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WHO reported that asthma was responsible for 455,000 deaths in 2019 and asthma patients was evaluated 262 million in May 2023. The incidence is expected to increase as the average life expectancy increases, highlighting asthma as a significant health challenge in an aging society. The etiology of asthma is linked to an imbalance of Th1 and Th2 cells, respiratory inflammation, and pulmonary cell proliferation. The purpose of this study is to investigate the anti-asthmatic effect and potential mechanism of oleic acid. The anti-inflammatory effect of oleic acid was evaluated in an LPS-induced RAW 264.7 cell model, and immune modulation and the anti-apoptotic effect were measured in an ovalbumin-induced BALB/c mouse model. A variety of analytical procedures, such as MTT, qPCR, ELISA, Western blotting, immunofluorescence, gene transfection, immunohistochemistry, and several staining methods (Diff Quik, H&E, PAS), were used to evaluate the effectiveness and mechanisms of these methods. The results from in vitro experiments showed that oleic acid could reduce the levels of inflammatory cytokines (TNF-α, IL-6, and IL-1β), and molecular docking studies suggested that oleic acid could interact with TLR3 and TLR4 proteins to form ligand-protein complexes, showing good binding affinity. Additionally, oleic acid attenuated the expression of MAPK pathway components (JNK, p38 MAPK) and NF-κB pathway constituents (IκB, NF-κB, COX-2, PGE 2 ). In vivo results indicated that oleic acid reduced the levels of inflammatory cells (WBCs and eosinophils) and IgE activity, reduced the expression of the Th2 cell transcription factor GATA-3, and decreased the levels of Th2/Th17-related cytokines (IL-4, TNF-α, and IL-6). Oleic acid also alleviated OVA-induced pathological changes in the lung, such as epithelial cell proliferation, inflammatory cell infiltration, and mucus hypersecretion. OVA restored apoptosis in lung epithelial cells by modulating the expression of Bcl-2 and Bax. In summary, oleic acid has potential as a novel candidate for asthma treatment through its ability to regulate immune cells, exert anti-inflammatory effects, and promote apoptosis, thereby ameliorating asthma manifestations., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Lee, Le, Bae, Park, Lee, Cho and Park.)

Alveolar bone loss, the major feature of periodontitis, results from the activation of osteoclasts, which can consequently cause teeth to become loose and fall out; the development of drugs capable of suppressing excessive osteoclast differentiation and function is beneficial for periodontal disease patients. Given the difficulties associated with drug discovery, drug repurposing is an efficient approach for identifying alternative uses of commercially available compounds. Here, we examined the effects of PF-3845, a selective fatty acid amide hydrolase (FAAH) inhibitor, on receptor activator of nuclear factor kappa B ligand (RANKL)-mediated osteoclastogenesis, its function, and the therapeutic potential for the treatment of alveolar bone destruction in experimental periodontitis. PF-3845 significantly suppressed osteoclast differentiation and decreased the induction of nuclear factor of activated T-cells cytoplasmic 1 (NFATc1) and the expression of osteoclast-specific markers. Actin ring formation and osteoclastic bone resorption were also reduced by PF-3845, and the anti-osteoclastogenic and anti-resorptive activities were mediated by the suppression of phosphorylation of rapidly accelerated fibrosarcoma (RAF), mitogen-activated protein kinase (MEK), extracellular signal-regulated kinase, (ERK) and nuclear factor κB (NF-κB) inhibitor (IκBα). Furthermore, the administration of PF-3845 decreased the number of osteoclasts and the amount of alveolar bone destruction caused by ligature placement in experimental periodontitis in vivo. The present study provides evidence that PF-3845 is able to suppress osteoclastogenesis and prevent alveolar bone loss, and may give new insights into its role as a treatment for osteoclast-related diseases.

