Role of Akt/NF-κB pathway in immune-complexes-induced MCP-1 and CSF-1 expression in murine glomerular mesangial cells

AIM: To explore the role of Akt/NF-κB pathway in immune-complexes-induced monocyte chemoattractant protein-1 (MCP-1) and colony stimulating factor-1 (CSF-1) expression in Mesangial Cells. METHODS: Primary murine glomerular mesangial cells were cultured in vitro and divided into control group, stimulation group and antisense, sense and mismatched oligodeoxynucleotide group. In control group, the cells were stimulated with monomeric IgG after treatment with 0.5% lipofectin for 8 h. In stimulation group, the cells, which had been treated with 0.5% lipofectin for 8 h, were stimulated with aggregated IgG. In antisense, sense and mismatched oligodeoxynucleotide group, being transduced antisense, sense and mismatched oligodeoxynucleotide respectively with 0.5% lipofectin 8 h, the cells were stimulated with AIgG. MCP-1 and CSF-1 in supernatant were deteced with ELISA. In addition, RT-PCR was used to determine MCP-1 and CSF-1 mRNA expression, and EMSA to investigated the activation of NF-κB. RESULTS: Mesangial cells cultured in vitro had a low level NF-κB activation and a low level constitutive expression of MCP-1 and CSF-1. Stimulated with AIgG, activation of NF-κB was markedly increased(0.35±0.06 vs 0.75±0.16, P＜0.01), expression of MCP-1 and CSF-1 mRNA (0.48±0.03 vs 0.72±0.02, P＜0.05; 0.44±0.01 vs 0.59±0.02, P＜0.05), MCP-1 and CSF-1 levels in supernatant(15.52±1.81 vs 43.05±3.18, P＜0.05; 389.06±13.75 vs 764.22±31.78, P＜0.05) were markedly increased. Akt1 antisense oligodeoxynucleotide markedly inhibited immune-complexes-induced NF-κB activation, MCP-1 and CSF-1 mRNA and protein expression. CONCLUSION: Akt/NF-κB pathway mediates immune-complexes-induced MCP-1 and CSF-1 expression in mesangial cells. It suggests that Akt/NF-κB pathway may be a new therapy target for macrophage recruitment and activation in immune complexes nephritis.     

Establishing a three-dimensional angiogenesis model in vitro and secretion of MCP-1 and VEGF by tumor cells

AIM: To establish a three-dimensional angiogenesis model in vitro for observing the influence of tumor cells on angiogenesis, and to explore its possible molecular mechanism. METHODS: Human umbilical vein endothelial cells (HUVECs) and mouse endothelial cells SVEC4-10EE2 were coated on the surface of beads, and then mixed with fibrinogen and seeded in cell culture plates containing thrombin. The cultured endothelial cells coated on the beads grew into a vessel-like structure in a three-dimensional space containing fibrin condensate to establish an in vitro three-dimensional angiogenesis model. Tumor cells MDA-MB-231 and E0771 were co-cultured in the model to observe the effect of tumor cells on angiogenesis in vitro,respectively. The concentrations of monocyte chemoattractant protein-1 (MCP-1) and vascular endothelial growth factor (VEGF) in the tumor cells culture supernatant were measured by ELISA. An antagonist of CCR2 (receptor of MCP-1), along with SU5416 (an inhibitor of VEGF receptor), were added to the tumor cell co-culture system. The supernatant of the tumor cells was collected as a conditioned medium, which was then added to the angiogenesis system of HUVECs or SVEC4-10EE2 cultured individually. The effect of conditioned medium on angiogenesis was observed under the conditions of with or without SU5416, as well as with or without CCR2 antagonist. RESULTS: Under normal condition, HUVECs and SVEC4-10EE2 formed a multi-cellular vascular structure the three-dimensional angiogenesis model in vitro. The co-culture of MDA-MB-231 (E0771) cells significantly promoted in the formation of membrane-like structures. The ELISA results showed that the levels of MCP-1 and VEGF in the supernatant of tumor cells were significantly elevated (P<0.05). MCP-1 promoted the formation of membrane tube in three-dimensional culture system in vitro. After adding the antagonists of MCP-1 receptor CCR2 and VEGF (SU5416), the angiogenesis was significantly inhibited (P<0.05). At the same time, conditioned medium promoted the formation of extracorporeal membranes in the endothelial cells. The promoting effect was blocked by CCR2 antagonists and SU5416 (P<0.05). CONCLUSION: The in vitro three-dimensional angiogenesis model is successfully established. Tumor cells significantly promote the formation of membrane tubes. The effect of tumor cells might be related to MCP-1 and VEGF secretion.     

