Human epididymis protein 4 aggravates airway inflammation and remodeling in chronic obstructive pulmonary disease

SHP-1 mediates cigarette smoke extract-induced epithelial-mesenchymal transformation and inflammation in 16HBE cells

Src-homology region 2 domain-containing phosphatase 1 (SHP-1) is considered an anti-inflammatory factor, but its role in chronic obstructive pulmonary disease (COPD) remains unknown. Herein, overexpression of SHP-1 was utilized to explore the functions of SHP-1 in COPD models established by stimulating 16HBE cells with cigarette smoke extracts (CSE) in vitro. SHP-1 was downregulated in both COPD patients and CES-treated 16HBE cells. SHP-1 overexpression reinforced cell viability and significantly prevented CSE-induced cell apoptosis in 16HBE cells. Furthermore, SHP-1 overexpression greatly reversed the CSE-induced migration, epithelial-mesenchymal transition (EMT), and pro-inflammatory factor production in 16HBE cells. In addition, CSE activated the P65 and PI3K/AKT pathways in 16HBE cells, which was also reversed by SHP-1 overexpression. Our findings indicated that SHP-1 alleviated CSE-induced EMT and inflammation in 16HBE cells, suggesting that SHP-1 regulated the development of COPD, and these functions may be linked to the inhibition of the PI3K/AKT pathway.

DNA hypomethylation-mediated upregulation of GADD45B facilitates airway inflammation and epithelial cell senescence in COPD

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease typically characterized by chronic airway inflammation, with emerging evidence highlighting the driving role of cellular senescence-related lung aging. Accelerated lung aging and inflammation mutually reinforce each other, creating a detrimental cycle that contributes to disease progression. Growth arrest and DNA damage-inducible (GADD45) family has been reported to involve in multiple biological processes, including inflammation and senescence. However, the role of GADD45 family in COPD remains elusive.

OBJECTIVES

To investigate the role and mechanism of GADD45 family in COPD pathogenesis.

METHODS

Expressions of GADD45 family were evaluated by bioinformatic analysis combined with detections in clinical specimens. The effects of GADD45B on inflammation and senescence were investigated via constructing cell model with siRNA transfection or overexpression lentivirus infection and animal model with Gadd45b knockout. Targeted bisulfite sequencing was performed to probe the influence of DNA methylation in GADD45B expression in COPD.

RESULTS

GADD45B expression was significantly increased in COPD patients and strongly associated with lung function, whereas other family members presented no changes. GADD45B upregulation was confirmed in mice exposed by cigarette smoke (CS) and HBE cells treated by CS extract as well. Moreover, experiments involving bidirectional modulation of GADD45B expression in HBE cells further substantiated its positive regulatory role in inflammatory response and cellular senescence. Mechanically, GADD45B-facilitated inflammation was directly mediated by p38 phosphorylation, while GADD45B interacted with FOS to promote cellular senescence in a p38 phosphorylation-independent manner. Furthermore, Gadd45b deficiency remarkably alleviated inflammation and senescence of lungs in CS-exposed mice, as well as improved emphysema and lung function. Eventually, in vivo and vitro experiments demonstrated that GADD45B overexpression was partially mediated by CS-induced DNA hypomethylation.

CONCLUSION

Our findings have shed light on the impact of GADD45B in the pathogenesis of COPD, thereby offering a promising target for intervention in clinical settings.

Possible role of HE4 level elevation in the pathogenesis of TH2-high asthma

OBJECTIVES

As a heterogeneous disease, asthma is characterized by airway hyperresponsiveness, airway inflammation, and airway mucus hypersecretion. According to the pathological changes, symptoms, preventive and treatment methods, asthma can be divided into TH2-high and TH2-low asthma. We show that the expression of the tumor biomarker human epididymis protein 4 (HE4) was significantly increased in TH2-high asthma group, while there was no marked difference in its expression between TH2-low asthma and healthy control groups. HE4 levels were significantly increased in plasma, induced sputum, and alveolar lavage fluid (BALF) samples and airway epithelial cells from TH2-high asthma group, showing that HE4 has a possible role in the pathogenesis of TH2-high asthma.

