Potent Paracrine Effects of human induced Pluripotent Stem Cell-derived Mesenchymal Stem Cells Attenuate Doxorubicin-induced Cardiomyopathy

Exosomal miR-9-5p derived from iPSC-MSCs ameliorates doxorubicin-induced cardiomyopathy by inhibiting cardiomyocyte senescence

Doxorubicin (DOX) is a chemotherapeutic agent widely used for tumor treatment. Nonetheless its clinical application is heavily limited by its cardiotoxicity. There is accumulated evidence that transplantation of mesenchymal stem cell-derived exosomes (MSC-EXOs) can protect against Dox-induced cardiomyopathy (DIC). This study aimed to examine the cardioprotective effects of EXOs isolated from human induced pluripotent stem cell-derived MSCs (iPSC-MSCs) against DIC and explore the potential mechanisms. EXOs were isolated from the cultural supernatant of human BM-MSCs (BM-MSC-EXOs) and iPSC-MSCs (iPSC-MSC-EXOs) by ultracentrifugation. A mouse model of DIC was induced by intraperitoneal injection of Dox followed by tail vein injection of PBS, BM-MSC-EXOs, or iPSC-MSC-EXOs. Cardiac function, cardiomyocyte senescence and mitochondrial dynamics in each group were assessed. In vitro, neonatal mouse cardiomyocytes (NMCMs) were subjected to Dox and treated with BM-MSC-EXOs or iPSC-MSC-EXOs. The mitochondrial morphology and cellular senescence of NMCMs were examined by Mitotracker staining and senescence-associated-β-galactosidase assay, respectively. Compared with BM-MSC-EXOs, mice treated with iPSC-MSC-EXOs displayed improved cardiac function and decreased cardiomyocyte mitochondrial fragmentation and senescence. In vitro, iPSC-MSC-EXOs were superior to BM-MSC-EXOs in attenuation of cardiomyocyte mitochondrial fragmentation and senescence caused by DOX. MicroRNA sequencing revealed a higher level of miR-9-5p in iPSC-MSC-EXOs than BM-MSC-EXOs. Mechanistically, iPSC-MSC-EXOs transported miR-9-5p into DOX-treated cardiomyocytes, thereby suppressing cardiomyocyte mitochondrial fragmentation and senescence via regulation of the VPO1/ERK signal pathway. These protective effects and cardioprotection against DIC were largely reversed by knockdown of miR-9-5p in iPSC-MSC-EXOs. Our results showed that miR-9-5p transferred by iPSC-MSC-EXOs protected against DIC by alleviating cardiomyocyte senescence via inhibition of the VPO1/ERK pathway. This study offers new insight into the application of iPSC-MSC-EXOs as a novel therapeutic strategy for DIC treatment.

Mesenchymal stem cell-derived exosomes: Characteristics and applications in disease pathology and management

Mesenchymal stem cells (MSCs) possess a role in tissue regeneration and homeostasis because of inherent immunomodulatory capacity and the production of factors that encourage healing. There is substantial evidence that MSCs' therapeutic efficacy is primarily determined by their paracrine function including in cancers. Extracellular vesicles (EVs) are basic paracrine effectors of MSCs that reside in numerous bodily fluids and cell homogenates and play an important role in bidirectional communication. MSC-derived EVs (MSC-EVs) offer a wide range of potential therapeutic uses that exceed cell treatment, while maintaining protocell function and having less immunogenicity. We describe characteristics and isolation methods of MSC-EVs, and focus on their therapeutic potential describing its roles in tissue repair, anti-fibrosis, and cancer with an emphasis on the molecular mechanism and immune modulation and clinical trials. We also explain current understanding and challenges in the clinical applications of MSC-EVs as a cell free therapy.

Mesenchymal stem cell-derived exosomes in myocardial infarction: Therapeutic potential and application

Myocardial infarction refers to the irreversible impairment of cardiac function resulting from the permanent loss of numerous cardiomyocytes and the formation of scar tissue. This condition is caused by acute and persistent inadequate blood supply to the heart's arteries. In the treatment of myocardial infarction, Mesenchymal stem cells (MSCs) play a crucial role because of their powerful therapeutic effects. These effects primarily stem from the paracrine secretion of multiple factors by MSCs, with exosome-carried microRNAs being the most effective component in promoting cardiac function recovery after infarction. Exosome therapy has emerged as a promising cell-free treatment for myocardial infarction as a result of its relatively simple composition, low immunogenicity and controlled transplantation dose. Despite these advantages, maintaining the stability of exosomes after transplantation and enhancing their targeting effect remain significant challenges in clinical applications. In recent developments, several approaches have been designed to optimize exosome therapy. These include enhancing exosome retention, improving their ability to target specific effects, pretreating MSC-derived exosomes and employing transgenic MSC-derived exosomes. This review primarily focuses on describing the biological characteristics of exosomes, their therapeutic potential and their application in treating myocardial infarction.

iPSC-derived mesenchymal stem cells attenuate cerebral ischemia-reperfusion injury by inhibiting inflammatory signaling and oxidative stress

Induced pluripotent stem cell-derived mesenchymal stem cells (iMSCs) hold great promise as a cell source for transplantation into injured tissues to alleviate inflammation. However, the therapeutic efficacy of iMSC transplantation for ischemic stroke remains unknown. In this study, we evaluated the therapeutic effects of iMSC transplantation on brain injury after ischemia-reperfusion using a rat transient middle cerebral artery occlusion model and compared its therapeutic efficacy with that of bone marrow mesenchymal stem cells (BMMSCs). We showed that iMSCs and BMMSCs reduced infarct volumes after reperfusion and significantly improved motor function on days 3, 7, 14, 28, and 56 and cognitive function on days 28 and 56 after reperfusion compared with the vehicle group. Furthermore, immunological analyses revealed that transplantation of iMSCs and BMMSCs inhibited microglial activation and expression of proinflammatory cytokines and suppressed oxidative stress and neuronal cell death in the cerebral cortex at the ischemic border zone. No difference in therapeutic effect was observed between the iMSC and BMMSC groups. Taken together, our results demonstrate that iMSC therapy can be a practical alternative as a cell source for attenuation of brain injury and improvement of neurological function because of the unlimited supply of uniform therapeutic cells.

The developing role of extracellular vesicles in autoimmune diseases: special attention to mesenchymal stem cell-derived extracellular vesicles

Autoimmune diseases are complex, chronic inflammatory conditions initiated by the loss of immunological tolerance to self-antigens. Nowadays, there is no effective and useful therapy for autoimmune diseases, and the existing medications have some limitations due to their nonspecific targets and side effects. During the last few decades, it has been established that mesenchymal stem cells (MSCs) have immunomodulatory functions. It is proposed that MSCs can exert an important therapeutic effect on autoimmune disorders. In parallel with these findings, several investigations have shown that MSCs alleviate autoimmune diseases. Intriguingly, the results of studies have demonstrated that the effective roles of MSCs in autoimmune diseases do not depend on direct intercellular communication but on their ability to release a wide spectrum of paracrine mediators such as growth factors, cytokines and extracellular vehicles (EVs). EVs that range from 50 to 5,000 nm were produced by almost any cell type, and these nanoparticles participate in homeostasis and intercellular communication via the transfer of a broad range of biomolecules such as modulatory proteins, nucleic acids (DNA and RNA), lipids, cytokines, and metabolites. EVs derived from MSCs display the exact properties of MSCs and can be safer and more beneficial than their parent cells. In this review, we will discuss the features of MSCs and their EVs, EVs biogenesis, and their cargos, and then we will highlight the existing discoveries on the impacts of EVs from MSCs on autoimmune diseases such as multiple sclerosis, arthritis rheumatic, inflammatory bowel disease, Type 1 diabetes mellitus, systemic lupus erythematosus, autoimmune liver diseases, Sjögren syndrome, and osteoarthritis, suggesting a potential alternative for autoimmune conditions therapy.

Bone marrow mesenchymal stromal cell-derived small extracellular vesicles: A novel therapeutic agent in ischemic heart diseases

Myocardial injury is a major pathological factor that causes death in patients with heart diseases. In recent years, mesenchymal stromal cells (MSCs) have been generally used in treating many diseases in animal models and clinical trials. mesenchymal stromal cells have the ability to differentiate into osteocytes, adipocytes and chondrocytes. Thus, these cells are considered suitable for cardiac injury repair. However, mechanistic studies have shown that the secretomes of mesenchymal stromal cells, mainly small extracellular vesicles (sEVs), have better therapeutic effects than mesenchymal stromal cells themselves. In addition, small extracellular vesicles have easier quality control characteristics and better safety profiles. Therefore, mesenchymal stromal cell-small extracellular vesicles are emerging as novel therapeutic agents for damaged myocardial treatment. To date, many clinical trials and preclinical experimental results have demonstrated the beneficial effects of bone marrow-derived mesenchymal stromal cells (BMMSCs) and bone marrow-derived mesenchymal stromal cells-small extracellular vesicles on ischemic heart disease. However, the validation of therapeutic efficacy and the use of tissue engineering methods require an exacting scientific rigor and robustness. This review summarizes the current knowledge of bone marrow-derived mesenchymal stromal cells- or bone marrow-derived mesenchymal stromal cells-small extracellular vesicle-based therapy for cardiac injury and discusses critical scientific issues in the development of these therapeutic strategies.

