Quality Control Optimization for Minimizing Security Risks Associated with Mesenchymal Stromal Cell-Based Product Development

Mesenchymal stromal cells (MSCs) have been considered a therapeutic strategy in regenerative medicine because of their regenerative and immunomodulatory properties. The translation of MSC-based products has some challenges, such as regulatory and scientific issues. Quality control should be standardized and optimized to guarantee the reproducibility, safety, and efficacy of MSC-based products to be administered to patients. The aim of this study was to develop MSC-based products for use in clinical practice. Quality control assays include cell characterization, cell viability, immunogenicity, and cell differentiation; safety tests such as procoagulant tissue factor (TF), microbiological, mycoplasma, endotoxin, genomic stability, and tumorigenicity tests; and potency tests. The results confirm that the cells express MSC markers; an average cell viability of 96.9%; a low expression of HLA-DR and costimulatory molecules; differentiation potential; a high expression of TF/CD142; an absence of pathogenic microorganisms; negative endotoxins; an absence of chromosomal abnormalities; an absence of genotoxicity and tumorigenicity; and T-lymphocyte proliferation inhibition potential. This study shows the relevance of standardizing the manufacturing process and quality controls to reduce variability due to the heterogeneity between donors. The results might also be useful for the implementation and optimization of new analytical techniques and automated methods to improve safety, which are the major concerns related to MSC-based therapy.

Mesenchymal Stem/Stromal Cells in Asthma Therapy: Mechanisms and Strategies for Enhancement

Asthma is a complex and heterogeneous disease characterized by chronic airway inflammation, airway hyperresponsiveness, and airway remodeling. Most asthmatic patients are well-established using standard treatment strategies and advanced biologicals. However, a small group of patients who do not respond to biological treatments or are not effectively controlled by available treatment strategies remain a clinical challenge. Therefore, new therapies are urgently needed for poorly controlled asthma. Mesenchymal stem/stromal cells (MSCs) have shown therapeutic potential in relieving airway inflammation and repairing impaired immune balance in preclinical trials owing to their immunomodulatory abilities. Noteworthy, MSCs exerted a therapeutic effect on steroid-resistant asthma with rare side effects in asthmatic models. Nevertheless, adverse factors such as limited obtained number, nutrient and oxygen deprivation in vitro, and cell senescence or apoptosis affected the survival rate and homing efficiency of MSCs, thus limiting the efficacy of MSCs in asthma. In this review, we elaborate on the roles and underlying mechanisms of MSCs in the treatment of asthma from the perspective of their source, immunogenicity, homing, differentiation, and immunomodulatory capacity and summarize strategies to improve their therapeutic effect.

Heterogeneity of mesenchymal stem cell-derived extracellular vesicles is highly impacted by the tissue/cell source and culture conditions

Extracellular vesicles (EVs) are cell-derived membrane structures exerting major effects in physiological as well as pathological processes by functioning as vehicles for the delivery of biomolecules to their target cells. An increasing number of effects previously attributed to cell-based therapies have been recognized to be actually mediated by EVs derived from the respective cells, suggesting the administration of purified EVs instead of living cells for cell-based therapies. In this review, we focus on the heterogeneity of EVs derived from mesenchymal stem/stromal cells (MSC) and summarize upstream process parameters that crucially affect the resulting therapeutic properties and biological functions. Hereby, we discuss the effects of the cell source, medium composition, 3D culture, bioreactor culture and hypoxia. Furthermore, aspects of the isolation and storage strategies influences EVs are described. Conclusively, optimization of upstream process parameters should focus on controlling MSC-derived EV heterogeneity for specific therapeutic applications.