METHODS

Using RT-qPCR, ELISA, Western blot (WB), and immunohistochemistry, we assessed differences in HE4 expression in plasma, induced sputum, BALF, and airway epithelial cells among patients with the TH2-related asthma subtypes and healthy controls. To explore the role of HE4 in TH2-high asthma, we conducted a correlation analysis between HE4 levels in plasma, induced sputum, BALF, and airway epithelial cells and multiple indicators of airway eosinophilic inflammation, airway mucus secretion, and airway remodeling.

CONCLUSION

We found for the first time that HE4 was differentially expressed in the TH2-related asthma subtypes. In TH2-high asthma, HE4 levels were markedly elevated in airway epithelial cells, plasma, induced sputum, and BALF. HE4 may play an important role in various pathogenic mechanisms of asthma, such as airway eosinophilic inflammation, airway mucus secretion, and airway remodeling. HE4 in plasma may be a clinically biomarker for differentiating TH2-related asthma subtypes.

Alpinetin ameliorates bleomycin-induced pulmonary fibrosis by repressing fibroblast differentiation and proliferation

OBJECTIVE

Idiopathic pulmonary fibrosis (IPF) is a progressive and irreversible interstitial lung disease with a poor prognosis. Alpinetin (ALP), derived from Alpinia katsumadai Hayata, has shown potential as a therapeutic measure of various diseases. However, the utilization of ALP in managing pulmonary fibrosis and its underlying mechanisms are still not fully understood.

METHODS

A well-established mouse model of pulmonary fibrosis induced by bleomycin (BLM) was used in this study. The antifibrotic effects of ALP on histopathologic manifestations and expression levels of fibrotic markers were examined. Subsequently, the impact of ALP on fibroblast differentiation, proliferation, apoptosis, and associated signaling pathways was investigated to elucidate the underlying mechanisms.

RESULTS

In the present study, we observed that ALP effectively mitigated BLM-induced pulmonary fibrosis in mice, as evidenced by histopathological manifestations and the expression levels of fibrotic markers. Furthermore, the in vitro experiments demonstrated that ALP treatment attenuated the ability of fibroblasts to differentiate into myofibroblasts. Mechanically, our findings provided evidence that ALP suppressed fibroblast-to-myofibroblast differentiation by repressing TGF-β/ALK5/Smad signaling pathway. ALP was found to possess the capability of inhibiting fibroblast proliferation and promoting apoptosis of fibroblasts induced by TGF-β.

CONCLUSION

In general, ALP may exert therapeutic effects on pulmonary fibrosis by modulating the differentiation, proliferation, and apoptosis of fibroblasts. Although its safety has been demonstrated in mice, further studies are required to investigate the efficacy of ALP in treatment of patients with IPF.

Serum human epididymis protein 4 is associated with disease severity in patients with IgA nephropathy

BACKGROUND

Human epididymis protein 4 (HE4) is a promising tumor biomarker primarily utilized for the detection of ovarian cancer. However, its potential as a novel diagnostic indicator for immunoglobulin A nephropathy (IgAN) remains unknown. The objective of this study was to investigate the feasibility of serum HE4 as a novel biomarker for patients with IgAN.

METHODS

This study enrolled a total of 89 hospitalized patients with IgAN at Peking University Shenzhen Hospital between July 2020 and December 2022, along with 60 healthy control subjects matched for sex and age without evidence of comorbidities. Serum HE4 levels were measured using the Abbott Alinity automated immune analyzer, and the correlation between serum HE4 levels and biochemical markers of renal damage as well as clinicopathologic features in IgAN patients were analyzed.

