Gut最新文献

Background: The microbiota is emerging as a key factor in the predisposition to insulin resistance and obesity.

Objective: To understand the interplay among gut microbiota and insulin sensitivity in multiple tissues.

Design: Integrative multiomics and multitissue approach across six studies, combining euglycaemic clamp measurements (used in four of the six studies) with other measurements of glucose metabolism and insulin resistance (glycated haemoglobin (HbA1c) and fasting glucose).

Results: Several genera and species from the Proteobacteria phylum were consistently negatively associated with insulin sensitivity in four studies (ADIPOINST, n=15; IRONMET, n=121, FLORINASH, n=67 and FLOROMIDIA, n=24). Transcriptomic analysis of the jejunum, ileum and colon revealed T cell-related signatures positively linked to insulin sensitivity. Proteobacteria in the ileum and colon were positively associated with HbA1c but negatively with the number of T cells. Jejunal deoxycholic acid was negatively associated with insulin sensitivity. Transcriptomics of subcutaneous adipose tissue (ADIPOMIT, n=740) and visceral adipose tissue (VAT) (ADIPOINST, n=29) revealed T cell-related signatures linked to HbA1c and insulin sensitivity, respectively. VAT Proteobacteria were negatively associated with insulin sensitivity. Multiomics and multitissue integration in the ADIPOINST and FLORINASH studies linked faecal Proteobacteria with jejunal and liver deoxycholic acid, as well as jejunal, VAT and liver transcriptomic signatures involved in the actin cytoskeleton, insulin and T cell signalling. Fasting glucose was consistently linked to interferon-induced genes and antiviral responses in the intestine and VAT. Studies in Drosophila melanogaster validated these human insulin sensitivity-associated changes.

Conclusion: These data provide comprehensive insights into the microbiome-gut-adipose-liver axis and its impact on systemic insulin action, suggesting potential therapeutic targets.Cite Now.

Background: PARP inhibitors (PARPi) have been licensed for the maintenance therapy of patients with metastatic pancreatic cancer carrying pathogenic germline BRCA1/2 mutations. However, mutations in BRCA1/2 are notably rare in pancreatic cancer.

Objective: There is a significant unmet clinical need to broaden the utility of PARPi.

Design: RNA sequencing was performed to screen potential targets for PARPi sensitivity. The synthetic lethal effects were verified in patient-derived xenograft (PDX), xenograft and patient-derived organoid models. Mechanisms were explored via LC‒MS/MS, coimmunoprecipitation, laser microirradiation, immunofluorescence, the homologous recombination (HR) or non-homologous end joining (NHEJ) reporter system, in situ proximity ligation assay and live-cell time-lapse imaging analyses.

Results: Targeting protein for Xenopus kinesin-like protein 2 (TPX2) is an exploitable vulnerability. TPX2 was downregulated in PDX models sensitive to PARPi, and TPX2 inhibition conferred synthetic lethality to PARPi both in vitro and in vivo. Mechanistically, TPX2 functions in a cell cycle-dependent manner. In the S/G2 phase, ATM-mediated TPX2 S634 phosphorylation promotes BRCA1 recruitment to double-strand breaks (DSBs) for HR repair, whereas non-phosphorylated TPX2 interacts with 53BP1 to recruit it for NHEJ. The balance between phosphorylated and non-phosphorylated TPX2 determines the DSB repair pathway choice. During mitosis, TPX2 phosphorylation enhances Aurora A activity, promoting mitotic progression and chromosomal stability. Targeting TPX2 S634 phosphorylation with a cell-penetrating peptide causes genomic instability and mitotic catastrophe and enhances PARPi sensitivity. Additionally, the inhibition of TPX2 or S634 phosphorylation combined with gemcitabine further sensitised pancreatic cancer to PARPi.

Conclusions: Our findings revealed the dual-functional significance of TPX2 in controlling DNA DSB repair pathway choice and mitotic progression, suggesting a potential therapeutic strategy involving PARPi for patients with pancreatic cancer.

Background: Hepatocellular carcinoma (HCC) is plagued by failures across the cancer care continuum, leading to frequent late-stage diagnoses and high mortality. We evaluated the effectiveness of mailed outreach invitations plus patient navigation to promote HCC screening process completion in patients with cirrhosis.

Methods: Between April 2018 and September 2021, we conducted a multicentre pragmatic randomised clinical trial comparing mailed outreach plus patient navigation for HCC screening (n=1436) versus usual care with visit-based screening (n=1436) among patients with cirrhosis at three US health systems. Our primary outcome was screening process completion over a 36-month period, and our secondary outcome was the proportion of time covered (PTC) by screening. All patients were included in intention-to-screen analyses.

Results: All 2872 participants (median age 61.3 years; 32.3% women) were included in intention-to-screen analyses. Screening process completion was observed in 6.6% (95% CI: 5.3% to 7.9%) of patients randomised to outreach and 3.3% (95% CI: 2.4% to 4.3%) of those randomised to usual care (OR 2.05, 95% CI: 1.44 to 2.92). The intervention increased HCC screening process completion across most subgroups including age, sex, race and ethnicity, Child-Turcotte-Pugh class and health system. PTC was also significantly higher in the outreach arm than usual care (mean 37.5% vs 28.2%; RR 1.33, 95% CI: 1.31 to 1.35). Despite screening underuse, most HCC in both arms were detected at an early stage.

Conclusion: Mailed outreach plus navigation significantly increased HCC screening process completion versus usual care in patients with cirrhosis, with a consistent effect across most examined subgroups. However, screening completion remained suboptimal in both arms, underscoring a need for more intensive interventions.

Trial registration number: NCT02582918.