Protein Kinase C Theta Inhibition Attenuates Lipopolysaccharide-Induced Acute Lung Injury through Notch Signaling Pathway via Suppressing Th17 Cell Response in Mice

Experimental Insights on the Use of Secukinumab and Magnolol in Acute Respiratory Diseases in Mice

This study investigates the combined treatment of secukinumab (SECU) and magnolol (MAGN) in a mouse model of LPS-induced ALI overlapped with allergic pulmonary inflammation, aiming to better understand the mechanism behind this pathology and to assess the therapeutic potential of this novel approach in addressing the severity of ALI. The combined treatment reveals intricate immunomodulatory effects. Both treatments inhibit IL-17 and promote M2 macrophage polarization, which enhances anti-inflammatory cytokine production such as IL-4, IL-5, IL-10, and IL-13, crucial for lung repair and inflammation resolution. However, the combination treatment exacerbates allergic responses and increases OVA-specific IgE, potentially worsening ALI outcomes. MAGN pretreatment alone demonstrates higher potency in reducing neutrophils and enhancing IFN-γ, suggesting its potential in mitigating severe asthma symptoms and modulating immune responses. The study highlights the need for careful consideration in therapeutic applications due to the combination treatment's inability to reduce IL-6 and its potential to exacerbate allergic inflammation. Elevated IL-6 levels correlate with worsened oxygenation and increased mortality in ALI patients, underscoring its critical role in disease severity. These findings offer valuable insights for the advancement of precision medicine within the realm of respiratory illnesses, emphasizing the importance of tailored therapeutic strategies.

Gut-derived immune cells and the gut-lung axis in ARDS

The gut serves as a vital immunological organ orchestrating immune responses and influencing distant mucosal sites, notably the respiratory mucosa. It is increasingly recognized as a central driver of critical illnesses, with intestinal hyperpermeability facilitating bacterial translocation, systemic inflammation, and organ damage. The "gut-lung" axis emerges as a pivotal pathway, where gut-derived injurious factors trigger acute lung injury (ALI) through the systemic circulation. Direct and indirect effects of gut microbiota significantly impact immune responses. Dysbiosis, particularly intestinal dysbiosis, termed as an imbalance of microbial species and a reduction in microbial diversity within certain bodily microbiomes, influences adaptive immune responses, including differentiating T regulatory cells (Tregs) and T helper 17 (Th17) cells, which are critical in various lung inflammatory conditions. Additionally, gut and bone marrow immune cells impact pulmonary immune activity, underscoring the complex gut-lung interplay. Moreover, lung microbiota alterations are implicated in diverse gut pathologies, affecting local and systemic immune landscapes. Notably, lung dysbiosis can reciprocally influence gut microbiota composition, indicating bidirectional gut-lung communication. In this review, we investigate the pathophysiology of ALI/acute respiratory distress syndrome (ARDS), elucidating the role of immune cells in the gut-lung axis based on recent experimental and clinical research. This exploration aims to enhance understanding of ALI/ARDS pathogenesis and to underscore the significance of gut-lung interactions in respiratory diseases.

From pancreas to lungs: The role of immune cells in severe acute pancreatitis and acute lung injury

BACKGROUND

Severe acute pancreatitis (SAP) is a potentially lethal inflammatory pancreatitis condition that is usually linked to multiple organ failure. When it comes to SAP, the lung is the main organ that is frequently involved. Many SAP patients experience respiratory failure following an acute lung injury (ALI). Clinicians provide insufficient care for compounded ALI since the underlying pathophysiology is unknown. The mortality rate of SAP patients is severely impacted by it.

OBJECTIVE

The study aims to provide insight into immune cells, specifically their roles and modifications during SAP and ALI, through a comprehensive literature review. The emphasis is on immune cells as a therapeutic approach for treating SAP and ALI.

FINDINGS

Immune cells play an important role in the complicated pathophysiology ofSAP and ALI by maintaining the right balance of pro- and anti-inflammatory responses. Immunomodulatory drugs now in the market have low thepeutic efficacy because they selectively target one immune cell while ignoring immune cell interactions. Accurate management of dysregulated immune responses is necessary. A critical initial step is precisely characterizing the activity of the immune cells during SAP and ALI.

