Tityus serrulatus causes numerous scorpion envenomation accidents and deaths worldwide. The symptoms vary from local to systemic manifestations, culminating in pulmonary edema and cardiogenic shock. Among these events, transitory hyperglycemia is a severe manifestation that influences pulmonary edema, hemodynamic alterations, and cardiac disturbances. However, the molecular mechanism that leads to increased glucose levels after T. serrulatus envenomation remains unknown. This study aimed to investigate our hypothesis that hyperglycemia due to scorpion envenomation involves inflammatory signaling in the pancreas. The present study showed that T. serrulatus venom induces the production of IL-1α and IL-1β in the pancreas, which signal via IL-1R and provoke nitric oxide (NO) production as well as edema in β-cells in islets. Il1r1−/− mice were protected from transitory hyperglycemia and did not present disturbances in insulin levels in the serum. These results suggest that the pathway driven by IL-1α/IL-1β-IL-1R-NO inhibits insulin release by β-cells, which increases systemic glucose concentration during severe scorpion envenomation. A supportive therapy that inhibits NO production, combined with antiserum, may help to prevent fatal outcomes of scorpion envenomation. Our findings provide novel insights into the design of supportive therapy with NO inhibitors combined with antiscorpion venom serum to overcome fatal outcomes of scorpion envenomation.

Objective and design Our research aimed to investigate the role of CD14 in pulmonary infection by Achromobacter xylosoxidans in an experimental murine model. Methods C57Bl/6 or CD14-deficient mice were infected intratracheally with non-lethal inoculum of A. xylosoxidans . At times 1, 3 and 7 days after infection, lungs, bronchoalveolar lavage and blood were collected. CD14 gene expression was determined by RT-PCR. The bacterial load in the lungs was assessed by counting colony forming units (CFU). Cytokines, chemokines, lipocalin-2 and sCD14 were quantified by the ELISA method. Inflammatory infiltrate was observed on histological sections stained with HE, and leukocyte subtypes were assessed by flow cytometry. In another set of experiments, C57Bl/6 or CD14-deficient mice were inoculated with lethal inoculum and the survival rate determined. Results CD14-deficient mice are protected from A. xylosoxidans -induced death, which is unrelated to bacterial load. The lungs of CD14-deficient mice presented a smaller area of tissue damage, less neutrophil and macrophage infiltration, less pulmonary edema, and a lower concentration of IL-6, TNF-α, CXCL1, CCL2 and CCL3 when compared with lungs of C57Bl/6 mice. We also observed that A. xylosoxidans infection increases the number of leukocytes expressing mCD14 and the levels of sCD14 in BALF and serum of C57Bl/6-infected mice. Conclusions In summary, our data show that in A. xylosoxidans infection, the activation of CD14 induces intense pulmonary inflammatory response resulting in mice death. Supplementary Information The online version contains supplementary material available at 10.1007/s00011-022-01641-8.

Objective and design: Our research aimed to investigate the role of CD14 in pulmonary infection by Achromobacter xylosoxidans in an experimental murine model. Methods C57Bl/6 or CD14-deficient mice were infected intratracheally with A. xylosoxidans. At times 1, 3 and 7 days after infection, lungs, bronchoalveolar lavage and blood were collected. CD14 gene expression was determined by RT-PCR. The bacterial load in the lungs was assessed by counting colony forming units (CFU). Cytokines, chemokines, lipocalin-2 and sCD14 were quantified by the ELISA method. Inflammatory infiltrate was observed on histological sections stained with HE, and leukocyte subtypes were assessed by flow cytometry. Results CD14-deficient mice are protected from A. xylosoxidans-induced death, which is unrelated to bacterial load control. The lungs of CD14-deficient mice presented a smaller area of ​​tissue damage, less neutrophil and macrophage infiltration, less pulmonary edema, and a lower concentration of IL-6, TNF-α, CXCL1, CCL2 and CCL3 when compared with lungs of C57Bl/6 mice. We also observed that A. xylosoxidans infection increases the number of leukocytes expressing mCD14 and sCD14 levels in BALF and serum of infected mice. Conclusions In summary, our data show that in A. xylosoxidans infection, the activation of CD14 induces intense pulmonary inflammatory response resulting in mice death.

PASTORE, M. R. Function and metabolic profile of platelets on the experimental infection by Achromobacter xylosoxidans. 2021. 89 f. Dissertation (Master).