LRRK2 enhances Nod1/2-mediated inflammatory cytokine production by promoting Rip2 phosphorylation

The innate immune system is critical for clearing infection, and is tightly regulated to avert excessive tissue damage. Nod1/2-Rip2 signaling, which is essential for initiating the innate immune response to bacterial infection and ER stress, is subject to many regulatory mechanisms. In this study, we found that LRRK2, encoded by a gene implicated in Crohn's disease, leprosy and familial Parkinson's disease, modulates the strength of Nod1/2-Rip2 signaling by enhancing Rip2 phosphorylation. LRRK2 deficiency markedly reduces cytokine production in macrophages upon Nod2 activation by muramyl dipeptide (MDP), Nod1 activation by D-gamma-Glu-meso-diaminopimelic acid (iE-DAP) or ER stress. Our biochemical study shows that the presence of LRRK2 is necessary for optimal phosphorylation of Rip2 upon Nod2 activation. Therefore, this study reveals that LRRK2 is a new positive regulator of Rip2 and promotes inflammatory cytokine induction through the Nod1/2-Rip2 pathway.

Brazilein inhibits neuronal inflammation induced by cerebral ischemia and oxygen-glucose deprivation through targeting NOD2 expression / 中国天然药物

Brazilein is reported to have immunosuppressive effect on cardiovascular and cerebral-vascular diseases. The essential roles of innate immunity in cerebral ischemia are increasingly identified, but no studies concerning the influence of brazilein on the innate immunity receptors have been reported. The present study was designed to investigate the regulation of NOD2 (Nucleotide-binding oligomerization domain-containing protein 2) by brazilein for its protection of neuron in cerebral ischemia in vivo and oxygen-glucose deprivation in vitro. The results showed that brazilein could reverse the elevated expression of NOD2 and TNFα (tumor necrosis factor alpha) elicited by cerebral ischemia and reperfusion. This reduction could also be detected in normal mice and C17.2 cells, indicating that this suppressive effect of brazilein was correlated with NOD2. The results from GFP reporter plasmid assay suggested brazilein inhibited NOD2 gene transcription. In conclusion, brazilein could attenuate NOD2 and TNFα expression in cerebral ischemia and NOD2 may be one possible target of brazilein for its immune suppressive effect in neuro-inflammation.

Clinical and Genetic Features of Korean Patients with Recurrent Fever and Multi-System Inflammation without Infectious or Autoimmune Evidence

Autoinflammatory disease (AID) is a newly proposed category of disorders characterized by unprovoked episodes of inflammation without any infectious or autoimmune evidence. We aimed to characterize the clinical and genetic features of patients who had recurrent fever and multi-system inflammation but remain unclassified for any established AIDs. Medical records of 1,777 patients who visited our Rheumatology Clinic between March 2009 and December 2010 were reviewed to identify those who met the following criteria; 1) presence of fever, 2) inflammation in two or more organ systems, 3) recurrent nature of fever or inflammation, 4) no evidence of infection or malignancy, 5) absence of high titer autoantibodies, and 6) failure to satisfy any classification criteria for known AIDs. Genotyping was performed for common missense variants in MEFV, NOD2/CARD15, and TNFRSF1A. A small number of patients (17/1,777, 0.95%) were identified to meet the above criteria. Muco-cutaneous and musculoskeletal features were most common, but there was a considerable heterogeneity in symptom combination. Although they did not satisfy any established classification criteria for AIDs, substantial overlap was observed between the clinical spectrum of these patients and known AIDs. According to the newly proposed Eurofever criteria for periodic fevers, eleven of them were classified as TNF receptor-associated periodic syndrome and two as mevalonate kinase deficiency. However, no examined genetic variants including those in TNFRSF1A were found in these patients. A new set of classification criteria needs to be developed and validated for Asian patients with unclassified AIDs.

