Junjie Wang

Background: Despite advances in therapeutic strategies, acute respiratory distress syndrome (ARDS) mortality remains high. Growing evidence links respiratory microbiome composition to ARDS outcomes. This investigation sought to elucidate how colonizing bacteria and their metabolites influence ARDS pathogenesis. Methods: Bronchoalveolar lavage fluid (BALF) from patients with pulmonary infections was analyzed by metagenomic next-generation sequencing (mNGS) to identify characteristic bacteria. Bacterial culture supernatants were analyzed by untargeted metabolomics (LC-MS) to identify metabolites. A murine ARDS model was established through intratracheal LPS instillation. Single-cell sequencing datasets from the GEO database were analyzed to reveal differential cell populations and functional alterations in murine ARDS. Potential molecular mechanisms were explored through molecular docking, RNA-seq analysis, Western boltting, and targeted gene knockdown in murine and cellular model. Results: R. mucilaginosa demonstrated enrichment in patients without ARDS (nARDS). The bacterial culture supernatant conferred substantial protection in murine models, whereas viable bacteria showed minimal efficacy. LC-MS analysis identified indole-3-acetaldehyde (IAAld) as the predominant metabolite in the supernatant. Single-cell sequencing suggested that resident alveolar macrophages (RAMs) were pivotal cells in murine ARDS model. IAAld enhanced RAMs phagocytosis, facilitating neutrophil and LPS clearance. Mechanistic studies revealed that IAAld likely activated PXR signaling, promoted NRF2 nuclear translocation, and upregulated the phagocytosis-related gene CD36 . Targeted PXR knockdown eliminated these protective effects. Conclusion: The respiratory commensal R. mucilaginosa synthesizes IAAld, which—independent of bacterial colonization per se—ameliorates ARDS through PXR/NRF2/CD36 axis activation, thereby enhancing macrophage phagocytic function. These findings suggest that therapeutic targeting of microbial metabolites represents a novel ARDS treatment paradigm.

This study aimed to clarify the role and mechanism of tetrahedral framework nucleic acids (tFNAs) in regulating M2 macrophages to reduce intestinal injury. An intestinal injury model was established by intraperitoneal injection of lipopolysaccharides (LPS) in mice to explore the alleviating effects of tFNAs on intestinal injury. Inflammatory factors were detected by quantitative polymerase chain reaction (qPCR) and enzyme‐linked immunosorbent assay (ELISA). The intestinal barrier and permeability were assessed using western blotting and immunohistochemistry. Macrophages in the gut were localised and quantified using immunofluorescence. Western blotting was used to investigate the role and mechanism of tFNAs in regulating macrophages and alleviating inflammation in the injured intestines. These results show that tFNAs attenuated sepsis‐induced intestinal injury. tFNAs can also promote the intestinal barrier reconstruction and reduce intestinal permeability. In vivo, tFNAs accelerated the aggregation of M2 macrophages at an early stage of injury and reduced the number of M1 macrophages in the intestine. In addition, tFNAs enhanced the clearance ability of intestinal macrophages. They activated the signalling and transcription activating factor 1(STAT1) and cytokine signalling inhibitory factor 1/3 (SOCS1/3) pathways by increasing the expression of the phagocytic receptor Mertk. These findings indicated that tFNAs can alleviate sepsis‐induced intestinal injury by regulating M2 macrophages, providing a new option for treating intestinal injury.

Background and Objectives: Ventilator-associated pneumonia (VAP) was a common and severe complication of invasive mechanical ventilation. The traditional VAP diagnostic model relied on laboratory microbiological cultures. However, VAP had unclear pathogenesis, and its accurate identification was difficult due to the varying levels of pathogen detection in different laboratories. There was an urgent need for new diagnostic biomarkers for VAP. Methods: The transcriptome of VAP patients was analyzed and computed using bioinformatics techniques in this study. The screen identified differentially expressed genes (DEGs) from the chemokine CC family, the S-100 family, and the α-defensin family, which are highly associated with immune-related antimicrobial functions. Single-cell landscape data revealed an increase in MTRNR2L12+ cells and a decrease in naïve CD4+ T cells, ciliated cells, and CD8+ T cells in VAP patients, indicating a significant change in the homeostatic profile in patients. Moreover, this paper explored differential gene expression at the single-cell level. Results: The study analyzed 46 VAP samples and 48 normal samples to explore VAP pathogenesis and identify potential biomarkers. Both bulk RNA seq and scRNA-seq analysis revealed that S100A8 was highly expressed in the VAP group. This phenomenon was caused by the cellular level differential expression of B cells. In contrast, the reduced FN1 and HLA-DRB5 expressions in the VAP group may be influenced by the expression of T cells, macrophages, and ciliated cells. Western blot experiments detected S100A8 expression in the patient samples. Conclusion: In this study, we combine bulk RNA-seq and scRNA-seq analyses to screen and validate the potential of S100A8, a gene with consistent expression, as a biomarker, providing a new perspective for VAP diagnosis.

