Apoptosis during β-mercaptoethanol-induced differentiation of adult adipose-derived stromal cells into neurons

β-mercaptoethanol can induce adipose-derived stromal cells to rapidly and efficiently differentiate into neurons in vitro.However,because of the short survival time of the differentiated cells,clinical applications for this technique are limited.As such,we examined apoptosis of neurons differentiated from adipose-derived stromal cells induced with β-mercaptoethanol in vitro using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling and transmission electron microscopy.The results revealed that the number of surviving cells decreased and apoptosis rate increased as induction time extended.Taken together,these results suggest that apoptosis occurring in the process of adipose-derived stromal cells differentiating into neurons is the main cause of cell death.However,the mechanism underlying cellular apoptosis should be researched further to develop methods of controlling apoptosis for clinical applications.

Ultrastructure of neuronal-like cells differentiated from adult adipose-derived stromal cells

β-mercaptoethanol induces in vitro adult adipose-derived stromal cells （ADSCs） to differentiate into neurons. However, the ultrastructural features of the differentiated neuronal-like cells remain unknown. In the present study, inverted phase contrast microscopy was utilized to observe β-mercaptoethanol-induced differentiation of neuronal-like cells from human ADSCs, and immunocytochemistry and real-time polymerase chain reaction were employed to detect expression of a neural stem cells marker （nestin）, a neuronal marker （neuron-specific enolase）, and a glial marker （glial fibrillary acidic protein）. In addition, ultrastructure of neuronal-like cells was observed by transmission election microscopy. Results revealed highest expression rate of nestin and neuron-specific enolase at 3 and 5 hours following induced differentiation; cells in the 5-hour induction group exhibited a neuronal-specific structure, i.e., Nissl bodies. However, when induction solution was replaced by complete culture medium after 8-hour induction, the differentiated cells reverted to the fibroblast-like morphology from day 1. These results demonstrate that β-mercaptoethanol-induced ADSCs induced differentiation into neural stem cells, followed by morphology of neuronal-like cells. However, this differentiation state was not stable.

A novel ethanol-based method to induce differentiation of adipose-derived stromal cells into astrocytes

The quantity and survival time of astrocytes,which were differentiated from adult adipose-derived stromal cells after exposure to an inducer containing 3-isobutyl-1-methylxanthine,have thus far been unsatisfactory.The present study investigated the growth and differentiation characteristics of induced astrocytes by observing their growth curves.After induction for 48 hours with an inducer containing 0.5% ethanol,some adult adult adipose-derived stromal cells displayed typical astrocytic morphology.The cell quantity gradually decreased with prolonged induction time.Nestin,glial fibrillary acidic protein,and S-100 expression reached peak levels at 14 days,but neuron-specific enolase was not expressed.These results suggest that the induced astrocytes reached their peak at 14 days.Further optimization of the culture environment may yield mature astrocytes with normal functions,in greater quantity,and prolonged survival time.

Adult adipose-derived stromal cells differentiate into neurons with normal electrophysiological functions

β-mercaptoethanol was used to induce in vitro neuronal differentiation of adipose-derived stromal cells. Within an 8-hour period post-differentiation, the induced cells exhibited typical neuronal morphology, and expression of microtubule-associated protein 2 and neuron-specific enolase, which are markers of mature neurons, reached a peak at 5 hours. Specific organelle Nissl bodies of neurons were observed under transmission electron microscopy. Results of membrane potential showed that fluorescence intensity of cells was greater after 5 hours than adipose-derived stromal cells prior to induction. In addition, following stimulation with high-concentration potassium solution, fluorescence intensity increased. These experimental findings suggested that neurons differentiated from adipose-derived stromal cells and expressed mature K^＋ channels. In addition, following stimulation with high potassium solution, the membrane potential depolarized and fired an action potential, confirming that the induced cells possessed electrophysiological functions.

