Raman spectroscopy analysis of human amniotic fluid cells from fetuses with myelomeningocele.

Prenatal surgery for the treatment of spina bifida (myelomeningocele, MMC) significantly enhances the neurological prognosis of the patient. To ensure better protection of the spinal cord by large defects, the application of skin grafts produced with cells gained from the amniotic fluid is presently studied. In order to determine the most appropriate cells for this purpose, we tried to shed light on the extremely complex amniotic fluid cellular composition in healthy and MMC pregnancies. We exploited the potential of micro-Raman spectroscopy to analyse and characterize human amniotic fluid cells in total and putative (cKit/CD117-positive) stem cells of fetuses with MMC in comparison with amniotic fluid cells from healthy individuals, human fetal dermal fibroblasts and adult adipose derived stem cells. We found that (i) the differences between healthy and MMC amniocytes can be attributed to specific spectral regions involving collagen, lipids, sugars, tryptophan, aspartate, glutamate, and carotenoids, (ii) MMC amniotic fluid contains two particular cell populations which are absent or reduced in normal pregnancies, (iii) the cKit-negative healthy amniocyte subpopulation shares molecular features with human fetal fibroblasts. On the one hand we demonstrate a different amniotic fluid cellular composition in healthy and MMC pregnancies, on the other our work confirms micro-Raman spectroscopy to be a valuable tool for discriminating cell populations in unknown mixtures of cells.

Immersed in a reservoir of potential: amniotic fluid-derived extracellular vesicles.

This review aims to encapsulate the current knowledge in extracellular vesicles extracted from amniotic fluid and amniotic fluid derived stem/stromal cells. Amniotic fluid (AF) bathes the developing fetus, providing nutrients and protection from biological and mechanical dangers. In addition to containing a myriad of proteins, immunoglobulins and growth factors, AF is a rich source of extracellular vesicles (EVs). These vesicles originate from cells in the fetoplacental unit. They are biological messengers carrying an active cargo enveloped within the lipid bilayer. EVs in reproduction are known to play key roles in all stages of pregnancy, starting from fertilisation through to parturition. The intriguing biology of AF-derived EVs (AF-EVs) in pregnancy and their untapped potential as biomarkers is currently gaining attention. EV studies in numerous animal and human disease models have raised expectations of their utility as therapeutics. Amniotic fluid stem cell and mesenchymal stromal cell-derived EVs (AFSC-EVs) provide an established supply of laboratory-made EVs. This cell-free mode of therapy is popular as an alternative to stem cell therapy, revealing similar, if not better therapeutic outcomes. Research has demonstrated the successful application of AF-EVs and AFSC-EVs in therapy, harnessing their anti-inflammatory, angiogenic and regenerative properties. This review provides an overview of such studies and discusses concerns in this emerging field of research.

Polycaprolactone/poly L-lactic acid nanofibrous scaffold improves osteogenic differentiation of the amniotic fluid-derived stem cells.

Using stem cells is one of the most important determining factors in repairing lesions using regenerative medicine. Obtaining adult stem cells from patients is a perfect choice, but it is worth noting that their differentiation and proliferation potential decreases as the patient ages. For this reason, the use of amniotic fluid stem cells can be one of the excellent alternatives. This research aimed to investigate the osteogenic differentiation potential of the amniotic fluid stem cells while cultured on the polycaprolactone/poly L-lactic acid nanofibrous scaffold. Scaffolds were qualitatively evaluated by a scanning electron microscope, and their hydrophilicity and mechanical properties were studied using contact angle and tensile test, respectively. The biocompatibility and non-toxicity of the nanofibers were also evaluated using viability assay. The osteo-supportive capacity of the nanofibers was examined using alizarin red staining, alkaline phosphatase activity, and calcium release measurement. Finally, the expression level of four important bone-related genes was determined quantitatively. The results demonstrated that the mineralization rate, alkaline phosphatase activity, intracellular calcium, and bone-related genes increased significantly in the cells cultured on the polycaprolactone/poly L-lactic acid scaffold compared to the cells cultured on the tissue culture plate as a control. According to the results, it can be concluded that the polycaprolactone/poly L-lactic acid nanofibrous scaffold surprisingly improved the osteogenic differentiation potential of the amniotic fluid stem cells and, in combination with polycaprolactone/poly L-lactic acid nanofibers could be a promising candidate as bone implants.

Nicotine-induced Genetic and Epigenetic Modifications in Primary Human Amniotic Fluid Stem Cells.

