Comparison of phenotypic markers and neural differentiation potential of multipotent adult progenitor cells and mesenchymal stem cells

AIM: To compare the phenotypic and neural differentiation potential of human bone marrow derived multipotent adult progenitor cells (MAPC) and mesenchymal stem cells (MSC). METHODS: Cultures of MAPC and MSC were established in parallel from same samples of human bone marrow (n = 5). Both stem cell types were evaluated for expression of pluripotency markers including Oct-4 and Nanog by immunocytochemistry and reversetranscription polymerase chain reaction (RT-PCR) and expression of standard mesenchymal markers including CD14, CD34, CD44, CD45, CD73, CD90, CD105 andhuman leukocyte antigen (HLA)-ABC by flow cytometry. After treatment with neural induction medium both MAPC and MSC were evaluated for expression of neural proteins [neuronal filament-200 (NF-200) and glial fibrillar acidic protein (GFAP)] by immunocytochemistry and Western blotting and neural genes [NF-200, GFAP, Tau, microtubule-associated protein (MAP)-1B, MAP-2, neuron-specific enolase (NSE) and oligodendrocyte-1 (Olig-1)] by quantitative real-time-PCR. RESULTS: MAPC had small trigonal shaped while MSC had elongated spindle-shaped morphology. The MAPC expressed Oct-4 and Nanog both at gene and protein levels, whereas MSC were negative for these pluripotent markers. MAPC were negative for HLA-ABC while MSC had high expression of HLA-ABC. In addition, MAPC as compared to MSC had significantly lower expression of CD44 (36.56% ± 1.92% vs 98.23% ± 0.51%), CD73 (15.11% ± 2.24% vs 98.53% ± 2.22%) and CD105 (13.81% ± 3.82%vs 95.12% ± 5.65%) (P < 0.001, for all) MAPC cultures compared to MSC cultures treated with neural induction medium had significantly higher fold change expression of NF-200 (0.64), GFAP (0.52), Tau (0.59), MAP-2 (0.72), Olig-1 (0.18) and NSE (0.29) proteins (P < 0.01 for Olig-1 and P < 0.001 for rest) as well as higher fold change expression of genes of NF-200 (1.34),GFAP (1.12),Tau (1.08),MAP-1B (0.92), MAP-2 (1.14) andNSE (0.4) (P < 0.001 for all). CONCLUSION: MAPC can be differentially characterized from MSC as Oct-4 and Nanog positive stem cells with no expression of HLA-ABC and low expression of mesenchymal markers CD44, CD73 and CD105 and when compared to MSC they possess greater predilection for differentiation into neuro-ectodermal lineage.

Transplantation of placenta-derived mesenchymal stem cell-induced neural stem cells to treat spinal cord injury

Because of their strong proliferative capacity and multi-potency, placenta-derived mesenchymal stem cells have gained interest as a cell source in the field of nerve damage repair. In the present study, human placenta-derived mesenchymal stem ceils were induced to differentiate into neural stem cells, which were then transplanted into the spinal cord after local spinal cord injury in rats. The motor functional recovery and pathological changes in the injured spinal cord were observed for 3 successive weeks. The results showed that human placenta-derived mesenchymal stem cells can differentiate into neuron-like cells and that induced neural stem cells contribute to the restoration of injured spinal cord without causing transplant rejection. Thus, these cells promote the recovery of motor and sensory functions in a rat model of spinal cord injury. Therefore, human placenta-derived mesenchymal stem cells may be useful as seed cells during the repair of spinal cord injury.

