Therapeutic potential of human adipose-derived stem cells (ADSCs) from cancer patients: a pilot study

Contents of exosomes derived from adipose tissue and their regulation on inflammation, tumors, and diabetes

Adipose tissue (AT) serves as an energy-capacitive organ and performs functions involving paracrine- and endocrine-mediated regulation via extracellular vesicles (EVs) secretion. Exosomes, a subtype of EVs, contain various bioactive molecules with regulatory effects, such as nucleic acids, proteins, and lipids. AT-derived exosomes (AT-exos) include exosomes derived from various cells in AT, including adipocytes, adipose-derived stem cells (ADSCs), macrophages, and endothelial cells. This review aimed to comprehensively evaluate the impacts of different AT-exos on the regulation of physiological and pathological processes. The contents and functions of adipocyte-derived exosomes and ADSC-derived exosomes are compared simultaneously, highlighting their similarities and differences. The contents of AT-exos have been shown to exert complex regulatory effects on local inflammation, tumor dynamics, and insulin resistance. Significantly, differences in the cargoes of AT-exos have been observed among diabetes patients, obese individuals, and healthy individuals. These differences could be used to predict the development of diabetes mellitus and as therapeutic targets for improving insulin sensitivity and glucose tolerance. However, further research is needed to elucidate the underlying mechanisms and potential applications of AT-exos.

Angiopoietin-like growth factor-derived peptides as biological activators of adipose-derived mesenchymal stromal cells

Adipose-derived mesenchymal stromal cells (AD-MSCs) are an essential issue in modern medicine. Extensive preclinical and clinical studies have shown that mesenchymal stromal/stem cells, including AD-MSCs, have specific properties (ability to differentiate into other cells, recruitment to the site of injury) of particular importance in the regenerative process. Ongoing research aims to elucidate factors supporting AD-MSC culture and differentiation in vitro. Angiopoietin-like proteins (ANGPTLs), known for their pleiotropic effects in lipid and glucose metabolism, may play a significant role in this context. Regeneration is a complex and dynamic process controlled by many factors. ANGPTL6 (Angiopoietin-related growth factor, AGF), among many activities modulated the biological activity of stem cells. This study examined the influence of synthesized AGF-derived peptides, designated as AGF9 and AGF27, on AD-MSCs. AGF9 and AGF27 enhanced the viability and migration of AD-MSCs and acted as a chemotactic factor for these cells. AGF9 stimulated chondrogenesis and lipid synthesis during AD-MSCs differentiation, influenced AD-MSCs cytokine secretion and modulated transcriptome for such basic cell activities as migration, transport of molecules, and apoptosis. The ability of AGF9 to modulate the biological activity of AD-MSCs warrants the consideration of this peptide a noteworthy therapeutic agent that deserves further investigation for applications in regenerative medicine.

Adipose-derived miRNAs as potential biomarkers for predicting adulthood obesity and its complications: A systematic review and bioinformatic analysis

Adipose tissue is the first and primary target organ of obesity and the main source of circulating miRNAs in patients with obesity. This systematic review aimed to analyze and summarize the generation and mechanisms of adipose-derived miRNAs and their role as early predictors of various obesity-related complications. Literature searches in the PubMed and Web of Science databases using terms related to miRNAs, obesity, and adipose tissue. Pre-miRNAs from the Human MicroRNA Disease Database, known to regulate obesity-related metabolic disorders, were combined for intersection processing. Validated miRNA targets were sorted through literature review, and enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes via the KOBAS online tool, disease analysis, and miRNA transcription factor prediction using the TransmiR v. 2.0 database were also performed. Thirty miRNAs were identified using both obesity and adipose secretion as criteria. Seventy-nine functionally validated targets associated with 30 comorbidities of these miRNAs were identified, implicating pathways such as autophagy, p53 pathways, and inflammation. The miRNA precursors were analyzed to predict their transcription factors and explore their biosynthesis mechanisms. Our findings offer potential insights into the epigenetic changes related to adipose-driven obesity-related comorbidities.

Modulation of adipose-derived stem cell behavior by prostate pathology-associated plasma: insights from in vitro exposure

Adipose-derived stem cells (ADSCs) are promising in regenerative medicine. Their proliferation, survival and activation are influenced by specific signals within their microenvironment, also known as niche. The stem cell niche is regulated by complex interactions between multiple cell types. When transplanted in a specific area, ADSCs can secrete several immunomodulatory factors. At the same time, a tumor microenvironment can influence stem cell behavior, modulating proliferation and their ability to differentiate into a specific phenotype. Whitin this context, we exposed ADSCs to plasma samples derived from human patients diagnosed with prostate cancer (PC), or precancerous lesions (PL), or benign prostatic hyperplasia (BPH) for 4, 7 or 10 days. We then analyzed the expression of main stemness-related markers and cell-cycle regulators. We also measured cytokine production and polyamine secretion in culture medium and evaluated cell morphology and collagen production by confocal microscopy. The results obtained from this study show significant changes in the morphology of ADSCs exposed to plasma samples, especially in the presence of prostate cancer plasma, suggesting important implications in the use of ADSCs for the development of new treatments and application in regenerative medicine.

Advancements in culture technology of adipose-derived stromal/stem cells: implications for diabetes and its complications

Stem cell-based therapies exhibit considerable promise in the treatment of diabetes and its complications. Extensive research has been dedicated to elucidate the characteristics and potential applications of adipose-derived stromal/stem cells (ASCs). Three-dimensional (3D) culture, characterized by rapid advancements, holds promise for efficacious treatment of diabetes and its complications. Notably, 3D cultured ASCs manifest enhanced cellular properties and functions compared to traditional monolayer-culture. In this review, the factors influencing the biological functions of ASCs during culture are summarized. Additionally, the effects of 3D cultured techniques on cellular properties compared to two-dimensional culture is described. Furthermore, the therapeutic potential of 3D cultured ASCs in diabetes and its complications are discussed to provide insights for future research.

Adipose tissue‑derived extracellular vesicles: Systemic messengers in health and disease (Review)

Adipose tissue (AT) is a complicated metabolic organ consisting of a heterogeneous population of cells that exert wide‑ranging effects on the regulation of systemic metabolism and in maintaining metabolic homeostasis. Various obesity‑related complications are associated with the development of dysfunctional AT. As an essential transmitter of intercellular information, extracellular vesicles (EVs) have recently been recognized as crucial in regulating multiple physiological functions. AT‑derived extracellular vesicles (ADEVs) have been shown to facilitate cellular communication both inside and between ATs and other peripheral organs. Here, the role of EVs released from ATs in the homeostasis of metabolic and cardiovascular diseases, cancer, and neurological disorders by delivering lipids, proteins, and nucleic acids between different cells is summarized. Furthermore, the differences in the sources of ADEVs, such as adipocytes, AT macrophages, AT‑derived stem cells, and AT‑derived mesenchymal stem cells, are also discussed. This review may provide valuable information for the potential application of ADEVs in metabolic syndrome, cardiovascular diseases, cancer, and neurological disorders.

