The metabolic syndrome modifies the mRNA expression profile of extracellular vesicles derived from porcine mesenchymal stem cells

Optimizing Mesenchymal Stem Cells for Regenerative Medicine: Influence of Diabetes, Obesity, Autoimmune, and Inflammatory Conditions on Therapeutic Efficacy: A Review

Mesenchymal stem cells (MSCs) are a promising tool that may be used in regenerative medicine. Thanks to their ability to differentiate and paracrine signaling, they can be used in the treatment of many diseases. Undifferentiated MSCs can support the regeneration of surrounding tissues through secreted substances and exosomes. This is possible thanks to the production of growth factors. These factors stimulate the growth of neighboring cells, have an anti-apoptotic effect, and support angiogenesis, and MSCs also have an immunomodulatory effect. The level of secreted factors may vary depending on many factors. Apart from the donor's health condition, it is also influenced by the source of MSCs, methods of harvesting, and even the banking of cells. This work is a review of research on how the patient's health condition affects the properties of obtained MSCs. The review discusses the impact of the patient's diabetes, obesity, autoimmune diseases, and inflammation, as well as the impact of the source of MSCs and methods of harvesting and banking cells on the phenotype, differentiation capacity, anti-inflammatory, angiogenic effects, and proliferation potential of MSCs. Knowledge about specific clinical factors allows for better use of the potential of stem cells and more appropriate targeting of procedures for collecting, multiplying, and banking these cells, as well as for their subsequent use. This article aims to review the characteristics, harvesting, banking, and paracrine signaling of MSCs and their role in diabetes, obesity, autoimmune and inflammatory diseases, and potential role in regenerative medicine.

Therapeutic Application of Extracellular Vesicles Derived from Mesenchymal Stem Cells in Domestic Animals

Recently, the therapeutic potential of extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) has been extensively studied in both human and veterinary medicine. EVs are nano-sized particles containing biological components commonly found in other biological materials. For that reason, EV isolation and characterization are critical to draw precise conclusions during their investigation. Research on EVs within veterinary medicine is still considered in its early phases, yet numerous papers were published in recent years. The conventional adult tissues for deriving MSCs include adipose tissue and bone marrow. Nonetheless, alternative sources such as synovial fluid, endometrium, gingiva, and milk have also been intermittently used. Fetal adnexa are amniotic membrane/fluid, umbilical cord and Wharton's jelly. Cells derived from fetal adnexa exhibit an intermediate state between embryonic and adult cells, demonstrating higher proliferative and differentiative potential and longer telomeres compared to cells from adult tissues. Summarized here are the principal and recent preclinical and clinical studies performed in domestic animals such as horse, cattle, dog and cat. To minimize the use of antibiotics and address the serious issue of antibiotic resistance as a public health concern, they will undoubtedly also be utilized in the future to treat infections in domestic animals. A number of concerns, including large-scale production with standardization of EV separation and characterization techniques, must be resolved for clinical application.

Obesity Blunts the Effect of Mesenchymal Stem Cell-Derived Extracellular Vesicles

Introduction

Mesenchymal stem/stromal cell-derived extracellular vesicles (MSC-EVs) are paracrine vectors with therapeutic functions comparable to their parent cells. However, it remains unclear if donor obesity affects their therapeutic functions. We tested the hypothesis that the curative effect of human adipose tissue-derived MSC-EVs (A-MSC-EVs) is blunted by obesity.

Methods

MSC-EVs were isolated by ultracentrifugation from mesenchymal stem/stromal cells (MSCs) collected from abdominal subcutaneous fat of obese and lean human subjects (obese and lean-MSC-EVs, respectively) and injected into the aorta of mice 2 weeks after renal artery stenosis (RAS) induction. Magnetic resonance imaging studies were conducted 2 weeks after MSC-EVs delivery to determine renal function. The effect of MSC-EVs on tissue injury was assessed by histology and gene expression of inflammatory factors, including interleukin (IL)-1β, IL-6, monocyte chemotactic protein-1 (MCP-1), and tumor necrosis factor alpha (TNF-α). Oxidative damage, macrophage infiltration, plasma renin, and hypoxia inducible factor-1α (HIF-1α) were also assessed.

Results

Tracking showed that MSC-EVs localized in the kidney tissue, including glomeruli and tubules. All MSC-EVs decreased systolic blood pressure (SBP) and plasma renin and improved the poststenotic kidney (STK) volume, but obese-MSC-EVs were less effective than lean-MSC-EVs in improving medullary hypoxia, fibrosis, and tubular injury. Lean-MSC-EVs decreased inflammation, whereas obesity attenuated this effect. Only lean-MSC-EVs decreased STK cortical HIF-1α expression.

Conclusion

Obesity attenuates the antihypoxia, antifibrosis, antiinflammation, and tubular repair functions of human MSC-EVs in chronic ischemic kidney disease. These observations may have implications for the self-repair potency of obese subjects and for the use of autologous MSC-EVs in regenerative medicine.

