NF-κB Pathways in the Pathogenesis of Multiple Sclerosis and the Therapeutic Implications

Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathways are involved in cell immune responses, apoptosis and infections. In multiple sclerosis (MS), NF-κB pathways are changed, leading to increased levels of NF-κB activation in cells. This may indicate a key role for NF-κB in MS pathogenesis. NF-κB signaling is complex, with many elements involved in its activation and regulation. Interestingly, current MS treatments are found to be directly or indirectly linked to NF-κB pathways and act to adjust the innate and adaptive immune system in patients. In this review, we will first focus on the intricacies of NF-κB signaling, including the activating pathways and regulatory elements. Next, we will theorize about the role of NF-κB in MS pathogenesis, based on current research findings, and discuss some of the associated therapeutic implications. Lastly, we will review four new MS treatments which interrupt NF-κB pathways—fingolimod, teriflunomide, dimethyl fumarate (DMF) and laquinimod (LAQ)—and explain their mechanisms, and the possible strategy for MS treatments in the future.

Lactobacillus acidophilus ATCC 4356 attenuates the atherosclerotic progression through modulation of oxidative stress and inflammatory process

The aim of this study was to investigate the effect of Lactobacillus (L.) acidophilus ATCC 4356 on the progression of atherosclerosis in Apoliprotein-E knockout (ApoE(-/-)) mice and the underlying mechanisms. Eight week-old ApoE(-/-) mice were treated with L. acidophilus ATCC 4356 daily for 12 weeks. The wild type (WT) mice or ApoE(-/-) mice in the vehicle group were treated with saline only. Body weights, serum lipid levels, aortic atherosclerotic lesions, and tissue oxidative and inflammatory statuses were examined among the groups. As compared to ApoE(-/-) mice in the vehicle group, ApoE(-/-) mice treated with L. acidophilus ATCC 4356 had no changes in body weights and serum lipid profiles, but showed decreased atherosclerotic lesion size in en face aorta. In comparison with WT mice, ApoE(-/-) mice in the vehicle group showed higher levels of serum malondialdehyde (MDA), oxidized low density lipoprotein (oxLDL) and tumor necrosis factor-alpha (TNF-α), but lower levels of interleukin-10 (IL-10) and superoxide dismutase (SOD) activities in serum. Administration of L. acidophilus ATCC 4356 could reverse these trends in a dose-dependent manner in ApoE(-/-) mice. Furthermore, ApoE(-/-) mice treated with L. acidophilus ATCC 4356 showed an inhibition of translocation of NF-κB p65 from cytoplasm to nucleus, suppression of degradation of aortic IκB-α, and improvements of gut microbiota distribution, as compared to ApoE(-/-) mice in the vehicle group. Our findings suggest that administration of L. acidophilus ATCC 4356 can attenuate the development of atherosclerotic lesions in ApoE(-/-) mice through reducing oxidative stress and inflammatory response.

Immunostimulatory activity of polysaccharides from Cheonggukjang

Cheonggukjang is a Korean whole soybean paste fermented by Bacillus subtilis and regarded as a healthy food. The objective of this study was to investigate the immunostimulatory activity of polysaccharides from Cheonggukjang (PSCJ) in RAW 264.7 macrophages and an animal model. PSCJ induced mRNA expressions of inducible nitric oxide synthase and tumor necrosis factor-α (TNF-α) by activating nuclear factor-κB, and subsequently increased the productions of nitric oxide (NO) and TNF-α in murine recombinant interferon-γ-primed RAW 264.7 macrophages. Furthermore, after daily oral administration of PSCJ, immobility time decreased significantly in the PSCJ-administered group (200 or 400 mg/kg) on day 10. Taken together, these results suggest that the PSCJ has a possible role improving immune function through regulatory effects on immunological parameters, such as NO and TNF-α productions and changes in indicators related to fatigue.

Piperine, a functional food alkaloid, exhibits inhibitory potential against TNBS-induced colitis via the inhibition of IκB-α/NF-κB and induces tight junction protein (claudin-1, occludin, and ZO-1) signaling pathway in experimental mice

BACKGROUND

Inflammatory bowel disease is a chronic immunoinflammatory disease of the gastrointestinal tract. Piperine, an alkaloid, has been reported to possess antioxidant, anti-inflammatory, antiapoptotic, and antiulcer potential.

AIM

To elucidate the plausible mechanisms of action of piperine on experimental trinitrobenzenesufonic acid (TNBS)-induced colitis by assessing various biochemical, molecular, histological, and ultrastructural modifications.

METHODS

Colitis was induced in male Sprague-Dawley rats via intrarectal instillation of TNBS. Then, the rats were treated with piperine (10, 20, and 40 mg/kg, p.o.) for 14 days.

