• Reproductive and Developmental Biology
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• 제28권3호
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• pp.147-153
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• 2004

The oocyte and its surrounding granulosa cells co-exist in a closed compartment called a follicle, although they receive many signals from other parts of the body. It is well established that the intercellular communications between the oocyte and granulosa cells are required for normal oocyte development and ovulation during folliculogenesis. Gap junctions are intercellular channels allowing the direct transmission of ions and small molecules between coupled cells. Several lines of studies have shown that multiple connexins (Cx, subunits of gap junction) are expressed in mammalian ovarian follicles. Among them, two major connexins Cx37 and Cx43 are expressed in different manner. While the gap junction channels formed by Cx37 are localized between the oocyte and encompassing granulosa cells, the intercellular channels by Cx43 are located between granulosa cells. In this review, I will summarize the general properties of gap junction channels and discuss their possible formation (or compatibility) of intercellular channels formed by the oocyte and granulosa cells.

• 한국발생생물학회지:발생과생식
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• 제25권3호
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• pp.173-183
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• 2021

The incidence of infertility among individuals of reproductive age has been growing due to genetic and environmental factors, and considerable research efforts are focused on solving this issue. Ovarian development is an overly complex process in the body, involving the interaction between primordial germ cells and gonad somatic cells. However, follicles located in the center of the in vitro ovary are poorly formed owing to ovarian complexity, nutrient deficiency, and signaling deficiency. In the present study, we optimized methods for dissociating gonads and culture conditions for the in vitro generation of miniaturized ovaries. The gonads from embryos were dissociated into cell masses and cultured on a Transwell-COL membrane for 3-5 weeks. Approximately 12 follicles were present per in vitro ovary. We observed that miniaturized ovaries successfully matured to MII oocytes in vitro from 150 to 100 ㎛ gonad masses. This method will be useful for investigating follicle development and oocyte production.

• International Journal of Stem Cells
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• 제16권2호
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• pp.135-144
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• 2023

Background and Objectives: Melanocyte (MC), derived from neural crest stem cell (NCSC), are involved in the production of melanin. The mechanism by which NCSC differentiates to MC remains unclear. N6-methyladenosine (m6A) modification was applied to discuss the potential mechanism. Methods and Results: NCSCs were isolated from hair follicles of rats, and were obtained for differentiation. Cell viability, tyrosinase secretion and activity, and transcription factors were combined to evaluated the MC differentiation. RT-qPCR was applied to determine mRNA levels, and western blot were used for protein expression detection. Total m6A level was measured using methylated RNA immunoprecipitation (MeRIP) assay, and RNA immunoprecipitation was used to access the protein binding relationship. In current work, NCSCs were successfully differentiated into MCs. Fat mass and obesity associated gene (FTO) was aberrant downregulated in MCs, and elevated FTO suppressed the differentiation progress of NCSCs into MCs. Furthermore, microphthalmia-associated transcription factor (Mitf), a key gene involved in MC synthesis, was enriched by FTO in a m6A modification manner and degraded by FTO. Meanwhile, the suppression functions of FTO in the differentiation of NCSCs into MCs were reversed by elevated Mitf. Conclusions: In short, FTO suppressed the differentiating ability of hair follicle-derived NCSCs into MCs by m6A modifying Mitf.

• KSBB Journal
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• 제22권2호
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• pp.109-113
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• 2007