Multipotent stromal cells stimulate liver regeneration by influencing the macrophage polarization in rat

AIM To investigate the influence of the umbilical cordderived multipotent stromal cells(MSCs) on recovery of the liver after the subtotal resection, that is, removal of 80% of the organ mass, a renowned model of the small-for-size liver remnant syndrome. METHODS The MSCs were obtained from the intervascular tissue of umbilical cords, dissected from rat fetuses, by the explant culture technique. The vital labeling of MSCs with РКН26 was carried out on the 3 rd passage. The subtotal resection was performed on male Sprague-Dawley rats. The experimental group animals received a transplant 106 MSCs infused into the spleen. Hepatocyte proliferation was assessed by counting of either mitotic figures or Ki67-positive cells in microscopic images. MSC differentiation was assessed with antibodies to hepatocyte-specific marker cytokeratin 18(CK18), cholangiocyte-specific protein CK19, smooth muscle cell-specific protein α-SMA, the endothelial cell marker CD31, or the active fibroblast marker FAPα. Total macrophages of the liver were selectively stained in cryosections incubated with antiCD68 antibodies(1:100, Abcam), while the M2 a and M2 c macrophage populations were selectively stained with anti-CD206 antibodies. Expression of interleukin and growth factor genes was evaluated with PCR-RT.RESULTS Intrasplenic allogeneic transplantation of the umbilical cord-derived multipotent stromal cells stimulates reparative processes within the residual liver tissue after subtotal resection(removal of 80% of the organ mass), as indicated by increased rates of hepatocyte proliferation and accelerated organ mass recovery. These effects may result from paracrine influence of the transplanted cells on the resident macrophage population of the liver. The transplantation favors polarization of macrophages to M2 phenotype(the M2-polarized macrophages specifically express CD206; they are known to suppress inflammation and support tissue repair). No differentiation of the transplanted cells into any of the liver cell types have been observed in the study.CONCLUSION We found no direct evidence for the paracrine effect of MSCs on liver regeneration after the subtotal liver resection in rats. However, the paracrine mechanism of the therapeutic activity of transplanted MSC is indirectly indicated by a decrease in the total number of CD68 + macrophages and an increase in the proportion of M2 pro-repair macrophages in the regenerating liver as compared to animals in which the transplantation was only mimicked.

Neural differentiation of human placenta-derived mesenchymal stem cells following neural cell co-culture

We induced human placenta-derived mesenchymal stem cells （hPMSCs） to differentiate into neural cells by adding chemical reagents, despite the fact that toxic chemicals induce cell shrinkage or cytoskeletal formation, which does not represent a proper cell differentiation process. The present study established a co-culture system with hPMSCs and neural cells and analyzed the influence of neural cells on hPMSC differentiation in a co-culture system, hPMSCs were isolated and purified from human full-term placenta using collagenase digestion. Fetal neural cells were co-cultured with hPMSCs for 48 hours using the Transwell co-culture system, hPMSCs co-cultured with neural cells exhibited a slender morphology with a filament. After 96 hours, hPMSCs expressed neuron-specific enolase, which suggested that co-culture of hPMSCs and neural cells induced neural differentiation of hPMSCs.

Hierarchy of mesenchymal stem cells: Comparison of multipotentmesenchymal stromal cells with fibroblast colony forming units

The organization of the compartment of mesenchymal stem cells is still obscure. Two types of human stromal precursor cells are known. Both of them are analyzed in in vitro system: mesenchymal multipotent stromal cells (MMSC) and fibroblast colony forming units (CFU-F). The aim of this study was to compare the main characteristics of MMSC and CFU-F derived from the bone marrow of 24 healthy donors. Growth and differentiation parameters, as well as relative expression levels of different genes were analyzed in MMSC and CFU-F. MMSC were cultivated for 5 passages. CFU-F concentration was determined for each bone marrow sample. The data obtained demonstrated the heterogeneity and hierarchical organization of both studied populations of stromal precursor cells-MMSC and CFU-F. These two types of stromal precursor cells turned to be different in most parameters studied. Altogether MMSC seemed to be more immature cells than CFU-F and took up the higher position in hierarchical tree of mesenchymal stem cells. The rate of differentiation and proliferative potential decreased with the donor’s age in both populations MMSC and CFU-F.