Exosomes derived from miR-338-3p-modified adipose stem cells inhibited inflammation injury of chondrocytes via targeting RUNX2 in osteoarthritis

BACKGROUND

Osteoarthritis (OA) is a chronic degenerative disease that is one of the main causes of disability in middle-aged and elderly people. Adipose stem cell (ASC)-derived exosomes (ASC-Exo) could repair cartilage damage and treat OA. MiRNA-338-3p expression was confirmed to play a role in inhibiting proinflammatory cytokines. Herein, we aimed to explore the mechanism by which exosomes derived from miR-338-3p overexpressing ASCs protects chondrocytes from interleukin (IL)-1β-induced chondrocyte change.

METHODS

Exosomes were extracted from ASCs transfected with miR-338-3p or its antisense inhibitor. The ASC-Exos (miR-338-3p silencing/overexpression) were incubated with IL-1β-induced ATDC5 cells, followed by evaluation of the chondrocyte proliferation, degradation, and inflammation injury.

RESULTS

In vitro results revealed that ASC-Exos inhibited the expression of prostaglandin E2 (PGE2), IL-6, IL-1β, and TNF-α, as well as promoted the proliferation of ATDC5 cells. Moreover, ASC-Exos inhibited inflammation injury and degradation of ATDC5 cells by transferring miR-338-3p. Luciferase reporter assays showed that RUNX2 was a target gene of miR-338-3p. Additionally, RUNX2 overexpression in ATDC5 cells reversed the protective effect of miR-338-3p on chondrocytes. Taken together, this study demonstrated that exosomes secreted from miR-338-3p-modified ASCs were effective in the repair of IL-1β-induced chondrocyte change by inhibiting RUNX2 expression.

CONCLUSIONS

Our result provided valuable data for understanding the mechanism of ASC-Exos in OA treatment.

Co-overexpression of VEGF and Smad7 improved the therapeutic effects of adipose-derived stem cells on neurogenic erectile dysfunction in the rat model

Cavernous nerve injury is the main cause of erectile dysfunction (ED) after radical prostatectomy (RP). In our previous study, injection of adipose-derived stem cells (ADSCs) into the cavernosum can repair damaged cavernosum nerves and ED can be restored to a certain extent. In order to improve these therapeutic effects, we evaluated the efficacy of ADSCs co-modified with VEGF and Smad7 in a rat model. SD rats were randomly divided into six groups: a sham surgery group, and the five bilateral cavernous nerve injury (BCNI) groups were injected with ADSC or ADSCs genetically modified by VEGF (ADSC-V), Smad7 (ADSC-S), or VEGF&Smad7 (ADSC-V&S) or phosphate-buffered saline (PBS). The results indicated that the erectile function of the ADSC-V, ADSC-S, and ADSC-V&S groups was significantly recovered, and the erectile function of the ADSC-V&S group was more distinctly recovered as compared to the other groups. The same results are shown in the expression of neuronal nitric oxide synthase and the smooth muscle/collagen ratio of penile tissue comparing the ADSC-V&S group to the ADSC-V and ADSC-S group. These experimental data suggest that ADSCs co-overexpressed with VEGF and Smad7 can significantly improve erectile function after BCNI. This study provides new therapeutic thoughts for ED following RP.

Autophagy regulates the effects of ADSC-derived small extracellular vesicles on acute lung injury

Small extracellular vesicles (sEVs) have been recognized to be more effective than direct stem cell differentiation into functional target cells in preventing tissue injury and promoting tissue repair. Our previous study demonstrated the protective effect of adipose-derived stem cells (ADSCs) on lipopolysaccharide (LPS)-induced acute lung injury and the effect of autophagy on ADSC functions, but the role of ADSC-derived sEVs (ADSC-sEVs) and autophagy-mediated regulation of ADSC-sEVs in LPS-induced pulmonary microvascular barrier damage remains unclear. After treatment with sEVs from ADSCs with or without autophagy inhibition, LPS-induced human pulmonary microvascular endothelial cell (HPMVECs) barrier damage was detected. LPS-induced acute lung injury in mice was assessed in vivo after intravenous administration of sEVs from ADSCs with or without autophagy inhibition. The effects of autophagy on the bioactive miRNA components of ADSC-sEVs were assessed after prior inhibition of cell autophagy. We found that ADSC-sEV effectively alleviated LPS-induced apoptosis, tight junction damage and high permeability of PMVECs. Moreover, in vivo administration of ADSC-sEV markedly inhibited LPS-triggered lung injury. However, autophagy inhibition, markedly weakened the therapeutic effect of ADSC-sEVs on LPS-induced PMVECs barrier damage and acute lung injury. In addition, autophagy inhibition, prohibited the expression of five specific miRNAs in ADSC-sEVs -under LPS-induced inflammatory conditions. Our results indicate that ADSC-sEVs protect against LPS-induced pulmonary microvascular barrier damage and acute lung injury. Autophagy is a positive mediator of sEVs function, at least in part through controlling the expression of bioactive miRNAs in sEVs.

Bladder Cancer Cells Exert Pleiotropic Effects on Human Adipose-Derived Stem Cells

Stem cell-based therapies are considered one of the most promising disciplines in biomedicine. Bladder cancer patients could benefit from therapies directed to promote healing after invasive surgeries or to lessen urinary incontinence, a common side effect of both cancer itself and the treatment. However, the local delivery of cells producing large amounts of paracrine factors may alter interactions within the microenvironment. For this reason, reconstructive cellular therapies for patients with a history of cancer carry a potential risk of tumor reactivation. We used an indirect co-culture model to characterize the interplay between adipose-derived stem cells and bladder cancer cells. Incubation with ASCs increased MCP-1 secretion by bladder cancer cells (from 2.1-fold to 8.1-fold, depending on the cell line). Cancer cell-derived factors altered ASC morphology. Cells with atypical shapes and significantly enlarged volumes appeared within the monolayer. Incubation in a conditioned medium (CM) containing soluble mediators secreted by 5637 and HB-CLS-1 bladder cancer cell lines decreased ASC numbers by 47.5% and 45.7%. A significant increase in adhesion to ECM components, accompanied by reduced motility and sheet migration, was also observed after incubation in CM from 5637 and HB-CLS-1 cells. No differences were observed when ASCs were co-cultured with HT-1376 cells. Our previous and present results indicate that soluble mediators secreted by ASCs and bladder cancer cells induce opposite effects influencing cells that represent the non-muscle-invasive urinary bladder.

Comparison of Yield, Purity, and Functional Properties of Large-Volume Exosome Isolation Using Ultrafiltration and Polymer-Based Precipitation

BACKGROUND

Mesenchymal stem cell-derived exosomes are known to produce effects similar to those of source cells and therefore represent a new approach in cell-free regenerative medicine. Their potential clinical application demands efficient isolation of stable and functional exosomes from a large volume of biological fluid.

METHODS

Exosomes from adipose-tissue conditioned medium of the same volume were isolated using either (1) ultrafiltration with size exclusion or (2) ExoQuick-TC. The isolated exosomes were characterized by protein concentration, particle size, exosomal marker expression, RNA expression profiles, and roles in dermal fibroblast proliferation and migration.

