Pharmacological targeting cGAS/STING/NF-κB axis by tryptanthrin induces microglia polarization toward M2 phenotype and promotes functional recovery in a mouse model of spinal cord injury

The M1/M2 phenotypic shift of microglia after spinal cord injury plays an important role in the regulation of neuroinflammation during the secondary injury phase of spinal cord injury.Regulation of shifting microglia polarization from M1(neurotoxic and proinflammatory type)to M2(neuroprotective and anti-inflammatory type)after spinal cord injury appears to be crucial.Tryptanthrin possesses an anti-inflammatory biological function.However,its roles and the underlying molecular mechanisms in spinal cord injury remain unknown.In this study,we found that tryptanthrin inhibited microglia-derived inflammation by promoting polarization to the M2 phenotype in vitro.Tryptanthrin promoted M2 polarization through inactivating the cGAS/STING/NF-κB pathway.Additionally,we found that targeting the cGAS/STING/NF-κB pathway with tryptanthrin shifted microglia from the M1 to M2 phenotype after spinal cord injury,inhibited neuronal loss,and promoted tissue repair and functional recovery in a mouse model of spinal cord injury.Finally,using a conditional co-culture system,we found that microglia treated with tryptanthrin suppressed endoplasmic reticulum stress-related neuronal apoptosis.Taken together,these results suggest that by targeting the cGAS/STING/NF-κB axis,tryptanthrin attenuates microglia-derived neuroinflammation and promotes functional recovery after spinal cord injury through shifting microglia polarization to the M2 phenotype.

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 Transcription Factor-кB in Endotoxin induced Shock in Rats

Summary: To investigate the role of NF-κB in endotoxic shock in rats, the model of endotoxin-shock rats was induced by intravenous infusion of lipopolysaccharide (LPS). 1 h, 2 h, 4 h and 6 h after LPS injection, the activation of NF-κB in blood mononuclear cells and the content of TNF-α and IL-6 in plasma was detected by enzyme-linked immunoadsordent assay (ELISA). The level of mean arterial pressure (MAP) and the histopathological changes of lung and liver were also observed. The activation of NF-κB in mononuclear cells increased 1 h after LPS injection and reached its peak 2 h after the injection, and its level was higher than that of normal group. The level of TNF-α was increased 1 h after the infusion and peaked 2 h after the injection, and its level was higher than that of normal group after LPS infusion. The content of IL-6 increased gradually with time, the IL-6 level was higher than that of normal group after LPS injection. MAP was decreased gradually with time and its level was lower than that of normal group after LPS injection. Pathological examination showed that endotoxic shock could cause pulmonary alveolar hemorrhage, edema and infiltration of inflammatory cell in lung tissue and congestion, edema, capillary dilation and inflammatory cell infiltration in liver tissue. It is concluded that NF-κB can up-regulate the expression of TNF-α and IL-6 in plasma and play an important role in endotoxin-induced shock in rats.

Silencing of Jumonji domain-containing 1C inhibits the osteogenic differentiation of bone marrow mesenchymal stem cells via nuclear factor-κB signaling

BACKGROUND Osteoporosis is a common metabolic bone disorder induced by an imbalance between osteoclastic activity and osteogenic activity.During osteoporosis,bone mesenchymal stem cells(BMSCs)exhibit an increased ability to differentiate into adipocytes and a decreased ability to differentiate into osteoblasts,resulting in bone loss.Jumonji domain-containing 1C(JMJD1C)has been demonstrated to suppress osteoclastogenesis.AIM To examine the effect of JMJD1C on the osteogenesis of BMSCs and the potential underlying mechanism.METHODS BMSCs were isolated from mouse bone marrow tissues.Oil Red O staining,Alizarin red staining,alkaline phosphatase staining and the expression of adipo-genic and osteogenic-associated genes were assessed to determine the differen-tiation of BMSCs.Bone marrow-derived macrophages(BMMs)were incubated with receptor activator of nuclear factor-kappaΒligand to induce osteoclast differentiation,and osteoclast differen-tiation was confirmed by tartrate-resistant acid phosphatase staining.Other related genes were measured via reverse transcription coupled to the quantitative polymerase chain reaction and western blotting.Enzyme-linked immunosorbent assays were used to measure the levels of inflammatory cytokines,including tumor necrosis factor alpha,interleukin-6 and interleukin-1 beta.RESULTS The osteogenic and adipogenic differentiation potential of BMSCs isolated from mouse bone marrow samples was evaluated.JMJD1C mRNA and protein expression was upregulated in BMSCs after osteoblast induction,while p-nuclear factor-κB(NF-κB)and inflammatory cytokines were not significantly altered.Knockdown of JMJD1C repressed osteogenic differentiation and enhanced NF-κB activation and inflammatory cytokine release in BMSCs.Moreover,JMJD1C expression decreased during BMM osteoclast differentiation.CONCLUSION The JMJD1C/NF-κB signaling pathway is potentially involved in BMSC osteogenic differentiation and may play vital roles in the pathogenesis of osteoporosis.