RESULTS

In this study, serum HE4 levels were significantly elevated in patients with IgAN compared to healthy controls (116.43 ± 103.61 pmol/L vs. 35.57 ± 9.33 pmol/L, p < 0.001). There was a positive correlation between serum HE4 levels and blood urea nitrogen (r = 0.58, p < 0.001), creatinine (r = 0.73, p < 0.001), cystatin C (r = 0.82, p < 0.001), β2-microglobulin (r = 0.77, p < 0.001), α1-microglobulin (r = 0.75, p < 0.001), and glomerulosclerosis ratio (r = 0.56, p < 0.001). Conversely, a negative correlation was observed between serum HE4 levels and hemoglobin (r = -0.42, p < 0.001), albumin (r = -0.44, p < 0.001) and estimated glomerular filtration rate (eGFR) (r = -0.83, p < 0.001). In HE4+ IgAN patients, a higher glomerulosclerosis ratio (p < 0.01) and lower eGFR levels (p < 0.001) were observed compared to HE4- patients. Furthermore, patients with higher pathological classification grade also had higher serum HE4 levels.

CONCLUSIONS

Serum HE4 levels were significantly associated with both renal function and the pathological classification of patients with IgAN, indicating that HE4 may serve as a promising biomarker for assessing the severity of IgAN.

Lung Fibroblasts from Chronic Obstructive Pulmonary Disease Subjects Have a Deficient Gene Expression Response to Cigarette Smoke Extract Compared to Healthy

Background and aim

Cigarette smoking is the most common cause of chronic obstructive pulmonary disease (COPD) but more mechanistic studies are needed. Cigarette smoke extract (CSE) can elicit a strong response in many COPD-related cell types, but no studies have been performed in lung fibroblasts. Therefore, we aimed to investigate the effect of CSE on gene expression in lung fibroblasts from healthy and COPD subjects.

Patients and methods

Primary lung fibroblasts, derived from six healthy and six COPD subjects (all current or ex-smokers), were either unstimulated (baseline) or stimulated with 30% CSE for 4 h prior to RNA isolation. The mRNA expression levels were measured using the NanoString nCounter Human Fibrosis V2 panel (760 genes). Pathway enrichment was assessed for unique gene ontology terms of healthy and COPD.

Results

At baseline, a difference in the expression of 17 genes was found in healthy and COPD subjects. Differential expression of genes after CSE stimulation resulted in significantly less changes in COPD lung fibroblasts (70 genes) than in healthy (207 genes), with 51 genes changed in both. COPD maintained low NOTCH signaling throughout and upregulated JUN >80%, indicating an increase in apoptosis. Healthy downregulated the Mitogen-activated protein kinase (MAPK) signaling cascade, including a ≥50% reduction in FGF2, CRK, TGFBR1 and MEF2A. Healthy also downregulated KAT6A and genes related to cell proliferation, all together indicating possible cell senescence signaling.

Conclusion

Overall, COPD lung fibroblasts responded to CSE stimulation with a very different and deficient expression profile compared to healthy. Highlighting that stimulated healthy cells are not an appropriate substitute for COPD cells which is important when investigating the mechanisms of COPD.

Circulating proteome for pulmonary nodule malignancy

BACKGROUND

Although lung cancer screening with low-dose computed tomography is rolling out in many areas of the world, differentiating indeterminate pulmonary nodules remains a major challenge. We conducted one of the first systematic investigations of circulating protein markers to differentiate malignant from benign screen-detected pulmonary nodules.

METHODS

Based on 4 international low-dose computed tomography screening studies, we assayed 1078 protein markers using prediagnostic blood samples from 1253 participants based on a nested case-control design. Protein markers were measured using proximity extension assays, and data were analyzed using multivariable logistic regression, random forest, and penalized regressions. Protein burden scores (PBSs) for overall nodule malignancy and imminent tumors were estimated.

RESULTS

We identified 36 potentially informative circulating protein markers differentiating malignant from benign nodules, representing a tightly connected biological network. Ten markers were found to be particularly relevant for imminent lung cancer diagnoses within 1 year. Increases in PBSs for overall nodule malignancy and imminent tumors by 1 standard deviation were associated with odds ratios of 2.29 (95% confidence interval: 1.95 to 2.72) and 2.81 (95% confidence interval: 2.27 to 3.54) for nodule malignancy overall and within 1 year of diagnosis, respectively. Both PBSs for overall nodule malignancy and for imminent tumors were substantially higher for those with malignant nodules than for those with benign nodules, even when limited to Lung Computed Tomography Screening Reporting and Data System (LungRADS) category 4 (P < .001).