Objective: Sirtuin 6 (SIRT-6) is an NAD(+) -dependent deacetylase and mono-ADP-ribosyltransferase. It is known to interfere with the NF-κB signaling pathway and thereby has an antiinflammatory function. Due to the central role of NF-κB in rheumatoid arthritis (RA) development, we undertook this study to test our hypothesis that SIRT-6 could have antiarthritic effects., Methods: An adenovirus containing SIRT-6 complementary DNA (Ad-SIRT6) was used to deliver SIRT-6 to human RA fibroblast-like synoviocytes in vitro as well as to mice with collagen-induced arthritis (CIA) in vivo via bilateral intraarticular injections into the ankle joints., Results: In vitro experiments demonstrated that SIRT-6 overexpression suppressed NF-κB target gene expression induced by tumor necrosis factor α. SIRT-6 overexpression inhibited osteoclast differentiation induced by macrophage colony-stimulating factor and RANKL in bone marrow-derived macrophages. Mice with CIA had an increased incidence of disease and developed arthritis in the hind paws. In contrast, mice injected with Ad-SIRT6 showed attenuated severity of arthritis based on clinical scores, hind paw thickness, and radiographic and pathologic findings. Moreover, the injection of Ad-SIRT6 down-regulated local and systemic levels of proinflammatory cytokines. After induction of CIA, mice injected with Ad-SIRT6 showed significantly decreased arthritis severity, from the onset of clinical signs to the end of the study., Conclusion: These results suggest that blocking the NF-κB pathway by SIRT-6 in rheumatoid joints reduces both the inflammatory response and tissue destruction. Therefore, the development of an immunoregulatory strategy based on SIRT-6 may have therapeutic potential for the treatment of RA., (Copyright © 2013 by the American College of Rheumatology.)

Background & Aims: A20 is an intracellular ubiquitin-editing enzyme that plays an important role in the negative feedback regulation of NF-κB activation in response to a diverse range of stimuli. Liver ischemia/reperfusion injury is associated with rapid activation of NF-κB signaling, but the role of NF-κB in hepatic ischemia/reperfusion injury remains controversial. The NF-κB signaling pathway mediates both protective and deleterious effects in the liver. Here, we examined whether A20 inhibited or aggravated hepatic ischemia/reperfusion injury., Methods: We used IκBα super-repressor as a positive control and overexpressed A20 and IκBα super-repressor in the liver of C57BL/6 mice. Mice underwent 45min of partial hepatic ischemia and were then reperfused., Results: Protein level of A20 was increased after reperfusion. Mice subjected to ischemia/reperfusion injury showed increased NF-κB activation, as evidenced by phosphorylation of IκBα and nuclear translocation of NF-κB. Prior transfection with Ad-A20 or Ad-IκBα super-repressor attenuated NF-κB activation and aggravated liver injury. Serum aminotransferases and proinflammatory cytokines, hepatocellular necrosis, and hepatic neutrophil infiltration were markedly increased compared to those of uninfected or control virus infected mice. In addition, A20 abolished the beneficial effect of ischemic preconditioning., Conclusions: Our results suggest that inhibition of NF-κB activation by A20 aggravated partial hepatic ischemia/reperfusion injury. Understanding how the NF-κB pathway plays a role in directing a clinical outcome may lead to better prospects of more rational approaches to reduce post-ischemic liver injury., (Copyright © 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

The pathologic processes of rheumatoid arthritis are mediated by a number of cytokines, chemokines, and matrix metalloproteinases, the expressions of which are controlled by NF-κB. This study was performed to explore the effects of a benzothiazole analog, SPA0537, on the control of the NF-κB activation pathway. We also investigated whether SPA0537 had any anti-inflammatory effects in human rheumatoid fibroblast-like synoviocytes (FLS). SPA0537 inhibited the nuclear translocation and the DNA binding of NF-κB subunits, which correlated with the inhibitory effects on IKK phosphorylation and IκBα degradation in TNF-α-stimulated rheumatoid FLS. These events further suppressed chemokine production, matrix metalloproteinase secretion, and TNF-α-induced cell proliferation. In addition, SPA0537 inhibited the osteoclast differentiation induced by macrophage colony-stimulating factor (MCSF) and receptor activator of the NF-κB ligand (RANKL) in bone marrow macrophages. These findings suggest that SPA0537 exerts anti-inflammatory effects in rheumatoid FLS through the inhibition of the NF-κB pathway. Therefore, it may have therapeutic value for the treatment of rheumatoid arthritis., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Type II interferon (IFN-γ) plays an important role in defense against viral infection. Although this cytokine is found during influenza virus infection, it seems to have no protective function against the virus, and the reasons for this are not clear. To determine how the influenza virus overcomes the antiviral effects of IFN-γ, we examined the effect of A/Puerto-Rico/8/34 (H1N1) (PR8) infection on the expression of various IFN-γ inducible genes involved in defense against virus infection. The results showed that PR8 selectively affects IFN-γ induced MHC-II and iNOS expression in both the murine macrophage-like cell line, Raw264.7, and in primary alveolar macrophages. Infection of IFN-γ treated macrophages with PR8 resulted in decreased expression of CIITA/MHC-II and increased production of iNOS/NO. These changes correlate with activation of NF-κB but not with JAK/STAT signaling. The data indicate one possible mechanism underlying the ineffectiveness of IFN-γ against influenza virus, and suggest that NF-κB may be a promising target for anti-influenza drugs., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

