Changxue Xiao

OBJECTIVE: To investigate lncRNAs and their roles in regulating the pulmonary inflammatory response under dexamethasone (Dex) treatment. METHODS: IL-1β (10 ng/mL) and LPS (1 μg/mL) was used to construct inflammatory cell models with A549 cells; IL-1β performed better against LPS. Different concentrations of Dex were used to attenuate the inflammation induced by IL-1β, and its effect was assessed via RT-PCR to detect inflammatory cytokine-related mRNA levels, including those of IKβ-α, IKKβ, IL-6, IL-8, and TNF-α. Furthermore, ELISA was used to detect the levels of the inflammatory cytokines TNF-α, IL-6, and IL-8. RT-PCR was used to quantify the levels of lncRNAs, including lncMALAT1, lncHotair, lncH19, and lncNeat1. LncH19 was most closely associated with the inflammatory response, which was induced by IL-1β and attenuated by Dex. Among the lncRNAs, the level of lncH19 showed the highest increase following treatment with 1 and 10 μM Dex. Therefore, lncH19 was selected for further functional studies. LncH19 expression was inhibited by shRNA transduced with lentivirus. Cell assays for cell proliferation and apoptosis as well as RT-PCR, western blot, and ELISA for inflammatory genes were conducted to confirm the functions of lncH19. The predicted target miRNAs of lncH19 were hsa-miR-346, hsa-miR-324-3p, hsa-miR-18a-3p, hsa-miR-18b-5p, hsa-miR-146b-3p, hsa-miR-19b-3p, and hsa-miR-19a-3p. Following estimation via RT-PCR, hsa-miR-346, hsa-miR-18a-3p, and hsa-miR-324-3p showed consistent patterns in A549 NC and A549 shlncH19. An miRNA inhibitor was transfected into A549 NC and A549 shlncH19 cells, and the expression levels were determined via RT-PCR. hsa-miR-324-3p was inhibited the most compared with hsa-miR-346 and hsa-miR-18a-3p and was subjected to further functional studies. RT-PCR, ELISA, and western blotting for inflammatory gene detection were conducted to validate the functions of the target hsa-miR-324-3p. RESULTS: Treatment with 1 and 10 μM Dex could effectively attenuate the inflammatory response. During this process, lncH19 expression significantly increased (P < 0.05). Therefore, treatment with 1 μM Dex was used for further study. Under IL-1β treatment with or without Dex, lncH19 inhibition led to an increase in cell proliferation; a decrease in cell apoptosis; an increase in the protein levels of inflammatory genes; phosphorylation of P65, ICAM-1, and VCAM-1; and increase inflammatory cytokines. Prediction of the targets of lncH19 and validation via RT-PCR revealed that miR-346, miR-18a-3p, and miR-324-3p negatively correlate with lncH19. Additionally, Dex increased the lncH19 expression but reduced that of the miRNAs. Among the miRNAs, miR-324-3p was the most markedly downregulated miRNA following treatment of miRNA inhibitors. The MTS assay and cell apoptosis assay showed that the miR-324-3p inhibitor inhibited cell proliferation and induced cell apoptosis, thereby significantly attenuating the inflammatory response, which reversed the effect of lncH19 in regulating cell proliferation and the secretion of inflammatory cytokines (P < 0.05). Therefore, lncH19 might regulate miR-324-3p in pulmonary inflammatory response under Dex treatment. CONCLUSION: Dex can attenuate the pulmonary inflammatory response by regulating the lncH19/miR-324-3p cascade.

OBJECTIVES: To estimate the prevalence, management, and outcomes of pediatric severe sepsis in the main PICUs in Southwest China. DESIGN: A prospective, observational, and multicenter study. SETTING: Eight PICUs in Southwest China with 19 (13-24) beds and 1,322 (1,066-1,452) annual admissions each. PATIENTS: A total of 10,598 patients (29 d to 18 yr old) were consecutively admitted between September 1, 2016, and August 31, 2017. All patients were screened and evaluated for severe sepsis or septic shock. Of them, 10,353 patients were excluded due to incomplete data or not meeting the consensus criteria for severe sepsis or septic shock; 245 patients were included with complete data. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Finally, 245 patients who were diagnosed with severe sepsis or septic shock were included in the study, with an incidence rate of 2.3%. Of them, 64.0% of the enrolled patients were male with 80.8% being less than 5 years old and 60.8% being from rural areas. The respiratory system was the most common organ system in which dysfunction was observed (76.7%) as well as the most frequently infected site (37.6%). The primary therapies were antibiotics (99.0%), immunoglobulin (88.3%), mechanical ventilation (78.4%), vasoactive infusions (59.6%), and corticosteroids (46.1%). Among the 188 patients who had respiratory dysfunction, 173(92%) required mechanical ventilation and 39 (20.7%) met the criteria for pediatric acute respiratory distress syndrome. Seven of the patients with pediatric acute respiratory distress syndrome died (7/39, 17.9%). The median durations for mechanical ventilation and vasoactive medications were 123.5 hours (35.25-226.00 hr) and 2 days (1-5 d), respectively. Eighty-six percent of patients had multiple organ dysfunction syndrome at the point at which severe sepsis was recognized, and 31% had underlying conditions. The hospital mortality rate was 18.8%. CONCLUSIONS: This report is the first to present the prevalence, treatment, and outcomes of pediatric severe sepsis in the main PICU centers in Southwest China. The mortality rate remains high; therefore, improved clinical management and implementation of large-scale clinical trials are necessary to improve early diagnoses and treatment.

