LncRNA GUSBP5-AS promotes EPC migration and angiogenesis and deep vein thrombosis resolution by regulating FGF2 and MMP2/9 through the miR-223-3p/FOXO1/Akt pathway.

Long non-coding RNAs (lncRNAs) play an essential role in multitudinous physiological and pathological processes, including vascular disease. We previously showed that lncRNA GUSBP5-AS (enst00000511042) is upregulated in endothelial progenitor cells (EPCs) of deep veni thrombosis (DVT) patients. Here, we investigate the role and mechanism of GUSBP5-AS in EPCs and DVT. Using the DVT model, we found that GUSBP5-AS significantly reduced the thrombus size and weight and enhanced the homing ability of EPC to DVT sites to promote resolution and recanalization of thrombus. GUSBP5-AS promoted cell cycle progression, proliferation, migration and invasion in EPCs, enhanced EPC angiogenesis in vitro and in vivo, and inhibited apoptosis. Strikingly, this study showed that GUSBP5-AS was unbalanced and modulated Forkhead Box Protein O1 (FOXO1) in EPCs in patients with DVT by interacting with miR-223-3p. Mechanistically, GUSBP5-AS functions as a sponge of miR-223-3p, which targets FOXO1. Both GUSBP5-AS knockdown and miR-223-3p overexpression remarkably inhibited angiogenesis, migration and invasion in EPCs. Additionally, our data suggested that GUSBP-AS activated the Akt pathway and enhanced fibroblast growth factor 2 (FGF2), matrix metalloproteinase-2/9 (MMP2/9) and F-actin expression. Taken together, this study indicates that GUSBP5-AS modulates angiogenesis, proliferation and homing ability of EPCs via regulating FGF2 and MMP2/9 expression through the miR-223-3p/FOXO1/Akt pathway, which may provide a new direction for the development of DVT therapeutics.

TGF-ß Signaling Induces the Expression of OPN in Blood Vessel Endothelial Cells.

BACKGROUND: The mechanism of blood vessel formation and degeneration still remains unclear. Transforming growth factor-ß1 (TGF-ß1) signaling is a critical pathway in this progression and can induce multiple biological effects. Osteopontin (OPN) is involved in mineral metabolism and the inflammatory response associated with vascular calcification. METHODS: To identify the relationship between TGF-ß signaling pathway and OPN, we stimulated human vascular endothelial cells (HVECs) and human aortic endothelial cells (HAECs) using various concentration of TGF-ß1 in vitro. RESULTS: As assessed by flow cytometry and western blots, apoptosis levels were significantly increased with TGF-ß1 treatment. We also demonstrated that OPN increased in vitro with TGF-ß signaling by western blot and quantitative real time polymerase chain reaction (qRT-PCR) analyses. The inhibitory phosphorylation of endothelial nitric-oxide synthase (eNOS) (Thr495) was also up-regulated by TGF-ß signaling. Meanwhile, the anti-inflammatory factor Nrf2 and the activating phosphorylation of eNOS (Ser1177) were down-regulated. CONCLUSIONS: Taken together, our findings demonstrate that TGF-ß signaling can induce the expression of OPN, which may play an important role in the dysfunction of the vascular wall.

Diagnosis and endovascular treatment of iliac venous compression syndrome.

OBJECTIVES: To report *The first two authors contributed equally to this work. our clinical experience on diagnostic criteria and endovascular management in patients with iliac venous compression syndrome. METHOD: Between July 2013 and May 2015, 85 consecutive patients with suspected iliac venous compression syndrome were evaluated by transfemoral venography and intravascular ultrasonography. Venographic evidence of iliac venous occlusion, stenosis, or pelvic collateral vessels, and the degree of stenosis as examined with intravascular ultrasonography were recorded. The endovascular procedure, complications, clinical outcome, and the Venous Clinical Severity Score were evaluated before and after the intervention. RESULTS: Of the 85 limbs, 66 cases of iliac venous compression syndrome were confirmed and 19 cases were excluded. In all of the 66 patients, we successfully performed endovascular intervention (22 balloon dilations, 44 balloon dilations + stenting). Two patients with stent implantation developed acute lower extremity deep vein thrombosis, resulted in successful lysis of the thrombus with catheter-directed thrombolysis. CONCLUSIONS: The presence of intraluminal spurs and pelvic collateral vessels represents not only pathological and anatomical changes by long-term mechanical compression, but also indicators of the severity of iliac venous compression syndrome. The degree of stenosis cannot accurately represent the severity and treatment of iliac venous compression syndrome, especially in the right iliac vein. Endovascular intervention is a safe and effective treatment that reduces lower extremity symptoms. Full and intentional dilation of the intraluminal spurs is an important technical aspect, which is often ignored.

