The following is a summary of “Association between MUC5AC and MUC5B genes expression and remodeling progression in severe neutrophilic asthma: A direct relationship,” published in the JULY 2023 issue of Pulmonology by Khorasani, et al.
Dysregulation of MUC5, specifically MUC5AC and MUC5B, is a characteristic feature of severe neutrophilic asthma. Therefore, for a study, researchers sought to investigate the mRNA expression of MUC5AC and MUC5B and their association with asthma severity and airway wall thickness in patients with severe neutrophilic asthma.
A case-control clinical trial included twenty-five patients with severe neutrophilic asthma and ten control subjects. Participants underwent assessments such as the Asthma Control Test (ACT), pulmonary function tests, fractional exhaled nitric oxide (FENO) measurement, and collection of induced sputum. Real-time PCR was performed to evaluate the expression of MUC5AC and MUC5B mRNA. High-resolution computed tomography (HRCT) was used to assess airway wall thickness (WT). Bioinformatic analysis was utilized to validate gene selection and guide further investigations.
Significant differences were observed in the mRNA expression of MUC5AC and MUC5B between asthmatic and control subjects. The expression of MUC5AC increased significantly with asthma severity and was associated with airway wall thickness (WT) (both P-values < 0.05). On the other hand, the expression of MUC5B was lower in asthmatic patients compared to the control group. There was no significant correlation between MUC5B mRNA level and WT or asthma severity. Interestingly, the transcription level of MUC5AC was correlated with the percentage of neutrophils in sputum, while the transcription level of MUC5B was positively correlated with sputum macrophages and negatively correlated with sputum neutrophils.
In severe neutrophilic asthma, the overexpression of MUC5AC mRNA was associated with increased airway wall thickness, possibly contributing to asthma severity and the formation of mucus plugs. Conversely, the expression of MUC5B is decreased, which may result in impaired mucociliary clearance in the airways. The findings highlighted the role of MUC5 dysregulation in severe neutrophilic asthma and its impact on airway pathophysiology.
Source: resmedjournal.com/article/S0954-6111(23)00148-8/fulltext