Identification of an angiogenic factor that when mutated causes susceptibility to Klippel–Trenaunay syndrome

Functions and clinical significance of circular RNAs in glioma

CircRNAs are a class of single-stranded RNA molecules with a covalently closed loop structure and have been characterized by high stability, abundance, conservation, and display tissue/developmental stage-specific expression, furthermore, based on the abundance in distinct body fluids or exosomes, circRNAs present novel biomarkers and targets for the diagnosis and prognosis of cancers. Recently, the regulatory mechanisms of biogenesis and molecular functions, including miRNAs and RBPs sponge, translation as well as transcriptional and splicing regulation, have been gradually uncovered, although various aspects remained to be elucidated in combination with deep-sequence and bioinformatics. Accumulating studies have indicated that circRNAs are more enriched in neuronal tissues partly due to the abundance of specific genes promoting circularization, suggesting dysregulation of circRNAs is closely related to diseases of the nervous system, including glioma. In this review, we elaborate on the biogenesis, functions, databases as well as novel advances especially involved in the molecular pathways, highlight its great value as diagnostic or therapeutic targets in glioma.

The 3' Untranslated Region Protects the Heart from Angiotensin II-Induced Cardiac Dysfunction via AGGF1 Expression

The messenger RNA (mRNA) 3' untranslated regions (3' UTRs), as cis-regulated elements bound by microRNAs (miRNAs), affect their gene translation. However, the role of the trans-regulation of 3' UTRs during heart dysfunction remains elusive. Compared with administration of angiogenic factor with G-patch and forkhead-associate domains 1 (Aggf1), ectopic expression of Aggf1 with its 3' UTR significantly suppressed cardiac dysfunction in angiotensin II-infused mice, with upregulated expression of both Aggf1 and myeloid cell leukemia 1 (Mcl1). Along their 3' UTRs, Mcl1 and Aggf1 mRNAs share binding sites for the same miRNAs, including miR-105, miR-101, and miR-93. We demonstrated that the protein-coding Mcl1 and Aggf1 mRNAs communicate and co-regulate each other's expression through competition for these three miRNAs that target both transcripts via their 3' UTRs. Our results indicate that Aggf1 3' UTR, as a trans-regulatory element, accelerates the cardioprotective role of Aggf1 in response to hypertensive conditions by elevating Mcl1 expression. Our work broadens the scope of gene therapy targets and provides a new insight into gene therapy strategies involving 3' UTRs.

Elevated expression of AGGF1 predicts poor prognosis and promotes the metastasis of colorectal cancer

Background

Angiogenic factor with G-patch and FHA domains 1 (AGGF1) can promote angiogenesis and increasing evidence has highlighted the important roles of AGGF1 in tumorigenesis. However, the differential expression as well as the biological functions of AGGF1 in colorectal cancer (CRC) remain to be established. The purpose of the present study is therefore to identify the effect of AGGF1 on prognosis and metastasis in CRC patients.

Methods

The expression level of AGGF1 in CRC was examined by qPCR, western blot and immunohistochemistry in a tissue microarray containing 236 CRC specimens and paired normal mucosae. And the effect of AGGF1 on CRC cell malignance was investigated in our established stable AGGF1 upregulated and knockdown CRC cell lines.

Results

The expression level of AGGF1 in CRC tissue was not significantly different to that in adjacent normal mucosa at the mRNA level. However, at the protein level, AGGF1 expression in CRC tissues was significantly higher than in paired normal mucosa, which showed a clear association with TNM stage, AJCC stage, vascular invasion, and differentiation. Further, we revealed an apparent correlation between AGGF1 expression and poorer disease-free survival and overall survival of CRC patients. In addition, we discovered that AGGF1 significantly promoted CRC cell wound healing, migration, and invasion in vitro and distant metastasis in vivo.

Conclusions

Our study demonstrates the aberrant overexpression of AGGF1 in CRC and provides a basis on which to explore the application of AGGF1 as a potential therapeutic target for CRC patients, especially for CRC patients with distant metastasis.

Promiscuous Chemokine Antagonist (BKT130) Suppresses Laser-Induced Choroidal Neovascularization by Inhibition of Monocyte Recruitment

Background

Age-related macular degeneration (AMD), the most common cause of blindness in the developed world, usually affects individuals older than 60 years of age. The majority of visual loss in this disease is attributable to the development of choroidal neovascularization (CNV). Mononuclear phagocytes, including monocytes and their tissue descendants, macrophages, have long been implicated in the pathogenesis of neovascular AMD (nvAMD). Current therapies for nvAMD are based on targeting vascular endothelial growth factor (VEGF). This study is aimed at assessing if perturbation of chemokine signaling and mononuclear cell recruitment may serve as novel complementary therapeutic targets for nvAMD.

Methods

A promiscuous chemokine antagonist (BKT130), aflibercept treatment, or combined BKT130+aflibercept treatment was tested in an in vivo laser-induced model of choroidal neovascularization (LI-CNV) and in an ex vivo choroidal sprouting assay (CSA). Quantification of CD11b+ cell in the CNV area was performed, and mRNA levels of genes implicated in CNV growth were measured in the retina and RPE-choroid.

Results

BKT130 reduced the CNV area and recruitment of CD11b+ cells by 30-35%. No effect of BKT130 on macrophages' proangiogenic phenotype was demonstrated ex vivo, but a lower VEGFA and CCR2 expression was found in the RPE-choroid and a lower expression of TNFα and NOS1 was found in both RPE-choroid and retinal tissues in the LI-CNV model under treatment with BKT130.

Conclusions

Targeting monocyte recruitment via perturbation of chemokine signaling can reduce the size of experimental CNV and should be evaluated as a potential novel therapeutic modality for nvAMD.

Angiogenic Factor AGGF1-Primed Endothelial Progenitor Cells Repair Vascular Defect in Diabetic Mice

Hyperglycemia-triggered vascular abnormalities are the most serious complications of diabetes mellitus (DM). The major cause of vascular dysfunction in DM is endothelial injury and dysfunction associated with the reduced number and dysfunction of endothelial progenitor cells (EPCs). A major challenge is to identify key regulators of EPCs to restore DM-associated vascular dysfunction. We show that EPCs from heterozygous knockout Aggf1^+/- mice presented with impairment of proliferation, migration, angiogenesis, and transendothelial migration as in hyperglycemic mice fed a high-fat diet (HFD) or db/db mice. The number of EPCs from Aggf1^+/- mice was significantly reduced. Ex vivo, AGGF1 protein can fully reverse all damaging effects of hyperglycemia on EPCs. In vivo, transplantation of AGGF1-primed EPCs successfully restores blood flow and blocks tissue necrosis and ambulatory impairment in HFD-induced hyperglycemic mice or db/db mice with diabetic hindlimb ischemia. Mechanistically, AGGF1 activates AKT, reduces nuclear localization of Fyn, which increases the nuclear level of Nrf2 and expression of antioxidative genes, and inhibits reactive oxygen species generation. These results suggest that Aggf1 is required for essential function of EPCs, AGGF1 fully reverses the damaging effects of hyperglycemia on EPCs, and AGGF1 priming of EPCs is a novel treatment modality for vascular complications in DM.

Cerebral Cavernous Angioma Associated with Klippel Trenaunay Syndrome Treated with Gamma Knife Radiosurgery: Case Report and Literature Review

Klippel Trenaunay syndrome (KTS) is a rare, sporadic congenital syndrome characterized by cutaneous hemangiomas, venous varicosities, and osseous-soft tissue hypertrophy of the affected limb. It is genetically heterogeneous, and its clinical presentation is variable.

We report the case of a 13-year-old male with KTS, who presented with a cerebral cavernous angioma in the corpus callosum. To the best of our knowledge, this is the first reported case of its kind from Pakistan and the only known case in the literature of KTS to be treated with stereotactic radiosurgery.

