The Study Of Expression Of NAT1, CXCL9, BPI, And HLA-DQB1 In Patients With Ulcerative Colitis

Object The gene expression profiles of peripheral blood mononuclear cells from patients with ulcerative colitis have been investigated by us using the oligonucleotide microarrays. Comparative analysis revealed that 270 genes were differentially expressed between UC and controls, of which 206 genes were up-regulated whereas 64 were down-regulated. To validate the microarray data, Semiquantitative Reverse Transcriptase Polymerase Chain Reaction (Semiquantitative RT-PCR) was carried out to test the relative expression levels of three up-regulated genes (BPI,NAT1,CXCL9) and one down gene (HLA-DQB1). Through analyzing the relationship of clinic regulated pathology and expression levels of those four interesting genes, may not only support the result of microarray study, but also further provides us some information about the pathogenesis of UC and the molecular markers for diagnosis and therapy.Method Blood samples were collected at the First Affiliated Hospital of Kunming Medical University from a total of 21 UC patients (10 females,11 males, mean age 43.10±1.717 y; range 30-63 y) and 21 healthy individuals (10 females,11 males, mean age 43.67±11.83 y; range 22-71 y), from Oct,2008 to May,2009. The relative expression of the BPI, CXCL9, NAT1, and HLA-DQB1 in patients with UC was detected through Semiquantitative RT-PCR. Statistical analysis was performed using SPSS 16.0 stat software and analyzes the expression of the four genes and the relativity between the clinical pathological factors.Results The expression level of NAT1, BPI and CXCL9 in patients with UC (0.75±0.47,0.40±0.51,0.85±0.43) is higher than normal groups (0.31±0.24, 0.11±0.60,0.40±0.19), there are significant statistical difference (P＜0.05), and are consistent with the microarray results (NAT1 is 2.29 times than normal, BPI is 4.99 times, CXCL9 is 2.09 times), HLA-DQB1 is up-regulated in the UC group than normal groups, there is significant statistical difference (P＜0.05), and isn't consistent with the microarray results (HLA-DQB1 is 0.21 times than normal, down-regulated). The expression of BPI, CXCL9, NAT1 and HLA-DQB1 genes isn't related to sex, age and lesion degree (P> 0.05).Conclusion1. The high expression of BPI in patients with UC is suggesting that UC may be infected by gram-negative bacterial.2. The high expression of CXCL9 in patients with UC is related to the imbalance between pro-inflammatory cytokines and anti-inflammatory cytokines. CXCL9 and its receptor as the control target, prevented the recruitment of inflammatory cells to the sites of inflammation by activating or antagonizing the signaling function of the chemokines receptor, may be a new strategy for treatment of UC.3. The difference of NAT1 activity in human may be associated with the efficacy of amino acid preparations.4. The abnormal expression of HLA-DQB1 in patients with UC suggested that genetic factors is important in the pathogenesis of UC.5. The expression of BPI, NAT1, CXCL9 in patients with UC is consistent with the microarray results, which proved that the microarray is relatively reliable. However, the expression of HLA-DQB1 in patients with UC isn't consistent with the microarray result, there may be related to many factors, such as gene polymorphism, the small cases, the different groups and (or) race.