Gene expression of oligodendrocyte markers in human amniotic epithelial cells using neural cell-type-specific expression system

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.

Regulating Early Biological Events in Human Amniotic Epithelial Stem Cells Using Natural Bioactive Compounds: Extendable Multidirectional Research Avenues

Stem cells isolated from perinatal tissue sources possess tremendous potential for biomedical and clinical applications. On the other hand, emerging data have demonstrated that bioactive natural compounds regulate numerous cellular and biochemical functions in stem cells and promote cell migration, proliferation, and attachment, resulting in maintaining stem cell proliferation or inducing controlled differentiation. In our previous studies, we have reported for the first time that various natural compounds could induce targeted differentiation of hAESCs in a lineage-specific manner by modulating early biological and molecular events and enhance the therapeutic potential of hAESCs through modulating molecular signaling. In this perspective, we will discuss the advantages of using naturally occurring active compounds in hAESCs and their potential implications for biological research and clinical applications.

Human Amniotic Epithelial Stem Cells: A Promising Seed Cell for Clinical Applications

Perinatal stem cells have been regarded as an attractive and available cell source for medical research and clinical trials in recent years. Multiple stem cell types have been identified in the human placenta. Recent advances in knowledge on placental stem cells have revealed that human amniotic epithelial stem cells (hAESCs) have obvious advantages and can be used as a novel potential cell source for cellular therapy and clinical application. hAESCs are known to possess stem-cell-like plasticity, immune-privilege, and paracrine properties. In addition, non-tumorigenicity and a lack of ethical concerns are two major advantages compared with embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). All of the characteristics mentioned above and other additional advantages, including easy accessibility and a non-invasive application procedure, make hAESCs a potential ideal cell type for use in both research and regenerative medicine in the near future. This review article summarizes current knowledge on the characteristics, therapeutic potential, clinical advances and future challenges of hAESCs in detail.

Molecular characterization of bovine amniotic fluid derived stem cells with an underlying focus on their comparative neuronal potential at different passages

BACKGROUND

The excellence in the field of stem cell therapy demands alternative and more convenient stem cells for potential applications. Researchers have opted for least invasive and broadly multipotent cells with minimum ethical concerns. Bovine amniotic fluid derived mesenchymal stem cells (BAF-MSCs) due to their ease of collection and owing similar gestational length to that of human could be presumed as an attractive large animal model for biomedical and biotechnology research.

METHODS

Bovine amniotic fluid derived stem cells were isolated from abattoir based samples and characterized for epithelial, neuronal, mesenchymal and pluripotent markers by qPCR and immunofluorescence studies at P1, P3, P5 and P7 alongside population doubling time, growth curve and multilineage differentiation studies.

RESULTS

The cells were explored for unique expression of Sox2, which was observed to be up regulated with increase in passage number and Nestin was found to be downregulated during further passaging of mesenchymal cells in this study. The cells also co-expressed Oct ¾ at initial passages which diminished within further passages. Evidence regarding diversity and heterogeneity in different cell population in amniotic fluid was recorded by positive expression of epithelial cell markers like pan Cytokeratin and p63 during early passages. The study suggested that cells with higher expression of Sox2 generated comparatively larger neurospheres with comparative strong expression of Sox2 and Nestin by immunofluorescence staining and qPCR analysis. Besides BAF-MSCs derived neurospheres were also shown to express pro-neuronal markers like ß-III Tubulin, GAP43 and ASCL-1.

CONCLUSIONS

This study explores and characterizes BAF-MSCs for their multipotent and neurogenic potentials and their use for clinical applications, though more detailed studies are needed to determine the exact pathways linked with neurogenic capacities of these cells and their morphological assessments at different gestational ages in bovines. The knowledge from the bovine model after detailed studies, proven safety and efficacy could also be used to understand substitutive strategies to investigate MSCs physiology at different trimesters and potential application of these cells for human and veterinary regenerative medicine provided the animal ethics are carefully monitored.