CXCR4+ Sorted Adipose-Derived Stem Cells Enhance Their Functional Benefits and Improve Cardiac Function after Myocardial Infarction

Objective

The homing of adipose-derived stem cells (ASCs) to infarcted myocardium, which is important for improved cardiac function, has been investigated previously, but with poor efficiency. Substantial improvements in engraftments are required to optimize ASC treatment. Stromal derived factor-1α (SDF-1α) is upregulated early after MI, and its endogenous receptor, chemokine receptor 4 (CXCR4), is pivotal in stem cell survival, migration, and engraftment. We examined whether CXCR4⁺ ASCs enhance their efficacy of migration and engraftment posttransplantation and improve heart function following myocardial infarction (MI).

Methods and Results

CXCR4⁺ ASC subpopulations were sorted by fluorescence-activated cell sorting. CXCR4⁺ sorted ASCs exhibited the stronger cell viability, the faster proliferation rate, and the better migration capability in comparison with unfractionated ASCs. CXCR4⁺ sorted ASCs secreted a higher level of angiogenic growth factors including VEGF, HGF, and IGF-1 relative to unfractionated ASCs. Fewer apoptotic cells under oxygen-glucose deprivation were detected in CXCR4⁺ sorted ASCs than in unfractionated ASCs. Osteogenic and angiogenic differentiation were more pronounced in CXCR4⁺ sorted ASCs than in unfractionated ASCs. At 3 days after acute MI, rats were randomly allocated to receive intramyocardial injection of cell culture medium, CXCR4⁺ sorted ASCs, and unfractionated ASCs. Left ventricular function was assessed echocardiographically 4 weeks thereafter. Explanted hearts were then processed for the immunofluorescence detection of survived cells, quantification of angiogenesis, and cell engraftment. CXCR4⁺ sorted ASCs more obviously engrafted into infarcted myocardium, more markedly inhibited collagen remodeling, and more effectively improved heart function and promoted capillary formation than did unfractionated ASCs.

Conclusion

CXCR4⁺ sorted ASCs are superior to unfractionated ASCs due to better viability, faster proliferation, more cytokine secretion, and stronger migration. CXCR4⁺ sorted ASCs provide better curative benefits on MI than do unfractionated ASCs and can be efficiently harvested and purified from adipose tissue, they may serve as a promising candidate for MI.

TA-MSCs, TA-MSCs-EVs, MIF: their crosstalk in immunosuppressive tumor microenvironment

As an important component of the immunosuppressive tumor microenvironment (TME), it has been established that mesenchymal stem cells (MSCs) promote the progression of tumor cells. MSCs can directly promote the proliferation, migration, and invasion of tumor cells via cytokines and chemokines, as well as promote tumor progression by regulating the functions of anti-tumor immune and immunosuppressive cells. MSCs-derived extracellular vesicles (MSCs-EVs) contain part of the plasma membrane and signaling factors from MSCs; therefore, they display similar effects on tumors in the immunosuppressive TME. The tumor-promoting role of macrophage migration inhibitory factor (MIF) in the immunosuppressive TME has also been revealed. Interestingly, MIF exerts similar effects to those of MSCs in the immunosuppressive TME. In this review, we summarized the main effects and related mechanisms of tumor-associated MSCs (TA-MSCs), TA-MSCs-EVs, and MIF on tumors, and described their relationships. On this basis, we hypothesized that TA-MSCs-EVs, the MIF axis, and TA-MSCs form a positive feedback loop with tumor cells, influencing the occurrence and development of tumors. The functions of these three factors in the TME may undergo dynamic changes with tumor growth and continuously affect tumor development. This provides a new idea for the targeted treatment of tumors with EVs carrying MIF inhibitors.

Mesenchymal stem cell-derived extracellular vesicles for immunomodulation and regeneration: a next generation therapeutic tool?

Mesenchymal stem cells (MSCs) can be widely isolated from various tissues including bone marrow, umbilical cord, and adipose tissue, with the potential for self-renewal and multipotent differentiation. There is compelling evidence that the therapeutic effect of MSCs mainly depends on their paracrine action. Extracellular vesicles (EVs) are fundamental paracrine effectors of MSCs and play a crucial role in intercellular communication, existing in various body fluids and cell supernatants. Since MSC-derived EVs retain the function of protocells and have lower immunogenicity, they have a wide range of prospective therapeutic applications with advantages over cell therapy. We describe some characteristics of MSC-EVs, and discuss their role in immune regulation and regeneration, with emphasis on the molecular mechanism and application of MSC-EVs in the treatment of fibrosis and support tissue repair. We also highlight current challenges in the clinical application of MSC-EVs and potential ways to overcome the problem of quality heterogeneity.

Characteristics and regulation of mesenchymal stem cell plasticity by the microenvironment — specific factors involved in the regulation of MSC plasticity

Mesenchymal stem cells (MSCs), multipotent stromal cells, have attracted extensive attention in the field of regenerative medicine and cell therapy due to the capacity of self-renewal, multilineage differentiation, and immune regulation. MSCs have different cellular effects in different diseases, and even have markedly different curative effects with different tissue sources, indicating the plasticity of MSCs. The phenotypes, secreted factors, and proliferative, migratory, differentiating, and immunomodulatory effects of MSCs depend on certain mediators present in their microenvironment. Understanding microenvironmental factors and their internal mechanisms in MSC responses may help in subsequent prediction and improvement of clinical benefits. This review highlighted the recent advances in MSC plasticity in the physiological and pathological microenvironment and multiple microenvironmental factors regulating MSC plasticity. It also highlighted some progress in the underlying molecular mechanisms of MSC remodeling in the microenvironment. It might provide references for the improvement in vitro culture of MSCs, clinical application, and in vivo induction.

Application of mesenchymal stem cells derived from human pluripotent stem cells in regenerative medicine

Mesenchymal stem cells (MSCs) represent the most clinically used stem cells in regenerative medicine. However, due to the disadvantages with primary MSCs, such as limited cell proliferative capacity and rarity in the tissues leading to limited MSCs, gradual loss of differentiation during in vitro expansion reducing the efficacy of MSC application, and variation among donors increasing the uncertainty of MSC efficacy, the clinical application of MSCs has been greatly hampered. MSCs derived from human pluripotent stem cells (hPSC-MSCs) can circumvent these problems associated with primary MSCs. Due to the infinite self-renewal of hPSCs and their differentiation potential towards MSCs, hPSC-MSCs are emerging as an attractive alternative for regenerative medicine. This review summarizes the progress on derivation of MSCs from human pluripotent stem cells, disease modelling and drug screening using hPSC-MSCs, and various applications of hPSC-MSCs in regenerative medicine. In the end, the challenges and concerns with hPSC-MSC applications are also discussed.

The Secretome of Human Neonatal Mesenchymal Stem Cells Modulates Doxorubicin-Induced Cytotoxicity: Impact in Non-Tumor Cells

Doxorubicin (Dox) is one of the most widely used treatments for breast cancer, although limited by the well-documented cardiotoxicity and other off-target effects. Mesenchymal stem cell (MSC) secretome has shown immunomodulatory and regenerative properties, further potentiated under 3D conditions. This work aimed to uncover the effect of the MSC-derived secretome from 3D (CM3D) or 2D (CM2D) cultures, in human malignant breast cells (MDA-MB-231), non-tumor breast epithelial cells (MCF10A) and differentiated AC16 cardiomyocytes, co-treated with Dox. A comprehensive proteomic analysis of CM3D/CM2D was also performed to unravel the underlying mechanism. CM3D/CM2D co-incubation with Dox revealed no significant differences in MDA-MB-231 viability when compared to Dox alone, whereas MCF10A and AC16 viability was consistently improved in Dox+CM3D-treated cells. Moreover, neither CM2D nor CM3D affected Dox anti-migratory and anti-invasive effects in MDA-MB-231. Notably, Ge-LC-MS/MS proteomic analysis revealed that CM3D displayed protective features that might be linked to the regulation of cell proliferation (CAPN1, CST1, LAMC2, RANBP3), migration (CCN3, MMP8, PDCD5), invasion (TIMP1/2), oxidative stress (COX6B1, AIFM1, CD9, GSR) and inflammation (CCN3, ANXA5, CDH13, GDF15). Overall, CM3D decreased Dox-induced cytotoxicity in non-tumor cells, without compromising Dox chemotherapeutic profile in malignant cells, suggesting its potential use as a chemotherapy adjuvant to reduce off-target side effects.

Magnetic Fe3 O4 @graphene oxide improves the therapeutic effects of embryonic stem cells on acute liver damage

OBJECTIVE

Acute liver failure is usually associated with inflammation and oxidation of hepatocytes and has high mortality and resource costs. Mesenchymal stem cell (MSCs) has occasionally been reported to have no beneficial effect due to poor transplantation and the survival of implanted cells. Recent studies showed that embryonic stem cell (ESC)-derived MSCs are an alternative for regenerative medicine. On the other hand, graphene-based nanostructures have proven useful in biomedicine. In this study, we investigated whether magnetic graphene oxide (MGO) improved the effects of ESC-MSC conditioned medium (CM) on protecting hepatocytes and stimulating the regeneration of damaged liver cells.

MATERIALS AND METHODS

To provide a rat model of acute liver failure, male rats were injected intraperitoneally with carbon tetrachloride (CCl4 ). The rats were randomly divided into six groups, namely control, sham, CCl4 , ESC-MSC-CM, MGO and ESC-MSC-CM + MGO. In the experimental groups, the rats received, depending on the group, 2 ml/kg body weight CCl4 and either ESC-MSC-CM with 5 × 106 MSCs or 300 μg/kg body weight MGO or both. Symptoms of acute liver failure appeared 4 days after the injection. All groups were compared and analysed both histologically and biochemically 4 days after the injection. Finally, the results of ESC-MSC-CM and MSC-CM were compared.

