The combination of lanthanum chloride and the calcimimetic calindol delays the progression of vascular smooth muscle cells calcification

Phosphate (Pi)-binders are commonly used in dialysis patients to control high Pi levels, that associated with vascular calcification (VC). The aim of this study was to investigate the effects of lanthanum chloride (LaCl(3)) on the progression of high Pi-induced VC, in rat vascular smooth muscle cells (VSMCs). Pi-induced Ca deposition was inhibited by LaCl(3), with a maximal effect at 100μM (59.0±2.5% inhibition). Furthermore, we studied the effects on VC of calcium sensing receptor (CaSR) agonists. Gadolinium chloride, neomycin, spermine, and the calcimimetic calindol significantly inhibited Pi-induced VC (55.9±2.2%, 37.3±4.7%, 30.2±5.7%, and 63.8±5.7%, respectively). To investigate the hypothesis that LaCl(3) reduces the progression of VC by interacting with the CaSR, we performed a concentration-response curve of LaCl(3) in presence of a sub-effective concentration of calindol (10nM). Interestingly, this curve was shifted to the left (IC(50) 9.6±2.6μM), compared to the curve in the presence of LaCl(3) alone (IC(50) 19.0±4.8μM). In conclusion, we demonstrated that lanthanum chloride effectively reduces the progression of high phosphate-induced vascular calcification. In addition, LaCl(3) cooperates with the calcimimetic calindol in decreasing Ca deposition in this in vitro model. These results suggest the potential role of lanthanum in the treatment of VC induced by high Pi.     

Lanthanum chloride bidirectionally influences calcification in bovine vascular smooth muscle cells

Vascular calcification (VC) is frequent prevalence in patients with chronic kidney disease (CKD) and atherosclerosis. Lanthanum carbonate is used as an orally administered phosphate-binding agent to reduce the gastrointestinal absorption of phosphate and ameliorate VC in advanced CKD. In this study, we used bovine vascular smooth muscle cells as a model VC in vitro and studied the effects of lanthanum chloride on calcium deposition. Exposure of cells to LaCl(3) at the concentration of 0.1 μM suppressed the β-glycerophosphate-induced alkaline phosphatase activity and calcium deposition. Furthermore, LaCl(3) upregulated the β-glycerophosphate-suppressed expression of calcium-sensing receptor. In contrast to the inhibitory effect of LaCl(3) on calcium deposition, higher level lanthanum (50 μM) was found to promote immediately precipitation of calcium phosphate in cell culture medium. At this concentration, LaCl(3) was found to induce cell apoptosis which involves caspases-9 and -3. These data indicate that the promotory effect of LaCl(3) on calcium deposition is likely mediated by induction of apoptosis. Our in vitro findings do suggest that, in the context of raised lanthanum, greater attention should be paid to potential toxic effects associated to the use of lanthanide-based drugs.     

Carvacrol modulates instability of xenobiotic metabolizing enzymes and downregulates the expressions of PCNA,MMP-2, and MMP-9 during diethylnitrosamine-induced hepatocarcinogenesis in rats

Vascular calcification (VC) is highly associated with increased morbidity and mortality in patients with advanced chronic kidney disease. Paracrine/autocrine factors such as vasoactive peptides are involved in VC development. Here, we investigated the expression of the novel peptide C-type natriuretic peptide (CNP) in the vasculature, tested its ability to prevent VC in vivo and in vitro, and examined the mechanism involved. Rat aortic VC was induced by vitamin D3 plus nicotine (VDN). CNP (500 ng/kg/h) was administered by mini-osmotic pump. Calcification was examined by von Kossa staining; CNP and cyclic guanosine monophosphate (cGMP) contents were detected by radioimmunoassay, and mRNA and protein levels were examined by real-time PCR and Western blot analysis in aortas and calcified vascular smooth muscle cells (VSMCs). VDN-treated rat aortas showed higher CNP content and decreased expression of its receptor natriuretic peptide receptor B, along with increased vascular calcium deposition and alkaline phosphatase (ALP) activity. Low CNP levels were accompanied by increased vascular calcium deposition and ALP activity in VDN-treated rats when compared to vehicle treatment, which was further confirmed in cultured VSMCs. Administration of CNP greatly reduced VC in VDN-treated aortas compared with controls, which was confirmed in calcified VSMCs. The decrease in alpha-actin expression was ameliorated by CNP in vitro. Moreover, protein expression levels of osteopontin (OPN) were significantly up-regulated in calcified aortas, and CNP increased OPN expression in calcified aortas. Furthermore, CNP downregulated OPN and bone morphogenic protein 2 (BMP-2) expression in calcified aortas and VSMCs. Modulation of OPN and BMP-2 expression by CNP and the beneficial effects of CNP on calcified VSMCs were blocked significantly by protein kinase G inhibitor H7. Impaired local endogenous CNP and its receptor system may be associated with increased mineralization in vivo in rat aortas with VC, and administration of CNP inhibits VC development in vivo and in vitro, at least in part, via a cGMP/PKG pathway.     

Exosomes derived from acute myeloid leukemia cells promote chemoresistance by enhancing glycolysis-mediated vascular remodeling

Acute myeloid leukemia (AML) is the most common type of leukemia in adults. AML cells secrete angiogenic factors to remodel vasculature and acquire chemoresistance; however, antiangiogenic drugs are often ineffective in AML treatment. Cancer cell-derived exosomes can induce angiogenesis, but their role in vascular remodeling during AML is unclear. Here, we found that exosomes secreted by AML cells promoted proliferation and migration and tube-forming activity of human umbilical vein endothelial cells (HUVECs), whereas HUVECs conferred chemoresistance to AML cells. AML cell-derived exosomes contained vascular endothelial growth factor (VEGF) and VEGF receptor (VEGFR) messenger RNA and induced VEGFR expression in HUVECs. Furthermore, they enhanced glycolysis, which correlated with HUVEC proliferation, tube formation, and resistance to apoptosis. Thus, AML cells secrete VEGF/VEGFR-containing exosomes that induce glycolysis in HUVECs leading to vascular remodeling and acquisition of chemoresistance. These findings may contribute to the development of novel therapeutic strategies targeting exosomes in AML.     

Roles of exosomes in liver metastases: Novel diagnosis and treatment choices

Tumors tend to metastasize to the liver. Premetastatic niche formation is a vital step in liver metastasis. Tumor-derived exosomes can influence premetastatic niche formation from three aspects: vascular leakiness and angiogenesis, recruitment of nonresident cells, and changes in local resident cells. Exosomes from other tissues, such as mesenchymal stem cell-derived exosomes and engineered exosomes, also have therapeutic potential, but further research on these exosomes is required. Based on the mechanism of premetastatic niche formation, we summarize the therapeutic and diagnostic potential of exosomes in inhibiting liver metastases in this review in an attempt to provide new avenues for the prevention and treatment of liver metastases.     

Tumor-derived exosomal miR-3157-3p promotes angiogenesis,vascular permeability and metastasis by targeting TIMP/KLF2 in non-small cell lung cancer

Metastasis is the main cause of death in patients with advanced lung cancer. The exosomes released by cancer cells create tumor microenvironment, and then accelerate tumor metastasis. Cancer-derived exosomes are considered to be the main driving force for metastasis niche formation at foreign sites, but the mechanism in Non-small cell lung carcinoma (NSCLC) is unclear. In metastatic NSCLC patients, the expression level of miR-3157-3p in circulating exosomes was significantly higher than that of non-metastatic NSCLC patients. Here, we found that miR-3157-3p can be transferred from NSCLC cells to vascular endothelial cells through exosomes. Our work indicates that exosome miR-3157-3p is involved in the formation of pre-metastatic niche formation before tumor metastasis and may be used as a blood-based biomarker for NSCLC metastasis. Exosome miR-3157-3p has regulated the expression of VEGF/MMP2/MMP9 and occludin in endothelial cells by targeting TIMP/KLF2, thereby promoted angiogenesis and increased vascular permeability. In addition, exosome miR-3157-3p promoted the metastasis of NSCLC in vivo.Subject terms: Cancer microenvironment, Non-small-cell lung cancer     

Exosomes in Mesenchymal Stem Cells,a New Therapeutic Strategy for Cardiovascular Diseases?

Cardiovascular diseases (CVDs) are still a major cause of people deaths worldwide, and mesenchymal stem cells (MSCs) transplantation holds great promise due to its capacity to differentiate into cardiovascular cells and secrete protective cytokines, which presents an important mechanism of MSCs therapy for CVDs. Although the capability of MSCs to differentiate into cardiomyocytes (CMCs), endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) has been well recognized in massive previous experiments both in vitro and in vivo, low survival rate of transplanted MSCs in recipient hearts suggests that therapeutic effects of MSCs transplantation might be also correlated with other underlying mechanisms. Notably, recent studies uncovered that MSCs were able to secret cholesterol-rich, phospholipid exosomes which were enriched with microRNAs (miRNAs). The released exosomes from MSCs acted on hearts and vessels, and then exerted anti-apoptosis, cardiac regeneration, anti-cardiac remodeling, anti-inflammatory effects, neovascularization and anti-vascular remodeling, which are considered as novel molecular mechanisms of therapeutic potential of MSCs transplantation. Here we summarized recent advances about the role of exosomes in MSCs therapy for CVDs, and discussed exosomes as a novel approach in the treatment of CVDs in the future.     

Implications of exosomes as diagnostic and therapeutic strategies in cancer

Exosomes offer a new perspective on the biology of cancer with both diagnostic and therapeutic concepts. Due to the cell-to-cell association, exosomes are involved in the progression, metastasis, and therapeutic efficacy of the tumor. They can be isolated from blood and other body fluids to determine the disease progression in the body, including cancer growth. In addition to being reservoirs of biochemical markers of cancer, exomes can be designed to restore tumor immunity. Tumor exosomes interact with different cells in the tumor microenvironment to confer beneficial modulations, responsible for stromal activity, angiogenesis, increased vascular permeability, and immune evasion. Exosomes also contribute to the metastasis with the aim of epithelial transmission to the mesenchyme and the formation of premetastatic niches. Moreover, exosomes protect cells against the cytotoxic effects of chemotherapeutic drugs and prevent the transmission of chemotherapy resistance to adjacent cells. Therefore, exosomes are essential for many fatal cancer agents, and understanding their origins and role in cancer is important. In this article, we attempted to clarify the potential of exosomes for the application in cancer diagnosis and therapy.     

Exosomes for angiogenesis induction in ischemic disorders

Ischaemic disorders are leading causes of morbidity and mortality worldwide. While the current therapeutic approaches have improved life expectancy and quality of life, they are unable to “cure” ischemic diseases and instate regeneration of damaged tissues. Exosomes are a class of extracellular vesicles with an average size of 100–150 nm, secreted by many cell types and considered a potent factor of cells for paracrine effects. Since exosomes contain multiple bioactive components such as growth factors, molecular intermediates of different intracellular pathways, microRNAs and nucleic acids, they are considered as cell-free therapeutics. Besides, exosomes do not rise cell therapy concerns such as teratoma formation, alloreactivity and thrombotic events. In addition, exosomes are stored and utilized more convenient. Interestingly, exosomes could be an ideal complementary therapeutic tool for ischemic disorders. In this review, we discussed therapeutic functions of exosomes in ischemic disorders including angiogenesis induction through various mechanisms with specific attention to vascular endothelial growth factor pathway. Furthermore, different delivery routes of exosomes and different modification strategies including cell preconditioning, gene modification and bioconjugation, were highlighted. Finally, pre-clinical and clinical investigations in which exosomes were used were discussed.     

Tumor-derived exosomal components: the multifaceted roles and mechanisms in breast cancer metastasis

Breast cancer (BC) is the most frequently invasive malignancy and the leading cause of tumor-related mortality among women worldwide. Cancer metastasis is a complex, multistage process, which eventually causes tumor cells to colonize and grow at the metastatic site. Distant organ metastases are the major obstacles to the management of advanced BC patients. Notably, exosomes are defined as specialized membrane-enclosed extracellular vesicles with specific biomarkers, which are found in a wide variety of body fluids. Recent studies have demonstrated that exosomes are essential mediators in shaping the tumor microenvironment and BC metastasis. The transferred tumor-derived exosomes modify the capability of invasive behavior and organ-specific metastasis in recipient cells. BC exosomal components, mainly including noncoding RNAs (ncRNAs), proteins, lipids, are the most investigated components in BC metastasis. In this review, we have emphasized the multifaceted roles and mechanisms of tumor-derived exosomes in BC metastasis based on these important components. The underlying mechanisms mainly include the invasion behavior change, tumor vascularization, the disruption of the vascular barrier, and the colonization of the targeted organ. Understanding the significance of tumor-derived exosomal components in BC metastasis is critical for yielding novel routes of BC intervention.Subject terms: Breast cancer, Cancer microenvironment, Non-coding RNAs     

Exosomes Derived from Squamous Head and Neck Cancer Promote Cell Survival after Ionizing Radiation

Exosomes are nanometer-sized extracellular vesicles that are believed to function as intercellular communicators. Here, we report that exosomes are able to modify the radiation response of the head and neck cancer cell lines BHY and FaDu. Exosomes were isolated from the conditioned medium of irradiated as well as non-irradiated head and neck cancer cells by serial centrifugation. Quantification using NanoSight technology indicated an increased exosome release from irradiated compared to non-irradiated cells 24 hours after treatment. To test whether the released exosomes influence the radiation response of other cells the exosomes were transferred to non-irradiated and irradiated recipient cells. We found an enhanced uptake of exosomes isolated from both irradiated and non-irradiated cells by irradiated recipient cells compared to non-irradiated recipient cells. Functional analyses by exosome transfer indicated that all exosomes (from non-irradiated and irradiated donor cells) increase the proliferation of non-irradiated recipient cells and the survival of irradiated recipient cells. The survival-promoting effects are more pronounced when exosomes isolated from irradiated compared to non-irradiated donor cells are transferred. A possible mechanism for the increased survival after irradiation could be the increase in DNA double-strand break repair monitored at 6, 8 and 10 h after the transfer of exosomes isolated from irradiated cells. This is abrogated by the destabilization of the exosomes. Our results demonstrate that radiation influences both the abundance and action of exosomes on recipient cells. Exosomes transmit prosurvival effects by promoting the proliferation and radioresistance of head and neck cancer cells. Taken together, this study indicates a functional role of exosomes in the response of tumor cells to radiation exposure within a therapeutic dose range and encourages that exosomes are useful objects of study for a better understanding of tumor radiation response.     

Communication in tiny packages: Exosomes as means of tumor-stroma communication

Tumor-derived exosomes are nano-sized vesicles acting as multi-signal devices influencing tumor growth at local and distant sites. Exosomes are derived from the endolysosomal compartment and can shuttle diverse biomolecules like nucleic acids (microRNAs and DNA fragments), lipids, proteins, and even pharmacological compounds from a donor cell to recipient cells. The transfer of cargo to recipient cells enables tumor-derived exosomes to influence diverse cellular functions like proliferation, cell survival, and migration in recipient cells, highlighting tumor-derived exosomes as important players in communication within the tumor microenvironment and at distant sites. In this review, we discuss the mechanisms associated with exosome biogenesis and cargo sorting. In addition, we highlight the communication of tumor-derived exosomes in the tumor microenvironment during different phases of tumor development, focusing on angiogenesis, immune escape mechanisms, drug resistance, and metastasis.     

Exosome 介导的细胞通讯在中枢神经系统疾病中的研究进展

Exosome(胞外体)是一种可由多种细胞分泌的纳米级膜性小泡,直径为40~100 nm,其中含有细胞特异性的信号分子、蛋白质、m RNA和mi RNA。这些成分因为有脂质膜的保护而具有充分的生物学活性,可以在细胞与细胞之间进行信息传递,从而有效发挥对受体细胞的调节作用。本文综述了近几年关于exosomes的研究成果,从exosome的基本特征、生物学功能、exosomes介导的细胞通讯在中枢神经系统疾病发病机制及治疗潜能四个方面,对exosomes的研究现状作一介绍,旨在探讨exosomes在细胞通讯研究中所面临的问题,为以exosomes作为调节靶点治疗中枢神经系统疾病提供理论参考。     

Tumor-derived exosomes: Implication in angiogenesis and antiangiogenesis cancer therapy

Tumor cells utilize different strategies to communicate with neighboring tissues for facilitating tumor progression and invasion, one of these strategies has been shown to be the release of exosomes. Exosomes are small nanovesicles secreted by all kind of cells in the body, especially cancer cells, and mediate cell to cell communications. Exosomes play an important role in cancer invasiveness by harboring various cargoes that could accelerate angiogenesis. Here first, we will present an overview of exosomes, their biology, and their function in the body. Then, we will focus on exosomes derived from tumor cells as tumor angiogenesis mediators with a particular emphasis on the underlying mechanisms in various cancer origins. Also, exosomes derived from stem cells and tumor-associated macrophages will be discussed in this regard. Finally, we will discuss the novel therapeutic strategies of exosomes as drug delivery vehicles against angiogenesis.     

Gastric Cancer Cell-Derived Exosomal GRP78 Enhances Angiogenesis upon Stimulation of Vascular Endothelial Cells

Exosomes containing glucose-regulated protein 78 (GRP78) are involved in cancer malignancy. GRP78 is thought to promote the tumor microenvironment, leading to angiogenesis. No direct evidence for this role has been reported, however, mainly because of difficulties in accurately measuring the GRP78 concentration in the exosomes. Recently, exosomal GRP78 concentrations were successfully measured using an ultrasensitive ELISA. In the present study, GRP78 concentrations in exosomes collected from gastric cancer AGS cells with overexpression of GRP78 (OE), knockdown of GRP78 (KD), or mock GRP78 (mock) were quantified. These three types of exosomes were then incubated with vascular endothelial cells to examine their effects on endothelial cell angiogenesis. Based on the results of a tube formation assay, GRP78-OE exosomes accelerated angiogenesis compared with GRP78-KD or GRP78-mock exosomes. To investigate the mechanisms underlying this effect, we examined the Ser473 phosphorylation state ratio of AKT, which is involved in the angiogenesis process, and found that AKT phosphorylation was increased by GRP78-OE exosome application to the endothelial cells. An MTT assay showed that GRP78-OE exosome treatment increased the proliferation rate of endothelial cells, and a wound healing assay showed that this treatment increased the migration capacity of the endothelial cells. These findings demonstrated that GRP78-containing exosomes promote the tumor microenvironment and induce angiogenesis.     

Exosomes: New insights into cancer mechanisms

Exosomes are mobile extracellular vesicles with a diameter 40 to 150 nm. They play a critical role in several processes such as the development of cancers, intercellular signaling, drug resistance mechanisms, and cell-to-cell communication by fusion onto the cell membrane of recipient cells. These vesicles contain endogenous proteins and both noncoding and coding RNAs (microRNA and messenger RNAs) that can be delivered to various types of cells. Furthermore, exosomes exist in body fluids such as plasma, cerebrospinal fluid, and urine. Therefore, they could be used as a novel carrier to deliver therapeutic nucleic-acid drugs for cancer therapy. It was recently documented that, hypoxia promotes exosomes secretion in different tumor types leading to the activation of vascular cells and angiogenesis. Cancer cell-derived exosomes (CCEs) have been used as prognostic and diagnostic markers in many types of cancers because exosomes are stable at 4°C and −70°C. CCEs have many functional roles in tumorigenesis, metastasis, and invasion. Consequently, this review presents the data about the therapeutic application of exosomes and the role of CCEs in cancer invasion, drug resistance, and metastasis.     