RESULTS

TNBS induced significant (p < 0.05) colonic damage, which was assessed by disease activity index, macroscopic score, and stool consistency. The administration of piperine (20 and 40 mg/kg) significantly inhibited (p < 0.05) these damages. Treatments with piperine (20 and 40 mg/kg) notably inhibited (p < 0.05) the TNBS-induced elevation of oxido-nitrosative stress (superoxide dismutase, glutathione, malondialdehyde, and nitric oxide), 5-hydroxytryptamine, and hydroxyproline content in the colon. Furthermore, colonic inducible nitric oxide synthase (iNOs), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, IL-6, interferon-gamma, and cyclooxygenase-2 (COX-2) messenger RNA (mRNA) expressions were upregulated after TNBS instillation and piperine (20 and 40 mg/kg) significantly attenuated (p < 0.05) these elevated mRNA expressions. TNBS decreased the expressions of tight junction (TJ) protein (claudin-1, occludin, and zonula occludens-1 (ZO-1)) and increased the expressions of proapoptotic (caspase-1) protein. These expressions were markedly inhibited (p < 0.05) by piperine treatment. Histological and ultrastructural studies of transmission electron microscopy suggested that piperine significantly ameliorated (p < 0.05) TNBS-induced colonic aberrations.

CONCLUSION

Piperine ameliorated the progression of TNBS-induced colitis by modulating the nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-alpha/nuclear factor-kappa B signaling pathway, thus inhibiting the overexpression of proinflammatory cytokines (TNF-α and IL's), COX-2, iNOs, oxido-nitrosative stress, and proapoptotic proteins (caspase-1) that may improve the expression of TJ protein (claudin-1, occludin, and ZO-1).

In vitro and in vivo immunostimulatory effects of hot water extracts from the leaves of Artemisia princeps Pampanini cv. Sajabal

ETHNOPHARMACOLOGICAL RELEVANCE

Artemisia princeps Pampanini (Asteraceae) is used as a traditional medicine to immune function-related diseases, such as dysmenorrhea, inflammation, cancer, and ulcers.

AIM OF THE STUDY

The purpose of this study is to evaluate the immunostimulatory effects of the hot water extract from the leaves of Artemisia princeps Pampanini (WAPP) in recombinant interferon-γ (rIFN-γ)-primed RAW 264.7 macrophages and in cyclophosphamide (20mg/kg, i.p.)-induced immunosuppressed Sprague-Dawley rats.

MATERIALS AND METHODS

RAW 264.7 macrophages were treated with WAPP and production and expressions of nitric oxide (NO) and tumor necrosis factor-α (TNF-α) via nuclear factor-κB (NF-κB) were detected by immunoassay, western blot, qRT-PCR and reporter gene assay. In addition, in vivo immunomodulatory activity was studied by cyclophosphamide-induced myelosuppression in rats.

RESULTS

In rIFN-γ-primed RAW 264.7 macrophages, pretreatment with WAPP increased the productions of nitric oxide (NO) and tumor necrosis factor-α (TNF-α),and increased the expressions of inducible nitric oxide synthase (iNOS) at the protein level and of iNOS and TNF-α at the mRNA level. Molecular data revealed that WAPP upregulated the transcriptional activity and translocation of nuclear factor-κB (NF-κB) by activating inhibitory kappa B-α (IκB-α) degradation and phosphorylation. Furthermore, WAPP upregulated the phosphorylations of p38 MAP kinase, c-Jun NH2-terminal kinase (JNK), and extracellular signal-regulated kinase 1/2 (ERK1/2). In cycloheximide-induced immunosuppressed rats, pretreatment with WAPP (100, 200, or 400mg/kg, p.o.) increased the serum levels of albumin and globulin, and reduced immobility times.

CONCLUSION

Our results suggest that upregulations of the expressions of iNOS and TNF-α via the activations of NF-κB and MAPK are responsible for the immunostimulatory effects of WAPP.

The BCR-ABL/NF-κB signal transduction network: a long lasting relationship in Philadelphia positive Leukemias

The Nuclear Factor-kappa B (NF-κB) family of transcription factors plays a key role in cancer pathogenesis due to the ability to promote cellular proliferation and survival, to induce resistance to chemotherapy and to mediate invasion and metastasis. NF-κB is recruited through different mechanisms involving either canonical (RelA/p50) or non-canonical pathways (RelB/p50 or RelB/p52), which transduce the signals originated from growth-factors, cytokines, oncogenic stress and DNA damage, bacterial and viral products or other stimuli. The pharmacological inhibition of the NF-κB pathway has clearly been associated with significant clinical activity in different cancers. Almost 20 years ago, NF-κB was described as an essential modulator of BCR-ABL signaling in Chronic Myeloid Leukemia and Philadelphia-positive Acute Lymphoblastic Leukemia. This review summarizes the role of NF-κB in BCR-ABL-mediated leukemogenesis and provides new insights on the long lasting BCR-ABL/NF-κB connection.

