Introduction

Acute pancreatitis (AP) is an acute inflammatory autodigestive disorder triggered by dysfunction of pancreatic exocrine activity and represents the most common gastrointestinal emergency in clinical practice. Global data indicate an annual incidence rate of 33.74 per 100,000 population and a mortality rate of 1.16 per 100,000. Despite ongoing optimization of therapeutic strategies, current clinical management primarily relies on supportive care and surgery. Hypertriglyceridemia (HTG) is the second leading etiological factor for AP, accounting for 10.36% of cases. Compared to other causes, HTG-associated acute pancreatitis (HTG-AP) exhibits higher recurrence rates and more severe complications (e.g., pancreatic necrosis and renal insufficiency). With the rising prevalence of HTG, the disease burden of HTG-AP is increasing, yet its specific pathogenic mechanisms remain unclear.

Aims & Methods

This study integrated whole-genome sequencing (WGS) and next-generation sequencing (NGS) to screen for shared mutations in the exonic regions of 5 HTG-AP family members. Candidate genes were identified based on MutationTaster classification and CADD scores. A mouse model carrying the PDLIM2 gene rs145349678 mutation was constructed using CRISPR/Cas9 technology, and an HTG-AP animal model was established. Pancreatic and hepatic histopathology (HE staining) and serological markers (TG, lipase, amylase, IL-6) were analyzed to evaluate the impact of the mutation on pancreatitis severity and hepatic lipid deposition.

Results

A clinical HTG-AP family was identified, with all 5 members exhibiting hypertriglyceridemia, including 2 cases of recurrent pancreatitis. WGS revealed 278 mutation sites across 10 chromosomes (involving 23 genes) in the family, and NGS validation narrowed these to 7 candidate loci. The PDLIM2 rs145349678 mutation (NM_001368120.1:exon9:c.C1055T:p.A352V), located within the LIM domain (which mediates protein localization and signaling transduction), was selected as the target due to cross-species conservation. Experimental results demonstrated that HTG-AP mice with the PDLIM2 mutation exhibited significantly aggravated pancreatic pathological damage (edema, hemorrhage, and inflammatory cell infiltration; *P* < 0.05), elevated serological markers (TG: 2.3 ± 0.4 vs. 1.5 ± 0.3 mmol/L; lipase: 520 ± 68 vs. 320 ± 45 U/L; IL-6: 48.2 ± 6.1 vs. 28.5 ± 4.3 pg/mL; *P* < 0.01 for all), and a 2.3-fold increase in hepatic lipid deposition (*P* < 0.001) compared to controls.

Conclusion

The PDLIM2 rs145349678 mutation exacerbates inflammatory responses and hepatic lipid accumulation in HTG-AP by modulating lipid metabolism. This finding provides new insights into the pathogenesis of HTG-AP and potential therapeutic targets.

Introduction

Inflammatory bowel disease (IBD) is a growing global health problem with increasing prevalence. Current therapeutic strategies for IBD are mainly aimed at modulating the dysregulated immune activity in the intestinal mucosa. Targeting the JAK/STAT signalling pathway has been shown to be highly effective in ulcerative colitis, but not in Crohn's disease (CD), where efficacy was found to be insufficient in the initiation phase of a clinical trial [1]. Failure of the therapeutic response in Crohn’s disease may be influenced by the unique immune microenvironments in the small and large intestine and their characteristic cytokine profiles and immune cell compositions.

Aims & Methods

To gain deeper insight into region-specific efficacy in the inflamed ileum versus colon, this study investigates the immunomodulatory effects of filgotinib, a Jak1 inhibitor, using precision-cut intestinal slices (PCIS) from patients with Crohn's diseases. PCIS are viable, ultra-thin human tissue slices that retain the original intestinal architecture ex vivo and contain important cell types, including resident immune cells.
PCIS were prepared from resected ileal and colonic tissue of CD patients. The slices were cultured ex vivo and stimulated with concanavalin A or anti-CD3/CD28 antibodies to induce T cell-driven inflammatory responses. Filgotinib (1-100 µM) was applied to assess the immunomodulatory effects of JAK1 inhibition following Concanavalin A preactivation. To exclude treatment-related toxicity, cellular integrity was evaluated using an LDH release assay. Tissue morphology was examined by H&E staining and immunofluorescence. The immune response was assessed by multiplex ELISA of 20 cytokines.

Results

After filgotinib treatment, primary tissue slices from the ileum and colon of CD patients remained viable. Regional morphological characteristics of ileum and colon tissue were preserved after ex vivo cultivation, with prominent villi and smaller crypts in the ileum, and larger, more frequent crypts and flattened villi in the colon. Compared to non-CD tissue slices, Crohn’s disease-related changes, such as immune cell accumulation, were also observed in CD tissue slices ex vivo. Upon T cell-specific stimulation with anti-CD3/CD28 antibodies, region-specific immune reactivity was observed. Colonic PCIS showed an increased release of IL-2 (~3-fold), IL-10 (~2‑fold) and TRAIL (~4-fold) compared to ileal PCIS, indicating a stronger involvement of Th and regulatory T cells in the colon. In contrast, ileal PCIS showed higher levels of MIP-3α (2-fold) and granzyme A (~8-fold) after stimulation, suggesting increased cytotoxic T cell activity in this region. Filgotinib treatment showed region-specific differences in its ability to modulate cytokine release in PCIS of CD patients. In colonic PCIS, filgotinib reduced the induced secretion of Th17-associated cytokines such as IL-17F and IL-22 by up to 95%, whereas in ileal PCIS it showed no effect on the same cytokines.