A study on the activity of dermal multipotent stem cells in initiation of wound repair

Background: Wound healing is a process of cell-cell interaction and cell-extracellular matrix interaction. Dermal multipotent stem cells (dMSCs) have the abilities to promote survival and wound healing, but the potential function of dMSCs in wound healing, particularly in the initiation of wound repair, has not been fully understood. Methods: dMSCs and fibroblasts were isolated from neonatal rat dermis and were further purified and expanded. The cell cycles were determined with flow cytometry, while the radiosensitivity was measured by MTT assay. Rats were wounded with a 7-cm incision on the back skin and the wound fluids were collected by inserting two pieces of sterile polyvinyl alcohol sponge (1 cmin diameter and0.4 cmin thickness) subcutaneously into the dorsum of each rat through the midline of incision on the 1st, 2nd, 3rd and 4th day after incision. The effects of wound fluids on the proliferation of dMSCs and fibroblasts were measured with MTT assays. dMSC’s abilities of adhesion and attachment and its migration in response to wound fluids collected on the 1st day after incision were explored by measuring the percentage of floating cells and the cells migrated into wounding area in vitro, respectively. Results: The isolated dMSCs were morphologically homogenous and highly proliferative. Most of the cultured dMSCs were quiescent with few apoptotic cells. Compared with fibroblasts, dMSCs were more sensitive to radiation and more proliferative in response to wound fluids, especially to the wound fluids collected on the 1st day after wounding. Moreover, their abilities to attach, adhere and migrate were significantly enhanced with the early-phase wound fluids. Conclusions: As primitive stem cells, dMSCs are very responsive to wound fluids, which suggests dMSCs’ important role in wound healing, especially in initiating wound repair.

Uric acid promotes neuronal differentiation of human placenta-derived mesenchymal stem cells in a time- and concentration-dependent manner

Uric acid is an important, naturally occurring serum antioxidant. The present study investigates the use of uric acid for promoting proliferation and neuronal differentiation of mesenchymal stem cells derived from human placenta tissue. Human placenta-derived mesenchymal stem cells were pre-induced in the presence of either 0, 0.2, 0.4 or 0.8 mM uric acid in combination with 1 mM β-mercaptoethanol for 24 hours, followed by exposure to identical uric acid concentrations and 5 mM β-mercaptoethanol for 6 and 10 hours. Cells developed a neuronal-like morphology, with formation of interconnected process extensions, typical of neural cells. Immunocytochemistry and immunofluorescence staining showed neuron specific enolase positive cells were present in each group except the control group. A greater number of neuron specific enolase positive cells were observed in 0.8 mM uric acid in combination with 5 mM β-mercaptoethanol at 10 hours. After 24 hours of induction, Nissl bodies were detected in the cytoplasm of all differentiated cell groups except the control group and Nissl body numbers were greatest in human placenta-derived mesenchymal stem cells grown in the presence of 0.8 mM uric acid and 5 mM β-mercaptoethanol. These results suggest uric acid accelerates differentiation of human placenta-derived mesenchymal stem cells into neuronal-like cells in a time-and concentration-dependent manner.

Skinny people serum factors promote the differentiation of multipotent stem cells into brown adipose tissue

The original study by Alessio et al reported that skinny people (SP) serum canpromote the formation of brown adipocytes, but not the differentiation of whiteadipocytes. This finding may explain why SP do not often become obese, despiteconsuming more calories than the body needs. More importantly, theydemonstrated that circulating factors in SP serum can promote the expression ofUCP-1 protein, thereby reducing fat accumulation. In this study, only male serumsamples were evaluated to avoid the interference of sex hormones in experiments,but adult males also synthesize estrogen, which is produced by the cells of thetestes. At the same time, adult females secrete androgens, and females synthesizeandrogens that are mainly produced by the adrenal cortex. We believe that theapproach of excluding sex hormone interference by sex selection alone may beflawed, so we comment on the article and debate the statistical analysis of thearticle.

