Ethanol extract from Artemisia vestita, a traditional Tibetan medicine, exerts anti-sepsis action through down-regulating the MAPK and NF-kappaB pathways

Artemisia vestita Wall., a traditional Tibetan medicine, has wide clinical application for inflammatory diseases. However, its molecular mechanism of anti-inflammatory effect is poorly understood. In the present study, we investigated the anti-inflammatory activity and underlying mechanism of the ethanol extract from Artemisia vestita (AV-ext) on lipopolysaccharide (LPS)-induced sepsis. Pretreatment with AV-ext significantly decreased the levels of tumor necrosis factor-alpha (TNF-alpha) in serum and liver and lung tissues, and improved the survival of mice with experimental sepsis. AV-ext also remarkably reduced the expression levels of TNF-alpha, interleukin-1beta and cyclooxygenase-2 in LPS-stimulated RAW 264.7 macrophages and dose dependently suppressed the activation of mitogen-activated protein kinases (MAPKs), such as p38, extracellular signal-regulated kinase (ERK1/2) and c-Jun NH2-terminal kinase (JNK). Furthermore, pretreatment with AV-ext dose dependently inhibited the activation of nuclear factor-kappaB (NF-kappaB), as well as the degradation and phosphorylation of inhibitory kappaB (IkappaB) in LPS-activated RAW 264.7 macrophages. These results collectively reveal that AV-ext inhibits TNF-alpha release from macrophages by suppressing MAPK and NF-kappaB signaling pathways and suggest that AV-ext may be beneficial for the treatment of endotoxin shock or sepsis.     

Nuclear BCL-10 expression is common in lymphoplasmacytic lymphoma/Waldenstr?m macroglobulinemia and does not correlate with p65 NF-kappaB activation.

B-cell lymphoma 10 (BCL-10) is expressed in the cytoplasm of normal germinal center and marginal zone B-cells and is involved in lymphocyte development and activation. Aberrant nuclear expression of BCL-10 occurs in a subset of extranodal marginal zone B-cell lymphomas (MALT lymphomas), primarily those with the t(1;14)(p22;q32) or t(11;18)(q21;q21). Little is known about BCL-10 expression in lymphoplasmacytic lymphoma/Waldenstr?m macroglobulinemia (LPL/WM). We assessed for BCL-10 in 51 bone marrow (BM) specimens involved by LPL/WM using immunohistochemical methods. All patients had monoclonal IgM in serum. Extent of BM involvement was assessed using PAX-5/BSAP and CD20 immunostains and the pattern and percentage of B-cells positive for BCL-10 was determined. The p65 subunit of nuclear factor-kappa B (NF-kappaB), a molecule downstream of BCL-10, was also assessed immunohistochemically. Nuclear BCL-10 staining was present in 28/51 (55%) specimens. BCL-10 expression correlated with greater extent of BM involvement (P=0.001), but did not correlate with serum IgM paraprotein levels, type of immunoglobulin light chain, or clinical variables. Nuclear expression of the p65 subunit of NF-kappaB was detected in 17/50 (34%) specimens, suggesting that NF-kappaB is active in a subset of LPL/WM. p65 NF-kappaB activation did not correlate with nuclear BCL-10 immunostaining. Cytogenetic analysis in 29 cases showed no evidence of the t(1;14) or t(11;18). These results indicate that nuclear BCL-10 expression is common in LPL/WM and does not correlate with MALT lymphoma-associated translocations or p65 NF-kappaB nuclear staining.     

TNF-α Induces Transient Resistance to Fas-Induced Apoptosis in Eosinophilic Acute Myeloid Leukemia Cells

Tumor necrosis factor α （TNF-α） has been recognized as an activator of nuclear factor kB （NF-kB）, a factor implicated in the protection of many cell types from apoptosis. We and others have presented evidence to suggest that Fas-induced apoptosis may be an important aspect of the resolution of inflammation, and that delayed resolution of inflammation may be directly associated with NF-kB-dependent resistance to Fas. Because TNF-α activates NF-kB in many cell types including inflammatory cells such as eosinophils, we examined effects of TNF-α signaling on the Fas-mediated killing of an eosinophilic cell line AML14. While agonist anti-Fas （CHII） treatment induced apoptosis in AML14 cells, no significant cell death occurred in response to TNF-α alone. Electrophoretic mobility shift assay （EMSA） revealed that TNF-α induced NF-kB transactivation in AMLI4 cells in a time- and dose-dependent fashion, and subsequent supershift assays indicated that the translocated NF-kB was the heterodimer p65 （RelA）/p50. Pre-treatment of cells with TNF-α dramatically decreased the CHll-induced cell death in a transient fashion, accompanied by suppression of activation of caspase-8 and caspase-3 activation. Inhibition of NF-kB transactivation by inhibitors, BAY 11-7085 and parthenolide, reversed the suppression of Fas-mediated apoptosis by TNF-α. Furthermore, TNF-α up-regulated X-linked inhibitor of apoptosis protein （XIAP） transiently and XIAP levels were correlated with the temporal pattern of TNF-α protection against Fas-mediated apoptosis. This finding suggested that TNF-α may contribute to the prolonged survival of inflammatory cells by suppression of Fas-mediated apoptosis, the process involved with NF-kB transactivation, anti-apoptotic XIAP up-regulation and caspase suppression. Cellular ＆ Molecular Immunology. 2007;4（1）：43-52.     

