Dual expression of hTERT and VEGF prolongs life span and enhances angiogenic ability of aged BMSCs

The other side of the coin: mesenchymal stromal cell immortalization beyond evasion of senescence

Mesenchymal stromal cells (MSC) are promising options to cellular therapy to several clinical disorders, mainly because of its ability to immunomodulate and differentiate into different cell types. Even though MSC can be isolated from different sources, a major challenge to understanding the biological effects is that the primary cells undergo replicative senescence after a limited number of cell divisions in culture, requiring time-consuming and technically challenging approaches to get a sufficient cell number for clinical applications. Therefore, a new isolation, characterization, and expansion is necessary every time, which increases the variability and is time-consuming. Immortalization is a strategy that can overcome these challenges. Therefore, here, we review the different methodologies available to cellular immortalization, and discuss the literature regarding MSC immortalization and the broader biological consequences that extend beyond the mere increase in proliferation potential.

Rejuvenation of Mesenchymal Stem Cells to Ameliorate Skeletal Aging

Advanced age is a shared risk factor for many chronic and debilitating skeletal diseases including osteoporosis and periodontitis. Mesenchymal stem cells develop various aging phenotypes including the onset of senescence, intrinsic loss of regenerative potential and exacerbation of inflammatory microenvironment via secretory factors. This review elaborates on the emerging concepts on the molecular and epigenetic mechanisms of MSC senescence, such as the accumulation of oxidative stress, DNA damage and mitochondrial dysfunction. Senescent MSCs aggravate local inflammation, disrupt bone remodeling and bone-fat balance, thereby contributing to the progression of age-related bone diseases. Various rejuvenation strategies to target senescent MSCs could present a promising paradigm to restore skeletal aging.

The transplantation of rapamycin-treated senescent human mesenchymal stem cells with enhanced proangiogenic activity promotes neovascularization and ischemic limb salvage in mice

Few therapies can reverse the proangiogenic activity of senescent mesenchymal stromal/stem cells (MSCs). In this study, we investigated the effects of rapamycin on the proangiogenic ability of senescent human umbilical cord MSCs (UCMSCs). An in vitro replicative senescent cell model was established in cultured UCMSCs. We found that late passage (P25 or later) UCMSCs (LP-UCMSCs) exhibited impaired proangiogenic abilities. Treatment of P25 UCMSCs with rapamycin (900 nM) reversed the senescent phenotype and notably enhanced the proangiogenic activity of senescent UCMSCs. In a nude mouse model of hindlimb ischemia, intramuscular injection of rapamycin-treated P25 UCMSCs into the ischemic limb significantly promoted neovascularization and ischemic limb salvage. We further analyzed the changes in the expression of angiogenesis-associated genes in rapamycin-primed MSCs and found higher expression of several genes related to angiogenesis, such as VEGFR2 and CTGF/CCN2, in primed cells than in unprimed MSCs. Taken together, our data demonstrate that rapamycin is a potential drug to restore the proangiogenic activity of senescent MSCs, which is of importance in treating ischemic diseases and tissue engineering.

Heparin/collagen surface coatings modulate the growth, secretome, and morphology of human mesenchymal stromal cell response to interferon-gamma

The therapeutic potential of human mesenchymal stromal cells (h-MSC) is dependent on the viability and secretory capacity of cells both modulated by the culture environment. Our previous studies introduced heparin and collagen I (HEP/COL) alternating stacked layers as a potential substrate to enhance the secretion of immunosuppressive factors of h-MSCs. Herein, we examined the impact of HEP/COL multilayers on the growth, morphology, and secretome of bone marrow and adipose-derived h-MSCs. The physicochemical properties and stability of the HEP/COL coatings were confirmed at 0 and 30 days. Cell growth was examined using cell culture media supplemented with 2 and 10% serum for 5 days. Results showed that HEP/COL multilayers supported h-MSC growth in 2% serum at levels equivalent to 10% serum. COL and HEP as single component coatings had limited impact on cell growth. Senescent studies performed over three sequential passages showed that HEP/COL multilayers did not impair the replicative capacity of h-MSCs. Examination of 27 cytokines showed significant enhancements in eight factors, including intracellular indoleamine 2, 3-dioxygenase, on HEP/COL multilayers when stimulated with interferon-gamma (IFN-γ). Image-based analysis of cell micrographs showed that serum influences h-MSC morphology; however, HEP-ended multilayers generated distinct morphological changes in response to IFN-γ, suggesting an optical detectable assessment of h-MSCs immunosuppressive potency. This study supports HEP/COL multilayers as a culture substrate for undifferentiated h-MSCs cultured in reduced serum conditions.

