Potential therapeutic effects of interleukin-35 on the differentiation of naïve T cells into Helios+Foxp3+ Tregs in clinical and experimental acute respiratory distress syndrome

Dexmedetomidine improve lung inflammation by regulating autophagy and apoptosis of CD4+ T cell via AMPK/mTOR signaling

OBJECTIVES

To investigate the protective effect and potential mechanism of dexmedetomidine (Dex) in acute lung injury (ALI).

MATERIALS AND METHODS

C57BL/6 mice and EL-4 cells were used for in vivo and in vitro studies, respectively. Cecal ligation and puncture (CLP) method was used to prepare an acute lung injury model. After dexmedetomidine intervention, tissue and cell samples were collected to evaluate and measure the severity of lung damage, the proportion of Treg cells, the expression of autophagy-related protein levels and AMPK/mTOR pathways.

RESULTS

Dex reduced lung damage, and IL-17a, MPO positive cells in the lung, decreased the levels of pro-inflammatory cytokines, and restrain autophagy and apoptosis via the activation of the AMPK/mTOR pathway and increase of the proportion of Tregs.

CONCLUSIONS

Dex can inhibit the levels of autophagy and apoptosis, increase the proportion of Treg cells, and reduce CLP induced acute lung injury through regulating AKMP/MTOR pathway.

Characterization of lactylation-based phenotypes and molecular biomarkers in sepsis-associated acute respiratory distress syndrome

Sepsis-associated acute respiratory distress syndrome (ARDS) is a heterogeneous disease with high morbidity and mortality. Lactylation plays a crucial role in sepsis and sepsis-induced lung injury. This study aimed to identify distinct lactylation-based phenotypes in patients with sepsis-associated ARDS and determine relevant molecular biomarkers. We analyzed blood transcriptome and clinical data from patients with sepsis-associated ARDS and calculated the lactylation activity. KEGG pathway analysis, drug sensitivity prediction, and immune cell infiltration analysis were performed. Candidate molecular biomarkers were identified by intersecting the feature genes extracted from four machine learning models. Lactylation activity showed significant heterogeneity among patients with sepsis-associated ARDS, which enabled the classification into low- and high-lactylation activity phenotypes. Patients with high-lactylation experienced longer hospital stays and higher mortality rates, as well as distinct signaling pathways, drug responses, and circulating immune cell abundances. Six key markers (ALDOB, CCT5, EP300, PFKP, PPIA, and SIRT1) were identified to differentiate the two lactylation activity phenotypes, all significantly correlated with circulating immune cell populations. This study revealed significant heterogeneity in lactylation activity phenotypes among patients with sepsis-associated ARDS and identified potential biomarkers to facilitate the application of these phenotypes in clinical practice.

Novel therapeutic role of Ganoderma Polysaccharides in a septic mouse model - The key role of macrophages

Ganoderma lucidum polysaccharides (G. PS) have been recognized for their immune-modulating properties. In this study, we investigated the impact of G. PS in a sepsis mouse model, exploring its effects on survival, inflammatory cytokines, Treg cell differentiation, bacterial load, organ dysfunction, and related pathways. We also probed the role of macrophages through chlorphosphon-liposome pretreatment. Using the cecal ligation and puncture (CLP) model, we categorized mice into normal, PBS, and G. PS injection groups. G. PS significantly enhanced septic mouse survival, regulated inflammatory cytokines (TNF-α, IL-17A, IL-6, IL-10), and promoted CD4+Foxp3+ Treg cell differentiation in spleens. Additionally, G. PS reduced bacterial load, mitigated organ damage, and suppressed the NF-κB pathway. In vitro, G. PS facilitated CD4+ T cell differentiation into Treg cells via the p-STAT5 pathway. Chlorphosphon-liposome pretreatment heightened septic mortality, bacterial load, biochemical markers, and organ damage, emphasizing macrophages' involvement. G. PS demonstrated significant protective effects in septic mice by modulating inflammatory responses, enhancing Treg cell differentiation, diminishing bacterial load, and inhibiting inflammatory pathways. These findings illuminate the therapeutic potential of G. PS in sepsis treatment.

The immunoregulatory role of IL-35 in patients with interstitial lung disease

Pulmonary fibrosis involves various types of immune cells and soluble mediators, including TGF-β and IL-35, a recently identified heterodimeric cytokine that belongs to the IL-12 cytokine family. However, the effect of regulatory IL-35 may play an important role in fibrotic diseases. The aim of this paper is to explore the immunoregulatory role of IL-35 in the development of fibrosis in interstitial lung disease (ILD). To gain a better understanding of this issue, the concentrations of IL-35 and different profibrotic cytokines in fibrotic (F-ILD) and non-fibrotic (NF-ILD) patients by ELISA were compared to that of intracellular IL-35 and IL-17 on CD4+ T cells stimulated in the presence of BAL or with different ratios of recombinant IL-35 (rIL-35) and TGF-β (rTGF-β), which were evaluated by flow cytometry. We observed that BAL concentration of IL-35 was lower in F patients (p < 0.001) and was negatively correlated with concentrations of TGF-β (p < 0.001) and IL-17 (p < 0.001). In supplemented cell cultures, BAL from NF but not F patients enhanced the percentage of IL-35 + CD4+ T (p < 0.001) cells and decreased the percentage of IL-17 + CD4+ T cells (p < 0.001). The percentage of IL-35 + CD4+ T cells correlated positively with BAL concentration of IL-35 (p = 0.02), but correlated negatively with BAL concentrations of IL-17 (p = 0.007) and TGF-β (p = 0.01). After adjusting the concentrations of recombinant cytokines to establish a TGF-β: IL-35 ratio of 1:4, an enhanced percentage of IL-35 + CD4+ T cells (p < 0.001) but a decreased percentage of IL-17 + CD4+ T cells (p < 0.001) was observed. After adding recombinant IL-35 to the BAL from F patients until a 1:4 ratio of TGF-β: IL-35 was reached, a significantly increased percentage of IL-35 + CD4+ T cells (p < 0.001) and a decreased percentage of IL-17 + CD4+ T cells (p = 0.003) was found. These results suggest that IL-35 may induce an anti-fibrotic response, regulating the effect of TGF-β and the inflammatory response on CD4+ T cells. In addition, the TGF-β: IL-35 ratio in BAL has been shown to be a potential biomarker to predict the outcome of F patients with ILD.

