Hypoxia-inducible factor (HIF-1α), a core transcription factor responding to changes in cellular oxygen levels, is closely associated with a wide range of physiological and pathological conditions. However, its differential impacts on vascular cell types and molecular programs modulating human vascular homeostasis and regeneration remain largely elusive. Here, we applied CRISPR/Cas9-mediated gene editing of human embryonic stem cells and directed differentiation to generate HIF-1α-deficient human vascular cells including vascular endothelial cells, vascular smooth muscle cells, and mesenchymal stem cells (MSCs), as a platform for discovering cell type-specific hypoxia-induced response mechanisms. Through comparative molecular profiling across cell types under normoxic and hypoxic conditions, we provide insight into the indispensable role of HIF-1α in the promotion of ischemic vascular regeneration. We found human MSCs to be the vascular cell type most susceptible to HIF-1α deficiency, and that transcriptional inactivation of ANKZF1, an effector of HIF-1α, impaired pro-angiogenic processes. Altogether, our findings deepen the understanding of HIF-1α in human angiogenesis and support further explorations of novel therapeutic strategies of vascular regeneration against ischemic damage.
Humans ; Vascular Endothelial Growth Factor A/metabolism* ; Endothelial Cells/metabolism* ; Transcription Factors/metabolism* ; Gene Expression Regulation ; Hypoxia/metabolism* ; Cell Hypoxia/physiology*

Ischemic stroke is a major public health problem worldwide. Although the circadian clock is involved in the process of ischemic stroke, the exact mechanism of the circadian clock in regulating angiogenesis after cerebral infarction remains unclear. In the present study, we determined that environmental circadian disruption (ECD) increased the stroke severity and impaired angiogenesis in the rat middle cerebral artery occlusion model, by measuring the infarct volume, neurological tests, and angiogenesis-related protein. We further report that Bmal1 plays an irreplaceable role in angiogenesis. Overexpression of Bmal1 promoted tube-forming, migration, and wound healing, and upregulated the vascular endothelial growth factor (VEGF) and Notch pathway protein levels. This promoting effect was reversed by the Notch pathway inhibitor DAPT, according to the results of angiogenesis capacity and VEGF pathway protein level. In conclusion, our study reveals the intervention of ECD in angiogenesis in ischemic stroke and further identifies the exact mechanism by which Bmal1 regulates angiogenesis through the VEGF-Notch1 pathway.
Rats ; Animals ; Vascular Endothelial Growth Factor A/pharmacology* ; Brain Ischemia/metabolism* ; Ischemic Stroke ; Signal Transduction ; ARNTL Transcription Factors/pharmacology* ; Neovascularization, Physiologic/physiology*

OBJECTIVETo explore the formation of pre-metastatic niche in the mouse lung and to study the underlying molecular mechanisms whereby primary breast carcinoma-derived factors mediate recruitment of bone marrow-derived cells (BMDCs) and affect the formation of pre-metastatic lung environment before the arrival of tumor cells.

METHODSMammary carcinoma 4T1 cells were inoculated into the mammary gland to construct mouse model of breast cancer. Confocal microscopy was used to detect the recruitment of BMDCs in the pre-metastatic lungs. The expression of factors in the mouse sera and 4T1 cell culture media was assayed using RayBio Custom mouse cytokine antibody array kit. The mice were injected daily with recombinant VEGF for 7 consecutive days to observe the effect of VEGF on BMDCs recruitment in the mouse lung.