RESULTS

The results indicated that the use of MGO enhanced the effect of ESC-MSC-CM on reducing necrosis, inflammation, aspartate transaminase, alanine aminotransferase and alkaline phosphatase in the CCl4 -induced liver failure of the rat model. Also, the expression of vascular endothelial growth factor and matrix metalloproteinase-9 (MMP-9) was significantly upregulated after treatment with MGO. Also, the results showed that the ESC-MSC-CM has more efficient effective compared to MSC-CM.

CONCLUSION

Magnetic graphene oxide improved the hepatoprotective effects of ESC-MSC-CM on acute liver damage, probably by suppressing necrosis, apoptosis and inflammation of hepatocytes.

MSCs enhances the protective effects of valsartan on attenuating the doxorubicin-induced myocardial injury via AngII/NOX/ROS/MAPK signaling pathway

OBJECTIVE

To verify if AngII/NOX/ROS/MAPK signaling pathway is involved in Doxorubicin (DOX)-induced myocardial injury and if mesenchymal stem cells (MSCs) could enhance the protective effects of valsartan (Val) on attenuating DOX-induced injury in vitro.

METHODS

Reactive oxygen species (ROS) formation and the protein expression of AT1R, NOX2, NOX4, caspase-3, caspase-9 and MAPK signaling were assessed in H9c2 cardiomyocytes exposed to DOX for 24 h in the absence or presence of Val, NADPH oxidase inhibitor DPI or knockdown and overexpression of NADPH oxidase subunit: NOX2 and NOX4, co-culture with MSCs, respectively. Finally, MTT assay was used to determine the cell viability of H9c2 cells, MDA-MB-231 breast cancer cells and A549 pulmonary cancer cells under Val, DOX and Val+ DOX treatments.

RESULTS

DOX increased ROS formation and upregulated proteins expression of AT1R, NOX2, NOX4, caspase-3, caspase-9 and MAPK signaling including p-p38, p-JNK, p-ERK in H9c2 cells. These effects could be attenuated by Val, DPI, NOX2 siRNA and NOX4 siRNA. Meanwhile, overexpression of NOX2 and NOX4 could significantly increase DOX-induced ROS formation and further upregulate apoptotic protein expressions and protein expressions of MAPK signaling. MSCs on top of Val further enhanced the protective effects of Val on reducing the DOX-induced ROS formation and downregulating the expression of apoptotic proteins and MAPK signaling as compared with Val alone in DOX-treated H9c2 cells. Simultaneous Val and DOX treatment did not affect cell viability of DOX-treated MDA-MB-231 breast cancer cells or A549 pulmonary cancer cells but significantly improved cell viability of DOX-treated H9c2 cardiomyocytes.

CONCLUSIONS

AT1R/NOX/ROS/MAPK signaling pathway is involved in DOX-induced cardiotoxicity. Val treatment significantly attenuated DOX-induced cardiotoxicity, without affecting the anti-tumor effect of DOX. MSCs enhance the protective effects of Val on reducing the DOX-induced toxicity in H9c2 cells.

Application of mesenchymal stem cell sheet to treatment of ischemic heart disease

In recent years, mesenchymal stem cells (MSCs) have been used to improve cardiac function and attenuate adverse ventricular remodeling of the ischemic myocardium through paracrine effects and immunoregulation functions. In combination with cell sheet technology, MSCs could be more easily transplanted to the ischemic area. The long-term retention of MSCs in the affected area was realized and significantly improved the curative effect. In this review, we summarized the research and the applications of MSC sheets to the treatment of ischemic heart tissue. At present, many types of MSCs have been considered as multipotent cells in the treatment of heart failure, such as bone marrow-derived mesenchymal stem cells (BM-MSCs), adipose-derived mesenchymal stem cells (AD-MSCs), umbilical cord-derived mesenchymal stem cells (UC-MSCs), and skeletal myoblasts (SMs). Since UC-MSCs have few human leukocyte antigen-II and major histocompatibility complex class I molecules, and are easy to isolate and culture, UC-MSC sheets have been proposed as a candidate for clinical applications to ischemic heart disease.

A Preclinical Study of Human Embryonic Stem Cell-Derived Mesenchymal Stem Cells for Treating Detrusor Underactivity by Chronic Bladder Ischemia

Background

The therapeutic effects of human embryonic stem cell-derived multipotent mesenchymal stem cells (M-MSCs) were evaluated for detrusor underactivity (DUA) in a rat model with atherosclerosis-induced chronic bladder ischemia (CBI) and associated mechanisms.

Methods

Sixteen-week-old male Sprague–Dawley rats were divided into five groups (n = 10). The DUA groups underwent 30 bilateral repetitions of endothelial injury to the iliac arteries to induce CBI, while the sham control group underwent a sham operation. All rats used in this study received a 1.25% cholesterol diet for 8 weeks. M-MSCs at a density of 2.5, 5.0, or 10.0 × 10⁵ cells (250 K, 500 K, or 1000 K; K = a thousand) were injected directly into the bladder 7 weeks post-injury, while the sham and DUA group were treated only with vehicle (phosphate buffer solution). One week after M-MSC injection, awake cystometry was performed on the rats. Then, the bladders were harvested, studied in an organ bath, and prepared for histological and gene expression analyses.

Results

CBI by iliac artery injury reproduced voiding defects characteristic of DUA with decreased micturition pressure, increased micturition interval, and a larger residual volume. The pathological DUA properties were improved by M-MSC treatment in a dose-dependent manner, with the 1000 K group producing the best efficacy. Histological analysis revealed that M-MSC therapy reduced CBI-induced injuries including bladder fibrosis, muscular loss, and apoptosis. Transplanted M-MSCs mainly engrafted as vimentin and NG2 positive pericytes rather than myocytes, leading to increased angiogenesis in the CBI bladder. Transcriptomes of the CBI-injured bladders were characterized by the complement system, inflammatory, and ion transport-related pathways, which were restored by M-MSC therapy.

Conclusions

Single injection of M-MSCs directly into the bladder of a CBI-induced DUA rat model improved voiding profiles and repaired the bladder muscle atrophy in a dose-dependent manner.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s12015-021-10204-z.

Mesenchymal Stem Cell and MicroRNA Therapy of Musculoskeletal Diseases

The therapeutic effects of mesenchymal stem cells (MSCs) in musculoskeletal diseases (MSDs) have been verified in many human and animal studies. Although some tissues contain MSCs, the number of cells harvested from those tissues and rate of proliferation in vitro are not enough for continuous transplantation. In order to produce and maintain stable MSCs, many attempts are made to induce differentiation from pluripotent stem cells (iPSCs) into MSCs. In particular, it is also known that the paracrine action of stem cell-secreted factors could promote the regeneration and differentiation of target cells in damaged tissue. MicroRNAs (miRNAs), one of the secreted factors, are small non-coding RNAs that regulate the translation of a gene. It is known that miRNAs help communication between stem cells and their surrounding niches through exosomes to regulate the proliferation and differentiation of stem cells. While studies have so far been underway targeting therapeutic miRNAs of MSDs, studies on specific miRNAs secreted from MSCs are still minimal. Hence, our ultimate goal is to obtain sufficient amounts of exosomes from iPSC-MSCs and develop them into therapeutic agents, furthermore to select specific miRNAs and provide safe cell-free clinical setting as a cell-free status with purpose of delivering them to target cells. This review article focuses on stem cell therapy on MSDs, specific microRNAs regulating MSDs and updates on novel approaches.

Exploration of Alternative Splicing Events in Mesenchymal Stem Cells from Human Induced Pluripotent Stem Cells

Although comparative genome-wide transcriptomic analysis has provided insight into the biology of human induced pluripotent stem cell-derived mesenchymal stem cells (iMSCs), the distinct alternative splicing (AS) signatures of iMSCs remain elusive. Here, we performed Illumina RNA sequencing analysis to characterize AS events in iMSCs compared with tissue-derived MSCs. A total of 4586 differentially expressed genes (|FC| > 2) were identified between iMSCs and umbilical cord blood-derived MSCs (UCB-MSCs), including 2169 upregulated and 2417 downregulated genes. Of these, 164 differentially spliced events (BF > 20) in 112 genes were identified between iMSCs and UCB-MSCs. The predominant type of AS found in iMSCs was skipped exons (43.3%), followed by retained introns (19.5%), alternative 3′ (15.2%) and 5′ (12.8%) splice sites, and mutually exclusive exons (9.1%). Functional enrichment analysis showed that the differentially spliced genes (|FC| > 2 and BF > 20) were mainly enriched in functions associated with focal adhesion, extracellular exosomes, extracellular matrix organization, cell adhesion, and actin binding. Splice isoforms of selected genes including TRPT1, CNN2, and AP1G2, identified in sashimi plots, were further validated by RT-PCR analysis. This study provides valuable insight into the biology of iMSCs and the translation of mechanistic understanding of iMSCs into therapeutic applications.

