Effect of curcumin on the expression of NOD2 receptor and pro-inflammatory cytokines in fibroblast-like synoviocytes (FLSs) of rheumatoid arthritis (RA) patients

Abstract Background Previous studies has shown that nucleotide-binding and oligomerization domain-containing protein 2 (NOD2) is expressed in Fibroblast-like synoviocytes (FLSs) of rheumatoid arthritis (RA) patients which is stimulated by muramyl dipeptide (MDP) present in the joint environment and induces inflammation via the NF-κB pathway. Also, other studies have shown that curcumin inhibits proliferation, migration, invasion, and Inflammation and on the other hand increases the apoptosis of RA FLSs. In this study, we aim to evaluate the effect of curcumin, a natural antiinflammatory micronutrient, on the expression of NOD2 and inflammatory cytokines. Methods Synovial membranes were collected from ten patients diagnosed with RA and ten individuals with traumatic injuries scheduled for knee surgery. The FLSs were isolated and treated with 40 μM curcumin alone or in combination with 20.3 μM MDP for 24 h. mRNA was extracted, and real-time PCR was performed to quantitatively measure gene expression levels of NOD2, p65, IL-6, TNF-α, and IL-1β. Results The study findings indicate that administering MDP alone can significantly increase the mRNA expression levels of IL-6 and IL-1β in the trauma group and TNF-α in the RA group. Conversely, administering curcumin alone or in combination whit MDP can significantly reduce mRNA expression levels of P65 and IL-6 in FLSs of both groups. Moreover, in FLSs of RA patients, a single curcumin treatment leads to a significant reduction in NOD2 gene expression. Conclusion This study provides preliminary in vitro evidence of the potential benefits of curcumin as a nutritional supplement for RA patients. Despite the limitations of the study being an investigation of the FLSs of RA patients, the results demonstrate that curcumin has an anti-inflammatory effect on NOD2 and NF-κB genes. These findings suggest that curcumin could be a promising approach to relieve symptoms of RA.

Role of NOD2 in dorsal root ganglion in development of neuropathic pain in rats / 中华麻醉学杂志

Objective:To evaluate the role of nucleotide-binding oligomerization domain-2 (NOD2) in dorsal root ganglion in the development of neuropathic pain (NP) in rats.Methods:Thirty-two adult male SPF Sprague-Dawley rats, weighing 240-260 g, aged 2-3 months, were divided into 4 groups ( n=8 each) using a random number table method: control group (group C), NP group (group S), negative control siRAN group (group N), and NOD2-siRNA group (group R). In N and R groups, 1×10 8 IFU/ml negative control siRNA and NOD2-siRNA 10 μl were intrathecally injected, respectively, once a day for 3 consecutive days.Normal saline 10 μl was intrathecally injected once a day for 3 consecutive days in C and S groups.The model of NP was established using spared nerve injury (SNI) at 2 weeks after intrathecal injection.The mechanical paw withdrawal threshold (MWT) was measured at 1 day before surgery and 1, 3, 7, 10, 14 and 28 days after SNI.Animals were sacrificed after measuring pain threshold on day 28, and the dorsal root ganglions (DRGs) of the lumbar segment (L 4-6) were removed for determination of the expression of NOD2 (by Western blot) and expression of tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), IL-6 and NOD2 mRNA (using quantitative real-time polymerase chain reaction). Results:Compared with group C, MWT was significantly decreased at each time point after SNI, and the expression of NOD2 protein and mRNA and TNF-α, IL-1β and IL-6 mRNA in DRGs was up-regulated in group NP ( P<0.01). Compared with group NP, MWT was significantly increased at each time point after SNI, and the expression of NOD2 protein and mRNA and TNF-α, IL-1β and IL-6 mRNA in DRGs was down-regulated in group R ( P<0.01), and no significant change was found in the parameters mentioned above in group N ( P>0.05). Conclusion:The mechanism underlying the development of NP may be related to the up-regulation of NOD2 expression in DRGs, thus further promoting the expression of pro-inflammatory factors in rats.

