Intravitreal Pharmacokinetic Study of the Antiangiogenic Glycoprotein Opticin.

Opticin is an endogenous vitreous glycoprotein that may have therapeutic potential as it has been shown that supranormal concentrations suppress preretinal neovascularization. Herein we investigated the pharmacokinetics of opticin following intravitreal injection in rabbits. To measure simultaneously concentrations of human and rabbit opticin, a selected reaction monitoring mass spectrometry assay was developed. The mean concentration of endogenous rabbit opticin in 7 uninjected eyes was measured and found to be 19.2 nM or 0.62 µg/mL. When the vitreous was separated by centrifugation into a supernatant and collagen-containing pellet, 94% of the rabbit opticin was in the supernatant. Intravitreal injection of human opticin (40 µg) into both eyes of rabbits was followed by enucleation at 5, 24, and 72 h and 7, 14, and 28 days postinjection (n = 6 at each time point) and measurement of vitreous human and rabbit opticin concentrations in the supernatant and collagen-containing pellet following centrifugation. The volume of distribution of human opticin was calculated to be 3.31 mL, and the vitreous half-life was 4.2 days. Assuming that rabbit and human opticin are cleared from rabbit vitreous at the same rate, opticin is secreted into the vitreous at a rate of 0.14 µg/day. We conclude that intravitreally injected opticin has a vitreous half-life that is similar to currently available antiangiogenic therapeutics. While opticin was first identified bound to vitreous collagen fibrils, here we demonstrate that >90% of endogenous opticin is not bound to collagen. Endogenous opticin is secreted by the nonpigmented ciliary epithelium into the rabbit vitreous at a remarkably high rate, and the turnover in vitreous is approximately 15% per day.

Total Biosynthesis of Antiangiogenic Agent (-)-Terpestacin by Artificial Reconstitution of the Biosynthetic Machinery in Aspergillus oryzae.

The total biosynthesis of (-)-terpestacin was achieved by heterologous expression of four biosynthetic enzyme genes ( tpcA- D) in Aspergillus oryzae. After construction of preterpestacin I by the action of bifunctional terpene synthase (TpcA), two cytochrome P450s (TpcBC) activate inert C-H bond to install three hydroxyl groups on the A-ring in stereo- and regioselective manners. Subsequently, a flavin-dependent oxidase (TpcD) catalyzes oxidation of the vicinal diol moiety to give a α-diketone, which undergoes an enolization to furnish terpestacin. The successful synthesis of structurally elaborated terpestacin showed that a reconstitution approach that harnesses several biosynthetic enzyme genes in A. oryzae could be a promising alternative to the current chemical synthesis of natural terpenoids.

AAV-mediated gene delivery of the calreticulin anti-angiogenic domain inhibits ocular neovascularization.

Ocular neovascularization is a common pathological feature in diabetic retinopathy and neovascular age-related macular degeneration that can lead to severe vision loss. We evaluated the therapeutic efficacy of a novel endogenous inhibitor of angiogenesis, the calreticulin anti-angiogenic domain (CAD180), and its functional 112-residue fragment, CAD-like peptide 112 (CAD112), delivered using a self-complementary adeno-associated virus serotype 2 (scAAV2) in rodent models of oxygen-induced retinopathy and laser-induced choroidal neovascularization. The expression of CAD180 and CAD112 was elevated in human umbilical vein endothelial cells transduced with scAAV2-CAD180 or scAAV2-CAD112, respectively, and both inhibited angiogenic activity in vitro. Intravitreal gene delivery of scAAV2-CAD180 or scAAV2-CAD112 significantly inhibited ischemia-induced retinal neovascularization in rat eyes (CAD180: 52.7% reduction; CAD112: 49.2% reduction) compared to scAAV2-mCherry, as measured in retinal flatmounts stained with isolectin B4. Moreover, the retinal structure and function were unaffected by scAAV2-CAD180 or scAAV2-CAD112, as measured by optical coherence tomography and electroretinography. Moreover, subretinal delivery of scAAV2-CAD180 or scAAV2-CAD112 significantly attenuated laser-induced choroidal neovascularization in mouse eyes compared to scAAV2-mCherry, as measured by fundus fluorescein angiography (CAD180: 62.4% reduction; CAD112: 57.5% reduction) and choroidal flatmounts (CAD180: 40.21% reduction; CAD112: 43.03% reduction). Gene delivery using scAAV2-CAD180 or scAAV2-CAD112 has significant potential as a therapeutic option for the management of ocular neovascularization.

