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.

创伤性脑损伤患者血清AQP4和NF-κB p65表达与神经功能缺损程度及预后的关系

目的探讨创伤性脑损伤(TBI)患者血清水通道蛋白4(AQP4)和核因子κB(NF-κB p65)表达与神经功能缺损程度及预后的关系。方法选取2021年3月至2023年3月于河南科技大学第一附属医院开元急诊科收治的128例TBI患者作为研究对象(观察组),根据美国国立卫生院神经缺损评估量表(NIHSS)将患者分为重度组31例、中度组45例和轻度组52例;根据格拉斯哥预后量表(GOS)评分将患者分为预后不良组37例和预后良好组91例。另选取同期于本院体检的128例健康志愿者作为对照组。比较各组受检者的一般资料及血清AQP4和NF-κB p65水平,采用Spearman法分析血清AQP4、NF-κB p65水平与NIHSS评分的相关性,采用受试者工作特征曲线(ROC)分析血清AQP4、NF-κB p65对TBI患者预后不良的预测价值。结果观察组患者的血清AQP4、NF-κB p65水平分别为(27.37±6.34)μg/L、(2.27±0.24)ng/mL,明显高于对照组的(12.65±3.21)μg/L、(0.36±0.11)ng/mL,差异均具有统计学意义(P<0.05)。Spearman相关性分析结果显示,TBI患者血清AQP4、NF-κB p65水平与NIHSS评分均呈正相关(r=0.605、0.612,P<0.05)。入院24 h血清AQP4、NF-κB p65水平比较,重度组>中度组>轻度组,48 h、72 h有同样的趋势,差异均具有统计学意义(P<0.05)。预后不良组患者的血清AQP4、NF-κB p65水平分别为(34.65±7.51)μg/L、(2.71±0.40)ng/mL,明显高于预后良好组的(24.41±6.48)μg/L、(2.09±0.22)ng/mL,差异均有统计学意义(P<0.05)。血清AQP4、NF-κB p65两者联合预测TBI患者预后不良的曲线下面积(AUC)为0.938,高于各单一指标的0.873、0.830,联合预测的敏感度为91.89%,特异度为85.71%,两者联合优于血清AQP4、NF-κB p65各自单独预测(Z两者联合-AQP4=2.564、Z两者联合-NF-κB p65=2.555,P=0.010、0.011)。结论TBI患者血清AQP4、NF-κB p65水平上升与神经功能缺损程度和不良预后有关,可作为预测预后的潜在标志物。

Role of osteoprotegerin/receptor activator of nuclear factor kappa B/receptor activator of nuclear factor kappa B ligand axis in nonalcoholic fatty liver disease

Concomitantly with the increase in the prevalences of overweight/obesity, nonalcoholic fatty liver disease(NAFLD) has worldwide become the main cause of chronic liver disease in both adults and children. Patients with fatty liver display features of metabolic syndrome(Met S), like insulin resistance(IR), glucose intolerance, hypertension and dyslipidemia. Recently, epidemiological studies have linked obesity, Met S, and NAFLD to decreased bone mineral density and osteoporosis, highlighting an intricate interplay among bone, adipose tissue, and liver. Osteoprotegerin(OPG), an important symbol of the receptor activator of nuclear factor-B ligand/receptor activator of nuclear factor kappa B/OPG system activation, typically considered for its role in bone metabolism, may also play critical roles in the initiation and perpetuation of obesityrelated comorbidities. Clinical data have indicated that OPG concentrations are associated with hypertension, left ventricular hypertrophy, vascular calcification, endothelial dysfunction, and severity of liver damage in chronic hepatitis C. Nonetheless, the relationship between circulating OPG and IR as a key feature of Met S as well as between OPG and NAFLD remains uncertain. Thus, the aims of the present review are to provide the existent knowledge on these associations and to discuss briefly the underlying mechanisms linking OPG and NAFLD.

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.