Clinical and Genetic Features of Korean Patients with Recurrent Fever and Multi-System Inflammation without Infectious or Autoimmune Evidence

Autoinflammatory disease (AID) is a newly proposed category of disorders characterized by unprovoked episodes of inflammation without any infectious or autoimmune evidence. We aimed to characterize the clinical and genetic features of patients who had recurrent fever and multi-system inflammation but remain unclassified for any established AIDs. Medical records of 1,777 patients who visited our Rheumatology Clinic between March 2009 and December 2010 were reviewed to identify those who met the following criteria; 1) presence of fever, 2) inflammation in two or more organ systems, 3) recurrent nature of fever or inflammation, 4) no evidence of infection or malignancy, 5) absence of high titer autoantibodies, and 6) failure to satisfy any classification criteria for known AIDs. Genotyping was performed for common missense variants in MEFV, NOD2/CARD15, and TNFRSF1A. A small number of patients (17/1,777, 0.95%) were identified to meet the above criteria. Muco-cutaneous and musculoskeletal features were most common, but there was a considerable heterogeneity in symptom combination. Although they did not satisfy any established classification criteria for AIDs, substantial overlap was observed between the clinical spectrum of these patients and known AIDs. According to the newly proposed Eurofever criteria for periodic fevers, eleven of them were classified as TNF receptor-associated periodic syndrome and two as mevalonate kinase deficiency. However, no examined genetic variants including those in TNFRSF1A were found in these patients. A new set of classification criteria needs to be developed and validated for Asian patients with unclassified AIDs.

The role of Nods like receptors in the patients with allergic rhinitis / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To explore role of Nods (nucleotide-binding oligomerization domain Nod Like receptors) kind of pattern recognition receptors (PRR) in patients with allergic rhinitis.@*METHOD@#The mRNA and protein of Nod1, Nod2 of Nalp3 were analyzed in the turbinate mucosa of patients with allergic rhinitis, nasal septum deviation (NSD) nasal mucosa of patients and nasal polyp mucosa with Real-Time RT-PCR, Western blot and immunohistochemistry respectively, and Nod1 expression changes was explored in PBMC with wad explored Western-blot and then the level of IL-4, IL-6, IL-10, IFN-γ were detected in serum of AR after desensitization treatment.@*RESULT@#These Nods like receptors, mainly found in nasal mucosa epithelial cells, glandular epithelium and inflammatory cells (e. g. plasma cells, eosinophils), were expressed in the nasal mucosa tissues. In AR group, Nod1 (mRNA and protein) expression were lower than NSD group (P0.05.@*CONCLUSION@#Nod1, Nod2 and Nalp3 expression were seen in the two groups,and the Nod1 expression in allergic rhinitis group was lower than other two groups, while, the Nalp3 was higher than other two groups. It showed Nod1, Nalp3 may be involved in the pathogenesis of allergic rhinitis. Expression of Nod1 in PBMC reduced after sublingual desensitization treatment. Besides, the change of Nod1 was negatively correlated with the change of IL-10 in PBMC. So,it seemed that Nod1 may regulate IL-10 changes and be involved in sublingual desensitization therapy.

Oral microbiota and host innate immune response in bisphosphonate-related osteonecrosis of the jaw / 国际口腔科学杂志·英文版

Bacterial biofilms have emerged as potential critical triggers in the pathogenesis of bisphosphonate (BP)-related osteonecrosis of the jaw (ONJ) or BRONJ. BRONJ lesions have shown to be heavily colonized by oral bacteria, most of these difficult to cultivate and presents many clinical challenges. The purpose of this study was to characterize the bacterial diversity in BRONJ lesions and to determine host immune response. We examined tissue specimens from three cohorts (n=30); patients with periodontal disease without a history of BP therapy (Control, n=10), patients with periodontal disease having history of BP therapy but without ONJ (BP, n=5) and patients with BRONJ (BRONJ, n=15). Denaturing gradient gel electrophoresis of polymerase chain reaction (PCR)-amplified 16S rRNA gene fragments revealed less bacterial diversity in BRONJ than BP and Control cohorts. Sequence analysis detected six phyla with predominant affiliation to Firmicutes in BRONJ (71.6%), BP (70.3%) and Control (59.1%). Significant differences (P<0.05) in genera were observed, between Control/BP, Control/BRONJ and BP/BRONJ cohorts. Enzyme-linked immunosorbent assay (ELISA) results indicated that the levels of myeloperoxidase were significantly lower, whereas interleukin-6 and tumor necrosis factor-alpha levels were moderately elevated in BRONJ patients as compared to Controls. PCR array showed significant changes in BRONJ patients with downregulation of host genes, such as nucleotide-binding oligomerization domain containing protein 2, and cathepsin G, the key modulators for antibacterial response and upregulation of secretory leukocyte protease inhibitor, proteinase 3 and conserved helix-loop-helix ubiquitous kinase. The results suggest that colonization of unique bacterial communities coupled with deficient innate immune response is likely to impact the pathogenesis of ONJ.