BACKGROUND: Smoking during pregnancy has been linked to adverse health outcomes in offspring, but the underlying mechanisms are not fully understood. To date, the effect of maternal smoking has been tested in primary tissues and animal models, but the scarcity of human tissues limits experimental studies. Evidence regarding smoking-related molecular alteration and gene expression profiles in stem cells is still lacking. METHODS: We developed a cell culture model of human amniotic fluid stem cells (hAFSCs) of nicotine (NIC) exposure to examine the impact of maternal smoking on epigenetic alterations of the fetus. RESULTS: NIC 0.1 µM(equivalent to "light" smoking, i.e., 5 cigarettes/day) did not significantly affect cell viability; however, significant alterations in DNA methylation and N6-methyladenosine (m6A) RNA methylation in hAFSCs occurred. These epigenetic changes may influence the gene expression and function of hAFSCs. Furthermore, NIC exposure caused time-dependent alterations of the expression of pluripotency genes and cell surface markers, suggesting enhanced cell stemness and impaired differentiation potential. Furthermore, NICtreated cells showed reduced mRNA levels of key adipogenic markers and hypomethylation of the promoter region of the imprinted gene H19 during adipogenic differentiation, potentially suppressing adipo/lipogenesis. Differential expression of 16 miRNAs, with predicted target genes involved in various metabolic pathways and linked to pathological conditions, including cognitive delay and fetal growth retardation, has been detected. CONCLUSIONS: Our findings highlight multi-level effects of NIC on hAFSCs, including epigenetic modifications, altered gene expression, and impaired cellular differentiation, which may contribute to long-term consequences of smoking in pregnancy and its potential impact on offspring health and development.

Amniotic fluid stem cell-derived extracellular vesicles educate type 2 conventional dendritic cells to rescue autoimmune disorders in a multiple sclerosis mouse model.

Dendritic cells (DCs) are essential orchestrators of immune responses and represent potential targets for immunomodulation in autoimmune diseases. Human amniotic fluid secretome is abundant in immunoregulatory factors, with extracellular vesicles (EVs) being a significant component. However, the impact of these EVs on dendritic cells subsets remain unexplored. In this study, we investigated the interaction between highly purified dendritic cell subsets and EVs derived from amniotic fluid stem cell lines (HAFSC-EVs). Our results suggest that HAFSC-EVs are preferentially taken up by conventional dendritic cell type 2 (cDC2) through CD29 receptor-mediated internalization, resulting in a tolerogenic DC phenotype characterized by reduced expression and production of pro-inflammatory mediators. Furthermore, treatment of cDC2 cells with HAFSC-EVs in coculture systems resulted in a higher proportion of T cells expressing the regulatory T cell marker Foxp3 compared to vehicle-treated control cells. Moreover, transfer of HAFSC-EV-treated cDC2s into an EAE mouse model resulted in the suppression of autoimmune responses and clinical improvement. These results suggest that HAFSC-EVs may serve as a promising tool for reprogramming inflammatory cDC2s towards a tolerogenic phenotype and for controlling autoimmune responses in the central nervous system, representing a potential platform for the study of the effects of EVs in DC subsets.

The system for directional and stable differentiation of amniotic fluid stem cells into neuron-like cells / 中国组织工程研究

BACKGROUND: Neuronal regeneration using stem cell differentiation has gained a lot of attentions from researchers. Although embryonic stem cells and induced pluripotent stem cells have good potential for neuronal differentiation, a high risk of tumor development in vivo limits the further study. OBJECTIVE: To establish a stable system for sorting, culture and neuronal differentiation of amniotic fluid stem cells, and to explore the feasibility as seed cells for neuronal regeneration. METHODS: Amniotic fluid sample (10 mL) was obtained at 19-22 weeks of pregnancy under B-ultrasound guidance, and amniotic fluid stem cells were isolated by c-Kit magnetic beads. The markers Oct-4 and Sox2 of amniotic fluid stem cells were identified by immunofluorescence. The expression levels of c-Kit, Oct-4, Sox2 and Nestin in amniotic fluid stem cells after multiple passages were detected by RT-PCR. Then, the cells were cultured by hanging drop for 4 days to observe the embryoid bodies-like structures. Amniotic fluid stem cells were induced to differentiate into neurons using two-stage method. The expression levels of Neuro D and Tuj1 were observed by immunofluorescence. RESULTS AND CONCLUSION: (1) About 1% of amniotic fluid stem cells were positive for c-Kit. (2) (75.0±4.6)% of amniotic fluid stem cells expressed Oct-4 and (86.0±2.8)% of the cells expressed Sox2. (3) The expression levels of c-Kit, Oct-4, Sox2 and Nestin detected by RT-PCR did not change with passage times. (4) Embryoid bodies-like structures formed after hanging drop culture. (5) Immunofluorescence results showed that amniotic fluid stem cells expressed neuronal marker Tuj1, but without the typical morphological features. RT-PCR detected the expression of Tuj1 in different amniotic fluid stem cell specimens as well as in the same sample after several passages. (6) Amniotic fluid stem cells could have the characteristics of neuron-like cells after induction with basic fibroblast growth factor, brain-derived neurotrophic factor, and neurotrophin factor 3 in two stages, and could express neural stem cell marker Neuro D and neuronal marker Tuj1.

