Expression of dopamine-associated genes on conjunctiva stromal-derived human mesenchymal stem cells

Therapeutic potentials of human microfluidic encapsulated conjunctival mesenchymal stem cells on the rat model of Parkinson's disease

BACKGROUND AND AIM

Parkinson's disease (PD) is a progressive neurodegenerative disorder caused by the destruction of the dopaminergic neurons in the nigrostriatal pathway, leading to motor-behavioral complications. Cell therapy has been proposed as a promising approach for PD treatment using various cellular sources. Despite a few disadvantages mesenchymal stem cells (MSCs) represent, they have more auspicious effects for PD cell therapy. The present study aimed to evaluate a new source of MSCs isolated from human Conjunctiva (CJ-MSCs) impact on PD complications for the first time.

MATERIALS AND METHODS

Parkinson's was induced by stereotactic injection of 6-hydroxydopamine (6-OHDA) into the right medial forebrain bundle (MFB). An apomorphine-induced rotation test was used to confirm the model establishment. After PD model confirmation, green fluorescent protein (GFP) labeled CJ-MSCs and induced CJ-MSCs (microfluidic encapsulated and non-capsulated) were transplanted into the rats' right striatum. Then Rotation, Rotarod, and Open-field tests were performed to evaluate the behavioral assessment. Additionally, the immunohistochemistry technique was used for identifying tyrosine hydroxylase (TH).

RESULTS

According to the obtained data, the cell transplantation caused a reduction in the rats' rotation number and improved locomotion compared to the control group. The previous results were also more pronounced in induced and microfluidic encapsulated cells compared to other cells. Rats recipient CJ-MSCs also have represented more TH-expressed GFP-labeled cell numbers in the striatum than the control group.

CONCLUSION

It can be concluded that CJ-MSCs therapy can have protective effects against PD complications and nerve induction of cells due to their ability to express dopamine. On the other hand, CJ-MSCs microencapsulating leads to enhance even more protective effect of CJ-MSCs. However, confirmation of this hypothesis requires further studies and investigation of these cells' possible mechanisms of action.

Effect of let-7a overexpression on the differentiation of conjunctiva mesenchymal stem cells into photoreceptor-like cells

Objective(s):

MicroRNAs (miRNAs) could regulate many cellular processes such as proliferation and differentiation. let-7a miRNA is one of the key regulators in the developmental transition of retinal progenitor cells into differentiated cells. Current evidence suggests that mesenchymal stem cells (MSCs) can isolate from various tissues such as bone marrow and conjunctiva. In this study, we investigated the effect of let-7a overexpression on induced differentiation of conjunctiva mesenchymal stem cells (CJMSCs) into photoreceptor-like cells.

Materials and Methods:

After isolation and characterization, CJMSCs were transduced with lentiviruses containing let-7a or empty vector. The effect of let-7a overexpression on expression of photoreceptor-specific markers was evaluated by quantitative real-time PCR (RT-qPCR) after 28 and 42 days of transduction.

Results:

The relative expression of rhodopsin and recoverin genes was evaluated by RT-qPCR in let-7a overexpressing cells, control vector transduced cells and untransduced CJMSCs (control cells). Our results indicated that following overexpression of let-7a, after 28 and 42 days of transduction, significant up-regulation in the expression of recoverin (574.7 and 43.9 folds) and rhodopsin (3334.7 and 53.1 folds) were observed, respectively.

Conclusion:

Our findings indicate that overexpression of let-7a microRNA can increase the expression of photoreceptor-specific genes in CJMSCs. Moreover, it is prospective that let-7a overexpression can use as an alternative protocol for the differentiation of mesenchymal stem cells into photoreceptors. It seems that the effect of let-7a on the differentiation of CJMSCs into photoreceptors is also time-dependent.

Stress and catecholamines modulate the bone marrow microenvironment to promote tumorigenesis

High vascularization and locally secreted factors make the bone marrow (BM) microenvironment particularly hospitable for tumor cells and bones to a preferred metastatic site for disseminated cancer cells of different origins. Cancer cell homing and proliferation in the BM are amongst other regulated by complex interactions with BM niche cells (e.g. osteoblasts, endothelial cells and mesenchymal stromal cells (MSCs)), resident hematopoietic stem and progenitor cells (HSPCs) and pro-angiogenic cytokines leading to enhanced BM microvessel densities during malignant progression. Stress and catecholamine neurotransmitters released in response to activation of the sympathetic nervous system (SNS) reportedly modulate various BM cells and may thereby influence cancer progression. Here we review the role of catecholamines during tumorigenesis with particular focus on pro-tumorigenic effects mediated by the BM niche.

Retina tissue engineering by conjunctiva mesenchymal stem cells encapsulated in fibrin gel: Hypotheses on novel approach to retinal diseases treatment

BACKGROUND

Retinitis pigmentosa (RP) and age related macular degeneration (AMD) are two retinal diseases that progress by photoreceptor cells death. In retinal transplantation studies, stem and progenitor cells inject into the sub retinal space or vitreous and then these cells can be migrate to the site of retinal degeneration and locate in the host retina and restitute vision.

PRESENTATION OF THE HYPOTHESIS

Our hypothesis suggests that using human conjunctiva stem cells (as the source for increasing the number of human stem cells progenitor cells in retina dysfunction diseases) with fibrin gel and also assessing its relating in vitro (cellular and molecular processes) and in vivo (vision tests and pathology) could be a promising strategy for treatment of AMD and RP disorders.

TESTING THE HYPOTHESIS

In this idea, we describe a novel approach for retina tissue engineering with differentiation of conjunctiva mesenchymal stem cells (CJMSCs) into photoreceptor-like cells in fibrin gel with induction medium contain taurine. For assessment of differentiation, immunocytochemistry and real time PCR are used for the expression of Rhodopsin, RPE65, Nestin as differentiated photoreceptor cell markers in 2D and 3D culture. The results show that fibrin gel will offer a proper 3D scaffold for CJMSCs derived photoreceptor cell-like cells.

IMPLICATIONS OF THE HYPOTHESIS

Application of immune-privileged, readily available sources of adult stem cells like human conjunctiva stem cells with fibrin gel would be a promising strategy to increase the number of photoreceptor progenitor cells and promote involuntary angiogenesis needed in retina layer repair and regeneration.

Mesenchymal stem cells as a double-edged sword in suppression or progression of solid tumor cells

Tumor cells are able to attract mesenchymal stem cells (MSCs) to primary tumor site. On the other hand, MSCs secrete various factors to attract tumor cells towards BM. In this review, in addition to assessment of MSCs function at tumor sites and their impact on growth and metastasis of tumor cells, the importance of MSC in attraction of malignant cells to BM and their involvement in drug resistance of tumor cells have also been studied. Relevant literature was identified by a PubMed search (2000-2015) of English-language literature using the terms mesenchymal stem cells, cancer cell, metastasis, and tumor microenvironment. MSCs migrate towards tumor microenvironment and are involved in both pro-tumorigenic and antitumorigenic functions. The dual function of MSCs at tumor sites is dependent upon a variety of factors, including the type and origin of MSCs, the cancer cell line under study, in vivo or in vitro conditions, the factors secreted by MSCs and interactions between MSCs, host immune cells and cancer cells. Therefore, MSCs can be regarded both as friends and enemies of cancer cells. Although the role of a number of pathways, including IL-6/STAT3 pathway, has been indicated in controlling the interaction between MSCs and tumor cells, other mechanisms by which MSCs can control the tumor cells are not clear yet. A better understanding of these mechanisms through further studies can determine the exact role of MSCs in cancer progression and identify them as important therapeutic agents or targets.

The role of catecholamines in mesenchymal stem cell fate

Mesenchymal stem cells (MSCs) are multipotent stem cells found in many adult tissues, especially bone marrow (BM) and are capable of differentiation into various lineage cells such as osteoblasts, adipocytes, chondrocytes and myocytes. Moreover, MSCs can be mobilized from connective tissue into circulation and from there to damaged sites to contribute to regeneration processes. MSCs commitment and differentiation are controlled by complex activities involving signal transduction through cytokines and catecholamines. There has been an increasing interest in recent years in the neural system, functioning in the support of stem cells like MSCs. Recent efforts have indicated that the catecholamine released from neural and not neural cells could be affected characteristics of MSCs. However, there have not been review studies of most aspects involved in catecholamines-mediated functions of MSCs. Thus, in this review paper, we will try to describe the current state of catecholamines in MSCs destination and discuss strategies being used for catecholamines for migration of these cells to damaged tissues. Then, the role of the nervous system in the induction of osteogenesis, adipogenesis, chondrogenesis and myogenesis from MSCs is discussed. Recent progress in studies of signaling transduction of catecholamines in determination of the final fate of MSCs is highlighted. Hence, the knowledge of interaction between MSCs with the neural system could be applied towards the development of new diagnostic and treatment alternatives for human diseases.

The role of the nervous system in hematopoietic stem cell mobilization

Hematopoietic stem cells (HSCs) and blood cell progenitors, such as maturing leucocytes, steadily enter from bone marrow (BM) into the circulation under steady-state conditions, and their mobilization is dramatically amplified during stress conditions and by mediators such as granulocyte colony-stimulating factor (G-CSF). This mobilization is dependent upon bone remodeling, the proteolytic enzymes of bone marrow-derived stromal cells, and adhesion molecules such as integrin, but the main mechanisms controlling this traffic are still unclear. The nervous system, as the most important regulator of the body, can affect the mobilization network by secreting catecholamines, so that denervation of catecholaminergic fibers in the BM of mice could lead to declining mobilization in steady state and stress situations, even in the presence of other intact environmental factors in the BM. Thus, due to the importance of the nervous system, we have attempted to give a general overview of how the nervous system is involved in the mobilization of HSCs in this review. Then, we will try to describe the mobilization process induced by the nervous system, which consists of 3 mechanisms: stromal cell-derived factor 1 (SDF-1)/CXC chemokine receptor type 4 (CXCR4), proteolytic enzymes, and bone remodeling.

An effective inducer of dopaminergic neuron-like differentiation

Rat bone marrow-derived mesenchymal stem cells were cultured and passaged in vitro. After induction with basic fibroblast growth factor for 24 hours, passage 3 bone marrow-derived mesenchymal stem cells were additionally induced into dopaminergic neurons using three different combinations with basic fibroblast growth factor as follows: 20% Xiangdan injection; all-trans retinoic acid + glial-derived neurotrophic factor; or sonic hedgehog + fibroblast growth factor 8. Results suggest that the bone marrow-derived mesenchymal stem cells showed typical neuronal morphological characteristics after induction. In particular, after treatment with sonic hedgehog + fibroblast growth factor 8, the expressions of nestin, neuron-specific enolase, microtubuleassociated protein 2, tyrosine hydroxylase and vesicular monoamine transporter-2 in cells were significantly increased. Moreover, the levels of catecholamines in the culture supernatant were significantly increased. These findings indicate that Xiangdan injection, all-trans retinoic acid + glial-derived neurotrophic factor, and sonic hedgehog + fibroblast growth factor 8 can all induce dopaminergic neuronal differentiation from bone marrow-derived mesenchymal stem cells. In particular, the efficiency of sonic hedgehog + fibroblast growth factor 8 was highest.

Stem cell and tissue engineering research in the Islamic republic of Iran

During the last few years, the Islamic republic of Iran has consistently grown in nearly all scientific fields and achieved considerable success in producing science and developing technology. The Iranian government and scientific community have jointly started programs to support the creation of new scientific opportunities and technology platforms for research in the domain of stem cell and tissue engineering. In addition, clinical translation of basic researches in the fields of stem cell and regenerative medicine has been amongst the top priorities. Interestingly, the public sector, media, and authorities are also actively monitoring these attainments. In spite of this nationwide interest, however, there is currently a dearth of analytical information on these accomplishments. To address this issue, here we introduce the key decisions made by the country's policy makers and also review some of the Iranian researchers' publications in this field.

MicroRNAs as markers for neurally committed CD133+/CD34+ stem cells derived from human umbilical cord blood

Neural differentiation of the CD133+/CD34+ subpopulation of human umbilical cord blood stem cells was investigated, and neuro-miR (mir-9 and mir-124) expression was examined. An efficient induction protocol for neural differentiation of hematopoietic stem cells together with the exclusion of retinoic acid in this process was also studied. Transcription of some neural markers such as microtubule-associated protein-2, beta-tubulin III, and neuron-specific enolase was evaluated by real-time PCR, immunocytochemistry, and western blotting. Increased expression of neural indicators in the treated cells confirmed the appropriate neural differentiation, which supported the high efficiency of our defined neuronal induction protocol. Verified high expression of neuro-miRNAs along with neuronal specific proteins not only strengthens the regulatory role of miRNAs in determining stem cell fate but also introduces these miRNAs as novel indicators of neural differentiation. These data highlight the prominent therapeutic potential of hematopoietic stem cells for use in cell therapy of neurodegenerative diseases.

Cell Therapy From Bench to Bedside Translation in CNS Neurorestoratology Era

Recent advances in cell biology, neural injury and repair, and the progress towards development of neurorestorative interventions are the basis for increased optimism. Based on the complexity of the processes of demyelination and remyelination, degeneration and regeneration, damage and repair, functional loss and recovery, it would be expected that effective therapeutic approaches will require a combination of strategies encompassing neuroplasticity, immunomodulation, neuroprotection, neurorepair, neuroreplacement, and neuromodulation. Cell-based restorative treatment has become a new trend, and increasing data worldwide have strongly proven that it has a pivotal therapeutic value in CNS disease. Moreover, functional neurorestoration has been achieved to a certain extent in the CNS clinically. Up to now, the cells successfully used in preclinical experiments and/or clinical trial/treatment include fetal/embryonic brain and spinal cord tissue, stem cells (embryonic stem cells, neural stem/progenitor cells, hematopoietic stem cells, adipose-derived adult stem/precursor cells, skin-derived precursor, induced pluripotent stem cells), glial cells (Schwann cells, oligodendrocyte, olfactory ensheathing cells, astrocytes, microglia, tanycytes), neuronal cells (various phenotypic neurons and Purkinje cells), mesenchymal stromal cells originating from bone marrow, umbilical cord, and umbilical cord blood, epithelial cells derived from the layer of retina and amnion, menstrual blood-derived stem cells, Sertoli cells, and active macrophages, etc. Proof-of-concept indicates that we have now entered a new era in neurorestoratology.

