Curcuminoids Inhibit Angiogenic Behaviors of Human Umbilical Vein Endothelial Cells via Endoglin/Smad1 Signaling.

BACKGROUND: Angiogenesis is primarily attributed to the excessive proliferation and migration of endothelial cells. Targeting the vascular endothelial growth factor (VEGF) is therefore significant in anti-angiogenic therapy. Although these treatments have not reached clinical expectations, the upregulation of alternative angiogenic pathways (endoglin/Smad1) may play a critical role in drug (VEGF-neutralizing agents) resistance. Enhanced endoglin expression following a VEGF-neutralizing therapy (semaxanib®) was noted in patients. Treatment with an endoglin-targeting antibody augmented VEGF expression in human umbilical vein endothelial cells (HUVECs). Therefore, approaches that inhibit both the androgen and VEGF pathways enhance the HUVECs cytotoxicity and reverse semaxanib resistance. The purpose of this study was to find natural-occurring compounds that inhibited the endoglin-targeting pathway. METHODS: Curcuminoids targeting endoglin were recognized from two thousand compounds in the Traditional Chinese Medicine Database@Taiwan (TCM Database@Taiwan) using Discovery Studio 4.5. RESULTS: Our results, obtained using cytotoxicity, migration/invasion, and flow cytometry assays, showed that curcumin (Cur) and demethoxycurcumin (DMC) reduced angiogenesis. In addition, Cur and DMC downregulated endoglin/pSmad1 phosphorylation. CONCLUSIONS: The study first showed that Cur and DMC demonstrated antiangiogenic activity via the inhibition of endoglin/Smad1 signaling. Synergistic effects of curcuminoids (i.e., curcumin and DMC) and semaxanib on HUVECs were found. This might be attributed to endoglin/pSmad1 downregulation in HUVECs. Combination treatment with curcuminoids and a semaxanib is therefore expected to reverse semaxanib resistance.

Uncaria tomentosa extract (AC-11) improves pregnancy hypertension together with suppression of sFlt-1 and sEng.

Disruption of well-controlled reproductive functions leads to pregnancy complications such as hypertensive disorders of pregnancy (HDP). Uncaria tomentosa (Wild), known as cat's claw, is widely used for the treatment of a various types of health problems; AC-11 (AC-11®, hot-water extract of U. tomentosa) is unique phytochemical compound and has potential roles as anti-inflammatory or anti-oxidant processes. We investigated whether AC-11 has a protective effect on pathogenesis of HDP in vivo and production of anti-angiogenic factors (sFlt-1 and sEng, major factors for the onset of HDP) in in vitro. Non-pregnant or pregnant mice were administered AC-11 (4 mg/mL), then, angiotensin II (Ang II) was subcutaneously infused to increase blood pressure. Human placental tissues or human umbilical vein endothelial cells (HUVECs) were incubated with or without AC-11. Treatment with AC-11 significantly reduced blood pressure induced by Ang II infusion. The population of CD8+T cells, the ratio of CD8/CD4, and plasma interleukin-6 levels were increased by Ang II infusion, and were decreased by AC-11 both in pregnant and non-pregnant mice. In pregnant mice, plasma levels of sFlt-1 and sEng were decreased by AC-11. In in vitro cell culture of HUVECs or placental tissue culture, treatment with AC-11 significantly inhibited secretion of sFlt-1 and sEng. We suggest a novel role of AC-11 in regulating blood pressure by controlling the balance of T cell population and inflammatory cytokine production both in non-pregnant and pregnant conditions. In addition, AC-11 inhibits HDP-related factors, including sFlt-1 and sEng, suggesting that AC-11 may useful for relieving HDP.

Thiamine increases resident endoglin positive cardiac progenitor cells and atrial contractile force in humans: A randomised controlled trial.

