One-step cell biomanufacturing platform:porous gelatin microcarrier beads promote human embryonic stem cell-derived midbrain dopaminergic progenitor cell differentiation in vitro and survival after transplantation in vivo

Numerous studies have shown that cell replacement therapy can replenish lost cells and rebuild neural circuitry in animal models of Parkinson’s disease.Transplantation of midbrain dopaminergic progenitor cells is a promising treatment for Parkinson’s disease.However,transplanted cells can be injured by mechanical damage during handling and by changes in the transplantation niche.Here,we developed a one-step biomanufacturing platform that uses small-aperture gelatin microcarriers to produce beads carrying midbrain dopaminergic progenitor cells.These beads allow midbrain dopaminergic progenitor cell differentiation and cryopreservation without digestion,effectively maintaining axonal integrity in vitro.Importantly,midbrain dopaminergic progenitor cell bead grafts showed increased survival and only mild immunoreactivity in vivo compared with suspended midbrain dopaminergic progenitor cell grafts.Overall,our findings show that these midbrain dopaminergic progenitor cell beads enhance the effectiveness of neuronal cell transplantation.

Niosome-encapsulated auraptene reduced the mRNA expression of VEGF-A and PDGFs genes in human retinaderived RPE cell line

AIM:To evaluate the effect of auraptene(AUR)treatment in forms of free and encapsulated in niosome nanoparticles by investigating the mRNA expression level of vascular endothelium growth factor(VEGF)-A and platelet-derived growth factors(PDGFs)in human retinal pigment epithelium(RPE)cell line.METHODS:Niosome nanocarriers were produced using two surfactants Span 60 and Tween 80.RPE cell line was treated with both free AUR and niosome-encapsulated.Optimum dosage of treatments was calculated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay.Expression of VEGF-A and PDGF-A,PDGF-B,PDGF-C,PDGF-D genes was measured after total RNA extraction and cDNA synthesis,using real-time polymerase chain reaction(RT-PCR).RESULTS:The highest entrapment efficiency(EE)was achieved by Span 60:cholesterol(1:1)with 64.3%.The half maximal inhibitory concentration(IC50)of free and niosome-encapsulated AUR were 38.5 and 27.78µg/mL,respectively.Release study revealed that niosomal AUR had more gradual delivery to the cells.RT-PCR results showed reduced expression levels of VEGF-A,PDGF-A,PDGF-B,PDGF-C,and PDGF-D after treatment with both free and niosomal AUR.CONCLUSION:Niosomal formulation of Span 60:cholesterol(1:1)is an effective drug delivery approach to transfer AUR to RPE cells.VEGF-A,PDGF-A,PDGF-B,PDGF-C,and PDGF-D are four angiogenic factors,inhibiting which by niosomal AUR may be effective in age-related macular degeneration.

Impact of umbelliprenin-containing niosome nanoparticles on VEGF-A and CTGF genes expression in retinal pigment epithelium cells

AIM:To investigate the impact of niosome nanoparticles carrying umbelliprenin(UMB),an anti-angiogenic and anti-inflammatory plant compound,on the expression of vascular endothelial growth factor(VEGF-A)and connective tissue growth factor(CTGF)genes in a human retinal pigment epithelium(RPE)-like retina-derived cell line.METHODS:UMB-containing niosomes were created,optimized,and characterized.RPE-like cells were treated with free UMB and UMB-containing niosomes.The IC_(50)values of the treatments were determined using an MTT assay.Gene expression of VEGF-A and CTGF was evaluated using real-time polymerase chain reaction after RNA extraction and cDNA synthesis.Niosomes’characteristics,including drug entrapment efficiency,size,dispersion index,and zeta potential were assessed.Free UMB had an IC_(50)of 96.2μg/mL,while UMB-containing niosomes had an IC_(50)of 25μg/mL.RESULTS:Treatment with UMB-containing niosomes and free UMB resulted in a significant reduction in VEGF-A expression compared to control cells(P=0.001).Additionally,UMB-containing niosomes demonstrated a significant reduction in CTGF expression compared to control cells(P=0.05).However,there was no significant reduction in the expression of both genes in cells treated with free UMB.CONCLUSION:Both free UMB and niosome-encapsulated UMB inhibits VEGF-A and CTGF genes expression.However,the latter demonstrates significantly greater efficacy,potentially due to the lower UMB dosage and gradual delivery.These findings have implications for anti-angiogenesis therapeutic approaches targeting age-related macular degeneration.