Identification of tumorigenic risk genes in human placenta-derived mesenchymal stem cells treated with 3-methylcholanthrene

Mesenchymal stem cells(MSCs)capable of tumour topotaxis have been served as cellular vehicles to deliver anti-tumour agents.As cellular components of the tumour microenvironment,MSCs also affect tumour progression.However,the tumour transformation-related genes of MSCs remain unclear since either tumorigenic or tumour suppressor effects within these cells have been researched.Hence,we aimed to identify potential biomarkers indicative of tumorigenic risk by RNA-seq analysis of human placenta tissue-derived MSCs(hPTMSCs)exposed to the carcinogenic agent,3-methylcholanthrene(3-MC).Twenty-nine tumour transformation-related genes and three pluripotency-related genes were appraised as differentially expressed genes(DEGs)in hPTMSCs.Overexpression of sfrp1 led to reduced cell viability,migration,and colony formation in A549.In contrast,the overexpression of ptgs2 exerted the opposite effect.These results indicate that A549 cells with high ptgs2 expression but low sfrp1 expression may have a more potential tumorigenic capacity.Taken together,this study suggests that ptgs2 and sfrp1 may be tumorigenic risk genes.

Effect of acoustic pulses and EHF radiation on multipotent marrow stromal cells in tissue engineering constructs

In this paper,we studied the effects of physical factors,such as,acoustic pulses of laser-induced hydrodynamics(ALIH)and extremely-high frequencies(EHF)radiation,on the formation of heterotopic bone marrow organs.A suspension of precipitated bone marrow cells from CBA mice were exposed to ALIH pulses and EHF radiation separately and in their com bination tissue engineering constructs,presenting gelatin sponges 2 by 2 by 2 mm in size containing 10^(7)nucleated bone marrow cells,were exposed to physical factors and were implanted under the renal capsules of syngeneic mice.The newly formed hematopoietic organs were examined in three and five months later after treatment.The five months old transplants were bigger in size than the three months old transplants.The number of hematopoietic cells in the rest of the groups increased during this period by a factor from 3 to 10,the increase being as high as 20-fold in the:ALH+EHF group.Maximal concentration of multipotent stromal cells(MSCs)was in the EHF+ALIH,and minimal concentration was in the ALIH+EHF.The accumulation rate of bone capsule weight was highest for the transplants of EHF+ALIH and ALIH-sponge groups during the first three months.These data showed that the combined impact of the EHF+ALIH on MSCs is the most effective for the formation of bone marrow transplantation.

Immunophenotypic characteristics of multipotent mesenchymal stromal cells that affect the efficacy of their use in the prevention of acute graft vs host disease

BACKGROUND Multipotent mesenchymal stromal cells(MSCs)are widely used in the clinic due to their unique properties,namely,their ability to differentiate in all mesenchymal directions and their immunomodulatory activity.Healthy donor MSCs were used to prevent the development of acute graft vs host disease(GVHD)after allogeneic bone marrow transplantation(allo-BMT).The administration of MSCs to patients was not always effective.The MSCs obtained from different donors have individual characteristics.The differences between MSC samples may affect their clinical efficacy.AIM To study the differences between effective and ineffective MSCs.METHODS MSCs derived from the bone marrow of a hematopoietic stem cells donor were injected intravenously into allo-BMT recipients for GVHD prophylaxis at the moment of blood cell reconstitution.Aliquots of 52 MSC samples that were administered to patients were examined,and the same cells were cultured in the presence of peripheral blood mononuclear cells(PBMCs)from a third-party donor or treated with the pro-inflammatory cytokines IL-1β,IFN and TNF.Flow cytometry revealed the immunophenotype of the nontreated MSCs,the MSCs cocultured with PBMCs for 4 d and the MSCs exposed to cytokines.The proportions of CD25-,CD146-,CD69-,HLA-DR-and PD-1-positive CD4+and CD8+cells and the distribution of various effector and memory cell subpopulations in the PBMCs cocultured with the MSCs were also determined.RESULTS Differences in the immunophenotypes of effective and ineffective MSCs were observed.In the effective samples,the mean fluorescence intensity(MFI)of HLAABC,HLA-DR,CD105,and CD146 was significantly higher.After MSCs were treated with IFN or cocultured with PBMCs,the HLA-ABC,HLA-DR,CD90 and CD54 MFI showed a stronger increase in the effective MSCs,which indicated an increase in the immunomodulatory activity of these cells.When PBMCs were cocultured with effective MSCs,the proportions of CD4+and CD8+central memory cells significantly decreased,and the proportion of CD8+CD146+lymphocytes increased more than in the subpopulations of lymphocytes cocultured with MSC samples that were ineffective in the prevention of GVHD;in addition,the proportion of CD8+effector memory lymphocytes decreased in the PBMCs cocultured with the effective MSC samples but increased in the PBMCs cocultured with the ineffective MSC samples.The proportion of CD4+CD146+lymphocytes increased only when cocultured with the inefficient samples.CONCLUSION For the first time,differences were observed between MSC samples that were effective for GVHD prophylaxis and those that were ineffective.Thus,it was shown that the immunomodulatory activity of MSCs depends on the individual characteristics of the MSC population.