RESULTS

Both isolation methods produced exosomes within the size range defined for exosomes (50 to 200 nm) and common markers were enriched. Compared to the ExoQuick-TC precipitation method, the ultrafiltration method produced a significantly higher protein yield (p < 0.001) but a lower particle-to-protein ratio (p < 0.05); it also yielded higher RNA contents from the same fat tissue indicated by housekeeping genes, but with overall lower purity. The expression of several mRNAs and miRNAs related to tissue regeneration showed that there was no statistical difference between both methods, except miR-155 and miR-223 (p < 0.05). However, there was no difference in overall fibroblast proliferation and migration between exosomes isolated by these two methods.

CONCLUSIONS

Ultrafiltration with size exclusion demonstrated higher yields, acceptable purity, and comparable biophysical properties and biological functions to the more expensive commercial precipitation method. Therefore, it may conceivably be translated into yield-efficient and cost-effective modalities for therapeutic purposes.

CLINICAL RELEVANCE STATEMENT

Ultrafiltration with size exclusion may be amenable for exosome isolation from large-volume complex fluids such as tissue conditioned media for clinical application in future regenerative medicine.

OUP accepted manuscript

Adipose-derived stem or stromal cells (ASCs) possess promising potential in the fields of tissue engineering and regenerative medicine due to their secretory activity, their multilineage differentiation potential, their easy harvest, and their rich yield compared to other stem cell sources. After the first identification of ASCs in humans in 2001, the knowledge of their cell biology and cell characteristics have advanced, and respective therapeutic options were determined. Nowadays, ASC-based therapies are on the verge of translation into clinical practice. However, conflicting evidence emerged in recent years about the safety profile of ASC applications as they may induce tumor progression and invasion. Numerous in-vitro and in-vivo studies demonstrate a potential pro-oncogenic effect of ASCs on various cancer entities. This raises questions about the safety profile of ASCs and their broad handling and administration. However, these findings spark controversy as in clinical studies ASC application did not elevate tumor incidence rates, and other experimental studies reported an inhibitory effect of ASCs on different cancer cell types. This comprehensive review aims at providing up-to-date information about ASCs and cancer cell interactions, and their potential carcinogenesis and tumor tropism. The extracellular signaling activity of ASCs, the interaction of ASCs with the tumor microenvironment, and 3 major organ systems (the breast, the skin, and genitourinary system) will be presented with regard to cancer formation and progression.

Composition, isolation, identification and function of adipose tissue-derived exosomes

Exosomes are nano-sized extracellular vesicles (30–160 nm diameter) with lipid bilayer membrane secrete by various cells that mediate the communication between cells and tissue, which contain a variety of non-coding RNAs, mRNAs, proteins, lipids and other functional substances. Adipose tissue is important energy storage and endocrine organ in the organism. Recent studies have revealed that adipose tissue-derived exosomes (AT-Exosomes) play a critical role in many physiologically and pathologically functions. Physiologically, AT-Exosomes could regulate the metabolic homoeostasis of various organs or cells including liver and skeletal muscle. Pathologically, they could be used in the treatment of disease and or that they may be involved in the progression of the disease. In this review, we describe the basic principles and methods of exosomes isolation and identification, as well as further summary the specific methods. Moreover, we categorize the relevant studies of AT-Exosomes and summarize the different components and biological functions of mammalian exosomes. Most importantly, we elaborate AT-Exosomes crosstalk within adipose tissue and their functions on other tissues or organs from the physiological and pathological perspective. Based on the above analysis, we discuss what remains to be discovered problems in AT-Exosomes studies and prospect their directions needed to be further explored in the future.

Hypoxic ADSCs-derived EVs promote the proliferation and chondrogenic differentiation of cartilage stem/progenitor cells

Cartilage tissue engineering is a promising option for repairing cartilage defects, although harvesting a large number of seeding cells remains a major challenge. Cartilage stem/progenitor cells (CSPCs) seem to be a promising cell source. Hypoxic extracellular vesicles (EVs) may play a major role in cell-cell and tissue-tissue communication. In the current study, we aimed to evaluate the effect of hypoxic adipose-derived stem cells (ADSCs)-derived EVs on CSPCs proliferation and differentiation. The characteristics of ADSCs-derived EVs were identified, and proliferation, migration, and cartilage-related gene expression of CSPCs were measured with or without the presence of hypoxic ADSCs-derived EVs. SEM, histological staining, biochemical and biomechanical analysis was performed to evaluate the effect of hypoxic ADSCs-derived EVs on CSPCs in alginate hydrogel culture. The results indicated that the majority of ADSC-derived EVs exhibited a round-shaped or cup-shaped morphology with a diameter of 40-1000 nm and expressed CD9, CD63, and CD81. CSPCs migration and proliferation were enhanced by hypoxic ADSCs-derived EVs, which also increased the expression of cartilage-related genes. The hypoxic ADSCs-derived EVs induce CSPCs to produce significantly more cartilage matrix and proteoglycan. In conclusion, hypoxic ADSCs-derived EVs improved the proliferation and chondrogenic differentiation of CSPCs for cartilage tissue engineering.

Application of ADSCs and their Exosomes in Scar Prevention

Scar is a common way of healing after tissue injury. The poor scar healing will not only cause dysfunction of tissues and organs but also affect the appearance of the patients’ body surface, which causes the pressure of life and spirit to the patients. However, the formation of scar tissue is an extremely complex process and its mechanism is not fully understood. At present, there is no treatment method to eliminate scars completely. Fibroblasts are the most abundant cells in the dermis, which have the ability to synthesize and remodel extracellular matrix (ECM). Myofibroblasts actively participate in the wound healing process and influence the outcome. Therefore, both of them play important roles in wound healing and scar formation. Adipose tissue-derived stem cells (ADSCs) are pluripotent stem cells that can act on target cells by paracrine. Adipose tissue stem cell-derived exosomes (ADSC-Exos) are important secretory substances of ADSCs. They are nanomembrane vesicles that can transport a variety of cellular components and fuse with target cells. In this review, we will discuss the effects of ADSCs and ADSC-Exos on the behavior of fibroblasts and myofibroblasts during wound healing and scarring stage in combination with recent studies.

Stem cells part of the innate and adaptive immune systems as a therapeutic for Covid-19

Some stem cell types not only release molecules that reduce viral replication, but also reduce the hypercytokinemia and inflammation induced by the immune system, and have been found to be part of the innate and adaptive immune systems. An important component of the stem cell's ability to ameliorate viral diseases, especially the complications post-clearance of the pathogen, is the ability of adult stem cells to reset the innate and adaptive immune systems from an inflammatory state to a repair state. Thus, the molecules released from certain stem cell types found to be safe and efficacious, may be an important new means for therapeutic development in Covid-19, especially for late-stage inflammation and tissue damage once the virus has cleared, particularly in the aged population.

