Adipose-derived cells

A Comprehensive Review of Stem Cell Conditioned Media Role for Anti-Aging on Skin

Various studies have been widely conducted on conditioned medium for the development of anti-aging preparations, including the utilization of stem cells, which present a promising alternative solution. This narrative review aims to understand the latest developments in various conditioned medium stem cell applications for anti-aging on the skin. A search of the Scopus database yielded publications of interest. The research focused on articles published without restrictions on the year. After finding 68 articles in the search results, they moved on to the checking phase. Upon comprehensive literature review, 23 articles met the inclusion criteria, while 45 articles were deemed ineligible for participation in this research. The results of the review indicate that conditioned medium from various stem cells has demonstrated success in reducing risk factors for skin aging, as proven in various tests. The successful reduction of the risk of skin aging has been established in vitro, in vivo, and in clinical trials. Given the numerous studies on the progress of exploring and utilizing conditioned medium, it is expected to provide a solution to the problem of skin aging.

Stem cell and exosome therapies for regenerating damaged myocardium in heart failure

Finding novel treatments for cardiovascular diseases (CVDs) is a hot topic in medicine; cell-based therapies have reported promising news for controlling dangerous complications of heart disease such as myocardial infarction (MI) and heart failure (HF). Various progenitor/stem cells were tested in various in-vivo, in-vitro, and clinical studies for regeneration or repairing the injured tissue in the myocardial to accelerate the healing. Fetal, adult, embryonic, and induced pluripotent stem cells (iPSC) have revealed the proper potency for cardiac tissue repair. As an essential communicator among cells, exosomes with specific contacts (proteins, lncRNAs, and miRNAs) greatly promote cardiac rehabilitation. Interestingly, stem cell-derived exosomes have more efficiency than stem cell transplantation. Therefore, stem cells induced pluripotent stem cells (iPSCs), embryonic stem cells (ESCs), cardiac stem cells (CDC), and skeletal myoblasts) and their-derived exosomes will probably be considered an alternative therapy for CVDs remedy. In addition, stem cell-derived exosomes have been used in the diagnosis/prognosis of heart diseases. In this review, we explained the advances of stem cells/exosome-based treatment, their beneficial effects, and underlying mechanisms, which will present new insights in the clinical field in the future.

MST1/2 regulates fibro/adipogenic progenitor fate decisions in skeletal muscle regeneration

Defective skeletal muscle regeneration is often accompanied by fibrosis. Fibroblast/adipose progenitors (FAPs) are important in these processes, however, the regulation of FAP fate decisions is unclear. Here, using inducible conditional knockout mice, we show that blocking mammalian Ste20-like kinases 1/2 (MST1/2) of FAPs prevented apoptosis and reduced interleukin-6 secretion in vivo and in vitro, which impaired myoblast proliferation and differentiation, as well as impaired muscle regeneration. Deletion of Mst1/2 increased co-localization of Yes-associated protein (YAP) with Smad2/3 in nuclei and promoted differentiation of FAPs toward myofibroblasts, resulting in excessive collagen deposition and skeletal muscle fibrosis. Meanwhile, inhibition of MST1/2 increased YAP/Transcriptional co-activator with PDZ-binding motif activation, which promoted activation of the WNT/β-catenin pathway and impaired the differentiation of FAPs toward adipocytes. These results reveal a new mechanism for MST1/2 action in disrupted skeletal muscle regeneration and fibrosis via regulation of FAP apoptosis and differentiation. MST1/2 is a potential therapeutic target for the treatment of some myopathies.

Uncovering the link between diabetes and cardiovascular diseases: insights from adipose-derived stem cells

Cardiovascular diseases (CVDs) are the leading causes of morbidity and mortality worldwide. The escalating global occurrence of obesity and diabetes mellitus (DM) has led to a significant upsurge in individuals afflicted with CVDs. As the prevalence of CVDs continues to rise, it is becoming increasingly important to identify the underlying cellular and molecular mechanisms that contribute to their development and progression, which will help discover novel therapeutic avenues. Adipose tissue (AT) is a connective tissue that plays a crucial role in maintaining lipid and glucose homeostasis. However, when AT is exposed to diseased conditions, such as DM, this tissue will alter its phenotype to become dysfunctional. AT is now recognized as a critical contributor to CVDs, especially in patients with DM. AT is comprised of a heterogeneous cellular population, which includes adipose-derived stem cells (ADSCs). ADSCs resident in AT are believed to regulate physiological cardiac function and have potential cardioprotective roles. However, recent studies have also shown that ADSCs from various adipose tissue depots become pro-apoptotic, pro-inflammatory, less angiogenic, and lose their ability to differentiate into various cell lineages upon exposure to diabetic conditions. This review aims to summarize the current understanding of the physiological roles of ADSCs, the impact of DM on ADSC phenotypic changes, and how these alterations may contribute to the pathogenesis of CVDs.

Inhibition of PTEN promotes osteointegration of titanium implants in type 2 diabetes by enhancing anti-inflammation and osteogenic capacity of adipose-derived stem cells

Background: The low osteogenic differentiation potential and attenuated anti-inflammatory effect of adipose-derived stem cells (ADSCs) from animals with type 2 diabetes mellitus (T2DM) limits osseointegration of the implant. However, the underlying mechanisms are not fully understood. Methods: Western blotting and qRT-PCR analyses were performed to investigate the effects of PTEN on the osteogenic capacity of ADSCs of T2DM rats (TADSCs). We conducted animal experiments in T2DM-Sprague Dawley (SD) rats to evaluate the osteogenic capacity of modified TADSC sheets in vivo. New bone formation was assessed by micro-CT and histological analyses. Results: In this study, adipose-derived stem cells of T2DM rats exhibited an impaired osteogenic capacity. RNA-seq analysis showed that PTEN mRNA expression was upregulated in TADSCs, which attenuated the osteogenic capacity of TADSCs by inhibiting the AKT/mTOR/HIF-1α signaling pathway. miR-140-3p, which inhibits PTEN, was suppressed in TADSCs. Overexpression or inhibition of PTEN could correspondingly reduce or enhance the osteogenic ability of TADSCs by regulating the AKT/mTOR/HIF-1α signaling pathway. TADSCs transfected with PTEN siRNA resulted in higher and lower expressions of genes encoded in M2 macrophages (Arg1) and M1 macrophages (iNOS), respectively. In the T2DM rat model, PTEN inhibition in TADSC sheets promoted macrophage polarization toward the M2 phenotype, attenuated inflammation, and enhanced osseointegration around implants. Conclusion: Upregulation of PTEN, which was partially due to the inhibition of miR-140-3p, is important for the attenuated osteogenesis by TADSCs owing to the inhibition of the AKT/mTOR/HIF-1α signaling pathway. Inhibition of PTEN significantly improves the anti-inflammatory effect and osteogenic capacity of TADSCs, thus promoting peri-implant bone formation in T2DM rats. Our findings offer a potential therapeutic approach for modifying stem cells derived from patients with T2DM to enhance osseointegration.

Paracrine signalling between keratinocytes and SVF cells results in a new secreted cytokine profile during wound closure

Stromal vascular fraction (SVF) cells, and the adipose-derived mesenchymal stem cells they contain, have shown enhanced wound healing in vitro and in vivo, yet their clinical application has been limited. In this regard, understanding the mechanisms that govern SVF-enhanced wound healing would improve their application in the clinic. Here, we show that the SVF cells and keratinocytes engage in a paracrine crosstalk during wound closure, which results in a new cytokine profile that is distinct from the cytokines regularly secreted by either cell type on their own. We identify 11 cytokines, 5 of which are not regularly secreted by the SVF cells, whose expressions are significantly increased during wound closure by the keratinocytes. This new cytokine profile could be used to accelerate wound closure and initiate re-epithelialization without the need to obtain the SVF cells from the patient.