五味子乙素通过TLR4/NF-κB信号通路对急性胰腺炎大鼠肺部损伤的影响

目的:探讨五味子乙素通过Toll样受体4(TLR4)/核转录因子-κB(NF-κB)信号通路对急性胰腺炎(AP)大鼠肺部损伤的影响。方法:取SD大鼠,通过胆胰管内逆行注射5%牛磺胆酸钠方法诱导建立AP肺损伤模型,经随机数表法分为模型组、五味子乙素组、TLR4过表达载体组、TLR4空载组、五味子乙素+TLR4过表达载体组,每组12只大鼠,再取12只SD大鼠仅翻动肠管不注射5%牛磺胆酸钠,作为假手术组。以药物分别干预大鼠后,检测各组大鼠肺功能及各组大鼠腹水量与肺组织湿重/干重(W/D);HE染色检测各组大鼠肺组织病理形态并评分;检测各组大鼠动脉血气;全自动生化分析仪检测大鼠血清淀粉酶,ELISA检测炎症细胞因子IL-6、IL-18水平;蛋白免疫印迹法检测肺组织TLR4/NF-κB通路蛋白表达;免疫组织化学染色检测肺组织TLR4蛋白表达。结果:与假手术组相比,模型组大鼠肺组织出现病理损伤改变,模型组大鼠MV、PEF、PaO_(2)、OI显著降低(P<0.05),Ri、腹水量与W/D、PaCO_(2)、Holfbauer评分、血清淀粉酶、IL-6与IL-18水平、肺组织TLR4阳性细胞比例、TLR4与MYD88蛋白表达、p-NF-κB p65/NF-κB p65水平显著升高(P<0.05)。与模型组、五味子乙素+TLR4过表达载体组分别相比,五味子乙素组大鼠肺组织病理损伤改变程度均减轻,MV、PEF、PaO_(2)、OI均升高(P<0.05),Ri、腹水量与W/D、PaCO_(2)、Holfbauer评分、血清淀粉酶、IL-6与IL-18水平、肺组织TLR4阳性细胞比例、TLR4与MYD88蛋白表达、p-NF-κB p65/NF-κB p65水平均降低(P<0.05);TLR4过表达载体组大鼠肺组织病理损伤改变程度均加重,MV、PEF、PaO_(2)、OI均降低(P<0.05),Ri、腹水量与W/D、PaCO_(2)、Holfbauer评分、血清淀粉酶、IL-6与IL-18水平、肺组织TLR4阳性细胞比例、TLR4与MYD88蛋白表达、p-NF-κB p65/NF-κB p65水平均升高(P<0.05)。与模型组相比,TLR4空载组大鼠各指标差异无统计学意义(P>0.05)。结论:五味子乙素可通过下调TLR4/NF-κB信号通路,抑制炎症,减轻AP大鼠肺部损伤,修复肺功能。

A Nonradioactive Method for Detecting DNA-binding Activity of Nuclear Transcription Factors

To determine the feasibility of a nonradioactive electrophoresis mobility shift assay for detecting nuclear transcription factor, double-stranded oligonucleotides encoding the consensus target sequence of NF-κB were labled with DIG by terminal transferase After nuclear protein stimulated with phorbol 12-myristate 13-acetate (PMA) or PMA and pyrrolidine dithiocarbamate (PDTC) electrophoresed on 8 % nondenaturing poliacrylamide gel together with oligeonucleotide probe, they were electro-blotted nylon membrane positively charged Anti-DIG-AP antibody catalyzed chemiluminescent substrate CSPD to image on X-film The results showed that nuclear proteins binded specifically to the NF-κB consensus sequence in the EMSA by chemiluminescent technique method and the activity of NF-κB in PMA group was more than that in PMA+PDTC group It is suggested that detection of NF-κB by EMSA with chemiluminescent technique is feasible and simple, which can be performed in ordinary laboratories