Background: Early diagnosis of septic cardiomyopathy is essential to reduce the mortality rate of sepsis. Previous studies indicated that iron metabolism plays a vital role in sepsis-induced cardiomyopathy. Here, we aimed to identify shared iron metabolism-related genes (IMRGs) in the myocardium and blood monocytes of patients with sepsis and to determine their prognostic signature.Methods: First, an applied bioinformatics-based analysis was conducted to identify shared IMRGs differentially expressed in the myocardium and peripheral blood monocytes of patients with sepsis. Second, Cytoscape was used to construct a protein–protein interaction network, and immune infiltration of the septic myocardium was assessed using single-sample gene set enrichment analysis. In addition, a prognostic prediction model for IMRGs was established by Cox regression analysis. Finally, the expression of key mRNAs in the myocardium of mice with sepsis was verified using quantitative polymerase chain reaction analysis.Results: We screened common differentially expressed genes in septic myocardium and blood monocytes and identified 14 that were related to iron metabolism. We found that HBB, SLC25A37, SLC11A1, and HMOX1 strongly correlated with monocytes and neutrophils, whereas HMOX1 and SLC11A1 strongly correlated with macrophages. We then established a prognostic model (HIF1A and SLC25A37) using the common differentially expressed IMRGs. The prognostic model we established was expected to better aid in diagnosing septic cardiomyopathy. Moreover, we verified these genes using datasets and experiments and found a significant difference between the sepsis and control groups.Conclusion: Common differential expression of IMRGs was identified in blood monocytes and myocardium between sepsis and control groups, among which HIF1A and SLC25A37 might predict prognosis in septic cardiomyopathy. The study may help us deeply understand the molecular mechanisms of iron metabolism and aid in the diagnosis and treatment of septic cardiomyopathy.

Partially hydrolyzed guar gum (PHGG), a water-soluble dietary fiber, has shown beneficial physiological effects in various disease models and is used as a prebiotic to regulate intestinal function. However, its role in healthy states remains unclear. The purpose of this study was to investigate the effects of PHGG on gut flora composition and predict metabolic function in healthy mice. Our study showed that PHGG supplementation had significant duration-dependent effects on the composition and function of the intestinal flora of healthy mice. In specific, although the long-term supplementation of PHGG may increase the abundance of some beneficial bacterial species and promote beneficial phenotypes, it may also cause increased body weight and decreased abundance and diversity of gut microorganisms. Therefore, the long-term use of PHGG as a nutritional product still requires further investigation. PRACTICAL APPLICATIONS: As the importance of the gut microbiota has become more widely recognized, interventions that modulate the microbiome and its interaction with the host have gained much attention. While the capability of some prebiotics has largely been shown to have many beneficial effects, the evidence leaves much desirable, and microbiota regulation is explored differently in healthy or diseased states. Currently, the scientific community and regulatory authorities are beginning to pay attention to these unregulated and over-the-counter products claiming to possess probiotic and prebiotic properties. Studies exploring the rationality of these prebiotics as nutraceuticals for use in health states are essential. This study focuses on the effects of PHGG, a prebiotic, on intestinal flora, metabolism, and function when used in a healthy state over a long period. It is helpful to have a clearer understanding of the effect of PHGG on intestinal flora and the possible mechanisms of action to exert effects, which are indicative for the future application of PHGG as a nutraceutical or therapeutic agent..

