NF-kappa B and Rel: participants in a multiform transcriptional regulatory system

Lower malathion concentrations reduce testosterone biosynthesis by Leydig TM3 cells in vitro by altering cellular redox profile and inducing oxidative damage

Malathion is an organophosphate pesticide used in agriculture and control of the Aedes aegypti mosquito. As previous reports have indicated the potential of malathion to compromise testosterone production in in vivo models, the objective of this study was to elucidate the mechanisms underlying the impairment of Leydig cell function, considering its critical role in male reproductive function. To this end, murine Leydig TM3 cells were exposed to concentrations of 1, 10, 100 or 1000 μM malathion for 24 h for evaluation of the compound on cell viability. Subsequently, concentrations of 1, 10, and 100 μM malathion were employed for a 24-h period to assess testosterone biosynthesis, levels of cytokines IL-1β, IL-6, IL-10, and TNF-α, as well as the redox profile. Malathion exerted a concentration-dependent impact on cell viability. Notably, the lower concentrations of malathion (1 and 10 μM) were found to impair testosterone biosynthesis in TM3 cells. While there were changes in IL-1 and TNF-α levels at specific concentrations, no direct correlation with altered hormone production was established. Our investigation revealed that varied malathion concentrations induced oxidative stress by increase in superoxide anion and a compensatory rise in antioxidants. In conclusion, the observed changes in the oxidative profile of TM3 cells were linked to functional impairment, evidenced by reduced testosterone biosynthesis at lower malathion concentrations.

STAM2 negatively regulates the MyD88-mediated NF-κB signaling pathway in miiuy croaker, Miichthys miiuy

Signal transducing adapter molecule 2 (STAM2), a member of the Signal Transducing Adapter Molecule (STAM) family, is a protein with significant implications in diverse signaling pathways and endocytic membrane trafficking. However, the role of the STAM2, especially in fish, remains largely unknown. In this study, we discovered that STAM2 negatively regulates the NF-κB signaling pathway, and its inhibitory effect is enhanced upon LPS induction. Our study confirmed that STAM2 can enhance the degradation of myeloid differentiation primary-response protein 88 (MyD88), an upstream regulator of NF-κB pathway. Furthermore, the UIM domain of STAM2 is important for the inhibition of MyD88. Mechanistically, STAM2 inhibits the NF-κB signaling pathway by targeting the MyD88 autophagy pathway. In addition, we showed that STAM2 promotes the proliferation of Vibrio harveyi. In summary, our study reveals that STAM2 inhibits NF-κB signaling activation and mediates innate immunity in teleost via the autophagy pathway.

Protein kinase double-stranded RNA-dependent (PKR) in antiviral defence in fish and mammals

The interferon-inducible double-stranded RNA-dependent protein kinase (PKR) is one of the key antiviral arms of the innate immune system. Upon binding of viral double stranded RNA, a viral Pattern Associated Molecular Pattern (PAMP), PKR gets activated and phosphorylates the eukaryotic initiation factor 2α (eIF2α) resulting in a protein shut-down that limits viral replication. Since its discovery in the mid-seventies, PKR has been shown to be involved in multiple important cellular processes including apoptosis, proinflammatory and innate immune responses. Viral subversion mechanisms of PKR underline its importance in the antiviral response of the host. PKR activation pathways and its mechanisms of action were previously identified and characterised mostly in mammalian models. However, fish Pkr and fish-specific paralogue Z-DNA-dependent protein kinase (Pkz) also play key role in antiviral defence. This review gives an update on the current knowledge on fish Pkr/Pkz, their conditions of activation and their implication in the immune responses to viruses, in comparison to their mammalian counterparts.

Conferone, a coumarin from Ferula flabelliloba, induced toxic effects on adult T-cell leukemia/lymphoma cells

BACKGROUND

Adult T-cell leukemia/lymphoma (ATL) is a lymphoid malignancy caused by HTLV-1 infection, with distinct geographical distribution. Despite advances in cancer treatment, the average survival rate of ATL is low. Conferone is a natural coumarin extracted from Ferula species with a wide range of pharmaceutical effects. In search for a novel chemotherapeutic agent, we investigated the cytotoxicity of conferone on ATL cells.

METHODS

To obtain conferone, the methanolic extract of the roots of F. flabelliloba was subjected to silica gel column chromatography, followed by 1H- and 13C-NMR to confirm its structure. For cytotoxicity assay, MT-2 cells were treated with different concentrations of conferone (2.5, 5, 10, 20, and 40 µM) for 24, 48, and 72 h, and viability was evaluated by a colorimetric assay using alamarBlue. Cell cycle was analyzed by PI staining and flow cytometry, and qPCR was used to study the expression of candidate genes.

RESULTS AND CONCLUSION

Obtained findings indicated that conferone induced considerable cytotoxic effects on MT-2 cells in a time- and dose-dependent manner. In addition, accumulation of cells in the sub-G1 phase of the cell cycle was detected upon conferone administration. Moreover, conferone reduced the expression of CDK6, c-MYC, CFLIPL, and NF-κB (Rel-A) in MT-2 cells. Accordingly, conferone could be considered as a potent agent against ATL, although complementary investigations are required to define more precisely its mechanism of action.

Non-coding RNAs targeting NF-κB pathways in aquatic animals: A review

Nuclear factor-kappa B (NF-κB) pathways have a close relationship with many diseases, especially in terms of the regulation of inflammation and the immune response. Non-coding RNAs (ncRNAs) are a heterogeneous subset of endogenous RNAs that directly affect cellular function in the absence of proteins or peptide products; these include microRNAs (miRNAs), long noncoding RNAs (lncRNAs), circular RNAs (circRNAs), etc. Studies on the roles of ncRNAs in targeting the NF-κB pathways in aquatic animals are scarce. A few research studies have confirmed detailed regulatory mechanisms among ncRNAs and the NF-κB pathways in aquatic animals. This comprehensive review is presented concerning ncRNAs targeting the NF-κB pathway in aquatic animals and provides new insights into NF-κB pathways regulatory mechanisms of aquatic animals. The review discusses new possibilities for developing non-coding-RNA-based antiviral applications in fisheries.

Induction of Human Oral Squamous Carcinoma Apoptosis by Derris scandens Benth and Elephantopus scaber Linn Extracts

D scandens ( Derris scandens Benth.) and E scaber ( Elephantopus scaber Linn.) contain flavonoids and phenolic acids, which have antitumor activity in various cancer cell lines. Oral cancer is among the most common cancers in Southeast Asia, and the survival rate remains low. Thus, this study screened 2 ethanolic plant extracts for cytotoxicity on the oral human squamous carcinoma cell line (HSC-2), and compared the mechanisms of action. Extracts of D scandens and E scaber showed cytotoxicity against HSC-2 cells in a dose-dependent manner. Observation of nuclear morphology by Hoechst 33342 staining revealed chromatin condensation. Apoptosis was confirmed by Annexin V-FITC staining and cell sorting (fluorescence-activated cell sorting) analysis. We demonstrated that cancer apoptosis was accompanied by changes in the expression of procaspase 3 and that D scandens-mediated apoptosis in HSC-2 cells was potentiated by protein kinase B (Akt) and B-cell lymphoma-2 (Bcl-2), while E scaber apoptosis was mediated by mitogen-activated protein kinase (MAPK) pathways, involving stress-activated protein kinases/jun amino-terminal kinase (SAPK/JNK) and p38-MAPK. Further investigation into targets for apoptosis induction by these plant extracts may have potential in oral cancer therapy.