The regulatory role of microRNAs in angiogenesis-related diseases.

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression at a post-transcriptional level via either the degradation or translational repression of a target mRNA. They play an irreplaceable role in angiogenesis by regulating the proliferation, differentiation, apoptosis, migration and tube formation of angiogenesis-related cells, which are indispensable for multitudinous physiological and pathological processes, especially for the occurrence and development of vascular diseases. Imbalance between the regulation of miRNAs and angiogenesis may cause many diseases such as cancer, cardiovascular disease, aneurysm, Kawasaki disease, aortic dissection, phlebothrombosis and diabetic microvascular complication. Therefore, it is important to explore the essential role of miRNAs in angiogenesis, which might help to uncover new and effective therapeutic strategies for vascular diseases. This review focuses on the interactions between miRNAs and angiogenesis, and miRNA-based biomarkers in the diagnosis, treatment and prognosis of angiogenesis-related diseases, providing an update on the understanding of the clinical value of miRNAs in targeting angiogenesis.

HMGB1 Promotes Mitochondrial Dysfunction-Triggered Striatal Neurodegeneration via Autophagy and Apoptosis Activation.

Impairments in mitochondrial energy metabolism are thought to be involved in many neurodegenerative diseases. The mitochondrial inhibitor 3-nitropropionic acid (3-NP) induces striatal pathology mimicking neurodegeneration in vivo. Previous studies showed that 3-NP also triggered autophagy activation and apoptosis. In this study, we focused on the high-mobility group box 1 (HMGB1) protein, which is important in oxidative stress signaling as well as in autophagy and apoptosis, to explore whether the mechanisms of autophagy and apoptosis in neurodegenerative diseases are associated with metabolic impairment. To elucidate the role of HMGB1 in striatal degeneration, we investigated the impact of HMGB1 on autophagy activation and cell death induced by 3-NP. We intoxicated rat striata with 3-NP by stereotaxic injection and analyzed changes in expression HMGB1, proapoptotic proteins caspase-3 and phospho-c-Jun amino-terminal kinases (p-JNK). 3-NP-induced elevations in p-JNK, cleaved caspase-3, and autophagic marker LC3-II as well as reduction in SQSTM1 (p62), were significantly reduced by the HMGB1 inhibitor glycyrrhizin. Glycyrrhizin also significantly inhibited 3-NP-induced striatal damage. Neuronal death was replicated by exposing primary striatal neurons in culture to 3-NP. It was clear that HMGB1 was important for basal autophagy which was shown by rescue of cells through HMGB1 targeting shRNA approach.3-NP also induced the expression of HMGB1, p-JNK, and LC3-II in striatal neurons, and p-JNK expression was significantly reduced by shRNA knockdown of HMGB1, an effect that was reversed by exogenously increased expression of HMGB1. These results suggest that HMGB1 plays important roles in signaling for both autophagy and apoptosis in neurodegeneration induced by mitochondrial dysfunction.

Autophagy inhibits endothelial progenitor cells migration via the regulation of MMP2, MMP9 and uPA under normoxia condition.

OBJECTIVE: The aim of this study was to explore the role of autophagy on the regulation of endothelial progenitor cells (EPCs) migration under normoxic condition. METHODS: After EPCs were isolated and characterized in vitro, we employed Atg5 knocking down and rapamycin to monitor the autophagy, and performed wound healing and transwell assay to assess the cell migration. On the mechanism, the expression of matrix metalloproteinases (MMPs) and urokinase type plasminogen activator (uPA) was evaluated. RESULTS: Atg5 knocking down and rapamycin could respectively inhibit and enhance autophagy, which could result in significantly increased and decreased cell migration in wound healing and transwell assay under normoxic condition. Moreover, Atg5 knocking down could significantly increase the expression of MMP2, MMP9 and uPA in EPCs while rapamycin could decrease the expression of uPA and MMP9. In addition, the mTOR-P70 S6K pathway was also involved in EPCs migration regulation. CONCLUSIONS: These results demonstrated that autophagy could regulate the EPCs migration through mTOR-P70 S6K pathway, and MMP2, MMP9 and uPA may also involve in the regulation mechanism.

Rapamycin and 3-methyladenine regulate apoptosis and autophagy in bone-derived endothelial progenitor cells.

