High-mobility group box-1 (HMGB1) is a nuclear factor released by necrotic cells and by activated immune cells. HMGB1 signals via members of the toll-like receptor family and the receptor for ...advanced glycation end products (RAGE). Although HMGB1 has been implicated in ischemia/reperfusion (I/R) injury of the liver and lung, its role in I/R injury of the heart remains unclear.
Here, we demonstrate that HMGB1 acts as an early mediator of inflammation and organ damage in I/R injury of the heart. HMGB1 levels were already elevated 30 minutes after hypoxia in vitro and in ischemic injury of the heart in vivo. Treatment of mice with recombinant HMGB1 worsened I/R injury, whereas treatment with HMGB1 box A significantly reduced infarct size and markers of tissue damage. In addition, HMGB1 inhibition with recombinant HMGB1 box A suggested an involvement of the mitogen-activated protein kinases jun N-terminal kinase and extracellular signal-regulated kinase 1/2, as well as the nuclear transcription factor nuclear factor-kappaB in I/R injury. Interestingly, infarct size and markers of tissue damage were not affected by administration of recombinant HMGB1 or HMGB1 antagonists in RAGE(-/-) mice, which demonstrated significantly reduced damage in reperfused hearts compared with wild-type mice. Coincubation studies using recombinant HMGB1 in vitro induced an inflammatory response in isolated macrophages from wild-type mice but not in macrophages from RAGE(-/-) mice.
HMGB1 plays a major role in the early event of I/R injury by binding to RAGE, resulting in the activation of proinflammatory pathways and enhanced myocardial injury. Therefore, blockage of HMGB1 might represent a novel therapeutic strategy in I/R injury.
Heme oxygenase-1 (HO-1) is believed to represent a key enzyme for the protection of cells against “stress.” Its overexpression
in different types of human cancers supports the notion that HO-1 ...provides a growth advantage and contributes to cellular
resistance against chemotherapy and radiotherapy. Given the poor survival rates of patients with pancreatic cancer due to
its aggressive growth behavior and its exceptional resistance to all known forms of anticancer treatment, we have investigated
the expression of HO-1 in human pancreatic cancer cells growth behavior and prognosis. Expression of HO-1 was analyzed in
human pancreatic cancer samples in comparison with normal pancreas by quantitative PCR, Western blot, and confocal microscopy.
The influence of radiotherapy and chemotherapy on HO-1 expression in pancreatic cancer cell lines was evaluated. Furthermore,
HO-1 expression was specifically suppressed by small interfering RNA transfection and subsequently the alterations of growth
behavior and resistance to anticancer treatment were tested. Human pancreatic cancer showed a 6-fold and 3.5-fold HO-1 up-regulation
in comparison to normal pancreas based on mRNA and protein level, respectively ( P < 0.05). Cancer tissues revealed marked HO-1 immunoreactivity in tumor cells and in tumor associated immunocytes. Treatment
of the pancreatic cancer cell lines with gemcitabine or radiation strongly induced HO-1 expression. Targeted knockdown of
HO-1 expression led to pronounced growth inhibition of the pancreatic cancer cells and made tumor cells significantly more
sensitive to radiotherapy and chemotherapy. Therefore, specific inhibition of HO-1 expression may be a new option in pancreatic
cancer therapy and may be used as sensitizer to chemotherapy and radiotherapy.
Mucosal epithelial cell layers are constantly exposed to a complex resident microflora. Deleted in malignant brain tumors 1 (DMBT1) belongs to the group of secreted scavenger receptor cysteine-rich ...proteins and is considered to be involved in host defense by pathogen binding. This report describes the regulation and function of DMBT1 in intestinal epithelial cells, which form the primary immunological barrier for invading pathogens. We report that intestinal epithelial cells up-regulate DMBT1 upon proinflammatory stimuli (e.g., TNF-alpha, LPS). We demonstrate that DMBT1 is a target gene for the intracellular pathogen receptor NOD2 via NF-kappaB activation. DMBT1 is strongly up-regulated in the inflamed intestinal mucosa of Crohn's disease patients with wild-type, but not with mutant NOD2. We show that DMBT1 inhibits cytoinvasion of Salmonella enterica and LPS- and muramyl dipeptide-induced NF-kappaB activation and cytokine secretion in vitro. Thus, DMBT1 may play an important role in the first line of mucosal defense conferring immune exclusion of bacterial cell wall components. Dysregulated intestinal DMBT1 expression due to mutations in the NOD2/CARD15 gene may be part of the complex pathophysiology of barrier dysfunction in Crohn's disease.
Purpose: Cell surface HLA class I molecules present peptides derived from human cellular proteins to T cells. In the present study,
we investigated the expression of HLA class I in human pancreatic ...carcinoma.
Experimental Design: The expression of HLA class I antigen and the extent of tumor infiltration by T cells were investigated in 46 primary tumors
and in 14 metastases of pancreatic cancer by standard immunohistochemistry.
Results: The locus-specific expression of HLA I was reduced in 61% of primary tumors and in 93% of metastases. The total loss of this
molecule complex was detected in 6% of primary tumors and in 43% of metastases. Pancreatic carcinoma and peritumoral tissue
showed a significantly higher infiltration by CD3+, CD4+, and CD8+ T-cells compared with the tumor-distant pancreatic tissue.