Association Between TLR2, TLR4 and NOD2/CARD15 Gene Polymorphisms and Ulcerative Colitis: A Meta-analysis / 胃肠病学

Background: The prevalence rate of ulcerative colitis (UC) in China has increased significantly in recent years, and Toll-like receptor 2 (TLR2), TLR4 and NOD2/CARD15 may be closely related to the development of UC. Aims: To explore the influence of TLR2, TLR4 and NOD2/CARD15 gene polymorphisms on the pathogenesis of UC. Methods: Studies on correlation of TLR2, TLR4 and NOD2/CARD15 gene polymorphisms with UC were retrieved from PubMed, CBM, CNKI, Wanfang, VIP databases. Literatures were enrolled according to the inclusion and exclusion criteria, and the quality was evaluated and data were extracted. RevMan 5.3 software was used to conducted meta-analysis. Results: Fifteen eligible articles were included. Meta-analysis showed that TLR2 Arg753Gln gene polymorphism was not associated with risk of UC (P>0.05). Except the recessive model, TLR4 Asp299Gly gene polymorphism could increase the risk of UC (P0.05). No significant association between NOD2/CARD15 (Arg702Trp, Gly908Arg and Leu1007fsinsC) gene polymorphism and UC was found (P>0.05). Conclusions: Existing evidence shows that TLR4 (Asp299Gly, Thr399Ile) gene polymorphisms are associated with an increased risk of UC, however, NOD2/CARD15 (Arg702Trp, Gly908Arg and Leu1007fsinsC) and TLR2 (Arg753Gln) gene polymorphisms are not associated with UC.

Familial Blau syndrome:First molecularly confirmed report from India

Blau syndrome (BS) is a rare autoinflammatory disorder characterized by the clinical triad of arthritis, uveitis, and dermatitis due to heterozygous gain-of-function mutations in the NOD2 gene. BS can mimic juvenile idiopathic arthritis (JIA)-associated uveitis, rheumatoid arthritis, and ocular tuberculosis. We report a family comprising a mother and her two children, all presenting with uveitis and arthritis. A NOD2 mutation was confirmed in all the three patients – the first such molecularly proven case report of familial BS from India.

The expression and immune function of pattern recognition receptor NOD2 signal in Myd88-/- mice model of Mycobacterium infection / 中国感染与化疗杂志

Objective To investigate the expression and immune function of NOD2 signal in MyD88-/- mice. Methods MyD88-/- mice and wild-type C57 BL/6 mice were characterized by PCR. Mice model of pulmonary infection was constructed by tracheal instillation of BCG vaccine strain(attenuated strain of Mycobacterium). PBS tracheal instillation was used as negative control.Peripheral blood sample and lung tissue were collected aseptically 24 h after Mycobacterium challenge. Real-time PCR and Western blot were used to detect the expression of NOD2 gene and protein. IL-6 level in the peripheral blood was determined by enzymelinked immunosorbent assay. Results The expression of NOD2 protein in BCG infected mice was significantly higher than PBS negative control group. NOD2 protein expression in MyD88-/- mice was higher than in wild-type mice. BCG infection was associated with higher NOD2 protein expression than infection-free PBS control in both groups of animals. The IL-6 level in peripheral blood was significantly higher after BCG infection than PBS group in both MyD88-/- mice and wild type mice. Conclusions BCG can activate the NOD2 signaling pathway when MyD88-dependent pathway is deficient.

The 468th case: periodic fever, abdominal pain, small intestinal ulcers, NOD2 gene mutation / 中华内科杂志

Fever and abdominal pain are common symptoms and could be main manifestations in patients with autoinflammatory diseases.A 48-year-old female patient was admitted with recurrent fever and abdominal pain for 9 years.Serum level of inflammatory markers synchronously fluctuated with fever,and returned to normal when fever subsided.The periodic episodes of fever occurred every 1 to 4 months and failed to respond to empirical antibiotics.Whole exome sequencing showed heterozygous mutation of NOD2 gene q902k,leading to the final diagnosis of autoinflammatory disease.Corticosteroid and tripterygiumglycosides were effective for the disease remission.