Contribution of IL-38 in Lung Immunity during Pseudomonas Aeruginosa-induced Pneumonia

OBJECTIVE

Interleukin-38 (IL-38), a new type of cytokine, is involved in processes such as tissue repair, inflammatory response, and immune response. However, its function in pneumonia caused by Pseudomonas aeruginosa (P. aeruginosa) is still unclear.

METHODS

In this study, we detected circulating IL-38 and cytokines such as IL-1β, IL-6, IL-17A, TNF-α, IL-8, and IL-10 in adults affected by early stage pneumonia caused by P. aeruginosa. Collected clinical data of these patients, such as the APACHE II score, levels of PCT, and oxygenation index when they entering the ICU. Using P. aeruginosa-induced pneumonia WT murine model to evaluate the effect of IL-38 on Treg differentiation, cell apoptosis, survival, tissue damage, inflammation, and bacterial removal.

RESULTS

In clinical research, although IL-38 is significantly increased during the early stages of clinical P. aeruginosa pneumonia, the concentration of IL-38 in the serum of patients who died with P. aeruginosa pneumonia was relatively lower than that of surviving patients. It reveals IL-38 may insufficiently secreted in patients who died with P. aeruginosa pneumonia. Besides, the serum IL-38 level of patients with P. aeruginosa pneumonia on the day of admission to the ICU showed significantly positive correlations with IL-10 and the PaO2/FiO2 ratio but negative correlations with IL-1β, IL-6, IL-8, IL-17, TNF-α, APACHE II score, and PCT In summary, IL-38 might be a molecule for adjuvant therapy in P. aeruginosa pneumonia. In experimental animal models, first recombinant IL-38 improved survival, whereas anti-IL-38 antibody reduced survival in the experimental pneumonia murine model. Secondly, IL-38 exposure reduced the inflammatory response, as suggested by the lung injury, and reduced cytokine levels (IL-1β, IL-6, IL- 17A, TNF-α, and IL-8, but not IL-10). It also increased bacterial clearance and reduced cell apoptosis in the lungs. Furthermore, IL-38 was shown to reduce TBK1 expression in vitro when naive CD4+ T lymphocytes were differentiated to Tregs and played a protective role in P. aeruginosa pneumonia.

CONCLUSIONS

To summarize, the above findings provide additional insights into the mechanism of IL-38 in the treatment of P. aeruginosa pneumonia.

Prognostic value of glucose-to-lymphocyte ratio in critically ill patients with acute respiratory distress syndrome: A retrospective cohort study

Background

There is need to identify biomarkers for prognosis of acute respiratory distress syndrome (ADRS). This may allow early and accurate identification of patients with high‐risk ARDS to guide adjustment of clinical treatment and nursing intervention, which would ultimately improve prognosis of patients with ARDS. Biomarkers based on a combination of fasting glucose and lymphocyte counts to predict prognosis in critically ill patients with ARDS remain undefined. In this study, we investigated the association between glucose‐to‐lymphocyte ratio (GLR) and in‐hospital mortality.

Methods

The study obtained data from Medical Information Mart for Intensive Care‐IV (MIMIC‐IV Version 1.0) database. We defined the GLR as fasting glucose/lymphocyte count and the patient in‐hospital mortality was considered as the outcome. In addition, we employed linear and logistic regression models for analysis.

Results

In total, 1,085 patients with ARDS were included in this study. The eligible participants included 498 female and 587 males, with a mean age of 64.2 ± 17.5 years. Logistic regression analysis demonstrated that higher GLR was an independent risk factor for all‐cause mortality (OR =1.67, 95% CI: 1.26–2.22) after adjusting for age, sex, anion gap, white blood cell count, congestive heart failure, sequential organ failure assessment (SOFA), SBP, DBP, and respiratory rate in both the dichotomized group and subgroups. We also analyzed the in‐hospital mortality to ROC curves by comparing the value between SOFA + GLR and SOFA. The area under the curve (AUC) was 0.6991 for the SOFA + GLR (95% CI: 0.6634–0.7348), and 0.6613 for the SOFA (95% CI: 0.6238–0.6988).

Conclusion

Our data showed that the GLR was an independent predictor of in‐hospital mortality for patients with ARDS. The GLR is an integrated, readily available clinical biomarker for mortality in patients with ARDS.