Recruitment of dendritic cells in oral lichen planus

Using immunohistochemistry the presence of different dendritic cell (DC) subsets was analysed in 16 biopsies from patients with oral lichen planus (OLP). A significant increase of CD1a+/Langerin+ Langerhans cells, DC-SIGN+ DC and CD123+/BDCA2+ plasmacytoid DCs (PDCs) was found in the epithelium and in the stroma of OLP biopsies compared to normal oral mucosa. A proportion of DCs were mature DC-LAMP+ and expressed S100 or CD11c, typically found in the interdigitating DCs of nodal T-cell areas. Double staining revealed that mature DCs co-expressed CCR7, thus indicating the development of a nodal migratory phenotype upon maturation. Significant recruitment of PDCs producing IFN-alpha was demonstrated by the expression of MxA within the lichenoid inflammatory infiltrate and close cell-to-cell contacts between PDCs and mature DCs were observed, with a significant correlation between the numbers of these two populations. Moreover, PDCs were also found to contain Granzyme-B, an associated-cytotoxic granule protein, inducing target cell apoptosis. Taken together, these results suggest that PDCs may promote maturation of DCs and amplify the cytotoxicity of lymphoid cells. Finally, the recruitment of different subtypes of DC, such as Langerhans cells, stromal DC-SIGN+ DCs and PDCs, associated with a significant proportion of mature DCs, acquiring a CCR7+ 'migratory' phenotype, indicate that they may play a pivotal role in the development of the lichenoid inflammatory infiltrate that occurs typically in OLP.     

Keratin expression in cutaneous lichen planus

The characteristic expression of keratins by keratinocytes is well documented. A typical 'hyperproliferative' profile of epidermal keratin expression occurs in psoriasis, wound healing and warts. This study analyses keratin expression in cutaneous lichen planus to determine abnormalities of differentiation occuring in this inflammatory disorder. Using a panel of monoclonal antibodies 28 samples (20 patients) were studied. The results showed that squamous differentiation was unaffected, with keratins K1 and K10 being expressed normally for the site sampled. The main abnormalities included extension of reactivity of the basal cell marker, LH8, into the suprabasal compartment. Keratin K17, usually restricted to adnexal structures, was variably expressed in the basal and suprabasal layers of the interfollicular epithelium of affected epidermis. Keratins K6 and K16, found suprabasally in hyperproliferative states, were detected both basally and suprabasally in all diseased samples. The keratin profile in lichen planus is analogous to the wound healing response. Suprabasal keratin K17 is found in psoriasis, wound healing and viral warts so the changes in keratin K17 may reflect hyperproliferative changes. It is likely that the changes in epidermal keratin expression are due to up-regulation of specific keratin genes by the production of cytokines and inflammatory mediators from the lymphocytic infiltrate typical of lichen planus.     

Clinicopathologic and prognostic significance of p21 (Cip1/Waf1) expression in bladder cancer

Recent studies have shown that altered expression p21 is shown to associate with tumorigenesis and tumor progression. To investigate the clinicopathological significance and prognostic value of p21 in bladder cancer (BCa). A total of 48 patients with BCa were included in this study. The correlation between p21 expression and clinicopathologic features and survival was studied. Also, a meta-analysis was performed to investigate the relationship between the p21 and BCa survival. Low p21 expression was detected both in tumor tissues compared with adjacent normal tissues. The expression of p21 was closely associated with advanced pathologic TNM stage (P = 0.001) and tumor grade (P = 0.013). Moreover, patients with low p21 expression had shorter recurrence-free survival (P = 0.016) and overall survival rates (P = 0.039). Multivariate Cox regression analysis revealed that p21 low expression was an independent prognostic factor for recurrence free survival (P = 0.03). Additionally, our meta-analysis. The available outcome data from six articles were examined. A meta-analysis of the HR indicated a significantly poor overall survival (OS, HR: 1.75, 95% CI: 1.38-2.21), recurrence free survival (RFS, HR: 1.83, 95% CI: 1.57-2.15), progression free survival (PFS, HR: 2.02, 95% CI: 1.48-2.75), and cancer specific survival (CSS, HR: 1.89, 95% CI: 1.53-2.33) in patients with low expression levels of p21. Our present results indicated that low p21 expression predicated tumor recurrence and poor prognosis in bladder cancer.     

