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.

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.

Atsttrin reduces lipopolysaccharide-induced neuroinflammation by inhibiting the nuclear factor kappa B signaling pathway

Progranulin is closely related to neuronal survival in a neuroinflammatory mouse model and attenuates inflammatory reactions. Atsttrin is an engineered protein composed of three progranulin fragments and has been shown to have an effect similar to that of progranulin. Atsttrin has anti-inflammatory actions in multiple arthritis mouse models, and it protects against further arthritis development. However, whether Atsttrin has a role in neuroinflammation remains to be elucidated. In this study, we produced a neuroinflammatory mouse model by intracerebroventricular injection of 1 μL lipopolysaccharide(10 μg/μL). Atsttrin(2.5 mg/kg) was administered via intraperitoneal injection every 3 days over a period of 7 days before intracerebroventricular injection of 1 μL lipopolysaccharide(10 μg/μL). In addition, astrocyte cultures were treated with 0, 100 or 300 ng/mL lipopolysaccharide, with 200 ng/mL Atsttrin simultaneously. Immunohistochemistry, enzyme-linked immunosorbent assay and real-time reverse transcription-polymerase chain reaction were performed to examine the protein and mRNA levels of inflammatory mediators and to assess activation of the nuclear factor kappa B signaling pathway. Progranulin expression in the brain of wild-type mice and in astrocyte cultures was increased after lipopolysaccharide administration. The protein and mRNA expression levels of tumor necrosis factor-α, interleukin-1β and inducible nitric oxide synthase were increased in the brain of progranulin knockout mice after lipopolysaccharide administration. Atsttrin treatment reduced the lipopolysaccharide-induced increase in the protein and mRNA levels of tumor necrosis factor-α, interleukin-1β, matrix metalloproteinase-3 and inducible nitric oxide synthase in the brain of progranulin knockout mice. Atsttrin also reduced the expression of cyclooxygenase-2, inducible nitric oxide synthase and matrix metalloproteinase 3 mRNA in lipopolysaccharide-treated astrocytes in vitro, and decreased the concentration of tumor necrosis factor α and interleukin-1β in the supernatant. Furthermore, Atsttrin significantly reduced the levels of phospho-nuclear factor kappa B inhibitor α in the brain of lipopolysaccharide-treated progranulin knockout mice and astrocytes, and it decreased the expression of nuclear factor kappa B2 in astrocytes. Collectively, our findings show that the anti-neuroinflammatory effect of Atsttrin involves inhibiton of the nuclear factor kappa B signaling pathway, and they suggest that Atsttrin may have clinical potential in neuroinflammatory therapy.

Acacetin protects against cerebral ischemia-reperfusion injury via the NLRP3 signaling pathway

Acacetin(5,7-dihydroxy-4′-methoxyflavone), a potential neuroprotective agent, has an inhibitory effect on lipopolysaccharide-induced neuroinflammatory reactions. However, whether acacetin has an effect on inflammatory corpuscle 3(NLRP3) after cerebral ischemia-reperfusion injury has not been fully determined. This study used an improved suture method to establish a cerebral ischemia-reperfusion injury model in C57BL/6 mice. After ischemia with middle cerebral artery occlusion for 1 hour, reperfusion with intraperitoneal injection of 25 mg/kg of acacetin(acacetin group) or an equal volume of saline(0.1 mL/10 g, middle cerebral artery occlusion group) was used to investigate the effect of acacetin on cerebral ischemia-reperfusion injury. Infarct volume and neurological function scores were determined by 2,3,5-triphenyltetrazolium chloride staining and the Zea-Longa scoring method. Compared with the middle cerebral artery occlusion group, neurological function scores and cerebral infarction volumes were significantly reduced in the acacetin group. To understand the effect of acacetin on microglia-mediated inflammatory response after cerebral ischemia-reperfusion injury, immunohistochemistry for the microglia marker calcium adapter protein ionized calcium-binding adaptor molecule 1(Iba1) was examined in the hippocampus of ischemic brain tissue. In addition, tumor necrosis factor-α, interleukin-1β, and interleukin-6 expression in ischemic brain tissue of mice was quantified by enzyme-linked immunosorbent assay. Expression of Iba1, tumor necrosis factor-α, interleukin-1β and interleukin-6 was significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Western blot assay results showed that expression of Toll-like receptor 4, nuclear factor kappa B, NLRP3, procaspase-1, caspase-1, pro-interleukin-1β, and interleukin-1β were significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Our findings indicate that acacetin has a protective effect on cerebral ischemia-reperfusion injury, and its mechanism of action is associated with inhibition of microglia-mediated inflammation and the NLRP3 signaling pathway.