HIF-1α increases the osteogenic capacity of ADSCs by coupling angiogenesis and osteogenesis via the HIF-1α/VEGF/AKT/mTOR signaling pathway

BACKGROUND

Stabilization and increased activity of hypoxia-inducible factor 1-α (HIF-1α) can directly increase cancellous bone formation and play an essential role in bone modeling and remodeling. However, whether an increased HIF-1α expression in adipose-derived stem cells (ADSCs) increases osteogenic capacity and promotes bone regeneration is not known.

RESULTS

In this study, ADSCs transfected with small interfering RNA and HIF-1α overexpression plasmid were established to investigate the proliferation, migration, adhesion, and osteogenic capacity of ADSCs and the angiogenic ability of human umbilical vein endothelial cells (HUVECs). Overexpression of HIF-1α could promote the biological functions of ADSCs, and the angiogenic ability of HUVECs. Western blotting showed that the protein levels of osteogenesis-related factors were increased when HIF-1α was overexpressed. Furthermore, the influence of upregulation of HIF-1α in ADSC sheets on osseointegration was evaluated using a Sprague-Dawley (SD) rats implant model, in which the bone mass and osteoid mineralization speed were evaluated by radiological and histological analysis. The overexpression of HIF-1α in ADSCs enhanced bone remodeling and osseointegration around titanium implants. However, transfecting the small interfering RNA (siRNA) of HIF-1α in ADSCs attenuated their osteogenic and angiogenic capacity. Finally, it was confirmed in vitro that HIF-1α promotes osteogenic differentiation and the biological functions in ADSCs via the VEGF/AKT/mTOR pathway.

CONCLUSIONS

This study demonstrates that HIF-1α has a critical ability to promote osteogenic differentiation in ADSCs by coupling osteogenesis and angiogenesis via the VEGF/AKT/mTOR signaling pathway, which in turn increases osteointegration and bone formation around titanium implants.

Substrate stiffness can affect the crosstalk between adipose derived mesenchymal stem cells and macrophages in bone tissue engineering

Purpose: This study aimed to explore the effect of biomaterials with different stiffness on Adipose Derived Mesenchymal Stem Cells (ADSC)-macrophage crosstalk in bone tissue engineering and its role in bone repair. Methods: Biomaterials with Young's modulus of 64 and 0.2 kPa were selected, and the crosstalk between ADSCs and macrophages was investigated by means of conditioned medium treatment and cell co-culture, respectively. Polymerase chain reaction (PCR) and flow cytometry were used to evaluate the polarization of macrophages. Alkaline phosphatase (ALP) and alizarin red staining (ARS) solutions were used to evaluate the osteogenic differentiation of ADSCs. Transwell assay was used to evaluate the chemotaxis of ADSCs and macrophages. Moreover, mass spectrometry proteomics was used to analyze the secreted protein profile of ADSCs of different substrates and macrophages in different polarization states. Results: On exploring the influence of biomaterials on macrophages from ADSCs on different substrates, we found that CD163 and CD206 expression levels in macrophages were significantly higher in the 64-kPa group than in the 0.2-kPa group in conditioned medium treatment and cell co-culture. Flow cytometry showed that more cells became CD163+ or CD206+ cells in the 64-kPa group under conditioned medium treatment or cell co-culture. The Transwell assay showed that more macrophages migrated to the lower chamber in the 64-kPa group. The proteomic analysis found that ADSCs in the 64-kPa group secreted more immunomodulatory proteins, such as LBP and RBP4, to improve the repair microenvironment. On exploring the influence of biomaterials on ADSCs from macrophages in different polarization states, we found that ALP and ARS levels in ADSCs were significantly higher in the M2 group than in the other three groups (NC, M0, and M1 groups) in both conditioned medium treatment and cell co-culture. The Transwell assay showed that more ADSCs migrated to the lower chamber in the M2 group. The proteomic analysis found that M2 macrophages secreted more extracellular remodeling proteins, such as LRP1, to promote bone repair. Conclusion: In bone tissue engineering, the stiffness of repair biomaterials can affect the crosstalk between ADSCs and macrophages, thereby regulating local repair immunity and affecting bone repair.

Pulsed Electromagnetic Fields Combined With Adipose-Derived Stem Cells Protect Ischemic Myocardium by Regulating miR-20a-5p/E2F1/p73 Signaling

Myocardial infarction (MI) is a serious threat to human health. Although monotherapy with pulsed electromagnetic fields (PEMFs) or adipose-derived stem cells (ADSCs) has been reported to have positive effect on the treatment of MI, a satisfactory outcome has not yet been achieved. In recent years, combination therapy has attracted widespread interest. Herein, we explored the synergistic therapeutic effect of combination therapy with PEMFs and ADSCs on MI and found that the combination of PEMFs and ADSCs effectively reduced infarct size, inhibited cardiomyocyte apoptosis and protected the cardiac function in mice with MI. In addition, bioinformatics analysis and RT-qPCR showed that the combination therapy could affect apoptosis by regulating the expression of miR-20a-5p. A dual-luciferase reporter gene assay also confirmed that the miR-20a-5p could target E2F transcription factor 1 (E2F1) and inhibit cardiomyocyte apoptosis by regulating the E2F1/p73 signaling pathway. Therefore, our study systematically demonstrated the effectiveness of combination therapy on the inhibition of cardiomyocyte apoptosis by regulating the miR-20a-5p/E2F1/p73 signaling pathway in mice with MI. Thus, our study underscored the effectiveness of the combination of PEMFs and ADSCs and identified miR-20a-5p as a promising therapeutic target for the treatment of MI in the future.

Cryopreserved allogeneic mesenchymal stem cells enhance wound repair in full thickness skin wound model and cattle clinical teat injuries

The study was aimed to evaluate and compare the healing potential of mesenchymal stem cells (MSCs) derived from two common sources (iliac crest derived bone marrow and omental fat) in a full thickness skin wound model. Bone marrow derived MSCs clinical efficacy in the repair of cattle teat fistulae (cutaneous and muco-cutaneous wounds) was also evaluated. In a completely randomized placebo controlled experimental full thickness skin wound model, n=36 were randomly divided into three equal groups: groups I, II and III receiving Phosphate buffered saline (PBS), BM-MSCs and adipose tissue MSCs (AD-MSCs), respectively. Grossly early reduction in inflammation and enhanced epithelialization in the cell-treated groups as compared to the control was seen. Microscopy, ultramicroscopy, gene expression analysis and mechanical testing revealed better and early matrix formation with a reduced scar formation and a higher tensile strength in the cell-treated groups as compared to the control. An overall comparable healing in the cell treated groups was observed, although BM-MSCs had led to the better matrix formation tending to scarless healing while the AD-MSCs had led to the early wound closure with a good tissue strength. In the case controlled bovine clinical teat injuries study (n=17) repaired surgically, BM-MSCs (n=13) or PBS (n=4) was injected locally. In surgico-MSCs treated cases, 84.6% non-recurrence rate was observed as compared to the 50% seen in the control. It was concluded that MSCs irrespective of the donor tissue have potential to improve healing of full thickness cutaneous wounds and/ fistulae.

The Effect of Adipose Derived Stromal Vascular Fraction on Flap Viability in Experimental Diabetes Mellitus and Chronic Renal Disease

BACKGROUND

The presence of chronic renal disease(CRD) concurrently with diabetes mellitus(DM) increases the flap failure. Adipose derived stromal vascular fraction (SVF) is known to enhance skin flap viability in both healthy and diabetic individuals. The aim of this experimental study was to investigate the effect of SVF on skin flap viability in rats with DM and CRD.

