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        검색결과 14

        1.
        2008.12 구독 인증기관 무료, 개인회원 유료
        The HMG box containing protein (HBP) has a high mobility group domain and involved in the regulation of proliferation and differentiation of tissues. We screened HBP2 in glioblastoma using Suppression Subtractive Hybridization (SSH) and isolated human spermatogonial stem cell‐like cells (hSSC‐like cells) derived from patients of nonobstructive azoospermia (NOA). Expression of HBP2 was analyzed by RT‐PCR in undifferentiated stem cells (human Embryonic Stem Cells, hSSC‐like cells 2P) and spontaneous differentiated stem cells (hSSC‐like cells 4P). It was overexpressed in hESC and hSSC‐like cells 2P but not in hSSC‐like cells 4P. Also, the expression level of HBP2 was downregulated in colon tumor tissues compared to normal tissues. Specifically in synchronized WI‐38 cells, HBP2 was highly upregulated until the G1 phase of the cell cycle and gradually decreased during the S phase. Our results suggest that HBP2 was downregulated during the spontaneous differentiation of hSSC‐like cells. HBP2 was differently expressed in colon tissues and was related to G1‐progression in WI‐38 cells. It may play a role in the maintenance of an undifferentiated hSSC‐like cell state and transits from G1 to S in WI‐38 cells. This research was important that it identified a biomarker for an undifferentiated state of hSSC‐like cells and characterized its involvement to arrest during cell cycle in colon cancer.
        4,000원
        2.
        2006.12 구독 인증기관 무료, 개인회원 유료
        Vitrification has been suggested to be an effective method for the cryopreservation of human ES cells. However, the efficiency of vitrification with different vehicles remains a matter of ongoing controversy. The objective of this study was to assess the efficiency of cryopreservation in human ES cells by vitrification using different vehicles. A human ES cell line and a variety of vehicles, including microdroplet (MD), openpulled straw (OPS) and electron microscopic grid (EMgrid), were employed in an attempt to assess vitrification efficiency. In order to evaluate the survivability and the undifferentiated state of the postvitrified human ES cells, we conducted alkaline phosphatase staining and characterization via both RTPCR and immunofluorescence assays. The survival rates of the postvitrified human ES cells using MD, OPS and EMgrid were determined to be 61.5%, 66.6% and 53.8%, respectively. There also exist significant differences between slowfreezing and vitrification (p<0.01). However, no significant differences were detected between the vehicle types. Finally, the pluripotency of human ES cells after thawing was verified by teratoma formation. Cryopreservation using vitrification is more effective than slowfreezing, and the efficiency of vehicles proved effective with regard to the preservation of human ES cells.
        4,000원
        3.
        2017.12 KCI 등재 서비스 종료(열람 제한)
        Polyploidy is occurred by the process of endomitosis or cell fusion and usually represent terminally differentiated stage. Their effects on the developmental process were mainly investigated in the amphibian and fishes, and only observed in some rodents as mammalian model. Recently, we have established tetraploidy somatic cell nuclear transfer-derived human embryonic stem cells (SCNT-hESCs) and examined whether it could be available as a research model for the polyploidy cells existed in the human tissues. Two tetraploid hESC lines were artificially acquired by reintroduction of remained 1st polar body during the establishment of SCNT-hESC using MII oocytes obtained from female donors and dermal fibroblasts (DFB) from a 35-year-old adult male. These tetraploid SCNT-hESC lines (CHA-NT1 and CHA-NT3) were identified by the cytogenetic genotyping (91, XXXY,-6, t[2:6] / 92,XXXY,-12,+20) and have shown of indefinite proliferation, but slow speed when compared to euploid SCNT-hESCs. Using the eight Short Tendem Repeat (STR) markers, it was confirmed that both CHA-NT1 and CHA-NT3 lines contain both nuclear and oocyte donor genotypes. These hESCs expressed pluripotency markers and their embryoid bodies (EB) also expressed markers of the three embryonic germ layers and formed teratoma after transplantation into immune deficient mice. This study showed that tetraploidy does not affect the activities of proliferation and differentiation in SCNT-hESC. Therefore, tetraploid hESC lines established after SCNT procedure could be differentiated into various types of cells and could be an useful model for the study of the polyploidy cells in the tissues.
        4.