Synergistic Effects of Mesenchymal Stem Cell Transplantation and Repetitive Transcranial Magnetic Stimulation on Promoting Autophagy and Synaptic Plasticity in Vascular Dementia

Repetitive transcranial magnetic stimulation (rTMS) and mesenchymal stem cells (MSCs) transplantation both showed therapeutic effects on cognition impairment in vascular dementia (VD) model rats. However, whether these two therapies have synergistic effects and the molecular mechanisms remain unclear. In our present study, rats were randomly divided into six groups: control group, sham operation group, VD group, MSC group, rTMS group, and MSC+rTMS group. The VD model rats were prepared using a modified 2VO method. rTMS treatment was implemented at a frequency of 5 Hz, the stimulation intensity for 0.5 Tesla, 20 strings every day with 10 pulses per string and six treatment courses. The results of the Morris water maze test showed that the learning and memory abilities of the MSC group, rTMS group, and MSC+rTMS group were better than that of the VD group, and the MSC+rTMS group showed the most significant effect. The protein expression levels of brain-derived neurotrophic factor, NR1, LC3-II, and Beclin-1 were the highest and p62 protein was the lowest in the MSC+rTMS group. Our findings demonstrated that rTMS could further enhance the effect of MSC transplantation on VD rats and provided an important basis for the combined application of MSC transplantation and rTMS to treat VD or other neurological diseases.

Insulin-Producing Cell Transplantation Platform for Veterinary Practice

Diabetes mellitus (DM) remains a global concern in both human and veterinary medicine. Type I DM requires prolonged and consistent exogenous insulin administration to address hyperglycemia, which can increase the risk of diabetes complications such as retinopathy, nephropathy, neuropathy, and heart disorders. Cell-based therapies have been successful in human medicine using the Edmonton protocol. These therapies help maintain the production of endogenous insulin and stabilize blood glucose levels and may possibly be adapted to veterinary clinical practice. The limited number of cadaveric pancreas donors and the long-term use of immunosuppressive agents are the main obstacles for this protocol. Over the past decade, the development of potential therapies for DM has mainly focused on the generation of effective insulin-producing cells (IPCs) from various sources of stem cells that can be transplanted into the body. Another successful application of stem cells in type I DM therapies is transplanting generated IPCs. Encapsulation can be an alternative strategy to protect IPCs from rejection by the body due to their immunoisolation properties. This review summarizes current concepts of IPCs and encapsulation technology for veterinary clinical application and proposes a potential stem-cell-based platform for veterinary diabetic regenerative therapy.

Generation and characterization of a functional human adipose-derived multipotent mesenchymal stromal cell line

Multipotent mesenchymal stromal cells (MSC) and MSC-derived products have emerged as promising therapeutic tools. To fully exploit their potential, further mechanistic studies are still necessary and bioprocessing needs to be optimized, which requires an abundant supply of functional MSC for basic research. To address this need, here we used a novel technology to establish a human adipose-derived MSC line with functional characteristics representative of primary MSC. Primary MSC were isolated and subjected to lentiviral transduction with a library of expansion genes. Clonal cell lines were generated and evaluated on the basis of their morphology, immunophenotype, and proliferation potential. One clone (K5 iMSC) was then selected for further characterization. This clone had integrated a specific transgene combination including genes involved in stemness and maintenance of adult stem cells. Favorably, the K5 iMSC showed cell characteristics resembling juvenile MSC, as they displayed a shorter cell length and enhanced migration and proliferation compared with the non-immortalized original primary MSC (p < 0.05). Still, their immunophenotype and differentiation potential corresponded to the original primary MSC and the MSC definition criteria, and cytogenetic analyses revealed no clonal aberrations. We conclude that the technology used is applicable to generate functional MSC lines for basic research and possible future bioprocessing applications.