METHODS

48 Sprague-Dawley rats were separated into four groups as follows: group I (control), group II (diabetes mellitus), group III (chronic renal disease), and group IV (diabetes with chronic renal disease).Two dorsal flaps were elevated. Flaps on left side of all groups received 0.5 cc of SVF, while same amount of plasma-buffered saline (PBS) was injected into right side. On postoperative day 7, flaps were harvested for macroscopic, histopathologic and biochemical assessments. Areas of flap survival were measured macroscopically. Blood level of vascular endothelial growth factor (VEGF) was measured after injection of SVF.

RESULTS

Macroscopically, SVF has significantly improved flap viability (p < 0.05). Flap viability percentage was lower in DM and CRD groups when compared with healthy control group. In respect of new capillary formation, there was a statistically significant difference between SVF injected flaps and PBS injected sides (p < 0.05). Similarly, VEGF levels were higher in all study groups and there was a significant difference in comparison to control group (p < 0.05).

CONCLUSIONS

The study showed that injection of SVF increased flap viability via endothelial differentiation and neovascularization. In vivo function of stem cells might be impaired due to uremia and diabetes-related microenviromental changes.

Role of miRNA-324-5p-Modified Adipose-Derived Stem Cells in Post-Myocardial Infarction Repair

Background and Objectives

To seek out the role of mircoRNA (miR)-324-5p-modified adipose-derived stem cells (ADSCs) in post-myocardial infarction (MI) myocardial repair.

Methods and Results

Rat ADSCs were cultivated and then identified by morphologic observation, osteogenesis and adipogenesis induction assays and flow cytometry. Afterwards, ADSCs were modified by miR-324-5p lentiviral vector, with ADSC proliferation and migration measured. Then, rat MI model was established, which was treated by ADSCs or miR-324-5p-modified ADSCs. Subsequently, the function of miR-324-5p-modified ADSCs in myocardial repair of MI rats was assessed through functional assays. Next, the binding relation of miR-324-5p and Toll-interacting protein (TOLLIP) was validated. Eventually, functional rescue assay of TOLLIP was performed to verify the role of TOLLIP in MI. First, rat ADSCs were harvested. Overexpressed miR-324-5p improved ADSC viability. ADSC transplantation moderately enhanced cardiac function of MI rats, reduced enzyme levels and decreased infarct size and apoptosis; while miR-324-5p-modified ADSCs could better promote post-MI repair. Mechanically, miR-324-5p targeted TOLLIP in myocardial tissues. Moreover, TOLLIP overexpression debilitated the promotive role of miR-324-5p-modified ADSCs in post-MI repair in rats.

Conclusions

miR-324-5p-modified ADSCs evidently strengthened post-MI myocardial repair by targeting TOLLIP in myocardial tissues.

Comparison of the Characteristics of Breast Milk-derived Stem Cells with the Stem Cells Derived from the Other Sources: A Comparative Review

Breast milk (BrM) not only supplies nutrition, but it also contains a diverse population of cells. It has been estimated that up to 6% of the cells in human milk possess the characteristics of mesenchymal stem cells (MSC). Available data also indicate that these cells are multipotent and capable of self-renewal and differentiation with other cells. In this review, we have compared different characteristics, such as CD markers, differentiation capacity, and morphology of stem cells, derived from human breast milk (hBr-MSC) with human bone marrow (hBMSC), Wharton's jelly (WJMSC), and human adipose tissue (hADMSC). Through the literature review, it was revealed that human breast milk-derived stem cells specifically express a group of cell surface markers, including CD14, CD31, CD45, and CD86. Importantly, a group of markers, CD13, CD29, CD44, CD105, CD106, CD146, and CD166, were identified, which were common in the four sources of stem cells. WJMSC, hBMSC, hADMSC, and hBr-MSC are potently able to differentiate into the mesoderm, ectoderm, and endoderm cell lineages. The ability of hBr-MSCs todifferentiate into the neural stem cells, neurons, adipocyte, hepatocyte, chondrocyte, osteocyte, and cardiomyocytes has made these cells a promising source of stem cells in regenerative medicine, while isolation of stem cells from the commonly used sources, such as bone marrow, requires invasive procedures. Although autologous breast milk-derived stem cells are an accessible source for women who are in the lactation period, breast milk can be considered as a source of stem cells with high differentiation potential without any ethical concern.

Comparison of Fat Harvested from Flank and Falciform Regions for Stem Cell Therapy in Dogs

Background: Adipose tissue has recently gained attention as a source of mesenchymal stem cells (AdMSCs) for applications in treating degenerative joint disease in veterinary patients. This study aimed to quantify the stromal vascular fractions (SVFs) and colony forming units (CFU) of AdMSCs from the falciform and flank regions and compare dogs of different ages and weights. Methods: Fat tissue was harvested from the flank (21 dogs) and falciform regions (17 dogs). The fat tissue was enzymatically digested and the number of nucleated cells in the SVF was counted. The SVF was cultured in vitro and the cell growth was assessed by counting the CFU per gram of fat and the aspect ratio of the cells. Conclusions: There was no significant difference in the number of nucleated cells in the SVF from the two sites. The CFU/g of fat from falciform was 378.9 ± 293 g and from flank was 486.8 ± 517 g, and this was also insignificant. Neither age nor weight of the patient had an impact on the SVF or CFU/g. No surgical complications were reported from either of the sites. Harvesting fat for stem cell therapy for intra-articular therapy of degenerative joint disease can be an easy and fast process when obtaining the fat either from the flank or the falciform region, and it is not age or weight dependent. The harvest site for clinical canine patients can be left to the surgeon’s discretion and comfort.

Overexpressing of caveolin-1 in mesenchymal stem cells promotes deep second-degree burn wound healing

Burn injury is one of the most common physical injuries in clinic. It is a big challenge to find an ideal treatment for burn injury. Mesenchymal stem cells (MSCs) have been suggested as a promising candidate for wound healing. However, it is critical to improve the therapeutic efficiency of MSCs for treatment of burn injury. Here, we demonstrated that overexpression of caveolin-1, the main component of the caveolae plasma membranes, promoted the proliferation of MSCs both in vitro and in vivo. Moreover, transplantation of MSCs overexpressing caveolin-1 facilitated the expression of various growth factors and immunoregulatory cytokines and accelerated deep second-degree burn wound healing in a rat model of burn injury. Our results suggest that overexpression of caveolin-1 can improve the therapeutic efficiency of MSCs, which may be a promising strategy for the treatment of deep second-degree burn injury in clinic.

Daphne mucronata enhances cell proliferation and protects human adipose stem cells against monosodium iodoacetate induced oxidative stress in vitro

Mesenchymal stem cells (MSCs) are being used to treat many diseases as they exhibit great regenerative potential. However, MSC's transplantation sometimes does not yield the maximum regenerative outcome as they are unable to survive in inflammatory conditions. Several approaches including preconditioning are used to improve the survival rate of mesenchymal stem cells. One such recently reported approach is preconditioning MSCs with plant extracts. The present study was designed to evaluate the effect of Daphne mucronata extract on stressed human adipose-derived mesenchymal stem cells (hADMSCs). Isolated hADMSCs were preconditioned with different concentrations of Daphne muconata extract and the protective, proliferative, antioxidant and anti-inflammatory effect was assessed through various assays and expression analysis of inflammatory markers regulated through NF-κB pathway. Results suggest that preconditioning hADMSCs with Daphne mucronata increased the cell viability, proliferative and protective potential of hADMSCs with a concomitant reduction in LDH, ROS and elevation in SOD activity. Moreover, both the ELISA and gene expression analysis demonstrated down regulations of inflammatory markers (IL1-β, TNF-α, p65, p50, MMP13) in Daphne mucronata preconditioned hADMSCs as compared to stress. This is the first study to report the use of MIA induced oxidative stress against hADMSC's and effect of Daphne mucronata on stressed hADMSCs. Results of these studies provided evidence that Daphne mucronata protects the hADMSCs during stress conditions by down regulating the inflammatory markers and hence increase the viability and proliferative potential of hADMSCs that is crucial for transplantation purposes.