BACKGROUND: The heart has an intrinsic ability to regenerate, orchestrated by progenitor or stem cells. However, the relative complexity of non-resident cardiac progenitor cell (CPC) therapy makes modulation of resident CPCs a more attractive treatment target. Thiamine analogues improve resident CPC function in pre-clinical models. In this double blinded randomised controlled trial (identifier: ACTRN12614000755639), we examined whether thiamine would improve CPC function in humans. METHODS AND RESULTS: High dose oral thiamine (one gram twice daily) or matching placebo was administered 3-5 days prior to coronary artery bypass surgery (CABG). Right atrial appendages were collected at the time of CABG, and CPCs isolated. There was no difference in the primary outcome (proliferation ability of CPCs) between treatment groups. Older age was not associated with decreased proliferation ability. In exploratory analyses, isolated CPCs in the thiamine group showed an increase in the proportion of CD34-/CD105+ (endoglin) cells, but no difference in CD34-/CD90+ or CD34+ cells. Thiamine increased maximum force developed by isolated trabeculae, with no difference in relaxation time or beta-adrenergic responsiveness. CONCLUSION: Thiamine does not improve proliferation ability of CPC in patients undergoing CABG, but increases the proportion of CD34-/CD105+ cells. Having not met its primary endpoint, this study provides the impetus to re-examine CPC biology prior to any clinical outcome-based trial examining potential beneficial cardiovascular effects of thiamine.

Endoglin Targeting: Lessons Learned and Questions That Remain.

Approximately 30 years ago, endoglin was identified as a transforming growth factor (TGF)-ß coreceptor with a crucial role in developmental biology and tumor angiogenesis. Its selectively high expression on tumor vessels and its correlation with poor survival in cancer patients led to the exploration of endoglin as a therapeutic target for cancer. The endoglin neutralizing antibody TRC105 (Carotuximab®, Tracon Pharmaceuticals (San Diego, CA, USA) was subsequently tested in a wide variety of preclinical cancer models before being tested in phase I-III clinical studies in cancer patients as both a monotherapy and in combination with other chemotherapeutic and anti-angiogenic therapies. The combined data of these studies have revealed new insights into the role of endoglin in angiogenesis and its expression and functional role on other cells in the tumor microenvironment. In this review, we will summarize the preclinical work, clinical trials and biomarker studies of TRC105 and explore what these studies have enabled us to learn and what questions remain unanswered.

Bioenergetic effects of hydrogen sulfide suppress soluble Flt-1 and soluble endoglin in cystathionine gamma-lyase compromised endothelial cells.

Endothelial dysfunction is a hallmark of preeclampsia, a life-threatening complication of pregnancy characterised by hypertension and elevated soluble Fms-Like Tyrosine Kinase-1 (sFlt-1). Dysregulation of hydrogen sulfide (H2S) by inhibition of cystathionine γ-lyase (CSE) increases sFlt-1 and soluble endoglin (sEng) release. We explored whether compromise in CSE/H2S pathway is linked to dysregulation of the mitochondrial bioenergetics and oxidative status. We investigated whether these effects were linked to CSE-induced sFlt-1 and sEng production in endothelial cells. Here, we demonstrate that CSE/H2S pathway sustain endothelial mitochondrial bioenergetics and loss of CSE increases the production of mitochondrial-specific superoxide. As a compensatory effect, low CSE environment enhances the reliance on glycolysis. The mitochondrial-targeted H2S donor, AP39, suppressed the antiangiogenic response and restored the mitochondrial bioenergetics in endothelial cells. AP39 revealed that upregulation of sFlt-1, but not sEng, is independent of the mitochondrial H2S metabolising enzyme, SQR. These data provide new insights into the molecular mechanisms for antiangiogenic upregulation in a mitochondrial-driven environment. Targeting H2S to the mitochondria may be of therapeutic benefit in the prevention of endothelial dysfunction associated with preeclampsia.

Intra-pancreatic tissue-derived mesenchymal stromal cells: a promising therapeutic potential with anti-inflammatory and pro-angiogenic profiles.

