Histologic analysis and lipid profiling reveal reproductive age-associated changes in peri-ovarian adipose tissue

• Published in: Reproductive biology and endocrinology 2019-06, Vol.17 (1), p.46-13, Article 46
• Main Authors: Dipali, Shweta S, Ferreira, Christina R, Zhou, Luhan T, Pritchard, Michele T, Duncan, Francesca E
• Format: Article
• Language: English
• Subjects: Adipocytes; Adipocytes - cytology; Adipocytes - metabolism; Adipose; Adipose tissue; Adipose Tissue - cytology; Adipose Tissue - metabolism; Age; Age Factors; Aging; Aging (Biology); Aging - physiology; Animals; Body fat; Cytokines; Defects; Fatty acids; Female; Fertility; Fibroblasts; Gene expression; Growth factors; Hypertrophy; Hypothyroidism; Infertility; Lipids; Lipids - analysis; Liver diseases; Mass spectroscopy; Metabolism; Metabolites; Mice; Obesity; Observations; Oocytes - cytology; Oocytes - metabolism; Ovarian Follicle - cytology; Ovarian Follicle - metabolism; Ovary; Ovary - cytology; Ovary - metabolism; Peri-gonadal; Phenotypes; Physiological aspects; Physiology; Reproduction - physiology; Reproductive status; Sexual cycle; Stem cells; Transplants & implants; Triacylglycerol; Womens health
• ISSN: 1477-7827; 1477-7827
• DOI: 10.1186/s12958-019-0487-6

Reproductive aging is a robust phenotype that occurs in all females and is characterized by a significant reduction in gamete quantity and quality, which can have negative consequences on both endocrine function and fertility. Age-associated differences in the oocyte, follicle, and ovary have been well-documented, but how the broader environment changes with age is less well understood. Fat is one of the largest organs in the body, and peri-gonadal adipose tissue surrounds the rodent ovary and comprises a local ovarian environment. The goal of this study was to characterize how peri-ovarian adipose tissue changes with advanced reproductive age. We isolated peri-gonadal adipose tissue from two cohorts of CB6F1 mice: reproductively young (6-12 weeks) and reproductively old (14-17 months). A comparative histological analysis was performed to evaluate adipocyte architecture. We then extracted lipids from the tissue and performed multiple reaction monitoring (MRM)-profiling, a mass spectrometry-based method of metabolite profiling, to compare the lipid profiles of peri-gonadal adipose tissue in these age cohorts. We found that advanced reproductive age was associated with adipocyte hypertrophy and a corresponding decrease in the number of adipocytes per area. Of the 10 lipid classes examined, triacylglycerols (TAGs) had significantly different profiles between young and old cohorts, despite quantitative analysis revealing a decrease in the total amount of TAGs per weight of peri-gonadal adipose tissue with age. These findings pinpoint age-associated physiological changes in peri-gonadal adipose tissue with respect to adipocyte morphology and lipid profiles and lay the foundation for future studies to examine how these alterations may influence both adipocyte and ovarian function.