EGFL6 is increasingly expressed in human obesity and promotes proliferation of adipose tissue-derived stromal vascular cells

EGFL6 promotes endometrial cancer cell migration and proliferation

OBJECTIVE

EGFL6, a growth factor produced by adipocytes, is upregulated in and implicated in the tumorigenesis of multiple tumor types. Given the strong link between obesity and endometrial cancer, we sought to determine the impact of EGFL6 on endometrial cancer.

METHODS

EGFL6 expression in endometrial cancer and correlation with patient outcomes was evaluated in the human protein atlas and TCGA. EGFL6 treatment, expression upregulation, and shRNA knockdown were used to evaluate the impact of EGFL6 on the proliferation and migration of 3 endometrial cancer cell lines in vitro. Similarly, the impact of EGFL6 expression and knockdown on tumor growth was evaluated. Western blotting was used to evaluate the impact of EGFL6 on MAPK phosphorylation.

RESULTS

EGFL6 is upregulated in endometrial cancer, primarily in cony-number high tumors. High tumor endometrial cancer expression of EGFL6 predicts poor patient prognosis. We find that EGFL6 acts to activate the MAPK pathway increasing cellular proliferation and migration. In xenograft models, EGFL6 overexpression increases endometrial cancer tumor growth while EGFL6 knockdown decreases endometrial cancer tumor growth.

CONCLUSIONS

EGFL6 is a marker of poor prognosis endometrial cancers, driving cancer cell proliferation and growth. As such EGFL6 represents a potential therapeutic target in endometrial cancer.

Transcriptome Analyses of Adipose Tissue Samples Identify EGFL6 as a Candidate Gene Involved in Obesity-Related Adipose Tissue Dysfunction in Children

Obesity develops early in childhood and is accompanied by early signs of adipose tissue (AT) dysfunction and metabolic disease in children. In order to analyse the molecular processes during obesity-related AT accumulation in children, we investigated genome-wide expression profiles in AT samples, isolated adipocytes, and stromal vascular fraction (SVF) cells and assessed their relation to obesity as well as biological and functional AT parameters. We detected alterations in gene expression associated with obesity and related parameters, i.e., BMI SDS, adipocyte size, macrophage infiltration, adiponectin, and/or leptin. While differential gene expression in AT and adipocytes shared an enrichment in metabolic pathways and pathways related to extracellular structural organisation, SVF cells showed an overrepresentation in inflammatory pathways. In adipocytes, we found the strongest positive association for epidermal growth factor-like protein 6 (EGFL6) with adipocyte hypertrophy. EGFL6 was also upregulated during in vitro adipocyte differentiation. In children, EGFL6 expression was positively correlated to parameters of AT dysfunction and metabolic disease such as macrophage infiltration into AT, hs-CRP, leptin levels, and HOMA-IR. In conclusion, we provide evidence for early alterations in AT gene expression related to AT dysfunction in children and identified EGFL6 as potentially being involved in processes underlying the pathogenesis of metabolic disease.

Epidermal growth factor-like domain protein 6 recombinant protein facilitates osteogenic differentiation in adipose stem cells via bone morphogenetic protein 2/recombinant mothers against decapentaplegic homolog 4 signaling pathway

Adipose-derived mesenchymal stem cells (ADSCs) are a class of pluripotent stem cells isolated from the adipose tissue; they can differentiate into osteoblasts after induction and play an important role in bone repair. EGFL6 protein is secreted by adipocytes and osteoblasts and can promote endothelial cell migration and angiogenesis. This study aimed to explore the effect of recombinant EGFL6 protein on the osteogenic differentiation of ADSCs. The cells were incubated with fluorescein isothiocyanate-conjugated antibodies and analyzed by flow cytometry. Alizarin red staining and alkaline phosphatase staining were used to detect the osteogenic differentiation ability. mRNA expression was analyzed by real-time quantitative polymerase chain reaction (RT-qPCR). Protein expression was determined using Western blotting. The osteogenic differentiation ability of ADSCs isolated from the adipose tissue was significantly weakened after EGFL6 knockdown; this ability was restored upon the addition of EGFL6 recombinant protein. BMP2 knockdown inhibited the effect of EGFL6 recombinant protein on osteogenic differentiation. EGFL6 recombinant protein promoted osteogenic differentiation of ADSCs through the BMP2/SMAD4 signaling pathway. This may provide a potential target for the osteogenic differentiation of ADSCs.

Maternal high-fat diet programs white and brown adipose tissue lipidome and transcriptome in offspring in a sex- and tissue-dependent manner in mice

Objective

The prevalence of overweight and obesity among children has drastically increased during the last decades and maternal obesity has been demonstrated as one of the ultimate factors. Nutrition-stimulated transgenerational regulation of key metabolic genes is fundamental to the developmental origins of the metabolic syndrome. Fetal nutrition may differently influence female and male offspring.

