Cardiovascular changes after pneumonia in a dual disease mouse model
Benjamin Bartlett1,2, Herbert P Ludewick1, Shipra Verma3,4
1Department of Advanced Clinical and Translational Cardiovascular Imaging, Harry Perkins Institute of Medical Research, Murdoch, Australia.
Scientific Reports
|July 1, 2022
Summary
Pneumonia caused by Streptococcus pneumoniae TIGR4 increases cardiovascular disease risk by altering aorta plaque characteristics and promoting aortic wall remodeling in ApoE-/- mice. This study highlights the link between infection-induced inflammation and atherosclerosis progression.
Area of Science:
- Cardiovascular Research
- Infectious Disease Immunology
- Atherosclerosis Pathogenesis
Background:
- Residual inflammation in cardiovascular organs is linked to increased cardiovascular complications post-pneumonia.
- The precise mechanisms by which pneumonia affects cardiovascular health remain incompletely understood.
Purpose of the Study:
- To investigate the impact of Streptococcus pneumoniae infection on plaque characteristics and inflammation in the aorta and heart of ApoE-/- mice.
- To determine if pneumonia contributes to cardiovascular complications through altered plaque stability and aortic remodeling.
Main Methods:
- ApoE-/- mice on a high-fat diet were intranasally inoculated with Streptococcus pneumoniae TIGR4 or PBS.
- Aortic plaque burden and characteristics were assessed using Oil red O and Trichrome staining.
- Inflammatory changes and aortic remodeling were evaluated via FDG-PET imaging and immunofluorescence staining at 2, 7, and 28 days post-infection.
Main Results:
- S. pneumoniae TIGR4 infection led to increased plaque presence in the aortic root and thoracic aorta at specific time points.
- Infected mice exhibited more pronounced aortic wall remodeling at 28 days post-infection.
- Aortic root plaques in infected mice showed reduced collagen and smooth muscle cells, indicating plaque instability.
Conclusions:
- Pneumonia significantly alters plaque burden, plaque characteristics, and aortic wall remodeling in a mouse model of atherosclerosis.
- These Streptococcus pneumoniae-induced cardiovascular changes may explain the heightened risk of cardiovascular complications in pneumonia survivors.