Adipose-derived stromal cells for nonhealing wounds: Emerging opportunities and challenges

Wound healing complications affect thousands of people each year, thus constituting a profound economic and medical burden. Chronic wounds are a highly complex problem that usually affects elderly patients as well as patients with comorbidities such as diabetes, cancer (surgery, radiotherapy/chemotherapy) or autoimmune diseases. Currently available methods of their treatment are not fully effective, so new solutions are constantly being sought. Cell-based therapies seem to have great potential for use in stimulating wound healing. In recent years, much effort has been focused on characterizing of adipose-derived mesenchymal stromal cells (AD-MSCs) and evaluating their clinical use in regenerative medicine and other medical fields. These cells are easily obtained in large amounts from adipose tissue and show a high proregenerative potential, mainly through paracrine activities. In this review, the process of healing acute and nonhealing (chronic) wounds is detailed, with a special attention paid to the wounds of patients with diabetes and cancer. In addition, the methods and technical aspects of AD-MSCs isolation, culture and transplantation in chronic wounds are described, and the characteristics, genetic stability and role of AD-MSCs in wound healing are also summarized. The biological properties of AD-MSCs isolated from subcutaneous and visceral adipose tissue are compared. Additionally, methods to increase their therapeutic potential as well as factors that may affect their biological functions are summarized. Finally, their therapeutic potential in the treatment of diabetic and oncological wounds is also discussed.

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

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

Comparative Analysis Between Mesenchymal Stem Cells From Subcutaneous Adipose Tissue and Omentum in Three Types of Patients: Cancer, Morbid Obese and Healthy Control

Objective. The aims of this study are to compare 2 origins of adipose-derived mesenchymal stem cells (MSCs) (omentum and subcutaneous) from 2 pathologies (morbid obesity and cancer) vs healthy donors. Adipose tissue has revealed to be the ideal MSC source. However, in developing adipose-derived stem cells (ASCs) for clinical use, it is important to consider the effects of different fat depots and also the effect of donor variability. Methods. We isolated and characterized the membrane markers and differentiation capacities of ASCs obtained from patients with these diseases and different origin. During the culture period, we further analysed the cells' proliferation capacity in an in vitro assay as well as their secretome. Results. Adipose-derived stem cells isolated from obese and cancer patients have mesenchymal phenotype and similar cell proliferation as ASCs derived from healthy donors, some higher in cells derived from subcutaneous fat. However, cells from these 2 types of patients do not have the same differentiation potential, especially in cancer patients from omentum, and exhibit distinct secretion of both pro-inflammatory and regulatory cytokines, which could explain the differences in use due to origin as well as pathology associated with the donor. Conclusion. Subcutaneous and omentum ASCs are slightly different; omentum generates fewer cells but with greater anti-inflammatory capacity. Adipose-derived stem cells from patients with either obesity or cancer are slightly altered, which limits their therapeutic properties.

Biological Aspects and Clinical Applications of Mesenchymal Stem Cells: Key Features You Need to be Aware of

Mesenchymal Stem Cells (MSCs), a form of adult stem cells, are known to have a selfrenewing property and the potential to specialize into a multitude of cells and tissues such as adipocytes, cartilage cells, and fibroblasts. MSCs can migrate and home to the desired target zone where inflammation is present. The unique characteristics of MSCs in repairing, differentiation, regeneration, and the high capacity of immune modulation have attracted tremendous attention for exerting them in clinical purposes, as they contribute to the tissue regeneration process and anti-tumor activity. The MSCs-based treatment has demonstrated remarkable applicability towards various diseases such as heart and bone malignancies, and cancer cells. Importantly, genetically engineered MSCs, as a stateof- the-art therapeutic approach, could address some clinical hurdles by systemic secretion of cytokines and other agents with a short half-life and high toxicity. Therefore, understanding the biological aspects and the characteristics of MSCs is an imperative issue of concern. Herein, we provide an overview of the therapeutic application and the biological features of MSCs against different inflammatory diseases and cancer cells. We further shed light on MSCs' physiological interaction, such as migration, homing, and tissue repairing mechanisms in different healthy and inflamed tissues.

Adipose Extracellular Vesicles in Intercellular and Inter-Organ Crosstalk in Metabolic Health and Diseases

Adipose tissue (AT) is a highly heterogeneous and dynamic organ that plays important roles in regulating energy metabolism and insulin sensitivity. In addition to its classical roles in nutrient sensing and energy storage/dissipation, AT secretes a large number of bioactive molecules (termed adipokines) participating in immune responses and metabolic regulation through their paracrine and/or endocrine actions. Adipose-derived extracellular vesicles (ADEVs), including exosomes, microvesicles (MVs), and apoptotic bodies, have recently emerged as a novel class of signal messengers, mediating intercellular communications and inter-organ crosstalk. In AT, ADEVs derived from adipocytes, immune cells, mesenchymal stem cells, endothelial cells are actively involved in modulation of immune microenvironment, adipogenesis, browing of white adipose tissue, adipokine release and tissue remodeling. Furthermore, ADEVs exert their metabolic actions in distal organs (such as liver, skeletal muscle, pancreas and brain) by sending genetic information (mainly in the form of microRNAs) to their target cells for regulation of gene expression. Here, we provide an updated summary on the nature and composition of ADEVs, and their pathophysiological functions in regulating immune responses, whole-body insulin sensitivity and metabolism. Furthermore, we highlight the latest clinical evidence supporting aberrant production and/or function of ADEVs as a contributor to obesity-related chronic inflammation and metabolic complications and discuss the opportunities and challenges in developing novel therapies by targeting ADEVs.

CAR T-cells profiling in carcinogenesis and tumorigenesis: An overview of CAR T-cells cancer therapy

Immunotherapy of cancer by chimeric antigen receptors (CAR) modified T-cell has a remarkable clinical potential for malignancies. Meaningly, it is a suitable cancer therapy to treat different solid tumors. CAR is a special recombinant protein combination with an antibody targeting structure alongside with signaling domain capacity on order to activate T cells. It is confirmed that the CAR-modified T cells have this ability to terminate and remove B cell malignancies. So, methodologies for investigations the pro risks and also strategies for neutralizing possible off-tumor consequences of are great importance successful protocols and strategies of CAR T-cell therapy can improve the efficacy and safety of this type of cancers. In this review article, we try to classify and illustrate main optimized plans in cancer CAR T-cell therapy.

Tissue engineering in female pelvic floor reconstruction

Pelvic organ prolapse is a common and frequently occurring disease in middle-aged and elderly women. Mesh implantation is an ideal surgical treatment. The polypropylene mesh commonly used in clinical practice has good mechanical properties, but there are long-term complications. The application of tissue engineering technology in the treatment of pelvic organ prolapse disease can not only meet the mechanical requirements of pelvic floor support, but also be more biocompatible than traditional polypropylene mesh, and can promote tissue repair to a certain extent. In this paper, the progress of tissue engineering was summarized to understand the application of tissue engineering in the treatment of pelvic organ prolapse disease and will help in research.

