Endothelial Cells Can Regulate Smooth Muscle Cells in Contractile Phenotype through the miR-206/ARF6&NCX1/Exosome Axis

Mechanosensory entities and functionality of endothelial cells

The endothelial cells of the blood circulation are exposed to hemodynamic forces, such as cyclic strain, hydrostatic forces, and shear stress caused by the blood fluid's frictional force. Endothelial cells perceive mechanical forces via mechanosensors and thus elicit physiological reactions such as alterations in vessel width. The mechanosensors considered comprise ion channels, structures linked to the plasma membrane, cytoskeletal spectrin scaffold, mechanoreceptors, and junctional proteins. This review focuses on endothelial mechanosensors and how they alter the vascular functions of endothelial cells. The current state of knowledge on the dysregulation of endothelial mechanosensitivity in disease is briefly presented. The interplay in mechanical perception between endothelial cells and vascular smooth muscle cells is briefly outlined. Finally, future research avenues are highlighted, which are necessary to overcome existing limitations.

Extracellular Vesicles as Mediators in Atherosclerotic Cardiovascular Disease

Atherosclerosis is a chronic inflammatory disease of the arterial intima, characterized by accumulation of lipoproteins and accompanying inflammation, leading to the formation of plaques that eventually trigger occlusive thrombotic events, such as myocardial infarction and ischemic stroke. Although many aspects of plaque development have been elucidated, the role of extracellular vesicles (EVs), which are lipid bilayer-delimited vesicles released by cells as mediators of intercellular communication, has only recently come into focus of atherosclerosis research. EVs comprise several subtypes that may be differentiated by their size, mode of biogenesis, or surface marker expression and cargo. The functional effects of EVs in atherosclerosis depend on their cellular origin and the specific pathophysiological context. EVs have been suggested to play a role in all stages of plaque formation. In this review, we highlight the known mechanisms by which EVs modulate atherogenesis and outline current limitations and challenges in the field.

Investigation of the Dysfunction Caused by High Glucose, Advanced Glycation End Products, and Interleukin-1 Beta and the Effects of Therapeutic Agents on the Microphysiological Artery Model

Diabetes mellitus (DM) has substantial global implications and contributes to vascular inflammation and the onset of atherosclerotic cardiovascular diseases. However, translating the findings from animal models to humans has inherent limitations, necessitating a novel platform. Therefore, herein, an arterial model is established using a microphysiological system. This model successfully replicates the stratified characteristics of human arteries by integrating collagen, endothelial cells (ECs), and vascular smooth muscle cells (VSMCs). Perfusion via a peristaltic pump shows dynamic characteristics distinct from those of static culture models. High glucose, advanced glycation end products (AGEs), and interleukin-1 beta are employed to stimulate diabetic conditions, resulting in notable cellular changes and different levels of cytokines and nitric oxide. Additionally, the interactions between the disease models and oxidized low-density lipoproteins (LDL) are examined. Finally, the potential therapeutic effects of metformin, atorvastatin, and diphenyleneiodonium are investigated. Metformin and diphenyleneiodonium mitigate high-glucose- and AGE-associated pathological changes, whereas atorvastatin affects only the morphology of ECs. Altogether, the arterial model represents a pivotal advancement, offering a robust and insightful platform for investigating cardiovascular diseases and their corresponding drug development.

Danhong Injection Up-regulates miR-125b in Endothelial Exosomes and Attenuates Apoptosis in Post-Infarction Myocardium

OBJECTIVE

To investigate the involvement of endothelial cells (ECs)-derived exosomes in the anti-apoptotic effect of Danhong Injection (DHI) and the mechanism of DHI-induced exosomal protection against postinfarction myocardial apoptosis.

METHODS

A mouse permanent myocardial infarction (MI) model was established, followed by a 14-day daily treatment with DHI, DHI plus GW4869 (an exosomal inhibitor), or saline. Phosphate-buffered saline (PBS)-induced ECs-derived exosomes were isolated, analyzed by miRNA microarray and validated by droplet digital polymerase chain reaction (ddPCR). The exosomes induced by DHI (DHI-exo), PBS (PBS-exo), or DHI+GW4869 (GW-exo) were isolated and injected into the peri-infarct zone following MI. The protective effects of DHI and DHI-exo on MI hearts were measured by echocardiography, Masson's trichrome staining, and TUNEL apoptosis assay. The Western blotting and quantitative reverse transcription PCR (qRT-PCR) were used to evaluate the expression levels of miR-125b/p53-mediated pathway components, including miR-125b, p53, Bak, Bax, and caspase-3 activities.

RESULTS

DHI significantly improved cardiac function and reduced infarct size in MI mice (P<0.01), which was abolished by the GW4869 intervention. DHI promoted the exosomal secretion in ECs (P<0.01). According to the results of exosomal miRNA microarray assay, 30 differentially expressed miRNAs in the DHI-exo were identified (28 up-regulated miRNAs and 2 down-regulated miRNAs). Among them, DHI significantly elevated miR-125b level in DHI-exo and DHI-treated ECs, a recognized apoptotic inhibitor impeding p53 signaling (P<0.05). Remarkably, treatment with DHI and DHI-exo attenuated apoptosis, elevated miR-125b expression level, inhibited capsase-3 activity, and down-regulated the expression levels of proapoptotic effectors (p53, Bak, and Bax) in post-MI hearts, whereas these effects were blocked by GW4869 (P<0.05 or P<0.01).

CONCLUSION

DHI and DHI-induced exosomes inhibited apoptosis, promoted the miR-125b expression level, and regulated the p53 apoptotic pathway in post-infarction myocardium.

Tongxinluo promotes endothelium-dependent arteriogenesis to attenuate diabetic peripheral arterial disease

BACKGROUND

Peripheral arterial disease (PAD) has become one of the leading causes of disa-bility and death in diabetic patients. Restoring blood supply to the hindlimbs, especially by promoting arteriogenesis, is currently the most effective strategy, in which endothelial cells play an important role. Tongxinluo (TXL) has been widely used for the treatment of cardio-cerebrovascular diseases and extended for diabetes-related vascular disease.

AIM

To investigate the effect of TXL on diabetic PAD and its underlying mechanisms.

METHODS

An animal model of diabetic PAD was established by ligating the femoral artery of db/db mice. Laser Doppler imaging and micro-computed tomography (micro-CT) were performed to assess the recovery of blood flow and arteriogenesis. Endothelial cell function related to arteriogenesis and cellular pyroptosis was assessed using histopathology, Western blot analysis, enzyme-linked immuno-sorbent assay and real-time polymerase chain reaction assays. In vitro, human vascular endothelial cells (HUVECs) and human vascular smooth muscle cells (VSMCs) were pretreated with TXL for 4 h, followed by incubation in high glucose and hypoxia conditions to induce cell injury. Then, indicators of HUVEC pyroptosis and function, HUVEC-VSMC interactions and the migration of VSMCs were measured.

RESULTS

Laser Doppler imaging and micro-CT showed that TXL restored blood flow to the hindlimbs and enhanced arteriogenesis. TXL also inhibited endothelial cell pyroptosis via the reactive oxygen species/nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3/Caspase-1/GSDMD signaling pathway. In addition, TXL restored endothelial cell functions, including maintaining the balance of vasodilation, acting as a barrier to reduce inflammation, and enhancing endothelial-smooth muscle cell interactions through the Jagged-1/Notch-1/ephrin-B2 signaling pathway. Similar results were observed in vitro.

