The Association Between Serum Human Epididymis Protein 4 Level and Cardiovascular Events in Patients with Chronic Obstructive Pulmonary Disease

A Nomogram for Predicting Cardiovascular Diseases in Chronic Obstructive Pulmonary Disease Patients

Cardiovascular diseases (CVDs) are the most common comorbidities in the chronic obstructive pulmonary disease (COPD), which increase the risk of hospitalization, length of stay, and death in COPD patients. This study aimed to identify the predictors for CVDs in COPD patients and construct a prediction model based on these predictors. In total, 1022 COPD patients in National Health and Nutrition Examination Surveys (NHANES) were involved in the cross-sectional study. All subjects were randomly divided into the training set (n = 709) and testing set (n = 313). The differences before and after the manipulation of the missing data were compared via sensitivity analysis. Univariate and multivariable analyses were employed to screen the predictors of CVDs in COPD patients. The performance of the prediction model was evaluated via the area under the curve (AUC), accuracy, sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and calibration. Subgroup analysis was performed in patients using different COPD diagnosis methods and patients smoking or not smoking in the testing set. We found that male, older age, a smoking history, overweight, a history of blood transfusion, a history of heart disease in close relatives, higher levels of white blood cell (WBC), and monocyte (MONO) were associated with the increased risk of CVDs in COPD patients. Higher levels of platelets (PLT) and lymphocyte (LYM) were associated with reduced risk of CVDs in COPD patients. A prediction model for the risk of CVDs in COPD patients was established based on predictors including gender, age, a smoking history, BMI, a history of blood transfusion, a history of heart disease in close relatives, WBC, MONO, PLT, and LYM. The AUC value of the prediction model was 0.75 (95% CI: 0.71–0.79) in the training set and 0.79 (95%CI: 0.73–0.85) in the testing set. The prediction model established showed good predictive performance in predicting CVDs in COPD patients.

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

Background

Chronic obstructive pulmonary disease (COPD) is a progressive disease characterized by chronic inflammation and airway remodeling. Human epididymis protein 4 (HE4) plays a critical role in various inflammatory or fibrotic diseases. However, the role of HE4 in COPD remains unidentified.

Methods

HE4 expression was determined in the lung tissues from COPD patients and cigarette smoke (CS)-exposed mice using immunohistochemical staining, qPCR, or western blot. The plasma level of HE4 was detected by ELISA. The regulations of HE4 in the expressions of CS extract (CSE)-induced inflammatory cytokines in human bronchial epithelial cells (HBE) were investigated through knockdown or overexpression of HE4. The role of secretory HE4 (sHE4) in the differentiation and proliferation in human pulmonary fibroblast cells (HPF) was explored via qPCR, western blot, CCK8 assay or 5-ethynyl-2′-deoxyuridine (EdU) staining. The probe of related mechanism in CSE-induced HE4 increase in HBE was conducted by administrating N-acetylcysteine (NAC).

Results

HE4 was up-regulated in both the lung tissue and plasma of COPD patients relative to controls, and the plasma HE4 was negatively associated with lung function in COPD patients. The same enhanced HE4 expression was verified in CS-exposed mice and CSE-induced HBE, but CSE failed to increase HE4 expression in HPF. In vitro experiments showed that reducing HE4 expression in HBE alleviated CSE-induced IL-6 release while overexpressing HE4 facilitated IL-6 expression, mechanistically through affecting phosphorylation of NFκB-p65, whereas intervening HE4 expression had no distinctive influence on IL-8 secretion. Furthermore, we confirmed that sHE4 promoted fibroblast-myofibroblast transition, as indicated by promoting the expression of fibronectin, collagen I and α-SMA via phosphorylation of Smad2. EdU staining and CCK-8 assay demonstrated the pro-proliferative role of sHE4 in HPF, which was further confirmed by enhanced expression of survivin and PCNA. Pretreatment of NAC in CSE or H₂O₂-induced HBE mitigated HE4 expression.

Conclusions

Our study indicates that HE4 may participate in airway inflammation and remodeling of COPD. Cigarette smoke enhances HE4 expression and secretion in bronchial epithelium mediated by oxidative stress. Increased HE4 promotes IL-6 release in HBE via phosphorylation of NFκB-p65, and sHE4 promotes fibroblastic differentiation and proliferation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02040-7.

Elevated Serum HE4 Concentrations and Risk of Cardiac Complications among Hospitalized Patients with Burns

BACKGROUND

The decrease in effective blood volume after burns is closely related to abnormal heart function.

OBJECTIVE

To investigate whether serum human epididymis protein 4 (HE4), an indicator of early renal injury, contributes to increased risk of cardiac complications in patients with burns.

METHODS

Within 24 hours after hospital admission, clinical condition assessment and biochemical testing in patients with burns were performed. Multivariate analysis was performed by evaluating the relationship between serum HE4 levels and risk of cardiac complications (cardiac insufficiency, arrhythmia, and myocardial infarction) during hospitalization.

RESULTS

The number (percentage) of cardiac complications in all included patients with burns was 80 (15.6%). The results of sensitivity analysis suggest that elevated serum HE4 levels were related to higher risk of cardiac complications in patients with sepsis (OR = 2.1; 95% CI, 1.19-3.17; P <.001) and in patients without sepsis (OR = 2.29; 95% CI, 1.33-4.71l; P = .005), respectively, after adjustments for clinical confounding factors were made. Sepsis did not have a modification effect on the association between serum and cardiac complications among these patients. Also, the results of ROC curve analysis showed that serum HE4 levels have good predictive value for predicting cardiac complications in patients with burns (AUC = 0.708; 95% CI, 0.61-0.81; P <.001).

CONCLUSIONS

In the current study, we identified that elevated HE4 levels contributed to increased risk of cardiac complications in the hospital in patients with burns. This novel finding suggests that burn patients with serum HE4 may provide the opportunity to predict cardiac complications before hospital admission.

Large-Scale Plasma Protein Profiling of Incident Myocardial Infarction, Ischemic Stroke, and Heart Failure

Background

We recently reported a link between plasma levels of 2 of 84 cardiovascular disease (CVD)–related proteins and the 3 major CVDs, myocardial infarction, ischemic stroke, and heart failure. The present study investigated whether measurement of almost 10 times the number of proteins could lead to discovery of additional risk markers for CVD.

Methods and Results

We measured 742 proteins using the proximity extension assay in 826 male participants of ULSAM (Uppsala Longitudinal Study of Adult Men) who were free from CVD at the age of 70 years. Cox proportional hazards models were adjusted for age only, as well as all traditional risk factors. During a 12.5‐year median follow‐up (maximal, 22.0 years), 283 incident CVDs occurred. Forty‐one proteins were significantly (false discovery rate <0.05) related to the combined end point of incident CVD, with N‐terminal pro–brain natriuretic peptide as the top finding, while 53 proteins were related to incident myocardial infarction. A total of 13 and 16 proteins were significantly related to incident ischemic stroke and heart failure, respectively. Growth differentiation factor 15, 4‐disulfide core domain protein 2, and kidney injury molecule were related to all of the 3 major CVD outcomes. A lasso selection of 11 proteins improved discrimination of incident CVD by 5.0% (P=0.0038).

Conclusions

Large‐scale proteomics seem useful for the discovery of new risk markers for CVD and to improve risk prediction in an elderly population of men. Further studies are needed to replicate the findings in independent samples of both men and women of different ages.