Stem Cell Therapy for Hepatocellular Carcinoma: Future Perspectives

Hepatocellular carcinoma (HCC) is one of the most common types of cancer and results in a high mortality rate worldwide. Unfortunately, most cases of HCC are diagnosed in an advanced stage, resulting in a poor prognosis and ineffective treatment. HCC is often resistant to both radiotherapy and chemotherapy, resulting in a high recurrence rate. Although the use of stem cells is evolving into a potentially effective approach for the treatment of cancer, few studies on stem cell therapy in HCC have been published. The administration of stem cells from bone marrow, adipose tissue, the amnion, and the umbilical cord to experimental animal models of HCC has not yielded consistent responses. However, it is possible to induce the apoptosis of cancer cells, repress angiogenesis, and cause tumor regression by administration of genetically modified stem cells. New alternative approaches to cancer therapy, such as the use of stem cell derivatives, exosomes or stem cell extracts, have been proposed. In this review, we highlight these experimental approaches for the use of stem cells as a vehicle for local drug delivery.

[Effect of the local application of stem cells on repairing facial nerve defects: a systematic review]

OBJECTIVE

To systematically evaluate the repairing effect of stem cells on facial nerve defects.

METHODS

Articles regarding the regenerating effect of stem cells on facial nerves in animals were collected from the databases of Pubmed, Cochrane Library, Web of Science, Embase, Scopus, and CBM. Two professionals independently completed the article screening, data extraction, and bias risk assessment. RevMan 5.3 and random-effects models were used for the statistical analysis, and the results were presented in the form of mean differences (MD) with a 95%CI. The results of functional evaluation (vibrissae movement, facial paralysis) and histological evaluation (density of myelinated fibers, diameter of fibers, thickness of myelin sheath, G ratio) of facial nerve were Meta-analyzed.

RESULTS

A total of 4 614 articles were retrieved from the 6 databases, and 15 of these articles were included in the Meta-analysis. For vibrissae movement and facial paralysis, the stem cell group scored significantly higher than the non-stem cell group (P<0.05). The density of myelinated fibers and thickness of the myelin sheath in the stem cell group were higher than those in the non-stem cell group (P<0.05). The G ratio in the stem cell group was smaller than that in the non-stem cell group (P=0.001). There was no significant difference in fiber diameter (P=0.08).

CONCLUSIONS

Stem cells have potential in promoting facial nerve regeneration.

Comparison of the proteome patterns of adipose-derived stem cells with those treated with selegiline using a two dimensional gel electrophoresis analysis

Adipose derived stem cells (ADSCs) are multipotent and can transdifferentiate into neural stem cells. We investigated the transdifferentiation of ADSCs to neural phenotype (NP) cells using selegiline and two-dimensional electrophoresis (2-DE). The perinephric and inguinal fat of rats was collected and used to isolate ADSCs that were characterized by immunophenotyping using flow cytometry. The ADSCs were differentiated into osteogenic and lipogenic cells. The NP cells were generated using 10^-9 mM selegiline and characterized by immunocytochemical staining of nestin and neurofilament 68 (NF-68), and by qRT-PCR of nestin, neurod1 and NF68. Total protein of ADSCs and NP cells was extracted and their proteome patterns were examined using 2-DE. ADSCs carried CD73, CD44 and CD90 cell markers, but not CD34. ADSCs were differentiated into osteocyte and adipocyte lineages. The differentiated NP cells expressed nestin, neuro d1 and NF-68. The proteome pattern of ADSCs was compared with that of NP cells and eight spots showed more than a two fold increase in protein expression. The molecular weights and isoelectric points of these highly expressed proteins were estimated using Melanie software. We compared these results with those of the mouse proteomic database using the protein isoelectric point database, and the functions of the eight proteins in differentiation of NP cells were predicted using the UniProt database. The probable identities of the proteins that showed higher expression in NP cells included cholinesterase, GFRa2, protein kinase C (PKC-eta) and RING finger protein 121. The sequences of the proteins identified from mouse database were aligned by comparing them with similar proteins in rat database using the Basic Local Alignment Search Tool (BLAST). The E values of all aligned proteins were zero, which indicates consistency of the matched protein. These proteins participate in differentiation of the neuron and their overexpression causes ADSCs transdifferentiation into NP cells.

The Effect of Conditioned Media of Stem Cells Derived from Lipoma and Adipose Tissue on Macrophages' Response and Wound Healing in Indirect Co-culture System In Vitro

Immunomodulatory and wound healing activities of adipose-derived stem cells (ADSCs) have been reported in various in vitro and in vivo experimental models suggesting their beneficial role in regenerative medicine and treatments of inflammatory-related disorders. Lipoma-derived stem cells (LDSCs) were reported as a potential tool in regenerative medicine due to the similarity with ADSCs but we have previously shown that LDSCs have different differentiation capacity than ADSCs despite a similar mesenchymal phenotype. To further analyze the potential differences and/or similarities between those two stem cell types, in the present study we examined the macrophages (MΦs)’ response, immunomodulatory and wound healing effect of conditioned media (CM) of LDSCs and ADSCs in indirect co-culture system in vitro. We confirmed similar mesenchymal phenotype and stemness state of LDSCs and ADSCs but indicated differences in expression of some inflammatory-related genes. Anti-inflammatory potential of CM of LDSCs and ADSCs, with pronounced effect of LDSCs, in unstimulated RAW 264.7 MΦs was evaluated by decrease in Tnf and increase in Il10 gene expression, which was confirmed by corresponding cytokines’ secretion analysis. Conditioned media of both LDSCs and ADSCs led to the functional activation of MΦs, with slightly more pronounced effect of CM of LDSCs, while both stimulated wound healing in vitro in a similar manner. Results of this study suggest that LDSCs secrete soluble factors like ADSCs and therefore may have a potential for application in regenerative medicine, due to immunomodulatory and wound healing activity, and indicate that LDSCs through secretome may interact with other cells in lipoma tissue.

Rationale and design of the European multicentre study on Stem Cell therapy in IschEmic Non-treatable Cardiac diseasE (SCIENCE)

AIMS

Ischaemic heart failure (IHF) patients have a poor prognosis even with current guideline-derived therapy. Intramyocardial injections of autologous or allogeneic mesenchymal stromal cells might improve cardiac function leading to better clinical outcome.

METHODS

The SCIENCE (Stem Cell therapy in IschEmic Non-treatable Cardiac diseasE) consortium has initiated a Horizon 2020 funded multicentre phase II study in six European countries. It is a double-blind, placebo-controlled trial testing the safety and efficacy of allogeneic Cardiology Stem Cell Centre Adipose-derived Stromal Cells (CSCC_ASC) from healthy donors or placebo in 138 symptomatic IHF patients. Main inclusion criteria are New York Heart Association class II-III, left ventricular ejection fraction < 45% and N-terminal pro-B-type natriuretic peptide levels > 300 pg/mL. Patients are randomized in a 2:1 pattern to receive intramyocardial injections of either CSCC_ASC or placebo. CSCC_ASC and placebo treatments are prepared centralized at Rigshospitalet in 5 mL vials as an off-the-shelf product. Vials are distributed to all clinical partners and stored in nitrogen vapour tanks ready to be used directly after thawing. A total of 100 × 10⁶ CSCC_ASC or placebo are injected directly into viable myocardium in the infarct border zone using the NOGA XP system (BDS, Cordis, Johnson & Johnson, USA). Primary endpoint is a centralized core-laboratory assessed change in left ventricular end-systolic volume at 6-month follow-up measured by echocardiography. The trial started in January 2017, 58 patients were included and treated until July 2018.

