Nuclear factor-κB activation in primary lymphoma of bone

Primary lymphoma of bone is a rare type of extranodal diffuse large B-cell lymphoma with a relatively favourable outcome. Recent scientific interest has focused on elucidating the role of nuclear factor-κB pathway in lymphomagenesis and its potential significance as a therapeutic target. In nodal B-cell non-Hodgkin lymphomas, constitutive activation of nuclear factor-κB appears to be involved in tumour cell survival, notably in the non-germinal centre type of diffuse large B-cell lymphoma. We investigated nuclear factor-κB activation via the classical and alternative pathway in primary lymphoma of bone, through immunohistochemical staining for nuclear factor-κB family members on tumour tissues of 50 patients. Nine cases (18 %) showed nuclear staining for p50, and one case showed nuclear co-expression of p52. None of the cases showed nuclear staining for c-Rel. The nuclear staining of p50 suggests that in a minority of primary lymphomas of bone nuclear factor-κB is constitutively activated via the classical pathway. In contrast to other extranodal types of diffuse large B-cell lymphoma, there was a lack of nuclear co-expression of p65, which might suggest activation of a different pathway. Activation of nuclear factor-κB through the alternative pathway does not appear to be significantly involved, as only one case showed significant nuclear expression for p52. Finally, nuclear expression of p50 was neither preferentially detected in non-germinal centre type or germinal centre type primary lymphoma of bone, nor related to poor prognosis. Therefore, in contrast to nodal diffuse large B-cell lymphoma, the nuclear factor-κB pathway does not appear to be an attractive therapeutic target in primary lymphoma of bone.     

Higenamine regulates Nrf2-HO-1-Hmgb1 axis and attenuates intestinal ischemia–reperfusion injury in mice

Inflammation Research - Intestinal ischemia and reperfusion (IR) syndrome is a life-threatening dilemma caused by diverse events. Higenamine (HG), an active ingredient of Aconiti Lateralis Radix...     

Human β2-glycoprotein I attenuates mouse intestinal ischemia/reperfusion induced injury and inflammation

Intestinal ischemia-reperfusion (IR)-induced injury results from a complex cascade of inflammatory components. In the mouse model of intestinal IR, the serum protein, β2-glycoprotein I (β2-GPI) binds to the cell surface early in the cascade. The bound β2-GPI undergoes a conformational change which exposes a neoantigen recognized by naturally occurring antibodies and initiates the complement cascade. We hypothesized that providing additional antigen with exogenous β2-GPI would alter IR-induced tissue injury. Administration of human but not mouse β2-GPI attenuated IR-induced tissue damage and prostaglandin E₂ production indicating a physiological difference between β2-GPI isolated from the two species. To investigate whether structural features were responsible for this physiological difference, we compared the chemical, physical and biochemical properties of the two proteins. Despite possessing 76% amino acid identity and 86% sequence homology, we found that mouse β2-GPI differs from the human protein in size, carbohydrate chain location, heterogeneity and secondary structural content. These data suggest that the structural differences result in mouse Ab recognition of soluble human but not mouse β2-GPI and attenuated IR-induced injury. We conclude that caution should be exercised in interpreting results obtained by using human β2-GPI in a mouse model.     

Human β2-glycoprotein I attenuates mouse intestinal ischemia/reperfusion induced injury and inflammation

Intestinal ischemia-reperfusion (IR)-induced injury results from a complex cascade of inflammatory components. In the mouse model of intestinal IR, the serum protein, β2-glycoprotein I (β2-GPI) binds to the cell surface early in the cascade. The bound β2-GPI undergoes a conformational change which exposes a neoantigen recognized by naturally occurring antibodies and initiates the complement cascade. We hypothesized that providing additional antigen with exogenous β2-GPI would alter IR-induced tissue injury. Administration of human but not mouse β2-GPI attenuated IR-induced tissue damage and prostaglandin E(2) production indicating a physiological difference between β2-GPI isolated from the two species. To investigate whether structural features were responsible for this physiological difference, we compared the chemical, physical and biochemical properties of the two proteins. Despite possessing 76% amino acid identity and 86% sequence homology, we found that mouse β2-GPI differs from the human protein in size, carbohydrate chain location, heterogeneity and secondary structural content. These data suggest that the structural differences result in mouse Ab recognition of soluble human but not mouse β2-GPI and attenuated IR-induced injury. We conclude that caution should be exercised in interpreting results obtained by using human β2-GPI in a mouse model.     