Methods

Mice dam were fed either a control diet or a high-fat diet (HFD) for 6-week prior mating and continued their respective diet during gestation and lactation. At weaning, female and male offspring were fed the HFD until sacrifice. White (WAT) and brown (BAT) adipose tissues were investigated in vivo by nuclear magnetic resonance at two different timepoints in life (midterm and endterm) and tissues were collected at endterm for lipidomic analysis and RNA sequencing. We explored the sex-dependent metabolic adaptation and gene programming changes by maternal HFD in visceral AT (VAT), subcutaneous AT (SAT) and BAT of offspring.

Results

We show that the triglyceride profile varies between adipose depots, sexes and maternal diet. In female offspring, maternal HFD remodels the triglycerides profile in SAT and BAT, and increases thermogenesis and cell differentiation in BAT, which may prevent metabolic complication later in life. Male offspring exhibit whitening of BAT and hyperplasia in VAT when born from high-fat mothers, with impaired metabolic profile. Maternal HFD differentially programs gene expression in WAT and BAT of female and male offspring.

Conclusion

Maternal HFD modulates metabolic profile in offspring in a sex-dependent manner. A sex- and maternal diet-dependent gene programming exists in VAT, SAT, and BAT which may be key player in the sexual dimorphism in the metabolic adaptation later in life.

Blood biomarkers reflect the effects of obesity and inflammation on the human breast transcriptome

Obesity is a risk factor for the development of post-menopausal breast cancer. Breast white adipose tissue (WAT) inflammation, which is commonly found in women with excess body fat, is also associated with increased breast cancer risk. Both local and systemic effects are probably important for explaining the link between excess body fat, adipose inflammation and breast cancer. The first goal of this cross-sectional study of 196 women was to carry out transcriptome profiling to define the molecular changes that occur in the breast related to excess body fat and WAT inflammation. A second objective was to determine if commonly measured blood biomarkers of risk and prognosis reflect molecular changes in the breast. Breast WAT inflammation was assessed by immunohistochemistry. Bulk RNA-sequencing was carried out to assess gene expression in non-tumorous breast. Obesity and WAT inflammation were associated with a large number of differentially expressed genes and changes in multiple pathways linked to the development and progression of breast cancer. Altered pathways included inflammatory response, complement, KRAS signaling, tumor necrosis factor α signaling via NFkB, interleukin (IL)6-JAK-STAT3 signaling, epithelial mesenchymal transition, angiogenesis, interferon γ response and transforming growth factor (TGF)-β signaling. Increased expression of several drug targets such as aromatase, TGF-β1, IDO-1 and PD-1 were observed. Levels of various blood biomarkers including high sensitivity C-reactive protein, IL6, leptin, adiponectin, triglycerides, high-density lipoprotein cholesterol and insulin were altered and correlated with molecular changes in the breast. Collectively, this study helps to explain both the link between obesity and breast cancer and the utility of blood biomarkers for determining risk and prognosis.

Integrated bioinformatics analysis reveals novel key biomarkers and potential candidate small molecule drugs in gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is the metabolic disorder that appears during pregnancy. The current investigation aimed to identify central differentially expressed genes (DEGs) in GDM. The transcription profiling by array data (E-MTAB-6418) was obtained from the ArrayExpress database. The DEGs between GDM samples and non-GDM samples were analyzed. Functional enrichment analysis were performed using ToppGene. Then we constructed the protein–protein interaction (PPI) network of DEGs by the Search Tool for the Retrieval of Interacting Genes database (STRING) and module analysis was performed. Subsequently, we constructed the miRNA–hub gene network and TF–hub gene regulatory network. The validation of hub genes was performed through receiver operating characteristic curve (ROC). Finally, the candidate small molecules as potential drugs to treat GDM were predicted by using molecular docking. Through transcription profiling by array data, a total of 869 DEGs were detected including 439 up-regulated and 430 down-regulated genes. Functional enrichment analysis showed these DEGs were mainly enriched in reproduction, cell adhesion, cell surface interactions at the vascular wall and extracellular matrix organization. Ten genes, HSP90AA1, EGFR, RPS13, RBX1, PAK1, FYN, ABL1, SMAD3, STAT3 and PRKCA were associated with GDM, according to ROC analysis. Finally, the most significant small molecules were predicted based on molecular docking. This investigation identified hub genes, signal pathways and therapeutic agents, which might help us, enhance our understanding of the mechanisms of GDM and find some novel therapeutic agents for GDM.