Mutations of NOD2 gene and clinical features in Chinese Blau syndrome patients / 中华儿科杂志

<p><b>OBJECTIVE</b>Blau syndrome (BS), an autosomal dominant inherited autoinflammatory disease, is caused by NOD2 mutations. This study aimed to analyze NOD2 gene of suspected BS patients to make definite diagnosis, find NOD2 mutation types and clinical features of Chinese BS cases, and find some clinical indications to identify BS by comparing BS and non-BS cases.</p><p><b>METHOD</b>Eighteen suspected BS children (7 boys and 11 girls, age of first visit was from 1 y 8 m to 9 y 6 m) who visited Peking Union Medical College Hospital from 2006 to 2014 and their parents's DNA were extracted from 4 ml blood specimens. PCR was performed for exon 4 of NOD2 and PCR products were purified by 2% gel electrophoresis and sequenced directly. Role of novel missense mutations in pathogenicity was analyzed by SIFT and sequencing NOD 2 of fifty normal controls. Clinical data of BS children diagnosed by NOD2 analysis were summarized and compared with the data of non-BS group.</p><p><b>RESULT</b>(1) Twelve of eighteen suspected BS children were diagnosed as BS by NOD2 analysis, and the remaining 6 were excluded. Seven missense mutations were detected, 4 were reported before: c.1000C>T, p. Arg 334Trp; c.1001G>A, p. Arg334Gln; c.1538T>C, p. Met513Thr; c.1759C>T, p. Arg587Cys. Three novel mutations were found: c. 1147 G>C, p.Glu383Gln; c.1471A>T, p. Met491Leu; c.2006A>G, p.His669Arg. (2) Chronic symmetric arthritis and multi-joints periarticular hydatoncus, which were painless with fluctuation, were found in all 12 BS children with NOD2 mutations. Skin rash, chronic symmetric arthritis, and recurrent uveitis were identified in 7 patients. Three patients had no skin rash, while 1 had no uveitis, 1 only had symmetric arthritis and multi-joints periarticular hydatoncus. Four children inherited the disease from father. (3) Compared with other 6 non-BS children, BS children had such different clinical characteristic (P < 0.05): All the BS cases had multiple periarticular hydatoncus, which always had no persistent fever, most had no elevated CRP, while non-BS group always had no hydatoncus, most had persistent fever, all had elevated CRP.</p><p><b>CONCLUSION</b>The 12 BS children were diagnosed by NOD2 analysis; 7 missense mutations were detected, 3 were novel mutations, adding new findings to human NOD2 mutations. Although classic BS was characterized by skin rash, arthritis, and eye involvement, some presented with less than 3 of the classic features. Chronic symmetric arthritis and multi-joints periarticular hydatoncus were the most comment fetures. Comparing with non-BS group, all BS cases had multi hydatoncus surrounding multi-joints, always had no persistent fever, most had no elevated CRP. Those features may distinguish BS in clinical settings.</p>

Role of Nods like receptors in the patients with nasal polyps / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To investigate the expression and role of a new pattern-recognition receptors (PRR), nucleotide binding oligomerization domain (Nod) like receptors (NLRs), in the patients with nasal polyps and nasal septum normal control group.@*METHOD@#The expressions of Nod1, Nod2 and Nalp3 mRNA and protein were explored with real-time RT-PCR, Western-Blot and immunohistochemistry respectively.@*RESULT@#The protein levels of Nod1, Nod2 and Nalp3 were expressed in nasal polyp and the control, but the expression of Nod1 and Nalp3 in nasal polyps were higher than those in control. No significant difference of Nod2 was seen between the two groups. And then, there was no significant difference of Nod1, Nod2, Nalp3 mRNA between two groups with Real-time RT-PCR.@*CONCLUSION@#The expression of Nod1 and Nalp3 are increased in nasal polyp tissues and maybe a etiological factors in the formation of nasal polyps.