Neuroprotection mediated by the Wnt/Frizzled signaling pathway in early brain injury induced by subarachnoid hemorrhage

The Wnt/Frizzled signaling pathway participates in many inflammation-linked diseases. However, the inflammatory response mediated by the Wnt/Frizzled signaling pathway in experimental subarachnoid hemorrhage has not been thoroughly investigated. Consequently, in this study, we examined the potential role of the Wnt/Frizzled signaling pathway in early brain injury in rat models of subarachnoid hemorrhage.Simultaneously, possible neuroprotective mechanisms were also investigated. Experimental subarachnoid hemorrhage rat models were induced by injecting autologous blood into the prechiasmatic cistern. Experiment 1 was designed to examine expression of the Wnt/Frizzled signaling pathway in early brain injury induced by subarachnoid hemorrhage. In total, 42 adult rats were divided into sham(injection of equivalent volume of saline), 6-, 12-, 24-, 48-, 72-hour, and 1-week subarachnoid hemorrhage groups. Experiment 2 was designed to examine neuroprotective mechanisms of the Wnt/Frizzled signaling pathway in early brain injury induced by subarachnoid hemorrhage. Rats were treated with recombinant human Wnt1(rhwnt1), small interfering Wnt1(siwnt1) RNA, and monoclonal antibody of Frizzled1(anti-Frizzled1) at 48 hours after subarachnoid hemorrhage. Expression levels of Wnt1, Frizzled1, β-catenin, peroxisome proliferator-activated receptor-γ, CD36, and active nuclear factor-κB were examined by western blot assay and immunofluorescence staining. Microglia type conversion and inflammatory cytokine levels in brain tissue were examined by immunofluorescence staining and enzyme-linked immunosorbent assay. Our results show that compared with the sham group, expression levels of Wnt1, Frizzled1, and β-catenin were low and reduced to a minimum at 48 hours, gradually returning to baseline at 1 week after subarachnoid hemorrhage. rhwnt1 treatment markedly increased Wnt1 expression and alleviated subarachnoid hemorrhage-induced early brain injury(within 72 hours), including cortical cell apoptosis, brain edema, and neurobehavioral deficits, accompanied by increasing protein levels of β-catenin, CD36, and peroxisome proliferator-activated receptor-γ and decreasing protein levels of nuclear factor-κB. Of note, rhwnt1 promoted M2-type microglia conversion and inhibited release of inflammatory cytokines(interleukin-1β, interleukin-6, and tumor necrosis factor-α). In contrast, siwnt1 RNA and anti-Frizzled1 treatment both resulted in an opposite effect. In conclusion, the Wnt/Frizzled1 signaling pathway may participate in subarachnoid hemorrhage-induced early brain injury via inhibiting the inflammatory response, including regulating microglia type conversion and decreasing inflammatory cytokine release. The study was approved by the Animal Ethics Committee of Anhui Medical University and First Affiliated Hospital of USTC,Division of Life Sciences and Medicine, University of Science and Technology of China(approval No. LLSC-20180202) in May 2017.

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.