中药单体治疗脊髓损伤后神经炎症:核转录因子κB信号通路的作用

背景:基于核转录因子κB通路探究神经炎症的靶向治疗越来越值得探究,中药靶点多、范围广、机制丰富及不良反应少等优点在治疗各类疾病时都具有十分巨大的潜力。目的:基于核转录因子κB信号通路,对近年研究中出现的山奈酚、红花黄、汉黄芩苷及雷公藤甲素等中药单体治疗脊髓损伤后神经炎症的研究进展进行系统的阐述与归纳。方法:以“脊髓损伤,炎症,抗炎,中药单体,单体化合物,NF-κB信号通路,黄酮,糖苷,酚类,酯类,生物碱”为检索词在中国知网数据库中进行检索;以“Spinal cord injury,inflammation,anti-inflammatory,traditional Chinese medicine monomer,monomeric compound,NF-κB signaling pathway,flavonoids,glycosides,phenols,esters,alkaloids”为检索词在PubMed数据库中进行检索,最终共纳入67篇文献进行综述分析。结果与结论:①核转录因子κB信号通路在神经系统中的作用复杂多样,能够调控中性粒细胞、小胶质细胞、星形胶质细胞和巨噬细胞等,介导损伤后炎症的发生与发展;②中药单体如汉黄芩苷对核转录因子κB抑制蛋白的降解、红花黄素对核转录因子κB信号通路磷酸化过程的抑制、山奈酚对核转录因子κB信号通路p65核易位的抑制等作用可以降低炎症反应对机体造成的影响,从而促进神经功能恢复;③核转录因子κB信号通路在损伤早期能够促进炎症反应和免疫细胞迁移活化,在损伤中后期能够促进损伤部位的修复和纤维化的发生等,适当的激活核转录因子κB信号通路具有促进炎症因子的释放、提高细胞的抗氧化能力及促进免疫细胞的活化等能力,但过度激活的核转录因子κB信号通路则容易导致慢性炎症的发生和持续、细胞凋亡受到抑制等;④未来的研究可以进一步探索如何准确调控核转录因子κB信号通路的活化水平、如何实现对神经系统炎症和损伤的精准干预展开,也可围绕中药单体的制备及中药单体对信号通路的作用机制展开,以期为神经系统疾病的康复和功能恢复提供更有效的治疗策略。

Apigenin ameliorates imiquimod-induced psoriasis in C57BL/6J mice by inactivating STAT3 and NF-κB

Psoriasis is a chronic autoimmune disease featured by patches on the skin.It is caused by malfunction of immune cells and keratinocytes with inflammation as one of its key features.Apigenin(API)is a natural flavonoid with anti-inflammatory and immunoregulatory properties.Therefore,we speculated that API can ameliorate psoriasis,and determined its effect on the development of psoriasis by using imiquimod(IMQ)-induced psoriasis mouse model.Our results showed that API attenuated IMQ-induced phenotypic changes,such as erythema,scaling and epidermal thickening,and improved splenic hyperplasia.Abnormal differentiation of immune cells was restored in API-treated mice.Mechanistically,we revealed that API is a key regulator of signal transducer activator of transcription 3(STAT3).API regulated immune responses by reducing interleukin-23(IL-23)/STAT3/IL-17A axis.Moreover,it suppressed IMQ-caused cell hyperproliferation by inactivating STAT3 through regulation of extracellular signal-regulated kinase 1/2 and nuclear factor-κB(NF-κB)pathway.Furthermore,API reduced expression of inflammatory cytokines through inactivation of NF-κB.Taken together,our study demonstrates that API can ameliorate psoriasis and may be considered as a strategy for psoriasis treatment.