Graphical Abstract

Paracrine Factors Released by Stem Cells of Mesenchymal Origin and their Effects in Cardiovascular Disease: A Systematic Review of Pre-clinical Studies

Mesenchymal stem cell (MSC) therapy has gained significant traction in the context of cardiovascular repair, and have been proposed to exert their regenerative effects via the secretion of paracrine factors. In this systematic review, we examined the literature and consolidated available evidence for the "paracrine hypothesis". Two Ovid SP databases were searched using a strategy encompassing paracrine mediated MSC therapy in the context of ischemic heart disease. This yielded 86 articles which met the selection criteria for inclusion in this study. We found that the MSCs utilized in these articles were primarily derived from bone marrow, cardiac tissue, and adipose tissue. We identified 234 individual protective factors across these studies, including VEGF, HGF, and FGF2; which are proposed to exert their effects in a paracrine manner. The data collated in this systematic review identifies secreted paracrine factors that could decrease apoptosis, and increase angiogenesis, cell proliferation, and cell viability. These included studies have also demonstrated that the administration of MSCs and indirectly, their secreted factors can reduce infarct size, and improve left ventricular ejection fraction, contractility, compliance, and vessel density. Furthering our understanding of the way these factors mediate repair could lead to the identification of therapeutic targets for cardiac regeneration.

Hyperthermia-stimulated tonsil-mesenchymal stromal cells suppress hematological cancer cells through downregulation of IL-6

There are contradictory reports on the use of mesenchymal stromal cells (MSCs) in cancer therapy. Variable outcomes have been associated with several factors including cancer pathology, experimental procedure, MSC source tissue, and individual genetic differences. It is also known that MSCs exert their therapeutic effects with various paracrine factors released from these cells. The profiles of the factors released from MSCs are altered by heat shock, hypoxia, oxidative stress, starvation or various agents such as inflammatory cytokines, and their therapeutic potential is affected. In this study, the antitumor potential of conditioned media (CM), which contains paracrine factors, of mild hyperthermia-stimulated mesenchymal stromal cells derived from lymphoid organ tonsil tissue (T-MSC) was investigated in comparison with CM obtained from T-MSCs grew under normal culture conditions. CM was obtained from T-MSCs that were successfully isolated from palatine tonsil tissue and characterized. The cytotoxic effect of CM on the growth of hematological cancer cell lines at different concentrations (1:1 and 1:2) was demonstrated by methylthiazoldiphenyl-tetrazolium bromide analysis. In addition, the apoptotic effect of T-MSC-CM treatment was evaluated on the cancer cells using Annexin-V/PI detection method by flow cytometry. The pro/anti-apoptotic and cytokine-related gene expressions were also analyzed by real-time polymerase chain reaction post T-MSC-CM treatment. In conclusion, we demonstrated that the factors released from hyperthermia-stimulated T-MSCs induced apoptosis in hematological cancer cell lines in a dose-dependent manner. Importantly, our results at the transcriptional level support that the factors and cytokines released from hyperthermia-stimulated T-MSC may exert antitumoral effects in cancer cells by downregulation of IL-6 that promotes tumorigenesis. These findings reveal that T-MSC-CM can be a powerful cell-free therapeutical strategy for cancer therapy.

Mesenchymal Stem/Progenitor Cells and Their Derivates in Tissue Regeneration

Mesenchymal stem/stromal cells (MSC) have been extensively studied over the last 30 years in the context of their regenerative and immunomodulatory activities for potential application in regenerative medicine [...].

Expression of proliferation-related genes in BM-MSC-treated ALL cells in hypoxia condition is regulated under the influence of epigenetic factors in-vitro

Mesenchymal stem cells affect ALL cell biology under hypoxic conditions. We studied survival, proliferation, expression, and promoter methylation levels of essential genes involved in expanding MOLT-4 cells co-cultured with BM-MSC under the hypoxic condition. Here, MOLT-4 cells were co-cultured with BMMSCs under hypoxic conditions. First, the apoptosis rate was evaluated by Flow cytometry. Then, MOLT-4 cells' proliferation rate was assessed using MTT assay, and the expressions and methylation rates of genes were determined by qRT-PCR and MS-qPCR, respectively. The results showed that although MOLT-4 cells proliferation and survival rates were reduced under hypoxic conditions, this reduction was not statistically significant. Also, we showed that hypoxic conditions caused upregulation of candidate genes and affected their methylation status. Besides, it was revealed that Pontin was downregulated, while KDM3A, SKP2, and AURKA had an upward trend in the presence of MOLT-4 cells plus BM-MSC. The co-culture of leukemia cells with BMMSCs under hypoxic conditions may be a potential therapeutic approach for ALL.