MYD88 Mutations: Transforming the Landscape of IgM Monoclonal Gammopathies

The MYD88 gene has a physiological role in the innate immune system. Somatic mutations in MYD88, including the most common L265P, have been associated with the development of certain types of lymphoma. MYD88L265P is present in more than 90% of patients with Waldenström's macroglobulinemia (WM) and IgM monoclonal gammopathy of undetermined significance (IgM-MGUS). The absence of MYD88 mutations in WM patients has been associated with a higher risk of transformation into aggressive lymphoma, resistance to certain therapies (BTK inhibitors), and shorter overall survival. The MyD88 signaling pathway has also been used as a target for specific therapies. In this review, we summarize the clinical applications of MYD88 testing in the diagnosis, prognosis, follow-up, and treatment of patients. Although MYD88L265P is not specific to WM, few tumors present a single causative mutation in a recurrent position. The role of the oncogene in the pathogenesis of WM is still unclear, especially considering that the mutation can be found in normal B cells of patients, as recently reported. This may have important implications for early lymphoma detection in healthy elderly individuals and for the treatment response assessment based on a MYD88L265P analysis.

microRNA-144 modulates the NF-κB pathway in miiuy croaker (Miichthys miiuy) by targeting IκBα gene

MicroRNAs (miRNA) are non-coding RNAs that regulate many biochemical processes, such as cell growth, proliferation and immune responses. In this study, we investigated miR-144 as a regulator of IκBα that promotes the activation of NF-κB signaling pathway. And IκBα interact with p65 blocks nuclear translocation of NF-κB and anchors NF-κB in cytoplasmic quiescent cells in an inactive form. The seed region of miR-144 can regulate gene expression by binding to the 3' UTR of IκBα and repress IκBα expression at the post-transcriptional level. More importantly, miR-144 can promote the activation of p65 by inhibiting IκBα, thus affecting the NF-κB signaling pathway. Thus, preventing excessive inflammatory responses from causing autoimmune diseases will help to further understand the immunoregulatory mechanisms of miRNAs in fish after invasion by pathogens.

NOP56 negatively regulates MyD88-mediated NF-κB signaling in miiuy croaker, Miichthys miiuy

MyD88 is a critical adaptor in the TLRs signaling pathway, which can activate NF-κB signaling pathway and promote proinflammatory cytokines production. However, the molecular mechanisms that modulate MyD88 expression, especially in teleost, remain largely unknown. In this study, we showed that NOP56 serve as a negative regulator of the MyD88-mediated NF-κB signaling pathway. NOP56 overexpression inhibited the protein expression of MyD88. Whereas, siRNA knockdown of NOP56 had opposite effect. Furthermore, we found that the NOSIC domain is responsible for the suppressive effect of NOP56 in MyD88 expression at protein level. Therefore, we identified NOP56 as a negative regulator of MyD88-mediated NF-κB signaling by inhibiting MyD88 expression and provided new insight into the regulation mechanism in teleost fish.

Luteolin-3'-O-Phosphate Inhibits Lipopolysaccharide-Induced Inflammatory Responses by Regulating NF-κB/MAPK Cascade Signaling in RAW 264.7 Cells

Luteolin (LT), present in most plants, has potent anti-inflammatory properties both in vitro and in vivo. Furthermore, some of its derivatives, such as luteolin-7-O-glucoside, also exhibit anti-inflammatory activity. However, the molecular mechanisms underlying luteolin-3′-O-phosphate (LTP)-mediated immune regulation are not fully understood. In this paper, we compared the anti-inflammatory properties of LT and LTP and analyzed their molecular mechanisms of action; we obtained LTP via the biorenovation of LT. We investigated the anti-inflammatory activities of LT and LTP in macrophage RAW 264.7 cells. We confirmed from previously reported literature that LT inhibits the production of nitric oxide and prostaglandin E₂, as well as the expression of inducible NO synthetase and cyclooxygenase-2. In addition, expressions of inflammatory genes and mediators, such as tumor necrosis factor-α, interleukin-6, and interleukin-1β, were suppressed. LTP showed anti-inflammatory activity similar to LT, but better anti-inflammatory activity in all the experiments, while also inhibiting mitogen-activated protein kinase and nuclear factor-kappa B more effectively than LT. At a concentration of 10 μM, LTP showed differences of 2.1 to 44.5% in the activity compared to LT; it also showed higher anti-inflammatory activity. Our findings suggest that LTP has stronger anti-inflammatory activity than LT.

TC2N: A Novel Vital Oncogene or Tumor Suppressor Gene In Cancers

Several C2 domain-containing proteins play key roles in tumorigenesis, signal transduction, and mediating protein–protein interactions. Tandem C2 domains nuclear protein (TC2N) is a tandem C2 domain-containing protein that is differentially expressed in several types of cancers and is closely associated with tumorigenesis and tumor progression. Notably, TC2N has been identified as an oncogene in lung and gastric cancer but as a tumor suppressor gene in breast cancer. Recently, a large number of tumor-associated antigens (TAAs), such as heat shock proteins, alpha-fetoprotein, and carcinoembryonic antigen, have been identified in a variety of malignant tumors. Differences in the expression levels of TAAs between cancer cells and normal cells have led to these antigens being investigated as diagnostic and prognostic biomarkers and as novel targets in cancer treatment. In this review, we summarize the clinical characteristics of TC2N-positive cancers and potential mechanisms of action of TC2N in the occurrence and development of specific cancers. This article provides an exploration of TC2N as a potential target for the diagnosis and treatment of different types of cancers.

microRNA-132 as a negative regulator in NF-κB signaling pathway via targeting IL-1β in miiuy croaker

The innate immune system is the first line of defense against the invasion of pathogens. It can make a rapid immune response to the invading pathogenic microorganisms, thereby eliminating the invading pathogens and protecting the body from harm. microRNAs are a family of small non-coding ribonucleic acid molecules, which are important and multifunctional regulator of immune response. In this study, we studied the role of miR-132 as a key regulatory factor of IL-1β-mediated inflammation. The seed region of miR-132 can regulate gene expression by binding to the 3'UTR of IL-1β, and inhibit the expression of IL-1β at the post-transcriptional level. More importantly, miR-132 inhibits LPS-induced NF-κB signaling pathway by targeting IL-1β, thereby preventing excessive inflammatory response from causing autoimmune diseases. These results will help to better understand the complex regulatory mechanisms of teleost fishes.

Investigating the effects of carvacrol in rats using oxygen-induced retinopathy model

Purpose:

Investigating the effects of intraperitoneal carvacrol administration in rats using the oxygen-induced retinopathy (OIR) model.

Methods:

A total of 28 newborn Sprague Dawley rats were used and the OIR model was created using the 50/10% oxygen model. The study composed of four groups in total. While the OIR model was not used in Group I (control group), it was created for Groups II, III, and IV. About 0.01 mL carvacrol, bevacizumab, or 0.9% NaCl was administered intraperitoneal (IP) to the rats in all groups on postnatal day (PND) 14 as follows: Group I and Group II were administered 0.9% NaCl, Group III was administered bevacizumab, and Group IV was administered carvacrol. On PND 18, rats were sacrificed and their right eyes were enucleated.

Results:

Histopathological and immunohistochemical studies showed that the number of vascular endothelial cells (VECs), vascular endothelial growth factor (VEGF), and tumor necrosis factor-α (TNF-α) decreased similarly in Group III and Group IV compared with Group II. VECs values for Group I, Group II, Group III, and Group IV were measured as 0 ± 0, 26.45 ± 4.57, 7.75 ± 1.98, and 5.78 ± 1.72, respectively, and it differed significantly between groups (P < 0.001). Likewise, VEGF levels were observed as 0.06 ± 0.01, 3.31 ± 0.53, 2.47 ± 0.44, and 2.49 ± 0.52, respectively, and it differed significantly between groups (P < 0.001). TNF-α levels were recorded as 0.06 ± 0.01, 3.58 ± 0.38, 2.46 ± 0.49, and 2.29 ± 0.25, respectively, and it differed significantly between groups (P < 0.001). VECs, VEGF, and TNF-α were similar between Group III and IV (range of P values were 0.486–0.998).