0Adipose-derived stem cells: Implications in tissue regeneration

Adipose-derived stem cells(ASCs) are mesenchymal stem cells(MSCs) that are obtained from abundant adipose tissue, adherent on plastic culture flasks, can be expanded in vitro, and have the capacity to differ-entiate into multiple cell lineages. Unlike bone marrow-derived MSCs, ASCs can be obtained from abundant adipose tissue by a minimally invasive procedure, which results in a high number of cells. Therefore, ASCs are promising for regenerating tissues and organs dam-aged by injury and diseases. This article reviews the implications of ASCs in tissue regeneration.

Upregulation of FIk-1 by bFGF via the ERK pathway is essential for VEGF-mediated promotion of neural stem cell proliferation

神经干细胞(NSC ) 为胚胎的大脑开发和神经发生组成细胞的基础。这个过程被 NSC 壁龛包括邻居房间例如调整脉管并且 glial 房间。自从脉管并且 glial 房间分泌脉管的 endothelial 生长因素(VEGF ) 和基本成纤维细胞生长因素(bFGF ) ，我们用被区分开来与老鼠的将近同类的 NSC 估计了 VEGF 和 bFGF onNSC 增长的效果胚胎的干细胞。VEGF 独自没有任何重要效果。当 bFGF 被增加时，然而，以一种剂量依赖者方式的 VEGF stimulatedNSC 增长，和这刺激被 ZM323881 禁止， aVEGF 受体(Flk-1 ) 特定的禁止者。有趣地， ZM323881 也当外长的 VEGF 不在时禁止了细胞增殖，建议 VEGF autocrine 起在 NSC 的增长的一个作用。NSC 增长上的 VEGF 的 stimulatory 效果取决于 bFGF，它由于 Flk-1 的表示起来的事实是可能的经由 ERK1/2.Collectively 的磷酸化由 bFGF 调整了，这研究可以提供卓见进微环境壁龛信号由调整 NSC 的机制。

A multi-channel collagen scaffold loaded with neural stem cells for the repair of spinal cord injury

Collagen scaffolds possess a three-dimensional porous structure that provides sufficient space for cell growth and proliferation,the passage of nutrients and oxygen,and the discharge of metabolites.In this study,a porous collagen scaffold with axially-aligned luminal conduits was prepared.In vitro biocompatibility analysis of the collagen scaffold revealed that it enhances the activity of neural stem cells and promotes cell extension,without affecting cell differentiation.The collagen scaffold loaded with neural stem cells improved the hindlimb motor function in the rat model of T8 complete transection and promoted nerve regeneration.The collagen scaffold was completely degraded in vivo within 5 weeks of implantation,exhibiting good biodegradability.Rectal temperature,C-reactive protein expression and CD68 staining demonstrated that rats with spinal cord injury that underwent implantation of the collagen scaffold had no notable inflammatory reaction.These findings suggest that this novel collagen scaffold is a good carrier for neural stem cell transplantation,thereby enhancing spinal cord repair following injury.This study was approved by the Animal Ethics Committee of Nanjing Drum Tower Hospital(the Affiliated Hospital of Nanjing University Medical School),China(approval No.2019AE02005)on June 15,2019.