Autologous Endothelial Progenitor Cells Transplantation for Acute Ischemic Stroke: A 4-Year Follow-Up Study

Transplantation of endothelial progenitor cells (EPCs) is a proven safe and effective method for treatment of cerebral ischemia in animal experiments. However, safety and efficacy need to be determined in clinical trials. We performed a two‐center, randomized, placebo‐controlled phase I/IIa trial with blinded outcome assessment on 18 patients with acute cerebral infarct within the middle cerebral artery territory, and followed for up to 4 years. Autologous ex vivo expanded EPCs were injected intravenously in the EPC group, and patients who received saline or autologous bone marrow stromal cells served as control groups. Mortality of any cause, adverse events, and new‐onset comorbidities were monitored. Changes in neurological deficits were assessed at different time points. We found no toxicity events or infusional or allergic reactions in any treated group. Three patients in the placebo group died during the 4‐year follow‐up. We found that the EPC group had fewer serious adverse events compared with the placebo‐controlled group, although there were no statistical differences in mortality among the three groups. Furthermore, there was no significant difference in neurological or functional improvement observed among the three groups, except for the Scandinavia Stroke Scale score at 3 months between the EPC group and placebo‐controlled group. Autologous transplantation of EPCs appears to improve long‐term safety in acute cerebral infarct patients, supporting the feasibility of this novel method for treatment of ischemic stroke (ClinicalTrials.gov: NCT01468064). Stem Cells Translational Medicine2019;8:14–21

Platelet-derived growth factor subunit B is required for tendon-bone healing using bone marrow-derived mesenchymal stem cells after rotator cuff repair in rats

As a common cause of shoulder pain and disability, rotator cuff injury (RCI) represents a debilitating condition affecting an individual's quality of life. Although surgical repair has been shown to be somewhat effective, many patients may still suffer from reduced shoulder function. The aim of the current study was to identify a more effective mode of RCI treatment by investigating the effect of platelet-derived growth factor subunit B (PDGF-B) on tendon-bone healing after RCI repair by modifying bone marrow-derived mesenchymal stem cells (BMSCs). Surface markers of BMSCs were initially detected by means of flow cytometry, followed by establishment of the rat models and construction of the lentiviral vector. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, Thiazolyl Blue Tetrazolium Bromide (MTT) assay, alizarin red staining, and oil red O staining were used to provide verification that PDGF-B was indeed capable of promoting BMSC viability, osteogenic and adipogenic differentiation capability. Furthermore, biomechanical assessment results indicated that PDGF-B could increase the ultimate load and stiffness of the tendon tissue. Real-time reverse-transcription quantitative polymerase chain reaction and Western blot analysis methods provided evidence suggesting that PDGF-B facilitated the expression of tendon-bone healing-related genes and proteins, while contrasting results were obtained after PDGF-B silencing. Taken together, the key findings of the current study provided evidence suggesting that overexpressed PDGF-B could act to enhance tendon-bone healing after RCI repair, thus highlighting the potential of the functional promotion of PDGF-B as a future RCI therapeutic approach.