CONCLUSION

The SCIENCE trial will provide clinical data on efficacy and safety of intramyocardial cell therapy of allogeneic adipose-derived stromal cells from healthy donors in patients with IHF.

An Update on the Therapeutic Potential of Stem Cells

The seeming setbacks noted for stem cells underscore the need for experimental studies for safe and efficacious application to patients. Both clinical and experimental researchers have gained valuable knowledge on the characteristics of stem cells, and their behavior in different microenvironment. This introductory chapter focuses on adult mesenchymal stem cells (MSCs) based on the predominance in the clinic. MSCs can be influenced by inflammatory mediators to exert immune suppressive properties, commonly referred to as "licensing." Interestingly, while there are questions if other stem cells can be delivered across allogeneic barrier, there is no question on the ability of MSCs to provide this benefit. This property has been a great advantage since MSCs could be available for immediate application as "off-the-shelf" stem cells for several disorders, tissue repair and gene/drug delivery. Despite the benefit of MSCs, it is imperative that research continues with the various types of stem cells. The method needed to isolate these cells is outlined in this book. In parallel, safety studies are needed; particularly links to oncogenic event. In summary, this introductory chapter discusses several potential areas that need to be addressed for safe and efficient delivery of stem cells, and argue for the incorporation of microenvironmental factors in the studies. The method described in this chapter could be extrapolated to the field of chimeric antigen receptor T-cells (CAR-T). This will require application to stem cell hierarchy of memory T-cells.

Adipose Tissue-Derived Stem Cells for Myocardial Regeneration

Over the past decade, stem cell therapy has been extensively studied for clinical application for heart diseases. Among various stem cells, adipose tissue-derived stem cell (ADSC) is still an attractive stem cell resource due to its abundance and easy accessibility. In vitro studies showed the multipotent differentiation potentials of ADSC, even differentiation into cardiomyocytes. Many pre-clinical animal studies have also demonstrated promising therapeutic results of ADSC. Furthermore, there were several clinical trials showing the positive results in acute myocardial infarction using ADSC. The present article covers the brief introduction, the suggested therapeutic mechanisms, application methods including cell dose and delivery, and human clinical trials of ADSC for myocardial regeneration.

The regenerative role of adipose-derived stem cells (ADSC) in plastic and reconstructive surgery

The potential use of stem cell-based therapies for the repair and regeneration of various tissues and organs offers a paradigm shift in plastic and reconstructive surgery. The use of either embryonic stem cells (ESC) or induced pluripotent stem cells (iPSC) in clinical situations is limited because of regulations and ethical considerations even though these cells are theoretically highly beneficial. Adult mesenchymal stem cells appear to be an ideal stem cell population for practical regenerative medicine. Among these cells, adipose-derived stem cells (ADSC) have the potential to differentiate the mesenchymal, ectodermal and endodermal lineages and are easy to harvest. Additionally, adipose tissue yields a high number of ADSC per volume of tissue. Based on this background knowledge, the purpose of this review is to summarise and describe the proliferation and differentiation capacities of ADSC together with current preclinical data regarding the use of ADSC as regenerative tools in plastic and reconstructive surgery.

Amniotic membrane and adipose-derived stem cell co-culture system enhances bone regeneration in a rat periodontal defect model

BACKGROUND/PURPOSE

Periodontal disease is a chronic inflammatory process that potentially leads to alveolar bone destruction and tooth loss. Tissue engineering combined with stem cell therapy is a potential effective treatment for periodontal bone loss. Amniotic membrane (AM) is a potential scaffold enriched with multiple growth factors. It has the effects of anti-inflammation, antiangiogenesis, and immunosuppression. Herein, we used adipose-derived stem cells (ADSCs) and an AM co-cultured system to study bone regeneration in a rat periodontal defect model in vivo.

METHODS

Human ADSCs were isolated from the infrapatellar fat pad, and characterized by flow cytometry, reverse transcription-polymerase chain reaction, and multipotent differentiation assays. The co-culture system was applied in the periodontal two-wall osseous defect in a rat model, and computed tomography was used to measure the effect.

RESULTS

Human ADSCs isolated from the infrapatellar fat pad showed spindle-like morphology. Flow cytometry results demonstrated that ADSCs expressed a high level of CD90 and CD105, but not CD31, CD34, and CD45. ADSCs strongly expressed stemness genes, including SOX2, OCT4, NANOG, and KLF4 on different passages. Furthermore, ADSCs were able to differentiate into osteogenic, chondrogenic, and adipogenic cells. In the periodontal osseous defect rat model, ADSCs and the AM co-culture system significantly increased bone regeneration.

CONCLUSION

This study provides the basis for using ADSCs with an AM co-culture system as stem cell therapy and scaffold transplantation in clinical periodontology.

Isolation and Characterization of Vessel-Associated Stem/Progenitor Cells from Skeletal Muscle

More than 10 years ago, we isolated from mouse embryonic dorsal aorta a population of vessel-associated stem/progenitor cells, originally named mesoangioblasts (MABs ) , capable to differentiate in all mesodermal-derived tissues, including skeletal muscle. Similar though not identical cells have been later isolated and characterized from small vessels of adult mouse and human skeletal muscles. When delivered through the arterial circulation, MABs cross the blood vessel wall and participate in skeletal muscle regeneration , leading to an amelioration of muscular dystrophies in different preclinical animal models. As such, human MABs have been used under clinical-grade conditions for a Phase I/II clinical trial for Duchenne muscular dystrophy , just concluded. Although some pericyte markers can be used to identify mouse and human MABs , no single unequivocal marker can be used to isolate MABs . As a result, MABs are mainly defined by their isolation method and functional properties. This chapter provides detailed methods for isolation, culture, and characterization of MABs in light of the recent identification of a new marker, PW1 /Peg3, to screen and identify competent MABs before their use in cell therapy.

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 adipose-derived 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.

Cell Sheet Transplantation for Esophageal Stricture Prevention after Endoscopic Submucosal Dissection in a Porcine Model

Background & Aims

Extended esophageal endoscopic submucosal dissection (ESD) is highly responsible for esophageal stricture. We conducted a comparative study in a porcine model to evaluate the effectiveness of adipose tissue-derived stromal cell (ADSC) double cell sheet transplantation.

Methods

Twelve female pigs were treated with 5 cm long hemi-circumferential ESD and randomized in two groups. ADSC group (n = 6) received 4 double cell sheets of allogenic ADSC on a paper support membrane and control group (n = 6) received 4 paper support membranes. ADSC were labelled with PKH-67 fluorophore to allow probe-based confocal laser endomicroscopie (pCLE) monitoring. After 28 days follow-up, animals were sacrificed. At days 3, 14 and 28, endoscopic evaluation with pCLE and esophagography were performed.

Results

One animal from the control group was excluded (anesthetic complication). Animals from ADSC group showed less frequent alimentary trouble (17% vs 80%; P = 0.08) and higher gain weight on day 28. pCLE demonstrated a compatible cell signal in 4 animals of the ADSC group at day 3. In ADSC group, endoscopy showed that 1 out of 6(17%) animals developed a severe esophageal stricture comparatively to 100% (5/5) in the control group; P = 0.015. Esophagography demonstrated a decreased degree of stricture in the ADSC group on day 14 (44% vs 81%; P = 0.017) and day 28 (46% vs 90%; P = 0.035). Histological analysis showed a decreased fibrosis development in the ADSC group, in terms of surface (9.7 vs 26.1 mm²; P = 0.017) and maximal depth (1.6 vs 3.2 mm; P = 0.052).