The expression of NOD1 and NOD2 and the regulation of glucocorticoids on them in allergic rhinitis / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To investigate the expression of NOD1 and NOD2 in the nasal mucosa of healthy individuals and allergic rhinitis(AR), and explored the regulation of glucocorticoids on them.@*METHOD@#RT-PCR and immunohistochemistry were used to detect the expression of NOD1 and NOD2 in nasal mucosa from healthy control and AR. Nasal explant culture was used to explore the effect of glucocorticoids on NOD1 and NOD2 expression.@*RESULT@#NOD1 and NOD2 mRNA expression level was significantly increased in AR compared with control. Immunohistochemical staining demonstrated that NOD1 and NOD2 were mainly expressed by epithelial cells and some unknown cells in lamina propria and there were significantly more positive staining cells were observed in AR tissue when compared with control. Glucocorticoids down-regulated NOD1 and NOD2 expression in AR.@*CONCLUSION@#NOD1 and NOD2 as two PRRs may take part in the pathogenesis of AR, glucocorticoids may play a therapeutical role on allergic rhinitis through down-regulated the expression of NOD1 and NOD2.

Effect of baicalin on pattern recognition receptor TLR2/4-NOD2 and its significance of druggability / 中国中药杂志

Activation pattern recognition receptors can cause the startup of downstream signaling pathways, the expression of inflammatory factors, and finally immunological inflammatory reaction. Either exogenous pathogenic microorganisms or endogenous tissue components can activate these pattern recognition receptors as ligands at varying degrees, and then cause the immunological inflammatory reaction. Therefore, it is of great significance to inhibit relevant receptors, as well as the immunological inflammatory reaction, in order to avoid tissue injury during the course of disease. Baicalin is able to specifically inhibit the expression of TLR2/4-NOD2, inhibit the expression of inflammatory factors IL-1beta, IL-6 and TNF-alpha, and thereby reducing the injury of the tissue cells during the course of disease. This effect is non-specific with tissues, which is of great theoretical and practical significance in druggability. In addition, the drug metabolism and toxicity of baicalin are also discussed for its druggability in this article.

Activation of NOD2 signalling pathway stimulates the function of human dendritic cells loaded with leukemia cell lysates / 中国实验血液学杂志

The purpose of this study was to explore the effect of NOD2 signalling pathway activated by muramyl dipeptide (MDP) on the immunomodulation effect of human monocyte-derived dendritic cells (DC) loaded with leukemia cell lysates. Peripheral blood mononuclear cells (PBMNC) were isolated by density gradient centrifugation, These cells were cultured with three cytokines for 7 days to induce their maturation. On the 5th day, cells were loaded with leukemia cell HL-60 lysates. NOD2 expression was detected by RT-PCR and Western blot. The phenotype of DC were analyzed by flow cytometry, and ELISA was used to assay levels of IL-12 (p40) . The results showed that MDP could trigger NOD2 mRNA and protein expression in different groups of DC, especially in sensitized DC+MDP group, which was significantly higher than that in the DC+MDP group and sensitized DC without MDP stimulation, the difference was statistically significant (P < 0.05). Besides, the expression of surface molecules (HLA-DR, CD80, CD83, CD86, CD40) in the group of DC loaded with leukemia cell lysate and stimulated by MDP (sensitized DC+MDP) reached the highest level, followed by the group of DC loaded with leukemia cell lysate without MDP and DC only stimulated by MDP, non-treated DC were the lowest (P < 0.05). Similarly, compared with untreated unstimulated DC, after loading with HL-60 lysates or only stimulating with MDP, the secretion of IL-12p40 increased, but IL-12p40 level (573.86 ± 32.09 pg/ml) in DC+MDP group was higher than that in group of sensitized DC (365.03 ± 28.86 pg/ml) (P < 0.05), and it in sensitized DC+MDP group reached the highest (898.30 ± 61.08) pg/ml, compared to other groups (P < 0.05). It is concluded that MDP can significantly enhance the NOD2 mRNA and protein expression in sensitized DC, promote the expression of HLA-DR, synergistic costimulatory molecules and adhesion molecules of DC, at the same time, MDP can increase secretion of inflammatory factors IL-12p40. This study will provide a new ideas for DC application in leukemia immunotherapy.

