Oligoprogenitor Cells Derived from Spermatogonia Stem Cells Improve Remyelination in Demyelination Model

Epigenetic inheritance of acquired traits via stem cells dedifferentiation/differentiation or transdifferentiation cycles

Inheritance of acquired characteristics is the once widely accepted idea that multiple modifications acquired by an organism during its life, can be inherited by the offspring. This belief is at least as old as Hippocrates and became popular in early 19th century, leading Lamarck to suggest his theory of evolution. Charles Darwin, along with other thinkers of the time attempted to explain the mechanism of acquired traits' inheritance by proposing the theory of pangenesis. While later this and similar theories were rejected because of the lack of hard evidence, the studies aimed at revealing the mechanism by which somatic information can be passed to germ cells have continued up to the present. In this paper, we present a new theory and provide supporting literature to explain this phenomenon. We hypothesize existence of pluripotent adult stem cells that can serve as collectors and carriers of new epigenetic traits by entering different developmentally active organ/tissue compartments through blood circulation and acquiring new epigenetic marks though cycles of differentiation/dedifferentiation or transdifferentiation. During gametogenesis, these epigenetically modified cells are attracted by gonads, transdifferentiate into germ cells, and pass the acquired epigenetic modifications collected from the entire body's somatic cells to the offspring.

Engineering of gelatin scaffold by extracellular matrix of Sertoli cells for embryonic stem cell proliferation

Mimicking the microenvironment of seminiferous tubules plays an indispensable role in directing differentiation of stem cells toward germ cells in vitro. In this work, we fabricated electrospun gelatin (EG) mats (i.e., with diameter <500 nm) conditioned with Sertoli cells' extracellular matrix (ECM) to simulate both 3D structures and composition of normal testis tissue. Sertoli cells were isolated from mice testis and represented through immunocytochemistry (ICC) staining for expression of vimentin, a specific marker of Sertoli cells. The morphological characteristics of ECM-coated scaffold were investigated under scanning electron microscope (SEM). The efficient elimination of cells was confirmed by MTT assay. Furthermore, the cyto/biocompatibility of ECM-conditioned EG scaffold was determined for Sertoli cells and embryonic stem cells (ESCs), alone and as in co-culture. According to the results, the designed scaffold provided a mat for cell proliferation with negligible toxicity (almost 100% cell viability). SEM micrographs displayed cells with elongated shape and complete stretching morphology when compared with those cultured on scaffold without ECM. Moreover, an enhanced differentiation of ESCs toward sperm-generating cells was obtained through co-culturing of Sertoli cells and ESCs, where cell viability was found almost 100%. Our findings introduce the ECM-conditioned EG scaffold as a potentially influential engineered substrate for in vitro guidance of stem cells differentiation by mimicking the native microenvironment.

The effect of Zingiber Officinale Extract on Preventing Demyelination of Corpus Callosum in a Rat Model of Multiple Sclerosis

Background

Multiple sclerosis (MS) is the most prevalent neurological disability of young adults. Anti-inflammatory drugs have relative effects on MS. The anti-inflammatory and antioxidative effects of Zingiber officinale (ginger) have been proven in some experimental and clinical investigations. The aim of this study was to evaluate the effects of ginger extract on preventing myelin degradation in a rat model of MS.

Methods

Forty nine male Wistar rats were used in this study and divided into four control groups: the normal group, cuprizone-induced group, sham group (cuprizone [CPZ] + sodium carboxymethyl cellulose [NaCMC]), standard control group (fingolimod + cuprizone), including three experimental groups of CPZ, each receiving three different doses of ginger extract: 150, 300, and 600mg/kg /kg/day.

Results

Ginger extract of 600 mg/kg prevented corpus callosum from demyelination; however, a significant difference was observed in the fingolimod group (p < 0.05). Difference in the CPZ group was quite significant (p < 0.05).

Conclusion

Treatment with ginger inhibited demyelination and alleviated remyelination of corpus callosum in rats. Therefore, it could serve as a therapeutic agent in the MS.

Study of the Diffusion Tensor Imaging for Preclinical Therapeutic Efficacy of Umbilical Cord Mesenchymal Stem Cell Transplantation in the Treatment of Spinal Cord Injury

Objective

In this study, umbilical cord mesenchymal stem cell (UC-MSC) transplantation was used to treat patients with spinal cord injury (SCI). The microstructural changes of the spinal cord before and after transplantation were observed by diffusion tensor imaging (DTI).

