Vascular endothelial growth factor (VEGF) is a major regulator of blood vessel formation during development and in the adult organism. Recent evidence indicates that this factor also plays an important role in sustaining the proliferation and differentiation of different cell types, including progenitor cells of different tissues, including bone marrow, bone, and the central nervous system. Here we show that the delivery of the 165-aa isoform of VEGF-A cDNA using an adeno-associated virus (AAV) vector exerts a powerful effect on skeletal muscle regeneration in vivo. Following ischemia-, glycerol-, or cardiotoxin-induced damage in mouse skeletal muscle, the delivery of AAV-VEGF markedly improved muscle fiber reconstitution with a dose-dependent effect. The expression of both VEGF receptor-1 (VEGFR-1) and VEGFR-2 was upregulated both in the satellite cells of the damaged muscles and during myotube formation in vitro; the VEGF effect was mediated by the VEGFR-2, since the transfer of PlGF, a VEGF family member interacting with the VEGFR-1, was ineffective. These results are consistent with the observation that VEGF promotes the growth of myogenic fibers and protects the myogenic cells from apoptosis in vitro and prompt a therapeutic use for VEGF gene transfer in a variety of muscular disorders.

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Background-Active myocarditis is characterized by large heterogeneity of clinical presentation and evolution. This study describes the characteristics and the long-term evolution of a large sample of patients with biopsy-proven active myocarditis, looking for accessible and valid early predictors of long-term prognosis. Methods and Results-From 1981 to 2009, 82 patients with biopsy-proven active myocarditis were consecutively enrolled and followed-up for 147±107 months. All patients underwent clinical and echocardiographic evaluation at baseline and at 6 months. At this time, improvement/normality of left ventricular ejection fraction (LVEF), defined as a LVEF increase > 20 percentage points or presence of LVEF≥50%, was assessed. At baseline, left ventricular dysfunction (LVEF<50%) and left atrium enlargement were independently associated with long-term heart transplantation-free survival, regardless of the clinical pattern of disease onset. At 6 months, improvement/normality of LVEF was observed in 53% of patients. Persistence of New York Heart Association III to IV classes, left atrium enlargement, and improvement/normality of LVEF at 6 months emerged as independent predictors of long-term outcome. Notably, the short-term reevaluation showed a significant incremental prognostic value in comparison with the baseline evaluation (baseline model versus 6 months model: area under the curve 0.79 versus 0.90, P=0.03). Conclusions-Baseline left ventricular function is a marker for prognosis regardless of the clinical pattern of disease onset,and its reassessment at 6 months appears useful for assessing longer-term outcome.

Urokinase‐type plasminogen activator (uPA) and c‐met play a major role in cancer invasion and metastasis. Evidence has suggested that uPA and c‐met overexpression may be coordinated in human hepatocellular carcinoma (HCC). In the present study, to understand whether the expression of these genes might be coregulated by specific microRNAs (miRs) in human cells, we predicted that Homo sapiens microRNA‐23b could recognize two sites in the 3′‐UTR of uPA and four sites in the c‐met 3′‐UTR by the algorithm pictar. The miR‐23b expression analysis in human tumor and normal cells revealed an inverse trend with uPA and c‐met expression, indicating that uPA and c‐met negative regulation might depend on miR‐23b expression. Transfection of miR‐23b molecules in HCC cells (SKHep1C3) led to inhibition of protein expression of the target genes and caused a decrease in cell migration and proliferation capabilities. Furthermore, anti‐miR‐23b transfection in human normal AB2 dermal fibroblasts upregulated the expression of endogenous uPA and c‐met. Cotransfection experiments in HCC cells of the miR‐23b with pGL4.71 Renilla luciferase reporter gene constructs, containing the putative uPA and c‐met 3′‐UTR target sites, and with the pGL3 firefly luciferase‐expressing vector showed a decrease in the relative luciferase activity. This would indicate that miR‐23b can recognize target sites in the 3′‐UTR of uPA and of c‐met mRNAs and translationally repress the expression of uPA and c‐met in HCC cells. The evidence obtained shows that overexpression of miR‐23b leads to uPA and c‐met downregulation and to decreased migration and proliferation abilities of HCC cells.