Highly potent stem cells from full-term amniotic fluid: A realistic perspective

Amniotic fluid (AF) is now known to harbor highly potent stem cells, making it an excellent source for cell therapy. However, most of the stem cells isolated are from AF of mid-term pregnancies in which the collection procedure involves an invasive technique termed amniocentesis. This has limited the access in getting the fluid as the technique imposes certain level of risks to the mother as well as to the fetus. Alternatively, getting AF from full-term pregnancies or during deliveries would be a better resolution. Unfortunately, very few studies have isolated stem cells from AF at this stage of gestation, the fluid that is merely discarded. The question remains whether full-term AF harbors stem cells of similar potency as of the stem cells of mid-term AF. Here, we aim to review the prospect of having this type of stem cells by first looking at the origin and contents of AF particularly during different gestation period. We will then discuss the possibility that the AF, at full term, contains a population of highly potent stem cells. These stem cells are distinct from, and probably more potent than the AF mesenchymal stem cells (AF-MSCs) isolated from full-term AF. By comparing the studies on stem cells isolated from mid-term versus full-term AF from various species, we intend to address the prospect of having highly potent amniotic fluid stem cells from AF of full-term pregnancies in human and animals.

Comparative analysis of neural differentiation potential in human mesenchymal stem cells derived from chorion and adult bone marrow

The finding of a reliable and abundant source of stem cells for the replacement of missing neurons in nervous system diseases requires extensive characterization of neural-differentiation-associated markers in stem cells from various sources. Chorion-derived stem cells from the human placenta have recently been described as an abundant, ethically acceptable, and easily accessible source of cells that are not limited in the same way as bone marrow (BM) mesenchymal stem cells (MSCs). We have isolated and cultured chorion MSCs (C-MSCs) and compared their proliferative capacity, multipotency, and neural differentiation ability with BM-MSCs. C-MSCs showed a higher proliferative capacity compared with BM-MSCs. The expression and histone modification of Nestin, as a marker for neural stem/progenitor cells, was evaluated quantitatively between the two groups. The Nestin expression level in C-MSCs was significantly higher than that in BM-MSCs. Notably, modifications of lys9, lys4, and lys27 of histone H3 agreed with the remarkable higher expression of Nestin in C-MSCs than in BM-MSCs. Furthermore, after neural differentiation of MSCs upon retinoic acid induction, both immunocytochemical and flow cytometry analyses demonstrated that the expression of neural marker genes was significantly higher in neural-induced C-MSCs compared with BM-MSCs. Mature neuron marker genes were also expressed at a significantly higher level in C-MSCs than in BM-MSCs. Thus, C-MSCs have a greater potential than BM-MSCs for differentiation to neural cell lineages and can be regarded as a promising source of stem cells for the cell therapy of neurological disorders.

Amnion-derived stem cells: in quest of clinical applications

In the promising field of regenerative medicine, human perinatal stem cells are of great interest as potential stem cells with clinical applications. Perinatal stem cells could be isolated from normally discarded human placentae, which are an ideal cell source in terms of availability, the fewer number of ethical concerns, less DNA damage, and so on. Numerous studies have demonstrated that some of the placenta-derived cells possess stem cell characteristics like pluripotent differentiation ability, particularly in amniotic epithelial (AE) cells. Term human amniotic epithelium contains a relatively large number of stem cell marker-positive cells as an adult stem cell source. In this review, we introduce a model theory of why so many AE cells possess stem cell characteristics. We also describe previous work concerning the therapeutic applications and discuss the pluripotency of the AE cells and potential pitfalls for amnion-derived stem cell research.

An experimental study on intracerebroventricular transplantation of human amniotic epithelial cells in a rat model of Parkinson's disease

OBJECTIVES

Human amniotic epithelial (HAE) cells are formed from amnioblasts, separated from the epiblast at about the eighth day after fertilization. In the present study, we attempt to investigate the effects of intracerebroventricular transplantation of HAE cells on Parkinson's disease (PD) rats.

METHODS

A PD rat model was induced by 6-OHDA injections. Then the rats were transplanted intracerebroventricularly with HAE cells. Apomorphin-induced turns were used to assess the neurobehavioral deficit in rats. Immunofluorescence cytochemistry was used to track the survival of HAE cells. Tyrosinehydroxylase (TH) immunohistochemistry was used to determine the density of TH-positive cells in rat substantia nigra and the differentiation of HAE cells. High performance liquid chromatography (HPLC) was used to measure the levels of dopamine (DA) and its metabolites 3, 4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in rat striatum. HVA levels in the cerebrospinal fluid of rats were also determined by HPLC.