Comprehensive Profiling of Secretome Formulations from Fetal- and Perinatal Human Amniotic Fluid Stem Cells

We previously reported that c-KIT+ human amniotic-fluid derived stem cells obtained from leftover samples of routine II trimester prenatal diagnosis (fetal hAFS) are endowed with regenerative paracrine potential driving pro-survival, anti-fibrotic and proliferative effects. hAFS may also be isolated from III trimester clinical waste samples during scheduled C-sections (perinatal hAFS), thus offering a more easily accessible alternative when compared to fetal hAFS. Nonetheless, little is known about the paracrine profile of perinatal hAFS. Here we provide a detailed characterization of the hAFS total secretome (i.e., the entirety of soluble paracrine factors released by cells in the conditioned medium, hAFS-CM) and the extracellular vesicles (hAFS-EVs) within it, from II trimester fetal- versus III trimester perinatal cells. Fetal- and perinatal hAFS were characterized and subject to hypoxic preconditioning to enhance their paracrine potential. hAFS-CM and hAFS-EV formulations were analyzed for protein and chemokine/cytokine content, and the EV cargo was further investigated by RNA sequencing. The phenotype of fetal- and perinatal hAFS, along with their corresponding secretome formulations, overlapped; yet, fetal hAFS showed immature oxidative phosphorylation activity when compared to perinatal ones. The profiling of their paracrine cargo revealed some differences according to gestational stage and hypoxic preconditioning. Both cell sources provided formulations enriched with neurotrophic, immunomodulatory, anti-fibrotic and endothelial stimulating factors, and the immature fetal hAFS secretome was defined by a more pronounced pro-vasculogenic, regenerative, pro-resolving and anti-aging profile. Small RNA profiling showed microRNA enrichment in both fetal- and perinatal hAFS-EV cargo, with a stably- expressed pro-resolving core as a reference molecular signature. Here we confirm that hAFS represents an appealing source of regenerative paracrine factors; the selection of either fetal or perinatal hAFS secretome formulations for future paracrine therapy should be evaluated considering the specific clinical scenario.

Optimizing In Vitro Osteogenesis in Canine Autologous and Induced Pluripotent Stem Cell-Derived Mesenchymal Stromal Cells with Dexamethasone and BMP-2

A growing body of work suggests that canine mesenchymal stromal cells (cMSCs) require additional agonists such as bone morphogenic protein-2 (BMP-2) for consistent in vitro osteogenic differentiation. BMP-2 is costly and may challenge the translational relevance of the canine model. Dexamethasone enhances osteogenic differentiation of human MSCs (hMSCs) and is widely utilized in osteogenic protocols. The aim of this study was to determine the effect of BMP-2 and dexamethasone on early- and late-stage osteogenesis of autologous and induced pluripotent stem cell (iPS)-derived cMSCs. Two preparations of marrow-derived cMSCs were selected to represent exceptionally or marginally osteogenic autologous cMSCs. iPS-derived cMSCs were generated from canine fibroblasts. All preparations were evaluated using alkaline phosphatase (ALP) activity, Alizarin Red staining of osteogenic monolayers, and quantitative polymerase chain reaction. Data were reported as mean ± standard deviation and compared using one- or two-way analysis of variance and Tukey or Sidak post hoc tests. Significance was established at P < 0.05. In early-stage assays, dexamethasone decreased ALP activity for all cMSCs in the presence of BMP-2. In late-stage assays, inclusion of dexamethasone and BMP-2 at Day 1 of culture produced robust monolayer mineralization for autologous cMSCs. Delivering 100 nM dexamethasone at Day 1 improved mineralization and reduced the BMP-2 concentrations required to achieve mineralization of the marginal cMSCs. For iPS-cMSCs, dexamethasone was inhibitory to both ALP activity and monolayer mineralization. There was increased expression of osteocalcin and osterix with BMP-2 in autologous cMSCs but a more modest expression occurred in iPS cMSCs. While autologous and iPS-derived cMSCs respond similarly in early-stage osteogenic assays, they exhibit unique responses to dexamethasone and BMP-2 in late-stage mineralization assays. This study demonstrates that dexamethasone and BMP-2 can be titrated in a time- and concentration-dependent manner to enhance osteogenesis of autologous cMSC preparations. These results will prove useful for investigators performing translational studies with cMSCs while providing insight into iPS-derived cMSC osteogenesis.

The emerging therapeutic role of mesenchymal stem cells in anthracycline-induced cardiotoxicity

Mesenchymal stem cell (MSC)-based tissue regeneration therapy has been extensively investigated for cardiac regeneration over the past two decades. Numerous animal and clinical investigations demonstrated the efficacy of various types of MSCs towards myocardial protection and restoration against anthracycline-induced cardiotoxicity (AIC). It has been established that local or systemic administration of MSCs considerably improved the cardiac function, while ameliorating inflammatory responses and myocardial fibrosis. Several factors influence the outcomes of MSC treatment for AIC, including MSC types, dosages, and routes and duration of administration. In this review, we discuss the recent (from 2015 to 2020) experimental and clinical research on the preventive and regeneration efficacy of different types of MSCs (with or without supporting agents) against AIC, as well as the key factors responsible for MSC-mediated cardiac repair. In addition, challenges and future perspectives of MSC-based cardiac regeneration therapy are also outlined.

Hypoxia-induced amniotic fluid stem cell secretome augments cardiomyocyte proliferation and enhances cardioprotective effects under hypoxic-ischemic conditions

Secretome derived from human amniotic fluid stem cells (AFSC-S) is rich in soluble bioactive factors (SBF) and offers untapped therapeutic potential for regenerative medicine while avoiding putative cell-related complications. Characterization and optimal generation of AFSC-S remains challenging. We hypothesized that modulation of oxygen conditions during AFSC-S generation enriches SBF and confers enhanced regenerative and cardioprotective effects on cardiovascular cells. We collected secretome at 6-hourly intervals up to 30 h following incubation of AFSC in normoxic (21%O₂, nAFSC-S) and hypoxic (1%O₂, hAFSC-S) conditions. Proliferation of human adult cardiomyocytes (hCM) and umbilical cord endothelial cells (HUVEC) incubated with nAFSC-S or hAFSC-S were examined following culture in normoxia or hypoxia. Lower AFSC counts and richer protein content in AFSC-S were observed in hypoxia. Characterization of AFSC-S by multiplex immunoassay showed higher concentrations of pro-angiogenic and anti-inflammatory SBF. hCM demonstrated highest proliferation with 30h-hAFSC-S in hypoxic culture. The cardioprotective potential of concentrated 30h-hAFSC-S treatment was demonstrated in a myocardial ischemia–reperfusion injury mouse model by infarct size and cell apoptosis reduction and cell proliferation increase when compared to saline treatment controls. Thus, we project that hypoxic-generated AFSC-S, with higher pro-angiogenic and anti-inflammatory SBF, can be harnessed and refined for tailored regenerative applications in ischemic cardiovascular disease.

Myocardial repair of bioengineered cardiac patches with decellularized placental scaffold and human-induced pluripotent stem cells in a rat model of myocardial infarction

Background

The creation of a bioengineered cardiac patch (BCP) is a potential novel strategy for myocardial repair. Nevertheless, the ideal scaffold for BCP is unknown.

Objective

We investigated whether the decellularized placenta (DP) could serve as natural scaffold material to create a BCP for myocardial repair.

Methods and results

A BCP was created by seeding human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs; 1 × 106/cm2) onto DP. The functional and electrophysiological properties of the BCP were first characterized by in vitro analysis and optical mapping. Next, in vivo therapeutic efficacy of the BCP was evaluated in a rat model of myocardial infarction (MI), created by left descending coronary artery ligation (MI + BCP group), and compared with MI alone (MI group), transplantation of DP (MI + DP group), and hiPSC-CMs (MI + CM group). Cytokine profiling demonstrated that the BCP contained multiple growth and angiogenic factors, including vascular endothelial growth factor, platelet-derived growth factor, insulin-like growth factor-1, basic fibroblast growth factor, angiogenin, and angiopoietin-2. In vitro optical mapping showed that the BCP exhibited organized mechanical contraction and synchronized electrical propagation. RNA sequencing showed that DP enhanced the maturation of hiPSC-CMs compared with the monolayer of cultured hiPSC-CMs. At 4 weeks follow-up, the BCP significantly improved left ventricular (LV) function, as determined by LV ejection fraction, fractional shortening, + dP/dt_max, and end-systolic pressure-volume relationship, compared with the MI, MI + DP, and MI + CM groups. Moreover, histological examination revealed that engraftment of the BCP at the infarct zone decreased infarct size and increased cell retention and neovascularization compared with the MI, MI + DP, and MI + CM groups.

Conclusions

Our results demonstrate that a DP scaffold contains multiple growth and angiogenic factors that enhance the maturation and survival of seeded hiPSC-CMs. Transplantation of a BCP is superior to DP or hiPSC-CMs alone in reducing infarct size and improving cell retention and neovascularization, thus providing a novel therapy for myocardial repair following MI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-020-02066-y.

