Second and third trimester amniotic fluid mesenchymal stem cells can repopulate a de-cellularized lung scaffold and express lung markers

Comparative Analysis of Fluorescent Labeling Techniques for Tracking Canine Amniotic Stem Cells

The utmost aim of regenerative medicine is to promote the regeneration of injured tissues using stem cells. Amniotic mesenchymal stem cells (AmMSCs) have been used in several studies mainly because of their easy isolation from amniotic tissue postpartum and immunomodulatory and angiogenic properties and the low level of rejection. These cells share characteristics of both embryonic/fetal and adult stem cells and are particularly advantageous because they do not trigger tumorigenic activity when injected into immunocompromised animals. The large-scale use of AmMSCs for cellular therapies would greatly benefit from fluorescence labeling studies to validate their tracking in future therapies. This study evaluated the fluorophore positivity, fluorescence intensity, and longevity of canine AmMSCs. For this purpose, canine AmMSCs from the GDTI/USP biobank were submitted to three labeling conditions, two commercial fluorophores [CellTrace CFSE Cell Proliferation kit - CTrace, and CellTracker Green CMFDA - CTracker (CellTracker Green CMFDA, CT, #C2925, Molecular Probes®; Life Technologies)] and green fluorescent protein (GFP) expression after lentiviral transduction, to select the most suitable tracer in terms of adequate persistence and easy handling and analysis that could be used in studies of domestic animals. Fluorescence was detected in all groups; however, the patterns were different. Specifically, CTrace and CTracker fluorescence was detected 6 h after labeling, while GFP was visualized no earlier than 48 h after transduction. Flow cytometry analysis revealed more than 70% of positive cells on day 7 in the CTrace and CTracker groups, while fluorescence decreased significantly to 10% or less on day 20. Variations between repetitions were observed in the GFP group under the present conditions. Our results showed earlier fluorescence detection and more uniform results across repetitions for the commercial fluorophores. In contrast, fluorescence persisted for more extended periods in the GFP group. These results indicate a promising direction for assessing the roles of canine AmMSCs in regenerative medicine without genomic integration.

Combination of human platelet lysate and 3D gelatin scaffolds to enhance osteogenic differentiation of human amniotic fluid derived mesenchymal stem cells

Bone disorders are major health issues requiring specialized care; however, the traditional bone grafting method had several limitations. Thus, bone tissue engineering has become a potential alternative. In therapeutic treatments, using fetal bovine serum (FBS) as a culture supplement may result in the risk of contamination and host immunological response; therefore, human platelet lysate (hPL) has been considered a viable alternative source. This study attempted to compare the effectiveness and safety of different culture supplements, either FBS or hPL, on the osteoblastic differentiation potential of mesenchymal stem cells derived from human amniotic fluid (hAF-MSCs) under a three-dimensional gelatin scaffold. The results indicate that hAF-MSCs have the potential to be used in clinical applications as they meet the criteria for mesenchymal stem cells based on their morphology, the expression of a particular surface antigen, their proliferation ability, and their capacity for multipotent differentiation. After evaluation by MTT and Alamar blue proliferation assay, 10% of hPL was selected. The osteogenic differentiation of hAF-MSCs under three-dimensional gelatin scaffold using osteogenic-induced media supplemented with hPL was achievable and markedly stimulated osteoblast differentiation. Moreover, the expressions of osteoblastogenic related genes, including OCN, ALP, and COL1A1, exhibited the highest degree of expression under hPL-supplemented circumstances when compared with the control and the FBS-supplemented group. The induced cells under hPL-supplemented conditions also presented the highest ALP activity level and the greatest degree of calcium accumulation. These outcomes would indicate that hPL is a suitable substitute for animal derived serum. Importantly, osteogenic differentiation of human amniotic fluid derived mesenchymal stem cells using hPL-supplemented media and three-dimensional scaffolds may open the door to developing an alternative construct for repairing bone defects.