Autophagy and apoptosis during adult adipose-derived stromal cells differentiation into neuron-like cells in vitro

β-mercaptoethanol can induce adult adipose-derived stromal cells to rapidly and efficiently differentiate into typical neuron-like cells in vitro. Immunohistochemistry showed that neuron specific enolase and neurofilament-200 expression gradually increased with the extension of induction time, and peaked at 5 hours. By contrast, glial fibrillary acidic protein was negatively expressed at all time points. Induced cells possessed a typical Nissl body, apoptosis showing condensed chromatin in the nucleus, autophagosomes with a bilayered membrane and autolysosomes in the cytoplasm at 5 hours. TUNEL assay and immunohistochemistry and immunofluorescence demonstrated that apoptosis and caspase-3 expression increased and peaked at 8 hours. Immunohistochemistry and immunofluorescence showed that microtubuleassociated protein light chain 3 gradually increased with induction and reached a peak at 5 hours These results indicate that autophagy played an important role in protecting cells during adult adipose-derived stromal cells differentiation into neuron-like cells in vitro.

Adipose-derived stromal cells resemble bone marrow stromal cells in hepatocyte differentiation potential in vitro and in vivo

AIM To investigate whether mesenchymal stem cells(MSCs) from adipose-derived stromal cells(ADSCs) and bone marrow stromal cells(BMSCs) have similar hepatic differentiation potential.METHODS Mouse ADSCs and BMSCs were isolated and cultured. Their morphological and phenotypic characteristics, as well as their multiple differentiation capacity were compared. A new culture system was established to induce ADSCs and BMSCs into functional hepatocytes. Reverse transcription polymerase chain reaction, Western blot, and immunofluorescence analyses were performed to identify the induced hepatocytelike cells. CM-Dil-labeled ADSCs and BMSCs were then transplanted into a mouse model of CCl4-induced acute liver failure. fluorescence microscopy was used to track the transplanted MSCs. Liver function was tested by an automatic biochemistry analyzer, and liver tissue histology was observed by hematoxylin and eosin(HE) staining.RESULTS ADSCs and BMSCs shared a similar morphology and multiple differentiation capacity, as well as a similar phenotype(with expression of CD29 and CD90 and no expression of CD11 b or CD45). Morphologically, ADSCs and BMSCs became round and epithelioid following hepatic induction. These two cell types differentiated into hepatocyte-like cells with similar expression of albumin, cytokeratin 18, cytokeratin 19, alpha fetoprotein, and cytochrome P450. fluorescence microscopy revealed that both ADSCs and BMSCs were observed in the mouse liver at different time points. Compared to the control group, both the function of the injured livers and HE staining showed significant improvement in the ADSC-and BMSC-transplanted mice. There was no significant difference between the two MSC groups.CONCLUSION ADSCs share a similar hepatic differentiation capacity and therapeutic effect with BMSCs in an acute liver failure model. ADSCs may represent an ideal seed cell type for cell transplantation or a bio-artificial liver support system.

Apoptosis is an obstacle to the differentiation of adipose-derived stromal cells into astrocytes

Previous studies have demonstrated that nerve cells differentiated from adipose-derived stro-mal cells after chemical induction have reduced viability;however, the underlying mechanisms remained unclear. In this study, we induced the differentiation of adult adipose-derived stromal cells into astrocytes using chemical induction. 3-（4,5-Dimethylthiazol-2-yl）-2,5-diphenyltetra-zolium bromide assay and flow cytometry showed that, with increasing induction time, the apoptotic rate gradually increased, and the number of living cells gradually decreased. Im-munohistochemical staining demonstrated that the number of glial fibrillary acidic protein-, caspase-3- and caspase-9-positive cells gradually increased with increasing induction time. Transmission electron microscopy revealed typical signs of apoptosis after differentiation. Taken together, our results indicate that caspase-dependent apoptosis is an obstacle to the differentia-tion of adipose-derived stromal cells into astrocytes. Inhibiting apoptosis may be an important strategy for increasing the efifciency of induction.