山姜素调控PI3K/Akt/NF-κB信号通路对冠心病大鼠心肌损伤的影响

目的:探讨山姜素调控磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(Akt)/核转录因子-κB(NF-κB)信号通路对冠心病(CHD)大鼠心肌损伤的影响。方法:选取健康成年SPF级SD雄性大鼠60只,随机分为空白组、模型组、山姜素小剂量组、山姜素中剂量组、山姜素高剂量组各12只,采用Western blot法检测大鼠PI3K/Akt/NF-κB信号通路蛋白表达,采用ELISA法检测大鼠炎症因子指标[肿瘤坏死因子α(TNF-α)、白介素-1β(IL-1β)、白介素-18(IL-18)]和氧化应激指标[活性氧(ROS)、谷胱甘肽过氧化物酶(GSH-Px)、丙二醛(MDA)],观察并记录大鼠心肌损伤情况。结果:与空白组比较,模型组的心肌缺血和心肌梗死面积更大(P<0.05),与模型组比较,山姜素小、中、高剂量组的心肌缺血和心肌梗死面积均缩小(P<0.05),且高剂量组的心肌缺血和心肌梗死面积小于山姜素中、小剂量组,中剂量组心肌缺血和心肌梗死面积小于山姜素小剂量组(P<0.05)。与空白组比较,模型组的PI3K、Akt、NF-κB更高(P<0.05),与模型组比较,山姜素小、中、高剂量组的PI3K、Akt、NF-κB均升高(P<0.05),且高剂量组的PI3K、Akt、NF-κB高于山姜素中、小剂量组,中剂量组PI3K、Akt、NF-κB高于山姜素小剂量组(P<0.05)。与空白组比较,模型组的TNF-α、IL-1β、IL-18更高(P<0.05),与模型组比较,山姜素小、中、高剂量组的TNF-α、IL-1β、IL-18均降低(P<0.05),且山姜素高剂量组的TNF-α、IL-1β、IL-18低于中、小剂量组,山姜素中剂量组的TNF-α、IL-1β、IL-18低于山姜素小剂量组(P<0.05)。与空白组比较,模型组的ROS、GSH-Px、MDA更高(P<0.05),与模型组比较,山姜素小、中、高剂量组的ROS、GSH-Px、MDA均降低(P<0.05),且山姜素高剂量组ROS、GSH-Px、MDA低于山姜素中、小剂量组,山姜素中剂量组的ROS、GSH-Px、MDA低于山姜素小剂量组(P<0.05)。结论:山姜素可通过调控PI3K/Akt/NF-κB信号通路改善CHD大鼠心肌炎症和氧化应激状况,进而发挥心肌保护作用。

N-acetylserotonin alleviates retinal ischemia-reperfusion injury via HMGB1/RAGE/NF-κB pathway in rats

AIM:To observe the effects of N-acetylserotonin(NAS)administration on retinal ischemia-reperfusion(RIR)injury in rats and explore the underlying mechanisms involving the high mobility group box 1(HMGB1)/receptor for advanced glycation end-products(RAGE)/nuclear factor-kappa B(NF-κB)signaling pathway.METHODS:A rat model of RIR was developed by increasing the pressure of the anterior chamber of the eye.Eighty male Sprague Dawley were randomly divided into five groups:sham group(n=8),RIR group(n=28),RIR+NAS group(n=28),RIR+FPS-ZM1 group(n=8)and RIR+NAS+FPS-ZM1 group(n=8).The therapeutic effects of NAS were examined by hematoxylin-eosin(H&E)staining,and retinal ganglion cells(RGCs)counting.The expression of interleukin 1 beta(IL-1β),HMGB1,RAGE,and nod-like receptor 3(NLRP3)proteins and the phosphorylation of nuclear factorkappa B(p-NF-κB)were analyzed by immunohistochemistry staining and Western blot analysis.The expression of HMGB1 protein was also detected by enzyme-linked immunosorbent assay(ELISA).RESULTS:H&E staining results showed that NAS significantly reduced retinal edema and increased the number of RGCs in RIR rats.With NAS therapy,the HMGB1 and RAGE expression decreased significantly,and the activation of the NF-κB/NLRP3 pathway was antagonized along with the inhibition of p-NF-κB and NLRP3 protein expression.Additionally,NAS exhibited an anti-inflammatory effect by reducing IL-1βexpression.The inhibitory of RAGE binding to HMGB1 by RAGE inhibitor FPS-ZM1 led to a significant decrease of p-NF-κB and NLRP3 expression,so as to the IL-1βexpression and retinal edema,accompanied by an increase of RGCs in RIR rats.CONCLUSION:NAS may exhibit a neuroprotective effect against RIR via the HMGB1/RAGE/NF-κB signaling pathway,which may be a useful therapeutic target for retinal disease.

