NCA-029

Inflammatory bowel disease (IBD) is an autoimmune disorder, and despite the availability of multiple Food and Drug Administration (FDA)-approved therapies, current clinical needs remain unmet. In this study, we find that caseinolytic protease P (ClpP) expression is markedly upregulated in colonic tissues from IBD patients and preclinical colitis models, particularly in CD4⁺ T cells. Subsequently, a small molecule, namely NCA029, is identified, and its therapeutic efficacy and mechanism of action are investigated both in vitro and in vivo. Oral administration of NCA029 significantly alleviates symptoms associated with dextran sulfate sodium (DSS)-induced acute and interleukin (IL)-10-deficient chronic colitis. The effects of NCA029 are largely dependent on its selective binding to ClpP in CD4⁺ T cells, thereby mitigating inflammation and restoring intestinal barrier function. Furthermore, NCA029 activates ClpP to promote oxidative phosphorylation (OXPHOS) inhibition and concomitantly modulate the Th17/Treg balance. In conclusion, our study develops a therapeutic strategy for treating IBD through the chemical activation of ClpP.

Based on the founding member of imipridones, ONC201, a class of dehydrogenated imipridone derivatives was designed, synthesized, and evaluated in a series of biochemical and biological assays as human caseinolytic protease P (hClpP) activators. Mechanism studies for one of the most potent compounds, XT6, indicated that it can potently bind to both recombinant and cellular hClpP, effectively promote the formation of hClpP tetradecamer, efficiently induce the degradation of hClpP substrates, robustly upregulate the expression of ATF4, and strongly inhibit the phosphorylations of AKT and ERK. More importantly, XT6 exhibited a promising pharmacokinetic profile in rats and could penetrate the blood brain barrier. It showed highly potent in vivo antitumor activity in a MIAPACA2 cell line derived pancreatic cancer model in BALB/c nude mice.