Magnetic resonance evaluation of human mesenchymal stem cells in corpus cavernosa of rats and rabbits

Aim： To investigate whether the biological process of superparamagnetic iron oxide （SPIO）-labeled human mesenchymal stem cells （hMSCs） may be monitored non-invasively by using in vivo magnetic resonance （MR） imaging with conventional 1.5-T system examinations in corpus cavernosa of rats and rabbits. Methods： The labeling efficiency and viability of SP10-labeled hMSCs were examined with Prussian blue and Tripan blue, respectively. After SPIO-labeled hMSCs were transplanted to the corpus cavernosa of rats and rabbits, serial T2-weighted MR images were taken and histological examinations were carried out over a 4-week period. Results： hMSCs loaded with SPIO compared to unlabeled cells had a similar viability. For SPIO-labeled hMSCs more than lx 105 concentration in vitro, MR images showed a decrease in signal intensity. MR signal intensity at the areas of SPIO-labeled hMSCs in the rat and rabbit corpus cavernosa decreased and was confined locally. After injection of SPIO-labeled hMSCs into the corpus cavernosum, MR imaging demonstrated that hMSCs could be seen for at least 12 weeks after injection. The presence of iron was confirmed with Prussian blue staining in histological sections. Conclusion： SP10-labeled hMSCs in corpus cavernosa of rats and rabbits can be evaluated non-invasively by molecular MR imaging. Our findings suggest that MR imaging has the ability to test the long-term therapeutic potential of hMSCs in animals in the setting of erectile dysfunction.

Induced pluripotent stem cell technology for spinal cord injury: a promising alternative therapy

Spinal cord injury has long been a prominent challenge in the trauma repair process. Spinal cord injury is a research hotspot by virtue of its difficulty to treat and its escalating morbidity. Furthermore, spinal cord injury has a long period of disease progression and leads to complications that exert a lot of mental and economic pressure on patients. There are currently a large number of therapeutic strategies for treating spinal cord injury, which range from pharmacological and surgical methods to cell therapy and rehabilitation training. All of these strategies have positive effects in the course of spinal cord injury treatment. This review mainly discusses the problems regarding stem cell therapy for spinal cord injury, including the characteristics and action modes of all relevant cell types. Induced pluripotent stem cells, which represent a special kind of stem cell population, have gained impetus in cell therapy development because of a range of advantages. Induced pluripotent stem cells can be developed into the precursor cells of each neural cell type at the site of spinal cord injury, and have great potential for application in spinal cord injury therapy.

Local signals in stem cell-based bone marrow regeneration

骨头髓(BM ) 的细胞的基础织物开发和新生通过造血的干细胞(HSC ) 和间充质的干细胞(MSC ) 被调停。在造血的房间和 BM stromal 房间(BMSC ) 之间的本地相互影响在 myelosuppression 以后决定造血作用的体质。这里，我们在侮辱以后控制 BM 新生考察 BM 本地信号。造血的生长因素(HGF ) 和 BMSC 生产的 cytokines 是在 BM 造血作用的规定的主要因素。对在多重种类的早胚胎开发批评的 Morphogens 被加到 HSC 管理者的家庭，包括 Wnt 蛋白质，槽口 ligands， BMP，和刺猬的家庭。HSC 和 BMSC 的全球基因表示分析开始为两种房间类型揭示了基因的签名组。更重要地，生物化学、生物的结合的全球基因表示的分析在 BM 期间本地信号学习新生强烈建议了 HGF 和 cytokines 不能是为 BM 恢复的主要本地管理者， chemokines ( SDF-1 ， FGF-4 )并且 angiogenic 生长因素( VEGF --一， Ang-1 )在 myelosuppression 以后在 BM 宪法起有启发性的作用。BM 毒性的管理的一个新方向从 BM 再生管理者的鉴定正在出现。

Two outward potassium current types are expressed during the neural differentiation of neural stem cells