EGFL6 promotes colorectal cancer cell growth and mobility and the anti-cancer property of anti-EGFL6 antibody

BACKGROUND

The availability of a reliable tumor target for advanced colorectal cancer (CRC) therapeutic approaches is critical since current treatments are limited. Epidermal growth factor-like domain 6 (EGFL6) has been reported to be associated with cancer development. Here, we focused on the role of EGFL6 in CRC progression and its clinical relevance. In addition, an anti-EGFL6 antibody was generated by phage display technology to investigate its potential therapeutic efficacy in CRC.

RESULTS

EGFL6 expression significantly increased in the colon tissues from CRC patients and mice showing spontaneous tumorigenesis, but not in normal tissue. Under hypoxic condition, EGFL6 expression was enhanced at both protein and transcript levels. Moreover, EGFL6 could promote cancer cell migration invasion, and proliferation of CRC cells via up-regulation of the ERK/ AKT pathway. EGFL6 also regulated cell migration, invasion, proliferation, and self-renewal through EGFR/αvβ3 integrin receptors. Treatment with the anti-EGFL6 antibody EGFL6-E5-IgG showed tumor-inhibition and anti-metastasis abilities in the xenograft and syngeneic mouse models, respectively. Moreover, EGFL6-E5-IgG treatment had no adverse effect on angiogenesis and wound healing CONCLUSIONS: We demonstrated that EGFL6 plays a role in CRC tumorigenesis and tumor progression, indicating that EGFL6 is a potential therapeutic target worth further investigation.

Identification of Key Pathways and Genes in Obesity Using Bioinformatics Analysis and Molecular Docking Studies

Obesity is an excess accumulation of body fat. Its progression rate has remained high in recent years. Therefore, the aim of this study was to diagnose important differentially expressed genes (DEGs) associated in its development, which may be used as novel biomarkers or potential therapeutic targets for obesity. The gene expression profile of E-MTAB-6728 was downloaded from the database. After screening DEGs in each ArrayExpress dataset, we further used the robust rank aggregation method to diagnose 876 significant DEGs including 438 up regulated and 438 down regulated genes. Functional enrichment analysis was performed. These DEGs were shown to be significantly enriched in different obesity related pathways and GO functions. Then protein-protein interaction network, target genes - miRNA regulatory network and target genes - TF regulatory network were constructed and analyzed. The module analysis was performed based on the whole PPI network. We finally filtered out STAT3, CORO1C, SERPINH1, MVP, ITGB5, PCM1, SIRT1, EEF1G, PTEN and RPS2 hub genes. Hub genes were validated by ICH analysis, receiver operating curve (ROC) analysis and RT-PCR. Finally a molecular docking study was performed to find small drug molecules. The robust DEGs linked with the development of obesity were screened through the expression profile, and integrated bioinformatics analysis was conducted. Our study provides reliable molecular biomarkers for screening and diagnosis, prognosis as well as novel therapeutic targets for obesity.

Epidermal growth factor-like domain multiple 6 (EGFL6) promotes the migration and invasion of gastric cancer cells by inducing epithelial-mesenchymal transition

Epidermal growth factor-like domain multiple 6 (EGFL6) is implicated in tumor growth, metastasis and angiogenesis, and its ectopic alteration has been detected in aggressive malignancies. However, the pathophysiologic roles and molecular mechanisms of EGFL6 in gastric cancer (GC) remain to be elucidated. In this study, we investigated EGFL6 expression in GC cell lines and tissues using western blotting and immunohistochemistry. We found that EGFL6 was elevated expression in GC cell lines and tissues. The high expression of EGFL6 significantly was correlated with histological grade, depth of invasion, lymph node involvement, distant metastasis and TNM stage in GC and predicted poorer prognosis, and it could act an independent prognostic factor for GC patients. EGFL6 enhanced the proliferation, migration and invasion of GC cells. In addition, we identified the possible molecular mechanisms of EGFL6-involved epithelial-mesenchymal transition (EMT). EGFL6 regulated EMT process and induced metastasis partly through FAK/PI3K/AKT/mTOR, Notch and MAPK signaling pathways. In conclusion, EGFL6 confers an oncogenic function in GC progression and may be proposed as a potential therapeutic target for GC.