The possibilities of shared genetic pathways between KTS and cavernous angiomas and the need for neurovascular scrutiny in patients with this syndrome are discussed.

Knockdown of AGGF1 inhibits the invasion and migration of gastric cancer via epithelial-mesenchymal transition through Wnt/β-catenin pathway

Background

Angiogenic factor with G-patch and FHA domain 1 (AGGF1), as a newly identified human angiogenic factor, is overexpressed in some types of malignant tumors and closely associated with patient’s prognosis. However, the mechanisms involved in the regulation of AGGF1 in gastric cancer (GC) still remain unclear.

Methods

In this study, AGGF1 level in GC tissues and cell lines was analyzed by western blot and quantitative real-time polymerase chain reaction (qRT-PCR). After knockdown of AGGF expression by RNA interference in GC cell lines MKN-45 and MGC-803, wound healing and transwell assays were conducted to examine the effects of AGGF1 on migration and invasion. Tumor growth was assessed in a mouse xenograft model in vivo. Furthermore, expression levels of epithelial–mesenchymal transition (EMT) biomarkers and involvement of the Wnt/β-catenin pathway were detected by western blot and qRT-PCR.

Results

Compared to those in normal groups, the protein and mRNA of AGGF1 expression levels were significantly higher both in GC tissues and cell lines (all P < 0.05). Knockdown of AGGF1 dramatically inhibited the invasion and migration of MKN-45 and MGC-803 cells (all P < 0.01) in vitro, and suppressed the tumor growth of nude mice xenograft model in vivo. Western blot revealed alterations in EMT biomarkers, suggesting the role of AGGF1 in EMT. Moreover, we found that downregulated expression of AGGF1 attenuated Wnt/β-catenin related protein expression.

Conclusions

Collectively, knockdown of AGGF1 inhibits the invasion and migration of gastric cancer via epithelial–mesenchymal transition through Wnt/β-catenin pathway.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0765-6) contains supplementary material, which is available to authorized users.

High Expression Levels of AGGF1 and MFAP4 Predict Primary Platinum-Based Chemoresistance and are Associated with Adverse Prognosis in Patients with Serous Ovarian Cancer

Primary platinum-based chemoresistance occurs in approximately one-third of patients with serous ovarian cancer (SOC); however, traditional clinical indicators are poor predictors of chemoresistance. So we aimed to identify novel genes as predictors of primary platinum-based chemoresistance. Gene expression microarray analyses were performed to identify the genes related to primary platinum resistance in SOC on two discovery datasets (GSE51373, GSE63885) and one validation dataset (TCGA). Univariate and multivariate analyses with logistic regression were performed to evaluate the predictive values of the genes for platinum resistance. Machine learning algorithms (linear kernel support vector machine and artificial neural network) were applied to build prediction models. Univariate and multivariate analyses with Cox proportional hazards regression and log-rank tests were used to assess the effects of these gene signatures for platinum resistance on prognosis in two independent datasets (GSE9891, GSE32062). AGGF1 and MFAP4 were found highly expressed in patients with platinum-resistant SOC and independently predicted platinum resistance. Platinum resistance prediction models based on these targets had robust predictive power (highest AUC: 0.8056, 95% CI: 0.6338-0.9773; lowest AUC: 0.7245, 95% CI: 0.6052-0.8438). An AGGF1- and MFAP4-centered protein interaction network was built, and hypothetical regulatory pathways were identified. Enrichment analysis indicated that aberrations of extracellular matrix may play important roles in platinum resistance in SOC. High AGGF1 and MFAP4 expression levels were also related to shorter recurrence-free and overall survival in patients with SOC after adjustment for other clinical variables. Therefore, AGGF1 and MFAP4 are potential predictive biomarkers for response to platinum-based chemotherapy and survival outcomes in SOC.

Pseudoacromegaly

Individuals with acromegaloid physical appearance or tall stature may be referred to endocrinologists to exclude growth hormone (GH) excess. While some of these subjects could be healthy individuals with normal variants of growth or physical traits, others will have acromegaly or pituitary gigantism, which are, in general, straightforward diagnoses upon assessment of the GH/IGF-1 axis. However, some patients with physical features resembling acromegaly - usually affecting the face and extremities -, or gigantism - accelerated growth/tall stature - will have no abnormalities in the GH axis. This scenario is termed pseudoacromegaly, and its correct diagnosis can be challenging due to the rarity and variability of these conditions, as well as due to significant overlap in their characteristics. In this review we aim to provide a comprehensive overview of pseudoacromegaly conditions, highlighting their similarities and differences with acromegaly and pituitary gigantism, to aid physicians with the diagnosis of patients with pseudoacromegaly.

Mechanistic insights into the interaction of the MOG1 protein with the cardiac sodium channel Nav1.5 clarify the molecular basis of Brugada syndrome

Na_v1.5 is the α-subunit of the cardiac sodium channel complex. Abnormal expression of Na_v1.5 on the cell surface because of mutations that disrupt Na_v1.5 trafficking causes Brugada syndrome (BrS), sick sinus syndrome (SSS), cardiac conduction disease, dilated cardiomyopathy, and sudden infant death syndrome. We and others previously reported that Ran-binding protein MOG1 (MOG1), a small protein that interacts with Na_v1.5, promotes Na_v1.5 intracellular trafficking to plasma membranes and that a substitution in MOG1, E83D, causes BrS. However, the molecular basis for the MOG1/Nav1.5 interaction and how the E83D substitution causes BrS remains unknown. Here, we assessed the effects of defined MOG1 deletions and alanine-scanning substitutions on MOG1's interaction with Na_v1.5. Large deletion analysis mapped the MOG1 domain required for the interaction with Na_v1.5 to the region spanning amino acids 146-174, and a refined deletion analysis further narrowed this domain to amino acids 146-155. Site-directed mutagenesis further revealed that Asp-148, Arg-150, and Ser-151 cluster in a peptide loop essential for binding to Na_v1.5. GST pulldown and electrophysiological analyses disclosed that the substitutions E83D, D148Q, R150Q, and S151Q disrupt MOG1's interaction with Na_v1.5 and significantly reduce its trafficking to the cell surface. Examination of MOG1's 3D structure revealed that Glu-83 and the loop containing Asp-148, Arg-150, and Ser-151 are spatially proximal, suggesting that these residues form a critical binding site for Na_v1.5. In conclusion, our findings identify the structural elements in MOG1 that are crucial for its interaction with Na_v1.5 and improve our understanding of how the E83D substitution causes BrS.

Advances of circular RNAs in carcinoma

Circular RNAs (circRNAs) are a type of non-coding RNAs with single-stranded closed structure. The rapid development of high-throughput sequencing technology has allowed for the widespread presence of circRNAs in transcriptomes. Moreover, increasing studies have identified a correlation between circRNAs and different cancers. In addition, most circRNAs are dysregulated in various cancers, and some of them have been reported be vital in the occurrence and development of tumors. For example, ciRS-7 plays a role in tumor promotion and circ-ITCH acts as a tumor suppressor. This review summarizes the latest progressions in the field regarding the functions of circRNAs in relation with cancers, and anticipates the emerging roles of circRNAs and future challenges in cancer research.

[ole of AGGF1 in DNA damage repair and modulating chemotherapy resistance in human colon cancer cells in vitro]

OBJECTIVE

To investigate the role of AGGF1 in DNA damage repair and modulating chemotherapy resistance in human colon cancer cells.

METHODS

Cisplatin-induced human colon cancer HCT116 cells transfected with AGGF1 siRNA and siNC via Lipofectamine 2000 were examined for AGGF1, γH2AX and pNBS1 expressions using Western blotting. Immunofluorescence analysis was used to detect the recruitment of phosphorylated γH2AX and AGGF1 at the site of cisplatin-induced double-strand DNA breaks, and MTS method was used to investigate the proliferation of the damaged cells. Immunohistochemical method was used to detect the expression level of AGGF1 in human colon cancer and adjacent normal tissues.