Conclusion

In this model, transplantation of allogenic ADSC organized in double cell sheets after extended esophegeal ESD is strongly associated with a lower esophageal stricture’s rate.

Systems-based technologies in profiling the stem cell molecular framework for cardioregenerative medicine

Over the last decade, advancements in stem cell biology have yielded a variety of sources for stem cell-based cardiovascular investigation. Stem cell behavior, whether to maintain its stable state of pluripotency or to prime toward the cardiovascular lineage is governed by a set of coordinated interactions between epigenetic, transcriptional, and translational mechanisms. The science of incorporating genes (genomics), RNA (transcriptomics), proteins (proteomics), and metabolites (metabolomics) data in a specific biological sample is known as systems biology. Integrating systems biology in progression with stem cell biologics can contribute to our knowledge of mechanisms that underlie pluripotency maintenance and guarantee fidelity of cardiac lineage specification. This review provides a brief summarization of OMICS-based strategies including transcriptomics, proteomics, and metabolomics used to understand stem cell fate and to outline molecular processes involved in heart development. Additionally, current efforts in cardioregeneration based on the "one-size-fits-all" principle limit the potential of individualized therapy in regenerative medicine. Here, we summarize recent studies that introduced systems biology into cardiovascular clinical outcomes analysis, allowing for predictive assessment for disease recurrence and patient-specific therapeutic response.

Human olfactory stem cells for injured facial nerve reconstruction in a rat model

BACKGROUND

The purpose of this study was to show the efficacy of olfactory stem cells for injured facial nerve reconstruction in a rat model.

METHODS

Olfactory stem cells were isolated from the olfactory mucosa of human participants. A 2-mm excision was performed on the right facial nerve of all rats. Reconstruction was performed with a conduit in group 1 (n = 9); a conduit and phosphate-buffered saline in group 2 (n = 9); and a conduit and labeled olfactory stem cell in group 3 (n = 9). Rats were followed for whisker movements and electroneuronography (ENoG) analyses.

RESULTS

The whisker-movement scores for group 3 were significantly different from other groups (p < .001). ENoG showed that the amplitude values for group 3 were significantly different from group 1 and group 2 (p = .030; p < .001). Group 3 showed marked olfactory stem cell under a fluorescence microscope.

CONCLUSION

This study suggests that olfactory stem cells may be used as a potent cellular therapy for accelerating the regeneration of peripheral nerve injuries. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2011-E2020, 2016.

RESCUE-HF Trial: Retrograde Delivery of Allogeneic Umbilical Cord Lining Subepithelial Cells in Patients With Heart Failure

Cell therapy is an evolving option for patients with end-stage heart failure. First-generation cell therapy trials have had marginal success. Our goal was to evaluate retrograde delivery of allogeneic umbilical cord subepithelial cells (UCSECs) in patients with heart failure. A prospective open-label dose escalation study of the safety and feasibility of UCSECs infused retrogradely into the coronary sinus was performed. Patients received a single dose of either 100 million (M), 200M, or 400M cells. The patients were followed for 2 years. Twenty-four patients were successfully enrolled in the study. The patients had UCSEC infusion without procedure-related complications. The ejection fraction in patients receiving UCSECs demonstrated improvement compared to baseline; from 25.4% (±5.5) at screening to 34.9% (±4.1) at 12 months. End-systolic diameter decreased significantly from 59.9 (±5.3) mm to 52.6 (±2.7) mm (p < 0.05). Retrograde UCSEC delivery was safe and feasible in all three dosage groups. Patients receiving 200M and 400M UCSECs showed signs of early improvement in left ventricular ejection fraction (LVEF) and remodeling. This study provides the basis for a larger clinical trial in heart failure (HF) patients using the middle or high dose of UCSECs.

Intravenous administration of adipose tissue-derived stem cells enhances nerve healing and promotes BDNF expression via the TrkB signaling in a rat stroke model

Previous studies have shown the beneficial effects of adipose-derived stem cells (ADSCs) transplantation in stroke. However, the molecular mechanism by which transplanted ADSCs promote nerve healing is not yet elucidated. In order to make clear the molecular mechanism for the neuroprotective effects of ADSCs and investigate roles of the BDNF-TrkB signaling in neuroprotection of ADSCs, we, therefore, examined the neurological function, brain water content, and the protein expression in middle cerebral artery occlusion (MCAO) rats with or without ADSCs transplantation. ADSCs were transplanted intravenously into rats at 30 minutes after MCAO. K252a, an inhibitor of TrkB, was administered into rats by intraventricular and brain stereotaxic injection. Modified neurological severity score tests were performed to measure behavioral outcomes. The results showed that ADSCs significantly alleviated neurological deficits and reduced brain water content in MCAO rats. The protein expression levels of BDNF and TrkB significantly increased in the cortex of MCAO rats with ADSCs treatment. However, K252a administration reversed the ADSCs-induced elevation of BDNF, TrkB, and Bcl-2 and reduction of Bax protein in MCAO rats. ADSCs promote BDNF expression via the TrkB signaling and improve functional neurological recovery in stroke rats.

17β-Estradiol and testosterone in sarcopenia: Role of satellite cells

The loss of muscle mass and strength with aging, referred to as sarcopenia, is a prevalent condition among the elderly. Although the molecular mechanisms underlying sarcopenia are unclear, evidence suggests that an age-related acceleration of myocyte loss via apoptosis might be responsible for muscle perfomance decline. Interestingly, sarcopenia has been associated to a deficit of sex hormones which decrease upon aging. The skeletal muscle ability to repair and regenerate itself would not be possible without satellite cells, a subpopulation of cells that remain quiescent throughout life. They are activated in response to stress, enabling them to guide skeletal muscle regeneration. Thus, these cells could be a key factor to overcome sarcopenia. Of importance, satellite cells are 17β-estradiol (E2) and testosterone (T) targets. In this review, we summarize potential mechanisms through which these hormones regulate satellite cells activation during skeletal muscle regeneration in the elderly. The advance in its understanding will help to the development of potential therapeutic agents to alleviate and treat sarcopenia and other related myophaties.

REVIVE Trial: Retrograde Delivery of Autologous Bone Marrow in Patients With Heart Failure

Cell therapy is an evolving option for patients with end-stage heart failure and ongoing symptoms despite optimal medical therapy. Our goal was to evaluate retrograde bone marrow cell delivery in patients with either ischemic heart failure (IHF) or nonischemic heart failure (NIHF). This was a prospective randomized, multicenter, open-label study of the safety and feasibility of bone marrow aspirate concentrate (BMAC) infused retrograde into the coronary sinus. Sixty patients were stratified by IHF and NIHF and randomized to receive either BMAC infusion or control (standard heart failure care) in a 4:1 ratio. Accordingly, 24 subjects were randomized to the ischemic BMAC group and 6 to the ischemic control group. Similarly, 24 subjects were randomized to the nonischemic BMAC group and 6 to the nonischemic control group. All 60 patients were successfully enrolled in the study. The treatment groups received BMAC infusion without complications. The left ventricular ejection fraction in the patients receiving BMAC demonstrated significant improvement compared with baseline, from 25.1% at screening to 31.1% at 12 months (p=.007) in the NIHF group and from 26.3% to 31.1% in the IHF group (p=.035). The end-systolic diameter decreased significantly in the nonischemic BMAC group from 55.6 to 50.9 mm (p=.020). Retrograde BMAC delivery is safe. All patients receiving BMAC experienced improvements in left ventricular ejection fraction, but only those with NIHF showed improvements in left ventricular end-systolic diameter and B-type natriuretic peptide. These results provide the basis for a larger clinical trial in HF patients.