Methods

From January 2014 to May 2015, seven patients who met the inclusion criteria were enrolled in this study. In the experimental group, both UC-MSC transplantation and comprehensive rehabilitation treatment were applied, while the control group received only comprehensive rehabilitation treatment. American Spinal Injury Association (ASIA) sensory and motor scores and the degree of SCI, spasticity, and urine/defecation functions were measured and evaluated together with DTI before the treatment and again at two and six months after the first treatment.

Results

From the DTI, the changes in the fractional anisotropy (FA) value and the apparent diffusion coefficient (ADC) value were as follows: in the experimental group, there were significant differences in the FA and ADC values before and after treatment (P < 0.05) with a decreased ADC value and an increased FA value. The differences in the ADC and FA values of the normal layer and the lesion layer before and after treatment were compared. The differences in ADC and FA at the lesion layer before and after transplantation were greater than those of the normal layer, and the differences were statistically significant (P < 0.05). In the experimental group, one patient with incomplete SCI and one patient with a short course of complete SCI improved in terms of light touch, acupuncture sensation, and motor score. One patient with incomplete SCI achieved improvement in spasticity and urine/defecation functions.

Conclusion

The combination of UC-MSC transplantation and comprehensive rehabilitation therapy could help to promote the structural repair of the spinal nerve in patients with SCI.

Role of cerebrospinal fluid in differentiation of human dental pulp stem cells into neuron-like cells

Human dental pulp stem cells (hDPSCs) could be differentiated into neuron like-cells under particular microenvironments. It has been reported that a wide range of factors, presented in cerebrospinal fluid (CSF), playing part in neuronal differentiation during embryonic stages, we herein introduce a novel culture media complex to differentiate hDPSCs into neuron-like cells. The hDPSCs were initially isolated and characterized. The CSF was prepared from the Cisterna magna of 19-day-old Wistar rat embryos, embryonic cerebrospinal fluid (E-CSF). The hDPSCs were treated by 5% E-CSF for 2 days, then neurospheres were cultured in DMEM/F12 supplemented with 10^-6 μm retinoic acid (RA), glial-derived neurotrophic factor and brain-derived neurotrophic factor for 6 days. The cells which were cultured in basic culture medium were considered as control group. Morphology of differentiated cells as well as process elongation were examined by an inverted microscope. In addition, the neural differentiation markers (Nestin and MAP2) were studied employing immunocytochemistry. Neuronal-like processes appeared 8 days after treatment. Neural progenitor marker (Nestin) and a mature neural marker (MAP2) were expressed in treated group. Moreover Nissl bodies were found in the cytoplasm of treated group. Taking these together, we have designed a simple protocol for generating neuron-like cells using CSF from the hDPSCs, applicable for cell therapy in several neurodegenerative disorders including Alzheimer's disease.

Crosstalk between stem cell and spinal cord injury: pathophysiology and treatment strategies

The injured spinal cord is difficult to repair and regenerate. Traditional treatments are not effective. Stem cells are a type of cells that have the potential to differentiate into various cells, including neurons. They exert a therapeutic effect by safely and effectively differentiating into neurons or replacing damaged cells, secreting neurotrophic factors, and inhibiting the inflammatory response. Many types of stem cells have been used for transplantation, and each has its own advantages and disadvantages. This review discusses the possible mechanisms of stem cell therapy for spinal cord injury, and the types of stem cells commonly used in experiments, to provide a reference for basic and clinical research on stem cell therapy for spinal cord injury.

Generation of functional dopaminergic neurons from human spermatogonial stem cells to rescue parkinsonian phenotypes

Background

Recent progress in the induced generation of dopaminergic (DA) neurons from different types of stem cells or reprogrammed somatic cells holds tremendous potential for the treatment of Parkinson’s disease (PD). However, the lack of a reliable source for cell replacement therapy remains a major limitation in the treatment of human neurological disorders. Additionally, the current protocols for in vitro differentiation or cell reprogramming to generate human DA neurons are laborious, time-consuming, and expensive, and efficient conversion of human spermatogonial stem cells (hSSCs) to functional DA neurons has not yet been achieved.