        2017.08 서비스 종료(열람 제한)
        BACKGROUND Ca2+ oscillations during fertilization induce eggs activation and embryonic development in mammalian eggs.. The type 1 inositol 1,4,5-trisphosphate receptor (IP3R1) is in charge of Ca2+ oscillations for the release of stored Ca2+ from the endoplasmic reticulum. The capacity of this oscillation is obtained during egg maturation and corresponds with an increase in the sensitivity of the IP3R1 and their localization in cytoplasm. Cluster formation of IP3R1 in the egg cortex is important to initiation of Ca2+ oscillations during egg and sperm fusion. In this study, we investigated that cell cycle–coupled redistribution of IP3R1 and Ca2+- oscillatory activity in mouse zygotes. MATERIALS AND METHODS Metaphase II arrested eggs were collected from ICR female mouse after super ovulation induction. At 14 hr post hCG, MII eggs were collected, and artificially activated in Ca2+ free CZB medium with 10 mM SrCl2 for 2 hrs. Pronuclear zygotes (PN) were collected from Strontium activated eggs at 8 hr post activation, and the first mitotic eggs were collected at 16~17 hr post activation. To identify cell cycle coupled IP3R1 redistribution, MII eggs, zygotes, and first mitotic eggs were collected, and fixed for immunostaining with anti-IP3R1antibody (CT-1) and observed on CLSM. Ca2+-oscillatory activity was monitored with fluorescence microscope mounted SimplePCI program (Hamamatsu) after injection of cRNA of mouse phospholipase C zeta (mPLCZ). RESULT IP3R1 were shown clusters, 1~2 um in diameter, in cortex of ovulated MII eggs with high Ca2+ oscillatory activity by mPLCZ injection. These eggs represent more than 6 spikes per 60 min. However, IP3R1 clusters were disappeared in PN eggs and these eggs showed very low Ca2+- oscillatory activity by mPLCZ. In mitosis I stage eggs, clusters of IP3R1 were appeared and Ca2+-oscillatory activity was reactivated slightly (2 spikes per 60 min). CONCLUSIOINS This study introduced the redistribution of IP3R1 clusters were occurred in egg activation according to cell cycle dependent manner. Also, functional modification of IP3R1 including protein phosphorylation was associated with cortical clustering of IP3R1 in cell cycle coupled Ca2+ oscillatory activity.
        5.
        2015.09 서비스 종료(열람 제한)
        To overcome the risk of the ovarian hyperstimulation syndrome (OHSS) in patients have polycystic ovarian syndrome (PCOS) and to prepare emergency fertility preservation in patients undergoing anticancer treatment, several researchers have reported IVM of oocytes retrieved from ovaries exposed by only hCG priming. However, the maturation rate and the developmental potential of embryos from IVM oocytes are significantly lower than those of oocytes matured in vivo. Here, we investigated the optimal time point for immature oocyte collection at post hCG only injection for in vitro maturation, in vitro fertilization and blastocyst formation. Immature GV oocytes were collected from 25 days old B6D2F1 female mouse at 12 hr, 14 hr, 16 hr or 24 hr post hCG injection. Oocytes were collected from antral or late secondary follicle by puncturing with 26 G needle. Collected oocytes were cultured in G2 medium with 10% FBS, FSH, estradiol, and hCG for 16 hr in vitro and subjected in vitro fertilization and further embryonic development. To examine follicular maturation, we estimated the numbers of primordial, primary, secondary follicle and antral follicle on ovaries of each time point post hCG. To confirm the optimal time point post hCG injection for collecting immature oocytes, we recovered the oocytes from each time point. There is no difference in the number of oocytes per mice. Oocytes collected at 14 hr post hCG injection were shown higher maturation rate to MII stage and blastocyst formation compare to other three groups (p<0.01). However, there is no difference in the maturation rate on the other three groups. Also, apoptotic signal with TUNEL assay or anti-PARP staining was not change in ovaries from all experimental groups. Granulosa cell proliferation test with anti Ki-67 or anti AMH was not show any difference. According to these results, there are no significant differences in four different time points at 12 hr, 14 hr, 16 hr or 24 hr of collection of immature oocytes in hCG primed mouse. However, oocytes from 14 hr post hCG injection showed higher percentages of maturation rate, in vitro fertilization rate, blastocyst formation.
        6.