BACKGROUND: Human pancreata contain many types of cells, such as endocrine islets, acinar, ductal, fat, and mesenchymal stromal cells (MSCs). MSCs are important and shown to have a promising therapeutic potential to treat various disease conditions. METHODS: We investigated intra-pancreatic tissue-derived (IPTD) MSCs isolated from tissue fractions that are routinely discarded during pancreatic islet isolation of human cadaveric donors. Furthermore, whether pro-angiogenic and anti-inflammatory properties of these cells could be enhanced was investigated. RESULTS: IPTD-MSCs were expanded in GMP-compatible CMRL-1066 medium supplemented with 5% human platelet lysate (hPL). IPTD-MSCs were found to be highly pure, with > 95% positive for CD90, CD105, and CD73, and negative for CD45, CD34, CD14, and HLA-DR. Immunofluorescence staining of pancreas tissue demonstrated the presence of CD105+ cells in the vicinity of islets. IPTD-MSCs were capable of differentiation into adipocytes, chondrocytes, and osteoblasts in vitro, underscoring their multipotent features. When these cells were cultured in the presence of a low dose of TNF-α, gene expression of tumor necrosis factor alpha-stimulated gene-6 (TSG-6) was significantly increased, compared to control. In contrast, treating cells with dimethyloxallyl glycine (DMOG) (a prolyl 4-hydroxylase inhibitor) enhanced mRNA levels of nuclear factor erythroid 2-related factor 2 (NRF2) and vascular endothelial growth factor (VEGF). Interestingly, a combination of TNF-α and DMOG stimulated the optimal expression of all three genes in IPTD-MSCs. Conditioned medium of IPTD-MSCs treated with a combination of DMOG and TNF-α contained higher levels of pro-angiogenic (VEGF, IL-6, and IL-8) compared to controls, promoting angiogenesis of human endothelial cells in vitro. In contrast, levels of MCP-1, a pro-inflammatory cytokine, were reduced in the conditioned medium of IPTD-MSCs treated with a combination of DMOG and TNF-α. CONCLUSIONS: The results demonstrate that IPTD-MSCs reside within the pancreas and can be separated as part of a standard islet-isolation protocol. These IPTD-MSCs can be expanded and potentiated ex vivo to enhance their anti-inflammatory and pro-angiogenic profiles. The fact that IPTD-MSCs are generated in a GMP-compatible procedure implicates a direct clinical application.

Epigallocatechin-3-gallate inhibits tumor angiogenesis: involvement of endoglin/Smad1 signaling in human umbilical vein endothelium cells.

Strategies targeting endoglin are currently being investigated in clinical trials as an anti-angiogenic therapy. The redundancy between endoglin and vascular endothelial growth factor (VEGF) signaling in angiogenesis was verified. Increased endoglin signaling after an anti-VEGF treatment was observed in patients. Treatment with an endoglin-neutralizing antibody increased VEGF signaling in endothelial cells. Therefore, strategies targeting both the endoglin and VEGF pathways were applied to determine whether the anti-angiogenic effects were increased in vitro. Five possible hits for endoglin were identified from 2000 compounds in the Traditional Chinese Medicine Database using Discovery Studio 4.5 Epigallocatechin-3-gallate (EGCG) attenuates angiogenesis by downregulating VEGF; however, researchers have not determined whether its anti-angiogenic effects are mediated by endoglin/Smad1 signaling. A major contribution of this study is that EGCG significantly inhibited the upregulation of endoglin in semaxanib-treated human umbilical vein endothelial cell. Thus, a combination treatment with EGCG and a VEGF tyrosine kinase inhibitor would be appropriate to reverse drug resistance. EGCG alone significantly decreased endoglin/pSmad1 levels in HUVECs. In the angiogenesis assay, the migration, invasion, and tube formation of HUVECs were markedly suppressed by higher concentrations of EGCG. A combination treatment with EGCG and semaxanib further produced increased anti-angiogenic effects. The main contribution of the study indicated that EGCG significantly decreased the semaxanib-induced overexpression of endoglin. Therefore, a combination treatment including EGCG will probably solve the drug resistance to anti-VEGF treatments.

AP39, a Modulator of Mitochondrial Bioenergetics, Reduces Antiangiogenic Response and Oxidative Stress in Hypoxia-Exposed Trophoblasts: Relevance for Preeclampsia Pathogenesis.