Intravitreous injection of AAV2-sFLT01 in patients with advanced neovascular age-related macular degeneration: a phase 1, open-label trial.

BACKGROUND: Long-term intraocular injections of vascular endothelial growth factor (VEGF)-neutralising proteins can preserve central vision in many patients with neovascular age-related macular degeneration. We tested the safety and tolerability of a single intravitreous injection of an AAV2 vector expressing the VEGF-neutralising protein sFLT01 in patients with advanced neovascular age-related macular degeneration. METHODS: This was a phase 1, open-label, dose-escalating study done at four outpatient retina clinics in the USA. Patients were assigned to each cohort in order of enrolment, with the first three patients being assigned to and completing the first cohort before filling positions in the following treatment groups. Patients aged 50 years or older with neovascular age-related macular degeneration and a baseline best-corrected visual acuity score of 20/100 or less in the study eye were enrolled in four dose-ranging cohorts (cohort 1, 2 × 108 vector genomes (vg); cohort 2, 2 × 109 vg; cohort 3, 6 × 109 vg; and cohort 4, 2 × 1010 vg, n=3 per cohort) and one maximum tolerated dose cohort (cohort 5, 2 × 1010 vg, n=7) and followed up for 52 weeks. The primary objective of the study was to assess the safety and tolerability of a single intravitreous injection of AAV2-sFLT01, through the measurement of eye-related adverse events. This trial is registered with ClinicalTrials.gov, number NCT01024998. FINDINGS: 19 patients with advanced neovascular age-related macular degeneration were enrolled in the study between May 18, 2010, and July 14, 2014. All patients completed the 52-week trial period. Two patients in cohort 4 (2 × 1010 vg) experienced adverse events that were possibly study-drug related: pyrexia and intraocular inflammation that resolved with a topical steroid. Five of ten patients who received 2 × 1010 vg had aqueous humour concentrations of sFLT01 that peaked at 32·7-112·0 ng/mL (mean 73·7 ng/mL, SD 30·5) by week 26 with a slight decrease to a mean of 53·2 ng/mL at week 52 (SD 17·1). At baseline, four of these five patients were negative for anti-AAV2 serum antibodies and the fifth had a very low titre (1:100) of anti-AAV2 antibodies, whereas four of the five non-expressers of sFLT01 had titres of 1:400 or greater. In 11 of 19 patients with intraretinal or subretinal fluid at baseline judged to be reversible, six showed substantial fluid reduction and improvement in vision, whereas five showed no fluid reduction. One patient in cohort 5 showed a large decrease in vision between weeks 26 and 52 that was not thought to be vector-related. INTERPRETATION: Intravitreous injection of AAV2-sFLT01 seemed to be safe and well tolerated at all doses. Additional studies are needed to identify sources of variability in expression and anti-permeability activity, including the potential effect of baseline anti-AAV2 serum antibodies. FUNDING: Sanofi Genzyme, Framingham, MA, USA.

A MicroRNA302-367-Erk1/2-Klf2-S1pr1 Pathway Prevents Tumor Growth via Restricting Angiogenesis and Improving Vascular Stability.