CONCLUSIONS

Circulating protein markers can help differentiate malignant from benign pulmonary nodules. Validation with an independent computed tomographic screening study will be required before clinical implementation.

Regulatory roles of Osteopontin in lung epithelial inflammation and epithelial-telocyte interaction

BACKGROUND

Lung epithelial cells play important roles in lung inflammation and injury, although mechanisms remain unclear. Osteopontin (OPN) has essential roles in epithelial damage and repair and in lung cancer biological behaviours. Telocyte (TC) is a type of interstitial cell that interacts with epithelial cells to alleviate acute inflammation and lung injury. The present studies aim at exploring potential mechanisms by which OPN regulates the epithelial origin lung inflammation and the interaction of epithelial cells with TCs in acute and chronic lung injury.

METHODS

The lung disease specificity of OPN and epithelial inflammation were defined by bioinformatics. We evaluated the regulatory roles of OPN in OPN-knockdown or over-expressed bronchial epithelia (HBEs) challenged with cigarette smoke extracts (CSE) or in animals with genome OPN knockout (gKO) or lung conditional OPN knockout (cKO). Acute lung injury and chronic obstructive pulmonary disease (COPD) were induced by smoking or lipopolysaccharide (LPS). Effects of OPN on PI3K subunits and ERK were assessed using the inhibitors. Spatialization and distribution of OPN, OPN-positive epithelial subtypes, and TCs were defined by spatial transcriptomics. The interaction between HBEs and TCs was assayed by the co-culture system.

RESULTS

Levels of OPN expression increased in smokers, smokers with COPD, and smokers with COPD and lung cancer, as compared with healthy nonsmokers. LPS and/or CSE induced over-production of cytokines from HBEs, dependent upon the dysfunction of OPN. The severity of lung inflammation and injury was significantly lower in OPN-gKO or OPN-cKO mice. HBEs transferred with OPN enhanced the expression of phosphoinositide 3-kinase (PI3K)CA/p110α, PIK3CB/p110β, PIK3CD/p110δ, PIK3CG/p110γ, PIK3R1, PIK3R2 or PIK3R3. Spatial locations of OPN and OPN-positive epithelial subtypes showed the tight contact of airway epithelia and TCs. Epithelial OPN regulated the epithelial communication with TCs, and the down-regulation of OPN induced more alterations in transcriptomic profiles than the up-regulation.

CONCLUSION

Our data evidenced that OPN regulated lung epithelial inflammation, injury, and cell communication between epithelium and TCs in acute and chronic lung injury. The conditional control of lung epithelial OPN may be an alternative for preventing and treating epithelial-origin lung inflammation and injury.

Association between serum HE4 and poor periodontal health in adult women

OBJECTIVES

The aim of this study is to explore the association between serum human epididymal protein (HE4) levels and poor periodontal health.

MATERIALS AND METHODS

Data used in our study from the National Health and Nutrition Examination Survey (NHANES) 2001-2002 and Gene Expression Omnibus database (GSE10334 and GSE16134). Periodontitis category was defined by the 2017 classification scheme based on clinical periodontal parameters. Univariate and multivariate logistic regression analyses were used to explore the relationship between serum HE4 levels and the risk of periodontitis. GSEA analysis was performed to investigate the function of HE4.

RESULTS

A total of 1715 adult women over the age of 30 were included in our study. Compared with the lowest tertile, individuals in the highest tertile of HE4 levels were more likely to be Stage III/IV periodontitis (ORtertile3vs1 = 2.35, 95% CI: 1.35-4.21). The association was still significant in populations who were less than 60 years old, non-Hispanic white, high school graduate, 1.3 < PI ≤ 3.5, non-smoker, current smoker, non-obese, obese, and who had not diabetes mellitus or had not hypertension. In addition, HE4 expression was upregulated in diseased gingival tissues and involved in cell proliferation and immunity.