CABYR RNAi plasmid construction and NF-κB signal transduction pathway

AIM:To construct the CABYR RNAi plasmid and study its relation with the nuclear factor(NF)-κB signal transduction pathway.METHODS:Human CABYR mRNA sequence was obtained from GenBank.The structure of cDNA sequence for the short hairpin RNA was BbsⅠ+sense+loop+ antisense+transcription terminator+KpnⅠ+Bam HⅠ.A CABYR silencing plasmid was constructed and transfected into the human embryo cell line 293T.Quantitative real-time polymerase chain reaction was used to analyze CABYR and NF-κB gene expression.RESULTS:The CABYR and NF-κB expressions were detected in 293T cells.The oligonucleotide(5'-GCT-CAGATGTTAGGTAAAG-3')efficiently silenced the expression of CABYR.The expression of NF-κB was not significantly affected by silencing CABYR(P=0.743).CONCLUSION:CABYR can be found in the human embryo cell line 293T.Cabyrmid 2 can efficiently silence its target,CABYR,indicating that CABYR is not related with the NF-κB signal transduction pathway.

Glycine Attenuates Myocardial Fibrosis in Myocardial Infarction in Rats Partly through Modulating Signal Transducer and Activator of Transcription 3/Nuclear Factor-κB/Transforming Growth Factor-β axis

Objective: Inflammation and fibrosis are strongly associated with each other. Glycine is present in various traditional Chinese medicines and exhibits anti-inflammatory activity. However, the effects of glycine on myocardial fibrosis(MF) in rats with myocardial infarction(MI) have not been reported. The purpose of this study is to investigate the effects of glycine therapy on MF and comprehend its underlying mechanisms. Materials and Methods: Left anterior descending artery ligation-induced MI in Sprague Dawley rats was leveraged to assess the therapeutic effects of Glycine. Rats received either normal saline or glycine(0.5 mg/g bodyweight) for 7 days. Results: Glycine upregulated cardiac ejection fraction and fractional shortening to improve cardiac function, as evaluated by echocardiography. Histological and immunohistochemical analyses demonstrated that glycine could decrease inflammatory cell infiltration and alleviate collagen deposition. Western blotting revealed that nuclear factor-κB(NF-κB)-mediated inflammatory signaling was also downregulated by glycine treatment. The expression of signal transducer and activator of transcription 3(STAT3), tumor necrosis factor-α, and transforming growth factor-β(TGF-β) was decreased significantly in the glycine-treated group compared to the model group. Thus, glycine plays a protective role against myocardial ischemia and subsequent MF. Conclusion: The protective effects of glycine were achieved partly through STAT3/NF-κB/TGF-β signaling pathway.

Scorpiones,Scolopendra and Gekko Inhibit Lung Cancer Growth and Metastasis by Ameliorating Hypoxic Tumor Microenvironment via PI3K/AKT/mTOR/HIF-1αSignaling Pathway

Objective:To investigate whether Buthus martensii karsch(Scorpiones),Scolopendra subspinipes mutilans L.Koch(Scolopendra)and Gekko gecko Linnaeus(Gekko)could ameliorate the hypoxic tumor microenvironment and inhibit lung cancer growth and metastasis by regulating phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin/hypoxia-inducible factor-1α(PI3K/AKT/mTOR/HIF-1α)signaling pathway.Methods:Male C57BL/6J mice were inoculated with luciferase labeled LL/2-luc-M38 cell suspension to develop lung cancer models,with rapamycin and cyclophosphamide as positive controls.Carboxy methyl cellulose solutions of Scorpiones,Scolopendra and Gekko were administered intragastrically as 0.33,0.33,and 0.83 g/kg,respectively once daily for 21 days.Fluorescent expression were detected every 7 days after inoculation,and tumor growth curves were plotted.Immunohistochemistry was performed to determine CD31 and HIF-1αexpressions in tumor tissue and microvessel density(MVD)was analyzed.Western blot was performed to detect the expression of PI3K/AKT/mTOR/HIF-1αsignaling pathway-related proteins.Enzyme-linked immunosorbent assay was performed to detect serum basic fibroblast growth factor(bFGF),transforming growth factor-β1(TGF-β1)and vascular endothelial growth factor(VEGF)in mice.Results:Scorpiones,Scolopendra and Gekko prolonged the survival time and inhibited lung cancer metastasis and expression of HIF-1α(all P<0.01).Moreover,Scorpiones,Scolopendra and Gekko inhibited the phosphorylation of AKT and ribosomal protein S6 kinase(p70S6K)(P<0.05 or P<0.01).In addition,they also decreased the expression of CD31,MVD,bFGF,TGF-β1 and VEGF compared with the model group(P<0.05 or P<0.01).Conclusion:Scorpiones,Scolopendra and Gekko all showed beneficial effects on lung cancer by ameliorating the hypoxic tumor microenvironment via PI3K/AKT/mTOR/HIF-1αsignaling pathway.