본 연구에서는 FSH를 생산하도록 유전자 조작된 CHO 세포의 저온배양이 세포성장과 FSH의 생산에 미치는 영향을 알아보았다. 28$^{\circ}C$에서 배양하였을 때 세포의 성장은 억제되었으나 37$^{\circ}C$에서의 배양에 비하여 세포생존율이 더 오랫동안 높게 유지되었고 최대 FSH의 양도 14배 증가하였다. 28$^{\circ}C$에서의 회분식 배양의 경우 배지에 15 mM의 GB를 첨가하였을 때 최대세포농도와 FSH 양은 GB를 첨가하지 않았을 때에 비하여 각각 11%, 17% 증가하였다. 28$^{\circ}C$에서의 유사배지 교환식 배양의 경우 15 mM의 GB를 포함하는 배지를 교환하였을 때 세포생존율이 GB를 포함하지 않는 배지를 교환하였을 때에 비하여 더 높게 오랫동안 유지되어 최종적으로 배양기간을 4일간 더 연장할 수 있었다. 이러한 배양기간의 연장으로 인하여 15 mM의 GB를 포함하는 배지를 교환하는 유사배지 교환식 배양에서 총 $2,058{\mu}g$의 FSH를 얻었고 이는 GB를 포함하지 않는 배지를 교환하는 유사배지 교환식 배양에 비하여 1.4배 증가한 것이다. 본 연구를 통하여 저온배양에 있어서 배지에 GB를 첨가함으로써 CHO 세포에서의 재조합단백질 생산을 증대시킬 수 있다는 것을 알았다.

• Applied Microscopy
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• 제37권2호
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• pp.135-142
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• 2007

본 연구는 6 MeV LINAC에서 발생한 X-선을 생쥐 생체에 조사한 후 난소에서 난포의 형태적 변화 양상과 난포의 세포자연사가 일어나는 과정을 TUNEL 염색방법을 이용하여 광학현미경으로 관찰하였다. 정상난포와 퇴화난포 및 방사선이 조사된 난포에서 세포예정사가 발생하는 것을 확인하기 위해서 TUNEL 염색을 실시한 결과, 정상난소의 퇴화난포에서 양성반응을 보이는 과립층세포들은 갈색을 띠고 있었고, 핵은 응축되어 나타났다. 그러나, 정상난포에서는 양성반응이 나타나지 않았다. X-선을 조사한 난소의 난포는 TUNEL 염색에 강한 양성반응이 나타났고, 600 cGy의 X-선 조사에서 난모세포는 이미 세포예정사가 진행되어 파괴되었음을 확인할 수 있었다. 그리고 난포막을 형성하고 있는 난막세포의 핵들도 양성반응으로 나타나, 갈색으로 염색이 되었으며, 수질의 결합조직세포들의 핵도 갈색으로 염색되어 관찰되었다. 또한, 대부분의 세포들은 세포예정사가 진행되어 있으며, apoptotic body들이 난포 내에 산재되어 있었다. 이 시기의 난소조직의 전반적인 염색도는 저선량의 X-선 조사에서보다 더 현저히 강한 염색성이 나타났다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권3호
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• pp.186-196
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• 2010

Introduction: The first aim of this study was to isolate the dental tissue-derived stem cells from the dental follicle (DF), dental pulp (DP), and root apical papilla (RAP) of the extracted wisdom teeth. Second was to evaluate their characterization with the expressions of transcription factors and cell surface markers. Finally, their ability of the in vitro multi-lineage differentiations into osteogenic and adipogenic cells were compared, respectively. Materials and Methods: Dental tissues, including dental follicle, dental pulp, and root apical papilla, were separated in the extracted wisdom teeth. These three dental tissues were cultured in Dulbecco’s modified Eagle’s medium (DMEM) with supplements, respectively. After passage 3, the homogeneous shaped dental tissue-derived cells were analyzed the expression of transcription factors (Oct-4, Nanog and Sox-2) and cell surface markers (CD44, CD90 and CD105) with reverse transcription polymerase chain reaction (RT-PCR) and fluorescence-activated cell sorting (FACS) analysis. In order to evaluate in vitro multi-lineage differentiations, the culture media were changed to the osteogenic and adipogenic induction mediums when the dental tissue-derived cells reached to passage 3. The characteristics of these three dental tissue-derived cells were compared with immunohistochemistry. Results: During primary culture, heterogenous and colony formatted dental tissue-derived cells were observed in the culture plates. After passage 2 or 3, homogenous spindle-like cells were observed in all culture plates. Transcription factors and mesenchymal stem cell markers were positively observed in all three types of dental tissue-derived cells. However, the quantity of expressed transcription factors was most large in RAP-derived cells. In all three types of dental tissue-derived cells, osteogenic and adipogenic differentiations were observed after treatment of specific induction media. In vitro adipogenic differentiation was similar among these three types of cells. In vitro osteogenic differentiation was most strongly and frequently observed in the RAP-derived cells, whereas rarely osteogenic differentiation was observed in the DP-derived cells. Conclusion: These findings suggest that three types of human dental tissue-derived cells from extracted wisdom teeth were multipotent mesenchymal stem cells, have the properties of multi-lineage differentiations. Especially, stem cells from root apical papilla (SCAP) have much advantage in osteogenic differentiation, whereas dental follicle cells (DFCs) have a characteristic of easy adipogenic differentiation.

