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BACKGROUND: Abdominal aortic aneurysm (AAA) is a catastrophic disease with little effective therapy, likely due to the limited understanding of the mechanisms underlying AAA development and progression. ATF3 (activating transcription factor 3) has been increasingly recognized as a key regulator of cardiovascular diseases. However, the role of ATF3 in AAA development and progression remains elusive. METHODS: Genome-wide RNA sequencing analysis was performed on the aorta isolated from saline or Ang II (angiotensin II)-induced AAA mice, and ATF3 was identified as the potential key gene for AAA development. To examine the role of ATF3 in AAA development, vascular smooth muscle cell-specific ATF3 knockdown or overexpressed mice by recombinant adeno-associated virus serotype 9 vectors carrying ATF3, or shRNA-ATF3 with SM22α (smooth muscle protein 22-α) promoter were used in Ang II-induced AAA mice. In human and murine vascular smooth muscle cells, gain or loss of function experiments were performed to investigate the role of ATF3 in vascular smooth muscle cell proliferation and apoptosis. RESULTS: In both Ang II-induced AAA mice and patients with AAA, the expression of ATF3 was reduced in aneurysm tissues but increased in aortic lesion tissues. The deficiency of ATF3 in vascular smooth muscle cell promoted AAA formation in Ang II-induced AAA mice. PDGFRB (platelet-derived growth factor receptor ß) was identified as the target of ATF3, which mediated vascular smooth muscle cell proliferation in response to TNF-alpha (tumor necrosis factor-α) at the early stage of AAA. ATF3 suppressed the mitochondria-dependent apoptosis at the advanced stage by upregulating its direct target BCL2. Our chromatin immunoprecipitation results also demonstrated that the recruitment of NFκB1 and P300/BAF/H3K27ac complex to the ATF3 promoter induces ATF3 transcription via enhancer activation. NFKB1 inhibitor (andrographolide) inhibits the expression of ATF3 by blocking the recruiters NFKB1 and ATF3-enhancer to the ATF3-promoter region, ultimately leading to AAA development. CONCLUSIONS: Our results demonstrate a previously unrecognized role of ATF3 in AAA development and progression, and ATF3 may serve as a novel therapeutic and prognostic marker for AAA.
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Factor de Transcripción Activador 3 , Aneurisma de la Aorta Abdominal , Músculo Liso Vascular , Miocitos del Músculo Liso , Factor de Transcripción Activador 3/genética , Factor de Transcripción Activador 3/metabolismo , Animales , Aneurisma de la Aorta Abdominal/metabolismo , Aneurisma de la Aorta Abdominal/patología , Aneurisma de la Aorta Abdominal/genética , Aneurisma de la Aorta Abdominal/inducido químicamente , Humanos , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patología , Miocitos del Músculo Liso/metabolismo , Miocitos del Músculo Liso/patología , Ratones , Masculino , Ratones Endogámicos C57BL , Apoptosis , Células Cultivadas , Angiotensina II , Proliferación Celular , Aorta Abdominal/patología , Aorta Abdominal/metabolismo , Modelos Animales de EnfermedadRESUMEN
BACKGROUND: The integration of single-cell RNA sequencing data from multiple experimental batches and diverse biological conditions holds significant importance in the study of cellular heterogeneity. RESULTS: To expedite the exploration of systematic disparities under various biological contexts, we propose a scRNA-seq integration method called scDisco, which involves a domain-adaptive decoupling representation learning strategy for the integration of dissimilar single-cell RNA data. It constructs a condition-specific domain-adaptive network founded on variational autoencoders. scDisco not only effectively reduces batch effects but also successfully disentangles biological effects and condition-specific effects, and further augmenting condition-specific representations through the utilization of condition-specific Domain-Specific Batch Normalization layers. This enhancement enables the identification of genes specific to particular conditions. The effectiveness and robustness of scDisco as an integration method were analyzed using both simulated and real datasets, and the results demonstrate that scDisco can yield high-quality visualizations and quantitative outcomes. Furthermore, scDisco has been validated using real datasets, affirming its proficiency in cell clustering quality, retaining batch-specific cell types and identifying condition-specific genes. CONCLUSION: scDisco is an effective integration method based on variational autoencoders, which improves analytical tasks of reducing batch effects, cell clustering, retaining batch-specific cell types and identifying condition-specific genes.
