Enhanced neural differentiation of neural stem cells and neurite growth by amniotic epithelial cell co-culture

The roles of lncRNAs and miRNAs in pancreatic cancer: a focus on cancer development and progression and their roles as potential biomarkers

Pancreatic ductal adenocarcinoma (PDAC) is among the most penetrative malignancies affecting humans, with mounting incidence prevalence worldwide. This cancer is usually not diagnosed in the early stages. There is also no effective therapy against PDAC, and most patients have chemo-resistance. The combination of these factors causes PDAC to have a poor prognosis, and often patients do not live longer than six months. Because of the failure of conventional therapies, the identification of key biomarkers is crucial in the early diagnosis, treatment, and prognosis of pancreatic cancer. 65% of the human genome encodes ncRNAs. There are different types of ncRNAs that are classified based on their sequence lengths and functions. They play a vital role in replication, transcription, translation, and epigenetic regulation. They also participate in some cellular processes, such as proliferation, differentiation, metabolism, and apoptosis. The roles of ncRNAs as tumor suppressors or oncogenes in the growth of tumors in a variety of tissues, including the pancreas, have been demonstrated in several studies. This study discusses the key roles of some lncRNAs and miRNAs in the growth and advancement of pancreatic carcinoma. Because they are involved not only in the premature identification, chemo-resistance and prognostication, also their roles as potential biomarkers for better management of PDAC patients.

Current advances in stem cell therapy in the treatment of multiple sclerosis

Multiple sclerosis (MS) is an inflammatory disease related to the central nervous system (CNS) with a significant global burden. In this illness, the immune system plays an essential role in its pathophysiology and progression. The currently available treatments are not recognized as curable options and, at best, might slow the progression of MS injuries to the CNS. However, stem cell treatment has provided a new avenue for treating MS. Stem cells may enhance CNS healing and regulate immunological responses. Likewise, stem cells can come from various sources, including adipose, neuronal, bone marrow, and embryonic tissues. Choosing the optimal cell source for stem cell therapy is still a difficult verdict. A type of stem cell known as mesenchymal stem cells (MSCs) is obtainable from different sources and has a strong immunomodulatory impact on the immune system. According to mounting data, the umbilical cord and adipose tissue may serve as appropriate sources for the isolation of MSCs. Human amniotic epithelial cells (hAECs), as novel stem cell sources with immune-regulatory effects, regenerative properties, and decreased antigenicity, can also be thought of as a new upcoming contender for MS treatment. Overall, the administration of stem cells in different sets of animal and clinical trials has shown immunomodulatory and neuroprotective results. Therefore, this review aims to discuss the different types of stem cells by focusing on MSCs and their mechanisms, which can be used to treat and improve the outcomes of MS disease.

Biomaterial-Based bFGF Delivery for Nerve Repair

Diseases in the nervous system are common in the human body. People have to suffer a great burden due to huge economic costs and poor prognosis of the diseases. Many treatment modalities are now available that can make recovery better. Managing nutritional factors is also helpful for such diseases. The basic fibroblast growth factor (bFGF) is one of the major nutritional factors, which plays a crucial role in organogenesis and tissue homeostasis. It plays a role in cell proliferation, migration, and differentiation, thereby regulating angiogenesis and wound healing and repair of the muscle, bone, and nerve. The study on how to improve the stability of bFGF to increase the treatment effect for different diseases has garnered tremendous attention. Biomaterials are the popular methods to improve the stability of bFGF because they are safe for the living body as they are biocompatible. Biomaterials can be loaded with bFGF and delivered locally to achieve the goal of sustained bFGF release. In the present review, we report different types of biomaterials that are used for bFGF delivery for nerve repair and briefly report how the introduced bFGF can function in the nervous system. We aim to provide summative guidance for future studies about nerve injury using bFGF.