CONCLUSIONS

Serum HE4 is positively associated with poor periodontal health in adult women.

CLINICAL RELEVANCE

Patients with high serum HE4 levels are more likely to have Stage III/IV periodontitis. HE4 has the potential to be used as a biomarker to predict the severity of periodontitis.

Elevated serum levels of human epididymis protein 4 in adult patients with proliferative lupus nephritis

Background

This study aimed to access whether serum human epididymis protein 4 (HE4) level could identify lupus nephritis (LN) pathological classes in adults and children.

Methods

The serum HE4 levels of 190 healthy subjects and 182 patients with systemic lupus erythematosus (SLE) (61 adult-onset LN [aLN], 39 childhood-onset LN [cLN], and 82 SLE without LN) were determined using Architect HE4 kits and an Abbott ARCHITECT i2000SR Immunoassay Analyzer.

Results

Serum HE4 level was significantly higher in the aLN patients (median, 85.5 pmol/L) than in the patients with cLN (44 pmol/L, P < 0.001) or SLE without LN (37 pmol/L, P < 0.001), or the healthy controls (30 pmol/L, P < 0.001). Multivariate analysis showed that serum HE4 level was independently associated with aLN. Stratified by LN class, serum HE4 level was significantly higher in the patients with proliferative LN (PLN) than in those with non-PLN, and this difference was found only in aLN (median, 98.3 versus 49.3 pmol/L, P = 0.021) but not in cLN. Stratified by activity (A) and chronicity (C) indices, the aLN patients with class IV (A/C) possessed significantly higher serum HE4 levels than those with class IV (A) (median, 195.5 versus 60.8 pmol/L, P = 0.006), and this difference was not seen in the class III aLN or cLN patients.

Conclusion

Serum HE4 level is elevated in patients with class IV (A/C) aLN. The role of HE4 in the pathogenesis of chronic lesions of class IV aLN needs further investigation.

Regulatory B cells protect against chronic hypoxia-induced pulmonary hypertension by modulating the Tfh/Tfr immune balance

Hypoxia-induced pulmonary hypertension (HPH) is a progressive and lethal disease characterized by the uncontrolled proliferation of pulmonary artery smooth muscle cells (PASMCs) and obstructive vascular remodelling. Previous research demonstrated that Breg cells were involved in the pathogenesis of pulmonary hypertension. This work aimed to evaluate the regulatory function of Breg cells in HPH. HPH mice model were established and induced by exposing to chronic hypoxia for 21 days. Mice with HPH were treated with anti-CD22 or adoptive transferred of Breg cells. The coculture systems of Breg cells with CD4⁺ T cells and Breg cells with PASMCs in vitro were constructed. Lung pathology was evaluated by HE staining and immunofluorescence staining. The frequencies of Breg cells, Tfh cells and Tfr cells were analysed by flow cytometry. Serum IL-21 and IL-10 levels were determined by ELISA. Protein levels of Blimp-1, Bcl-6 and CTLA-4 were determined by western blot and RT-PCR. Proliferation rate of PASMCs was measured by EdU. Compared to the control group, mean PAP, RV/(LV + S) ratio, WA% and WT% were significantly increased in the model group. Anti-CD22 exacerbated abnormal hemodynamics, pulmonary vascular remodelling and right ventricle hypertrophy in HPH, which ameliorated by adoptive transfer of Breg cells into HPH mice. The proportion of Breg cells on day 7 induced by chronic hypoxia was significantly higher than control group, which significantly decreased on day 14 and day 21. The percentage of Tfh cells was significantly increased, while percentage of Tfr cells was significantly decreased in HPH than those of control group. Anti-CD22 treatment increased the percentage of Tfh cells and decreased the percentage of Tfr cells in HPH mice. However, Breg cells restrained the Tfh cells differentiation and expanded Tfr cells differentiation in vivo and in vitro. Additionally, Breg cells inhibited the proliferation of PASMCs under hypoxic condition in vitro. Collectively, these findings suggested that Breg cells may be a new therapeutic target for modulating the Tfh/Tfr immune balance in HPH.