Autologous Extracellular Vesicles Attenuate Cardiac Injury in Experimental Atherosclerotic Renovascular Disease More Effectively Than Their Parent Mesenchymal Stem/Stromal Cells

Atherosclerotic renovascular disease (RVD) leads to hypertension, chronic kidney disease (CKD), and heart disease. Intrarenal delivery of mesenchymal stem cells (MSCs) and MSC-derived extracellular vesicles (EVs) attenuate renal injury and suppress release of inflammatory cytokines in porcine RVD. We hypothesized that this strategy would also be useful for cardioprotection. Pigs with renovascular hypertension and metabolic syndrome were studied 4 weeks after treatment with a single intrarenal infusion of autologous MSCs, EVs, or vehicle. Cardiac structure and function were assessed in vivo, and myocardial remodeling and expression of the pro-fibrotic factor growth factor receptor-bound protein-2 (Grb2) were measured ex-vivo. Inflammatory cytokine levels were measured in the systemic circulation and myocardial tissue. Blood pressure was elevated in all RVD groups, but serum creatinine increased in RVD and decreased in both RVD + MSCs and RVD + EVs. RVD-induced diastolic dysfunction (lower E/A ratio) was normalized in both MSCs- and EVs- treated pigs. Intrarenal delivery of MSCs and EVs also attenuated RVD-induced myocardial fibrosis, collagen deposition, and Grb2 expression, yet EVs restored capillary density and inflammation more effectively than MSCs. These observations suggest that autologous EVs attenuate cardiac injury in experimental RVD more effectively than their parent MSCs.

Extracellular Vesicles as Carriers of Adipokines and Their Role in Obesity

Extracellular vesicles (EVs) have lately arisen as new metabolic players in energy homeostasis participating in intercellular communication at the local and distant levels. These nanosized lipid bilayer spheres, carrying bioactive molecular cargo, have somehow changed the paradigm of biomedical research not only as a non-classic cell secretion mechanism, but as a rich source of biomarkers and as useful drug-delivery vehicles. Although the research about the role of EVs on metabolism and its deregulation on obesity and associated pathologies lagged slightly behind other diseases, the knowledge about their function under normal and pathological homeostasis is rapidly increasing. In this review, we are focusing on the current research regarding adipose tissue shed extracellular vesicles including their characterization, size profile, and molecular cargo content comprising miRNAs and membrane and intra-vesicular proteins. Finally, we will focus on the functional aspects attributed to vesicles secreted not only by adipocytes, but also by other cells comprising adipose tissue, describing the evidence to date on the deleterious effects of extracellular vesicles released by obese adipose tissue both locally and at the distant level by interacting with other peripheral organs and even at the central level.

High-fidelity porcine models of metabolic syndrome: a contemporary synthesis

This review aims to describe and compare porcine models of metabolic syndrome. This syndrome and its associated secondary comorbidities are set to become the greatest challenge to healthcare providers and policy makers in the coming century. However, an incomplete understanding of the pathogenesis has left significant knowledge gaps in terms of efficacious therapeutics. To further our comprehension and, in turn, management of metabolic syndrome, appropriate high-fidelity models of the disease complex are of great importance. In this context, our review aims to assess the most promising porcine models of metabolic syndrome currently available for their similarity to the human phenotype. In addition, we aim to highlight the strengths and shortcomings of each model in an attempt to identify the most appropriate application of each. Although no porcine model perfectly recapitulates the human metabolic syndrome, several pose satisfactory approximations. The Ossabaw miniature swine in particular represents a highly translatable model that develops each of the core parameters of the syndrome with many of the associated secondary comorbidities. Future high-fidelity porcine models of metabolic syndrome need to focus on secondary sequelae replication, which may require extended induction period to reveal.

Klotho and Mesenchymal Stem Cells: A Review on Cell and Gene Therapy for Chronic Kidney Disease and Acute Kidney Disease

Chronic kidney disease (CKD) and acute kidney injury (AKI) are public health problems, and their prevalence rates have increased with the aging of the population. They are associated with the presence of comorbidities, in particular diabetes mellitus and hypertension, resulting in a high financial burden for the health system. Studies have indicated Klotho as a promising therapeutic approach for these conditions. Klotho reduces inflammation, oxidative stress and fibrosis and counter-regulates the renin-angiotensin-aldosterone system. In CKD and AKI, Klotho expression is downregulated from early stages and correlates with disease progression. Therefore, the restoration of its levels, through exogenous or endogenous pathways, has renoprotective effects. An important strategy for administering Klotho is through mesenchymal stem cells (MSCs). In summary, this review comprises in vitro and in vivo studies on the therapeutic potential of Klotho for the treatment of CKD and AKI through the administration of MSCs.

miR-6869-5p Transported by Plasma Extracellular Vesicles Mediates Renal Tubule Injury and Renin-Angiotensin System Activation in Obesity

Obesity increases the risk of other diseases, including kidney disease. Local renal tubular renin-angiotensin system (RAS) activation may play a role in obesity-associated kidney disease. Extracellular vehicles (EVs) transmit necessary information in obesity and cause remote organ damage, but the mechanism is unclear. The aim of the study was to investigate whether the plasma EVs cargo miR-6869-5p causes RAS activation and renal tubular damage. We isolated plasma EVs from obese and lean subjects and analyzed differentially-expressed miRNAs using RNA-seq. Then, EVs were co-cultured with human proximal renal tubular epithelial cells (PTECs) in vitro. Immunohistochemical pathology was used to assess the degree of RAS activation and tubule injury in vivo. The tubule damage-associated protein and RAS activation components were detected by Western blot. Obesity led to renal tubule injury and RAS activation in humans and mice. Obese-EVs induce RAS activation and renal tubular injury in PTECs. Importantly, miR-6869-5p-treated PTECs caused RAS activation and renal tubular injury, similar to Obese-EVs. Inhibiting miR-6869-5p decreased RAS activation and renal tubular damage. Our findings indicate that plasma Obese-EVs induce renal tubule injury and RAS activation via miR-6869-5p transport. Thus, miR-6869-5p in plasma Obese-EVs could be a therapeutic target for local RAS activation in obesity-associated kidney disease.