The generation of nitric oxide (NO) via inducible NO synthase (iNOS) and reactive oxygen species plays a key role in cytokine-mediated pancreatic β-cell damage. Oxidative stress due to reactive oxygen species activates the nuclear factor-κB (NF-κB) transcription factor, which regulates iNOS expression. In this regard, suppression of the NF-κB pathway is a novel strategy for protecting β-cells from damage. This study was performed to explore the effects of kazinol U, a prenylated flavan from Broussonetia kazinoki, on the NF-κB activation pathway in interleukin-1β (IL-1β)- and interferon-γ (IFN-γ)-treated β-cells. The cytotoxic effects of cytokines were completely abolished when RINm5F cells or islets were pretreated with kazinol U. Kazinol U inhibited the nuclear translocation and DNA binding of NF-κB subunits, which correlated with the inhibitory effects on IκB kinase (IKK) phosphorylation and IκBα degradation. In addition, kazinol U suppressed NO and hydrogen peroxide production and apoptotic cell death by cytokines in RINm5F cells. The protective effects of kazinol U were further demonstrated by normal insulin secretion of cytokine-treated islets in response to glucose. Taken together, these results suggest that using kazinol U to block the NF-κB pathway in pancreatic β-cells reduces cell damage. Therefore, kazinol U may have therapeutic value in delaying pancreatic β-cell destruction in type 1 diabetes.

NF-kappaB activation has been implicated as a key signaling mechanism for pancreatic beta-cell damage. Sulfuretin is one of the main flavonoids produced by Rhus verniciflua, which is reported to inhibit the inflammatory response by suppressing the NF-kappaB pathway. Therefore, we isolated sulfuretin from Rhus verniciflua and evaluated if sulfuretin could inhibit cytokine- or streptozotocin-induced beta-cell damage. Rat insulinoma RINm5F cells and isolated rat islets were treated with IL-1 beta and IFN-gamma to induce cytotoxicity. Incubation of cells and islets with sulfuretin resulted in a significant reduction of cytokine-induced NF-gamma B activation and its downstream events, iNOS expression, and nitric oxide production. The cytotoxic effects of cytokines were completely abolished when cells or islets were pretreated with sulfuretin. The protective effect of sulfuretin was further demonstrated by normal insulin secretion of cytokine-treated islets in response to glucose. Treatment of mice with streptozotocin resulted in hyperglycemia and hypoinsulinemia, which was further evidenced by immunohistochemical staining of islets. However, the diabetogenic effects of streptozotocin were completely prevented when mice were pretreated with sulfuretin. The anti-diabetogenic effects of sulfuretin were also mediated by suppression of NF-kappaB activation. Collectively, these results indicate that sulfuretin may have therapeutic value in preventing beta-cell damage.