红景天苷通过NF-κB/Bcl-2信号通路对重症肺炎大鼠肺血管内皮细胞凋亡及IL-23、Th17表达的影响

目的:探讨红景天苷通过核转录因子(NF-κB)/B淋巴细胞瘤2(Bcl-2)信号通路对重症肺炎大鼠肺血管内皮细胞(PVECs)凋亡及白介素-23(IL-23)、辅助性T细胞17(Th17)表达的影响。方法:将50只大鼠随机分为假手术组、模型组、红景天苷组、抑制剂组、红景天苷+抑制剂组五组,每组10只。除假手术组外,均建立重症肺炎大鼠模型。造模成功后红景天苷组大鼠腹腔注射红景天苷(100 mg/kg);抑制剂组大鼠腹腔注射NF-κB抑制剂喹唑啉化合物(EVP4593)(5 mg/kg);红景天苷+抑制剂组大鼠腹腔注射红景天苷(200 mg/kg)+EVP4593(3 mg/kg);假手术组、模型组腹腔注射等容积的0.9%氯化钠溶液。所有大鼠持续干预7 d后使用酶联免疫吸附测定法(ELISA法)检测各组大鼠血清中白介素(IL)-17、IL-23,流式细胞术检测血清中Th17细胞比例,HE染色观察肺组织病理形态,免疫印记检测大鼠肺组织中NF-κB/Bcl-2蛋白表达。取肺组织进行PVECs培养并检测第2代PVECs的增殖率及凋亡率。结果:与假手术组相比,各建模组大鼠血清中IL-23、IL-17、Th17细胞比例,肺组织中NF-κB/Bcl-2蛋白表达以及PVECs凋亡率均明显升高,PVECs增殖率明显降低(P<0.05),肺组织病变严重;与模型组相比,红景天苷组、抑制剂组、红景天苷+抑制剂组大鼠血清中IL-23、IL-17、Th17细胞比例,肺组织中NF-κB/Bcl-2蛋白表达以及PVECs凋亡率均明显降低,PVECs增殖率明显升高(P<0.05),肺组织病变有所好转;与红景天苷组、抑制剂组相比,红景天苷+抑制剂组大鼠血清中IL-23、IL-17、Th17细胞比例,肺组织中NF-κB/Bcl-2蛋白表达以及PVECs凋亡率均明显降低,PVECs增殖率明显升高(P<0.05),肺组织形态基本恢复正常;红景天苷组与抑制剂组相比,血清中IL-23、IL-17、Th17细胞比例、肺组织中NF-κB/Bcl-2蛋白表达、PVECs凋亡/增殖率以及肺组织形态差异无统计学意义(P>0.05)。结论:红景天苷可通过降低NF-κB/Bcl-2水平调节重症肺炎大鼠IL-23/Th17平衡,并有效抑制PVECs凋亡。

Hepatitis B virus X protein up-regulates tumor necrosis factor-α expression in cultured mesangial cells via ERKs and NF-κB pathways

Objective:To investigate the effects of hepatitis B virus(HBV)X protein(HBx)on the expression of tumor necrosis factor-α(TNF-α)in glomerular mesangial cells(GMCs)and the underlying intracellular signal pathways.Methods:The plasmid pCI-neo-X that carries the X gene of hepatitis B virus was transfected into cultured GMCs.HBx expression in the transfected GMCs was assessed by Western-blot.TNF-αprotein and mRNA were assessed by ELISA and semi-quantitative RT-PCR,respectively.Three kinase inhibitors-U0126,an inhibitor of extracellular signal-regulated kinases(ERKs);lactacvstin,an inhibitor of nuclear factor-κB(NF-κB);and SB203580,a selective inhibitor of p38 MAP kinase(p38 MAPK)were used to determine which intracellular signal pathways may underlie the action of HBx on TNF-αexpression in transfected GMCs.Results:A significant increase in HBx expression in pCI-neo-X transfected GMCs was detected at 36 h and 48 h,which was not affected by any of those kinase inhibitors mentioned above.A similar increase in the expression of both TNF-αprotein and mRNA was also observed at 36 h and 48 h,which was significantly decreased in the presence of U0126 or lactacytin,but not SB203580.Conclusions:HBx upregulates TNF-αexpression in cultured GMCs,possibly through ERKs and NF-κB pathway,but not p38 MAPK pathway.