Conclusion:

The study demonstrated that carvacrol significantly reduced retinal pathological angiogenesis, NV, VEC nuclei count, VEGF, and TNF-α levels. Moreover, the observed effects were comparable to those of bevacizumab.

Suprabasin-derived bioactive peptides identified by plasma peptidomics

Identification of low-abundance, low-molecular-weight native peptides using non-tryptic plasma has long remained an unmet challenge, leaving potential bioactive/biomarker peptides undiscovered. We have succeeded in efficiently removing high-abundance plasma proteins to enrich and comprehensively identify low-molecular-weight native peptides using mass spectrometry. Native peptide sequences were chemically synthesized and subsequent functional analyses resulted in the discovery of three novel bioactive polypeptides derived from an epidermal differentiation marker protein, suprabasin. SBSN_HUMAN[279-295] potently suppressed food/water intake and induced locomotor activity when injected intraperitoneally, while SBSN_HUMAN[225-237] and SBSN_HUMAN[243-259] stimulated the expression of proinflammatory cytokines via activation of NF-κB signaling in vascular cells. SBSN_HUMAN[225-237] and SBSN_HUMAN[279-295] immunoreactivities were present in almost all human organs analyzed, while immunoreactive SBSN_HUMAN[243-259] was abundant in the liver and pancreas. Human macrophages expressed the three suprabasin-derived peptides. This study illustrates a new approach for discovering unknown bioactive peptides in plasma via the generation of peptide libraries using a novel peptidomic strategy.

IRF11 enhances the inhibitory effect of IκBα on NF-κB activation in miiuy croaker

NF-κB is a typical transcription factor that regulates expression of various genes involved in inflammatory and immune responses. Therefore, it is essential that NF-κB signaling tightly regulated to maintain immune balance. Compared with those of mammals, the regulatory mechanisms of NF-κB signaling is rarely reported in teleost fish. IκBα is a prominent negative feedback regulator in the NF-κB signaling system. In this study, we determined that IRF11 enhances the inhibitory effect of IκBα on NF-κB activation in teleost fish. Overexpression of IRF11 can inhibit IκBα degradation, whereas its knockdown has the opposite effect of IκBα. Our study further indicates that IκBα was regulated via ubiquitin-proteasome degradation pathway, IRF11 inhibits IκBα in ubiquitin-proteasome degradation. This study provides a novel evidence on the regulation of innate immune signaling pathways in teleost fish and thus provides new insights into the regulatory mechanisms in mammals.

Human galectin-16 has a pseudo ligand binding site and plays a role in regulating c-Rel-mediated lymphocyte activity

BACKGROUND

The structure of human galectin-16 (Gal-16) has yet to be solved, and its function has remained elusive.

METHODS

X-ray crystallography was used to determine the atomic structures of Gal-16 and two of its mutants. The Gal-16 oligomer state was investigated by gel filtration, its hemagglutination activity was determined along with its ability to bind lactose using ITC. The cellular distribution of EGFP-tagged Gal-16 in various cell lines was also investigated, and the interaction between Gal-16 and c-Rel was assessed by pull-down studies, microscale thermophoresis and immunofluorescence.

RESULTS

Unlike other galectins, Gal-16 lacks the ability to bind the β-galactoside lactose. Lactose binding could be regained by replacing an arginine (Arg55) with asparagine, as shown in the crystal structures of two lactose-loaded Gal-16 mutants (R55N and R55N/H57R). Gal-16 was also shown to be monomeric by gel filtration, as well as in crystal structures. Thus, this galectin could not induce erythrocyte agglutination. EGFP-tagged Gal-16 was found to be localized mostly in the nucleus of various cell types, and can interact with c-Rel, a member of NF-κB family.

CONCLUSIONS

Gal-16 exists as a monomer and its ligand binding is significantly different from that of other prototype galectins, suggesting that it has a novel function(s). The interaction between Gal-16 and c-Rel indicates that Gal-16 may regulate signal transduction pathways via the c-Rel hub in B or T cells at the maternal-fetal interface.

GENERAL SIGNIFICANCE

The present study lays the foundation for further studies into the cellular and physiological functions of Gal-16.

Downregulation of miR-1225-5p is pivotal for proliferation, invasion, and migration of HCC cells through NFκB regulation

Background

As one of the most frequently seen malignancies, hepatocellular carcinoma (HCC) serves as the second largest contributor to malignancy‐specific mortality worldwide. MicroRNA‐1225‐5p (miR‐1225) exerts an essential impact on the growth and metastasis of many malignancies. However, the contribution of miR‐125 to HCC and the molecular mechanism of cancer cell viability and apoptosis are still unclear. We focused our research on exploring the function and molecular mechanism of miR‐1225 in regulating HCC cell growth, migration, and invasion.

Material

Quantitative PCR data showed that miR‐1225 expression was repressed in HCC cell lines and in the tissues of HCC patients, compared to that in normal human hepatic cells and tissues. Transfection of a miR‐1225 mimic inhibited cell viability and proliferation as indicated by CCK‐8 staining and MTT assay. Transwell invasion, wound healing assay, and Western blotting were performed to assess whether miR‐1225 repressed the metastasis and invasion of HCC cells, and decreased matrix metalloproteinase 9 (MMP9) expression. Further bioinformatic prediction and dual‐luciferase reporter assay suggested that miR‐1225 targeted the 3′‐UTR of NFκB p65.

Results

Overexpression of p65 protein counteracted the repressive impact of miR‐1225 on invasion, migration, and proliferation of HCC cells.

Conclusion

This research provided new evidences that miR‐1225 inhibits the viability, migration, and invasion of HCC cells by downregulation of p65.

Molecular Targets of Natural Products for Chondroprotection in Destructive Joint Diseases

Osteoarthritis (OA) is the most common type of arthritis that occurs in an aged population. It affects any joints in the body and degenerates the articular cartilage and the subchondral bone. Despite the pathophysiology of OA being different, cartilage resorption is still a symbol of osteoarthritis. Matrix metalloproteinases (MMPs) are important proteolytic enzymes that degrade extra-cellular matrix proteins (ECM) in the body. MMPs contribute to the turnover of cartilage and its break down; their levels have increased in the joint tissues of OA patients. Application of chondroprotective drugs neutralize the activities of MMPs. Natural products derived from herbs and plants developed as traditional medicine have been paid attention to, due to their potential biological effects. The therapeutic value of natural products in OA has increased in reputation due to their clinical impact and insignificant side effects. Several MMPs inhibitor have been used as therapeutic drugs, for a long time. Recently, different types of compounds were reviewed for their biological activities. In this review, we summarize numerous natural products for the development of MMPs inhibitors in arthritic diseases and describe the major signaling targets that were involved for the treatments of these destructive joint diseases.

7-Acetoxycoumarin Inhibits LPS-Induced Inflammatory Cytokine Synthesis by IκBα Degradation and MAPK Activation in Macrophage Cells

Acetylation involves the chemical introduction of an acetyl group in place of an active hydrogen group into a compound. In this study, we synthesized 7-acetoxycoumarin (7AC) from acetylation of umbelliferone (UMB). We examined the anti-inflammatory properties of 7AC in lipopolysaccharide (LPS)-treated RAW 264.7 macrophage cells. The anti-inflammatory activity of 7AC on viability of treated cells was assessed by measuring the level of expression of NO, PGE₂ and pro-inflammatory cytokines, namely interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in 7AC-treated RAW 264.7 macrophages. The 7AC was nontoxic to cells and inhibited the production of cytokines in a concentration-dependent manner. In addition, its treatment suppressed the production of pro-inflammatory cytokines in a dose-dependent manner and concomitantly decreased the protein and mRNA expressions of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2). Moreover, the levels of the phosphorylation of mitogen-activated protein kinase (MAPK) family proteins such as extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38 and nuclear factor kappa B (NF-κB) were reduced by 7AC. In conclusion, we generated an anti-inflammatory compound through acetylation and demonstrated its efficacy in cell-based in vitro assays.

