Yoon Young Kim

Efficient biomaterials for tissue engineering of female reproductive organs

Current investigations on the bioengineering of female reproductive tissues have created new hopes for the women suffering from reproductive organ failure including congenital anomaly of the female reproductive tract or serious injuries. There are many surgically restore forms that constitute congenital anomaly, however, to date, there is no treatment except surgical treatment of transplantation for patients who are suffering from anomaly or dysfunction organs like vagina and uterus. Restoring and maintaining the normal function of ovary and uterus require the establishment of biological substitutes that can cover the roles of structural support for cells and passage of secreting molecules. As in the case of constructing other functional organs, reproductive organ manufacturing also needs biological matrices which can provide an appropriate condition for attachment, growth, proliferation and signaling of various kinds of grafted cells. Among the organs, uterus needs special features such as plasticity due to their amazing changes in volume when they are in the state of pregnancy. Although numerous natural and synthetic biomaterials are still at the experimental stage, some biomaterials have already been evaluated their efficacy for the reconstruction of female reproductive tissues. In this review, all the biomaterials cited in recent literature that have ever been used and that have a potential for the tissue engineering of female reproductive organs were reviewed, especially focused on bioengineered ovary and uterus.

Gonadotropin ratio affects the in vitro growth of rhesus ovarian preantral follicles

In vitro follicle growth (IVFG) strategy is critical in the fertility preservation of cancer survivors; however, its optimal protocol needs to be developed using primate models since the availability of human samples is limited. Only a few previous studies have reported the successful IVFG of rhesus monkey ovaries using low-dose follicle-stimulating hormone (FSH) (0.3 or 3u2005ng/mL) and long-term culture (up to 5u2005weeks) and it is still uncertain in regard to the optimal culture duration and effective dose of treated gonadotropins applicable to the IVFG of rhesus preantral follicles. Recently, we have reported that the FSH to luteinizing hormone (LH) ratio affects the in vitro growth of murine ovarian follicles. We aimed to investigate whether gonadotropin ratios affect the efficiency of rhesus follicular growth in vitro. Ovaries were collected from six necropsied rhesus macaques (4–9u2005years) and preantral follicles were retrieved and cultured for 14u2005days using 200u2005mIU/mL FSH. The characteristics of follicular growth were compared between the FSH:LH=1:1 (n=24) and FSH:LH=2:1 (n=24) groups. High concentration gonadotropin treatment shortened the duration required for in vitro maturation of rhesus preantral follicles. The FSH:LH=2:1 group showed a faster follicular growth and enabled the acquisition of mature oocytes, although the expression of growth differentiation factor (GDF)-9 and anti-Müllerian hormone (AMH) did not differ significantly between the two groups. Taken together, high dose gonadotropin treatment can shorten the duration of IVFG and the gonadotropin ratio is important in the IVFG of rhesus monkey ovaries.

Induction of multiple ovulation via modulation of angiotensin II receptors in in vitro ovarian follicle culture models

In vitro culture of ovarian follicles is a promising bioengineering technique for retrieving fertilizable oocytes from preserved ovarian tissues of cancer survivors. However, current in vitro follicle culture techniques are labour‐intensive and of low efficiency, as only single follicle culture (SFC) has been possible to date. The present study investigated the feasibility of multifollicular cluster culture (MFCC) system using angiotensin II receptor (ATII‐Rc) analogues. Ovarian pre‐antral follicles isolated from 2‐week‐old C57BL6 mice were cultured with ATII‐Rc agonist or antagonist and their maturation outcomes were compared with control group. When single follicles were cultured, the ovulation and maturation rates were similar in all three groups. When three‐follicle clusters were cultured, up to three follicles were ovulated in the ATII‐Rc agonist group while none or one follicle ovulated in control or antagonist groups (p < 0.0001). Significantly higher numbers of mature oocytes were obtained in the agonist group (three‐follicle 28.2 ± 4.9 vs. SFC 11.0 ± 1.3, per 25 cultured droplets) (p < 0.0001), and the development of each fertilized oocytes was comparable to those from SFC. It is therefore concluded that this novel MFCC system can significantly improve the efficiency of in vitro mature oocyte retrieval via ATII‐Rc modulation. Copyright