Advanced single-cell technologies to guide the development of bioengineered lungs

Lung transplantation remains the only viable option for individuals suffering from end-stage lung failure. However, a number of current limitations exist including a continuing shortage of suitable donor lungs and immune rejection following transplantation. To address these concerns, engineering a decellularized biocompatible lung scaffold from cadavers reseeded with autologous lung cells to promote tissue regeneration is being explored. Proof-of-concept transplantation of these bioengineered lungs into animal models has been accomplished. However, these lungs were incompletely recellularized with resulting epithelial and endothelial leakage and insufficient basement membrane integrity. Failure to repopulate lung scaffolds with all of the distinct cell populations necessary for proper function remains a significant hurdle for the progression of current engineering approaches and precludes clinical translation. Advancements in 3D bioprinting, lung organoid models, and microfluidic device and bioreactor development have enhanced our knowledge of pulmonary lung development, as well as important cell-cell and cell-matrix interactions, all of which will help in the path to a bioengineered transplantable lung. However, a significant gap in knowledge of the spatiotemporal interactions between cell populations as well as relative quantities and localization within each compartment of the lung necessary for its proper growth and function remains. This review will provide an update on cells currently used for reseeding decellularized scaffolds with outcomes of recent lung engineering attempts. Focus will then be on how data obtained from advanced single-cell analyses, coupled with multiomics approaches and high-resolution 3D imaging, can guide current lung bioengineering efforts for the development of fully functional, transplantable lungs.

Differentiation of cardiomyocyte-like cells from human amniotic fluid mesenchymal stem cells by combined induction with human platelet lysate and 5-azacytidine

Human amniotic fluid mesenchymal stem cells (hAF-MSCs) have been shown to be effective in the treatment of many diseases. Platelet lysate (PL) contains multiple growth and differentiation factors; therefore, it can be used as a differentiation inducer. In this study, we attempted to evaluate the efficiency of human platelet lysate (hPL) on cell viability and the effects on cardiomyogenic differentiation of hAF-MSCs. When treating the cells with hPL, the result showed an increase in cell viability. Expressions of cardiomyogenic specific genes, including GATA4, cTnT, Cx43 and Nkx2.5, were higher in the combined treatment groups of 5-azacytidine (5-aza) and hPL than the expressions of cardiomyogenic specific genes in the control group and in the 5-aza treatment group. In terms of the results of immunofluorescence and immunoenzymatic staining, the highest expressions of cardiomyogenic specific proteins were revealed in combined treatment groups. It can be summarized that hPL may be an effective supporting cardiomyogenic supplementary factor for cardiomyogenic differentiation in hAF-MSCs.

Enhanced efficiency in isolation and expansion of hAMSCs via dual enzyme digestion and micro-carrier

A two-stage method of obtaining viable human amniotic stem cells (hAMSCs) in large-scale is described. First, human amniotic stem cells are isolated via dual enzyme (collagenase II and DNAase I) digestion. Next, relying on a culture of the cells from porous chitosan-based microspheres in vitro, high purity hAMSCs are obtained in large-scale. Dual enzymatic (collagenase II and DNase I) digestion provides a primary cell culture and first subculture with a lower contamination rate, higher purity and a larger number of isolated cells. The obtained hAMSCs were seeded onto chitosan microspheres (CM), gelatin-chitosan microspheres (GCM) and collagen-chitosan microspheres (CCM) to produce large numbers of hAMSCs for clinical trials. Growth activity measurement and differentiation essays of hAMSCs were realized. Within 2 weeks of culturing, GCMs achieved over 1.28 ± 0.06 × 107 hAMSCs whereas CCMs and CMs achieved 7.86 ± 0.11 × 106 and 1.98 ± 0.86 × 106 respectively within this time. In conclusion, hAMSCs showed excellent attachment and viability on GCM-chitosan microspheres, matching the hAMSCs' normal culture medium. Therefore, dual enzyme (collagenase II and DNAase I) digestion may be a more useful isolation process and culture of hAMSCs on porous GCM in vitro as an ideal environment for the large-scale expansion of highly functional hAMSCs for eventual use in stem cell-based therapy.

Polyurethane scaffolds seeded with autologous cells can regenerate long esophageal gaps: An esophageal atresia treatment model

BACKGROUND

Pediatric patients suffering from long gap esophageal defects or injuries are in desperate need of innovative treatment options. Our study demonstrates that two different cell sources can adhere to and proliferate on a retrievable synthetic scaffold. In feasibility testing of translational applicability, these cell seeded scaffolds were implanted into piglets and demonstrated esophageal regeneration.