Puerarin partly counteracts the inflammatory response after cerebral ischemia/reperfusion via activating the cholinergic anti-inflammatory pathway

Puerarin, a major isoflavonoid derived from the Chinese medical herb radix puerariae （Gegen）, has been reported to inhibit neuronal apoptosis and play an anti-inflammatory role in focal cerebral ischemia model rats. Recent findings regarding stroke pathophysiology have recognized that anti-inflammation is an important target for the treatment of ischemic stroke. The cholinergic anti-inflammatory pathway is a highly robust neural-immune mechanism for inflammation control. This study was to investigate whether activating the cholinergic anti-inflammatory pathway can be involved in the mechanism of inhibiting the inflammatory response during puerarin-induced cerebral ischemia/reperfusion in rats. Results showed that puerarin pretreatment （intravenous injection） re- duced the ischemic infarct volume, improved neurological deficit after cerebral ischemia/reperfusion and decreased the levels of interleukin-1β, interleukin-6 and tumor necrosis factor-a in brain tissue. Pretreatment with puerarin （intravenous injection） attenuated the inflammatory response in rats, which was accompanied by janus-activated kinase 2 （JAK2） and signal transducers and activators of transcription 3 （STAT3） activation and nuclear factor kappa B （NF-KB） inhibition. These observa- tions were inhibited by the alpha7 nicotinic acetylcholine receptor （a7nAchR） antagonist a-bungarotoxin （a-BGT）. In addition, puerarin pretreatment increased the expression of a7nAchR mRNA in ischemic cerebral tissue. These data demonstrate that puerarin pretreatment strongly protects the brain against cerebral ischemia/reperfusion injury and inhibits the inflammatory re- sponse. Our results also indicated that the anti-inflammatory effect of puerarin may partly be medi- ated through the activation of the cholinergic anti-inflammatory pathway.

Targeting key signalling pathways in oesophageal adenocarcinoma:A reality for personalised medicine?

Cancer treatments are rapidly changing.Curative treatment for oesophageal adenocarcinoma currently involves surgery and cytotoxic chemotherapy or chemoradiotherapy.Outcomes for both regimes are generally poor as a result of tumor recurrence.We have reviewed the key signalling pathways associated with oesophageal adenocarcinomas and discussed the recent trials of novel agents that attempt to target these pathways.There are many trials underway with the aim of improving survival in oesophageal cancer.Currently,phase 2 and 3 trials are focused on MAP kinase inhibition,either through inhibition of growth factor receptors or signal transducer proteins.In order to avoid tumor resistance,it appears to be clear that targeted therapy will be needed to combat the multiple signalling pathways that are in operation in oesophageal adenocarcinomas.This may be achievable in the future with the advent of gene signatures and a combinatorial approach.

Effect of Allicin on the Formation of Kidney Stones in Rats by Regulating the Expression of OPN and NF-κB Signaling Pathway