Study on protective mechanism of kushenin injection on colonic mucosa of experimental colitis rats / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effect of NOD2 on colitis pathogenesis in experimental rats, and discuss therapeutical effect and mechanism of kushenin injection (OMT) on colitis in experimental rats.</p><p><b>METHOD</b>Fourty Sprague-Dawley (SD) rats were randomly divided into four groups: the normal control group, the model group, the SASP group, and the OMT group, with 10 rats in each group. Except the normal control group, models were established in the remaining three groups with TNBS. The OMT group was injected with kushenin injection, the SASP group was orally administered with mesalazine suspension, the model group and the normal group were orally administered with distilled water for 15 days. Colon lesion score and histological score of experimental rats were observed. Expression of NOD2, NF-kappaB p65 protein in rats colonic mucous was detected by immunohistochemistry. Expression of IL-6 in rat colon mucous was detected by ELISA.</p><p><b>RESULT</b>Compared with normal control group, the expression of NOD2, NF-kappaB p65 and IL-6 in colonic mucosa of the model group were significantly increased (P < 0.01). The SASP group and the OMT group showed lower expressions of NOD2, NF-kappaB p65 and IL-6 in colonic mucosa than the model group (P < 0.01, P < 0.05).</p><p><b>CONCLUSION</b>The over expression of colonic mucosa proteins NOD2 and NF-kappaB p65 and increasing secretion of IL-6 take part in the appearance and development of ulcerative colitis. OMT can attenuate ulcerative colitis and protect colonic mucosa by inhibiting expression of NOD2, NF-kappaB p65 and decreasing IL-6.</p>

Intracellular Staphylococcus aureus-induced NF-κB activation and proinflammatory responses of P815 cells are mediated by NOD2 / 华中科技大学学报（医学）（英德文版）

Staphylococcus aureus (S. aureus) is an important human pathogen which can cause a chronic condition with a high relapse rate despite the aggressive antimicrobial treatment. Recent studies showed that intracellular pattern recognition receptors (including NOD) in response to bacteria or bacterial products play a proinflammatory role by activating nuclear transcription factor-κB (NF-κB). But how NOD2 mediates the proinflammatory response to S. aureus in mast cells (MCs) is unclear. So, in this study, we attempted to examine the role of NOD2 in inflammatory responses of MCs to S. aureus. P815 cells (a mouse mast cell line) were cultured. Real-time PCR was used to detect the NOD2 mRNA expression in P815 cells during S. aureus infection. The siRNA against NOD2 gene was synthesized and transfected into S. aureus-infected P815 cells. By using the methods of ELISA and flow cytometry, the effects of NOD2 gene silencing on cell phagocytosis, cytokine secretion, NF-κB activation and cell apoptosis of the S. aureus-infected P815 cells were examined. It was found that S. aureus infection could increase the expression of NOD2 mRNA in P815 cells. NOD2 gene interference in P815 cells reduced the number of S. aureus engulfed by P815 cells, the level of cytokines and the activation of NF-κB. In addition, S. aureus could induce the apoptosis of P815 cells, but NOD2 gene silencing did not affect the cell apoptosis rate. Our data suggested that NOD2 plays a key role in pathogen recognition, signal transduction, and NF-κB activation in the inflammatory responses of MCs infected by S. aureus.