Dickkopf-1 silencing inhibits invasion and epithelial-mesenchymal transition in gastric carcinoma cells by down-regulating β-catenin

AIM: To explore the expression of Dickkopf-1 (DKK1) in human gastric carcinoma cells, and the influences of DKK1 gene silencing on cell invasion. METHODS: The levels of DKK1 in the human gastric mucosa cell line GES-1 and gastric carcinoma cell lines MKN-45 and SGC-7901 were detected by real-time PCR and Western blot. DKK1 gene was silenced by RNA interference, which was verified by real-time PCR, Western blot and ELISA. The cell invasion ability was determined by Transwell assay, and the cell proliferation was inhibited by mitomycin C. The levels of E-cadherin, N-cadherin, vimentin and β-catenin were determined by real-time PCR and Western blot. RESULTS: The expression of DKK1 was significantly higher in MKN-45 cells and SGC-7901 cells than that in GES-1 cells, indicating that DKK1 expression was obviously increased in gastric carcinoma cells. After successful silencing of DKK1 gene in the MKN-45 cells and SGC-7901 cells, the cell invasion ability was markedly decreased in a time-dependent pattern with increased expression of E-cadherin and decreased expression of N-cadherin and vimentin, indicating that DKK1 silencing dramatically inhibited gastric carcinoma cell invasion and epithelial-mesenchymal transition (EMT). The introduction of exogenous recombinant DKK1 (rDKK1) demonstrated the promoting effect of DKK1 on gastric carcinoma cell invasion and EMT. In addition, the inhibitory effects of DKK1 silencing on gastric carcinoma cell invasion and EMT were fulfilled by down-regulating β-catenin. CONCLUSION: The expression of DKK1 is significantly increased in human gastric carcinoma cells. Silencing of DKK1 markedly inhibits gastric carcinoma cell invasion and EMT by down-regulating β-catenin.     

Effects of resveratrol on TNF-α-induced injury and expression of MCP-1 in isolated rat pulmonary artery endothelial cells

AIM: To investigate the possible mechanism of resveratrol (Res) on tumor necrosis factor-α (TNF-α)-induced monocyte chemoattractant protein-1 (MCP-1) expression in primary rat pulmonary artery endothelial cells (RPAECs).METHODS: RPAECs were randomly divided into 4 groups:control group, solvent (1% DMSO) group, TNF-α group and Res group. Each group was divided into 1 h, 4 h and 8 h subgroups (n=6 per time point). The TNF-α+C1142 (a rodent chimeric mAb that neutralizes rat MCP-1) group was set up at the 8 h time point. At each time point, the protein and mRNA expression of MCP-1 was measured by Western blot and real-time PCR.RESULTS: Pretreatment of the RPAECs with C1142 significantly down-regulated the expression of MCP-1 (P<0.05). The protein and mRNA expression of MCP-1 was markedly increased in TNF-α group (P<0.05). Notably, incubation with Res down-re-gulated the protein and mRNA expression of MCP-1, which was significantly lower than that in TNF-α group (P<0.05).CONCLUSION: MCP-1 was involved in the process of TNF-α-induced injury of RPAECs. Res down-regulates the expression of MCP-1 in RPAECs, thus attenuating cell injury.     