Conclusion

In conclusion, filgotinib exhibited more potent anti‑inflammatory effect on Th17 cells in the colon, and a markedly reduced efficacy in the ileum. This study demonstrates for the first time that precision-cut intestinal slices can be used to predict region-specific drug response in inflamed intestinal tissue ex vivo, underscoring the critical importance of region-specific immune profiling in IBD and highlight the limited efficacy of JAK1 inhibition in ileum. This ex vivo, patient-derived model represents a valuable platform for evaluating localised treatment efficacy and advancing personalised therapeutic strategies in IBD.

References

[1] Rogler G. Efficacy of JAK inhibitors in Crohn's Disease. J Crohns Colitis. 2020 Aug 1;14(Supplement_2):S746-S754. doi: 10.1093/ecco-jcc/jjz186

Introduction

Microplastic particles (MPs), defined as plastic fragments smaller than 5 mm, are pervasive pollutants that accumulate in ecosystems and the human food chain (1). Literature points at various health risks, including the induction of carcinogenesis (2). Emerging evidence from animal models (3) suggests that MPs may influence the gut microbiome, but the impact on the human gut microbiome remains poorly understood.

Aims & Methods

This study aimed to evaluate how various MP types influence gut microbial composition and metabolism using an ex vivo bioreactor model, with a focus on exploring potential carcinogenic effects arising from MP–microbiome interactions.
Stool samples from healthy donors were used to inoculate bioreactor cultures, which were maintained under anaerobic conditions for five days with daily nutrient feeding. These cultures were exposed to five common MP types—polystyrene (PS), polypropylene (PP), low-density polyethylene (LDPE), poly(methyl methacrylate) (PMMA), and polyethylene terephthalate (PET)—at concentrations mimicking both estimated human exposure (4) and higher doses to assess dose-dependence. Cell viability and total bacterial counts, as well as culture pH, were measured throughout the experiment. To further explore potential microbiome and metabolic alterations, 16S rRNA gene sequencing and targeted metabolomics were performed.

Results

MP exposure did not lead to significant changes in total or viable bacterial cell counts. However, MP-treated cultures exhibited a consistent and significant decrease in pH compared to controls, suggesting changes in microbial metabolic activity. Microbiome sequencing revealed plastic-type-dependent alterations in microbial composition, with certain bacterial taxa increasing or decreasing in abundance depending on the MP type. These shifts occurred across multiple genera within diverse families, including Lachnospiraceae, Oscillospiraceae, Enterobacteriaceae, and Ruminococcaceae, with the majority of changes occurring withing the phylum Bacillota. These compositional changes were accompanied by shifts in the metabolomic profiles, some of which correlated with the observed pH changes. Several plastic types induced changes in valeric acid levels, while individual MP types were associated with alterations in distinct metabolites such as uracil, lactic acid, and acetic acid.

Conclusion

This study demonstrates that MPs can affect gut microbial activity and metabolism without significantly altering overall bacterial abundance in the short term. The variation in microbiome response across plastic types highlights the complexity of MP-microbiome interactions. Changes in faecal pH are known to be associated with various gastrointestinal diseases (5). Interestingly, some of the MP-induced changes in microbial composition resembled patterns linked to diseases such as depression and colorectal cancer. In contrast, other changes showed patterns that differed from those typically associated with conditions like Parkinson’s disease and irritable bowel syndrome, highlighting the complexity of these associations and the dependency on the context. The bioreactor model provided a controlled environment for identifying direct MP-microbiome interactions; however, in humans, additional factors like diet, immune response, and individual microbiome variations play a role in determining long-term effects. Exposure duration may also play a critical role in shaping the extent and nature of microbiome alterations (6), underscoring the need for further research into the effects of chronic MP exposure and associated health risks.

References

(1) Mamun, A. A., Prasetya, T. A. E., Dewi, I. R., & Ahmad, M. (2023). Microplastics in human food chains: Food becoming a threat to health safety. The Science of the total environment, 858(Pt 1), 159834. https://doi.org/10.1016/j.scitotenv.2022.159834
(2) Kumar, R., Manna, C., Padha, S., Verma, A., Sharma, P., Dhar, A., Ghosh, A., & Bhattacharya, P. (2022). Micro(nano)plastics pollution and human health: How plastics can induce carcinogenesis to humans?. Chemosphere, 298, 134267. https://doi.org/10.1016/j.chemosphere.2022.134267
(3) Hirt, N., & Body-Malapel, M. (2020). Immunotoxicity and intestinal effects of nano- and microplastics: a review of the literature. Particle and fibre toxicology, 17(1), 57. https://doi.org/10.1186/s12989-020-00387-7
(4) Senathirajah, K., Attwood, S., Bhagwat, G., Carbery, M., Wilson, S., & Palanisami, T. (2021). Estimation of the mass of microplastics ingested - A pivotal first step towards human health risk assessment. Journal of hazardous materials, 404(Pt B), 124004. https://doi.org/10.1016/j.jhazmat.2020.124004
(5) Yamamura, R., Inoue, K. Y., Nishino, K., & Yamasaki, S. (2023). Intestinal and fecal pH in human health. Frontiers in Microbiomes, 2, 1192316.
(6) Yin, L., Yang, M., Teng, A., Ni, C., Wang, P., & Tang, S. (2025). Unraveling Microplastic Effects on Gut Microbiota across Various Animals Using Machine Learning. ACS nano, 19(1), 369–380. https://doi.org/10.1021/acsnano.4c07885