RESULTS

The results showed that transplanted HAE cells can survive for at least 10 weeks and differentiate into TH-positive cells in PD rats. The grafts significantly ameliorated apomorphine-induced turns in PD rats. TH immunohistochemistry showed that HAE cells attenuated the loss of TH-positive cells in rat substantia nigra. In addition, HAE cells prevented the fall of DA and its metabolites DOPAC and HVA in PD rats. Increased HVA levels in the cerebrospinal fluid of PD rats were also observed.

CONCLUSION

These results demonstrate that HAE cells have beneficial effect on 6-OHDA-induced PD rats, which may be due to the neurotrophic factors secrete by HAE cells.

Differential expression patterns of OCC1-related, extracellular matrix proteins in the lateral geniculate nucleus of macaque monkeys

The extracellular matrix (ECM) plays important roles in the development and plasticity of the central nervous system, and it has been shown that it regulates reorganization of the neuronal network. We have found that expression of OCC1, testican-1, testican-2, testican-3, SPARC and SC1 mRNAs, which encode members of the OCC1-related family of ECM proteins, exhibits distinct activity-dependent expression patterns in the adult macaque visual cortex. This finding suggests that OCC1-related proteins play crucial roles in the visual processing pathway. In the present study, we examined mRNA expression patterns of OCC1-related genes in the dorsal lateral geniculate nucleus (dLGN) of macaques. The mRNAs of testican-1 and testican-2 were strongly expressed in both excitatory projection neurons and GABAergic interneurons in the dLGN. Expression of testican-3 mRNA, which is predominantly observed in GABAergic interneurons in the cortex, was restricted to excitatory projection neurons in the dLGN. SPARC mRNA was strongly, and exclusively, expressed in glial cells in the dLGN. Interestingly, neuronal SC1 mRNA expression was abundantly observed in intercalated, koniocellular layers of the dLGN, while it was preferentially observed in blob regions of the primary visual area that receives color coding K-pathway projection from dLGN koniocellular layers, suggesting a pathway preference of expression. Finally, monocular inactivation experiments demonstrated that expression of testican-1, testican-2 and testican-3 mRNAs in the dLGN is dependent on sensory activity. Given their differential expression patterns and activity dependence, products of OCC1-related genes may modulate visual processing and plasticity at the level of the dLGN and the visual cortex.

Neural differentiation potential of rat amniotic epithelial cells

Amniotic epithelial cells (AEC) are thought to represent a stem-like cell population and to be an attractive cell source for regenerative medicine, because abundant cells can be obtained noninvasively at delivery. The authors investigated the neural differentiation potential of rat AEC. Rat AEC expressed vimentin and nestin, but not c-kit, oct-4, or nanog. The expression of the neural lineage markers, including betaIII-tubulin, neuron specific enolase (NSE), neurofilament-M, neuroD, glial fibrillary acidic protein (GFAP), myelin basic protein (MBP), tyrosine hydroxylase (TH), acetylcholinesterase (AChE), cholin acetyltransferase (ChAT), and mammalian achaete-scute homolog1 (MASH1), was detected by RT-PCR in the cultured rat AEC. After neural induction, rat AEC dramatically changed their shapes, projecting dendrite-like structures. Immunocytochemically, approximately 20% of the induced cells expressed an immature neuronal marker, betaIII-tubulin. Our findings suggested that rat AEC might be already committed to differentiate to various neural lineages and that they could differentiate to immature neurons in vitro.

Amniotic membrane and amniotic fluid-derived cells: potential tools for regenerative medicine?

Human amniotic membranes and amniotic fluid have attracted increasing attention in recent years as a possible reserve of stem cells that may be useful for clinical application in regenerative medicine. Many studies have been conducted to date in terms of the differentiation potential of these cells, with several reports demonstrating that cells from both the amniotic fluid and membrane display high plasticity. In addition, cells from the amniotic membrane have also been shown to display immunomodulatory characteristics both in vivo and in vitro, which could make them useful in an allotransplantation setting. Here, we provide an overview comparing the latest findings regarding the stem characteristics of cells from both the amniotic membrane and amniotic fluid, as well as on the potential utility of these cells for future clinical application in regenerative medicine.