Interaction of polymorphisms in resistin gene promoter -420C/G,cytochromes P4501A1 gene MspI and cigarette smoking on nonalcoholic fatty liver disease

AIM: To investigate the interaction of polymorphisms of resistin gene promoter -420C/G, cytochromes P4501A1-MspI and cigarette smoking in nonalcoholic fatty liver disease (NAFLD). METHODS: The genetic polymorphisms in resistin gene promoter -420C/G and CYP1A1-MspI were analyzed by the technique of polymerase chain reaction (PCR) in peripheral blood leukocytes of 900 NAFLD cases and 900 healthy persons. RESULTS: The frequencies of -420C/G (GG) and CYP1A1-MspI (m2/m2) were 49.75% and 50.08% in NAFLD cases and 24.00% and 24.25% in healthy controls, respectively. Statistical tests showed a significant difference in the frequencies between the 2 groups (P<0.01). The risk of NAFLD with -420C/G (GG) was significantly higher than that of controls. Individuals who carried with CYP1A1-MspI (m2/m2) had a high risk of NAFLD. Combined analysis of the polymorphisms showed that the percentages of -420C/G (GG)/CYP1A1-MspI (m2/m2) in NAFLD and control groups were 39.83% and 12.83%, respectively (P<0.01). The people who carried with -420C/G (GG)/CYP1A1-MspI(m2/m2) had a high risk in NAFLD group. The cigarette smoking rate in NAFLD group was signi-ficantly higher than that in control group (P<0.01), and the statistic analysis suggested an interaction between cigarette smoking and -420C/G (GG) and CYP1A1-MspI (m2/m2), which increased the risk of NAFLD.CONCLUSION: -420C/G (GG), CYP1A1-MspI (m2/m2) and cigarette smoking are the risk factors in NAFLD. The interactions between genetic polymorphisms in -420C/G, CYP1A1- MspI (m2/m2) and cigarette smoking increase the risk of NAFLD.     

Relationship between UGT1A1 gene polymorphisms and toxicity/efficacy of irinotecan-based chemotherapy in metastatic colorectal cancer

AIM: To investigate the correlation of UGT1A1 ^*28 and UGT1A1 ^*6 gene polymorphisms with irinotecan-associated adverse events and efficacy in the patients with metastatic colorectal cancer (mCRC) treated with irinotecan-based chemotherapy. METHODS: Analysis of UGT1A1 ^*28 and UGT1A1 ^*6 gene polymorphisms was performed in 207 gastrointestinal cancer patients admitted to our hospital from April 2010 to March 2012 by amplifying the gene fragments using PCR and direct sequencing. Fifty six cases with mCRC treated with irinotecan were chosen to observe the adverse events and efficacy during chemotherapy, and the time to progression (TTP) was also recorded. The incidence of different genotypes was compared. RESULTS: The distribution of the genotypes in 207 gastrointestinal cancer patients was as follows: UGT1A1 ^*28 wild-type (WT) genotype TA6/6 (164, 79.2%), heterozygous genotype TA6/7 (41, 19.8%), and homozygous genotype TA7/7 (2, 1.0%); UGT1A1 ^*6 WT genotype G/G (154, 74.4%), heterozygous genotype G/A (51, 24.6%), and homozygous genotype A/A (2, 1.0%). In the 56 mCRC cases, the incidence of grade 3 and 4 delayed diarrhea and neutropenia in the patients carrying UGT1A1 ^*6 (G/A and A/A) was higher than that in the WT genotype (6/6) (38.9% vs 7.9%,61.1% vs 29.0%, both P<0.05). The incidence of grade 3 and 4 thrombocytopenia in the patients carrying UGT1A1 ^*28 (TA6/7 and TA7/7) was higher than that in the WT genotype (TA6/6) (33.3% vs 2.1%, P<0.05). No significant difference of TTP and chemotherapeutic effect was observed between different genotypes. CONCLUSION: The UGT1A1 ^*6 (G/A and A/A) genotypes increase the risk of grade 3 and 4 delayed diarrhea and neutropenia, and the UGT1A1 ^*28 (TA6/7 and TA7/7) genotypes increase the risk of grade 3 and 4 thrombocytopenia in mCRC patients treated with irinotecan-based chemotherapy.     

