LncRNA GAS5 regulates vascular smooth muscle cell cycle arrest and apoptosis via p53 pathway.

Vascular remodeling is a pathological process following cardiovascular intervention. Vascular smooth muscle cells (VSMC) play a critical role in the vascular remodeling. Long noncoding RNAs (lncRNA) are a class of gene regulators functioning through various mechanisms in physiological and pathological conditions. By using cultured VSMC and rat carotid artery balloon injury model, we found that lncRNA growth arrest specific 5 (GAS5) serves as a negative regulator for VSMC survival in vascular remodeling. By manipulating GAS5 expression via adenoviral overexpression or short hairpin RNA knockdown, we found that GAS5 suppresses VSMC proliferation while promoting cell cycle arrest and inducing cell apoptosis. Mechanistically, GAS5 directly binds to p53 and p300, stabilizes p53-p300 interaction, and thus regulates VSMC cell survival via induction of p53-downstream target genes. Importantly, local delivery of GAS5 via adenoviral vector suppresses balloon injury-induced neointima formation along with an increased expression of p53 and apoptosis in neointimal SMCs. Our study demonstrated for the first time that GAS5 negatively impacts VSMC survival via activation the p53 pathway during vascular remodeling.

Exosomes derived from M1 macrophages aggravate neointimal hyperplasia following carotid artery injuries in mice through miR-222/CDKN1B/CDKN1C pathway.

The role of M1 macrophages (M1M)-derived exosomes in the progression of neointimal hyperplasia remains unclear now. Using a transwell co-culture system, we demonstrated that M1M contributed to functional change of vascular smooth muscle cell (VSMC). We further stimulated VSMCs with exosomes isolated from M1M. Our results demonstrated that these exosomes could be taken up by VSMCs through macropinocytosis. Using a microRNA array assay, we identified that miR-222 originated from M1M-derived exosomes triggered the functional changes of VSMCs. In addition, we confirmed that miR-222 played a key role in promoting VSMCs proliferation and migration by targeting Cyclin Dependent Kinase Inhibitor 1B (CDKN1B) and Cyclin Dependent Kinase Inhibitor 1C (CDKN1C) in vitro. In vivo, M1M-derived exosomes significantly aggravated neointima formation following carotid artery ligation injury and wire injury and these effects were partly abolished by miR-222 inhibitor 2'OMe-miR-222. Our findings thus suggest that exosomes derived from M1M could aggravate neointimal hyperplasia through delivering miR-222 into VSMCs. Future studies are warranted to validate if the post-injury vascular neointimal hyperplasia and restenosis could be attenuated by inhibiting miR-222.

Circular RNA Expression in the Brain of a Neonatal Rat Model of Periventricular White Matter Damage.

BACKGROUND/AIMS: Periventricular white matter damage (PWMD) is the predominant neurologic lesion in preterm infants who survive brain injury. In this study, we assessed the global changes in and characteristics of the transcriptome of circular RNAs (circRNAs) in the brain tissues of rats with PWMD. METHODS: We compared the expression profiles of circRNAs in brain samples from three rats with PWMD and three paired control tissues using deep RNA sequencing. Bioinformatics analysis was applied to investigate these differentially expressed circRNAs, and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analysis was performed to confirm the results. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to predict associated cell signaling pathways and functions. Network analysis was performed to predict circRNAs-microRNAs, and target genes related to PWMD. RESULTS: A total of 2151 more reliable circRNAs were dysregulated in the brain tissues of rats with PWMD, indicating a potential role in the condition. Of the 98 circRNAs significantly differentially expressed in rat brains with PWMD (P< 0.05), 52 were significantly over-expressed and 46 were significantly under-expressed. The expression profiles of seven of 10 randomly selected circRNAs were confirmed by qRT-PCR analysis. The glutamatergic synapse pathway and the VEGF signaling pathway, both associated with hypoxia/ischemia induced brain damage, were inriched. Relationship between miRNA (rno-miR-433-3p and rno-miR-206-3p) and HIF-1α were evident and potential associations between chr6: 48820833|48857932 and their target genes (rno-miR-433-3p and rno-miR-206-3p) were identified. CONCLUSION: The distinct expression patterns of circRNAs in the brain tissues of rats with PWMD suggest that circRNAs actively respond to hypoxia-ischemia. These findings could assist the development of novel diagnostic and therapeutic targets for PWMD therapy.

MiR-140-3p is Involved in In-Stent Restenosis by Targeting C-Myb and BCL-2 in Peripheral Artery Disease.

