The Secretome of Bone Marrow and Wharton Jelly Derived Mesenchymal Stem Cells Induces Differentiation and Neurite Outgrowth in SH-SY5Y Cells. Stem Cells Int. 2014;2014:438352. [PMID: 25132857 PMCID: PMC4124228 DOI: 10.1155/2014/438352]

Human platelet lysate supports SH-SY5Y neuroblastoma cell proliferation and differentiation into a dopaminergic-like neuronal phenotype under xenogeneic-free culture conditions

SH-SY5Y is a human neuroblastoma cell line that can be differentiated into several neuronal phenotypes, depending on culture conditions. For this reason, this cell line has been widely used as an in vitro model of neurodegenerative conditions, such as Parkinson's disease (PD). However, most studies published to date used fetal bovine serum (FBS) as culture medium supplement for SH-SY5Y cell differentiation. We report on the testing of human platelet lysate (hPL) as a culture medium supplement to support SH-SY5Y cell culture. Both standard hPL and a fibrinogen-depleted hPL (FD-hPL) formulation, which does not require the addition of anticoagulants to culture media, promoted an increase in SH-SY5Y cell proliferation in comparison to FBS, without compromising metabolic activity. SH-SY5Y cells cultured in hPL or FD-hPL also displayed a higher number of neurite extensions and stained positive for MAP2 and synaptophysin, in the absence of differentiation stimuli; reducing hPL or FD-hPL concentration to 1% v/v did not affect cell proliferation or metabolic activity. Furthermore, following treatment with retinoic acid (RA) and further stimulation with brain-derived neurotrophic factor (BDNF) and nerve growth factor beta (NGF-β), the percentage of SH-SY5Y cells stained positive for dopaminergic neuronal differentiation markers (tyrosine hydroxylase [TH] and Dopamine Transporter [DAT]) was higher in hPL or FD-hPL than in FBS, and gene expression of dopaminergic markers TH, DAT, and DR2 was also detected. Overall, the data herein presented supports the use of hPL to differentiate SH-SY5Y cells into a neuronal phenotype with dopaminergic features, and the adoption of FD-hPL as a fully xenogeneic free alternative to FBS to support the use of SH-SY5Y cells as a neurodegeneration model.

Effects of dedifferentiated fat cells on neurogenic differentiation and cell proliferation in neuroblastoma cells

PURPOSE

Mesenchymal stem cells (MSCs) can induce differentiation of neuroblastoma (NB) cells. Properties of dedifferentiated fat cells (DFATs) are similar to those of MSCs. Here, we investigated whether DFATs can induce NB cell differentiation and suppress cell proliferation.

METHODS

DFATs were obtained from mature adipocytes isolated from adipose tissue from a ceiling culture. NB cells were cultured in a medium with or without DFATs and, subsequently, cultured in a DFAT-conditioned medium (CM) with or without phosphatidylinositol 3-kinase (PI3K) inhibitor. The neurite lengths were measured, and mRNA expression levels of the neurofilament (NF) and tubulin beta III (TUBβ3) were assessed using quantitative real-time RT-PCR. Cell viability was assessed using the WST-1 assay.

RESULTS

NB cells cultured with DFATs caused elongation of the neurites and upregulated the expression of NF and Tubβ3. NB cells cultured in DFAT-CM demonstrated increased cell viability. NB cells cultured with DFAT-CM and PI3K inhibitors suppressed cell viability. NB cells cultured with DFAT-CM and PI3K inhibitor demonstrated increased neurite length and expression, and upregulation of Tubβ3.

CONCLUSION

The combined use of DFAT-CM and PI3K inhibitors suppresses the proliferation of NB cells and induces their differentiation. Thus, DFAT may offer new insights into therapeutic approaches in neuroblastoma.

Combination Therapy of Mesenchymal Stem Cell Transplantation and Astrocyte Ablation Improve Remyelination in a Cuprizone-Induced Demyelination Mouse Model

Astrocytes display an active, dual, and controversial role in multiple sclerosis (MS), a chronic inflammatory demyelination disorder. However, mesenchymal stem cells (MSCs) can affect myelination in demyelinating disorders. This study aimed to investigate the effect of single and combination therapies of astrocyte ablation and MSC transplantation on remyelination in the cuprizone (CPZ) model of MS. C57BL/6 mice were fed 0.2% CPZ diet for 12 weeks. Astrocytes were ablated twice by L-a-aminoadipate (L-AAA) at the beginning of weeks 13 and 14 whereas MSCs were injected in the corpus callosum at the beginning of week 13. Motor coordination and balance were assessed through rotarod test whereas myelin content was evaluated by Luxol-fast blue (LFB) staining and transmission electron microscopy (TEM). Glial cells were assessed by immunofluorescence staining while mRNA expression was evaluated by quantitative real-time PCR. Combination treatment of ablation of astrocytes and MSC transplantation (CPZ + MSC + L-AAA) significantly decreased motor coordination deficits better than single treatments (CPZ + MSCs or CPZ + L-AAA), in comparison to CPZ mice. In addition, L-AAA and MSCs treatment significantly enhanced remyelination compared to CPZ group. Moreover, combination therapy caused a significant decrease in the number of GFAP⁺ and Iba-1⁺ cells, whereas oligodendrocytes were significantly increased in comparison to CPZ mice. Finally, MSC administration resulted in a significant upregulation of BDNF and NGF mRNA expression levels. Our data indicate that transient ablation of astrocytes along with MSCs treatment improve remyelination through enhancing oligodendrocytes and attenuating gliosis in a chronic demyelinating mouse model of MS.