JANEX-1/WHI-P131, a selective Janus kinase 3 (JAK3) inhibitor, has been shown to delay the onset of diabetes in the NOD mouse model. However, the molecular mechanism by which JANEX-1 protects pancreatic beta-cells is unknown. In the current study, we investigated the role of JANEX-1 on interleukin (IL)-1beta and interferon (IFN)-gamma-induced beta-cell damage using isolated islets. JANEX-1-pretreated islets showed resistance to cytokine toxicity, namely suppressed nitric oxide (NO) production, reduced inducible form of NO synthase (iNOS) expression, and decreased islet destruction. The molecular mechanism by which JANEX-1 inhibits iNOS expression was mediated through suppression of the nuclear factor kappaB (NF-kappaB) and JAK/signal transducer and activator of transcription (STAT) pathways. Islets treated with the cytokines downregulated the protein levels of suppressor of cytokine signaling (SOCS)-1 and SOCS-3, but pretreatment with JANEX-1 attenuated these decreases. Additionally, islets from JAK3(-/-) mice were more resistant to cytokine toxicity than islets from control mice. These results demonstrate that JANEX-1 protects beta-cells from cytokine toxicity through suppression of the NF-kappaB and JAK/STAT pathways and upregulation of SOCS proteins, suggesting that JANEX-1 may be used to preserve functional beta-cell mass.

Cytokines released by infiltrating inflammatory cells around the pancreatic islets are involved in the pathogenesis of type 1 diabetes. Interleukin (IL)-1beta and interferon (IFN)-gamma are the primary cytokines responsible for stimulation of inducible nitric oxide synthase (iNOS) expression and nitric oxide overproduction, which leads to beta-cell damage. In addition, nuclear factor-kappaB (NF-kappaB) plays a crucial role in the activation of this pathway. Therefore, suppression of the cytokine-NF-kappaB pathway is considered an effective therapeutic strategy for preventing inflammatory reactions in pancreatic beta-cells. In this study, the effects of Fructus Xanthii extract (FXE) on IL-1beta and IFN-gamma-induced beta-cell damage were examined. Treatment of RINm5F cells with IL-1beta and IFN-gamma reduced cell viability, however, FXE completely protected cells from IL-1beta and IFN-gamma-mediated reduction in viability in a concentration-dependent manner. In addition, incubation with FXE resulted in a significant suppression of IL-1beta and IFN-gamma-induced nitric oxide (NO) production, which correlated with the reduced levels of the inducible form of iNOS mRNA and protein observed. The IL-1beta and IFN-gamma-stimulated RIN cells showed increases in NF-kappaB binding activity and p50 subunit levels in the nucleus, as well as increased IkappaBalpha degradation in cytosol when compared to unstimulated cells, which indicates that the mechanism by which FXE inhibited the iNOS gene involves inhibition of NF-kappaB activation. Furthermore, a protective effect of FXE was demonstrated by reduction in NO generation and iNOS expression, as well as the normal insulin secreting responses to glucose observed in IL-1beta and IFN-gamma-treated islets.

Sulforaphane (SFN) is an indirect antioxidant that protects animal tissues from chemical or biological insults by stimulating the expression of several NF-E2-related factor-2 (Nrf2)-regulated phase 2 enzymes. Treatment of RINm5F insulinoma cells with SFN increases Nrf2 nuclear translocation and expression of phase 2 enzymes. In this study, we investigated whether the activation of Nrf2 by SFN treatment or ectopic overexpression of Nrf2 inhibited cytokine-induced beta-cell damage. Treatment of RIN cells with IL-1beta and IFN-gamma induced beta-cell damage through a NF-kappaB-dependent signaling pathway. Activation of Nrf2 by treatment with SFN and induction of Nrf2 overexpression by transfection with Nrf2 prevented cytokine toxicity. The mechanism by which Nrf2 activation inhibited NF-kappaB-dependent cell death signals appeared to involve the reduction of oxidative stress, as demonstrated by the inhibition of cytokine-induced H(2)O(2) production. The protective effect of SFN was further demonstrated by the restoration of normal insulin secreting responses to glucose in cytokine-treated rat pancreatic islets. Furthermore, pretreatment with SFN blocked the development of type 1 diabetes in streptozotocin-treated mice.

