Human amniotic epithelial stem cell is a cell therapy candidate for preventing acute graft-versus-host disease.

Graft-versus-host disease (GVHD), an immunological disorder that arises from donor T cell activation through recognition of host alloantigens, is the major limitation in the application of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Traditional immunosuppressive agents can relieve GVHD, but they induce serious side effects. It is highly required to explore alternative therapeutic strategy. Human amniotic epithelial stem cells (hAESCs) were recently considered as an ideal source for cell therapy with special immune regulatory property. In this study, we evaluated the therapeutic role of hAESCs in the treatment of GVHD, based on our previous developed cGMP-grade hAESCs product. Humanized mouse model of acute GVHD (aGVHD) was established by injection of huPBMCs via the tail vein. For prevention or treatment of aGVHD, hAESCs were injected to the mice on day -1 or on day 7 post-PBMC infusion, respectively. We showed that hAESCs infusion significantly alleviated the disease phenotype, increased the survival rate of aGVHD mice, and ameliorated pathological injuries in aGVHD target organs. We demonstrated that hAESCs directly induced CD4+ T cell polarization, in which Th1 and Th17 subsets were downregulated, and Treg subset was elevated. Correspondingly, the levels of a series of pro-inflammatory cytokines were reduced while the levels of the anti-inflammatory cytokines were upregulated in the presence of hAESCs. We found that hAESCs regulated CD4+ subset polarization in a paracrine mode, in which TGFß and PGE2 were selectively secreted to mediate Treg elevation and Th1/Th17 inhibition, respectively. In addition, transplanted hAESCs preserved the graft-versus-leukemia (GVL) effect by inhibiting leukemia cell growth. More intriguingly, hAESCs infusion in HSCT patients displayed potential anti-GVHD effect with no safety concerns and confirmed the immunoregulatory mechanisms in the preclinical study. We conclude that hAESCs infusion is a promising therapeutic strategy for post-HSCT GVHD without compromising the GVL effect. The clinical trial was registered at www.clinicaltrials.gov as #NCT03764228.

Improved Tribological Performance of MOF@MXene/PI under High Temperature.

High-temperature-resistant and self-lubricating polymer composites with long life and high reliability are increasingly indispensable in the aerospace field. Herein, ZIF-67 grown on the MXene lamella was successfully prepared, and ZIF-67@MXene/PI composites with a regular layered structure were obtained by a hot-pressing three-dimensional network aerogel. It was revealed that incorporating ZIF-67@MXene into PI dramatically reduced the friction and abrasion with elevated temperatures. Largely, aerogel walls always paralleled the sliding direction by compressing, providing a significant antifriction effect. More notably, the presence of a vigorous tribofilm composed of a PI matrix and a diamond-type lattice MOF-modified MXene provided rolling and sliding interface friction under high temperatures, simultaneously. In addition, the uniform tribofilm with a thickness of about 200 nm can effectively avoid the direct contact of the friction pair during the sliding process. Hence, the combination of the constructed multiscale nanocomposites and nanostructured tribofilm with outstanding tribological performance endow the material potentially useful in reducing energy consumption, thus addressing the energy wastage problem caused by friction.

Synergistic Improvement of Dielectric and Thermal Conductivity Properties for Polymers Filled with Multifunctional Modified Nanowires.