Exosomes Released from Breast Cancer Carcinomas Stimulate Cell Movement

For metastasis to occur cells must communicate with to their local environment to initiate growth and invasion. Exosomes have emerged as an important mediator of cell-to-cell signalling through the transfer of molecules such as mRNAs, microRNAs, and proteins between cells. Exosomes have been proposed to act as regulators of cancer progression. Here, we study the effect of exosomes on cell migration, an important step in metastasis. We performed cell migration assays, endocytosis assays, and exosome proteomic profiling on exosomes released from three breast cancer cell lines that model progressive stages of metastasis. Results from these experiments suggest: (1) exosomes promote cell migration and (2) the signal is stronger from exosomes isolated from cells with higher metastatic potentials; (3) exosomes are endocytosed at the same rate regardless of the cell type; (4) exosomes released from cells show differential enrichment of proteins with unique protein signatures of both identity and abundance. We conclude that breast cancer cells of increasing metastatic potential secrete exosomes with distinct protein signatures that proportionally increase cell movement and suggest that released exosomes could play an active role in metastasis.     

外泌体在免疫调控及肿瘤发生中的功能

已知细胞间的信息交流不仅可以通过直接接触,或释放信号分子等方式,同时还存在另一种细胞通讯方式即释放外泌体。外泌体是由细胞分泌,直径为30～100 nm的囊泡结构。外泌体含有蛋白质、脂质、mRNAs和miRNAs等成分,并且能够靶向运输到其他细胞或组织中,从而在细胞间的信息交流、物质传递方面发挥重要作用。本文对外泌体的基本特征、形成过程、功能以及在疾病诊断与治疗中的应用等方面进行简要综述,重点介绍外泌体在免疫调控和肿瘤发生方面的功能。外泌体作为一种广泛存在的亚细胞成分,虽然体积小,组成成分简单,然而,其复杂功能具有重要的研究价值。对外泌体功能的深入了解将为肿瘤等疾病的预防和治疗提供更多的诊断标志物、疫苗以及治疗思路与手段。     

A membranous form of ICAM-1 on exosomes efficiently blocks leukocyte adhesion to activated endothelial cells

While intercellular adhesion molecule-1 (ICAM-1) is a transmembrane protein, two types of extracellular ICAM-1 have been detected in cell culture supernatants as well as in the serum: a soluble form of ICAM-1 (sICAM-1) and a membranous form of ICAM-1 (mICAM-1) associated with exosomes. Previous observations have demonstrated that sICAM-1 cannot exert potent immune modulatory activity due to its low affinity for leukocyte function-associated antigen-1 (LFA-1) or membrane attack complex-1. In this report, we initially observed that human cancer cells shed mICAM-1(+)-exosomes but were devoid of vascular cell adhesion molecule-1 and E-selectin. We demonstrate that mICAM-1 on exosomes retained its topology similar to that of cell surface ICAM-1, and could bind to leukocytes. In addition, we show that exosomal mICAM-1 exhibits potent anti-leukocyte adhesion activity to tumor necrosis factor-α-activated endothelial cells compared to that of sICAM-1. Taken together with previous findings, our results indicate that mICAM-1 on exosomes exhibits potent immune modulatory activity.     

Reviewing the role of cardiac exosomes in myocardial repair at a glance

Exosome-based therapy is an emerging novel approach for myocardial infarction (MI) treatment. Exosomes are identified as extracellular vesicles that are produced within multivesicular bodies in the cells' cytosols and then are secreted from the cells. Exosomes are 30–100 nm in diameter that are released from viable cells and are different from other secreted vesicles such as apoptotic bodies and microvesicles in their origin and contents such as RNAs, proteins, and nucleic acid. The recent advances in exosome research have demonstrated the role of these bionanovesicles in the physiological, pathological, and molecular aspects of the heart. The results of in vitro and preclinical models have shown that exosomes from different cardiac cells can improve cardiac function following MI. For example, mesenchymal stem cells (MSCs) and cardiac progenitor cells (CPCs) containing exosomes can affect the proliferation, survival, and differentiation of cardiac fibroblasts and cardiomyocytes. Moreover, MSCs- and CPCs-derived exosomes can enhance the migration of endothelial cells. Exosome-based therapy approaches augment the cardiac function by multiple means, such as reducing fibrosis, stimulation of vascular angiogenesis, and proliferation of cardiomyocytes that result in replacing damaged heart tissue with newly generated functional myocytes. This review article aims to briefly discuss the recent advancements in the role of secreted exosomes in myocardial repair by focusing on cardiac cells-derived exosomes.