• 한국동물생명공학회지
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• 제34권2호
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• pp.117-122
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• 2019

The objective of this study was to establish an in vitro culture system for ovarian preantral follicles of B6D2F1. First, we optimized the in vitro preantral-follicle culture by culture duration, follicle stimulating hormone (FSH) type, and activin A concentration. Duration of in vitro culture for 9, 11, and 13 days was sufficient for the normal development of preantral follicles to antral follicles. Formation of cumulus cell-oocyte complex (COC) was induced by treatment with human chorionic gonadotropin (hCG; 2.5 IU/mL) and epidermal growth factor (EGF; 5 ng/mL). In addition, metaphase II (MII) oocytes formed during this in vitro culture of preantral follicles. In vitro preantralfollicle culture for 9 days showed higher rates of growth and maturation, thus yielding a greater number of antral follicles, and there were significant differences (p < 0.05) in the number of MII oocytes (that formed from these preantral follicles via differentiation) between the 9-day culture and 11-day or 13-day culture. The follicles cultured for 9 days contained a tightly packed well-defined COC, whereas in follicles cultured for 11 days, the COC was not well defined (spreading was observed in the culture dish); the follicles cultured for 13 days disintegrated and released the oocyte. Second, we compared the growth of the preantral follicles in vitro in the presence of various FSH types. There were no significant differences in the growth and maturation rates and in differentiation into MII oocytes during in vitro culture between preantral follicles supplemented with FSH from Merck and those supplemented with FSH from Sigma. To increase the efficiency of MII oocyte formation, the preantral follicles were cultured at different activin A concentrations (0 to 200 ng/mL). The control follicles, which were not treated with activin A, showed the highest rate of differentiation into antral follicles and into MII oocytes among all the groups (0 to 200 ng/mL). Therefore, activin A (50 to 200 ng/mL) had a negative effect on oocyte maturation. Thus, in this study, we propose an in vitro system of preantral-follicle culture that can serve as a therapeutic strategy for fertility preservation of human oocytes for assisted reproductive medicine, for conservation of endangered species, and for creation of superior breeds.

• Clinical and Experimental Reproductive Medicine
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• 제32권3호
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• pp.207-216
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• 2005

Objective: To understand the crucial requirement for the normal early folliculogenesis, we evaluated molecular as well as physiological differences during in vitro ovarian culture. Among the important regulators for follicle development, anti-Müllerian hormone (AMH) and FSH Receptor (FSHR) have been known to be expressed in the cuboidal granulosa cells. Meanwhile, it is known that c-kit is germ cell-specific and GDF-9 is also oocyte-specific regulator. To evaluate the functional requirement for the competence of normal follicular development, we investigated the differential mRNA expression of several factors secreted from granulosa cells and oocytes between in vivo and in vitro developed ovaries. Materials and Methods: Ovaries from ICR neonates (the day of birth) were cultured for 4 days (for primordial to primary transition) or 8 days (for secondary follicle formation) in ${\alpha}$-MEM glutamax supplemented with 3 mg/ml BSA without serum or growth factors. The mRNA levels of the several factors were investigated by quantitative real-time PCR analysis. Freshly isolated 0-, 4-, and 8-day-old ovaries were used as control. Results: The mRNA of AMH and FSHR as granulosa cell factors was highly increased according to the ovarian development in both of 4- and 8-day-old control. However, the mRNA expression was not induced in both of 4- and 8-day in vitro cultured ovaries. The mRNA expression of GDF-9 known to regulate follicle growth as an oocyte factor was different between in vivo and in vitro developed ovaries. In addition, the transcript of GDF-9 was expressed in the primordial follicles of mouse ovaries. The mRNA expression of c-kit was not significantly different during the early folliculogenesis in vitro. Conclusion: This is the first report regarding endogenous AMH and FSHR expression during the early folliculogenesis in vitro. In conclusion, it will be very valuable to evaluate cuboidal granulosa cell factors as functional marker(s) for normal early folliculogenesis in vitro.