Crohn's Disease: current state of biological therapy / Doença de Crohn: estado atual da terapia biológica

The inflammatory bowel diseases (IBD) are defined as nonspecific chronic intestinal inflammations with possible systemic involvement. IBD have unknown etiology. The inflammatory process is complex and heterogeneous, both as to the characterization of the disease that affects the digestive tract, without an intelligible pattern of revelation and balance, and in its different systemic damages when including the extensive and severe extraintestinal symptoms. Aparently, the natural history of the disease is irregular in relation to the offending agent system and the attacked system, both in the intestinal and extraintestinal teguments. Isolated aspects showing irregularity in this balance gives us the notion that IBD, especially Crohn's disease, can be caused by the stimulation of an immune response caused by damaging agents (intestinal bacteria), but mediated by inadequate genetic factors, whose expressions determine different individual susceptibilities. These observations have been shown in genetic studies that emphasize the importance of pathological interaction between host and bacteria subsidized by a genomic region that contains genes producing proteins (NOD2 - nucleotide-binding oligomerization domain containing 2) participating in an enhanced defense response by the tissue. Increased numbers and the activation of these cells in the intestinal mucosa elevate local levels of tumor necrosis factor α (TNF-α), interleukin-1ß, interferon-γ, and cytokines of the interleukin-23-Th17 pathway. So, it can be assumed that the susceptibility, which is a result of genetic alterations, is connected to an exaggerated response in the pro-inflammatory phase because of a dysfunction in the intestinal immune system. The identification of tumor necrosis factor (TNF-α) as the active element in the pro-inflammatory inadequate response gave rise to the heightened production of biological substances that could block TNF-α, at different levels, opening a large field of view to new treatment of IBD. (AU)

As doenças intestinais inflamatórias (DII), definidas como inflamação crônica inespecífica dos intestinos, com eventual comprometimento sistêmico, são de etiologia desconhecida. O processo inflamatório é complexo e heterogêneo, tanto na caracterização da doença que atinge o trato digestório, onde não obedece a um padrão inteligível de revelação e de equilíbrio, como em seus variados danos sistêmicos, quando englobam os extensos e graves sintomas extraintestinais. Tudo indica que, na história natural da doença, há uma notável irregularidade entre agente agressor e sistema agredido, tanto a nível intestinal, como nos tegumentos extraintestinais. Aspectos isolados ou de conjunto que denotam irregularidade nesse equilíbrio dão-nos a noção de que as DII, sobretudo a doença de Crohn, podem ser originadas pela estimulação de uma resposta imune, provocada por agentes agressores (bactérias intestinais, por exemplo), mas mediadas de forma inadequada por fatores genéticos, cujas expressões determinam diferentes susceptibilidades individuais. Essas observações têm sido realçadas em estudos genéticos, que destacam a importância da interação patológica entre hospedeiro e bactéria, subsidiados por uma região genômica que contém genes produtores de proteínas (proteína de dois domínios de oligomerização de nucleotídeos - NOD2), com participação na resposta de defesa tecidual pela sinalização da ativação do sistema de resposta imune; por genes autofágicos e por vias de reações com componentes de interleucinas-23 com a concorrência de linfócitos-T (Th-17). Nessas condições, o que pode ser suposto é que a susceptibilidade, que decorre de alterações gênicas, esteja ligada a uma exagerada resposta na fase pró-inflamatória, decorrente de uma disfunção do sistema imune intestinal. A identificação do fator de necrose tumoral (TNF-α) como o elemento ativo na resposta pró-inflamatória inadequada e exacerbada ensejou a produção de substâncias biológicas que fossem capazes de bloquear o TNF-α, em diferentes níveis, abrindo um campo grande de perspectiva para novo tipo de tratamento das DII. (AU)

[NOD2 novel mutations in Iranian Crohn's patients]