Mesenchymal Stem/Stromal Cell-Derived Extracellular Vesicles for Chronic Kidney Disease: Are We There Yet?

Mesenchymal stem/stromal cells (MSCs) are the most utilized cell type for cellular therapy, partly due to their important proliferative potential and ability to differentiate into various cell types. MSCs produce large amounts of extracellular vesicles (EVs), which carry genetic and protein cargo to mediate MSC paracrine function. Recently, MSC-derived EVs have been successfully used in several preclinical models of chronic kidney disease. However, uncertainty remains regarding EV fate, safety, and long-term effects, which might impose important limitations on their path to clinical translation. This review discusses the therapeutic application of MSC-derived EV therapy for renal disease, with particular emphasis on potential mechanisms of kidney repair and major translational barriers. Emerging evidence indicates that the cargo of MSC-derived EVs is capable of modulating several pathways responsible for renal injury, including inflammation, oxidative stress, apoptosis, fibrosis, and microvascular remodeling. EV-induced modulation of these pathways has been associated with important renoprotective effects in experimental studies. However, scarce clinical data are available, and several challenges need to be addressed as we move toward clinical translation, including standardization of methods for EV isolation and characterization, EV fate, duration of EV effects, and effects of cardiovascular risk factors. MSC-derived EVs have the potential to preserve renal structure and function, but further experimental and clinical evidence is needed to confirm their protective effects in patients with chronic kidney disease.

Porcine models of acute kidney injury

Pigs represent a potentially attractive model for medical research. Similar body size and physiological patterns of kidney injury that more closely mimic those described in humans make larger animals attractive for experimentation. Using larger animals, including pigs, to investigate the pathogenesis of acute kidney injury (AKI) also serves as an experimental bridge, narrowing the gap between clinical disease and preclinical discoveries. This article compares the advantages and disadvantages of large versus small AKI animal models and provides a comprehensive overview of the development and application of porcine models of AKI induced by clinically relevant insults, including ischemia-reperfusion, sepsis, and nephrotoxin exposure. The primary focus of this review is to evaluate the use of pigs for AKI studies by current investigators, including areas where more information is needed.

Therapeutic Applications of Stem Cells and Extracellular Vesicles in Emergency Care: Futuristic Perspectives

Regenerative medicine (RM) is an interdisciplinary field that aims to repair, replace or regenerate damaged or missing tissue or organs to function as close as possible to its physiological architecture and functions. Stem cells, which are undifferentiated cells retaining self-renewal potential, excessive proliferation and differentiation capacity into offspring or daughter cells that form different lineage cells of an organism, are considered as an important part of the RM approaches. They have been widely investigated in preclinical and clinical studies for therapeutic purposes. Extracellular vesicles (EVs) are the vital mediators that regulate the therapeutic effects of stem cells. Besides, they carry various types of cargo between cells which make them a significant contributor of intercellular communication. Given their role in physiological and pathological conditions in living cells, EVs are considered as a new therapeutic alternative solution for a variety of diseases in which there is a high unmet clinical need. This review aims to summarize and identify therapeutic potential of stem cells and EVs in diseases requiring acute emergency care such as trauma, heart diseases, stroke, acute respiratory distress syndrome and burn injury. Diseases that affect militaries or societies including acute radiation syndrome, sepsis and viral pandemics such as novel coronavirus disease 2019 are also discussed. Additionally, featuring and problematic issues that hamper clinical translation of stem cells and EVs are debated in a comparative manner with a futuristic perspective. Graphical Abstract.

Potential role of extracellular vesicles in the pathophysiology of glomerular diseases

Extracellular vesicles (EVs) are membrane-bound vesicles released by most cells and are found in diverse biological fluids. The release of EVs provides a new mechanism for intercellular communication, allowing cells to transfer their functional cargoes to target cells. Glomerular diseases account for a large proportion of end-stage renal disease (ESRD) worldwide. In recent years, an increasing number of research groups have focused their effort on identifying the functional role of EVs in renal diseases. However, the involvement of EVs in the pathophysiology of glomerular diseases has not been comprehensively described and discussed. In this review, we first briefly introduce the characteristics of EVs. Then, we describe the involvement of EVs in the mechanisms underlying glomerular diseases, including immunological and fibrotic processes. We also discuss what functions EVs derived from different kidney cells have in glomerular diseases and how EVs exert their effects through different signaling pathways. Furthermore, we summarize recent advances in the knowledge of EV involvement in the pathogenesis of various glomerular diseases. Finally, we propose future research directions for identifying better management strategies for glomerular diseases.