3,5,4′-Tri-O-acetylresveratrol attenuates seawater aspiration-induced lung injury by inhibiting activation of nuclear factor-kappa B and hypoxia-inducible factor-1α

Resveratrol is a phytoalexin synthesized by a wide variety of plants, which has been proven to be effective in suppressing oxidative stress and inflammation. The aim of the present study was to investigate the effect of Resveratrol's prodrug: 3,5,4′-tri-O-acetylresveratrol, on seawater drowning-induced acute lung injury (SWD-ALI). Histological changes were assessed to study lung injuries; cytokines in lung samples were monitored by ELISA to reflect inflammation; T-SOD and MDA activity were detected to examine oxidative stress in lung tissues. Besides, we also tested the expression of NF-κB and HIF-1α to probe the possible protecting mechanism of 3,5,4′-tri-O-acetylresveratrol on AWD-ALI. The results showed that pretreatment with different doses of 3,5,4′-tri-O-acetylresveratrol improved seawater-induced lung histopathologic changes, alleviated lung edema, reduced the production of inflammatory mediators including TNF-α and IL-1β, inhibited MDA activity, and enhanced T-SOD activity, which was possibly associated with inhibition of NF-κB and HIF-1α. In conclusion, the current study demonstrated that 3,5,4′-tri-O-acetylresveratrol exhibited a protective effect on SWD-ALI by inhibiting of the inflammatory response, which may also involve the suppression of oxidative stress in lung tissues.     

Inhibition of nuclear factor-κB by 6-O-acetyl shanzhiside methyl ester protects brain against injury in a rat model of ischemia and reperfusion

Background  

Recent studies have demonstrated an inflammatory response associated with the pathophysiology of cerebral ischemia. The beneficial effects of anti-inflammatory drugs in cerebral ischemia have been documented. When screening natural compounds for drug candidates in this category, we isolated 6-O-acetyl shanzhiside methyl ester (ND02), an iridoid glucoside compound, from the leaves of Lamiophlomis rotata (Benth.) Kudo. The objectives of this study were to determine the effects of ND02 on a cultured neuronal cell line, SH-SY5Y, in vitro, and on experimental ischemic stroke in vivo.     

Osteopontin expression correlates with nuclear factor-κB activation and apoptosis downregulation in clear cell renal cell carcinoma

Osteopontin (OPN) is a phosphoglycoprotein implicated in tumorigenesis and tumor cell metastasis. Apoptosis inhibition is one of the mechanisms that contribute to development and progression of cancer, and might be initiated by OPN interaction with tumor cells. The aim of this study was to analyze the relation between OPN and nuclear factor-kappa B (NF-κB) expression in clear cell renal cell carcinoma (CCRCC), as well as their relation to apoptotic activity of tumor cells.Expression of OPN protein and p65 NF-κB subunit was analyzed immunohistochemically in 87 CCRCC samples, and compared mutually and with apoptotic index. Expression of OPN mRNA was analyzed using quantitative real-time PCR and compared with OPN and NF-κB protein expression in 22 CCRCC samples.Statistical analysis showed an association of p65 NF-κB with OPN mRNA (p = 0.015) and protein (p < 0.001). Also, we found an inverse relationship of OPN with NF-κB protein expression and apoptotic activity of tumor cells (p = 0.006 and p = 0.022, respectively). Our results indicate that p65 NF-κB signaling pathway may be involved in OPN-mediated CCRCC progression, partly by protecting tumor cells from apoptosis. Therefore, both molecules can constitute potential targets for therapeutic intervention in CCRCC.     

