The possible presence of oocyte and granulosa cells originated from stem cells in the adult mammalian ovaries was claimed by some studies which will lead to major changes in reproductive biology and infertility treatm...The possible presence of oocyte and granulosa cells originated from stem cells in the adult mammalian ovaries was claimed by some studies which will lead to major changes in reproductive biology and infertility treatments. Purpose of this research is to investigate the possible existence and the location of the potential stem cells in mouse ovaries. In this study, the ovaries from 2-week (pre-puberty) and 8-week (adult) old BALB-C mice were used. For the investigation of the presence of possible stem cells, the expression profiles of three well known stem cell markers, Oct-4, Nanog and Sox2 were determined in the ovaries of two different age groups by real time quantitative RT-PCR (qRT-PCR). Protein expression levels and their localization in the ovary cells were immunohistochemically evaluated on fresh-frozen ovary tissue sections by using monoclonal antibodies specific to Sox2, Nanog and Oct-4. The gene expression levels of Oct-4 and Nanog were found to be significantly differentiated between 2-week old and 8-week old mice whereas no significant difference was observed in the expression level of Sox2 between two age groups. Immunohistochemistry results showed the presence of both Sox2 and Oct-4 protein in the cytoplasm of ovarian epithelial cells, granulosa cells, oocytes and theca cells. Nanog protein was observed only in the nucleus of the oocytes and furthermore the expression of Nanog was higher in eight weeks old samples compared to two weeks old ones according to qRT-PCR results. These results suggest for the first time that Nanog protein is expressed both in adult and pre-puberty mouse ovaries and locate at the nucleus of the oocytes and to the best of our knowledge this is the first study that shows the differential expression of Oct-4, Nanog and Sox2 in pre-puberty and adult mouse ovaries by qRT-PCR. Collectively, our results may suggest that both pre-puberty and adult mice ovaries accommodate cells carrying stem cell features.展开更多
A big issue in stem cell research is to derive prospective totipotential stem cells. In this study, fMSC-SSEA-4 cells expressing SSEA-4 anti- gen were isolated from fetal marrow masenchymal stem cells (fMSCs) using im...A big issue in stem cell research is to derive prospective totipotential stem cells. In this study, fMSC-SSEA-4 cells expressing SSEA-4 anti- gen were isolated from fetal marrow masenchymal stem cells (fMSCs) using immunomagnetic bead sorting technique. The totipotent cells were identified and their biological characteristics were further stud- ied. The expression of Oct-4 and SSEA-4, carcino- genicity, and the ability to differentiation of fMSC- SSEA-4 cells were evaluated to verify the totipotent potential. fMSC-SSEA-4 cells were isolated suc- cessfully from fMSCs (2.5% among fMSCs), while no obvious differences were seen in morphology, growth curve, cell cycle and immunophenotype, Oct-4 and SSEA-4 expression between fMSC-SSEA-4 cells and fMSCs. fMSC-SSEA-4 cells showed normal diploid chromosome karyotype and no carcinoma was in- duced after inoculation into nude mice. fMSC- SSEA-4 cells could be induced to fat cells, osteo- genic cells and neuron-like cells in vitro with different induced factors. The results indicated that there may be a few totipotent cells among the fMSCs and it may offer the experimental basis for the further study and application of fMSCs.展开更多
By transfecting an Oct-4 expression plasmid into embryonic stem cells (ES cells), the ES-O cell line was constructed, which sustained the expression of Oct-4 gene when induced by retinoic acid. Forced expression of Oc...By transfecting an Oct-4 expression plasmid into embryonic stem cells (ES cells), the ES-O cell line was constructed, which sustained the expression of Oct-4 gene when induced by retinoic acid. Forced expression of Oct-4 gene could not sustain the stem property of ES-O cells without the differentiation inhibiting factor LIF, but if LIF exists, forced expression of Oct-4 gene could enhance the ability to sustain the undifferentiation state and inhibit cell differentiation induced by retinoic acid. It was indicated that Oct-4 must cooperate with LIF to sustain the undifferentiation state of ES cells. During the cell differentiation, ES-O cells tend to differentiate into neural cells, suggesting that forced expression of Oct-4 gene may be in relation with the differentiation of neuroderm.展开更多
Objective Mesenchymal stem cells（MSCs） represent a promising population for supporting new clinical concepts in cellular therapy, and they can be reprogrammed into induced pluripotent stem cells（iPSCs） by defined ...Objective Mesenchymal stem cells（MSCs） represent a promising population for supporting new clinical concepts in cellular therapy, and they can be reprogrammed into induced pluripotent stem cells（iPSCs） by defined factors. Methods This method opened up a new era of stem cell research, because the transplantation rejection of iPSCs is the bottleneck of its clinical application, so seeking alternative compounds and animal origin diagnostic reagents to achieve full chemical iPSCs is to be done to solve this problem. Results The application of these iPSCs has largely been associated with well known undesirable effects such as the development of cancers in certain experimental models. This has called for the search and use of reprogramming factors that are safe. Chinese materia medica（CMM） with tonifying kidney function（TKF） offers an alternative source. On the other hand, human umbilical cord mesenchymal stem cells（hUMSCs） are known to be a ＂young＂ source of MSCs, hUMSCs transplantation is an attractive approach for acute kidney injury repair. Therefore, In this study, we investigated whether the treatment of CMM with TKF on hUMSCs could enhance the repair in mice model of acute kidney injury after transplantation. Conclusion Our results showed that the treatment of hUMSCs with kidney tonifying CMM increased their multipotency, improved the renal function of mice and enhanced subsequent homing to the injured kidney in an acute kidney injury mice model.展开更多