Distinctive effects of the cellular inhibitor of apoptosis protein c-IAP2 through stabilization by XIAP in glioblastoma multiforme cells

Inhibitor of apoptosis proteins (IAPs) are extensively involved in NFκB signaling pathways. Regulation of c-IAP2 turnover by other proteins was investigated in glioblastoma multiforme (GBM) cells in the present study. When overexpressed, X-linked IAP (XIAP) enhanced expression of ectopic c-IAP2, but not c-IAP1, and endogenous c-IAP2 levels were reduced once XIAP expression was silenced. TNFα stimulation substantially increased c-IAP2 expression, and this upregulation was impaired by suppression of XIAP. Similarly, when XIAP was limiting due to severe hypoxic conditions, c-IAP2 levels were downregulated. These data together indicate that XIAP is an important regulator responsible for stabilization of c-IAP2 levels under different conditions. Protein interactions occur through binding of BIR2 and BIR3 domains of c-IAP2 with the RING finger of XIAP. XIAP inhibition of c-IAP2 auto-degradation was dependent on this physical interaction, and it was independent of XIAP E3 ligase activity. Global c-IAP2 ubiquitination was not affected by XIAP, although c-IAP2 levels were significantly increased. A CARD-RING-containing fragment of c-IAP2 was found to target XIAP for proteasome-independent degradation, but it was unable to sensitize GBM cells to chemo-reagents. The XIAP-stabilized c-IAP2 was found to enhance IκB-α phosphorylation on serines 32 and 36, and to antagonize XIAP-induced increase in mature Smac and Bcl10. Taken together, our data identify a distinctive role of c-IAP2 as stabilizer of XIAP, which is likely involved in regulation of NFκB activation and apoptosis in GBM cells.

IκB-α: At the crossroad between oncogenic and tumor-suppressive signals

Nuclear factor κB (NF-κB) is an essential component of tumorigenesis and resistance to cancer treatments. NFKB inhibitor α (IκB-α) acts as a negative regulator of the classical NF-κB pathway through its ability to maintain the presence of NF-κB in the cytoplasm. However, IκB-α is also able to form a complex with tumor protein p53, promoting its inactivation. Recently, we demonstrated that IκB-α is able to mediate p53 nuclear exclusion and inactivation in chronic myeloid leukemia, indicating that IκB-α can modulate either oncogenic or tumor-suppressive functions, with important implications for cancer treatment. The present review describes the role of IκB-α in cancer pathogenesis, with particular attention to hematological cancers, and highlights the involvement of IκB-α in the regulation of p53 tumor-suppressive functions.

The procyanidin trimer C1 induces macrophage activation via NF-κB and MAPK pathways, leading to Th1 polarization in murine splenocytes

Numerous studies have shown various relationships between foods with a high nutritional value and a robust immune response, particularly studies that have focused on host protection and cytokine networks. This study aimed to clarify the role played by the procyanidin trimer C1 in innate and adaptive immunity. Procyanidin C1 did not exert cytotoxicity at concentrations ranging from 7.8 to 62.5 μg/ml in macrophage cells; therefore, concentration of 62.5 μg/ml was used as the maximum dose of procyanidin C1 throughout subsequent experiments. Procyanidin C1 enhanced inducible nitric oxide synthase-mediated nitric oxide production in a concentration-dependent manner. In addition, procyanidin C1 functionally induced macrophage activation by augmenting the expression of cell surface molecules (CD80, CD86, and MHC II) and proinflammatory cytokine production (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6) via activation of mitogen-activated protein kinase (MAPK), e.g., p38, ERK, and JNK and nuclear factor (NF)-κB signaling pathways. Interestingly, procyanidin C1 effectively polarized T helper type 1 (Th1) by secreting Th1-mediated cytokines (interferon-γ, IL-12p70, and IL-2) and inducing splenocyte proliferation, indicating that procyanidin C1 contributes to Th1 polarization of the immune response. Accordingly, these findings confirms that the procyanidin C1 induces macrophage activation via NF-κB and MAPK pathways, leading to Th1 polarization in murine splenocytes, which suggests that procyanidin C1 regulates innate and adaptive immunity by macrophage activation and Th1 polarization.

Astragalus mongholicus regulate the Toll-like-receptor 4 meditated signal transduction of dendritic cells to restrain stomach cancer cells

BACKGROUND

According to the traditional view, we depend on three methods to treat tumors; surgery, chemotherapy and radiotherapy. However, these methods have its own limitations in application. Traditional Chinese Medicine (TCM) is one of the oldest healing systems. Astragalus mongholicus (AMs) that is the common herbal medicine, the biggest part of TCM, have been proved to be effective in treating cancers from lots of clinical cases. However, we have not fully understood the anti-tumor mechanism of AMs, and this has lead to some doubt for some Western-Medicine scholars and restricts its wide use. The main objective of this research is to discuss the effect and mechanism of AMs to human stomach cancer.

MATERIALS AND METHODS

To observe the effect and mechanism of tumor treatment by AMs, we have done the research from three major aspects, the influence of DCs, the inhibition of tumor in vitro as well as the animal studies in vivo after treatment. First, we culture the mouse dendritic cells (DCs) from bone marrow of mouse hind legs according to the method using Interleukin-4(IL-4) and Granulocyte-macrophage colony stimulating factor (GM-CSF), which refer to the way established by Inaba (Inaba K, 1992). And then we investigate the growth-rate of the DCs co-cultured with AMs injection. We analyze the expression of the Toll-like-receptor 4 (TLR4), with SYBR-Green I Real-time PCR and the I-kappa-B-alpha (IκB-α) with Western-Blot, the main regulatory protein to control nuclear factor NFκB-p65 nuclear translocation. Second, we choose the human gastric cancer cell lines MKN 45 as the target cell, which was co-cultured with DCs, T cells from spleen of mouse and AMs injection, and use MTT assay to judge the amount of cell lines and Immnunoflurescene to analyze the expression of anti-active caspase 3 pAb anti-PARP P85 fragment pAb, the mark of apoptosis of cells. Third, we have conducted the animal studies beside the basic experiment in vitro. The nude mouse developed stomach cancer, due to intra-preritoneal injection with MKN45 have been divided into two groups: the treatment group challenged with AMs injection and the control group with saline injection. We took the average of the diameter of each group as the y axis and the days after administered with AMs as x axis. After 40 days, all animals were killed by detruncation, and the tumor were removed and measured. We compare the diameter (<40 days) and weight (>40 days) of the tumor as well as the survival days between different groups to investigate the effect of inhibition of cancer.