CONCLUSION

Given the increasing incidence of SAP, immunotherapy is emerging as a potential treatment option for these patients. Interactions among immune cells improve our understanding of the intricacy of concurrent ALI in SAP patients. Acquiring expertise in these domains will stimulate the development of innovative immunomodulation therapies that will improve the outlook for patients with SAP and ALI.

Signaling pathways and potential therapeutic targets in acute respiratory distress syndrome (ARDS)

Acute respiratory distress syndrome (ARDS) is a common condition associated with critically ill patients, characterized by bilateral chest radiographical opacities with refractory hypoxemia due to noncardiogenic pulmonary edema. Despite significant advances, the mortality of ARDS remains unacceptably high, and there are still no effective targeted pharmacotherapeutic agents. With the outbreak of coronavirus disease 19 worldwide, the mortality of ARDS has increased correspondingly. Comprehending the pathophysiology and the underlying molecular mechanisms of ARDS may thus be essential to developing effective therapeutic strategies and reducing mortality. To facilitate further understanding of its pathogenesis and exploring novel therapeutics, this review provides comprehensive information of ARDS from pathophysiology to molecular mechanisms and presents targeted therapeutics. We first describe the pathogenesis and pathophysiology of ARDS that involve dysregulated inflammation, alveolar-capillary barrier dysfunction, impaired alveolar fluid clearance and oxidative stress. Next, we summarize the molecular mechanisms and signaling pathways related to the above four aspects of ARDS pathophysiology, along with the latest research progress. Finally, we discuss the emerging therapeutic strategies that show exciting promise in ARDS, including several pharmacologic therapies, microRNA-based therapies and mesenchymal stromal cell therapies, highlighting the pathophysiological basis and the influences on signal transduction pathways for their use.

Cellular and molecular mechanisms of Notch signal in pulmonary microvascular endothelial cells after acute lung injury

This study focused on the effect and mechanism of Notch signal on pulmonary microvascular endothelial cells (PMVECs) following acute lung injury. PMVECs were cultured in vitro and randomly divided into eight groups. Grouping was based on whether cells were co-cultured with T cells (splenic CD4+T cells were isolated using MACS microbeads) and the level of Notch expression: Normal group and Normal+T cells group, Model group and Model+T cells group, Notch low-expression group and Notch low-expression+T cells group, and Notch overexpression group and Notch overexpression+T cells group. Except for the Normal group and Normal+T cells group, all other groups were treated with 500 μL lipopolysaccharide (1 μg/mL). The expression of VE-cadherin and Zo-1 protein in the Model group (with or without T cells) was lower than that in the normal group (with or without T cells), their expression in the Notch low-expression group (with or without T cells) was significantly increased, and their expression in the Notch overexpression group (with or without T cells) was significantly decreased. Compared with the normal+T cells group, the number of Treg cells in the Notch low-expression+T cells group decreased significantly (P<0.01). The number of Th17 cells in the Notch overexpression+T cells group was higher than that in the Model+T cells group (P<0.01), while the number of Treg cells decreased (P<0.01). Our results demonstrated that activated Notch signal can down-regulate the expression of the tight junction proteins VE-Cadherin and Zo-1 in PMVECs and affect Th17/Treg immune imbalance. Autophagy was discovered to be involved in this process.

Diagnostic and prognostic value of autophagy-related key genes in sepsis and potential correlation with immune cell signatures