RESULTS

Western blotting showed that AGGF1 expression was significantly down-regulated in HCT116 cells after cisplatin exposure, and transfection withAGGF1 siRNAobviously inhibited the expression of phosphorylated γH2AX and NBS1. Immunofluorescence assay showed the co-localization of AGGF1 and γH2AX. Down-regulation of AGGF1 mediated by siRNA obviously increased the chemosensitivity of the cells (P < 0.01). In the clinical specimens, AGGF1 was found to be overexpressed in colon cancer tissues as compared with the adjacent normal tissues (P < 0.01), suggesting its association with the malignant phenotype of the tumor.

CONCLUSIONS

Down-regulation of AGGF1 inhibits DNA damage repair and increases the chemosensitivity in colon cancer cells possibly in relation with the suppressed phosphorylation of NBS1.

High levels of serum sclerostin and DKK1 in a case of Klippel-Trénaunay syndrome

Klippel-Trénaunay syndrome (KTS) is described as a complex syndrome characterized by various combinations of capillary, venous, and lymphatic malformations associated with bone and soft tissue hypertrophy. We report a case of a 67-year-old postmenopausal Caucasian women with KTS that shows elevated levels of sclerostin and Dickkopf-related protein 1 (DKK1). Dual-energy X-ray absorptiometry (DXA) BMD T-scores at lumbar spine and femur were normal. Serum calcium and phosphorus levels were consistently normal, 25-hydroxyvitamin D (25OHD) < 30 ng/mL, and normal parathyroid hormone (PTH). Turnover markers (serum osteocalcin [OCN], and carboxy-terminal cross-linking telopeptide of type 1 collagen [CTx]) were in the reference limits. It is interesting to note that the serum levels of sclerostin and DKK-1 were significantly higher in our patient with KTS than in a healthy volunteer (control), without impact on bone mineral density and bone formation markers. In fact, in our patient, the BMD at lumbar spine and femur was normal, and osteocalcin was not suppressed. Based on what is known, we would have expected to find low levels of the inhibitors of the Wnt system, perhaps we can explain the data as a response to the compensation for β-catenin hyper-transformation.

Aggf1 attenuates neuroinflammation and BBB disruption via PI3K/Akt/NF-κB pathway after subarachnoid hemorrhage in rats

Background

Neuroinflammation and blood-brain barrier (BBB) disruption are two critical mechanisms of subarachnoid hemorrhage (SAH)-induced brain injury, which are closely related to patient prognosis. Recently, angiogenic factor with G-patch and FHA domain 1 (Aggf1) was shown to inhibit inflammatory effect and preserve vascular integrity in non-nervous system diseases. This study aimed to determine whether Aggf1 could attenuate neuroinflammation and preserve BBB integrity after experimental SAH, as well as the underlying mechanisms of its protective roles.

Methods

Two hundred forty-nine male Sprague-Dawley rats were subjected to the endovascular perforation model of SAH. Recombinant human Aggf1 (rh-Aggf1) was administered intravenously via tail vein injection at 1 h after SAH induction. To investigate the underlying neuroprotection mechanism, Aggf1 small interfering RNA (Aggf1 siRNA) and PI3K-specific inhibitor LY294002 were administered through intracerebroventricular (i.c.v.) before SAH induction. SAH grade, neurological score, brain water content, BBB permeability, Western blot, and immunohistochemistry were performed.

Results

Expression of endogenous Aggf1 was markedly increased after SAH. Aggf1 was primarily expressed in endothelial cells and astrocytes, as well as microglia after SAH. Administration of rh-Aggf1 significantly reduced brain water content and BBB permeability, decreased the numbers of infiltrating neutrophils, and activated microglia in the ipsilateral cerebral cortex following SAH. Furthermore, rh-Aggf1 treatment improved both short- and long-term neurological functions after SAH. Meanwhile, exogenous rh-Aggf1 significantly increased the expression of PI3K, p-Akt, VE-cadherin, Occludin, and Claudin-5, as well as decreased the expression of p-NF-κB p65, albumin, myeloperoxidase (MPO), TNF-α, and IL-1β. Conversely, knockdown of endogenous Aggf1 aggravated BBB breakdown, inflammatory response and neurological impairments at 24 h after SAH. Additionally, the protective roles of rh-Aggf1 were abolished by LY294002.

Conclusions

Taken together, exogenous Aggf1 treatment attenuated neuroinflammation and BBB disruption, improved neurological deficits after SAH in rats, at least in part through the PI3K/Akt/NF-κB pathway.

Electronic supplementary material

The online version of this article (10.1186/s12974-018-1211-8) contains supplementary material, which is available to authorized users.

Angiotensin II increases angiogenesis by NF-κB-mediated transcriptional activation of angiogenic factor AGGF1

Angiogenic factor with G-patch and FHA domains 1 (AGGF1) is involved in vascular development, angiogenesis, specification of hemangioblasts, and differentiation of veins. When mutated, however, it causes Klippel-Trenaunay syndrome, a vascular disorder. In this study, we show that angiotensin II (AngII)-the major effector of the renin-angiotensin system and one of the most important regulators of the cardiovascular system-induces the expression of AGGF1 through NF-κB, and that AGGF1 plays a key role in AngII-induced angiogenesis. AngII significantly up-regulated the levels of AGGF1 mRNA and protein in HUVECs at concentrations of 10-40 μg/ml but not >60 μg/ml. AngII type 1 receptor (AT1R) inhibitor losartan inhibited AngII-induced up-regulation of AGGF1, whereas AT2R inhibitor PD123319 further increased AngII-induced up-regulation of AGGF1. Up-regulation of AGGF1 by AngII was blocked by NF-κB inhibitors, and p65 binds directly to a binding site at the promoter/regulatory region of AGGF1 and transcriptionally activates AGGF1 expression. AngII-induced endothelial tube formation was blocked by small interfering RNAs (siRNAs) for RELA (RELA proto-oncogene, NF-κB subunit)/p65 or AGGF1, and the effect of RELA siRNA was rescued by AGGF1. AngII-induced angiogenesis from aortic rings was severely impaired in Aggf1^+/- mice, and the effect was restored by AGGF1. These data suggest that AngII acts as a critical regulator of AGGF1 expression through NF-κB, and that AGGF1 plays a key role in AngII-induced angiogenesis.-Si, W., Xie, W., Deng, W., Xiao, Y., Karnik, S. S., Xu, C., Chen, Q., Wang, Q. K. Angiotensin II increases angiogenesis by NF-κB-mediated transcriptional activation of angiogenic factor AGGF1.

circ-SHKBP1 Regulates the Angiogenesis of U87 Glioma-Exposed Endothelial Cells through miR-544a/FOXP1 and miR-379/FOXP2 Pathways

Circular RNAs (circRNAs) are a type of endogenous non-coding RNAs, which have been considered to mediate diverse tumorigenesis including angiogenesis. The present study aims to elucidate the potential role and molecular mechanism of circ-SHKBP1 in regulating the angiogenesis of U87 glioma-exposed endothelial cells (GECs). The expression of circ-SHKBP1, but not linear SHKBP1, was significantly upregulated in GECs compared with astrocyte-exposed endothelial cells (AECs). circ-SHKBP1 knockdown inhibited the viability, migration, and tube formation of GECs dramatically. The expressions of miR-379/miR-544a were downregulated in GECs, and circ-SHKBP1 functionally targeted miR-544a/miR-379 in an RNA-induced silencing complex (RISC) manner. Dual-luciferase reporter assay demonstrated that forkhead box P1/P2 (FOXP1/FOXP2) were targets of miR-544a/miR-379. The expressions of FOXP1/FOXP2 were upregulated in GECs, and silencing of FOXP1/FOXP2 inhibited the viability, migration, and tube formation of GECs. Meanwhile, FOXP1/FOXP2 promoted angiogenic factor with G patch and FHA domains 1 (AGGF1) expression at the transcriptional level. Furthermore, knockdown of AGGF1 suppressed the viability, migration, and tube formation of GECs via phosphatidylinositol 3-kinase (PI3K)/AKT and extracellular signal-regulated kinase (ERK)1/2 pathways. Taken together, the present study demonstrated that circ-SHKBP1 regulated the angiogenesis of GECs through miR-544a/FOXP1 and miR-379/FOXP2 pathways, and these findings might provide a potential target and effective strategy for combined therapy of gliomas.