IRF3 enhances NF-κB activation by targeting IκBα for degradation in teleost fish

Tightly regulation of NF-κB signaling is essential to innate and adaptive immune responses, but its regulatory mechanism remains unclear in various organisms, especially teleost fish. In this study, we reported that IRF3 attenuates the inhibitory effect of IκBα on NF-κB activation in teleost fish. Overexpression of IRF3 can promote IκBα degradation, whereas its knockdown can relieve degradation of IκBα. IRF3 promoted the degradation of IκBα protein, but this effect could be inhibited by MG132 treatment. IRF3 is crucial for the polyubiquitination and proteasomal degradation of IκBα. Our findings indicate that IRF3 regulates NF-κB pathway by targeting IκBα for ubiquitination and degradation. This study provides novel evidence on the regulation of innate immune signaling pathways in teleost fish and thus provides new insights into the regulatory mechanisms in mammals.

Phytol, a Chlorophyll Component, Produces Antihyperalgesic, Anti-inflammatory, and Antiarthritic Effects: Possible NFκB Pathway Involvement and Reduced Levels of the Proinflammatory Cytokines TNF-α and IL-6

Phytol is a diterpene constituent of chlorophyll and has been shown to have several pharmacological properties, particularly in relation to the management of painful inflammatory diseases. Arthritis is one of the most common of these inflammatory diseases, mainly affecting the synovial membrane, cartilage, and bone in joints. Proinflammatory cytokines, such as TNF-α and IL-6, and the NFκB signaling pathway play a pivotal role in arthritis. However, as the mechanisms of action of phytol and its ability to reduce the levels of these cytokines are poorly understood, we decided to investigate its pharmacological effects using a mouse model of complete Freund's adjuvant (CFA)-induced arthritis. Our results showed that phytol was able to inhibit joint swelling and hyperalgesia throughout the whole treatment period. Moreover, phytol reduced myeloperoxidase (MPO) activity and proinflammatory cytokine release in synovial fluid and decreased IL-6 production as well as the COX-2 immunocontent in the spinal cord. It also downregulated the p38MAPK and NFκB signaling pathways. Therefore, our findings demonstrated that phytol can be an innovative antiarthritic agent due to its capacity to attenuate inflammatory reactions in joints and the spinal cord, mainly through the modulation of mediators that are key to the establishment of arthritic pain.

Identification and functional characterization of the transcription factor NF-κB subunit p65 in common carp (Cyprinus carpio L.)

p65 is an important subunit of the transcription factor NF-κB in the regulation of immune response. In the present study, the p65 cDNA was identified from common carp (Cyprinus carpio L.) (named Ccp65). Phylogenetic analysis revealed that Ccp65 located in the same clade as piscine p65 and exhibited closest relationship to that of Ctenopharyngodon idella. Ccp65 was constitutively expressed in all the examined tissues. Aeromonas hydrophila and poly(I:C) can induce the expression of Ccp65 in the designated tissues and the Ccp65 expression was up-regulated in HKLs following LPS and poly(I:C) stimulation. In addition, the nuclear localization signal (NLS) and C-terminal domain are the important elements of Ccp65. Immunofluorescence assay revealed that the nuclear localization signal deletion mutation of Ccp65 (Ccp65ΔNLS) failed to translocate to the nucleus even though stimulation with poly(I:C) or LPS, and the C-terminal domain deletion mutation of Ccp65 (Ccp65ΔC) did not up-regulate the luciferase activity. Furthermore, Ccp65 can induce the expression of il-1β and tnf-α. And LPS and poly(I:C) inducing the expression of il-1β and tnf-α, is dependent on the Ccp65. Taken altogether, these findings lay the foundations for future research to investigate the mechanisms underlying fish p65.

Involvement of the PKA pathway and inhibition of voltage gated Ca2+ channels in antihyperalgesic activity of Lippia grata/β-cyclodextrin

Neuropathic pain (NP) is a difficult condition to treat because of the modest efficacy of available drugs. New treatments are required. In the study we aimed to investigate the effects of the essential oil from Lippia grata alone or complexed in β-cyclodextrin (LG or LG-βCD) on persistent inflammatory and neuropathic pain in a mouse model. We also investigated Ca²⁺ currents in rat dorsal root ganglion (DRG) neurons. Male Swiss mice were treated with LG or LG/β-CD (24 mg/kg, i.g.) and their effect was evaluated using an acute inflammatory pleurisy model and nociception triggered by intraplantar injection of an agonist of the TRPs channels. We also tested their effect in chronic pain models: injection of Freund's Complete Adjuvant and partial sciatic nerve ligation (PSNL). In the pleurisy model, LG reduced the number of leukocytes and the levels of TNF-α and IL-1β. It also inhibited cinnamaldehyde and menthol-induced nociceptive behavior. The pain threshold in mechanical and thermal hyperalgesia was increased and paw edema was decreased in models of inflammatory and neuropathic pain. PSNL increased inflammatory protein contents and LG and LG-βCD restored the protein contents of TNF-α, NF-κB, and PKA, but not IL-1β and IL-10. LG inhibited voltage gated Ca²⁺ channels from DRG neurons. Our results suggested that LG or LG-βCD produce anti-hyperalgesic effect in chronic pain models through reductions in TNF-α levels and PKA, and inhibited voltage-gated calcium channels and may be innovative therapeutic agents for the management of NP.

2-methylquinazoline derivative F7 as a potent and selective HDAC6 inhibitor protected against rhabdomyolysis-induced acute kidney injury

Histone deacetylases 6 (HDAC6) has been reported to be involved in the pathogenesis of rhabdomyolysis-induced acute kidney injury (AKI). Selective inhibition of HDAC6 activity might be a potential treatment for AKI. In our lab, N-hydroxy-6-(4-(methyl(2-methylquinazolin-4-yl)amino)phenoxy)nicotinamide (F7) has been synthesized and inhibited HDAC6 activity with the IC₅₀ of 5.8 nM. However, whether F7 possessed favorable renoprotection against rhabdomyolysis-induced AKI and the involved mechanisms remained unclear. In the study, glycerol-injected mice developed severe AKI symptoms as indicated by acute renal dysfunction and pathological changes, accompanied by the overexpression of HDAC6 in tubular epithelial cells. Pretreatment with F7 at a dose of 40 mg/kg/d for 3 days significantly attenuated serum creatinine, serum urea, renal tubular damage and suppressed renal inflammatory responses. Mechanistically, F7 enhanced the acetylation of histone H3 and α-tubulin to reduce HDAC6 activity. Glycerol-induced AKI triggered multiple signal mediators of NF-κB pathway as well as the elevation of ERK1/2 protein and p38 phosphorylation. Glycerol also induced the high expression of proinflammatory cytokine IL-1β and IL-6 in kidney and human renal proximal tubule HK-2 cells. Treatment of F7 notably improved above-mentioned inflammatory responses in the injured kidney tissue and HK-2 cell. Overall, these data highlighted that 2-methylquinazoline derivative F7 inhibited renal HDAC6 activity and inflammatory responses to protect against rhabdomyolysis-induced AKI.

Targeting Oncogenic Nuclear Factor Kappa B Signaling with Redox-Active Agents for Cancer Treatment

SIGNIFICANCE

Nuclear factor kappa B (NF-κB) signaling is essential under physiologically relevant conditions. However, aberrant activation of this pathway plays a pertinent role in tumorigenesis and contributes to resistance. Recent Advances: The importance of the NF-κB pathway means that its targeting must be specific to avoid side effects. For many currently used therapeutics and those under development, the ability to generate reactive oxygen species (ROS) is a promising strategy.