Quercetin ameliorates peripheral nerve ischemia–reperfusion injury through the NF-kappa B pathway

This study aimed to investigate the protective effect of quercetin against ischemia–reperfusion (IR) injury induced in the sciatic nerve of the rat. Quercetin (20 mg/kg) was given during ischemia just before reperfusion. Four groups of rats (Q+IR3, Q+IR7, Q+IR14, and Q+IR28) received 3, 7, 14, and 28 days of reperfusion, respectively, after the intraperitoneal injection of quercetin. After reperfusion, a behavioral test was performed and the sciatic functional index was calculated. Each sciatic nerve was stained to check for edema and ischemic fiber degeneration. Immunohistochemical staining was performed to detect TNF-alpha and NF-kappa B, and TUNEL staining was carried out to detect apoptosis. The Q+IR3, Q+IR7, and Q+IR14 groups showed significantly increased behavioral scores and ameliorated sciatic functional index values compared to IR-injured rats that received vehicle alone during ischemia and then the same period of reperfusion. The Q+IR3, Q+IR7, Q+IR14, and Q+IR28 groups presented significant ischemic fiber degeneration (IFD), TNF-alpha expression, and apoptosis as compared with the IR-injured and perfused rats that did not receive quercetin. The Q+IR3, Q+IR7, and Q+IR28 groups also exhibited significantly decreased NF-kappa B expression (p < 0.001, p = 0.001, p = 0.026) as compared with the IR-injured rats that were perfused but did not receive quercetin. These results imply that quercetin may be beneficial in the treatment of sciatic IR injury because of its antiapoptotic and antiinflammatory effects and its ability to decrease the expression of NF-kappa B.     

Sevoflurane pretreatment enhance HIF-2α expression in mice after renal ischemia/reperfusion injury

Ischemia/reperfusion (I/R) injury often occurs, which is one of the major causes of acute kidney injury, thus increasing in-hospital mortality. HIF-2α has a protective role against ischemia of the kidney. Renal ischemia/reperfusion under sevoflurane anesthesia resulted in drastic improvements in renal function. We hypothesized that underlying mechanism responsible for renal protection from sevoflurane pretreatment involves the upregulation of HIF-2α. Sevoflurane pretreatment were performed on WT and HIF-2α knockout mice before renal ischemia/reperfusion. Levels of blood urea nitrogen (BUN) and serum creatinine (Cr) were determined with a standard clinical automatic analyzer. The left kidneys were taken for morphological examination. Expression of HIF-2α in kidney tissue was examined by western blotting. In WT mice, group I/R injury had significantly higher BUN and Cr levels than group control, whereas group I/R + Sev had significantly lower BUN and Cr levels than group I/R injury. Renal HIF-2α expression levels were significantly higher in WT mice of group I/R + Sev than group control and group I/R. In HIF-2α^-/- mice, group I/R + Sev showed much higher BUN and Cr levels and severer histological damage than group I/R and group control. Renal HIF-2α expression levels were significantly higher in WT mice of group I/R + Sev than group control and group I/R. Our findings suggested that HIF-2α might contribute to the beneficial effect of sevoflurane in renal ischemia/reperfusion injury.     

Icaritin inhibits PD-L1 expression by Targeting Protein IκB Kinase α

Icaritin, a small molecule currently being investigated in phase III clinical trials in China (NCT03236636 and NCT03236649) for treatment of advanced hepatocellular carcinoma (HCC), is a prenylflavonoid derivative obtained from the Epimedium genus. Previously, it was found that Icaritin decreased the expression of PD-L1, but its direct molecular targets and the underlying mechanisms have not been identified. In this study, we report the identification of IKK-α as the protein target of Icaritin by biotin-based affinity binding assay. The further mutagenesis assay has provided evidence that C46 and C178 in IKK-α were essential amino acids for Icaritin binding to IKK-α, revealing the binding sites of Icaritin to IKK-α for the first time. Functionally, Icaritin inhibited the NF-κB signalling pathway by blocking IKK complex formation, which led to decreased nuclear translocation of NF-κB p65, and subsequent downregulation of PD-L1 expression in a dose–dependent manner. More importantly, PD-L1-positive patients exhibited longer overall survival upon Icaritin therapy. Finally, Icaritin in combination with checkpoints antibodies, such as α-PD-1, has demonstrated much better efficacy than any single therapy in animal models. This is the first report that anticancer effects of Icaritin are mediated, at least in part, by impairing functions of IKK-α.     