        2015.09 서비스 종료(열람 제한)
        Harmonized actions of ovarian estrogen (E2) and progesterone (P4) regulate cell proliferation and differentiation in the uterus with a spatiotemporal manner. Imbalance between the actions and levels of two major regulators often lead to infertility and gynecological diseases, such as endometriosis and endometrial cancer. While numerous works have shown that reduced expression and/or deletion of uterine factors associated with P4 signaling could disturb uterine physiology, local factor(s) to mediate E2 actions has not been extensively studied yet. Here we demonstrate that early growth response 1 (Egr1), a transcription factor which is rapidly induced in the uterus by E2, is required to maintain coordinated actions of E2 and P4 for uterine receptivity for embryo implantation. Given exogenous gonadotrophins to overcome LHβ deficiency in the pituitary of Egr1(-/-) mice, ovulation, fertilization and embryo development normally occurred in these mice. However, they showed complete failure of embryo implantation with reduced uterine responses to artificial decidualization stimuli. While serum levels of E2 and P4 in Egr1(-/-) mice were comparable, genes regulated by E2 and/or P4 in uterine epithelial cells (ECs) were aberrantly expressed on day 4 of pregnancy. Impaired P4 signaling along with absence of PR in ECs caused hypersensitive E2 responses shown as enhanced expression of E2-responsive genes such Muc1 and Ltf as well as reduced levels of P4-dependent genes, such as Ihh and Areg, in ECs of Egr1(-/-) mice. This is consistent with persistent proliferation in ECs and severely impaired proliferation in stromal cells (SCs) in Egr1(-/-) mice treated with E2+P4. Furthermore, primary co-culture of Egr1(-/-) ECs with Egr1(+/+) SCs and vice versa supported a notion that Egr1 itself is required for proper responses to two major regulators, E2 and P4, in both uterine cell compartments. Collectively, our results show that E2-induced Egr1 participates in P4-dependent modulation on E2 activities in the uterus by regulating a spectrum of genes essential for uterine receptivity and embryo implantation.
        7.
        2015.09 서비스 종료(열람 제한)
        DGCR8 is a RNA-binding protein working with DROSHA to produce pre-microRNA in the nucleus, while DICER does not only mature microRNA but also endogenous siRNAs in the cytoplasm. Here, we have produced Dgcr8 conditional knock-out mice using progesterone receptor (PR)-Cre (Dgcr8flox/flox; PRcre/+ mice, Dgcr8d/d) and demonstrated that canonical microRNAs dependent of DROSHA-DGCR8 complex are required for uterine development as well as female fertility in mice. Adult Dgcr8d/d females did not undergo regular reproductive cycle and produce any pups when housed with fertile males, whereas administration of exogenous gonadotropins induced normal ovulation with corpus luteal formation in these mice. Ovulated oocytes from Dgcr8d/d mice had comparable fertilization potentials and were normally developed to the blastocyst after fertilization as compared to those in control Dgcr8f/f mice. Interestingly, PR-Cre-dependent Dgcr8 deletion showed aberrant infiltration of acute inflammatory immune cells to female reproductive organs only when Dgcr8d/d mice were mated with male mice. With respect to uterine development, gross morphology, histology, and weight of Dgcr8d/d uterus were similar to those of control at 3-week-old age. However, multiple uterine abnormalities were noticeable at 4-week-old age when PR expression is significantly increased, and these deformities became severe onwards. Gland formation and myometrial layers were significantly reduced, and stromal cell compartment did not expand and became atrophic during uterine development in these mice. These results were consistent with aberrantly reduced cell proliferation in stromal cell compartments of Dgcr8d/d mice. Collectively, our results suggest that DGCR8 dependent-canonical microRNAs are essential for development and physiology of the uterus with respect to morphogenesis, proper immune modulation, reproductive cycle, and steroid hormone responsiveness in mice.
        8.
