Dataset Information

Probiotic Bacteria-Released Extracellular Vesicles Enhance Macrophage Phagocytosis in Polymicrobial Sepsis Through Activating the FPR1/2 Pathway

ABSTRACT: Background: Sepsis-induced organ failure and high mortality are largely ascribed to the failure of bacterial clearance from the infected tissues. Recently, probiotic bacteria-released extracellular vesicles (BEVs) have been implicated as critical mediators of intercellular communication which are widely involved in the regulation inflammatory response. However, their functional role in macrophage phagocytosis during sepsis has never been explored. Methods: BEVs were collected from three different strains of probiotics including Lactobacillus plantarum WCFS1 (LP WCFS1), Lactobacillus rhamnosus Gorbach-Goldin (LGG), and Escherichia coli Nissle 1917 (EcN), or from LGG cultured under three pH conditions (pH5-acid, pH6.5-standard, pH8-akaline) through differential centrifugation, filtering, and ultracentrifugation of their culture supernatants. In vitro phagocytosis was measured in Raw264.7 and bone marrow-derived macrophages using pHrodo red E. coli BioParticles. The in vivo therapeutic effects of BEVs were tested using a feces-intraperitoneal-injection (FIP) model of polymicrobial sepsis. Results: LGG-derived EVs (BEVLGG) were the best among these three probiotics BEVs in stimulating macrophages to take up bacteria. Furthermore, BEVLGG collected from pH8 culture condition (BEVpH8) exhibited the strongest capacity of phagocytosis, compared with BEVpH5 and BEVpH6.5. Treatment of septic mice with BEVpH8 significantly prolonged animal survival, increased bacterial clearance from the blood, peritoneal lavage, and multiple organs, decreased serum levels of pro-inflammatory cytokines, alanine aminotransferase (ALT, marker of liver injury) and creatinine (Cr, marker of kidney injury), in comparison with control-treated septic mice. Mechanistically, RNA-seq and bioinformatic analysis identified that the FPR1/2 signaling was remarkably activated, along with its downstream pathways (PI3K-Akt-MARCO and NADPH-ROS) in BEVpH8-treated macrophages, compared with control cells. Accordingly, pre-addition of Boc2, a specific antagonist of FPR1/FPR2, to macrophages significantly attenuated BEVpH8-mediated phagocytosis, compared to controls. Conclusions: This study demonstrates that LGG-derived BEVs may have therapeutic effects against sepsis-induced organ injury and mortality through enhancing FPR1/2-mediated macrophage phagocytosis.

ORGANISM(S): Mus musculus

PROVIDER: GSE274800 | GEO | 2024/11/20

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Analysis of human primary macrophages after live Lactobacillus rhamnosus GG (LGG) or LC705 stimulation for 6h and 24h. The results reveal novel mechanisms for probiotics-induced activation of the healthy human innate immune system. Macrophages are phagocytic cells of the innate immune system that perform sentinel functions to initiate appropriate responses to surrounding stimuli. Macrophages that reside at mucosa encounter ingested bacteria. Our understanding of the responses elicited by nonpathogenic bacteria in human innate immune system is limited. Lactobacillus are nonpathogenic bacteria commonly used in food and as supplements with health-promoting probiotic potential. In this study, we have utilized global gene expression profiling to compare the responses of human primary macrophages to two closely related, well-characterized L. rhamnosus strains LGG and LC705. Our results demonstrate that live LGG and LC705 induced quantitatively different gene expression in macrophages. A gene ontology analysis revealed functional similarities and differences in responses to LGG and LC705. Both LGG and LC705 induced IL-1b production in macrophages that required caspase-1 activity. LC705 but not LGG induced a strong type I IFN-dependent gene activation that correlated with the ability of LC705 to prevent influenza A virus replication and production of viral proteins in macrophages. Differentiated 7d human primary macrophages from 18 healthy individuals were stimulated with either live L. rhamnosus GG (LGG) or LC705 for 6 h and 24 h in RPMI medium containing penicillin and streptomycin. As a control, macrophages were stimulated with the medium only. The experiment was performed three times, each time with cells from six different individuals (samples 1-3). For each experiment, macrophages were stimulated separately as described, and macrophages from different donors were pooled after each stimulation experiment. Extracted RNA was hybridized to AffymetrixM-BM-. U133-plus2.0 GeneChipM-BM-. arrays.

Project description:Background: Sepsis can lead to multiple organ damage, and the heart is one of the most vulnerable organs. Vagal nerve stimulation can reduce myocardial injury in sepsis and improve survival rate. However, the relative effect of disparate cell populations on sepsis induced myocardial dysfunction and the low-level tragus stimulation on it, remain unclear. Methods: We used the cardiac single-cell transcriptomic strategy to characterize the cardiac cell population and the network of cells that forms the heart. And we selected all cardiac macrophage from CD45+ cells using single-cell mRNA sequencing data. Then we used echocardiography performing, western blot and immunofluorescence and immunohistochemical technology to verify the data of the single-cell mRNA sequencing results. Results: In single-cell mRNA sequencing data, our analysis provides a comprehensive map of the cardiac cellular landscape uncovering multiple cell populations that contribute to sepsis induced myocardial dysfunction under low-level tragus stimulation. Pseudo timing analysis in single-cell sequencing showed that low level vagal nerve stimulation could induce the transformation of cardiac monocytes into M2 macrophages and play an anti-inflammatory role. After low-level tragus stimulation, the expression of α7nAChR in the heart tissue increased significantly. Echocardiography showed that low-level tragus stimulation could improve the cardiac function of septic myocardial injury of the mice. Comparing with the sepsis group, the expression of interleukin-1β in heart tissue of the mice in sepsis with low-level tragus stimulation group is significantly lower. Conclusion: Low-level tragus stimulation can improve sepsis-induced myocardial dysfunction by promoting cardiac monocytes to M2 macrophages. Goal of the study: In the present study, we aimed to screen macrophages, their crosstalk with other cells, and macrophages associated with cardiac injury and further verify their origins and roles in the septic myocardial injury process and low-level tragus stimulation (LL-TS) to treat septic myocardial dysfunction.

Dataset Information

Probiotic Bacteria-Released Extracellular Vesicles Enhance Macrophage Phagocytosis in Polymicrobial Sepsis Through Activating the FPR1/2 Pathway

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets