Microvesicles released from human embryonic stem cell derived-mesenchymal stem cells inhibit proliferation of leukemia cells

Human Umbilical Cord Mesenchymal Stem Cell-Derived Microvesicles Could Induce Apoptosis and Autophagy in Acute Myeloid Leukemia

Background

Microvesicles (MV) have been identified as candidate biomarkers for treating acute myeloid leukemia (AML). This study investigated the effects of human umbilical cord-derived mesenchymal stem cell (hUCMSC)-derived MVs on apoptosis and autophagy in the KG-1 leukemic cell line.

Methods

The hUCMSCs were cultured and characterized by flow cytometry. MVs were isolated by ultracentrifugation, and the concentration was determined using the Bradford method. The characteristics of MVs were confirmed using transmission electron microscopy, flow cytometry, and dynamic light scattering methods. KG-1 cells were treated with the desired concentrations of MVs for 24 h. The apoptosis induction and reactive oxygen species production were evaluated using flow cytometry. RT-PCR was performed to evaluate apoptosis- and autophagy-related genes expression.

Results

Following tretment of KG-1 cells with 25, 50, and 100 μg/ml concentrations of MVs, the apoptosis rates were 47.85%, 47.15%, and 51.35% (p < 0.0001), and the autophagy-induced ROS levels were 73.9% (p < 0.0002), 84.8% (p < 0.0001), and 85.4% (p < 0.0001), respectively. BAX and ATG7 gene expression increased significantly at all concentrations compared to the control, and this level was higher at 50 μg/ml than that of the other concentrations. In addition, LC3 and Beclin 1 expression increased significantly in a concentration-dependen manner. Conversely, BCL2 expression decreased compared to the control.

Conclusion

Our findings indicate that hUCMSC-MVs could induce cell death pathways of autophagy and apoptosis in the KG-1 cell lines and exert potent antiproliferative and proapoptotic effects on KG-1 cells in vitro. Therefore, hUCMSC-MVs may be a potential approach for cancer therapy as a novel cell-to-cell communication strategy.

Extracellular Vesicles Derived from Human Bone Marrow Stem Cells Inhibit Acute Lymphoblastic Leukemia Cell Growth by Inhibiting MAPK Pathway via the miR-29b-3p/GDF15 Axis

INTRODUCTION

Acute lymphoblastic leukemia (ALL) is a common hematologic neoplastic disease. This study discussed the effect of extracellular vesicles (EVs) released from bone marrow mesenchymal stem cells (BMSCs) on ALL cells and the mechanism.

METHODS

BMSCs-EVs were isolated by differential centrifugation and identified. The effect of BMSCs-EVs on ALL cell proliferation and apoptosis was evaluated. The expression of miR-29b-3p in ALL cells and EVs was detected. The uptake of EVs by ALL cells was observed. The effect of miR-29b-3p on ALL cell proliferation and apoptosis was assessed after silencing miR-29b-3p. The targeting relation of miR-29b-3p and GDF15 was analyzed by bioinformatics website and dual-luciferase assay. The role of GDF15 in proliferation and apoptosis of ALL cells was further confirmed, and Western blot assay was performed to measure MAPK pathway-related protein levels.

RESULTS

BMSC-derived EVs inhibited proliferation and promoted apoptosis of ALL cells, as shown by the up-regulation of caspase-3 and Bax expressions and down-regulation of Bcl-2 expression. EVs carried miR-29b-3p into ALL cells, upregulated miR-29b-3p expression in ALL cells, and inhibited GDF15 expression. Silencing of miR-29b-3p or overexpression of GDF15 partially reversed the effect of EVs. EVs inhibited the MAPK pathway through the miR-29b-3p/GDF15 axis.

CONCLUSION

BMSCs-EVs carried miR-29b-3p into ALL cells, upregulated miR-29b-3p, and inhibited GDF15 to suppress the MAPK pathway and further inhibit proliferation and promote apoptosis of ALL cells.