RESULTS

All results show that AMs is effective in treating human stomach cancer and the mechanism might be regulated by TLR4 mediated signal transduction of DCs. The results are briefly introduced as follows: First, we succeed in culturing the DCs induced by IL-4 and GM-CSF and find the positive rate of CD11c expression, the mark of DCs, is beyond 90% (Fig-1). We detect AMs can precipitate DCs maturation by upregulating TLR4 in SYBR-Green I Real-time PCR (Fig-2) and suppressing I.B-aby Western-Blot (Fig-3). Second, after the MKN45 co-cultured with DCs, T cells and AMs injection, the result show that AMs can great reduce the amount of cell lines by MTT assay (Fig-4) and induce apoptosis with Immunofluorescence (Fig-5). Finally, we have conducted animal studies beside the experiment in vitro, and the result in vivo show that AMs can delay tumor development from the diameter and weight of the tumor (Fig-6, Fig-7), prolong life-span and improve life-quality. Figure 1the morphology and phenotypic identification of DCs.The form of DCs observed by microscope with field 20*.The isotype antibody control using FCM.The positive rate of CD11c expression.Figure 2the melting curve and the chart of TLR4 expressiona) the melting curve of beta-actin; b)the melting curve of TLR4;c)the TLR4 expression of DCs stimulated with AM at different dose. There is significant statistic difference between the 60ng/mL and 80ng/mL group and other group (P<0.05 by rank test)Figure 3the IκB-α expression of DCs with different dose of AMsL0: 0ng/mL; L1:20ng/mL; L2:40ng/mL; L3:60ng/mL; L4:80ng/mLFigure 4MTT assay to analyse the viability and proliferation of the two cell lines (P<0.05 between the group with the dose of 60ng/mL and 80ng/mL and other group). the horizontal axis is the group treated with AM and saline at different dose, the vertical axis is the cell number.Figure 5the anti-active caspase-3 pAb (a) and anti-PARP P85 fragment pAb (b) actived by immunofluorescence.The cell mix were treated with 100uL anti-active caspase-3 pAb at a 1:250 dilution and anti-PARP P85 fragment pAb at a 1:100 dilution, and the secondary Ab was donkey anti-rabbit Cy®3 conjugate diluted 1:500 in PBS (Jackson Cat#711-165-152). From the photo, we find that anti-active caspase-3 pAb and anti-PARP P86 fragment pAb can express which is very important to indicate cell-apoptosis.Figure 6The difference of tumor between treatment group and control group.

CONCLUSION

Ams Can play a great role in treating human stomach cancers as a good Chinese herbal medicine by precipitating DCs maturation, which is probably due to its effects by regulating the TLR4 mediated signal transduction.

PPARα Agonist Suppresses Inflammation after Corneal Alkali Burn by Suppressing Proinflammatory Cytokines, MCP-1, and Nuclear Translocation of NF-κB

We investigated the effect of a peroxisome proliferator-activated receptor α (PPARα) agonist after corneal alkali injury. Fenofibrate 0.05% (PPARα agonist group) or vehicle (Vehicle group) was topically instilled onto the rat cornea after injury. Histological, immunohistochemical, and real-time reverse transcription PCR analyses were performed. PPARα-positive cells were observed among basal cells of the corneal epithelium in normal and alkali-burned corneas. The number of infiltrating neutrophils and macrophages at the corneal limbus was lower in the PPARα agonist group. Interleukin-1β (IL-1β), IL-6, IL-8, monocyte chemoattractant protein-1 (MCP-1), and vascular endothelial growth factor-An mRNA expression was suppressed in the PPARα agonist group compared to the Vehicle group. mRNA levels of nuclear factor kappa B (NF-κB) in corneal tissue were not different. However, NF-κB was expressed in the cytoplasm of basal cells in the PPARα agonist group and in the nucleus in the Vehicle group. MCP-1 was more weakly expressed in the PPARα agonist group. The PPARα agonist inhibited inflammation during the early phase after injury. Anti-inflammatory effects of the PPARα agonist included prevention of up-regulation of proinflammatory cytokines and MCP-1, and prevention of inflammatory cell infiltration into the injured cornea. Thus, a PPARα agonist may be a promising treatment for corneal injury.