Induced Differentiation of Adipose-derived Stromal Cells into Myoblasts

This study aimed to induce the differentiation of isolated and purified adipose-derived stromal cells(ADSCs) into myoblasts,which may provide a new strategy for tissue engineering in patients with stress urinary incontinence(SUI).ADSCs,isolated and cultured ex vivo,were identified by flow cytometry and induced to differentiate into myoblasts in the presence of an induction solution consisting of DMEM supplemented with 5-azacytidine(5-aza),5% FBS,and 5% horse serum.Cellular morphology was observed under an inverted microscope.Ultrastructural changes occurring during the differentiation were observed by transmission electron microscopy and confocal laser scanning microscopy.Cellular immunohistochemical staining was applied to determine the expression of desmin protein in cells with and without induced differentiation.Reverse transcription-polymerase chain reaction(RT-PCR) and Western blotting were used to detect mRNA and protein expression,respectively,of sarcomeric and desmin smooth muscle proteins.The results showed that ADSCs were mainly of a spindle or polygon shape.Flow cytometry analysis revealed that ADSCs did not express CD34,CD45,and CD106 but high levels of CD44 and CD90,which confirmed that the cultured cells were indeed ADSCs.After induction with a 5-aza-containing solution,morphological changes in ADSCs,including irregular cell size,were observed.Cells gradually changed from long spindles to polygons and star-shaped cells with microvilli on the cell surface.Many organelles were observed and the cytoplasm was found to contain many mitochondria,rough endoplasmic reticulum(rER),and myofilament-like structures.Cell immunohistochemical staining revealed different levels of desmin expression in each phase of the induction process,with the highest expression level found on day 28 of induction.RT-PCR and Western blot results confirmed significantly higher desmin gene expression in induced cells compared with control cells,but no significant difference between the two groups of cells in sarcomeric protein expression.It was concluded that under specific induction setting,ADSCs can be induced to differentiate into myoblasts,providing a potential new option in stem cell transplantation therapy for SUI.

Adult adipose-derived stromal cells differentiating into neurons and neuron-like cells

Totally three articles regarding autophagy and apoptosis during differentiation of adult adipose-derived stromal cells into neurons and neuron-like cells were published in Neural Regeneration Research. We hope that our readers find these papers useful to their research.

Role of adipose-derived stromal cells in pedicle skin flap survival in experimental animal models

The use of skin flaps in reconstructive surgery is the first-line surgical treatment for the reconstruction of skin defects and is essentially considered the starting point of plastic surgery. Despite their excellent usability, their application includes general surgical risks or possible complications, the primary and most common is necrosis of the flap. To improve flap survival, researchers have used different methods, including the use of adiposederived stem cells, with significant positive results. In our research we will report the use of adipose-derived stem cells in pedicle skin flap survival based on current literature on various experimental models in animals.

Autophagy activator promotes neuronal differentiation of adult adipose-derived stromal cells

Preliminary research from our group found altered autophagy intensity during adipose-derived stromal cell differentiation into neuronal-like cells, and that this change was associated with morphological changes in differentiated cells. This study aimed to verify the role of rapamycin, an autophagy activator, in the process of adipose-derived stromal cell differentiation into neuronal-like cells. Immunohistochemical staining showed that expression of neuron-specific enolase and neurofilament-200 were gradually upregulated in adipose-derived stromal cells after 5 mM 13-mercaptoethanol induction, and the differentiation rate gradually increased with induction time. Using transmission electron microscopy, induced cells were shown to exhibit cytoplasmic autophagosomes, with bilayer membranes, and autolysosomes. After rapamycin （200 IJg/L） induction for 1 hour, adipose-derived stromal cells began to extend long processes, similar to the morphology of neuronal-like cells, while untreated cells did not exhibit similar morphologies until 3 hours after induction. Moreover, the differentiation rate was significantly increased after rapamycin treatment. Compared with untreated cells, expression of LC3, an autophagy protein, was also significantly upregulated. Positive LC3 expression tended to concentrate at cell nuclei with increasing induction times. Our experimental findings indicate that autophagy can significantly increase the speed of adipose-derived stromal cell differentiation into neuronal-like cells.

Intravenous administration of adipose-derived stromal cells does not ameliorate bleomycin-induced lung injury in rats

Background: Mesenchymal stromal cells (MSCs) have been studied intensively in regenerative medicine. Among MSCs, adipose tissue-derived stromal cells (ASCs) are relatively easy to obtain from a patient. Since ASCs are ideal candidates for use in the treatment of disease states including pulmonary fibrosis, we investigated whether intravenous injection of ASCs could exert a therapeutic effect against bleomycin-induced lung injury in rats. Methods: Rats were intratracheally administered bleomycin, and one week later ASCs were isolated and cultured. Two weeks after bleomycin treatment ASCs or PBS (phosphate-buffered saline) were injected to the rats. Three or six weeks after bleomycin instillation, the total cell counts and their profile in bronchoalveolar lavage fluid (BALF) were measured, and a histological evaluation was semi-quantitatively assessed for the injured lungs, followed by cell tracing. Results: The BALF cell counts and its profiles were not significantly different in the ASCs and PBS groups. Furthermore, ASC treatment led to no significant histological effect compared with the PBS treatment. Using a fluorescent cell tracer, it was noted that the ASCs homed to the injured lung areas, but some ASCs accumulated around scars, and scarcely migrated into the fibrotic areas. Conclusions: In the present study, the intravenous administration of ASCs could not reduce the severity of bleomycin-induced lung injury in a rat model. Although the ASC counts and passage numbers were suitable, the older age and fibrotic disease stage of the rats were likely responsible for the treatment failure.

