RESUMEN
Objective To investigate the expressions of 5-lipoxygenase (5-LOX) protein and mRNA in colon mucosa of ulcerative colitis (UC) and to analyze its correlation with endoscopic and histological grading. Methods The biopsies from 32 UC patients and 26 healthy controls were collected, and the expressions of 5-LOX mRNA and protein in colonic mucosa was determined by real-time fluorescent quantitative reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry assay, respectively. The endoscopic and histological grading of 32 UC patients were also recorded. Results According to endoscopic grading, there were 10 cases of grade Ⅰ , 19 of grade Ⅱ and 3 of grade Ⅲ in 32 UC patients, and there were 19 cases of grade Ⅰ , 9 of grade Ⅱ and 4 of grade Ⅲ according to histological grading. The expressions of 5-LOX mRNA and protein in UC patients were significantly higher than those in healthy controls (P ＜0. 05 ). The rate of 5-LOX protein expression increased with endoscopic and histological grades, which was also positively correlated with endoscopic grades ( P ＜ 0. 05 ), but not with histological grades ( P ＞0. 05 ). Conclusion The expressions of 5-LOX mRNA and protein in colon mucosa from UC patients might be a marker for disease activity. 5-LOX may play a pivotal role in inflammation of UC and be a target site for treatment.
RESUMEN
Objective To investigate the expressions of cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) in colonic mucosa of patients with ulcerative colitis (UC)and to analyze the relationship between them. Methods The specimens of colonic mucosa from 32 UC patients were graded according to endoscopic and histological grading standards, and specimens of colonic mucosa from 26 healthy controls were also collected. The expressions of COX-2 and 5-LOX mRNA and protein in colonic mucosa were determined using real-time fluorescent quantitative reverse transcription polymerase chain reaction(RT-PCR) and immunohistochemistry. The correlation between COX-2 and 5-LOX was analyzed. Results For UC patients,10 were class 1, 19 class 2 and 3 class 3 according to endoscopic grading, whereas 19 were class Ⅰ , 9 class Ⅱ and 4 class Ⅲ according to histological grading. The expressions of COX-2 and 5-LOX mRNA in active UC patients were 81. 25% and 53.13%, respectively, and were 11.54% and 19. 23% in healthy controls, respectively, with significant differences between the two groups (all P values＜0.01). The positive expressions of COX2 and 5-LOX increased in accordance with increasing of endoscopic grading and histological grading.The levels of COX-2 and 5-LOX were 20. 08±1.17 and 37.83 ±1.48 in colonic mucosa tissues of UC patients, respectively, and 48.42 ± 1.69 and 11.28 ± 1.62 in healthy controls, respectively. There was significant difference between the two groups (all P values＜0.05). A good positive correlation was found between COX-2 and 5-LOX. Conclusions The expressions of COX-2 is closely related to 5-LOX in UC patients. Both may play a pivotal role in inflammation of UC.