AIM: In-Stent Restenosis (ISR) is the major reason for recurrent ischemia and amputation after endovascular treatment of Peripheral Artery Disease (PAD). Our previous study demonstrated that miR-140-3p is significantly down-regulated in PAD arteries. However, expression and function of miR-140-3p in ISR of human PAD are currently unclear.The aim of this study is to determine the miR-140-3p expression and its regulative role in ISR of PAD. METHODS: The RNA level was determined by quantitative real-time polymerase chain Reaction (qRT-PCR) and in situ hybridization. Primary cultured ASMCs were isolated from human femoral arterial of the healthy donors or ISR patients. Cell proliferation was determined by Edu incorporation and CCK-8 assay. Apoptosis was determined by Annexin-Ⅴ/PI Double-Staining assay and TUNEL assay. A rat carotid artery balloon angioplasty model was used to investigate the effect of miR-140-3p on restenosis. RESULTS: MiR-140-3p was significantly down-regulated in PAD and ISR arteries than normal arteries. Primary cultured ISR ASMCs exhibited elevated proliferation and down-regulated miR-140-3p than normal ASMCs. Transfection of miR-140-3p mimic attenuated PDGF-BB-induced proliferation in cultured ASMCs and induced apoptosis. Luciferase reporter assay indicated that miR-140-3p transfection significantly down-regulated C-Myb and BCL-2 in ISR ASMCs by targeting to their 3'-UTRs. MiR-140-3p transfection induced anti-proliferation and apoptosis in ASMCs, which were ameliorated by over-expression of C-Myb or BCL-2. Moreover, the animal study showed that miR-140-3p can reduce restenosis following angioplasty via targeting C-Myb and BCL-2. CONCLUSIONS: The result suggests that miR-140-3p regulates ASMC function via targeting C-Myb and BCL-2 in the process of ISR in PAD. The novel findings may offer a hopeful therapeutic target for human PAD.

Hydrogen Sulfide-Preconditioning of Human Endothelial Progenitor Cells Transplantation Improves Re-Endothelialization in Nude Mice with Carotid Artery Injury.

BACKGROUND/AIMS: The aim of present study was to test the hypothesis that preconditioning with sodium hydrosulfide (NaHS) could enhance the capacity of migration, adhesion and proliferation of endothelial progenitor cells (EPCs) in vitro, and also could improve the efficacy of EPCs transplantation for re-endothelialization in nude mice with carotid artery injury. The paper further addressed the underlying mechanisms. METHODS: EPCs were isolated from peripheral blood mononuclear cells of healthy male volunteers and the markers of EPCs were analyzed by flow cytometry. Thereafter, different concentrations of NaHS (25, 50, 100, 200 and 500 uM) were used for preconditioning EPCs. In vitro and in vivo migration, adhesion and proliferation as well as nitric oxide (NO) production of EPCs were evaluated. Carotid artery injury model was produced in nude mice and thereafter, NaHS-preconditioned EPCs were transplanted in order to evaluate their capacity of re-endothelialization. RESULTS: Cellular immuno-staining showed that isolated cells expressed the key markers of EPCs. In vitro, EPCs proliferation rates and NO production were gradually increased in a NaHS-concentration dependent manner, while these benefits were blocked at a concentration of 500 uM NaHS. Similarly, the migration and adhesion rates of EPCs were also increased the most prominently at a concentration of 200 µM NaHS. In vivo, compared to the control group, treatment with NaHS-preconditioned EPCs significantly enhanced the capacity of re-endothelialization of EPCs. Fluorescent microscope revealed that there were more EPCs homing to the injury vessels in the NaHS-preconditioned EPCs group than the non-preconditioned group. With the administration of AMPK or eNOS inhibitors respectively, the above benefits of NaHS-preconditioning were abrogated. CONCLUSION: These results suggested that NaHS-preconditioning enhanced the biological function and re-endothelialization of EPCs through the AMPK/eNOS signaling pathway.

Mir-22-3p Inhibits Arterial Smooth Muscle Cell Proliferation and Migration and Neointimal Hyperplasia by Targeting HMGB1 in Arteriosclerosis Obliterans.

BACKGROUND: Aberrant vascular smooth muscle cell (VSMC) proliferation and migration contribute to the development of vascular pathologies, such as atherosclerosis and post-angioplasty restenosis. The aim of this study was to determine whether miR-22-3p plays a role in regulating human artery vascular smooth muscle cell (HASMC) function and neointima formation. METHODS: Quantitative real-time PCR (qRT-PCR) and fluorescence in situ hybridization (FISH) were used to detect miR-22-3p expression in human arteries. Cell Counting Kit-8 (CCK-8) and EdU assays were performed to assess cell proliferation, and transwell and wound closure assays were performed to assess cell migration. Moreover, luciferase reporter assays were performed to identify the target genes of miR-22-3p. Finally, a rat carotid artery balloon-injury model was used to determine the role of miR-22-3p in neointima formation. RESULTS: MiR-22-3p expression was downregulated in arteriosclerosis obliterans (ASO) arteries compared with normal arteries, as well as in platelet-derived growth factor-BB (PDGF-BB)-stimulated HASMCs compared with control cells. MiR-22-3p overexpression had anti-proliferative and anti-migratory effects and dual-luciferase assay showed that high mobility group box-1 (HMGB1) is a direct target of miR-22-3p in HASMCs. Furthermore, miR-22-3p expression was negatively correlated with HMGB1 expression in ASO tissue specimens. Finally, LV-miR-22-3p-mediated miR-22-3p upregulation significantly suppressed neointimal hyperplasia specifically by reducing HMGB1 expression in vivo. CONCLUSIONS: Our results indicate that miR-22-3p is a key molecule in regulating HASMC proliferation and migration by targeting HMGB1 and that miR-22-3p and HMGB1 may be therapeutic targets in the treatment of human ASO.