Photobiomodulation:a novel approach to promote trans-differentiation of adipose-derived stem cells into neuronal-like cells

Photobiomodulation,originally used red and near-infrared lasers,can alter cellular metabolism.It has been demonstrated that the visible spectrum at 451-540 nm does not necessarily increase cell proliferation,near-infrared light promotes adipose stem cell proliferation and affects adipose stem cell migration,which is necessary for the cells homing to the site of injury.In this in vitro study,we explored the potential of adipose-derived stem cells to differentiate into neurons for future translational regenerative treatments in neurodegenerative disorders and brain injuries.We investigated the effects of various biological and chemical inducers on trans-differentiation and evaluated the impact of photobiomodulation using 825 nm near-infrared and 525 nm green laser light at 5 J/cm2.As adipose-derived stem cells can be used in autologous grafting and photobiomodulation has been shown to have biostimulatory effects.Our findings reveal that adipose-derived stem cells can indeed trans-differentiate into neuronal cells when exposed to inducers,with pre-induced cells exhibiting higher rates of proliferation and trans-differentiation compared with the control group.Interestingly,green laser light stimulation led to notable morphological changes indicative of enhanced trans-differentiation,while near-infrared photobiomodulation notably increased the expression of neuronal markers.Through biochemical analysis and enzyme-linked immunosorbent assays,we observed marked improvements in viability,proliferation,membrane permeability,and mitochondrial membrane potential,as well as increased protein levels of neuron-specific enolase and ciliary neurotrophic factor.Overall,our results demonstrate the efficacy of photobiomodulation in enhancing the trans-differentiation ability of adipose-derived stem cells,offering promising prospects for their use in regenerative medicine for neurodegenerative disorders and brain injuries.

Non-enzymatic methods for isolation of stromal vascular fraction and adipose-derived stem cells:A systematic review

BACKGROUND Adipose-derived stem cells(ADSCs)and the stromal vascular fraction(SVF)have garnered substantial interest in regenerative medicine due to their potential to treat a wide range of conditions.Traditional enzymatic methods for isolating these cells face challenges such as high costs,lengthy processing time,and regulatory complexities.AIM This systematic review aimed to assess the efficacy and practicality of nonenzymatic,mechanical methods for isolating SVF and ADSCs,comparing these to conventional enzymatic approaches.METHODS Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines,a comprehensive literature search was conducted across multiple databases.Studies were selected based on inclusion criteria focused on non-enzymatic isolation methods for SVF and ADSCs from adipose tissue.The risk of bias was assessed,and a qualitative synthesis of findings was performed due to the methodological heterogeneity of the included studies.RESULTS Nineteen studies met the inclusion criteria,highlighting various mechanical techniques such as centrifugation,vortexing,and ultrasonic cavitation.The review identified significant variability in cell yield and viability,and the integrity of isolated cells across different non-enzymatic methods compared to enzymatic procedures.Despite some advantages of mechanical methods,including reduced processing time and avoidance of enzymatic reagents,the evidence suggests a need for optimization to match the cell quality and therapeutic efficacy achievable with enzymatic isolation.CONCLUSION Non-enzymatic,mechanical methods offer a promising alternative to enzymatic isolation of SVF and ADSCs,potentially simplifying the isolation process and reducing regulatory hurdles.However,further research is necessary to standardize these techniques and ensure consistent,high-quality cell yields for clinical applications.The development of efficient,safe,and reproducible non-enzymatic isolation methods could significantly advance the field of regenerative medicine.