文摘The possible presence of oocyte and granulosa cells originated from stem cells in the adult mammalian ovaries was claimed by some studies which will lead to major changes in reproductive biology and infertility treatments. Purpose of this research is to investigate the possible existence and the location of the potential stem cells in mouse ovaries. In this study, the ovaries from 2-week (pre-puberty) and 8-week (adult) old BALB-C mice were used. For the investigation of the presence of possible stem cells, the expression profiles of three well known stem cell markers, Oct-4, Nanog and Sox2 were determined in the ovaries of two different age groups by real time quantitative RT-PCR (qRT-PCR). Protein expression levels and their localization in the ovary cells were immunohistochemically evaluated on fresh-frozen ovary tissue sections by using monoclonal antibodies specific to Sox2, Nanog and Oct-4. The gene expression levels of Oct-4 and Nanog were found to be significantly differentiated between 2-week old and 8-week old mice whereas no significant difference was observed in the expression level of Sox2 between two age groups. Immunohistochemistry results showed the presence of both Sox2 and Oct-4 protein in the cytoplasm of ovarian epithelial cells, granulosa cells, oocytes and theca cells. Nanog protein was observed only in the nucleus of the oocytes and furthermore the expression of Nanog was higher in eight weeks old samples compared to two weeks old ones according to qRT-PCR results. These results suggest for the first time that Nanog protein is expressed both in adult and pre-puberty mouse ovaries and locate at the nucleus of the oocytes and to the best of our knowledge this is the first study that shows the differential expression of Oct-4, Nanog and Sox2 in pre-puberty and adult mouse ovaries by qRT-PCR. Collectively, our results may suggest that both pre-puberty and adult mice ovaries accommodate cells carrying stem cell features.
文摘A big issue in stem cell research is to derive prospective totipotential stem cells. In this study, fMSC-SSEA-4 cells expressing SSEA-4 anti- gen were isolated from fetal marrow masenchymal stem cells (fMSCs) using immunomagnetic bead sorting technique. The totipotent cells were identified and their biological characteristics were further stud- ied. The expression of Oct-4 and SSEA-4, carcino- genicity, and the ability to differentiation of fMSC- SSEA-4 cells were evaluated to verify the totipotent potential. fMSC-SSEA-4 cells were isolated suc- cessfully from fMSCs (2.5% among fMSCs), while no obvious differences were seen in morphology, growth curve, cell cycle and immunophenotype, Oct-4 and SSEA-4 expression between fMSC-SSEA-4 cells and fMSCs. fMSC-SSEA-4 cells showed normal diploid chromosome karyotype and no carcinoma was in- duced after inoculation into nude mice. fMSC- SSEA-4 cells could be induced to fat cells, osteo- genic cells and neuron-like cells in vitro with different induced factors. The results indicated that there may be a few totipotent cells among the fMSCs and it may offer the experimental basis for the further study and application of fMSCs.
基金the National Natural Science Foundation of China (Grant No. 39870377).
文摘By transfecting an Oct-4 expression plasmid into embryonic stem cells (ES cells), the ES-O cell line was constructed, which sustained the expression of Oct-4 gene when induced by retinoic acid. Forced expression of Oct-4 gene could not sustain the stem property of ES-O cells without the differentiation inhibiting factor LIF, but if LIF exists, forced expression of Oct-4 gene could enhance the ability to sustain the undifferentiation state and inhibit cell differentiation induced by retinoic acid. It was indicated that Oct-4 must cooperate with LIF to sustain the undifferentiation state of ES cells. During the cell differentiation, ES-O cells tend to differentiate into neural cells, suggesting that forced expression of Oct-4 gene may be in relation with the differentiation of neuroderm.
基金National Natural Science Foundation of China(No.81072741)Program for Changjiang Scholars and Innovative Research Team in University(PCSIRT,No.IRT_14R41)
文摘Objective Mesenchymal stem cells（MSCs） represent a promising population for supporting new clinical concepts in cellular therapy, and they can be reprogrammed into induced pluripotent stem cells（iPSCs） by defined factors. Methods This method opened up a new era of stem cell research, because the transplantation rejection of iPSCs is the bottleneck of its clinical application, so seeking alternative compounds and animal origin diagnostic reagents to achieve full chemical iPSCs is to be done to solve this problem. Results The application of these iPSCs has largely been associated with well known undesirable effects such as the development of cancers in certain experimental models. This has called for the search and use of reprogramming factors that are safe. Chinese materia medica（CMM） with tonifying kidney function（TKF） offers an alternative source. On the other hand, human umbilical cord mesenchymal stem cells（hUMSCs） are known to be a ＂young＂ source of MSCs, hUMSCs transplantation is an attractive approach for acute kidney injury repair. Therefore, In this study, we investigated whether the treatment of CMM with TKF on hUMSCs could enhance the repair in mice model of acute kidney injury after transplantation. Conclusion Our results showed that the treatment of hUMSCs with kidney tonifying CMM increased their multipotency, improved the renal function of mice and enhanced subsequent homing to the injured kidney in an acute kidney injury mice model.
