Abstract. Regenerative medicine is a new field based on the use of stem cells to generate biological substitutes and improve tissue functions, restoring damaged tissue with high proliferability and differentiability. It is of interest as a potential alternative to complicated tissue / organ transplantation. Recently, amnion-derived cells have been reported to have multipotent differentiation ability, and these cells have attracted attention as a cell source for cell-transplantation therapy. The amnion possesses considerable advantageous characteristics: the isolated cells can differentiate into all three germ layers; they have low immunogenicity and anti-inflammatory functions; and they do not require the sacrifice of human embryos for their isolation, thus avoiding the current controversies associated with the use of human embryonic stem cells. Moreover, we developed human amniotic cell-sheets using a novel culture surface coated with a noncytotoxic, temperature-responsive elastic protein-based polymer. We also generated a "hyperdry-amnion", which has already been applied clinically in the ophthalmological field. Compared to cryopreserved fresh amnion, "hyper-dry-amnion" is easy to handle and has started to bring good results to patients. These materials from the amnion are also expected to open a new field in tissue engineering. Thus, amnion, which had been discarded after parturition, has started to be appreciated as an attractive material in the field of regenerative medicine. In this review, the most recent and relevant clinical and experimental data about the use of amniotic membrane and cells derived from it are described.
In early pregnancy, trophoblasts and the fetus experience hypoxic and low-nutrient conditions; nevertheless, trophoblasts invade the uterine myometrium up to one third of its depth and migrate along the lumina of spiral arterioles, replacing the maternal endothelial lining. Here, we showed that autophagy, an intracellular bulk degradation system, occurred in extravillous trophoblast (EVT) cells under hypoxia in vitro and in vivo. An enhancement of autophagy was observed in EVTs in early placental tissues, which suffer from physiological hypoxia. The invasion and vascular remodeling under hypoxia were significantly reduced in autophagy-deficient EVT cells compared with wild-type EVT cells. Interestingly, soluble endoglin (sENG), which increased in sera in preeclamptic cases, suppressed EVT invasion by inhibiting autophagy. The sENG-inhibited EVT invasion was recovered by TGFB1 treatment in a dose-dependent manner. A high dose of sENG inhibited the vascular construction by EVT cells and human umbilical vein endothelial cells (HUVECs), meanwhile a low dose of sENG inhibited the replacement of HUVECs by EVT cells. A protein selectively degraded by autophagy, SQSTM1, accumulated in EVT cells in preeclamptic placental biopsy samples showing impaired autophagy. This is the first report showing that impaired autophagy in EVT contributes to the pathophysiology of preeclampsia.
The amnion membrane is developed from embryo-derived cells, and amniotic cells have been shown to exhibit multidifferentiation potential. These cells represent a desirable source for stem cells for a variety of reasons. However, to date very few molecular analyses of amnion-derived cells have been reported, and efficient markers for isolating the stem cells remain unclear. This paper assesses the characterization of amnion-derived cells as stem cells by examining stemness marker expressions for amnion-derived epithelial cells and mesenchymal cells by flow cytometry, immunocytochemistry, and quantitative PCR. Flow cytometry revealed that amnion epithelial cells expressed CD133, CD 271, and TRA-1-60, whereas mecenchymal cells expressed CD44, CD73, CD90, and CD105. Immunohistochemistry showed that both cells expressed the stemness markers Oct3/4, Sox2, Klf4, and SSEA4. Stemness genes' expression in amnion epithelial cells, mesenchymal cells, fibroblast, bone marrow-derived mesenchymal stem cells (MSCs), and induced pluripotent stem cells (iPSCs) was compared by quantitative reverse-transcription polymerase chain reaction (RT-PCR). Amnion-derived epithelial cells and mesenchymal cells expressed Oct3/4, Nanog, and Klf4 more than bone marrow-derived MSCs. The sorted TRA1-60-positive cells expressed Oct3/4, Nanog, and Klf4 more than unsorted cells or TRA1-60-negative cells. TRA1-60 can be a marker for isolating amnion epithelial stem cells.
In order to improve the effectiveness of boron neutron capture therapy (BNCT) for malignant gliomas, we examined the optimization of the administration of boron compounds in brain tumor animal model. We analyzed the concentration of boron atoms in intracranial C6 glioma -bearing rats using inductively coupled plasma atomic emission spectrometry. Each tumor-bearing rat received one of two different amounts of sodium borocaptate (BSH) and/or 500 mg/kg of boronophenylalanine (BPA) via intraperitoneal injection. We compared the boron concentrations of the tumor, the contralateral normal brain and the blood in rats of 3 different treatment groups (BSH alone, BPA alone and a combination of both BSH and BPA). Our results show that the tumor boron concentration increased much more than 30 microg/g by the coadministration of both compounds. Additionally, the blood boron concentration remained below 30 microg/g and the boron concentration in the normal brain was low (mean 4.7+/-1.1 microg/g). Even in comparison with the administration of BPA alone, coadministration of BPA and BSH shows an improved tumor/normal brain ratio of boron concentrations.
Return to daily life Early mobilization program Comprehensive CR (disease management program) Discharge from hospital, Return to home Maintain comfortable life, Prevention of recurrence Returning to society-workforce, Establish new healthy lifestyle Inpatient rehabilitation program (CCU/ICU/ward) *Notation of corporation is omitted.
Objectives?Cerebrospinal fluid (CSF) leakage is an undesirable complication of skull base surgery. We used dried human amniotic membrane (AM) as a patch graft for dural repair to determine its efficacy in preventing CSF leakage. Design?Frontoparietal craniotomy and removal of dura were performed in 20 Wistar rats. A dried AM was placed to cover the dural defect without suturing in 16 animals. In four animals, an expanded polytetrafluoroethylene was implanted. At 2 weeks and 1, 3, and 6 months, histological examination was performed. Dried AM was also used as a substitute in 10 patients who underwent skull base surgery, after approval by the Ethics Committee of the University of Toyama. Results?At 2 weeks after implantation, thick connective tissue completely enclosed the dried AM. At 1?month after implantation, the connective tissue became thin and the implanted AM shortened. At 3 and 6 months after implantation, histological examination revealed disappearance of the dried AM and formation of membranous tissue. In the clinical study, neither CSF leakage nor clinical adverse reactions directly related to the dried AM were observed. Conclusion?Dried human AM appears to be an ideal substitute for dura, since it is replaced by natural tissue.
Human amnion-derived cells are considered to be a promising alternative cell source for their potential clinical use in tissue engineering and regenerative medicine because of their proliferation and differentiation ability. The cells can easily be obtained from human amnion, offering a potential source without medical intervention. It has been proven that human amnion-derived cells express immunosuppressive factors CD59 and HLA-G, implying that they may have an immunosuppressive function. To assess the immunosuppressive activity, we investigated the effect of human amnion-derived cells on NK cell and monocyte function. Amnion-derived cells inhibited the cytotoxicity of NK cells to K562 cells. The inhibition depended on the NK/amnion-derived cell ratio. The inhibition of NK cytotoxicity was recovered by continuous culturing without amnion-derived cells. The inhibition of NK cytotoxicity was related to the downregulation of the expression of the activated NK receptors and the production of IFN-g, as well as the upregulation of the expression of IL-10 and PGE 2 in human amnionderived cells. The addition of antibody to IL-10 or PGE 2 inhibitor tended to increase NK cytotoxicity. IL-10 and PGE 2 might be involved in the immunosuppressive activity of amniotic cells toward NK cells. Amniotic cells also suppressed the activity of cytokine production in monocytes analyzed with TNF-a and IL-6. These data suggested that amniotic cells have immunosuppressive activity.
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