Therapeutic Efficacy of Human Embryonic Stem Cell-Derived Multipotent Stem/Stromal Cells in Diabetic Detrusor Underactivity: A Preclinical Study

Mesenchymal stem/stromal cell (MSC) therapy is a promising approach for treatment of as yet incurable detrusor underactivity (DUA), which is characterized by decreased detrusor contraction strength and/or duration, leading to prolonged bladder emptying. In the present study, we demonstrated the therapeutic potential of human embryonic stem cell (ESC)-derived multipotent MSCs (M-MSCs) in a diabetic rat model of DUA. Diabetes mellitus (DM) was induced by intraperitoneal injection of streptozotocin (STZ) (50 mg/kg) into 8-week-old female Sprague-Dawley rats. Three weeks later, various doses of M-MSCs (0.25, 0.5, and 1 × 10⁶ cells) or an equivalent volume of PBS were injected into the outer layer of the bladder. Awake cystometry, organ bath, histological, and gene expression analyses were evaluated 1 week (short-term) or 2 and 4 weeks (long-term) after M-MSC transplantation. STZ-induced diabetic rats developed DUA, including phenotypes with significantly longer micturition intervals, increased residual urine amounts and bladder capacity, decreased micturition pressure on awake cystometry, and contractile responses to various stimuli in organ bath studies. Muscle degeneration, mast cell infiltration, fibrosis, and apoptosis were present in the bladders of DM animals. A single local transplantation of M-MSCs ameliorated DUA bladder pathology, including functional changes and histological evaluation, and caused few adverse outcomes. Immunostaining and gene expression analysis revealed that the transplanted M-MSCs supported myogenic restoration primarily by engrafting into bladder tissue via pericytes, and subsequently exerting paracrine effects to prevent apoptotic cell death in bladder tissue. The therapeutic efficacy of M-MSCs was superior to that of human umbilical cord-derived MSCs at the early time point (1 week). However, the difference in efficacy between M-MSCs and human umbilical cord-derived MSCs was statistically insignificant at the later time points (2 and 4 weeks). Collectively, the present study provides the first evidence for improved therapeutic efficacy of a human ESC derivative in a preclinical model of DM-associated DUA.

Human pluripotent stem cell-derived cardiomyocytes as a target platform for paracrine protection by cardiac mesenchymal stromal cells

Ischemic heart disease remains the foremost cause of death globally, with survivors at risk for subsequent heart failure. Paradoxically, cell therapies to offset cardiomyocyte loss after ischemic injury improve long-term cardiac function despite a lack of durable engraftment. An evolving consensus, inferred preponderantly from non-human models, is that transplanted cells benefit the heart via early paracrine signals. Here, we tested the impact of paracrine signals on human cardiomyocytes, using human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) as the target of mouse and human cardiac mesenchymal stromal cells (cMSC) with progenitor-like features. In co-culture and conditioned medium studies, cMSCs markedly inhibited human cardiomyocyte death. Little or no protection was conferred by mouse tail tip or human skin fibroblasts. Consistent with the results of transcriptomic profiling, functional analyses showed that the cMSC secretome suppressed apoptosis and preserved cardiac mitochondrial transmembrane potential. Protection was independent of exosomes under the conditions tested. In mice, injecting cMSC-conditioned media into the infarct border zone reduced apoptotic cardiomyocytes > 70% locally. Thus, hPSC-CMs provide an auspicious, relevant human platform to investigate extracellular signals for cardiac muscle survival, substantiating human cardioprotection by cMSCs, and suggesting the cMSC secretome or its components as potential cell-free therapeutic products.

Growth differentiation factor 15 in adverse cardiac remodelling: from biomarker to causal player

Heart failure is a growing health issue as a negative consequence of improved survival upon myocardial infarction, unhealthy lifestyle, and the ageing of our population. The large and complex pathology underlying heart failure makes diagnosis and especially treatment very difficult. There is an urgent demand for discriminative biomarkers to aid disease management of heart failure. Studying cellular pathways and pathophysiological mechanisms contributing to disease initiation and progression is crucial for understanding the disease process and will aid to identification of novel biomarkers and potential therapeutic targets. Growth differentiation factor 15 (GDF15) is a proven valuable biomarker for different pathologies, including cancer, type 2 diabetes, and cardiovascular diseases. Although the prognostic value of GDF15 in heart failure is robust, the biological function of GDF15 in adverse cardiac remodelling is not fully understood. GDF15 is a distant member of the transforming growth factor-β family and involved in various biological processes including inflammation, cell cycle, and apoptosis. However, more research is suggesting a role in fibrosis, hypertrophy, and endothelial dysfunction. As GDF15 is a pleiotropic protein, elucidating the exact role of GDF15 in complex disease processes has proven to be a challenge. In this review, we provide an overview of the role GDF15 plays in various intracellular and extracellular processes underlying heart failure, and we touch upon crucial points that need consideration before GDF15 can be integrated as a biomarker in standard care or when considering GDF15 for therapeutic intervention.

Effects of Early MSC Intervention on Preventing the Streptozotocin-Induced T1DM Progression in Mice

Type 1 diabetes mellitus is characterized by progressive pancreatic β-cells failure and progressive autoimmunity. It is difficult to diagnose T1DM and to prevent the pancreatic β-cells destruction because of the undetectable pancreatic β-cell necrosis and abnormal autoimmunity. Here, we built streptozotocin-induced T1DM mouse model and performed MSC injection at the early stage of T1DM. We found that MSC infusion displayed enhanced effects on reducing the pathological damage and improving the survival quality. Moreover, the delivery of MSCs inhibited Th1 cell polarization and downregulated the Th1 subset ratio. The immunomodulatory mechanism of MSC was further investigated. Real-time PCR and ELISA assays demonstrated that IFN-γ expression at both mRNA and protein level in MSC infusion T1DM mice was downregulated, partially regulated by MSC-exosome-derived miR-148a-3p. Taken together, this early therapeutic strategy may improve the clinical efficacy of MSC-based therapy in T1DM.

TGF-β mediates aortic smooth muscle cell senescence in Marfan syndrome

Formation of aortic aneurysms as a consequence of augmented transforming growth factor β (TGF-β) signaling and vascular smooth muscle cell (VSMC) dysfunction is a potentially lethal complication of Marfan syndrome (MFS). Here, we examined VSMC senescence in patients with MFS and explored the potential mechanisms that link VSMC senescence and TGF-β. Tissue was harvested from the ascending aorta of control donors and MFS patients, and VSMCs were isolated. Senescence-associated β-galactosidase (SA-β-gal) activity and expression of senescence-related proteins (p53, p21) were significantly higher in aneurysmal tissue from MFS patients than in healthy aortic tissue from control donors. Compared to control-VSMCs, MFS-VSMCs were larger with higher levels of both SA-β-gal activity and mitochondrial reactive oxygen species (ROS). In addition, TGF-β1 levels were much higher in MFS- than control-VSMCs. TGF-β1 induced VSMC senescence through excessive ROS generation. This effect was suppressed by Mito-tempo, a mitochondria-targeted antioxidant, or SC-514, a NF-κB inhibitor. This suggests TGF-β1 induces VSMC senescence through ROS-mediated activation of NF-κB signaling. It thus appears that a TGF-β1/ROS/NF-κB axis may mediate VSMC senescence and aneurysm formation in MFS patients. This finding could serve as the basis for a novel strategy for treating aortic aneurysm in MFS.

Mesenchymal Stem/Stromal Cell-Mediated Mitochondrial Transfer and the Therapeutic Potential in Treatment of Neurological Diseases

Mesenchymal stem/stromal cells (MSCs) are multipotent stem cells that can be derived from various tissues. Due to their regenerative and immunomodulatory properties, MSCs have been extensively researched and tested for treatment of different diseases/indications. One mechanism that MSCs exert functions is through the transfer of mitochondria, a key player involved in many biological processes in health and disease. Mitochondria transfer is bidirectional and has an impact on both donor and recipient cells. In this review, we discussed how MSC-mediated mitochondrial transfer may affect cellular metabolism, survival, proliferation, and differentiation; how this process influences inflammatory processes; and what is the molecular machinery that mediates mitochondrial transfer. In the end, we summarized recent advances in preclinical research and clinical trials for the treatment of stroke and spinal cord injury, through application of MSCs and/or MSC-derived mitochondria.

Extracellular vesicles derived from human ES-MSCs protect retinal ganglion cells and preserve retinal function in a rodent model of optic nerve injury

Background

Retinal and/or optic nerve injury is one of the leading causes of blindness due to retinal ganglion cell (RGC) degeneration. There have been extensive efforts to suppress this neurodegeneration. Various somatic tissue-derived mesenchymal stem cells (MSCs) demonstrated significant neuroprotective and axogenic effects on RGCs. An alternative source of MSCs could be human embryonic stem cells (ES-MSCs), which proliferate faster, express lower levels of inflammatory cytokines, and are capable of immune modulation. It has been demonstrated that MSCs secrete factors or extracellular vesicles that may heal the injury. However, possible therapeutic effects and underlying mechanism of human ES-MSC extracellular vesicles (EVs) on optic nerve injury have not been assessed.

Methods

EVs were isolated from human ES-MSCs. Then, ES-MSC EV was applied to an optic nerve crush (ONC) mouse model. Immunohistofluorescence, retro- and anterograde tracing of RGCs, Western blot, tauopathy in RGCs, and function assessments were performed during 2-month post-treatment to evaluate ONC improvement and underlying mechanism of human ES-MSC EV in in vivo.

Results

We found that the ES-MSC EV significantly improved Brn3a+ RGCs survival and retro- and anterograde tracing of RGCs, while preventing retinal nerve fiber layer (RNFL) degenerative thinning compared to the vehicle group. The EVs also significantly promoted GAP43+ axon counts in the optic nerve and improved cognitive visual behavior. Furthermore, cis p-tau, a central mediator of neurodegeneration in the injured RGCs, is detectable after the ONC at the early stages demonstrated tauopathy in RGCs. Notably, after EV treatment cis p-tau was downregulated.