HATMSC Secreted Factors in the Hydrogel as a Potential Treatment for Chronic Wounds-In Vitro Study

Mesenchymal stem cells (MSCs) can improve chronic wound healing; however, recent studies suggest that the therapeutic effect of MSCs is mediated mainly through the growth factors and cytokines secreted by these cells, referred to as the MSC secretome. To overcome difficulties related to the translation of cell therapy into clinical use such as efficacy, safety and cost, we propose a hydrogel loaded with a secretome from the recently established human adipose tissue mesenchymal stem cell line (HATMSC2) as a potential treatment for chronic wounds. Biocompatibility and biological activity of hydrogel-released HATMSC2 supernatant were investigated in vitro by assessing the proliferation and metabolic activity of human fibroblast, endothelial cells and keratinocytes. Hydrogel degradation was measured using hydroxyproline assay while protein released from the hydrogel was assessed by interleukin-8 (IL-8) and macrophage chemoattractant protein-1 (MCP-1) ELISAs. Pro-angiogenic activity of the developed treatment was assessed by tube formation assay while the presence of pro-angiogenic miRNAs in the HATMSC2 supernatant was investigated using real-time RT-PCR. The results demonstrated that the therapeutic effect of the HATMSC2-produced factors is maintained following incorporation into collagen hydrogel as confirmed by increased proliferation of skin-origin cells and improved angiogenic properties of endothelial cells. In addition, HATMSC2 supernatant revealed antimicrobial activity, and which therefore, in combination with the hydrogel has a potential to be used as advanced wound-healing dressing.

High-Molecular-Weight Hyaluronic Acid Inhibits IL-1β-Induced Synovial Inflammation and Macrophage Polarization through the GRP78-NF-κB Signaling Pathway

Recent evidence has suggested that synovial inflammation and macrophage polarization were involved in the pathogenesis of osteoarthritis (OA). Additionally, high-molecular-weight hyaluronic acid (HMW-HA) was often used clinically to treat OA. GRP78, an endoplasmic reticulum (ER) stress chaperone, was suggested to contribute to the hyperplasia of synovial cells in OA. However, it was still unclear whether HMW-HA affected macrophage polarization through GRP78. Therefore, we aimed to identify the effect of HMW-HA in primary synovial cells and macrophage polarization and to investigate the role of GRP78 signaling. We used IL-1β to treat primary synoviocytes to mimic OA, and then treated them with HMW-HA. We also collected conditioned medium (CM) to culture THP-1 macrophages and examine the changes in the phenotype. IL-1β increased the expression of GRP78, NF-κB (p65 phosphorylation), IL-6, and PGE2 in primary synoviocytes, accompanied by an increased macrophage M1/M2 polarization. GRP78 knockdown significantly reversed the expression of IL-1β-induced GRP78-related downstream molecules and macrophage polarization. HMW-HA with GRP78 knockdown had additive effects in an IL-1β culture. Finally, the synovial fluid from OA patients revealed significantly decreased IL-6 and PGE2 levels after the HMW-HA treatment. Our study elucidated a new form of signal transduction for HMW-HA-mediated protection against synovial inflammation and macrophage polarization and highlighted the involvement of the GRP78-NF-κB signaling pathway.