METHODS

Either porcine esophageal epithelial cells or porcine amniotic fluid was obtained and cultured in 3 dimensions on a polyurethane scaffold (Biostage). The amniotic fluid was obtained prior to birth of the piglet and was a source of mesenchymal stem cells (AF-MSC). Scaffolds that had been seeded were implanted into their respective Yucatan mini-swine. The cell seeded scaffolds in the bioreactor were evaluated for cell viability, proliferation, genotypic expression, and metabolism. Feasibility studies with implantation evaluated tissue regeneration and functional recovery of the esophagus.

RESULTS

Both cell types seeded onto scaffolds in the bioreactor demonstrated viability, adherence and metabolism over time. The seeded scaffolds demonstrated increased expression of VEGF after 6 days in culture. Once implanted, endoscopy 3 weeks after surgery revealed an extruded scaffold with newly regenerated tissue. Both cell seeded scaffolds demonstrated epithelial and muscle regeneration and the piglets were able to eat and grow over time.

CONCLUSIONS

Autologous esophageal epithelial cells or maternal AF-MSC can be cultured on a 3D scaffold in a bioreactor. These cells maintain viability, proliferation, and adherence over time. Implantation into piglets demonstrated esophageal regeneration with extrusion of the scaffold. This sets the stage for translational application in a neonatal model of esophageal atresia.

Effect of ascorbic acid on differentiation of human amniotic fluid mesenchymal stem cells into cardiomyocyte-like cells

The aim of this study was to evaluate the efficiency of ascorbic acid (AA) on cell viability, cytotoxicity and the effects on cardiomyogenic differentiation of the human amniotic fluid mesenchymal stem cells (hAF-MSCs). The results of methylthiazole tetrazolium (MTT) assay and cell apoptosis assay indicated that after 24, 48 and 72 h of treatment, AA had no effect on cells viability and cytotoxicity. After treating the hAF-MSCs with 5-azacytidine (5-aza) and a combination of AA and 5-aza, the alamar blue cells proliferation assay showed the normal growth characteristic similar to control group. Especially, the morphological changes were observed between day 0 and day 21, and it was revealed that the hAF-MSCs exhibited myotube-like morphology after 7 days of cell culturing. Moreover, the treatment with a combination of AA and 5-aza was able to up-regulate the cardiomyogenic specific gene levels, which are known to play an important role in cardiomyogenesis. This was specifically notable with the results of immunofluorescence and immunoenzymatic staining in the AA combined with 5-aza treatment group, the highest expression of cardiomyogenic specific proteins was revealed including for GATA4, cTnT, Cx43 and Nkx2.5. It could be concluded that AA may be a good alternative cardiomyogenic inducing factor for hAF-MSCs and may open new insights into future biomedical applications for a clinically treatment.

Predifferentiated amniotic fluid mesenchymal stem cells enhance lung alveolar epithelium regeneration and reverse elastase-induced pulmonary emphysema

INTRODUCTION

Pulmonary emphysema is a major component of chronic obstructive pulmonary disease (COPD). Emphysema progression attributed not only to alveolar structure loss and pulmonary regeneration impairment, but also to excessive inflammatory response, proteolytic and anti-proteolytic activity imbalance, lung epithelial cells apoptosis, and abnormal lung remodeling. To ameliorate lung damage with higher efficiency in lung tissue engineering and cell therapy, pre-differentiating graft cells into more restricted cell types before transplantation could enhance their ability to anatomically and functionally integrate into damaged lung. In this study, we aimed to evaluate the regenerative and repair ability of lung alveolar epithelium in emphysema model by using lung epithelial progenitors which pre-differentiated from amniotic fluid mesenchymal stem cells (AFMSCs).

METHODS

Pre-differentiation of eGFP-expressing AFMSCs to lung epithelial progenitor-like cells (LEPLCs) was established under a modified small airway growth media (mSAGM) for 7-day induction. Pre-differentiated AFMSCs were intratracheally injected into porcine pancreatic elastase (PPE)-induced emphysema mice at day 14, and then inflammatory-, fibrotic-, and emphysema-related indices and pathological changes were assessed at 6 weeks after PPE administration.