Exosomal miR-19a from adipose-derived stem cells suppresses differentiation of corneal keratocytes into myofibroblasts

In this study, we investigated the effects of exosomal microRNAs (miRNAs) from adipose-derived stem cells (ADSCs) on the differentiation of rabbit corneal keratocytes. Keratocytes grown in 10% FBS differentiated into myofibroblasts by increasing HIPK2 kinase levels and activity. HIPK2 enhanced p53 and Smad3 pathways in FBS-induced keratocytes. Keratocytes grown in 10% FBS also showed increased levels of pro-fibrotic proteins, including collagen III, MMP9, fibronectin, and α-SMA. These effects were reversed by knocking down HIPK2. Moreover, ADSCs and exosomes derived from ADSCs (ADSCs-Exo) suppressed FBS-induced differentiation of keratocytes into myofibroblasts by inhibiting HIPK2. Quantitative RT-PCR analysis showed that ADSCs-Exos were significantly enriched in miRNA-19a as compared to ADSCs. Targetscan and dual luciferase reporter assays confirmed that the HIPK2 3'UTR is a direct binding target of miR-19a. Keratocytes treated with 10% FBS and ADSCs-Exo-miR-19a-agomir or ADSCs-Exo-NC-antagomir showed significantly lower levels of HIPK2, phospho-Smad3, phospho-p53, collagen III, MMP9, fibronectin and α-SMA than those treated with 10% FBS plus ADSCs-Exo-NC-agomir or ADSCs-Exo-miR-19a-antagomir. Thus, exosomal miR-19a derived from the ADSCs suppresses FBS-induced differentiation of rabbit corneal keratocytes into myofibroblasts by inhibiting HIPK2 expression. This suggests their potential use in the treatment of corneal fibrosis.

The effect of human platelet lysate on the differentiation ability of human adipose-derived stem cells cultured on ECM-coated surfaces

Human mesenchymal stem cells (hMSCs), such as human adipose-derived stem cells (hADSCs), present heterogeneous characteristics, including varying differentiation abilities and genotypes. hADSCs isolated under different conditions exhibit differences in stemness. We isolated hADSCs from human fat tissues via culture on different cell culture biomaterials including tissue culture polystyrene (TCPS) dishes and extracellular matrix protein (ECM)-coated dishes in medium supplemented with 5% or 10% serum-converted human platelet lysate (hPL) or 10% fetal bovine serum (FBS) as a control. Currently, it is not clear whether xeno-free hPL in the cell culture medium promotes the ability of hMSCs such as hADSCs to differentiate into several cell lineages compared to the xenomaterial FBS. We investigated whether a synchronized effect of ECM (Matrigel, fibronectin, and recombinant vitronectin) coatings on TCPS dishes for efficient hADSC differentiation could be observed when hADSCs were cultured in hPL medium. We found that Matrigel-coated dishes promoted hADSC differentiation into osteoblasts and suppressed differentiation into chondrocytes in 10% hPL medium. Recombinant vitronectin- and fibronectin-coated dishes greatly promoted hADSC differentiation into osteoblasts and chondrocytes in 5% and 10% hPL media. hPL promoted hADSC differentiation into osteoblasts and chondrocytes compared to FBS on the fibronectin-coated surface and recombinant vitronectin-coated surface.

The Safe and Efficacious Use of Secretome From Fibroblasts and Adipose-derived (but not Bone Marrow-derived) Mesenchymal Stem Cells for Skin Therapeutics

Stem cell-based products are rapidly emerging in the marketplace as topical skin care and wound care products. Confusion is prevalent among healthcare providers and end-users about these products. Adipose-derived stem cells, fibroblasts, platelets, and bone marrow-derived stem cells are the most common cells used for stem cell therapeutic development, medical procedures, and skin care products. In this review, the significant advantages of adipose-derived stem cells and fibroblasts in terms of safety and efficacy are highlighted and compared to relatively risky platelets and bone marrow stem cells.

Adipose-Derived Stem Cells in Cancer Progression: New Perspectives and Opportunities

Growing importance has been attributed to interactions between tumors, the stromal microenvironment and adult mesenchymal stem cells. Adipose-derived stem cells (ASCs) are routinely employed in regenerative medicine and in autologous fat transfer procedures. To date, clinical trials have failed to demonstrate the potential pro-oncogenic role of ASC enrichment. Nevertheless, some pre-clinical studies from in vitro and in vivo models have suggested that ASCs act as a potential tumor promoter for different cancer cell types, and support tumor progression and invasiveness through the activation of several intracellular signals. Interaction with the tumor microenvironment and extracellular matrix remodeling, the exosomal release of pro-oncogenic factors as well as the induction of epithelial-mesenchymal transitions are the most investigated mechanisms. Moreover, ASCs have also demonstrated an elective tumor homing capacity and this tumor-targeting capacity makes them a suitable carrier for anti-cancer drug delivery. New genetic and applied nanotechnologies may help to design promising anti-cancer cell-based approaches through the release of loaded intracellular nanoparticles. These new anti-cancer therapies can more effectively target tumor cells, reaching higher local concentrations even in pharmacological sanctuaries, and thus minimizing systemic adverse drug effects. The potential interplay between ASCs and tumors and potential ASCs-based therapeutic approaches are discussed.

The effects of adipose-derived stem cells on CD133-expressing bladder cancer cells

Mesenchymal stem cells (MSCs) hold great promise as therapeutic agents in regenerative medicine. They are also considered as a preferred cell source for urinary tract reconstruction. However, as MSCs exhibit affinity to tumor microenvironment, possible activation of tumor-initiating cells remains a major concern in the application of stem cell-based therapies for patients with a bladder cancer history. To analyze the influence of adipose-derived stem cells (ASCs) on bladder cancer cells with stem cell-like properties, we isolated CD133-positive bladder cancer cells and cultured them in conditioned medium from ASCs (ASC-CM). Our results showed that parental 5637 and HB-CLS-1 cells showed induced clonogenic potential when cultured in ASC-CM. Soluble mediators secreted by ASCs increased proliferation and viability of unsorted cells as well as CD133+ and CD133- subpopulations. Furthermore, incubation with ASC-CM modulated activation of intracellular signaling pathways. Soluble mediators secreted by ASCs increased phosphorylation of AKT1/2/3 (1.4-fold, P < 0.05), ERK1/2 (1.6-fold, P < 0.02), and p70 S6K (1.4-fold) in CD133+ cells isolated from 5637 cell line. In turn, decreased phosphorylation of those three proteins involved in PI3K/Akt and MAPK signaling was observed in CD133+ cells isolated from HB-CLS-1 cell line. Our results revealed that bladder cancer stem-like cells are responsive to signals from ASCs. Paracrine factors secreted by locally-delivered ASCs may, therefore, contribute to the modulation of signaling pathways involved in cancer progression, metastasis, and drug resistance.

Adipose-derived stem cell extracellular vesicles: A systematic review✰

INTRODUCTION

Extracellular vesicles (EVs) are cell-secreted packages that deliver cargo to target cells to effect functional and phenotypic changes. They are secreted by many different cell types, including adipose-derived stem cells (ADSCs), which are a promising field of study in regenerative medicine. Our aim was to perform a systematic review of the literature to summarize the scientific work that has been conducted on ADSC EVs to date.

METHODS

The Pubmed database was queried with keywords (and variations of) "adipose derived stem cell," "stromal vascular fraction," and "extracellular vesicles." We excluded review papers, then manually screened articles based on title and abstract. Full-text articles were assessed for eligibility to include in final review.