IMPACT OF CTLA-4 AND NOD2/CARD15 GENE VARIATIONS ON GRAFT- VERSUS-HOST DISEASE AFTER ALLOGENEIC HSCT: A STRUCTURED REVIEW

@#Graft-versus-host Disease (GVHD) is the main cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (alloHSCT). In spite of immune-suppressive prophylaxis, most survivors suffer from acute and chronic GVHD (aGVHD and cGVHD). The outcome of alloHSCT may be affected by the presence of single nucleotide polymorphism (SNP) in non-HLA genes including those involved in innate immune responses. This study aimed to evaluate the impact of cytotoxic T-lymphocyte antigen-4 (CTLA-4) and caspase recruitment domain 15 (NOD2/CARD15) gene polymorphisms on the incidence and severity of aGVHD and cGVHD following alloHSCT. A structured literature review was carried out using various keywords and MESH terms such as stem cell transplantation, allogenic haematopoietic stem cell transplantation, GVHD, and non-HLA gene polymorphism, in PubMed, Google Scholar and Cochrane Database. A total of 8 studies that met inclusion criteria (English publications from 2006 to 2017) were included. Ten SNPs in CTLA-4 gene and three SNPs in NOD2/CARD15 gene were tested in patients with underlying haematological malignancies. Four studies tested the SNPs of CTLA-4 gene and two were found to have an association with CTLA-4 SNPs (rs3087243, rs231775) and increased incidence of aGVHD. The other four studies tested the SNPs of NOD2/CARD15 gene and one found an association between SNP13 and increased incidence of aGVHD. None of these eight studies found any effect on severity of GVHD. In conclusion, two SNPs in CTLA-4 and one SNP in NOD2/CARD15 increased the incidence of aGVHD but not its severity. The higher incidence of aGVHD in studies with larger sample size could support the impact of SNPs in the outcome of alloHSCT. However, due to the heterogeneity of studies in regard to the age of patients and donor, and conditioning regimen, it is difficult to draw a definite conclusion

Protective effects of naringenin against hypoxic-ischemic brain damage in neonatal rats through suppression of NOD2/RIP2/NF-κB pathway / 中国药理学通报

Aim To explore the protective effects of naringin on hypoxic ischemic brain injury in neonatal rats and its mechanism. Methods Ninety-six healthy 7-day neonatal SD rats were randomly divided into sham operation group, hypoxic-ischemic brain damage group (HIBD group),HIBD with low-dose naringenin group(50 mg·kg-1, NG-L) and HIBD with high-dose naringenin group(100 mg·kg-1,NG-H). Neu-rological deficit, HE staining and brain water content were measured 48h after operation. Immunoblotting was used to detect the expressions of NOD2,RIP2 and NF-κB. Enzyme linked immunosorbent assay(ELISA) method was adopted to detect TNF-α and IL-1β ex-pression. Results Compared with HIBD group, the neurological deficit score decreased, the pathological damage was reduced, and the water content of brain tissues markedly decreased by naringenin(50,100 mg ·kg-1) treatment(P<0.05). Western blot revealed the down-regulation of NOD2,RIP2 and NF-κB by na-ringenin (50,100mg·kg-1) treatment (P<0.05). The content of TNF-α and IL-1β in brain tissues was lower than that of HIBD group (P <0.05). Conclu-sion Naringenin is likely to exert a protective role in neonatal rats of hypoxic ischemic brain injury perhaps through decreasing the expression of NOD2, RIP2 and NF-κB,and reducing the secretion of TNF-α and IL-1β.

Role of NOD2-regulated Snail expression in epithelial-mesenchymal transition in podocyte of diabetic nephropathy / 中华肾脏病杂志

Objective To observe the expression of NOD2 and epithelial-mesenchymal transition (EMT) related proteins in podocytes in high glucose environment,and explore the molecular mechanism of NOD2 involved in EMT.Methods The human glomerular podocytes were the subjects of study.α-SMA and Nephrin expressions were detected by immunofluorescence;the mRNA and protein expressions of NOD2,Snail and EMT related proteins (α-SMA,Desmin,E-cadherin,Nephrin) were detected by real-time fluorescence quantitative PCR and Western blotting.The podocytes were stimulated by high-glucose after shRNA interfering the of NOD2 expression,and the expressions of Snail and subsequent EMT-related proteins were detected by Western blotting.Prior to the activation of NOD2 by muramyl dipeptide (MDP),shRNA was used to interfere with the expression of Snail.E-cadherin,Nephrin,Desmin,and α-SMA were detected by Western blotting.Results After 24 hours of high glucose stimulation,PCR and Western blotting results showed that the expressions of NOD2 and Snail were significantly increased;the expressions of epithelial phenotype proteins E-cadherin and Nephrin were down-regulated;and the expressions of interstitial phenotype proteins Desmin and α-SMA were increased (all P ＜ 0.05);while there was no significant change in the hypertonic control group.After interference with NOD2,the abnormal expression of Snail and EMT related proteins were all recovered.After interference with Snail expression,Compared with the MDP group,the protein expressions of E-cadherin and Nephrin were significantly increased (all P ＜ 0.05);the expressions of Desmin and α-SMA were significantly decreased.Conclusions High glucose can induce NOD2 expression in podocytes,and promote podocyte epithelial-mesenchymal transition by upregulating Snail expression.Gene intervention targeting the NOD2/Snail/EMT pathway can reduce high-glucose-induced podocyte injury and may provide new ideas for the treatment of diabetic nephropathy.