Mesenchymal Stem Cell-Derived Exosomes and MicroRNAs in Cartilage Regeneration: Biogenesis, Efficacy, miRNA Enrichment and Delivery

Exosomes are the small extracellular vesicles secreted by cells for intercellular communication. Exosomes are rich in therapeutic cargos such as microRNA (miRNA), long non-coding RNA (lncRNA), small interfering RNA (siRNA), DNA, protein, and lipids. Recently, many studies have focused on miRNAs as a promising therapeutic factor to support cartilage regeneration. Exosomes are known to contain a substantial amount of a variety of miRNAs. miRNAs regulate the post-transcriptional gene expression by base-pairing with the target messenger RNA (mRNA), leading to gene silencing. Several exosomal miRNAs have been found to play a role in cartilage regeneration by promoting chondrocyte proliferation and matrix secretion, reducing scar tissue formation, and subsiding inflammation. The exosomal miRNA cargo can be modulated using techniques such as cell transfection and priming as well as post-secretion modifications to upregulate specific miRNAs to enhance the therapeutic effect. Exosomes are delivered to the joints through direct injection or via encapsulation within a scaffold for sustained release. To date, exosome therapy for cartilage injuries has yet to be optimized as the ideal cell source for exosomes, and the dose and method of delivery have yet to be identified. More importantly, a deeper understanding of the role of exosomal miRNAs in cartilage repair is paramount for the development of more effective exosome therapy.

MicroRNA-26a/b-5p promotes myocardial infarction-induced cell death by downregulating cytochrome c oxidase 5a

Myocardial infarction (MI) damage induces various types of cell death, and persistent ischemia causes cardiac contractile decline. An effective therapeutic strategy is needed to reduce myocardial cell death and induce cardiac recovery. Therefore, studies on molecular and genetic biomarkers of MI, such as microRNAs (miRs), have recently been increasing and attracting attention due to the ideal characteristics of miRs. The aim of the present study was to discover novel causative factors of MI using multiomics-based functional experiments. Through proteomic, MALDI-TOF-MS, RNA sequencing, and network analyses of myocardial infarcted rat hearts and in vitro functional analyses of myocardial cells, we found that cytochrome c oxidase subunit 5a (Cox5a) expression is noticeably decreased in myocardial infarcted rat hearts and myocardial cells under hypoxic conditions, regulates other identified proteins and is closely related to hypoxia-induced cell death. Moreover, using in silico and in vitro analyses, we found that miR-26a-5p and miR-26b-5p (miR-26a/b-5p) may directly modulate Cox5a, which regulates hypoxia-related cell death. The results of this study elucidate the direct molecular mechanisms linking miR-26a/b-5p and Cox5a in cell death induced by oxygen tension, which may contribute to the identification of new therapeutic targets to modulate cardiac function under physiological and pathological conditions.

Monitoring the activity of two microRNAs, small non-coding RNAs, may provide a useful biomarker for heart attack prognosis and inform novel treatments for repairing heart cells. Ki-Chul Hwang and Jung-Won Choi at the Catholic Kwandong University in Gangwon-do, South Korea, and co-workers examined potential causative factors for heart attacks by exploring the activity of microRNAs in rat models and heart cell cultures. They found that levels of a key protein involved in maintaining mitochondrial function and energy metabolism, cytochrome c oxidase subunit 5a (Cox5a), were significantly decreased in heart cells during oxygen deprivation. Further, they identified two microRNAs that acted to inhibit Cox5a after a heart attack. Suppressing these two microRNAs could boost Cox5a activity and limit cell death, although the authors urge caution because microRNAs also play physiological roles in the body.