Background: Autophagy is involved in the pathophysiological process of sepsis. This study was designed to identify autophagy-related key genes in sepsis, analyze their correlation with immune cell signatures, and search for new diagnostic and prognostic biomarkers. Methods: Whole blood RNA datasets GSE65682, GSE134347, and GSE134358 were downloaded and processed. Differential expression analysis and weighted gene co-expression network analysis (WGCNA) were used to identify autophagy-related key genes in sepsis. Then, key genes were analyzed by functional enrichment, protein-protein interaction (PPI), transcription factor (TF)-gene and competing endogenous RNA (ceRNA) network analysis. Subsequently, key genes with diagnostic efficiency and prognostic value were identified by receiver operating characteristic (ROC) curves and survival analysis respectively. The signatures of immune cells were estimated using CIBERSORT algorithm. The correlation between significantly different immune cell signatures and key genes was assessed by correlation analysis. Finally, key genes with both diagnostic and prognostic value were verified by RT-qPCR. Results: 14 autophagy-related key genes were identified and their TF-gene and ceRNA regulatory networks were constructed. Among the key genes, 11 genes (ATIC, BCL2, EEF2, EIF2AK3, HSPA8, IKBKB, NLRC4, PARP1, PRKCQ, SH3GLB1, and WIPI1) had diagnostic efficiency (AUC > 0.90) and 5 genes (CAPN2, IKBKB, PRKCQ, SH3GLB1 and WIPI1) were associated with survival prognosis (p-value < 0.05). IKBKB, PRKCQ, SH3GLB1 and WIPI1 had both diagnostic and prognostic value, and their expression were verified by RT-qPCR. Analysis of immune cell signatures showed that the abundance of neutrophil, monocyte, M0 macrophage, gamma delta T cell, activated mast cell and M1 macrophage subtypes increased in the sepsis group, while the abundance of resting NK cell, resting memory CD4+ T cell, CD8+ T cell, naive B cell and resting dendritic cell subtypes decreased. Most of the key genes correlated with the predicted frequencies of CD8+ T cells, resting memory CD4+ T cells, M1 macrophages and naive B cells. Conclusion: We identified autophagy-related key genes with diagnostic and prognostic value in sepsis and discovered associations between key genes and immune cell signatures. This work may provide new directions for the discovery of promising biomarkers for sepsis.

IL-33 Deficiency Attenuates Lung Inflammation by Inducing Th17 Response and Impacting the Th17/Treg Balance in LPS-Induced ARDS Mice via Dendritic Cells

Objectives

The characteristic pathophysiological feature of acute respiratory distress syndrome (ARDS) is a dysregulated inflammatory response. T helper 17 (Th17) cells in the lung are inflammatory cells that contribute to pulmonary inflammatory cascades. In addition, Th17/regulatory T cells (Treg cells) also play an important role in the inflammatory process. Dendritic cells (DCs) can regulate the differentiation of CD4+ T cells, including Th17 and Treg cells. Recent evidence revealed that interleukin-33 (IL-33) signaling could activate and mature DCs. Therefore, the aim of this study was to investigate the effects of IL-33 on inflammation and immunoregulation by inducing the Th17 response and influencing the Th17/Treg balance in LPS-induced ARDS.

Methods

IL-33 gene knockout mice and the administration of recombinant mouse IL-33 (rmIL-33) were used to investigate the role of IL-33 and the underlying mechanisms in an LPS-induced ARDS model. Hematoxylin and eosin (H&E) staining, wet/dry (W/D) weight ratios, cell counts, and the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-17 (IL-17), and interleukin-10 (IL-10) in bronchoalveolar lavage fluid (BALF) were investigated. The levels of IL-33, orphan nuclear receptor gamma t (RORγt), and forkhead transcription factor protein 3 (FOXP3) protein in lung tissue were evaluated by Western blotting. The mRNA expression levels of IL-33 and RORγt were measured by quantitative real-time polymerase chain reaction (qRT-PCR). Th17 and Treg cell frequencies were determined by flow cytometry. The levels of IL-6 in the supernatant in a dendritic cell culture system were examined by ELISA.

Results

Increased expression of IL-33 was observed in mice with LPS-induced ARDS. IL-33 deficiency significantly inhibited inflammation and attenuated LPS-induced ARDS, whereas pretreatment with rmIL-33 aggravated pulmonary inflammatory response. Furthermore, depletion of IL-33 inhibited Th17 cells, significantly decreased RORγt mRNA and protein expression and IL-17 levels in BALF, and led to less differentiation of T cells into Th17 cells than Treg cells. Moreover, IL-33^-/- DCs secreted less IL-6 and IL-23 than normal control DCs.

Conclusion

IL-33 deficiency alleviated lung injury in the LPS-induced ARDS model, which was closely related to suppressing Th17 responses and regulating the Th17/Treg balance. The expansion of Th17 cells and imbalance in Th17/Treg cells may be associated with IL-6 and IL-23 secreted from IL-33-activated DCs.