The electrophysiological properties of potassium ion channels are regarded as a basic index for determining the functional differentiation of neural stem cells. In this study, neural stem cells from the hippocampus of newborn rats were induced to differentiate with neurotrophic growth factor, and the electrophysiological properties of the voltage-gated potassium ion channels were observed. Immunofluorescence staining showed that the rapidly proliferating neural stem cells formed spheres in vitro that expressed high levels of nestin. The differentiated neurons were shown to express neuron-specific enolase. Flow cytometric analysis revealed that the neural stem cells were actively dividing and the percentage of cells in the S ＋ G2/M phase was high. However, the ratio of cells in the S ＋ G2/M phase decreased obviously as differentiation proceeded. Whole-cell patch-clamp re- cordings revealed apparent changes in potassium ion currents as the neurons differentiated. The potassium ion currents consisted of one transient outward potassium ion current and one delayed rectifier potassium ion current, which were blocked by 4-aminopyridine and tetraethylammonium, respectively. The experimental findings indicate that neural stem cells from newborn rat hippo- campus could be cultured and induced to differentiate into functional neurons under defined condi- tions in vitro. The differentiated neurons expressed two types of outward potassium ion cur＇ents similar to those of mature neurons in vivo.

Cell viability and dopamine secretion of 6-hydroxydopamine-treated PC12 cells co-cultured with bone marrow-derived mesenchymal stem cells

In the present study, PC12 cells induced by 6-hydroxydopamine as a model of Parkinson＇s Disease, were used to investigate the protective effects of bone marrow-derived mesenchymal stem cells bone marrow-derived mesenchymal stem cells against 6-hydroxydopamine-induced neurotoxicity and to verify whether the mechanism of action relates to abnormal a-synuclein accumulation in cells Results showed that co-culture with bone marrow-derived mesenchymal stem cells enhanced PC12 cell viability and dopamine secretion in a cell dose-dependent manner. MitoLight staining was used to confirm that PC12 cells co-cultured with bone marrow-derived mesenchymal stem cells demonstrate reduced levels of cell apoptosis. Immunocytochemistry and western blot analysis found the quantity of α-synuclein accumulation was significantly reduced in PC12 cell and bone marrow-derived mesenchymal stem cell co-cultures. These results indicate that bone marrow-derived mesenchymal stem cells can attenuate 6-hydroxydopamine-induced cytotoxicity by reducing abnormal α-synuclein accumulation in PC12 cells.

Generation of male germ cells from induced pluripotent stem cells （iPS cells）： an in vitro and in vivo study

Recent studies have reported that induced pluripotent stem （iPS） cells from mice and humans can differentiate into primordial germ cells. However, whether iPS cells are capable of producing male germ cells is not known. The objective of this study was to investigate the differentiation potential of mouse iPS cells into spermatogonial stem cells and late-stage male germ cells. We used an approach that combines in vitrodifferentiation and in vivotransplantation. Embryoid bodies （EBs） were obtained from iPS cells using leukaemia inhibitor factor （LIF）-free medium. Quantitative PCR revealed a decrease in Oct4 expression and an increase in StraSand Vasa mRNA in the EBs derived from iPS cells, iPS cell-derived EBs were induced by retinoic acid to differentiate into spermatogonial stem cells （SSCs）, as evidenced by their expression of VASA, as well as CDH1 and GFRal, which are markers of SSCs. Furthermore, these germ cells derived from iPS cells were transplanted into recipient testes of mice that had been pre-treated with busulfan. Notably, iPS cell-derived SSCs were able to differentiate into male germ cells ranging from spermatogonia to round spermatids, as shown by VASA and SCP3 expression. This study demonstrates that iPS cells have the potential to differentiate into late-stage male germ cells. The derivation of male germ cells from iPS cells has potential applications in the treatment of male infertility and provides a model for uncovering the molecular mechanisms underlying male germ cell development.