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Aprendizaje , Análisis de Expresión Génica de una Sola Célula , Análisis por Conglomerados , ARN , Análisis de la Célula Individual , Análisis de Secuencia de ARN , Perfilación de la Expresión Génica , AlgoritmosRESUMEN
The epicardium provides epicardial-derived cells and molecular signals to support cardiac development and regeneration. Zebrafish and mouse studies have shown that ccm2, a cerebral cavernous malformation disease gene, is essential for cardiac development. Endocardial cell-specific deletion of Ccm2 in mice has previously established that Ccm2 is essential for maintenance of the cardiac jelly for cardiac development during early gestation. The current study aimed to explore the function of Ccm2 in epicardial cells for heart development and regeneration. Through genetic deletion of Ccm2 in epicardial cells, our in vivo and ex vivo experiments revealed that Ccm2 is required by epicardial cells to support heart development. Ccm2 regulates epicardial cell adhesion, cell polarity, cell spreading, and migration. Importantly, the loss of Ccm2 in epicardial cells delays cardiac function recovery and aggravates cardiac fibrosis following myocardial infarction. Molecularly, Ccm2 targets the production of cytoskeletal and matrix proteins to maintain epicardial cell function and behaviors. Epicardial Ccm2 plays a critical role in heart development and regeneration via its regulation of cytoskeleton reorganization.
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Equilibrio Ácido-Base , Diferenciación Celular , Factores de Transcripción Forkhead , Animales , Factores de Transcripción Forkhead/metabolismo , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/fisiología , Ratones , Equilibrio Ácido-Base/fisiología , Proteínas Represoras/metabolismo , Proteínas Represoras/genética , Riñón/citología , Riñón/metabolismoRESUMEN
MicroRNAs (miRNAs) are increasingly recognised as key regulators of the development and progression of many diseases due to their ability to modulate gene expression post-translationally. While this makes them an attractive therapeutic target, clinical application of miRNA therapy remains at an early stage and in part is limited by the lack of effective delivery modalities. Here, we determined the feasibility of delivering miRNA using a new class of plasma-polymerised nanoparticles (PPNs), which we have recently isolated and characterised. We showed that PPN-miRNAs have no significant effect on endothelial cell viability in vitro in either normal media or in the presence of high-glucose conditions. Delivery of a miRNA inhibitor targeting miR-503 suppressed glucose-induced miR-503 upregulation and restored the downstream mRNA expression of CCNE1 and CDC25a in endothelial cells. Subsequently, PPN delivery of miR-503 inhibitors enhanced endothelial angiogenesis, including tubulogenesis and migration, in culture conditions that mimic diabetic ischemia. An intramuscular injection of a PPN-miR-503 inhibitor promoted blood-perfusion recovery in the hindlimb of diabetic mice following surgically induced ischemia, linked with an increase in new blood vessel formation. Together, this study demonstrates the effective use of PPN to deliver therapeutic miRNAs in the context of diabetes.
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Vascular injury resulting from lower limb amputation leads to the redistribution of blood flow and changes in vascular terminal resistance, which can affect the cardiovascular system. However, there was no clear understanding of how different amputation levels affect the cardiovascular system in animal experiments. Therefore, this study established two animal models of above-knee amputation (AKA) and below-knee amputation (BKA) to explore the effects of different amputation levels on the cardiovascular system through blood and histopathological examinations. The results showed that amputation caused pathological changes in the cardiovascular system of animals, including endothelial injury, inflammation, and angiosclerosis. The degree of cardiovascular injury was higher in the AKA group than in the BKA group. This study sheds light on the internal mechanisms of amputation's impact on the cardiovascular system. Based on the amputation level of patients, the findings recommend more comprehensive and targeted monitoring after surgery and necessary interventions to prevent cardiovascular diseases.