RESULTS

While an extensive body of research exists on EVs, a much smaller proportion of that is original research on ADSC EVs. Of 44 manuscripts that met our database search criteria, 21 articles were selected for our systematic review.

CONCLUSION

ADSC EVs were found to exert effects on angiogenesis, cell survival and apoptosis, inflammation, tissue regeneration, and reduction of disease pathology. Further studies examine characteristics of ADSC EVs. Future work should aim to further detail the safety profiles of ADSC EVs given their potential for cell-based therapies. The body of research studies characterizing ADSC EVs continues to expand, and much work remains to be done before human pilot studies can be considered. To our knowledge, we offer the first systematic review summarizing the research on ADSC EVs and their determined roles to date.

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.

The interplay between adipose-derived stem cells and bladder cancer cells

Tissue engineering approaches offer alternative strategies for urinary diversion after radical cystectomy. Possible triggering of cancer recurrence remains, however, a significant concern in the application of stem-cell based therapies for oncological patients. Soluble mediators secreted by stem cells induce tissue remodelling effects, but may also promote cancer cells growth and metastasis. We observed a substantial increase in the concentration of IL-6 and IL-8 in the secretome of adipose-derived stem cells (ASCs) co-cultured with bladder cancer cells. Concentrations of GM-CSF, MCP-1 and RANTES were also elevated. Bioactive molecules produced by ASCs increased the viability of 5637 and HT-1376 cells by respectively 15.4% and 10.4% (p < 0.0001). A trend in reduction of adhesion to ECM components was also noted, even though no differences in β-catenin expression were detected. When HT-1376 cells were co-cultured with ASCs their migration and invasion increased by 24.5% (p < 0.0002) and 18.2% (p < 0.002). Expression of p-ERK1/2 increased in 5637 cells (2.2-fold; p < 0.001) and p-AKT in HB-CLS-1 cells (2.0-fold; p < 0.001). Our results confirm that ASCs crosstalk with bladder cancer cells in vitro what influences their proliferation and invasive properties. Since ASCs tropism to tumour microenvironment is well documented their application towards post-oncologic reconstruction should be approached with caution.

Immunophenotyping and transcriptional profiling of in vitro cultured human adipose tissue derived stem cells

Adipose-derived stem cells (ASCs) have become an important research model in regenerative medicine. However, there are controversies regarding the impact of prolonged cell culture on the ASCs phenotype and their differentiation potential. Hence, we studied 10 clinical ASCs replicates from plastic and oncological surgery patients, in six-passage FBS supplemented cultures. We quantified basic mesenchymal cell surface marker transcripts and the encoded proteins after each passage. In parallel, we investigated the differentiation potential of ASCs into chondrocytes, osteocytes and adipocytes. We further determined the effects of FBS supplementation and subsequent deprivation on the whole transcriptome by comprehensive mRNA and miRNA sequencing. Our results show that ASCs maintain differentiation potential and consistent profile of key mesenchymal markers, with apparent expression of distinct isoforms, in long-term cultures. No significant differences were observed between plastic and oncological surgery cohorts. ASCs in FBS supplemented primary cultures are almost committed to mesenchymal lineages as they express key epithelial-mesenchymal transition genes including early mesenchymal markers. Furthermore, combined mRNA/miRNA expression profiling strongly supports a modulatory role for the miR-30 family in the commitment process to mesenchymal lineages. Finally, we propose improvements to existing qPCR based assays that address alternative isoform expression of mesenchymal markers.

Revisiting the Advances in Isolation, Characterization and Secretome of Adipose-Derived Stromal/Stem Cells

Adipose-derived stromal/stem cells (ASCs) seems to be a promising regenerative therapeutic agent due to the minimally invasive approach of their harvest and multi-lineage differentiation potential. The harvested adipose tissues are further digested to extract stromal vascular fraction (SVF), which is cultured, and the anchorage-dependent cells are isolated in order to characterize their stemness, surface markers, and multi-differentiation potential. The differentiation potential of ASCs is directed through manipulating culture medium composition with an introduction of growth factors to obtain the desired cell type. ASCs have been widely studied for its regenerative therapeutic solution to neurologic, skin, wound, muscle, bone, and other disorders. These therapeutic outcomes of ASCs are achieved possibly via autocrine and paracrine effects of their secretome comprising of cytokines, extracellular proteins and RNAs. Therefore, secretome-derivatives might offer huge advantages over cells through their synthesis and storage for long-term use. When considering the therapeutic significance and future prospects of ASCs, this review summarizes the recent developments made in harvesting, isolation, and characterization. Furthermore, this article also provides a deeper insight into secretome of ASCs mediating regenerative efficacy.

Cell-free therapy based on adipose tissue stem cell-derived exosomes promotes wound healing via the PI3K/Akt signaling pathway

INTRODUCTION

Adipose tissue-derived stem cells (ADSCs) have been shown to enhance wound healing via their paracrine function. Exosomes, as one of the most important paracrine factors, play an essential role in this process. However, the concrete mechanisms that underlie this effect are poorly understood. In this study, we aim to explore the potential roles and molecular mechanisms of exosomes derived from ADSCs in cutaneous wound healing.

METHODS

Normal human skin fibroblasts and ADSCs were isolated from patient skin and adipose tissues. ADSCs were characterized by using flow cytometric analysis and adipogenic and osteogenic differentiation assays. Exosomes were purified from human ADSCs by differential ultracentrifugation and identified by electron microscopy, nanoparticle tracking, fluorescence confocal microscopy and western blotting. Fibroblasts were treated with different concentrations of exosomes, and the synthesis of collagen was analyzed by western blotting; the levels of growth factors were analyzed by real-time quantitative PCR (RT-PCR) and ELISA; and the proliferation and migration abilities of fibroblasts were analyzed by real-time cell analysis, CCK-8 assays and scratch assays. A mouse model with a full-thickness incision wound was used to evaluate the effect of ADSC-derived exosomes on wound healing. The level of p-Akt/Akt was analyzed by western blotting. Ly294002, a phosphatidylinositol 3-kinases (PI3K) inhibitor, was used to identify the underlying mechanisms by which ADSC-derived exosomes promote wound healing.

RESULTS

ADSC-derived exosomes were taken up by the fibroblasts, which showed significant, dose-dependent increases in cell proliferation and migration compared to the behavior of cells without exosome treatment. More importantly, both the mRNA and protein levels of type I collagen (Col 1), type III collagen (Col 3), MMP1, bFGF, and TGF-β1 were increased in fibroblasts after stimulation with exosomes. Furthermore, exosomes significantly accelerated wound healing in vivo and increased the level of p-Akt/Akt in vitro. However, Ly294002 alleviated these exosome-induced changes, suggesting that exosomes from ADSCs could promote and optimize collagen deposition in vitro and in vivo and further promote wound healing via the PI3K/Akt signaling pathway.

CONCLUSIONS

This study demonstrates that ADSC-derived exosomes can promote fibroblast proliferation and migration and optimize collagen deposition via the PI3K/Akt signaling pathway to further accelerate wound healing. Our results suggest that ADSCs likely facilitate wound healing via the release of exosomes, and the PI3K/Akt pathway may play a role in this process. Our data also suggest that the clinical application of ADSC-derived exosomes may shed new light on the use of cell-free therapy to accelerate full-thickness skin wound healing and attenuate scar formation.