RESULTSNo BMDCs were observed in the lungs of control and 4T1-tumor-bearing mice on day 0. On day 7 and 14, clusters of BMDCs observed in the lungs of 4T1-tumor-bearing mice were 8.7±2.2/objective field and 48.8±3.2/objective field, respectively, significantly higher than those in the control mice (1.1±0.8/objective field and 3.1±1.7/objective field) (P<0.05 for both). Confocal microscopic observation found that metastatic breast cancer cells preferentially facilitate BMDCs recruitment sites in the pre-metastatic mouse lungs. The levels of VEGF, GM-CSF, and IL-6 in the serum of 4T1-tumor-bearing mice were significantly increased compared with those in the control group (P<0.05 for all). However, VEGF was detected only in the culture media of 4T1 cells. The amount of BMDCs in the mouse lung tissue was (22.8±3.6)/objective field in the VEGF group and (3.1±0.4)/objective field in the control group (P<0.05). There were 36.8±5.4 metastatic foci in the lung tissue of VEGF group and 12.6±2.2 in the control group (P<0.05).

CONCLUSIONSThe results of this study demonstrate that primary breast cancer cells can alter the lung microenvironment during the pre-metastatic phase and induce the formation of pre-metastatic niche. Primary tumor cell-derived VEGF may be a crucial factor responsible for the formation of pre-metastatic niche.

Animals ; Bone Marrow Cells ; Breast Neoplasms ; metabolism ; pathology ; Cell Line, Tumor ; Disease Models, Animal ; Female ; Granulocyte-Macrophage Colony-Stimulating Factor ; blood ; Humans ; Interleukin-6 ; blood ; Lung ; pathology ; Lung Neoplasms ; secondary ; Mice ; Recombinant Proteins ; administration & dosage ; Time Factors ; Tumor Microenvironment ; Vascular Endothelial Growth Factor A ; administration & dosage ; physiology ; secretion

Cell Hypoxia ; physiology ; Cells, Cultured ; Diabetic Retinopathy ; metabolism ; Female ; Humans ; Intercellular Adhesion Molecule-1 ; metabolism ; Male ; Middle Aged ; Monocytes ; metabolism ; Prospective Studies ; Vascular Endothelial Growth Factors ; metabolism

OBJECTIVETo investigate the effect of extracellular signal-regulated kinase (ERK) signaling pathway on the endothelial differentiation of periodontal ligament stem cells (PDLSC).

METHODSHuman PDLSC was cultured in the medium with vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF) to induce endothelial differentiation. Endothelial inducing cells was incubated with U0126, a specific p-ERK1/2 inhibitor. PDLSC from one person were randomly divided into four groups: control group, endothelial induced group, endothelial induced+DMSO group and endothelial induced+U0126 group. The protein expression of the p-EKR1/2 was analyzed by Western blotting at 0, 1, 3, 6 and 12 hours during endonthelial induction. The mRNA expressions of CD31, VE-cadherin, and VEGF were detected by quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) after a 7-day induction. The proportion of CD31(+) to VE-cadherin(+) cells was identified by flow cytometry, and the ability of capillary-like tubes formation was detected by Matrigel assay after a 14-day induction. The measurement data were statistically analyzed.

RESULTSPhosphorylated ERK1/2 protein level in PDLSC was increased to 1.24±0.12 and 1.03±0.24 at 1 h and 3 h respectively, during the endothelial induction (P<0.01). The mRNA expressions of CD31 and VEGF in induced+U0126 group were decreased to 0.09±0.18 and 0.49±0.17, which were both significantly different with those in induced group (P<0.05). The proportion of CD31(+) to VE-cadherin(+) cells of induced+U0126 group were decreased to 5.22±0.85 and 3.56±0.87, which were both significantly different with those in induced group (P<0.05). In Matrigel assay, the branching points, tube number and tube length were decreased to 7.0±2.7, 33.5±6.4, and (15 951.0±758.1) pixels, which were all significantly different with those in induced group (P<0.05).

CONCLUSIONSThe endothelial differentiation of PDLSC is positively regulated by ERK signaling pathway. Inhibition of ERK1/2 phosphorylation could suppress endothelial differentiation of PDLSC.