Dielectric composites are widely used in power electronics, power systems, aerospace, and other fields due to their extremely high power density. However, if their energy density can be further increased, the application range will be greatly improved. Improving the dielectric constant of composites is one of the most effective ways to increase the energy density. In this study, a preparation method for copper calcium titanate nanowires (CCTO-NWs) with adjustable aspect ratio was investigated. Upon incorporation of these CCTO-NWs into the polymer matrix, the nanocomposites exhibit a significantly higher dielectric constant and a lower dielectric loss. In addition, a thin layer of Al2O3 with excellent thermal conductivity is coated on the surface of the CCTO-NWs to form a core-shell structure nanowire CCTO-NW@Al2O3. The introduction of the thermal conductive layer of Al2O3 not only creates a continuous heat transfer path within the dielectric composite, increasing the thermal conductivity of the composite from 0.11 W/(m·K) of pure HIPS to 1.12 W/(m·K), but also serves as a buffer layer between HIPS and CCTO-NWs, effectively alleviating the electric field distortion caused by the large difference in the dielectric constant between them, thereby optimizing the dielectric properties of the composite and reducing the dielectric permeability threshold from 30 to 20 vol %. This work provides an effective strategy for synergistically improving the dielectric constant and thermal conductivity of dielectric composites while also taking into account the good flexibility of polymer/ceramic nanocomposites.

Repair of Retinal Degeneration by Human Amniotic Epithelial Stem Cell-Derived Photoreceptor-like Cells.

The loss of photoreceptors is a major event of retinal degeneration that accounts for most cases of untreatable blindness globally. To date, there are no efficient therapeutic approaches to treat this condition. In the present study, we aimed to investigate whether human amniotic epithelial stem cells (hAESCs) could serve as a novel seed cell source of photoreceptors for therapy. Here, a two-step treatment with combined Wnt, Nodal, and BMP inhibitors, followed by another cocktail of retinoic acid, taurine, and noggin induced photoreceptor-like cell differentiation of hAESCs. The differentiated cells demonstrated the morphology and signature marker expression of native photoreceptor cells and, intriguingly, bore very low levels of major histocompatibility complex (MHC) class II molecules and a high level of non-classical MHC class I molecule HLA-G. Importantly, subretinal transplantation of the hAESCs-derived PR-like cells leads to partial restoration of visual function and retinal structure in Royal College of Surgeon (RCS) rats, the classic preclinical model of retinal degeneration. Together, our results reveal hAESCs as a potential source of functional photoreceptor cells; the hAESCs-derived photoreceptor-like cells could be a promising cell-replacement candidate for therapy of retinal degeneration diseases.

Human Amniotic Epithelial Stem Cell-Derived Retinal Pigment Epithelium Cells Repair Retinal Degeneration.

Age-related macular degeneration (AMD), featured with dysfunction and loss of retinal pigment epithelium (RPE), is lacking efficient therapeutic approaches. According to our previous studies, human amniotic epithelial stem cells (hAESCs) may serve as a potential seed cell source of RPE cells for therapy because they have no ethical concerns, no tumorigenicity, and little immunogenicity. Herein, trichostatin A and nicotinamide can direct hAESCs differentiation into RPE like cells. The differentiated cells display the morphology, marker expression and cellular function of the native RPE cells, and noticeably express little MHC class II antigens and high level of HLA-G. Moreover, visual function and retinal structure of Royal College of Surgeon (RCS) rats, a classical animal model of retinal degeneration, were rescued after subretinal transplantation with the hAESCs-derived RPE like cells. Our study possibly makes some contribution to the resource of functional RPE cells for cell therapy. Subretinal transplantation of hAESCs-RPE could be an optional therapeutic strategy for retinal degeneration diseases.

3D bioprinting and in vitro study of bilayered membranous construct with human cells-laden alginate/gelatin composite hydrogels.