Interferon-γ and Hypoxia Priming Have Limited Effect on the miRNA Landscape of Human Mesenchymal Stromal Cells-Derived Extracellular Vesicles

Mesenchymal stromal cell (MSC)-based cell therapy has received great interest in regenerative medicine. Priming the cells during the culture phase can improve their efficacy and/or survival after injection. The literature suggests that MSC extracellular vesicles (EV) can recapitulate a substantial part of the beneficial effects of the cells they originate from, and that micro-RNAs (miRNAs) are important players in EV biological action. Here, our aim was to determine if two classical priming methods of MSC, interferon-gamma (IFNγ) and hypoxia (HYP), could modify their EV miRNA content. Human bone marrow MSCs (BM-MSCs) from five healthy donors were cultured with IFNγ or in HYP or in control (CONT) conditions. The conditioned media were collected after 48 h in serum-free condition and EV were isolated by ultracentrifugation. Total RNA was isolated, pools of CONT, IFN, and HYP cDNA were prepared, and a miRNA profiling was performed using RT-qPCR. Then, miRNAs were selected based on their detectability and measured on each individual EV sample. Priming had no effect on EV amount or size distribution. A set of 81 miRNAs was detected in at least one of the pools of EVs. They were measured on each individual sample; 41 miRNAs were detected in all samples. The principal component analysis (PCA) failed to discriminate the groups. HYP induced a significant decrease in EV hsa-miR-34a-3p content and IFN induced a significant increase in five miRNAs (hsa-miR-25-3p, hsa-miR-106a-5p, hsa-miR-126-3p, hsa-miR-451a, and hsa-miR-665). Taken together, we found only limited alterations in the miRNA landscape of MSC EV with a high inter-individual variability.

Emergence of the Stem Cell Secretome in Regenerative Engineering

The secretome is defined as the set of molecules and biological factors that are secreted by cells into the extracellular space. In the past decade, secretome-based therapies have emerged as a promising approach to overcome the limitations associated with cell-based therapies for tissue and organ regeneration. Considering the growing number of recent publications related to secretome-based therapies, this review takes a step-by-step engineering approach to evaluate the role of the stem cell secretome in regenerative engineering. We discuss the functional benefits of the secretome, the techniques used to engineer the secretome and tailor its therapeutic effects, and the delivery systems and strategies that have been developed to use the secretome for tissue regeneration.

Hypoxic Wharton's Jelly Stem Cell Conditioned Medium Induces Immunogenic Cell Death in Lymphoma Cells

Mesenchymal stem cells from Wharton's jelly of the human umbilical cord (hWJSCs), and the conditioned medium (hWJSC-CM) prepared from them, were shown to be tumoricidal on many cancers. However, these tumoricidal effects were observed in hWJSCs grown under normoxic conditions of 21% oxygen in the laboratory. Since oxygen concentrations in the stem cell niche or physiological microenvironment are hypoxic and help to maintain stemness properties, the objective of this work was to evaluate whether there were differences in the tumoricidal properties of hWJSC-CM grown in 21% O₂ (normoxic) or 5% O₂ (hypoxic) environments. The results showed that hWJSCs grown under normoxic or hypoxic conditions showed no distinct morphological differences in culture and remained positive in trilineage differentiation into adipocytes, osteocytes, and chondrocytes. Hypoxic hWJSCs expressed the mesenchymal stem cell surface markers CD105, CD90, CD73, CD146, and CD108 similar to normoxic hWJSCs but were negative for the hematopoietic markers CD14, CD19, CD34, CD45, CD117, and HLA-DR. Hypoxic hWJSC-CM produced a significantly greater reduction in cell viability and a significantly greater increase in apoptosis, oxidative stress, and lipid peroxidation in human lymphoma cells compared to normoxic hWJSC-CM. Hypoxic hWJSC-CM also produced significantly greater expression of immunogenic cell death (ICD) hallmarks such as surface-bound calreticulin, HSP70, HSP90, and high mobility group binding 1 proteins and significantly decreased expression of the defense molecules CD47 and PD-L1. This study showed that the tumoricidal effect of hypoxic hWJSC-CM was superior to normoxic hWJSC-CM and should be the preferred choice of preparing hWJSC-CM for the induction of ICD on lymphoma cells.