Identification of a mutation in CNNM4 by whole exome sequencing in an Amish family and functional link between CNNM4 and IQCB1

We investigated an Amish family in which three siblings presented with an early-onset childhood retinal dystrophy inherited in an autosomal recessive fashion. Genome-wide linkage analysis identified significant linkage to marker D2S2216 on 2q11 with a two-point LOD score of 1.95 and a multi-point LOD score of 3.76. Whole exome sequencing was then performed for the three affected individuals and identified a homozygous nonsense mutation (c.C1813T, p.R605X) in the cyclin and CBS domain divalent metal cation transport mediator 4 (CNNM4) gene located within the 2p14-2q14 Jalili syndrome locus. The initial assessment and collection of the family were performed before the clinical delineation of Jalili syndrome. Another assessment was made after the discovery of the responsible gene and the dental abnormalities characteristic of Jalili syndrome were retrospectively identified. The p.R605X mutation represents the first probable founder mutation of Jalili syndrome identified in the Amish community. The molecular mechanism underlying Jalili syndrome is unknown. Here we show that CNNM4 interacts with IQCB1, which causes Leber congenital amaurosis (LCA) when mutated. A truncated CNNM4 protein starting at R605 significantly increased the rate of apoptosis, and significantly increased the interaction between CNNM4 and IQCB1. Mutation p.R605X may cause Jalili syndrome by a nonsense-mediated decay mechanism, affecting the function of IQCB1 and apoptosis, or both. Our data, for the first time, functionally link Jalili syndrome gene CNNM4 to LCA gene IQCB1, providing important insights into the molecular pathogenic mechanism of retinal dystrophy in Jalili syndrome.

High expression of angiogenic factor AGGF1 is an independent prognostic factor for hepatocellular carcinoma

Background

Angiogenesis plays a critical role in tumor growth and metastasis. Angiogenic factor with G patch and FHA domains 1 (AGGF1) has been recently identified as a novel initiator of angiogenesis. However, the function and the prognostic values of AGGF1 in hepatocellular carcinoma remain poorly understood. Our aim is to provide more information to assist design the angiogenesis therapy that targets AGGF1 in HCC.

Results

AGGF1-positive frequency in HCC tissues was significantly higher than in peritumor tissues. The high expression of AGGF1 expression in HCC tissue was well associated with the increased expression of VEGF and the high microvessel density (MVD). AGGF1 expression predicts a poor prognosis and AGGF1 was an independent prognostic factor for DFS.

Methods

The expression levels of AGGF1, vascular endothelial growth factor (VEGF) and microvessel density (MVD) were identified by immunohistochemistry in 79 HCC tumor tissues and 24 corresponding peritumor tissues. The expression level of AGGF1 and MVD were quantified by counting the positively stained endothelial cells in the HCC and the peritumor tissue on the immunohistochemically stained tissue slides. The prognostic value of AGGF1 was evaluated by survival analysis.

Conclusions

Our study shows that AGGF1 is identified as the independent prognostic factor for the disease-free survival (DFS) of patients after the surgical resection. contribute to tumor angiogenesis in HCC, which indicates that AGGF1 may be a new potential therapeutic target for anti-angiogenesis treatment for patients with HCC.

A non-canonical pathway regulates ER stress signaling and blocks ER stress-induced apoptosis and heart failure

Endoplasmic reticulum stress is an evolutionarily conserved cell stress response associated with numerous diseases, including cardiac hypertrophy and heart failure. The major endoplasmic reticulum stress signaling pathway causing cardiac hypertrophy involves endoplasmic reticulum stress sensor PERK (protein kinase-like kinase) and eIF2α-ATF4-CHOP signaling. Here, we describe a non-canonical, AGGF1-mediated regulatory system for endoplasmic reticulum stress signaling associated with increased p-eIF2α and ATF4 and decreased sXBP1 and CHOP. Specifically, we see a reduced AGGF1 level consistently associated with induction of endoplasmic reticulum stress signaling in mouse models and human patients with heart failure. Mechanistically, AGGF1 regulates endoplasmic reticulum stress signaling by inhibiting ERK1/2 activation, which reduces the level of transcriptional repressor ZEB1, leading to induced expression of miR-183-5p. miR-183-5p post-transcriptionally downregulates CHOP and inhibits endoplasmic reticulum stress-induced apoptosis. AGGF1 protein therapy and miR-183-5p regulate endoplasmic reticulum stress signaling and block endoplasmic reticulum stress-induced apoptosis, cardiac hypertrophy, and heart failure, providing an attractive paradigm for treatment of cardiac hypertrophy and heart failure.

Endoplasmic reticulum (ER) stress promotes cardiac dysfunction. Here the authors uncover a pathway whereby AGGF1 blocks ER stress by inhibiting ERK1/2 activation and the transcriptional repressor ZEB1, leading to induction of miR-183-5p and down-regulation of CHOP, and show that AGGF1 can effectively treat cardiac hypertrophy and heart failure.

Haploinsufficiency of Klippel-Trenaunay syndrome gene Aggf1 inhibits developmental and pathological angiogenesis by inactivating PI3K and AKT and disrupts vascular integrity by activating VE-cadherin

Aggf1 is the first gene identified for Klippel-Trenaunay syndrome (KTS), and encodes an angiogenic factor. However, the in vivo roles of Aggf1 are incompletely defined. Here we demonstrate that Aggf1 is essential for both physiological angiogenesis and pathological tumour angiogenesis in vivo. Two lines of Aggf1 knockout (KO) mice showed a particularly severe phenotype as no homozygous embryos were observed and heterozygous mice also showed embryonic lethality (haploinsufficient lethality) observed only for Vegfa and Dll4. Aggf1+/- KO caused defective angiogenesis in yolk sacs and embryos. Survived adult heterozygous mice exhibit frequent haemorrhages and increased vascular permeability due to increased phosphorylation and reduced membrane localization of VE-cadherin. AGGF1 inhibits VE-cadherin phosphorylation, increases plasma membrane VE-cadherin in ECs and in mice, blocks vascular permeability induced by ischaemia-reperfusion (IR), restores depressed cardiac function and contraction, reduces infarct sizes, cardiac fibrosis and necrosis, haemorrhages, edema, and macrophage density associated with IR. Mechanistically, AGGF1 promotes angiogenesis by activating catalytic p110α subunit and p85α regulatory subunit of PI3K, leading to activation of AKT, GSK3β and p70S6K. AKT activation is significantly reduced in heterozygous KO mice and isolated KO ECs, which can be rescued by exogenous AGGF1. ECs from KO mice show reduced capillary angiogenesis, which is rescued by AGGF1 and AKT. Tumour growth/angiogenesis is reduced in heterozygous mice, which was associated with reduced activation of p110α, p85α and AKT. Together with recent identification of somatic mutations in p110α (encoded by PIK3CA), our data establish a potential mechanistic link between AGGF1 and PIK3CA, the two genes identified for KTS.

Targeting AGGF1 (angiogenic factor with G patch and FHA domains 1) for Blocking Neointimal Formation After Vascular Injury

Background

Despite recent improvements in angioplasty and placement of drug‐eluting stents in treatment of atherosclerosis, restenosis and in‐stent thrombosis impede treatment efficacy and cause numerous deaths. Research efforts are needed to identify new molecular targets for blocking restenosis. We aim to establish angiogenic factor AGGF1 (angiogenic factor with G patch and FHA domains 1) as a novel target for blocking neointimal formation and restenosis after vascular injury.

Methods and Results

AGGF1 shows strong expression in carotid arteries; however, its expression is markedly decreased in arteries after vascular injury. AGGF1^+/− mice show increased neointimal formation accompanied with increased proliferation of vascular smooth muscle cells (VSMCs) in carotid arteries after vascular injury. Importantly, AGGF1 protein therapy blocks neointimal formation after vascular injury by inhibiting the proliferation and promoting phenotypic switching of VSMCs to the contractile phenotype in mice in vivo. In vitro, AGGF1 significantly inhibits VSMCs proliferation and decreases the cell numbers at the S phase. AGGF1 also blocks platelet‐derived growth factor‐BB–induced proliferation, migration of VSMCs, increases expression of cyclin D, and decreases expression of p21 and p27. AGGF1 inhibits phenotypic switching of VSMCs to the synthetic phenotype by countering the inhibitory effect of platelet‐derived growth factor‐BB on SRF expression and the formation of the myocardin/SRF/CArG‐box complex involved in activation of VSMCs markers. Finally, we show that AGGF1 inhibits platelet‐derived growth factor‐BB–induced phosphorylation of MEK1/2, ERK1/2, and Elk phosphorylation involved in the phenotypic switching of VSMCs, and that overexpression of Elk abolishes the effect of AGGF1.

Conclusions

AGGF1 protein therapy is effective in blocking neointimal formation after vascular injury by regulating a novel AGGF1‐MEK1/2‐ERK1/2‐Elk‐myocardin‐SRF/p27 signaling pathway.

Androgen inhibits key atherosclerotic processes by directly activating ADTRP transcription

Low androgen levels are associated with an increased risk of coronary artery disease (CAD), thrombosis and myocardial infarction (MI), suggesting that androgen has a protective role. However, little is known about the underlying molecular mechanism. Our genome-wide association study identified the ADTRP gene encoding the androgen-dependent TFPI regulating protein as a susceptibility gene for CAD and MI. The expression level of ADTRP was regulated by androgen, but the molecular mechanism is unknown. In this study, we identified the molecular mechanism by which androgen regulates ADTRP expression and tested the hypothesis that androgen plays a protective role in cardiovascular disease by activating ADTRP expression. Luciferase assays with an ADTRP promoter luciferase reporter revealed that androgen regulated ADTRP transcription in a dose- and time-dependent manner, and the effect was abolished by three different androgen inhibitors, including pyrvinium pamoate, bicalutamide, and cyproterone acetate. Chromatin-immunoprecipitation showed that the androgen receptor bound to a half androgen response element (ARE, TGTTCT) located at +324bp from the ADTRP transcription start site. The ARE is required for concentration-dependent transcriptional activation of ADTRP. HL-60 monocyte adhesion to EAhy926 endothelial cells (ECs) and transmigration across the EC layer, the two processes critical to development of CAD and MI, were inhibited by androgen, but the effect was rescued by ADTRP siRNA and exacerbated by overexpression of ADTRP and its downstream genes PIK3R3 and MIA3. These data suggest that one molecular mechanism by which androgen confers protection against CAD is stimulation of ADTRP expression.

Klippel–Trenaunay Syndrome: Current Management

Klippel–Trenaunay syndrome (KTS) is a rare, sporadic, complex malformation characterized by the clinical triad of (1) capillary malformations (port wine stain); (2) soft tissue and bone hypertrophy or, occasionally, hypotrophy of usually one lower limb; and (3) atypical, mostly lateral varicosity. KTS is a mixed vascular malformation, with predominant capillary, venous and lymphatic components, without significant arteriovenous shunting. Management is largely conservative and the extent of diagnostic evaluation is determined by the planned treatment. Compression is the hallmark of conservative management; laser can be used to treat port wine stains. Imaging before vascular interventions must confirm venous anatomy and deep venous drainage. Techniques for ablation of superficial veins and malformations are individualized and may include sclerotherapy with alcohol or foam, endovenous thermal ablation or, as used most frequently in our practice, surgical stripping and phlebectomy. Intraoperative use of tourniquet will decrease bleeding, selective use of an inferior vena cava filter will prevent pulmonary embolism. A multidisciplinary approach to management of KTS is warranted.

High Expression of Angiogenic Factor with G-Patch and FHA Domain1 (AGGF1) Predicts Poor Prognosis in Gastric Cancer

Background

Angiogenic factor with G-patch and FHA domain1 (AGGF1 or VG5Q) is a newly identified human angiogenic factor. The aim of this study was to explore AGGF1 expression level in gastric cancer and detect its correlation with the prognosis.

Material/Methods

Immunohistochemistry was performed to detect AGGF1 level in gastric cancer and its adjacent noncancerous samples of 198 cases, and the relationships among the expression levels of AGGF1, vascular endothelial growth factor (VEGF), and prognosis were analyzed.

Results

Expression of AGGF1 in gastric cancer samples was significantly higher than that in adjacent noncancerous samples (P<0.001). The overall survival rate (OS) of patients with high AGGF1 expression was significantly lower than that of patients with low AGGF1 expression (P=0.000). The Cox model analysis demonstrated that expression of AGGF1 was an independent biomarker for prediction of patients’ survival in gastric cancer.

Conclusions

High expression of AGGF1 predicts poor prognosis in gastric cancer patients. AGGF1 can be used as an independent factor to predict postoperative survival of patients with gastric cancer.

Angiogenic Factor With G Patch and FHA Domains 1 Is a Novel Regulator of Vascular Injury

OBJECTIVE

Phenotypic modulation of vascular smooth muscle cells represents a hallmark event in vascular injury. The underlying mechanism is not completely sorted out. We investigated the involvement of angiogenic factor with G patch and FHA domains 1 (Aggf1) in vascular injury focusing on the transcriptional regulation of vascular smooth muscle cell signature genes.

APPROACH AND RESULTS

We report here that Aggf1 expression was downregulated in several different cell models of phenotypic modulation in vitro and in the vessels after carotid artery ligation in mice. Adenovirus-mediated Aggf1 overexpression dampened vascular injury and normalized vascular smooth muscle cell signature gene expression. Mechanistically, Aggf1 interacted with myocardin and was imperative for the formation of a serum response factor-myocardin complex on gene promoters. In response to injurious stimuli, kruppel-like factor 4 was recruited to the Aggf1 promoter and enlisted histone deacetylase 11 to repress Aggf1 transcription. In accordance, depletion of kruppel-like factor 4 or histone deacetylase 11 restored Aggf1 expression and abrogated vascular smooth muscle cell phenotypic modulation. Finally, treatment of a histone deacetylase 11 inhibitor attenuated vascular injury in mice.

CONCLUSIONS

Therefore, we have unveiled a previously unrecognized role for Aggf1 in regulating vascular injury.

Copy number variants in a population-based investigation of Klippel-Trenaunay syndrome

Klippel-Trenaunay syndrome (KTS) is a rare congenital vascular disorder that is thought to occur sporadically; however, reports of familial occurrence suggest a genetic component. We examined KTS cases to identify novel, potentially causal copy number variants (CNVs). We identified 17 KTS cases from all live-births occurring in New York (1998-2010). Extracted DNA was genotyped using Illumina microarrays and CNVs were called using PennCNV software. CNVs selected for follow-up had ≥10 single nucleotide polymorphisms (SNPs) and minimal overlap with in-house controls or controls from the Database of Genomic Variants. We identified 15 candidate CNVs in seven cases; among them a deletion in two cases within transcripts of HDAC9, a histone deacetylase essential for angiogenic sprouting of endothelial cells. One of them also had a duplication upstream of SALL3, a transcription factor essential for embryonic development that inhibits DNMT3A, a DNA methyltransferase responsible for embryonic de novo DNA methylation. Another case had a duplication spanning ING5, a histone acetylation regulator active during embryogenesis. We identified rare genetic variants related to chromatin modification which may have a key role in regulating vascular development during embryogenesis. Further investigation of their implications in the pathogenesis of KTS is warranted. © 2016 Wiley Periodicals, Inc.