Ectopic Telomerase Expression Fails to Maintain Chondrogenic Capacity in Three-Dimensional Cultures of Clinically Relevant Cell Types

The poor healing capacity of cartilage and lack of effective treatment for associated disease and trauma makes it a strong candidate for a regenerative medicine approach. Potential therapies tested to date, although effective, have met with a number of intrinsic difficulties possibly related to limited autologous chondrocyte cell yield and quality of cartilage produced. A potential mechanism to bypass limited cell yields and improve quality of differentiation is to immortalize relevant cell types through the ectopic expression of telomerase. Pellet cultures of human chondrocytes (OK3), bone marrow mesenchymal stem cells (BMA13), and embryonic stem cell (H1 line)-derived cells (1C6) and their human telomerase reverse transcriptase (hTERT) transduced counterparts were maintained for 20 days in standard maintenance medium (MM) or transforming growth factor-β3-supplemented prochondrogenic medium (PChM). Pellets were assessed for volume and density by microcomputed tomography. Quantitative gene expression (COL1A2, COL2A1, COL3A1, COL6A3, COL10A1, ACAN, COMP, SOX9); sulfated glycosaminoglycans (sGAGs), and DNA quantification were performed. Histology and immunohistochemistry were used to determine matrix constituent distribution. Pellet culture in PChM resulted in significantly larger pellets with an overall increased density when compared with MM culture. Gene expression analysis revealed similarities in expression patterns between telomerase-transduced and parental cells in both MM and PChM. Of the three parental cell types examined OK3 and BMA13 produced similar amounts of pellet-associated sGAG in PChM (4.62 ± 1.20 and 4.91 ± 1.37 μg, respectively) with lower amounts in 1C6 (2.89 ± 0.52 μg), corresponding to 3.1, 2.3, and 1.6-fold increases from day 0. In comparison, telomerase-transduced cells all had much lower sGAG with OK3H at 2.74 ± 0.11 μg, BMA13H 1.29 ± 0.34 μg, and 1C6H 0.52 ± 0.01 μg corresponding to 1.2, 0.87, and 0.34-fold changes compared with day 0. Histology of day 20 pellets displayed reduced staining overall for collagens and sGAG in telomerase-transduced cells, most notably with alterations in aggrecan and collagen VI; all cells stained positively for collagen II. We conclude that while telomerase transduction may be an effective technique to extend cellular proliferative capacity, it is not sufficient in isolation to sustain a naive chondrogenic phenotype across multiple cell types.

Usage of Human Mesenchymal Stem Cells in Cell-based Therapy: Advantages and Disadvantages

The use of human mesenchymal stem cells (hMSCs) in cell-based therapy has attracted extensive interest in the field of regenerative medicine, and it shows applications to numerous incurable diseases. hMSCs show several superior properties for therapeutic use compared to other types of stem cells. Different cell types are discussed in terms of their advantages and disadvantages, with focus on the characteristics of hMSCs. hMSCs can proliferate readily and produce differentiated cells that can substitute for the targeted affected tissue. To maximize the therapeutic effects of hMSCs, a substantial number of these cells are essential, requiring extensive ex vivo cell expansion. However, hMSCs have a limited lifespan in an in vitro culture condition. The senescence of hMSCs is a double-edged sword from the viewpoint of clinical applications. Although their limited cell proliferation potency protects them from malignant transformation after transplantation, senescence can alter various cell functions including proliferation, differentiation, and migration, that are essential for their therapeutic efficacy. Numerous trials to overcome the limited lifespan of mesenchymal stem cells are discussed.

Melatonin Treatment Improves Mesenchymal Stem Cells Therapy by Preserving Stemness during Long-term In Vitro Expansion