NF-kappaB p50 and p65 subunits control intestinal homeostasis

Mice which lack the p50 subunit of NF-kappaB and are heterozygous for the p65 subunit (3X mice), are exquisitely sensitive to LPS-induced shock. Here, we demonstrate that prior to becoming moribund, 3X mice challenged with LPS develop a profound enteropathy. The enteropathy is characterized by defects in intestinal barrier function, increased epithelial apoptosis, and deregulated intestinal cytokine gene expression. The defect that sensitizes 3X mice to LPS-induced enteropathy is located within the innate immune compartment, as LPS induced similar findings in 3X mice lacking lymphocytes (3X/RAG). TNF-alpha depletion ameliorated the ability of LPS to induce pathology and TNF-alpha was able to independently induce similar findings, suggesting that TNF-alpha plays a critical role in the development of LPS-induced pathology in these mice. These data highlight that NF-kappaB subunits have essential functions in regulating intestinal homeostasis during acute inflammation.     

Direct role of NF-kappaB activation in Toll-like receptor-triggered HLA-DRA expression

Microbial components, such as DNA containing immunostimulatory CpG motifs (CpG-DNA) and lipopolysaccharides (LPS), elicit the cell surface expression of MHC class II (MHC-II) through Toll-like receptor (TLR)/IL-1R. Here, we show that CpG-DNA and LPS induce expression of the HLA-DRA in the human B cell line, RPMI 8226. Ectopic expression of the dominant negative mutant of CIITA and RNA interference targeting the CIITA gene indicate that CIITA activation is not enough for the maximal MHC-II expression induced by CpG-DNA and LPS. Additionally, nuclear factor (NF)-kappaB activation is required for the CpG-DNA-activated and LPS-activated HLA-DRA expression, whereas IFN-gamma-induced MHC-II expression depends on CIITA rather than on NF-kappaB. Comprehensive mutant analyses, electrophoretic mobility shift assays and chromatin immunoprecipitation assays, reveal that the functional interaction of NF-kappaB with the promoter element is necessary for the TLR-mediated HLA-DRA induction by CpG-DNA and LPS. This novel mechanism provides the regulation of MHC-II gene expression with complexity and functional diversity.     

Enhancement of NF-kappaB activity by resveratrol in cytokine-exposed mesangial cells

Resveratrol, a natural polyphenolic phytoalexin, has been considered as a potential anti-inflammatory agent because of its suppressive effect on nuclear factor-kappaB (NF-kappaB). However, we recently found that treatment of glomerular mesangial cells with resveratrol significantly and dose-dependently enhanced NF-kappaB activation triggered by proinflammatory cytokines. This finding was evidenced by different reporter assays as well as by expression of an endogenous NF-kappaB-dependent gene, intercellular adhesion molecule-1. The NF-kappaB promoting effect of resveratrol was also observed in renal tubular LLCPK1 cells, but not in HepG2 hepatoma cells. In all cell types tested, treatment with resveratrol alone did not affect NF-kappaB activity. The enhanced activation of NF-kappaB by resveratrol progressed for at least 24 h and was accompanied by sustained down-regulation of an endogenous NF-kappaB inhibitor, IkappaBbeta, but not IkappaBalpha. Although expression of inducible nitric oxide synthase was suppressed by resveratrol, nitric oxide, a negative regulator of NF-kappaB, was not involved in the regulation of NF-kappaB by resveratrol. These data elucidated, for the first time, that resveratrol may enhance activation of NF-kappaB under certain circumstances.     

