Mesenteric adipose tissue B lymphocytes promote intestinal injury in severe acute pancreatitis by mediating enteric pyroptosis

Regulatory B cells attenuate sepsis-associated pancreatic injury by regulating T cell homeostasis

Sepsis is a common and life-threatening syndrome resulting from systemic and dysregulated immune response to severe infection, which contributes to morbidity and mortality in critically ill patients. This work aimed to evaluate the regulatory function of Breg cells in sepsis-associated pancreatic injury. We established mice model of sepsis-associated pancreatic injury by cecal ligation and puncture (CLP). Pancreatic injury was assessed by measuring the levels of amylase activity and histologic pancreatic injury scores. The proportions of Breg cells and T cell subsets were analyzed by flow cytometry, their secreted cytokines were detected by ELISA. The expressions of T-bet, RORγt and Foxp3 in spleen were determined by RT-PCR. The apoptosis of pancreatic cells was examined by LDH assay and Tunel, and the cell viability was detected by MTT assay. Compared to the sham group, a significantly lower percentage of Breg cells was observed in model mice. Anti-CD22 treatment exacerbated pancreatic injury, and significantly increased the percentages of Th1, Th17 cells along with the levels of IFN-γ, IL-17 in CLP-induced sepsis model, but did not affect the differentiation of Treg cells and expression of IL-10. Anti-CD22 administration promoted the expressions of T-bet and RORγt, but did not affect the Foxp3 expression. Adoptive transfer Breg cells remarkably alleviated pancreatic injury, and significantly decreased the percentages of Th1, Th17 cells along with the levels of IFN-γ, IL-17 and further promoted the percentage of Treg cells and expression of IL-10 in CLP-induced sepsis model. Moreover, adoptive transfer Breg cells inhibited the expressions of T-bet and RORγt, and promoted Foxp3 expression in model mice. Lipopolysaccharide (LPS) promoted the apoptosis in pancreatic acinar cells, which was inhibited after culturing with Breg cells in vitro. LPS remarkably upregulated the differentiation of Th1 and Th17 cells, and downregulated the differentiation of Treg cells, which could be significantly reversed by Breg cells in vitro. In conclusion, Breg cells may exhibit the protective effects by modulating T cell responses along with the cytokines in sepsis-associated pancreatic injury.

Gut microbial metabolite indole-3-propionic acid alleviates polycystic ovary syndrome in mice by regulating the AhR-NLRP3 axis

Polycystic ovary syndrome (PCOS) is a complex disorder that significantly impacts female reproductive health and increases the risk of metabolic and reproductive diseases. Emerging evidence suggests that alterations in gut microbiota and their metabolic activities contribute to PCOS pathogenesis, although the underlying mechanisms remain elusive. In the current study, we found that patients with PCOS had altered metabolic profiles, particularly characterized by reduced levels of indole-3-propionic acid (IPA). Administration of IPA alleviated dehydroepiandrosterone (DHEA)-induced PCOS in mice, as demonstrated by improved estrus cycle, insulin sensitivity, ovarian morphology and hormone levels. Additionally, IPA treatment alleviated DHEA-induced oxidative stress in the ovaries and enhanced thermogenesis in brown adipose tissue. Furthermore, IPA attenuated DHEA-induced inflammation both in vivo and in vitro. Mechanistically, IPA treatment suppressed DHEA-induced inflammatory responses and inhibited NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activation by activating the aryl hydrocarbon receptor (AhR). Collectively, our findings indicate that IPA ameliorates DHEA-induced PCOS through modulation of the AhR-NLRP3 pathway in mice, suggesting that regulating gut microbial tryptophan metabolism and AhR activation may represent a promising therapeutic strategy for PCOS prevention.

The Mechanism of Baicalin in the Treatment of Mycoplasma Pneumoniae Pneumonia by Regulating NLRP3/Caspase-1 Signaling Pathway

OBJECTIVE

This study investigated the mechanism of baicalin (BIA) attenuating the inflammatory response and lung injury in mycoplasma pneumoniae pneumonia (MPP) mice.

METHODS

MPP mouse models were established and then treated with BIA, azithromycin, or NLRP3 inflammasome activator. Lung wet-to-dry weight (W/D) ratio were weighed. Serum levels of MP-IgM, C-reactive protein (CRP) and bronchoalveolar lavage fluid (BALF) protein were detected by kits, NLRP3/Caspase-1 pathway-related protein levels by Western blot, and IL-1β, IL-18, IL-6 and TNF-α levels by ELISA. HE staining was performed to detect lung injury.

RESULTS

MPP mice showed elevated mouse lung W/D ratio, upregulated serum MP-IgM and CRP levels and BALF protein, and enhanced IL-6 and TNF-α levels, which were reversed by BIA or azithromycin treatment, suggesting that BIA attenuated pulmonary inflammatory response in MPP mice. The lung tissue of MPP mice showed upregulated NLRP3, cleaved Caspase-1,Caspase-1, GSDMD-N and GSDMD levels and raised IL-1β and IL-18 levels, and changes were annulled by BIA or azithromycin treatment, suggesting that BIA inhibited the NLRP3/Caspase-1 pathway activation. NLRP3/Caspase-1 pathway activation partially abrogated the alleviative effect of BIA on the pulmonary inflammatory response of MPP mice.

CONCLUSION

BIA mitigates inflammatory response and lung injury in MPP mice by inhibiting NLRP3/Caspase-1 pathway activation.

Genetic insights into across pancreatitis types: the causal influence of immunoglobulin G N-glycosylation variants on disease risk

Background

While a few case-control studies indicated a possible correlation of IgG N-glycosylation patterns with pancreatitis, their restricted sample sizes and methodologies prevented conclusive insights into causality or distinguishing traits across pancreatitis types.

Method

We conducted a two-sample Mendelian Randomization (MR) analysis to investigate the causal relationship between 77 IgG N-glycosylation traits and various types of pancreatitis, including acute pancreatitis (AP), chronic pancreatitis (CP), alcohol acute pancreatitis (AAP), and alcohol chronic pancreatitis (ACP). This analysis utilized summary-level data from genome-wide association studies (GWAS), employing methods such as IVW, MR-Egger, and weighted median. To ensure the robustness of our findings, several sensitivity analyses, including Cochran's Q statistic, leave-one-out, MR-Egger intercept, and MR-PRESSO global test were conducted.

Result

Our study uncovered the causal relationship between specific IgG N-glycosylation traits and various types of pancreatitis. Notably, an increase in genetically predicted IGP7 levels was associated with a decreased risk of developing AP. For CP, our data suggested a protective effect associated with higher levels of both IGP7 and IGP31, contrasting with increased levels of IGP27 and IGP65, which were linked to a heightened risk. Moreover, in the case of AAP, elevated IGP31 levels were causatively associated with a lower incidence, while higher IGP26 levels correlated with an increased risk for ACP.

Conclusion

This study establishes causal relationship between specific IgG N-glycosylation patterns and varying risks of different pancreatitis forms, underscoring their potential as predictive biomarkers. These findings necessitate further exploration into the underlying mechanisms, promising to inform more personalized diagnostic and therapeutic strategies in pancreatitis management.