Circulating miRNA expression in asthmatics is age-related and associated with clinical asthma parameters, respiratory function and systemic inflammation

Aleksandra Wardzyńska,Marek L Kowalski,Małgorzata Pawełczyk,Joanna Makowska,Joanna Rywaniak,Joanna Jamroz-Brzeska

doi:10.1186/s12931-021-01769-x

Aleksandra Wardzyńska, Marek L Kowalski + Show 4 more

Open Access

https://doi.org/10.1186/s12931-021-01769-x

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Abstract

BackgroundThe course of asthma may differ between elderly asthmatics (EA) and non-elderly asthmatics (nEA), which may be partially associated with an age-dependent aberrant immune response. The aim of the study was to determine the influence of serum miRNA expression on asthma characteristics and systemic inflammation markers in EA and nEA.MethodsControl and severity of asthma, pulmonary function and FeNO were assessed in 28 EA and 31 nEA patients. The control group included 59 elderly and non-elderly healthy individuals. The expression of selected miRNAs in serum was measured with rt-PCR, and proinflammatory cytokine activity was assayed by ELISA or flow cytometry.ResultsNo difference in serum miRNA expression was observed between the asthmatics and healthy controls. EA demonstrated lower expression of miRNA-106a and miRNA-126a than nEA (p = 0.003 and p = 0.02) and EC had lower expression of miRNA-146a, -126a, -106a and 19b than nEC (p = 0.001, p = 0.003, p = 0.005 and p < 0.001 respectively). Only nEA demonstrated a relationship between the expression of selected miRNAs and the level of asthma control (assessed with ACT) and with airway inflammation, measured by FeNO level. All patients with asthma demonstrated elevated TNFα, IL-6 and sTNF RI levels compared to controls (p = 0.026, p = 0.03 and p < 0.001 respectively). EA demonstrated a higher TNFα level than EC (p < 0.001), and EA had a higher level of sTNF RI than nEA (p < 0.001). A significant correlation was observed between serum levels of proinflammatory cytokines and selected miRNAs.ConclusionSerum miRNA expression was found to correlate with clinical characteristics of asthma and systemic inflammation in an age-dependent fashion, suggesting that miRNA may differentially contribute to asthma pathogenesis in elderly and non-elderly patients.

Highlights

In elderly patients, asthma may be a challenging problem for clinicians as this group display almost all known phenotypes of asthma, which are further modified by physiological ageing and presence of comorbidities [1, 2]
Clinical characteristic of patients No difference in spirometry or impulse oscillometry (IOS) parameters were observed between elderly asthmatics (EA) and non-elderly asthmatics (nEA)
Circulating miRNA expression in elderly and non‐elderly asthmatics No difference in the serum miRNA expression was observed between the asthmatics and healthy controls (Fig. 1A)

Summary

Introduction

Asthma may be a challenging problem for clinicians as this group display almost all known phenotypes of asthma, which are further modified by physiological ageing and presence of comorbidities [1, 2]. An important factor that can affect asthma is the progressive impairment of the immune response with age, referred to as Immunosenecence [4]. It seems to be associated with an elevated level of proinflammatory cytokines, referred to as systemic inflammation (SI), which may originate from the non-specific activation of innate cells, oxidative stress or persistent viral infections [5, 6]. The aim of the study was to determine the influence of serum miRNA expression on asthma characteristics and systemic inflammation markers in EA and nEA

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