BACKGROUND: Mammalian target of rapamycin (mTOR) is involved in a caspase independent form of programmed cell death called autophagy. The aim of this research was to investigate the effects of rapamycin and 3-methyladenine (3-MA) on autophagy, proliferation, apoptosis, and cell-cycle parameters of rat bone marrow-derived endothelial progenitor cells (EPCs). METHODS: Mononuclear cells isolated from rat bone marrow were treated with rapamycin (0.01, 0.1, 1, or 10 µg/L) or 3-MA (1.25, 2.5, 5, or 10 mmol/L) for 24 hours. Expression of the autophagy marker protein LC3-II was analyzed by Western blotting. Apoptosis and cell-cycle progression were analyzed by flow cytometry. Cell proliferation was measured using the MTT assay. RESULTS: Rapamycin treatment of EPCs induced apoptosis and autophagy and inhibited proliferation and cell-cycle progression in a dose-dependent manner. Treatment with 5 mmol/L 3-MA promoted cell proliferation; in contrast, treatment with 10 mmol/L 3-MA promoted apoptosis and induced S-phase arrest. CONCLUSIONS: Rapamycin treatment of EPCs induced apoptosis and autophagy. Low concentrations of 3-MA had no significant effect on the proliferation and apoptosis of EPCs; The 5 mmol/L group promoted cell proliferation, but had no effect on the apoptosis; the 10 mmol/L group inhibited the proliferation and promoted apoptosis through the cell cycle.

Transplantation of VEGF165-gene-transfected endothelial progenitor cells in the treatment of chronic venous thrombosis in rats.

BACKGROUND: The organization and recanalization of thrombi is a dynamic and complex process. The aim of this research was to study the cotherapeutic effect of stem cell transplantation and gene transfection on chronic venous thrombosis. METHODS: We constructed a recombinant adenoviral vector carrying the vascular endothelial growth factor 165 (VEGF165) gene by using the pAdEasy system, which was subsequently identified and amplified. Simultaneously, endothelial progenitor cells (EPCs) were isolated from rat bone marrow using Ficoll, cultured in EBM-2MV medium, and identified. Then, the cells were transfected with the recombinant Ad-VEGF165. The EPCs were labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine (Dil) before transplantation. A rat model of chronic vein thrombosis was developed by partial ligation of the inferior vena cava. The rats were randomly divided into 4 groups (n = 25, each): A, Ad-VEGF165/EPC-transplantation group received 1 ml (10(6)) of Ad-VEGF165/EPCs; B, EPC-transplantation group received 1 ml (10(6)) of EPCs; C, Ad/EPC-transplantation group received 1 ml (10(6)) of Ad/EPCs; D, control group received 1 ml of the transplantation medium. The thrombi and adjacent caval walls were harvested 28 days after transplantation; real-time quantitative polymerase chain reaction was used to detect the expression level of vascular endothelial growth factor (VEGF) mRNA; and western blotting was used to measure changes in VEGF protein expression. Hematoxylin-eosin staining and immunohistochemical staining were performed to detect recanalization. Neovascularization was detected by immunohistochemical staining using the antibody for von Willebrand factor (vWF), which is a component of endothelial cells. The capillary density was quantitatively determined by counting the capillaries under a high-power microscope. RESULTS: The Ad-VEGF165 was constructed, and bone-marrow-derived EPCs were cultivated and successfully identified. We determined the optimum transfection ratio that promoted the growth of EPCs. After transfection, the EPCs secreted the VEGF protein. After transplantation, the in vivo survival of EPCs and their differentiation into endothelial cells were determined by detecting the fluorescence associated with the Dil stain. VEGF mRNA was expressed in groups A, B, C and D after transplantation, and the VEGF mRNA level in group A was significantly higher than those in groups B, C and D (P < 0.05); the VEGF mRNA levels in groups B and C were significantly higher than those in group D (P < 0.05), and there was no statistical significance between the VEGF mRNA levels in groups B and C. The recanalization capillary density in group A was significantly higher than those in groups B, C (P < 0.05) and D (P < 0.01); the recanalization capillary densities in groups B and C were significantly higher than that in group D (P < 0.05). Moreover, there was no statistical significant difference between the values for groups B and C. CONCLUSIONS: The EPCs were successfully transfected by Ad-VEGF165. A suitable transfection ratio can improve the efficiency of EPCs and the possibility of promotion of angiogenesis after transplantation. Transfected EPCs caused accelerated organization and recanalization of vein thrombi.