Antigens, CD ; genetics ; metabolism ; Butadienes ; pharmacology ; Cadherins ; genetics ; metabolism ; Cell Differentiation ; Endothelial Cells ; cytology ; physiology ; Enzyme Inhibitors ; pharmacology ; Extracellular Signal-Regulated MAP Kinases ; physiology ; Fibroblast Growth Factor 2 ; pharmacology ; Humans ; Mitogen-Activated Protein Kinase 3 ; antagonists & inhibitors ; metabolism ; Nitriles ; pharmacology ; Periodontal Ligament ; cytology ; metabolism ; Phosphorylation ; Platelet Endothelial Cell Adhesion Molecule-1 ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Random Allocation ; Signal Transduction ; Stem Cells ; cytology ; physiology ; Time Factors ; Vascular Endothelial Growth Factor A ; genetics ; metabolism ; pharmacology

OBJECTIVETo explore the effect of epidermal growth factor-like domain 7(EGFL7) on the migration and angiogenesis of endothelial cells.

METHODSEGFL7 overexpression vectors were constructed and transfected into human microvascular endothelial cells. The expression levels of EGFL7-mRNA and EGFL7 protein were examined by real-time RT-PCR and Western blot. Cell migration was analyzed by the wound healing. The capability of cell to form capillary-like tubes in vitro was evaluated on matrigel assay. Protein expression of p-AKT, AKT, p-ERK and ERK in endothelial cells was detected by Western blot upon transfection with EGFL7 overexpression vectors and vehicle control for 0, 10, 30 and 60 min.

RESULTSMigration and angiogenesis of endothelial cells were notably enhanced by EGFL7 overexpression. ERK pathway was strongly activated by EGFL7, whereas AKT remained constant in endothelial cells. Inhibition of ERK impaired EGFL7 induced ERK activation and endothelial cell migration and angiogenesis.

CONCLUSIONEGFL7 effectively promotes migration and angiogenesis through ERK signaling pathway in endothelial cells.

Blotting, Western ; Cell Movement ; Endothelial Cells ; physiology ; Endothelial Growth Factors ; genetics ; physiology ; Humans ; MAP Kinase Signaling System ; physiology ; Neovascularization, Physiologic ; RNA, Messenger ; metabolism ; Signal Transduction

BACKGROUNDBreast cancer is one of the most common malignant female diseases worldwide. It is a significant threat to every woman's health. Vascular endothelial growth inhibitor (VEGI) is known to be abundant in endothelial cells. According to previous literature, overexpression of VEGI has been shown to inhibit tumor neovascularisation and progression in cellular and animal models, but there has been limited research on the significance of VEGI in the breast cancer.

METHODSIn our study, cell lines MDA-MB-231 were first constructed in which VEGI mediated by lentivirus over-expressed. The effects of VEGI over-expression on MDA-MB-231 cells were investigated both in vitro and in vivo. The expression of VEGI in the MDA-MB-231 cells after infection of lentivirus was analyzed using real-time PCR and Western blotting. The effect of the biological characteristics of MDA-MB-231 cells was assessed by growth, invasion, adhesion, and migration assay with subcutaneous tumor-bearing nude mice models. Then the growth curves of the subcutaneous tumors were studied. Expressions of VEGI, CD31 and CD34 in the tumors were analyzed by immunohistochemistry and apoptosis was detected by flow cytometry and immunohistochemistry.

RESULTSInfection of MDA-MB-231 cells within the lentivirus resulted in approximately a 1 000-fold increase in the expression of VEGI. As can be seen in the invasion, adhesion and migration assay, the over-expression of VEGI can inhibit the ability of MDA-MB-231 cells during migration, adhesion and invasion. The volume of the subcutaneous tumor in the over-expression group was distinctly and significantly less than that of the control groups. Immunohistochemistry analysis of the tumor biopsies clearly showed the expression of VEGI in the over-expression group increased while CD31 and CD34 decreased significantly. In vitro and in vivo, the early apoptosis rate and the apoptosis index were increased within the VEGI over-expression group as compared with the control group.

