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Abstract Background Ischemia-reperfusion (I/R) injury is a major factor in liver damage following hepatic resection and liver transplantation, with anesthetics demonstrating the ability to shield organs from this type of injury. Methods Hypoxia-reoxygenation (H/R) was used to create in vitro I/R hepatocyte cell injury models. The CCK-8 assay, flow cytometer, LDH assay, and ELSIA were utilized to assess hepatocyte injury. The in vivo I/R injury rat model was then built. HE and TUNEL staining were used to assess liver tissue damage. Western-blot was applied to assess the activation of the MAPK/ERK pathway. Results Remimazolam (RMZL) remarkably improved cell viability and decreased apoptosis in H/R-induced hepatocyte injury. RMZL reduced the release of H/R-induced inflammatory mediators (TNF-α and IL-6) as well as LDH levels. We also discovered that RMZL inhibited p38 and ERK1/2 phosphorylation in vivo and in vitro. The stimulation of MAPK/ERK, on the other hand, abolished RMZL’s anti-inflammation effects in H/R-induced hepatocyte injury. Furthermore, RMZL reduced liver tissue injury in I/R rats. Conclusion RMZL prevented hepatic I/R damage by inhibiting MAPK/ERK signaling.

Background. In situ vaccination-induced local inflammatory response resulted in the establishment of a pool of tissue-resident memory T (TRM) cells and new vessels after the resolution of inflammation. TRM cells have received increasing attention; however, the role of new vessels in protective response is still unknown. Materials and Methods. We performed the laparotomy to access the stomach and injected alum-based vaccine into the gastric subserous layer (GSL). At 28 days post vaccination, a parabiosis mouse model along with depletion of anti-CD90.2 antibody was employed to explore the function of perivascular lymphocyte clusters in recall responses. The composition of the gastric lymphocyte clusters was analyzed by immunofluorescence staining. Antibody responses were detected using ELISA. Gastric lymphocytes were analyzed using flow cytometry. Results. GSL vaccination induced the formation of new vessels in the inflamed region. These new vessels were different from native vessels in that they were generally accompanied by perivascular lymphocyte clusters that mainly consisted of CD90-expressing cells. Additionally, histological analysis revealed the presence of CD4+ and CD8+ T cells in the perivascular lymphocyte clusters. Administration of a dose of an anti-CD90.2 antibody to GSL-vaccinated mice resolved these clusters. The efficacy of protection was compared in the parabiosis mice. Upon challenge, the presence of perivascular lymphocyte clusters was responsible for the fast recall response, as depletion of these clusters by CD90.2 antibody administration resulted in decreased expressions of VCAM-1, Madcam-1, and TNF-α, as well as lower recruitment of proinflammatory immune cells, decreased antibody levels, and poor protection. Conclusions. Our research demonstrates that in situ vaccination-induced regional inflammatory response contributes to optimal recall response not only by establishing a CD4+ TRM pool but also by creating an “expressway,” i.e., perivascular lymphocyte cluster.

Tissue-resident memory T (Trm) cells are enriched at the sites of previous infection and required for enhanced protective immunity. However, the emergence of Trm cells and their roles in providing protection are unclear in the field of Helicobacter pylori (H. pylori) vaccinology. Here, our results suggest that conventional vaccine strategies are unable to establish a measurable antigen (Ag)-specific memory cell pool in stomach; in comparison, gastric subserous injection of mice with micro-dose of Alum-based H. pylori vaccine can induce a pool of local CD4+ Trm cells. Regional recruitment of Ag-specific CD4+ T cells depends on the engagement of Ag and adjuvant-induced inflammation. Prior subcutaneous vaccination enhanced this recruitment. A stable pool of Ag-specific CD4+ T cells can be detected for 240 days. Two weeks of FTY720 administration in immune mice suggests that these cells do not experience the recirculation. Immunohistochemistry results show that close to the vaccination site, abundant CD4+T cells locate on epithelial niches, independent of lymphocyte cluster. Paradigmatically, Ag-specific CD4+ T cells with a phenotype of CD69+CD103- are preferential on lymphocytes isolated from epithelium. Upon Helicobacter infection, CD4+ Trm cells orchestrate a swift recall response with the recruitment of circulating antigen-specific Th1/Th17 cells to trigger a tissue-wide pathogen clearance. This study investigates the vaccine-induced gastric CD4+ Trm cells in a mice model, and highlights the need for designing a vaccine strategy against H. pylori by establishing the protective CD4+ Trm cells.