Metabolic Syndrome Is Associated With Altered mRNA and miRNA Content in Human Circulating Extracellular Vesicles

As mediators of intercellular communication, circulating extracellular vehicles (EVs) can modulate tissue and cellular pathways by altering transcription profiles in recipient cells, and their content may reflect the status of their parent cells. However, whether their cargo is altered in the metabolic syndrome (Mets) remains unclear. We hypothesized that MetS altered mRNAs and miRNAs packed within circulating-EVs. EVs were collected from plasma of patients with MetS or age-matched Lean controls (n=4 each). RNA sequencing was performed to identify dysregulated mRNAs and miRNAs, and analyze genes targeted by miRNAs, top pathways, and diseases associated with MetS-EVs. MetS patients showed elevated body weight, blood pressure, glucose, insulin, and liver injury markers levels. 1,446 mRNAs were downregulated and 32 upregulated in MetS- compared to Lean-EVs, whereas 40 miRNAs were selectively enriched and 10 downregulated in MetS-EVs. MetS upregulated in EVs genes involved in apoptosis, mitochondrial regulation, transport, and lipoproteins, but downregulated vessel and heart development, protein complex biogenesis, and angiogenesis. MetS also upregulated miRNAs targeting genes implicated in cellular processes, including oxidation-reduction, and downregulated miRNAs capable of modulating catalytic activity, as well as heart, blood vessel, and skeletal development, transcriptional regulation, apoptosis, and cell cycle. Our study, thus, indicates that human subjects with MetS show modified cargo of circulating EVs, which in turn may modulate several critical cellular functions and fate. These EVs may reflect the anomalous status of their parent cells, and potentially serve as important regulators, biomarkers, and targets in the progression and treatment of MetS.

Extracellular vesicles-derived miR-150-5p secreted by adipose-derived mesenchymal stem cells inhibits CXCL1 expression to attenuate hepatic fibrosis

Hepatic fibrosis (HF) is involved in aggravated wound‐healing response as chronic liver injury. Extracellular vesicles (EVs) carrying microRNA (miR) have been reported as therapeutic targets for liver diseases. In this study, we set out to explore whether adipose‐derived mesenchymal stem cells (ADMSCs)‐derived EVs containing miR‐150‐5p affect the progression of HF. Carbon tetrachloride (CCl₄) was firstly used to induce HF mouse models in C57BL/6J mice, and activation of hepatic stellate cells (HSCs) was achieved using transforming growth factor β (TGF‐β). EVs were then isolated from ADMSCs and co‐cultured with HSCs. The relationship between miR‐150‐5p and CXCL1 was identified using dual luciferase gene reporter assay. Following loss‐ and gain‐function experimentation, HSC proliferation was examined by MTT assay, and levels of fibrosis‐, HSC activation‐ and apoptosis‐related genes were determined in vitro. Additionally, pathological scores, collagen volume fraction (CVF) as well as levels of inflammation‐ and hepatic injury‐associated genes were determined in in vivo. Down‐regulated miR‐150‐5p and elevated CXCL1 expression levels were detected in HF tissues. ADMSCs‐derived EVs transferred miR‐150‐5p to HSCs. CXCL1 was further verified as the downstream target gene of miR‐150‐5p. Moreover, ADMSCs‐EVs containing miR‐150‐5p markedly inhibited HSC proliferation and activation in vitro. Meanwhile, in vivo experiments also concurred with the aforementioned results as demonstrated by inhibited CVF, reduced inflammatory factor levels and hepatic injury‐associated indicators. Both experiments results were could be reversed by CXCL1 over‐expression. Collectively, our findings indicate that ADMSCs‐derived EVs containing miR‐150‐5p attenuate HF by inhibiting the CXCL1 expression.

Deciphering Adipose Tissue Extracellular Vesicles Protein Cargo and Its Role in Obesity

The extracellular vesicles (EVs) have emerged as key players in metabolic disorders rising as an alternative way of paracrine/endocrine communication. In particular, in relation to adipose tissue (AT) secreted EVs, the current knowledge about its composition and function is still very limited. Nevertheless, those vesicles have been lately suggested as key players in AT communication at local level, and also with other metabolic peripheral and central organs participating in physiological homoeostasis, and also contributing to the metabolic deregulation related to obesity, diabetes, and associated comorbidities. The aim of this review is to summarize the most relevant data around the EVs secreted by adipose tissue, and especially in the context of obesity, focusing in its protein cargo. The description of the most frequent proteins identified in EVs shed by AT and its components, including their changes under pathological status, will give the reader a whole picture about the membrane/antigens, and intracellular proteins known so far, in an attempt to elucidate functional roles, and also suggesting biomarkers and new paths of therapeutic action.

Metabolic Syndrome Alters the Cargo of Mitochondria-Related microRNAs in Swine Mesenchymal Stem Cell-Derived Extracellular Vesicles, Impairing Their Capacity to Repair the Stenotic Kidney

Background

Coexisting metabolic syndrome (MetS) and renal artery stenosis (RAS) are linked to poor renal outcomes. Mesenchymal stem/stromal cell- (MSC-) derived extracellular vesicles (EVs) from lean animals show superior ability to repair the experimental MetS+RAS kidney compared to EVs from MetS pig MSCs. We hypothesized that MetS leads to selective packaging in porcine EVs of microRNAs capable of targeting mitochondrial genes, interfering with their capacity to repair the MetS+RAS kidney.