Stem cells derived from human fetal membranes display multilineage differentiation potential

The amnion is the inner of two membranes surrounding the fetus. That it arises from embryonic epiblast cells prior to gastrulation suggests that it may retain a reservoir of stem cells throughout pregnancy. We found that human amniotic epithelial cells (hAECs) harvested from term-delivered fetal membranes express mRNA and proteins present in human embryonic stem cells (hESCs), including POU domain, class 5, transcription factor 1; Nanog homeobox; SRY-box 2; and stage-specific embryonic antigen-4. In keeping with possible stem cell-like activity, hAECs were also clonogenic, and primary hAEC cultures could be induced to differentiate into cardiomyocytic, myocytic, osteocytic, adipocytic (mesodermal), pancreatic, hepatic (endodermal), neural, and astrocytic (neuroectodermal) cells in vitro, as defined by phenotypic, mRNA expression, immunocytochemical, and/or ultrastructural characteristics. However, unlike hESCs, hAECs did not form teratomas upon transplantation into severe combined immunodeficiency mice testes. Last, using flow cytometry we have shown that only a very small proportion of primary hAECs contain class IA and class II human leukocyte antigens (HLAs), consistent with a low risk of tissue rejection. However, following differentiation into hepatic and pancreatic lineages, significant proportions of cells contained class IA, but not class II, HLAs. These observations suggest that the term amnion, an abundant and easily accessible tissue, may be a useful source of multipotent stem cells that possess a degree of immune privilege.

Myelination of congenitally dysmyelinated spinal cord axons by adult neural precursor cells results in formation of nodes of Ranvier and improved axonal conduction

Emerging evidence suggests that cell-based remyelination strategies may be a feasible therapeutic approach for CNS diseases characterized by myelin deficiency as a result of trauma, congenital anomalies, or diseases. Although experimental demyelination models targeted at the transient elimination of oligodendrocytes have suggested that transplantation-based remyelination can partially restore axonal molecular structure and function, it is not clear whether such therapeutic approaches can be used to achieve functional remyelination in models associated with long-term, irreversible myelin deficiency. In this study, we transplanted adult neural precursor cells (aNPCs) from the brain of adult transgenic mice into the spinal cords of adult Shiverer (shi/shi) mice, which lack compact CNS myelin. Six weeks after transplantation, the transplanted aNPCs expressed oligodendrocyte markers, including MBP, migrated extensively along the white matter tracts of the spinal cord, and formed compact myelin. Conventional and three-dimensional confocal and electron microscopy revealed axonal ensheathment, establishment of paranodal junctional complexes leading to de novo formation of nodes of Ranvier, and partial reconstruction of the juxtaparanodal and paranodal molecular regions of axons based on Kv1.2 and Caspr (contactin-associated protein) expression by the transplanted aNPCs. Electrophysiological recordings revealed improved axonal conduction along the transplanted segments of spinal cords. We conclude that myelination of congenitally dysmyelinated adult CNS axons by grafted aNPCs results in the formation of compact myelin, reconstruction of nodes of Ranvier, and enhanced axonal conduction. These data suggest the therapeutic potential of aNPCs to promote functionally significant myelination in CNS disorders characterized by longstanding myelin deficiency.

Molecular and phenotypic characterization of human amniotic fluid cells and their differentiation potential

The main goal of the study was to identify a novel source of human multipotent cells, overcoming ethical issues involved in embryonic stem cell research and the limited availability of most adult stem cells. Amniotic fluid cells (AFCs) are routinely obtained for prenatal diagnosis and can be expanded in vitro; nevertheless current knowledge about their origin and properties is limited. Twenty samples of AFCs were exposed in culture to adipogenic, osteogenic, neurogenic and myogenic media. Differentiation was evaluated using immunocytochemistry, RT-PCR and Western blotting. Before treatments, AFCs showed heterogeneous morphologies. They were negative for MyoD, Myf-5, MRF4, Myogenin and Desmin but positive for osteocalcin, PPARgamma2, GAP43, NSE, Nestin, MAP2, GFAP and beta tubulin III by RT-PCR. The cells expressed Oct-4, Rex-1 and Runx-1, which characterize the undifferentiated stem cell state. By immunocytochemistry they expressed neural-glial proteins, mesenchymal and epithelial markers. After culture, AFCs differentiated into adipocytes and osteoblasts when the predominant cellular component was fibroblastic. Early and late neuronal antigens were still present after 2 week culture in neural specific media even if no neuronal morphologies were detectable. Our results provide evidence that human amniotic fluid contains progenitor cells with multi-lineage potential showing stem and tissue-specific gene/protein presence for several lineages.