A familial case of Blau syndrome caused by dual NOD2 genetic mutations / 中华实用儿科临床杂志

Objective To provide the diagnostic proof for a suspected Chinese family with BS,and NOD2 gene mutation types and clinical features were analyzed in this study.Methods Nine members (4 males and 5 females) of this family were enrolled.To clarify the genotype,the whole exome sequencing by next-generation sequencing from the proband and his parents was performed,and all members were subjected to Sanger sequencing.For the newly discovered NOD2 missense mutation,its pathological predictions were conducted online by adopting polyphen software.Clinical data of affected cases diagnosed by NOD2 analysis were collected to analyze illustrate the clinical features.Results (1)The proband of the family was a 5-year-old Chinese Han boy,who had the clinical triad of dermatitis,polyarthritis and uveitis.The body temperature and C-reactive protein (CRP) was normal.Besides the proband,2 members were diagnosed as BS by means of NOD2 analysis.The coexistence of 2 missense mutations was detected.One novel mutation was c.1981G ＞ C,p.A661 P,and another previously reported one was c.2006A ＞ G,p.H669A.(2) Mutations identified in the male proband were inherited from his father.Tracing the other pedigree members,it was disclosed that his grandmother had the heterozygous dual NOD2 mutations.The proband displayed a phenotype featuring the symptom triad of granulomatous dermatitis,symmetric arthritis,and recurrent uveitis,with normal temperature and CRP level.Conclusions The coexistence of A661P and H669A mutations in NOD2 caused BS in a Chinese pedigree,which derived from the proband's grandmother.This is the first report of A661P mutation in NOD2 in a Chinese pedigree of this disease.The proband has multi hydatoncus surrounding multi-joints,but no persistent fever and no elevated CRP,which may help to differentiate BS from other inherited autoinllammatory diseases in clinical settings.

The roles of NOD1 and NOD2 in tumorigenesis and development / 中国生化药物杂志

Theinnate immunity system of human body has more and more attention for its antibacterial, antiviral, maintainingimmunehemostasis and promoting tissue damage and repair and other physiological functions.As members of NOD-like receptors(NLRs), NOD1 and NOD2 receptors are identified as intracellular pattern recognition receptors(PRRs), can be identified with molecular damage endogenous(damage-associated molecular patterns, DAMPs)and exogenous injury-molecular pathogen associated molecular(pathogen-associated molecular patterns, PAMPs), and initiation of innate and specific immune response, maintain the steady balance of body.Recently, a bunch of evidence have demonstrated that the importance of NOD1 receptor and NOD2 receptor is not limited in field of anti-infection, and the insulin resistance, kidney and liver damage recovery, cardiovascular disease and tumorigenesis are also closely related with these two receptors.So the aim of this article is to interpret the NOD1 and NOD2 general structure and function, and summarize the link between these two PRRs and tumorigenesis and finally make a clue for cancer immunotherapy.

Relationship between inflammatory responses and autophagy in lung tissues after scald and NOD2 signaling pathway in septic rats / 中华麻醉学杂志