CONCLUSIONSTaken together, recombinant lentivirus that were successfully constructed, demonstrated up-regulated VEGI gene expression in breast cancer cells. Lentivirus-mediated over-expression of VEGI weakened the ability of the breast cancer cell migration, adhesion and invasion. Over-expression of VEGI diminished the tumorigenic capacity of breast cancer cells in vivo. Up-regulation of VEGI gene expression however inhibited breast cancer MDA-MB-231 cell in the early apoptosis.

Apoptosis ; genetics ; physiology ; Breast Neoplasms ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; genetics ; physiology ; Female ; Gene Expression Regulation, Neoplastic ; genetics ; physiology ; Genetic Vectors ; genetics ; Humans ; Lentivirus ; genetics ; Vascular Endothelial Growth Factors ; genetics ; metabolism

OBJECTIVE: The purpose of this study was to evaluate the expression of epidermal growth factor-like domain 7 (EGFL7) in epithelial ovarian cancer, and to assess its relevance to clinicopathological characteristics and patients' survival. METHODS: A total of 177 patients with epithelial ovarian cancer were enrolled in the current study. For each patient, a retrospective review of medical records was conducted. Immunohistochemical staining for EGFL7 was performed using tissue microarrays made with paraffin-embedded tissue block. EGFL7 expression levels were graded on a grade of 0 to 3 based on the percentage of positive cancer cells. We analyzed the correlations between the expression of EGFL7 and various clinical parameters, and also analyzed the survival outcome according to the EGFL7 expression. RESULTS: The expression of EGFL7 in ovarian cancer tissues was observed in 98 patients (55.4%). High expression of EGFL7 (grade 2 or 3) was significantly correlated with pathologic type, differentiation, stage, residual tumor after debulking surgery, lymphovascular space involvement, lymph node metastasis, high cancer antigen 125, peritoneal cytology, and ascites. Among these clinicopathologic factors, differentiation was significantly correlated with EGFL7 expression in multivariate analysis (p<0.05). Survival analysis showed that the patients with high EGFL7 expression had a poorer disease free survival than those with low EGFL7 expression (p=0.002). CONCLUSION: Our data suggest that EGFL7 expression is a novel predictive factor for the clinical progression of epithelial ovarian cancer, and may constitute a therapeutic target for antiangiogenesis therapy in patients with epithelial ovarian cancer.
Adult ; CA-125 Antigen/blood ; Cell Differentiation/physiology ; Endothelial Growth Factors/*metabolism ; Female ; Humans ; Lymphatic Metastasis ; Middle Aged ; Neoplasm Proteins/metabolism ; Neoplasm Staging ; Neoplasm, Residual ; Neoplasms, Glandular and Epithelial/*diagnosis/pathology/surgery ; Ovarian Neoplasms/*diagnosis/pathology/surgery ; Prognosis ; Retrospective Studies ; Survival Analysis ; Tumor Markers, Biological/*metabolism

BACKGROUNDThe mechanism of retinal neovascularization is not understood completely. Many growth factors are involved in the process of retinal neovascularization, such as vascular endothelial growth factor (VEGF) and pigment epithelium-deprived factor (PEDF), which are the representatives of angiogenic and antiangiogenic molecules respectively. Oxygen induced retinopathy (OIR) is a useful model to investigate retinal neovascularization. The present study was conducted to investigate the feasibility of small interference RNA (siRNA) targeting VEGF gene in attenuating oxygen induced retinopathy (OIR) by regulating VEGF to PEDF ratio (VEGF/PEDF).

METHODSIn vitro, cultured EOMA cells were transfected with VEGF-siRNA (psi-HI(TM)/EGFP/VEGF siRNA) and Lipofectamine(TM) 2000 for 24, 48, and 72 hours, respectively. Expression of VEGF mRNA was evaluated by real time polymerase chain reaction (PCR) and the level of VEGF protein was analyzed by Western blotting. In vivo, OIR model mice were established, the mice (C57BL/6J) received an intra-vitreal injection of 1 µl of mixture of psi-HI(TM)/EGFP/VEGF siRNA and Lipofectamine 2000. Expressions of retinal VEGF and PEDF protein were measured by Western blotting, retinal neovascularization was observed by fluorescein angiography, and quantified.