Expressions of VEGF,ANG-1,ANG-2 and TSP-1 in cholangiocellular carcinoma and relationship with tumor angiogenesis,differentiation,invasion and metastasis

AIM: To investigate the angiogenesis status,the expression of vascular endothelial growth factor (VEGF),angiopoietin-1 (ANG-1),angiopoietin-2 (ANG-2),thrombospondin-1 (TSP-1) in cholangiocellular carcinoma (CCC) and relationship with tumor angiogenesis,differentiation,invasion and metastasis.METHODS: 33 specimen of surgically resected CCC were investigated.Immunohistochemical staining of CD34,VEGF,ANG-1,ANG-2 and TSP-1 was carried out.RESULTS: The mean MVD was (87.2±52.6)/mm2.VEGF positive expression was found in 75.6% cases;ANG-1 positive expression was observed in 36% cases;ANG-2 positive was detected in 57.6% cases and 45.5% cases exhibited positive TSP-1 expression.VEGF and ANG-2 expressions were found to be associated with significant higher level of MVD (P<0.01 and P<0.05,respectively).TSP-1 expression was found to be associated with significant low level of MVD (P<0.01).Positive TSP-1 expression was also found to be associated with higher level of intrahepatic metastasis (46.7% vs 5.6%,P<0.05).CONCLUSION: Considerable angiogenesis compared to other solid tumors can be observed in CCC.VEGF and ANG-2 might play a proangiogenic role and TSP-1 may play an inhibitory role.Although TSP-1 may increase the intrahepatic metastasis of CCC,neither MVD levels nor the expression of VEGF,ANG-1,or ANG-2 is associated with tumor differentiation,invasion and metastasis.     

Effects of CADM1 overexpression on proliferation and invasion of human gastric carcinoma cell line MKN-45

AIM: To investigate the effects of CADM1 overexpression on proliferation and invasion of human gastric carcinoma cell line MKN-45. METHODS: The protein levels of CADM1 in 3 human gastric carcinoma cell lines were detected by Western blotting. Eukaryotic expression vector pcDNA-CADM1 was constructed and transfected into MKN-45 cells. The MKN-45 cells stably expressing CADM1 were selected by G418 and identified by Western blotting. Furthermore, CCK-8 assay and Boyden chamber were used to analyze the effects of CADM1 overexpression on the prolife ration and invasion of gastric carcinoma cells. Western blotting was also utilized to detect the levels of cell proliferation- and invasion-related proteins. RESULTS: Relative level of CADM1 protein in MKN-45 cells was significantly lower than that in MKN-28 cells and SGC-7901 cells. Additionally, eukaryotic expression vector pcDNA-CADM1 was successfully constructed and MKN-45 cells stably expressing CADM1 were obtained. Compared with non-treatment and pcDNA3.1 groups, the proliferation of MKN-45 cells was obviously inhibited in pcDNA-CADM1 group. The result of Boyden chamber showed that the migrated cell numbers in pcDNA-CADM1 group (52.35±3.89) were significantly lower than that in untreated group (101.53±6.89) and pcDNA3.1 group (98.77±7.03). Compared with non-treatment and pcDNA3.1 groups, the protein level of p21 was significantly up-regulated and protein expression of MMP-2 and MMP-9 was obviously down-regulated. CONCLUSION: Overexpression of CADM1 may markedly inhibit cell proliferation and reduce invasion ability, and thus may be a novel target for treating gastric carcinoma.     