Objective To evaluate the relationship between inflammatory responses and autophagy in lung tissues after scald and nucleotide-binding oligomerization domain-containing protein 2 (NOD2) signaling pathway in septic rats.Methods Twenty SPF healthy male Sprague-Dawley rats,weighing 200-250 g,were divided into control group (group C,n=10) and sepsis after scald group (group SS,n=10) using a random number table.The rats were subjected to a third-degree scald burn covering 20％ of total body surface area (body surface was shaved and then exposed to 99-100 ℃ water for 12 s),and 24 h later muramyldipeptide 5 mg/kg was intravenously injected to induce sepsis.The rats were only exposed to 20 ℃ water,and 24 h later normal saline 1 ml was given instead in group C.At 6 h after muramyldipeptide injection in group SS and at 6 h after normal saline injection in group C,arterial blood samples were collected for determination of serum tumor necrosis factor-r and interleukin-6 concentrations by enzyme-linked immunosorbent assay.Then rats were sacrificed and lungs were removed tor measurement of activity of myeloperoxidase,NOD2 mRNA expression (using real-time polymerase chain reaction) and expression of receptor interacting protein 2,nuclear factor kappa Bp65 and microtubule-associated protein 1 light chain 3 Ⅰ (LC3 Ⅰ) and LC3 Ⅱ in lung tissues (by Western blot).The LC3 Ⅱ / Ⅰ ratio was calculated.Results Compared with group C,the expression of NOD2 mRNA,receptor interacting protein 2 and nuclear factor kappa Bp65 was significantly up-regulated,and the LC3 Ⅱ / Ⅰ ratio and serum tumor necrosis factor-α and interleukin-6 concentrations were increased in group SS (P＜0.05).Conclusion The mechanism underlying enhanced inflammatory responses and autophagy in lung tissues during sepsis after scald may be related to activation of NOD2 signaling pathway in rats.

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.

Frequency of Three Common Mutations of CARD15/NOD2 Gene in Jordanian Patients with Crohn’s Disease.

Background and Aims: CARD15/NOD2 is recognized as a major susceptibility gene for Crohn’s disease. Several mutations of CARD15/NOD2 have been reported in different racial groups. We aimed to investigate the frequency of three common CARD15/NOD2 mutations in a Jordanian Crohn’s disease cohort. Methodology: Fifty one unrelated Crohn’s disease patients and fifty one age- and sex-matched healthy controls were recruited at two hospitals in Jordan. Demographic and phenotypic characteristics of patients were ascertained. Allele frequencies for three CARD15/NOD2 mutations (G2722C, C2104T, 3020insC) were determined by PCR-RFLP, ARM-PCR, and direct sequencing using allele specific primers. Results: The frequencies of G2722C alleles in Crohn’s disease patients were higher but not statistically significant as compared to healthy controls (5.9% vs. 1.9%; P = 0.32). On the other hand, C2104T and 3020insC mutations have not been detected in Crohn’s disease patients or healthy controls. Conclusion: Our findings indicate that common mutations of CARD15/NOD2 gene in White patients with Crohn’s disease are not associated with Crohn’s disease in the Jordanian population. Further studies are needed to ascertain the effect of these and other mutations on Crohn’s disease susceptibility and behavior in our population.

Expression of Nucleotide-oligomerization Domain (NOD) and Related Genes in Mouse Tissues Infected with Mycobacterium leprae

The nucleotide-oligomerization domain (NOD) is an important molecule involved in host defense against bacterial infection. To study the role of NODs in the host response to Mycobacterium leprae, we measured the mRNA levels of NODs and related genes in infected mouse tissues. The mRNA expression of NOD1, NOD2, caspase-1 and ASC was increased in mouse footpads. Whereas NOD2 expression in macrophages was increased at 2 and 24 h post-infection with M. leprae, there was no expression of NOD1 at these time points. An increase in caspase-1 expression was observed at 2 h and continued at 24 h. However, the expression of ASC was increased only at the early time point. The expression of caspase-1 is regulated by NOD2-dependent pathway in established HEK 293. Our results suggest NOD2, rather than NOD1, may be associated with the host response to M. leprae and that caspase-1 activation is essential for the host response.

NOD2 up-regulates the autophagy and inhibites the proliferation and migration of SCC-1 5 cells / 实用口腔医学杂志

Objective:To investigate the affects of NOD2 on rapamycin (Rap)induced autophagy and on the proliferation and mi-gration of tongue squamous carcinoma SCC-1 5 cells.Methods:① Synthesized NOD2 over-expression plasmid and NOD2-shRNA were transfected into SCC-1 5 cells respectively.②Normal control SCC-1 5 cells,NOD2 over-expression cells and NOD2-shRNA cells were treated with Rap to induce autophagy.Then,the expression of LC3 and Beclin-1 was examined by Western blot.Cell pro-liferation was tested by MTT assay.Cell migration was assessed by wound healing assay.Results:①After Rap treatment,the expres-sion of protein LC3-Ⅱand Beclin-1 in NOD2 over-expression cells increased(P <0.05)and in NOD2-shRNA cells were suppressed (P <0.05).② Compared with control group,the proliferation and migration ability were decreased in NOD2 over-expression cells (P <0.05),but in NOD2-shRNA cells the proliferation and migration ability were increased(P <0.05).Conclusion:NOD2 can up-regulate the autophagy and suppress the proliferation and migration of tongue squamous SCC-1 5 cells.