Extrusion-based 3D bioprinting of cell-laden hydrogels is a potential technology for regenerative medicine, which enables the fabrication of constructs with spatially defined cell distribution. However, the limited assessment of rheological behaviors of hydrogel before printing is still a major issue for the advancement of 3D bioprinting. In this work, we systematically investigated the rheological behaviors (i.e. viscosity, storage modulus (G'), and loss modulus (G")) of alginate/gelatin composite hydrogels first for 3D printing complex constructs. The rheological studies revealed that viscosity of alginate/gelatin hydrogels is temperature-dependent and shear thinning. Sol-gel transition (intersection of G' and G") study provided indication for printing temperature, which are in the range of 18.8 °C (H2/7.5) to 24.5 °C (H2/24.5). The alginate (2 wt%) /gelatin (15 wt%) composite hydrogel sample was chosen to print the constructs and subsequent bioprinting. Complex constructs (i.e. nose and ear) were obtained with high printing resolution (151 ±â€¯13.04 µm) in a low temperature (4 °C) chamber and crosslinking with 2 wt% CaCl2 subsequently without extra supports. Human amniotic epithelial cells (AECs) showed superior potential to differentiate into epithelial cells, while Wharton's jelly derived mesenchymal stem cells (WJMSCs) showed a superior angiogenic potential and fibroblastic phenotype. For the in vitro study, AECs and WJMSCs as seed cells, encapsulated in alginate/gelatin composite hydrogels, were bioprinted to form biomimetic bilayered membranous construct. High cell viability (> 95%) were observed up to 6 days after printing. The presented 3D bioprinting of human AECs and WJMSCs-laden alginate/gelatin composite hydrogels provides promising potentials for future skin tissue engineering.

Human amniotic epithelial cell transplantation promotes neurogenesis and ameliorates social deficits in BTBR mice.

BACKGROUND: Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social interactions and communication and stereotypical patterns of behaviors, interests, or activities. Even with the increased prevalence of ASD, there is no defined standard drug treatment for ASD patients. Currently, stem cells, including human amniotic epithelial cell (hAEC) transplantation, seem to be a promising treatment for ASD, but the effectiveness needs to be verified, and the mechanism has not been clarified. METHODS: We intraventricularly transplanted hAECs into a 2-month-old BTBR T+tf/J (BTBR) mouse model of ASD. Behavior tests were detected 1 month later; hippocampal neurogenesis, neuroprogenitor cell (NPC) pool, and microglia activation were analyzed with immunohistochemistry and immunofluorescence; the levels of pro-inflammatory cytokines, brain-derived neurotrophic factor (BDNF), and TrkB in the hippocampus were determined by real-time PCR or western blotting. RESULTS: After intraventricular injection of hAECs into adult males, social deficits in BTBR mice were significantly ameliorated. In addition, hAEC transplantation restored the decline of neurogenesis and NPCs in the hippocampus of BTBR mice by expanding the stem cell pool, and the decreased levels of BDNF and TrkB were also rescued in the hippocampus of the hAEC-injected BTBR mice. Meanwhile, the transplantation of hAECs did not induce microglial overactivation or excessive production of pro-inflammatory cytokines in the hippocampus of BTBR mice. CONCLUSIONS: Based on these results, we found that hAEC transplantation ameliorated social deficits and promoted hippocampal neurogenesis in BTBR mice. Our study indicates a promising therapeutic option that could be applied to ASD patients in the future.

Subretinal Transplantation of Human Amniotic Epithelial Cells in the Treatment of Autoimmune Uveitis in Rats.

As a featured ocular inflammatory disease, autoimmune uveitis is the major cause of blindness in the clinic. Although current immunosuppressive regimens can alleviate the progression of autoimmune uveitis, they have serious side effects. Therefore, an alternative therapeutic strategy is urgently required. The present study investigated the therapeutic efficacy of human amniotic epithelial cells (hAECs) on autoimmune uveitis in a rat model. Herein, experimental autoimmune uveitis (EAU) was induced in rats via a subcutaneous injection of interphotoreceptor retinoid-binding protein. EAU rats were treated with hAECs or the vehicle solution via a subretinal injection on day 0 and day 6 after immunization, and rats were sacrificed on day 12 and day 18 for further analysis. The pathological development of EAU was evaluated by slit lamp microscopy. Immune cell infiltration and retinal structure damage were examined by histological examination of hematoxylin and eosin (H&E) and immunofluorescence staining. T-cell subsets were detected by flow cytometry, and the levels of inflammatory cytokines were quantified by enzyme-linked immunosorbent assay (ELISA). hAEC treatment ameliorated the pathological progression of EAU and preserved the retinal structure organization and thickness, especially in the preventive group that received a subretinal injection on day 0. Moreover, hAECs inhibited the retinal infiltration of macrophages and T-cells. Mechanistically, hAECs modulated the balance of T-cell subsets by downregulating T helper (Th)17 cells and upregulating T regulatory (Treg) cells, as confirmed by decreased interleukin (IL)-17 and increased IL-10 levels in the spleens and lymph nodes of EAU rats. Furthermore, hAECs improved the local cytokine environment in EAU rats by suppressing the monocyte chemoattractant protein (MCP)-1, IL-17 and interferon (IFN)-γ levels and enhancing the IL-10 in the aqueous humor. Therefore, subretinal transplantation of hAECs in EAU rats ameliorated ocular inflammation, preserved the retinal structure and coordinated the immune balance. The current study provides a novel therapeutic strategy for autoimmune uveitis and related ocular inflammatory diseases in the clinic.