Therapeutic Aspects of Mesenchymal Stem Cell-Based Cell Therapy with a Focus on Human Amniotic Epithelial Cells in Multiple Sclerosis: A Mechanistic Review

Multiple sclerosis (MS) is an inflammatory disease of central nervous system (CNS). The mmune system plays an important role in its pathogenesis. Current treatments are unable to cure patients and prevent the progression of MS lesions. Stem cell-based cell therapy has opened a new window for MS treatment. Stem cells regulate immune responses and improve axonal remyelination. Stem cells can be obtained from different origins such as embryonic, neural, bone marrow, and adipose tissues. But yet there is a challenge for the selection of the best cell source for stem cell therapy. Mesenchymal stem cells (MSCs) are a type of stem cell obtained from different origins and have significant immunomodulatory effects on the immune system. The increasing evidence have suggested that umbilical cord and adipose tissue can be a suitable source for isolation of MSCs. Moreover, human amniotic epithelial cells (hAECs) as novel stem cell origins by having immunoregulatory effects, regenerative effects, and less capacity of antigenicity can be a candidate for MS treatment. This review discussed the mechanistic effects of MSCs with a focus on human amniotic epithelial cells, which can be used to treatment and improvement of outcome in MS disease.

Sutureless Transplantation of Amniotic Membrane Using a Visible Light-Curable Protein Bioadhesive for Ocular Surface Reconstruction

The conjunctiva is a thin mucous membrane of the eye. Pterygium, a commonly appearing disease on the ocular surface, requires surgery to excise the conjunctiva to prevent visual deterioration. Recently, transplantation of the amniotic membrane (AM), which is the innermost membrane of the placenta, has been highlighted as an efficient method to cure conjunctiva defects because of its advantages of no side effects compared to mitomycin C treatment and not leaving additional scars on donor site compared to conjunctival autografting. However, to minimize additional damage to the ocular surface by suturing, AM transplantation (AMT) needs to be simplified by using a less invasive, time-saving method. In this work, a visible light-curable protein bioadhesive (named FixLight) for efficient sutureless AMT is applied. FixLight, which is based on bioengineered mussel adhesive protein (MAP), is easily applied between damaged ocular surfaces and transplanted AM, and rapidly cured by harmless blue light activation. Through in vivo evaluation using a rabbit model, the authors demonstrated that FixLight enabled facile, fast, and strong attachment of AM on sclera and promoted ocular surface reconstruction with good biocompatibility. Thus, FixLight can be successfully used as a promising clinical bioadhesive in opthalmological surgeries that require sutureless and rapid operation.

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.

Immunomodulatory Properties of Amniotic Membrane Derivatives and Their Potential in Regenerative Medicine

PURPOSE OF REVIEW

During the last decades, the field of regenerative medicine has been rapidly evolving. Major progress has been made in the development of biological substitutes applying the principles of cell transplantation, material science, and bioengineering.

RECENT FINDINGS

Among other sources, amniotic-derived products have been used for decades in various fields of medicine as a biomaterial for the wound care and tissue replacement. Moreover, human amniotic epithelial and mesenchymal cells have been intensively studied for their immunomodulatory capacities. Amniotic cells possess two major characteristics that have already been widely exploited. The first is their ability to modulate and suppress the innate and adaptive immunities, making them a true asset for chronic inflammatory disorders and for the induction of tolerance in transplantation models. The second is their multilineage differentiation capacity, offering a source of cells for tissue engineering. The latter combined with the use of amniotic membrane as a scaffold offers all components necessary to create an optimal environment for cell and tissue regeneration. This review summarizes beneficial properties of hAM and its derivatives and discusses their potential in regenerative medicine.

Therapeutic Potential of Human Amniotic Epithelial Cells on Injuries and Disorders in the Central Nervous System

Despite recent advances in neurosurgery and pharmaceuticals, contemporary treatments are ineffective in restoring lost neurological functions in patients with injuries and disorders of the central nervous system (CNS). Therefore, novel and effective therapies are urgently needed. Recent studies have indicated that stem cells, including embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), and mesenchymal stem cells (MSCs), could repair/replace damaged or degenerative neurons and improve functional recovery in both preclinical and clinical trials. However, there are many unanswered questions and unsolved issues regarding stem cell therapy in terms of potency, stability, oncogenicity, immune response, cell sources, and ethics. Currently, human amniotic epithelial cells (hAECs) derived from the amnion exhibit considerable advantages over other stem cells and have drawn much attention from researchers. hAECs are readily available, pose no ethical concerns, and have little risk of tumorigenicity and immunogenicity. Mounting evidence has shown that hAECs can promote neural cell survival and regeneration, repair affected neurons, and reestablish damaged neural connections. It is suggested that hAECs may be the most promising candidate for cell-based therapy of neurological diseases. In this review, we mainly focus on recent advances and potential applications of hAECs for treating various CNS injuries and neurodegenerative disorders. We also discuss current hurdles and challenges regarding hAEC therapies.

Controlled release of dextrin-conjugated growth factors to support growth and differentiation of neural stem cells

An essential aspect of stem cell in vitro culture and in vivo therapy is achieving sustained levels of growth factors to support stem cell survival and expansion, while maintaining their multipotency and differentiation potential. This study investigated the ability of dextrin (~74,000 g/mol; 27.8 mol% succinoylation) conjugated to epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF; or FGF-2) (3.9 and 6.7% w/w protein loading, respectively) to support the expansion and differentiation of stem cells in vitro via sustained, controllable growth factor release. Supplementation of mouse neural stem cells (mNSCs) with dextrin-growth factor conjugates led to greater and prolonged proliferation compared to unbound EGF/bFGF controls, with no detectable apoptosis after 7 days of treatment. Immunocytochemical detection of neural precursor (nestin) and differentiation (Olig2, MAP2, GFAP) markers verified that controlled release of dextrin-conjugated growth factors preserves stem cell properties of mNSCs for up to 7 days. These results show the potential of dextrin-growth factor conjugates for localized delivery of bioactive therapeutic agents to support stem cell expansion and differentiation, and as an adjunct to direct neuronal repair.

Emerging Strategies for Stem Cell Lineage Commitment in Tissue Engineering and Regenerative Medicine

Stem cells have transformed the fields of tissue engineering and regenerative medicine, and their potential to further advance these fields cannot be overstated. The stem cell niche is a dynamic microenvironment that determines cell fate during development and tissue repair following an injury. Classically, stem cells were studied in isolation of their microenvironment; however, contemporary research has produced a myriad of evidence that shows the importance of multiple aspects of the stem cell niche in regulating their processes. In the context of tissue engineering and regenerative medicine studies, the niche is an artificial environment provided by culture conditions. In vitro culture conditions may involve coculturing with other cell types, developing specific biomaterials, and applying relevant forces to promote the desired lineage commitment. Considerable advance has been made over the past few years toward directed stem cell differentiation; however, the unspecific differentiation of stem cells yielding a mixed population of cells has been a challenge. In this review, we provide a systematic review of the emerging strategies used for lineage commitment within the context of tissue engineering and regenerative medicine. These strategies include scaffold pore-size and pore-shape gradients, stress relaxation, sonic and electromagnetic effects, and magnetic forces. Finally, we provide insights and perspectives into future directions focusing on signaling pathways activated during lineage commitment using external stimuli.

Human Amnion Membrane: Potential Applications in Oral and Periodontal Field

Human amniotic membrane (HAM) is derived from the fetal membranes which consist of the inner amniotic membrane made of single layer of amnion cells fixed to collagen-rich mesenchyme attached to chorion. HAM has low immunogenicity, anti-inflammatory properties and their cells can be isolated without the sacrifice of human embryos. Amniotic membrane has biological properties which are important for the experimental and clinical applications in managing patients of various medical specialties. Abundant, natural and wonderful biomembrane not only protects the foetus but also has various clinical applications in the field of dermatology, ophthalmology, ENT surgery, orthopedics and dental surgery. As it is discarded post-partum it may be useful for regenerative medicine and cell therapy to treat damaged or diseased tissues.

Combination of amniotic epithelial cells with NDGA promotes the survival of transplanted AECs in spinal cord-injured rats

Our previous research has shown that seeding amniotic epithelial cells (AECs) in chemically extracted acellular muscle scaffold (CEAMC) better promotes the functional recovery of spinal cord injury (SCI) than scaffold alone. However, the massive death of transplanted cells, which is related to early inflammatory response, is still a problem in cell therapy. Our previous study proved that nordihydroguaiaretic acid (NDGA) inhibits inflammation after SCI. In this study, we tested a strategy of combining the early administration of NDGA and the transplantation of AEC-seeded CEAMC to treat SCI. The results showed that simply increasing the number of surviving AECs had no significant benefits in SCI therapy, but NDGA administration ameliorated transplanted AEC survival demonstrating the potential value of NDGA in the cellular transplantation treatment of SCI.

Characteristics and neural-like differentiation of mesenchymal stem cells derived from foetal porcine bone marrow

MSCs (mesenchymal stem cells) are a stem cell source that can be easily obtained from bone marrow. Despite the increasing importance of the pig as a large animal model, little is known about foetal pMSCs (porcine MSCs). In this study, we observed the gene expression of pluripotent markers in foetal pMSCs and the capacity of pMSCs to differentiate into adipocytes, osteocytes and neural-like cells using quantitative RT–PCR (reverse transcription–PCR), normal histological staining and immunohistochemistry. Foetal pMSCs have either a spindle or a flattened shape, and flow cytometry revealed the expression of the MSC-related proteins CD44 and CD105 (endoglin) but not CD34 and CD45. pMSCs express pluripotent markers such as Oct4 (octamer-binding transcription factor 4) and Nanog at the protein and mRNA levels. qRT-PCR (quantitative real-time PCR) analyses revealed that pMSCs expressed nestin [for NSCs (neural stem cells)]. Immunocytochemical and RT–PCR data showed that 29% and 23% of pMSCs expressed MAP2 (microtubule-associated protein 2) for neurons and β-tubulin III (Tuj1) for immature neurons, respectively, after induction of neural differentiation. These findings demonstrate the plasticity of pMSCs and their potential for use in cellular replacement therapy for neural diseases.

Recovery of fertility in azoospermia rats after injection of adipose-tissue-derived mesenchymal stem cells: the sperm generation

The recent reports on the treatment of azoospermia patients, in which spermatozoa could not be traced in their testes, are focused more on the potential use of adult stem cells, like mesenchymal stem cells (MSCs). The aim of this study was to demonstrate the potential use of MSCs derived from adipose tissue in the treatment of azoospermia using rat disease models. After busulfan application, the rats (n = 20) were injected with the GFP⁺ MSCs into left rete testes. After 12 weeks, the testes with cell injection (right testes) were compared to control (left testes) after dimensional and immunohistochemical analyses. Testes treated with MSCs appeared morphologically normal, but they were atrophic in rats without stem cell treatment, in which the seminiferous tubules were empty. Spermatogenesis was detected, not in every but in some tubules of cell-treated testes. GFP⁺/VASA⁺ and GFP⁺/SCP1⁺ cells in testes indicated the transdifferentiation of MSCs into spermatogenetic cells in the appropriate microenvironment. Rats with cell treatment were mated to show the full recovery of spermatogenesis, and continuous generations were obtained. The expression of GFP was detected in the mesenchymal stem cells derived from adipose tissue and bone marrow and also in the sperms of offspring. In conclusion, MSCs might be studied for the same purpose in humans in future.

Post-stroke inflammation and the potential efficacy of novel stem cell therapies: focus on amnion epithelial cells

Ischemic stroke is a debilitating disease for which there are currently no effective treatments besides the clot-buster, tissue plasminogen activator (t-PA), which is administered to less than 10% of patients due to a limited (4.5 h) time window of efficacy. Thus, there is an urgent need for novel therapies that can prevent or reverse the effects of stroke-induced brain injury. Recent encouraging reports have revealed that stem cells derived from human tissue, including embryonic, induced pluripotent, neural, and mesenchymal cells, can rescue injured brain tissue and improve functional recovery in experimental models of stroke. However, there are potentially major limitations to each of these types of stem cells that may ultimately prevent or restrict their use as viable mainstream treatment options for stroke patients. Conversely, stem cells derived from the placenta, such as human amnion epithelial cells (hAECs), appear to have several important advantages over other stem cell lineages, in particular their non-tumorigenic and non-immunogenic characteristics. Surprisingly, so far hAECs have received little attention as a potential stroke therapy. This brief review will firstly describe the inflammatory response and immune cell involvement following stroke, and then consider the potential for hAECs to improve stroke outcome given their unique characteristics. These actions of hAECs may involve a reduction of local inflammation and modulation of the immune response, promotion of neural recovery, differentiation into neural tissue, re-innervation of lost connections, and secretion of necessary cytokines, growth factors, hormones and/or neurotransmitters to restore cellular function.