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Experimentación Animal , Enfermedades Cardiovasculares , Sistema Cardiovascular , Hipertensión , Animales , Amputación QuirúrgicaRESUMEN
Virilizer-like m6A methyltransferase-associated protein (VIRMA) maintains the stability of the m6A writer complex. Although VIRMA is critical for RNA m6A deposition, the impact of aberrant VIRMA expression in human diseases remains unclear. We show that VIRMA is amplified and overexpressed in 15-20% of breast cancers. Of the two known VIRMA isoforms, the nuclear-enriched full-length but not the cytoplasmic-localised N-terminal VIRMA promotes m6A-dependent breast tumourigenesis in vitro and in vivo. Mechanistically, we reveal that VIRMA overexpression upregulates the m6A-modified long non-coding RNA, NEAT1, which contributes to breast cancer cell growth. We also show that VIRMA overexpression enriches m6A on transcripts that regulate the unfolded protein response (UPR) pathway but does not promote their translation to activate the UPR under optimal growth conditions. Under stressful conditions that are often present in tumour microenvironments, VIRMA-overexpressing cells display enhanced UPR and increased susceptibility to death. Our study identifies oncogenic VIRMA overexpression as a vulnerability that may be exploited for cancer therapy.
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Neoplasias de la Mama , Humanos , Femenino , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Respuesta de Proteína Desplegada/genética , ARN/metabolismo , Interferencia de ARN , Microambiente TumoralRESUMEN
BACKGROUND: Online health communities (OHCs) provide a new channel for users to obtain more health-related information and support, playing an important role in alleviating hospital congestion and uneven medical resource distribution, especially during the COVID-19 pandemic in China. An in-depth study of users' continuous usage is of great value for the long-term development of OHCs. OBJECTIVE: The purpose of this study is to explore the factors that influence users' continuous usage in online health communities based on the theory of planned behavior (TPB) and social cognitive theory (SCT). METHODS: Data from 480 users with experience in online health communities were collected through a questionnaire survey, and structural equations were applied to verify the model hypotheses empirically. RESULTS: Self-efficacy and controllability have significant effects on users' continuous intention; attitude has a significant relationship with continuous intention; social norms have a positive effect on continuous intention. Moreover, the relationship between continuous intention and behavior is positive. Self-efficacy and outcome expectations have significant positive associations with continuous usage. Finally, system quality, information quality, and social interaction ties have significant and positive relationships to continuous usage. CONCLUSION: To improve the level of user's continuous usage, online health service providers can improve the quality of the community by organizing the website's page layout, navigation menus, and site elements to ensure users quickly search and find what they want meanwhile try to change people's cognition gradually, in addition, decision and policymakers should provide more favorable policies to stimulate and help provider in building and managing strategic plans for sustaining a thriving online community. A supportive climate in society through public service advertisements and others for the sake of OHCs is necessary. LIMITATIONS: (1) This study collected data through a cross-sectional survey. Thus, it lacked the process of capturing the changes in participants' attitudes toward all variables. (2) The environmental factors in SCT theory need to be more comprehensive, containing online factors without offline factors. (3) The dates were obtained from China, which neglects the different cultural content.
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Loss-of-function mutations in cerebral cavernous malformation (CCM) genes and gain-of-function mutation in the MAP3K3 gene encoding MEKK3 cause CCM. Deficiency of CCM proteins leads to the activation of MEKK3-KLF2/4 signaling, but it is not clear how this occurs. Here, we demonstrate that deletion of the CCM3 interacting kinases STK24/25 in endothelial cells causes defects in vascular patterning during development as well as CCM lesion formation during postnatal life. While permanent deletion of STK24/25 in endothelial cells caused developmental defects of the vascular system, inducible postnatal deletion of STK24/25 impaired angiogenesis in the retina and brain. More importantly, deletion of STK24/25 in neonatal mice led to the development of severe CCM lesions. At the molecular level, a hybrid protein consisting of the STK kinase domain and the MEKK3 interacting domain of CCM2 rescued the vascular phenotype caused by the loss of ccm gene function in zebrafish. Our study suggests that CCM2/3 proteins act as adapters to allow recruitment of STK24/25 to limit the constitutive MEKK3 activity, thus contributing to vessel stability. Loss of STK24/25 causes MEKK3 activation, leading to CCM lesion formation.
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Hemangioma Cavernoso del Sistema Nervioso Central , Animales , Ratones , Células Endoteliales , Hemangioma Cavernoso del Sistema Nervioso Central/genética , Fosforilación , Procesamiento Proteico-Postraduccional , Proteínas Serina-Treonina Quinasas/genética , Pez CebraRESUMEN
Arterial dissections, which involve an abrupt tear in the wall of a major artery resulting in the intramural accumulation of blood, are a family of catastrophic disorders causing major, potentially fatal sequelae. Involving diverse vascular beds, including the aorta or coronary, cervical, pulmonary, and visceral arteries, each type of dissection is devastating in its own way. Traditionally they have been studied in isolation, rather than collectively, owing largely to the distinct clinical consequences of dissections in different anatomical locations - such as stroke, myocardial infarction, and renal failure. Here, we review the shared and unique features of these arteriopathies to provide a better understanding of this family of disorders. Arterial dissections occur commonly in the young to middle-aged, and often in conjunction with hypertension and/or migraine; the latter suggesting they are part of a generalized vasculopathy. Genetic studies as well as cellular and molecular investigations of arterial dissections reveal striking similarities between dissection types, particularly their pathophysiology, which includes the presence or absence of an intimal tear and vasa vasorum dysfunction as a cause of intramural hemorrhage. Pathway perturbations common to all types of dissections include disruption of TGF-ß signaling, the extracellular matrix, the cytoskeleton or metabolism, as evidenced by the finding of mutations in critical genes regulating these processes, including LRP1, collagen genes, fibrillin and TGF-ß receptors, or their coupled pathways. Perturbances in these connected signaling pathways contribute to phenotype switching in endothelial and vascular smooth muscle cells of the affected artery, in which their physiological quiescent state is lost and replaced by a proliferative activated phenotype. Of interest, dissections in various anatomical locations are associated with distinct sex and age predilections, suggesting involvement of gene and environment interactions in disease pathogenesis. Importantly, these cellular mechanisms are potentially therapeutically targetable. Consideration of arterial dissections as a collective pathology allows insight from the better characterized dissection types, such as that involving the thoracic aorta, to be leveraged to inform the less common forms of dissections, including the potential to apply known therapeutic interventions already clinically available for the former.
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Platelets have emerged as key inflammatory cells implicated in the pathology of sepsis, but their contributions to rapid clinical deterioration and dysregulated inflammation have not been defined. Here, we show that the incidence of thrombocytopathy and inflammatory cytokine release was significantly increased in patients with severe sepsis. Platelet proteomic analysis revealed significant upregulation of gasdermin D (GSDMD). Using platelet-specific Gsdmd-deficient mice, we demonstrated a requirement for GSDMD in triggering platelet pyroptosis in cecal ligation and puncture (CLP)-induced sepsis. GSDMD-dependent platelet pyroptosis was induced by high levels of S100A8/A9 targeting toll-like receptor 4 (TLR4). Pyroptotic platelet-derived oxidized mitochondrial DNA (ox-mtDNA) potentially promoted neutrophil extracellular trap (NET) formation, which contributed to platelet pyroptosis by releasing S100A8/A9, forming a positive feedback loop that led to the excessive release of inflammatory cytokines. Both pharmacological inhibition using Paquinimod and genetic ablation of the S100A8/A9-TLR4 signaling axis improved survival in mice with CLP-induced sepsis by suppressing platelet pyroptosis.
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Cerebral cavernous malformation (CCM) is a brain vascular disease which can cause stroke, cerebral hemorrhage and neurological deficits in affected individuals. Loss-of-function mutations in three genes (CCM1, CCM2 and CCM3) cause CCM disease. Multiple mouse models for CCM disease have been developed although each of them are associated with various limitations. Here, we employed the Dre-Cre dual recombinase system to specifically delete Ccm genes in brain endothelial cells. In this new series of CCM mouse models, robust CCM lesions now develop in the cerebrum. The survival curve and lesion burden analysis revealed that Ccm2 deletion causes modest CCM lesions with a median life expectance of â¼10 months and Ccm3 gene deletion leads to the most severe CCM lesions with median life expectance of â¼2 months. The extended lifespan of these mutant mice enables their utility in behavioral analyses of neurologic deficits in adult mice, and allow the development of methods to quantify lesion burden in mice over time and also permit longitudinal drug testing in live animals.
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Hemangioma Cavernoso del Sistema Nervioso Central , Animales , Ratones , Hemangioma Cavernoso del Sistema Nervioso Central/genética , Células Endoteliales/metabolismo , Eliminación de Gen , Recombinasas/genética , Recombinasas/metabolismo , Modelos Animales de Enfermedad , Encéfalo/irrigación sanguíneaRESUMEN
BACKGROUND & AIMS: The liver has complex interconnecting blood vessel and biliary networks; however, how the vascular and biliary network form and regulate each other and liver function are not well-understood. We aimed to examine the role of Heg in mammalian liver development and functional maintenance. METHODS: Global (Heg-/-) or liver endothelial cell (EC)-specific deletion of Heg (Lyve1-Cre;Hegfl/fl ) mice were used to study the in vivo function of Heg in the liver. Carbon-ink anterograde and retrograde injection were used to visualize the 3-dimensional patterning of liver portal and biliary networks, respectively. RNA sequencing, histology, and molecular and biochemical assays were used to assess liver gene expression, protein distribution, liver injury response, and function. RESULTS: Heg deficiency in liver ECs led to a sparse liver vascular and biliary network. This network paucity does not compromise liver function under baseline conditions but did alter liver zonation. Molecular analysis revealed that endothelial Heg deficiency decreased expression of Wnt ligands/agonists including Wnt2, Wnt9b, and Rspo3 in ECs, which limits Axin2 mediated canonical Wnt signaling and the expression of cytochrome P450 enzymes in hepatocytes. Under chemical-induced stressed conditions, Heg-deficiency in liver ECs protected mice from drug-induced liver injuries. CONCLUSION: Our study found that endothelial Heg is essential for the 3-D patterning of the liver vascular and indirectly regulates biliary networks and proper liver zonation via its regulation of Wnt ligand production in liver endothelial cells. The endothelial Heg-initiated changes of the liver metabolic zonation and metabolic enzyme expression in hepatocytes was functionally relevant to xenobiotic metabolism and drug induced liver toxicity.
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Proteínas Wnt , Vía de Señalización Wnt , Animales , Células Endoteliales , Hígado/patología , Mamíferos/metabolismo , Ratones , Proteínas Wnt/genética , Vía de Señalización Wnt/genética , beta Catenina/metabolismoRESUMEN
Vascular smooth muscle cells (VSMCs) display extraordinary phenotypic plasticity. This allows them to differentiate or dedifferentiate, depending on environmental cues. The ability to 'switch' between a quiescent contractile phenotype to a highly proliferative synthetic state renders VSMCs as primary mediators of vascular repair and remodelling. When their plasticity is pathological, it can lead to cardiovascular diseases such as atherosclerosis and restenosis. Coinciding with significant technological and conceptual innovations in RNA biology, there has been a growing focus on the role of alternative splicing in VSMC gene expression regulation. Herein, we review how alternative splicing and its regulatory factors are involved in generating protein diversity and altering gene expression levels in VSMC plasticity. Moreover, we explore how recent advancements in the development of splicing-modulating therapies may be applied to VSMC-related pathologies.
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Empalme Alternativo/fisiología , Plasticidad de la Célula/genética , Músculo Liso Vascular/metabolismo , Empalme Alternativo/efectos de los fármacos , Animales , Aterosclerosis/etiología , Aterosclerosis/genética , Reestenosis Coronaria/etiología , Reestenosis Coronaria/genética , Humanos , Músculo Liso Vascular/citología , Oligonucleótidos Antisentido/uso terapéutico , FenotipoRESUMEN
PDCD10, also known as CCM3, is a gene found to be associated with the human disease cerebral cavernous malformations (CCMs). PDCD10 forms a complex with GCKIII kinases including STK24, STK25, and MST4. Studies in C. elegans and Drosophila have shown a pivotal role of the PDCD10-GCKIII complex in maintaining epithelial integrity. Here, we found that mice deficient of Pdcd10 or Stk24/25 in the kidney tubules developed polyuria and displayed increased water consumption. Although the expression levels of aquaporin genes were not decreased, the levels of total and phosphorylated aquaporin 2 (Aqp2) protein in the apical membrane of tubular epithelial cells were decreased in Pdcd10- and Stk24/25-deficient mice. This loss of Aqp2 was associated with increased expression and membrane targeting of Ezrin and phosphorylated Ezrin, Radixin, Moesin (p-ERM) proteins and impaired intracellular vesicle trafficking. Treatment with Erlotinib, a tyrosine kinase inhibitor promoting exocytosis and inhibiting endocytosis, normalized the expression level and membrane abundance of Aqp2 protein, and partially rescued the water reabsorption defect observed in the Pdcd10-deficient mice. Our current study identified the PDCD10-STK-ERM signaling pathway as a potentially novel pathway required for water balance control by regulating vesicle trafficking and protein abundance of AQP2 in the kidneys.
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Proteínas Reguladoras de la Apoptosis/metabolismo , Acuaporina 2/metabolismo , Riñón , Agua/metabolismo , Animales , Proteínas Reguladoras de la Apoptosis/genética , Acuaporina 2/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Riñón/metabolismo , Riñón/fisiología , Ratones , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismoRESUMEN
PURPOSE: The neonatal mouse possesses a transient capacity for cardiac regeneration during the first few days of life. The regenerative response of neonatal mouse is primarily mediated by pre-existing cardiomyocyte (CM) proliferation, which has been identified as the primary source of myocardial regeneration. Postnatal 4-day-old (P4) mouse CMs appear to undergo a rapid transition from hyperplastic to hypertrophic growth and binucleation. By 7 days following birth this regenerative potential is lost which coincidently correspond with CM cell cycle arrest and binucleation. CCM2-like (Ccm2l) plays pivotal roles in cardiovascular development and cardiac growth, indicating a potential function in heart regeneration postnatally. The aim of this study was to determine the cardiac regeneration ability of P4 neonatal mouse using a novel and more reproducible injury model and to determine whether Ccm2l has any functional roles in heart repair following ischemic injury. METHODS: We performed a modified left anterior descending artery (LAD) ligation procedure on P4 mice to examine cardiac regenerative responses at different time points. Additionally, we generated an endothelial-specific Ccm2l gain-of-function transgenic mouse to determine the role of Ccm2l in neonatal cardiac regeneration. RESULTS: We found that the P4 mouse heart harbor a robust regenerative response after injury that was through the proliferation of pre-existing CMs but cardiac hypertrophy and subsequent remodeling was still evident 60 days after LAD ligation. Furthermore, we show that endothelial-specific overexpression of Ccm2l does not promote CM proliferation and heart repair after LAD ligation. CONCLUSION: The neonatal heart at P4 harbors a robust but incomplete capacity for cardiac regeneration. Endothelial overexpression of Ccm2l has no effect on cardiac regeneration.
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Infarto del Miocardio , Miocitos Cardíacos , Animales , Animales Recién Nacidos , Ciclo Celular , Corazón , Ratones , RegeneraciónRESUMEN
BACKGROUND: Aberrant expression of circular RNA contributes to human diseases. Circular RNAs regulate gene expression by sequestering specific microRNAs. In this study, we investigated whether circMAP3K5 (circular mitogen-activated protein kinase 5) could act as a competing endogenous microRNA-22-3p (miR-22-3p) sponge and regulate neointimal hyperplasia. METHODS: Circular RNA profiling from genome-wide RNA sequencing data was compared between human coronary artery smooth muscle cells (SMCs) treated with or without platelet-derived growth factor. Expression levels of circMAP3K5 were assessed in human coronary arteries from autopsies on patients with dilated cardiomyopathy or coronary heart disease. The role of circMAP3K5 in intimal hyperplasia was further investigated in mice with adeno-associated virus 9-mediated circMAP3K5 transfection. SMC-specific Tet2 (ten-eleven translocation-2) knockout mice and global miR-22-3p knockout mice were used to delineate the mechanism by which circMAP3K5 attenuated neointimal hyperplasia using the femoral arterial wire injury model. RESULTS: RNA sequencing demonstrated that treatment with platelet-derived growth factor-BB significantly reduced expression of circMAP3K5 in human coronary artery SMCs. Wire-injured mouse femoral arteries and diseased arteries from patients with coronary heart disease (where platelet-derived growth factor-BB is increased) confirmed in vivo downregulation of circMAP3K5 associated with injury and disease. Lentivirus-mediated overexpression of circMAP3K5 inhibited the proliferation of human coronary artery SMCs. In vivo adeno-associated virus 9-mediated transfection of circMap3k5 (mouse circular Map3k5) specifically inhibited SMC proliferation in the wire-injured mouse arteries, resulting in reduced neointima formation. Using a luciferase reporter assay and RNA pull-down, circMAP3K5 (human circular MAP3K5) was found to sequester miR-22-3p, which, in turn, inhibited the expression of TET2. Both in vitro and in vivo results demonstrate that the loss of miR-22-3p recapitulated the antiproliferative effect of circMap3k5 on vascular SMCs. In SMC-specific Tet2 knockout mice, loss of Tet2 abolished the circMap3k5-mediated antiproliferative effect on vascular SMCs. CONCLUSIONS: We identify circMAP3K5 as a master regulator of TET2-mediated vascular SMC differentiation. Targeting the circMAP3K5/miR-22-3p/TET2 axis may provide a potential therapeutic strategy for diseases associated with intimal hyperplasia, including restenosis and atherosclerosis.
