Early growth response factor 1 is essential for cigarette smoke-induced MUC5AC expression in human bronchial epithelial cells

Role of early growth response 1 in inflammation-associated lung diseases

Early growth response 1 (EGR1), which is involved in cell proliferation, differentiation, apoptosis, adhesion, migration, and immune and inflammatory responses, is a zinc finger transcription factor. EGR1 is a member of the EGR family of early response genes and can be activated by external stimuli such as neurotransmitters, cytokines, hormones, endotoxins, hypoxia, and oxidative stress. EGR1 expression is upregulated during several common respiratory diseases, such as acute lung injury/acute respiratory distress syndrome, chronic obstructive pulmonary disease, asthma, pneumonia, and novel coronavirus disease 2019. Inflammatory response is the common pathophysiological basis of these common respiratory diseases. EGR1 is highly expressed early in the disease, amplifying pathological signals from the extracellular environment and driving disease progression. Thus, EGR1 may be a target for early and effective intervention in these inflammation-associated lung diseases.

S14G-Humanin ameliorates ovalbumin-induced airway inflammation in asthma mediated by inhibition of toll-like receptor 4 (TLR4) expression and the nuclear factor κ-B (NF-κB)/early growth response protein-1 (Egr-1) pathway

Asthma is a chronic inflammatory disease with a high morbidity rate in children and significantly impacts their healthy growth. It is reported that Th2 cell-mediated airway inflammation and activated oxidative stress are involved in the pathogenesis of asthma. S14G-humanin (HNG) is a derivative of Humanin with higher activity. The present study proposes to explore the potential treating property of HNG on asthma. An asthma model was constructed in mice using ovalbumin (OVA), the mice were treated with 2.5 mg/kg and 5 mg/kg HNG for 16 days. Dramatically increased lung weight index, elevated number of monocytes, eosinophils, and neutrophils, promoted production of Th2 cytokines including interleukin-4 (IL-4), interleukin-5 (IL-5), and interleukin-13 (IL-13), and severe histological pathology were observed in OVA-challenged mice, all of which were extremely alleviated by 2.5 mg/kg and 5 mg/kg HNG. Furthermore, the increased malondialdehyde (MDA) level and declined superoxide dismutase (SOD) activity in OVA-challenged mice were abolished by 2.5 mg/kg and 5 mg/kg HNG. Lastly, the upregulated TLR4, p-NF-κB p65, and early growth response 1 (Egr-1) in lung tissues of OVA-challenged mice were pronouncedly downregulated by 2.5 mg/kg and 5 mg/kg HNG. Collectively, our data suggested that HNG ameliorated airway inflammation in asthma partially due to NF-κB and Egr-1-mediated responses.

Verproside, the Most Active Ingredient in YPL-001 Isolated from Pseudolysimachion rotundum var. subintegrum, Decreases Inflammatory Response by Inhibiting PKCδ Activation in Human Lung Epithelial Cells

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease which causes breathing problems. YPL-001, consisting of six iridoids, has potent inhibitory efficacy against COPD. Although YPL-001 has completed clinical trial phase 2a as a natural drug for COPD treatment, the most effective iridoid in YPL-001 and its mechanism for reducing airway inflammation remain unclear. To find an iridoid most effectively reducing airway inflammation, we examined the inhibitory effects of the six iridoids in YPL-001 on TNF or PMA-stimulated inflammation (IL-6, IL-8, or MUC5AC) in NCI-H292 cells. Here, we show that verproside among the six iridoids most strongly suppresses inflammation. Both TNF/NF-κB-induced MUC5AC expression and PMA/PKCδ/EGR-1-induced IL-6/-8 expression are successfully reduced by verproside. Verproside also shows anti-inflammatory effects on a broad range of airway stimulants in NCI-H292 cells. The inhibitory effect of verproside on the phosphorylation of PKC enzymes is specific to PKCδ. Finally, in vivo assay using the COPD-mouse model shows that verproside effectively reduces lung inflammation by suppressing PKCδ activation and mucus overproduction. Altogether, we propose YPL-001 and verproside as candidate drugs for treating inflammatory lung diseases that act by inhibiting PKCδ activation and its downstream pathways.

Multi-omic association study identifies DNA methylation-mediated genotype and smoking exposure effects on lung function in children living in urban settings

Impaired lung function in early life is associated with the subsequent development of chronic respiratory disease. Most genetic associations with lung function have been identified in adults of European descent and therefore may not represent those most relevant to pediatric populations and populations of different ancestries. In this study, we performed genome-wide association analyses of lung function in a multiethnic cohort of children (n = 1,035) living in low-income urban neighborhoods. We identified one novel locus at the TDRD9 gene in chromosome 14q32.33 associated with percent predicted forced expiratory volume in one second (FEV1) (p = 2.4x10-9; βz = -0.31, 95% CI = -0.41- -0.21). Mendelian randomization and mediation analyses revealed that this genetic effect on FEV1 was partially mediated by DNA methylation levels at this locus in airway epithelial cells, which were also associated with environmental tobacco smoke exposure (p = 0.015). Promoter-enhancer interactions in airway epithelial cells revealed chromatin interaction loops between FEV1-associated variants in TDRD9 and the promoter region of the PPP1R13B gene, a stimulator of p53-mediated apoptosis. Expression of PPP1R13B in airway epithelial cells was significantly associated the FEV1 risk alleles (p = 1.3x10-5; β = 0.12, 95% CI = 0.06-0.17). These combined results highlight a potential novel mechanism for reduced lung function in urban youth resulting from both genetics and smoking exposure.

