Elevated plasma and bile levels of corisin, a microbiota-derived proapoptotic peptide, in patients with severe acute cholangitis

Biliary HMGB1 levels and biochemical indices in the assessment of acute obstructive septic cholangitis combined with septic shock

BACKGROUND

Acute Obstructive Septic Cholangitis (AOSC) is a serious infectious disease of the biliary system. It is prone to develop into septic shock without prompt management.

METHODS

Bile was collected from 71 AOSC patients (45 AOSC without septic shock, 26 AOSC with septic shock) during biliary drainage and on days 1 and 3 postoperatively. The levels of High Mobility Group Protein 1 (HMGB1), Interleukin (IL)-1, IL-6, and Tumor Necrosis Factor alpha (TNF-α) were measured. The differences in the levels of biliary factors and their correlation with clinical biochemical indicators were assessed in the two groups.

RESULTS

HMGB1 gradually decreased in both groups in the postoperative period. Intraoperative levels of biliary HMGB1 were significantly higher in patients with AOSC with septic shock. TNF-α and HMGB1 decreased slowly in patients with AOSC with septic shock on postoperative days 1 and 3, and the levels of the factors decreased less. Biliary HMGB1 levels were negatively correlated with white blood cell count and positively correlated with blood urea nitrogen, blood creatinine, procalcitonin, and C-reactive protein. A bile HMGB1 level of 1108.3 pg/mL was the cut-off value to differentiate patients with AOSC with or without septic shock.

CONCLUSION

Biliary HMGB1 levels are elevated in patients with AOSC with septic shock and decrease slowly in the postoperative period. This suggests that HMGB1 is of considerable importance as a potential therapeutic target in the pathogenesis of septic shock in AOSC patients.

Aldehyde-based Activation of C2α-lactylthiamin Diphosphate Decarboxylation on Bacterial 1-deoxy-d-xylulose 5-phosphate Synthase

1-Deoxy-d-xylulose 5-phosphate synthase (DXPS) catalyzes the thiamin diphosphate (ThDP)-dependent formation of DXP from pyruvate (donor substrate) and d-glyceraldehyde 3-phosphate (d-GAP, acceptor substrate) in bacterial central metabolism. DXPS uses a ligand-gated mechanism in which binding of a small molecule "trigger" activates the first enzyme-bound intermediate, C2α-lactylThDP (LThDP), to form the reactive carbanion via LThDP decarboxylation. d-GAP is the natural acceptor substrate for DXPS and also serves a role as a trigger to induce LThDP decarboxylation in the gated step. Additionally, we have shown that O2 and d-glyceraldehyde (d-GA) can induce LThDP decarboxylation. We hypothesize this ligand-gated mechanism poises DXPS to sense and respond to cellular cues in metabolic remodeling during bacterial adaptation. Here we sought to characterize features of small molecule inducers of LThDP decarboxylation. Using a combination of CD, NMR and biochemical methods, we demonstrate that the α-hydroxy aldehyde moiety of d-GAP is sufficient to induce LThDP decarboxylation en route to DXP formation. A variety of aliphatic aldehydes also induce LThDP decarboxylation. The study highlights the capacity of DXPS to respond to different molecular cues, lending support to potential multifunctionality of DXPS and its metabolic regulation by this mechanism.

Role of microbiota-derived corisin in coagulation activation during SARS-CoV-2 infection

BACKGROUND

Coagulopathy is a major cause of morbidity and mortality in COVID-19 patients. Hypercoagulability in COVID-19 results in deep vein thrombosis, thromboembolic complications, and diffuse intravascular coagulation. Microbiome dysbiosis influences the clinical course of COVID-19. However, the role of dysbiosis in COVID-19-associated coagulopathy is not fully understood.

OBJECTIVES

The present study tested the hypothesis that the microbiota-derived proapoptotic corisin is involved in the coagulation system activation during SARS-CoV-2 infection.

METHODS

This cross-sectional study included 47 consecutive patients who consulted for symptoms of COVID-19. A mouse acute lung injury model was used to recapitulate the clinical findings. A549 alveolar epithelial, THP-1, and human umbilical vein endothelial cells were used to evaluate procoagulant and anticoagulant activity of corisin.

RESULTS

COVID-19 patients showed significantly high circulating levels of corisin, thrombin-antithrombin complex, D-dimer, tumor necrosis factor-α, and monocyte-chemoattractant protein-1 with reduced levels of free protein S compared with healthy subjects. The levels of thrombin-antithrombin complex, D-dimer, and corisin were significantly correlated. A monoclonal anticorisin-neutralizing antibody significantly inhibited the inflammatory response and coagulation system activation in a SARS-CoV-2 spike protein-associated acute lung injury mouse model, and the levels of corisin and thrombin-antithrombin complex were significantly correlated. In an in vitro experiment, corisin increased the tissue factor activity and decreased the anticoagulant activity of thrombomodulin in epithelial, endothelial, and monocytic cells.

CONCLUSION

The microbiota-derived corisin is significantly increased and correlated with activation of the coagulation system during SARS-CoV-2 infection, and corisin may directly increase the procoagulant activity in epithelial, endothelial, and monocytic cells.