OBJECTIVES: To describe the epidemiological characteristics of pediatric sepsis in Southwest China PICUs. DESIGN: A prospective, multicenter, and observational study. SETTING: Twelve PICUs in Southwest China. PATIENTS: The patients admitted to the PICU from April 1, 2022, to March 31, 2023. The age ranged from 28 days to 18 years. All patients met the criteria of severe sepsis or septic shock. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 31 PICUs invited to participate, 12 PICUs (capacity of 292 beds) enrolled patients in the study. During the study period, 11,238 children were admitted to the participating PICUs, 367 (3.3%) of whom met the diagnosis of severe sepsis or septic shock. The most prevalent sites of infection were the respiratory system (55%) and the digestive system (15%). The primary treatments administered to these patients included antibiotics (100%), albumin (61.3%), invasive mechanical ventilation (58.7%), glucocorticoids (55.6%), blood products (51%), gammaglobulin (51%), and vasoactive medications (46.6%). Sepsis-related mortality in the PICU was 11.2% (41/367). Nearly half of the sepsis deaths occurred within the first 3 days of PICU admission (22/41, 53.7%). The mortality rate of septic shock (32/167, 19.2%) was significantly higher than that of severe sepsis (9/200, 4.5%; p < 0.001). The outcomes of a multivariate logistic regression analysis suggested that a higher pediatric Sequential Organ Failure Assessment score, and the use of invasive mechanical ventilation and vasoactive medications were independently associated with PICU mortality in children with sepsis. CONCLUSIONS: This report updates the epidemiological data of pediatric sepsis in PICUs in Southwest China. Sepsis is still a life-threatening disease in children.

Purpose/Aim: Exposure to hyperoxia leads to lung injury both in vivo and in vitro, molecular hydrogen has been reported to protect against hyperoxia-induced lung injury; however, the underlying molecular mechanisms remain largely unknown. The objective of this study was to characterize differentially regulated proteins and biological processes in hydrogen-treated hyperoxic primary type II alveolar epithelial cells (AECIIs) to elucidate the protective mechanism of hydrogen using quantitative proteomics. Materials and Methods: AECIIs were divided into three groups that were cultured for 24 h in three different conditions: control (21% oxygen), hyperoxia (95% oxygen), and hyperoxia + hydrogen. Morphologic examination, flow cytometric analysis, cell viability assessment and analysis of the expression of apoptosis-associated proteins Bax and Bcl-2 as well as AECI markers (AQP5, T1α) and an AECII marker (SP-C) were performed for each group. The TMT labeling quantitative proteome technique was used to detect changes in the protein expression profile, and bioinformatics analysis was performed. Results: Hydrogen plays a protective role in hyperoxia-induced damage in AECIIs, as evidenced by reduced apoptosis, increased viability and survival, improved morphology, and enhanced transdifferentiation of AECIIs into AECIs. A total of 5782 proteins were identified in our study, of which 162 were significantly altered in abundance after hyperoxia exposure, and 97 were significantly altered in abundance in response to hydrogen treatment. The Gene Ontology and KEGG enrichment analyses identified a large number of proteins and biological processes that may responsible for the protective effect of hydrogen, including VEGFA, PDGFB, IGFBP3, EDN1, NADPH oxidase, the coagulation cascade, etc. Conclusions: Molecular hydrogen protects AECIIs from hyperoxic injury by complex mechanisms involving a variety of proteins and biological processes, such as VEGFA, PDGFB, IGFBP3, EDN1, NADPH oxidase and the coagulation cascade. These findings suggest novel pathways that need to be investigated as possible therapeutic targets for hyperoxia-induced lung injury.