Profile of MicroRNA Expression in Endometrial Cell during In Vitro Culture According to Progesterone Concentration

AbstractnArtificial uterus using endometrium implant can be a novel treatment strategy for infertile women with refractory endometrial dysfunction. At early pregnancy, the function of uterine endometrial cells for the communication between the conceptus of pre-implantation period and maternal reproductive system is essential. MicroRNA (miR) expression profile of endometrial cells according to progesterone, a crucial pregnancy-maintaining hormone, provides important data for in vitro endometrial cell culture strategy that is useful for engineering artificial uteri using endometrial implants. The present study aimed to evaluate the miR expression profile of in vitro cultured endometrial cells under hormonal milieu mimicking early pregnancy period in terms of progesterone concentration. We cultured murine uterine endometrial cells, human uterine endometrial carcinoma cells, and immortalized human uterine endometrial cells using different progesterone concentrations, and analyzed the expression of miRs critical for early pregnancy. The expression of miR-20a, -21, -196a, -199a, and -200a was differently regulated according to progesterone concentration in different endometrial cell lines. The analysis of candidate target genes showed that the expression of phosphatase and tensin homolog, mucin 1 (MUC1), progesterone receptor, transforming growth factor β receptor II, matrix metallopeptidase-9 was up-regulated by progesterone treatment in mouse and human endometrial cell lines. These results indicate that physiological concentration range (10−7 and 10−9 M) of progesterone affect the survival and target gene expression via modulating miR expression. Taken together, progesterone can be a crucial factor in regulating miR expression on in vitro cultured endometrial cells.n

BMP2 Induces Direct Differentiation into Cardiomyocytes from Human Embryonic Stem Cells during Short-Tem Culture In Vitro

Abstract 367 presented at Poster Session: Basic Parturition/Prematurity II (Friday, 3/26/2010, 10:00 AM - 12:00 PM)Plenary Session: Presidents New Investigator (Thursday, 3/25/2010, 9:00AM 10:00 AM) Scientific Abstracts

Proliferation Profile of Uterine Endometrial Stromal Cells during In Vitro Culture with Gonadotropins: Recombinant versus Urinary Follicle Stimulating Hormone

Background:Provision of optimal endometrial stromal cells is essential in uterine tissue engineering. Culture of these cells is significantly influenced by gonadotropin hormones. This investigation attempted to define the proliferation profiles of murine uterine endometrial stromal cells during in vitro culture with recombinant follicle stimulating hormone (rFSH), urinary follicle stimulating hormone (uFSH), and human chorionic gonadotropin (hCG).Methods:Murine uterine endometrial stromal cells were collected from 8-week-old mice and cultured in vitro up to 72xa0h, with rFSH, uFSH, or hCG. Cell cycles were analyzed by BrdU assay, and cyclin D1 expression was evaluated according to dose and duration of gonadotropin treatment.Results:BrdU assay showed a further inhibitory effect on murine uterine endometrial stromal cell proliferation when cultured with rFSH compared to uFSH, and a similar inhibitory proliferation profile when cultured with hCG at a specific range of concentrations. The expression of cyclin D1 of murine uterine endometrial stromal cells was down-regulated when cultured with rFSH, uFSH, or hCG, compared to control.Conclusions:FSH may inhibit the proliferation of murine uterine endometrial stromal cells during in vitro culture. rFSH may have more significant inhibitory effects on the proliferation of endometrial stromal cells than uFSH. Establishing an optimal endocrine milieu is necessary using more advanced combination of female hormones for in vitro culture of this type of cells.