Pyrrolidine dithiocarbamate inhibits nuclear factor-κB pathway activation, and regulates adhesion, migration, invasion and apoptosis of endometriotic stromal cells

The activation of nuclear factor-κB (NF-κB) has been implicated in the development and progression of endometriosis. The aim of this study is to investigate the potential application of pyrrolidine dithiocarbamate (PDTC), a potent NF-κB inhibitor, in the treatment of endometriosis. NF-κB-DNA-binding activity, IκB phosphorylation and expression of nuclear p65 protein in endometriotic ectopic stromal cells (EcSCs), endometriotic eutopic stromal cells (EuSCs) and normal endometrial stromal cells (NESCs) were detected by electrophoretic mobility shift assay and western blot analysis. Adhesion, migration, invasion and apoptosis of EcSCs were observed by means of adhesion, migration, invasion and terminal deoxynucleotidyl transferase-mediated dUDP nick-end labeling assay, respectively. Gene and protein expressions of CD44s, matrix metalloproteinase (MMP)-2, MMP-9 and survivin in EcSCs were measured by RT-PCR and western blot analysis. The results showed that PDTC in the absence or presence of interleukin (IL)-1β showed stronger inhibitory effects on NF-κB-DNA-binding activity, IκB phosphorylation and expression of nuclear p65 protein in EcSCs than those in EuSCs or NESCs. PDTC enhanced apoptosis, and suppressed IL-1β-induced cellular adhesion, migration and invasion of EcSCs. Pretreatment of EcSCs with PDTC attenuated IL-1β-induced expressions of CD44s, MMP-2, MMP-9 and survivin at gene and protein levels. All these findings suggest that PDTC induces apoptosis and down-regulates adhesion, migration and invasion of EcSCs through the suppression of various molecules. Therefore, PDTC could be used as a therapeutic agent for the treatment of endometriosis.     

Piceatannol inhibits phorbol ester-induced expression of COX-2 and iNOS in HR-1 hairless mouse skin by blocking the activation of NF-κB and AP-1

Objectives

The present study was aimed at elucidating the molecular mechanisms of anti-inflammatory activity of piceatannol (trans-3,4,3′,5′-tetrahydroxystilbene) in mouse skin in vivo.

Methods

Female HR-1 hairless mice were topically treated with 12-O-tetradecanoylphorbol-13-acetate (TPA) with or without piceatannol pretreatment. Epidermal protein expression was assessed by Western blot analysis. The cyclooxygenase-2 (COX-2) expression was detected by immunohistochemistry. The DNA binding of nuclear factor-kappaB (NF-κB) and activator protein-1 (AP-1) was examined by the electrophoretic mobility gel shift assay. The catalytic activity of IκBα kinase-β (IKKβ) was measured by in vitro kinase assay.

Results

Pretreatment with piceatannol attenuated TPA-induced expression of COX-2 and inducible nitric oxide synthase (iNOS) in mouse skin. Piceatannol diminished nuclear translocation and the DNA binding of NF-κB through the blockade of phosphorylation and subsequent degradation of IκBα. Piceatannol attenuated the catalytic activity of IKKβ and inhibited the phosphorylation of mitogen-activated protein (MAP) kinases in TPA-treated mouse skin. In addition, piceatannol decreased TPA-induced expression of c-Fos and the DNA binding of AP-1.

Conclusion

Piceatannol inhibits TPA-induced COX-2 and iNOS expression by blocking the activation of NF-κB and AP-1 via suppression of the IKKβ activity and phosphorylation of MAP kinases, which provides a mechanistic basis of its anti-inflammatory effects in mouse skin.