CONCLUSION

TXL has a pro-arteriogenic effect in the treatment of diabetic PAD, and the mechanism may be related to the inhibition of endothelial cell pyroptosis, restoration of endothelial cell function and promotion of endothelial cell-smooth muscle cell interactions.

Updates in the chronic kidney disease-mineral bone disorder show the role of osteocytic proteins, a potential mechanism of the bone-Vascular paradox, a therapeutic target, and a biomarker

The chronic kidney disease-mineral bone disorder (CKD-MBD) is a complex multi-component syndrome occurring during kidney disease and its progression. Here, we update progress in the components of the syndrome, and synthesize recent investigations, which suggest a potential mechanism of the bone-vascular paradox. The discovery that calcified arteries in chronic kidney disease inhibit bone remodeling lead to the identification of factors produced by the vasculature that inhibit the skeleton, thus providing a potential explanation for the bone-vascular paradox. Among the factors produced by calcifying arteries, sclerostin secretion is especially enlightening. Sclerostin is a potent inhibitor of bone remodeling and an osteocyte specific protein. Its production by the vasculature in chronic kidney disease identifies the key role of vascular cell osteoblastic/osteocytic transdifferentiation in vascular calcification and renal osteodystrophy. Subsequent studies showing that inhibition of sclerostin activity by a monoclonal antibody improved bone remodeling as expected, but stimulated vascular calcification, demonstrate that vascular sclerostin functions to brake the Wnt stimulation of the calcification milieu. Thus, the target of therapy in the chronic kidney disease-mineral bone disorder is not inhibition of sclerostin function, which would intensify vascular calcification. Rather, decreasing sclerostin production by decreasing the vascular osteoblastic/osteocytic transdifferentiation is the goal. This might decrease vascular calcification, decrease vascular stiffness, decrease cardiac hypertrophy, decrease sclerostin production, reduce serum sclerostin and improve skeletal remodeling. Thus, the therapeutic target of the chronic kidney disease-mineral bone disorder may be vascular osteoblastic transdifferentiation, and sclerostin levels may be a useful biomarker for the diagnosis of the chronic kidney disease-mineral bone disorder and the progress of its therapy.

Research progress on the mechanism of phenotypic transformation of pulmonary artery smooth muscle cells induced by hypoxia

Phenotypic transformation of pulmonary artery smooth muscle cells (PASMCs) is a key factor in pulmonary vascular remodeling. Inhibiting or reversing phenotypic transformation can inhibit pulmonary vascular remodeling and control the progression of hypoxic pulmonary hypertension. Recent studies have shown that hypoxia causes intracellular peroxide metabolism to induce oxidative stress, induces multi-pathway signal transduction, including those related to autophagy, endoplasmic reticulum stress and mitochondrial dysfunction, and also induces non-coding RNA regulation of cell marker protein expression, resulting in PASMCs phenotypic transformation. This article reviews recent research progress on mechanisms of hypoxia-induced phenotypic transformation of PASMCs, which may be helpful for finding targets to inhibit phenotypic transformation and to improve pulmonary vascular remodeling diseases such as hypoxia-induced pulmonary hypertension.

How vascular smooth muscle cell phenotype switching contributes to vascular disease

Vascular smooth muscle cells (VSMCs) are the most abundant cell in vessels. Earlier experiments have found that VSMCs possess high plasticity. Vascular injury stimulates VSMCs to switch into a dedifferentiated type, also known as synthetic VSMCs, with a high migration and proliferation capacity for repairing vascular injury. In recent years, largely owing to rapid technological advances in single-cell sequencing and cell-lineage tracing techniques, multiple VSMCs phenotypes have been uncovered in vascular aging, atherosclerosis (AS), aortic aneurysm (AA), etc. These VSMCs all down-regulate contractile proteins such as α-SMA and calponin1, and obtain specific markers and similar cellular functions of osteoblast, fibroblast, macrophage, and mesenchymal cells. This highly plastic phenotype transformation is regulated by a complex network consisting of circulating plasma substances, transcription factors, growth factors, inflammatory factors, non-coding RNAs, integrin family, and Notch pathway. This review focuses on phenotypic characteristics, molecular profile and the functional role of VSMCs phenotype landscape; the molecular mechanism regulating VSMCs phenotype switching; and the contribution of VSMCs phenotype switching to vascular aging, AS, and AA. Video Abstract.

Proteomic and miRNA Profiles of Exosomes Derived from Myometrial Tissue in Laboring Women

Myometrial contraction is essential for successful delivery. Recent studies have highlighted the vital roles of tissue-derived exosomes in disease diagnostic, prognostic, and therapeutic applications; however, the characteristics of uterine myometrium-derived exosomes are unclear. Here, we successfully isolated exosomes from myometrial tissues, human myometrial smooth muscle cells (HMSMCs), and human umbilical vein endothelial cells (HUVECs), then performed quantitative liquid chromatography-tandem mass spectrometry and miRNA sequencing to investigate the cargo of the exosomes. Fifty-two proteins and five miRNAs were differentially expressed (DE) in term non-labor and term labor myometrium-derived exosomes. Among them, seven proteins (SERPINE1, THBS1, MGAT1, VIM, FGB, FGG, and VWF) were differentially expressed both in the myometrial exosomes and tissues, three miRNAs (miR-363-3p, miR-203a-3p, and miR-205-5p) target 13 DE genes. The top three miRNA derived from HMSMCs (miR-125b-1-3p, miR-337-5p, and miR-503-5p) and HUVECs (miR-663a, miR-4463, and miR-3622a-5p) were identified. Two proteins, GJA1 and SLC39A14, exist in female blood exosomes and are highly expressed in HMSMCs exosomes, are also upregulated in the laboring myometrium, which verified increased in laboring blood samples, might be novel potential biomarkers for myometrial activation. The proteomic and miRNA profile of exosomes derived from laboring myometrium revealed some molecules in the exosomes that affect the intercellular communication and the function of the myometrium.

Extracellular vesicles in vascular remodeling

Vascular remodeling contributes to the development of a variety of vascular diseases including hypertension and atherosclerosis. Phenotypic transformation of vascular cells, oxidative stress, inflammation and vascular calcification are closely associated with vascular remodeling. Extracellular vesicles (EVs) are naturally released from almost all types of cells and can be detected in nearly all body fluids including blood and urine. EVs affect vascular oxidative stress, inflammation, calcification, and lipid plaque formation; and thereby impact vascular remodeling in a variety of cardiovascular diseases. EVs may be used as biomarkers for diagnosis and prognosis, and therapeutic strategies for vascular remodeling and cardiovascular diseases. This review includes a comprehensive analysis of the roles of EVs in the vascular remodeling in vascular diseases, and the prospects of EVs in the diagnosis and treatment of vascular diseases.