        2015.09 서비스 종료(열람 제한)
        Cryopreservation has become a powerful method of the assisted reproduction technology and supports fertility preservation of cancer and other indication patients. After controlled ovarian hyperstimulation, surplus oocytes and embryos were recommended to store using cryopreservation. Recently, vitrification is replaced with traditional slow freezing protocol, because of improved survival rates and clinical outcomes. Vitrification requires a high concentration of CPAs that may induce significant osmotic and metabolic damage to cells including oocytes even in a short exposure of a few minutes. Generally, MPF plays a crucial role in the cell cycle regulation and maintaining the meiotic arrest of oocytes. In fact, it has been observed to decline in MII ovine oocytes after vitrification and would be suggested that one of the main causes of low fertilization rate and developmental competence derived from cryoinjury during vitrification. Therefore, the aim of this study was to evaluate the effect of caffeine treatment on the activity of MPF, MAPK level in vitrified/warmed mouse mature eggs. Caffeine, Phosphataseinhibitor, may maintain active form of MPF. We evaluated their survival after warming procedure, fertilization, cleavage, and developmental rates. Ovulated MII eggs were retrieved from 6 weeks old B6D2F1 female mouse at 14hr post hCG injection. Collected MII eggs were maintained in HTF medium containing 10% KSR with or without caffeine for 1hr. Eggs were vitrified in 7.5%EG +7.5%DMSO equilibrium solution, 15%EG + 15%DMSO + 0.5M sucrose vitrification solution with or without caffeine. Also warming solution contained sucrose (0.5M, 0.25M, 0.125M, and 0M) with or without caffeine. After warming, eggs were cultured in HTF medium with or without caffeine for 2 hr then fertilized with epididymal sperm in vitro and cultured in KSOM for 5 days to analyze embryonic development. Survival rates were similar in all experimental groups. However, fertilization rate was higher in with caffeine group compare to without caffeine significantly (80% vs. 85%, p<0.05). 2-cell and blastocyst formation were increased in caffeine group (p<0.05). MPF activity and MAP kinase activity were recovered in with caffeine group after vitrification/warming process. In conclusion, Caffeine may maintain MPF and MAPK level in vitrified/warmed MII eggs, and enhance fertilization and further embryonic development.
        9.
        2015.09 서비스 종료(열람 제한)
        Somatic cell nuclear transfer (SCNT) has long been envisioned as a means for generating patient-specific stem cells to treat a range of age-related diseases. Until now, only three research groups have reported the successful derivation of SCNT-derived pluripotent stem cells (SCNT-PSCs). Our group has shown for the first time that human SCNT-PSCs can be successfully generated using dermal fibroblasts from 35 and 75 year-old males, and also recently established another SCNT-PSC from a patient with disease. However, despite cloning success in these groups, the derivation of stem cell lines from cloned human embryos has proven elusive. So, several approaches for the optimization of SCNT conditions, such as the use of protein phosphatase inhibitors, oocyte activation method and epigenetic regulation have been applied in order to overcome the obstacle. This study reveals mechanistic insights and establishes a promising method for improving human SCNT for regenerative medicine.
        10.
        2013.08 서비스 종료(열람 제한)
        Tdrd family members contain Tudor domain repeat which is found in polar granules in Drophila. Tdrd12 is one of Tdrd family members. Tdrd12 contains a DEAD-box and a Tudor domain. However, the molecular mechanism and physiological function of Tdrd12 has not been described. To examine the expression pattern of Tdrd12, RT-PCR and Northern blot analysis were performed using total RNAs extracted from tissues; liver, intestine, heart, brain, kidney, lung, brain, uterus, ovary, and testis. The full-length of Tdrd12 was amplified from total RNA from mouse testis and cloning into the cloning vector. Cloned PCR products were purified,sequenced and analyzed using the ABI Prism Sequencer 3130XL. To look into Tdrd12 protein location, rabbit antibodies against mouse Tdrd12 were made using two epitopes: 1st epitope: (318~334)- SQRPNEKPLRLTEKKDC and 2nd epitope: (737~750)- LEAKEDKKARRPLC, and its specificity was tested using tissue extracts including the gonad. Here, we identified that Tdrd12 mRNA is detected in the ovary and testis, but not in other tissues. The size of its transcript is about 4.5kb on the northern blot. Antibody against Tdrd12 detects about 150 kDa protein on the western blot analysis. Immunostaining assay shows that Tdrd12 is localized at the spermatid in the seminiferous tubules. The current study is the first to investigate Tdrd12 expression is limited in the gonad. Thissuggest that Tdrd12 plays a role in the gonad like other known Tdrd family members, Tdrd1, Tdrd6, Tdrd7, and Tdrd9.
        11.