Knockout of EGFL6 by CRISPR/Cas9 Mediated Inhibition of Tumor Angiogenesis in Ovarian Cancer

Tumor angiogenesis plays an important role in the progression and metastasis of ovarian cancer. EGFL6 protein is highly expressed in ovarian cancer and has been proposed to play an important role in promoting tumor angiogenesis. Here, a CRISPR/Cas9 system was used to knockout the EGFL6 gene in the ovarian cancer cell line SKOV3, using specific guide RNA targeting the exons of EGFL6. The knockout of EGFL6 markedly inhibited the proliferation, migration, and invasion of SKOV3 cells, as well as promoted apoptosis of tumor cells. In the nude mouse model of ovarian cancer, knockout of EGFL6 remarkably inhibited tumor growth and angiogenesis. The transcript profile assays detected 4,220 differentially expressed genes in the knockout cells, including 87 genes that were correlated to proliferation, migration, invasion, and angiogenesis. Moreover, Western blotting confirmed that EGFL6 knockout downregulated the FGF-2/PDGFB signaling pathway. Thus, the results of this study indicated that EGFL6 could regulate cell proliferation, migration, and angiogenesis in ovarian cancer cells by regulating the FGF-2/PDGFB signaling pathway.

The emerging role of EGFL6 in angiogenesis and tumor progression

Epidermal growth factor-like domain-containing protein 6 (EGFL6) belongs to the epidermal growth factor (EGF) superfamily. EGFL6 is expressed at higher levels in embryos and various malignant tumors than in normal tissues. Recent studies suggest that EGFL6 participates in the development of a variety of tumors. In this review, we summarize findings that support the role for EGFL6 in tumor proliferation, invasion and migration. Furthermore, our review results indicate the mechanism of EGFL6 activity angiogenesis. We also describe work toward the preparation of monoclonal antibodies against EGFL6. Altogether, the work of this review promotes understanding of the role of EGFL6 in tumor development, the mechanism of that action, and the potential of EGFL6 as a therapeutic target for tumor prevention and treatment.

Differential Gene Expression between Limbal Niche Progenitors and Bone Marrow Derived Mesenchymal Stem Cells

Purpose: To compare the difference in gene expression between human limbal niche cells (LNC) and bone marrow derived mesenchymal stem cells (BMMSC). Methods: LNC were isolated by collagenase and expanded in modified embryonic stem cell medium (MESCM) on a Matrigel coated plastic plate. Cell diameters were measured with Image J software. Relative gene expression levels between LNC and BMMSC were compared using Affymetrix Human Primer View Gene Expression Array. A subset of differentially expressed genes was verified by RT-qPCR. The protein level of LAMA1 and COL4A1 was confirmed by Western blot and immunostaining. Results: The average diameter of LNC was 10.2±2.4 μm, which was significantly smaller than that of BMMSC (14 ±3.4 μm) (p<0.0001). Expression of 20,432 genes was examined by Gene Expression Array, among which expression of 349 genes in LNC was 10-fold or higher than that of BMMSC and expression of 8 genes in LNC was 100-fold or higher than that of BMMSC, while expression of 3 genes in BMMSC was 100-fold higher than that of LNC. GO analysis and pathway analysis showed that the differentially expressed genes were mainly enriched in the extracellular matrix receptor interaction pathway and Wnt signaling pathway. In addition, RT-qPCR results demonstrated that the expression of CD73, CD90, CD105, PDGFRβ, Vimentin, SCF, KIT (CD117), COL14A1, LAMA2, THBS2, FZD1, BMP2 and CXCL12 genes in LNC were at least 2 folds higher than BMMSC. The protein level of LAMA1 was higher but the protein level of COL4A1 was lower in LNC than that in BMMSC. Conclusion: LNC exhibit differential gene expression from BMMSC in the extracellular matrix (ECM) receptor interaction pathway and Wnt signaling pathway, suggesting that LNC have their unique signaling pathways to support limbal stem cell niches.

EGFL6 promotes cell proliferation in colorectal cancer via regulation of the WNT/β-catenin pathway

Epidermal growth factor-like protein 6 (EGFL6) serves as an exocrine protein promoting proliferation and migration during carcinogenesis in ovarian cancer. However, its function and mechanisms in colorectal cancer (CRC) have not been completely explored. To investigate the role of EGFL6 in CRC cell growth, in vitro CCK8, colony formation assays, flow cytometric analysis of the cell cycle and apoptosis, and an in vivo tumor xenograft model were utilized. Additionally, Western blotting and luciferase reporter assays were used to investigate the underlying mechanisms of EGFL6 function on the WNT/β-catenin signaling pathway. Immunohistochemical staining showed that EGFL6 is overexpressed in CRCs and this overexpression was highly correlated with advanced T classification, N classification, distant metastasis, and poor survival. Knocking down EGFL6 in CRC cell lines induced the inhibition of cell growth, cell cycle arrest at the G0/G1 phase, and apoptosis. Further, knockdown of EGFL6 blocked WNT/β-catenin signaling as measured by Western blotting and luciferase reporter assay. Results also showed that recombinant EGFL6 (rEGFL6) induced β-catenin in a concentration- and time-dependent manner. Further experiments showed that administration of rEGFL6 to cell cultures with EGFL6 knocked down or treated with the WNT/β-catenin inhibitor ICG-001 increased β-catenin and its downstream protein CyclinD1. The CCK8 assay showed that EGFL6 promoted CRC cell growth partly by the promotion of TCF7L2 expression. These findings suggest that EGFL6 plays a crucial role in the progression of CRC by regulation of the WNT/β-catenin signaling pathway.

Hair follicle epidermal stem cells define a niche for tactile sensation

The heterogeneity and compartmentalization of stem cells is a common principle in many epithelia, and is known to function in epithelial maintenance, but its other physiological roles remain elusive. Here we show transcriptional and anatomical contributions of compartmentalized epidermal stem cells in tactile sensory unit formation in the mouse hair follicle. Epidermal stem cells in the follicle upper-bulge, where mechanosensory lanceolate complexes innervate, express a unique set of extracellular matrix (ECM) and neurogenesis-related genes. These epidermal stem cells deposit an ECM protein called EGFL6 into the collar matrix, a novel ECM that tightly ensheathes lanceolate complexes. EGFL6 is required for the proper patterning, touch responses, and αv integrin-enrichment of lanceolate complexes. By maintaining a quiescent original epidermal stem cell niche, the old bulge, epidermal stem cells provide anatomically stable follicle-lanceolate complex interfaces, irrespective of the stage of follicle regeneration cycle. Thus, compartmentalized epidermal stem cells provide a niche linking the hair follicle and the nervous system throughout the hair cycle.

The somite-secreted factor Maeg promotes zebrafish embryonic angiogenesis

MAM and EGF containing gene (MAEG), also called Epidermal Growth Factor-like domain multiple 6 (EGFL6), belongs to the epidermal growth factor repeat superfamily. The role of Maeg in zebrafish angiogenesis remains unclear. It was demonstrated that maeg was dynamically expressed in zebrafish developing somite during a time window encompassing many key steps in embryonic angiogenesis. Maeg loss-of-function embryos showed reduced endothelial cell number and filopodia extensions of intersegmental vessels (ISVs). Maeg gain-of-function induced ectopic sprouting evolving into a hyperbranched and functional perfused vasculature. Mechanistically we demonstrate that Maeg promotes angiogenesis dependent on RGD domain and stimulates activation of Akt and Erk signaling in vivo. Loss of Maeg or Itgb1, augmented expression of Notch receptors, and inhibiting Notch signaling or Dll4 partially rescued angiogenic phenotypes suggesting that Notch acts downstream of Itgb1. We conclude that Maeg acts as a positive regulator of angiogenic cell behavior and formation of functional vessels.

Differential Effects of EGFL6 on Tumor versus Wound Angiogenesis

Angiogenesis inhibitors are important for cancer therapy, but clinically approved anti-angiogenic agents have shown only modest efficacy and can compromise wound healing. This necessitates the development of novel anti-angiogenesis therapies. Here, we show significantly increased EGFL6 expression in tumor versus wound or normal endothelial cells. Using a series of in vitro and in vivo studies with orthotopic and genetically engineered mouse models, we demonstrate the mechanisms by which EGFL6 stimulates tumor angiogenesis. In contrast to its antagonistic effects on tumor angiogenesis, EGFL6 blockage did not affect normal wound healing. These findings have significant implications for development of anti-angiogenesis therapies.

Genetic and Epigenetic Profiling Reveals EZH2-mediated Down Regulation of OCT-4 Involves NR2F2 during Cardiac Differentiation of Human Embryonic Stem Cells

Human embryonic (hES) stem cells are widely used as an in vitro model to understand global genetic and epigenetic changes that occur during early embryonic development. In-house derived hES cells (KIND1) were subjected to directed differentiation into cardiovascular progenitors (D12) and beating cardiomyocytes (D20). Transcriptome profiling of undifferentiated (D0) and differentiated (D12 and 20) cells was undertaken by microarray analysis. ChIP and sequential ChIP were employed to study role of transcription factor NR2F2 during hES cells differentiation. Microarray profiling showed that an alteration of about 1400 and 1900 transcripts occurred on D12 and D20 respectively compared to D0 whereas only 19 genes were altered between D12 and D20. This was found associated with corresponding expression pattern of chromatin remodelers, histone modifiers, miRNAs and lncRNAs marking the formation of progenitors and cardiomyocytes on D12 and D20 respectively. ChIP sequencing and sequential ChIP revealed the binding of NR2F2 with polycomb group member EZH2 and pluripotent factor OCT4 indicating its crucial involvement in cardiac differentiation. The study provides a detailed insight into genetic and epigenetic changes associated with hES cells differentiation into cardiac cells and a role for NR2F2 is deciphered for the first time to down-regulate OCT-4 via EZH2 during cardiac differentiation.