RATIONALE: Angiogenic hypersprouting and leaky vessels are essential for tumor growth. MicroRNAs have unique therapeutic advantages by targeting multiple pathways of tumor-associated angiogenesis, but the function of individual miRNAs of miR302-367 cluster in angiogenesis and tumors has not yet been fully evaluated. OBJECTIVE: To investigate the functions of miR302-367 in developmental angiogenesis and tumor angiogenesis and explore the molecular mechanisms of microRNA for the treatment of pathological neovascularization-related diseases. METHODS AND RESULTS: Here, we show that miR302-367 elevation in endothelial cells reduces retinal sprouting angiogenesis and promotes vascular stability in vivo, ex vivo, and in vitro. Erk1/2 is identified as direct target of miR302-367, and downregulation of Erk1/2 on miR302-367 elevation in endothelial cells increases the expression of Klf2 and in turn S1pr1 and its downstream target VE-cadherin, suppressing angiogenesis and improving vascular stability. Conversely, both pharmacological blockade and genetic deletion of S1pr1 in endothelial cells reverse the antiangiogenic and vascular stabilizing effect of miR302-367 in mice. Tumor angiogenesis shares features of developmental angiogenesis, and endothelial specific elevation of miR302-367 reduces tumor growth by restricting sprout angiogenesis and decreasing vascular permeability via the same Erk1/2-Klf2-S1pr1 pathways. CONCLUSIONS: MiR302-367 regulation of an Erk1/2-Klf2-S1pr1 pathway in the endothelium advances our understanding of angiogenesis, meanwhile also provides opportunities for therapeutic intervention of tumor growth.

Potent and long-term antiangiogenic efficacy mediated by FP3-expressing oncolytic adenovirus.

Various ways to inhibit vascular endothelial growth factor (VEGF), a key facilitator in tumor angiogenesis, are being developed to treat cancer. The soluble VEGF decoy receptor (FP3), due to its high affinity to VEGF, is a highly effective and promising strategy to disrupt VEGF signaling pathway. Despite potential advantage and potent therapeutic efficacy, its employment has been limited by very poor in vivo pharmacokinetic properties. To address this challenge, we designed a novel oncolytic adenovirus (Ad) expressing FP3 (RdB/FP3). To demonstrate the VEGF-specific nature of RdB/FP3, replication-incompetent Ad expressing FP3 (dE1/FP3) was also generated. dE1/FP3 was highly effective in reducing VEGF expression and functionally elicited an antiangiogeneic effect. Furthermore, RdB/FP3 exhibited a potent antitumor effect compared with RdB or recombinant FP3. Consistent with these data, RdB/FP3 was shown to greatly decrease VEGF expression level and vessel density and increase apoptosis in both tumor endothelial and tumor cells, verifying potent suppressive effects of RdB/FP3 on VEGF-mediated tumor angiogenesis in vivo. Importantly, the therapeutic mechanism of antitumor effect mediated by RdB/FP3 is associated with prolonged VEGF silencing efficacy and enhanced oncolysis via cancer cell-specific replication of oncolytic Ad. Taken together, RdB/FP3 provides a new promising therapeutic approach in the treatment of cancer and angiogenesis-related diseases.

Recombinant mutated human TNF in combination with chemotherapy for stage IIIB/IV non-small cell lung cancer: a randomized, phase III study.

Tumor necrosis factor (TNF), an anti-angiogenic agent in cancer treatment, is limited to isolated limb perfusion due to systemic toxicities. We previously prepared a TNF mutant (rmhTNF) that significantly improved responses in lung cancer patients and exhibited a promising safety profile in phase I and II studies. To further investigate whether rmhTNF with standard chemotherapy provides a survival benefit, 529 patients with stage IIIB/IV non-small cell lung cancer (NSCLC) were randomly assigned to receive docetaxel plus carboplatin/cisplatin with rmhTNF (265) or chemotherapy alone (264). After four cycles of treatment, the median overall survival was 13.7 months in the chemotherapy plus rmhTNF group compared with 10.3 months in the chemotherapy group (hazard ratio (HR) 0.75, P = 0.001). The median progression-free survival in the chemotherapy plus rmhTNF group and the chemotherapy group was 8.6 and 4.5 months (HR 0.76, P = 0.001), respectively, with corresponding response rates of 38.5% and 27.7% (P = 0.008). Increased hyperpyrexia and pulmonary hemorrhage were associated with rmhTNF, but most effects were well tolerated. The results indicated that rmhTNF effectively potentiated chemotherapy in patients with advanced NSCLC and was comparable with bevacizumab, an angiogenesis inhibitor approved by the Food and Drug Administration (FDA) for NSCLC.

Endostar attenuates melanoma tumor growth via its interruption of b-FGF mediated angiogenesis.