Aggf1 attenuates hepatic inflammation and activation of hepatic stellate cells by repressing Ccl2 transcription

Liver injury represents a continuum of pathophysiological processes involving a complex interplay between hepatocytes, macrophages, and hepatic stellate cells. The mechanism whereby these intercellular interactions contribute to liver injury and fibrosis is not completely understood. We report here that angiogenic factor with G patch and FHA domains 1 (Aggf1) was downregulated in the livers of cirrhotic patients compared to healthy controls and in primary hepatocytes in response to carbon tetrachloride (CCl4) stimulation. Overexpression of Aggf1 attenuated macrophage chemotaxis. Aggf1 interacted with NF-κB to block its binding to theCcl2 gene promoter and repressed Ccl2 transcription in hepatocytes. Macrophages cultured in the conditioned media collected from Aggf1-overexpressing hepatocytes antagonized HSC activation. Taken together, our data illustrate a novel role for Aggf1 in regulating hepatic inflammation and provide insights on the development of interventional strategies against cirrhosis.

Angiogenic factor with G patch and FHA domains 1 (Aggf1) promotes hepatic steatosis in mice

Increased uptake of nutrients coupled with reduced activity leads to the development of a host of metabolic disorders in humans. In the present study we examined the role of angiogenic factor with G patch and FHA domains 1 (Aggf1) in the pathogenesis of steatosis, characterized by accumulation of lipids in the liver and consequently hepatic insulin resistance. We report here that Aggf1 expression was up-regulated in the liver in both genetically predisposed and diet-induced mouse model of steatosis. Aggf1 expression was also stimulated by free fatty acids in primary hepatocytes. Over-expression of Aggf1 in mice promoted steatosis. On the contrary, Aggf1 depletion ameliorated steatosis in mice. Mechanistically, Aggf1 activated the expression of gluconeogenesis gene and skewed the insulin signaling pathway to induce insulin resistance. Taken together, our data suggest that Aggf1 plays a role in steatosis in vivo and as such may be a new target in the development of therapeutics solutions against steatosis.

Polymorphic Variants rs13155212 (T/C) and rs7704267 (G/C) in the AGGF1 Gene and Risk of Varicose Veins of the Lower Extremities in the Population of Ethnic Russians

We analyzed associations between single nucleotide polymorphisms (SNP) rs13155212 and rs7704267 in the AGGF1 gene (angiogenic factor with G patch and FHA domains 1) and the risk of risk of varicose veins of the legs in ethnic Russians. Frequencies of alleles, genotypes, and haplotypes were estimated in the sample of patients with this disease (474 patients) and in the control group of participants (478 volunteers) without a history of chronic venous disease. None of the studied polymorphisms was associated with the risk of this pathology. The whole AGGF1 gene sequence lies in a single block of high linkage disequilibrium, and both studied polymorphic variants are representative of all other SNP within this region. From these results, a conclusion was made that AGGF1 gene polymorphism does not affect the risk of varicose veins of the legs in ethnic Russians, or its contribution is low and can be revealed only after analysis of larger cohorts.

Up-regulation of miR-95-3p in hepatocellular carcinoma promotes tumorigenesis by targeting p21 expression

Hepatocellular carcinoma (HCC) is one of the most common malignant cancers. To elucidate new regulatory mechanisms for heptocarcinogenesis, we investigated the regulation of p21, a cyclin-dependent kinase (CDK) inhibitor encoded by CDKN1A, in HCC. The expression level of p21 is decreased with the progression of HCC. Luciferase assays with a luciferase-p21-3' UTR reporter and its serial deletions identified a 15-bp repressor element at the 3'-UTR of CDKN1A, which contains a binding site for miR-95-3p. Mutation of the binding site eliminated the regulatory effect of miR-95-3p on p21 expression. Posttranscriptional regulation of p21 expression by miR-95-3p is mainly on the protein level (suppression of translation). Overexpression of miR-95-3p in two different HCC cell lines, HepG2 and SMMC7721, significantly promoted cell proliferation, cell cycle progression and cell migration, whereas a miR-95-3p specific inhibitor decreased cell proliferation, cell cycle progression and cell migration. The effects of miR-95-3p on cellular functions were rescued by overexpression of p21. Overexpression of miR-95-3p promoted cell proliferation and tumor growth in HCC xenograft mouse models. Expression of miR-95-3p was significantly higher in HCC samples than in adjacent non-cancerous samples. These results demonstrate that miR-95-3p is a potential new marker for HCC and regulates hepatocarcinogenesis by directly targeting CDKN1A/p21 expression.

Angiogenic Factor AGGF1 Activates Autophagy with an Essential Role in Therapeutic Angiogenesis for Heart Disease

AGGF1 is an angiogenic factor with therapeutic potential to treat coronary artery disease (CAD) and myocardial infarction (MI). However, the underlying mechanism for AGGF1-mediated therapeutic angiogenesis is unknown. Here, we show for the first time that AGGF1 activates autophagy, a housekeeping catabolic cellular process, in endothelial cells (ECs), HL1, H9C2, and vascular smooth muscle cells. Studies with Atg5 small interfering RNA (siRNA) and the autophagy inhibitors bafilomycin A1 (Baf) and chloroquine demonstrate that autophagy is required for AGGF1-mediated EC proliferation, migration, capillary tube formation, and aortic ring-based angiogenesis. Aggf1^+/- knockout (KO) mice show reduced autophagy, which was associated with inhibition of angiogenesis, larger infarct areas, and contractile dysfunction after MI. Protein therapy with AGGF1 leads to robust recovery of myocardial function and contraction with increased survival, increased ejection fraction, reduction of infarct areas, and inhibition of cardiac apoptosis and fibrosis by promoting therapeutic angiogenesis in mice with MI. Inhibition of autophagy in mice by bafilomycin A1 or in Becn1^+/- and Atg5 KO mice eliminates AGGF1-mediated angiogenesis and therapeutic actions, indicating that autophagy acts upstream of and is essential for angiogenesis. Mechanistically, AGGF1 initiates autophagy by activating JNK, which leads to activation of Vps34 lipid kinase and the assembly of Becn1-Vps34-Atg14 complex involved in the initiation of autophagy. Our data demonstrate that (1) autophagy is essential for effective therapeutic angiogenesis to treat CAD and MI; (2) AGGF1 is critical to induction of autophagy; and (3) AGGF1 is a novel agent for treatment of CAD and MI. Our data suggest that maintaining or increasing autophagy is a highly innovative strategy to robustly boost the efficacy of therapeutic angiogenesis.

Treatment with the angiogenic factor AGGF1 dramatically improves survival and cardiac function in mouse models for coronary artery disease and myocardial infarction by activating autophagy and angiogenesis.

Coronary artery disease is the number one killer disease worldwide. Recently, therapeutic angiogenesis has been proposed as an attractive new strategy for treating this and other ischemic diseases. This study establishes the angiogenic factor AGGF1 as a novel target and agent that can successfully treat coronary artery disease and acute myocardial infarction and dramatically improve survival and cardiac function in mouse models. We present the unexpected finding that AGGF1 has these effects via activating autophagy, and that autophagy is essential for therapeutic angiogenesis in animals. We find that AGGF1 is a novel master regulator of autophagy not only in endothelial cells but also in all other cell types examined in the study. Mechanistically, AGGF1 activates autophagy by activating JNK, which leads to activation of the Vps34 lipid kinase and assembly of the Becn1-Vps34-Atg14 complex involved in the initiation of autophagy. The study thus provides a link connecting the therapeutic angiogenesis and autophagy pathways in heart disease.