Protective role of small extracellular vesicles derived from HUVECs treated with AGEs in diabetic vascular calcification

The pathogenesis of vascular calcification in diabetic patients remains elusive. As an effective information transmitter, small extracellular vesicles (sEVs) carry abundant microRNAs (miRNAs) that regulate the physiological and pathological states of recipient cells. In the present study, significant up-regulation of miR-126-5p was observed in sEVs isolated from human umbilical vein endothelial cells (HUVECs) stimulated with advanced glycation end-products (A-EC/sEVs). Intriguingly, these sEVs suppressed the osteogenic differentiation of vascular smooth muscle cells (VSMCs) by targeting BMPR1B, which encodes the receptor for BMP, thereby blocking the smad1/5/9 signalling pathway. In addition, knocking down miR-126-5p in HUVECs significantly diminished the anti-calcification effect of A-EC/sEVs in a mouse model of type 2 diabetes. Overall, miR-126-5p is highly enriched in sEVs derived from AGEs stimulated HUVECs and can target BMPR1B to negatively regulate the trans-differentiation of VSMCs both in vitro and in vivo.

EVOO Promotes a Less Atherogenic Profile Than Sunflower Oil in Smooth Muscle Cells Through the Extracellular Vesicles Secreted by Endothelial Cells

Background

Little is known about the effect of extra virgin olive (EVOO) and sunflower oil (SO) on the composition of extracellular vesicles (EVs) secreted by endothelial cells and the effects of these EVs on smooth muscle cells (SMCs). These cells play an important role in the development of atherosclerosis.

Methods

We evaluated the effects of endothelial cells-derived EVs incubated with triglyceride-rich lipoproteins obtained after a high-fat meal with EVOO (EVOO-EVs) and SO (SO-EVs), on the transcriptomic profile of SMCs.

Results

We found 41 upregulated and 19 downregulated differentially expressed (DE)-miRNAs in EVOO-EVs. Afterwards, SMCs were incubated with EVOO-EVs and SO-EVs. SMCs incubated with SO-EVs showed a greater number of DE-mRNA involved in pathways related to cancer, focal adhesion, regulation of actin cytoskeleton, and MAPK, toll-like receptor, chemokine and Wnt signaling pathways than in SMCs incubated with EVOO-EVs. These DE-mRNAs were involved in biological processes related to the response to endogenous stimulus, cell motility, regulation of intracellular signal transduction and cell population proliferation.

Conclusion

EVOO and SO can differently modify the miRNA composition of HUVEC-derived EVs. These EVs can regulate the SMCs transcriptomic profile, with SO-EVs promoting a profile more closely linked to the development of atherosclerosis than EVOO-EVs.

Extracellular Vesicles Mediate Communication between Endothelial and Vascular Smooth Muscle Cells

The recruitment of pericytes and vascular smooth muscle cells (SMCs) that enwrap endothelial cells (ECs) is a crucial process for vascular maturation and stabilization. Communication between these two cell types is crucial during vascular development and in maintaining vessel homeostasis. Extracellular vesicles (EVs) have emerged as a new communication tool involving the exchange of microRNAs between cells. In the present study, we searched for microRNAs that could be transferred via EVs from ECs to SMCs and vice versa. Thanks to a microRNA profiling experiment, we found that two microRNAs are more exported in each cell type in coculture experiments: while miR-539 is more secreted by ECs, miR-582 is more present in EVs from SMCs. Functional assays revealed that both microRNAs can modulate both cell-type phenotypes. We further identified miR-539 and miR-582 targets, in agreement with their respective cell functions. The results obtained in vivo in the neovascularization model suggest that miR-539 and miR-582 might cooperate to trigger the process of blood vessel coverage by smooth muscle cells in a mature plexus. Taken together, these results are the first to highlight the role of miR-539 and miR-582 in angiogenesis and communication between ECs and SMCs.

Hypertension in Diabetes: An Update of Basic Mechanisms and Clinical Disease

Epidemiological studies have documented that insulin resistance and diabetes not only constitute metabolic abnormalities but also predispose to hypertension, vascular stiffness, and associated cardiovascular disease. Meanwhile, excessive arterial stiffness and impaired vasorelaxation, in turn, contribute to worsening insulin resistance and the development of diabetes. Molecular mechanisms promoting hypertension in diabetes include inappropriate activation of the renin-angiotensin-aldosterone system and sympathetic nervous system, mitochondria dysfunction, excessive oxidative stress, and systemic inflammation. This review highlights recent studies which have uncovered new underlying mechanisms for the increased propensity for the development of hypertension in association with diabetes. These include enhanced activation of epithelial sodium channels, alterations in extracellular vesicles and their microRNAs, abnormal gut microbiota, and increased renal sodium-glucose cotransporter activity, which collectively predispose to hypertension in association with diabetes. This review also covers socioeconomic factors and currently recommended blood pressure targets and related treatment strategies in diabetic patients with hypertension.

Intracellular and exosomal microRNAome profiling of human vascular smooth muscle cells during replicative senescence

Vascular aging is highly associated with cardiovascular morbidity and mortality. Although the senescence of vascular smooth muscle cells (VSMCs) has been well established as a major contributor to vascular aging, intracellular and exosomal microRNA (miRNA) signaling pathways in senescent VSMCs have not been fully elucidated. This study aimed to identify the differential expression of intracellular and exosomal miRNA in human VSMCs (hVSMCs) during replicative senescence. To achieve this aim, intracellular and exosomal miRNAs were isolated from hVSMCs and subsequently subjected to whole genome small RNA next-generation sequencing, bioinformatics analyses, and qPCR validation. Three significant findings were obtained. First, senescent hVSMC-derived exosomes tended to cluster together during replicative senescence and the molecular weight of the exosomal protein tumor susceptibility gene 101 (TSG-101) increased relative to the intracellular TSG-101, suggesting potential posttranslational modifications of exosomal TSG-101. Second, there was a significant decrease in both intracellular and exosomal hsa-miR-155-5p expression [n = 3, false discovery rate (FDR) < 0.05], potentially being a cell type-specific biomarker of hVSMCs during replicative senescence. Importantly, hsa-miR-155-5p was found to associate with cell-cycle arrest and elevated oxidative stress. Lastly, miRNAs from the intracellular pool, that is, hsa-miR-664a-3p, hsa-miR-664a-5p, hsa-miR-664b-3p, hsa-miR-4485-3p, hsa-miR-10527-5p, and hsa-miR-12136, and that from the exosomal pool, that is, hsa-miR-7704, were upregulated in hVSMCs during replicative senescence (n = 3, FDR < 0.05). Interestingly, these novel upregulated miRNAs were not functionally well annotated in hVSMCs to date. In conclusion, hVSMC-specific miRNA expression profiles during replicative senescence potentially provide valuable insights into the signaling pathways leading to vascular aging.NEW & NOTEWORTHY This is the first study on intracellular and exosomal miRNA profiling on human vascular smooth muscle cells during replicative senescence. Specific dysregulated sets of miRNAs were identified from human vascular smooth muscle cells. Hsa-miR-155-5p was significantly downregulated in both intracellular and exosomal hVSMCs, suggesting its crucial role in cellular senescence. Hsa-miR-155-5p might be the mediator in linking cellular senescence to vascular aging and atherosclerosis.

