Sepsis is a life-threatening condition, and treatment for sepsis in clinic is often not available, partially due to insufficient understanding of the pathogenesis of sepsis.Extensive study to elucidate the pathogenesis is required to improve the clinical management and outcome of sepsis. In this study, we investigated the pathogenesis of sepsis using peripheral blood mononuclear cells (PBMCs) from septic patients and studied the underlying mechanism of miR-16-5p on aerobic glycolysis in lipopolysaccharide (LPS)-treated THP1 and Raw264.7 cells. The levels of RNA and protein were determined by real-time quantitative PCR and immunoblotting assay, respectively. The production of high mobility group box 1 (HMGB1) was measured by enzyme-linked immunosorbent assay. The levels of succinate and lactate were determined using colorimetric kits. The extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) were measured by extracellular flux analyzer. The results showed that the expression of miR-16-5p was elevated, while sirtuin 3 (SIRT3) was decreased in PBMCs from septic patients and LPS-treated cells, along with accumulation of acetylated succinate dehydrogenase complex, subunit A.Concomitantly, an increase in HMGB1, succinate, lactate, as well as ECAR and a decrease in OCR were observed. Knockdown of miR-16-5p upregulated SIRT3 expression, facilitated SDHA deacetylation, and attenuated sepsis-related aerobic glycolysis. Further study identified that SIRT3 is targeted by miR-16-5p, and overexpression of SIRT3 rescued LPS-induced responses via deacetylation of SDHA.Our findings revealed a novel miR-16-5p-regulated SIRT3-SDHA axis in sepsis and provided novel insights for sepsis treatment.

Background Exosome from adipose-derived stem cells (ADSCs-Exo) has been shown to inhibit the progression of human diseases, including sepsis-related acute kidney injury (AKI). CircVMA21 is considered to be an important regulator for sepsis-related AKI. However, whether ADSCs-Exo affected sepsis-induced AKI by delivering circVMA21 is not clear. Methods ADSCs was identified by alizarin red staining, oil red O staining, and flow cytometry. ADSCs-Exo was authenticated by transmission electron microscopy, nanoparticle tracking analysis, western blot analysis, and immunofluorescence assay. Cell apoptosis was assessed by flow cytometry, and inflammation cytokine levels were determined by ELISA. Lactate production was assessed using Lactate Acid Content Assay Kit. The expression levels of aerobic glycolysis-related markers, circVMA21 and miR-16-5p were evaluated by qRT-PCR. Dual-luciferase reporter assay and RIP assay were employed to detect RNA interaction. Animal experiments were used to evaluate the role of ADSCs-Exo on renal function and cell injury in LPS-induced AKI mice model. Results ADSCs-Exo inhibited LPS-induced HK-2 cell apoptosis, inflammation and aerobic glycolysis. Knockdown of exosomal circVMA21 derived from ADSCs enhanced HK-2 cell injury induced by LPS. In terms of mechanism, circVMA21 could serve as sponge for miR-16-5p. Besides, miR-16-5p inhibitor reversed the promotion effect of Exo-sh-circVMA21 on LPS-induced cell injury. In addition, ADSCs-Exo protected LPS-induced AKI in mice by increasing circVMA21 expression and decreasing miR-16-5p expression. Conclusion Exosomal circVMA21 derived by ADSCs relieved LPS-induced AKI through targeting miR-16-5p, which provided a potential molecular target for treating sepsis-related AKI.

Background Severe fatal human adenoviral (HAdV) pneumonia is associated with significant mortality and no effective drug is available for clinical therapy. We evaluated the association and safety of high titer neutralizing antibodies (NAbs) plasma in pediatric patients with severe fatal HAdV pneumonia. Methods A retrospective cohort study was performed between January 2016 to June 2021 in pediatric intensive care unit. Pediatric patients with severe fatal HAdV pneumonia were included and divided into plasma group (conventional treatment plus high titer NAbs plasma treatment) and control group (conventional treatment alone). The primary outcome was mortality in hospital. Secondary outcomes were the duration of fever after adenovirus genotype determined, duration of invasive mechanical ventilation, length of hospital stay. T-test, Mann-Whitney U-test, chi-square test, univariable and multivariable logistic regression analysis, Kaplan-Meier method and log-rank test were adopted to compare differences between two groups. Results A total of 59 pediatric patients with severe fatal HAdV pneumonia were enrolled. They were divided into plasma group (n = 33) and control group (n = 26). The mortality in hospital was 28.8% (17/ 59). Significantly fewer patients progressed to death in plasma group than control group (18.2% vs 42.3%, p = 0.042). Sequential organ failure assessment (SOFA) score, oxygen index (OI) and high titer NAbs plasma treatment were included in multivariable logistic regression analysis for mortality risk factors. Consequentially, SOFA score (Hazard Ratio [HR] 7.686, 95% Confidence Interval [CI] 1.735–34.054, p = 0.007) and without high titer NAbs plasma treatment (HR 4.298, 95%CI 1.030–17.934, p = 0.045) were significantly associated with mortality. In addition, high titer NAbs plasma treatment were associated with faster temperature recovering in survivors (p = 0.031). No serious adverse effects occurred. Conclusions Administration of high titer NAbs plasma were associated with a lower hazard for mortality in pediatric patients with severe fatal HAdV pneumonia. For survivors, high titer NAbs plasma treatment shorten the duration of fever.