Conclusions

Our findings propose that human ES-MSC EVs, as an off-the-shelf and cell-free product, may have profound clinical implications in treating injured RGCs and degenerative ocular disease. Moreover, the possible mechanisms of human ES-MSC EV are related to the rescue of tauopathy process of RGC degeneration.

miR-155-5p inhibition rejuvenates aged mesenchymal stem cells and enhances cardioprotection following infarction

Aging impairs the functions of human mesenchymal stem cells (MSCs), thereby severely reducing their beneficial effects on myocardial infarction (MI). MicroRNAs (miRNAs) play crucial roles in regulating the senescence of MSCs; however, the underlying mechanisms remain unclear. Here, we investigated the significance of miR‐155‐5p in regulating MSC senescence and whether inhibition of miR‐155‐5p could rejuvenate aged MSCs (AMSCs) to enhance their therapeutic efficacy for MI. Young MSCs (YMSCs) and AMSCs were isolated from young and aged donors, respectively. The cellular senescence of MSCs was evaluated by senescence‐associated β‐galactosidase (SA‐β‐gal) staining. Compared with YMSCs, AMSCs exhibited increased cellular senescence as evidenced by increased SA‐β‐gal activity and decreased proliferative capacity and paracrine effects. The expression of miR‐155‐5p was much higher in both serum and MSCs from aged donors than young donors. Upregulation of miR‐155‐5p in YMSCs led to increased cellular senescence, whereas downregulation of miR‐155‐5p decreased AMSC senescence. Mechanistically, miR‐155‐5p inhibited mitochondrial fission and increased mitochondrial fusion in MSCs via the AMPK signaling pathway, thereby resulting in cellular senescence by repressing the expression of Cab39. These effects were partially reversed by treatment with AMPK activator or mitofusin2‐specific siRNA (Mfn2‐siRNA). By enhancing angiogenesis and promoting cell survival, transplantation of anti‐miR‐155‐5p‐AMSCs led to improved cardiac function in an aged mouse model of MI compared with transplantation of AMSCs. In summary, our study shows that miR‐155‐5p mediates MSC senescence by regulating the Cab39/AMPK signaling pathway and miR‐155‐5p is a novel target to rejuvenate AMSCs and enhance their cardioprotective effects.

Transfer of mitochondria from mesenchymal stem cells derived from induced pluripotent stem cells attenuates hypoxia-ischemia-induced mitochondrial dysfunction in PC12 cells

Mitochondrial dysfunction in neurons has been implicated in hypoxia-ischemia-induced brain injury. Although mesenchymal stem cell therapy has emerged as a novel treatment for this pathology, the mechanisms are not fully understood. To address this issue, we first co-cultured 1.5 × 10⁵ PC12 cells with mesenchymal stem cells that were derived from induced pluripotent stem cells at a ratio of 1:1, and then intervened with cobalt chloride (CoCl₂) for 24 hours. Reactive oxygen species in PC12 cells was measured by Mito-sox. Mitochondrial membrane potential (?Ψm) in PC12 cells was determined by JC-1 staining. Apoptosis of PC12 cells was detected by terminal deoxynucleotidal transferase-mediated dUTP nick end-labeling staining. Mitochondrial morphology in PC12 cells was examined by transmission electron microscopy. Transfer of mitochondria from the mesenchymal stem cells derived from induced pluripotent stem cells to damaged PC12 cells was measured by flow cytometry. Mesenchymal stem cells were induced from pluripotent stem cells by lentivirus infection containing green fluorescent protein in mitochondria. Then they were co-cultured with PC12 cells in Transwell chambers and treated with CoCl₂ for 24 hours to detect adenosine triphosphate level in PC12 cells. CoCl₂-induced PC12 cell damage was dose-dependent. Co-culture with mesenchymal stem cells significantly reduced apoptosis and restored ?Ψm in the injured PC12 cells under CoCl₂ challenge. Co-culture with mesenchymal stem cells ameliorated mitochondrial swelling, the disappearance of cristae, and chromatin margination in the injured PC12 cells. After direct co-culture, mitochondrial transfer from the mesenchymal stem cells stem cells to PC12 cells was detected via formed tunneling nanotubes between these two types of cells. The transfer efficiency was greatly enhanced in the presence of CoCl₂. More importantly, inhibition of tunneling nanotubes partially abrogated the beneficial effects of mesenchymal stem cells on CoCl₂-induced PC12 cell injury. Mesenchymal stem cells reduced CoCl₂-induced PC12 cell injury and these effects were in part due to efficacious mitochondrial transfer.

Exosomes from mesenchymal stem cells overexpressing MIF enhance myocardial repair

Accumulating evidence has shown that mesenchymal stem cell (MSC)-derived exosomes (exo) mediate cardiac repair following myocardial infarction (MI). Macrophage migration inhibitory factor (MIF), a proinflammatory cytokine, plays a critical role in regulating cell homeostasis. This study aimed to investigate the cardioprotective effects of exo secreted from bone marrow-MSCs (BM-MSCs) overexpressing MIF in a rat model of MI. MIF plasmid was transducted in BM-MSCs. Exo were isolated from the supernatants of BM-MSCs and MIF-BM-MSCs, respectively. The morphology of mitochondria in neonatal mice cardiomyocytes (NRCMs) was determined by MitoTracker staining. The apoptosis of NRCMs was examined by deoxynucleotidyl transferase-mediated dUTP nick end-labeling. BM-MSC-exo and MIF-BM-MSC-exo were intramuscularly injected into the peri-infarct region in a rat model of MI. The heart function of rats was assessed by echocardiography. The expression of MIF was greatly enhanced in MIF-BM-MSCs compared with BM-MSCs. Both BM-MSC-exo and MIF-BM-MSC-exo expressed CD63 and CD81. NRCMs treated with MIF-BM-MSC-exo exhibited less mitochondrial fragmentation and cell apoptosis under hypoxia/serum deprivation (H/SD) challenge than those treated with BM-MSC-exo via activating adenosine 5'-monophosphate-activated protein kinase signaling. Moreover, these effects were partially abrogated by Compound C. Injection of BM-MSC-exo or MIF-BM-MSC-exo greatly restored heart function in a rat model of MI. Compared with BM-MSC-exo, injection of MIF-BM-MSC-exo was associated with enhanced heart function, reduced heart remodeling, less cardiomyocyte mitochondrial fragmentation, reactive oxygen species generation, and apoptosis. Our study reveals a new mechanism of MIF-BM-MSC-exo-based therapy for MI and provides a novel strategy for cardiovascular disease treatment.

Macrophage migration inhibitory factor rejuvenates aged human mesenchymal stem cells and improves myocardial repair

The beneficial functions of mesenchymal stem cells (MSCs) decline with age, limiting their therapeutic efficacy for myocardial infarction (MI). Macrophage migration inhibitory factor (MIF) promotes cell proliferation and survival. We investigated whether MIF overexpression could rejuvenate aged MSCs and increase their therapeutic efficacy in MI. Young and aged MSCs were isolated from the bone marrow of young and aged donors. Young MSCs, aged MSCs, and MIF-overexpressing aged MSCs were transplanted into the peri-infarct region in a rat MI model. Aged MSCs exhibited a lower proliferative capacity, lower MIF level, greater cell size, greater senescence-associated-β-galactosidase activity, and weaker paracrine effects than young MSCs. Knocking down MIF in young MSCs induced cellular senescence, whereas overexpressing MIF in aged MSCs reduced cellular senescence. MIF rejuvenated aged MSCs by activating autophagy, an effect largely reversed by the autophagy inhibitor 3-methyladenine. MIF-overexpressing aged MSCs induced angiogenesis and prevented cardiomyocyte apoptosis to a greater extent than aged MSCs, and had improved heart function and cell survival more effectively than aged MSCs four weeks after MI. Thus, MIF rejuvenated aged MSCs by activating autophagy and enhanced their therapeutic efficacy in MI, suggesting a novel MSC-based therapeutic strategy for cardiovascular diseases in the aged population.

Adipose-Derived Mesenchymal Stem Cells Isolated from Patients with Abdominal Aortic Aneurysm Exhibit Senescence Phenomena

Mesenchymal stem cells (MSCs) have shown beneficial effects in the treatment of abdominal aortic aneurysm (AAA). Nonetheless, the biological properties of adipose-derived MSCs (ASCs) from patients with AAA (AAA-ASCs) remain unclear. This study is aimed at investigating the properties of cell phenotype and function of AAA-ASCs compared with ASCs from age-matched healthy donors (H-ASCs). H-ASCs and AAA-ASCs were studied for cell phenotype, differentiation capacity, senescence, and mitochondrial and autophagic functions. Cellular senescence was examined by senescence-associated β-galactosidase (SA-β-gal) staining. Mitochondrial morphology was determined by MitoTracker staining. Despite the similar surface markers of AAA-ASCs and H-ASCs, AAA-ASCs exhibited altered multidifferentiation potential. Compared with H-ASCs, AAA-ASCs displayed enhanced senescence manifested by increased SA-β-gal activity and decreased proliferation and migration ability. Furthermore, AAA-ASCs showed increased mitochondrial fusion, reactive oxygen species (ROS) production, and decreased mitochondrial membrane potential. In addition, AAA-ASCs exhibited decreased autophagy level, upregulation of IL-6 and TNF-α secretion, and downregulation of IL-10 secretion compared with H-ASCs. Nonetheless, treatment of AAA-ASCs with rapamycin (an autophagy activator) dramatically reduced secretion of IL-6 and TNF-α and enhanced secretion of IL-10. In conclusion, our study showed that AAA-ASCs exhibit senescence phenomena and decreased cell function. Understanding the specific alterations in AAA-ASCs will help explore novel strategies to restore cell function for AAA treatment.