To develop optimal therapeutics is one of the hotspots in both clinical and basic melanoma studies. Previous studies indicate that fibroblast growth factors (b-FGF/FGF-2), an angiogenesis inducer beyond VEGF, might be a potential drug target in melanoma. As a novel anti-angiogenesis peptide drug, Endostar has shown promising therapeutic efficacy in non-small cell lung cancer. However, the effect of Endostar on b-FGF-induced angiogenesis in melanoma is unraveled. To this end, both in vivo and in vitro experiments were conducted and it was found that treatment of Endostar could inhibit tumor growth, which was accompanied by decreased micro-vessel density and serum b-FGF levels in a mouse melanoma model. In addition, treatment with Endostar in blood vessel endothelial cells could reduce their proliferation, cell migration and tube formation capacity in a dosage-dependent manner. Moreover, treatment of Endostar could also attenuate b-FGF-activated phosphorylation of p38 and ERK1/2 in HUVECs. These findings indicate that Endostar might exert its anti-tumor effect via suppressing b-FGF-induced angiogenesis and b-FGF-activated MAPK signaling pathway, suggesting that Endostar might be a potential choice for clinical melanoma treatment.

Identification and characterization of the biosynthetic gene cluster of thiolutin, a tumor angiogenesis inhibitor, in Saccharothrix algeriensis NRRL B-24137.

In this study, a new dithiolopyrrolone biosynthetic pathway was identified in Saccharothrix algeriensis NRRL B-24137, which was reported to produce a variety of dithiolopyrrolone natural products including thiolutin, a potential drug candidate for tumor angiogenesis inhibition. Bioinformatics analysis of the cluster revealed that it contains all the essential genes for holothin core biosynthesis and several other auxiliary genes. Interestingly, heterologous expression of the gene cluster in Streptomyces albus only induced the production of holomycin, implying that the gene responsible for the N4-methylation and the gene(s) involved in the formation of various acylated chains on N7 position of the holothin may locate outside the gene cluster. Incubation of holomycin with S-adenosyl-L-methionine (SAM) in the cell-free extract of Sa. algeriensis resulted in the production of thiolutin, suggesting that the N4-methyl group of thiolutin is originated from SAM, and the N4-methylation could be in the late stage of biosynthesis of thiolutin type dithiolopyrrolones. An evolution-based model for biosynthesis of thiolutin and its analogs was further proposed based on these results.

Salinity-induced anti-angiogenesis activities and structural changes of the polysaccharides from cultured Cordyceps Militaris.

Cordyceps is a rare and exotic mushroom that grows out of the head of a mummified caterpillar. Many companies are cultivating Cordyceps to meet the increased demand for its medicinal applications. However, the structures and functions of polysaccharides, one of the pharmaceutical active ingredients in Cordyceps, are difficult to reproduce in vitro. We hypothesized that mimicking the salty environment inside caterpillar bodies might make the cultured fungus synthesize polysaccharides with similar structures and functions to that of wild Cordyceps. By adding either sodium sulfate or sodium chloride into growth media, we observed the salinity-induced anti-angiogenesis activities of the polysaccharides purified from the cultured C. Militaris. To correlate the activities with the polysaccharide structures, we performed the (13)C-NMR analysis and observed profound structural changes including different proportions of α and ß glycosidic bonds and appearances of uronic acid signals in the polysaccharides purified from the culture after the salts were added. By coupling the techniques of stable (34)S-sulfate isotope labeling, aniline- and D5-aniline tagging, and stable isotope facilitated uronic acid-reduction with LC-MS analysis, our data revealed for the first time the existence of covalently linked sulfate and the presence of polygalacuronic acids in the polysaccharides purified from the salt added C. Militaris culture. Our data showed that culturing C. Militaris with added salts changed the biosynthetic scheme and resulted in novel polysaccharide structures and functions. These findings might be insightful in terms of how to make C. Militaris cultures to reach or to exceed the potency of wild Cordyceps in future.

Glycosylation and subsequent malonylation of isoflavonoids in E. coli: strain development, production and insights into future metabolic perspectives.