Angiogenic Factor with G-patch and FHA Domain 1 (AGGF1) Expression in Human Vascular Lesions

Angiogenic factor with G-patch and FHA domain 1 (AGGF1) is a novel angiogenic factor that was first described in Klippel-Trenaunay syndrome, a congenital vascular disease associated with capillary and venous malformations. AGGF1, similar to vascular endothelial growth factor (VEGF), has been shown to promote strong angiogenesis in chick embryos in vivo. Blocking AGGF1 expression prevented vessel formation, which suggests AGGF1 is a potent angiogenic factor linked to vascular malformations. So far, AGGF1 expression studies in human vascular lesions have not been performed. Here, we immunohistochemically investigated AGGF1 expression in venous, arteriovenous or capillary malformations, and infantile or congenital hemangioma. We found that AGGF1 was mostly expressed in endothelial cells with plump morphology. Moreover, the majority of mast cells strongly expressed AGGF1. Notwithstanding our incomplete knowledge of the molecular mechanism of AGGF1 in angiogenesis, our results show for the first time that AGGF1 is expressed in plump endothelial cells and mast cells.

Somatic PIK3CA mutations as a driver of sporadic venous malformations

Venous malformations (VM) are vascular malformations characterized by enlarged and distorted blood vessel channels. VM grow over time and cause substantial morbidity because of disfigurement, bleeding, and pain, representing a clinical challenge in the absence of effective treatments (Nguyenet al, 2014; Uebelhoeret al, 2012). Somatic mutations may act as drivers of these lesions, as suggested by the identification of TEK mutations in a proportion of VM (Limayeet al, 2009). We report that activating PIK3CA mutations gives rise to sporadic VM in mice, which closely resemble the histology of the human disease. Furthermore, we identified mutations in PIK3CA and related genes of the PI3K (phosphatidylinositol 3-kinase)/AKT pathway in about 30% of human VM that lack TEK alterations. PIK3CA mutations promote downstream signaling and proliferation in endothelial cells and impair normal vasculogenesis in embryonic development. We successfully treated VM in mouse models using pharmacological inhibitors of PI3Kα administered either systemically or topically. This study elucidates the etiology of a proportion of VM and proposes a therapeutic approach for this disease.

αB-Crystallin Interacts with Nav1.5 and Regulates Ubiquitination and Internalization of Cell Surface Nav1.5

Nav1.5, the pore-forming α subunit of the cardiac voltage-gated Na(+) channel complex, is required for the initiation and propagation of the cardiac action potential. Mutations in Nav1.5 cause cardiac arrhythmias and sudden death. The cardiac Na(+) channel functions as a protein complex; however, its complete components remain to be fully elucidated. A yeast two-hybrid screen identified a new candidate Nav1.5-interacting protein, αB-crystallin. GST pull-down, co-immunoprecipitation, and immunostaining analyses validated the interaction between Nav1.5 and αB-crystallin. Whole-cell patch clamping showed that overexpression of αB-crystallin significantly increased peak sodium current (INa) density, and the underlying molecular mechanism is the increased cell surface expression level of Nav1.5 via reduced internalization of cell surface Nav1.5 and ubiquitination of Nav1.5. Knock-out of αB-crystallin expression significantly decreased the cell surface expression level of Nav1.5. Co-immunoprecipitation analysis showed that αB-crystallin interacted with Nedd4-2; however, a catalytically inactive Nedd4-2-C801S mutant impaired the interaction and abolished the up-regulation of INa by αB-crystallin. Nav1.5 mutation V1980A at the interaction site for Nedd4-2 eliminated the effect of αB-crystallin on reduction of Nav1.5 ubiquitination and increases of INa density. Two disease-causing mutations in αB-crystallin, R109H and R151X (nonsense mutation), eliminated the effect of αB-crystallin on INa This study identifies αB-crystallin as a new binding partner for Nav1.5. αB-Crystallin interacts with Nav1.5 and increases INa by modulating the expression level and internalization of cell surface Nav1.5 and ubiquitination of Nav1.5, which requires the protein-protein interactions between αB-crystallin and Nav1.5 and between αB-crystallin and functionally active Nedd4-2.

TBX5 mutations contribute to early-onset atrial fibrillation in Chinese and Caucasians

AIMS

Atrial fibrillation (AF) is a common arrhythmia with an important heritable aspect. The genetic factors underlying AF have not been fully elucidated.

METHODS AND RESULTS

We screened six candidate genes (CAV1, KCNJ2, KCNQ1, NKX2.5, PITX2, and TBX5) for novel mutations in 139 patients of Chinese descent with early-onset AF and 576 controls. Four missense TBX5 mutations, p.R355C, p.Q376R, p.A428S, and p.S372L, were identified in evolutionarily conserved regions. We did not find any mutations in CAV1, KCNJ2, KCNQ1, NKX2.5, and PITX2. These mutations increased the expression of atrial natriuretic peptide (ANP) and connexin-40 (CX40) in the primarily cultured rat atrial myocytes but did not alter the expression of cardiac structural genes, atrial myosin heavy chain-α (MHC-α) and myosin light chain-2α (MLC-2α). Overexpression of p.R355C developed an atrial arrhythmia suggestive of paroxysmal AF in the zebrafish model. To replicate our findings, we screened TBX5 in 527 early-onset AF cases from the Massachusetts General Hospital AF study. A novel TBX5 deletion (ΔAsp118, p.D118del) was identified, while no TBX5 mutations were identified in 1176 control subjects.

CONCLUSION

Our results provide both genetic and functional evidence to support the contribution of TBX5 gene in the pathogenesis of AF. The potential mechanism of arrhythmia may be due in part to the disturbed expression of ANP and CX40.

Identification of rare variants in TNNI3 with atrial fibrillation in a Chinese GeneID population

Despite advances by genome-wide association studies (GWAS), much of heritability of common human diseases remains missing, a phenomenon referred to as 'missing heritability'. One potential cause for 'missing heritability' is the rare susceptibility variants overlooked by GWAS. Atrial fibrillation (AF) is the most common arrhythmia seen at hospitals and increases risk of stroke by fivefold and doubles risk of heart failure and sudden death. Here, we studied one large Chinese family with AF and hypertrophic cardiomyopathy (HCM). Whole-exome sequencing analysis identified a mutation in TNNI3, R186Q, that co-segregated with the disease in the family, but did not exist in >1583 controls, suggesting that R186Q causes AF and HCM. High-resolution melting curve analysis and direct DNA sequence analysis were then used to screen mutations in all exons and exon-intron boundaries of TNNI3 in a panel of 1127 unrelated AF patients and 1583 non-AF subjects. Four novel missense variants were identified in TNNI3, including E64G, M154L, E187G and D196G in four independent AF patients, but no variant was found in 1583 non-AF subjects. All variants were not found in public databases, including the ExAC Browser database with 60,706 exomes. These data suggest that rare TNNI3 variants are associated with AF (P = 0.03). TNNI3 encodes troponin I, a key regulator of the contraction-relaxation function of cardiac muscle and was not previously implicated in AF. Thus, this study may identify a new biological pathway for the pathogenesis of AF and provides evidence to support the rare variant hypothesis for missing heritability.