Objective: SIRT1, a class III histone/protein deacetylase, is known to interfere with the nuclear factor-kappaB (NF-kappaB) signaling pathway and thereby has an anti-inflammatory function. Because of the central role of NF-kappaB in cytokine-mediated pancreatic beta-cell damage, we postulated that SIRT1 might work in pancreatic beta-cell damage models., Research Design and Methods: RINm5F (RIN) cells or isolated rat islets were treated with interleukin-1beta and interferon-gamma. SIRT1 was activated by resveratrol, a pharmacological activator, or ectopic overexpression. The underlying mechanisms of SIRT1 against cytokine toxicity were further explored., Results: Treatment of RIN cells with cytokines induced cell damage, and this damage was well correlated with the expression of the inducible form of nitric oxide (NO) synthase (iNOS) and NO production. However, SIRT1 overexpression completely prevented cytokine-mediated cytotoxicity, NO production, and iNOS expression. The molecular mechanism by which SIRT1 inhibits iNOS expression appeared to involve the inhibition of the NF-kappaB signaling pathway through deacetylation of p65. In addition, SIRT1 activation by either resveratrol or adenoviral-directed overexpression of SIRT1 could prevent cytokine toxicity and maintain normal insulin-secreting responses to glucose in isolated rat islets., Conclusions: This study will provide valuable information not only into the mechanisms underlying beta-cell destruction but also into the regulation of SIRT1 as a possible target to attenuate cytokine-induced beta-cell damage.

Although Radix clematidis has commonly been used in Chinese medicine for the treatment of arthralgia, the anti-diabetic effects of Radix clematidis have not yet been reported. In the present study, we demonstrated that Radix clematidis extract (RCE) could prevent cytokine-induced beta-cell damage and streptozotocin (STZ)-induced diabetes in mice. Treatment of RINm5F insulinoma cells with interleukin-1beta and interferon-gamma reduced cell viability; however, RCE protected the cells from this cytokine-mediated viability reduction in a concentration-dependent manner. Additionally, incubation with RCE resulted in a significant suppression of cytokine-induced nitric oxide (NO) production, which was correlated with reduced levels of the inducible form of NO synthase (iNOS) mRNA and protein. The molecular mechanism by which RCE inhibited iNOS gene expression appeared to involve inhibition of NF-kappaB activation. Furthermore, RCE abolished the cytokine-induced increases in NF-kappaB binding activity and p65 subunit levels in the nucleus, as well as IkappaBalphadegradation in the cytosol when compared to unstimulated cells. The protective effect of RCE was further demonstrated by the observed suppression of NF-kappaB-dependent iNOS expression and normal insulin secreting responses to glucose in cytokines-treated islets. The anti-diabetic effect of RCE was even more striking in vivo, where nearly complete protection against STZ-induced diabetes was observed. Treatment of mice with STZ resulted in hyperglycemia and hypoinsulinemia, which was further evidenced by immunohistochemical staining; however, pretreatment of mice with RCE blocked the destruction of STZ-induced islets and the development of type 1 diabetes.

Guggulsterone has been used to treat hyperlipidemia, arthritis, and obesity. Although its anti-inflammatory and anti-hyperlipidemic effects have been well documented, the effect of guggulsterone on pancreatic beta cells is unknown. Therefore, in this study, the effect of guggulsterone on IL-1beta- and IFN-gamma-induced beta-cell damage was investigated. Treatment of RINm5F (RIN) rat insulinoma cells with IL-1beta and IFN-gamma induced cell damage, and this damage was well correlated with nitric oxide (NO) and prostaglandin E2 (PGE2) production. However, guggulsterone completely prevented cytokines-mediated cytotoxicity, as well as NO and PGE2 production, and these effects were correlated with reduced levels of the inducible form of NO synthase (iNOS) and cyclooxygenase-2 (COX-2) mRNA and protein expressions. The molecular mechanism by which guggulsterone inhibits iNOS and COX-2 gene expressions appeared to involve the inhibition of NF-kappaB activation. The cytoprotective effects of guggulsterone were also mediated through the suppression of the JAK/STAT pathway. Cells treated with the cytokines downregulated the protein level of SOCS-3, however pretreatment with guggulsterone attenuated this decrease. Additionally, in a second set of experiments in which rat islets were used, the findings regarding the beta-cell protective effects of guggulsterone were essentially the same as those observed when RIN cells were used; guggulsterone prevented cytokines-induced NO and PGE2 production, iNOS and COX-2 expressions, JAK/STAT activation, NF-kappaB activation, downregulation of SOCS-3, and impairment of glucose-stimulated insulin secretion. Collectively, these results suggest that guggulsterone may be used to preserve functional beta-cell mass.