Genistin and daidzein exhibit a protective effect on DNA damage and inhibit cell proliferation. Glycosylation and malonylation of the compounds increase water solubility and stability. Constructed pET15b-GmIF7GT and pET28a-GmIF7MAT were used for the transformation of Escherichia coli and bioconversion of genistein and daidzein. To increase the availability of malonyl-CoA, a critical precursor of GmIF7MAT, genes for the acyl-CoA carboxylase α and ß subunits (nfa9890 and nfa9940), biotin ligase (nfa9950), and acetyl-CoA synthetase (nfa3550) from Nocardia farcinia were also introduced. Thus, the isoflavonoids were glycosylated at position 7 by 7-O-glycosyltranferase and were further malonylated at position 6(″) of glucose by malonyl-CoA: isoflavone 7-O-glucoside-6(″)-O-malonyltransferase both from Glycine max. Engineered E. coli produced 175.7 µM (75.90 mg/L) of genistin and 14.2 µM (7.37 mg/L) genistin 6''-O-malonate. Similar conditions produced 162.2 µM (67.65 mg/L) daidzin and 12.4 µM (6.23 mg/L) daidzin 6''-O-malonate when 200 µM of each substrate was supplemented in the culture. Based on our findings, we speculate that isoflavonoids and their glycosides may prove useful as anticancer drugs with added advantage of increased solubility, stability and bioavailability.

Interferon-ß inhibits glioma angiogenesis through downregulation of vascular endothelial growth factor and upregulation of interferon inducible protein 10.

Interferon-ß (IFN-ß) has been used clinically for malignant glioma growth inhibition. Recently IFN-ß is re-evaluated for its sensitization mechanism to the chemotherapeutic agent temozolomide, because angiogenesis is essential for malignant glioma growth. In this study, we investigated new mechanisms of inhibition of glioma angiogenesis by IFN-ß. Three malignant glioma cell lines, U87, TK2 and Becker, were used for in vitro study. The effect of IFN-ß for these cell lines were evaluated by means of proliferation (MTT assay), conditioned medium induced HUVEC migration, VEGF and interferon inducible protein 10 (IP10, angiogenesis inhibitor) expression by RT-PCR and western blot analysis. SCID mouse U87 subcutaneous model and U87 implant cranial window model were used for in vivo study. The effect of IFN-ß with the models was evaluated by means of tumor growth, tumor tissue expression for VEGF and IP10, tumor tissue CD31 positive vessel densities, apoptosis and tumor microcirculation (blood velocity, interaction between leukocytes and endothelial cells). In vitro, IFN-ß upregulated IP10 expression and downregulated VEGF expression time- (4-48 h) and dose- (10-5,000 U/ml) dependently. At the same dose, glioma cell-induced HUVEC migration was inhibited, but cell proliferation was not affected. IFN-ß local and systemic injection at 105 U and at 5x10(5) U/day, for 15 days inhibited U87 subcutaneous growth significantly. In the tumor tissues, VEGF expression and vessel densities were downregulated, but IP10 expression and apoptosis index upregulated. In addition, IFN-ß local injection increased collagen fiber deposition in the tumor tissues. IFN-ß 5x10(5) U/day, s.c. injection for 7 days reversed the decreased leukocyte adhesion to endothelial cells, but did not affect blood velocity and vessel images. One of the important roles of IFN-ß for malignant glioma growth inhibition was anti-angiogenesis by directly inhibiting angiogenesis through downregulation of VEGF and upregulation of IP-10 and indirectly changing the tumor microcirculation and regulating the interstitial pressure.

Molecular cloning, expression and purification of recombinant soluble mouse endostatin as an anti-angiogenic protein in Escherichia coli.

Inhibition of angiogenesis has become a particular interest for treatment of solid tumors. Endostatin, a C-terminal fragment of collagen XVIII, has been reported to exhibit potent inhibitory effect on endothelial cells proliferation, migration and tube formation. In this research, the cDNA library of endostatin was synthesized from mouse liver and inserted into the SacI and SalI enzyme-cutting sites of pUC18 cloning vector. The recombinant vector was transferred into Escherichia coli DH5a and the recombinant clone was selected on LB agar plate plus ampicillin. PCR analysis and DNA sequencing proved the presence of intact endostatin gene in pUC18. The endostatin gene subcloned into pET32a expression vector and the competent bacterial cells of E. coli BL21 were transformed by the vector harboring endostatin gene. In the optimum conditions, expression plasmid was induced with IPTG and recombinant soluble endostatin as a fusion with thioredoxin was purified with Ni-NTA (Ni(2+)-nitrilotriacetate) resin. The results showed that soluble recombinant endostatin as a fusion protein with thioredoxin is a homogenous polypeptide that inhibits angiogenesis (capillary tube formation) in human umbilical vein endothelial cells by 200 ng/ml.

