Functional, Ultrastructural, and Transcriptomic Changes in Rat Diaphragms with Different Durations of Cigarette Smoke Exposure
Autor: | Baosen Pang, Haiyan Sheng, Jiawei Jin, Yijie Zhang, Xiaoqian Shi, Yingmin Ma, Yuhan Hu |
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Rok vydání: | 2020 |
Předmět: |
medicine.medical_specialty
COPD Lung business.industry General Medicine Protein degradation medicine.disease Pulmonary function testing 03 medical and health sciences FEV1/FVC ratio 0302 clinical medicine medicine.anatomical_structure Endocrinology 030228 respiratory system Internal medicine Gene expression Room air distribution medicine Histopathology 030212 general & internal medicine business |
Zdroj: | International Journal of Chronic Obstructive Pulmonary Disease. 15:3135-3145 |
ISSN: | 1178-2005 |
DOI: | 10.2147/copd.s278327 |
Popis: | Aims The aim of the study was to explore the functional and structural changes of the diaphragm and underlying mechanisms in response to 12 or 24 weeks of cigarette smoke (CS) exposure in rats. Materials and methods Rats were exposed to CS to develop a COPD model and the rats exposed to room air served as a control group. Rats were randomly divided into four groups: CS12W, CON12W, CS24W, and CON24W. Pulmonary function, lung histopathology, and the contractile properties and ultrastructure of diaphragm muscle were examined in these rats. The changes of transcriptomic profiling of diaphragm muscle were further compared between CS and control rats by the RNA Seq. Results Both CS groups showed lower FEV0.3/FVC, elevated mean linear intercept (MLI), and reduced mean alveolar numbers (MAN) vs the control groups. The fatigue index (FI) of the diaphragm muscle from the CS12W group, but not CS24W, was significantly increased. Conversely, the force-frequency curves of the diaphragm muscle from the CS24W group, but not CS12W group, were significantly decreased. Consistently, mitochondrial number density (NA) and volume density (Vv) were increased in the CS12W diaphragm muscle, while being decreased in the CS24W group. Furthermore, the diaphragm transcriptomic profiling results showed that genes regulating cell proliferation and energy metabolic activity were un-regulated and genes regulating protein degradation were down-regulated in the CS12W diaphragm, while CS24W diaphragm showed opposite changes. Conclusion These observations suggested a transition of diaphragm muscle from initial compensatory to decompensatory changes in function, structure, and gene expression during the development of COPD. |
Databáze: | OpenAIRE |
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