Therapeutic effect of human amniotic epithelial cells in murine models of Hashimoto's thyroiditis and Systemic lupus erythematosus.

BACKGROUND AIMS: The chronic inflammation of autoimmune diseases develops repetitive localized destruction or systemic disorders, represented by Hashimoto's thyroiditis (HT) and Systemic lupus erythematosus (SLE) respectively. Currently, there are no efficient ways to treat these autoimmune diseases. Therefore, it is critically important to explore new therapeutic strategies. The aim of this study was to investigate the therapeutic efficacy of human amniotic epithelial cells (hAECs) in murine models of HT and SLE. METHODS: Experimental autoimmune thyroiditis (EAT) was induced in female CBA/J mice by immunization with porcine thyroglobulin (pTg). hAECs were intravenously administered at different time points during the disease course. MRL-Faslpr mice, a strain with spontaneously occurring SLE, were intravenously administered hAECs when their sera were positive for both anti-nuclear antibodies (ANAs) and anti-double-stranded DNA (anti-dsDNA) antibodies. Two weeks after the last cell transplantation, blood and tissue samples were collected for histological examination and immune system analysis. RESULTS: hAECs prevented lymphocytes infiltration into the thyroid and improved the damage of thyroid follicular in EAT mice. Correspondingly, hAECs administration reduced anti-thyroglobulin antibodies (TGAb), anti-thyroid peroxidase antibodies (TPOAb) and thyroid stimulating hormone (TSH) levels. SLE mice injected with hAECs appeared negative for ANAs and anti-dsDNA antibodies and showed reduced immunoglobulin profiles. Mechanically, hAECs modulated the immune cells balance in EAT and SLE mice, by downregulating the ratios of Th17/Treg cells in both EAT and SLE mice and upregulating the proportion of B10 cells in EAT mice. This was confirmed by in vitro assay, in which hAECs inhibited the activation of EAT mice-derived splenocytes. Moreover, hAECs improved the cytokine environment in both EAT and SLE mice, by suppressing the levels of IL-17A and IFN-γ and enhancing TGF-ß. CONCLUSION: These results demonstrated the immunoregulatory effect of hAECs for inflammation inhibition and injury recovery in HT and SLE murine models. The current study may provide a novel therapeutic strategy for these autoimmune diseases in clinic.

Δ3,2-Hydroxybakuchiol Attenuates Depression in Multiple Rodent Models Possibly by Inhibition of Monoamine Transporters in Brain.