Tyrosine hydroxylase-positive cells and dopaminergic neuronal function in human embryonic stem cells: An electrophysiological validation

BACKGROUND： Induced differentiation strategies and cytochemical properties of human embryonic stem ceils （hESCs） have been investigated. However, the electrophysiological functions of tyrosine hydroxylase （TH）-positive cells dedved from hESCs remain unclear. OBJECTIVE： To investigate the differentiation efficiency of TH-positive cells from hESCs in vitro using modified four-step culture methods, including embryoid body formation, and to examine the functional characteristics of the differentiated TH-positive cells using electrophysiological techniques. DESIGN, TIME AND SETTING： Neuroelectrophysiology was performed at the Reproductive Medicine Center and Stem Cell Research Center, Peking University Third Hospital, and the Neuroscience Research Institute and Department of Neurobiology, Peking University, from September 2004 to August 2008. MATERIALS： The hESC line, PKU-1.1, a monoclonal cell line derived from a pre-implantation human blastocyst in the Reproductive Medical Center of Peking University Third Hospital. The patch clamp recording system was provided by the Neuroscience Research Institute and Department of Neurobiology, Peking University. METHODS： The hESC line was induced to differentiate into TH-positive cells in vitro using a modified four-step culture method, including the formation of embryoid body, as well as the presence of sonic hedgehog and fibroblast growth factor 8. The cell karyotype was assessed by G-banding karyotype analysis techniques and specific markers were detected immunocytochemically. Whole-cell configuration was obtained after obtaining a tight seal of over 1 GΩ. Ionic currents were detected by holding the cells at -70 mV and stepping to test voltages between -80 and 40 mV in 10-mV increments in voltage-clamp configuration. MAIN OUTCOME MEASURES： We measured the cell karyotype, specific cell markers, and the electrophysiological properties of the voltage-gated ion channels on the cell membrane of TH-positive dopaminergic cells differentiated from our hESCs line in vitro. RESULTS： The differentiated cells had a consistent appearance, and the majority of cells （〉 90%） expressed TH and β-tubulion, as well as the neural progenitor marker, nestino Cell karyotype analysis demonstrated that all of the hESCs had a stable and normal karyotype （46, XX） after differentiation. In addition, patch clamp recording showed that the 10 recorded TH-positive cells exhibited a fast inward current when the test voltage depolarized to -30 mV, and a delayed outward current when the test voltage depolarized to -10 mV. The peak of inward current was obtained at voltage between 10 mV and 0 mV, while the peak of outward current was obtained at 40 mV. The average peak of inward current density was （ -50.05 ± 15.50） pA/pF, and the average peak of outward current density was （41.98 ± 13.55） pA/pE CONCLUSION： More than 90% of the differentiated hESC-derived cells induced by the modified four-step culture method exhibit dopaminergic neuronal properties, including general electrophysiological functional properties, such as functional potassium and sodium channels.

Stem cell transplantation and/or adenoviral glial cell line-derived neurotrophic factor promote functional recovery in hemiparkinsonian rats

BACKGROUND Parkinson’s disease(PD)is a neurological disorder characterized by the progressive loss of midbrain dopamine(DA)neurons.Bone marrow mesenchymal stem cells(BMSCs)can differentiate into multiple cell types including neurons and glia.Transplantation of BMSCs is regarded as a potential approach for promoting neural regeneration.Glial cell line-derived neurotrophic factor(GDNF)can induce BMSC differentiation into neuron-like cells.This work evaluated the efficacy of nigral grafts of human BMSCs(hMSCs)and/or adenoviral(Ad)GDNF gene transfer in 6-hydroxydopamine(6-OHDA)-lesioned hemiparkinsonian rats.AIM To evaluate the efficacy of nigral grafts of hMSCs and/or Ad-GDNF gene transfer in 6-OHDA-lesioned hemiparkinsonian rats.METHODS We used immortalized hMSCs,which retain their potential for neuronal differentiation.hMSCs,preinduced hMSCs,or Ad-GDNF effectively enhanced neuronal connections in cultured neurons.In vivo,preinduced hMSCs and/or Ad-GDNF were injected into the substantia nigra(SN)after induction of a unilateral 6-OHDA lesion in the nigrostriatal pathway.RESULTS Hemiparkinsonian rats that received preinduced hMSC graft and/or Ad-GDNF showed significant recovery of apomorphine-induced rotational behavior and the number of nigral DA neurons.However,DA levels in the striatum were not restored by these therapeutic treatments.Grafted hMSCs might reconstitute a niche to support tissue repair rather than contribute to the generation of new neurons in the injured SN.CONCLUSION The results suggest that preinduced hMSC grafts exert a regenerative effect and may have the potential to improve clinical outcome.