Exploring the neurogenic differentiation of human dental pulp stem cells

Human dental pulp stem cells (hDPSCs) have increasingly gained interest as a potential therapy for nerve regeneration in medicine and dentistry, however their neurogenic potential remains a matter of debate. This study aimed to characterize hDPSC neuronal differentiation in comparison with the human SH-SY5Y neuronal stem cell differentiation model. Both hDPSCs and SH-SY5Y could be differentiated to generate typical neuronal-like cells following sequential treatment with all-trans retinoic acid (ATRA) and brain-derived neurotrophic factor (BDNF), as evidenced by significant expression of neuronal proteins βIII-tubulin (TUBB3) and neurofilament medium (NF-M). Both cell types also expressed multiple neural gene markers including growth-associated protein 43 (GAP43), enolase 2/neuron-specific enolase (ENO2/NSE), synapsin I (SYN1), nestin (NES), and peripherin (PRPH), and exhibited measurable voltage-activated Na⁺ and K⁺ currents. In hDPSCs, upregulation of acetylcholinesterase (ACHE), choline O-acetyltransferase (CHAT), sodium channel alpha subunit 9 (SCN9A), POU class 4 homeobox 1 (POU4F1/BRN3A) along with a downregulation of motor neuron and pancreas homeobox 1 (MNX1) indicated that differentiation was more guided toward a cholinergic sensory neuronal lineage. Furthermore, the Extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitor U0126 significantly impaired hDPSC neuronal differentiation and was associated with reduction of the ERK1/2 phosphorylation. In conclusion, this study demonstrates that extracellular signal-regulated kinase/Mitogen-activated protein kinase (ERK/MAPK) is necessary for sensory cholinergic neuronal differentiation of hDPSCs. hDPSC-derived cholinergic sensory neuronal-like cells represent a novel model and potential source for neuronal regeneration therapies.

Therapeutic uses of post-partum tissue-derived mesenchymal stromal cell secretome

Human post-partum tissue mesenchymal stromal cells (hPPT-MSCs) are widely used in research to investigate their differentiation capabilities and therapeutic effects as potential agents in cell-based therapy. This is ascribed to the advantages offered by the use of MSCs isolated from hPPT over other MSC sources. A paradigm shift in related research is evident that focuses on the secretome of the human MSCs (hMSCs), as therapeutic effects of hMSCs are attributed more so to their secreted growth factors, cytokines and chemokines and to the extracellular vesicles (EVs), all of which are components of the hMSC secretome. Positive therapeutic effects of the hPPT-MSC secretome have been demonstrated in diseases related to skin, kidney, heart, nervous system, cartilage and bones, that have aided fast recovery by replacing damaged, non-functional tissues, via differentiating and regenerating cells. Although certain limitations such as short half -life of the secretome components and irregular secreting patterns exist in secretome therapy, these issues are successfully addressed with the use of cutting-edge technologies such as genome editing and recombinant cytokine treatment. If the current limitations can be successfully overcome, the hPPT-MSC secretome including its EVs may be developed into a cost-effective therapeutic agent amenable to be used against a wide range of diseases/disorders.

Mesenchymal stem cells accelerated growth and metastasis of neuroblastoma and preferentially homed towards both primary and metastatic loci in orthotopic neuroblastoma model

Background

Majority of neuroblastoma patients develop metastatic disease at diagnosis and their prognosis is poor with current therapeutic approach. Major challenges are how to tackle the mechanisms responsible for tumorigenesis and metastasis. Human mesenchymal stem cells (hMSCs) may be actively involved in the constitution of cancer microenvironment.

Methods

An orthotopic neuroblastoma murine model was utilized to mimic the clinical scenario. Human neuroblastoma cell line SK-N-LP was transfected with luciferase gene, which were inoculated with/without hMSCs into the adrenal area of SCID-beige mice. The growth and metastasis of neuroblastoma was observed by using Xenogen IVIS 100 in vivo imaging and evaluating gross tumors ex vivo. The homing of hMSCs towards tumor was analyzed by tracing fluorescence signal tagged on hMSCs using CRI Maestro™ imaging system.