RESULTS

An optimal LEPLCs pre-differentiation condition has been achieved, which resulted in a yield of approximately 20% lung epithelial progenitors-like cells from AFMSCs in a 7-day period. In PPE-induced emphysema mice, transplantation of LEPLCs significantly improved regeneration of lung tissues through integrating into the lung alveolar structure, relieved airway inflammation, increased expression of growth factors such as vascular endothelial growth factor (VEGF), and reduced matrix metalloproteinases and lung remodeling factors when compared with mice injected with AFMSCs. Histopathologic examination observed a significant amelioration in DNA damage in alveolar cells, detected by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL), the mean linear intercept, and the collagen deposition in the LEPLC-transplanted groups.

CONCLUSION

Transplantation of predifferentiated AFMSCs through intratracheal injection showed better alveolar regeneration and reverse elastase-induced pulmonary emphysema in PPE-induced pulmonary emphysema mice.

Amniotic fluid: Source of valuable mesenchymal stem cells and alternatively used as cryopreserved solution

Mesenchymal stem cells (MSCs), which possess remarkable capabilities, are found in amniotic fluid (AF). The findings of several studies have shown the potential benefits of these cells in applications of regenerative medicine. In clinical applications, an over-period of time is required in a preparation process that makes cell collection become more necessary. Herein, the aim of this study was to preserve and characterize the cell's properties after cell cryopreservation into an appropriate cryogenic medium. The results illustrated that the highest hAF-MSCs viability was found when the cells were conserved in a solution of 5% DMSO + 10% FBS in AF. However, no statistical differences were identified in a chromosomal aberration of the post-thawed cells when compared to the non-frozen cells. These cells could also maintain their MSC features through the ability to express cell prolific quality, illustrating the typical MSC markers and immune privilege properties of CD44, CD73, CD90 and HLA-ABC. Additionally, post-thawed cells were able to differentiate into chondrogenic lineage by exhibiting chondrogenic related genes (SOX9, AGC, COL2A1) and proteins (transcription factor SOX9 protein (SOX9), cartilage oligomeric matrix protein (COMP) and aggrecan core protein (AGC)), as well as to present sGAGs accumulation. Interestingly, the use of a transmission electron microscope (TEM) uncovered the enrichment of the rough endoplasmic reticulum (rER) that coincided with euchromatin and the prominent nucleolus in the chondrogenic-induced cells that are normally found in the cells of natural cartilage. All in all, this study manifested that AF can be a major consideration and applied for use as a co-mixture of cryogenic medium.

Osteoblastic differentiation potential of human amniotic fluid-derived mesenchymal stem cells in different culture conditions

Osteoporosis is a bone degenerative disease characterized by a decrease in bone strength and an alteration in the osseous micro-architecture causing an increase in the risk of fractures. These diseases usually happen in post-menopausal women and elderly men. The most common treatment involves anti-resorptive agent drugs. However, the inhibition of bone resorption alone is not adequate for recovery in patients at the severe stage of osteoporosis who already have a fracture. Therefore, the combination of utilizing osteoblast micro mimetic scaffold in cultivation with the stimulation of osteoblastic differentiations to regain bone formation is a treatment strategy of considerable interest. The aims of this current study are to investigate the osteoblastic differentiation potential of mesenchymal stem cells derived from human amniotic fluid and to compare the monolayer culture and scaffold culture conditions. The results showed the morphology of cells in human amniotic fluid as f-type, which is a typical cell shape of mesenchymal stem cells. In addition, the proliferation rate of cells in human amniotic fluid reached the highest peak after 14 days of culturing. After which time, the growth rate slowly decreased. Moreover, the positive expression of specific mesenchymal cell surface markers including CD44, CD73, CD90, and also HLA-ABC (MHC class I) were recorded. On the other hand, the negative expressions of the endothelial stem cells markers (CD31), the hematopoietic stem cells markers (CD34, 45), the amniotic stem cells markers (CD117), and also the HLA-DR (MHC class II) were also recorded. The expressions of osteoblastogenic related genes including OCN, COL1A1, and ALP were higher in the osteogenic-induced group when compared to the control group. Interestingly, the osteoblastogenic related gene expressions that occurred under scaffold culture conditions were superior to the monolayer culture conditions. Additionally, higher ALP activity and greater calcium deposition were recorded in the extracellular matrix in the osteogenic-induced group than in the culture in the scaffold group. In summary, the mesenchymal stem cells derived from human amniotic fluid can be induced to be differentiated into osteoblastic-like cells and can promote osteoblastic differentiation using the applied scaffold.