STEM CELLS AND PROTEOMICS

The distinctive features of proteomics are large-scale and high throughput. The key techniques of proteomics are two-dimensional gel electrophoresis, mass spectrometry and bioinformatics. Stem cell can differentiate into all kinds of cells, tissues and organs. There are many proteins and cytokines involved in the process of differentiation. Applying proteomics techniques to the research of the complex process of stem cell differentiation is of great importance to study the mechanism and applications of stem cell differentiation.

Advancement in high dose therapy and autologous stem cell rescue in lymphoma

A lthough advanced stage aggressive non-Hodgkin'slymphomas and Hodgkin's disease are thought to be che-motherapy-responsive cancers, a considerable number of patients either relapse or never attain a remission. High-dose therapy(HDT) followed by autologous stem cell transplantation(ASCT) is often the only possibility of cure for most of these patients. However, many controversial issues still remain with respect to HDT/ASCT for lymphomas, including its role for, the optimal timing of transplantation, the best conditioning regimen and the potential use of localized radiotherapy or immunologic methods to decrease post-transplant recurrence. Recently, mainly due to the unavailability of carmustine, several novel conditioning protocols have been clinically developed, with the aim of improving the overall outcome by enhancing the anti-lymphoma effect and, at the same time, by reducing short and long-term toxicity. Furthermore, the better safety profiles of novel approaches would definitively allow patients aged more than 65-70 years to benefit from this therapeutic option. In this review, we will briefly discuss the most relevant and recent data available regarding HDT/ASCT in lymphomas.

Ameliorative effects of human adipose tissue-derived mesenchymal stem cells on myelin basic protein-induced experimental autoimmune encephalomyelitis in Lewis rats

Mesenchymal stem cells have been previously shown to exert an immunomodulatory function. The present study sought to investigate the effects of multipotential human adipose tissue-derived mesenchymal stem cells （hAdMSCs） on disease progression and cytokine expression in Lewis rats with experimental autoimmune encephalomyelitis （EAE） induced by myelin basic protein. The duration of EAE paralysis in the group treated on day 7 posfimmunization with 5 × 10^6 hAdMSCs was significantly reduced compared with the vehicle-treated controls and the 1 x 106 hAdMSC- treated group. The duration of EAE paralysis in the groups treated with 5 × 10^6 hAdMSCs on both day 1 and day 7 postimmunization was significantly reduced compared with the vehicle-treated controls and the groups treated with 5 × 10^6 hAdMSCs on both day 7 and day 10 postimmunization. The mRNA expression of interleukin-10 and indoleamine 2, 3-dioxygenase was significantly decreased in the hAdMSC-treated group compared with the vehicle-treated group. These findings suggest that the ameliorative effects of hAdMSCs on EAE symptoms operate in a dose- and time-dependent manner and can be mediated in part by the ample production of anti-inflammatory cytokines.