CRITICAL ISSUES

As cancer cells exhibit greater ROS levels than their normal counterparts, they are more sensitive to additional ROS, which may be a potential therapeutic niche. It is known that ROS are involved in (i) the activation of NF-κB signaling, when in sublethal amounts; and (ii) high levels induce cytotoxicity resulting in apoptosis. Indeed, ROS-induced cytotoxicity is valuable for its capabilities in killing cancer cells, but establishing the potency of ROS for effective inhibition of NF-κB signaling is necessary. Indeed, some cancer treatments, currently used, activate NF-κB and may stimulate oncogenesis and confer resistance.

FUTURE DIRECTIONS

Thus, combinatorial approaches using ROS-generating agents alongside conventional therapeutics may prove an effective tactic to reduce NF-κB activity to kill cancer cells. One strategy is the use of thiosemicarbazones, which form redox-active metal complexes that generate high ROS levels to deliver potent antitumor activity. These agents also upregulate the metastasis suppressor, N-myc downstream regulated gene 1 (NDRG1), which functions as an NF-κB signaling inhibitor. It is proposed that targeting NF-κB signaling may proffer a new therapeutic niche to improve the efficacy of anticancer regimens.

Toll-like Interleukin 1 Receptor Regulator Is an Important Modulator of Inflammation Responsive Genes

TILRR (Toll-like interleukin-1 receptor regulator), a transcript variant of FREM1, is a novel regulatory component, which stimulates innate immune responses through binding to IL-1R1 (Interleukin-1 receptor, type 1) and TLR (Toll-like receptor) complex. However, it is not known whether TILRR expression influences other genes in the NFκB signal transduction and pro-inflammatory responses. Our previous study identified FREM1 as a novel candidate gene in HIV-1 resistance/susceptibility in the Pumwani Sex worker cohort. In this study, we investigated the effect of TILRR overexpression on expression of genes in the NFκB signaling pathway in vitro. The effect of TILRR on mRNA expression of 84 genes related to NFκB signal transduction pathway was investigated by qRT-PCR. Overexpression of TILRR on pro-inflammatory cytokine/chemokine(s) secretion in cell culture supernatants was analyzed using Bioplex multiplex bead assay. We found that TILRR overexpression significantly influenced expression of many genes in HeLa and VK2/E6E7 cells. Several cytokine/chemokine(s), including IL-6, IL-8 (CXCL8), IP-10, MCP-1, MIP-1β, and RANTES (CCL5) were significantly increased in the cell culture supernatants following TILRR overexpression. Although how TILRR influences the expression of these genes needs to be further studied, we are the first to show the influence of TILRR on many genes in the NFκB inflammatory pathways. The NFκB inflammatory response pathways are extremely important in microbial infection and pathogenesis, including HIV-1 transmission. Further study of the role of TILRR may identify the novel intervention targets and strategies against HIV infection.

3,3'-Diindolylmethane protects cardiomyocytes from LPS-induced inflammatory response and apoptosis

BACKGROUND

3,3'-Diindolylmethane (DIM) has been extensively studied as a potential therapeutic drug with free radical scavenging, antioxidant and anti-angiogenic effects. However, whether DIM has similar effects on cardiomyocytes remains unknown. Here we evaluated DIM's influence on inflammation and apoptosis of H9C2 cardiomyocytes induced by LPS and to explore the possible mechanism of the effects.

METHODS

H9C2 cells were incubated with DIM (10, 20 and 30 μM) with or without LPS for 24 h. The cytotoxicity of DIM was detected by CCK-8. The levels of tumour necrosis factor (TNF)-α and interleukin (IL)-6 were then measured using RT-qPCR and ELISA. Cell apoptosis rate and reactive oxygen species (ROS) content after DIM treatment were measured by flow cytometry. Expressions of NFκB, P-NFκB, IκBa, P-IκBa, Bax and Bcl-2 after DIM treatment were detected by western blot. The rate of NFκB nuclear translocation after DIM treatment was determined by immunocytochemical analysis.

RESULTS

LPS stimulation promoted TNF-α and IL-6 mRNA expression. After treatment with various concentrations of DIM (10, 20 and 30 μM), TNF-α and IL-6 mRNA expression was clearly impaired, especially in the LPS + DIM30(μM) group. ELISA was used to measure TNF-α and IL-6 concentrations in cellular supernatant, and the result was verified to be consistent with RT-qPCR. Additionally, DIM treatment significantly blocked LPS-induced oxidative stress and inhibited LPS-induced apoptosis in H9C2 cardiomyocytes according to the results detected by flow cytometry. Moreover, compared with LPS alone, DIM significantly inhibited the LPS-induced phosphorylation of NFκB (p-NFκB) and Bax expression and increased Bcl-2 expression.

CONCLUSIONS

DIM may have a protective effect for H9C2 cardiomyocytes against LPS-induced inflammatory response and apoptosis. DIM may be a new insight into the treatment of septic cardiomyopathy.

Computing of Low Shear Stress-Driven Endothelial Gene Network Involved in Early Stages of Atherosclerotic Process

Background

In the pathogenesis of atherosclerosis, a central role is represented by endothelial inflammation with influx of chemokine-mediated leukocytes in the vascular wall. Aim of this study was to analyze the effect of different shear stresses on endothelial gene expression and compute gene network involved in atherosclerotic disease, in particular to homeostasis, inflammatory cell migration, and apoptotic processes.

Methods

HUVECs were subjected to shear stress of 1, 5, and 10 dyne/cm² in a Flow Bioreactor for 24 hours to compare gene expression modulation. Total RNA was analyzed by Affymetrix technology and the expression of two specific genes (CXCR4 and ICAM-1) was validated by RT-PCR. To highlight possible regulations between genes and as further validation, a bioinformatics analysis was performed.

Results

At low shear stress (1 dyne/cm²) we observed the following: (a) strong upregulation of CXCR4; (b) mild upregulation of Caspase-8; (c) mild downregulation of ICAM-1; (d) marked downexpression of TNFAIP3. Bioinformatics analysis showed the presence of network composed by 59 new interactors (14 transcription factors and 45 microRNAs) appearing strongly related to shear stress.

Conclusions

The significant modulation of these genes at low shear stress and their close relationships through transcription factors and microRNAs suggest that all may promote an initial inflamed endothelial cell phenotype, favoring the atherosclerotic disease.

MicroRNA-216a Inhibits NF-κB-Mediated Inflammatory Cytokine Production in Teleost Fish by Modulating p65

Inflammation is the host self-protection mechanism to eliminate pathogen invasion. The excessive inflammatory response can result in uncontrolled inflammation, autoimmune diseases, or pathogen dissemination. Recent studies have widely shown that microRNAs (miRNAs) contribute to the regulation of inflammation in mammals by repressing gene expression at the posttranscriptional level. However, the miRNA-mediated mechanism in the inflammatory response in fish remains hazy. In the present study, the regulatory mechanism of the miR-216a-mediated inflammatory response in teleost fish was addressed. We found that the expression of miR-216a could be significantly upregulated in the miiuy croaker after challenge with Vibrio anguillarum and lipopolysaccharide. Bioinformatics predictions demonstrated a potential binding site of miR-216a in the 3' untranslated region of the p65 gene, and the result was further confirmed by luciferase assay. Moreover, both the mRNA and protein levels of p65 in macrophages were downregulated by miR-216a. Deletion mutant analysis of the miR-216a promoter showed that the Ap1 and Sp1 transcription factor binding sites are indispensable for the transcription of miR-216a. Further study revealed that overexpression of miR-216a suppresses inflammatory cytokine expression and negatively regulates NF-κB signaling, which inhibit an excessive inflammatory response. The collective results indicate that miR-216a plays a role as a negative regulator involved in modulating the bacterium-induced inflammatory response.

l-Acetylcarnitine: A Mechanistically Distinctive and Potentially Rapid-Acting Antidepressant Drug

Current therapy of mood disorders has several limitations. Although a high number of drugs are clinically available, as of today, nearly two-thirds of individuals do not achieve full symptomatic remission after treatment with conventional antidepressants. Moreover, several weeks of drug treatment are usually required to obtain clinical effects, a limitation that has considerable clinical implications, ranging from high suicide risk to reduced compliance. The characteristic lag time in classical antidepressant effectiveness has given great impulse to the search for novel therapeutics with more rapid effects. l-acetylcarnitine (LAC), a small molecule of growing interest for its pharmacological properties, is currently marketed for treatment of neuropathic pain. Recent preclinical and clinical data suggested that LAC may exert antidepressant effects with a more rapid onset than conventional drugs. Herein, we review data supporting LAC antidepressant activity and its distinctive mechanisms of action compared with monoaminergic antidepressants. Furthermore, we discuss the unique pharmacological properties of LAC that allow us to look at this molecule as representative of next generation antidepressants with a safe profile.