Engraftment potential of human amnion and chorion cells derived from term placenta

BACKGROUND

Fetal membranes are tissues of particular interest for several reasons, including their role in preventing rejection of the fetus and their early embryologic origin. which may entail progenitor potential. The immunologic reactivity and the transplantation potential of amnion and chorion cells, however, remain to be elucidated.

METHODS

Amnion and chorion cells were isolated from human term placenta and characterized by immunohistochemistry, flow cytometric analysis, and expression profile of relevant genes. The immunomodulatory characteristics of these cells were studied in allogeneic and xenogeneic mixed lymphocyte reactions and their engraftment potential analyzed by transplantation into neonatal swine and rats. Posttransplant chimerism was determined by polymerase chain reaction analysis with probes specific for human DNA.

RESULTS

Phenotypic and gene expression studies indicated mesenchymal stem cell-like profiles in both amnion and chorion cells that were positive for neuronal, pulmonary, adhesion, and migration markers. In addition, cells isolated both from amnion and chorion did not induce allogeneic nor xenogeneic lymphocyte proliferation responses and were able to actively suppress lymphocyte responsiveness. Transplantation in neonatal swine and rats resulted in human microchimerism in various organs and tissues.

CONCLUSIONS

Human amnion and chorion cells from term placenta can successfully engraft neonatal swine and rats. These results may be explained by the peculiar immunologic characteristics and mesenchymal stem cell-like phenotype of these cells. These findings suggest that amnion and chorion cells may represent an advantageous source of progenitor cells with potential applications in a variety of cell therapy and transplantation procedures.

Evidence of dopamine D1 receptor mRNA and binding sites in cultured human amniotic epithelial cells

In this study, we employed RT-PCR and radioligand binding studies to evaluate the gene expression and binding characteristics, respectively, of dopamine D(1) receptors in human amniotic epithelial cells (HAEC). The results showed that HAEC natively expressed D(1) receptor mRNA, as measured by RT-PCR, which was identical to that of human brain. Saturation binding studies using [(3)H]SCH 23390 demonstrated the presence of a high affinity D(1) site in HAEC with K(D) and B(max) values of 2.01+/-0.25 nM and 32.5+/-3.7 fmol/mg protein, respectively. Competition studies showed that selective D(1) antagonists were potent displacers of [(3)H]SCH 23390 binding with a potency order consistent with D(1) receptor characteristics. The current results present compelling evidence that HAEC natively express D(1) receptor mRNA and binding sites. The results also establish a primate cell model that can possibly be used for studying D(1) receptor signal transduction and molecular mechanisms and exploring newly developed drugs acting at these receptors.

Characterization of dopamine D2 receptor gene expression and binding sites in human placenta amniotic epithelial cells

This study was to investigate the presence of dopamine (DA) D(2)receptors mRNA and binding sites in human amniotic epithelial cells (HAEC). RT-PCR revealed that HAEC express DA D(2)receptor mRNA that is having 100 per cent homology with human DA D(2)receptors. Radioligand saturation binding studies showed a [3H]YM-09151-2 high affinity binding site with a K(D)and B(max)values of 0.53+/-0.09 nM and 119.6+/-8.5 fmol/mg protein, respectively. Competition experiments demonstrated that selective D(2)antagonists such as spiroperidol, domperidone and eticlopride potently competed with [3H]YM-09151-2 binding, whereas selective D(1)antagonists like SCH 23390 displayed weaker competition for the binding sites. The rank order of potency of these compounds in competing with [3H]YM-09151-2 for the binding sites was consistent with the pharmacology of the DA D(2)receptors. All competition curves were better fitted to a one-site model with a Hill coefficient around unity, indicating that [3H]YM-09151-2 is labelling a single population of receptors. These results provide evidence that HAEC natively express DA D(2)receptor mRNA and binding sites. Although the physiological function of D2 receptors in HAEC is currently unclear, the present results suggest that these cells could represent a source of human DA D(2)receptors without transformation or cloning procedures.