Stem cell-derived biofactors fight against coronavirus infection

Despite various treatment protocols and newly recognized therapeutics,there are no effective treatment approaches against coronavirus disease.New therapeutic strategies including the use of stem cells-derived secretome as a cell-free therapy have been recommended for patients with critical illness.The pro-regenerative,pro-angiogenic,anti-inflammatory,anti-apoptotic,immunomodulatory,and trophic properties of stem cells-derived secretome,extracellular vesicles(EVs),and bioactive factors have made them suitable candidates for respiratory tract regeneration in coronavirus disease 2019(COVID-19)patients.EVs including microvesicles and exosomes can be applied for communication at the intercellular level due to their abilities in the long-distance transfer of biological messages such as mRNAs,growth factors,transcription factors,microRNAs,and cytokines,and therefore,simulate the specifications of the parent cell,influencing target cells upon internalization and/or binding.EVs exhibit both anti-inflammatory and tolerogenic immune responses by regulation of proliferation,polarization,activation,and migration of different immune cells.Due to effective immunomodulatory and high safety including a minimum risk of immunogenicity and tumorigenicity,mesenchymal stem cell(MSC)-EVs are more preferable to MSC-based therapies.Thus,as an endogenous repair and inflammation-reducing agent,MSCEVs could be used against COVID-19 induced morbidity and mortality after further mechanistic and preclinical/clinical investigations.This review is focused on the therapeutic perspective of the secretome of stem cells in alleviating the cytokine storm and organ injury in COVID-19 patients.

Derivation of male germ cells from induced pluripotent stem （iPS） cells： a novel and crucial source for generating male gametes

One of the most significant findings in recent stem cell research is the establishment of the induced pluripotent stem （iPS） cells, because they could have critical implications in both regenerative and repro- ductive medicine. Male gametes play a crucial role in transmitting genetic information to subsequent generations, and notably there are more and more patients with azoospermia, due to genetic and environmental factors. Recent advancements on generation of male gametes from human iPS cells would bring great promise to produce patient own male gametes for treating male infertility and provide an excellent platform for unveiling molecular mechanisms of male germ cell development.

SmartFlare^(TM) is a reliable method for assessing mRNA expression in single neural stem cells

BACKGROUND One of the most challenging tasks of modern biology concerns the real-time tracking and quantification of mRNA expression in living cells.On this matter,a novel platform called SmartFlare^(TM) has taken advantage of fluorophore-linked nanoconstructs for targeting RNA transcripts.Although fluorescence emission does not account for the spatial mRNA distribution,NanoFlare technology has grown a range of theranostic applications starting from detecting biomarkers related to diseases,such as cancer,neurodegenerative pathologies or embryonic developmental disorders.AIM To investigate the potential of SmartFlare^(TM) in determining time-dependent mRNA expression of prominin 1(CD133)and octamer-binding transcription factor 4(OCT4)in single living cells through differentiation.METHODS Brain fragments from the striatum of aborted human fetuses aged 8 wk postconception were processed to obtain neurospheres.For the in vitro differentiation,neurospheres were gently dissociated with Accutase solution.Single cells were resuspended in a basic medium enriched with fetal bovine serum,plated on poly-L-lysine-coated glass coverslips,and grown in a lapse of time from 1 to 4 wk.Live cell mRNA detection was performed using SmartFlare^(TM) probes(CD133,Oct4,Actin,and Scramble).All the samples were incubated at 37°C for 24 h.For nuclear staining,Hoechst 33342 was added.SmartFlare^(TM) CD133-and OCT4-specific fluorescence signal was assessed using a semiquantitative visual approach,taking into account the fluorescence intensity and the number of labeled cells.RESULTS In agreement with previous PCR experiments,a unique expression trend was observed for CD133 and OCT4 genes until 7 d in vitro(DIV).Fluorescence resulted in a mixture of diffuse cytoplasmic and spotted-like pattern,also detectable in the contacting neural branches.From 15 to 30 DIV,only few cells showed a scattered fluorescent pattern,in line with the differentiation progression and coherent with mRNA downregulation of these stemness-related genes.CONCLUSION SmartFlare^(TM) appears to be a reliable,easy-to-handle tool for investigating CD133 and OCT4 expression in a neural stem cell model,preserving cell biological properties in anticipation of downstream experiments.