The negative expression of HLA class I was uniformly accompanied by a low density of tumor-infiltrating cytotoxic T-cells
whereas the HLA class I–positive tumors were characterized by a substantial lymphocyte accumulation. However, the infiltration
by cytotoxic T-cells was not correlated with the density of tumor cells. Patients with a high accumulation of cytotoxic cells
showed a longer median survival.
Conclusions: Pancreatic carcinoma frequently induces a cellular immune response that results in intratumoral and peritumoral T-cell infiltration.
The expression of HLA class I is frequently lost in pancreatic carcinoma, which represents an effective mechanism to escape
the tumor infiltration by cytotoxic T-cells. However, the infiltration by cytotoxic cells represents a favorable prognostic
sign in pancreatic cancer patients.
To analyze the association between pre- and perioperative factors and pouch-related septic complications (PRSC) in ulcerative colitis (UC) and in familial adenomatous polyposis (FAP) after ileal ...pouch-anal anastomosis (IPAA).
For patients with UC and FAP, IPAA is the surgical therapy of choice, but in some patients the outcome is compromised by PRSC.
A total of 706 consecutive patients (494 UC, 212 FAP) were assessed in a study aimed at identifying subgroups of patients who were at high risk for PRSC. The rate of PRSC was analyzed as a time-dependent function (Kaplan-Meier estimation). Patients with UC and FAP were stratified separately according to associated factors (age, sex, surgeon's experience, temporary ileostomy, colectomy before IPAA, anastomotic tension, and several factors specific for UC).
In all, 131 (19.2%) patients had PRSC (23.4% UC, 9.4% FAP). In patients with UC, the estimated 1-year PRSC rate was 15.6% and the estimated 3-year PRSC rate was 24.2%. In patients with FAP, the estimated 1-year and 3-year PRSC rates were 9.2%. The difference between the estimated rates of PRSC was significant (P <.001). In the univariate analysis, patients with UC younger than 50 years, with severe proctitis, with preoperative hemoglobin levels less than 10 g/L, or receiving corticoid medication had a significantly higher risk for PRSC (P =.039, P =.037, P =.047, P =.003, respectively). Multivariate analysis showed that patients with UC receiving a systemic prednisolone-equivalent corticoid medication of more than 40 mg/day had a significantly greater risk of developing pouch-related complications than patients with UC receiving 1 to 40 mg/day and patients with UC who were not receiving corticoid medication (RR: 3.78, 2.25, 1, respectively, P <.001). Patients with FAP proved to have a significantly higher risk for PRSC in the univariate and multivariate analyses if anastomotic tension had occurred (RR 3.60, P =.0086).
Pouch-related septic complications occur as late complications and should therefore be considered in regular, specific long-term follow-up examinations. The authors identified significant risk factors for PRSC specific to patients with UC and FAP; these must be considered for each individual surgical strategy.
BACKGROUND: Decoy receptor 3 (DcR3) is a soluble protein that binds to and inactivates the death ligand CD95L. Here, we studied a possible association between DcR3 expression and prognosis in ...patients with renal cell carcinomas (RCCs). METHODS: A tissue microarray containing RCC tumor tissue samples and corresponding normal tissue samples was generated. Decoy receptor 3 expression in tumors of 560 patients was examined by immunohistochemistry. The effect of DcR3 expression on disease-specific survival and progression-free survival was assessed using univariate analysis and multivariate Cox regression analysis. Decoy receptor 3 serum levels were determined by ELISA. FINDINGS: High DcR3 expression was associated with high-grade (P = .005) and high-stage (P = .048) RCCs. The incidence of distant metastasis (P = .03) and lymph node metastasis (P = .002) was significantly higher in the group with high DcR3 expression. Decoy receptor 3 expression correlated negatively with disease-specific survival (P < .001) and progression-free survival (P < .001) in univariate analyses. A multivariate Cox regression analysis retained DcR3 expression as an independent prognostic factor that outperformed the Karnofsky performance status. In patients with high-stage RCCs expressing DcR3, the 2-year survival probability was 25%, whereas in patients with DcR3-negative tumors, the survival probability was 65% (P < .001). Moreover, DcR3 serum levels were significantly higher in patients with high-stage localized disease (P = .007) and metastatic disease (P = .001). INTERPRETATION: DcR3 expression is an independent prognostic factor of RCC progression and mortality. Therefore, the assessment of DcR3 expression levels offers valuable prognostic information that could be used to select patients for adjuvant therapy studies.
Purpose: The death ligand tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) and its receptors (TRAIL-R) are involved
in immune surveillance and tumor development. Here, we studied a ...possible association between the expression of TRAIL/TRAIL-Rs
and the prognosis in patients with renal cell carcinomas (RCC).
Experimental Design: A tissue microarray containing RCC tumor tissue samples and corresponding normal tissue samples from 838 patients was generated.
Expression of TRAIL and TRAIL-Rs was examined by immunohistochemistry and the effect of TRAIL and TRAIL-R expression on disease-specific
survival was assessed.