A Comparative Analysis of Multipotent Mesenchymal Stromal Cells derived from Different Sources, with a Focus on Neuroregenerative Potential

Multipotent mesenchymal stromal cells (MSCs) can be considered an accessible therapeutic tool for regenerative medicine. Here, we compared the growth kinetics, immunophenotypic and immunomodulatory properties, gene expression and secretome profile of MSCs derived from human adult bone marrow (BM-MSCs), adipose tissue (AT-MSCs) and Wharton’s jelly (WJ-MSCs) cultured in clinically-relevant conditions, with the focus on the neuroregenerative potential. All the cell types were positive for CD10/CD29/CD44/CD73/CD90/CD105/HLA-ABC and negative for CD14/CD45/CD235a/CD271/HLA-DR/VEGFR2 markers, but they differed in the expression of CD34/CD133/CD146/SSEA-4/MSCA-1/CD271/HLA-DR markers. BM-MSCs displayed the highest immunomodulatory activity compared to AT- and WJ-MSCs. On the other hand, BM-MSCs secreted the lower content and had the lower gene expression of neurotrophic growth factors compared to other cell lines, which may be caused by the higher sensitivity of BM-MSCs to nutrient limitations. Despite the differences in growth factor secretion, the MSC secretome derived from all cell sources had a pronounced neurotrophic potential to stimulate the neurite outgrowth of DRG-neurons and reduce the cell death of neural stem/progenitor cells after H₂O₂ treatment. Overall, our study provides important information for the transfer of basic MSC research towards clinical-grade manufacturing and therapeutic applications.

Lung Tissue Damage Associated with Allergic Asthma in BALB/c Mice Could Be Controlled with a Single Injection of Mesenchymal Stem Cells from Human Bone Marrow up to 14 d After Transplantation

Mesenchymal stem cell (MSC) research has demonstrated the potential of these cells to modulate lung inflammatory processes and tissue repair; however, the underlying mechanisms and treatment durability remain unknown. Here, we investigated the therapeutic potential of human bone marrow-derived MSCs in the inflammatory process and pulmonary remodeling of asthmatic BALB/c mice up to 14 d after transplantation. Our study used ovalbumin to induce allergic asthma in male BALB/c mice. MSCs were injected intratracheally in the asthma groups. Bronchoalveolar lavage fluid (BALF) was collected, and cytology was performed to measure the total protein, hydrogen peroxide (H2O2), and proinflammatory (IL-5, IL-13, and IL-17A) and anti-inflammatory (IL-10) interleukin (IL) levels. The lungs were removed for the histopathological evaluation. On day zero, the eosinophil and lymphochte percentages, total protein concentrations, and IL-13 and IL-17A levels in the BALF were significantly increased in the asthma group, proving the efficacy of the experimental model of allergic asthma. On day 7, the MSC-treated group exhibited significant reductions in the eosinophil, lymphocyte, total protein, H2O2, IL-5, IL-13, and IL-17A levels in the BALF, while the IL-10 levels were significantly increased. On day 14, the total cell numbers and lymphocyte, total protein, IL-13, and IL-17A levels in the BALF in the MSC-treated group were significantly decreased. A significant decrease in airway remodeling was observed on days 7 and 14 in almost all bronchioles, which showed reduced inflammatory infiltration, collagen deposition, muscle and epithelial thickening, and mucus production. These results demonstrate that treatment with a single injection of MSCs reduces the pathophysiological events occurring in an experimental model of allergic asthma by controlling the inflammatory process up to 14 d after transplantation.

Enhanced Anti-Cancer Effects of Conditioned Medium from Hypoxic Human Umbilical Cord-Derived Mesenchymal Stem Cells

Background and Objectives

There have been contradictory reports on the pro-cancer or anti-cancer effects of mesenchymal stem cells. In this study, we investigated whether conditioned medium (CM) from hypoxic human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) (H-CM) showed enhanced anti-cancer effects compared with CM from normoxic hUC-MSCs (N-CM).