Guggulsterone is a plant sterol that is used to treat hyperlipidemia, arthritis, and obesity. Although its anti-inflammatory and anti-hyperlipidemic effects have been well documented, the effect of guggulsterone on fibroblast-like synoviocytes (FLS) has not yet been reported. Therefore, in this study, the effect of guggulsterone on interleukin (IL)-1beta-induced inflammatory responses in the FLS of rheumatic patients was investigated. Treatment of FLS with IL-1beta induced production of chemokines such as RANTES and ENA-78. In addition, Western blot analysis and gelatin zymography revealed that IL-1beta activated matrix metalloproteinase (MMP)-1 and -3 in FLS. However, pre-incubation with guggulsterone completely inhibited the ability of IL-1beta to induce the production of chemokines and to activate MMPs. Although the NF-kappaB binding activity and nuclear p50 and p65 subunit levels, as well as IkappaBalpha degradation in the cytoplasm was greater in cells stimulated with IL-1beta than in unstimulated cells, treatment with guggulsterone abolished all of these increases. Collectively, these results suggest that guggulsterone would be useful as an inhibitor of joint destruction in patients with rheumatoid arthritis.

In this study, we assessed the preventive effects of Radix asari extract (RAE) against cytokine-induced beta-cell destruction. Cytokines secreted by immune cells that have infiltrated pancreatic islets are crucial mediators of beta-cell destruction in insulin-dependent diabetes mellitus. Treatment of RINm5F (RIN) cells with interleukin (IL)-1beta and interferon (IFN)-gamma resulted in a reduction of cell viability and proliferation. However, treatment of RIN cells with RAE protected the IL-1beta and IFN-gamma- mediated viability and proliferation reduction in a concentration-dependent manner. Incubation with RAE also resulted in significant suppression of IL-1beta and IFN-gamma-induced nitric oxide (NO) production, and this reduction was correlated with reduced levels of mRNA and protein associated with the inducible form of NO synthase (iNOS). The molecular mechanism by which RAE inhibited iNOS gene expression appeared to involve the inhibition of NF-kappaB activation as a result of RAE's suppression of IL-1beta and IFN-gamma-induced IkappaBalpha degradation. The protective effects of RAE were verified via the observation of reduced NO generation and iNOS expression, as well as the observation of normal insulin-secretion responses to glucose in IL-1beta and IFN-gamma-treated rat islets. These results suggest that RAE protects beta cells from cytokine toxicity by suppression of NF-kappaB activation.

We demonstrated previously that Coptidis rhizoma extract (CRE) prevented S-nitroso-N-acetylpenicillamine-induced apoptotic cell death via the inhibition of mitochondrial membrane potential disruption and cytochrome c release in RINm5F (RIN) rat insulinoma cells. In this study, the preventive effects of CRE against cytokine-induced beta-cell death was assessed. Cytokines generated by immune cells infiltrating pancreatic islets are crucial mediators of beta-cell destruction in insulin-dependent diabetes mellitus. The treatment of RIN cells with IL-1beta and IFN-gamma resulted in a reduction of cell viability. CRE completely protected IL-1beta and IFN-gamma-mediated cell death in a concentration-dependent manner. Incubation with CRE induced a significant suppression of IL-1beta and IFN-gamma-induced nitric oxide (NO) production, a finding which correlated well with reduced levels of the iNOS mRNA and protein. The molecular mechanism by which CRE inhibited iNOS gene expression appeared to involve the inhibition of NF-kappaB activation. The IL-1beta and IFN-gamma-stimulated RIN cells showed increases in NF-kappaB binding activity and p65 subunit levels in nucleus, and IkappaB alpha degradation in cytosol compared to unstimulated cells. Furthermore, the protective effects of CRE were verified via the observation of reduced NO generation and iNOS expression, and normal insulin-secretion responses to glucose in IL-1beta and IFN-gamma-treated islets.