Objective:To investigate the effect of allicin on the formation of kidney stones in rats by regulating the expression of osteopontin(OPN)and nuclear factor-κB(NF-κB)signaling pathway.Methods:A total of 50 healthy adult male SD rats with SPF grade were selected and divided into five groups by random number and computer random combination,with 10 rats in each group.Except the blank group,the other four groups were given 2 m L/d mixed solution of 1%ethylene glycol+2%ammonium chloride to construct the nephrolith model.During the modeling process,the blank group and the model group were given normal saline by gavage.The positive group was given 600 mg/(kg·d)of potassium sodium hydrogen citrate granules by gavage,the low-dose group was given 7.5 mg/(kg·d)of allicin by gavage,and the high-dose group was given 15 mg/(kg·d)of allicin by gavage.After administration,renal function,urine related indicators,calcium oxalate crystallization score,OPN protein expression and NF-κB signaling pathwayrelated protein expression were observed and compared among the five groups of rats.Results:There were significant differences in kidney index,urea nitrogen(BUN)and blood creatinine(Cr)levels among the five groups(P<0.05).There were no differences in kidney index,BUN and Cr levels between the high-dose group and the positive group(P>0.05),and were all lower than those in the model group and low-dose group(P<0.05).There were significant differences in the levels of oxalic acid(OA),calcium(Ca),magnesium(Mg),and phosphorus(P)in the urine of five groups of rats(P<0.05).The high-dose group showed no difference in the levels of OA,Ca,Mg,and P compared to the positive control group(P>0.05),and all were lower than the model group and low-dose group(P<0.05).There were significant differences in the scores of calcium oxalate crystallization and the expression of OPN protein in the five groups(P<0.05).There was no difference in the scores of calcium oxalate crystallization between the high-dose group and the positive group(P>0.05).The expression of OPN protein was higher than that in the positive group(P<0.05),and both were lower than that in the model group and low-dose group(P<0.05).There were significant differences in the expression levels of NF-κB inhibitory protein-α(IκB-α)and NF-κB in five groups(P<0.05),and the expression levels of IκB-αand NF-κB in the high-dose group were lower than those in the model group,positive control group,and low-dose group(P<0.05).Conclusion:Allicin may inhibit the formation of kidney stones in rats by down-regulating the expression levels of OPN and NF-κB signaling pathway-related proteins,and a high dose of allicin can obtain a similar effect of kidney stones inhibition as that of potassium sodium hydrogen citrate granules.

Cross-talk between microRNA-let7c and transforming growth factor-β2 during epithelial-to-mesenchymal transition of retinal pigment epithelial cells

AIM: To explore the roles of microRNA-let7 c(miR-let7 c) and transforming growth factor-β2(TGF-β2) and cellular signaling during epithelial-to-mesenchymal transition(EMT) of retinal pigment epithelial cells. METHODS: Retinal pigment epithelial(ARPE-19) cells were cultured with no serum for 12 h, and then with recombinant human TGF-β2 for different lengths of time. ARPE-19 cells were transfected with 1×106 TU/mL miR-let7 c mimcs(miR-let7 cM), miR-let7 c mimcs negative control(miR-let7cMNC) and miR-let7 c inhibitor(miR-let7 cI) using the transfection reagent. The expression of keratin-18, vimentin, N-cadherin, IKB alpha, p65 were detected by Western blot, quantitative polymerase chain reaction and immunofluorescence. RESULTS: The expression of miR-let7c was dramatically reduced and the nuclear factor-kappa B(NF-κB) signaling pathway was activated after induction by TGF-β2(P<0.05). In turn, overexpressed miR-let7 c significantly inhibited TGF-β2-induced EMT(P<0.05). However, miR-let7 c was unable to inhibit TGF-β2-induced EMT when the NF-κB signaling pathway was inhibited by BAY11-7082(P<0.01). CONCLUSION: The miR-let7 c regulates TGF-β2-induced EMT through the NF-κB signaling pathway in ARPE-19 cells.

Maraviroc promotes recovery from traumatic brain injury in mice by suppression of neuroinflammation and activation of neurotoxic reactive astrocytes

Neuroinflammation and the NACHT,LRR,and PYD domains-containing protein 3 inflammasome play crucial roles in secondary tissue damage following an initial insult in patients with traumatic brain injury(TBI).Maraviroc,a C-C chemokine receptor type 5 antagonist,has been viewed as a new therapeutic strategy for many neuroinflammatory diseases.We studied the effect of maraviroc on TBI-induced neuroinflammation.A moderate-TBI mouse model was subjected to a controlled cortical impact device.Maraviroc or vehicle was injected intraperitoneally 1 hour after TBI and then once per day for 3 consecutive days.Western blot,immunohistochemistry,and TUNEL(terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling)analyses were performed to evaluate the molecular mechanisms of maraviroc at 3 days post-TBI.Our results suggest that maraviroc administration reduced NACHT,LRR,and PYD domains-containing protein 3 inflammasome activation,modulated microglial polarization from M1 to M2,decreased neutrophil and macrophage infiltration,and inhibited the release of inflammatory factors after TBI.Moreover,maraviroc treatment decreased the activation of neurotoxic reactive astrocytes,which,in turn,exacerbated neuronal cell death.Additionally,we confirmed the neuroprotective effect of maraviroc using the modified neurological severity score,rotarod test,Morris water maze test,and lesion volume measurements.In summary,our findings indicate that maraviroc might be a desirable pharmacotherapeutic strategy for TBI,and C-C chemokine receptor type 5 might be a promising pharmacotherapeutic target to improve recovery after TBI.