Nanopartículas calcificantes como factor etiológico del desarrollo de hiperplasia y calcificación vascular / Calcifying nanoparticles in the aetiology of hyperplasia and calcification

OBJETIVO: Nanopartículas calcificantes (NP) se han detectado recientemente en muestras arteriales humanas y parecen estar involucradas en el proceso de calcificación. Este estudio fue diseñado para probar la hipótesis de que las NP de origen humano podrían agravar la respuesta a la lesión arterial endotelial e inducir la calcificación vascular. MÉTODOS: La arteria carótida derecha de 24 conejos neozelandeses fue lesionada con un balón de angioplastia. Los animales fueron perfundidos por vía intravenosa con solución salina (100 ml) durante el experimento y se dividieron en 3 grupos: grupo A, control; grupo B, expuesto a NP (2 ml) obtenidas a partir de válvulas aórticas calcificadas y el grupo C, expuesto a NP (2 ml) y tratado después de la operación con atorvastatina (2,5 mg/kg/24 h). A los 30 días, los animales fueron sacrificados y se extirparon las 2 arterias carótidas, que fueron examinadas histológicamente. Análisis bioquímicos de sangre fueron realizados durante el estudio. RESULTADOS: El área de hiperplasia intimal fue significativamente mayor en la arteria carótida derecha lesionada en comparación con la arteria carótida izquierda no operada, en todos los grupos. No hubo variación significativa en la zona medial entre los animales. Morfométricamente, la relación de íntima/media (IMR) fue significativamente mayor en las carótidas dañadas en comparación con los controles. Un aumento significativo de IMR se encontró en el grupo B (1,81 ± 0,41) en comparación con el grupo A (0,38 ± 0,59; p = 0,004) o el grupo C (0,89 ± 0,79; p = 0,035). Las diferencias entre los grupos C y A no fueron significativas (p = 0,064). Se observaron calcificaciones en 6 animales, todos los cuales habían sido expuestos a NP (4 en el grupo B, 2 en el grupo C, p = 0,027). Los niveles plasmáticos de colesterol y triglicéridos se mantuvieron estables. CONCLUSIONES: Este estudio confirma la capacidad de las NP de origen humano de acelerar la hiperplasia y estimular la calcificación de zonas arteriales endoteliales previamente dañadas. Su administración sistémica resultó inofensiva en las arterias sanas. La atorvastatina demostró la capacidad de ralentizar este proceso

OBJECTIVE: Calcifying nanoparticles (NP) have been detected recently in calcified human arterial specimens, and are involved in the process of calcification. This study was designed to test the hypothesis that human-derived NP could worsen the response to arterial endothelial injury and induce vascular calcification. METHODS: The right carotid artery of 24 New Zealand rabbits was injured with an angioplasty balloon. Animals were perfused intravenously with saline (100 mL) during the experiment and divided into 3 groups: group A, control; group B, exposed to NP (2 mL) obtained from calcified aortic valves; and group C, exposed to NP (2 mL) and treated post-operatively with atorvastatin (2.5 mg/kg/24 h). At 30 days, both carotid arteries were removed and examined histologically. Blood measurements were monitored during the study. RESULTS: The intimal hyperplasia area was significantly larger in the injured right carotid artery compared with the left un-operated carotid artery in all groups. There was no significant variation in medial area between groups. Morphometrically, the intima/media ratio (IMR) was significantly higher in damaged carotids compared with controls. A significant increase in the IMR was found in group B (1.81 ± 0.41) compared with group A (0.38 ± 0.59; P=.004) or group C (0.89 ± 0.79; P=.035). Differences between groups C and A were not significant (P=.064). Calcifications were observed in 6 animals, all of which had been exposed to NP (4 in group B, and 2 in group C, P=.027). Plasma levels of cholesterol and triglycerides remained stable. CONCLUSIONS: his study confirms the ability of systemic inoculation of human-derived NP to accelerate hyperplasia and stimulate calcification in localised areas of arteries previously submitted to endothelial damage, while it was harmless in healthy arteries. Atorvastatin was demonstrated to slow down this process

Carotid artery pseudoaneurysm in a cat.

UNLABELLED: CLINICAL SUMMARY: A 4-month-old female intact domestic shorthair cat presented to Kansas State University Veterinary Medical Teaching Hospital for investigation of a large, firmly adhered mass in the left mid-cervical region that developed after phlebotomy performed at the referring veterinarian's clinic. Ultrasound examination of the mass revealed a cystic structure in communication with the left carotid artery, with bidirectional blood flow through the area. A diagnosis of pseudoaneurysm secondary to accidental needle penetration of the carotid artery during jugular venepuncture was made. OUTCOME: Strict cage rest and pain management resulted in complete resolution of clinical and ultrasonographic signs in this cat.