Exosomes from adipose-derived stem cells overexpressing Nrf2 accelerate cutaneous wound healing by promoting vascularization in a diabetic foot ulcer rat model

Diabetic foot ulcers (DFU) increase the risks of infection and amputation in patients with diabetes mellitus (DM). The impaired function and senescence of endothelial progenitor cells (EPCs) and high glucose-induced ROS likely exacerbate DFUs. We assessed EPCs in 60 patients with DM in a hospital or primary care setting. We also evaluated the therapeutic effects of exosomes secreted from adipose-derived stem cells (ADSCs) on stress-mediated senescence of EPCs induced by high glucose. Additionally, the effects of exosomes and Nrf2 overexpression in ADSCs were investigated in vitro and in vivo in a diabetic rat model. We found that ADSCs that secreted exosomes promoted proliferation and angiopoiesis in EPCs in a high glucose environment and that overexpression of Nrf2 increased this protective effect. Wounds in the feet of diabetic rats had a significantly reduced ulcerated area when treated with exosomes from ADSCs overexpressing Nrf2. Increased granulation tissue formation, angiogenesis, and levels of growth factor expression as well as reduced levels of inflammation and oxidative stress-related proteins were detected in wound beds. Our data suggest that exosomes from ADSCs can potentially promote wound healing, particularly when overexpressing Nrf2 and therefore that the transplantation of exosomes may be suitable for clinical application in the treatment of DFUs.

Tiny membrane-bound sacs released by some stem cells carry chemicals that can heal the foot ulcers that are a major complication of diabetes. The sacs, called exosomes, are released by many cells for signaling between cells and other functions. Xue Li of Tongji University in Shanghai and co-workers focused on the effects of exosomes from stem cells derived from body fat cells. They found that the exosomes could encourage the healing of diabetic foot ulcers in rats. The research also uncovered useful information about the molecular interactions involved in the accelerated healing. It revealed the significance of one particular protein in the formation of new blood vessels, which is central to the healing. The authors suggest that collecting and transplanting suitable exosomes could offer a new approach for treating diabetic foot ulcers.

Dental pulp stem cells used to deliver the anticancer drug paclitaxel

Background

Understanding stem cell behavior as a delivery tool in cancer therapy is essential for evaluating their future clinical potential. Previous in-vivo studies proved the use of mesenchymal stem cells (MSCs) for local delivery of the commonest anticancer drug, paclitaxel (PTX). Dental pulp is a relatively abundant noninvasive source of MSCs. We assess dental pulp stem cells (DPSCs), for the first time, as anticancer drug carriers. Confocal Raman microscopy is a unique tool to trace drug and cell viability without labeling.

Methods

Drug uptake and cell apoptosis are identified through confocal Raman microscope. We traced translocation of cytochrome c enzyme from the mitochondria, as a biomarker for apoptosis, after testing both cancer and stem cells. The viability of stem cells was checked by means of confocal Raman microscope and by cytotoxicity assays.

Results

In this study, we prove that DPSCs can be loaded in vitro with the anticancerous drug without affecting their viability, which is later released in the culture medium of breast cancer cells (MCF-7 cells) in a time-dependent fashion. The induced cytotoxic damage in MCF-7 cells was observed consequently after PTX release by DPSCs. Additionally, quantitative Raman images of intracellular drug uptake in DPSCs and MCF-7 cells were obtained. Cytotoxic assays prove the DPSCs to be more resistant to PTX as compared to bone marrow-derived MSCs, provided similar conditions.

Conclusions

Applications of dental stem cells for targeted treatment of cancer could be a revolution to reduce morbidity due to chemotherapy, and to increase the efficacy of systemic cancer treatment.

Role of stem cell derived exosomes in tumor biology

Exosomes are nano-scale messengers loaded with bio-molecular cargo of RNA, DNA, and Proteins. As a master regulator of cellular signaling, stem cell (both normal, and cancer stem cells) secreted exosome orchestrate various autocrine and paracrine functions which alter tumor micro-environment, growth and progression. Exosomes secreted by one of the two important stem cell phenotypes in cancers a) Mesenchymal stem cells, and b) Cancer stem cells not only promote cancerous growth but also impart therapy resistance in cancer cells. In tumors, normal or mesenchymal stem cell (MSCs) derived exosomes (MSC-exo) modulate tumor hallmarks by delivering unique miRNA species to neighboring cells and help in tumor progression. Apart from regulating tumor cell fate, MSC-exo are also capable of inducing physiological processes, for example, angiogenesis, metastasis and so forth. Similarly, cancer stem cells (CSCs) derived exosomes (CSC-exo) contain stemness-specific proteins, self-renewal promoting regulatory miRNAs, and survival factors. CSC-exo specific cargo maintains tumor heterogeneity and alters tumor progression. In this review we critically discuss the importance of stem cell specific exosomes in tumor cell signaling pathways with their role in tumor biology.

Identification, isolation, quantification and systems approach towards CD34, a biomarker present in the progenitor/stem cells from diverse lineages

Mesenchymal stem cells (MSCs) constitute the diverse progenitor populations in almost every tissue and are of immense importance in the field of regenerative medicine. CD34 is a cell surface glycoprotein identified first as a marker for the MSCs of hematopoietic origin. CD34 is now known to be expressed in cells of diverse lineages (tissues of non-hematopoietic origin) such as ectoderm, mesoderm and endoderm and is considered as a general marker for progenitor cells. Here, we present detailed protocols to obtain pure populations of MSCs from three diverse lineages such as skeletal muscle, skin, and liver from mouse tissues. We also present here the protocol for systems biology approach (proteomic analysis) of these purified cells. This proteomic approach can elucidate key signalling pathways and proteins utilized by these CD34 positive cells in undifferentiated and differentiated conditions. Furthermore in-depth proteomic analysis can also identify the altered proteome which is responsible for their function during non-clinical and clinical conditions.

Xenogeneic transplantation of human adipose-derived stem cell sheets accelerate angiogenesis and the healing of skin wounds in a Zucker Diabetic Fatty rat model of obese diabetes

Introduction

Diabetic patients with foot ulcers often suffer impaired wound healing due to diabetic neuropathy and blood flow disturbances. Direct injection of human adipose-derived stem cells (hASCs) effectively accelerates wound healing, although hASCs are relatively unstable.

Methods

We developed an optimized protocol to engineer hASC sheets using temperature-responsive culture dishes to enhance the function and stability of transplanted cells used for regenerative medicine. Here, we evaluated the efficacy of hASC sheets for enhancing wound healing. For this purpose, we used a xenogeneic model of obese type 2 diabetes, the Zucker Diabetic Fatty rat (ZDF rat), which displays full-thickness skin defects. We isolated hASCs from five donors, created hASC sheets, and transplanted the hASC sheets along with artificial skin into full-thickness, large skin defects (15-mm diameter) of ZDF rats.

