Caspase 5c Amplifies Wnt via APC Cleavage to Promote Intestinal Homeostasis

Why It Matters

By linking an inflammatory caspase to Wnt activation, the findings uncover a new axis that could be targeted to boost intestinal repair or curb tumorigenesis, reshaping strategies in gastro‑intestinal disease management.

Key Takeaways

• CASP5c cleaves APC, releasing β‑catenin for Wnt activation
• Enhanced Wnt signaling drives intestinal stem‑cell proliferation and repair
• CASP5c deficiency leads to impaired crypt regeneration and inflammation
• Targeting CASP5c‑APC interaction offers a potential IBD/CRC therapy

Pulse Analysis

The discovery that caspase 5c (CASP5c) can directly cleave the adenomatous polyposis coli (APC) protein adds a surprising layer to our understanding of intestinal signaling networks. APC traditionally functions as a gatekeeper of the Wnt pathway by promoting β‑catenin degradation. When CASP5c truncates APC, the destruction complex destabilizes, allowing β‑catenin to accumulate and activate transcriptional programs that sustain stem‑cell niches in the crypt. This mechanistic insight bridges innate immune sensing with epithelial regeneration, suggesting that inflammatory cues can be co‑opted for tissue repair.

Experimental validation across multiple platforms strengthens the claim. Human colonic organoids engineered to overexpress CASP5c displayed heightened Wnt target gene expression, increased Lgr5⁺ stem‑cell markers, and accelerated wound closure in live‑cell imaging. Conversely, CRISPR‑mediated CASP5c knockout organoids and Casp11‑deficient mice showed reduced β‑catenin ubiquitination, blunted crypt budding, and heightened susceptibility to dextran‑sodium sulfate‑induced colitis. Integrative analysis of single‑cell RNA‑seq datasets (SCP259, Gut Cell Atlas) confirmed that CASP5c is enriched in Paneth‑like and transit‑amplifying cells, positioning it as a spatially restricted modulator of the niche.

Clinically, the CASP5c‑APC axis opens new therapeutic avenues. Modulating CASP5c activity could enhance mucosal healing in inflammatory bowel disease without the oncogenic risk associated with broad Wnt agonists. Conversely, inhibiting CASP5c‑mediated APC cleavage might restore APC function in early colorectal neoplasia, offering a precision‑medicine approach. Ongoing translational work will need to balance the dual roles of CASP5c in inflammation and regeneration, but the study provides a compelling blueprint for drug development targeting this newly defined pathway.