[The role of alveolar macrophages in airway remodeling in asthmatic rats]
Related Experiment Video
Updated: Jul 16, 2026
Isolation and In Vitro Culture of Murine and Human Alveolar Macrophages
Published on: April 20, 2018
Chuan-xia Wang1, Chang-chong Li, Yun-chun Luo
1Affiliated Yuying Children's Hospital, Wenzhou Medical College, Wenzhou 325027, China.
Objective:
To study the role of alveolar macrophages (AM) in the processes of airway remodeling in asthmatic rats.
Methods:
Forty-eight young male Sprague-Dawley rats (Grade II) were divided randomly into a control group (A group), a 3 day asthma group (B group), a 14 day asthma group (C group) and a 30 day asthma group (D group). The rats were sensitized and challenged by ovalbumin to establish the asthmatic model. AM were purified from bronchoalveolar lavage. The content of tumor necrosis factor-alpha (TNF-alpha) in AM was measured by enzyme-linked immunosorbent assay, prostaglandin E2 (PGE2) by radioimmunoassay, matrix metalloproteinase-9 mRNA (MMP-9 mRNA) and tissue inhibitor of metalloproteinase-1 mRNA (TIMP-1 mRNA) by hybridization in situ. The total bronchial wall area (WAt) and the smooth muscle area (WAm) were measured by image analysis system. The WAt and the WAm were quantified per unit length of basement membrane (Pbm).
Results:
The bronchial wall thickness and the smooth muscle thickness of D group [(85 +/- 9) microm2/microm, (28.6 +/- 4.9) microm2/microm] were significantly higher than those of A group [(67 +/- 10) microm2/microm, (16.8 +/- 2.4) microm2/microm, t = 2.938, 3.227, all P < 0.01]. The contents of TNF-alpha and PGE2 in D group [(0.68 +/- 0.25) microg/L, (0.122 +/- 0.030) microg/L] were significantly higher than those in A group [(0.37 +/- 0.09) microg/L, (0.079 +/- 0.018) microg/L, t = 2.683, 3.016, all P < 0.01]. When A group was compared with B group [(0.74 +/- 0.29) microg/L, (0.120 +/- 0.028) microg/L] and C group [(0.71 +/- 0.23) microg/L, (0.117 +/- 0.028) microg/L], there was no significant difference (t = 1.624, 0.472, all P > 0.05) and (t = 0.935, 0.533, all P > 0.05). The contents (light density) of MMP-9 mRNA and TIMP-1 mRNA in D group (0.346 +/- 0.033, 0.361 +/- 0.040) were significantly higher than C group (0.279 +/- 0.015, 0.259 +/- 0.015, t = 2.574, 2.716, all P < 0.01), and so did D group and B group (0.183 +/- 0.025, 0.136 +/- 0.014, t = 2.913, 3.017, all P < 0.01), D group and A group (0.104 +/- 0.007, 0.109 +/- 0.008, t = 3.632, 3.487, all P < 0.01). There were significant correlations between the contents of MMP-9 mRNA and WAt (r = 0.693, P < 0.01), between MMP-9 mRNA and WAm (r = 0.738, P < 0.01), between TIMP-1 mRNA and WAt (r = 0.823, P < 0.01), and between TIMP-1 mRNA and WAm (r = 0.876, P < 0.01).
Conclusion:
AM and AM-derived cytokines are associated with airway remodeling in asthmatic rats.
Insights
Alveolar macrophages (AM) and their derived cytokines are linked to airway remodeling in rats with asthma. This study highlights the role of AM in the progression of asthmatic airway changes.
Area of Science:
- Respiratory Medicine
- Immunology
- Pathology
Context:
- Asthma is a chronic respiratory disease characterized by airway inflammation and remodeling.
- Alveolar macrophages (AM) play a crucial role in the innate immune response within the lungs.
- Understanding the specific contributions of AM to airway remodeling is essential for developing targeted therapies.
Purpose:
- To investigate the involvement of alveolar macrophages (AM) in the airway remodeling processes observed in a rat model of asthma.
- To quantify the expression of key inflammatory mediators and matrix remodeling factors within AM during asthma progression.
Summary:
- Ovalbumin-induced asthma model in Sprague-Dawley rats was established and divided into control and varying duration asthma groups (3, 14, 30 days).
- AM were isolated, and levels of tumor necrosis factor-alpha (TNF-alpha), prostaglandin E2 (PGE2), matrix metalloproteinase-9 mRNA (MMP-9 mRNA), and tissue inhibitor of metalloproteinase-1 mRNA (TIMP-1 mRNA) were measured.
- Significant increases in bronchial wall thickness, smooth muscle area, TNF-alpha, PGE2, MMP-9 mRNA, and TIMP-1 mRNA were observed in later stages of asthma, correlating with AM activity.
Impact:
- This research establishes a direct association between alveolar macrophages, their secreted cytokines, and the pathological changes constituting airway remodeling in asthma.
- Findings suggest that targeting AM-derived mediators could be a potential therapeutic strategy for mitigating airway remodeling in asthma patients.
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