Inflammatory effects of acrolein, crotonaldehyde and hexanal vapors on human primary bronchial epithelial cells cultured at air-liquid interface

The cytotoxicity of aldehydes was studied using human primary bronchial epithelial cells (PBEC) cultured at the air-liquid interface (ALI) or under submerged conditions. PBEC were exposed for 30min via the air phase to acrolein (0.1-1mg/m³), crotonaldehyde (1.5-15mg/m³) or hexanal (22-221mg/m³) or under submerged conditions to acrolein (0.1 and 0.2mg/L), crotonaldehyde (1 and 2mg/L) or hexanal (10 and 20mg/L). Cell culture medium was collected 8h and 24h post-exposure and analyzed for interleukin-8 (IL-8) and matrix metalloprotein-9 (MMP-9). The gene expression of inflammatory and oxidative stress markers were measured 6h post-exposure. In the ALI setup, all three aldehydes caused increased secretion of IL-8, acrolein and crotonaldehyde also increased the gene expression of inflammatory and oxidative stress markers. In contrast, exposure under submerged conditions resulted in significantly reduced IL-8 secretion. The inflammatory response seen in the air phase exposures correspond well with previous in vivo studies. This indicates that lung models cultured at ALI are more suitable than submerged cell cultures in toxicity assessment studies of inhaled agents.

Anti-nociceptive effect of dexmedetomidine in a rat model of monoarthritis via suppression of the TLR4/NF-κB p65 pathway

As a therapeutic target for neuropathic pain, the anti-nociceptive effects of α 2-adrenoceptors (α2AR) have attracted attention. Dexmedetomidine (DEX), a potent and highly selective α2AR agonist, has exhibited significant analgesic effects in neuropathic pain, but the underlying mechanism has remained elusive. The present study investigated the effect of DEX on Toll-like receptor (TLR)4 and nuclear factor (NF)-κB p65 expression, as well as the production of pro-inflammatory cytokines. The rat monoarthritis (MA) model was induced by intra-articular injection of complete Freund's adjuvant (CFA) at the ankle joint. After induction of MA, the rats were intrathecally treated with normal saline or DEX (2.5 µg) for 3 consecutive days. The concentration of interleukin-1β and -6 as well as tumor necrosis factor-α was examined by ELISA. The expression levels of TLR4 and NF-κB p65 were determined by western blot analysis and immunohistochemistry. The results indicated that the pro-inflammatory cytokines TLR4 and NF-κB p65 were significantly upregulated in MA rats. DEX treatment markedly reduced mechanical and thermal hyperalgesia, suppressed MA-induced elevation of the pro-inflammatory cytokines and inhibited the TLR4/NF-κB p65 pathway, while these effects were blocked by pre-treatment with the selective α2AR antagonist BRL44408 (15 µg) at 30 min prior to CFA injection. These results suggested that DEX has an anti-nociceptive effect via suppressing the TLR4/NF-κB p65 pathway.

Effects of Mollugo pentaphylla extract on monosodium urate crystal-induced gouty arthritis in mice

Background

Gout is an inflammatory condition induced by the deposition of monosodium urate (MSU) crystals in joints and soft tissues, and it can lead to acute or chronic arthritis. MSU are pro-inflammatory stimuli that can initiate, amplify and sustain an intense inflammatory response. In this study, we evaluated the anti-inflammatory effect of an extract of Mollugo pentaphylla (MPE) on MSU-induced gouty arthritis in a mouse model.

Method

An MSU crystal suspension (4 mg/50 μL) was injected intradermally into the right paw. The mice were orally administered MPE (150 mg/kg or 300 mg/kg) or the positive control drug colchicine (1 mg/kg) 1 h before the MSU crystals were injected and then once daily for 3 days. The effects of MPE included inflammatory paw edema and pain upon weight-bearing activity, and we evaluated the inflammatory cytokine expression and paw tissue inflammation-related gene expression.

Results

MPE suppressed inflammatory paw edema and pain in the MSU-induced mice. MPE showed anti-inflammatory activity by inhibiting the production of TNF-α, interleukin (IL)-1β, NLRP3 inflammasome and NF-κB.

Conclusion

These results suggest that MPE has potent anti-inflammatory activities and may be useful as a therapeutic agent against gouty arthritis.

Transcriptomics, NF-κB Pathway, and Their Potential Spaceflight-Related Health Consequences

In space, living organisms are exposed to multiple stress factors including microgravity and space radiation. For humans, these harmful environmental factors have been known to cause negative health impacts such as bone loss and immune dysfunction. Understanding the mechanisms by which spaceflight impacts human health at the molecular level is critical not only for accurately assessing the risks associated with spaceflight, but also for developing effective countermeasures. Over the years, a number of studies have been conducted under real or simulated space conditions. RNA and protein levels in cellular and animal models have been targeted in order to identify pathways affected by spaceflight. Of the many pathways responsive to the space environment, the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) network appears to commonly be affected across many different cell types under the true or simulated spaceflight conditions. NF-κB is of particular interest, as it is associated with many of the spaceflight-related health consequences. This review intends to summarize the transcriptomics studies that identified NF-κB as a responsive pathway to ground-based simulated microgravity or the true spaceflight condition. These studies were carried out using either human cell or animal models. In addition, the review summarizes the studies that focused specifically on NF-κB pathway in specific cell types or organ tissues as related to the known spaceflight-related health risks including immune dysfunction, bone loss, muscle atrophy, central nerve system (CNS) dysfunction, and risks associated with space radiation. Whether the NF-κB pathway is activated or inhibited in space is dependent on the cell type, but the potential health impact appeared to be always negative. It is argued that more studies on NF-κB should be conducted to fully understand this particular pathway for the benefit of crew health in space.

Identification of NF-κB related genes in channel catfish and their expression profiles in mucosal tissues after columnaris bacterial infection

Interactions of NF-κB family, IκB family and IKK complex are the key components of NF-κB pathway that is essential for many biological processes including innate and adaptive immunity, inflammation and stress responses. In spite of their importance, systematic analysis of these genes in fish has been lacking. Here we report a systematic study of the NF-κB related genes in channel catfish. Five NF-κB family genes, five IκB family genes and three IKK complex genes were identified in the channel catfish genome. Annotation of these 13 NF-κB related genes was further confirmed by phylogenetic and syntenic analysis. Negative selection was found to play a crucial role in the adaptive evolution of these genes. Expression profiles of NF-κB related genes after Flavobacterium columnare (columnaris) infection were determined by analysis of the existing RNA-Seq dataset. The majority of NF-κB related genes were significantly regulated in mucosal tissues of gill, skin and intestine after columnaris infection, indicating their potential involvement in host defense responses. Distinct expression patterns of NF-κB related genes were observed in susceptible and resistant catfish in response to columnaris infection, suggesting that expression of these genes may contribute to the variations in disease resistance/susceptibility of catfish.