• 한국발생생물학회지:발생과생식
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• 제2권1호
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• pp.45-52
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• 1998

강화인자 검출법을 이용 X염색체에 P[1ArB]이 형질전환되어 극세포 및 경게세포에서 표시유전자 lacZ를 발현하는 노랑초파리 (EDL 149)를 이용하여 난자형성과정 동안의 경계새포의 분화 및 이동을 조사하였다. 경계세포는 9기 난포의 선단에 위치한 난포 세포로부터 분화하여 9기와 10기에 이동하는 것을 확인하였다. 난소내 \beta -galactosidase의 활성은 우화 후 처음 4일간 급격히 증가하는 것을 확인하였으며 이 시기는 난포 내에서 경계세포가 분화하는 시기와 일치하였다. EDL149의 P[1ArB]삽입의 동형접합체의 난포 내에서 일부 경계세포의 불완전한 이동 또는 지연이 관찰되었다. 감수분열을 진행중인 정소내 세포 및 더듬이에서 확인된 lacZ 유전자의 발현양상은 P[1ArB]의 삽입부위가 난소특이 유전자부위가 아니지만 경계세포 이동의 조절에 역할을 하는 유전자임을 암시한다. 이 형질전환초파리 및 삽입위치 부근의 유전자는 발생중 진행되는 세포이동의 연구에 좋은 모델로 생각된다.

• Clinical and Experimental Reproductive Medicine
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• 제32권3호
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• pp.269-277
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• 2005

Objectives: Previously, we sought to compile a list of genes expressed during early folliculogenesis by using cDNA microarray to investigate follicular gene expression and changes during primordialprimary follicle transition and development of secondary follicles (Yoon et al., 2005). Among those genes, a group of genes related to the cell size growth was characterized during the ovarian development in the present study. Methods: We determined ovarian expression pattern of six genes related to the cell size growth (cyr61, emp1, fhl1, socs2, wig1 and wisp1) and extended into CCN family (${\underline{c}}onnective$ tissue growth factor/${\underline{c}}ysteine$-rich 61/${\underline{n}}ephroblastoma$-overexpressed), ctgf, nov, wisp2, wisp3, including cyr61 and wisp1 genes. Expression of mRNA and protein according to the ovarian developmental stage was evaluated by in situ hybridization, and/or semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR), and immunohistochemistry, respectively. Results: Among 6 genes related to the cell size growth, cyr61 and wisp1 mRNA was detected only in oocytes in the postnatal day5 mouse ovaries. cyr61 mRNA expression was limited to the nucleolus of oocytes, while wisp1 was expressed in the cytoplasm and nucleolus of oocytes, except nucleus. cyr61 mRNA expression, however, was found in granulosa cells from secondary follicles. The rest 4 genes in the cell size growth group were detected in oocytes, granulosa and theca cells. Cyr61 and Wisp1 proteins were expressed in the oocyte cytoplasm from primordial follicle stage. Especially, Cyr61 protein was detected in pre-granulosa cells, Wisp1 protein was not. By using RT-PCR, we evaluated and decided that Cyr61 protein is produced by their own mRNA in pre-granulosa cells that was not detected by in situ hybridization. cyr61 and wisp1 genes are happen to be the CCN family members. The other members of CCN family were also studied, but their expression was detected in oocytes, granulose and theca cells. Conclusions: We firstly characterized the ovarian expression of genes related to the cell size growth and CCN family according to the early folliculogenesis. Cyr61 protein expression in the pre-granulosa cells is profound in meaning. Further functional analysis for cyr61 in early folliculogenesis is under investigation.