Methods

Five groups of pigs (n = 7 each) were studied after 16 weeks of diet-induced MetS and RAS (MetS+RAS) and MetS+RAS 4 weeks after a single intrarenal delivery of EVs harvested from allogeneic adipose tissue-derived MSCs isolated from Lean or MetS pigs, and Lean or MetS sham controls. Single-kidney blood flow (RBF) and glomerular filtration rate (GFR) were assessed in vivo with multidetector CT, whereas EV microRNA cargo, renal tubular mitochondrial structure and bioenergetics, and renal injury pathways were assessed ex vivo.

Results

microRNA sequencing revealed 19 dysregulated microRNAs capable of targeting several mitochondrial genes in MetS-EVs versus Lean-EVs. Lean- and MetS-EVs were detected in the stenotic kidney 4 weeks after administration. However, only MetS-EVs failed to improve renal mitochondrial density, structure, and function or attenuate oxidative stress, tubular injury, and fibrosis. Furthermore, Lean-EVs but not MetS-EVs restored RBF and GFR in MetS+RAS.

Conclusion

MetS alters the cargo of mitochondria-related microRNAs in swine MSC-derived EVs, which might impair their capacity to repair the poststenotic kidney in MetS+RAS. These observations may contribute to develop approaches to improve the efficacy of MSC-EVs for patients with MetS.

Global epigenetic alterations of mesenchymal stem cells in obesity: the role of vitamin C reprogramming

Obesity promotes dysfunction and impairs the reparative capacity of mesenchymal stem/stromal cells (MSCs), and alters their transcription, protein content, and paracrine function. Whether these adverse effects are mediated by chromatin-modifying epigenetic changes remains unclear. We tested the hypothesis that obesity imposes global DNA hydroxymethylation and histone tri-methylation alterations in obese swine abdominal adipose tissue-derived MSCs compared to lean pig MSCs. MSCs from female lean (n = 7) and high-fat-diet fed obese (n = 7) domestic pigs were assessed using global epigenetic assays, before and after in-vitro co-incubation with the epigenetic modulator vitamin-C (VIT-C) (50 μg/ml). Dot blotting was used to measure across the whole genome 5-hydroxyemthycytosine (5hmC) residues, and Western blotting to quantify in genomic histone-3 protein tri-methylated lysine-4 (H3K4me3), lysine-9 (H3K9me3), and lysine-27 (H3K27me3) residues. MSC migration and proliferation were studied in-vitro. Obese MSCs displayed reduced global 5hmC and H3K4m3 levels, but comparable H3K9me3 and H3K27me3, compared to lean MSCs. Global 5hmC, H3K4me3, and HK9me3 marks correlated with MSC migration and reduced proliferation, as well as clinical and metabolic characteristics of obesity. Co-incubation of obese MSCs with VIT-C enhanced 5hmC marks, and reduced their global levels of H3K9me3 and H3K27me3. Contrarily, VIT-C did not affect 5hmC, and decreased H3K4me3 in lean MSCs. Obesity induces global genomic epigenetic alterations in swine MSCs, involving primarily genomic transcriptional repression, which are associated with MSC function and clinical features of obesity. Some of these alterations might be reversible using the epigenetic modulator VIT-C, suggesting epigenetic modifications as therapeutic targets in obesity.

Could Mesenchymal Stem Cell-Derived Exosomes Be a Therapeutic Option for Critically Ill COVID-19 Patients?

Coronavirus disease 2019 (COVID-19) is a pandemic viral disease originated in Wuhan, China, in December 2019, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The severe form of the disease is often associated with acute respiratory distress syndrome (ARDS), and most critically ill patients require mechanical ventilation and support in intensive care units. A significant portion of COVID-19 patients also develop complications of the cardiovascular system, primarily acute myocardial injury, arrhythmia, or heart failure. To date, no specific antiviral therapy is available for patients with SARS-CoV-2 infection. Exosomes derived from mesenchymal stem cells (MSCs) are being explored for the management of a number of diseases that currently have limited or no therapeutic options, thanks to their anti-inflammatory, immunomodulatory, and pro-angiogenic properties. Here, we briefly introduce the pathogenesis of SARS-CoV-2 and its implications in the heart and lungs. Next, we describe some of the most significant clinical evidence of the successful use of MSC-derived exosomes in animal models of lung and heart injuries, which might strengthen our hypothesis in terms of their utility for also treating critically ill COVID-19 patients.

Plasma small extracellular vesicles in hypertensive rats impair reactivity of isolated blood vessels

Extracellular vesicles (EV) consist of a lipid-bilayered membrane and are typically classified as small EV (sEV or exosome) or large EV (or microvesicle). sEV mediate cell-to-cell communication and play a key role in various disease states. We recently reported that plasma sEV in normotensive Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR), an animal model of human essential hypertension, regulate systemic blood pressure (BP). An abnormal vascular reactivity is involved in the onset and progression of hypertension. In the present study, we tested the hypothesis that plasma sEV may affect the reactivity of isolated blood vessels. sEV were isolated from plasma in male WKY and SHR (WsEV and SsEV, respectively) by precipitation with polyethylene-glycol and ultracentrifugation. The particle distribution and concentration of sEV were measured by a tunable resistive pulse sensing method. Isolated mesenteric arteries from normal male Wistar rats were cultured for 24 hr with WsEV, SsEV, or vehicle. There was no difference in particle distribution and total concentration between WsEV and SsEV. Both SsEV and WsEV had no significant effect on the KCl-induced maximal contraction, while SsEV specifically attenuated contraction induced by noradrenaline compared with WsEV- and vehicle-treatment. In summary, it was for the first time revealed that SsEV attenuate the agonist-induced contractility of isolated blood vessels, which might be at least partly responsible for the BP regulation by SsEV.

