RESUMO
Total retocolectomy with ileal pouch-anal anastomosis (IPAA) is the surgery of choice for patients with ulcerative colitis (UC) that are refractory to clinical treatment. Pouchitis is one of the most common complications after this procedure. Defects in autophagy have been reported in inflammatory bowel diseases. However, there are no studies on the IP. Therefore, we studied markers for autophagy in the IP mucosa of UC and FAP patients comparing them to controls with a normal distal ileum. Sixteen patients with IP in "J" shape, asymptomatic and with endoscopically normal IP were evaluated. The control group consisted of eight patients with normal colonoscopy. There was a significant decrease in the transcriptional levels of ATG5, MAP1LC3A and BAX in the FAP group. There was also a decrease in the protein level of Beclin-1 in the UC and FAP compared to the control group. Although the LC3II levels by immunoblot were higher in the UC group, LC3/p62 co-localization were lower in the immunofluorescence analysis in the UC and FAP compared to the control group. Corroborating these results, there was an increase of p62 by immunoblot in the UC group. These findings indicated a modulation of macroautophagy markers in the IP, which may explain the mucosa inflammation predisposition.
Assuntos
Polipose Adenomatosa do Colo/metabolismo , Autofagia , Colite Ulcerativa/metabolismo , Mucosa Intestinal/metabolismo , Pouchite/metabolismo , Adulto , Idoso , Proteína 5 Relacionada à Autofagia/metabolismo , Biomarcadores/metabolismo , Bolsas Cólicas/patologia , Feminino , Humanos , Masculino , Proteínas Associadas aos Microtúbulos/metabolismo , Pessoa de Meia-Idade , Proctocolectomia Restauradora/efeitos adversos , Proctocolectomia Restauradora/métodos , Proteínas de Ligação a RNA/metabolismoRESUMO
Pouchitis after total rectocolectomy is the most common complication of ulcerative colitis (UC). The immunological mechanisms involved in the genesis of pouchitis are unclear. Therefore, we evaluated the inflammatory activity in normal ileal pouch mucosa by determining signal transducers and activators of transcription (STAT-1) activation and cytokine expression in patients operated for UC and familial adenomatous polyposis (FAP). Eighteen asymptomatic patients, who underwent total rectocolectomy and J pouch, were evaluated: nine with UC and nine with FAP. The activation of STAT-1 and cytokine expression were determined by immunoblot of total protein extracts from pouch mucosal biopsies. The absence of pouchitis was assessed by clinical, histological and endoscopic parameters, according to the Pouchitis Disease Activity Index. The patients were not receiving any medication. Analysis of variance (anova) and Tukey-Kramer's test were applied. The local ethical committee approved the study and informed consent was signed by all participants. STAT-1 activation was increased in UC when compared to FAP and controls (P < 0.05). Higher levels of interferon (IFN)-gamma expression were observed in UC patients when compared to the control group (P < 0.05), but were similar to FAP. In contrast, cytokine signalling (SOCS-3) and interleukin (IL)-10 expression were similar in all groups (P > 0.05). These findings could explain the higher susceptibility to this inflammatory complication in UC when compared to FAP. A tendency towards increased levels of IFN-gamma and STAT-1 in patients with UC, even without clinical and endoscopic evidence of pouchitis, was observed; studying inflammatory activity in asymptomatic ileal pouches may help understanding of the pathogenesis of pouchitis.
Assuntos
Polipose Adenomatosa do Colo/imunologia , Colite Ulcerativa/imunologia , Regulação da Expressão Gênica/imunologia , Íleo/imunologia , Interferon gama/imunologia , Mucosa Intestinal/imunologia , Fator de Transcrição STAT1/imunologia , Polipose Adenomatosa do Colo/metabolismo , Polipose Adenomatosa do Colo/patologia , Polipose Adenomatosa do Colo/cirurgia , Adulto , Colite Ulcerativa/metabolismo , Colite Ulcerativa/patologia , Colite Ulcerativa/cirurgia , Feminino , Humanos , Íleo/metabolismo , Íleo/patologia , Íleo/cirurgia , Interferon gama/biossíntese , Interleucina-10/biossíntese , Interleucina-10/imunologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Mucosa Intestinal/cirurgia , Masculino , Pessoa de Meia-Idade , Pouchite/etiologia , Pouchite/imunologia , Pouchite/metabolismo , Pouchite/patologia , Fator de Transcrição STAT1/metabolismo , Proteína 3 Supressora da Sinalização de Citocinas , Proteínas Supressoras da Sinalização de Citocina/biossíntese , Proteínas Supressoras da Sinalização de Citocina/imunologiaRESUMO
BACKGROUND: Pouchitis after total rectocolectomy is among the most common complications of patients with ulcerative colitis (UC). However, its frequency is quite rare in patients with familial adenomatous polyposis (FAP). We evaluated the inflammatory and pro-apoptotic activity in endoscopically normal mucosa of the ileal pouch in patients with UC and FAP. METHODS: Twenty patients (10 with UC and 10 with FAP) with "J" pouch after total proctocolectomy were studied as were 10 normal controls. Biopsies were obtained from the mucosa of the pouch of UC and FAP patients and from the normal ileum of controls. The expression levels of TNF-alpha, IL-1beta, IL-6, IL-8 and phospho-BAD were determined by immunoblotting. Activated NFkappaB was evaluated by immuno-precipitation and immunoblotting for IkappaB kinase beta. RESULTS: Patients with UC had higher levels of IL-1beta, IL-6, IL-8 and TNF-alpha than patients with FAP. The level of TNF-alpha was higher in patients with UC than in patients with FAP; both patient groups had TNF-alpha levels higher than controls. Activation of NFkappaB was similar in all three groups. The expression of phospho-BAD was significantly lower in patients with FAP than in patients with UC. CONCLUSIONS: As compared with patients with FAP, patients with UC presented increased levels of some pro-inflammatory cytokines, even in the absence of clinical or endoscopic signs of pouchitis. Patients with FAP presented lower levels of pro-inflammatory proteins and of phospho-BAD. These findings may explain the higher rates of progression to pouchitis in UC patients, which could correlate with mucosal atrophy that occurs in inflamed tissue.