Interrelationship of aging and mitochondrial DNA deletion in luteinized granulosa cells / 대한산부인과학회지

ABSTRACT

OBJECTIVE: Many clinical trials have proven the close relationship between the loss of human mitochondrial DNA and aging process. The purpose of this study was to evaluate the different types of mitochondrial DNA deletion and its frequency in luteinized granulosa cells in different aged groups of women undergoing in vitro fertilization (IVF). METHODS: The ovum pick up was done in 51 women who participated in Konyang University IVF program, and mitochondrial DNAs extracted from luteinized granulosa cells, were screened to search for different types of deletion and its frequency. The deleted mitochondrial DNA were analyzed by polymerase chain reaction method. DNA sequencing was performed to reveal exact deletion point. RESULTS: Three different types of deletions (4,977 bp, 7,150 bp, and 5,777 bp) were confirmed. To find the difference between the aged groups, we have divided women into groups younger than 32 years, between 32 to 37 years, and older than 37 years. The deletion of 4,977 bp was 60.9% (14/23) in younger than 32 years, 46.2% (6/13) in 32 to 37 years, 46.7% (7/15) in older than 37 years. There was no statistical significance between aged groups and the incidence of the deletion. The deletion of 7150 bp was 34.8% (8/23), in younger than 32 years, 30.8% (4/13) in 32 to 37 years, 40% (6/15) in older than 37 years. We investigated relationship between the frequency of deletion and the aging, but there was no statistical significance. In case of 5,777 bp, the deletion was 43.5% (10/23) in younger than 32 years, 30.8% (4/13) in 32 to 37 years, 53.3% (8/15) in older than 37 years. It showed no statistical significance as well as other types. CONCLUSION: In this study we have found three different types of deletion of mitochondrial DNA obtained from luteinized granulosa cells in women with infertility. There were no significant differnces of each type of deletion in 3 different aged groups of infantile women. The limitation of this study is that the analyze were done qualitatively. If we could provide the quantitative analyze it could be applied clinically.