        2013.08 서비스 종료(열람 제한)
        Mature mammalian oocytes are ovulated at the metaphase II stage of meiosis and complete the cell cycle by fertilization with sperm. During fertilization sperm release an egg activation protein, pho-spholipase C zeta (PLCZ) into oocyte cytoplasm, PLCZ hydrolyze PIP2 into IP3 and DAG. The elevation of IP3 concentration induces Ca2+ release from endoplasmic reticulum (ER) by binding to the IP3 receptor (IP3R) on the membrane of ER. Recent studies have shown that sperm from patients lacking expression of PLCZ1 or expressing mutant forms of PLCZ1 fail to induce [Ca2+]i oscillations or oocyte activation. Purified recombinant human PLCZ1 (hPLCZ1) protein evaluated its [Ca2+]i oscillation activity in mouse and human oocytes. Here we investigated that produced mouse PLCZ-specific antibodyrecognized the PLCZ protein in mouse testes. PLCZ antibody was raised in rabbits against 19-mer sequence at the C-terminus (MENKWFLSMVRDDFKGGKI) of mouse PLCZ protein. Sperm were fixed in 3.7% paraformaldehyde followed by permeabilization. Sperm were incubated in 5% normal goat serum (NGS) and then incubated overnight with anti-mouse PLCZ. Peanut agglutinin (PNA)-lectin was used for detection of the acrosome. Mouse testes from 6~8 weeks old ICR mouse were fixed in 10% formalinand serial sectioned at 5~8um. Testes tissues were immunostained with anti PLCZ antibody and peanut agglutinin(PNA) for acrosome staining. Produced anti mouse PLCZ antibody recognized 74 kDa protein in western and PLCZ is localized to the post-acrosomal region of mouse sperm and to the equatorial region of bull sperm. Mouse PLCZ protein wasdetected on spermatocytes, spermatid, but not on spermatogonia in seminiferous tubules. Some residual bodies on sperm neck and tail showed strong signal of PLCZ, but this staining was still present with antigenic peptide pretreatment to reduce non specific antibody reaction. Also this antibody reacted with the apical region (arrowheads) of principal cells, where secretory vesicles accumulate on the epididymal tissue. But antigenic peptide pretreatment did not remove this apical region staining. This study presents PLCZ protein is localized on the post-acrosomal region or equatorial region of mouse and bull sperm head. Also PLCZ protein in mouse testes expressed from spermatocytes to mature sperm on later stage of spermatogenesis.
        14.
        2010.12 KCI 등재 서비스 종료(열람 제한)
        Estrogen related receptor β(Esrrb)는 오르판 수용체 중 하나로 전분화능 관련유전자인 Oct4와 Nanog의 발현을 조절함으로써 줄기세포의 미분화를 유지시키고, 지속적인 자기 복제를 가능케 하는 유전자로 알려져 있다. 또한 Feng 등 (2009)은 체세포에 Oct4, Sox2와 함께 Esrrb 유전자를 함께 도입하면, 유전자가 변형된 체세포가 배아 줄기세포와 유사한 유도만능줄기세포로 리프로그래밍(reprograming)되어 진다는 결과를 보고한 바 있다. 본 연구에서는 인간 ESRRB 단백질을 양수유래줄기세포 내로 직접도입하는 방법을 개발하고, 이를 통해 전분화능 관련유전자의 기능 조절을 확인하고자 하였다. 클로닝 된 인간 short-form ESRRB를 세포투과 펩타이드(cell-penetrating peptide, CPP)의 일종인 R7(아르기닌 7개)에 접합(Fusion)하였고, 합성단백질 (R7-ESRRB-His6)의 형태로 배양중인 인간 양수 유래 줄기세포에 처리하여 세포내로 도입하였다. R7-ESRRB-His6 단백질은 5시간 내에 세포막을 통과하였고, 24시간 내에 핵 내로 이동하였다. 또한 핵 내로 이동한 ESRRB 단백질은 OCT4와 NANOG 유전자의 발현을 증가시켰을 뿐만 아니라, 또 다른 전분화능 관련유전자인 SOX2의 발현도 함께 증가시킨다는 것을 확인하였다. 이상의 결과는 세포투과 펩타이드와 유전자의 접합을 통해 생산된 R7-ESRRB-His6 합성단백질이 양수유래줄기세포내로 원활하게 도입되는 것을 확인하였고, 유전자의 변형 없이 전분화능 관련유전자의 기능을 조절할 수 있는 방법임을 확인하였다.