Amniotic fluid cells: current progress and emerging challenges in renal regeneration

Amniotic fluid (AF) contains a heterogeneous population of cells that have been identified to possess pluripotent and progenitor-like characteristics. These cells have been applied in various regenerative medicine applications ranging from in vitro cell differentiation to tissue engineering to cellular therapies for different organs including the heart, the liver, the lung, and the kidneys. In this review, we examine the different methodologies used for the derivation of amniotic fluid stem cells and renal progenitors, and their application in renal repair and regeneration. Moreover, we discuss the recent achievements and newly emerging challenges in our understanding of their biology, their immunoregulatory characteristics, and their paracrine-mediated therapeutic potential for the treatment of acute and chronic kidney diseases.

The effect of meconium exposure on the expression and differentiation of amniotic fluid mesenchymal stem cells

BACKGROUND:

The goal of this study was to determine if exposure to meconium would alter the phenotype of amniotic fluid mesenchymal stem cells (AF-MSCs) and the ability of these cells to be differentiated into distal airway type cells.

METHODS:

Meconium was collected, lyophilized and resuspended in PBS at 3 different concentrations (high, medium, and low). AF-MSCs were cultured in the presence of this meconium suspension for 8 hours and then analyzed for changes in gene expression. Additionally, AF-MSCs exposed to meconium were differentiated for 14 days using modified small airway growth medium (mSAGM) and gene expression was determined. As a spontaneous differentiation control, meconium exposed AF-MSCs were cultured in amniotic fluid stem cell medium (AF medium).

RESULTS:

After 8 hours of exposure in culture, AF-MSCs had increased expression of distal airway genes aquaporin 5 (AQP5) and surfactant protein c (SPC) when cultured in AF medium containing meconium. These gene expression levels were similar to that of AF-MSCs that were differentiated in mSAGM for 14 days. Furthermore, there was an up regulation of pluripotency genes NANOG and OCT4 in response to low meconium concentration for 8 hours. Following 14 days of culture in mSAGM, there was an upregulation of TTF1, SPC and AQP5 expression in the control, as well as in the low and medium meconium exposed groups indicating that these cells were still able to be differentiated. High meconium concentration did, however, appear to influence the level of distal airway gene expression after 14 days in mSAGM. After 14 days in AF medium, there was significant downregulation in pluripotency and mesenchymal markers as well as distal airway gene expression in all groups.

CONCLUSION:

The phenotype of AF-MSCs is modulated by meconium exposure; however, the cells were still able to differentiate into distal airway gene and protein expression. This result supports the hypothesis that progenitor cells exist in the amniotic fluid and the presence of meconium may affect their initial phenotype. However, these cells were still able to be differentiated to a distal lung phenotype.

An Official American Thoracic Society Workshop Report 2015. Stem Cells and Cell Therapies in Lung Biology and Diseases

The University of Vermont College of Medicine, in collaboration with the NHLBI, Alpha-1 Foundation, American Thoracic Society, Cystic Fibrosis Foundation, European Respiratory Society, International Society for Cellular Therapy, and the Pulmonary Fibrosis Foundation, convened a workshop, "Stem Cells and Cell Therapies in Lung Biology and Lung Diseases," held July 27 to 30, 2015, at the University of Vermont. The conference objectives were to review the current understanding of the role of stem and progenitor cells in lung repair after injury and to review the current status of cell therapy and ex vivo bioengineering approaches for lung diseases. These are all rapidly expanding areas of study that both provide further insight into and challenge traditional views of mechanisms of lung repair after injury and pathogenesis of several lung diseases. The goals of the conference were to summarize the current state of the field, discuss and debate current controversies, and identify future research directions and opportunities for both basic and translational research in cell-based therapies for lung diseases. This 10th anniversary conference was a follow up to five previous biennial conferences held at the University of Vermont in 2005, 2007, 2009, 2011, and 2013. Each of those conferences, also sponsored by the National Institutes of Health, American Thoracic Society, and respiratory disease foundations, has been important in helping guide research and funding priorities. The major conference recommendations are summarized at the end of the report and highlight both the significant progress and major challenges in these rapidly progressing fields.