Jianpi Qingchang decoction alleviates ulcerative colitis by inhibiting nuclear factor-κB activation

To investigate the therapeutic effect of Jianpi Qingchang decoction (JPQCD) on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice.METHODSC57BL/c mice were injected intragastrically with 5% DSS instead of drinking water for 7 d, and their body weight, diarrhea severity and fecal bleeding were monitored, while the mice in the control group were treated with standard drinking water, without DSS. After 7 d, the DSS drinking water was changed to normal water and the DSS group continued with DSS water. The control and DSS groups were given normal saline by intragastric injection. The 5-aminosalicylic acid (5-ASA) group was treated orally with 5-ASA at a dose of 100 mg/kg daily. The JPQCD group was treated orally with JPQCD at a dose of 17.1 g/kg daily. On day 14, the colon length was measured, the colorectal histopathological damage score was assessed, and protein levels of interleukin (IL)-1β, IL-8 and tumor necrosis factor-alpha (TNF-α) in colon supernatants were measured by enzyme-linked immunosorbent assay. mRNA expression of IL-1β, IL-8, TNF-α and nuclear factor-kappa B (NF-κB) was detected by real-time quantitative polymerase chain reaction. Western blotting was used to detect the protein expression of NF-κB and inhibitor of kappa B.RESULTSAcute inflammation occurred in the mice administered DSS, including the symptoms of losing body weight, loose feces/watery diarrhea and presence of fecal blood; all these symptoms worsened at 7 d. The colons of mice treated with DSS were assessed by histological examination, and the results confirmed that acute inflammation had occurred, as evidenced by loss of colonic mucosa and chronic inflammatory cell infiltration, and these features extended into the deeper layer of the colon walls. The expression levels of IL-1β, IL-8 and TNF-α in the DSS group were higher than those in the control group (P < 0.05), and the expression levels of IL-1β, IL-8 and TNF-α in the JPQCD and 5-ASA groups were lower than those in the DSS group after treating with JPQCD and 5-ASA. Comparing with the DSS group, the mRNA level of IL-1β, IL-8, TNF-α and NF-κB was significantly reduced by 5-ASA and JPQCD. The difference between JPQCD and 5-ASA groups was not statistically significant (P > 0.05). Comparing with the DSS group, due to using JPQCD and 5-ASA, significant suppression of activation in DSS-induced NF-κB and increased phosphorylation of IκB in mice with experimental colitis occurred (P < 0.05). The difference between the JPQCD group and the 5-ASA group was not statistically significant (P > 0.05).CONCLUSIONActivation of the NF-κB signaling pathway is inhibited by JPQCD, which shows the potential mechanism by which JPQCD treats UC.

Blocking NF-kB nuclear translocation leads to p53-related autophagy activation and cell apoptosis

AIM: To investigate the anti-tumor effects of nuclear factor-κB (NF-κB) inhibitor SN50 and related mechanisms of SGC7901 human gastric carcinoma cells. METHODS: MTT assay was used to determine the cytotoxic effects of SN50 in gastric cancer cell line SGC7901. Hoechst 33258 staining was used to detect apoptosis morphological changes after SN50 treatment. Activation of autophagy was monitored with monodansylcadaverine (MDC) staining after SN50 treatment.Immunofluorescence staining was used to detect the expression of light chain 3 (LC3). Mitochondrial membrane potential was measured using the fluorescent probe JC-1. Western blotting analysis were used to determine the expression of proteins involved in apoptosis and autophagy including p53, p53 upregulated modulator of apoptosis (PUMA), damage-regulated autophagy modulator (DRAM), LC3 and Beclin 1. We detected the effects of p53-mediated autophagy activation on the apoptosis of SGC7901 cells with the p53 inhibitor pifithrin-α. RESULTS: The viability of SGC7901 cells was inhibited after SN50 treatment. Inductions in the expression of apoptotic protein p53 and PUMA as well as autophagic protein DRAM, LC3 and Beclin 1 were detected with Western blotting analysis. SN50-treated cells exhibited punctuate microtubule-associated protein 1 LC3 in immunoreactivity and MDC-labeled vesicles increased after treatment of SN50 by MDC staining. Collapse of mitochondrial membrane potential Δψ were detected for 6 to 24 h after SN50 treatment. SN50-induced increases in PUMA, DRAM, LC3 and Beclin 1 and cell death were blocked by the p53 specific inhibitor pifithrin-α. CONCLUSION: The anti-tumor activity of NF-κB inhibitors is associated with p53-mediated activation of autophagy.