Ultrastructure and electrophysiology of astrocytes differentiated from adult adipose-derived stromal cells

Background Adipose-derived stromal cell （ADSC） differentiation into neural cells in vitro is becoming widely studied. However, there are few reports on astrocytes following differentiation, and particularly on maturation and electrophysiology. In this study, we used various methods to determine ADSC-derived astrocyte maturity. Methods Chemical induction with isobutylmethylxanthine （IBMX） was used to differentiate adult ADSCs into astrocytes followed by hematoxylin-eosin （HE） staining to observe morphology and transmission electron microscopy for cellular ultrastructure assessment. Immunofluorescence was used to detect expression of neural stem cell marker nestin as well as glial markers glial fibrillary acidic protein （GFAP） and S-100. In addition, we measured membrane potentials in bis-（1,3-dibarbituric acid） trimethine oxanol-labeled ADSCs and astrocytes by stimulation with a high potassium solution under an inverted fluorescence microscope. Finally, cell cycle distribution was detected by flow cytometry. Results Typical astrocyte morphology was shown by HE staining after 48-hour differentiation. Glial fibril was observed with transmission electron microscopy. GFAP and S-100 were not expressed in the control group, but were expressed within 24-hour differentiation and reached a maximum at day 14 with no change up to day 28. Nestin was weakly expressed in control cells and also reached a maximum at day 14 with the percentage of positive cells constant until day 21 followed by a decrease. Differentiated cell membrane potentials after stimulation with potassium were slightly increased, and then gradually declined over time. There was no significant membrane potential change in the control group. Flow cytometry showed that the percentage of cells in G0/G1 phase was 93% and only 5% in S phase. Conclusion ADSCs were differentiated into mature astrocytes with typical characteristics including morphology, ultrastructure, marker protein expression, mature potassium channels and mitotic capacity.

Adipose-derived stem cells and knee osteoarthritis:New perspectives,old concerns

In this editorial,we comment on the paper by Muthu et al published in the recent issue of the journal.This editorial review focusses on the use of adipose-derived stem cells(ADSCs)in knee osteoarthritis treatment.We discuss the differences between the stromal vascular fraction and microfragmented adipose tissue and highlight the results of clinical studies comparing both treatments and the use of hyaluronic acid,platelet-rich plasma,and bone marrow aspirate concentrate.The use of expanded ADSCs is also discussed;moreover,concerns regarding treatment with ADSCs,particularly the heterogeneity of published studies and the need to standardize protocols to explore clinical potential is explored.

Immunomodulation of adipose-derived mesenchymal stem cells on peripheral blood mononuclear cells in colorectal cancer patients with COVID-19

BACKGROUND Accumulating evidence has shown that adipose tissue-derived mesenchymal stem cells(ADSCs)are an effective therapeutic approach for managing coronavirus disease 2019(COVID-19);however,further elucidation is required to determine their underlying immunomodulatory effect on the mRNA expression of T helper cell-related transcription factors(TFs)and cytokine release in peripheral blood mononuclear cells(PBMCs).AIM To investigate the impact of ADSCs on the mRNA expression of TFs and cytokine release in PBMCs from colorectal cancer(CRC)patients with severe COVID-19(CRC^(+)patients).METHODS PBMCs from CRC^(+)patients(PBMCs-C+)and age-matched CRC patients(PBMCs-C)were stimulated and cultured in the presence/absence of ADSCs.The mRNA levels of T-box TF TBX21(T-bet),GATA binding protein 3(GATA-3),RAR-related orphan receptor C(RORC),and forkhead box P3(FoxP3)in the PBMCs were determined by reverse transcriptase-polymerase chain reaction.Culture supernatants were evaluated for levels of interferon gamma(IFN-γ),interleukin 4(IL-4),IL-17A,and transforming growth factor beta 1(TGF-β1)using an enzyme-linked immunosorbent assay.RESULTS Compared with PBMCs-C,PBMCs-C+exhibited higher mRNA levels of T-bet and RORC,and increased levels of IFN-γ and IL-17A.Additionally,a significant decrease in FoxP3 mRNA and TGF-β1,as well as an increase in Tbet/GATA-3,RORC/FoxP3,IFN-γ/IL-4,and IL-17A/TGF-β1 ratios were observed in PBMCs-C+.Furthermore,ADSCs significantly induced a functional regulatory T cell(Treg)subset,as evidenced by an increase in FoxP3 mRNA and TGF-β1 release levels.This was accompanied by a significant decrease in the mRNA levels of T-bet and RORC,release of IFN-γ and IL-17A,and T-bet/GATA-3,RORC/FoxP3,IFN-γ/IL-4,and IL-17A/TGF-β1 ratios,compared with the PBMCs-C+alone.CONCLUSION The present in vitro studies showed that ADSCs contributed to the immunosuppressive effects on PBMCs-C+,favoring Treg responses.Thus,ADSC-based cell therapy could be a beneficial approach for patients with severe COVID-19 who fail to respond to conventional therapies.