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Proteínas de Unión al ADN/metabolismo , Dioxigenasas/metabolismo , MicroARNs/metabolismo , Miocitos del Músculo Liso/patología , ARN Circular/metabolismo , Túnica Íntima/metabolismo , Animales , Cardiomiopatías/genética , Cardiomiopatías/metabolismo , Cardiomiopatías/patología , Diferenciación Celular/fisiología , Modelos Animales de Enfermedad , Femenino , Humanos , Hiperplasia/metabolismo , Hiperplasia/patología , Masculino , Ratones , Ratones Noqueados , MicroARNs/genética , Miocitos del Músculo Liso/metabolismo , ARN Circular/genética , Túnica Íntima/patologíaRESUMEN
In order to study the effect of nitriding or shot peening on the surface modification and fatigue properties of martensitic stainless-steel Custom 465, the residual stress and micro-hardness of the strengthened layer are determined by X-ray and micro-hardness tester, respectively. The up-and-down method is used to measure the rotational bending fatigue strength at 1 × 107 cycles, and the fatigue fracture characteristic is observed by scanning electron microscopy. The relationship between surface residual stress and internal fatigue limit of surface strengthening treatment is discussed. Results show that nitriding or shot peening surface strengthening layer forms a certain depth of compressive residual stress, where in the surface compressive residual stress of the nitrided specimens is greater than the shot peened specimens. The micro-hardness of the nitrided or shot peened surface strengthening layer is significantly improved, where in the surface micro-hardness of nitriding specimens are higher than shot peening specimens. The nitriding or shot peening surface strengthening can significantly improve the fatigue limit of Custom 465, wherein the fatigue limits of nitrided and shot peened surface strengthened specimens are 50.09% and 50.66% higher than that of the un-surface strengthened specimens, respectively. That is, the effect of the two strengthening methods on fatigue limit is not very different. The fracture characteristics show that the fatigue crack of the un-surface strengthened specimens originates from the surface, while the fatigue crack of surface strengthened specimens originates from the subsurface layer under the strengthened layer. The relationship between the internal fatigue limit and the surface residual stress of the surface strengthened specimen can be used as a method for predicting the fatigue limit of the surface strengthened specimens.
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Upon arterial injury, endothelial denudation leads to platelet activation and delivery of multiple agents (e.g., TXA2, PDGF), promoting VSMC dedifferentiation and proliferation (intimal hyperplasia) during injury repair. The process of resolution of vessel injury repair, and prevention of excessive repair (switching VSMCs back to a differentiated quiescent state), is poorly understood. We now report that internalization of APs by VSMCs promotes resolution of arterial injury by switching on VSMC quiescence. Ex vivo and in vivo studies using lineage tracing reporter mice (PF4-cre × mT/mG) demonstrated uptake of GFP-labeled platelets (mG) by mTomato red-labeled VSMCs (mT) upon arterial wire injury. Genome-wide miRNA sequencing of VSMCs cocultured with APs identified significant increases in platelet-derived miR-223. miR-223 appears to directly target PDGFRß (in VSMCs), reversing the injury-induced dedifferentiation. Upon arterial injury, platelet miR-223-KO mice exhibited increased intimal hyperplasia, whereas miR-223 mimics reduced intimal hyperplasia. Diabetic mice with reduced expression of miR-223 exhibited enhanced VSMC dedifferentiation and proliferation and increased intimal hyperplasia. Our results suggest that horizontal transfer of platelet-derived miRNAs into VSMCs provides a novel mechanism for regulating VSMC phenotypic switching. Platelets thus play a dual role in vascular injury repair, initiating an immediate repair process and, concurrently, a delayed process to prevent excessive repair.