[Isolation and purification of recombinant soluble and non-fusion angiogenesis inhibitor Kringle 5 using chromatography].

The Kringle 5 domain of plasminogen is one of the most potent angiogenesis inhibitors known to date, which can inhibit cell proliferation and migration efficiently. In the study, on the foundation of successful clone and expression of recombinant soluble and non-fusion angiogenesis inhibitor Kringle 5, a two-step chromatographic method, including the use of SP Sepharose Fast Flow cation exchanger and Sephacryl S-100 HR size exclusion chromatography in sequence, was established to separate and purify angiogenesis inhibitor Kringle 5. On the SP Sepharose Fast Flow column, the buffer A consisted of 50.0 mmol/L acetic acid-sodium acetate (pH 5.2), and the buffer B consisted of buffer A with the addition of 0.5 mol/L sodium chloride (pH 5.2); on Sephacryl S-100 HR column, the elution buffer was 5.0 mmol/L phosphate solution (pH 7.0). Through the two-step chromatographic purification process, the purity of the obtained Kringle 5 was more than 98%. In addition, it was found that the obtained Kringle 5 could inhibit the blood vessel growth of chick embryo chorioallantoic membrane effectively. Finally it is concluded that this method can effectively separate active recombinant soluble and non-fusion angiogenesis inhibitor Kringle 5.

Endostatin gene therapy for endometriosis in rats.

OBJECTIVE: Endostatin gene therapy for endometriosis was studied in an experimental autotransplantation model in rats. METHODS: Endometriotic lesions were transfected by intralesional injection of the plasmid lipofectamine-endostatin-pBud (group 1), lipofectamine-pBud (empty vector; group 2) or phosphate-buffered saline (group 3). Endostatin mRNA and protein levels in lesions were evaluated by quantitative real-time reverse transcription-polymerase chain reaction and Western blot analysis. Endostatin and vascular endothelial growth factor (VEGF) protein levels in serum, and microvessel density (MVD) and matrix metalloproteinase (MMP)-2 protein levels in endometriotic lesions, were also determined. RESULTS: Lipofectamine-endostatin-pBud injection increased endostatin mRNA and protein levels in lesions. Lesions were significantly smaller, and serum VEGF levels significantly lower, in group 1 versus controls. Serum VEGF was significantly and negatively correlated with serum endostatin. In group 1, MMP-2 levels and MVD were significantly lower versus controls. MMP-2 level was negatively correlated with endostatin. CONCLUSIONS: Gene therapy with endostatin appears to be an effective treatment for endometriosis. Restoration of endostatin gene expression by gene transfer in vivo might be a potential gene therapy approach for human endometriosis.

[Optimization of expression conditions of recombinant Fuantai-03 and detection of its biological activities].

Fuantai-03(FAT-03), isolated from the Dasyatis akajei, has a strong antiangiogenic activity. The recombinant Fuantai-03 (GST/rFAT-03) fusion protein can be obtained with the DNA recombination technology. In this study, expression conditions of GST/rFAT-03 were optimized by response surface experimental design method. The constructed engineering bacteria containing GST/rFAT-03 plasmid was induced by isopropy-beta-D-thiogalactosid (IPTG), the GST affinity column was used for isolation and purification, and then the effects of different culture time, IPTG concentration, induction temperature and induction time on the amount of soluble GST/rFAT-03 fusion protein were compared. The culture time for optimal expression was 6.13 h, IPTG concentration was 0.36 mmol/L, induction temperature was 19.71 degrees C, and induction time was 13.60 h. The amount of soluble GST/rFAT-03 fusion protein was 7.57 mg/L under above mentioned expression conditions. The results also showed that rFAT-03 significantly inhibited angiogenesis in chicken chorioallantoic membrane in a dose-dependent manner. Moreover, the soluble form of the target protein is useful for further work on purification and on studying its biological function.