Nuclear factor kappa B: A marker of chemotherapy for human stage Ⅳ gastric carcinoma

AIM： To detect the nuclear factor kappa B （NF-κB） condition in human stage IV gastric carcinoma patients and to explore the correlation between NF-κB activation and survival of these patients after chemotherapy. METHODS： Expression of NF-κB-p65 was determined by immunohistochemical analysis. Activity of NF-κB DNA-binding in carcinoma tissue was detected by electrophoretic mobility shift assay. Kaplan-Meier survival analysis was performed to show the relation between NF-κB and progression-free survival （PFS） or overall survival （OS） of the patients. RESULTS： The positive expression rate of NF-κB-p65 in 60 gastric cancer tissue samples was 76.7% （46160）. The expression of NF-κB-p65 was reduced in adjacent carcinoma and normal tissue samples. Electrophoretic mobility shift assay （EMSA） analysis showed a strong activation of NF-κB in cancer tissue samples. A survival difference was found in NF-κB-p65 positive and negative patients. NF-κB-p65 expression was negative in cancer tissue samples （n = 14）. PFS was 191.40 ± 59.88 d and 152.93 ±16.99 d, respectively, in patients with positive NF-κB-p65 expression （n = 46） （P = 0.4028）. The survival time of patients with negative and positive NF-κB-p65 expression was 425.16 ±61.61 d and 418.85 ±42.98 d, respectively （P = 0.7303）. Kaplan-Meier analysis showed no significant difference in PFS or OS. The 46 patient tissue which positive NF-κB-p65 expression was found in the tissue samples from the 46 patients whose PFS and OS were 564.89 ± 75.94 d and s 352.37 ±41.32 d, respectively （P = 0.0165）. CONCLUSION： NF-κB is activated in gastric carcinoma tissue, which is related to the OS after chemotherapy.

Tumor metastasis and the reciprocal regulation of heparanase gene expression by nuclear factor kappa B in human gastric carcinoma tissue

AIM: To investigate whether NF-kB is activated in human gastric carcinoma tissues and, if so, to study whether there is any correlation between NF-kB activity and heparanase expression in gastric carcinoma. METHODS: NF-kB activation was assayed by immunohistochemical staining in formalin-fixed, paraffin-embedded specimens from 45 gastric carcinoma patients. Electrophoretic mobility shift assay (EMSA) method was used for nuclear protein from these fresh tissue specimens. Heparanase gene expression was quantified using quantitative RT-PCR. RESULTS: The nuclear translocation of RelA (marker of NF-kB activation) was significantly higher in tumor cells compared to adjacent and normal epithelial cells [(41.3±3.52)% vs (0.38±0.22) %, t=10.993, P= 0.000<0.05; (41.3±3.52)% vs(0±0.31)%, t=11.484, P= 0.000<0.05]. NF-kB activation was correlated with tumor invasion-related clinicopathological features such as lymphatic invasion, pathological stage, and depth of invasion (Z= 2.148, P= 0.032<0.05; t = 8.758, P= 0.033<0.05; t = 18.531, P = 0.006<0.05). NF-KB activation was significantly correlated with expression of heparanase gene (r= 0.194, P=0.046<0.05). CONCLUSION: NF-KB RelA (p65) activation was related with increased heparanase gene expression and correlated with poor clinicopathological characteristics in gastric cancers. This suggests NF-kB as a major controller of the metastatic phenotype through its reciprocal regulation of some metastasis-related genes.

Up-regulation of intestinal nuclear factor kappa B and intercellular adhesion molecule-1 following traumatic brain injury in rats

AIM: Nuclear factor kappa B (NF-κB) regulates a large number of genes involved in the inflammatory response to critical illnesses, but it is not known if and how NF-KB is activated and intercellular adhesion molecule-1 (ICAM-1) expressed in the gut following traumatic brain injury (TBI). The aim of current study was to investigate the temporal pattern of intestinal NF-κB activation and ICAM-1 expression following TBI. METHODS: Male Wistar rats were randomly divided into six groups (6 rats in each group) including controls with sham operation and TBI groups at hours 3, 12, 24, and 72, and on d 7. Parietal brain contusion was adopted using weight-dropping method. All rats were decapitated at corresponding time point and mid-jejunum samples were taken. NF-KB binding activity in jejunal tissue was measured using EMSA. Immunohistochemistry was used for detection of ICAM-1 expression in jejunal samples. RESULTS: There was a very low NF-κB binding activity and little ICAM-1 expression in the gut of control rats after sham surgery. NF-KB binding activity in jejunum significantly increased by 160% at 3 h following TBI (P<0.05 vs control), peaked at 72 h (500% increase) and remained elevated on d 7 post-injury by 390% increase. Compared to controls, ICAM-1 was significantly up-regulated on the endothelia of microvessels in villous interstitium and lamina propria by 24 h following TBI and maximally expressed at 72 h post-injury (P<0.001). The endothelial ICAM-1 immunoreactivity in jejunal mucosa still remained strong on d 7 post-injury. The peak of NF-κB activation and endothelial ICAM-1 expression coincided in time with the period during which secondary mucosal injury of the gut was also at their culmination following TBI. CONCLUSION: TBI could induce an immediate and persistent up-regulation of NF-κB activity and subsequent up-regulation of ICAM-1 expression in the intestine. Inflammatory response mediated by increased NF-κB activation and ICAM-1 expression may play an important role in the pathogenesis of acute gut mucosal injury following TBI.