Development and validation of the prognostic model based on autophagy-associated genes in idiopathic pulmonary fibrosis

Background

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease. Many studies suggest that autophagy may be related to disease progression and prognosis in IPF. However, the mechanisms involved have not been fully elucidated.

Methods

We incorporated 232 autophagy-associated genes (AAGs) and two datasets, GSE28042 and GSE27957, from the GEO database. Univariate Cox analysis and least absolute shrinkage and selection operator (LASSO) regression were used to construct the autophagy-associated prognostic model. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to investigate the functions of these autophagy-associated genes. CIBERSORT algorithm was used to calculate the immune cell infiltration between patients in the high-risk score and low-risk score groups. Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) was performed to explore the mRNA expression of five genes in the autophagy-associated risk model.

Results

We constructed a 5-autophagy-associated genes signature based on Univariate Cox analysis and LASSO regression. In our autophagy-associated risk model, IPF patients in the high-risk group demonstrated a poor overall survival rate compared to patients in the low-risk group. For 1-, 2-, and 3-year survival rates, the AUC predictive value of the AAG signature was 0.670, 0.787, and 0.864, respectively. These results were validated in the GSE27957 cohort, confirming the good prognostic effect of our model. GO and KEGG pathway analyses enriched immune-related pathways between the high-risk and low-risk groups. And there was also a significant difference in immune cell infiltration between two groups. And the results of qRT-PCR showed that the expression levels of FOXO1, IRGM, MYC, and PRKCQ were significantly decreased in the Peripheral Blood Mononuclear Cell (PBMC) of IPF patient samples.

Conclusion

Our study constructed and validated an autophagy-associated risk model based on MYC, MAPK1, IRGM, PRKCQ, and FOXO1. And those five genes may influence the progression of IPF by regulating immune responses and immune cells.

Dynamic Monitoring of Serum Protein in Acute Respiratory Distress Syndrome Based on Artificial Neural Network

Acute respiratory distress syndrome (ARDS) is one of the more serious diseases in human lung disease. Reducing its incidence rate is an important task in current clinical research. Dynamic monitoring of serum protein in patients will help to achieve the early diagnosis and treatment of ARDS. In this study, a protein monitoring model based on artificial neural network is proposed. First, surface enhanced laser desorption ionization time-of-flight mass spectrometry is used for protein detection, and then BP neural network is used for protein classification and content analysis. In the experimental analysis, serum samples from patients with acute respiratory distress syndrome in our hospital from November 2020 to August 2021 were selected for experimental testing. The experimental results show that the serum protein monitoring model based on BP neural network has low error and high convergence ability and can monitor individual protein in protein monitoring, and the area under the ROC curve in diagnostic performance reaches 0.854. The above results show that the artificial neural network has a good effect on the dynamic monitoring of serum protein in acute respiratory distress syndrome, and the diagnostic performance evaluation can reach 0.854, which has the ability to significantly improve the clinical diagnosis and treatment of acute respiratory distress syndrome.

Inhibition of PKCθ Improves Dystrophic Heart Phenotype and Function in a Novel Model of DMD Cardiomyopathy

Chronic cardiac muscle inflammation and subsequent fibrotic tissue deposition are key features in Duchenne Muscular Dystrophy (DMD). The treatment of choice for delaying DMD progression both in skeletal and cardiac muscle are corticosteroids, supporting the notion that chronic inflammation in the heart plays a pivotal role in fibrosis deposition and subsequent cardiac dysfunction. Nevertheless, considering the adverse effects associated with long-term corticosteroid treatments, there is a need for novel anti-inflammatory therapies. In this study, we used our recently described exercised mdx (ex mdx) mouse model characterised by accelerated heart pathology, and the specific PKCθ inhibitor Compound 20 (C20), to show that inhibition of this kinase leads to a significant reduction in the number of immune cells infiltrating the heart, as well as necrosis and fibrosis. Functionally, C20 treatment also prevented the reduction in left ventricle fractional shortening, which was typically observed in the vehicle-treated ex mdx mice. Based on these findings, we propose that PKCθ pharmacological inhibition could be an attractive therapeutic approach to treating dystrophic cardiomyopathy