Δ3,2-Hydroxybakuchiol is isolated from Psoralea corylifolia (L.), which has therapeutic applications in traditional Chinese medicine. Our previous studies have showed that Δ3,2-hydroxybakuchiol inhibited the decreased activity of reserpinized mice, suggestive of its antidepressive potential. In this study, we explored the antidepressant profile of Δ3,2-hydroxybakuchiol in various rodent models and its possible monoamine-modulating mechanism. Δ3,2-Hydroxybakuchiol significantly reduced immobility time of mice in forced swim test and tail suspension test. Δ3,2-Hydroxybakuchiol also significantly increased sucrose consumption in chronic unpredictable mild stress (CUMS) rat model. Furthermore, isotope uptake study showed that Δ3,2-hydroxybakuchiol inhibited the activity of human dopamine transporter (DAT) and norepinephrine transporter (NET) in transporter-overexpressing pheochromocytoma (PC12) cells with IC50 values similar to the potency of bupropion. Microdialysis showed that Δ3,2-hydroxybakuchiol increased dopamine and norepinephrine concentration in rat striatum. In summary, Δ3,2-hydroxybakuchiol exerts antidepressant effects on various types of depression models through a possible mechanism of monoamine transporter inhibition.

Biological characterization of human amniotic epithelial cells in a serum-free system and their safety evaluation.

Human amniotic epithelial cells (hAECs), derived from the innermost layer of the term placenta closest to the fetus, have been shown to be potential seed cells for allogeneic cell therapy. Previous studies have shown a certain therapeutic effect of hAECs. However, no appropriate isolation and culture system for hAECs has been developed for clinical applications. In the present study, we established a serum-free protocol for hAEC isolation and cultivation, in which better cell growth was observed compared with that in a traditional culture system with serum. In addition to specific expression of cell surface markers (CD29, CD166 and CD90), characterization of the biological features of hAECs revealed expression of the pluripotent markers SSEA4, OCT4 and NANOG, which was greater than that in human mesenchymal stem cells, whereas very low levels of HLA-DR and HLA-DQ were detected, suggesting the weak immunogenicity of hAECs. Intriguingly, CD90+ hAECs were identified as a unique population with a powerful immunoregulatory capacity. In a systemic safety evaluation, intravenous administration of hAEC did not result in hemolytic, allergy, toxicity issues or, more importantly, tumorigenicity. Finally, the therapeutic effect of hAECs was demonstrated in mice with radiation-induced damage. The results revealed a novel function of hAECs in systemic injury recovery. Therefore, the current study provides an applicable and safe strategy for hAEC cell therapy administration in the clinical setting.

MicroRNA­32 silences WWP2 expression to maintain the pluripotency of human amniotic epithelial stem cells and ß islet­like cell differentiation.

Human amniotic epithelial stem cells (HuAECs) exhibit pluripotent characteristics, which are similar to those of embryonic stem cells, and can differentiate into various adult tissues and cells through directed induction. However, in culture, HuAECs tend to lose their pluripotency, and their directed differentiation capability declines with increasing passage number. The stem cell pluripotency factor octamer­binding protein 4 (Oct4) is an important transcription factor that promotes stem cell self­proliferation and maintains their pluripotency. Previous studies have demonstrated that WW domain containing E3 ubiquitin protein ligase 2 (WWP2) negatively regulates Oct4 expression and stem cell pluripotency. Therefore, the present study aimed to investigate the regulation of WWP2 by microRNAs (miRs), and to evaluate the expression of the downstream factor Oct4 and the maintenance of HuAEC pluripotency. Bioinformatics analysis identified a complementary binding site for miR­32 in the 3'untranslated region of the WWP2 gene, thus suggesting that it may be a target gene of miR­32. Post­infection of HuAECs with a vector overexpressing miR­32, the endogenous expression of WWP2 was significantly decreased, whereas Oct4 expression was significantly increased. Furthermore, miR­32­infected cells differentiated into ß islet­like cells by directed induction. The results indicated that after induction, HuAECs overexpressing miR­32 also overexpressed the biomarkers of ß islet­like cells. In addition, the ability to secrete insulin was markedly enhanced in response to glucose stimulation, in cells overexpressing miR­32. In conclusion, the present study suggested that miR­32 may effectively inhibit WWP2 expression in HuAECs and promote Oct4 overexpression to maintain their pluripotency.