Inhibition of p38 mitogen-activated protein kinase attenuates experimental autoimmune hepatitis: Involvement of nuclear factor kappa B

To investigate the role of p38 mitogen-activated protein kinase （p38MAPK） in murine experimental autoimmune hepatitis （EAH）.METHODS： To induce EAH, the syngeneic S-100 antigen emulsified in complete Freud＇s adjuvant was injected intraperitoneally into adult male C57BI/6 mice. Liver injury was assessed by serum ALT and liver histology. The expression and activity of p38 MAPK were measured by Western blot and kinase activity assays. In addition, DNA binding activities of nuclear factor kappa B （NF-KB） were analyzed by electrophoretic mobility shift assay. The effects of SB203580, a specific p38 MAPK inhibitor, on liver injuries and expression of proinflammatory cytokines （interferon-y, IL-12, IL-1β and TNF-α） were observed.RESULTS： The activity of p38 MAPK and NF-~：B was increased and reached its peak 14 or 21 d after the first syngeneic S-100 administration. Inhibition of p38 MAPK activation by SB203580 decreased the activation of NF-~：B and the expression of proinflammatory cytokines. Moreover, hepatic injuries were improved significantly after SB203580 administration.

High levels of homocysteine downregulate apolipoprotein E expression via nuclear factor kappa B

AIM: To investigate the effect of high homocysteine(Hcy) levels on apolipoprotein E(apoE) expression and the signaling pathways involved in this gene regulation.METHODS: Reverse transcriptase polymerase chain reaction(RT-PCR) and Western blot were used to assess apo E expression in cells treated with various concentrations(50-500 μmol/L) of Hcy. Calcium phosphatetransient transfections were performed in HEK-293 and RAW 264.7 cells to evaluate the effect of Hcy on apoE regulatory elements [promoter and distal multienhancer 2(ME2)]. To this aim, plasmids containing the proximal apoE promoter [(-500/+73)apoE construct] alone or in the presence of ME2 [ME2/(-500/+73)apoE construct] to drive the expression of the reporter luciferase gene were used. Co-transfection experiments were carried out to investigate the downstream effectors of Hcymediated regulation of apoE promoter by using specific inhibitors or a dominant negative form of IKβ. In other co-transfections, the luciferase reporter was under the control of synthetic promoters containing multiple specific binding sites for nuclear factor kappa B(NF-κB), activator protein-1(AP-1) or nuclear factor of activated T cells(NFAT). Chromatin immunoprecipitation(ChI P)assay was accomplished to detect the binding of NF-κB p65 subunit to the apoE promoter in HEK-293 treated with 500 μmol/L Hcy. As control, cells were incubated with similar concentration of cysteine. NF-κB p65 proteins bound to DNA were immunoprecipitated with anti-p65 antibodies and DNA was identified by PCR using primers amplifying the region-100/+4 of the apoE gene. RESULTS: RT-PCR revealed that high levels of Hcy(250-750 μmol/L) induced a 2-3 fold decrease in apoE m RNA levels in HEK-293 cells, while apo E gene expression was not significantly affected by treatment with lower concentrations of Hcy(100 μmol/L). Immunoblotting data provided additional evidence for the negative role of Hcy in apoE expression. Hcy decreased apoE promoter activity, in the presence or absence of ME2, in a dose dependent manner, in both RAW 264.7 and HEK-293 cells, as revealed by transient transfection experiments. The downstream effectors of the signaling pathways of Hcy were also investigated. The inhibitory effect of Hcy on the apo E promoter activity was counteracted by MAPK/ERK kinase 1/2(MEK1/2) inhibitor U0126, suggesting that MEK1/2 is involved in the downregulation of apoE promoter activity by Hcy. Our data demonstrated that Hcy-induced inhibition of apoE took place through activation of NF-κB. Moreover, we demonstrated that Hcy activated a synthetic promoter containing three NF-κB binding sites, but did not affect promoters containing AP-1 or NFAT binding sites. ChI P experiments revealed that NF-κB p65 subunit is recruited to the apoE promoter following Hcy treatment of cells.CONCLUSION: Hcy-induced stress negatively modulates apoE expression via MEK1/2 and NF-κB activation. The decreased apo E expression in peripheral tissues may aggravate atherosclerosis, neurodegenerative diseases and renal dysfunctions.