Methods and Results

Compared with N-CM, H-CM not only strongly reduced cell viability and increased apoptosis of human cervical cancer cells (HeLa cells), but also increased caspase-3/7 activity, decreased mitochondrial membrane potential (MMP), and induced cell cycle arrest. In contrast, cell viability, apoptosis, MMP, and cell cycle of human dermal fibroblast (hDFs) were not significantly changed by either CM whereas caspase-3/7 activity was decreased by H-CM. Protein antibody array showed that activin A, Beta IG-H3, TIMP-2, RET, and IGFBP-3 were upregulated in H-CM compared with N-CM. Intracellular proteins that were upregulated by H-CM in HeLa cells were represented by apoptosis and cell cycle arrest terms of biological processes of Gene Ontology (GO), and by cell cycle of Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. In hDFs, negative regulation of apoptosis in biological process of GO and PI3K-Akt signaling pathway of KEGG pathways were represented.

Conclusions

H-CM showed enhanced anti-cancer effects on HeLa cells but did not influence cell viability or apoptosis of hDFs and these different effects were supported by profiling of secretory proteins in both kinds of CM and intracellular signaling of HeLa cells and hDFs.

Secretomes from Mesenchymal Stem Cells against Acute Kidney Injury: Possible Heterogeneity

A kidney has the ability to regenerate itself after a variety of renal injuries. Mesenchymal stem cells (MSCs) have been shown to ameliorate tissue damages during renal injuries and diseases. The regenerations induced by MSCs are primarily mediated by the paracrine release of soluble factors and extracellular vesicles, including exosomes and microvesicles. Extracellular vesicles contain proteins, microRNAs, and mRNAs that are transferred into recipient cells to induce several repair signaling pathways. Over the past few decades, many studies identified trophic factors from MSCs, which attenuate renal injury in a variety of animal acute kidney injury models, including renal ischemia-reperfusion injury and drug-induced renal injury, using microarray and proteomic analysis. Nevertheless, these studies have revealed the heterogeneity of trophic factors from MSCs that depend on the cell origins and different stimuli including hypoxia, inflammatory stimuli, and aging. In this review article, we summarize the secretomes and regenerative mechanisms induced by MSCs and highlight the possible heterogeneity of trophic factors from different types of MSC and different circumstances for renal regeneration.

Hypoxic conditioned medium derived from bone marrow mesenchymal stromal cells protects against ischemic stroke in rats

In recent years, studies have shown that the secretome of bone marrow mesenchymal stromal cells (BMSCs) contains many growth factors, cytokines, and antioxidants, which may provide novel approaches to treat ischemic diseases. Furthermore, the secretome may be modulated by hypoxic preconditioning. We hypothesized that conditioned medium (CM) derived from BMSCs plays a crucial role in reducing tissue damage and improving neurological recovery after ischemic stroke and that hypoxic preconditioning of BMSCs robustly improves these activities. Rats were subjected to ischemic stroke by middle cerebral artery occlusion and then intravenously administered hypoxic CM, normoxic CM, or Dulbecco modified Eagle medium (DMEM, control). Cytokine antibody arrays and label-free quantitative proteomics analysis were used to compare the differences between hypoxic CM and normoxic CM. Injection of normoxic CM significantly reduced the infarct area and improved neurological recovery after stroke compared with administering DMEM. These outcomes may be associated with the attenuation of apoptosis and promotion of angiogenesis. Hypoxic preconditioning significantly enhanced these therapeutic effects. Fourteen proteins were significantly increased in hypoxic CM compared with normoxic CM as measured by cytokine arrays. The label-free quantitative proteomics analysis revealed 163 proteins that were differentially expressed between the two groups, including 107 upregulated proteins and 56 downregulated proteins. Collectively, our results demonstrate that hypoxic CM protected brain tissue from ischemic injury and promoted functional recovery after stroke in rats and that hypoxic CM may be the basis of a potential therapy for stroke patients.

Conditioned medium from umbilical cord mesenchymal stem cells improves nasal mucosa damage by radiation

OBJECTIVES

To explore therapeutic effects of conditioned medium from human umbilical cord mesenchymal stem cells (hUC-MSCs) on nasal mucosa radiation damage both in vivo and in vitro.