Results

hMSCs mixed with neuroblastoma cells significantly accelerated tumor growth and apparently enhanced metastasis of neuroblastoma in vivo. hMSCs could be recruited by primary tumor and also become part of the tumor microenvironment in the metastatic lesion. The metastatic potential was consistently reduced in lung and tumor when hMSCs were pre-treated with stromal cell derived factor-1 (SDF-1) blocker, AMD3100, suggesting that the SDF-1/CXCR4 axis was one of the prime movers in the metastatic process.

Conclusions

hMSCs accelerated and facilitated tumor formation, growth and metastasis. Furthermore, the homing propensity of hMSCs towards both primary tumor and metastatic loci can also provide new therapeutic insights in utilizing bio-engineered hMSCs as vehicles for targeted anti-cancer therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08090-2.

Role of the CXCR4-SDF1-HMGB1 pathway in the directional migration of cells and regeneration of affected organs

In recent years, several studies have reported positive outcomes of cell-based therapies despite insufficient engraftment of transplanted cells. These findings have created a huge interest in the regenerative potential of paracrine factors released from transplanted stem or progenitor cells. Interestingly, this notion has also led scientists to question the role of proteins in the secretome produced by cells, tissues or organisms under certain conditions or at a particular time of regenerative therapy. Further studies have revealed that the secretomes derived from different cell types contain paracrine factors that could help to prevent apoptosis and induce proliferation of cells residing within the tissues of affected organs. This could also facilitate the migration of immune, progenitor and stem cells within the body to the site of inflammation. Of these different paracrine factors present within the secretome, researchers have given proper consideration to stromal cell-derived factor-1 (SDF1) that plays a vital role in tissue-specific migration of the cells needed for regeneration. Recently researchers recognized that SDF1 could facilitate site-specific migration of cells by regulating SDF1-CXCR4 and/or HMGB1-SDF1-CXCR4 pathways which is vital for tissue regeneration. Hence in this study, we have attempted to describe the role of different types of cells within the body in facilitating regeneration while emphasizing the HMGB1-SDF1-CXCR4 pathway that orchestrates the migration of cells to the site where regeneration is needed.

Inflammatory response of stem cell secreting conditioned media in SH-SY5Y cell line

Mesenchymal stem cells (MSCs) are reported to secrete anti-inflammatory cytokines and growth factors, which makes MSCs a promising candidate in the treatment of various neurodegenerative diseases. SH-SY5Y show extreme inflammatory response under LPS and an inadequate inflammatory response when treated with Wharton's jelly, conditioned media. This study mainly focuses on the inflammatory (pro and anti-inflammatory) response of SH-SY5Y by gene expression study. SH-SY5Y cell line used for cell culture and RT- q PCR was done with 5 different primers. In this article, lipopolysaccharides (LPS) show a significant result in pro-inflammatory and pro-apoptotic. In this article, we focus on the therapeutic approach of stem cells, which reduce inflammation by secreting stem cell factors to cure various neurodegenerative diseases.

Human Mesenchymal Stem Cells Overexpressing Interleukin 2 Can Suppress Proliferation of Neuroblastoma Cells in Co-Culture and Activate Mononuclear Cells In Vitro

High-dose recombinant interleukin 2 (IL2) therapy has been shown to be successful in renal cell carcinoma and metastatic melanoma. However, systemic administration of high doses of IL2 can be toxic, causing capillary leakage syndrome and stimulating pro-tumor immune response. One of the strategies to reduce the systemic toxicity of IL2 is the use of mesenchymal stem cells (MSCs) as a vehicle for the targeted delivery of IL2. Human adipose tissue-derived MSCs were transduced with lentivirus encoding IL2 (hADSCs-IL2) or blue fluorescent protein (BFP) (hADSCs-BFP). The proliferation, immunophenotype, cytokine profile and ultrastructure of hADSCs-IL2 and hADSCs-BFP were determined. The effect of hADSCs on activation of peripheral blood mononuclear cells (PBMCs) and proliferation and viability of SH-SY5Y neuroblastoma cells after co-culture with native hADSCs, hADSCs-BFP or hADSCs-IL2 on plastic and Matrigel was evaluated. Ultrastructure and cytokine production by hADSCs-IL2 showed modest changes in comparison with hADSCs and hADSCs-BFP. Conditioned medium from hADSC-IL2 affected tumor cell proliferation, increasing the proliferation of SH-SY5Y cells and also increasing the number of late-activated T-cells, natural killer (NK) cells, NKT-cells and activated T-killers. Conversely, hADSC-IL2 co-culture led to a decrease in SH-SY5Y proliferation on plastic and Matrigel. These data show that hADSCs-IL2 can reduce SH-SY5Y proliferation and activate PBMCs in vitro. However, IL2-mediated therapeutic effects of hADSCs could be offset by the increased expression of pro-oncogenes, as well as the natural ability of hADSCs to promote the progression of some tumors.