New insights for pelvic radiation disease treatment:Multipotent stromal cell is a promise mainstay treatment for the restoration of abdominopelvic severe chronic damages induced by radiotherapy

Radiotherapy may induce irreversible damage on healthy tissues surrounding the tumor. It has been reported that the majority of patients receiving pelvic radiation therapy show early or late tissue reactions of graded severity as radiotherapy affects not only the targeted tumor cells but also the surrounding healthy tissues. The late adverse effects of pelvic radiotherapy concern 5% to 10% of them, which could be life threatening. However, a clear medical consensus concerning the clinical management of such healthy tissue sequelae does not exist. Although no pharmacologic interventions have yet been proven to efficiently mitigate radiotherapy severe side effects, few preclinical researches show the potential of combined and sequential pharmacological treatments to prevent the onset of tissue damage. Our group has demonstrated in preclinical animal models that systemic mesenchymal stromal cell(MSC) injection is a promising approach for the medical management of gastrointestinal disorder after irradiation. We have shown that MSCs migrate to damaged tissues and restore gut functions after irradiation.We carefully studied side effects of stem cell injection for further application in patients. We have shown that clinical status of four patients suffering from severe pelvic side effects resulting from an over-dosage was improved following MSC injection in a compationnal situation.

Hypoxic pre-conditioned adipose-derived stem/progenitor cells embedded in fibrin conduits promote peripheral nerve regeneration in a sciatic nerve graft model

Recent results emphasize the supportive effects of adipose-derived multipotent stem/progenitor cells(ADSPCs)in peripheral nerve recovery.Cultivation under hypoxia is considered to enhance the release of the regenerative potential of ADSPCs.This study aimed to examine whether peripheral nerve regeneration in a rat model of autologous sciatic nerve graft benefits from an additional custom-made fibrin conduit seeded with hypoxic pre-conditioned(2%oxygen for 72 hours)autologous ADSPCs(n=9).This treatment mode was compared with three others:fibrin conduit seeded with ADSPCs cultivated under normoxic conditions(n=9);non-cell-carrying conduit(n=9);and nerve autograft only(n=9).A 16-week follow-up included functional testing(sciatic functional index and static sciatic index)as well as postmortem muscle mass analyses and morphometric nerve evaluations(histology,g-ratio,axon density,and diameter).At 8 weeks,the hypoxic pre-conditioned group achieved significantly higher sciatic functional index/static sciatic index scores than the other three groups,indicating faster functional regeneration.Furthermore,histologic evaluation showed significantly increased axon outgrowth/branching,axon density,remyelination,and a reduced relative connective tissue area.Hypoxic pre-conditioned ADSPCs seeded in fibrin conduits are a promising adjunct to current nerve autografts.Further studies are needed to understand the underlying cellular mechanism and to investigate a potential application in clinical practice.