Anti-fibrotic mechanisms of exogenously-expanded mesenchymal stromal cells for fibrotic diseases

Most chronic diseases involving inflammation have a fibrotic component that involves remodeling and excess accumulation of extracellular matrix components. Left unchecked, fibrosis leads to organ failure and death. Mesenchymal stromal cells (MSCs) are emerging as a potent cell-based therapy for a wide spectrum of fibrotic conditions due to their immunomodulatory, anti-inflammatory and anti-fibrotic properties. This review provides an overview of known mechanisms by which MSCs mediate their anti-fibrotic actions and in relation to animal models of pulmonary, liver, renal and cardiac fibrosis. Recent MSC clinical trials results in liver, lung, skin, kidney and hearts are discussed and next steps for future MSC-based therapies including pre-activated or genetically-modified cells, or extracellular vesicles are also considered.

Haemin pre-treatment augments the cardiac protection of mesenchymal stem cells by inhibiting mitochondrial fission and improving survival

The cardiac protection of mesenchymal stem cell (MSC) transplantation for myocardial infarction (MI) is largely hampered by low cell survival. Haem oxygenase 1 (HO‐1) plays a critical role in regulation of cell survival under many stress conditions. This study aimed to investigate whether pre‐treatment with haemin, a potent HO‐1 inducer, would promote the survival of MSCs under serum deprivation and hypoxia (SD/H) and enhance the cardioprotective effects of MSCs in MI. Bone marrow (BM)‐MSCs were pretreated with or without haemin and then exposed to SD/H. The mitochondrial morphology of MSCs was determined by MitoTracker staining. BM‐MSCs and haemin‐pretreated BM‐MSCs were transplanted into the peri‐infarct region in MI mice. SD/H induced mitochondrial fragmentation, as shown by increased mitochondrial fission and apoptosis of BM‐MSCs. Pre‐treatment with haemin greatly inhibited SD/H‐induced mitochondrial fragmentation and apoptosis of BM‐MSCs. These effects were partially abrogated by knocking down HO‐1. At 4 weeks after transplantation, compared with BM‐MSCs, haemin‐pretreated BM‐MSCs had greatly improved the heart function of mice with MI. These cardioprotective effects were associated with increased cell survival, decreased cardiomyocytes apoptosis and enhanced angiogenesis. Collectively, our study identifies haemin as a regulator of MSC survival and suggests a novel strategy for improving MSC‐based therapy for MI.

Mesenchymal Stem Cell Therapy for Doxorubicin-Induced Cardiomyopathy: Potential Mechanisms, Governing Factors, and Implications of the Heart Stem Cell Debate

Over the past decades, researchers have reported several mechanisms for doxorubicin (DOX)-induced cardiomyopathy, including oxidative stress, inflammation, and apoptosis. Another mechanism that has been suggested is that DOX interferes with the cell cycle and induces oxidative stress in C-kit+ cells (commonly known as cardiac progenitor cells), reducing their regenerative capacity. Cardiac regeneration through enhancing the regenerative capacity of these cells or administration of other stem cells types has been the axis of several studies over the past 20 years. Several experiments revealed that local or systemic injections with mesenchymal stem cells (MSCs) were associated with significantly improved cardiac function, ameliorated inflammatory response, and reduced myocardial fibrosis. They also showed that several factors can affect the outcome of MSC treatment for DOX cardiomyopathy, including the MSC type, dose, route, and timing of administration. However, there is growing evidence that the C-kit+ cells do not have a cardiac regenerative potential in the adult mammalian heart. Similarly, the protective mechanisms of MSCs against DOX-induced cardiomyopathy are not likely to include direct differentiation into cardiomyocytes and probably occur through paracrine secretion, antioxidant and anti-inflammatory effects. Better understanding of the involved mechanisms and the factors governing the outcomes of MSCs therapy are essential before moving to clinical application in patients with DOX-induced cardiomyopathy.

Production of Mesenchymal Stem Cells Through Stem Cell Reprogramming

Mesenchymal stem cells (MSCs) possess a broad spectrum of therapeutic applications and have been used in clinical trials. MSCs are mainly retrieved from adult or fetal tissues. However, there are many obstacles with the use of tissue-derived MSCs, such as shortages of tissue sources, difficult and invasive retrieval methods, cell population heterogeneity, low purity, cell senescence, and loss of pluripotency and proliferative capacities over continuous passages. Therefore, other methods to obtain high-quality MSCs need to be developed to overcome the limitations of tissue-derived MSCs. Pluripotent stem cells (PSCs), including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), are considered potent sources for the derivation of MSCs. PSC-derived MSCs (PSC-MSCs) may surpass tissue-derived MSCs in proliferation capacity, immunomodulatory activity, and in vivo therapeutic applications. In this review, we will discuss basic as well as recent protocols for the production of PSC-MSCs and their in vitro and in vivo therapeutic efficacies. A better understanding of the current advances in the production of PSC-MSCs will inspire scientists to devise more efficient differentiation methods that will be a breakthrough in the clinical application of PSC-MSCs.

Personalized medicine in cardio-oncology: the role of induced pluripotent stem cell

Treatment of cancer has evolved in the last decade with the introduction of new therapies. Despite these successes, the lingering cardiotoxic side-effects from chemotherapy remain a major cause of morbidity and mortality in cancer survivors. These effects can develop acutely during treatment, or even years later. Although many risk factors can be identified prior to beginning therapy, unexpected toxicity still occurs, often with lasting consequences. Specifically, cardiotoxicity results in cardiac cell death, eventually leading to cardiomyopathy and heart failure. Certain risk factors may predispose an individual to experiencing adverse cardiovascular effects, and when unexpected cardiotoxicity occurs, it is generally managed with supportive care. Animal models of chemotherapy-induced cardiotoxicity have provided some mechanistic insights, but the precise mechanisms by which these drugs affect the heart remains unknown. Moreover, the genetic rationale as to why some patients are more susceptible to developing cardiotoxicity has yet to be determined. Many genome-wide association studies have identified genomic variants that could be associated with chemotherapy-induced cardiotoxicity, but the lack of validation has made these studies more speculative rather than definitive. With the advent of human induced pluripotent stem cell (iPSC) technology, researchers not only have the opportunity to model human diseases, but also to screen drugs for their efficacy and toxicity using human cell models. Furthermore, it allows us to conduct validation studies to confirm the role of genomic variants in human diseases. In this review, we discuss the role of iPSCs in modelling chemotherapy-induced cardiotoxicity.

Potent immunomodulation and angiogenic effects of mesenchymal stem cells versus cardiomyocytes derived from pluripotent stem cells for treatment of heart failure

BACKGROUND

Optimal cell type as cell-based therapies for heart failure (HF) remains unclear. We sought to compare the safety and efficacy of direct intramyocardial transplantation of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) and human induced pluripotent stem cell-derived mesenchymal stem cells (hiPSC-MSCs) in a porcine model of HF.

METHODS

Eight weeks after induction of HF with myocardial infarction (MI) and rapid pacing, animals with impaired left ventricular ejection fraction (LVEF) were randomly assigned to receive direct intramyocardial injection of saline (MI group), 2 × 10⁸ hESC-CMs (hESC-CM group), or 2 × 10⁸ hiPSC-MSCs (hiPSC-MSC group). The hearts were harvested for immunohistochemical evaluation after serial echocardiography and hemodynamic evaluation and ventricular tachyarrhythmia (VT) induction by in vivo programmed electrical stimulation.

RESULTS

At 8 weeks post-transplantation, LVEF, left ventricular maximal positive pressure derivative, and end systolic pressure-volume relationship were significantly higher in the hiPSC-MSC group but not in the hESC-CM group compared with the MI group. The incidence of early spontaneous ventricular tachyarrhythmia (VT) episodes was higher in the hESC-CM group but the incidence of inducible VT was similar among the different groups. Histological examination showed no tumor formation but hiPSC-MSCs exhibited a stronger survival capacity by activating regulatory T cells and reducing the inflammatory cells. In vitro study showed that hiPSC-MSCs were insensitive to pro-inflammatory interferon-gamma-induced human leukocyte antigen class II expression compared with hESC-CMs. Moreover, hiPSC-MSCs also significantly enhanced angiogenesis compared with other groups via increasing expression of distinct angiogenic factors.

CONCLUSIONS

Our results demonstrate that transplantation of hiPSC-MSCs is safe and does not increase proarrhythmia or tumor formation and superior to hESC-CMs for the improvement of cardiac function in HF. This is due to their immunomodulation that improves in vivo survival and enhanced angiogenesis via paracrine effects.