Mesenchymal stem cells (MSCs) are promising candidates for tissue regeneration and disease treatment. However, long-term in vitro passaging leads to stemness loss of MSCs, resulting in failure of MSCs therapy. Here, we report a melatonin-based strategy to improve cell therapy of in vitro cultured MSCs. Among four small molecules with anti-aging and stem cell-protection properties (rapamycin, resveratrol, quercetin and melatonin), colony forming, proliferation, and osteogenic differentiation assay showed that melatonin was the most efficient to preserve self-renewal and differentiation properties of rat bone marrow MSCs (BMMSCs) after long-term passaging. Functional assays confirmed melatonin treatment did not affect the colony forming, proliferation and osteogenic differentiation of BMMSCs cultured for 1 or 4 passages, but largely prevented the decline of self-renew and differentiation capacity of BMMSCs cultured for 15 passages in vitro. Furthermore, heterotopic osteogenesis assay, critical size calvarial defects repair assay, osteoporosis treatment and experimental colitis therapy assay strongly certified that melatonin preserved the therapeutic effect of long-term passaged BMMSCs on bone regeneration and immunotherapy in vivo. Mechanistically, melatonin functioned by activating antioxidant defense system, inhibiting the pathway of cell senescence, and preserving the expression of gene governing the stemness. Taken together, our findings showed that melatonin treatment efficiently prevented the dysfunction and therapeutic failure of BMMSCs after long-term passaging, providing a practical strategy to improve the application of BMMSCs in tissue engineering and cytotherapy.

Senescence in Human Mesenchymal Stem Cells: Functional Changes and Implications in Stem Cell-Based Therapy

Regenerative medicine is extensively interested in developing cell therapies using mesenchymal stem cells (MSCs), with applications to several aging-associated diseases. For successful therapies, a substantial number of cells are needed, requiring extensive ex vivo cell expansion. However, MSC proliferation is limited and it is quite likely that long-term culture evokes continuous changes in MSCs. Therefore, a substantial proportion of cells may undergo senescence. In the present review, we will first present the phenotypic characterization of senescent human MSCs (hMSCs) and their possible consequent functional alterations. The accumulation of oxidative stress and dysregulation of key differentiation regulatory factors determine decreased differentiation potential of senescent hMSCs. Senescent hMSCs also show a marked impairment in their migratory and homing ability. Finally, many factors present in the secretome of senescent hMSCs are able to exacerbate the inflammatory response at a systemic level, decreasing the immune modulation activity of hMSCs and promoting either proliferation or migration of cancer cells. Considering the deleterious effects that these changes could evoke, it would appear of primary importance to monitor the occurrence of senescent phenotype in clinically expanded hMSCs and to evaluate possible ways to prevent in vitro MSC senescence. An updated critical presentation of the possible strategies for in vitro senescence monitoring and prevention constitutes the second part of this review. Understanding the mechanisms that drive toward hMSC growth arrest and evaluating how to counteract these for preserving a functional stem cell pool is of fundamental importance for the development of efficient cell-based therapeutic approaches.

Genetic Engineering of Mesenchymal Stem Cells for Regenerative Medicine

Mesenchymal stem cells (MSCs), which can be obtained from various organs and easily propagated in vitro, are one of the most extensively used types of stem cells and have been shown to be efficacious in a broad set of diseases. The unique and highly desirable properties of MSCs include high migratory capacities toward injured areas, immunomodulatory features, and the natural ability to differentiate into connective tissue phenotypes. These phenotypes include bone and cartilage, and these properties predispose MSCs to be therapeutically useful. In addition, MSCs elicit their therapeutic effects by paracrine actions, in which the metabolism of target tissues is modulated. Genetic engineering methods can greatly amplify these properties and broaden the therapeutic capabilities of MSCs, including transdifferentiation toward diverse cell lineages. However, cell engineering can also affect safety and increase the cost of therapy based on MSCs; thus, the advantages and disadvantages of these procedures should be discussed. In this review, the latest applications of genetic engineering methods for MSCs with regenerative medicine purposes are presented.

Immortalisation with hTERT Impacts on Sulphated Glycosaminoglycan Secretion and Immunophenotype in a Variable and Cell Specific Manner

Background

Limited options for the treatment of cartilage damage have driven the development of tissue engineered or cell therapy alternatives reliant on ex vivo cell expansion. The study of chondrogenesis in primary cells is difficult due to progressive cellular aging and senescence. Immortalisation via the reintroduction of the catalytic component of telomerase, hTERT, could allow repeated, longitudinal studies to be performed while bypassing senescent phenotypes.