Long non-coding RNA SNHG16 promotes human placenta-derived mesenchymal stem cell proliferation capacity through the PI3K/AKT pathway under hypoxia

BACKGROUND The effect of hypoxia on mesenchymal stem cells(MSCs)is an emerging topic in MSC biology.Although long non-coding RNAs(lncRNAs)and messenger RNAs(mRNAs)are reported to play a critical role in regulating the biological characteristics of MSCs,their specific expression and co-expression profiles in human placenta-derived MSCs(hP-MSCs)under hypoxia and the underlying mechanisms of lncRNAs in hP-MSC biology are unknown.AIM To reveal the specific expression profiles of lncRNAs in hP-MSCs under hypoxia and initially explored the possible mechanism of lncRNAs on hP-MSC biology.METHODS Here,we used a multigas incubator(92.5%N_(2),5%CO_(2),and 2.5%O_(2))to mimic the potential of hP-MSCs.RNA sequencing technology was applied to identify the exact expression profiles of lncRNAs and mRNAs under hypoxia.RESULTS We identified 289 differentially expressed lncRNAs and 240 differentially expressed mRNAs between the hypoxia and normoxia groups.Among them,the lncRNA SNHG16 was upregulated under hypoxia,which was also validated by reverse transcription-polymerase chain reaction.SNHG16 was confirmed to affect hP-MSC proliferation rates using a SNHG16 knockdown model.SNHG16 overexpression could significantly enhance the proliferation capacity of hP-MSCs,activate the PI3K/AKT pathway,and upregulate the expression of cell cycle-related proteins.CONCLUSION Our results revealed the specific expression characteristics of lncRNAs and mRNAs in hypoxiacultured hP-MSCs and that lncRNA SNHG16 can promote hP-MSC proliferation through the PI3K/AKT pathway.

WJSC 6^(th) Anniversary Special Issues(2):Mesenchymal stem cells Umbilical cord-derived mesenchymal stem cells:Their advantages and potential clinical utility

Human umbilical cord(UC)is a promising source of mesenchymal stem cells(MSCs).Apart from their prominent advantages,such as a painless collection procedure and faster self-renewal,UC-MSCs have shown the ability to differentiate into three germ layers,to accumulate in damaged tissue or inflamed regions,to promote tissue repair,and to modulate immune response.There are diverse protocols and culture methods for the isolation of MSCs from the various compartments of UC,such as Wharton’s jelly,vein,arteries,UC lining and subamnion and perivascular regions.In this review,we give a brief introduction to various compartments of UC as a source of MSCs and emphasize the potential clinical utility of UC-MSCs for regenerative medicine and immunotherapy.

Long non-coding RNA: The functional regulator of mesenchymal stem cells

Mesenchymal stem cells(MSCs) are a subset of multipotent stroma cells residing in various tissues of the body. Apart from supporting the hematopoietic stem cell niche, MSCs possess strong immunoregulatory ability and multiple differentiation potentials. These powerful capacities allow the extensive application of MSCs in clinical practice as an effective treatment for diseases.Therefore, illuminating the functional mechanism of MSCs will help to improve their curative effect and promote their clinical use. Long noncoding RNA(LncRNA) is a novel class of noncoding RNA longer than 200 nt. Recently,multiple studies have demonstrated that LncRNA is widely involved in growth and development through controlling the fate of cells, including MSCs. In this review, we highlight the role of LncRNA in regulating the functions of MSCs and discuss their participation in the pathogenesis of diseases and clinical use in diagnosis and treatment.

Sox2 transcription network acts as a molecular switch to regulate properties of neural stem cells

Neural stem cells(NSCs) contribute to ontogeny by producing neurons at the appropriate time and location. Neurogenesis from NSCs is also involved in various biological functions in adults. Thus, NSCs continue to exert their effects throughout the lifespan of the organism. The mechanism regulating the core functional properties of NSCs is governed by intra- and extracellular signals. Among the transcription factors that serve as molecular switches, Sox2 is considered a key factor in NSCs. Sox2 forms a core network with partner factors, thereby functioning as a molecular switch. This review discusses how the network of Sox2 partner and target genes illustrates the molecular characteristics of the mechanism underlying the self-renewal and multipotency of NSCs.