Identification of Ferroptosis-Related Hub Genes and Their Association with Immune Infiltration in Chronic Obstructive Pulmonary Disease by Bioinformatics Analysis

Purpose

Ferroptosis and immune infiltration are involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). We aim to identify ferroptosis-related hub genes and analyze their association with immune infiltration in COPD through bioinformatics methods.

Materials and Methods

The mRNA microarray data of GSE38974 were downloaded from Gene Expression Omnibus to obtain differentially expressed genes (DEGs). The DEGs were intersected with ferroptosis-related genes (FRGs) from FerrDb to obtain differentially expressed FRGs. GO and KEGG enrichment and protein–protein interaction (PPI) analyses of differentially expressed FRGs were conducted in R software and STRING database. The key module and hub genes were screened by Cytoscape software. MiRNAs, transcription factors and signal molecules were predicted in miRNet and NetworkAnalyst. The disease correlation in the Comparative Toxicomics Database (CTD) and the receiver operating characteristic (ROC) curves of hub genes were analyzed. Immune infiltration was evaluated by CIBERSORT algorithm. Spearman correlation analyses were conducted between hub genes and differentially infiltrated immune cells.

Results

Fifteen differentially expressed FRGs were identified, which were enriched in some terms involving airway inflammatory responses and structural remodeling. Five hub genes were selected including HIF1A, IL6, PTGS2, CDKN1A and ATM. Inference scores in CTD indicated their association with COPD. Two miRNAs, five transcription factors and one signal molecule were predicted. The combination of hub genes could be a fine diagnostic indicator of COPD (AUC: 0.981, CI: 0.940-1.000). Immune infiltration evaluation showed that monocytes and M0 macrophages were upregulated in COPD lung tissues, while CD8 T cells, activated NK cells, M2 macrophages, resting dendritic cells and resting mast cells were downregulated. The hub genes were significantly associated with differentially infiltrated immune cells.

Conclusion

We identified five ferroptosis-related hub genes (HIF1A, IL6, PTGS2, CDKN1A and ATM) in COPD, and found that they may influence the pathogenesis of COPD by regulating ferroptosis and thus affecting infiltrating immune cells.

[Liuwei Buqi capsule modulates immune function by targeting multiple immune cell subsets in lung tissue of patients with COPD]

OBJECTIVE

To investigate the characteristics of immune cell subsets in the lung tissues of patients with chronic obstructive pulmonary disease (COPD) and the mechanism of Liuwei Buqi capsule in modulating immune and inflammatory imbalance in COPD.

METHODS

We downloaded COPD-related single-cell RNA sequencing data from Gene Expression Omnibus (GEO) and identified COPD immune cell subsets using the Seurat package in the R software to construct an immune cell subsets-differential genes network. The target genes and active ingredients of Liuwei Buqi capsule were obtained from the Chinese Medicine System Pharmacology Database and Analysis Platform (TCMSP), and the Liuwei Buqi capsule-immune cell subsets-target genes network was constructed by mapping the target genes to the differentially expressed genes in each immune cell subset. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was performed to analyze significantly enriched pathways of the target genes, and the key genes involved in the top 20 pathways were identified. In a rat model of COPD, we investigated the effects of Liuwei Buqi capsule on pulmonary function, lung tissue pathology, serum levels of IL-1β, NF-κB, and TNF-α, and expressions of IKBα, JNK, c-JUN, and c-FOS proteins in the lung tissue.

RESULTS

A total of 18 immune-related cell subsets, including macrophages and alveolar macrophages, were identified in both COPD patients and healthy control subjects, and the patients with COPD showed significant changes the percentages of macrophages, cDC1, pDC, mast cells, T cells, and mature dendritic cells (P < 0.05). Liuwei Buqi capsules targeted multiple immune cell subsets, and the identified target genes were enriched mostly in such immune and inflammation-related signaling pathways as lipids and atherosclerosis, IL-17 signaling pathway, Toll-like receptor signaling pathway, and TNF signaling pathway; the genes CXCL8, IL1B, JUN, NFKBIA, MAPK8, and FOS were the key genes involved in the significantly enriched pathways. In the rat models of COPD, treatment with Liuwei Buqi capsule significantly improved pulmonary function, alleviated lung pathologies, reduced serum levels of IL-1β, TNF-α, and NF-κB (P < 0.05) and pulmonary expressions of JNK, c-JUN, and c-FOS (P < 0.01) protein, and increased pulmonary expression of IκBα (P < 0.01).