Methods

Three human cell types: bone marrow-derived stromal cells (BMA13), embryonic stem cell-derived (1C6) and chondrocytes (OK3) were transduced with hTERT (BMA13H, 1C6H and OK3H) and proliferation, surface marker expression and tri-lineage differentiation capacity determined. The sulphated glycosaminoglycan (sGAG) content of the monolayer and spent media was quantified in maintenance media (MM) and pro-chondrogenic media (PChM) and normalised to DNA.

Results

hTERT expression was confirmed in transduced cells with proliferation enhancement in 1C6H and OK3H cells but not BMA13H. All cells were negative for leukocyte markers (CD19, CD34, CD45) and CD73 positive. CD14 was expressed at low levels on OK3 and OK3H and HLA-DR on BMA13 (84.8%). CD90 was high for BMA13 (84.9%) and OK3 (97.3%) and moderate for 1C6 (56.7%), expression was reduced in BMA13H (33.7%) and 1C6H (1.6%). CD105 levels varied (BMA13 87.7%, 1C6 8.2%, OK3 43.3%) and underwent reduction in OK3H (25.1%). 1C6 and BMA13 demonstrated osteogenic and adipogenic differentiation but mineralised matrix and lipid accumulation appeared reduced post hTERT transduction. Chondrogenic differentiation resulted in increased monolayer-associated sGAG in all primary cells and 1C6H (p<0.001), and BMA13H (p<0.05). In contrast OK3H demonstrated reduced monolayer-associated sGAG in PChM (p<0.001). Media-associated sGAG accounted for ≥55% (PChM-1C6) and ≥74% (MM-1C6H).

Conclusion

In conclusion, hTERT transduction could, but did not always, prevent senescence and cell phenotype, including differentiation potential, was affected in a variable manner. As such, these cells are not a direct substitute for primary cells in cartilage regeneration research.

The influence of the telomere-telomerase system on diabetes mellitus and its vascular complications

INTRODUCTION

The telomere-telomerase system plays an important role in the pathogenesis and disease progression of diabetes mellitus as well as in its vascular complications. Recent studies suggest that telomere shortening and abnormal telomerase activity occur in patients with diabetes mellitus, and targeting the telomere-telomerase system has become a prospective treatment for diabetes mellitus and its vascular complications. This review highlights the significance of the telomere-telomerase system and supports its role as a possible therapeutic target for patients with diabetes mellitus and its vascular complications Areas covered: This review covers the advances in understanding the telomere-telomerase system over the last 30 years and its significance in diabetes mellitus. In addition, it provides knowledge regarding the significance of the telomere-telomerase system in diabetes mellitus and its vascular complications as well as its role and mechanisms in oxidative stress, cell therapy and antioxidant activity Expert opinion: The telomere-telomerase system may be a potential therapeutic target that can protect against DNA damage and apoptosis in patients with diabetes mellitus and its vascular complications. DNA damage and apoptosis are associated with oxidative stress and are involved in the dysfunction of pancreatic β cells, insulin resistance, and its vascular complications. Abnormalities in the telomere-telomerase system may be associated with diabetes mellitus and its vascular complications. Therapies targeting telomere-telomerase system, telomerase reverse transcriptase transfection and alterative telomere lengthening must be identified before gene therapy can commence.

Autologous Stem Cell Therapy: How Aging and Chronic Diseases Affect Stem and Progenitor Cells

During recent years different types of adult stem/progenitor cells have been successfully applied for the treatment of many pathologies, including cardiovascular diseases. The regenerative potential of these cells is considered to be due to their high proliferation and differentiation capacities, paracrine activity, and immunologic privilege. However, therapeutic efficacy of the autologous stem/progenitor cells for most clinical applications remains modest, possibly because of the attenuation of their regenerative potential in aged patients with chronic diseases such as cardiovascular diseases and metabolic disorders. In this review we will discuss the risk factors affecting the therapeutic potential of adult stem/progenitor cells as well as the main approaches to mitigating them using the methods of regenerative medicine.