Inhibitory effect of midazolam on MMP-9, MMP-1 and MMP-13 expression in PMA-stimulated human chondrocytes via recovery of NF-κB signaling

INTRODUCTION

Midazolam, a benzodiazepine, has a hypnotic effect and is widely used as an intravenous sedative. Past studies have clearly established that midazolam has beneficial effects in attenuating ischemia-reperfusion injury more than other currently used sedative drugs. However, the role of midazolam on chondroprotection via inhibition of matrix metalloproteinases (MMPs) is warrant investigation. The aim of this study was to examine the mechanisms of action of midazolam on MMP expression via nuclear factor κB (NF-κB) signaling in activated chondrosarcoma cells maintained in vitro.

MATERIAL AND METHODS

Chondrocytes, SW1353 cells, were stimulated with phorbol 12-myristate 13-acetate (PMA) in the absence or presence of various concentrations of midazolam (5-20 µM). Release of MMP-9 into the culture media was determined by gelatin zymography. The expressions of MMP-1, MMP-9 and MMP-13, phosphorylation of extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinases and degradation of IκB-α were determined by western blotting assay.

RESULTS

Midazolam significantly down-regulated PMA-induced MMP-9 protein expression at concentrations of 5, 10 and 20 µM, the values were 1.95 ±0.09 (p < 0.01), 1.71 ±0.12 (p < 0.01) and 1.35 ±0.20 (p < 0.001), respectively. At concentrations of 5, 10 and 20 µM, it was significantly inhibited the PMA-induced expressions of MMP-1 (2.27 ±0.10, 1.98 ±0.11 and 1.56 ±0.15; p < 0.001) and MMP-13 (0.89 ±0.04, 0.81 ±0.07, and 0.74 ±0.09; p < 0.001), respectively. Midazolam at concentrations of 10 and 20 µM for 15 min significantly reversed the rate of degradation (0.895 ±0.051; p < 0.05 and 0.926 ±0.060; p < 0.01, respectively) of IκB-α in PMA-chondrocyte cells. In addition, this sedative drug inhibited PMA-induced levels of phos-ERK (1.243 ±0.12, 1.108 ±0.16 and 0.903 ±0.19, respectively) and phos-p38 (1.146 ±0.10, 1.063 ±0.13 and 0.946 ±0.18, at concentrations of (5, 10 and 20 µM), respectively.

CONCLUSIONS

These results are important for understanding the mechanism of midazolam in inhibiting PMA-induced MMP expression through the signaling pathways of either NF-κB or ERK/p38 MAPKs down-regulation.

Activation of c-Src: a hub for exogenous pro-oxidant-mediated activation of Toll-like receptor 4 signaling

To study the role of c-Src kinase in pro-oxidant-induced stimulation of Toll-like receptor 4 (TLR4), we used lipopolysaccharide from Escherichia coli K12 (LPS-EK) and monophosphoryl lipid A, as TLR4-specific agonists and positive controls, and SIN-1 and potassium peroxychromate as pro-oxidant sources. We used the HEK-Blue mTLR4 cell line, which is stably transfected with mouse TLR4 and expresses optimized SEAP reporter under the control of a promoter inducible by NF-κB transcription factor. The level of SEAP released due to TLR4 stimulation was a measure of NF-κB activation. Treatment with either the pro-oxidants or LPS-EK increased SEAP release and TNF-α production in these cells. These treatments also increased intracellular reactive oxygen species accumulation, with an enhanced production of nitric oxide and TBARS to confirm oxidant stress in these cells. Pretreatment with c-Src kinase inhibitors, PP2 and Ca-pY, which act by different mechanisms, decreased these parameters. Pretreatment with SSG, a c-Src activator, enhanced the effects promoted by LPS-EK and pro-oxidants and rescued cells from the PP2- and Ca-pY-induced effects. Curiously, pro-oxidants, but not TLR4 agonist, increased the ratio of TNF-α to IL-10 released, suggesting that pro-oxidants can initiate and maintain an imbalance of TNF-α production over IL-10. To different degrees, both pro-oxidants and TLR4 agonist increased formation of c-Src complexes with TLR4 and IκB-α as coimmunoprecipitates. Both pro-oxidants and TLR4 agonist increased c-Src phosphorylation of the Tyr42 residue in IκB-α, but the pro-oxidant-induced effect was more robust and much longer lasting. Taken together, these studies provide a mechanism whereby c-Src assumes a central role in pro-oxidant-induced NF-κB activation in TLR4 signaling. Pro-oxidant-induced activation of TLR4 through c-Src/NF-κB/IκB-α coupling provides a basis for a molecular dissection of the initiation and maintenance of sterile inflammation that may serve as a "pathophysiologic primer" for many diseases.