Role of Nucleotide-binding and Oligomerization Domain 2 Protein (NOD2) in the Development of Atherosclerosis

NOD2 (nucleotide-binding and oligomerization domain 2) was initially reported as a susceptibility gene for Crohn's disease, with several studies focused on elucidating its molecular mechanism in the progression of Crohn's disease. We now know that NOD2 is an intracellular bacterial sensing receptor, and that MDP-mediated NOD2 activation drives inflammatory signaling. Various mutations in NOD2 have been reported, with NOD2 loss of function being associated with the development of Crohn's disease and other autoimmune diseases. These results suggest that NOD2 not only has an immune stimulatory function, but also an immune regulatory function. Atherosclerosis is a chronic inflammatory disease of the arterial wall; its pathologic progression is highly dependent on the immune balance. This immune balance is regulated by infiltrating monocytes and macrophages, both of which express NOD2. These findings indicate a potential role of NOD2 in atherosclerosis. The purpose of this review is to outline the known roles of NOD2 signaling in the pathogenesis of atherosclerosis.

The effects of NOD2 gene on the proliferation and apoptosis of human tongue squamous cell carcinoma Tca8113cells / 实用口腔医学杂志

Objective:To explore the effects of NOD2 gene on the proliferation and apoptosis of tongue squamous cell carcinoma Tca8113 cells.Methods:NOD2 expression vector(NOD2-pEZ-M29)and NOD2-shRNA vector were established,then were trans-fected into Tca8113 cells respectively.Expressions of HBD-2 and NOD2 in the cells was detected by RT-PCR and Western blot.Cell proliferation was examined by MTT assay and apoptosis by flow cytometry at 48h post transfection.Results:Compared with the control group,the expression of NOD2 and HBD-2 in NOD2-pEZ-M29 transfection group was significantly higher and markedly lower in NOD2-shRNA group.The proliferation rate of Tca8113 cells was markedly lower in NOD2-pEZ-M29 transfection group and signifi-cantly higher in NOD2-shRNA group while the apoptosis rate was significantly higher in NOD2-pEZ-M29 transfection group and sig-nificantly lower in NOD2-shRNA group.Conclusion:In Tca8113 cells NOD2 expression was positively correlated with HBD-2 ex-pression.NOD2 gene may promote the apoptosis,inhibit the proliferation of Tca8113 cells.

NOD1 and NOD2 receptors in mrigal (Cirrhinus mrigala): Inductive expression and downstream signalling in ligand stimulation and bacterial infections.

Nucleotide binding and oligomerization domain (NOD)1 and NOD2 are important cytoplasmic pattern recognition receptors (PRRs) and key members of the NOD-like receptor (NLR) family. They sense a wide range of bacteria or their products and play a key role in inducing innate immunity. This report describes the role of NOD1 and NOD2 receptors signalling in innate immunity in the Indian major carp, mrigal (Cirrhinus mrigala). Tissue-specific expression analysis of NOD1 and NOD2 genes by quantitative real-time PCR (qRT-PCR) revealed their wide distribution in various organs/tissues. In the untreated fish, the highest expression of NOD1 and NOD2 was detected in liver and blood, respectively. Stimulation with NOD1- and NOD2-specific ligands, i.e. iE-DAP and MDP, activated NOD1 and NOD2 receptor signalling in vivo and in vitro resulting in significant (p<0.05) induction of downstream signalling molecule RICK, and the effector molecules IL-1β, IL-8 and IFN-γ in the treated group as compared to their controls. In response to both Gram-positive and Gram-negative bacterial infections, NOD1 and NOD2 receptors signalling were activated and IL-1β, IL-8 and IFN-γ were induced. These findings highlight the important role of NOD receptors in eliciting innate immune response during the pathogenic invasion to the fish.