MALT1 gene rearrangements and NF-kappaB activation involving p65 and p50 are absent or rare in primary MALT lymphomas of the breast.

Mucosa associated lymphoid tissue (MALT) lymphomas arising in the breast are uncommon and few cases have been assessed for MALT lymphoma-associated translocations, BCL-10 expression, or NF-kappaB activation. In this study, we analyzed eight cases of primary breast MALT lymphoma. We also included 14 cases of primary breast diffuse large B-cell lymphoma since some of these may represent transformation of MALT lymphoma, known to occur at extra-mammary MALT sites. All cases were assessed for MALT1 gene rearrangements by fluorescence in situ hybridization (FISH). Using immunohistochemical methods, all cases were assessed for BCL-10, and subsets were assessed for NF-kappaB p65 and p50. None of the cases had MALT1 gene rearrangements by FISH. Of eight MALT lymphomas, BCL-10 was positive in seven (88%), with moderate nuclear and cytoplasmic staining in six, and a weak cytoplasmic staining in one. NF-kappaB p65 (n=8) and p50 (n=5) were negative or showed only cytoplasmic staining (ie inactivated) in all cases. Of 14 diffuse large B-cell lymphoma cases, BCL-10 was positive in 12 (87%), with weak-to-moderate cytoplasmic staining in 10, weak cytoplasmic and focally nuclear staining in one, and a moderate-to-strong nuclear and cytoplasmic staining in one. NF-kappaB p65 (n=11) showed cytoplasmic staining in all cases, whereas p50 (n=8) showed nuclear positivity (ie activated) in two (25%) cases. We conclude that MALT1 gene rearrangements are absent or rare in primary breast MALT lymphoma and diffuse large B-cell lymphoma. In MALT lymphomas, the moderate BCL-10 nuclear expression in six neoplasms is inconsistent with the FISH results, suggesting that BCL-10 immunostaining overestimates the frequency of MALT1 gene rearrangements. We also could not demonstrate NF-kappaB activation using nuclear staining for p65 and p50. In contrast, breast diffuse large B-cell lymphomas are heterogeneous. Weak cytoplasmic BCL-10 staining in most cases and evidence of NF-kappaB p50 activation in a subset differs from breast MALT lymphomas.     

Acetaldehyde prevents nuclear factor-kappa B activation and hepatic inflammation in ethanol-fed rats.

Acetaldehyde has been proposed as one of the mediators of liver injury in alcoholic liver disease. We investigated whether increased acetaldehyde levels affected the development of alcoholic liver injury. Male Wistar rats were fed a liquid diet containing fish oil and ethanol by intragastric infusion. Sustained elevations of acetaldehyde were achieved by daily treatment with two inhibitors of aldehyde dehydrogenase (ALDH): disulfiram and benzcoprine. Pathologic changes, plasma and liver acetaldehyde, nuclear factor-kappa B (NF-kappaB) and I kappa B alpha (I kappaB alpha) protein, tumor necrosis factor-alpha (TNF-alpha) and cyclooxygenase 2 (COX-2) mRNA were evaluated. Treatment with the ALDH inhibitors led to increased acetaldehyde in liver and plasma but prevented necrosis and inflammation. Steatosis was not affected. Both inhibitors decreased activation of NF-kappaB and down-regulated TNF-alpha and COX-2 expression. Decreased activation of NF-kappaB was accompanied by I kappaB alpha preservation. Acetaldehyde probably inhibits NF-kappaB activation through I kappaB alpha preservation. Down-regulation of TNF-alpha and COX-2 occur secondary to inhibition of NF-kappaB and account for the absence of necrosis and inflammation in the ALDH inhibitor-treated groups.     

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and TNF-alpha promote the NF-kappaB-dependent maturation of normal and leukemic myeloid cells

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and TNF-alpha induced monocytic maturation of primary normal CD34-derived myeloid precursors and of the M2/M3-type acute myeloid leukemia HL-60 cell line, associated to increased nuclear factor (NF)-kappaB activity and nuclear translocation of p75, p65, and p50 NF-kappaB family members. Consistently, both cytokines also induced the degradation of the NF-kappaB inhibitors, IkappaBalpha and IkappaB epsilon, and up-regulated the surface expression of TRAIL-R3, a known NF-kappaB target. However, NF-kappaB activation and IkappaB degradation occurred with different time-courses, since TNF-alpha was more potent, rapid, and transient than TRAIL. Of the two TRAIL receptors constitutively expressed by HL-60 (TRAIL-R1 and TRAIL-R2), only the former was involved in IkappaB degradation, as demonstrated by using agonistic anti-TRAIL receptor antibodies. Moreover, NF-kappaB nuclear translocation induced by TRAIL but not by TNF-alpha was abrogated by z-IETD-fmk, a caspase-8-specific inhibitor. The key role of NF-kappaB in mediating the biological effects of TNF-alpha and TRAIL was demonstrated by the ability of unrelated pharmacological inhibitors of the NF-kappaB pathway (parthenolide and MG-132) to abrogate TNF-alpha- and TRAIL-induced monocytic maturation. These findings demonstrate that NF-kappaB is essential for monocytic maturation and is activated via distinct pathways, involving or not involving caspases, by the related cytokines TRAIL and TNF-alpha.