Allogenic banking of dental pulp stem cells for innovative therapeutics

Medical research in regenerative medicine and cellbased therapy has brought encouraging perspectives for the use of stem cells in clinical trials. Multiple types of stem cells, from progenitors to pluripotent stem cells, have been investigated. Among these, dental pulp stem cells(DPSCs) are mesenchymal multipotent cells coming from the dental pulp, which is the soft tissue within teeth. They represent an interesting adult stem cell source because they are recovered in large amount in dental pulps with non-invasive techniques compared to other adult stem cell sources. DPSCs can be obtained from discarded teeth, especially wisdom teeth extracted for orthodontic reasons. To shift from promising preclinical results to therapeutic applications to human, DPSCs must be prepared in clinical grade lots and transformed into advanced therapy medicinal products(ATMP). As the production of patient-specific stem cells is costly and time-consuming, allogenic biobanking of clinical grade human leukocyte antigen(HLA)-typed DPSC lines provides efficient innovative therapeutic products. DPSC biobanks represent industrial and therapeutic innovations by using discarded biological tissues(dental pulps) as a source of mesenchymal stem cells to produce and store, in good manufacturing practice(GMP) conditions, DPSC therapeutic batches. In this review, we discuss about the challenges to transfer biological samples from a donor to HLA-typed DPSC therapeutic lots, following regulations, GMP guidelines and ethical principles. We also present some clinical applications, for which there is no efficient therapeutics so far, but that DPSCs-based ATMP could potentially treat.

Applicability of tooth derived stem cells in neural regeneration

Within the nervous system, regeneration is limited, and this is due to the small amount of neural stem cells, the inhibitory origin of the stem cell niche and often to the development of a scar which constitutes a mechanical barrier for the regeneration. Regarding these aspects, many efforts have been done in the re- search of a cell component that combined with scaffolds and growth factors could be suitable for nervous regeneration in regenerative medicine approaches. Autologous mesenchymal stem cells represent nowa- days the ideal candidate for this aim, thank to their multipotency and to their amount inside adult tissues. However, issues in their harvesting, through the use of invasive techniques, and problems involved in their ageing, require the research of new autologous sources. To this purpose, the recent discovery of a stem cells component in teeth, and which derive from neural crest cells, has came to the light the possibility of using dental stem cells in nervous system regeneration. In this work, in order to give guidelines on the use of dental stem cells for neural regeneration, we briefly introduce the concepts of regeneration and regenerative medicine, we then focus the attention on odontogenesis, which involves the formation and the presence of a stem component in different parts of teeth, and finally we describe some experimental approaches which are exploiting dental stem cells for neural studies.

Neural regeneration by regionally induced stem cells within poststroke brains: Novel therapy perspectives for stroke patients

Ischemic stroke is a critical disease which causes serious neurological functional loss such as paresis. Hope for novel therapies is based on the increasing evidence of the presence of stem cell populations in the central nervous system (CNS) and the development of stem-cell-based therapies for stroke patients. Although mesenchymal stem cells (MSCs) represented initially a promising cell source, only a few transplanted MSCs were present near the injured areas of the CNS. Thus, regional stem cells that are present and/or induced in the CNS may be ideal when considering a treatment following ischemic stroke. In this context, we have recently showed that injury/ischemia-induced neural stem/progenitor cells (iNSPCs) and injury/ischemia-induced multipotent stem cells (iSCs) are present within post-stroke human brains and post-stroke mouse brains. This indicates that iNSPCs/iSCs could be developed for clinical applications treating patients with stroke. The present study introduces the traits of mouse and human iNSPCs, with a focus on the future perspective for CNS regenerative therapies using novel iNSPCs/iSCs.