Results

The hASC sheets secreted angiogenic growth factors. Transplantation of the hASC sheets combined with artificial skin increased blood vessel density and dermal thickness, thus accelerating wound healing compared with that in the controls. Immunohistochemical analysis revealed significantly more frequent neovascularization in xenografted rats of the transplantation group, and the transplanted hASCs were localized to the periphery of new blood vessels.

Conclusion

This xenograft model may contribute to the use of human cell tissue-based products (hCTPs) and the identification of factors produced by hCTPs that accelerate wound healing.

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We established a protocol for human adipose-derived stem cells (hASC) sheets.

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The hASC sheets secreted angiogenic growth factors.

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Xenogeneic hASC sheet transplantation accelerated wound healing in diabetic rats.

Extracellular Vesicles from Adipose Tissue-A Potential Role in Obesity and Type 2 Diabetes?

Adipose tissue plays a key role in the development of insulin resistance and its pathological sequelae, such as type 2 diabetes and non-alcoholic fatty liver disease. Dysfunction in the adipose tissue response to storing excess fatty acids as triglyceride can lead to adipose tissue inflammation and spillover of fatty acids from this tissue and accumulation of fatty acids as lipid droplets in ectopic sites, such as liver and muscle. Extracellular vesicles (EVs) are released from adipocytes and have been proposed to be involved in adipocyte/macrophage cross talk and to affect insulin signaling and transforming growth factor β expression in liver cells leading to metabolic disease. Furthermore EV produced by adipose tissue-derived mesenchymal stem cells (ADSC) can promote angiogenesis and cancer cell migration and have neuroprotective and neuroregenerative properties. ADSC EVs have therapeutic potential in vascular and neurodegenerative disease and may also be used to target specific functional miRNAs to cells. Obesity is associated with an increase in adipose-derived EV which may be related to the metabolic complications of obesity. In this review, we discuss our current knowledge of EV produced by adipose tissue and the potential impact of adipose tissue-derived EV on metabolic diseases associated with obesity.

Mesenchymal Stem Cell-derived Extracellular Vesicles for Renal Repair

INTRODUCTION

Transplantation of autologous mesenchymal stem cells (MSCs) has been shown to attenuate renal injury and dysfunction in several animal models, and its efficacy is currently being tested in clinical trials for patients with renal disease. Accumulating evidence indicates that MSCs release extracellular vesicles (EVs) that deliver genes, microRNAs and proteins to recipient cells, acting as mediators of MSC paracrine actions. In this context, it is critical to characterize the MSC-derived EV cargo to elucidate their potential contribution to renal repair. In recent years, researchers have performed high-throughput sequencing and proteomic analysis to detect and identify genes, microRNAs, and proteins enriched in MSC-derived EVs.

CONCLUSION

The present review summarizes the current knowledge of the MSC-derived EV secretome to shed light into the mechanisms mediating MSC renal repair, and discusses preclinical and clinical studies testing the efficacy of MSC-derived EVs for treating renal disease.

Differentiation potential of rabbit CD90-positive cells sorted from adipose-derived stem cells in vitro

To investigate the differentiation potential of purified CD90⁺ cells sorted from adipose-derived stem cells (ADSCs), CD90⁺ cells were sorted from rabbit ADSCs using flow cytometry. Then, cell expansion of CD90⁺ cells and unsorted ADSCs was observed using an inverted microscope. Furthermore, cell surface markers including CD40, CD105, and CD90 on CD90⁺ cells and unsorted ADSCs were quantified using flow cytometry. Additionally, multi-lineage differentiation ability between CD90⁺ cells and unsorted ADSCs was compared, and expression of adipocyte-related genes PPAR-r and CEBPA as well as stem cell-related gene SOX2 in CD90⁺ cells and unsorted ADSCs was determined using real-time quantitative PCR. We found that CD90⁺ cells had a stronger cell proliferation ability than unsorted ADSCs. CD90⁺ cells showed a stronger ability of osteoblast and chondrocyte differentiation than unsorted ADSCs and CD90^- cells, whereas the adipose differentiation ability of CD90⁺ cells was similar to that of ADSCs and CD90^- cells. CD14, CD105, and CD90 on CD90⁺ cells were expressed more highly than those on ADSCs. Additionally, the mRNA expression level of SOX2 in CD90⁺ cells was significantly higher than that in ADSCs, whereas the expression of PPAR-r and CEBPA was markedly lower than that in ADSCs. These results suggested that the purified CD90⁺ cells sorted from ADSCs exhibit a stronger differentiation potential than the unsorted ADSCs.

Exosome derived from murine adipose-derived stromal cells: Neuroprotective effect on in vitro model of amyotrophic lateral sclerosis

Therapeutic strategies for the fatal neurodegenerative disease amyotrophic lateral sclerosis (ALS) have not yet provided satisfactory results. Interest in stem cells for the treatment of neurodegenerative diseases is increasing and their beneficial action seems to be due to a paracrine effect via the release of exosomes, main mediators of cell-cell communication. Here we wished to assess, in vitro, the efficacy of a novel non-cell therapeutic approach based on the use of exosomes derived from murine adipose-derived stromal cells on motoneuron-like NSC-34 cells expressing ALS mutations, and used as in vitro models of disease. In particular, we set out to investigate the effect of exosomes on NSC-34 naïve cells and NSC-34 cells overexpressing human SOD1(G93A) or SOD1(G37R) or SOD1(A4V) mutants, exposed to oxidative stress. The data presented here indicate for the first time that exosomes (0.2 µg/ml) are able to protect NSC-34 cells from oxidative damage, which is one of the main mechanism of damage in ALS, increasing cell viability. These data highlight a promising role of exosomes derived from stem cells for potential therapeutic applications in motoneuron disease.

Transdifferentiation of mouse adipose-derived stromal cells into acinar cells of the submandibular gland using a co-culture system

A loss of salivary gland function often occurs after radiation therapy in head and neck tumors, though secretion of saliva by the salivary glands is essential for the health and maintenance of the oral environment. Transplantation of salivary acinar cells (ACs), in part, may overcome the side effects of therapy. Here we directly differentiated mouse adipose-derived stromal cells (ADSCs) into ACs using a co-culture system. Multipotent ADSCs can be easily collected from stromal vascular fractions of adipose tissues. The isolated ADSCs showed positive expression of markers such as integrin beta-1 (CD29), cell surface glycoprotein (CD44), endoglin (CD105), and Nanog. The cells were able to differentiate into adipocytes, osteoblasts, and neural-like cells after 14 days in culture. ADSCs at passage 2 were co-cultured with mouse ACs in AC culture medium using the double-chamber (co-culture system) to avoid mixing the cell types. The ADSCs in this co-culture system expressed markers of ACs, such as α-amylases and aquaporin5, in both mRNA and protein. ADSCs cultured in AC-conditioned medium also expressed AC markers. Cellular proliferation and senescence analyses demonstrated that cells in the co-culture group showed lower senescence and a higher proliferation rate than the AC-conditioned medium group at Days 14 and 21. The results above imply direct conversion of ADSCs into ACs under the co-culture system; therefore, ADSCs may be a stem cell source for the therapy for salivary gland damage.