PE (0:0/14:0), an endogenous metabolite of the gut microbiota, exerts protective effects against sepsis-induced intestinal injury by modulating the AHR/CYP1A1 pathway.

Sepsis is known to cause damage to the intestinal mucosa, leading to bacterial translocation, and exacerbation of both local and remote organ impairments. In the present study, fecal samples were collected from both septic and healthy individuals. Analysis through 16s rRNA sequencing of the fecal microbiota revealed that sepsis disrupts the balance of the gut microbial community. Recent research has highlighted the association of lipid metabolism with disease. By analyzing the fecal metabolome, four lipid metabolites that showed significant differences between the two groups were identified: PE (O-16:0/0:0), PE (17:0/0:0), PE (0:0/14:0), and PE (12:0/20:5 (5Z, 8Z, 11Z, 14Z, 17Z)). Notably, the serum levels of PE (0:0/14:0) were higher in the healthy group. Subsequent in vitro and in vivo experiments demonstrated the protective effects of this compound against sepsis-induced intestinal barrier damage. Label-free proteomic analysis showed significant differences in the expression levels of the aryl hydrocarbon receptor (AHR), a protein implicated in sepsis pathogenesis, between the LPS-Caco-2 and LPS-Caco-2 + PE (0:0/14:0) groups. Further analysis, with the help of Discovery Studio 3.5 software and co-immunoprecipitation assays, confirmed the direct interaction between AHR and PE (0:0/14:0). In the cecal ligation and puncture (CLP) model, treatment with PE (0:0 /14:0) was found to up-regulate the expression of tight junction proteins through the AHR/Cytochrome P450, family 1, subfamily A, and polypeptide 1 (CYP1A1) pathway. This highlights the potential therapeutic use of PE (0:0/14:0) in addressing sepsis-induced intestinal barrier damage.

Damaged male germ cells induce epididymitis in mice.

Epididymitis can be caused by infectious and noninfectious etiological factors. While microbial infections are responsible for infectious epididymitis, the etiological factors contributing to noninfectious epididymitis remain to be defined. The present study demonstrated that damaged male germ cells (DMGCs) induce epididymitis in mice. Intraperitoneal injection of the alkylating agent busulfan damaged murine male germ cells. Epididymitis was observed in mice 4 weeks after the injection of busulfan and was characterized by massive macrophage infiltration. Epididymitis was coincident with an accumulation of DMGCs in the epididymis. In contrast, busulfan injection into mice lacking male germ cells did not induce epididymitis. DMGCs induced innate immune responses in epididymal epithelial cells (EECs), thereby upregulating the pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1ß (IL-1ß), as well as the chemokines such as monocyte chemotactic protein-1 (MCP-1), monocyte chemotactic protein-5 (MCP-5), and chemokine ligand-10 (CXCL10). These results suggest that male germ cell damage may induce noninfectious epididymitis through the induction of innate immune responses in EECs. These findings provide novel insights into the mechanisms underlying noninfectious epididymitis, which might aid in the diagnosis and treatment of the disease.

[Study on Myelopoietic Functions of miR-191 by Using Zebrafish Model].

OBJECTIVES: To establish a method of gene analysis via zebrafish model to explore the effect of microRNA-191(miR-191) on myelopoiesis. METHODS: The hsa-miR-191 or cel-miR-67 was microinjected into the fertilized eggs of zebrafish, then the total RNA of embryos was extracted at 10 s, 24, 36 and 48 hpf for qRT-PCR to detect the expression levels of erythroid and granulocytic genes. Then embryos at the time-point of 24 hpf were collected for whole mount in situ hybridization to detect spatiotemporal expression of those genes. RESULTS: The antisense RNA probes with high sensitivity and specificity of erythroid genes (gata 1, scl, hbbe 3, lmo 2) and myelomonocytic genes (pu.1, L-plastin, mpx, cebpα) in zebrafish were obtained by molecular cloning and T7 RNA polymerase reaction; the expression levels of the erythroid and myelomonocytic genes of zebrafish microinjected with miR-191 mimics displayed higher than those in control group at the time-points of 24 hpf and 36 hpf. The spatiotemporal expression level of L-plastin at the time-point of 24 hpf was up-regulated, and the other genes were not significantly changed. It was worth mentioning that the mRNA expression level of mpx was significantly up-regulated by 10-20 times at the time-point of 10 s. CONCLUSION: The genetic analysis method of embryonic myeloid differentiation has been set up via zebrafish. Preliminary analysis of regulation in zebrafish myelopoiesis shows that miR-191 may be involved in the regulation of erythroid and myelomonocytic differentiation. The mechanism and corresponding function of mpx regulated by the other factors need to be further studied.