Extracellular Vesicles in Premature Aging and Diseases in Adulthood Due to Developmental Exposures

The developmental origins of health and disease (DOHaD) is a paradigm that links prenatal and early life exposures that occur during crucial periods of development to health outcome and risk of disease later in life. Maternal exposures to stress, some psychoactive drugs and alcohol, and environmental chemicals, among others, may result in functional changes in developing fetal tissues, creating a predisposition for disease in the individual as they age. Extracellular vesicles (EVs) may be mediators of both the immediate effects of exposure during development and early childhood as well as the long-term consequences of exposure that lead to increased risk and disease severity later in life. Given the prevalence of diseases with developmental origins, such as cardiovascular disease, neurodegenerative disorders, osteoporosis, metabolic dysfunction, and cancer, it is important to identify persistent mediators of disease risk. In this review, we take this approach, viewing diseases typically associated with aging in light of early life exposures and discuss the potential role of EVs as mediators of lasting consequences.

Cellular Crosstalk between Endothelial and Smooth Muscle Cells in Vascular Wall Remodeling

Pathological vascular wall remodeling refers to the structural and functional changes of the vessel wall that occur in response to injury that eventually leads to cardiovascular disease (CVD). Vessel wall are composed of two major primary cells types, endothelial cells (EC) and vascular smooth muscle cells (VSMCs). The physiological communications between these two cell types (EC–VSMCs) are crucial in the development of the vasculature and in the homeostasis of mature vessels. Moreover, aberrant EC–VSMCs communication has been associated to the promotor of various disease states including vascular wall remodeling. Paracrine regulations by bioactive molecules, communication via direct contact (junctions) or information transfer via extracellular vesicles or extracellular matrix are main crosstalk mechanisms. Identification of the nature of this EC–VSMCs crosstalk may offer strategies to develop new insights for prevention and treatment of disease that curse with vascular remodeling. Here, we will review the molecular mechanisms underlying the interplay between EC and VSMCs. Additionally, we highlight the potential applicable methodologies of the co-culture systems to identify cellular and molecular mechanisms involved in pathological vascular wall remodeling, opening questions about the future research directions.

Mueller polarimetric imaging for fast macroscopic mapping of microscopic collagen matrix remodeling by smooth muscle cells

Smooth muscle cells (SMCs) are critical players in cardiovascular disease development and undergo complex phenotype switching during disease progression. However, SMC phenotype is difficult to assess and track in co-culture studies. To determine the contractility of SMCs embedded within collagen hydrogels, we performed polarized light imaging and subsequent analysis based on Mueller matrices. Measurements were made both in the absence and presence of endothelial cells (ECs) in order to establish the impact of EC-SMC communication on SMC contractility. The results demonstrated that Mueller polarimetric imaging is indeed an appropriate tool for assessing SMC activity which significantly modifies the hydrogel retardance in the presence of ECs. These findings are consistent with the idea that EC-SMC communication promotes a more contractile SMC phenotype. More broadly, our findings suggest that Mueller polarimetry can be a useful tool for studies of spatial heterogeneities in hydrogel remodeling by SMCs.

Exosomal LINC00174 derived from vascular endothelial cells attenuates myocardial I/R injury via p53-mediated autophagy and apoptosis

In this study, we aim to investigate the regulation of specific long non-coding RNAs (lncRNAs) on the progression of ischemia/reperfusion (I/R) injury. We identified and characterized the exosomes derived from mouse primary aortic endothelial cells. Subsequently, we found that these exosomes expressed typical exosomal markers and high levels of LINC00174, which significantly ameliorated I/R-induced myocardial damage and suppressed the apoptosis, vacuolation, and autophagy of myocardial cells. Mechanistic approaches revealed that LINC00174 directly interacted with SRSF1 to suppress the expression of p53, thus restraining the transcription of myocardin and repressing the activation of the Akt/AMPK pathway that was crucial for autophagy initiation in I/R-induced myocardial damage. Moreover, this molecular mechanism was verified by in vivo study. In summary, exosomal LINC00174 generated from vascular endothelial cells repressed p53-mediated autophagy and apoptosis to mitigate I/R-induced myocardial damage, suggesting that targeting LINC00174 may be a novel strategy to treat I/R-induced myocardial infarction.

MicroRNA regulation of vascular smooth muscle cells and its significance in cardiovascular diseases

Cardiovascular disease (CVD) is among the leading causes of death worldwide. MicroRNAs (miRNAs), regulatory molecules that repress protein expression, have attracted considerable attention in CVD research. The vasculature plays a big role in CVD development and progression and dysregulation of vascular cells underlies the root of many vascular diseases. This review provides a brief introduction of the biogenesis of miRNAs and exosomes, followed by overview of the regulatory mechanisms of miRNAs in vascular smooth muscle cells (VSMCs) intracellular signaling during phenotypic switching, senescence, calcification, and neointimal hyperplasia. Evidence of extracellular signaling of VSMCs and other cells via exosomal and circulating miRNAs is also presented. Lastly, current drawbacks and limitations of miRNA studies in CVD research and potential ways to overcome these disadvantages are discussed in detail. In-depth understanding of VSMC regulation via miRNAs will add substantial knowledge and advance research in diagnosis, disease progression, and (or) miRNA-derived therapeutic approaches in CVD research.

Roles of exosomal miRNA in vascular aging

Aging is a major risk factor for human diseases. As global average life expectancy has lengthened, delaying or reducing aging and age-related diseases has become an urgent issue for improving the quality of life. The vascular aging process represents an important link between aging and age-related diseases. Exosomes are small extracellular vesicles (EV) that can be secreted by almost all eukaryotic cells, and they deliver characteristic biological information about donor cells to regulate the cellular microenvironment, mediate signal transmission between neighboring or distant cells, and affect the expression of target genes in recipient cells. Many recent studies have shown that exosomal microribonucleic acids (miRNA) are involved in the regulation of vascular aging by participating in the physiological functions of vascular cells and the destruction and remodeling of the extracellular matrix (ECM). This review summarizes the regulatory functions of exosomal miRNA in vascular aging because they interact with the ECM, and participate in vascular cell senescence, and the regulation of senescence-related functions such as proliferation, migration, apoptosis, inflammation, and differentiation.

Extracellular Vesicle-Mediated Vascular Cell Communications in Hypertension: Mechanism Insights and Therapeutic Potential of ncRNAs

Hypertension, a chronic and progressive disease, is an outstanding public health issue that affects nearly 40% of the adults worldwide. The increasing prevalence of hypertension is one of the leading causes of cardiovascular morbidity and mortality. Despite of the available treatment medications, an increasing number of hypertensive individuals continues to have uncontrolled blood pressure. In the vasculature, endothelial cells, vascular smooth muscle cells (VSMCs), and adventitial fibroblasts play a fundamental role in vascular homeostasis. The aberrant interactions between vascular cells might lead to hypertension and vascular remodeling. Identification of the precise mechanisms of vascular remodeling may be highly required to develop effective therapeutic approaches for hypertension. Recently, extracellular vesicle-mediated transfer of proteins or noncoding RNAs (ncRNAs) between vascular cells holds promise for the treatment of hypertension. Especially, extracellular vesicle-packaging ncRNAs have gained enormous attention of basic and clinical scientists because of their tremendous potential to act as novel clinical biomarkers and therapeutic targets of hypertension. Here we will discuss the current findings focusing on the emerging roles of extracellular vesicle-carrying ncRNAs in the pathologies of hypertension and its associated vascular remodeling. Furthermore, we will highlight the potential of extracellular vesicles and ncRNAs as biomarkers and therapeutic targets for hypertension. The future research directions on the challenges and perspectives of extracellular vesicles and ncRNAs in hypertensive vascular remodeling are also proposed.