PI3K/Akt pathway is involved in the activation of RAW 264.7 cells induced by hydroxypropyltrimethyl ammonium chloride chitosan

We previously demonstrated that 2-hydroxypropyltrimethyl ammonium chloride chitosan(HACC)promoted the production of nitric oxide(NO)and proinflammatory cytokines by activating the mitogen-activated protein kinases(MAPK)and Janus kinase(JAK)/STAT pathways in RAW 264.7 cells,indicating good immunomodulatory activity of HACC.In this study,to further investigate the immunomodulatory mechanisms of HACC,we determined the roles of phosphatidylinositol 3-kinase(PI3K)/Akt,activating protein(AP-1)and nuclear factor kappa B(NF-κB)in HACC-induced activation of RAW 264.7 cells by the western blotting.The results suggest that HACC promoted the phosphorylation of p85 and Akt.Furthermore,c-Jun and p65 were also increased after the treatment of RAW 264.7 cells with HACC,indicating the translocation of NF-κB and AP-1 from cytoplasm to nucleus.In addition,as scanning electron microscopy(SEM)analysis shows,the cell morphology changed after HACC treatment.These findings indicate that HACC activated MAPK,JAK/STAT,and PI3K/Akt signaling pathways dependent on AP-1 and NF-κB activation in RAW 264.7 cells,ultimately leading to the increase of NO and cytokines.

Electroacupuncture Delays Cartilage Degeneration by Modulating Nuclear Factor-κB Signaling Pathway

Objective: To illustrate the molecular mechanisms underlying the therapeutic effects of electroacupuncture(EA) on knee osteoarthritis(OA). Methods: Twenty-seven six-month-old New Zealand white rabbits were allocated into three groups in accordance with a random number table: normal group(no surgery-induced OA;without treatment), model group(surgery-induced OA;without treatment) and EA group [surgery-induced OA;received treatment with EA at acupoints Dubi(ST 35) and Neixiyan(EX-LE 5), 30 min twice a day]. After eight consecutive weeks of treatment, the histopathological alterations in cartilage were observed using optical microscopy and transmission electron microscopy, cartilage degeneration was evaluated by modified Mankin’s score principles, the synovial fluid concentration of interleukin-1β(IL-1β), interleukin-6(IL-6), tumor necrosis factor-α(TNF-α) and matrix metalloproteinase-3(MMP-3) were evaluated by enzyme-linked immunosorbent assay, and the protein expression levels of IL-1β, IL-6, TNF-α, MMP-3, IκB kinase-β(IKK-β), nuclear factor of α light polypeptide gene enhancer in B-cells inhibitor α(IκB-α) and nuclear factor-κB(NF-κB) p65 were quantified by Western blot analysis. Results: EA treatment significantly improved cartilage structure arrangement and reduced cellular degeneration. The IL-1β, IL-6, TNF-α and MMP-3 of synovial fluid in the EA-treated group were significantly decreased compared with the model group(all P<0.01). Compared with the model group, the IL-1β, IL-6, TNF-α, MMP-3, IKK-β and NF-κB p65 protein expressions in cartilage of EA-treated group were significantly decreased(all P<0.01), whereas IκB-α expression was significantly up-regulated(P<0.01). Conclusion: EA treatment may delay cartilage degeneration by down-regulating inflammatory factors through NF-κB signaling pathway, which may, in part, explain its clinical efficacy in the treatment of knee OA.

Role of β2-Adrenoceptor-β-Arrestin2-Nuclear Factor- k B Signal Transduction Pathway and Intervention Effects of Oxymatrine in Ulcerative Colitis

Objective： To investigate the β2-adrenoceptor （ β 2AR）-β-arrestin2-nuclear factor- K B （NF- κ B） signal transduction pathway and the intervention effects of oxymatrine in a rat model of ulcerative colitis. Methods： Forty SD rats were randomly divided into four groups, which included the normal control group, the model group, the mesalazine group and the oxymatrine treatment group, with 10 rats per group. Experimental colitis induced with trinitrobenzene sulfonic acid （TNBS） was established in each group except the normal control group, The rats in the oxymatrine treatment group were treated with intramuscular injection of oxymatrine 63 mg/（kg.d） for 15 days and the rats in the mesalazine group were treated with mesalazine solution 0.5 g/（kg.d） by gastric lavage for 15 days. The rats in the normal control group and model group were treated with 3 mL water by gastric lavage for 15 days. Diarrhea and bloody stool were carefully observed. Histological changes in colonic tissue were examined on day 7 in 2 rats per group that were randomly selected. The expression of β 2AR, β -arrestin2 and NF- κ B p65 in colon tissue and spleen lymphocytes were detected with immunohistochemistry and Western immunoblotting techniques on day 16 after fasting for 24 h. Six rats died of lavage with 2 each in the normal control, the model group and the mesalazine group; and were not included in the analysis. Results： The rats in the model group suffered from looser stool and bloody purulent stool after modeling. But in the oxymatrine and mesalazine groups, looser stool and bloody purulent stool reduced after treatment. And the colonic wall in the model group was thickened and the colon length shortened. The colon mucosa was congested in multiple areas with edema, erosion, superficial or linear ulcer and scar formation, while the intestinal mucosa injury reduced in the mesalazine and oxymatrine groups （P〈0.01）. In colonic mucosa and in spleen lymphocytes, compared with the normal control group, the expression of NF- κ Bp65 were significantly increased （P〈0.01） in the model group while the expressions of β 2AR and β-arrestin2 were significantly decreased （P〈0.01）. Compared with the model group, the expression of NF- κ Bp65 was significantly decreased in the mesalazine group （P〈0.01） and oxymatrine treatment group （P〈0.01） while the expressions of β 2AR and β -arrestin2 were significantly increased （P〈0.01）. There were no statistically significant differences in the expression of β 2AR, β -arrestin2 and NF- κ Bp65 between the mesalazine group and oxymatrine group （P〉0.05）. Conclusions： The β 2AR- β -arrestin2-NF- κ B signal transduction pathway participated in the pathologic course of ulcerative colitis. Oxymatrine attenuated ulcerative colitis through regulating the β 2AR- β -arrestin2-NF- κB signal transduction pathway.

Pathobiology of the neutrophil-intestinal epithelial cell interaction:Role in carcinogenesis

The role of chronic inflammation,acting as an independent factor,on the onset of gastrointestinal carcinogenesis is now well accepted.However,even if there is an increase in the number of elements directly involving polymorphonuclear leukocytes (PMNL),as a major actor in digestive carcinogenesis,the different cellular and molecular events occurring in this process are still not completely understood.The transepithelial migration of PMNL,which is the ultimate step of the afflux of PMNL into the digestive mucosa,is a complex phenomenon involving sequential interaction of molecules expressed both on PMNL and on digestive epithelial cells.Chronic inflammatory areas rich in PMNL [so-called (chronic active inflammation)] and iterative transepithelial migration of PMNL certainly evoke intracellular signals,which lead toward progressive transformation of epithelia.Among these different signals,the mutagenic effect of reactive oxygen species and nitrates,the activation of the nuclear factor-κB pathway,and the modulation of expression of certain microRNA are key actors.Following the initiation of carcinogenesis,PMNL are involved in the progression and invasion of digestive carcinomas,with which they interact.It is noteworthy that different subpopulations of PMNL,which can have some opposite effects on tumor growth,in association with different levels of transforming growth factor-β and with the number of CD8 positive T lymphocytes,could be present during the development of digestive carcinoma.Other factors that involve PMNL,such as massive elastase release,and the production of angiogenic factors,can participate in the progression of neoplastic cells through tissues.PMNL may play a major role in the onset of metastases,since they allow the tumor cells to cross the endothelial barrier and to migrate into the blood stream.Finally,PMNL play a role,alone or in association with other cell parameters,in the initiation,promotion,progression and dissemination of digestive carcinomas.This review focuses on the main currently accepted cellular and molecular mechanisms that involve PMNL as key actors in digestive carcinogenesis.