EGFL6 Regulates the Asymmetric Division, Maintenance, and Metastasis of ALDH+ Ovarian Cancer Cells

Little is known about the factors that regulate the asymmetric division of cancer stem-like cells (CSC). Here, we demonstrate that EGFL6, a stem cell regulatory factor expressed in ovarian tumor cells and vasculature, regulates ALDH⁺ ovarian CSC. EGFL6 signaled at least in part via the oncoprotein SHP2 with concomitant activation of ERK. EGFL6 signaling promoted the migration and asymmetric division of ALDH⁺ ovarian CSC. As such, EGFL6 increased not only tumor growth but also metastasis. Silencing of EGFL6 or SHP2 limited numbers of ALDH⁺ cells and reduced tumor growth, supporting a critical role for EGFL6/SHP2 in ALDH⁺ cell maintenance. Notably, systemic administration of an EGFL6-neutralizing antibody we generated restricted tumor growth and metastasis, specifically blocking ovarian cancer cell recruitment to the ovary. Together, our results offer a preclinical proof of concept for EGFL6 as a novel therapeutic target for the treatment of ovarian cancer. Cancer Res; 76(21); 6396-409. ©2016 AACR.

Molecular Biomarkers for Weight Control in Obese Individuals Subjected to a Multiphase Dietary Intervention

CONTEXT

Although calorie restriction has proven beneficial for weight loss, long-term weight control is variable between individuals.

OBJECTIVE

To identify biomarkers of successful weight control during a dietary intervention (DI).

DESIGN, SETTING, AND PARTICIPANTS

Adipose tissue (AT) transcriptomes were compared between 21 obese individuals who either maintained weight loss or regained weight during the DI. Results were validated on 310 individuals from the same study using quantitative reverse transcription polymerase chain reaction and protein levels of potential circulating biomarkers measured by enzyme-linked immunosorbent assay.

INTERVENTION

Individuals underwent 8 weeks of low-calorie diet, then 6 months of ad libitum diet.

OUTCOME MEASURE

Weight changes at the end of the DI.

RESULTS

We evaluated six genes that had altered expression during DI, encode secreted proteins, and have not previously been implicated in weight control (EGFL6, FSTL3, CRYAB, TNMD, SPARC, IGFBP3), as well as genes for which baseline expression differed between those with good and poor weight control (ASPN, USP53). Changes in plasma concentrations of EGFL6, FSTL3, and CRYAB mirrored AT messenger RNA expression; all decreased during DI in individuals with good weight control. ASPN and USP53 had higher baseline expression in individuals who went on to have good weight control. Expression quantitative trait loci analysis found polymorphisms associated with expression levels of USP53 in AT. A regulatory network was identified in which transforming growth factor β1 (TGF-β1) was responsible for downregulation of certain genes during DI in good controllers. Interestingly, ASPN is a TGF-β1 inhibitor.

CONCLUSIONS

We found circulating biomarkers associated with weight control that could influence weight management strategies and genes that may be prognostic for successful weight control.

NPNT is Expressed by Osteoblasts and Mediates Angiogenesis via the Activation of Extracellular Signal-regulated Kinase

Angiogenesis plays an important role in bone development and remodeling and is mediated by a plethora of potential angiogenic factors. However, data regarding specific angiogenic factors that are secreted within the bone microenvironment to regulate osteoporosis is lacking. Here, we report that Nephronectin (NPNT), a member of the epidermal growth factor (EGF) repeat superfamily proteins and a homologue of EGFL6, is expressed in osteoblasts. Intriguingly, the gene expression of NPNT is reduced in the bone of C57BL/6J ovariectomised mice and in osteoporosis patients. In addition, the protein levels of NPNT and CD31 are also found to be reduced in the tibias of OVX mice. Exogenous addition of mouse recombinant NPNT on endothelial cells stimulates migration and tube-like structure formation in vitro. Furthermore, NPNT promotes angiogenesis in an ex vivo fetal mouse metatarsal angiogenesis assay. We show that NPNT stimulates the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated kinase (MAPK) in endothelial cells. Inhibition of ERK1/2 impaired NPNT-induced endothelial cell migration, tube-like structure formation and angiogenesis. Taken together, these results demonstrate that NPNT is a paracrine angiogenic factor and may play a role in pathological osteoporosis. This may lead to new targets for treatment of bone diseases and injuries.