Concise Review: Mesenchymal Stem Cells Derived from Human Pluripotent Cells, an Unlimited and Quality-Controllable Source for Therapeutic Applications

Despite the long discrepancy over their definition, heterogeneity, and functions, mesenchymal stem cells (MSCs) have proved to be a key player in tissue repair and homeostasis. Generally, somatic tissue-derived MSCs (st-MSCs) are subject to quality variations related to donated samples and biosafety concern for transmission of potential pathogens from the donors. In contrast, human pluripotent stem cells (hPSCs) are unlimited in supply, clear in the biological background, and convenient for quality control, genetic modification, and scale-up production. We, and others, have shown that hPSCs can differentiate in two dimensions or three dimensions to MSCs (ps-MSCs) via embryonic (mesoderm and neural crest) or extraembryonic (trophoblast) cell types under serum-containing or xeno-free and defined conditions. Compared to st-MSCs, ps-MSCs appear less mature, proliferate faster, express lower levels of inflammatory cytokines, and respond less to traditional protocols for st-MSC differentiation to other cell types, especially adipocytes. Nevertheless, ps-MSCs are capable of immune modulation and treatment of an increasing number of animal disease models via mitochondria transfer, paracrine, exosomes, and direct differentiation, and can be potentially used as a universal and endless therapy for clinical application. This review summarizes the progress on ps-MSCs and discusses perspectives and challenges for their potential translation to the clinic. Stem Cells 2019;37:572-581.

Overexpression of ERBB4 rejuvenates aged mesenchymal stem cells and enhances angiogenesis via PI3K/AKT and MAPK/ERK pathways

The age-related functional exhaustion limits potential efficacy of mesenchymal stem cells (MSC) in treating cardiovascular disease. Therefore, rejuvenation of aged MSC in the elderly population is of great interest. We have previously reported that Erb-B2 receptor tyrosine kinase 4 ( ERBB4) plays a critical role in regulating MSC survival under hypoxia. The aim of this study was to investigate whether ERBB4 rejuvenates aged MSC and how ERBB4 enhances therapeutic efficacy of aged MSC in treating myocardial infarction (MI). Compared with vector aged MSC (aged-MSC), ERBB4-engineered aged MSC (ER4-aged-MSC) conferred resistance to oxidative stress-induced cell death and ameliorated the senescent phenotype in vitro. Four weeks after MI, the ER4-aged-MSC group exhibited enhanced blood vessel density, reduced cardiac remodeling and apoptosis with improved heart function compared with the aged-MSC group. Overexpression of ERBB4 caused an increase in phosphorylated v-akt murine thymoma viral oncogene homolog 1 (AKT), and phosphorylated ERK expression under hypoxia. ER4-aged-MSC secreted higher levels of angiopoietin, epithelial neutrophil activating peptide 78, VEGF, and fibroblast growth factor 2, and enhanced tube formation in HUVEC. The impact of ERBB4 on protein expression, proangiogenesis, cell behavior, and cytokine secretion was abolished by inhibiting PI3K/AKT and MAPK/ERK signaling pathway.-Liang, X., Ding, Y., Lin, F., Zhang, Y., Zhou, X., Meng, Q., Lu, X., Jiang, G., Zhu, H., Chen, Y., Lian, Q., Fan, H., Liu, Z. Overexpression of ERBB4 rejuvenates aged mesenchymal stem cells and enhances angiogenesis via PI3K/AKT and MAPK/ERK pathways.

Potential Applications of Induced Pluripotent Stem Cells for Cardiovascular Diseases

Owning the high incidence and disability rate in the past decades, to be expected, cardiovascular diseases (CVDs) have become one of the leading death causes worldwide. Currently, induced pluripotent stem cells (iPSCs), with the potential to form fresh myocardium and improve the functions of damaged hearts, have been studied widely in experimental CVD therapy. Moreover, iPSC-derived cardiomyocytes (CMs), as novel disease models, play a significant role in drug screening, drug safety assessment, along with the exploration of pathological mechanisms of diseases. Furthermore, a lot of studies have been carried out to clarify the biological basis of iPSCs and its derived cells in the treatment of CVDs. Their molecular mechanisms were associated with release of paracrine factors, regulation of miRNAs, mechanical support of new tissues, activation of specific pathways and specific enzymes, etc. In addition, a few small chemical molecules and suitable biological scaffolds play positive roles in enhancing the efficiency of iPSC transplantation. This article reviews the development and limitations of iPSCs in CVD therapy, and summarizes the latest research achievements regarding the application of iPSCs in CVDs.

Preconditioning strategies for improving the survival rate and paracrine ability of mesenchymal stem cells in acute kidney injury

Acute kidney injury (AKI) is a common, severe emergency case in clinics, with high incidence, significant mortality and increased costs. Despite development in the understanding of its pathophysiology, the therapeutic choices are still confined to dialysis and renal transplantation. Considering their antiapoptotic, immunomodulatory, antioxidative and pro‐angiogenic effects, mesenchymal stem cells (MSCs) may be a promising candidate for AKI management. Based on these findings, some clinical trials have been performed, but the results are contradictory (NCT00733876, NCT01602328). The low engraftment, poor survival rate, impaired paracrine ability and delayed administration of MSCs are the four main reasons for the limited clinical efficacy. Investigators have developed a series of preconditioning strategies to improve MSC survival rates and paracrine ability. In this review, by summarizing these encouraging studies, we intend to provide a comprehensive understanding of various preconditioning strategies on AKI therapy and improve the prognosis of AKI patients by regenerative medicine.

The mesenchymoangioblast, mesodermal precursor for mesenchymal and endothelial cells

Mesenchymoangioblast (MB) is the earliest precursor for endothelial and mesenchymal cells originating from APLNR+PDGFRα+KDR+ mesoderm in human pluripotent stem cell cultures. MBs are identified based on their capacity to form FGF2-dependent compact spheroid colonies in a serum-free semisolid medium. MBs colonies are composed of PDGFRβ+CD271+EMCN+DLK1+CD73- primitive mesenchymal cells which are generated through endothelial/angioblastic intermediates (cores) formed during first 3-4 days of clonogenic cultures. MB-derived primitive mesenchymal cells have potential to differentiate into mesenchymal stromal/stem cells (MSCs), pericytes, and smooth muscle cells. In this review, we summarize the specification and developmental potential of MBs, emphasize features that distinguish MBs from other mesenchymal progenitors described in the literature and discuss the value of these findings for identifying molecular pathways leading to MSC and vasculogenic cell specification, and developing cellular therapies using MB-derived progeny.

Unraveling local tissue changes within severely injured skeletal muscles in response to MSC-based intervention using MALDI Imaging mass spectrometry

Pre-clinical and clinical studies are now beginning to demonstrate the high potential of cell therapies in enhancing muscle regeneration. We previously demonstrated functional benefit after the transplantation of autologous bone marrow mesenchymal stromal cells (MSC-TX) into a severe muscle crush trauma model. Despite our increasing understanding of the molecular and cellular mechanisms underlying MSC's regenerative function, little is known about the local molecular alterations and their spatial distribution within the tissue after MSC-TX. Here, we used MALDI imaging mass spectrometry (MALDI-IMS) in combination with multivariate statistical strategies to uncover previously unknown peptide alterations within severely injured skeletal muscles. Our analysis revealed that very early molecular alterations in response to MSC-TX occur largely in the region adjacent to the trauma and only to a small extent in the actual trauma region. Using "bottom up" mass spectrometry, we subsequently identified the proteins corresponding to the differentially expressed peptide intensity distributions in the specific muscle regions and used immunohistochemistry to validate our results. These findings extend our current understanding about the early molecular processes of muscle healing and highlights the critical role of trauma adjacent tissue during the early therapeutic response upon treatment with MSC.

Amniotic Epithelial Cells Accelerate Diabetic Wound Healing by Modulating Inflammation and Promoting Neovascularization

Human amniotic epithelial cells (hAECs) are nontumorigenic, highly abundant, and low immunogenic and possess multipotent differentiation ability, which make them become ideal alternative stem cell source for regenerative medicine. Previous studies have demonstrated the therapeutic potential of hAECs in many tissue repairs. However, the therapeutic effect of hAECs on diabetic wound healing is still unknown. In this study, we injected hAECs intradermally around the full-thickness excisional skin wounds of db/db mice and found that hAECs significantly accelerated diabetic wound healing and granulation tissue formation. To explore the underlying mechanisms, we measured inflammation and neovascularization in diabetic wounds. hAECs could modulate macrophage phenotype toward M2 macrophage, promote switch from proinflammatory status to prohealing status of wounds, and increase capillary density in diabetic wounds. Furthermore, we found that the hAEC-conditioned medium promoted macrophage polarization toward M2 phenotype and facilitated migration, proliferation, and tube formation of endothelial cells through in vitro experiments. Taken together, we first reported that hAECs could promote diabetic wound healing, at least partially, through paracrine effects to regulate inflammation and promote neovascularization.

Generation and Applications of Induced Pluripotent Stem Cell-Derived Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) are adult stem cells with fibroblast-like morphology and isolated from the bone marrow via plastic adhesion. Their multipotency and immunoregulatory properties make MSCs possible therapeutic agents, and an increasing number of publications and clinical trials have highlighted their potential in regenerative medicine. However, the finite proliferative capacity of MSCs limits their scalability and global dissemination as a standardized therapeutic product. Furthermore, adult tissue provenance could constrain accessibility, impinge on cellular potency, and incur greater exposure to disease-causing pathogens based on the donor. These issues could be circumvented by the derivation of MSCs from pluripotent stem cells. In this paper, we review methods that induce and characterize MSCs derived from induced pluripotent stem cells (iPSCs) and introduce MSC applications to disease modeling, pathogenic mechanisms, and drug discovery. We also discuss the potential applications of MSCs in regenerative medicine including cell-based therapies and issues that should be overcome before iPSC-derived MSC therapy will be applied in the clinic.