Arginine Silicate Inositol Complex Accelerates Cutaneous Wound Healing

Arginine silicate inositol (ASI) complex is a composition of arginine, silicon, and inositol that has been shown to have beneficial effects on vascular health. This study reports the effects of an ASI ointment on wound healing in rats. A full-thickness excision wound was created by using a disposable 5 mm diameter skin punch biopsy tool. In this placebo-controlled study, the treatment group's wound areas were covered by 4 or 10 % ASI ointments twice a day for 5, 10, or 15 days. The rats were sacrificed either 5, 10, or 15 days after the wounds were created, and biopsy samples were taken for biochemical and histopathological analysis. Granulation tissue appeared significantly faster in the ASI-treated groups than in the control groups (P < 0.05). The mean unhealed wound area was significantly smaller, and the mean percentage of total wound healing was significantly higher in ASI-treated wounds than in the control wounds. Hydroxyproline, collagen, and matrix metalloproteinases were measured in the granulated tissue and found to be affected. Inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), collagen, matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), epidermal growth factor (EGF), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and various cytokines (TNF-α and IL-1β) measured in this study showed a significant fall in expression level in ASI-treated wounds. The results suggest that topical application of ASI ointment (especially 4 % concentration) has beneficial effects on the healing response of an excisional wound.

Role of Notch signaling pathway in pancreatic cancer

Pancreatic cancer (PC) is one of the highly aggressive malignancies in the United States. It has been shown that multiple signaling pathways are involved in the pathogenesis of PC, such as JNK, PI3K/AKT, Rho GTPase, Hedgehog (Hh) and Skp2. In recent years, accumulated evidence has demonstrated that Notch signaling pathway plays critical roles in the development and progression of PC. Therefore, in this review we discuss the recent literature regarding the function and regulation of Notch in the pathogenesis of PC. Moreover, we describe that Notch signaling pathway could be down-regulated by its inhibitors or natural compounds, which could be a novel approach for the treatment of PC patients.

Licocoumarone isolated from Glycyrrhiza uralensis selectively alters LPS-induced inflammatory responses in RAW 264.7 macrophages

The effects of licocoumarone (LC) isolated from Glycyrrhiza uralensis were studied in LPS-stimulated RAW 264.7 macrophages. Our study demonstrated that LC dose-dependently attenuated LPS-induced NO production by down-regulating iNOS expression. Additionally, the treatment with LC inhibited LPS-induced expression of cytokines including IL-1β, IL-6 and IL-10, but not TNF-α, at both mRNA and protein levels. Similar suppressive effects of LC were observed on LPS-stimulated murine peritoneal macrophages as well. Furthermore, LC significantly reduced LPS-stimulated NF-κB activation by inhibition of IκBα degradation and p65 phosphorylation. The results from NF-κB-luc reporter gene assay further support the inhibitory effect of LC on NF-κB activation. Further studies showed that LC also interfered with the MAPKs and STAT3 signaling pathways, which are typical inflammatory signaling pathways triggered by LPS. Taken together, these results show that LC attenuates LPS-induced cytokine gene expression in RAW 264.7 macrophages through mechanisms that involve NF-κB, MAPKs and STAT3 signaling pathways, but the pattern of inhibition differs from that of a global immunosuppresant. Our study indicates that LC is a functional constituent of Glycyrrhiza uralensis with potential implications in infectious and immune-related diseases.

The CpG Dinucleotide Adjacent to a κB Site Affects NF-κB Function through Its Methylation

NF-κB is an important transcription factor that plays critical roles in cell survival, proliferation, inflammation, and cancers. Although the majority of experimentally identified functional NF-κB binding sites (κB sites) match the consensus sequence, there are plenty of non-functional NF-κB consensus sequences in the genome. We analyzed the surrounding sequences of the known κB sites that perfectly match the GGGRNNYYCC consensus sequence and identified the nucleotide at the -1 position of κB sites as a key contributor to the binding of the κB sites by NF-κB. We demonstrated that a cytosine at the -1 position of a κB site (-1C) could be methylated, which thereafter impaired NF-κB binding and/or function. In addition, all -1C κB sites are located in CpG islands and are conserved during evolution only when they are within CpG islands. Interestingly, when there are multiple NF-κB binding possibilities, methylation of -1C might increase NF-κB binding. Our finding suggests that a single nucleotide at the -1 position of a κB site could be a critical factor in NF-κB functioning and could be exploited as an additional manner to regulate the expression of NF-κB target genes.

Buthionine sulfoximine, a glutathione depletor, attenuates endotoxic fever and reduces IL-1β and IL-6 level in rats

PURPOSE

The aim of our study was to investigate the effect of buthionine sulfoximine (BSO) - a glutathione depletor - on a course of endotoxic fever and IL-1β and IL-6 production.

MATERIAL AND METHODS

Male Wistar rats were subjected to intraperitoneal injection of lipopolysaccharide (LPS) from E. coli (50μg/kg, ip) to provoke fever. The level of spleen glutathione, plasma interleukin (IL)-1β, IL-6, and deep body temperature (Tb) were measured.

RESULTS

The LPS administration provoked fever (the average Tb was 38.14±0.05°C in NaCl/LPS-treated rats vs 37.10±0.03°C in control, not-treated rats; p<0.001). We observed that LPS injection induced a decrease in spleen glutathione level (7.67±0.92nM/g vs 13.27±0.47nM/g in not-treated rats; p<0.001). Furthermore, the injection of LPS provoked an elevation of plasma IL-1β and IL-6 concentration (from values below the lowest detectable standard in not-treated animals to 199.99±34.89pg/mL and 7500±542.21pg/mL, respectively; p<0.001). Pretreatment with BSO enhanced glutathione decrease in LPS-treated rats (5.05±0.49nM/g), and significantly affected fever (maximal Tb was 37.81±0.07°C in BSO/LPS-treated rats vs 38.76±0.11°C in NaCl/LPS-treated rats). BSO 4h after LPS injection decreased IL-1β and IL-6 gene expression (about 1.5 fold, and 2 fold, respectively). In a consequence we observed a decrease in plasma IL-6 concentration (4h after LPS injection plasma IL-6 was 4167.17±956.54pg/mL in BSO/LPS-treated rats vs 7500±542.21pg/mL in NaCl/LPS-treated rats; p<0.001), and later IL-1β (7h after LPS injection the IL-1β concentration was not detected).

CONCLUSION

Based on these data, we conclude that BSO, in addition to well-known application as an inhibitor of glutathione synthesis, is an antipyretic agent which reduces both IL-1β and IL-6 concentration.

Distinct Cell Stress Responses Induced by ATP Restriction in Quiescent Human Fibroblasts

Quiescence is the prevailing state of many cell types under homeostatic conditions. Yet, surprisingly little is known about how quiescent cells respond to energetic and metabolic challenges. To better understand compensatory responses of quiescent cells to metabolic stress, we established, in human primary dermal fibroblasts, an experimental ‘energy restriction’ model. Quiescence was achieved by short-term culture in serum-deprived media and ATP supply restricted using a combination of glucose transport inhibitors and mitochondrial uncouplers. In aggregate, these measures led to markedly reduced intracellular ATP levels while not compromising cell viability over the observation period of 48 h. Analysis of the transcription factor (TF) landscape induced by this treatment revealed alterations in several signal transduction nodes beyond the expected biosynthetic adaptations. These included increased abundance of NF-κB regulated TFs and altered TF subsets regulated by Akt and p53. The observed changes in gene regulation and corresponding alterations in key signaling nodes are likely to contribute to cell survival at intracellular ATP concentrations substantially below those achieved by growth factor deprivation alone. This experimental model provides a benchmark for the investigation of cell survival pathways and related molecular targets that are associated with restricted energy supply associated with biological aging and metabolic diseases.