Effects of ketamine on proinflammatory cytokines and nuclear factor kappaB in polymicrobial sepsis rats

AIM： To explore the effects of ketamine on hemodynamics, plasma proinflammatory cytokine （TNF-α and IL-6） levels and nuclear factor kappa B （NF-κB） activation during polymicrobial sepsis. METHODS： Male Sprague-Dawlay rats were subjected to cecal ligation and puncture （CLP） or sham operation. The rats were randomly assigned into four equal groups： sham CLP group, CLP group, ketamine （KT）Ⅰ group and KTⅡgroup. Thirty minutes before CLP, ketamine （5 mg/kg per hour and 10 mglkg per hour, respectively） was infused continuously through the left femoral vein cannula in KT Ⅰ group or KTⅡgroup. Sham CLP group and CLP group received 0.9% saline only （5 mL/kg per hour）. The right femoral artery was cannulated to monitor mean arterial pressure （MAP） and heart rates （HR）,and draw blood samples. The proinflammatory cytokine （TNF-α and IL-6） levels of plasma were measured using enzyme-linked immunosorbent assays （ELISA）. The hepatic NF-κB activation was determined by Western blot and HPIAS 2000 image analysis system. Twenty hours after CLP, the rats were killed by right femoral artery phlebotomization. RESULTS： CLP produced progressive hypotension, and a first increase followed by a decrease in HR. The hypotension was prevented, and the HR was slightly steady in ketamine treated rats. TNF-α levels of plasma reached a peak value at 2 h after CLP. Ketamine （KT Ⅰ group or KTⅡgroup） caused a significant decrease compared with CLP group at 2, 5 and 9 h time points after CLP （14.3 ± 1.9 vs 4.3 ± 0.9, 9.7 ± 1.4 vs 4.3 ± 0.9; 9.3 ± 1.5 vs 4.3 ± 0.9, 8.7 ± 1.4 vs 4.3 ±0.9; 6.0 ± 1.5 vs 5.0 ± 1.7, 5.3 ± 0.8 vs 5.0 ± 1.7; P 〈 0.01, respectively）. The IL-6 levels of plasma firstly ascended and then descended in CLP group, and reached a peak value at 9 h after CLP. Ketamine （KT I group or KTH group） caused a significant decrease compared with CLP group at 5, 9 or 20 h after CLP （135.0 ± 52.6 vs 60.0 ± 16.3, 112.5 ± 52.6 vs 60.0 ± 16.3; 410.0 ± 68.7 vs 62.5 ± 12.5, 250.0 ± 28.0 vs 62.5 ± 12.5; 320.0 ± 25.9 vs 52.5 ± 10.1, 215.0 ± 44.6 vs 52.5 ± 10.1; P 〈 0.05, respectively）. The IL-6 levels of plasma in KTⅡgroup were lower than those of KT Ⅰ group at 9 h after CLP （250.0 ± 28.0 vs 410.0 ± 68.7; P 〈 0.05）. In addition, CLP increased hepatic NF-κB expression compared with sham CLP. Ketamine suppressed NF-κB activation in a dose-dependent manner at 4 h after CLP （237.7 ± 3.5 vs 246.9 ± 3.1; P 〈 0.05）. CONCLUSION： Ketamine stabilizes the hemodynamics, attenuates the proinflammatory cytokine responses, and inhibits hepatic NF-κB activation. These findings suggest that ketamine has protective effects against polymicrobial sepsis in rats.