Comparative Analysis of the Paracrine Action of Neuronal and Glial Progenitor Cells Derived from Induced Human Pluripotent Stem Cells

We performed comparative analysis of paracrine activity of neuronal and glial progenitors derived from induced pluripotent stem cells under conditions of hypoxia modeled by addition of cobalt dichloride. Neuronal and glial progenitors produced neuroprotective and neurotrophic effects on SHSY-5Y neuroblastoma cells in co-culture during the post-hypoxic recovery and reduced the number of apoptotic and necrotic cells. Moreover, they produced a neurotrophic effect and promote the formation and growth of neurites in neuroblastoma cells. The paracrine effect of glial progenitors was more pronounced, which can be explained by more intensive expression and secretion of neurotrophic factors in these cells.

Expanded Differentiation Capability of Human Wharton's Jelly Stem Cells Toward Pluripotency: A Systematic Review

Human Wharton's jelly stem cells (HWJSC) can be efficiently isolated from the umbilical cord, and numerous reports have demonstrated that these cells can differentiate into several cell lineages. This fact, coupled with the high proliferation potential of HWJSC, makes them a promising source of stem cells for use in tissue engineering and regenerative medicine. However, their real potentiality has not been established to date. In the present study, we carried out a systematic review to determine the multilineage differentiation potential of HWJSC. After a systematic literature search, we selected 32 publications focused on the differentiation potential of these cells. Analysis of these studies showed that HWJSC display expanded differentiation potential toward some cell types corresponding to all three embryonic cell layers (ectodermal, mesodermal, and endodermal), which is consistent with their constitutive expression of key pluripotency markers such as OCT4, SOX2, and NANOG, and the embryonic marker SSEA4. We conclude that HWJSC can be considered cells in an intermediate state between multipotentiality and pluripotentiality, since their proliferation capability is not unlimited and differentiation to all cell types has not been demonstrated thus far. These findings support the clinical use of HWJSC for the treatment of diseases affecting not only mesoderm-type tissues but also other cell lineages. Impact statement Human Wharton's jelly stem cells (HWJSC) are mesenchymal stem cells that are easy to isolate and handle, and that readily proliferate. Their wide range of differentiation capabilities supports the view that these cells can be considered pluripotent. Accordingly, HWJSC are one of the most promising cell sources for clinical applications in advanced therapies.

The oligomerization mediated by the alanine 397 residue in the transmembrane domain is crucial to sydecan-3 functions

Syndecans are single-pass transmembrane proteins on the cell surface that are involved in various cellular functions. Previously, we reported that both homo- and hetero-form of syndecan dimers affected their functionality. However, little is known about the structural role of the transmembrane domain of syndecan-3. A series of glutathione-S-transferase syndecan-3 proteins showed that syndecan-3 formed SDS-resistant dimers and oligomers. SDS-resistant oligomer formation was barely observed in the syndecan deletion mutants lacking the transmembrane domain. Interestingly, the presence of an alanine 397 residue in the transmembrane domain correlated with SDS-resistant oligomer, and its replacement by phenylalanine (AF mutant) significantly reduced SDS-resistant oligomer formation. Beside the AF mutant significantly reduced syndecan-3 mediated cellular processes such as cell adhesion, migration and neurite outgrowth of SH-SY5Y neuroblastoma. Furthermore, the alanine residue regulated hetero-oligomer formation of syndecan-3, and hetero-oligomer formation significantly reduced syndecan-3-mediated neurite outgrowth of SH-SY5Y cells. Taken together, all these data suggest that syndecan-3 has a specific feature of oligomerization by the transmembrane domain and this oligomerization tendency is crucial for the function of syndecan-3.

Upcycling umbilical cords: bridging regenerative medicine with neonatology

Preterm birth is a major health concern that affects 10% of all worldwide deliveries. Many preterm infants are discharged from the hospital with morbidities that lead to an increased risk for neurodevelopmental impairment, recurrent hospitalizations, and life-long conditions. Unfortunately, the treatment of these conditions is palliative rather than curative, which calls for novel and innovative strategies. Progress in regenerative medicine has offered therapeutic options for many of these conditions. Specifically, human umbilical cord mesenchymal stem cells (MSCs) and cord blood (UCB) cells have shown promise in treating adult-onset diseases. Unlike bone-marrow and embryonic derived stem cells, umbilical cord-derived cells are easily and humanely obtained, have low immunogenicity, and offer the potential of autologous therapy. While there are several studies to uphold the efficacy of umbilical cord MSCs in adult therapies, there remains an unmet need for the investigation of its use in treating neonates. The purpose of this review is to provide a summary of current information on the potential therapeutic benefits and clinical applicability of umbilical cord MSCs and UCB cells. Promising preclinical studies have now led to a research movement that is focusing on cell-based therapies for preterm infants.