Egfl6 is involved in zebrafish notochord development

The epidermal growth factor (EGF) repeat motif defines a superfamily of diverse protein involved in regulating a variety of cellular and physiological processes, such as cell cycle, cell adhesion, proliferation, migration, and neural development. Egfl6, an EGF protein, also named MAGE was first cloned in human tissue. Up to date, the study of zebrafish Egfl6 expression pattern and functional analysis of Egfl6 involved in embryonic development of vertebrate in vivo is thus far lacking. Here we reported that Egfl6 was involved in zebrafish notochord development. It was shown that Egfl6 mRNA was expressed in zebrafish, developing somites, fin epidermis, pharyngeal arches, and hindbrain region. Particularly the secreted Egfl6 protein was significantly accumulated in notochord. Loss of Egfl6 function in zebrafish embryos resulted in curved body with distorted notochord in the posterior trunk. It was observed that expression of all Notch ligand and receptors in notochord of 28 hpf Egfl6 morphants was not affected, except notch2, which was up-regulated. We found that inhibition of Notch signaling by DAPT efficiently rescued notochord developmental defect of Egfl6 deficiency embryos.

Molecular characterization and expression analysis of mouse epidermal growth factor-like domain 8

Epidermal growth factor (EGF)-like (EGFL) domain, a common structural module in numerous secreted or transmembrane proteins, is generally involved in protein-protein interactions. To date, several EGFL proteins have been identified and characterized, but little is known about EGFL domain 8 (EGFL8). The present study reported the molecular characterization and expression analysis of EGFL8 in mice. Mouse EGFL8 amplified using a reverse transcription-polymerase chain reaction approach was sequenced and characterized. Mouse EGFL8 encodes a protein of 293 amino acids with two EGFL domains, an Emilin-like domain and a Ca(2+)-binding EGFL domain, which has a molecular mass of 32 kDa. The coding sequence has a high degree of amino acid sequence identity across species, and the EGFL domain has been highly conserved in various species during evolutionary radiation. A phylogenetic tree calculated using the neighbor-joining method revealed that EGFL8 and EGFL7 are more closely associated with each other than either is to EGFL3, and they cluster with EGFL6. It was found that mouse EGFL8 protein was highly expressed in diverse mouse tissue types, including the thymus, lymph nodes, testis, ovaries, epididymis, ductus deferens, ileum, colon, stomach, esophagus, lung, uterus, urinary bladder, skin, spleen, adrenal glands and penis. These results are of great use in understanding the biological roles of mouse EGFL8 for further study.

RNA-seq analysis of bovine intramuscular, subcutaneous and perirenal adipose tissues

The deposition of intramuscular fat is an important factor affecting the beef quality, such as flavour and palatability. In this study, for further identifying the differential molecular mechanisms regulating the deposition of fat between intramuscular and external adipose tissues, particularly subcutaneous and perirenal adipose tissues, it was designed to obtain transcript sequence data and compare the transcriptomes among intramuscular, subcutaneous, and perirenal adipose tissues by RNA-Seq. A total of 66,206,912, 55,114,070 and 67,320,426 fragments were sequenced for the intramuscular (IAT), subcutaneous (SAT), and perirenal adipose tissue (PAT) respectively. Among them, total 953, 1,534, 2,026 genes showing differential expression between IAT and SAT, IAT and PAT, SAT and PAT, were identified respectively (FDR < 0.05). When these data had been mixed and analyzed together, 110 genes were differentially expressed among these three adipose tissues. Using GO enrichment analysis, multiple biological pathways were found to be significantly enriched for differentially expressed genes (FDR < 0.01), including cellular process, biological regulation, and metabolic process. In addition, total 4,625, 4,775 and 4,147 alternative splicing events occurred in IAT, SAT, and PAT, had also been detected respectively. Thus, our results logically provide the evidence for further understanding the bovine fat deposition, especially intramuscular fat, at a fine scale.

Gene expression profiling in subcutaneous, visceral and epigastric adipose tissues of patients with extreme obesity

Objective

The goal of the present study was to identify differences in gene expression between SAT, VAT, and EAT depots in Class III severely obese individuals.

Design

Human subcutaneous (SAT) and visceral (VAT) adipose tissues exhibit differential gene expression profiles. There is little information, however, about the other proximal white adipose tissue, epigastric (EAT) in terms of its function and contribution to metabolism.

Subjects and Methods

Using RNA from adipose biospecimens obtained from Class III severely obese patients undergoing open Roux-en-Y gastric bypass surgery, we compared gene expression profiles between SAT, VAT, and EAT, using microarrays validated by real time quantitative PCR.