Characteristics of hepatic nuclear-transcription factor-kappa B expression and quantitative analysis in rat hepatocarcinogenesis

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. We analyzed the expression of miclear-transcription factor-kappa B (NF-kappa B) during hepatocarcinogenesis in order to evaluate its dynamic expression and its clinical value in the development and diagnosis of HCC. METHODS: Hepatoma models were induced by oral administration of 2-acetamidoflurene (2-FAA) to male Sprague-Dawley rats. Morphological changes were observed after hematoxylin and eosin staining. The cellular distribution of NF-kappa B expression during different stages of cancer development was investigated by immunohistochemistry, and the level of NF-kappa B expression in liver tissues was quantitatively analyzed by ELISA. The gene fragments of hepatic NF-kappa B were amplified by nested-polymerase chain reaction assay. RESULTS: Hepatocytes showed vacuole-like degeneration during the early stages, then had a hyperplastic nodal appearance during the middle stages, and finally progressed to tubercles of cancerous nests with high differentiation. The NF-kappa B-positive material was buff-colored, fine particles localized in the nucleus, and the incidence of NF-kappa B-positive cells was 81.8% in degeneration, 83.3% in precancerous lesions, and 100% in cancerous tissues. All of these values were higher than those in controls (P<0.01). Hepatic NF-kappa B expression and hepatic NF-kappa B-mRNA were also higher during the course of HCC development (P<0.01). CONCLUSION: The NF-kappa B signal transduction pathway is activated during the early stages of HCC development, and its abnormal expression may be associated with the occurrence of HCC.

Effect of Helicobacter pylori cdrA on interleukin-8 secretions and nuclear factor kappa B activation

AIM： To investigate genetic diversity of Helicobacter pylori （H. pylorl） cell division-related gene A （cdrA） and its effect on the host response.METHODS： Inactivation of H. py/ori cdrA, which is involved in ceil division and morphological elonga- tion, has a role in chronic persistent infections. Ge- netic property of H. pylori cdrA was evaluated using polymerase chain reaction and sequencing in 128 （77 American and 51 Japanese） clinical isolates obtained from 48 and 51 patients, respectively. Enzyme-linked immunosorbent assay was performed to measure in- terleukin-8 （IL-8） secretion with gastric biopsy speci- mens obtained from American patients colonized with cdrA-positive or -negative strains and AGS cells co- cultured with wild-type HPK5 （cdrA-positive） or its de- rivative HPKT510 （cdrA-disruptant）. Furthermore, the cytotoxin-associated gene A （cagA） status （transloca- tion and phosphorylation） and kinetics of transcription factors [nuclear factor-kappa B （NF-~：B） and inhibition kappa B] were investigated in AGS cells co-cultured with HPK5, HPKT510 and its derivative HPKSCA （cagA- disruptant） by western blotting analysis with immuno- precipitation. RESULTS： Genetic diversity of the H. pylori cdrA gene demonstrated that the cdrA status segregated into two categories including four allele types, cdrA-positive （al- lele types, I and 11 ） and cdrA-negative （allele types; 111 and IV） categories, respectively. Almost all Japanese isolates were cdrA-positive （ 1 ： 7.8% and 11 ： 90.2%）, whereas 16.9% of American isolates were cdrA-positive （11） and 83.1% were cdrA-negative （nl： 37.7% and IV： 45.5%）, indicating extended diversity of cdrA in individual American isolates. Comparison of each isolate from different regions （antrum and corpus） in the stomach of 29 Americans revealed that cdrA status was identical in both isolates from different regions in 17 cases. However, 12 cases had a different cdrA al- lele and 6 of them exhibited a different cdrA category between two regions in the stomach. Furthermore, in 5 of the 6 cases possessing a different cdrA category, cdrA-negative isolate existed in the corpus, suggesting that cdrA-negative strain is more adaptable to coloni- zation in the corpus. IL-8 secretions from AGS revealed that IL-8 levels induced by a cdrA-disrupted HPKT510 was significantly lower （P 〈 0.01） compared to wild- type HPK5： corresponding to 50%-60% of those of wild-type HPK5. These data coincided with in vivo data that an average value of IL-8 in biopsy specimens from cdrA-positive and cdrA-negative groups was 215.6 and 135.9 pg/mL, respectively. Western blotting analysis documented that HPKT510 had no effect on CagA translocation and phosphorylation, however, nuclear accumulation of NF-κB was lower by HPKT510 com- pared to HPK5. CONCLUSION： Colonization by a cdrA-negative or cdrA-dysfunctional strain resulted in decreased IL-8 production and repression of NF-κB, and hence, atten- uate the host immunity leading to persistent infection.