Despite the reported role of three common mutations of the CARD15/NOD2 gene including R702W, G908R and 1007fs in Crohn's disease [CD], only about 30% of Iranian CD patients carry one of these three variants [R702W]. The aim of this study was to screen the hot points of NOD2 gene to find any novel sequence variations in Iranian patients with CD. Eighty non-related Crohn's patients from Iranian origin, referred to a tertiary center in a three-year period [2006-2009], were enrolled in this study. The hot points of NOD2 gene [including exons 4 and 8] were evaluated by direct sequencing after amplification of related sequences with polymerase chain reaction [PCR]. A total of 17 sequence variations were identified among these exons of NOD2 gene including 7 novel ones. Three of these new mutations had an allele frequency more than 5%. All new mutations were a consequence of a single nucleotide change, 4 resulted in an aminoacid change while one formed a stop coden. No deletion or insertion mutation was observed in this part of the gene. This study demonstrated the existence of uncommon NOD2 variants in Iranian patients with CD. It is possible that these mutations play a role in susceptibility to CD in Iranian population

Effects of muramyl dipeptide on the differentiation of human dental pulp cells / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the nucleotide-binding oligomerization domain-2 (NOD-2) gene expression in deep caries and the effects of NOD-2 agonist muramyl dipeptide (MDP) on the differentiation of human dental pulp cells (hDPC).</p><p><b>METHODS</b>NOD-2 gene level in deep caries and healthy pulp tissue was determined by real-time quantitative polymerase chain reaction (realtime-PCR). Realtime-PCR, Western blotting and immunofluorescence were performed to evaluate NOD-2 gene and protein expression. Dentin sialoprotein (DSP) protein level was assessed when hDPC were challenged by different concentrations of MDP for 24 hours, and sialophosphoprotein (DSPP), osteocalcin (OCN) mRNA and osteopontin (OPN) protein level were detected at different time points after incubation with 0.1 mg/L MDP.</p><p><b>RESULTS</b>NOD-2 mRNA level was higher in pulp tissue of deep caries (0.2610 ± 0.0824) than that in healthy controls (0.0024 ± 0.0002), P < 0.05. The expression of NOD-2 gene and protein increased in a time denpendent manner upon stimulation with MDP. Immunofluorescence confirmed that NOD-2 protein was located in cytoplasm. Moreover, 0.1 mg/L MDP augmented DSP protein level. DSPP and OCN mRNA were elevated with time and reached the peak at 12 h and down-regulated. OPN protein level also increased with time.</p><p><b>CONCLUSIONS</b>Dental pulp NOD-2 expression are up-regulated in pulp tissue of deep caries. MDP may be related to the differentiation of hDPC.</p>

frequency of three common mutations of CARD15/NOD2 gene in Iranian IBD patients

CARD15/NOD2 gene, located on the pericentromeric region of chromosome 16 [IBD1] has been reported to have an association with IBD, especially Crohn's disease [CD]. Many independent studies have shown a variable association between three common mutations of CARD 15, with Crohn's disease in different ethnic groups. Thus, raising the hypothesis that genetic and / or allelic heterogeneity may influence the relationship between CARD 15 and Crohn's disease. In the present study, we have investigated the frequency of three main mutations of CARD 15 gene [Arg 702 Trp, Gly 908 Arg and Leu 1007 fsinsC] in Iranian IBD patients and compared it with healthy control population. For this case-control study, 100 ulcerative colitis [UC], 40 Crohn's disease patients and 100 sex- age- and ethnicity-matched controls were enrolled from a teaching hospital during a one year period [2003-2004]. All three mutations were assessed on DNA of leukocyte cells, by PCR [Polymerase Chain Reaction] and RFLP [Restriction Fragment Length Polymorphism] methods. The mean age of UC, CD and healthy controls were 38.6 +/- 14.3, 36.6 +/- 14.1, and 38.6 +/- 14.2 years. Among the three evaluated CARD 15 gene mutations, the frequency of Arg702Trp mutation was significantly higher in Iranian patients with Crohn's disease [OR19.2; 95%CI:4.2-87.3, p<0.001]. None of these mutations were associated with ulcerative colitis. This study showed that Arg702Trp mutation of CARD 15 gene is probably associated with Crohn's disease in Iranian population; indicating that genetic polymorphisms may differ between populations