Results: High TRAIL-R2 expression levels were associated with high-grade RCCs ( P < 0.001) and correlated negatively with disease-specific survival ( P = 0.01). Similarly, high TRAIL expression was associated with a shorter disease-specific survival ( P = 0.01). In contrast, low TRAIL-R4 expression was associated with high-stage RCCs ( P < 0.001) as well as with the incidence of distant metastasis ( P = 0.03) and correlated negatively with disease-specific survival ( P = 0.02). In patients without distant metastasis, multivariate Cox regression analyses revealed that TRAIL-R2 and TRAIL are
independent prognostic factors for cancer-specific survival (in addition to tumor extent, regional lymph node metastasis,
grade of malignancy, and type of surgery).
Conclusion: High TRAIL-R2, high TRAIL, and low TRAIL-R4 expression levels are associated with a worse disease-specific survival in patients
with RCCs. Therefore, the assessment of TRAIL/TRAIL-R expression offers valuable prognostic information that could be used
to select patients for adjuvant therapy studies. Moreover, our findings are of relevance for a potential experimental therapeutic
administration of TRAIL-R agonists in patients with RCCs.
AIM： To study susceptibility genes which may play a potential role in the pathogenesis and etiology of inflammatory bowel disease （IBD）. METHODS： To identify potential susceptibility genes we ...performed global gene expression profiling in patients with IBD and control specimens. For determination of an intrinsic gene expression profile in ulcerative colitis （UC） and Crohn＇s disease （CD） compared to normal subjects, mucosal biopsies of non-inflamed regions of the colon and the terminal ileum were subjected to DNA microarray analysis. Real-time RT-PCR and immunohistochemistry were used for verification of selected regulated candidate genes and a genetic analysis was performed. RESULTS： We could show that aquaporin-8 （AQP8） mRNA and protein levels were significantly increased in the colon of UC patients compared to controls. Genetic analysis of the six exons and the promoter region of AQPS, however, revealed no mutations or polymorphisms in IBD patients. CONCLUSION： Our results suggest that upregulation of AQP8 in the colon of UC patients represents a secondary phenomenon which may, due to altered water exchange of the distal intestinal mucosa, disturb the physiologic colonic mucus barrier and thus lead to chronic inflao mmation and ulceration.
Deleted in malignant brain tumors 1 (DMBT1) is a secreted glycoprotein displaying a broad bacterial-binding spectrum. Recent functional and genetic studies linked DMBT1 to the suppression of ...LPS-induced TLR4-mediated NF-κB activation and to the pathogenesis of Crohn's disease. Here, we aimed at unraveling the molecular basis of its function in mucosal protection and of its broad pathogen-binding specificity. We report that DMBT1 directly interacts with dextran sulfate sodium (DSS) and carrageenan, a structurally similar sulfated polysaccharide, which is used as a texturizer and thickener in human dietary products. However, binding of DMBT1 does not reduce the cytotoxic effects of these agents to intestinal epithelial cells in vitro. DSS and carrageenan compete for DMBT1-mediated bacterial aggregation via interaction with its bacterial-recognition motif. Competition and ELISA studies identify poly-sulfated and poly-phosphorylated structures as ligands for this recognition motif, such as heparansulfate, LPS, and lipoteichoic acid. Dose-response studies in Dmbt1⁻/⁻ and Dmbt1⁺/⁺ mice utilizing the DSS-induced colitis model demonstrate a differential response only to low but not to high DSS doses. We propose that DMBT1 functions as pattern-recognition molecule for poly-sulfated and poly-phosphorylated ligands providing a molecular basis for its broad bacterial-binding specificity and its inhibitory effects on LPS-induced TLR4-mediated NF-κB activation.
Oxidative and carbonyl stress leads to generation of
N
ε-carboxymethyllysine-modified proteins (CML-mps), which are known to bind the receptor for advanced glycation end products (RAGE) and induce ...nuclear factor (NF)-κB-dependent proinflammatory gene expression. To determine the impact of CML-mps
in vivo
, RAGE-dependent sustained NF-κB activation was studied in resection gut specimens from patients with inflammatory bowel disease. Inflamed gut biopsy tissue demonstrated a significant up-regulation of RAGE and increased NF-κB activation. Protein extracts from the inflamed zones, but not from noninflamed resection borders, caused perpetuated NF-κB activation in cultured endothelial cells, which was mediated by CML-mps including CML-modified S100 proteins. The resulting NF-κB activation, lasting 5 days, was primarily inhibited by either depletion of CML-mps or by the addition of sRAGE, p44/42 and p38 MAPKinase-specific inhibitors. Consistently, CML-mps isolated from inflamed gut areas and rectally applied into mice caused NF-κB activation, increased proinflammatory gene expression, and histologically detectable inflammation in wild-type mice, but not in RAGE
−/− mice. A comparable up-regulation of NF-κB and inflammation on rectal application of CML-mps was observed in IL-10
−/− mice. Thus, CML-mps generated in inflammatory lesions have the capacity to elicit a RAGE-dependent intestinal inflammatory response.
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