Lianhua Qingke Preserves Mucociliary Clearance in Rat with Acute Exacerbation of Chronic Obstructive Pulmonary Disease by Maintaining Ciliated Cells Proportion and Protecting Structural Integrity and Beat Function of Cilia

Abstract

Purpose

Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD) is a sudden worsening of symptoms in patients with Chronic Obstructive Pulmonary Disease (COPD), such as cough, increased sputum volume, and sputum purulence. COPD and AECOPD are characterized by damage to cilia and increased mucus secretion. Mucociliary clearance (MCC) functions as part of the primary innate system of the lung to remove harmful particles and pathogens together with airway mucus and is therefore crucial for patients with COPD.

Methods

AECOPD was induced by cigarette smoke exposure (80 cigarettes/day, 5 days/week for 12 weeks) and lipopolysaccharide (LPS) instillation (200 μg, on days 1, 14, and 84). Rats administered Lianhua Qingke (LHQK) (0.367, 0.732, and 1.465 g/kg/d) or Eucalyptol, Limonene, and Pinene Enteric Soft Capsules (ELP, 0.3 g/kg/d) intragastrically. Pulmonary pathology, Muc5ac+ goblet cell and β-tubulin IV+ ciliated cells, and mRNA levels of forkhead box J1 (Foxj1) and multiciliate differentiation and DNA synthesis associated cell cycle protein (MCIDAS) were assessed by hematoxylin and eosin staining, immunofluorescence staining, and RT-qPCR, respectively. Ciliary morphology and ultrastructure were examined through scanning electron microscopy and transmission electron microscopy. Ciliary beat frequency (CBF) was recorded using a high-speed camera.

Results

Compared to the model group, LHQK treatment groups showed a reduction in inflammatory cell infiltration, significantly reduced goblet cell and increased ciliated cell proportion. LHQK significantly upregulated mRNA levels of MCIDAS and Foxj1, indicating promoted ciliated cell differentiation. LHQK protected ciliary structure and maintained ciliary function via increasing the ciliary length and density, reducing ciliary ultrastructure damage, and ameliorating random ciliary oscillations, consequently enhancing CBF.

Conclusion

LHQK enhances the MCC capability of ciliated cells in rat with AECOPD by preserving the structural integrity and beating function of cilia, indicating its therapeutic potential on promoting sputum expulsion in patients with AECOPD.

Keywords:

• goblet hyperplasia
• ciliary density
• ciliary length
• ciliary ultrastructure
• ciliary beat frequency
• CBF

Author Contributions

All authors made a significant contribution to the work reported, whether in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all of these areas. All authors took part in drafting, revising, or critically reviewing the article, gave final approval for the version to be published, have agreed on the journal to which the article has been submitted and agreed to be accountable for all aspects of the work.

Disclosure

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Additional information

Funding

This work was funded by the Innovation Team and Talents Cultivation Program of National Administration of Traditional Chinese Medicine [No. ZYYCXTD-D-202206], Key Project of National Natural Science Foundation of China [NO.82130123], Natural Science Foundation of Hebei Province [NO. H2023106039], Scientific Research Project of Hebei Provincial Administration of Traditional Chinese Medicine [2024401].