Adipose-derived stem cells in diabetic foot care:Bridging clinical trials and practical application

Diabetic foot ulcers(DFUs)pose a critical medical challenge,significantly impairing the quality of life of patients.Adipose-derived stem cells(ADSCs)have been identified as a promising therapeutic approach for improving wound healing in DFUs.Despite extensive exploration of the mechanical aspects of ADSC therapy against DFU,its clinical applications remain elusive.In this review,we aimed to bridge this gap by evaluating the use and advancements of ADSCs in the clinical management of DFUs.The review begins with a discussion of the classification and clinical management of diabetic foot conditions.It then discusses the current landscape of clinical trials,focusing on their geographic distribution,reported efficacy,safety profiles,treatment timing,administration techniques,and dosing considerations.Finally,the review discusses the preclinical strategies to enhance ADSC efficacy.This review shows that many trials exhibit biases in study design,unclear inclusion criteria,and intervention protocols.In conclusion,this review underscores the potential of ADSCs in DFU treatment and emphasizes the critical need for further research and refinement of therapeutic approaches,with a focus on improving the quality of future clinical trials to enhance treatment outcomes and advance the field of diabetic wound care.

In vitro differentiation of adipose-derived stem cells and bone marrow-derived stromal stem cells into neuronal-like cells

Adipose-derived stem cells and bone marrow-derived stromal stem cells were co-cultured with untreated or Aβ1-40-treated PC12 cells, or grown in supernatant derived from untreated or Aβ1-40-treated PC12 cells. Analysis by western blot and quantitative real-time PCR showed that protein levels of Nanog, Oct4, and Sox2, and mRNA levels of miR/125a/3p were decreased, while expression of insulin-like growth factor-2 and neuron specific enolase was increased. In comparison the generation of neuron specific enolase-positive cells was most successful when adipose-derived stem cells were co-cultured with Aβ1-40-treated PC12 cells. Our results demonstrate that adipose-derived stem cells and bone marrow-derived stromal stem cells exhibit trends of neuronal-like cell differentiation after co-culture with Aβ1-40-treated PC12 cells. This process may relate to a downregulation of miR-125a-3p mRNA expression and increased levels of insulin-like growth factor-2 expression.

Adipose-derived mesenchymal stromal/stem cells: An update on their phenotype in vivo and in vitro

Adipose tissue is a rich, ubiquitous and easily acces-sible source for multipotent stromal/stem cells and has, therefore, several advantages compared to other sourc-es of mesenchymal stromal/stem cells. Several studies have tried to identify the origin of the stromal/stem cell population within adipose tissue in situ. This is a complicated attempt because no marker has currently been described which unambiguously identifies native adipose-derived stromal/stem cells(ASCs). Isolated and cultured ASCs are a non-uniform preparation consisting of several subsets of stem and precursor cells. Cultured ASCs are characterized by their expression of a panel of markers(and the absence of others), whereas their in vitro phenotype is dynamic. Some markers were ex-pressed de novo during culture, the expression of some markers is lost. For a long time, CD34 expression was solely used to characterize haematopoietic stem and progenitor cells, but now it has become evident that it is also a potential marker to identify an ASC subpopula-tion in situ and after a short culture time. Nevertheless, long-term cultured ASCs do not express CD34, perhaps due to the artificial environment. This review gives an update of the recently published data on the origin and phenotype of ASCs both in vivo and in vitro. In addition, the composition of ASCs(or their subpopula-tions) seems to vary between different laboratories andpreparations. This heterogeneity of ASC preparationsmay result from different reasons. One of the main problems in comparing results from different laborato-ries is the lack of a standardized isolation and culture protocol for ASCs. Since many aspects of ASCs, suchas the differential potential or the current use in clinical trials, are fully described in other recent reviews, this review further updates the more basic research issues concerning ASCs' subpopulations, heterogeneity andculture standardization.