Propofol induces apoptosis and increases gemcitabine sensitivity in pancreatic cancer cells in vitro by inhibition of nuclear factor-κ B activity

AIM:To investigate the effect of propofol on human pancreatic cells and the molecular mechanism of propofol action.METHODS:We used the human pancreatic cancer cell line MIAPaCa-2 for in vitro studies measuring growth inhibition and degree of apoptotic cell death induced by propofol alone,gemcitabine alone,or propofol followed by gemcitabine.All experiments were conducted in triplicate and carried out on three or more separate occasions.Data were means of the three or more independent experiments±SE.Statistically significant differences were determined by two-tailed unpaired Student’s t test and defined as P<0.05.RESULTS:Pretreatment of cells with propofol for 24 h followed by gemcitabine resulted in 24%-75% growth inhibition compared with 6%-18%when gemcitabine was used alone.Overall growth inhibition was directly correlated with apoptotic cell death.We also showed that propofol potentiated gemcitabine-induced killing by downregulation of nuclear factor-κB(NF-κB).In contrast,NF-κB was upregulated when pancreatic cancer cells were exposed to gemcitabine alone,suggesting a potential mechanism of acquired chemoresistance.CONCLUSION:Inactivation of the NF-κB signaling pathway by propofol might abrogate gemcitabineinduced activation of NF-κB,resulting in chemosensitization of pancreatic tumors to gemcitabine.

Total polysaccharides of the Sijunzi decoction attenuate tumor necrosis factor-α-induced damage to the barrier function of a Caco-2 cell monolayer via the nuclear factor-κB-myosin light chain kinase-myosin light chain pathway

AIM To explore the protective effects and underlying mechanisms of total polysaccharides of the Sijunzi decoction(TPSJ) on the epithelial barriers in vitro. METHODS Caco-2 cell monolayers were treated with or without TPSJ in the presence or absence of TNF-α, and paracellular permeability and transepithelial electrical resistance(TEER) were measured to evaluate the epithelial barrier function. Immunofluorescence and western blotting were respecti-vely used to evaluate the distribution and expression of the tight junction proteins claudin 1, claudin 2, zo3, and occludin in Caco-2 cells. western blotting was also used to evaluate the cellular expression of myosin light chain(MLC), phosphorylated MLC(pM LC), MLC kinase(MLCK), and nuclear factor(NF)-κB p65. RESULTS TPSJ promoted the proliferation of Caco-2 cells and inhibited TNF-α-induced secretion of pro-inflammatory cyto-kines. Furthermore, TPSJ significantly ameliorated both the reduction of TEER and the increased paracellular permeability observed in tumor necrosis factor(TNF)-α-damaged Caco-2 monolayers. Furthermore, TPSJ remarkably attenuated TNF-α-induced morphological changes, downregulated the expression of claudin 1, claudin 2, zo3, and occludin, and markedly suppressed TNF-α-mediated upregulation of p-MLC and MLCK expression. Finally, TPSJ inhibited the activation and expression of NF-κB p65. CONCLUSION Our results demonstrate that TPSJ alleviates the TNF-α-induced impairment of the intestinal epithelial cell barrier function by suppressing NF-κB p65-mediated phosphorylation of MLCK and MLC.

Helicobacter pylori tumor necrosis factor-α inducing protein promotes cytokine expression via nuclear factor-κB

AIM:To study the effects of Helicobacter pylori(H. pylori)tumor necrosis factor-α(TNF)inducing protein (Tip-α)on cytokine expression and its mechanism. METHODS:We cloned Tip-αfrom the H.pylori strain 26695,transformed Escherichia coli with an expression plasmid,and then confirmed the expression product by Western blotting.Using different concentrations of Tip-αthat affected SGC7901 and GES-1 cells at different times,we assessed cytokine levels using enzyme-linked immunosorbent assay.We blocked SGC7901 cells with pyrrolidine dithiocarbamate(PDTC),a specific inhibitor of nuclear factorκB(NF-κB).We then detected interleukin(IL)-1βand TNF-αlevels in SGC7901 cells. RESULTS:Western blot analysis using an anti-Tip-α antibody revealed a 23-kDa protein,which indicated that recombinant Tip-αprotein was recombined successfully.The levels of IL-1β,IL-8 and TNF-αwere sig-nificantly higher following Tip-αinterference,whether GES-1 cells or SGC-7901 cells were used(P<0.05).However,the levels of cytokines(including IL-1β,IL-8 and TNF-α)secreted by SGC-7901 cells were greater than those secreted by GES-1 cells following treatment with Tip-αat the same concentration and for the same duration(P<0.05).After blocking NF-κB with PDTC, the cells(GES-1 cells and SGC-7901 cells)underwent interference with Tip-α.We found that IL-1βand TNF-αlevels were significantly decreased compared to cells that only underwent Tip-αinterference(P<0.05). CONCLUSION:Tip-αplays an important role in cyto-kine expression through NF-κB.

