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Rationale Abnormal phenotypic switch of vascular smooth muscle cell (VSMC) is a hallmark of vascular disorders such as atherosclerosis and restenosis after angioplasty. MicroRNAs (miRNAs) have emerged as important regulators for VSMC function, and we recently identified miR-663 as critical for controlling human aortic smooth muscle cell proliferation. Objective To investigate whether miR-663 plays a role in human VSMC phenotypic switch and the development of neointima formation. Methods and Results By using quantitative reverse-transcription polymerase chain reaction, we found that miR-663 was significantly downregulated in human aortic VSMCs on platelet-derived growth factor treatment, whereas expression was markedly increased during VSMC differentiation. Furthermore, we demonstrated that overexpression of miR-663 increased expression of VSMC differentiation marker genes, such as smooth muscle 22α, smooth muscle α-actin, calponin, and smooth muscle myosin heavy chain, and potently inhibited platelet-derived growth factor-induced VSMC proliferation and migration. We identified the transcription factor JunB and myosin light chain 9 as downstream targets of miR-663 in human VSMCs, because overexpression of miR-663 markedly inhibited expression of JunB and its downstream molecules, such as myosin light chain 9 and matrix metalloproteinase 9. Finally, we showed that adeno-miR-663 markedly suppressed the neointimal lesion formation by ≈50% in mice after vascular injury induced by carotid artery ligation, specifically via decreased JunB expression. Conclusions These results indicate that miR-663 is a novel modulator of human VSMC phenotypic switch by targeting JunB/myosin light chain 9 expression. These findings suggest that targeting miR-663 or its specific downstream targets in human VSMCs may represent an attractive approach for the treatment of proliferative vascular diseases.

These results indicate that miR-638 is a key molecule in regulating human VSMC proliferation and migration by targeting the NOR1/cyclin D pathway and suggest that specific modulation of miR-638 in human VSMCs may represent an attractive approach for the treatment of proliferative vascular diseases.

Aims: Mitochondrial Ca 2+ homeostasis is crucial for balancing cell survival and death. The recent discovery of the molecular identity of the mitochondrial Ca 2+ uniporter pore (MCU) opens new possibilities for applying genetic approaches to study mitochondrial Ca 2+ regulation in various cell types, including cardiac myocytes. Basal tyrosine phosphorylation of MCU was reported from mass spectroscopy of human and mouse tissues, but the signaling pathways that regulate mitochondrial Ca 2+ entry through posttranslational modifications of MCU are completely unknown. Therefore, we investigated a 1 -adrenergic-mediated signal transduction of MCU posttranslational modification and function in cardiac cells. Results: a 1 -adrenoceptor (a 1 -AR) signaling translocated activated proline-rich tyrosine kinase 2 (Pyk2) from the cytosol to mitochondrial matrix and accelerates mitochondrial Ca 2+ uptake via Pyk2-dependent MCU phosphorylation and tetrametric MCU channel pore formation. Moreover, we found that a 1 -AR stimulation increases reactive oxygen species production at mitochondria, mitochondrial permeability transition pore activity, and initiates apoptotic signaling via Pyk2-dependent MCU activation and mitochondrial Ca 2+ overload. Innovation: Our data indicate that inhibition of a 1 -AR-Pyk2-MCU signaling represents a potential novel therapeutic target to limit or prevent mitochondrial Ca 2+ overload, oxidative stress, mitochondrial injury, and myocardial death during pathophysiological conditions, where chronic adrenergic stimulation is present. Conclusion: The a 1 -AR-Pyk2-dependent tyrosine phosphorylation of the MCU regulates mitochondrial Ca 2+ entry and apoptosis in cardiac cells. Antioxid. Redox Signal. 21, 863-879.