Micromass cultures are effective for differentiation of human amniotic fluid stem cells into chondrocytes

OBJECTIVES

Articular cartilage is vulnerable to injuries and undergoes an irreversible degenerative process. The use of amniotic fluid mesenchymal stromal stem cells for the reconstruction of articular cartilage is a promising therapeutic alternative. The aim of this study was to investigate the chondrogenic potential of amniotic fluid mesenchymal stromal stem cells from human amniotic fluid from second trimester pregnant women in a micromass system (high-density cell culture) with TGF-β3 for 21 days.

METHODS

Micromass was performed using amniotic fluid mesenchymal stromal stem cells previously cultured in a monolayer. Chondrocytes from adult human normal cartilage were used as controls. After 21 days, chondrogenic potential was determined by measuring the expression of genes, such as SOX-9, type II collagen and aggrecan, in newly differentiated cells by real-time PCR (qRT-PCR). The production of type II collagen protein was observed by western blotting. Immunohistochemistry analysis was also performed to detect collagen type II and aggrecan. This study was approved by the local ethics committee.

RESULTS

SOX-9, aggrecan and type II collagen were expressed in newly differentiated chondrocytes. The expression of SOX-9 was significantly higher in newly differentiated chondrocytes than in adult cartilage. Collagen type II protein was also detected.

CONCLUSION

We demonstrate that stem cells from human amniotic fluid are a suitable source for chondrogenesis when cultured in a micromass system. amniotic fluid mesenchymal stromal stem cells are an extremely viable source for clinical applications, and our results suggest the possibility of using human amniotic fluid as a source of mesenchymal stem cells.

Term amniotic fluid: an unexploited reserve of mesenchymal stromal cells for reprogramming and potential cell therapy applications

BACKGROUND

Mesenchymal stromal cells (MSCs) are currently being evaluated in numerous pre-clinical and clinical cell-based therapy studies. Furthermore, there is an increasing interest in exploring alternative uses of these cells in disease modelling, pharmaceutical screening, and regenerative medicine by applying reprogramming technologies. However, the limited availability of MSCs from various sources restricts their use. Term amniotic fluid has been proposed as an alternative source of MSCs. Previously, only low volumes of term fluid and its cellular constituents have been collected, and current knowledge of the MSCs derived from this fluid is limited. In this study, we collected amniotic fluid at term using a novel collection system and evaluated amniotic fluid MSC content and their characteristics, including their feasibility to undergo cellular reprogramming.

METHODS

Amniotic fluid was collected at term caesarean section deliveries using a closed catheter-based system. Following fluid processing, amniotic fluid was assessed for cellularity, MSC frequency, in-vitro proliferation, surface phenotype, differentiation, and gene expression characteristics. Cells were also reprogrammed to the pluripotent stem cell state and differentiated towards neural and haematopoietic lineages.

RESULTS

The average volume of term amniotic fluid collected was approximately 0.4 litres per donor, containing an average of 7 million viable mononuclear cells per litre, and a CFU-F content of 15 per 100,000 MNCs. Expanded CFU-F cultures showed similar surface phenotype, differentiation potential, and gene expression characteristics to MSCs isolated from traditional sources, and showed extensive expansion potential and rapid doubling times. Given the high proliferation rates of these neonatal source cells, we assessed them in a reprogramming application, where the derived induced pluripotent stem cells showed multigerm layer lineage differentiation potential.

CONCLUSIONS

The potentially large donor base from caesarean section deliveries, the high yield of term amniotic fluid MSCs obtainable, the properties of the MSCs identified, and the suitability of the cells to be reprogrammed into the pluripotent state demonstrated these cells to be a promising and plentiful resource for further evaluation in bio-banking, cell therapy, disease modelling, and regenerative medicine applications.