Licorice-derived dehydroglyasperin C increases MKP-1 expression and suppresses inflammation-mediated neurodegeneration

Recent studies have demonstrated that microglial hyperactivation-mediated neuroinflammation is involved in the pathogenesis of several neurodegenerative diseases. Thus, inhibiting microglial production of the neurotoxic mediator tumor necrosis factor-α (TNF-α) is considered a promising strategy to protect against neurodegeneration. Here, we investigated the inhibitory effect of licorice-derived dehydroglyasperin C (DGC) on lipopolysaccharide (LPS)-induced TNF-α production and inflammation-mediated neurodegeneration. We found that DGC pre-treatment attenuated TNF-α production in response to LPS stimulation of BV-2 microglia. DGC pre-treatment attenuated LPS-induced inhibitor of κB-α (IκB-α) and p65 phosphorylation and decreased the DNA binding activity of nuclear factor-κB (NF-κB). DGC pre-treatment also inhibited LPS-mediated phosphorylation of p38 mitogen-activated protein kinases (MAPKs) and extracellular signal-regulated kinase (ERK). Interestingly, DGC treatment of BV-2 microglia significantly increased MAPK phosphatase 1 (MKP-1) mRNA and protein expression, which is a phosphatase of p38 MAPK and ERK, suggesting that the DGC-mediated increase in MKP-1 expression might inhibit LPS-induced MAPKs and NF-κB activation and further TNF-α production. We also found that LPS-mediated microglial neurotoxicity can be attenuated by DGC. The addition of conditioned media (CM) from DGC- and LPS-treated microglia to neurons helped maintain healthy cell body and neurite morphology and increased the number of microtubule-associated protein 2-positive cells and the level of synaptophysin compared to treatment with CM from LPS-treated microglia. Taken together, these data suggest that DGC isolated from licorice may inhibit microglia hyperactivation by increasing MKP-1 expression and acting as a potent anti-neurodegenerative agent.

Mechanisms of p53 Functional De-Regulation: Role of the IκB-α/p53 Complex

TP53 is one of the most frequently-mutated and deleted tumor suppressors in cancer, with a dramatic correlation with dismal prognoses. In addition to genetic inactivation, the p53 protein can be functionally inactivated in cancer, through post-transductional modifications, changes in cellular compartmentalization, and interactions with other proteins. Here, we review the mechanisms of p53 functional inactivation, with a particular emphasis on the interaction between p53 and IκB-α, the NFKBIA gene product.

Emodin Reverses Gemcitabine Resistance of Pancreatic Cancer Cell Lines Through Inhibition of IKKβ/NF-κB Signaling Pathway

Background

Pancreatic cancer is one of the most malignant tumors, and gemcitabine has been considered as the standard treatment and been widely utilized as a first-line drug for advanced pancreatic cancer, but gemcitabine-resistance always occurs after a short period of treatment.

Methods

Two pancreatic cancer cell lines Panc-1 and MIA-PaCa-2 were used as the study subject and their gemcitabine-resistant cells were established. Both drug-resistant cells were divided into four groups: blank, emodin, gemcitabine, and emodin+gemcitabine. Cell viability was detected by MTT assay. Flow cytometry was performed to detect cell apoptosis rate and P-gp function. Quantitative real-time polymerase chain reaction and Western blotting were used to detect Survivin, XIAP, Caspase-9/3, NF-κB p65, IKKβ and IκB-α mRNA/protein expressions, respectively. Electrophoretic mobility shift assay (EMSA) was performed to detect NF-κB binding activity. Rhodamine 123 efflux assay was used to detect P-gp function.

Results

Emodin could inhibit cell activity in all cell lines. Both emodin and gemcitabine can significantly increase the apoptosis rate, and the combination of the two drugs can further significantly increase the apoptosis rate in normal pancreatic cancer cell lines. In both drug-resistant pancreatic cancer cell lines, it can be observed that although gemcitabine can increase the apoptosis rate, the effect of promoting apoptosis is significantly lower than that of emodin; the drug combination can still significantly increase the apoptosis rate on the basis of emodin alone. Emodin can significantly reduce the mRNA and protein expression levels of Survivin, XIAP, NF-κB, and IKKβ, and significantly increase the mRNA and protein expression levels of Caspase-3/9 and IκB-α. Emodin significantly reduced NF-κB activity and emodin significantly promoted P-gp fluorescence intensity from Rhodamine 123 efflux assay.

Conclusion

Emodin inhibits the expression of IKKβ, thereby inhibiting the expression and activity of downstream NF-κB, and inhibits P-gp function at the same time, ultimately achieving the purpose of reversing the drug-resistance of pancreatic cancer cell lines.

(5R)-5-hydroxytriptolide inhibits the inflammatory cascade reaction in astrocytes

Many studies have shown that (5R)-5-hydroxytriptolide is the optimal modified analogue of triptolide, possessing comparable immunosuppressive activity but much lower cytotoxicity than triptolide. Whether (5R)-5-hydroxytriptolide has preventive effects on neuroinflammation is unclear. This study was designed to pretreat primary astrocytes from the brains of neonatal Sprague-Dawley rats with 20, 100 and 500 nM (5R)-5-hydroxytriptolide for 1 hour before establishing an in vitro neuroinflammation model with 1.0 μg/mL lipopolysaccharide for 24 hours. The generation of nitric oxide was detected by Griess reagents. Astrocyte marker glial fibrillary acidic protein was measured by immunohistochemical staining. The levels of tumor necrosis factor-α and interleukin-1β in the culture supernatant were assayed by enzyme linked immunosorbent assay. Nuclear factor-κB/p65 expression was examined by immunofluorescence staining. The phosphorylation of inhibitor of nuclear factor IκB-α and the location of nuclear factor-κB/P65 were determined using western blot assay. Our data revealed that (5R)-5-hydroxytriptolide inhibited the generation of nitric oxide, tumor necrosis factor-α and interleukin-1β from primary astrocytes activated by lipopolysaccharide, decreased the positive reaction intensity of glial fibrillary acidic protein, reduced the expression of tumor necrosis factor alpha and interleukin-1β in culture supernatant, inhibited the phosphorylation of IκB-α and the translocation of nuclear factor-κB/P65 to the nucleus. These results have confirmed that (5R)-5-hydroxytriptolide inhibits lipopolysaccharide-induced glial inflammatory response and provides cytological experimental data for (5R)-5-hydroxytriptolide in the treatment of neurodegenerative diseases.