SPION-mediated miR-141 promotes the differentiation of HuAESCs into dopaminergic neuron-like cells via suppressing lncRNA-HOTAIR.

In this study, a bioinformatics analysis and luciferase reporter assay revealed that microRNA-141 could silence the expression of lncRNA-HOTAIR by binding to specific sites on lncRNA-HOTAIR. We used superparamagnetic iron oxide nanoparticles (SPIONs) to mediate the high expression of microRNA-141 (SPIONs@miR-141) in human amniotic epithelial stem cells (HuAESCs), which was followed by the induction of the differentiation of HuAESCs into dopaminergic neuron-like cells (iDNLCs). qPCR, western blot, immunofluorescence staining and HPLC all suggested that SPION-mediated overexpression of miR-141 could promote an increased expression of brain-derived neurotrophic factor (BDNF), DAT and 5-TH in HuAESC-derived iDNLCs. The RIP and ChIP assay also showed that overexpression of miR-141 could significantly inhibit the recruitment and binding of lncRNA-HOTAIR to EZH2 on BDNF gene promoter. cDNA microarray analysis revealed that the expression levels of 190 genes were much higher in iDNLCs than in HuAESCs. Finally, a protein interaction network analysis and identification showed that in the iDNLC group with SPIONs@miR-141, factors that interact with BDNF, such as FGF8, SHH, NTRK3 and CREB1, all showed significantly higher expression levels compared with those in the SPIONs@miR-Mut. Therefore, this study confirmed that the highly efficient expression of microRNA-141 mediated by SPIONs could improve the efficiency of HuAESCs differentiation into dopaminergic neuron-like cells.

Amniotic fluid-derived stem cells mixed with platelet rich plasma for restoration of rat alveolar bone defect.

Stem cells isolated from the amniotic fluid have been shown as a promising candidate for cell therapy and tissue engineering. However, the experimental and preclinical applications of amniotic fluid-derived stem cells (AFSCs) in the very field of maxillofacial bone tissue engineering are still limited. In this study, rat AFSCs were successfully harvested and characterized in vitro. The rat AFSCs showed typical fibroblastoid morphology, stable proliferation activity and multi-differentiation potential. Flow-cytometry analysis demonstrated that these cells were positive for CD29, CD44, and CD90, while negative for hematopoietic markers such as CD34 and CD45. The regenerative performance of AFSCs-premixed with platelet rich plasma (PRP) gel in restoration of alveolar bone defect was further investigated using a modified rat maxillary alveolar defect model. Micro-computer tomography and histological examination showed a superior regenerative capacity of AFSCs-premixed with PRP gel at both 4 and 8 weeks after operation comparing with control groups. Moreover, the implanted AFSCs can survive in the defect site and directly participate in the bone tissue regeneration. Taken together, these results indicated the feasibility of an AFSCs-based alveolar bone tissue engineering strategy for alveolar defect restoration.

Human amniotic epithelial cells inhibit CD4+ T cell activation in acute kidney injury patients by influencing the miR-101-c-Rel-IL-2 pathway.

