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Updated: May 19, 2026
Isolation of Pulmonary Artery Smooth Muscle Cells from Neonatal Mice
Published on: October 19, 2013
Oxygen dose responsiveness of human fetal airway smooth muscle cells
William R Hartman1, Dan F Smelter, Venkatachalem Sathish
1Department of Anesthesiology, Mayo Clinic, Rochester, MN 55905, USA.
Insights
Supplemental oxygen for premature infants can cause hyperoxia, impacting developing airway smooth muscle (ASM). This study reveals oxygen
Area of Science:
- Neonatal respiratory physiology
- Cellular biology
- Developmental pulmonology
Background:
- Supplemental oxygen is crucial for premature infants but hyperoxia may increase asthma risk.
- Mechanisms of oxygen's impact on airway structure and function relevant to asthma are not fully understood.
Purpose of the Study:
- To investigate the effects of varying oxygen concentrations on human fetal airway smooth muscle (fASM) cells.
- To examine oxygen-induced changes in intracellular calcium ([Ca(2+)](i)) and cellular proliferation in fASM.
Main Methods:
- Isolated human fASM cells (18-20 weeks postconceptual age) were cultured.
- Cells were exposed to hypoxia (10%) and hyperoxia (up to 90% oxygen).
- Intracellular calcium responses and cellular proliferation/apoptosis markers were measured.
Main Results:
- fASM cells exhibited functional calcium signaling and proliferation capacity.
- Hyperoxia showed dose-dependent effects: enhanced proliferation at <60% oxygen, increased apoptosis and mitochondrial fission at >60% oxygen.
- Acetylcholine-induced calcium responses were altered by oxygen levels, enhanced at <60% and blunted at >60% oxygen.
Conclusions:
- Oxygen exposure has dose-dependent effects on the structure and function of developing airway smooth muscle.
- These findings suggest potential long-term consequences for childhood airway diseases.
- Detrimental effects of hyperoxia on fASM should be considered when assessing risks of supplemental oxygen in premature infants.
Abstract:
Maintenance of blood oxygen saturation dictates supplemental oxygen administration to premature infants, but hyperoxia predisposes survivors to respiratory diseases such as asthma. Although much research has focused on oxygen effects on alveoli in the setting of bronchopulmonary dysplasia, the mechanisms by which oxygen affects airway structure or function relevant to asthma are still under investigation. We used isolated human fetal airway smooth muscle (fASM) cells from 18-20 postconceptual age lungs (canalicular stage) to examine oxygen effects on intracellular Ca(2+) ([Ca(2+)](i)) and cellular proliferation. fASM cells expressed substantial smooth muscle actin and myosin and several Ca(2+) regulatory proteins but not fibroblast or epithelial markers, profiles qualitatively comparable to adult human ASM. Fluorescence Ca(2+) imaging showed robust [Ca(2+)](i) responses to 1 microM acetylcholine (ACh) and 10 microM histamine (albeit smaller and slower than adult ASM), partly sensitive to zero extracellular Ca(2+). Compared with adult, fASM showed greater baseline proliferation. Based on this validation, we assessed fASM responses to 10% hypoxia through 90% hyperoxia and found enhanced proliferation at <60% oxygen but increased apoptosis at >60%, effects accompanied by appropriate changes in proliferative vs. apoptotic markers and enhanced mitochondrial fission at >60% oxygen. [Ca(2+)](i) responses to ACh were enhanced for <60% but blunted at >60% oxygen. These results suggest that hyperoxia has dose-dependent effects on structure and function of developing ASM, which could have consequences for airway diseases of childhood. Thus detrimental effects on ASM should be an additional consideration in assessing risks of supplemental oxygen in prematurity.