Heterostructured Silk-Nanofiber-Reduced Graphene Oxide Composite Scaffold for SH-SY5Y Cell Alignment and Differentiation

Stem cell therapy is promising for treating traumatic injuries of the central nervous system, where a major challenge is to effectively differentiate neural stem cells into neurons with uniaxial alignment. Recently, controlling stem cell fate by modulating biophysical cues (e.g., stiffness, conductivity, and patterns) has emerged as an attractive approach. Herein, we report a new heterostructure composite scaffold to induce cell-oriented growth and enhance the neuronal differentiation of SH-SY5Y cells. The scaffold is composed of aligned electrospinning silk nanofibers coated on reduced graphene paper with high conductivity and good biocompatibility. Our experimental results demonstrate that the composite scaffold can effectively induce the oriented growth and enhance neuronal differentiation of SH-SY5Y cells. Our study develops a novel scaffold for enhancing the differentiation of SH-SY5Y cells into neurons, which holds great potential in the treatment of neurological diseases and injuries.

Umbilical Cord-Derived Mesenchymal Stromal Cells Contribute to Neuroprotection in Neonatal Cortical Neurons Damaged by Oxygen-Glucose Deprivation

Several studies have reported that human umbilical cord-derived mesenchymal stromal cells (UC-MSCs) restore neurological damage in vivo through their secretion of paracrine factors. We previously found that UC-MSCs attenuate brain injury by secreting neurotrophic factors, such as brain-derived neurotrophic factor (BDNF) and hepatocyte growth factor (HGF). However, how these factors contribute to neuroprotection remains unknown. In this study, we aimed to investigate to what extent UC-MSC-derived HGF and BDNF contribute to neuroprotection using a Transwell co-culture system of neonatal cortical neurons damaged by oxygen-glucose deprivation. The influence of HGF and BDNF were determined by investigating neurons in both the presence and absence of UC-MSCs as these cells consistently secrete both factors and can be blocked by neutralizing antibodies. In the co-culture, UC-MSCs significantly improved neuronal injury, as indicated by an increase in immature neuron number, neurite outgrowth, and cell proliferation. Co-culture of damaged neurons with UC-MSCs also exhibited a reduction in the number of neurons displaying signs of apoptosis/necrosis. The neuroprotective actions of UC-MSCs were partially reverted by neutralizing antibodies. Together, our findings reveal that UC-MSC-secreted HGF and BDNF have neuroprotective effects on damaged neurons. Further studies should address the existence of other potential neurotrophic paracrine factors.

The secretome of adipose-derived mesenchymal stem cells protects SH-SY5Y cells from arsenic-induced toxicity, independent of a neuron-like differentiation mechanism

Arsenic exposure through contaminated food, water, and air causes irreversible neural damage and affects millions of people worldwide. Several studies have demonstrated that the secreted factors (secretome) from mesenchymal stromal/stem cells (MSCs) can promote neural recovery after several forms of injury including stroke and neurodegenerative diseases. The present study was conducted to determine if the secretome from adipose-derived MSCs (ADSCs) prevents arsenic damage to SH-SY5Y cells. To this end, human neuroblastoma cells (SH-SY5Y) were pre-treated with the secretome from ADSCs and then challenged with different concentrations of arsenic. After various doses and exposure times, the extent of neuronal injury was assessed using MTT reduction and LDH release assays as well as LIVE/DEAD staining. These data demonstrate that the ADSC secretome protects SH-SY5Y cells from arsenic-induced toxicity. Previous reports have shown that the secretome of MSCs can induce neuroblast differentiation and mature neurons are less susceptible to chemical-induced toxicity. In the current study, proliferation assays, neurite length assessment, and quantitative RT-PCR of differentiation markers indicated that the ADSC secretome does not induce SH-SY5Y differentiation into a mature neuron-like phenotype. In contrast, our results demonstrated that soluble factor(s) in the ADSC secretome enhance SH-SY5Y cell substrate-dependent adhesion. The present study is the first to illustrate that the secretome from ADSCs protects SH-SY5Y cells from arsenic-induced toxicity. Additionally, we showed that protection against arsenic toxicity is not dependent on SH-SY5Y cell differentiation into a mature neuron-like phenotype, but involves soluble factor(s) in the secretome that appear to enhance cell survival by an adhesion-dependent mechanism.

Secretome of Differentiated PC12 Cells Enhances Neuronal Differentiation in Human Mesenchymal Stem Cells Via NGF-Like Mechanism

The secretome-mediated responses over cellular physiology are well documented. Stem cells have been ruling the field of secretomics and its role in regenerative medicine since the past few years. However, the mechanistic aspects of secretome-mediated responses and the role of other cells in this area remain somewhat elusive. Here, we investigate the effects of secretome-enriched conditioned medium (CM) of neuronally differentiated PC12 cells on the neuronal differentiation of human mesenchymal stem cells (hMSCs). The exposure to CM at a ratio of 1:1 (CM: conditioned medium of PC12 cells) led to neuronal induction in hMSCs. This neuronal induction was compared with a parallel group of cells exposed to nerve growth factor (NGF). There was a marked increase in neurite length and expression of neuronal markers (β-III tubulin, neurofilament-M (NF-M), synaptophysin, NeuN in exposed hMSCs). Experimental group co-exposed to NGF and CM showed an additive response via MAPK signaling and directed the cells particularly towards cholinergic lineage. The ability of CM to enhance the neuronal properties of stem cells could aid in their rapid differentiation into neuronal subtypes in case of stem cell transplantation for neuronal injuries, thus broadening the scope of non-stem cell-based applications in the area of secretomics.

