Autophagy and proinflammatory cytokine expression in the intestinal mucosa and mesenteric fat tissue of patients with Crohn's disease

Autofagia e expressão de citocinas pró-inflamatórias na mucosa intestinal e no tecido mesenterial de pacientes com doença de Crohn

BACKGROUND:  Recently, mesenteric fat has been proposed to play a role in the pathophysiology of Crohn's disease (CD), as fat hypertrophy is detected close to the affected intestinal area; however, there are few studies regarding autophagy and creeping fat tissue in CD.

OBJECTIVE:  Evaluate autophagy-related proteins and proinflammatory cytokines in intestinal mucosa and mesenteric fat in patients with CD and controls.

PATIENTS AND METHODS:  Ten patients with CD, eight with non-inflammatory disease who underwent surgery, and eight with normal ileocolonoscopy were studied. The expression of LC3-II, TNF-α and IL-23 was determined by immunoblot of protein extracts. In addition, total RNA of LC3 and Atg16-L1 were determined using RT-PCR.

RESULTS:  The expression of LC3-II was significantly lower in the mesenteric tissue of CD when compared to controls (p < 0.05). In contrast, the intestinal mucosa of the CD group had higher levels of LC3-II (p < 0.05). However, mRNA expression of autophagy-related proteins was similar when compared to mesenteric fat groups. TNF-α and IL-23 expressions were higher in intestinal mucosa of CD than in control (p < 0.05).

CONCLUSION:  These findings suggest a defect in the autophagic activity of the creeping fat tissue in CD, which could be involved with the maintenance of the inflammatory process in the intestinal mucosa.

Crohn's disease; Inflammatory bowel diseases; Autophagy; Cytokines; Mesenteric fat