Methods

Primary hSSCs from testicular tissues of patients were exposed to an improved induction system, which consisted mainly of olfactory ensheathing cell conditioned culture medium (OECCM) and a set of defined cell-extrinsic factors and small molecules. Morphological changes were assessed, along with the expression of various DA neuron phenotypic markers (e.g., Tuj-1, TH, Nurr1, DAT) and several critical pro-DA neurogenesis effectors (e.g., EN-1, Pitx3, Foxa2, Lmx1a, Lmx1b, and OTX2). In addition, transcriptome analysis was used to further evaluate the genetic similarity between the artificially differentiated DA neurons and genuine ones. Concomitantly, the functional properties of converted DA neurons including synapse formation, dopamine release, electrophysiological activity, and neuron-specific Ca²⁺ signaling images were determined. Finally, hSSCs in the early stage of induction were evaluated for survival, differentiation, migration, tumorigenicity in the mouse striatum, and improvement of functional deficits in MPTP-induced PD animals.

Results

The hSSC-derived neurons not only acquired neuronal morphological features but also expressed various phenotypic genes and protein characteristic of DA neurons and several effectors critical for pro-DA neurogenesis. Strikingly, as the period of induction was prolonged, expression of the critical molecules for DA neuron epigenetic status gradually increased while hSSC-specific markers sharply decreased. After 3 weeks of induction, the transdifferentiation efficiency reached 21%. In addition, hierarchical clustering analysis showed that the differentiated DA neurons closely resembled genuine ones. Furthermore, the hSSC-derived neurons gained sophisticated functional properties of wild-type DA neurons, and pro-induced hSSCs efficiently survived, migrated, and differentiated into DA neurons without tumorigenesis after transplantation into mouse striatum, leading to improvement of functional deficits in PD animals.

Conclusions

The results showed that, using the present improved straightforward approach, hSSCs could acquire DA neuron morphological features and functional properties and rescue parkinsonian phenotypes. Our strategy for the conversion of hSSCs into DA neurons is very efficient and thus may provide an alternative approach suitable for clinical cell therapy to treat neurodegenerative diseases including PD.

Differential Proliferation Effects after Short-Term Cultivation of Mouse Spermatogonial Stem Cells on Different Feeder Layers

Objective

Spermatogonial stem cells (SSCs) provide the cellular basis for sperm production transforming the male’s genetic information to the next generation. We aimed to examine the effect of different feeder layer on proliferation of SSCs.

Materials and Methods

In this experimental study, we compared the in vitro effects of the co-culture of mouse SSCs with mouse embryonic fibroblasts (MEFs), sandos inbred mice (SIM) embryo-derived thioguanine- and ouabain- resistant (STO) feeders, and neonate and adult testicular stroma cell (TSC) feeders on the efficiency of mouse SSC proliferation and colony formation. Cells were cultivated on top of MEFs, STO, and neonate and adult TSCs feeder layers for 30 days. The number and diameter of colonies and also the number of cells were evaluated during day 7, 15, 25, and 30 of culture. The mRNA expression of germ cells and somatic cells were analyzed.

Results

In our study, we observed a significant difference in the proliferation rates and colony size of SSCs among the groups, especially for MEFs (P<0.05). SSCs can proliferate on MEFS, but not on STO, neonate or adult TSCs. Using immunocytochemistry by KI67 the proliferative activities of SSC colonies on MEFs were confirmed. The results of Fluidigm real-time polymerase chain reaction (RT-PCR) showed a high expression of the germ cell genes the promyelocytic leukemia zinc finger protein (PLZF), deleted in azoospermia-like (DAZL), octamer-binding transcription factor 4 (OCT4), and DEAD (Asp-Glu-Ala-Asp) box polypeptide 4 (DDX4 or VASA) in SSCs, and a low expression of these genes in the feeder layers. Furthermore, we observed a higher expression of vimentin and integrin-B1 in feeder layers than in SSCs (P<0.05).

Conclusion

Based on the optimal effect of MEFs for better colonization of SSCs, these feeder cells seem to be appropriate candidates for SSC cultures prior to transplantation. Therefore, it is suggested using these feeder cells for SSC cultivation.