Glucose-6-phosphatase-α participates in dopaminergic differentiation

OBJECTIVE

 Induction of dopaminergic (DA) differentiation is a cell-based therapy for Parkinson's disease (PD). Here, we explore the key factors of DA differentiation with a focus on glucose-6-phosphatase (G6Pase), a marker enzyme for the endoplasmic reticulum (ER) associated with cell differentiation.

METHODS

 We cultured SH-SY5Y human neuroblastoma cells, a model system for PD research, and added glial cell-derived neurotrophic factor (GDNF; 25, 50, or 100 ng/ml) to stimulate differentiation. Subsequently, several methods, such as microRNA/mRNA microarrays, quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were used to detect target genes and proteins respectively.

RESULTS

 Light microscopy revealed that 50 ng/ml GDNF most effectively induced DA differentiation. MicroRNA/mRNA microarrays identified that G6PC mRNA was significantly upregulated, which might be influenced by three downregulated microRNAs. Follow-up qRT-PCR results were consistent with the microarray findings, and western blots also supported the results.

DISCUSSION

Taken together, our results demonstrate that G6PC, a subunit of G6Pase, participates in DA differentiation. Our findings may contribute to provide a foundation for the research on the mechanism of DA differentiation as well as cell-based therapy for PD.

Insights into cell-free therapeutic approach: Role of stem cell "soup-ernatant"

Current advances in medicine have revolutionized the field of regenerative medicine dramatically with newly evolved therapies for repair or replacement of degenerating or injured tissues. Stem cells (SCs) can be harvested from different sources for clinical therapeutics, which include fetal tissues, umbilical cord blood, embryos, and adult tissues. SCs can be isolated and differentiated into desired lineages for tissue regeneration and cell replacement therapy. However, several loopholes need to be addressed properly before this can be extended for large-scale therapeutic application. These include a careful approach for patient safety during SC treatments and tolerance of recipients. SC treatments are associated with a number of risk factors and require successful integration and survival of transplanted cells in the desired microenvironment with concurrent tissue regeneration. Recent studies have focused on developing alternatives that can replace the cell-based therapy using paracrine factors. The development of stem "cell free" therapies can be devoted mainly to the use of soluble factors (secretome), extracellular vesicles, and mitochondrial transfer. The present review emphasizes on the paradigms related to the use of SC-based therapeutics and the potential applications of a cell-free approach as an alternative to cell-based therapy in the area of regenerative medicine.

Autologous serum supplement favours in vitro regenerative paracrine factors synthesis

OBJECTIVES

Foetal bovine serum (FBS) is often the serum supplement of choice for in vitro human cell culture. This study compares the effect of FBS and autologous human serum (AuHS) supplement in human peripheral blood mononuclear cell (PBMC) culture to prepare secretome.

MATERIALS AND METHODS

The PBMC (n = 7) were cultured either in RPMI-1640 containing L-glutamine and 50 units/ml Penicillin-Streptomycin (BM) or in BM with either AuHS or FBS. Viability, proliferation and differentiation of PBMC were evaluated. Paracrine factors present in the secretomes (n = 6) were analysed using ProcartaPlex Human Cytokine panel (17 plex). Ingenuity Pathway Analysis (IPA) was performed to predict activation or inhibition of biological functions related to tissue regeneration.

RESULTS

The viability of PBMC that were cultured with FBS supplement was significantly reduced at 96 h compared to those at 0 and 24 h (P < .05). While the reduction of the viability of PBMC that were cultured with AuHS supplement was not significantly different compared to those at 0 and 24 h. The FBS secretomes prepared at 24 h was found to contain significantly higher amount of EGF (P < .05) compared to that in AuHS or BM secretome. The AuHS secretomes contained significantly higher amount of HGF at 24 (P < .05) and 96 h (P < .01), and VEGF-A at 24 h (P < .05) compared to those in the FBS secretomes. SDF-1 was not detected in the FBS secretomes prepared at either 24 or 96 hours. Double immunocytochemical staining revealed a marked increase in co-localization of SDF-1 and its receptor in PBMC that were cultured with AuHS supplement compared to that cultured with FBS supplement.

CONCLUSION

In secretome preparation, AuHS supplement favours synthesis of paracrine factors that are needed for regenerative therapy.