Differential mechanisms of LPS-induced NFκB activation in macrophages and fibroblasts

Lipopolysaccharide is a prototypic stimulus of inflammatory gene expression which can act on a variety of cell types to produce different patterns of response. In the present report, the ability of LPS to stimulate NFKB activity was investigated in a fibroblast cell line (NIH3T3) and compared to LPS-induced response in a macrophage like cell line (RAW264.7). LPS was a potent stimulus of KB binding activity in both cell types though the protein composition of such binding activity varied. LPS caused nuclear translocation of KB binding activity in RAW 264.7 cells which contained NFKB1 (p50), RelA (p65), and high levels of c-Rel. Nuclei from LPS-stimulated NIH3T3 cells contained only NFKB1 and RelA but little c-Rel. Both cell types contain comparable levels of total c-Rel protein. Using two structurally distinct KB sequence motifs, LPS was shown to produce a different pattern of transacting activity in fibroblasts as compared to macrophages; both KB motifs were sensitive to LPS in RAW264.7 cells while only one of the two was functional in LPS-stimulated NIH3T3 cells. Thus LPS appears to utilize the NFKB family of transcription factors differentially depending upon the cell type being stimulated. Such differential activation of transcription factor family members may be an important determinant of the diverse nature of inflammatory response seen in different tissue settings.

Sam68/KHDRBS1 is critical for colon tumorigenesis by regulating genotoxic stress-induced NF-κB activation

Nuclear factor kappa B (NF-κB)-mediated transcription is an important mediator for cellular responses to DNA damage. Genotoxic agents trigger a 'nuclear-to-cytoplasmic' NF-κB activation signaling pathway; however, the early nuclear signaling cascade linking DNA damage and NF-κB activation is poorly understood. Here we report that Src-associated-substrate-during-mitosis-of-68kDa/KH domain containing, RNA binding, signal transduction associated 1 (Sam68/KHDRBS1) is a key NF-κB regulator in genotoxic stress-initiated signaling pathway. Sam68 deficiency abolishes DNA damage-stimulated polymers of ADP-ribose (PAR) production and the PAR-dependent NF-κB transactivation of anti-apoptotic genes. Sam68 deleted cells are hypersensitive to genotoxicity caused by DNA damaging agents. Upregulated Sam68 coincides with elevated PAR production and NF-κB-mediated anti-apoptotic transcription in human and mouse colon cancer. Knockdown of Sam68 sensitizes human colon cancer cells to genotoxic stress-induced apoptosis and genetic deletion of Sam68 dampens colon tumor burden in mice. Together our data reveal a novel function of Sam68 in the genotoxic stress-initiated nuclear signaling, which is crucial for colon tumorigenesis.

DOI:http://dx.doi.org/10.7554/eLife.15018.001

Cells use signaling pathways to detect and respond to harmful conditions by switching on genes that keep the cell healthy. One important pathway is the nuclear factor kappa B (NF-κB) signaling pathway, which is activated by many stimuli. These stimuli may come from infections from outside the cell or may originate inside the cell, as seen for DNA damage caused by irradiation, chemicals or rapid DNA replication in cancer cells.

Most of a cell’s DNA is located in the cell nucleus. However, NF-κB proteins are normally located outside the nucleus, in the cell’s cytoplasm. Damage to DNA triggers a signal from the nucleus to the cytoplasm. This signal activates the NF-κB proteins, which move into the nucleus and turn on genes that help the cell to recover from the damage. These genes include those that prevent the cell from self-destructing. In one step of the NF-κB activation process, chain-like molecules called polymers are made from a compound called poly(ADP-ribose), or PAR for short. However, few other details are known about how the damaged DNA in the nucleus signals to the cytoplasm.

A protein called Sam68, which is found in the cell nucleus, has been linked to DNA damage signaling. Fu, Sun et al. now present evidence that suggests that if mouse cells lack Sam68, they do not produce PAR polymers in response to DNA damage. In addition, these cells could not trigger the PAR-dependent signaling cascade that is essential for activating NF-κB and for turning on the protective genes. Consequently, cells that lacked Sam68 were extremely sensitive to agents that cause DNA damage, such as chemicals and irradiation.

The NF-κB pathway is regulated incorrectly in some cancers, but is also activated by DNA damage caused by cancer treatments. Therefore, Fu, Sun et al. also explored the role of Sam68 in cancer. Reducing the levels of Sam68 made human colon cancer cells more likely to self-destruct when they were exposed to DNA-damaging agents. Furthermore, removing Sam68 from mice that spontaneously grow colon cancer caused their tumors to develop more slowly than mice that retained Sam68 in their cells.

Overall, the findings presented by Fu, Sun et al. suggest that Sam68 regulates the signal from the nucleus to the cytoplasm that activates NF-κB proteins in response to DNA damage. Sam68 also appears to be important for helping colon cancer cells grow and survive. Future challenges will be to understand how Sam68 regulates the production of the PAR polymer in this response and to explore whether Sam68 can be targeted for treating cancer.

DOI:http://dx.doi.org/10.7554/eLife.15018.002

NF-κB signaling pathway as target for antiplatelet activity

In different nucleated cells, NF-κB has long been considered a prototypical proinflammatory signaling pathway with the expression of proinflammatory genes. Although platelets lack a nucleus, a number of functional transcription factors are involved in activated platelets, such as NF-κB. In platelet activation NF-κB regulation events include IKKβ phosphorylation, IκBα degradation, and p65 phosphorylation. Multiple pathways contribute to platelet activation and NF-κB is a common pathway in this activation. Therefore, in platelet activation the modulation of NF-κB pathway could be a potential new target in the treatment of inflammation-related vascular disease therapy (antiplatelet and antithrombotic activities).

Anti-inflammatory effects of Viola yedoensis and the application of cell extraction methods for investigating bioactive constituents in macrophages

BACKGROUND

Viola yedoensis (VY, Violaceae) is a popular medicinal herb used in traditional eastern medicine for treating lots of diseases, including inflammation and its related symptoms. However, the anti-inflammatory properties of VY have not been demonstrated. In the present study, we investigated the anti-inflammatory effects of VY ethanol extract (VYE) on macrophages and attempted to identify the bioactive components of VYE.

METHODS

We assessed the effects of VYE on secretion of nitric oxide (NO) and inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β. In addition, we explored the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, and changes in heme oxygenase (HO)-1, nuclear factor (NF)-kB, and mitogen-activated protein kinase (MAPK) signaling pathways in RAW 264.7 macrophages stimulated by lipopolysaccharide (LPS). In addition, a rapid and useful approach to identify potential bioactive components in VYE with anti-inflammatory effects was developed using murine macrophage cell extraction coupled with high-performance liquid chromatography tandem mass spectrometry (LC-MS).

RESULTS

We found that VYE exerted anti-inflammatory activity by inhibiting the production of key inflammation mediators and related products, as well as suppression of HO-1, NF-kB, and MAPK signaling pathway activation in RAW 264.7 cells. In addition, we identified two compounds in VYE via the cell extraction method.

CONCLUSIONS

Our results revealed that VYE exerts anti-inflammatory activities and its detailed inhibitory mechanism in macrophages. Furthermore, we identified bioactive components of VYE.

Association of cytomegalovirus infection with hypertension risk: a meta-analysis

Background

Information regarding association between cytomegalovirus (CMV) infection and essential hypertension (EH) risk is not consistent across studies. Therefore, we conducted a meta-analysis to investigate the association in detail.

Methods

We comprehensively searched the published literature from the PubMed and Embase databases for any study analyzing the association between CMV and EH risk. A random-effects model was used to calculate the pooled odds ratio (OR) with 95 % confidence interval (CI).

Results

Three studies involving 9657 patients were included in the meta-analysis, and the results showed a significantly increased risk of EH in patients with CMV infection. Overall, 79.3 % of the hypertension patients were CMV-positive, which was significantly higher than the percentage for controls (OR = 1.39, 95 % CI = 0.95–2.05, P = 0.017). There was significant heterogeneity among the studies included (I² = 70.5 %). The funnel plot and Egger’s test also indicated no publication bias.

Conclusions

The results showed a significant association between CMV and EH, which indicates that CMV infection is a possible cause of EH.