Clinicopathologic significance of expression of nuclear factor-kB RelA and its target gene products in gastric cancer patients

AIM:To assess the prognostic significance of nuclear factor-kB (NF-kB) and its target genes in gastric cancer. METHODS:The tumor tissues of 115 patients with gastric cancer were immunohistochemically evaluated using monoclonal antibodies against NF-kB RelA. Preoperative serum levels of vascular endothelial growth factor (VEGF), interleukin-6 (IL-6) were assessed via enzyme-linked immuno-sorbent assay. C-reactive protein (CRP) and serum amyloid A (SAA) were measured via immunotrubidimetry. RESULTS:Positive rate of NF-kB RelA was 42.6%. NF-kB RelA expression in tumor tissues was also related to serum levels of IL-6 (P = 0.044) and CRP (P = 0.010). IL-6, SAA, CRP were related to depth of invasion, VEGF and SAA were correlated with lymph node metastasis. IL-6, VEGF, SAA and CRP were related to the stage. Univariate analysis demonstrated that immunostaining of NF-kB RelA, levels of IL-6, VEGF, SAA were significantly related with both disease free survival and over-all survival (OS). Multivariate analysis verified that NF-kB RelA [hazard ratio (HR): 3.40, P = 0.024] and SAA (HR: 3.39, P = 0.045) were independently associated with OS. CONCLUSION: Increased expression of NF-kB RelA and high levels of serum SAA were associated with poor OS in gastric cancer patients.

Effects of ω-3 fatty acids on toll-like receptor 4 and nuclear factor-κB p56 in lungs of rats with severe acute pancreatitis

AIM To determine the effects of ω-3 fatty acids(ω-3FA) on the toll-like receptor 4(TLR4)/nuclear factor κB p56(NF-κBp56) signal pathway in the lungs of rats with severe acute pancreatitis(SAP).METHODS A total of 56 Sprague-Dawley rats were randomly divided into 4 groups: control group, SAP-saline group, SAP-soybean oil group and SAP-ω-3FA group. SAP was induced by the retrograde infusion of sodium taurocholate into the pancreatic duct. The expression of TLR4 and NF-κBp56 in the lungs was evaluated by immunohistochemistry and Western blot analysis. The levels of inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha in the lungs were measured by enzyme-linked immunosorbent assay. RESULTS The expression of TLR4 and NF-κBp56 in lungs and of inflammatory cytokines in serum significantly increased in the SAP group compared with the control group(P < 0.05), but was significantly decreased in the ω-3FA group compared with the soybean oil group at 12 and 24 h(P < 0.05).CONCLUSION During the initial stage of SAP, ω-3FA can efficiently lower the inflammatory response and reduce lung injury by triggering the TLR4/NF-κBp56 signal pathway.

Lysophosphatidic acid induced nuclear translocation of nuclear factor-κB in Panc-1 cells by mobilizing cytosolic free calcium

AIM: To clarify whether Lysophosphatidic acid (LPA) activates the nuclear translocation of nuclear factor-κB (NF-κB) in pancreatic cancer. METHODS: Panc-1, a human pancreatic cancer cell line, was used throughout the study. The expression of LPA receptors was confirmed by reverse-transcript polymerase chain reaction (RT-PCR). Cytosolic free calcium was measured by fluorescent calcium indicator fura-2, and the localization of NF-κB was visualized by immunofluorescent method with or without various agents, which effect cell signaling. RESULTS: Panc-1 expressed LPA receptors, LPA1, LPA2 and LPA3. LPA caused the elevation of cytosolic free calcium dose-dependently. LPA also caused the nuclear translocation of NF-κB. Cytosolic free calcium was attenuated by pertussis toxin (PTX) and U73122, an inhibitor of phospholipase C. The translocation of NF-κB was similarly attenuated by PTX and U73122, but phorbol ester, an activator of protein kinase C, alone did not translocate NF-κB. Furthermore, the translocation of NF-κB was completely blocked by Ca2+ chelator BAPTA-AM. Thapsigargin, an endoplasmic- reticulum Ca2+-ATPase pump inhibitor, also promoted the translocation of NF-κB. Staurosporine, a proteinkinase C inhibitor, attenuated translocation of NF-κB induced by LPA. CONCLUSION: These findings suggest that protein kinase C is activated endogenously in Panc-1, and protein kinase C is essential for activating NF-κB with cytosolic calcium and that LPA induces the nuclear translocation of NF-κB in Panc-1 by mobilizing cytosolic free calcium.