Sexual differences in mitochondrial and related proteins in rat cerebral microvessels: A proteomic approach

Abstract

Sex differences in mitochondrial numbers and function are present in large cerebral arteries, but it is unclear whether these differences extend to the microcirculation. We performed an assessment of mitochondria-related proteins in cerebral microvessels (MVs) isolated from young, male and female, Sprague-Dawley rats. MVs composed of arterioles, capillaries, and venules were isolated from the cerebrum and used to perform a 3 versus 3 quantitative, multiplexed proteomics experiment utilizing tandem mass tags (TMT), coupled with liquid chromatography/mass spectrometry (LC/MS). MS data and bioinformatic analyses were performed using Proteome Discoverer version 2.2 and Ingenuity Pathway Analysis. We identified a total of 1969 proteins, of which 1871 were quantified by TMT labels. Sixty-four proteins were expressed significantly ( p < 0.05) higher in female samples compared with male samples. Females expressed more mitochondrial proteins involved in energy production, mitochondrial membrane structure, anti-oxidant enzyme proteins, and those involved in fatty acid oxidation. Conversely, males had higher expression levels of mitochondria-destructive proteins. Our findings reveal, for the first time, the full extent of sexual dimorphism in the mitochondrial metabolic protein profiles of MVs, which may contribute to sex-dependent cerebrovascular and neurological pathologies.

Transcriptome analysis reveals sexual disparities in gene expression in rat brain microvessels

“…We previously reported substantial sexual dimorphism in the mitochondrial metabolic protein profiles of young male and female rat MVs using a liquid chromatography/mass spectrometry (LC/MS)-based proteomic approach. 11 Interestingly, we observed that females displayed higher levels of mitochondrial proteins involved in energy production, mitochondrial membrane structure, as well as higher levels of antioxidants than males. Conversely, males had higher expression levels of mitochondria-destructive proteins.…”

“…Our previous studies 3,6,7,11 of mitochondrial respiration have shown that MVs are viable for ex vivo studies. The MVs were isolated as previously described 11 (Supplementary Material). The purity of the MV preparation was verified by light and electron microscopy, immunostaining, and western blotting.…”

“…An alkaline phosphatase (AP) staining method was applied to differentiate MVs in arterioles, capillaries, and venules using our previously adopted protocol. 11 Color development was observed under light microscopy with 20X magnification.…”

“…8 The consequent dysfunction of the microvasculature leads to impaired nutrient supply to neurons and glia, 2 blood-brain barrier (BBB) disruption, 9 and detrimental vascular remodeling. 8 In addition, microvascular function and responsiveness to physiological stress varies considerably between the sexes 10,11 and may account for differential susceptibility and severity of neurological diseases in males and females. However, little is known about sexbased differences in gene expression in the cerebral MVs.…”

Comparative bioinformatics analysis between proteomes of rabbit aneurysm model and human intracranial aneurysm with label‐free quantitative proteomics

“…Therefore, we chose STA samples as control tissues in this study. Proteomics has been applied to explore the mechanism of many diseases 45,46 . Jiang et al 12 analyzed protein expression between ruptured and unruptured IAs and found phagosomes, focal adhesion, and ECM‐receptor interaction to be the most common pathways involved in aneurysm rupture.…”