In the pathogenesis of acute kidney injury (AKI), the release of multiple interleukins can lead to increased kidney damage. Human amniotic epithelial cells (HuAECs) can inhibit immune cell activation in vivo and in vitro. We hypothesized that HuAECs could weaken patient-derived peripheral blood CD4+ T-cell activation and decreasing the ability of these cells to express and release IL-2. -Cell proliferation assay revealed that under the same culture conditions, activated AKI patient-derived CD4+ T cells had a significantly reduced proliferation rate when were co-cultured with HuAECs. And the level of IL-2 released was also significantly reduced. Western blot and qRT-PCR assays showed that the expression of c-Rel in the CD4+ T cells was also significantly reduced. However, the expression level of endogenous miR-101 in the CD4+ T cells co-cultured with HuAECs was significantly increased. Luciferase reporter assay results suggested that miR-101 could bind to a specific site in the c-Rel 3' UTR and induce the post-transcriptional silencing of c-Rel. Subsequently, we over-expressed miR-101 in AKI patient-derived CD4+ T cells. The qRT-PCR and western blot assay results revealed that the expression of endogenous c-Rel was significantly reduced, while the ELISA results indicated that the level of IL-2 released was also significantly decreased. Finally, ChIP-PCR assay results showed that the miR-101-overexpressing CD4+ T-cell group and the HuAEC co-culture CD4+ T-cell group exhibited significantly decreased binding capacities between the 'c-Rel-NFκB' complex and the IL-2 gene promoter, and the transcriptional activity of IL-2 was also significantly decreased. Therefore, we confirmed that HuAECs can stimulate miR-101 expression in AKI patient-derived peripheral blood CD4+ T cells, thus inhibiting the expression of the miR-101 target gene c-Rel and leading to a reduction in IL-2 expression and release.

miR-145 modulates lncRNA-ROR and Sox2 expression to maintain human amniotic epithelial stem cell pluripotency and ß islet-like cell differentiation efficiency.

In this study, we observed a great reduction in the expression of the endogenous long noncoding RNA ROR (lncRNA-ROR) and the stem cell transcription factor Sox2, in contrast to a marked increase in miR-145 expression, during the course of in vitro induced differentiation of human amniotic epithelial stem cells (HuAECs). Bioinformatics analysis and the luciferase reporter assay revealed binding of miR-145 to specific sites in lncRNA-ROR and Sox2, silencing their expression. Overexpression of a lncRNA-ROR-specific siRNA effectively downregulated the expression levels of Sox2 and other stem cell markers in HuAECs while weakening the efficiency of HuAEC differentiation into ß islet-like cells. Moreover, the in vitro response of HuAEC-derived ß islet-like cells to extracellular stimuli and C-peptide release by these cells were markedly weakened in the siRNA-ROR transfection group. Furthermore, the in vivo expression of ß islet-like cell biomarkers was substantially reduced in HuAECs in the siRNA-ROR transfection group, and their in vivo ß islet-like cell differentiation and insulin release capacities were reduced in a streptozocin-induced diabetic rat model. The experimental results indicate that lncRNA-ROR effectively maintains Sox2 gene expression through competitive binding to miR-145, achieving pluripotency maintenance in HuAECs and regulation of their directed ß islet-like cell differentiation efficiency.

Growth hormone treatment of premature ovarian failure in a mouse model via stimulation of the Notch-1 signaling pathway.

Premature ovarian failure (POF) is a condition affecting 1% of women in the general population, causing amenorrhea, hypergonadotropism and hypoestrogenism before the age of 40. Currently, POF cannot be reversed and, although treatments are available, there is an urgent need for improved treatment strategies. Growth hormone (GH) is a pleiotropic hormone that affects a broad spectrum of physiological functions, from carbohydrate and lipid metabolism to the immune response. GH has previously been used to treat POF in non-transgenic preclinical trials, but the biochemical mechanism underlying these effects are unclear. In the present study, a mouse model of POF was generated using cyclophosphamide. Treatment of POF mice with recombinant mouse growth hormone (rmGH) was revealed to markedly reduce POF histopathology in ovarian tissue, relieve ovarian granulosa cell injury, reduce the number of atretic follicles and significantly increase the number of mature oocytes. Furthermore, an enzyme-linked immunosorbent assay revealed that plasma estradiol levels increased and plasma follicle stimulating hormone levels decreased with time in a group of mice treated with a medium dose of rmGH (0.8 mg/kg) when compared with the POF model group (P<0.05). In addition, reverse transcription-quantitative polymerase chain reaction and immunohistochemical analysis demonstrated elevated levels of Notch-1 signaling pathway factors (Notch1, CBF1, and HES1) in wild-type mice and those treated with medium and high doses of rmGH, but not in those treated with low doses of rmGH. In conclusion, GH may promote ovarian tissue repair, estrogen release and oocyte maturation via activation of the Notch-1 signaling pathway in ovarian tissue.