SIGNIFICANCE

This work is the first prospective randomized clinical trial using high-dose cell therapy delivered via a retrograde coronary sinus infusion in patients with heart failure. This was a multinational, multicenter study, and it is novel, translatable, and scalable. On the basis of this trial and the safety of retrograde coronary sinus infusion, there are three other trials under way using this route of delivery.

Mesenchymal stromal cells for cutaneous wound healing in a rabbit model: pre-clinical study applicable in the pediatric surgical setting

Objective

Mesenchymal stromal cells (MSCs) expanded in vitro have been proposed as a potential therapy for congenital or acquired skin defects in pediatrics. The aim of this pre-clinical study was to investigate the effects of intradermal injections of MSC in experimental cutaneous wound repair comparing allogeneic and autologous adipose stem cells (ASCs) and autologous bone marrow-mesenchymal stromal cells (BM-MSCs).

Methods

Mesenchymal stromal cells were in vitro expanded from adipose and BM tissues of young female New Zealand rabbits. MSCs were characterized for plastic adhesion, surface markers, proliferation and differentiation capacity. When an adequate number of cells (ASCs 10 × 10⁶ and BM-MSCs 3 × 10⁶, because of their low rate of proliferation) was reached, two skin wounds were surgically induced in each animal. The first was topically treated with cell infusions, the second was used as a control. The intradermal inoculation included autologous or allogeneic ASCs or autologous BM-MSCs. For histological examination, animals were sacrificed and wounds were harvested after 11 and 21 days of treatment.

Results

Rabbit ASCs were isolated and expanded in vitro with relative abundance, cells expressed typical surface markers (CD49e, CD90 and CD29). Topically, ASC inoculation provided more rapid wound healing than BM-MSCs and controls. Improved re-epithelization, reduced inflammatory infiltration and increased collagen deposition were observed in biopsies from wounds treated with ASCs, with the best result in the autologous setting. ASCs also improved restoration of skin architecture during wound healing.

Conclusion

The use of ASCs may offer a promising solution to treat extended wounds. Pre-clinical studies are however necessary to validate the best skin regeneration technique, which could be used in pediatric surgical translational research.

Application of stems cells in wound healing--an update

Wound healing is a complex but well-orchestrated tissue repair process composed of a series of molecular and cellular events conducted by various types of cells and extracellular matrix. Despite a variety of therapeutic strategies proposed to accelerate the healing of acute and/or chronic wounds over the past few decades, effective treatment of chronic nonhealing wounds still remains a challenge. Due to the recent advances in stem cell research, a dramatic enthusiasm has been drawn to the application of stem cells in regenerative medicine. Both embryonic and adult stem cells have prolonged self-renewal capacity and are able to differentiate into various tissue types. Nevertheless, use of embryonic stem cells is limited, owing to ethical concerns and legal restrictions. Adult stem cells, which could be isolated from bone marrow, umbilical cord blood, adipose tissue, skin and hair follicles,are being explored extensively to facilitate the healing of both acute and chronic wounds. The current article summarizes recent research on various types of stem cell-based strategies applied to improve wound healing. In addition, future directions of stem cell-based therapy in wound healing have also been discussed. Finally, despite its apparent advantages, limitations and challenges of stem cell therapy are discussed.

Adipose-derived stem cell adhesion on laminin-coated microcarriers improves commitment toward the cardiomyogenic lineage

For tissue-engineering studies of the infarcted heart it is essential to identify a source of cells that may provide cardiomyocyte progenitors, which is easy to amplify, accessible in adults, and allowing autologous grafts. Preclinical studies have shown that human adipose-derived stem cells (ADSCs) can differentiate into cardiomyocyte-like cells and improve heart function in myocardial infarction. We have developed pharmacologically active microcarriers (PAMs) which are biodegradable and biocompatible polymeric microspheres conveying cells on their biomimetic surface, therefore providing an adequate three-dimensional (3D) microenvironment. Moreover, they can release a growth factor in a prolonged manner. In order to implement ADSCs and PAMs for cardiac tissue engineering we first defined the biomimetic surface by studying the influence of matrix molecules laminin (LM) and fibronectin (FN), in combination with growth factors present in the cardiogenic niche, to further enhance the in vitro cardiac differentiation of ADSCs. We demonstrated that LM increased the expression of cardiac markers (Nkx2.5, GATA4, MEF2C) by ADSCs after 2 weeks in vitro. Interestingly, our results suggest that the 3D support provided by PAMs with a LM biomimetic surface (LM-PAMs) further enhanced the expression of cardiac markers and induced the expression of a more mature contractile protein, cardiac troponin I, compared with the 2D differentiating conditions after only 1 week in culture. The enrichment of the growth-factor cocktail with TGF-β1 potentiated the cardiomyogenic differentiation. These results suggest that PAMs offering a LM biomimetic surface may be efficiently used for applications combining adult stem cells in tissue-engineering strategies of the ischemic heart.

Human perivascular stem cell-based bone graft substitute induces rat spinal fusion

Adipose tissue is an attractive source of mesenchymal stem cells (MSCs) because of its abundance and accessibility. We have previously defined a population of native MSCs termed perivascular stem cells (PSCs), purified from diverse human tissues, including adipose tissue. Human PSCs (hPSCs) are a bipartite cell population composed of pericytes (CD146+CD34-CD45-) and adventitial cells (CD146-CD34+CD45-), isolated by fluorescence-activated cell sorting and with properties identical to those of culture identified MSCs. Our previous studies showed that hPSCs exhibit improved bone formation compared with a sample-matched unpurified population (termed stromal vascular fraction); however, it is not known whether hPSCs would be efficacious in a spinal fusion model. To investigate, we evaluated the osteogenic potential of freshly sorted hPSCs without culture expansion and differentiation in a rat model of posterolateral lumbar spinal fusion. We compared increasing dosages of implanted hPSCs to assess for dose-dependent efficacy. All hPSC treatment groups induced successful spinal fusion, assessed by manual palpation and microcomputed tomography. Computerized biomechanical simulation (finite element analysis) further demonstrated bone fusion with hPSC treatment. Histological analyses showed robust endochondral ossification in hPSC-treated samples. Finally, we confirmed that implanted hPSCs indeed differentiated into osteoblasts and osteocytes; however, the majority of the new bone formation was of host origin. These results suggest that implanted hPSCs positively regulate bone formation via direct and paracrine mechanisms. In summary, hPSCs are a readily available MSC population that effectively forms bone without requirements for culture or predifferentiation. Thus, hPSC-based products show promise for future efforts in clinical bone regeneration and repair.

Preliminary report of in vitro reconstruction of a vascularized tendonlike structure: a novel application for adipose-derived stem cells

INTRODUCTION

A greater supply of tendinous tissue can be obtained through tissue engineering technology with increasing application of adult stem cells. It is well known that adipose-derived stem cells (ADSCs), found in abundance in adipose tissue, have the same differentiating capacity as mesenchymal stem cells yet have the advantage of being easily isolated. In the present study, we combined the great facility of ADSCs to differentiate with the application of an external mechanical stimulus to successfully create an in vitro reconstructed tendonlike structure with a microcapillary network.

MATERIALS AND METHODS

Hyalonect meshes (Fidia Advanced Biopolymers, Abano Terme, Padova, Italy) were used as scaffold. Human ADSCs were seeded onto the biomaterials, and the cell/scaffold constructs were cultured under mechanical stress for up to 15 days. Human tenocytes were used in the same conditions as control. Performance was assessed by histology, immunochemistry, ultrastructure, and biomolecular analysis.

RESULTS

Adipose-derived stem cells seeded onto Hyalonect adhered and differentiated along the entire surface of the biomaterial and began to infiltrate within its structure. Subsequently, endothelial cells migrated, forming a capillary in the new extracellular matrix.