CONCLUSION

Liuwei Buqi capsule may play an immunomodulatory role by targeting multiple immune cell subsets in the lung tissue of COPD patients.

Inducible expression quantitative trait locus analysis of the MUC5AC gene in asthma in urban populations of children

BACKGROUND

Mucus plugging can worsen asthma control, lead to reduced lung function and fatal exacerbations. MUC5AC is the secretory mucin implicated in mucus plugging, and MUC5AC gene expression has been associated with development of airway obstruction and asthma exacerbations in urban children with asthma. However, the genetic determinants of MUC5AC expression are not established.

OBJECTIVES

This study sought to assess single-nucleotide polymorphisms (SNPs) that influence MUC5AC expression and relate to pulmonary functions in childhood asthma.

METHODS

This study used RNA-sequencing data from upper airway samples and performed cis-expression quantitative trait loci (eQTL) and allele-specific expression analyses in 2 cohorts of predominantly Black and Hispanic urban children, a high asthma-risk birth cohort, and an exacerbation-prone asthma cohort. Inducible MUC5AC eQTLs were further investigated during incipient asthma exacerbations. Significant eQTLs SNPs were tested for associations with lung function measurements and their functional consequences were investigated in DNA regulatory databases.

RESULTS

Two independent groups of SNPs in the MUC5AC gene that were significantly associated with MUC5AC expression were identified. Moreover, these SNPs showed stronger eQTL associations with MUC5AC expression during asthma exacerbations, which is consistent with inducible expression. SNPs in 1 group also showed significant association with decreased pulmonary functions. These SNPs included multiple EGR1 transcription factor binding sites, suggesting a mechanism of effect.

CONCLUSIONS

These findings demonstrate the applicability of organ-specific RNA-sequencing data to determine genetic factors contributing to a key disease pathway. Specifically, they suggest important genetic variations that may underlie propensity to mucus plugging in asthma and could be important in targeted asthma phenotyping and disease management strategies.

Tobacco Exposure Enhances Human Papillomavirus 16 Oncogene Expression via EGFR/PI3K/Akt/c-Jun Signaling Pathway in Cervical Cancer Cells

High-risk human papillomavirus (HR-HPV) infection is not a sufficient condition for cervical cancer development because most infections are benign and naturally cleared. Epidemiological studies revealed that tobacco smoking is a cofactor with HR-HPV for cervical cancer initiation and progression, even though the mechanism by which tobacco smoke cooperates with HR-HPV in this malignancy is poorly understood. As HR-HPV E6/E7 oncoproteins overexpressed in cervical carcinomas colocalize with cigarette smoke components (CSC), in this study we addressed the signaling pathways involved in a potential interaction between both carcinogenic agents. Cervical cancer-derived cell lines, CaSki (HPV16; 500 copies per cell) and SiHa (HPV16; 2 copies per cell), were acutely exposed to CSC at various non-toxic concentrations and we found that E6 and E7 levels were significantly increased in a dose-dependent manner. Using a reporter construct containing the luciferase gene under the control of the full HPV16 long control region (LCR), we also found that p97 promoter activity is dependent on CSC. Non-synonymous mutations in the LCR-resident TPA (12-O-tetradecanoylphorbol 13-acetate)-response elements (TRE) had significantly decreased p97 promoter activation. Phosphoproteomic arrays and specific inhibitors revealed that CSC-mediated E6/E7 overexpression is at least in part reliant on EGFR phosphorylation. In addition, we showed that the PI3K/Akt pathway is crucial for CSC-induced E6/E7 overexpression. Finally, we demonstrated that HPV16 E6/E7 overexpression is mediated by JUN. overexpression, c-Jun phosphorylation and recruitment of this transcription factor to TRE sites in the HPV16 LCR. We conclude that acute exposure to tobacco smoke activates the transcription of HPV16 E6 and E7 oncogenes through p97 promoter activation, which involves the EGFR/PI3K/Akt/C-Jun signaling pathway activation in cervical cancer cells.

Transcriptional and epigenetic profiling of nutrient-deprived cells to identify novel regulators of autophagy

Macroautophagy (hereafter autophagy) is a lysosomal degradation pathway critical for maintaining cellular homeostasis and viability, and is predominantly regarded as a rapid and dynamic cytoplasmic process. To increase our understanding of the transcriptional and epigenetic events associated with autophagy, we performed extensive genome-wide transcriptomic and epigenomic profiling after nutrient deprivation in human autophagy-proficient and autophagy-deficient cells. We observed that nutrient deprivation leads to the transcriptional induction of numerous autophagy-associated genes. These transcriptional changes are reflected at the epigenetic level (H3K4me3, H3K27ac, and H3K56ac) and are independent of autophagic flux. As a proof of principle that this resource can be used to identify novel autophagy regulators, we followed up on one identified target: EGR1 (early growth response 1), which indeed appears to be a central transcriptional regulator of autophagy by affecting autophagy-associated gene expression and autophagic flux. Taken together, these data stress the relevance of transcriptional and epigenetic regulation of autophagy and can be used as a resource to identify (novel) factors involved in autophagy regulation.