Soluble Fas antigen in the serum of women with oral lichen planus

Enzyme immunoassay showed that soluble Fas antigen is significantly more often detected in the serum of patients with oral lichen planus (72.5%) and oral squamous-cell cancer (75%) than in healthy postmenopausal women (36%). The level of soluble Fas antigen was significantly higher in patients with squamous-cell cancer and erosive ulcerative and exudative hyperemic lichen planus than in healthy women. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 143, No. 6, pp. 672–674, June, 2007     

Escherichia coli up-regulates proinflammatory cytokine expression in granulocyte/macrophage lineages of CD34 stem cells via p50 homodimeric NF-kappaB

Umbilical cord blood has emerged as an alternative source of haematopoietic CD34+ cells for allogeneic stem cell transplantation. Although bacteraemia induced by Escherichia coli is considered one of the complications of transplantation, expression of proinflammatory cytokines is poorly understood. In this study, we report the altered expression of proinflammatory cytokines in CD34+ cells and their in vitro cultured cells following E. coli infection. CD34+ stem cells and their cultured cells up-regulated expression of proinflammatory cytokines such as interleukin (IL)-1alpha, IL-6, IL-8 and tumour necrosis factor (TNF)-alpha after infection with E. coli. Expression of the proinflammatory cytokines was generated mainly by the granulocyte-macrophage lineages. E. coli infection activated the signals of p50/p50 nuclear factor-kappaB (NF-kappaB) homodimers and IkappaB kinase. Furthermore, inhibition of NF-kappaB activation lowered the up-regulated expression of the proinflammatory cytokines. These results suggest that CD34+ cells and their cultured cells infected with E. coli induce the expression of proinflammatory cytokines via the NF-kappaB pathway.     

Cholera toxin activates dendritic cells through dependence on GM1-ganglioside which is mediated by NF-kappaB translocation

Cholera toxin (CT) is a potent adjuvant; however, the mechanism for its ability to enhance mucosal immunity has not been fully elucidated. We report here that CT exerts its adjuvant properties by signaling through the GM1 ganglioside receptor. When ganglioside-defective mice were given the antigen (Ag) ovalbumin (OVA) with CT by the oral route, CT failed to support either OVA-specific antibody or CD4+ T cell responses. In vitro treatment of murine bone marrow-derived dendritic cells (DC) with CT induced full maturation as evidenced by up-regulation of the costimulatory molecules, as well as by an enhanced ability to effectively present OVA for Ag-specific T cell responses. On the other hand, ganglioside-defective DC failed to differentiate to full function as Ag-presenting cells in response to CT. Since ganglioside-defective DC showed a mature phenotype after stimulation with lipopolysaccharide (LPS), the effects of CT on DC was independent of signal transduction through adjuvant receptor for LPS, the Toll-like receptor 4. Furthermore, CT also induced nuclear translocation of nuclear factor (NF)-kappaB in DC in a GM1-dependent fashion. These results highlight gangliosides expressed by DC for recognition of the non-self protein bacterial enterotoxin, which employ a unique signaling pathway to induce both innate and adaptive immunity.     

A comparison of the pro-inflammatory, NF-κB-dependent cytokines: TNF-alpha, IL-1-alpha, IL-6, and IL-8 in different oral fluids from oral lichen planus patients

To explore the feasibility of detection of the level of NF-κB-dependent cytokines in oral fluids from patient with oral lichen planus (OLP) for clinical application, 13 OLP subjects were enrolled in the study as were 13 age–sex-matched controls. In each subject, the whole unstimulated saliva (WUS), mixture of saliva and isotonic saline oral rinse (Saliva-NaCl), and lesion tissue transudates (TT) were collected by standard techniques. The level of cytokines, TNF-alpha, IL-1-alpha, IL-6, and IL-8 in three types of oral fluids was determined by ELISA. In the three types of oral fluids, a significantly higher level of these cytokines was detected in OLP patients than in normal controls. These results indicate that NF-κB-dependent inflammatory cytokines may be detected at increased levels in certain oral fluids which may have diagnostic and prognostic potential for monitoring disease activity and making therapeutic decisions in patients with OLP.     