[Recombinant fragment of pigment epithelium-derived factor (44-77) prevents pathological corneal neovascularization].

Pigment epithelium-derived factor (PEDF), a 50 kDa secreted glycoprotein, is among the most potent endogenous inhibitors of angiogenesis. PEDF-derived fragment (44-77) possesses antiangiogenic properties of the full-sized protein and is a potential drug candidate for the treatment of ocular neovascular diseases. In this study we propose an efficient scalable biotechnological method for the production of PEDF (44-77) as part of a fusion protein with SspDnaB intein. The fusion protein was obtained in bacterial E. coli cells in the form of inclusion bodies, solubilized and subjected to autocatalytic cleavage with the release of PEDF (44-77) (yield, 77%). The target peptide was separated from the intein using tangential ultrafiltration. The final purification of PEDF (44-77) was performed by reversed-phase HPLC. The yield of the target peptide (purity, 99%) was 65 mg per 1 liter of culture. Antiangiogenic activity of the obtained peptide was studied in vitro using murine endothelial cells SVEC-4-10. PEDF (44-77) suppressed proliferation of endothelial cells by 53% and inhibited endothelial cell tube formation at the concentration of 1 nM. The ability of the recombinant PEDF (44-77) to block initial stages of angiogenesis was demonstrated using the model of rabbit corneal neovascularization.

Optimization of extracellular glucan production from Pleurotus eryngii and its impact on angiogenesis.

Pleurotus eryngii, an edible mushroom with therapeutic potential was optimized using response surface methodology of four-factor Box-Behnken design for maximum mycelial biomass and extracellular glucan (EPS) production. The model predicts to gain a maximal mycelial biomass and extracellular polysaccharide at 39.4 g/l; 36.04 g/l of glucose, 8.27 g/l; 7.51 g/l of yeast extract, pH 6.99; 7.07 and temperature 26.2°C; 25.84°C, respectively. The validation experiments showed that the model was significant and in close agreement with the model prediction. The evaluation of extracellular polysaccharide on angiogenesis by ex vivo CAM assay showed that there was significant inhibition in neo-vascularization.

Hypoxia stimulates the production of the angiogenesis inhibitor 2-methoxyestradiol by swine granulosa cells.

We previously demonstrated the presence of 2-methoxyestradiol (2-ME) in swine follicular fluid. Present study was aimed first of all to investigate if swine granulosa cell produce 2-ME; in addition, we tried to assess a potential effect of hypoxia in modulating 2-ME output. Finally, we explored the effect of 2-ME in an angiogenesis bioassay set up in our lab. Our data show that cultured granulosa cells are able to produce 2-ME; interestingly, the secretion of the hormone appeared to be stimulated by hypoxia. Angiogenesis bioassay points out that 2-ME displays an inhibitory effect on neovascularisation. Therefore our data suggest that 2-ME could be a local effector in determining the fine tuning responsible for follicle angiogenesis. These data deserve special attention since the ovary is a valuable experimental model in angiogenesis research.

Importance of anti-angiogenic factors in the regulation of skeletal muscle angiogenesis.

The microcirculation is essential for delivery of oxygen and nutrients to maintain skeletal muscle health and function. The network of microvessels surrounding skeletal myocytes has a remarkable plasticity that ensures a good match between muscle perfusion capacities and myofiber metabolic needs. Depending on physiologic conditions, this vascular plasticity can either involve growth (e.g., exercise-induced angiogenesis) or regression (e.g., physical deconditioning) of capillaries. This angio-adaptative response is thought to be controlled by a balance between pro- and anti-angiogenic factors and their receptors. While changes in the expression or activity for pro-angiogenic factors have been well studied in response to acute and chronic exercise during the past two decades, little attention thus far has been devoted to endogenous negative regulators that are also likely to be important in regulating capillary growth/regression. Indeed, the importance and contribution of anti-angiogenic factors in controlling skeletal muscle angiogenesis remains poorly understood. Here, we highlight the emerging research related to skeletal muscle expression of several negative angiogenic factors and discuss their potential importance in controlling skeletal muscle angio-adaptation, particularly in physiologic response to physical activity.