Reprogramming of palmitic acid induced by dephosphorylation of ACOX1 promotes ß-catenin palmitoylation to drive colorectal cancer progression.

Metabolic reprogramming is a hallmark of cancer. However, it is not well known how metabolism affects cancer progression. We identified that metabolic enzyme acyl-CoA oxidase 1 (ACOX1) suppresses colorectal cancer (CRC) progression by regulating palmitic acid (PA) reprogramming. ACOX1 is highly downregulated in CRC, which predicts poor clinical outcome in CRC patients. Functionally, ACOX1 depletion promotes CRC cell proliferation in vitro and colorectal tumorigenesis in mouse models, whereas ACOX1 overexpression inhibits patient-derived xenograft growth. Mechanistically, DUSP14 dephosphorylates ACOX1 at serine 26, promoting its polyubiquitination and proteasomal degradation, thereby leading to an increase of the ACOX1 substrate PA. Accumulated PA promotes ß-catenin cysteine 466 palmitoylation, which inhibits CK1- and GSK3-directed phosphorylation of ß-catenin and subsequent ß-Trcp-mediated proteasomal degradation. In return, stabilized ß-catenin directly represses ACOX1 transcription and indirectly activates DUSP14 transcription by upregulating c-Myc, a typical target of ß-catenin. Finally, we confirmed that the DUSP14-ACOX1-PA-ß-catenin axis is dysregulated in clinical CRC samples. Together, these results identify ACOX1 as a tumor suppressor, the downregulation of which increases PA-mediated ß-catenin palmitoylation and stabilization and hyperactivates ß-catenin signaling thus promoting CRC progression. Particularly, targeting ß-catenin palmitoylation by 2-bromopalmitate (2-BP) can efficiently inhibit ß-catenin-dependent tumor growth in vivo, and pharmacological inhibition of DUSP14-ACOX1-ß-catenin axis by Nu-7441 reduced the viability of CRC cells. Our results reveal an unexpected role of PA reprogramming induced by dephosphorylation of ACOX1 in activating ß-catenin signaling and promoting cancer progression, and propose the inhibition of the dephosphorylation of ACOX1 by DUSP14 or ß-catenin palmitoylation as a viable option for CRC treatment.

Mesenteric Adipose Tissue-Derived Klebsiella variicola Disrupts Intestinal Barrier and Promotes Colitis by Type VI Secretion System.

Mesenteric adipose tissue (MAT) in Crohn's disease (CD) is associated with transmural inflammation. Extended mesenteric excision can reduce surgical recurrence and improve long-term outcomes, indicating that MAT plays an important role in the pathogenesis of CD. Bacterial translocation has been reported to occur in the MAT of patients with CD (CD-MAT), but the mechanisms by which translocated bacteria lead to intestinal colitis remain unclear. Here it is shown that members of Enterobacteriaceae are highly enriched in CD-MAT compared with non-CD controls. Viable Klebsiella variicola in Enterobacteriaceae is isolated exclusively in CD-MAT and can induce a pro-inflammatory response in vitro and exacerbates colitis both in dextran sulfate sodium (DSS)-induced colitis mice model and IL-10-/- spontaneous colitis mice model. Mechanistically, active type VI secretion system (T6SS) is identified in the genome of K. variicola, which can impair the intestinal barrier by inhibiting the zonula occludens (ZO-1) expression. Dysfunction of T6SS by CRISPR interference system alleviates the inhibitory effect of K. variicola on ZO-1 expression and attenuated colitis in mice. Overall, these findings demonstrate that a novel colitis-promoting bacteria exist in the mesenteric adipose tissue of CD, opening a new therapeutic avenue for colitis management.

Microbiota in mesenteric adipose tissue from Crohn's disease promote colitis in mice.

BACKGROUND: Mesenteric adipose tissue (mAT) hyperplasia, known as creeping fat is a pathologic characteristic of Crohn's disease (CD). The reserve of creeping fat in surgery is associated with poor prognosis of CD patients, but the mechanism remains unknown. METHODS: Mesenteric microbiome, metabolome, and host transcriptome were characterized using a cohort of 48 patients with CD and 16 non-CD controls. Multidimensional data including 16S ribosomal RNA gene sequencing (16S rRNA), host RNA sequencing, and metabolome were integrated to reveal network interaction. Mesenteric resident bacteria were isolated from mAT and functionally investigated both in the dextran sulfate sodium (DSS) model and in the Il10 gene-deficient (Il10-/-) mouse colitis model to validate their pro-inflammatory roles. RESULTS: Mesenteric microbiota contributed to aberrant metabolites production and transcripts in mATs from patients with CD. The presence of mAT resident microbiota was associated with the development of CD. Achromobacter pulmonis (A. pulmonis) isolated from CD mAT could translocate to mAT and exacerbate both DSS-induced and Il10 gene-deficient (Il10-/-) spontaneous colitis in mice. The levels of A. pulmonis in both mAT and mucous layer from CD patients were higher compared to those from the non-CD group. CONCLUSIONS: This study suggests that the mesenteric microbiota from patients with CD sculpt a detrimental microenvironment and promote intestinal inflammation. Video abstract.

Measuring self-stigma of mental illness in China and its implications for recovery.

This study translated and validated the Chinese Version of the Self-stigma of Mental Illness Scale (CSSMIS), which may be used to measure self-stigma of mental health consumers in China. We also examined its correlation with self-esteem, self-efficacy and psychosocial treatment compliance. A cross-sectional observational study was implemented. Some 51 males and 57 females who suffered from severe mental illness were recruited from psychiatric settings in Hong Kong. They were required to complete the Chinese Version of the Self-stigma of Mental Illness Scale, the Rosenberg Self-esteem Scale and the Self-efficacy Scale. Their level of compliance during psychosocial treatment and their demographic information were recorded by their case managers. Exploratory factor analysis revealed two homologous factors for the four subscales of the CSSMIS. Factor 1 was related to the negative beliefs and consequences of having mental disorders, whereas Factor 2 was related to positive beliefs. The perceived stigma subscale and the three self-stigma subscales were strongly inter-correlated. Significant correlations were also found between almost all subscales of the CSSMIS and the remaining scales. The psychometric properties of the CSSMIS are statistically acceptable. The results also suggest that stigma played a detrimental role in undermining self-esteem, self-efficacy and psychosocial treatment compliance. Implications for recovery of mental health consumers are discussed.