Derivation and characterization of human embryonic stem cells on human amnion epithelial cells.

Culture conditions that support the growth of undifferentiated human embryonic stem cells (hESCs) have already been established using primary human amnion epithelial cells (hAECs) as an alternative to traditional mitotically inactivated mouse embryonic fibroblasts (MEFs). In the present work, inner cell masses (ICM) were isolated from frozen embryos obtained as donations from couples undergoing in vitro fertilization (IVF) treatment and four new hESC lines were derived using hAECs as feeder cells. This feeder system was able to support continuous growth of what were, according to their domed shape and markers, undifferentiated naïve-like hESCs. Their pluripotent potential were also demonstrated by embryoid bodies developing to the expected three germ layers in vitro and the productions of teratoma in vivo. The cell lines retained their karyotypic integrity for over 35 passages. Transmission electron microscopy (TEM) indicated that these newly derived hESCs consisted mostly of undifferentiated cells with large nuclei and scanty cytoplasm. The new hESCs cultured on hAECs showed distinct undifferentiated characteristics in comparison to hESCs of the same passage maintained on MEFs. This type of optimized culture system may provide a useful platform for establishing clinical-grade hESCs and assessing the undifferentiated potential of hESCs.

Comparative investigation of human amniotic epithelial cells and mesenchymal stem cells for application in bone tissue engineering.

Emerging evidence suggests amniotic epithelial cells (AECs) as a promising source of progenitor cells in regenerative medicine and bone tissue engineering. However, investigations comparing the regenerative properties of AECs with other sources of stem cells are particularly needed before the feasibility of AECs in bone tissue engineering can be determined. This study aimed to compare human amniotic epithelial cells (hAECs), human bone marrow mesenchymal stem cells (hBMSCs), and human amniotic fluid derived mesenchymal stem cells (hAFMSCs) in terms of their morphology, proliferation, immunophenotype profile, and osteogenic capacity in vitro and in vivo. Not only greatly distinguished by cell morphology and proliferation, hAECs, hAFMSCs, and hBMSCs exhibited remarkably different signature regarding immunophenotypical profile. Microarray analysis revealed a different expression profile of genes involved in ossification along the three cell sources, highlighting the impact of different anatomical origin and molecular response to osteogenic induction on the final tissue-forming potential. Furthermore, our data indicated a potential role of FOXC2 in early osteogenic commitment.

Characterization of a micro-roughened TiO2/ZrO2 coating: mechanical properties and HBMSC responses in vitro.

Previous studies have shown that using ZrO2 as a second phase to bioceramics can significantly increase the bonding strength of plasma-sprayed composite material. In the present study, micro-roughened titanium dioxide/zirconia (TiO2/ZrO2) (30 wt% ZrO2) coating and TiO2 coating were plasma-sprayed onto Ti plates. The micro-structural characteristics and mechanical properties of both coatings were investigated. Furthermore, the biological behavior and osteogenic differentiation of human bone marrow mesenchymal stem cells (HBMSCs) on both TiO2/ZrO2 and TiO2 coatings were compared. The results indicated that the shear bond strength and microhardness of TiO2/ZrO2 coating were statistically higher than those of TiO2 coating. Scanning electron microscope observation revealed that more irregularly shaped protuberances and denser pores were formed on the surface of TiO2/ZrO2 coating compared with those of TiO2 coating. Further comparative analysis of HBMSC proliferation and osteogenic differentiation on both coatings showed that significantly higher cellular alkaline phosphatase activity and expression levels of Runx2 and Osterix at day 10 after osteogenic culture were found on TiO2/ZrO2 coating compared with TiO2 coating, while no statistically significant difference in cell proliferation and extracellular calcium deposition was observed. The present study suggests that TiO2/ZrO2 coating may be favorable for dental implant applications.