Extracellular Vesicle-Mediated Mitochondrial Reprogramming in Cancer

Simple Summary

Mitochondria are important organelles involved in several key cellular processes including energy production and cell death regulation. For this reason, it is unsurprising that mitochondrial function and structure are altered in several pathological states including cancer. Cancer cells present variate strategies to generate sufficient energy to sustain their high proliferation rates. These adaptative strategies can be mediated by extracellular signals such as extracellular vesicles. These vesicles can alter recipient cellular behavior by delivering their molecular cargo. This review explores the different EV-mediated mitochondrial reprogramming mechanisms supporting cancer survival and progression.

Abstract

Altered metabolism is a defining hallmark of cancer. Metabolic adaptations are often linked to a reprogramming of the mitochondria due to the importance of these organelles in energy production and biosynthesis. Cancer cells present heterogeneous metabolic phenotypes that can be modulated by signals originating from the tumor microenvironment. Extracellular vesicles (EVs) are recognized as key players in intercellular communications and mediate many of the hallmarks of cancer via the delivery of their diverse biological cargo molecules. Firstly, this review introduces the most characteristic changes that the EV-biogenesis machinery and mitochondria undergo in the context of cancer. Then, it focuses on the EV-driven processes which alter mitochondrial structure, composition, and function to provide a survival advantage to cancer cells in the context of the hallmarks of cancers, such as altered metabolic strategies, migration and invasiveness, immune surveillance escape, and evasion of apoptosis. Finally, it explores the as yet untapped potential of targeting mitochondria using EVs as delivery vectors as a promising cancer therapeutic strategy.

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

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

Bone marrow-mesenchymal stem cell-derived extracellular vesicles affect proliferation and apoptosis of leukemia cells in vitro

Mesenchymal stem cells (MSCs) have been proposed to have potential for tissue engineering and cell therapy due to their multilineage differentiation potential and ability to secrete numerous paracrine factors, including extracellular vesicles (EVs). Increasing evidence has demonstrated that MSC‐derived EVs (MSC‐EVs) are able to induce the repair of tissue damage and regulate the immune system. However, their role in cancer development is still unclear. Reports have suggested that whether MSC‐EVs have an inhibitory or promoting effect on cancer is dependent on the type of cancer. In this study, the role of MSC‐EVs in the regulation of leukemic cell growth in vitro was investigated. The EVs were collected from conditioned media of MSCs by ultrafiltration using a 10 kDa molecular weight cutoff (MWCO) filter. The isolated MSC‐EVs were comprised of microvesicles and exosomes, as examined by the size of vesicles and exosomal proteins, CD81 and flotillin‐1. Cell proliferation, cell cycle status, apoptosis, and gene expression were examined in the leukemic cell lines NB4 and K562 after treatment with MSC‐EVs. Suppression of cell proliferation and induction of apoptosis was observed. Gene expression analysis revealed differential expression of apoptotic‐related genes in NB4 and K562. MSC‐EVs increased the expression of BID and BAX and decreased expression of BCL2, indicating the induction of intrinsic apoptosis in NB4. In contrast, MSC‐EVs increased the expression of the death receptor gene TRAILR2 and cell cycle regulator genes P21 and CCNE2 in K562. In conclusion, MSC‐EVs partially induce leukemic cell apoptosis, and thus may have potential for the development of supportive therapies for leukemia.

Microvesicles from Schwann-Like Cells as a New Biomaterial Promote Axonal Growth

Schwann cells promote axonal regeneration following peripheral nerve injury. However, in terms of clinical treatment, the therapeutic effects of Schwann cells are limited by their source. The transmission of microvesicles from neuroglia cells to axons is a novel communication mechanism in axon regeneration.To evaluate the effect of microvesicles released from Schwann-like cells on axonal regeneration, neural stem cells derived from human embryonic stem cells differentiated into Schwann-like cells, which presented a typical morphology and characteristics similar to those of schwann cells. The glial markers like MBP, P0, P75^NTR, PMP-22, GFAP, HNK-1 and S100 were upregulated, whereas the neural stem markers like NESTIN, SOX1 and SOX2 were significantly downregulated in schwann-like cells. Microvesicles enhanced axonal growth in dorsal root ganglia neurons and regulated GAP43 expression in neuron-like cells (N2A and PC12) through the PTEN/PI3 K/Akt signaling pathway. A 5 mm section of sciatic nerve was transected in Sprague-Dawley rats. With microvesicles transplantation, regenerative nerves were evaluated after 6 weeks. Microvesicles increased sciatic function index scores, delayed gastrocnemius muscle atrophy and elevated βIII-tubulin-labeled axons in vivo. Schwann-like cells serve as a convenient source and promote axonal growth by secreting microvesicles, which may potentially be used as bioengineering materials for nerve tissue repair.