Extracellular Vesicles Isolated from Human Induced Pluripotent Stem Cell-Derived Neurons Contain a Transcriptional Network

Healthy brain function is mediated by several complementary signalling pathways, many of which are driven by extracellular vesicles (EVs). EVs are heterogeneous in both size and cargo and are constitutively released from cells into the extracellular milieu. They are subsequently trafficked to recipient cells, whereupon their entry can modify the cellular phenotype. Here, in order to further analyse the mRNA and protein cargo of neuronal EVs, we isolated EVs by size exclusion chromatography from human induced pluripotent stem cell (iPSC)-derived neurons. Electron microscopy and dynamic light scattering revealed that the isolated EVs had a diameter of 30–100 nm. Transcriptomic and proteomics analyses of the EVs and neurons identified key molecules enriched in the EVs involved in cell surface interaction (integrins and collagens), internalisation pathways (clathrin- and caveolin-dependent), downstream signalling pathways (phospholipases, integrin-linked kinase and MAPKs), and long-term impacts on cellular development and maintenance. Overall, we show that key signalling networks and mechanisms are enriched in EVs isolated from human iPSC-derived neurons.

Mesenchymal Stem Cell-Derived Extracellular Vesicles Induce Regulatory T Cells to Ameliorate Chronic Kidney Injury

Metabolic syndrome (MetS) profoundly changes the contents of mesenchymal stem cells and mesenchymal stem cells-derived extracellular vesicles (EVs). The anti-inflammatory TGF-β (transforming growth factor-β) is selectively enriched in EVs from Lean but not from MetS pigs, but the functional impact of this endowment remains unknown. We hypothesized that Lean-EVs more effectively induce regulatory T cells in injured kidneys. Five groups of pigs (n=7 each) were studied after 16 weeks of diet-induced MetS and unilateral renal artery stenosis (RAS; MetS+RAS). Two groups of MetS+RAS were treated 4 weeks earlier with an intrarenal injection of either Lean-EVs or MetS-EVs. MetS+RAS had lower renal volume, renal blood flow, and glomerular filtration rate than MetS pigs. Compared with Lean-EVs, MetS-EVs were less effective in improving renal function and decreasing tubular injury and fibrosis in MetS+RAS. Lean-EVs upregulated TGF-β expression in stenotic kidney and increased regulatory T cells numbers more prominently. Furthermore, markedly upregulated anti-inflammatory M2 macrophages reduced proinflammatory M1 macrophages, and CD8⁺ T cells were detected in stenotic kidneys treated with Lean-EVs compared with MetS-EVs, and renal vein levels of interleukin-1β were reduced. In vitro, coculture of Lean-EVs with activated T cells led to greater TGF-β-dependent regulatory T cells induction than did MetS-EVs. Therefore, the beneficial effects of mesenchymal stem cells-derived EVs on injured kidneys might be partly mediated by their content of TGF-β signaling components, which permitting increased Treg preponderance. Modulating EV cargo and transforming their functionality might be useful for renal repair.

Upregulated tumor necrosis factor-α transcriptome and proteome in adipose tissue-derived mesenchymal stem cells from pigs with metabolic syndrome

INTRODUCTION

Mesenchymal stem cells (MSCs) have endogenous reparative properties, and may constitute an exogenous therapeutic intervention in patients with chronic kidney disease. The microenvironment of metabolic syndrome (MetS) induces fat inflammation, with abundant expression of tumor necrosis factor (TNF)-α. MetS may also alter the content of adipose tissue-derived MSCs, and we hypothesized that the inflammatory profile of MetS manifests via upregulating MSC mRNAs and proteins of the TNF-α pathway.

METHODS

Domestic pigs were fed a 16-week Lean or MetS diet (n = 4 each). MSCs were harvested from abdominal subcutaneous fat, and their extracellular vesicles (EVs) isolated. Expression profiles of mRNAs and proteins in MSCs and EVs were obtained by high-throughput sequencing and proteomics. Nuclear translocation of the pro-inflammatory transcription factor (NF)-kB was evaluated in MSC and in pig renal tubular cells (TEC) co-incubated with EVs.

RESULTS

We found 13 mRNAs and 4 proteins in the TNF-α pathway upregulated in MetS- vs. Lean-MSCs (fold-change > 1.4, p < 0.05), mostly via TNF-α receptor-1 (TNF-R1) signaling. Three mRNAs were upregulated in MetS-EVs. MetS-MSCs, as well as TECs co-incubated with MetS-EVs, showed increased nuclear translocation of NF-kB. Using qPCR, JUNB, MAP2K7 and TRAF2 genes followed the same direction of RNA-sequencing findings.