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.

Effects of L-3-n-butylphthalide on caspase-3 and nuclear factor kappa-B expression in primary basal forebrain and hippocampal cultures after beta-amyloid peptide 1-42 treatment

BACKGROUND： L-3-n-butylphthalide （L-NBP） can inhibit phosphorylation of tau protein and reduce the neurotoxicity of beta-amyloid peptide 1-42 （Aβ1-42）. OBJECTIVE： To observe the neuroprotective effects of L-NBP on caspase-3 and nuclear factor kappa-B （NF- K B） expression in a rat model of Alzheimer＇s disease. DESIGN, TIME AND SETTING： A cell experiment was performed at the Central Laboratory of Provincial Hospital affiliated to Shandong University between January 2008 and August 2008. MATERIALS： L-NBP （purity 〉 98%） was provided by Shijiazhuang Pharma Group NBP Pharmaceutical Company Limited. Aβ1-42, 3-[4,5-dimethylthiazolo-2]-2,5 iphenyltetrazolium bromide （MTT）, and rabbit anti-Caspase-3 polyclonal antibody were provided by Cell Signaling, USA; goat anti-choactase and rabbit anti-NF- kB antibodies were provided by Santa Cruz, USA. METHODS： Primary cultures were generated from rat basal forebrain and hippocampal neurons at 17 or 19 days of gestation. The cells were assigned into five groups： the control group, the Aβ1-42 group （2 μmol/L）, the Aβ1-42 ＋ 0.1 μmol/L L-NBP group, the Aβ1-42 ＋ 1 μ mol/L L-NBP group, and the Aβ1-42 ＋ 10μmol/L L-NBP group. The neurons were treated with Aβ1-42 （2 μmol/L） alone or in combination with L-NBP （0.1, 1, 10 μmol/L） for 48 hours. Cells in the control group were incubated in PBS. MAIN OUTCOME MEASURES： Morphologic changes were evaluated using inverted microscopy, viability using the M-I-I- method, and the changes in caspase-3 and NF- k B expression using Western blot. RESULTS： Induction with Aβ1-42 for 48 hours caused cell death and soma atrophy, and increased caspase-3 and NF- K B expression （P 〈 0.05）. L-NBP blocked these changes in cell morphology, decreased caspase-3 and NF- k B expression （P 〈 0.05）, and improved cell viability, especially at the high dose （P 〈 0.05）. CONCLUSION： AI3^-42 is toxic to basal forebrain and hippocampal primary neurons; L-NBP protects against this toxicity and inhibits the induction of caspase-3 and NF- K B expression.

Inhibitory effects of Shuanghuanglian injection on nuclear factor-kappa B expression in mice with viral encephalitis in a time-and dose-dependent manner

Previous studies have confirmed that the anti-virus effects of Shuanghuanglian injection may be associated with nuclear factor-kappa B activity. This study observed nuclear factor-kappa B expression in mice with viral encephalitis, and showed significant decreases in nuclear factor-kappa B protein and mRNA levels following Shuanghuanglian injection. The inhibitory effect was more significant with prolonged intervention duration and increased treatment dose. These findings verify that Shuanghuanglian injection plays a therapeutic role in viral encephalitis by reducing expression of nuclear factor-kappa B in a time- and dose-dependent manner.