Berberine administrated with different routes attenuates inhaled LPS-induced acute respiratory distress syndrome through TLR4/NF-κB and JAK2/STAT3 inhibition

Accumulating evidence showed that berberine possessed the anti-inflammatory action in various diseases caused by inflammation. However, it was still unclear whether both inhalation and injection with berberine produced pulmonary protective role in acute respiratory distress syndrome (ARDS). This study was aimed to evaluate the effects of both administration routes including inhalation and injection with berberine in ARDS induced by lipopolysaccharide (LPS) inhalation. Histopathological examination and weight of lung were evaluated. Phosphorylation of NF-κB, JAK2 and STAT3 were measured to assess the activity of inflammation related signaling pathways. Proinflammatory cytokines including interleukin (IL)-1β and tumor necrosis factor (TNF)-α in the bronchoalveolar lavage fluid (BALF) and serum were also detected. The results showed that LPS caused the lung injury, while both administration routes with berberine attenuated the injury and improved the pulmonary morphology. In addition, the primary TLR4/NF-κB and secondary JAK2/STAT3 signaling pathways which were activated by LPS in lung were totally inhibited by berberine administration. Moreover, proinflammatory cytokines in both BALF and serum were decreased by berberine. Considering that molecular docking simulation indicated that berberine could bind with TLR4, the present suggested that the inhibition of the inflammation related TLR4/NF-κB and JAK2/STAT3 signaling pathways might be involved in the pulmonary protective effect of berberine in LPS-induced ARDS.

Penehyclidine hydrochloride defends against LPS-induced ALI in rats by mitigating endoplasmic reticulum stress and promoting the Hes1/Notch1 pathway

Penehyclidine hydrochloride (PHC) is a novel anticholinergic drug applied broadly in surgeries as a preanesthetic medication. A substantial amount of research indicates that PHC has lung defensive properties. Considering that endoplasmic reticulum (ER) stress exerts a crucial function in cell apoptosis associated with the lipopolysaccharides (LPS)-induced acute lung injury (ALI) model, we aimed to determine whether regulation of ER stress in the LPS-induced ALI model was associated with the lung defensive role of PHC. Adult male SD rats were administered LPS (5 mg/kg, intratracheally) followed by PHC (1.0 mg/kg, intravenously) for 24 h. The NR8383 alveolar macrophages were randomly separated into Sham, LPS (100 ng/mL), and PHC (1, 2.5, or 5 μg/mL) + LPS groups. PHC (1, 2.5, or 5 μg/mL) + LPS groups were treated with PHC alone for 1 h after LPS exposure. Posttreatment with PHC relieved LPS-induced pulmonary impairment and blocked LPS-mediated lung apoptosis, indicated by the downregulation of the lung apoptotic indicators malondialdehyde and superoxide dismutase in serum at 24 h after LPS-induced ALI. PHC (1-5 μg/mL) did not influence the activity of cultivated NR8383 alveolar macrophages in vitro. However, postconditioning with PHC dosage-dependently reduced LPS-mediated cell apoptosis. Additionally, many studies have indicated that PHC administration inhibits ER stress and initiates hairy and enhancer of split 1 (Hes1)/(Notch1) signaling by decreasing phosphorylated α subunit of eukaryotic initiation factor 2α (p-eIF2α)/eukaryotic translation initiation factor 2α (eIF2α) and Phospho-protein kinase R-like ER kinase (p-PERK)/ protein kinase R-like ER kinase (PERK) proportions; inhibiting C/EBP-homologous protein (CHOP), activating transcription factor 4 (ATF4), caspase-3, and Bcl2-associated x (Bax) activity; and enhancing notch1 intracellular domain (NICD), Notch1, B-cell lymphoma-2 (Bcl-2), and Hes1 activity in vivo and in vitro. In addition, the defensive functions of PHC on LPS-activated NR8383 alveolar macrophages were abrogated through the Notch1 pathway antagonist [(3,5-difluorophenacetyl)-1-alanyl] -phenylglycine-butyl ester (DAPT). In conclusion, PHC alleviates LPS-induced ALI by ameliorating ER stress-mediated apoptosis and promoting Hes1/Notch1 signaling in vivo and in vitro.