A Review of Herbal Therapy in Multiple Sclerosis

Multiple sclerosis is a complex autoimmune disorder which characterized by demyelination and axonal loss in the central nervous system (CNS). Several evidences indicate that some new drugs and stem cell therapy have opened a new horizon for multiple sclerosis treatment, but current therapies are partially effective or not safe in the long term. Recently, herbal therapies represent a promising therapeutic approach for multiple sclerosis disease. Here, we consider the potential benefits of some herbal compounds on different aspects of multiple sclerosis disease. The medicinal plants and their derivatives; Ginkgo biloba, Zingiber officinale, Curcuma longa, Hypericum perforatum, Valeriana officinalis, Vaccinium macrocarpon, Nigella sativa,Piper methysticum, Crocus sativus, Panax ginseng, Boswellia papyrifera, Vitis vinifera, Gastrodia elata, Camellia sinensis, Oenothera biennis, MS14 and Cannabis sativa have been informed to have several therapeutic effects in MS patients.

Silk fibroin/amniotic membrane 3D bi-layered artificial skin

Burn injuries have been reported to be an important cause of morbidity and mortality and they are still considered as unmet clinical need. Although there is a myriad of effective stem cells that have been suggested for skin regeneration, there is no one ideal scaffold. The aim of this study was to develop a three-dimensional (3D) bi-layer scaffold made of biological decellularized human amniotic membrane (AM) with viscoelastic electrospun nanofibrous silk fibroin (ESF) spun on top. The fabricated 3D bi-layer AM/ESF scaffold was submerged in ethanol to induce β-sheet transformation as well as to get a tightly coated and inseparable bi-layer. The biomechanical and biological properties of the 3D bi-layer AM/ESF scaffold were investigated. The results indicate significantly improved mechanical properties of the AM/ESF compared with the AM alone. Both the AM and AM/ESF possess a variety of suitable adhesion cells without detectable cytotoxicity against adipose tissue-derived mesenchymal stem cells (AT-MSCs). The AT-MSCs show increased expression of two main pro-angiogenesis factors, vascular endothelial growth factor and basic fibroblast growth factor, when cultured on the AM/ESF for 7 days, when comparing with AM alone. The results suggest that the AM/ESF scaffold with autologous AT-MSCs has excellent cell adhesion and proliferation along with production of growth factors which serves as a possible application in a clinical setting for skin regeneration.

Transdifferentiation of Human Dental Pulp Stem Cells Into Oligoprogenitor Cells

Introduction

The nerve fibers in central nervous system are surrounded by myelin sheet which is formed by oligodendrocytes. Cell therapy based on oligodendrocytes and their precursors transplantation can hold a promising alternative treatment for myelin sheet repair in demyelinating diseases.

Methods

Human Dental Pulp Stem Cells (hDPSCs) are noninvasive, autologous and easy available source with multipotency characteristics, so they are in focus of interest in regenerative medicine. In the present study, hDPSCs were differentiated into oligoprogenitor using glial induction media, containing Retinoic Acid (RA), basic Fibroblast Growth Factor (bFGF), Platelet-Derived Growth Factor (PDGF), N2 and B27. The differentiated Oligoprogenitor Cells (OPCs) were evaluated for nestin, Olig2, NG2 and O4 using immunocytochemistry. Also, the expression of nestin, Olig2 and PDGFR-α gens (neuroprogenitor and oligoprogenitor markers) were investigated via RT-PCR technique.

Results

The results indicate that glial differentiation medium induces the generation of oligoprogenitor cells as revealed via exhibition of specific glial markers, including Olig2, NG2 and O4. The expersion of nestin gene (neuroprogenitor marker) and Olig2 and PDGFR-α genes (oligoprogentor markers) were detected in treated hDPSCs at the end of the induction stage.

Conclusion

hDPSCs can be induced to transdifferentiate into oligoprogenitor cells and respond to the routinely applied regents for glial differentiation of mesanchymal stem cells. These data suggest the hDPSCs as a valuable source for cell therapy in neurodegenerative diseases.