Protoplasmic astrocytes enhance the ability of neural stem cells to differentiate into neurons in vitro

Protoplasmic astrocytes have been reported to exhibit neuroprotective effects on neurons, but there has been no direct evidence for a functional relationship between protoplasmic astrocytes and neural stem cells (NSCs). In this study, we examined neuronal differentiation of NSCs induced by protoplasmic astrocytes in a co-culture model. Protoplasmic astrocytes were isolated from new-born and NSCs from the E13-15 cortex of rats respectively. The differentiated cells labeled with neuron-specific marker β-tubulin III, were dramatically increased at 7 days in the co-culture condition. Blocking the effects of brain-derived neurotrophic factor (BDNF) with an anti-BDNF antibody reduced the number of neurons differentiated from NSCs when co-cultured with protoplasmic astrocytes. In fact, the content of BDNF in the supernatant obtained from protoplasmic astrocytes and NSCs co-culture media was significantly greater than that from control media conditions. These results indicate that protoplasmic astrocytes promote neuronal differentiation of NSCs, which is driven, at least in part, by BDNF.

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.

Magnetic CoPt nanoparticles as MRI contrast agent for transplanted neural stem cells detection

Neural stem cells (NSCs) exhibit features that make them suitable candidates for stem cell replacement therapy and spinal cord reconstruction. Magnetic resonance imaging (MRI) offers the potential to track cells in vivo using innovative approaches to cell labeling and image acquisition. In this study, experiments were carried out to optimize the loading condition of magnetic CoPt hollow nanoparticles (CoPt NPs) into neural stem cells and to define appropriate MRI parameters. Both cell viability and multipotency analysis showed that CoPt NPs at a concentration of 16 µg ml(-1) reduced T2 relaxation times in labeled rat NSCs, producing greater contrast on spin echo acquisitions at 4.7 T, yet did not affect cell viability and in vitro differentiation potential compared to controls. After optimizing nanoparticle loading concentrations and labeled cell numbers for MRI detection, CoPt-loaded NSCs were transplanted into organotypic spinal cord slices. The results showed that MRI could efficiently detect low numbers of CoPt-labeled NSCs with the enhanced image contrast. Our study demonstrated that MRI of grafted NSCs labeled with CoPt NPs is a useful tool to evaluate organotypic spinal cord slice models and has potential applications in other biological systems.

Bone marrow-derived mesenchymal stem cells co-cultured with pancreatic islets display β cell plasticity

The direct co-culturing effect of rat bone-marrow-derived mesenchymal stem cells (rBM-MSCs) on the pancreatic-islets (PIs) was studied to obtain functional islet cells. MSCs were isolated from rat bone marrow and cultivated under standard conditions. Following their characterization, the rBM-MSCs were directly (with cell-islet contact) co-cultured with recovered PIs together with the single cell cultures of those cell cultures as a control. The effect of direct co-cultures of rBM-MSCs with the PIs of normal rats was investigated using immunophenotypical and functional methods. The change in the amount of insulin secretion was evaluated as an indicator for differentiation of rBM-MSCs. One approache for in vitro differentiation to achieve reprogramming for differentiation into suitable cell types by changing the microenvironment of the cells to provide signals that might activate metabolic pathways is to use co-cultures with the microenvironment of the specific cells of the desired cell type, tissue/organ extracts, extracellular matrix compounds or biologically absorbable materials. Differentiated rBM-MSCs were found to be immunopositive for the specific insulin-producing cell marker, insulin, but not in undifferentiated rBM-MSCs. The functionality tests by ELISA confirmed that insulin secretion of co-cultured MSCs with islets was higher than that of islets. These evidences indicated that PIs could be regarded as critical components of the stem cell niche, such that MSCs can be differentiated into insulin-producing cells (IPCs). Moreover, direct cell-to-cell contact might provide additional and independent support. This approach would circumvent the need for PI-stem cell co-culture and could potentially facilitate the production of functional IPCs for future clinical applications.