The Regulatory Effects of Polyporus Polysaccharide on the Nuclear Factor Kappa B Signal Pathway of Bladder Cancer Cells Stimulated by Bacillus Calmette-Guerin

Objective：To detect the effects of Polyporus polysaccharide（PPS）,Bacillus Calmette-Guerin （BCG）,and their combination on the nuclear factor kappa B（NF-κB）signaling pathway associated-gene expression and investigate the molecular mechanisms of the toxic-reducing effect of PPS in coordination with BCG against bladder cancer.Methods：After T739 cells were treated with PPS,BCG and their combination, the changes in mRNA and protein expression of inhibitor of kappa B kinase beta（IKKβ）,NF-κB subunit p65 （NF-κB p65）,intracellular adhesion molecule 1（ICAM1）and chemokine（C-c motif）ligand 2（CCL2）in bladder cancer cell line T739 were determined by relative quantitative real-time PCR,Western blot,and flow cytometry （FCM）.NF-κB p65 DNA-binding activity in T739 cell was detected by biotinylated probe-ELISA,and NF-κB p65 nuclear expression in T739 cell was observed by immunohistochemistry.Results：Compared with the T739 control group,the mRNA expression of IKBKB（IKKβ）,Rel A（NF-κB p65）,ICAM1 and CCL2 in T739 cells treated with BCG were increased obviously（Ratio2.0）,as well as the expression of IKKβ,CCL2 and ICAM1 proteins.Meanwhile,NF-κB p65 DNA-binding activity and NF-κB p65 nuclear expression in T739 cells treated with BCG were up-regulated significantly（P0.05）.Compared with the control,the increased expression in T739 cells were simultaneously down-regulated after PPS treatment,except for ICAM1 protein expression.With cells treated with a combination of BCG and PPS,the expression of genes associated with the NF-κB signaling pathway,such as IKBKB,ICAM1 and CCL2,were all down-regulated compared to the BCG group,as well as Rel A mRNA expression,NF-κB p65 DNA-binding activity and NF-κB p65 nuclear expression.Conclusions： PPS could inhibit the over-activation of the NF-κB signaling pathway induced by BCG in bladder cancer cells and accordingly attenuate the adverse reactions to BCG therapy.

Characteristics of Lymphocyte Nuclear Factor-κB Signal Transduction Kinase Expression in Aging Process and Regulatory Effect of Epimedium Flavonoids

Objective：To study the characteristics of lymphocyte nuclear factor kappa B（NF-κB） signal transduction kinase-related molecular mRNA differential expressions at various month age segments in aging process and the intervening effect of Epimedium flavonoids（EF） on it.Methods：Sixty SD rats were divided into six groups,according to animals＇ age,i.e.,the 3 days（d） group,the 4 months（m） group,the 10 m group,the 18 m group,the 27 m group,and the 27 m＋EF group.RNA was extracted from separated splenic lymphocytes. Adopting NF-κB signal path functional genome oligonucleotide gene-chip（128 related genes）,the integral characteristics and differences of NF-κB signal transduction kinase-related mRNA expressions were determined, and the intervening effect of EF was examined.Results：The mean level of the NF-κB signal transduction kinase-related mRNA expressions in rats＇ splenic lymphocytes lowered with aging;the highest expression was presented at 3 d after birth,and then,it lowered gradually,with the lowest level at 18 m or 27 m.After EF intervention,the expression level was raised to the 10-18 m level in the aged rats.Conclusion：The changing rules of lymphocyte NF-κB-signal-transduction-kinase-related mRNA expressions in various stages of aging are helpful for selecting the well time for preventing and intervening aging,and will also give a hint to the molecular index for assessment of senility retarding researches.