Effects of ambroxol combined with low-dose heparin on production of ICAM-1 and E,P-selectin in acute lung injury

AIM: To study the production of intercellular adhesion molecule-1(ICAM-1), E-selectin and P-selectin in serum, lung tissues and bronchoalveolar lavage fluid(BALF)of acute lung injury(ALI) model and to observe the effects of ambroxol combined with low-dose heparin on the changes of the 3 factors above.METHODS: Twenty-four healthy rabbits were randomly divided into 3 groups: normal saline control group (NC), oleic acid injury group (OA), ambroxol+ heparin treatment group (AH). The rabbit ALI model was induced by oleic acid injection through auricular vein. Partial pressure of O₂ in artery(PaO₂) was analyzed.The concentrations of ICAM-1 and E-selectin were detected by ELISA.The apoptosis index(AI) was measured by TUNEL method.The expression of P-selectin was determined by immunohistochemical method.The ultrastructural changes of the lung tissues were observed under electron microscope, and the lung wet/dry ratio(W/D) was calculated.RESULTS: PaO₂ in AH group and OA group was significantly lower (P<0.01) than that in NC group, and PaO₂ in AH group was significantly higher than that in OA group (P<0.01). The concentrations of ICAM-1 and E-selectin in serum, lung tissues and BALF, and AI and W/D in lung tissues in AH group were higher (P<0.05 or P<0.01) than those in NC group, and was lower than those in OA group (P<0.05 or P<0.01). In NC group, no significant change of the above parameters at all time points was observed (P>0.05). In OA group, PaO₂ was significantly decreased (P<0.01) with the pathological process developed, and the concentrations of ICAM-1 and E-selectin were significantly increased. In AH group, PaO₂ was decreased (P<0.05),and the concentrations of ICAM-1 and E-selectin were increased with the process of ALI developed. The P-selectin expression in lung tissues of OA group was distributed mainly in inflammatory cells, capillary endothelial cells and plasma. From low to high levels, the order was NC group < AH group < OA group in the expression of P-selectin. The most obvious apoptosis was observed in OA group. No apoptosis or occasional positive cells were found in NC group. The apoptotic rate in AH group was significantly reduced compared with that in OA group.CONCLUSION: In ALI induced by OA, ICAM-1, E-selectin and P-selectin are significantly increased and are involved in the occurrence and development of ALI. Ambroxol combined with low-dose heparin reduces the levels of ICAM-1, E-selectin and P-selectin, the pulmonary edema and the lung injury, improves pulmonary functions, and plays an important role in the prevention and treatment of acute lung injury.     

Association between IL-6-572C/G as well as IFNAR1-168G/C and hepatitis B virus infection in populations of Dai and Han ethnicities in Yunnan Province

ATM: To explore the association between IL-6-572C/G (rs1800796) as well as interferon alpha receptor 1 (IFNAR1)-168G/C (rs2257167) and prognosis after hepatitis B virus (HBV) infection in populations of Dai and Han ethnicities in Yunnan Province. METHODS: The blood samples were collected from Dai people and Han people, each nation including 100 healthy controls and 200 infected individuals (100 spontaneous recovery individuals and 100 chronic patients). Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing were used to identify the gene type. RESULTS: In Dai people, no significant difference was found between genetic polymorphism of -572C/G and prognosis after HBV infection. The differences of C and G alleles between spontaneous recovery group and chronic hepatitis B group, and healthy controls and HBV infection group were not statistically significant. Meanwhile, GG and CG genotypes were a vital protective factor for the person who developed into a chronic heptatitis B patient under the G allele dominance mode (GG+CG/CC) (P<0.05). In Han people, no statistically significance for IL-6-572C/G genotype and allele distribution in each group comparisons had been found, as well as the C allele recessive mode and C allele dominance mode. For the above 4 indicators, no statistically significant difference of IFNAR1-168C/G in Dai and Han people had been found.CONCLUSION: The GG+CG genotype of IL-6-572C/G may be a protective factor for the HBV-infected Dai people to develop into chronic hepatitis B patients. However, there is no significant association between the IFNAR1-168G/C polymorphism and prognosis after HBV infection in the 2 ethnicities.