Sex differences in cerebral microbleeds in aging C57BL/6 mice

Previous studies have shown the connection between aortic stiffness, cerebral microbleeds (CMBs) and increased cognitive decline in both human and mouse studies (Akoudad et al., 2016; Mitchell, 2015; Wang, 2018). However, most studies have been done only on males, leaving out a clear understanding of sex differences in CMBs. The purpose of the present study is to identify the changes in CMB levels in aging C57BL/6 female mice and compare this to the aging male mouse model. There were two hypotheses the study aimed to test: (1) female mice would show an increase in CMBs with age and (2) the level of CMBs in females would be less than in males until old age where both sexes will have similar levels of microbleeds. To test the hypotheses, histology via Prussian Blue staining was used to detect CMBs in the perfused C57BL/6 aging female mice and then compared to CMB levels in the males, found previously (Wang, 2018). The results support the first hypothesis that CMBs increase with age in the female mouse model. However, the level of CMBs is decreased in the old age female compared to the old male. The present study is the first to show sex differences in cerebral microbleeds with age. This is relevant to researchers and clinicians as it shows that sex differences need to be accounted for when identifying mechanisms and developing cures for diseases such as dementia.2021-06-18T00:00:00