Expression of complement messenger RNAs and proteins by human oligodendroglial cells

Neurons, astrocytes, microglia, and endothelial cells are capable of synthesizing most, if not all, of the complement proteins. Little is known, however, about the capacity of oligodendroglial cells to generate complement components. This study evaluated expression of complement mRNAs and their protein products by human oligodendrocytes. Cells were isolated and cultured from white matter of seven adult cases that had undergone surgical temporal lobe resection for epilepsy. Oligodendroglial cultures were characterized by the expression of such cell type-specific mRNAs as myelin proteolipid protein (PLP), oligodendrocyte-specific protein (OSP), and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) and were further characterized by immunostaining for such differentiation markers as myelin basic protein (MBP), PLP, CNPase, and O4. RT-PCR analysis showed that the oligodendroglial cells expressed detectable levels of complement mRNAs for the C1q B-chain, C1r, C1s, C2, C3, C4, C5, C6, C7, C8 gamma subunit, and C9. Immunostaining was positive for C1q, C1s, C2, C3, C4, C5, C6, C7, C8, and C9. Double immunostaining for the oligodendrocyte marker O4 and the complement protein C3 demonstrated that all O4-positive cells were also positive for C3, indicating constitutive C3 expression. These results indicate that oligodendroglial cells may be a source of complement proteins in human brain and thus could contribute to the pathogenesis of several neurodegenerative and inflammatory diseases of the CNS, such as Alzheimer's disease, multiple sclerosis, and progressive supranuclear palsy, where complement-activated oligodendrocytes are abundant.

Characterization of the dopamine transporter gene expression and binding sites in cultured human amniotic epithelial cells

In this study we sought to investigate whether the dopamine transporter, DAT, and its binding sites are expressed in the human amniotic epithelial cells (HAEC) using reverse transcription-polymerase chain reaction (RT-PCR) and radioligand binding studies, respectively. The RT-PCR findings showed that HAEC expressed DAT mRNA with 100% homology to the human brain DAT. Saturation binding studies using [3H]mazindol showed a high affinity DAT binding site with K(D) and B(max) values of 12.32+/-1.67 nM and 82.7+/-9.74 fmol/mg protein, respectively. Competition experiments showed that selective DAT blockers are potent displacers of [3H]mazindol binding. The rank order of potency of the competing drugs is consistent with the pharmacology of the DAT. The present results provide compelling evidence that HAEC natively express the DAT mRNA and binding sites. More importantly, these results may suggest that HAEC is an appropriate human cell model for studying dopamine release and uptake processes and potential ligands at these sites.

Transcriptional profiling reveals strict boundaries between hippocampal subregions

The hippocampus consists of distinct anatomic regions that have been demonstrated to have different biological functions. To explore the molecular differences between hippocampal subregions, we performed transcriptional profiling analysis by using DNA microarray technology. The cRNA derived from the CA1, CA3, and dentate gyrus regions of the hippocampus and from spinal cord was hybridized to Affymetrix high-density oligo arrays. This systematic approach revealed sets of genes that were expressed specifically in subregions of the hippocampus corresponding to predefined cytoarchitectural boundaries, which could be confirmed by in situ hybridization and Real Time quantitative polymerase chain reaction. The relative enrichment and absence of genes in the hippocampal subregions support the conclusion that there is a molecular basis for the previously defined anatomic subregions of the hippocampus and also reveal genes that could be important in defining the unique functions of the hippocampal subfields.

Non-neuronal neurotransmitters and neurotrophic factors in amniotic epithelial cells: expression and function in humans and monkey

Human amniotic epithelial cells (HAEC) are formed from epiblasts on the 8th day after fertilization. Because they lack major histocompatibility complex (MHC) antigen, human amniotic tissue transplantation has been used for allotranplantation to treat patients with lysosomal diseases. We have provided evidence that HAEC have multiple functions such as synthesis and release of acetylcholine (ACh) and catecholamine (CA) as well as expressing mRNA coding for dopamine receptors and dopamine (DA) transporter (DAT). On the other hand, we showed that monkey amniotic epithelial cells (MAEC) synthesize and release CA and posses DA receptors and DAT. Detection of muscarinic actylcholine receptors indicates the presence of an autocrine mechanism in HAEC. Recently, we found that HAEC have neurotrophic function in conditioned medium from HAEC, indicating the presence of a novel neurotrohpic factor that is synthesized and released from HAEC. The amniotic membrane may have a significant role in supplying neurotrophic factors as well as neurotransmitters to the amniotic fluid, suggesting an important function in the early stages of neural development of the embryo. This review will focus on the neuropharmacological aspects of HAEC and MAEC in relation to the physiology of amniotic membrane.