PI3K mediated electrotaxis of embryonic and adult neural progenitor cells in the presence of growth factors

Correct guidance of the migration of neural progenitor cells (NPCs) is essential for the development and repair of the central nervous system (CNS). Electric field (EF)-guided migration, electrotaxis, has been observed in many cell types. We report here that, in applied EFs of physiological magnitude, embryonic and adult NPCs show marked electrotaxis, which is dependent on the PI3K/Akt pathway. The electrotaxis was also evidenced by ex vivo investigation that transplanted NPCs migrated directionally towards cathode in organotypic spinal cord slice model when treated with EFs. Genetic disruption or pharmacological inhibition of phosphoinositide 3-kinase (PI3K) impaired electrotaxis, whereas EF exposure increased Akt phosphorylation in a growth factor-dependent manner and increased phosphatidylinositol-3,4,5-trisphosphate (PIP3) levels. EF treatments also induced asymmetric redistribution of PIP3, growth factor receptors, and actin cytoskeleton. Electrotaxis in both embryonic and adult NPCs requires epidermal growth factor (EGF) and fibroblast growth factor (FGF). Our results demonstrate the importance of the PI3K/Akt pathway in directed migration of NPCs driven by EFs and growth factors and highlight the potential of EFs to enhance the guidance of various NPC populations in CNS repair therapies.

Amnion: a potent graft source for cell therapy in stroke

Regenerative medicine is a new field primarily based on the concept of transplanting exogenous or stimulating endogenous stem cells to generate biological substitutes and improve tissue functions. Recently, amnion-derived cells have been reported to have multipotent differentiation ability, and these cells have attracted attention as a novel cell source for cell transplantation therapy. Cells isolated from amniotic membrane can differentiate into all three germ layers, have low immunogenicity and anti-inflammatory function, and do not require the destruction of human embryos for their isolation, thus circumventing the ethical debate commonly associated with the use of human embryonic stem cells. Accumulating evidence now suggests that the amnion, which had been discarded after parturition, is a highly potent transplant material in the field of regenerative medicine. In this report, we review the current progress on the characterization of MSCs derived from the amnion as a remarkable transplantable cell population with therapeutic potential for multiple CNS disorders, especially stroke.

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.

Inhibition of mouse GPM6A expression leads to decreased differentiation of neurons derived from mouse embryonic stem cells

Glycoprotein M6A (GPM6A) is known as a transmembrane protein and an abundant cell surface protein on neurons in the central nervous system (CNS). However, the function of GPM6A is still unknown in the differentiation of neurons derived from embryonic stem (ES) cells. To investigate the function of GPM6A, we generated knockdown mouse ES cell lines (D3m-shM6A) using a short hairpin RNA (shRNA) expression vector driven by the U6 small nuclear RNA promoter, which can significantly suppress the expression of mouse GPM6A mRNA. Real-time polymerase chain reaction (real-time PCR) and immunocytochemical analysis showed that expression of shRNA against GPM6A markedly reduced the expression of neuroectodermal-associated genes (OTX1, Lmx1b, En1, Pax2, Pax5, Sox1, Sox2, and Wnt1), and also the number of neural stem cells (NSC) derived from D3mshM6A cells compared to control vector-transfected mouse ES cells (D3m-Mock). Moreover, our results show a decrease in both the number of neuronal markers and the number of differentiating neuronal cells (cholinergic, catecholaminergic, and GABAergic neurons) from NSC in D3m-shM6A cells. Hence, our findings suggest that expression level of GPM6A is directly or indirectly associated with the differentiation of neurons derived from undifferentiated ES cells.