Sesamin encouraging effects on chondrogenic differentiation of human amniotic fluid-derived mesenchymal stem cells

Worldwide, the most recognized musculoskeletal degenerative disease is osteoarthritis (OA). Sesamin, a major abundant lignan compound present in Sesamun Indicum Linn, has been described for its various pharmacological effects and health benefits. However, the promoting effects of sesamin on chondrogenic differentiation have not yet been observed. Herein, the aim of this study was to investigate the effects of sesamin on cell cytotoxicity and the potent supporting effects on chondrogenic differentiation of human amniotic fluid-derived mesenchymal stem cells (hAF-MSCs). The results indicated that sesamin was not toxic to hAF-MSCs after sesamin treatment. When treating the cells with a combination of sesamin and inducing factors, sesamin was able to up-regulate the expression level of specific genes which play an essential role during the cartilage development process, including SOX9, AGC, COL2A1, COL11A1, and COMP and also simultaneously promote the cartilage extracellular protein synthesis, aggrecan and type II collagen. Additionally, histological analysis revealed a high amount of accumulated sGAG staining inside the porous scaffold in the sesamin co-treating group. In conclusion, the results of this study have indicated that sesamin can be considered a chondrogenic inducing factor and a beneficial dietary supplement for cartilage repair.

The Production of Pluripotent Stem Cells from Mouse Amniotic Fluid Cells Using a Transposon System

Induced pluripotent stem (iPS) cells are generated from mouse and human somatic cells by forced expression of defined transcription factors using different methods. Here, we produced iPS cells from mouse amniotic fluid cells, using a non-viral-based transposon system. All obtained iPS cell lines exhibited characteristics of pluripotent cells, including the ability to differentiate toward derivatives of all three germ layers in vitro and in vivo. This strategy opens up the possibility of using cells from diseased fetuses to develop new therapies for birth defects.

Mesenchymal stem cells differentiated into chondrocyte-Like cells

Among the stem cells contained in human amniotic fluid (hAF), the human amniotic fluid derived-mesenchymal stem cells (hAF-MSCs) are derived from fetal membranes and tissues that are produced during fetal development. The aim of this study was to characterize the 'stem-ness' properties of hAF-MSCs and their potency with regard to the chondrogenic differentiations using the scaffold cultivation method. This study revealed that the easily accessed and isolated MSCs were highly cell prolific and there were fewer ethical concerns regarding their usage. The MSCs were studied through the use of the alamar blue technique. In addition, after cell isolation, hAF-MSCs displayed typical MSCs morphologies including MSCs biomarker characteristics and immune privilege properties (CD44, CD73, CD90, CD105 and HLA-ABC) through immunofluorescence and flow cytometry. Interestingly, this result indicated a negative expression when using the C-Kit (CD117, tyrosine kinase receptor type III ligand for cytokine stem cell factor). This expression can be found at the cell's surface of the amniotic fluid-derived stem cells (AFSCs). This study found evidence that hAF-MSCs had the ability to differentiate the cells into the chondrogenic lineage by exhibiting chondrogenic related genes and proteins (SOX9, AGC, COL2A1 and COMP) through RT-qPCR, immunoenzymatic assays and immunofluorescence analysis. Furthermore, MSCs presented sGAGs accumulation, which was confirmed by histological analysis and SEM. Therefore, this study showed that the MSCs characteristics are contained in AF and are of significant value for further research. It appears that MSCs possess the potential for use in treatments that would necessitate the use of regenerative cell therapy.

Stem cells from amniotic fluid--Potential for regenerative medicine

Regenerative medicine has recently been established as an emerging field focussing on repair, replacement or regeneration of cells, tissues and whole organs. The significant recent advances in the field have intensified the search for novel sources of stem cells with potential for therapy. Recently, researchers have identified the amniotic fluid as an untapped source of stem cells that are multipotent, possess immunomodulatory properties and do not have the ethical and legal limitations of embryonic stem cells. Stem cells from the amniotic fluid have been shown to differentiate into cell lineages representing all three embryonic germ layers without generating tumours, which make them an ideal candidate for tissue engineering applications. In addition, their ability to engraft in injured organs and modulate immune and repair responses of host tissues suggest that transplantation of such cells may be useful for the treatment of various degenerative and inflammatory diseases affecting major tissues/organs. This review summarises the evidence on amniotic fluid cells over the past 15 years and explores the potential therapeutic applications of amniotic fluid stem cells and amniotic fluid mesenchymal stem cells.