Results

The three depots were found to share 1,907 genes. VAT had the greatest number of genes [66] expressed exclusively in this depot, followed by SAT [23], and then EAT [14]. Moreover, VAT shared more genes with EAT [65] than with SAT [38]. Further analyses using ratios of SAT/EAT, VAT/EAT, and SAT/VAT, identified specific as well as overlapping networks and pathways of genes representing dermatological diseases, inflammation, cell cycle and growth, cancer, and development. Targeted analysis of genes playing a role in adipose tissue development and function, revealed that Peroxisome proliferator-activated receptor Gamma Coactivator 1-alpha (PGC1-α) that regulates the precursor of the hormone Irisin (FNCD5), were abundantly expressed in all three fat depots, along with fibroblast growth factors (FGF) FGF1, FGF7, and FGF10, whereas, FGF19 and FGF21 were undetectable.

Conclusions

These data indicate that EAT has more in common with VAT suggesting similar metabolic potential. The human epigastric adipose depot could play a significant functional role in metabolic diseases and should be further investigated.

Analysis of gene expression profiling in meningioma: deregulated signaling pathways associated with meningioma and EGFL6 overexpression in benign meningioma tissue and serum

Molecular mechanisms underlying the pathogenesis of meningioma are not fully elucidated. In this study, we established differential gene expression profiles between meningiomas and brain arachnoidal tissue by using Affymetrix GeneChip Human U133 Plus 2.0 Array. KEGG pathway analysis demonstrated that PI3K/Akt and TGFβ signaling pathways were up-regulated in fibroblastic meningioma, and focal adhesion and ECM-receptor interaction pathways were activated in anaplastic meningioma. EGFL6 was one of the most up-regulated genes in fibroblastic meningioma by microarray analysis. Quantitative real-time PCR demonstrated that benign meningiomas had significantly higher levels of EGFL6 mRNA than brain arachnoidal tissue and atypical and anaplastic meningiomas (P<0.001). EGFL6 gene was also highly expressed in ovarian cancer, but expressed lowly in other investigated tumors. ELISA analysis showed that patients with benign meningiomas and ovarian cancers had the highest serum levels of EGFL6 (mean concentration: 672 pg/ml for benign meningiomas, and 616 pg/ml for ovarian cancers). Healthy people and patients with other tumors, however, had low levels of serum EGFL6. In conclusion, we proposed that activation of PI3K/Akt and integrin-mediated signaling pathways was involved in the pathogenesis of benign and anaplastic meningiomas, respectively. We also presented evidence that EGFL6 was overexpressed in benign meningioma tissues and serum.

Molecular analysis of the TGF-beta controlled gene expression program in chicken embryo dermal myofibroblasts

The myofibroblast is a mesenchymal cell characterized by synthesis of the extracellular matrix, plus contractile and secretory activities. Myofibroblasts participate in physiological tissue repair, but can also cause devastating fibrosis. They are present in the tumor stroma of carcinomas and contribute to tumor growth and spreading. As myofibroblasts derive from various cell types and appear in a variety of tissues, there is marked variability in their phenotype. As regulatory mechanisms of wound healing are likely conserved among vertebrates, detailed knowledge of these mechanisms in more distant species will help to distinguish general from specific phenomena. To provide this as yet missing comparison, we analyzed the impact of the chemical inhibition of TGF-beta signaling on gene expression in chicken embryo dermal myofibroblasts. We revealed genes previously reported in mammalian systems (e.g. SPON2, ASPN, COMP, LUM, HAS2, IL6, CXCL12, VEGFA) as well as novel TGF-beta dependent genes, among them PGF, VEGFC, PTN, FAM180A, FIBIN, ZIC1, ADCY2, RET, HHIP and DNER. Inhibition of TGF-beta signaling also induced multiple genes, including NPR3, AGTR2, MTUS1, SOD3 and NOV. We also analyzed the effects of long term inhibition, and found that it is not able to induce myofibroblast dedifferentiation.

Ovarian cancer stem cell markers: prognostic and therapeutic implications

Cancer stem cells are rare chemotherapy resistant cells within a tumor which can serve to populate the bulk of a tumor with more differentiated daughter cells and potentially contribute to recurrent disease. Ovarian cancer is a disease for which at the time of initial treatment we can obtain complete clinical remission in the majority of patients. Unfortunately, most will relapse and succumb to their disease. This clinical course is in line with the cancer stem cell model. In the past 5 years a significant amount of work has been done to identify cells with characteristics of ovarian cancer stem cells. This review will focus specifically on the markers used to define human ovarian cancer stem cells, the prognostic implications of the expression of these cancer stem cell markers in patient's primary tumors, and the potential of these cancer stem cell markers to serve as therapeutic targets.