CONCLUSIONS

This technique allowed for the creation of a vascularized tendon equivalent that could easily be detached from the bioreactor, thus facilitating its implant at the lesion site. These results highlight the biologic performance of biodegradable hyaluronic acid-based (HYAFF-11) scaffolds, which were shown to be suitable for deposition of the autologous extracellular matrix critical for ADSCs differentiation.

Anti-aging effect of adipose-derived stem cells in a mouse model of skin aging induced by D-galactose

Introduction

Glycation products accumulate during aging of slowly renewing tissue, including skin, and are suggested as an important mechanism underlying the skin aging process. Adipose-derived cells are widely used in the clinic to treat ischemic diseases and enhance wound healing. Interestingly, adipose-derived stem cells (ASCs) are also effective in anti-aging therapy, although the mechanism underlying their effects remains unknown. The purpose of the present study was to examine the anti-aging effect of ASCs in a D-galactose-induced aging animal model and to clarify the underlying mechanism.

Materials and Methods

Six-week-old nude mice were subcutaneously injected with D-gal daily for 8 weeks. Two weeks after completion of treatment, mice were randomized to receive subcutaneous injections of 10⁶ green fluorescent protein (GFP)-expressing ASCs, aminoguanidine (AG) or phosphate-buffered saline (PBS). Control mice received no treatment. We examined tissue histology and determined the activity of senescence-associated molecular markers such as superoxide dismutase (SOD) and malondialdehyde (MDA).

Results

Transplanted ASCs were detectable for 14 days and their GFP signal disappeared at day 28 after injection. ASCs inhibited advanced glycation end product (AGE) levels in our animal model as well as increased the SOD level and decreased the MDA level, all of which act to reverse the aging phenotype in a similar way to AG, an inhibitor of AGE formation. Furthermore, ASCs released angiogenic factors in vivo such as vascular endothelial growth factor, suggesting a skin trophic effect.

Conclusions

These results demonstrate that ASCs may contribute to the regeneration of skin during aging. In addition, the data shows that ASCs provide a functional benefit by glycation suppression, antioxidation, and trophic effects in a mouse model of aging.

Natural history of mesenchymal stem cells, from vessel walls to culture vessels

Mesenchymal stem/stromal cells (MSCs) can regenerate tissues by direct differentiation or indirectly by stimulating angiogenesis, limiting inflammation, and recruiting tissue-specific progenitor cells. MSCs emerge and multiply in long-term cultures of total cells from the bone marrow or multiple other organs. Such a derivation in vitro is simple and convenient, hence popular, but has long precluded understanding of the native identity, tissue distribution, frequency, and natural role of MSCs, which have been defined and validated exclusively in terms of surface marker expression and developmental potential in culture into bone, cartilage, and fat. Such simple, widely accepted criteria uniformly typify MSCs, even though some differences in potential exist, depending on tissue sources. Combined immunohistochemistry, flow cytometry, and cell culture have allowed tracking the artifactual cultured mesenchymal stem/stromal cells back to perivascular anatomical regions. Presently, both pericytes enveloping microvessels and adventitial cells surrounding larger arteries and veins have been described as possible MSC forerunners. While such a vascular association would explain why MSCs have been isolated from virtually all tissues tested, the origin of the MSCs grown from umbilical cord blood remains unknown. In fact, most aspects of the biology of perivascular MSCs are still obscure, from the emergence of these cells in the embryo to the molecular control of their activity in adult tissues. Such dark areas have not compromised intents to use these cells in clinical settings though, in which purified perivascular cells already exhibit decisive advantages over conventional MSCs, including purity, thorough characterization and, principally, total independence from in vitro culture. A growing body of experimental data is currently paving the way to the medical usage of autologous sorted perivascular cells for indications in which MSCs have been previously contemplated or actually used, such as bone regeneration and cardiovascular tissue repair.

Surface design of antibody-immobilized thermoresponsive cell culture dishes for recovering intact cells by low-temperature treatment

Antibody-immobilized thermoresponsive poly(N-isopropylacrylamide-co-2-carboxyisopropylacrylamide) [poly(IPAAm-co-CIPAAm)]-grafted cell culture surfaces were designed to enhance both the initial adhesion of weakly adhering cells and the ability of cells to detach in response to low temperature through the regulation of affinity binding between immobilized antibodies and antigens on the cellular surface. Ty-82 cells and neonatal normal human dermal fibroblasts (NHDFs), which express CD90 on the cell surface, adhered to anti-CD90 antibody-immobilized thermoresponsive surfaces at 37°C, a condition at which the grafted thermoresponsive polymer chains shrank. Adherent Ty-82 cells were detached from the surfaces by lowering the temperature to 20°C and applying external forces, such as pipetting, whereas cultured NHDF sheets spontaneously detached themselves from the surface in response to reduced temperature alone. When the temperature was decreased to 20°C, the swelling of grafted thermoresponsive polymer chains weakened the affinity binding between immobilized antibody and antigen on the cells due to the increasing steric hindrance of the polymer chains around the antigen-recognition site of the immobilized antibodies. No contamination was detected on cells harvested from covalently immobilized antibodies on the culture surfaces by low-temperature treatment, whereas a carryover of the antibody and avidin from the avidin-biotin binding surface was observed. Furthermore, the initial adhesion of adipose tissue-derived cells, which adhere weakly to PIPAAm-grafted surfaces, was enhanced on the antibody-immobilized thermoresponsive surfaces.

Intramyocardial injection of autologous bone marrow-derived ex vivo expanded mesenchymal stem cells in acute myocardial infarction patients is feasible and safe up to 5 years of follow-up

In experimental studies, mesenchymal stem cell (MSC) transplantation in acute myocardial infarction (AMI) models has been associated with enhanced neovascularization and myogenesis. Clinical data however, are scarce. Therefore, the present study evaluates the safety and feasibility of intramyocardial MSC injection in nine patients, shortly after AMI during short-term and 5-year follow-up. Periprocedural safety analysis demonstrated one transient ischemic attack. No other adverse events related to MSC treatment were observed during 5-year follow-up. Clinical events were compared to a nonrandomized control group comprising 45 matched controls. A 5-year event-free survival after MSC-treatment was comparable to controls (89 vs. 91 %, P = 0.87). Echocardiographic imaging for evaluation of left ventricular function demonstrated improvements up to 5 years after MSC treatment. These findings were not significantly different when compared to controls. The present safety and feasibility study suggest that intramyocardial injection of MSC in patients shortly after AMI is feasible and safe up to 5-year follow-up.

Mesenchymal stem cells in joint disease and repair

Osteoarthritis (OA), a prevalent chronic condition with a striking impact on quality of life, represents an enormous societal burden that increases greatly as populations age. Yet no approved pharmacological intervention, biologic therapy or procedure prevents the progressive destruction of the OA joint. Mesenchymal stem cells (MSCs)-multipotent precursors of connective tissue cells that can be isolated from many adult tissues, including those of the diarthrodial joint-have emerged as a potential therapy. Endogenous MSCs contribute to maintenance of healthy tissues by acting as reservoirs of repair cells or as immunomodulatory sentinels to reduce inflammation. The onset of degenerative changes in the joint is associated with aberrant activity or depletion of these cell reservoirs, leading to loss of chondrogenic potential and preponderance of a fibrogenic phenotype. Local delivery of ex vivo cultures of MSCs has produced promising outcomes in preclinical models of joint disease. Mechanistically, paracrine signalling by MSCs might be more important than differentiation in stimulating repair responses; thus, paracrine factors must be assessed as measures of MSC therapeutic potency, to replace traditional assays based on cell-surface markers and differentiation. Several early-stage clinical trials, initiated or underway in 2013, are testing the delivery of MSCs as an intra-articular injection into the knee, but optimal dose and vehicle are yet to be established.