Condition medium of cerebrospinal fluid and retinoic acid induces the transdifferentiation of human dental pulp stem cells into neuroglia and neural like cells

Cerebrospinal fluid (CSF) contains several molecules which are essential for neurogenesis. Human dental pulp stem cells (hDPSCs) are putatively neural crest cell-derived that can differentiate into neurons and glial cells under appropriate neurotrophic factors. The aim of this study was to induce differentiation of hDPSCs into neuroglial phenotypes using retinoic acid (RA) and CSF. The hDPSCs from an impacted third molar were isolated by mechanical and digestion and cultured. The cells have treated by 10⁻⁷ µM RA (RA group) for 8 days, 10% CSF (CSF group) for 8 days and RA with CSF for 8 days (RA/CSF group). Nestin, microtubule-associated protein 2 (MAP2), and glial fibrillary acidic protein immunostaining were used to examine the differentiated cells. Axonal outgrowth was detected using Bielschowsky's silver impregnation method and Nissl bodies were stained in differentiated cells by Cresyl violet. The morphology of differentiated cells in treated groups was significantly changed after 3–5 days. The results of immunocytochemistry showed the presence of neuroprogenitor marker nestin was seen in all groups. However, the high percentage of nestin positive cells and MAP2, as mature neural markers, were observed at the pre-induction and induction stage, respectively. Nissl bodies were detected as dark-blue particles in the cytoplasm of treated cells. Our findings showed the RA as pre-inducer and CSF as inducer for using in vitro differentiation of neuron-like cells and neuroglial cells from hDPSCs.

Chitosan-Intercalated Montmorillonite/Poly(vinyl alcohol) Nanofibers as a Platform to Guide Neuronlike Differentiation of Human Dental Pulp Stem Cells

In this study, we present a novel chitosan-intercalated montmorillonite/poly(vinyl alcohol) (OMMT/PVA) nanofibrous mesh as a microenvironment for guiding differentiation of human dental pulp stem cells (hDPSCs) toward neuronlike cells. The OMMT was prepared through ion exchange reaction between the montmorillonite (MMT) and chitosan. The PVA solutions containing various concentrations of OMMT were electrospun to form 3D OMMT-PVA nanofibrous meshes. The biomechanical and biological characteristics of the nanofibrous meshes were evaluated by ATR-FTIR, XRD, SEM, MTT, and LDH specific activity, contact angle, and DAPI staining. They were carried out for mechanical properties, overall viability, and toxicity of the cells. The hDPSCs were seeded on the prepared scaffolds and induced with neuronal specific differentiation media at two differentiation stages (2 days at preinduction stage and 6 days at induction stage). The neural differentiation of the cells cultured on the meshes was evaluated by determining the expression of Oct-4, Nestin, NF-M, NF-H, MAP2, and βIII-tubulin in the cells after preinduction, at induction stages by real-time PCR (RT-PCR) and immunostaining. All the synthesized nanofibers exhibited a homogeneous morphology with a favorable mechanical behavior. The population of the cells differentiated into neuronlike cells in all the experimental groups was significantly higher than that in control group. The expression level of the neuronal specific markers in the cells cultured on 5% OMMT/PVA meshes was significantly higher than the other groups. This study demonstrates the feasibility of the OMMT/PVA artificial nerve graft cultured with hDPSCs for regeneration of damaged neural tissues. These fabricated matrices may have a potential in neural tissue engineering applications.

Differentiation of Spermatogonia Stem Cells into Functional Mature Neurons Characterized with Differential Gene Expression

Transplantation of embryonic stem cells (ESCs) is a promising therapeutic approach for the treatment of neurodegenerative diseases. However, ESCs are not usable clinically due to immunological and ethical limitations. The identification of an alternative safe cell source opens novel options via autologous transplantation in neuro-regeneration circumventing these problems. Here, we examined the neurogenic capacity of embryonic stem-like cells (ES-like cells) derived from the testis using neural growth factor inducers and utilized them to generate functional mature neurons. The neuronal differentiation of ES-like cells is induced in three stages. Stage 1 is related to embryoid body (EB) formation. To induce neuroprogenitor cells, EBs were cultured in the presence of retinoic acid, N₂ supplement and fibroblast growth factor followed by culturing in a neurobasal medium containing B₂₇, N₂ supplements for additional 10 days, to allow the maturation and development of neuronal progenitor cells. The neurogenic differentiation was confirmed by immunostaining for markers of mature neurons. The differentiated neurons were positive for Tuj1 and Tau1. Real-time PCR dates indicated the expression of Nestin and Neuro D (neuroprogenitor markers) in induced cells at the second stage of the differentiation protocol. The differentiated mature neurons exhibited the specific neuron markers Map2 and β-tubulin. The functional maturity of neurons was confirmed by an electrophysiological analysis of passive and active neural membrane properties. These findings indicated a differentiation capacity of ES-like cells derived from the testis to functionally mature neurons, which proposes them as a novel cell source for neuroregenerative medicine.