Involvement of Myeloid Cells and Noncoding RNA in Abdominal Aortic Aneurysm Disease

Significance: Abdominal aortic aneurysm (AAA) is a potentially fatal condition, featuring the possibility of high-mortality rupture. To date, prophylactic surgery by means of open surgical repair or endovascular aortic repair at specific thresholds is considered standard therapy. Both surgical options hold different risk profiles of short- and long-term morbidity and mortality. Targeting early stages of AAA development to decelerate disease progression is desirable. Recent Advances: Understanding the pathomechanisms that initiate formation, maintain growth, and promote rupture of AAA is crucial to developing new medical therapeutic options. Inflammatory cells, in particular macrophages, have been investigated for their contribution to AAA disease for decades, whereas evidence on lymphocytes, mast cells, and neutrophils is sparse. Recently, there has been increasing interest in noncoding RNAs (ncRNAs) and their involvement in disease development, including AAA. Critical Issues: The current evidence on myeloid cells and ncRNAs in AAA largely originates from small animal models, making clinical extrapolation difficult. Although it is feasible to collect surgical human AAA samples, these tissues reflect end-stage disease, preventing examination of critical mechanisms behind early AAA formation. Future Directions: Gaining more insight into how myeloid cells and ncRNAs contribute to AAA disease, particularly in early stages, might suggest nonsurgical AAA treatment options. The utilization of large animal models might be helpful in this context to help bridge translational results to humans.

Uncovering the Potential Differentially Expressed miRNAs and mRNAs in Ischemic Stroke Based on Integrated Analysis in the Gene Expression Omnibus Database

INTRODUCTION

Ischemic stroke is the third leading cause of death. There is no known treatment or cure for the disease. Moreover, the pathological mechanism of ischemic stroke remains unclear.

OBJECTIVE

We aimed to identify potential microRNAs (miRNAs) and mRNAs, contributing to understanding the pathology of ischemic stroke.

METHODS

First, the data of miRNA and mRNA were downloaded for differential expression analysis. Then, the regulatory network between miRNA and mRNAs was constructed. Third, top 100 differentially expressed mRNAs were used to construct a protein-protein interaction network followed by the function annotation of mRNAs. In addition, in vitro experiment was used to validate the expression of mRNAs. Last, receiver operating characteristic diagnostic analysis of differentially methylated genes was performed.

RESULTS

Totally, up to 26 differentially expressed miRNAs and 1,345 differentially expressed mRNAs were identified. Several regulatory interaction pairs between miRNA and mRNAs were identified, such as hsa-miR-206-HMGCR/PICALM, hsa-miR-4491-TMEM97, hsa-miR-3622b-5p/hsa-miR-548k-KLF12, and hsa-miR-302a-3p/hsa-miR-3145-3p-CTSS. MAPK signaling pathway (involved DUSP1) and the Notch signaling pathway (involved NUMB and CREBBP) were identified. The expression validation of KLF12, ARG1, ITGAM, SIRT4, SERPINH1, and DUSP1 was consistent with the bioinformatics analysis. Interestingly, hsa-miR-206, hsa-miR-4491, hsa-miR-3622b-5p, hsa-miR-548k, hsa-miR-302a-3p, hsa-miR-3145-3p, KLF12, and ID3 had the potential diagnostic value of ischemic stroke.

CONCLUSIONS

The identified differentially expressed miRNAs and mRNAs may be associated with the development of ischemic stroke.

Extracellular vesicle signalling in atherosclerosis

Atherosclerosis is a major cardiovascular disease and in 2016, the World Health Organisation (WHO) estimated 17.5 million global deaths, corresponding to 31% of all global deaths, were driven by inflammation and deposition of lipids into the arterial wall. This leads to the development of plaques which narrow the vessel lumen, particularly in the coronary and carotid arteries. Atherosclerotic plaques can become unstable and rupture, leading to myocardial infarction or stroke. Extracellular vesicles (EVs) are a heterogeneous population of vesicles secreted from cells with a wide range of biological functions. EVs participate in cell-cell communication and signalling via transport of cargo including enzymes, DNA, RNA and microRNA in both physiological and patholophysiological settings. EVs are present in atherosclerotic plaques and have been implicated in cellular signalling processes in atherosclerosis development, including immune responses, inflammation, cell proliferation and migration, cell death and vascular remodeling during progression of the disease. In this review, we summarise the current knowledge regarding EV signalling in atherosclerosis progression and the potential of utilising EV signatures as biomarkers of disease.

Differential Expression and Bioinformatics Analysis of CircRNA in PDGF-BB-Induced Vascular Smooth Muscle Cells

Atherosclerosis is mediated by various factors and plays an important pathological foundation for cardiovascular and cerebrovascular diseases. Abnormal vascular smooth muscle cells (VSMCs) proliferation and migration have an essential role in atherosclerotic lesion formation. Circular RNAs (circRNA) have been widely detected in different species and are closely related to various diseases. However, the expression profiles and molecular regulatory mechanisms of circRNAs in VSMCs are still unknown. We used high-throughput RNA-seq as well as bioinformatics tools to systematically analyze circRNA expression profiles in samples from different VSMC phenotypes. Polymerase chain reaction (PCR), Sanger sequencing, and qRT-PCR were performed for circRNA validation. A total of 22191 circRNAs corresponding to 6273 genes (host genes) in the platelet-derived growth factor (PDGF-BB) treated group, the blank control group or both groups, were detected, and 112 differentially expressed circRNAs were identified between the PDGF-BB treated and control groups, of which 59 were upregulated, and 53 were downregulated. We selected 9 circRNAs for evaluation of specific head-to-tail splicing, and 10 differentially expressed circRNAs between the two groups for qRT-PCR validation. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses enrichment analyses revealed that the parental genes of the circRNAs mainly participated in cardiac myofibril assembly and positive regulation of DNA-templated transcription, indicating that they might be involved in cardiovascular diseases. Finally, we constructed a circRNA-miRNA network based on the dysregulated circRNAs and VSMC-related microRNAs. Our study is the first to show the differential expression of circRNAs in PDGF-BB-induced VSMCs and may provide new ideas and targets for the prevention and therapy of vascular diseases.

Targeting endothelial exosomes for the prevention of cardiovascular disease

Exosomes are small lipid bilayer-enclosed 30-140 nm diameter vesicles formed from endosomes. Exosomes are secreted by various cell types including endothelial cells, immune cells and other cardiovascular tissues, and they can be detected in plasma, urine, cerebrospinal fluid, as well as tissues. Exosomes were initially regarded as a disposal mechanism to discard unwanted materials from cells. Recent studies suggest that exosomes play an important role in mediating of intercellular communication through the delivery and transport of cellular components such as nucleic acids, lipids, and proteins and thus regulate cardiovascular disease. Further, the underlying mechanisms by which abnormally released exosomes promote cardiovascular disease are not well understood. This review highlights recent studies involving endothelial exosomes, gives a brief overview of exosome biogenesis and release, isolation and identification of exosomes, and provides a contemporary understanding of the endothelial exosome pathophysiology and potential therapeutic strategies.

CircRNA-0077930 from hyperglycaemia-stimulated vascular endothelial cell exosomes regulates senescence in vascular smooth muscle cells

Vascular smooth muscle aging leads to diabetic complications such as cardiovascular and kidney diseases or diabetic foot. Therefore, understanding the mechanism of smooth muscle cell senescence in a high-glucose (HG) environment is essential. The purpose of this study was to determine whether and how circRNA from human umbilical vein endothelial cell exosomes (HUVEC-Exos) under HG conditions regulates the senescence of vascular smooth muscle cells (VSMCs). Combining circRNA array analysis and bioinformatics, we postulated that the circRNA-0077930-miR-622-Kras CeRNA network plays an important role in inducing senescence in VSMCs. CircRNA-0077930 transmitted by HG-HUVEs-Exos induced senescence of VSMCs by down-regulation of miR-622 expression and up-regulation of Kras, p21, p53 and p16 expression. Moreover, the lactate dehydrogenase (LDH) activity was significantly increased while anti-oxidative stress marker (superoxide dismutase, SOD) activity was reduced in HG-HUVEC-Exos treatment VSMCs. Finally, HG-HUVEC-Exos with depleted-circRNA-0077930 is no longer able to induce cellular senescence in VSMCs. These findings provided a new light on the effective treatment of VSMC senescence. SIGNIFICANCE OF THE STUDY: Previous studies have shown that endothelial cell senescence is closely related to smooth muscle cell aging. Here, for the first time, we proved that the HG-HUVECs derived exosomes induced the VSMCs senescence by circRNA0077930-miR622-Kras CeRNA network. The circRNA-0077930-depleted exosomes would lose the ability to promote cellular senescence of VSMCs.

Targeting Vascular Calcification in Chronic Kidney Disease

Cardiovascular (CV) disease remains an important cause of morbidity and mortality for patients with chronic kidney disease (CKD). Although clustering of traditional risk factors with CKD is well recognized, kidney-specific mechanisms are believed to drive the disproportionate burden of CV disease. One perturbation that is frequently observed at high rates in patients with CKD is vascular calcification, which may be a central mediator for an array of CV sequelae. This review summarizes the pathophysiological bases of intimal and medial vascular calcification in CKD, current strategies for diagnosis and management, and posits vascular calcification as a risk marker and therapeutic target.

Spheroids of Endothelial Cells and Vascular Smooth Muscle Cells Promote Cell Migration in Hyaluronic Acid and Fibrinogen Composite Hydrogels

Cell migration plays a pivotal role in many pathological and physiological processes. So far, most of the studies have been focused on 2-dimensional cell adhesion and migration. Herein, the migration behaviors of cell spheroids in 3D hydrogels obtained by polymerization of methacrylated hyaluronic acid (HA-MA) and fibrinogen (Fg) with different ratios were studied. The Fg could be released to the medium gradually along with time prolongation, achieving the dynamic change of hydrogel structures and properties. Three types of cell spheroids, i.e., endothelial cell (EC), smooth muscle cell (SMC), and EC-SMC spheroids, were prepared with 10,000 cells in each, whose diameters were about 343, 108, and 224 μm, respectively. The composite hydrogels with an intermediate ratio of Fg allowed the fastest 3D migration of cell spheroids. The ECs-SMCs migrated longest up to 3200 μm at day 14, whereas the SMC spheroids migrated slowest with a distance of only ~400 μm at the same period of time. The addition of free RGD or anti-CD44 could significantly reduce the migration distance, revealing that the cell-substrate interactions take the major roles and the migration is mesenchymal dependent. Moreover, addition of anti-N-cadherin and MMP inhibitors also slowed down the migration rate, demonstrating that the degradation of hydrogels and cell-cell interactions are also largely involved in the cell migration. RT-PCR measurement showed that expression of genes related to cell adhesion and antiapoptosis, and angiogenesis was all upregulated in the EC-SMC spheroids than single EC or SMC spheroids, suggesting that the use of composite cell spheroids is more promising to promote cell-substrate interactions and maintenance of cell functions.

Roles and Functions of Exosomal Non-coding RNAs in Vascular Aging

Aging is a progressive loss of physiological integrity and functionality process which increases susceptibility and mortality to diseases. Vascular aging is a specific type of organic aging. The structure and function changes of endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) are the main cause of vascular aging, which could influence the threshold, process, and severity of vascular related diseases. Accumulating evidences demonstrate that exosomes serve as novel intercellular information communicator between cell to cell by delivering variety biologically active cargos, especially exosomal non-coding RNAs (ncRNAs), which are associated with most of aging-related biological and functional disorders. In this review, we will summerize the emerging roles and mechanisms of exosomal ncRNAs in vascular aging and vascular aging related diseases, focusing on the role of exosomal miRNAs and lncRNAs in regulating the functions of ECs and VSMCs. Moreover, the relationship between the ECs and VSMCs linked by exosomes, the potential diagnostic and therapeutic application of exosomes in vascular aging and the clinical evaluation and treatment of vascular aging and vascular aging related diseases will also be discussed.

Non-coding RNAs: key regulators of smooth muscle cell fate in vascular disease

The vascular smooth muscle cell (SMC) is one of the most plastic cells in the body. Understanding how non-coding RNAs (ncRNAs) regulate SMC cell-fate decision making in the vasculature has significantly enhanced our understanding of disease development, and opened up exciting new avenues for potential therapeutic applications. Recent studies on SMC physiology have in addition challenged our traditional view on their role and contribution to vascular disease, mainly in the setting of atherosclerosis as well as aneurysm disease, and restenosis after angioplasties. The impact of SMC behaviour on vascular disease is now recognized to be context dependent; SMC proliferation and migration can be harmful or beneficial, whereas their apoptosis, senescence, and switching into a more macrophage-like phenotype can promote inflammation and disease progression. This is in particular true for atherosclerosis-related diseases, where proliferation of SMCs was believed to promote lesion formation, but may also prevent plaque rupture by stabilizing the fibrous cap. Based on newer findings of genetic lineage tracing studies, it was revealed that SMC phenotypic switching can result in less-differentiated forms that lack classical SMC markers while exhibiting functions more related to macrophage-like cells. This switching can directly promote atherogenesis. The aim of this current review is to summarize and discuss how ncRNAs (mainly microRNAs and long ncRNAs) are involved in SMC plasticity, and how they directly affect vascular disease development and progression. Finally, we want to critically assess where potential future therapies could be useful to influence the burden of vascular diseases.

Biology and Role of Extracellular Vesicles (EVs) in the Pathogenesis of Thrombosis

Extracellular vesicles (EVs) are well-established mediators of cell-to-cell communication. EVs can be released by every cell type and they can be classified into three major groups according to their biogenesis, dimension, density, and predominant protein markers: exosomes, microvesicles, and apoptotic bodies. During their formation, EVs associate with specific cargo from their parental cell that can include RNAs, free fatty acids, surface receptors, and proteins. The biological function of EVs is to maintain cellular and tissue homeostasis by transferring critical biological cargos to distal or neighboring recipient cells. On the other hand, their role in intercellular communication may also contribute to the pathogenesis of several diseases, including thrombosis. More recently, their physiological and biochemical properties have suggested their use as a therapeutic tool in tissue regeneration as well as a novel option for drug delivery. In this review, we will summarize the impact of EVs released from blood and vascular cells in arterial and venous thrombosis, describing the mechanisms by which EVs affect thrombosis and their potential clinical applications.

MicroRNA-26a: An Emerging Regulator of Renal Biology and Disease

MicroRNAs (miRNAs) are short, single-stranded, noncoding RNAs that modulate many key biological processes by simultaneously suppressing multiple target genes. Among them, miR-26a, a conserved miRNA among vertebrates, is highly expressed in various tissues. Accumulating evidence demonstrates that miR-26a plays pivotal roles in cellular differentiation, cell growth, apoptosis, and metastasis, thereby participating in the initiation and development of various human diseases, such as metabolic disease and cancer. More recently, miR-26a was found as a versatile regulator of renal biology and disease. miR-26a is intensively involved in the maintenance of podocyte homeostasis and the actin cytoskeleton. It is also able to modulate the homeostasis and function of mesangial cells. In addition, miR-26a affects the expansion of regulatory T cells in the context of ischemia-reperfusion injury and autoimmune diabetes and thus protects the renal system from immune attack. These available data strongly suggest that renal miR-26a possesses critical pathological functions and represents a potential target for renal disease therapies. This review summarizes current knowledge of miR-26a in renal biology and disease, laying the foundation for exploring its previously unknown functions and mechanisms in the renal system.

Endothelial cell-derived small extracellular vesicles suppress cutaneous wound healing through regulating fibroblasts autophagy

Diabetic foot ulcer is a life-threatening clinical problem in diabetic patients. Endothelial cell-derived small extracellular vesicles (sEVs) are important mediators of intercellular communication in the pathogenesis of several diseases. However, the exact mechanisms of wound healing mediated by endothelial cell-derived sEVs remain unclear. sEVs were isolated from human umbilical vein endothelial cells (HUVECs) pretreated with or without advanced glycation end products (AGEs). The roles of HUVEC-derived sEVs on the biological characteristics of skin fibroblasts were investigated both in vitro and in vivo We demonstrate that sEVs derived from AGEs-pretreated HUVECs (AGEs-sEVs) could inhibit collagen synthesis by activating autophagy of human skin fibroblasts. Additionally, treatment with AGEs-sEVs could delay the wound healing process in Sprague-Dawley (SD) rats. Further analysis indicated that miR-106b-5p was up-regulated in AGEs-sEVs and importantly, in exudate-derived sEVs from patients with diabetic foot ulcer. Consequently, sEV-mediated uptake of miR-106b-5p in recipient fibroblasts reduces expression of extracellular signal-regulated kinase 1/2 (ERK1/2), resulting in fibroblasts autophagy activation and subsequent collagen degradation. Collectively, our data demonstrate that miR-106b-5p could be enriched in AGEs-sEVs, then decreases collagen synthesis and delays cutaneous wound healing by triggering fibroblasts autophagy through reducing ERK1/2 expression.

Exosomes from hyperglycemia-stimulated vascular endothelial cells contain versican that regulate calcification/senescence in vascular smooth muscle cells

Background

To determine whether and how exosomes from human umbilical vein endothelial cells (HUVEC-Exos) regulates vascular smooth muscle cells (VSMCs) calcification/senescence in high glucose condition.

Methods

HUVEC-Exos were isolated from normal glucose (NG) and high glucose (HG) stimulated HUVECs (NG/HG-HUVEC-Exos) by super speed centrifugation. HUVEC-Exos were identified by transmission electron microscopy and Western blot of CD63. Protein profile in HUVEC-Exos was examined to screen the candidate molecules that mediate HUVEC-Exos function. VSMCs were incubated with HUVEC-Exos. A series of functional assays in vitro were performed to assess the effects of HUVEC-Exos on the calcification/senescence of VSMCs. The role of the candidate protein in HUVEC-Exos-induced VSMCs dysfunction was assessed.

Results

Exosomes isolated from HG-HUVEC-Exos induced calcification/senescence in VSMCs as assessed by Alizarin Red Staining, senescence-associated β-galactosidase (SA-β-gal) staining, and the expression of ALP and p21. HG-HUVEC-Exos significantly increased LDH activity, as well as the product of lipid peroxidation (MDA content), and decreased oxidative stress marker activity, as compared with NG-HUVEC-Exos. Moreover, mechanism studies showed that mitochondrial membrane potential and the expression levels of mitochondrial function related protein HADHA and Cox-4 were significantly decreased in HG-HUVEC-Exos compared to controls. Proteomic analysis showed that HG-HUVEC-Exos consisted of higher level of versican (VCAN), as compared with NG-HUVEC-Exos. Observation under laser confocal microscopy revealed that most green fluorescence of VCAN could overlap with the red fluorescence came from mitochondria, indicating VCAN is mainly localized to the mitochondria of VSMCs. Knockdown of VCAN with siRNA in HUVECs, inhibited HG-HUVEC-Exos-induced mitochondrial dysfunction and calcification/senescence of VSMCs.

Conclusions

Our data indicate an intracellular role for VCAN in VSMCs. VCAN participates in hyperglycemia-induced calcification/senescence via modulation of mitochondrial function in VSMCs.

Electronic supplementary material

The online version of this article (10.1186/s13578-018-0263-x) contains supplementary material, which is available to authorized users.

Initiation and Propagation of Vascular Calcification Is Regulated by a Concert of Platelet- and Smooth Muscle Cell-Derived Extracellular Vesicles

The ageing population continues to suffer from its primary killer, cardiovascular disease (CVD). Despite recent advances in interventional medicinal and surgical therapies towards the end of the 20th century, the epidemic of cardiovascular disease has not been halted. Yet, rather than receding globally, the burden of CVD has risen to become a top cause of morbidity and mortality worldwide. Most CVD arises from thrombotic rupture of an atherosclerotic plaque, the pathologic thickening of coronary and carotid artery segments and subsequent distal ischemia in heart or brain. In fact, one-fifth of deaths are directly attributable to thrombotic rupture of a vulnerable plaque. Atherosclerotic lesion formation is caused by a concert of interactions between circulating leukocytes and platelets, interacting with the endothelial barrier, signalling into the arterial wall by the release of cytokines and extracellular vesicles (EVs). Both platelet- and cell-derived EVs represent a novel mechanism of cellular communication, particularly by the transport and transfer of cargo and by reprogramming of the recipient cell. These interactions result in phenotypic switching of vascular smooth muscle cells (VSMCs) causing migration and proliferation, and subsequent secretion of EVs. Loss of VSMCs attracts perivascular Mesenchymal Stem Cells (MSCs) from the adventitia, which are a source of VSMCs and contribute to repair after vascular injury. However, continuous stress stimuli eventually switch phenotype of cells into osteochondrogenic VSMCs facilitating vascular calcification. Although Virchow’s triad is over 100 years old, it is a reality that is accurate today. It can be briefly summarised as changes in the composition of blood (platelet EVs), alterations in the vessel wall (VSMC phenotypic switching, MSC infiltration and EV release) and disruption of blood flow (atherothrombosis). In this paper, we review the latest relevant advances in the identification of extracellular vesicle pathways as well as VSMCs and pericyte/MSC phenotypic switching, underlying vascular calcification.