CONCLUSIONS

MetS upregulates the TNF-α transcriptome and proteome in swine adipose tissue-derived MSCs, which are partly transmitted to their EV progeny, and are associated with activation of NF-kB in target cells. Hence, the MetS milieu may affect the profile of endogenous MSCs and their paracrine vectors and limit their use as an exogenous regenerative therapy. Anti-inflammatory strategies targeting the TNF-α pathway might be a novel strategy to restore MSC phenotype, and in turn function.

Extracellular Vesicles from Mesenchymal Stem Cells Exert Pleiotropic Effects on Amyloid-β, Inflammation, and Regeneration: A Spark of Hope for Alzheimer's Disease from Tiny Structures?

No cure yet exists for devastating Alzheimer's disease (AD), despite many years and humongous efforts to find efficacious pharmacological treatments. So far, neither designing drugs to disaggregate amyloid plaques nor tackling solely inflammation turned out to be decisive. Mesenchymal stem cells (MSCs) and, in particular, extracellular vesicles (EVs) originating from them could be proposed as an alternative, strategic approach to attack the pathology. Indeed, MSC-EVs-owing to their ability to deliver lipids/proteins/enzymes/microRNAs endowed with anti-inflammatory, amyloid-β degrading, and neurotrophic activities-may be exploited as therapeutic tools to restore synaptic function, prevent neuronal death, and slow down memory impairment in AD. Herein the results presented in the most recently published studies on this topic are critically evaluated, providing a strong rationale for possible employment of MSC-EVs in AD. Also see the video abstract here https://youtu.be/tBtDbnlRUhg.

Conditioned Medium of Mesenchymal Stromal Cells: A New Class of Therapeutics

Mesenchymal stromal cell (MSCs) represent a class of biologics with the prospects for employment as immunomodulatory, tissue-protective, and regenerative therapeutics. In parallel with cellular therapy, cell-free therapy based on MSC-secreted bioactive factors is being actively developed. MSCs secrete a variety of protein, peptide, RNA, and lipid mediators which can be concentrated, frozen, or even lyophilized without loss of activity, which gives them a certain advantage over cellular products requiring liquid nitrogen storage and infrastructure to revive frozen cells. This review (i) describes currently conducted clinical trials of cell-free products containing MSC secretome; (ii) summarizes main approaches to the generation and characterization of conditioned media concentrates and extracellular vesicle isolates; (iii) analyzes a variety of preclinical studies where effectiveness of secretome products has been shown; and (iv) summarizes current knowledge about secretome bioactive components obtained by analysis of in vivo models testing the therapeutic potential of the MSC secretome.

Stem cell-derived extracellular vesicles for renal repair: do cardiovascular comorbidities matter?

Extracellular vesicle (EV)-based regenerative therapy has shown promising results in preclinical models of renal disease and might be useful for patients with several forms of chronic kidney disease. However, individuals with chronic kidney disease often present with comorbidities, including obesity, hypertension, diabetes, or even metabolic syndrome, which may alter the endogenous characteristics and impair the reparative capacity of stem cells and their daughter EVs. This brief review summarizes evidence of alterations in the morphology, cargo, and function of mesenchymal stem cells and mesenchymal stem cell-derived EVs in the face of cardiovascular disease. We further discuss the important ramifications for their use in patients with kidney disease.

Metabolic Syndrome Induces Release of Smaller Extracellular Vesicles from Porcine Mesenchymal Stem Cells

Mesenchymal stromal/stem cells (MSCs) belong to the endogenous cellular reparative system, and can be used exogenously in cell-based therapy. MSCs release extracellular vesicles (EVs), including exosomes and microvesicles, which mediate some of their therapeutic activity through intercellular communication. We have previously demonstrated that metabolic syndrome (MetS) modifies the cargo packed within swine EV, but whether it influences their phenotypical characteristics remains unclear. This study tested the hypothesis that MetS shifts the size distribution of MSC-derived EVs. Adipose tissue-derived MSC-EV subpopulations from Lean (n = 6) and MetS (n = 6) pigs were characterized for number and size using nanoparticle-tracking analysis, flow cytometry, and transmission electron microscopy. Expression of exosomal genes was determined using next-generation RNA-sequencing (RNA-seq). The number of EV released from Lean and MetS pig MSCs was similar, yet MetS-MSCs yielded a higher proportion of small-size EVs (202.4 ± 17.7 nm vs. 280.3 ± 15.1 nm), consistent with exosomes. RNA-seq showed that their EVs were enriched with exosomal markers. Lysosomal activity remained unaltered in MetS-MSCs. Therefore, MetS alters the size distribution of MSC-derived EVs in favor of exosome release. These observations may reflect MSC injury and membrane recycling in MetS or increased expulsion of waste products, and may have important implications for development of adequate cell-based treatments.