Amniotic Fluid-Derived Mesenchymal Stem Cells Cut Short the Acuteness of Cisplatin-Induced Nephrotoxicity in Sprague-Dawley Rats

BACKGROUND AND OBJECTIVES: Cisplatin is a nephrotoxic chemotherapeutic agent. So, preventive measures worth to be evaluated. Human amniotic fluid stem cells (hAFSCs) in prevention or amelioration of cisplatin-induced acute kidney injury (AKI) in Sprague-Dawley rates have been tested. METHODS: 80 Sprague-Dawley rats (250~300 g) were used and divided into 4 major groups, 20 rats each. Group I: Saline-injected group. Group II: Cisplatin-injected group (5 mg/kg I.P). Group III: Cisplatin-injected and hAFSCs-treated group (5×106 hAFSCs I.V. one day after cisplatin administration). Group IV: Cisplatin-injected and culture media-treated group. Each major group was further divided into 4 equal subgroups according to the timing of sacrifice; 4, 7, 11 and 30 days post-cisplatin injection. Renal function tests were done. Kidney tissue homogenate oxidative stress parameters malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) were determined. Histopathological scoring systems for active injury, regenerative and chronic changes were analyzed separately. RESULTS: hAFSCs characterization and differentiation was proved. Cisplatin injection resulted in a significant increase in serum creatinine and MDA and decrease in SOD, GSH and creatinine clearance. These changes were attenuated early by day 4 with the use of hAFSCs. Cisplatin injection induced tubular necrosis, atrophy, inflammatory cells infiltration and fibrosis. The use of hAFSCs was associated with significantly lowered injury score at day 4, 7, 11 and 30 with marked regenerative changes starting from day 4. CONCLUSION: hAFSCs have both a protective and regenerative activities largely through an antioxidant activity. This activity cut short the acuteness of cisplatin nephrotoxicity.

A Mini Overview of Isolation, Characterization and Application of Amniotic Fluid Stem Cells

Amniotic fluid represents rich sources of stem cells that can be used in treatments for a wide range of diseases. Amniotic fluid- stem cells have properties intermediate between embryonic and adult mesenchymal stem cells which make them particularly attractive for cellular regeneration and tissue engineering. Furthermore, scientists are interested in these cells because they come from the amniotic fluid that is routinely discarded after birth. In this review we give a brief introduction of amniotic fluid followed by a description of the cells present within this fluid and aim to summarize the all existing isolation methods, culturing, characterization and application of these cells. Finally, we elaborate on the differentiation and potential for these cells to promote regeneration of various tissue defects, including fetal tissue, the nervous system, heart, lungs, kidneys, bones, and cartilage in the form of table.

Establishment of an in vitro system evaluating neurotoxicity using neural differentiation of human ES cells and amniotic fluid stem cells / 临床儿科杂志

Objective A lot of drugs have side effects on the central nerves system. Especially in children. In vivo neurotoxicity tests are time-consuming and expensive. The neural differentiation of human embryonic stem cells and amniotic fluid stem cells provides all ideal in vitro system that Can be applied to evaluate neurotoxicity of drugs. This study was to try to establish such a system. The kainie acid was selected to test the neurotoxicity. Methods The human embryonic stem cells and amniotic fluid stem cells were indueed to differentiate into neural cells by a chemically defined neural induction medium. The induced neural cells were propagated in the presence of basic fibroblast growth factor. Immunocytochemical staining Was applied to confirm these cells' neural identity. The induced cells were propagated under different concentration of kainic acid, then the gosh curve were made based on the cell numbers. Results Both of the human embryonic stem cells and amniotic fluid stem cells could be efficiently induced to be differentiated into neural cells. The neural differentiation efficiency of human embryonic stem cells is higher than that of human amniotic fluid stem cells. The kainic acid has neurotoxieity to the indueed neural cells. Conclusions The neural differentiation of human embryonic stem cells and amniotic fluid stem cells were proved to provide a rapid and convenient approach for estimating the neurotoxlcity of drugs.