Mesenchymal stem cells secretome-induced axonal outgrowth is mediated by BDNF

Mesenchymal stem cells (MSCs) have been used for cell-based therapies in regenerative medicine, with increasing importance in central and peripheral nervous system repair. However, MSCs grafting present disadvantages, such as, a high number of cells required for transplantation and low survival rate when transplanted into the central nervous system (CNS). In line with this, MSCs secretome which present on its composition a wide range of molecules (neurotrophins, cytokines) and microvesicles, can be a solution to surpass these problems. However, the effect of MSCs secretome in axonal elongation is poorly understood. In this study, we demonstrate that application of MSCs secretome to both rat cortical and hippocampal neurons induces an increase in axonal length. In addition, we show that this growth effect is axonal intrinsic with no contribution from the cell body. To further understand which are the molecules required for secretome-induced axonal outgrowth effect, we depleted brain-derived neurotrophic factor (BDNF) from the secretome. Our results show that in the absence of BDNF, secretome-induced axonal elongation effect is lost and that axons present a reduced axonal growth rate. Altogether, our results demonstrate that MSCs secretome is able to promote axonal outgrowth in CNS neurons and this effect is mediated by BDNF.

Retinoic acid-pretreated Wharton's jelly mesenchymal stem cells in combination with triiodothyronine improve expression of neurotrophic factors in the subventricular zone of the rat ischemic brain injury

Stroke is the consequence of limited blood flow to the brain with no established treatment to reduce the neurological deficits. Focusing on therapeutic protocols in targeting subventricular zone (SVZ) neurogenesis has been investigated recently. This study was designed to evaluate the effects of retinoic acid (RA)-pretreated Wharton's jelly mesenchymal stem cells (WJ-MSCs) in combination with triiodothyronine (T3) in the ischemia stroke model. Male Wistar rats were used to induce focal cerebral ischemia by middle cerebral artery occlusion (MCAO). There were seven groups of six animals: Sham, Ischemic, WJ-MSCs, RA-pretreated WJ-MSCs, T3, WJ-MSCs +T3, and RA-pretreated WJ-MSCs + T3. The treatment was performed at 24 h after ischemia, and animals were sacrificed one week later for assessments of retinoid X receptor β (RXRβ), brain-derived neurotrophic factor (BDNF), Sox2 and nestin in the SVZ. Pro-inflammatory cytokines in sera were measured at days four and seven after ischemia. RXRβ, BDNF, Sox2 and nestin had the significant expressions in gene and protein levels in the treatment groups, compared with the ischemic group, which were more vivid in the RA-pretreated WJ-MSCs + T3 (p ≤ 0.05). The same trend was also resulted for the levels of TNF-α and IL-6 at four days after ischemia (p ≤ 0.05). In conclusion, application of RA-pretreated WJ-MSCs + T3 could be beneficial in exerting better neurotrophic function probably via modulation of pro-inflammatory cytokines.

Paracrine Maturation and Migration of SH-SY5Y Cells by Dental Pulp Stem Cells

Neurological disorders are characterized by neurodegeneration and/or loss of neuronal function, which cannot be adequately repaired by the host. Therefore, there is need for novel treatment options such as cell-based therapies that aim to salvage or reconstitute the lost tissue or that stimulate host repair. The present study aimed to evaluate the paracrine effects of human dental pulp stem cells (hDPSCs) on the migration and neural maturation of human SH-SY5Y neuroblastoma cells. The hDPSC secretome had a significant chemoattractive effect on SH-SY5Y cells as shown by a transwell assay. To evaluate neural maturation, SH-SY5Y cells were first induced toward neuronal cells, after which they were exposed to the hDPSC secretome. In addition, SH-SY5Y cells subjected to the hDPSC secretome showed increased neuritogenesis compared with nonexposed cells. Maturated cells were shown to increase immune reactivity for neuronal markers compared with controls. Ultrastructurally, retinoic acid (RA) signaling and subsequent exposure to the hDPSC secretome induced a gradual rise in metabolic activity and neuronal features such as multivesicular bodies and cytoskeletal elements associated with cellular communication. In addition, electrophysiological recordings of differentiating cells demonstrated a transition toward a neuronal electrophysiological profile based on the maximum tetrodotoxin (TTX)–sensitive, Na+ current. Moreover, conditioned medium (CM)–hDPSC–maturated SH-SY5Y cells developed distinct features including, Cd2+-sensitive currents, which suggests that CM-hDPSC–maturated SH-SY5Y acquired voltage-gated Ca2+ channels. The results reported in this study demonstrate the potential of hDPSCs to support differentiation and recruitment of cells with neuronal precursor characteristics in a paracrine manner. Moreover, this in vitro experimental design showed that the widely used SH-SY5Y cell line can improve and simplify the preclinical in vitro research on the molecular mechanisms of stem cell–mediated neuronal regeneration.