In vitro and in vivo assessment of the protective effect of sufentanil in acute lung injury

Objectives

To investigate the mechanisms underlying the protective effect of sufentanil against acute lung injury (ALI).

Material and Methods

Rats were administered lipopolysaccharide (LPS) by endotracheal instillation to establish a model of ALI. LPS was used to stimulate BEAS-2B cells. The targets and promoter activities of IκB were assessed using a luciferase reporter assay. Apoptosis of BEAS-2B cells was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling.

Results

Sufentanil treatment markedly reduced pathological changes in lung tissue, pulmonary edema and secretion of inflammatory factors associated with ALI in vivo and in vitro. In addition, sufentanil suppressed apoptosis induced by LPS and activated NF-κB both in vivo and in vitro. Furthermore, upregulation of high mobility group box protein 1 (HMGB1) protein levels and downregulation of miR-129-5p levels were observed in vivo and in vitro following sufentanil treatment. miR-129-5p targeted the 3ʹ untranslated region and its inhibition decreased promoter activities of IκB-α. miR-129-5p inhibition significantly weakened the protective effect of sufentanil on LPS-treated BEAS-2B cells.

Conclusion

Sufentanil regulated the miR-129-5p/HMGB1 axis to enhance IκB-α expression, suggesting that sufentanil represents a candidate drug for ALI protection and providing avenues for clinical treatment.

Involvement of Rho-kinase/IκB-α/NF-κB activation in IL-1β-induced inflammatory response and oxidative stress in human chondrocytes

It has been clearly indicated that osteoarthritis (OA) is an inflammatory and degenerative disease that could be promoted by Rho-kinase (ROCK); however, little is known about the role of ROCK/inhibitor κB alpha (IκB-α)/nuclear factor-κB (NF-κB) p65 pathway activation in interleukin-1β (IL-1β) induced inflammatory response and oxidative stress in primary human chondrocytes. To test this hypothesis, we focused on determining ROCK-II, IκB-α, p-IκB-α, NF-κB p65, p-NF-κB p65, IL-6, tumor necrosis factor alpha (TNF-α), cyclooxygenase-2 (COX-2), p22phox, and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subtype 4 (NOX4) protein expression, ROCK-II activity, NADPH oxidase levels, and total antioxidant capacity (TAC) in the presence and absence of ROCK-inhibitor fasudil. IL-1β (2 ng·mL-1, 24 h) increased the expression of ROCK-II, p-IκB-α, NF-κB p65, p-NF-κB p65, IL-6, TNF-α, COX-2, and p22phox proteins, and decreased the expression of IκB-α, and the NOX4 protein level did not alter. ROCK activity and NADPH oxidase levels were increased, whereas the TAC was decreased by IL-1β. Fasudil (10-5-10-7 M) reversed all these changes induced by IL-1β. These results demonstrate that ROCK/IκB-α/NF-κB p65 pathway activation contributes to the IL-1β-induced inflammatory response and oxidative stress, and thus, ROCK inhibition might be a beneficial treatment option for OA patients mainly based on its anti-inflammatory and antioxidant effects.

Nuclear Factor-κB is Activated in Filter-Implanted Vena Cava

BACKGROUND

Implantation of a retrievable vena cava filter (VCF) is an effective method for preventing pulmonary embolism. Retrieval of filters, however, may be difficult due to intimal hyperplasia and inflammation in the cava wall. The transcription factor nuclear factor-kappaB (NF-κB) plays an important role in regulation of numerous genes participating in the inflammatory and proliferative responses of cells. The present study was to determine whether VCF implantation resulted in activation of NF-κB in the venous neointima.

METHODS

Filters were placed in vena cava (VC) in four swine for 30 days and then removed. Intimal specimens adhering to the filter struts were analyzed with reference to normal VC tissues. Immunohistochemical analyses were used to assess the NF-κB subunits p65 and p50 and the phosphorylated inhibitor of κB-α (phosphor-IκB-α) in the tissues. NF-κB DNA-binding activity was measured with enzyme-linked immunosorbent assay.

RESULTS

As compared to normal VC tissues, the intimal tissues contained higher percentages of cell nucleus-located p65 and p50, and NF-κB DNA-binding activity. Elevated immunoreactivities of p65, p50 and phosphor-IκB-α were also present in the intima.

CONCLUSION

The present study demonstrates for the first time that VCF implantation caused NF-κB activation in neointima. We further demonstrate the activation is at least partly due to phosphorylation of IκB-α. Our data suggest that NF-κB activation would significantly contribute to development of intimal hyperplasia and inflammation in filter-inserted vena cava walls. NF-κB might be a therapeutic target for inhibiting filter-induced neointima and improving filter retrieval.