Vectors based on the adeno-associated virus (AAV) deliver therapeutic genes to muscle and heart at high efficiency and maintain transgene expression for long periods of time. Here we report about the synergistic effect on blood vessel formation of AAV vectors expressing the 165 aa isoform of vascular endothelial growth factor (VEGF165), a powerful activator of endothelial cells, and of angiopoietin-1 (Ang-1), which is required for vessel maturation. High titer AAV-VEGF165 and AAV-Ang-1 vector preparations were injected either alone or in combination in the normoperfused tibialis anterior muscle of rats. Long term expression of VEGF165 determined massive cellular infiltration of the muscle tissues over time, with the formation of a large set of new vessels. Strikingly, some of the cells infiltrating the treated muscles were found positive for markers of activated endothelial precursors (VEGFR-2/KDR and Tie-2) and for c-kit, an antigen expressed by pluripotent bone marrow stem cells. Expression of VEGF165 eventually resulted in the formation of structured vessels surrounded by a layer of smooth muscle cells. Presence of these arteriolae correlated with significantly increased blood perfusion in the injected areas. Co-expression of VEGF165 with angiopoietin-1-which did not display angiogenic effect per se-remarkably reduced leakage of vessels produced by VEGF165 alone.

BackgroundHepatocellular carcinoma (HCC) is a challenging malignancy of global importance, it is the third most common cause of cancer-related mortality worldwide. In the last years the multikinase inhibitor sorafenib has been used for advanced HCC, but some patients do not benefit from this therapy; thus, novel therapeutic options based on molecular approaches are urgently needed. microRNAs are short non coding RNAs involved in several physiological and pathological conditions including HCC and increasing evidence describes miRs as good tools for the molecular targeted therapies in HCC. The purpose of this study was to identify novel approaches to sensitize the HCC cells to sorafenib by microRNAs targeting urokinase-type plasminogen activator (uPA).MethodsThe miR-193a was validated as negative regulator of urokinase-type plasminogen activator (uPA) in 2 HCC undifferentiated cell lines by transient transfection of miR and anti-miR molecules. The molecular interaction between miR-193a and uPA mRNA target was verified by luciferase reporter assay. The miR-193a expression level was evaluated by stem-loop real time PCR in tumoral tissues from 39 HCC patients. The HCC cells were co-treated with sorafenib and miR-193a and the effects on cellular proliferation, apoptosis were tested. The effect of sorafenib on c-met expression levels was assessed by western blotting.ResultsThe miR-193a has resulted a negative regulator of uPA in both the HCC cell lines tested. The miR-193a expression has resulted dysregulated in tumoral tissues from 39 HCC patients. We found miR-193a down-regulation in HCC respect to peritumoral (PT) tissues and more in the cirrhotic HCCs than in non-cirrhotic ones. Transfection of HA22T/VGH HCC cells with miR-193a decreased proliferation and increased apoptosis, and combined treatment with miR-193a and sorafenib led to further proliferation inhibition.ConclusionsOur results present new advances in the post-transcriptional miR-mediated mechanisms of uPA and they suggest a new strategy to impair the aggressive behavior of HCC cells. Our findings could be helpful to explore novel approaches for multi-target and multi-agent therapies of the HCC.

CDK5R1 encodes p35, a specific activator of the serine/threonine kinase CDK5, which plays crucial roles in CNS development and maintenance. CDK5 activity strongly depends on p35 levels and p35/CDK5 misregulation is deleterious for correct CNS function, suggesting that a tightly controlled regulation of CDK5R1 expression is needed for proper CDK5 activity. Accordingly, CDK5R1 expression was demonstrated to be controlled at both transcriptional and post-transcriptional levels, but a possible regulation through microRNAs (miRNAs) has never been investigated. We predicted, within the large CDK5R1 3′UTR several miRNA target sites. Among them, we selected for functional studies miR-103 and miR-107, whose expression has shown a strong inverse correlation with p35 levels in different cell lines. A significant reduction of CDK5R1 mRNA and p35 levels was observed after transfection of SK-N-BE neuroblastoma cells with the miR-103 or miR-107 precursor (pre-miR-103 or pre-miR-107). Conversely, p35 levels significantly increased following transfection of the corresponding antagonists (anti-miR-103 or anti-miR-107). Moreover, the level of CDK5R1 transcript shifts from the polysomal to the subpolysomal mRNA fraction after transfection with pre-miR-107 and, conversely, from the subpolysomal to the polysolmal mRNA fraction after transfection with anti-miR-107, suggesting a direct action on translation efficiency. We demonstrate, by means of luciferase assays, that miR-103 and miR-107 are able to directly interact with the CDK5R1 3′-UTR, in correspondence of a specific target site. Finally, miR-103 and miR-107 overexpression, as well as CDK5R1 silencing, caused a reduction in SK-N-BE migration ability, indicating that these miRNAs affect neuronal migration by modulating CDK5R1 expression. These findings indicate that miR-103 and miR-107 regulate CDK5R1 expression, allowing us to hypothesize that a miRNA-mediated mechanism may influence CDK5 activity and the associated molecular pathways.

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