Although the cause of preeclampsia, a pregnancy complication with significant maternal and neonatal morbidity, has not been fully characterized, placental ischemia attributable to impaired spiral artery remodeling and abnormal secretion of antiangiogenic factors are thought to be important in the pathogenesis of the disease. Placental ischemia could impair trophoblast mitochondrial function and energy production, leading to the release of reactive oxygen species (ROS). ROS have been shown to stabilize hypoxia-inducible factor (HIF)-1α, which, in turn, may induce transcription of antiangiogenic factors, soluble fms-like tyrosine kinase 1 (sFLT1), and soluble endoglin in trophoblasts. Herein, we tested whether the angiogenic imbalance and oxidative stress in the preeclamptic placenta may be prevented by improving mitochondrial function. First, to evaluate the cause-effect relationship between mitochondrial function and sFLT1 production, a human trophoblast primary cell culture model was established in which hypoxia induced mitochondrial ROS production and concurrent sFLT1 increase. Second, treatment with AP39, a novel mitochondria-targeted hydrogen sulfide donor, prevented ROS production, reduced HIF-1α protein levels, and diminished sFLT1 production. Finally, AP39, a modulator of mitochondrial bioenergetics enhanced cytochrome c oxidase activity, reversed oxidative stress and antiangiogenic response in hypoxic trophoblasts. These results suggest that placental hypoxia induces ROS production, HIF-1α stabilization, and sFLT1 up-regulation; these pathophysiological alterations can be attenuated by mitochondrial-targeted antioxidants.

Preclinical Efficacy of Endoglin-Targeting Antibody-Drug Conjugates for the Treatment of Ewing Sarcoma.

PURPOSE: Endoglin (ENG; CD105) is a coreceptor of the TGFß family that is highly expressed in proliferating endothelial cells. Often coopted by cancer cells, ENG can lead to neo-angiogenesis and vasculogenic mimicry in aggressive malignancies. It exists both as a transmembrane cell surface protein, where it primarily interacts with TGFß, and as a soluble matricellular protein (sENG) when cleaved by matrix metalloproteinase 14 (MMP14). High ENG expression has been associated with poor prognosis in Ewing sarcoma, an aggressive bone cancer that primarily occurs in adolescents and young adults. However, the therapeutic value of ENG targeting has not been fully explored in this disease. EXPERIMENTAL DESIGN: We characterized the expression pattern of transmembrane ENG, sENG, and MMP14 in preclinical and clinical samples. Subsequently, the antineoplastic potential of two novel ENG-targeting monoclonal antibody-drug conjugates (ADC), OMTX503 and OMTX703, which differed only by their drug payload (nigrin-b A chain and cytolysin, respectively), was assessed in cell lines and preclinical animal models of Ewing sarcoma. RESULTS: Both ADCs suppressed cell proliferation in proportion to the endogenous levels of ENG observed in vitro. Moreover, the ADCs significantly delayed tumor growth in Ewing sarcoma cell line-derived xenografts and patient-derived xenografts in a dose-dependent manner. CONCLUSIONS: Taken together, these studies demonstrate potent preclinical activity of first-in-class anti-ENG ADCs as a nascent strategy to eradicate Ewing sarcoma.

Targeting angiogenesis for radioimmunotherapy with a 177Lu-labeled antibody.

PURPOSE: Increased angiogenesis is a marker of aggressiveness in many cancers. Targeted radionuclide therapy of these cancers with angiogenesis-targeting agents may curtail this increased blood vessel formation and slow the growth of tumors, both primary and metastatic. CD105, or endoglin, has a primary role in angiogenesis in a number of cancers, making this a widely applicable target for targeted radioimmunotherapy. METHODS: The anti-CD105 antibody, TRC105 (TRACON Pharmaceuticals), was conjugated with DTPA for radiolabeling with 177Lu (t 1/2 6.65 days). Balb/c mice were implanted with 4T1 mammary carcinoma cells, and five study groups were used: 177Lu only, TRC105 only, 177Lu-DTPA-IgG (a nonspecific antibody), 177Lu-DTPA-TRC105 low-dose, and 177Lu-DTPA-TRC105 high-dose. Toxicity of the agent was monitored by body weight measurements and analysis of blood markers. Biodistribution studies of 177Lu-DTPA-TRC105 were also performed at 1 and 7 days after injection. Ex vivo histology studies of various tissues were conducted at 1, 7, and 30 days after injection of high-dose 177Lu-DTPA-TRC105. RESULTS: Biodistribution studies indicated steady uptake of 177Lu-DTPA-TRC105 in 4T1 tumors between 1 and 7 days after injection (14.3 ± 2.3%ID/g and 11.6 ± 6.1%ID/g, respectively; n = 3) and gradual clearance from other organs. Significant inhibition of tumor growth was observed in the high-dose group, with a corresponding significant increase in survival (p < 0.001, all groups). In most study groups (all except the nonspecific IgG group), the body weights of the mice did not decrease by more than 10%, indicating the safety of the injected agents. Serum alanine transaminase levels remained nearly constant indicating no damage to the liver (a primary clearance organ of the agent), and this was confirmed by ex vivo histological analyses. CONCLUSION: 177Lu-DTPA-TRC105, when administered at a sufficient dose, is able to curtail tumor growth and provide a significant survival benefit without off-target toxicity. Thus, this targeted agent could be used in combination with other treatment options to slow tumor growth allowing the other agents to be more effective.