Cigarette smoking induces overexpression of c-Met receptor in microvessels of oral lichen planus

Introduction

Cigarette smoking is related to many pathological conditions; however, chemical substances affect the oral cavity first, so it is important to consider its influence on oral mucosa and oral potentially pre-malignant lesions. The aim of this study was to investigate the effect of smoking on microvessel density in oral lichen planus. Special emphasis was placed on examining the relationship between the expression of c-Met receptor in blood vessels and smoking habits.

Material and methods

This study included 34 patients with oral lichen planus diagnosed clinically and verified by histopathological examination and 12 healthy individuals as controls. Biopsy of oral mucosa was performed and specimens were examined for immunohistochemical CD34 and c-Met receptor expression. The microvessel density was established by evaluation of the five most vascular areas within a section.

Results

Compared to normal oral mucosa, in lichen planus patients, significantly higher blood vessel density and c-Met expression were noted. Irregular distribution of microvessels was typical for oral lichen planus. Also, microvessel density was higher in cigarette smoking patients’ tissues than in non-smoker specimens. Furthermore, the association of c-Met expression with smoking habit was statistically significant.

Conclusions

Cigarette smoking habit has a direct impact on the oral lichen planus course; therefore, close follow-up of these patients is mandatory.     

Combined examination of p27(Kip1), p21(Waf1/Cip1) and p53 expression allows precise estimation of prognosis in patients with gastric carcinoma

AIMS: In order to estimate the prognostic values of p27(Kip1), p21(Waf1/Cip1), and p53, alone and in combination, we investigated immunohistochemically the expression of p27(Kip1), p21(Waf1/Cip1), and p53 proteins in gastric carcinomas. METHODS AND RESULTS: The expression of p27(Kip1), p21(Waf1/Cip1), and p53 was immunohistochemically examined in 140 gastric carcinomas. Positive expression of p27(Kip1) and p21(Waf1/Cip1) correlated significantly with a favourable prognosis (P < 0.05), whereas, positive expression of p53 tended to correlate with poor prognosis. Multivariate survival analysis revealed that TNM stage of tumour (P < 0.001), lymph node state (P=0.005), and p27(Kip1) expression (P=0.006) were independent prognostic factors. A striking stratification of mortality rate was found when patients were divided into four groups according to the expression of p21(Waf1/Cip1) and p27(Kip1). The mortality rate was higher in patients with both p21(Waf1/Cip1)- and p27(Kip1)-negative gastric carcinoma than in patients with one or both positive carcinomas (P < 0.01). In addition, if the four p21(Waf1/Cip1)/p27(Kip1) groups were compared based on p53 status, p53+ cases tended to have a higher mortality rate than p53- cases. CONCLUSION: Our results suggest that low expression of both p27(Kip1) and p21(Waf1/Cip1), could be useful as markers of poorer prognosis, and the combined examination of p27(Kip1), p21(Waf1/Cip1) and p53 expression allows reliable estimation of prognosis for patients with gastric carcinoma.     

Activation of the NF-kappaB signalling pathway in diffuse large B-cell lymphoma: clinical implications