RESULTSIn vitro psi-HI(TM)/EGFP/VEGF siRNA treatment significantly reduced VEGF mRNA and protein expression. In vivo, with decreased VEGF and VEGF-PEDF ratio, significant attenuation of neovascular tufts, avascular regions, tortuous, and dilated blood vessels were observed in the interfered animals.

CONCLUSIONSVEGF plays an important role in OIR, and the transfection of VEGF-siRNA can effectively downregulate VEGF expression in vivo, accompanied by the downregulation of VEGF-PEDF ratio, and simultaneous attenuation of retinal neovascularization was also observed. These findings suggest that VEGF/PEDF may serve as a potential target in the treatment of retinal neovascularization and RNA interference targeting VEGF expression, which represents a possible therapeutic strategy.

Animals ; Eye Proteins ; analysis ; Mice ; Mice, Inbred C57BL ; Nerve Growth Factors ; analysis ; RNA, Small Interfering ; genetics ; Retinal Neovascularization ; therapy ; Serpins ; analysis ; Vascular Endothelial Growth Factor A ; analysis ; genetics ; physiology

Formation of the periodontium begins following onset of tooth-root formation in a coordinated manner after birth. Dental follicle progenitor cells are thought to form the cementum, alveolar bone and Sharpey's fibers of the periodontal ligament (PDL). However, little is known about the regulatory morphogens that control differentiation and function of these progenitor cells, as well as the progenitor cells involved in crown and root formation. We investigated the role of bone morphogenetic protein-2 (Bmp2) in these processes by the conditional removal of the Bmp2 gene using the Sp7-Cre-EGFP mouse model. Sp7-Cre-EGFP first becomes active at E18 in the first molar, with robust Cre activity at postnatal day 0 (P0), followed by Cre activity in the second molar, which occurs after P0. There is robust Cre activity in the periodontium and third molars by 2 weeks of age. When the Bmp2 gene is removed from Sp7(+) (Osterix(+)) cells, major defects are noted in root, cellular cementum and periodontium formation. First, there are major cell autonomous defects in root-odontoblast terminal differentiation. Second, there are major alterations in formation of the PDLs and cellular cementum, correlated with decreased nuclear factor IC (Nfic), periostin and α-SMA(+) cells. Third, there is a failure to produce vascular endothelial growth factor A (VEGF-A) in the periodontium and the pulp leading to decreased formation of the microvascular and associated candidate stem cells in the Bmp2-cKO(Sp7-Cre-EGFP). Fourth, ameloblast function and enamel formation are indirectly altered in the Bmp2-cKO(Sp7-Cre-EGFP). These data demonstrate that the Bmp2 gene has complex roles in postnatal tooth development and periodontium formation.
Actins ; analysis ; Activating Transcription Factor 2 ; genetics ; Age Factors ; Ameloblasts ; pathology ; Amelogenesis ; genetics ; Animals ; Bone Morphogenetic Protein 2 ; genetics ; Cell Adhesion Molecules ; analysis ; Cell Differentiation ; genetics ; Cementogenesis ; genetics ; Dental Cementum ; pathology ; Dental Pulp ; blood supply ; Fluorescent Dyes ; Green Fluorescent Proteins ; Male ; Mice ; Mice, Knockout ; Microvessels ; pathology ; Molar ; growth & development ; Molar, Third ; growth & development ; NFI Transcription Factors ; analysis ; Odontoblasts ; pathology ; Odontogenesis ; genetics ; Periodontal Ligament ; growth & development ; Sp7 Transcription Factor ; Stem Cells ; physiology ; Tooth Root ; growth & development ; Transcription Factors ; genetics ; Vascular Endothelial Growth Factor A ; analysis ; Zinc Fingers ; genetics