Transplantation of a combination of autologous neural differentiated and undifferentiated mesenchymal stem cells into injured spinal cord of rats

STUDY DESIGN

The use of stem cells for functional recovery after spinal cord injury.

OBJECTIVE

The aim of this study was to evaluate the effects of a combination of autologous undifferentiated and neural-induced bone marrow mesenchymal stem cells (MSCs) on behavioral improvement in rats after inducing spinal cord injury and comparing with transplantation of undifferentiated and neural-induced MSCs alone.

SETTING

The study was conducted at the department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.

METHODS

The spinal cord was injured by contusion using a Fogarty embolectomy catheter at the T8-T9 level of the spinal cord, and autologous MSCs were transplanted into the center of the developing lesion cavity, 3 mm cranial and 3 mm caudal to the cavity, at 7 days after induction of spinal cord compression injury.

RESULTS

At 5 weeks after transplantation, the presence of transplanted cells was detected in the spinal cord parenchyma using immunohistochemistry analysis. In all treatment groups (differentiated, undifferentiated and mix), there was less cavitation than lesion sites in the control group. The Basso-Beattie-Bresnahan (BBB) score was significantly higher in rats transplanted with a combination of cells and in rats transplanted with neural-induced MSCs alone than in undifferentiated and control rats.

CONCLUSION

Pre-differentiation of MSCs to neuron-like cells has a very important role in achieving the best results for functional improvement.

CYP1B1, a developmental gene with a potential role in glaucoma therapy

The association of CYP1B1 gene alterations in primary congenital glaucoma individuals has been known for about a decade. Recent evidence has shown the involvement of CYP1B1 mutations in a number of forms of glaucoma and anterior segment disorders. This suggests a wide role for CYP1B1 in ocular physiology. Histochemical studies of eyes from individuals with primary congenital glaucoma revealed abnormalities in the anterior chamber angle, the region between the cornea and the iris, containing the trabecular meshwork. The cells of the trabecular meshwork serve as a filter to allow drainage of the aqueous humour, the fluid formed by the ciliary body that fills the anterior chamber. Mutations in CYP1B1 that affect its activity have frequently been shown to influence development of the trabecular meshwork, and it is thought that CYP1B1, a monooxygenase, acts to form or degrade some endobiotic compound that is necessary for proper development of the filtering structures. The rapidly developing area of stem cell research suggests a potential therapeutic approach for glaucomas resulting from deleterious mutations in CYP1B1, that is, the transfer of stem cells, differentiated to a specific lineage, containing wild-type CYP1B1 to specific regions of the eye, where they will develop into normal cells of that region and rectify the defect.

Can cellular models revolutionize drug discovery in Parkinson's disease?

The study of mechanisms that underlie Parkinson's disease (PD), as well as translational drug development, has been hindered by the lack of appropriate models. Both cell culture systems and animal models have limitations, and to date none faithfully recapitulate all of the clinical and pathological phenotypes of the disease. In this review we examine the various cell culture model systems of PD, with a focus on different stem cell models that can be used for investigating disease mechanisms as well as drug discovery for PD. We conclude with a discussion of recent discoveries in the field of stem cell biology that have led to the ability to reprogram somatic cells to a pluripotent state via the use of a combination of genetic factors; these reprogrammed cells are termed "induced pluripotent stem cells" (iPSCs). This groundbreaking technique allows for the derivation of patient-specific cell lines from individuals with sporadic forms of PD and also those with known disease-causing mutations. Such cell lines have the potential to serve as a human cellular model of neurodegeneration and PD when differentiated into dopaminergic neurons. The hope is that these iPSC-derived dopaminergic neurons can be used to replicate the key molecular aspects of neural degeneration associated with PD. If so, this approach could lead to transformative new tools for the study of disease mechanisms. In addition, such cell lines can be potentially used for high-throughput drug screening. While not the focus of this review, ultimately it is envisioned that techniques for reprogramming of somatic cells may be optimized to a point sufficient to provide potential new avenues for stem cell-based restorative therapies.