Matrix extracellular phosphoglycoprotein (MEPE) was proposed as a candidate for the phosphaturic hormone phosphatonin. We found that a synthetic peptide fragment of MEPE containing the RGD and SGDG sequence stimulated new bone formation in vitro and in vivo.Introduction: Matrix extracellular phosphoglycoprotein (MEPE) was recently identified as a candidate for the phosphaturic hormone phosphatonin, which has been implicated in disturbed phosphate metabolism, rickets, and osteomalacia associated with X-linked hypophosphatemic rickets (XLH) and oncogenic hypophosphatemic osteomalacia (OHO). MEPE expression was predominantly found in osteoblasts, and mice deficient in a homolog of MEPE showed increased bone density, suggesting that MEPE produced in osteoblasts negatively regulates bone formation. In this study, we examined the effects of a synthetic 23mer peptide fragment of MEPE (AC-100, region 242-264) containing the RGD (integrinbinding) and SGDG (glycosaminoglycan-attachment) motif on bone formation in vitro and in vivo. Materials and Methods:The osteogenic activity of AC-100 was examined in organ cultures of neonatal mouse calvariae and in vivo by injecting AC-100 onto the calvariae of mice. Results: Histomorphometric examination showed that AC-100 stimulated new bone formation with increased numbers of osteoblasts in neonatal mouse calvariae in organ culture. In contrast, synthetic MEPE fragment peptides without either the RGD or SGDG motif failed to increase new bone formation. Repeated daily subcutaneous injections of AC-100 onto the calvariae in mice increased bone thickness and stimulated new bone formation as determined by the calcein doublelabeling technique. However, peptides in which the RGD or SGDG sequence was scrambled did not stimulate new bone formation in vivo. AC-100 increased cell proliferation and alkaline phosphatase activity and activated focal adhesion kinase (FAK) and extracellular signal-regulated protein kinase (ERK) in human primary osteoblasts. Conclusion: Our results show that a synthetic peptide corresponding with the sequence of human MEPE fragment stimulates new bone formation with increased number of osteoblasts. The results also suggest that the RGD and SGDG motifs are critical to the osteogenic activity of AC-100, presumably through activating integrin signaling pathways in osteoblasts. The anabolic effects of AC-100 may be beneficial for bone diseases associated with decreased bone formation.

The orphan nuclear receptor Nur77 plays critical roles in cardiovascular diseases, and its expression is markedly induced in the heart after beta-adrenergic receptor (␤-AR) activation. However, the functional significance of Nur77 in ␤-AR signaling in the heart remains unclear. By using Northern blot, Western blot, and immunofluorescent staining assays, we showed that Nur77 expression was markedly upregulated in cardiomyocytes in response to multiple hypertrophic stimuli, including isoproterenol (ISO), phenylephrine (PE), and endothelin-1 (ET-1). In a time-and dose-dependent manner, ISO increases Nur77 expression in the nuclei of cardiomyocytes. Overexpression of Nur77 markedly inhibited ISO-induced cardiac hypertrophy by inducing nuclear translocation of Nur77 in cardiomyocytes. Furthermore, cardiac overexpression of Nur77 by intramyocardial injection of Ad-Nur77 substantially inhibited cardiac hypertrophy and ameliorated cardiac dysfunction after chronic infusion of ISO in mice. Mechanistically, we demonstrated that Nur77 functionally interacts with NFATc3 and GATA4 and inhibits their transcriptional activities, which are critical for the development of cardiac hypertrophy. These results demonstrate for the first time that Nur77 is a novel negative regulator for the ␤-AR-induced cardiac hypertrophy through inhibiting the NFATc3 and GATA4 transcriptional pathways. Targeting Nur77 may represent a potentially novel therapeutic strategy for preventing cardiac hypertrophy and heart failure. Cardiac hypertrophy is an adaptive process in response to various physiological or pathological stimuli associated with neurohumoral activation, elevated wall stress, and changes in volume load (1). Although initially adaptive, persistent hypertrophy induced by pathological conditions like myocardial infarction and hypertension has detrimental consequences on the heart and eventually progresses to heart failure, a major cause of death and disability in the industrialized world (1). At cellular and molecular levels, cardiac hypertrophy is characterized by increased myocyte size, sarcomerogenesis, and reexpression of a set of fetal genes, such as the atrial natriuretic factor, B-type natriuretic peptide, and ␤-myosin heavy chain genes, which are coordinately controlled by a subset of hypertrophy-responsive transcription factors, including myocyte enhancer factor 2 (MEF2), nuclear factor of activated T cells (NFAT), and GATA4 (2, 3) (4). Depending on the upstream hypertrophic stimuli, these transcriptional regulators can be directly phosphorylated or dephosphorylated by protein kinases, such as mitogen-activated protein (MAP) kinase and protein kinases A and C, as well as the calcium-activated phosphatase calcineurin, to facilitate hypertrophic gene expression (5-9). Disruption and/or attenuation of the activities of these transcription factors could serve as a potential therapeutic approach in terms of inhibiting the hypertrophic responses in the heart (10-12).NR4A receptors are immediate early genes that are regulated by various ...

Ligation of the intersphincteric fistula tract plus a bioprosthetic anal fistula plug is an easy, safe, effective and useful alternative in the management of anal fistula. Further randomized controlled studies are necessary to better evaluate long-term results.

Background: Protein arginine methyltransferase 5 (PRMT5) is a type II protein arginine methyltransferase that catalyzes the symmetrical dimethylation of arginine residues within target proteins. Results: PRMT5 interacts with and methylates GATA4 in cardiomyocytes. Conclusion: PRMT5 suppresses hypertrophic responses in cardiomyocytes by attenuating GATA4 transcriptional activity. Significance: Targeting PRMT5 may represent a novel therapeutic strategy for preventing cardiac hypertrophy and heart failure.