Targeting NCAPD2 as a Therapeutic Strategy for Crohn's Disease: Implications for Autophagy and Inflammation.

Background: Our earlier studies identified that non-SMC condensin I complex subunit D2 (NCAPD2) induces inflammation through the IKK/NF-κB pathway in ulcerative colitis. However, its role in the development of Crohn's disease (CD) and the specific molecular mechanism still need to be further studied.

Methods: NCAPD2 expression in clinical ileal CD mucosa vs normal mucosa was examined, alongside its correlation with CD patients' clinical characteristics via their medical records. The biological function and molecular mechanism of NCAPD2 in CD were explored using a 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced CD mouse model, along with immunofluorescence, western blot, quantitative real-time PCR, immunohistochemistry, hematoxylin and eosin staining, and cell functional analysis.

Results: NCAPD2 was overexpressed in CD tissues and significantly correlated with disease activity in CD patients (P = .016). In a TNBS-induced CD mouse model, NCAPD2 knockdown inhibited the development of TNBS-induced intestinal inflammation in mice. In addition, we found that NCAPD2 inhibited autophagy. Mechanistically, NCAPD2 promoted the phosphorylation of mammalian target of the rapamycin (mTOR) and its direct effector S6K and downregulated the expression of autophagy-related proteins Beclin1, LC3II, and Atg5. In addition, NCAPD2 activates the NF-κB signaling pathway, and the downstream inflammatory factors are continuously released, leading to the persistence of inflammation.

Conclusions: Our results show that NCAPD2 suppresses autophagy and worsens intestinal inflammation by modulating mTOR signaling and impacting the NF-κB pathway, suggesting a critical role in CD progression. Targeting NCAPD2 could be a promising therapeutic approach to stop CD advancement.