Background: Although inflammation is a known predictor for poor prognosis in patients with diabetics, few data report the synergistic association between inflammation, malnutrition, and mortality in patients with diabetics. We aim to explore whether malnutrition modifies the predictor of inflammation on prognosis.Methods: Nutritional status and inflammation were measured in 6,682 patients with diabetics undergoing coronary angiography or percutaneous coronary intervention between January 2007 to December 2018 from Cardiorenal Improvement Registry. Malnutrition was defined as Controlling Nutritional Status (CONUT) score, which was more than 1. High-sensitivity C-reactive protein (hs-CRP) exceeding the median was assessed as a high-risk inflammation. Cox regression models were used to estimate hazard ratios (HR) for mortality across combined hs-CRP and CONUT score categories.Results: During a median follow-up of 5.0 years (interquartile range: 3.0–7.6 years), 759 (11.36%) patients died. The mortality of the four groups (normal nutrition and low hs-CRP level; normal nutrition and high hs-CRP level; malnutrition and low hs-CRP level; and malnutrition and high hs-CRP level) were 7.29, 7.12, 10.71, and 17.31%, respectively. Compared with normal nutrition and low hs-CRP level, an isolated condition of either malnutrition or high hs-CRP level was not associated with any significant risk for all-cause mortality. However, concomitant presence of both high hs-CRP level and malnutrition condition was associated with a significantly increased risk of all-cause mortality (HR: 1.51; 95% CI: 1.20–1.89; p < 0.001). The p-value for interaction between nutritional status and hs-CRP level on all-cause mortality was 0.03.Conclusion: The interplay of inflammation and malnutrition in patients with diabetics significantly amplifies the deleterious effects of each as distinct disease entities. A prospective randomized clinical trial is needed in the future to verify the results.

Tumor-infiltrating immune cells (TIICs) play essential roles in cancer development and progression. However, the association of TIICs with prognosis in colorectal cancer (CRC) patients remains elusive. Infiltration of TIICs was assessed using ssGSEA and CIBERSORT tools. The association of TIICs with prognosis was analyzed in 1,802 CRC data downloaded from the GEO (https://www.ncbi.nlm.nih.gov/geo/) and TCGA (https://portal.gdc.cancer.gov/) databases. Three populations of TIICs, including CD66b+ tumor-associated neutrophils (TANs), FoxP3+ Tregs, and CD163+ tumor-associated macrophages (TAMs) were selected for immunohistochemistry (IHC) validation analysis in 1,008 CRC biopsies, and their influence on clinical features and prognosis of CRC patients was analyzed. Prognostic models were constructed based on the training cohort (359 patients). The models were further tested and verified in testing (249 patients) and validation cohorts (400 patients). Based on ssGSEA and CIBERSORT analysis, the correlation between TIICs and CRC prognosis was inconsistent in different datasets. Moreover, the results with disease-free survival (DFS) and overall survival (OS) data in the same dataset also differed. The high abundance of TIICs found by ssGSEA or CIBERSORT tools can be used for prognostic evaluation effectively. IHC results showed that TANs, Tregs, TAMs were significantly correlated with prognosis in CRC patients and were independent prognostic factors (P_DFS ≤ 0.001; P_OS ≤ 0.023). The prognostic predictive models were constructed based on the numbers of TANs, Tregs, TAMs (C-index_DFS&OS = 0.86; AIC_DFS = 448.43; AIC_OS = 184.30) and they were more reliable than traditional indicators for evaluating prognosis in CRC patients. Besides, TIICs may affect the response to chemotherapy. In conclusion, TIICs were correlated with clinical features and prognosis in patients with CRC and thus can be used as markers.

The purpose of this study was to evaluate burn-related variations of inflammation and immunity. Fifty-five mice were divided randomly into sham burn and burn groups. Eighty-seven hospitalized burn patients were also reviewed. In mice, neutrophils and monocytes were elevated significantly on post burn day (PBD 1). Lymphocytes were reduced on PBDs 1 and 3. Levels of serum tumor necrosis factor-α and interleukin-6 were highest on PBD 1. Interleukin-1β levels were the highest on PBD 3. On PBD 3, CD4+CD25+T regulatory cells/CD4+ cells in spleen were higher. On PBDs 1, 3, 7, and 14, percentage of splenic dendritic cells were significantly lower than the sham burn group. In patients, neutrophils and monocytes were significantly elevated on PBD 1. Levels declined but remained elevated at most days to PBD 7. Lymphocytes in burn groups 1 and 2 were reduced on PBDs 1 and 3, respectively. Our results exhibited that severe burn injury initiated a hyperinflammatory response and immunosuppression. PBDs 1 to 3 were important for changes in inflammation and immunosuppression.