5-FU resistant EMT-like pancreatic cancer cells are hypersensitive to photochemical internalization of the novel endoglin-targeting immunotoxin CD105-saporin.

BACKGROUND: Development of resistance to 5-fluorouracil (5-FU) is a major problem in treatment of various cancers including pancreatic cancer. In this study, we reveal important resistance mechanisms and photochemical strategies to overcome 5-FU resistance in pancreatic adenocarcinoma. METHODS: 5-FU resistant (5-FUR), epithelial-to-mesenchymal-like sub-clones of the wild type pancreatic cancer cell line Panc03.27 were previously generated in our lab. We investigated the cytotoxic effect of the endosomal/lysosomal-localizing photosensitizer TPCS2a (fimaporfin) combined with light (photochemical treatment, PCT) using MTS viability assay, and used fluorescence microscopy to show localization of TPCS2a and to investigate the effect of photodamage of lysosomes. Flow cytometric analysis was performed to investigate uptake of photosensitizer and to assess intracellular ROS levels. Expression and localization of LAMP1 was assessed using RT-qPCR, western blotting, and structured illumination microscopy. MTS viability assay was used to assess the effect of combinations of 5-FU, chloroquine (CQ), and photochemical treatment. Expression of CD105 was investigated using RT-qPCR, western blotting, flow cytometry, and fluorescence microscopy, and co-localization of TPCS2a and anti-CD105-saporin was assessed using microscopy. Lastly, the MTS assay was used to investigate cytotoxic effects of photochemical internalization (PCI) of the anti-CD105-immunotoxin. RESULTS: The 5-FUR cell lines display hypersensitivity to PCT, which was linked to increased uptake of TPCS2a, altered lysosomal distribution, lysosomal photodamage and increased expression of the lysosomal marker LAMP-1 in the 5-FUR cells. We show that inhibition of autophagy induced by either chloroquine or lysosomal photodamage increases the sensitivity to 5-FU in the resistant cells. The three 5-FUR sub-clones overexpress Endoglin (CD105). Treatment with the immunotoxin anti-CD105-saporin alone significantly reduced the viability of the CD105-expressing 5-FUR cells, whereas little effect was seen in the CD105-negative non-resistant parental cancer cell lines. Strikingly, using the intracellular drug delivery method photochemical internalization (PCI) by combining light-controlled activation of the TPCS2a with nanomolar levels of CD105-saporin resulted in strong cytotoxic effects in the 5-FUR cell population. CONCLUSION: Our findings suggested that autophagy is an important resistance mechanism against the chemotherapeutic drug 5-FU in pancreatic cancer cells, and that inhibition of the autophagy process, either by CQ or lysosomal photodamage, can contribute to increased sensitivity to 5-FU. For the first time, we demonstrate the promise of PCI-based targeting of CD105 in site-specific elimination of 5-FU resistant pancreatic cancer cells in vitro. In conclusion, PCI-based targeting of CD105 may represent a potent anticancer strategy and should be further evaluated in pre-clinical models.

Relationships between serum selenium and zinc concentrations versus profibrotic and proangiogenic cytokines (FGF-19 and endoglin) in patients with alcoholic liver cirrhosis.