Aim: To characterize the activation of the nuclear factor (NF)‐κB pathway in diffuse large B‐cell lymphoma (DLBCL) by immunohistochemistry. Methods and results: Sixty‐six DLBCLs treated with anthracycline‐containing chemotherapy were evaluated with antibodies against phosphorylated p65 (P‐p65), p65, p50, p52, IKKα, and phosphorylated IκB (P‐IκB). NF‐κB activation was based on the expression of P‐p65, P‐IκB, and nuclear expression of p65 or p52 in the tumour cells. P‐p65 and P‐IκB were expressed in 13 (20%) and 17 cases (26%), respectively. p65, p52 and IKKα were found in the cytoplasm. A correlation was found between expression of P‐p65 and P‐IκB (P < 0.0001), but not between the two subtypes of DLBCL [germinal centre B cell and non‐germinal centre (GC)]. P‐p65+ tumours showed a better response to chemotherapy (P = 0.025) and a trend to increased event‐free survival (P = 0.08). However, P‐IκB expression was not associated with either clinical response or survival. Bcl‐2 was not preferentially expressed on DLBCL tumours with NF‐κB activation, as determined by expression of P‐p65 and P‐IκB proteins. Conclusions: NF‐κB activation in DLBCL is preferentially mediated through the classical pathway and a novel mechanism involving phosphorylation of p65. Activation of NF‐κB by P‐p65 is associated with good prognosis. NF‐κB activation is not confined to non‐GC DLBCL exclusively.     

Caspase-8 and caspase-10 activate NF-kappaB through RIP,NIK and IKKalpha kinases

NF-kappaB regulates the expression of various genes involved in cell growth and differentiation, immune response and inhibition of apoptosis. Recently, some death effector domain (DED)-containing proteins, such as FADD and c-FLIP were reported to activate NF-kappaB. We previously reported that the prodomain-only isoforms of caspase-8 and -10 (PDCasp8/10), containing two DED motifs, could inhibit Fas-mediated apoptosis. Here, we demonstrate that these isoforms also activate NF-kappaB, implying this to be one of the mechanisms by which these polypeptides inhibit apoptosis. The GST pull-down assay revealed that, among upstream kinases that activate NF-kappaB, only NIK and RIP, but not RICK or IKKalpha/beta, could directly bind to PDCasp8/10. In addition, both modules ofDED in PDCasp8/10 were required for these interactions as well as NF-kappaB activation. Experiments using a kinase-dead mutant of IKKalpha and an RIP mutant lacking a kinase domain, both of which function as dominant-negative mutants for their wild-type counterparts, blocked PDCasp8/10-mediated NF-kappaB activation. Using small interfering RNA technology, we further demonstrate that the down-regulation of IKKalpha but not IKKbeta significantly inhibits PDCasp8-mediated NF-kappaB activation. Taken together, these results suggest that caspase-8 and -10 have roles in a non- or anti-apoptotic signaling pathway leading to NF-kappaB activation through RIP, NIK and IKKalpha.     

Essential role for platelet-activating factor-induced NF-kappaB activation in macrophage-derived angiogenesis

Activated monocyte-macrophages have been implicated in tumor angiogenesis via their capacity to produce many potent angiogenic factors. However, the mechanisms leading to production of these angiogenic factors in macrophages remain to be elucidated. In this study, we demonstrated by use of a mouse Matrigel implantation model that mouse peritoneal macrophages induce angiogenesis. mRNA expression and protein synthesis of macrophage-derived crucial angiogenic factors such as IL-1, TNF-alpha, basic fibroblast growth factor, and vascular endothelial growth factor (VEGF) were blocked by platelet-activating factor (PAF) receptor antagonists. It was also observed that inhibitors of NF-kappaB blocked macrophage production of these angiogenic factors. Gene expression and protein synthesis of the angiogenic factors cited above were also inhibited in IkappaBalpha-mutated macrophages. VEGF is the most potent angiogenic factor in macrophage-induced angiogenesis. PAF antagonists or NF-kappaB inhibitors also inhibit the capacity of conditioned medium from LPS-stimulated human peripheral blood monocytes to induce sprouting of porcine pulmonary arterial endothelial cells. These data indicate that PAF-induced NF-kappaB activation is a common upstream pathway leading to the production of crucial macrophage-derived angiogenic factors. This will provide an important clue for a better understanding of mechanisms involved in tumor angiogenesis.