Tumor-homing effect of human mesenchymal stem cells in a TH-MYCN mouse model of neuroblastoma

BACKGROUND

Human mesenchymal stem cells (hMSCs) are multipotent stem-like cells that are reported to have tumor-suppression effects and migration ability toward damaged tissues or tumors. The aim of this study was to analyze the tumor-homing ability of hMSCs and antitumor potency in a transgenic TH-MYCN mouse model of neuroblastoma (NB).

METHODS

hMSCs (3×10⁶) labeled with DiR, a lipophilic near-infrared dye, were intraperitoneally (i.p.) or intravenously (i.v.) administered to the TH-MYCN mice. hMSC in vivo kinetics were assayed using the IVIS® imaging system for 24h after injection. Immunohistochemistry using human CD90 antibody was also performed to confirm the location of hMSCs in various organs and tumors. Furthermore, the survival curve of TH-MYCN mice treated with hMSCs was compared to a control group administered PBS.

RESULTS

i.p. hMSCs were recognized in the tumors of TH-MYCN mice by IVIS. hMSCs were also located inside the tumor tissue. Conversely, most of the i.v. hMSCs were captured by the lungs, and migration into the tumors was not noted. There was no significant difference in the survival between the hMSC and control groups.

CONCLUSION

The present study suggested that hMSCs may be potential tumor-specific therapeutic delivery vehicles in NB according to their homing potential to tumors.

Mesenchymal stem/stromal cells-a key mediator for regeneration after perinatal morbidity?

Perinatal complications in both term- and preterm-born infants are a leading cause of neonatal morbidities and mortality. Infants face different challenges in the neonatal intensive care unit with long-term morbidities such as perinatal brain injury and bronchopulmonary dysplasia being particularly devastating. While advances in perinatal medicine have improved our understanding of the pathogenesis, effective therapies to prevent and/or reduce the severity of these disorders are still lacking. The potential of mesenchymal stem/stromal cell (MSC) therapy has emerged during the last two decades, and an increasing effort is conducted to address brain- and lung-related morbidities in neonates at risk. Various studies support the notion that MSCs have protective effects. MSCs are an easy source and may be readily available after birth in a clinical setting. MSCs' mechanisms of action are diverse, including migration and homing, release of growth factors and immunomodulation, and the potential to replace injured cells. Here, we review the pathophysiology of perinatally acquired brain and lung injuries and focus on MSCs as potential candidates for therapeutic strategies summarizing preclinical and clinical evidence.

Canine mesenchymal stem cells are neurotrophic and angiogenic: An in vitro assessment of their paracrine activity

Mesenchymal stem cells (MSCs) have been used in cell replacement therapies for connective tissue damage, but also can stimulate wound healing through paracrine activity. In order to further understand the potential use of MSCs to treat dogs with neurological disorders, this study examined the paracrine action of adipose-derived canine MSCs on neuronal and endothelial cell models. The culture-expanded MSCs exhibited a MSC phenotype according to plastic adherence, cell morphology, CD profiling and differentiation potential along mesenchymal lineages. Treating the SH-SY5Y neuronal cell line with serum-free MSC culture-conditioned medium (MSC CM) significantly increased SH-SY5Y cell proliferation (P <0.01), neurite outgrowth (P = 0.0055) and immunopositivity for the neuronal marker βIII-tubulin (P = 0.0002). Treatment of the EA.hy926 endothelial cell line with MSC CM significantly increased the rate of wound closure in endothelial cell scratch wound assays (P = 0.0409), which was associated with significantly increased endothelial cell proliferation (P <0.05) and migration (P = 0.0001). Furthermore, canine MSC CM induced endothelial tubule formation in EA.hy926 cells in a soluble basement membrane matrix. Hence, this study has demonstrated that adipose-derived canine MSC CM stimulated neuronal and endothelial cells probably through the paracrine activity of MSC-secreted factors. This supports the use of canine MSC transplants or their secreted products in the clinical treatment of dogs with neurological disorders and provides some insight into possible mechanisms of action.

Oxidative stress under ambient and physiological oxygen tension in tissue culture

Oxygen (O₂) levels range from 2-9% in vivo. However, cell culture experiments are performed at atmospheric O₂ levels (21%). Oxidative stress due to generation of reactive oxygen species (ROS) in cells cultured at higher than physiological levels is implicated in multitude of deleterious effects including DNA damage, genomic instability and senescence. In addition, oxidative stress activates redox sensitive transcription factors related to inflammatory signaling and apoptotic signaling. Furthermore, several chromatin-modifying enzymes are affected by ROS, potentially impacting epigenetic regulation of gene expression. While primary cells are cultured at lower O₂ levels due to their inability to grow at higher O₂, the immortalized cells, which display no such apparent growth difficulties, are typically cultured at 21% O₂. This review will provide an overview of issues associated with increased oxygen levels in in vitro cell culture and point out the benefits of using lower levels of oxygen tension even for immortalized cells.