Cytokines produced by immune cells infiltrating pancreatic islets are important mediators of beta-cell destruction in insulin-dependent diabetes mellitus. Scoparone (6,7-dimethoxycoumarin) is known to have a wide range of pharmacological properties in vitro. In this study, the effects of scoparone on cytokine-induced beta-cell dysfunction were examined. Presence of scoparone significantly protected interleukin-1beta (IL-1beta) and interferon-gamma (IFN-gamma)-mediated cytotoxicity of RINm5F, a rat insulinoma cell line, and preserved glucose-stimulated insulin secretion in rat pancreatic islets. Scoparone also resulted in a significant reduction in IL-1beta and IFN-gamma-induced nitric oxide (NO) production, a finding that correlated well with reduced levels of the inducible form of NO synthase (iNOS) mRNA and protein. The molecular mechanism by which scoparone inhibited iNOS gene expression appeared to involve the inhibition of NF-kappaB activation. These results revealed the possible therapeutic value of scoparone for the prevention of diabetes mellitus progression.

Diabetes mellitus is characterized by cytokine-induced insulitis and a deficit in beta-cell mass. Ligands for peroxisome proliferator-activated receptor-gamma (PPAR-gamma) have been shown to have anti-inflammatory effects in various experimental models. We questioned whether activation of endogenous PPAR-gamma by either PPAR-gamma ligands or adenoviral-directed overexpression of PPAR-gamma (Ad-PPAR-gamma) could inhibit cytokine-induced beta-cell death in RINm5F (RIN) cells, a rat insulinoma cell line. Treatment of RIN cells with interleukin-1 beta (IL-1 beta) and interferon-gamma (IFN-gamma) induced beta-cell damage through NF kappaB-dependent signaling pathways. Activation of PPAR-gamma by PPAR-gamma ligands or Ad-PPAR-gamma inhibited IL-1 beta and IFN-gamma-stimulated nuclear translocation of the p65 subunit and DNA binding activity. NF kappaB target gene expression and their product formation, namely inducible nitric oxide synthase and cyclooxygenase-2 were decreased by PPAR-gamma activation, as established by real-time PCR, Western blots and measurements of NO and PGE(2). The mechanism by which PPAR-gamma activation inhibited NF kappaB-dependent cell death signals appeared to involve the inhibition of I kappa B alpha degradation, evidenced by inhibition of cytokine-induced NF kappaB-dependent signaling events by Ad-I kappaB alpha (S32A, S36A), non-degradable I kappaB alpha mutant. I kappaB beta mutant, Ad-I kappaB beta (S19A, S23A) was not effective in preventing cytokine toxicity. Furthermore, a protective effect of PPAR-gamma ligands was proved by assaying for normal insulin secreting capacity in response to glucose in isolated rat pancreatic islets. The beta-cell protective function of PPAR-gamma ligands might serve to counteract cytokine-induced beta-cell destruction.

Aim: To clarify the mechanism underlying the anti-diabetic activities of cortex cinnamomi extract (CCE)., Methods: To induce in vivo diabetes, mice were injected with streptozotocin (STZ) via a tail vein (100 mg STZ/kg body weight). To determine the effects of CCE, mice were administered CCE twice daily for 7 d by oral gavage starting 1 wk before the STZ injection. Blood glucose and plasma insulin concentration were measured as an index of diabetes. Also, to induce cytotoxicity of RINm5F cells, we treated with cytokines (IL-1beta (2.0 ng/mL) and IFN-gamma (100 U/mL)). Cell viability and nitric oxide production were measured colorimetrically. Inducible nitric oxide synthase (iNOS) mRNA and protein expression were determined by RT-PCR and Western blotting, respectively. The activation of NF-kappaB was assayed by using gel mobility shift assays of nuclear extracts., Results: Treatment of mice with STZ resulted in hyperglycemia and hypoinsulinemia, which was further evidenced by immunohistochemical staining of islets. However, the diabetogenic effects of STZ were completely prevented when mice were pretreated with CCE. The inhibitory effect of CCE on STZ-induced hyperglycemia was mediated through the suppression of iNOS expression. In rat insulinoma RINm5F cells, CCE completely protected against interleukin-1beta and interferon-gamma-mediated cytotoxicity. Moreover, RINm5F cells incubated with CCE showed significant reductions in interleukin-1beta and interferon-gamma-induced nitric oxide production and in iNOS mRNA and protein expression, and these findings correlated well with in vivo observations., Conclusion: The molecular mechanism by which CCE inhibits iNOS gene expression appears to involve the inhibition of NF-kappaB activation. These results reveal the possible therapeutic value of CCE for the prevention of diabetes mellitus progression.