Hypoxia preconditioned renal tubular epithelial cell-derived extracellular vesicles alleviate renal ischaemia-reperfusion injury mediated by the HIF-1α/Rab22 pathway and potentially affected by microRNAs

We previously found that hypoxia induced renal tubular epithelial cells (RTECs) release functional extracellular vesicles (EVs), which mediate the protection of remote ischaemic preconditioning (RIPC) for kidney ischaemia-reperfusion (I/R) injury. We intend to investigate whether the EVs were regulated by hypoxia-inducible factor 1α (HIF-1α) and Rab22 during RIPC. We also attempted to determine the potentially protective cargo of the EVs and reveal their underlying mechanism. Hypoxia preconditioning (HPC) of human kidney 2 (HK2) cells was conducted at 1% oxygen (O₂) for different amounts of time to simulate IPC in vitro. EVs were isolated and then quantified. HIF-1α- and Rab22-inhibited HK2 cells were used to investigate the role of the HIF-1α/Rab22 pathway in HPC-induced EV production. Both normoxic and HPC EVs were treated in vivo to assess the protective effect of I/R injury. Moreover, microRNA (miRNA) sequencing analysis and bioinformatics analysis was performed. We revealed that the optimal conditions for simulating IPC in vitro was no more than 12 h under the 1% O₂ culture circumstance. HPC enhanced the production of EVs, and the production of EVs was regulated by the HIF-1α/Rab22 pathway during HPC. Moreover, HPC EVs were found to be more effective at attenuating mice renal I/R injury. Furthermore, 16 miRNAs were upregulated in HPC EVs. Functional and pathway analysis indicated that the miRNAs may participate in multiple processes and pathways by binding their targets to influence the biochemical results during RIPC. We demonstrated that HIF-1α/Rab22 pathway mediated RTEC-derived EVs during RIPC. The HPC EVs protected renal I/R injury potentially through differentially expressed miRNAs. Further study is needed to verify the effective EV-miRNAs and their underlying mechanism.

Alterations in genetic and protein content of swine adipose tissue-derived mesenchymal stem cells in the metabolic syndrome

INTRODUCTION

Mesenchymal stem cells (MSCs) possess endogenous reparative properties and may serve as an exogenous therapeutic intervention in patients with chronic kidney disease. Cardiovascular risk factors clustering in the metabolic syndrome (MetS) might adversely affect cellular properties. To test the hypothesis that Mets interferes with MSC characteristics, we performed comprehensive comparison of the mRNA, microRNA, and protein content of MSCs isolated from Lean and MetS pigs.

METHODS

Domestic pigs were fed a 16-week Lean or MetS diet (n = 4 each). Expression profiles of co-existing microRNAs, mRNAs, and proteins were obtained by high-throughput sequencing and liquid chromatography-mass spectrometry. TargetScan and ComiR were used to predict target genes of differentially expressed microRNAs, and DAVID 6.7 for functional annotation analysis to rank primary gene ontology categories for the microRNA target genes, mRNAs, and proteins.

RESULTS

Differential expression analysis revealed 12 microRNAs upregulated in MetS-MSCs compared to Lean-MSCs (fold change>1.4, p < .05), which target 7728 genes, whereas 33 mRNAs and 78 proteins were downregulated (fold change<0.7, p < .05). Integrated analysis showed that targets of those microRNAs upregulated in MetS-MSCs overlap with at least half of mRNAs and proteins dysregulated in those cells. Functional analysis of overlapping mRNAs and proteins suggest that they are primarily involved in mitochondria, inflammation and transcription. MetS-MSCs also exhibited increased nuclear translocation of nuclear factor kappa-B, associated with increased SA-β-Galactosidase and decreased cytochrome-c oxidase-IV activity.

CONCLUSION

MetS alters the transcriptome and proteome of swine adipose tissue-derived MSCs particularly genes involved in mitochondria, inflammation and transcription regulation. These alterations might limit the reparative function of endogenous MSC and their use as an exogenous regenerative therapy.

Metabolic Syndrome Interferes with Packaging of Proteins within Porcine Mesenchymal Stem Cell-Derived Extracellular Vesicles

Mesenchymal stem/stromal cells (MSCs) release extracellular vesicles (EVs), which shuttle proteins to recipient cells, promoting cellular repair. We hypothesized that cardiovascular risk factors may alter the pattern of proteins packed within MSC‐derived EVs. To test this, we compared the protein cargo of EVs to their parent MSCs in pigs with metabolic syndrome (MetS) and Lean controls. Porcine MSCs were harvested from abdominal fat after 16 weeks of Lean‐ or MetS‐diet (n = 5 each), and their EVs isolated. Following liquid chromatography mass spectrometry proteomic analysis, proteins were classified based on cellular component, molecular function, and protein class. Five candidate proteins were validated by Western blot. Clustering analysis was performed to identify primary functional categories of proteins enriched in or excluded from EVs. Proteomics analysis identified 6,690 and 6,790 distinct proteins in Lean‐ and MetS‐EVs, respectively. Differential expression analysis revealed that 146 proteins were upregulated and 273 downregulated in Lean‐EVs versus Lean‐MSCs, whereas 787 proteins were upregulated and 185 downregulated in MetS‐EVs versus MetS‐MSCs. Proteins enriched in both Lean‐ and MetS‐EVs participate in vesicle‐mediated transport and cell‐to‐cell communication. Proteins enriched exclusively in Lean‐EVs modulate pathways related to the MSC reparative capacity, including cell proliferation, differentiation, and activation, as well as transforming growth factor‐β signaling. Contrarily, proteins enriched only in MetS‐EVs are linked to proinflammatory pathways, including acute inflammatory response, leukocyte transendothelial migration, and cytokine production. Coculture with MetS‐EVs increased renal tubular cell inflammation. MetS alters the protein cargo of porcine MSC‐derived EVs, selectively packaging specific proinflammatory signatures that may impair their ability to repair damaged tissues. stem cells translational medicine2019;8:430–440