The effect of specific IKKβ inhibitors on the cytosolic expression of IκB-α and the nuclear expression of p65 in dystrophic (MDX) muscle

The efficacy of two highly specific IκB-α kinase β (IKK-β) inhibitors in reducing the enhanced basal activation of the NF-κB pathway in dystrophic muscle was assessed by determining the effects of these inhibitors in increasing the expression of cytosolic IκB-α and reducing the enhanced expression of nuclear p65 in adult mdx costal diaphragm preparations. In vivo and in vitro treatment with BMS-345541 was ineffective at altering these variables when administered at concentrations that were highly effective in models of acute inflammation. PHA-408 increased cytosolic IκB-α and reduced nuclear p65 at a concentration in vitro (20 μM) that was 500 fold higher than the IC50 for inhibiting purified activity. Long term daily oral administration of PHA-408 increased cytosolic IκB-α but did not influence nuclear p65. Long term intraperitoneal administration of PHA-408 reduced nuclear p65 by approximately 50%. In comparison to their potent effects in models of acute inflammation, these results indicate a reduced efficacy of the specific IKKβ inhibitors in ameliorating the enhanced basal activation of the NF-κB pathway in dystrophic muscle, and suggest that the therapeutic potential of IKK-β inhibitors in treating muscular dystrophy would be enhanced by simultaneous treatment with agents which more directly interfere with NF-κB transactivation.

Reduced IκB-α Protein Levels in Peripheral Blood Cells of Patients with Multiple Sclerosis-A Possible Cause of Constitutive NF-κB Activation

NF-κB signaling pathways are dysregulated in both the central nervous system (CNS) and peripheral blood cells in multiple sclerosis (MS), but the cause of this is unknown. We have recently reported that peripheral blood mononuclear cells (PBMC) of patients with MS have increased constitutive activation and translocation of the transcription factor NF-κB to the nucleus compared to healthy subjects. NF-κB can be activated through either canonical or non-canonical pathways. In the canonical pathway, activation of NF-κB is normally negatively regulated by the inhibitor IκB. We therefore hypothesized that the increased activation of NF-κB could be caused by reduced IκB-α in the cells of patients with MS, possibly due to increased activity of the IκB kinase (IKK) complex, which regulates IκB-α. Alternatively, changes to the activity of key molecules in the non-canonical pathway, such as IKKα, could also lead to increased NF-κB activation. We therefore used Western blotting to detect IκB-α levels and ELISA to investigate NF-κB DNA binding activity and phosphorylation of IKKα and IKKβ in samples from PBMC of MS patients and controls. The level of full-length IκB-α protein in the cytosolic fraction of PBMC of MS patients was significantly reduced compared to healthy subjects, with significantly more evidence of multiple low molecular weight putative degradation products of IκB-α present in MS patients compared to healthy subjects. Conversely, the level of NF-κB DNA binding activity was increased in whole cell lysates from MS patients. Both IKKα and IKKβ showed increased overall activity in MS compared to healthy subjects, although not all of the MS patients showed increased activity compared to the healthy subjects, suggesting that there may be several different mechanisms underlying the constitutive activation of NF-κB in MS. Taken together, these findings suggest that there may be multiple points at which the NF-κB pathway is dysregulated in MS and that decreased levels of the full-length IκB-α protein are a major component in this.

The Gastroprotective Effects of Anisomeles indica against Ethanol-Induced Gastric Ulcer through the Induction of IκB-α and the Inhibition of NF-κB Expression

Anisomeles indica (L.) Kuntze is a traditional herb with multiple medicinal properties and with potential for preventing or treating various diseases. Acteoside, one of the active ingredients in A. indica, is prepared into commercially available products of A. indica HP813 powder. In this study, the gastroprotective effects of A. indica HP813 powder were evaluated. Wistar rats were treated with A. indica HP813 powder at doses of 0, 207.5, 415, and 830 mg/kg body weight for 28 days. Then, gastric ulcers were induced by the oral administration of 70% ethanol (10 mL/kg body weight) on day 28. The rats were sacrificed at the end of the trial, and stomach tissues were collected. These stomach tissues were then used for macroscopic, microscopic, and immunohistochemical analyses. The results indicated that the area of gastric ulcer was 48.61%, 35.30%, and 27.16% in the ethanol-induced group, 415 mg/kg A. indica HP813 powder group, and 830 mg/kg A. indica HP813 powder group, respectively. In addition, the lesion scores were 2.9, 2.4, and 2.3 in the ethanol-induced group, 415 mg/kg A. indica HP813 powder group, and 830 mg/kg A. indica HP813 powder group, respectively. The immunochemical staining of the gastric tissue revealed that A. indica HP813 powder reduced the expressions of TNF-α and NF-κB proteins in the gastric tissue, which had been induced by ethanol. Finally, A. indica HP813 powder protected the gastric ulcer from ethanol damage through IκB-α induction. The present results demonstrated that A. indica HP813 powder has protective effects against ethanol-induced gastric ulcer.