Dimethylsulfoxide (DMSO) has been known to differentiate HL60 cells into neutrophil like cells. Here, we provide an evidence for the involvement of tumor suppressor PTEN, an antagonist of phosphatidylinositol 3-kinase (PI3K) in the DMSO-induced differentiation of HL60 cells. DMSO upregulated PTEN with unaffecting the expression of PI3K. The upregulation of PTEN by DMSO lead to the decrease of Akt phosphorylation, a downstream of PI3K. The DMSO-induced upregulation of PTEN might be mediated by NF-kappaB activation, which was evidenced by the blockage of DMSO-induced PTEN upregulation with an NF-kappaB inhibitor, pyrrolidine dithiocarbamate (PDTC).

Abstract: Dihydroavenanthramide D (DHAvD) is a synthetic analog to naturally occurring avenanthramide, which is the active component of oat. Previous study demonstrates that DHAvD strongly inhibits activation of nuclear factor-kappa B (NF-κB), which is a major component in cancer cell invasion. The present study investigated whether DHAvD can modulate MMP-9 expression and cell invasion in MCF-7 human breast cancer cells. MMP-9 expression and cell invasion in response to 12-O-tetradecanoylphorbol-13-acetate (TPA) was increased, whereas these inductions were muted by DHAvD. DHAvD also suppressed activation of mitogen-activated protein kinase (MAPK), and MAPK-mediated nuclear factor-kappa B (NF-κB) and activator protein-1 (AP-1) activations in TPA-treated MCF-7 cells. The results indicate that DHAvD-mediated inhibition of TPA-induced MMP-9 expression and cell invasion involves the suppression of the MAPK/NF-κB and MAPK/AP-1 pathways in MCF-7 cells. DHAvD may have potential value in breast cancer metastasis. [Copyright &y& Elsevier]

Abstract: Sulfuretin is one of the main flavonoids produced by Rhus verniciflua, which is reported to inhibit the inflammatory response by suppressing the NF-κB pathway. Because NF-κB activation plays a pivotal role in the pathogenesis of allergic airway inflammation, we here examined the effect of sulfuretin on an ovalbumin-induced airway inflammation model in mice. We isolated sulfuretin from R. verniciflua. Sulfuretin was delivered intraperitoneally after the last ovalbumin challenge. Airway hyper-responsiveness, cytokines, mucin, and eosinophilic infiltration were analyzed in bronchoalveolar lavage fluid and lung tissue. A single administration of sulfuretin reduced airway inflammatory cell recruitment and peribronchiolar inflammation and suppressed the production of various cytokines in bronchoalveolar fluid. In addition, sulfuretin suppressed mucin production and prevented the development of airway hyper-responsiveness. The protective effect of sulfuretin was mediated by the inhibition of the NF-κB signaling pathway. Our results suggest that sulfuretin may have therapeutic potential for the treatment of allergic airway inflammation. [ABSTRACT FROM AUTHOR]

Abstract: The IL-1β-NF-κB axis is a key pathway in the pathogenesis of rheumatoid arthritis (RA) and is central in the production of proinflammatory mediators in the inflamed synovium. Therefore, we examined whether fibroblast-like synoviocytes (FLS) could be spared from IL-1β-induced toxicity by an overexpressing IκB super-repressor. Infection of FLS with Ad-IκBα (S32A, S36A), an adenovirus-containing mutant IκBα, inhibited IL-1β-induced nuclear translocation and DNA binding of NF-κB. In addition, Ad-IκBα (S32A, S36A) prevented IL-1β-induced inflammatory responses; namely, the production of chemokines, such as ENA-78 and RANTES, and activation of MMP-1 and MMP-3. Finally, increased cellular proliferation of FLS after IL-1β treatment was significantly reduced by Ad-IκBα (S32A, S36A). However, Ad-IκBβ (S19A, S23A), the IκBβ mutant, was not effective in preventing IL-1β toxicity. These results suggest that inhibition of IκBα degradation is a potential target for the prevention of joint destruction in patients with RA. [Copyright &y& Elsevier]