Increased Expression and Activity of MMP-9 in C-reactive Protein-induced Human THP-1 Mononuclear Cells Is Related to Activation of Nuclear Factor Kappa-B

The relation between the expression and activity of MMP-9 in C-reactive protein （CRP）-induced human THP-1 mononuclear cells and the activation of nuclear factor kappa-B （NF-κB） was studied to investigate the possible role of CRP in plaque destabilization. Human THP-1 cells were incubated in the presence of CRP at 0 （control group）, 25, 50 and 100 μg/mL （CRP groups） for 24 h. In PDTC （a specific NF-κB inhibitor） group, the cells were pre-treated with PDTC at 10 μmol/L and then with 100 μg/mL CRP. The conditioned media （CM） and human THP-1 cells in different groups were harvested. MMP-9 expression in CM and human THP-1 cells was measured by ELISA and Western blotting. MMP-9 activity was assessed by fluorogenic substrates. The expression of NF-κB inhibitor α （IκB-α） and NF-κB p65 was detected by Western blotting and ELISA respectively. The results showed that CRP increased the expression and activity of MMP-9 in a dose-dependent manner in the human THP-1 cells. Western blotting revealed that IiB-α expression was decreased in the cells with the concentrations of CRP and ELISA demonstrated that NF-κB p65 expression in the CRP-induced cells was increased. After pre-treatment of the cells with PDTC at 10 μmol/L, the decrease in IκB-α expression and the increase in NF-κB p65 expression in the CRP-induced cells were inhibited, and the expression and activity of MMP-9 were lowered too. It is concluded that increased expression and activity of MMP-9 in CRP-induced human THP-1 cells may be associated with activation of NF-κB. Down-regulation of the expression and activity of MMP-9 may be a new treatment alternative for plaque stabilization by inhibiting the NF-κB activation.

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.

Effect of Nuclear Factor-kappa B on Vascular Endothelial Growth Factor mRNA Expression of Human Pulmonary Artery Smooth Muscle Cells in Hypoxia

In order to investigate the effect of nuclear factor kappa B (NF κB) on vascular endothelial growth factor (VEGF) mRNA expression of human pulmonary artery smooth muscle cells (HPASMCs) in hypoxia, the cultured HPASMCs in vitro were stimulated with pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF κB. The NF κB p65 nuclei positive expression was detected by immunocytochemical technique. The IκBα protein expression was measured by Western blot. RT PCR was used to detect the VEGF mRNA expression of HPASMCs. The results showed that no significant change was observed in the NF κB p65 nuclei positive expression of cultured HPASMCs during 6 h-24 h in normoxia, but the levels of NF κB p65 nuclei positive expression of cultured HPASMCs were significantly increased in hypoxia groups as compared with those in all normoxia groups ( P <0.05). The IκBα protein expression of cultured HPASMCs showed no significant change during 6 h-24 h in normoxia, but significantly decreased in hypoxia as comapred with that in normoxia groups ( P <0.05). PDTC (1 to 100 μmol/L) could inhibit the VEGF mRNA expression of HPASMCs in a concentration dependent manner in hypoxia. In conclusion, NF κB can be partly translocation activated from cytoplasm into nuclei in the cultured HPASMCs under hypoxia. The inhibition of NF κB activation can decrease the VEGF mRNA expression. It is suggested that the activation of NF κB is involved in the VEGF mRNA expression of HPASMCs under hypoxia.

Effects of Five Chitosan Oligosaccharides on Nuclear Factor-kappa B Signaling Pathway

The effects of five chito-oligomers, from dimer to hexamer （chitobiose, chitotriose, chitotetraose, chitopentaose, chitohexaose） separated from chitosan oligosaccharides, on nuclear factor -kappaB （NF-rd3） signaling pathway were investigated by using luciferase assay and laser scanning microscopy. The expression of NF-rd3 downstream genes （cyclin DI, TNFa and IL-6） were tested by real time PCR. We found that all five chitosan oligosaccharides increased NF-KB-dependent luciferase gene expression and NF-KB downstream genes transcription, and the most significant were chitotetraose and chitohexaose. In addition, laser scanning microscopy experiments showed that chitotetraose and chitohexaose also activated the p65 subunite of NF-kB translocating from cytoplasm to nucleus, which suggested that they were the most potent activators of NF-kB signaling pathway.

Treatment of COVID-19 by Controlling the Activity of the Nuclear Factor-Kappa B

Heavy infection of the virus leads to overproduction of cytokines. The overproduction of cytokine (cytokines storms) is responsible for the critical cases and deaths of COVID-19. The nuclear factor kappa-B stimulates the expression of the genes, which is responsible for cytokines storm and RNA transcription. The COVID-19 virus can be controlled by inhibition of nuclear factor kappa-B. Nuclear factor kappa-B is controlled by inhibition of hydrogen peroxide and inhibitor kappa-B kinase enzyme.