Nerve growth factor-chondroitin sulfate/hydroxyapatite-coating composite implant induces early osseointegration and nerve regeneration of peri-implant tissues in Beagle dogs

Background

Osseointegration is the premise of the chewing function of dental implant. Nerve growth factor (NGF), as a neurotrophic factor, can induce bone healing. However, the influence of NGF-chondroitin sulfate (CS)/hydroxyapatite (HA)-coating composite implant on the osseointegration and innervations is still not entirely clear.

Materials and methods

NGF-CS/HA-coating composite implants were prepared using the modified biomimetic method. The characteristics of NGF-CS/HA-coating implants were determined using a scanning electron microscope. After NGF-CS/HA-coating implants were placed in the mandible of Beagle dogs, the early osseointegration and innervation in peri-implant tissues were assessed through X-ray, Micro-CT, maximal pull-out force, double fluorescence staining, toluidine blue staining, DiI neural tracer, immunohistochemistry, and RT-qPCR assays.

Results

NGF-CS/HA-coating composite implants were made successfully, which presented porous mesh structures with the main components (Ti and HA). Besides, we revealed that implantation of NGF-CS/HA-coating implants significantly changed the morphology of bone tissues and elevated maximum output, MAR, BIC, and nerve fiber in the mandible of Beagle dogs. Moreover, we proved that the implantation of NGF-CS/HA-coating implants also markedly upregulated the levels of NGF, osteogenesis differentiation, and neurogenic differentiation-related genes in the mandible of Beagle dogs.

Conclusion

Implantation of NGF-CS/HA-coating composite implants has significant induction effects on the early osseointegration and nerve regeneration of peri-implant tissues in the mandible of Beagle dogs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-020-02177-5.

Manipulated Mesenchymal Stem Cells Applications in Neurodegenerative Diseases

Mesenchymal stem cells (MSCs) are multipotent stem cells that have multilinear differentiation and self-renewal abilities. These cells are immune-privileged as they express no or low level of class-II major histocompatibility complex (MHC-II) and other costimulatory molecules. Having neuroprotective and regenerative properties, MSCs can be used to ameliorate several intractable neurodegenerative disorders by affecting both innate and adaptive immune systems. Several manipulations like pretreating MSCs with different conditions or agents, and using molecules derived from MSCs or genetically manipulating them, are the common and practical ways that can be used to strengthen MSCs survival and potency. Improved MSCs can have significantly enhanced impacts on diseases compared to MSCs not manipulated. In this review, we describe some of the most important manipulations that have been exerted on MSCs to improve their therapeutic functions and their applications in ameliorating three prevalent neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and Huntington's disease.

Cell Death Pathways in Ischemic Stroke and Targeted Pharmacotherapy

Ischemic stroke is one of the significant causes of morbidity and mortality, affecting millions of people across the globe. Cell injury in the infarct region is an inevitable consequence of focal cerebral ischemia. Subsequent reperfusion exacerbates the harmful effect and increases the infarct volume. These cellular injuries follow either a regulated pathway involving tightly structured signaling cascades and molecularly defined effector mechanisms or a non-regulated pathway, also known as accidental cell death, where the process is biologically uncontrolled. Classical cell death pathways are long established and well reported in several articles that majorly define apoptotic cell death. A recent focus on cell death study also considers investigation on non-classical pathways that are tightly regulated, may or may not involve caspases, but non-apoptotic. Pathological cell death is a cardinal feature of different neurodegenerative diseases. Although ischemia cannot be classified as a neurodegenerative disease, it is a cerebrovascular event where the infarct region exhibits aberrant cell death. Over the past few decades, several therapeutic options have been implicated for ischemic stroke. However, their use has been hampered owing to the number of limitations that they possess. Ischemic penumbral neurons undergo apoptosis and become dysfunctional; however, they are salvageable. Thus, understanding the role of different cell death pathways is crucial to aid in the modern treatment of protecting apoptotic neurons.