RESULTS

The mucus cilia clearance time (7 and 30 days), degree of mucosal edema (7, 30, 90 and 180 days), cilia coverage (180 days) of concentrated conditioned medium group improved compared with radiotherapy control group. The proliferation and migration abilities of irradiated and non-irradiated nasal epithelial cells significantly increased after culture in bronchial epithelial cell growth medium (BEGM) containing 10% conditioned medium of hUC-MSCs compared to cells cultured in BEGM alone.

CONCLUSIONS

Soluble factors secreted by hUC-MSCs may promote nasal epithelial cell proliferation and migration. Intranasal administration of hUC-MSC conditioned medium effectively repairs nasal mucosa radiation damage.

Adipose-derived stem cell-released osteoprotegerin protects cardiomyocytes from reactive oxygen species-induced cell death

Background

The paracrine effect is likely the major mechanism of the adipose-derived stem cell (ASC)-mediated cardioprotective effect. However, the exact composition and nature of ASC-released paracrine factors remain elusive. In the present study, we examined the effect of osteoprotegerin (OPG), a stem cell-released decoy receptor for death ligand, on the survival of cardiomyocytes exposed to oxidative stress.

Methods

The production of OPG from ASCs under oxidative stress was determined by ELISA and immunohistochemistry. The effects of OPG and the OPG-containing conditioned media of ASCs on the survival of cardiomyocytes were determined using a cell viability assay.

Results

Hydrogen peroxide (H₂O₂) significantly increased OPG production from ASCs in vitro, and OPG production from the ASCs transplanted into the ischemia–reperfusion-injured heart was also observed. OPG significantly attenuated cardiomyocyte death in vitro. OPG-containing conditioned media of ASCs also significantly protected cardiomyocytes. Delivery of siRNA specific to OPG significantly decreased the OPG production of ASCs, and also offset the protective effect of the conditioned media of ASCs.

Conclusions

Our study strongly suggests that OPG is one of the prosurvival factors released from ASCs that may contribute to the ASC-mediated cardioprotection and calls for further studies to elucidate detailed underlying mechanisms.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-017-0647-6) contains supplementary material, which is available to authorized users.

Identification of potential serum biomarkers in pigs at early stage after Lipopolysaccharide injection

The identification of useful biological indicators to monitor the body response before the presentation of clinical diseases has practical value in livestock production. To identify potential biomarkers in pigs at the early stage during inflammation, 12 pigs were intramuscularly injected with 2mL of Lipopolysaccharide (LPS, 15μg/kg BW) or saline. Serum protein expression profiles were detected with two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) techniques. Serum biochemical indicators and acute phase protein (APP) concentrations were analyzed with an automatic biochemical analyzer and ELISA, respectively. Of the serum biochemical indicators, creatinine concentration significantly increased 6h post infection, whereas albumin showed a decreased tendency. The 2-DE and MALDI-TOF mass spectrometry technique detected 17 protein spots representing 10 proteins: α-1-antichymotrypsin, albumin, bovine lactoferrin, serotransferrin, serpin A3-6, immunoglobulin light chain (κ chain, mu chain), complement C3 precursor, zinc-α-2-glycoprotein (ZAG), and ceruloplasmin. Two proteins were selected to confirm the mass spectrometry results, and resulting differences accorded with the proteomics results. Of the four typical acute phase protein (APPs) measured, the C-reactive protein (CRP) and haptoglobin (HP) concentrations increased significantly, while no differences were observed in the pig-major acute phase protein (Pig-MAP) and transthyretin (TTR) contents. The results showed that serum creatinine, CRP, HP, and ten other proteins content changed significantly after LPS injection. Of these proteins, ZAG was first reported in pigs during inflammation. These proteins show great promise as biomarkers to monitor the health status and welfare of pigs during the early stage of LPS-induced inflammation.