新型3D培養基可培養原始卵細胞至早期基礎濾泡細胞
並維持分泌賀爾蒙功能達30日

Hum Reprod. 2016 Apr 24. pii: dew049. [Epub ahead of print]

Survival and growth of isolated pre-antral follicles from human ovarian medulla tissue during long-term 3D culture.

Yin H1, Kristensen SG2, Jiang H3, Rasmussen A2, Andersen CY4.

Author information

Abstract

STUDY QUESTION:

Can human pre-antral follicles isolated enzymatically from surplus medulla tissue survive and grow in vitro during long-term 3D culture?

SUMMARY ANSWER:

Secondary human follicles can develop to small antral follicles and remain hormonally active in an alginate-encapsulation culture system for more than 30 days.

WHAT IS KNOWN ALREADY:

Ovarian tissue cryopreservation followed by transplantation is a promising fertility preservation approach for cancer patients. However, transplantation of cryopreserved tissue to patients may carry the risk of re-implanting malignant cells. Grafting of follicles enzymatically isolated from ovarian tissue or developing a method for follicular culture and maturation in vitro may provide fertility to such patients without the risk of reintroducing the malignancy. However, the growth of pre-antral follicles isolated by enzymatic digestion from medulla tissue during long-term culture has received only little attention.

STUDY DESIGN, SIZE, DURATION:

Two to ten human pre-antral follicles were encapsulated together within an alginate bead and cultured with or without ovarian interstitial tissue for either 7 days or >30 days. Follicles were cultured in either 20% oxygen or 5% oxygen or encapsulated in a lower concentration of alginate together with a lower concentration of FSH in high oxygen.

PARTICIPANTS/MATERIALS, SETTING, METHODS:

A total of 395 pre-antral follicles from 16 cancer patients, aged 9-37 years, were co-cultured for either 7 days or >30 days. A proportion of follicle (64) were removed from culture on Day 7 and assessed for viability using confocal fluorescence microscopy following calcein-AM and ethidium homodimer-1 staining or histology. The remaining follicles (331) were continued in culture for >30 days then assessed for survival and growth. Anti-Müllerian hormone (AMH) and estradiol levels were quantified in the medium.

MAIN RESULTS AND THE ROLE OF CHANCE:

An optimized protocol for isolation of intact healthy pre-antral follicles from ovarian medulla was developed. After 7 days of culture, secondary follicles had a significantly higher survival rates compared with primary and primordial follicles (70 versus <38%). Primordial and primary follicles did not develop into the antral follicle stage. In contrast, secondary follicles continued to develop in all culture conditions examined. Based on growth rate and morphology, four distinct cohorts of surviving follicles, 'fast growth', 'slow growth', 'no growth' and 'extruded oocyte' were identified. From Day 1 to Day 30, the mean diameter of follicles increased from 184 ± 35 to 661 ± 120 μm (significant from Day 18), 145 ± 19 to 318 ± 68 μm and 136 ± 15 to 162 ± 25 μm (mean ± SD) in the 'fast growth', 'slow growth' and 'no growth' patterns, respectively. The fast growth follicles also contained a larger diameter oocyte than other follicle groups. From the pre-antral follicle to antral stage, follicles became steroidogenically active and secretion of AMH and estradiol increased. No significant difference between the follicles cultured with or without ovarian interstitial tissue was observed.