DFMG reverses proliferation and migration of vascular smooth muscle cells induced by co-culture with injured vascular endothelial cells via suppression of the TLR4-mediated signaling pathway

7-Difluoromethoxy-5,4′-dimethoxy-genistein (DFMG) is a novel chemical compound synthesized using genistein. Previous studies have indicated that DFMG can reverse the apoptosis of vascular endothelial cells (VECs) by regulating the mitochondrial apoptosis pathway. The present study aimed to investigate the activity and molecular mechanism underlying DFMG-mediated protection of vascular smooth muscle cell (VSMCs) using a non-contact co-culture model established by using Transwell insert. Secretion of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were measured by ELISA. Proliferation and migration of VSMCs were assessed using a Cell Counting kit-8 and wound healing assays, respectively. Toll-like receptor 4 (TLR4) mRNA and protein levels were detected by reverse transcription-quantitative polymerase chain reaction and western blotting analyses, respectively. In the present study, lysophosphatidylcholine (LPC) significantly increased the secretion of IL-6 and TNF-α in VECs. VECs treated with LPC markedly increased proliferation and migration of VSMCs, which were inhibited by DFMG. Transfection of either TLR4 short hairpin RNA (shRNA) or TLR4 cDNA in VECs inhibited and increased proliferation and migration of VSMCs, respectively. Furthermore, transfection of VECs with TLR4 shRNA suppressed the proliferation and migration of VSMCs induced by co-culture with injured VECs, which was further enhanced by treatment with DFMG. By contrast, transfection of VECs with TLR4 cDNA enhanced proliferation and migration of VSMCs and this effect was inhibited by treatment with DFMG. Taken together, the results of the present study demonstrated that DFMG can reverse proliferation and migration of VSMCs induced by co-culture with injured VECs via suppression of the TLR4-mediated signaling pathway.

microRNA-mediated regulation of splicing factors SRSF1, SRSF2 and hnRNP A1 in context of their alternatively spliced 3'UTRs

SRSF1, SRSF2 and hnRNP A1 are splicing factors that regulate the expression of oncogenes and tumor suppressors. SRSF1 and SRSF2 contribute to the carcinogenesis in the kidney. Despite their importance, the mechanisms regulating their expression in cancer are not entirely understood. Here, we investigated the microRNA-mediated regulation of SRSF1, SRSF2 and hnRNP A1 in renal cancer. The expression of microRNAs predicted to target SRSF1, SRSF2 and hnRNP A1 was disturbed in renal tumors compared with controls. Using qPCR, Western blot/ICC and luciferase reporter system assays we identified microRNAs that contribute to the regulation of expression of SRSF1 (miR-10b-5p, miR-203a-3p), SRSF2 (miR-183-5p, miR-200c-3p), and hnRNP A1 (miR-135a-5p, miR-149-5p). Silencing of SRSF1 and SRSF2 enhanced the expression of their targeting microRNAs. miR-183-5p and miR-200c-3p affected the expression of SRSF2-target genes, TNFRSF1B, TNFRSF9, CRADD and TP53. 3'UTR variants of SRSF1 and SRSF2 differed by the presence of miRNA-binding sites. In conclusion, we identified a group of microRNAs that contribute to the regulation of expression of SRSF1, SRSF2 and hnRNP A1. The microRNAs targeting SRSF1 and SRSF2 are involved in a regulatory feedback loop. microRNAs miR-183-5p and miR-200c-3p that target SRSF2, affect the expression of genes involved in apoptotic regulation.

miRNA-181a/b Regulates Phenotypes of Vessel Smooth Muscle Cells Through Serum Response Factor

The phenotypic modulation of vessel smooth muscle cells (VSMCs) plays a crucial role in the physiological and pathological conditions of vasculature in response to local environmental changes. The phenotypic transition of VSMCs is largely modulated by the serum response factor (SRF). miR-181a and miR-181b are members of the well-studied miR-181 family and both have complementary sequence in the 3' untranslated region (UTR) of SRF gene. In this article, evidence insinuates that miR-181a/b was involved in VSMCs differentiation through upregulating synthetic marker genes and downregulating contractile ones, respectively. We also confirmed the roles of the miR-181a/b in promoting SMC proliferation, migration, and synthetic phenotype transformation. In addition, miR-181a/b was indicated as directly targeting at 3' UTR of SRF by dual-luciferase assay and Western blot assay. In a word, miR-181a/b is one of the factors involved in VSMC differentiation toward a synthetic phenotype through targeting at SRF. These findings may provide a potential therapeutic approach that miR-181a/b took part in regulating the vessel disorders.

Role of noncoding RNA in vascular remodelling

PURPOSE OF REVIEW

Noncoding RNAs (ncRNAs), such as microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) are becoming fundamentally important in the pathophysiology relating to injury-induced vascular remodelling. We highlight recent studies that demonstrate the involvement of ncRNAs in vein graft disease, in in-stent restenosis and in pulmonary arterial hypertension, with a particular focus on endothelial cell and vascular smooth muscle cell function. We also briefly discuss the emerging role of exosomal-derived ncRNAs and how this mechanism impacts on vascular function.

RECENT FINDINGS

ncRNAs have been described as novel regulators in the pathophysiology of vascular injury, inflammation, and vessel wall remodelling. In particular, several studies have demonstrated that manipulation of miRNAs can reduce the burden of pathological vascular remodelling. Such studies have also shown that exosomal miRNA-mediated, cell-to-cell communication between endothelial cells and vascular smooth muscle cells is critical in the disease process. In addition to miRNAs, lncRNAs are emerging as regulators of vascular function in health and disease. Although lncRNAs are complex in both their sheer numbers and mechanisms of action, identifying their contribution to vascular disease is essential.

SUMMARY

Given the important roles of ncRNAs in vascular injury and remodelling together will their capacity for cell-to-cell communication, manipulating ncRNA might provide novel therapeutic interventions.

MiRNAs in Astrocyte-Derived Exosomes as Possible Mediators of Neuronal Plasticity

Astrocytes use gliotransmitters to modulate neuronal function and plasticity. However, the role of small extracellular vesicles, called exosomes, in astrocyte-to-neuron signaling is mostly unknown. Exosomes originate in multivesicular bodies of parent cells and are secreted by fusion of the multivesicular body limiting membrane with the plasma membrane. Their molecular cargo, consisting of RNA species, proteins, and lipids, is in part cell type and cell state specific. Among the RNA species transported by exosomes, microRNAs (miRNAs) are able to modify gene expression in recipient cells. Several miRNAs present in astrocytes are regulated under pathological conditions, and this may have far-reaching consequences if they are loaded in exosomes. We propose that astrocyte-derived miRNA-loaded exosomes, such as miR-26a, are dysregulated in several central nervous system diseases; thus potentially controlling neuronal morphology and synaptic transmission through validated and predicted targets. Unraveling the contribution of this new signaling mechanism to the maintenance and plasticity of neuronal networks will impact our understanding on the physiology and pathophysiology of the central nervous system.