노화는 말초 혈관 기능에 퇴행성 변화를 가져올 수 있으며 혈관의 기능은 혈관생성 지표의 영향을 받는 것으로 보고되고 있다. 따라서 이 연구는 젊은 흰쥐와 노화된 흰쥐를 대상으로 골격근(가자미근)에서 나타나는 혈관생성 지표인 Ang-1과 Ang-2의 단백질 발현의 차이를 비교하고 Ang-1 : Ang-2 ratio의 차이를 분석 및 관찰하기 위해 수행되었다. 연구의 목적을 위해 12주령 흰쥐(SD rats) 6마리와 20개월령 흰쥐 6마리를 Young 집단과 Old 집단으로 구분하였다. Old 집단의 경우 20개월 동안 직접 사육하여 노화 상태를 유도하였다. 골격근(가자미근)에서 관련 단백질의 발현 정도를 알아보기 위해 western blot 기법을 사용하였다. 연구결과, Ang-1 단백질은 젊은 집단에 비해 노화집단에서 낮게 나타나며 집단 간 차이를 보였다(p= .001). Ang-2 단백질의 경우, 젊은 집단에 비해 노화집단에서 유의하게 높게 나타났다(p= .007). 마지막으로 Ang-1:Ang-2 ratio는 젊은 집단에 비해 노화집단에서 유의하게 낮게 나타났다(p= .001). 따라서 골격근 내 혈관생성 관련 단백질들은 노화에 의해 변화되는 것으로 사료된다.
The follicle loss of transplanted ovarian tissue (OT) is caused by ischemia and slow revascularization. To shorten the ischemic period and promote angiogenesis, some angiogenic factors have been treated for transplanted tissues. Angiopoietin-2 (ANG-2) is one of the major angiogenic factors and has been reported to promote blood vessels and increase vascular permeability in the ischemic and/or hypoxic environment. So, this study was designed to assess the impact of ANG-2 on follicle integrity and revascularization of mouse OT grafts. The 5-week-old B6D2F1 female mice were divided into 3 groups (a control and 2 ANG-2 groups) followed by ovary collection and vitrification. After warming, the ovaries were autotransplanted into kidney capsules with/without ANG-2 injection (50 or 500 ng/kg), and then killed at day(D)2, 7, 21 and 42 after transplantation. Total 2,437 follicles in OT grafts were assessed for the follicular density, integrity and classification by H&E staining. Apoptosis, revascularization, and serum FSH levels were evaluated by TUNEL assay, CD31 immunohistochemistry, and ELISA respectively. All the ANG-2 groups showed remarkable increase of morphologically intact follicle ratio across all the grafting duration except D21 (no statistical difference). The numbers of CD31(+) vessels (the sum of 3 fields at ×400 magnification) were significantly increased in both ANG-2 groups compared with the control group at all the grafting duration. Especially at D42, the 500ng ANG-2 group showed significantly more vessels than the 50 ng ANG-2 group as well as the control group. However the mean follicle numbers of grafts, apoptosis ratio and serum FSH levels showed no significant difference among the groups. In this study, remarkably well preserved follicles and larger amount of vessels were appeared in ANG-2 treated groups. So we thought that ANG-2 treatment is effective for OT transplantation and improve transplantation outcomes.