyD88、NF-κB p65蛋白表达水平显著升高(P<0.01)。与模型组比较,各给药组小鼠体质量差异无统计学意义;MLE-H组、二甲双胍组小鼠肾脏绝对重量明显降低(P<0.05,P<0.01);第4~8周二甲双胍组、MLE-L组、MLE-H组FBG明显降低(P<0.05,P<0.01);MLE-H组、二甲双胍组小鼠AUC显著降低(P<0.01),MLE-L组小鼠AUC呈下降趋势,差异无统计学意义;MLE-H组、二甲双胍组小鼠SCr、BUN、U-mAlb含量显著降低(P<0.01),MLE-L组小鼠SCr、U-mAlb含量显著降低(P<0.01);MLE-H组、二甲双胍组小鼠血清TNF-α、IL-6含量显著降低(P<0.01);各给药组小鼠肾组织病变均得到不同程度改善;MLE-H组小鼠肾组织TLR4、MyD88、NF-κB p65蛋白表达水平明显降低(P<0.05,P<0.01)。结论:桑叶水提物可改善db/db糖尿病小鼠肾组织结构和功能,其机制可能与抑制TLR4/MyD88/NF-κB信号通路有关。