Klippel-Trenaunay and Sturge-Weber overlapping syndrome in a Saudi boy

Sturge-Weber Syndrome (SWS) is a rare, sporadic neurocutaneous disorder. It is typically characterized by unilateral, posterior leptomeningeal angiomas that calcify, glaucoma, and facial portwine tains. Klippel-Trenaunay syndrome (KTS) is a rare congenital syndrome characterized by ipsilateral cutaneous capillary malformations, venous varicosities, and bony or soft tissue overgrowth of the affected limbs. The clinical, neuroradiological features as well as the outcome of a Saudi boy who was referred to the Division of Pediatric Neurology, King Saud University Medical City, Riyadh, Saudi Arabia, with intractable focal seizure and left-sided hemiparesis who was eventually diagnosed with combined SWS and KTS is described here. The rare coexistence of SWS and KTS should be suspected in a child presenting with neurological manifestation such as epilepsy, mental sub normality, or hemiparesis, with port-wine staining or capillary hemangioma and enlarged limbs. Awareness may help in improving the quality of life and survival of these patients.

A case of newly diagnosed klippel trenaunay weber syndrome presenting with nephrotic syndrome

Klippel Trenaunay Weber syndrome (KTWS) is a rare disease characterized by hemihypertrophy, variceal enlargement of the veins, and arteriovenous (AV) malformations. Renal involvement in KTWS is not known except in rare case reports. Herein, we present a case of KTWS with nephrotic syndrome. A 52-year-old male was admitted due to dyspnea and swelling of the body for the last three months. The pathological physical findings were diffuse edema, decreased lung sounds at the right basal site, increased diameter and decreased length of the left leg compared with the right one, diffuse variceal enlargements, and a few hemangiomatous lesions on the left leg. The pathological laboratory findings were hypoalbuminemia, hyperlipidemia, increased creatinine level (1.23 mg/dL), and proteinuria (7.6 g/day). Radiographic pathological findings were cystic lesions in the liver, spleen, and kidneys, splenomegaly, AV malformation on the left posterolateral thigh, and hypertrophy of the soft tissues of the proximal left leg. He was diagnosed to have KTWS with these findings. Renal biopsy was performed to determine the cause of nephrotic syndrome. The pathologic examination was consistent with focal segmental sclerosis (FSGS). He was started on oral methylprednisolone at the dosage of 1 mg/kg and began to be followedup in the nephrology outpatient clinic.

Overexpression of AGGF1 is correlated with angiogenesis and poor prognosis of hepatocellular carcinoma

Angiogenic factor with G-patch and FHA domains 1 (AGGF1) is a factor implicating in vascular differentiation and angiogenesis. Several lines of evidence indicate that aberrant expression of AGGF1 is associated with tumor initiation and progression. The aim of this study was to investigate the expression and prognostic value of AGGF1 in hepatocellular carcinoma (HCC), as well as its relationship with clinicopathological factors and tumor angiogenesis. Immunohistochemistry was performed to evaluate the expression of AGGF1 in HCC and paracarcinomatous tissues collected from 70 patients. Vascular endothelial growth factor (VEGF) and CD34 expression levels were examined in the 70 HCC tissues. Prognostic significance of tumoral AGGF1 expression was determined. Notably, AGGF1 expression was significantly higher in HCC than in surrounding non-tumor tissues (65.7 vs. 25.7 %; P < 0.001). AGGF1 expression was significantly correlated with tumoral VEGF expression and CD34-positive microvessel density. Moreover, AGGF1 expression was significantly associated with tumor size, tumor capsule, vascular invasion, Edmondson grade, alpha-fetoprotein level, and TNM stage. Kaplan-Meier survival analysis showed that high AGGF1 was correlated with reduced overall survival (OS) rate (P = 0.001) and disease-free survival (DFS) rate (P < 0.001). Multivariate analysis identified AGGF1 as an independent poor prognostic factor of OS and DFS in HCC patients (P = 0.043 and P = 0.010, respectively). Taken together, increased AGGF1 expression is associated with tumor angiogenesis and serves as an independent unfavorable prognostic factor for OS and DFS in HCC. AGGF1 may represent a potential therapeutic target for HCC.

β-Catenin-dependent transcription is central to Bmp-mediated formation of venous vessels

β-catenin regulates the transcription of genes involved in diverse biological processes, including embryogenesis, tissue homeostasis and regeneration. Endothelial cell (EC)-specific gene-targeting analyses in mice have revealed that β-catenin is required for vascular development. However, the precise function of β-catenin-mediated gene regulation in vascular development is not well understood, since β-catenin regulates not only gene expression but also the formation of cell-cell junctions. To address this question, we have developed a novel transgenic zebrafish line that allows the visualization of β-catenin transcriptional activity specifically in ECs and discovered that β-catenin-dependent transcription is central to the bone morphogenetic protein (Bmp)-mediated formation of venous vessels. During caudal vein (CV) formation, Bmp induces the expression of aggf1, a putative causative gene for Klippel-Trenaunay syndrome, which is characterized by venous malformation and hypertrophy of bones and soft tissues. Subsequently, Aggf1 potentiates β-catenin transcriptional activity by acting as a transcriptional co-factor, suggesting that Bmp evokes β-catenin-mediated gene expression through Aggf1 expression. Bmp-mediated activation of β-catenin induces the expression of Nr2f2 (also known as Coup-TFII), a member of the nuclear receptor superfamily, to promote the differentiation of venous ECs, thereby contributing to CV formation. Furthermore, β-catenin stimulated by Bmp promotes the survival of venous ECs, but not that of arterial ECs. Collectively, these results indicate that Bmp-induced activation of β-catenin through Aggf1 regulates CV development by promoting the Nr2f2-dependent differentiation of venous ECs and their survival. This study demonstrates, for the first time, a crucial role of β-catenin-mediated gene expression in the development of venous vessels.

Cellular and molecular basis of Venous insufficiency

Chronic venous disease (CVD) has a range of clinical presentations, including tortuous, distended veins in lower extremities, increasing skin pigmentation, and in severe cases ulceration of the affected skin. Venous insufficiency, a precursor to CVD characterized by improper return of blood from the lower extremities to the heart, must be studied in its earliest stages at a time when preventative measures could be applied in man. This underscores the need for basic research into biomarkers and genetic predisposing factors affecting the progression of venous disease. Investigation over the past decade has yielded insight into these specific genetic, cellular and molecular mechanisms underlying the development of venous disease. Among the many advances include the elucidation of an increasing role for matrix metalloproteinases as important mediators of the degenerative process involved with venous insufficiency. This may be preceded by an inflammatory process which further contributes to venular degeneration and endothelial dysfunction seen in advanced presentation of disease. Furthermore, genomic analyses have shed light upon temporal expression patterns of matrix remodeling proteins in diseased tissue samples. In this review we examine some of the current findings surrounding cellular, molecular and genetic advances in delineating the etiology of chronic venous disease.

Biomolecular mechanisms in varicose veins development

Varicose veins (VVs) can be described as tortuous and dilated palpable veins, which are more than 3 mm in diameter. They are one of the clinical presentations of chronic venous disorders, which are a significant cause of morbidity. The prevalence of VVs has been estimated at 25-33% in women and 10-20% in men and is still increasing at an alarming rate. Family history, older age, female, pregnancy, obesity, standing occupations, and a history of deep venous thrombosis are the predominant risk factors. A great amount of factors are implicated in the pathogenesis of VVs, including changes in hydrostatic pressure, valvular incompetence, deep venous obstruction, ineffective function of calf muscle pump, biochemical and structural alterations of the vessel wall, extracellular matrix abnormalities, impaired balance between growth factors or cytokines, genetic alterations, and several other mechanisms. Nevertheless, the issue of pathogenesis in VVs is still not completely known, even if a great progress has been made in understanding their molecular basis. This kind of studies appears promising and should be encouraged, and perhaps the new insight in this matter may result in targeted therapy or possibly prevention.

A review of vascular anomalies: genetics and common syndromes

Vascular tumors and malformations are unique in that affected cells exhibit disrupted angiogenesis. The current treatment options often yield suboptimal results. New insight into the genetics and molecular basis of vascular anomalies may pave the way for potential development of targeted therapy. The authors review the genetic and molecular basis of vascular anomalies and common associated syndromes.