Characterization of bone marrow-derived mesenchymal stem cells in aging

Adult mesenchymal stem cells are a resource for autologous and allogeneic cell therapies for immune-modulation and regenerative medicine. However, patients most in need of such therapies are often of advanced age. Therefore, the effects of the aged milieu on these cells and their intrinsic aging in vivo are important considerations. Furthermore, these cells may require expansion in vitro before use as well as for future research. Their aging in vitro is thus also an important consideration. Here, we focus on bone marrow mesenchymal stem cells (BMSCs), which are unique compared to other stem cells due to their support of hematopoietic cells in addition to contributing to bone formation. BMSCs may be sensitive to age-related diseases and could perpetuate degenerative diseases in which bone remodeling is a contributory factor. Here, we review (1) the characterization of BMSCs, (2) the characterization of in vivo-aged BMSCs, (3) the characterization of in vitro-aged BMSCs, and (4) potential approaches to optimize the performance of aged BMSCs. This article is part of a Special Issue entitled "Stem Cells and Bone".

Hypoxia-cultured human adipose-derived mesenchymal stem cells are non-oncogenic and have enhanced viability, motility, and tropism to brain cancer

Adult human adipose-derived mesenchymal stem cells (hAMSCs) are multipotent cells, which are abundant, easily collected, and bypass the ethical concerns that plague embryonic stem cells. Their utility and accessibility have led to the rapid development of clinical investigations to explore their autologous and allogeneic cellular-based regenerative potential, tissue preservation capabilities, anti-inflammatory properties, and anticancer properties, among others. hAMSCs are typically cultured under ambient conditions with 21% oxygen. However, physiologically, hAMSCs exist in an environment of much lower oxygen tension. Furthermore, hAMSCs cultured in standard conditions have shown limited proliferative and migratory capabilities, as well as limited viability. This study investigated the effects hypoxic culture conditions have on primary intraoperatively derived hAMSCs. hAMSCs cultured under hypoxia (hAMSCs-H) remained multipotent, capable of differentiation into osteogenic, chondrogenic, and adipogenic lineages. In addition, hAMSCs-H grew faster and exhibited less cell death. Furthermore, hAMSCs-H had greater motility than normoxia-cultured hAMSCs and exhibited greater homing ability to glioblastoma (GBM) derived from brain tumor-initiating cells from our patients in vitro and in vivo. Importantly, hAMSCs-H did not transform into tumor-associated fibroblasts in vitro and were not tumorigenic in vivo. Rather, hAMSCs-H promoted the differentiation of brain cancer cells in vitro and in vivo. These findings suggest an alternative culturing technique that can enhance the function of hAMSCs, which may be necessary for their use in the treatment of various pathologies including stroke, myocardial infarction, amyotrophic lateral sclerosis, and GBM.

NGF and TERT co-transfected BMSCs improve the restoration of cognitive impairment in vascular dementia rats

Vascular dementia (VaD) is a mental disorder caused by brain damage due to cerebrovascular disease, and incidence of VaD is rising. To date, there is no known effective cure for VaD, so effort in developing an effective treatment for VaD is of great importance. The differentiation plasticity of BMSCs, in conjunction with its weak immunogenicity, makes manipulated BMSCs an attractive strategy for disease treatment. However, BMSCs often display disabled differentiation, premature aging, and unstable proliferation, reducing their neuroprotective function. These problems may be caused by the lack of telomerase activity in BMSCs. Our results show that NGF-TERT co-transfected BMSCs have a better therapeutic effect than BMSCs lacking NGF and TERT expression, demonstrated by significant improvements in learning and memory in VaD rats. The underlying mechanism might be increased expression of NGF, TrkA and SYN in the hippocampal CA1 area, which has potential implication in advancing therapeutics for VaD.

Identification of a small molecule preventing BMSC senescence in vitro by improving intracellular homeostasis via ANXA7 and Hmbox1

ABO was discovered to be a novel anti-aging chemical in cultured BMSCs by improving intracellular homeostasis.