Microvesicles Derived from Human Embryonic Neural Stem Cells Inhibit the Apoptosis of HL-1 Cardiomyocytes by Promoting Autophagy and Regulating AKT and mTOR via Transporting HSP-70

Myocardial reperfusion injury (MRI) induced by cardiomyocyte apoptosis plays an important role in the pathogenesis of a variety of cardiovascular diseases. New MRI treatments involving stem cells are currently being developed because these cells may exert their therapeutic effects primarily through paracrine mechanisms. Microvesicles (MVs) are small extracellular vesicles that have become the key mediators of intercellular communication. MVs derived from stem cells have been reported to play an important role in MRI. In this article, we attempted to explore the mechanisms by which MVs derived from human embryonic neural stem cells (hESC-NSC-derived MVs) rescue MRI. hESCs were differentiated into NSCs, and MVs were isolated from their supernatants by ultracentrifugation. H₂O₂ was used to induce apoptosis in HL-1 cardiomyocytes. Cell viability was detected by using the CCK-8 assay, apoptosis was detected by Annexin V-FITC/PI staining, and apoptosis-related proteins and signalling pathway-related proteins were detected by western blot analysis. Autophagic flux was measured using the tandem fluorescent mRFG-GFP-LC3 assay. Transmission electron microscopy and western blot analysis were adopted to evaluate autophagy levels. hESC-NSC-derived MVs increased the autophagy and inhibited the apoptosis of HL-1 cells exposed to H₂O₂ for 3 h in a dose-dependent manner. Additionally, hESC-NSC-derived MVs contained high levels of heat shock protein 70 (HSP-70), which can increase the level of HSP-70 in cells. Moreover, the same effect could be achieved by heat shock preconditioning of HL-1 cells overexpressing HSP-70. The benefits of NSC-MVs may be due to the involvement of AKT and mTOR signalling pathways. Importantly, hESC-NSC-derived MVs stimulated the activation of the AKTand mTOR signalling pathway in those cells by transporting HSP-70. Our results suggest that hESC-NSC-derived MVs inhibit the apoptosis of HL-1 cardiomyocytes by promoting autophagy and regulating AKT and mTOR via transporting HSP-70. However, this hypothesis requires in vivo confirmation.

The role of microvesicles and its active molecules in regulating cellular biology

Cell‐derived microvesicles are membrane vesicles produced by the outward budding of the plasma membrane and released by almost all types of cells. These have been considered as another mechanism of intercellular communication, because they carry active molecules, such as proteins, lipids and nucleic acids. Furthermore, these are present in circulating fluids, such as blood and urine, and are closely correlated to the progression of pathophysiological conditions in many diseases. Recent studies have revealed that microvesicles have a dual effect of damage and protection of receptor cells. However, the nature of the active molecules involved in this effect remains unclear. The present study mainly emphasized the mechanism of microvesicles and the active molecules mediating the different biological effects of receptor cells by affecting autophagy, apoptosis and inflammation pathways. The effective ways of blocking microvesicles and its active molecules in mediating cell damage when microvesicles exert harmful effects were also discussed.

Effects of Microvesicles on Cell Apoptosis under Hypoxia

Hypoxia, as one of the severe cellular stresses, can cause cellular injury and even cell death. Apoptosis is the main mechanism of regulating cell death and is closely related to the cell death caused by hypoxia. However, hypoxia-induced apoptosis is not entirely the result of direct hypoxic stimulus of cells. In recent years, it has been found that cells injured by hypoxia can shed a kind of membranous vesicles, which are called microvesicles (MVs). MVs can carry bioactive molecules from injured mother cells and appear in blood, cerebrospinal fluid, and other body fluids. MVs can induce normal cell apoptosis by transferring bioactive molecules into adjacent cells and amplifying the hypoxic injury in an organism. This review summarizes the characteristic changes of MVs derived from hypoxic cells and the mechanism of normal cell apoptosis mediated by hypoxic cell-derived MVs. Finally, we introduce the significance of this apoptosis-apoptosis cascade reaction in hypoxic diseases.