INTRODUCTION AND OBJECTIVE: Liver cirrhosis is a disease involving the liver parenchyma, which is characterised by fibrosis and impaired architectonics of the parenchyma with regenerative nodules. The aim of the study was to determine the relationship between stage of alcoholic liver cirrhosis, concentrations of selenium, zinc and profibrotic and proangiogenic cytokines (FGF-19, ENG). MATERIAL AND METHODS: The study included 99 patients with alcoholic cirrhosis and 20 healthy subjects. Ion chromatography with UV/VIS detection was used for determination of zinc ions in the previously mineralized serum samples. The measurements of selenium were performed with the ContrAA700 high-resolution continuum source graphite tube atomic absorption spectrometer. ELISA was used to determine concentration of FGF-19 and ENG in serum samples. RESULTS: Concentrations of zinc and selenium were significantly decreased in cirrhotic patients (p<0.001 for both). The highest concentration of FGF-19 was found in Child-Pugh stage C liver cirrhosis patients (806.9±650.3 pg/ml), and was significantly higher than observed in controls (p=0.005) and stage A patients (compensated cirrhosis) (p=0.02). The highest concentration of ENG was demonstrated in the control group (3.24±148 ng/ml) while the lowest in patients with decompensated cirrhosis (7.32±5.39 ng/ml and 7.92±4.18 ng/ml for stage B and C; p=0.03 and p=0.02, respectively). The use of the multiple-variable model demonstrated that the independent factors affecting the concentration of ENG were the concentration of bilirubin (p=0.02), INR (p=0.01) and duration of alcohol abuse (p=0.02). The independent determinants of FGF-19 concentrations were found to be the stage (severity) of liver cirrhosis (p=0.04) and INR (p=0.03). CONCLUSIONS: Concentrations of zinc and selenium in serum of patients with alcoholic liver cirrhosis are not independently related to concentrations of FGF-19 and ENG.

Maternal choline supplementation during murine pregnancy modulates placental markers of inflammation, apoptosis and vascularization in a fetal sex-dependent manner.

INTRODUCTION: Normal placental vascular development is influenced by inflammatory, angiogenic and apoptotic processes, which may be modulated by choline through its role in membrane biosynthesis, cellular signaling and gene expression regulation. The current study examined the effect of maternal choline supplementation (MCS) on placental inflammatory, angiogenic and apoptotic processes during murine pregnancy. METHOD: Pregnant dams were randomized to receive 1, 2 or 4 times (X) the normal choline content of rodent diets, and tissues were harvested on embryonic day (E) 10.5, 12.5, 15.5 or 18.5 for gene expression, protein abundance and immunohistochemical analyses. RESULTS: The choline-induced changes in the inflammatory and angiogenic markers were a function of fetal sex. Specifically, 4X (versus 1X) choline reduced the transcript (P ≤ 0.05) and protein (P ≤ 0.06) expression of TNF-a and IL-1ß in the male placentas at E10.5 and E18.5, respectively. In the female placentas, 4X (versus 1X) choline modulated the transcript expression of Il1b in a biphasic pattern with reduced Il1b at E12.5 (P = 0.045) and E18.5 (P = 0.067) but increased Il1b at E15.5 (P = 0.031). MCS also induced an upregulation of Vegfa expression in the female placentas at E15.5 (P = 0.034; 4X versus 2X) and E18.5 (P = 0.026; 4X versus 1X). MCS decreased (P = 0.011; 4X versus 1X) placental apoptosis at E10.5. Additionally, the luminal area of the maternal spiral arteries was larger (P ≤ 0.05; 4X versus 1X) in response to extra choline throughout gestation. DISCUSSION: MCS during murine pregnancy has fetal sex-specific effects on placental inflammation and angiogenesis, with possible consequences on placental vascular development.

Anti­angiogenic therapy for normalization of tumor vasculature: A potential effect of Buyang Huanwu decoction on nude mice bearing human hepatocellular carcinoma xenografts with high metastatic potential.

The present study aimed to investigate the effect of Buyang Huanwu decoction (BYHWD) on tumor growth, metastasis and angiogenesis in nude mice bearing human hepatocellular carcinoma (HCC) HCCLM3 xenografts. A total of 96 nude mice bearing HCCLM3 xenografts were randomly divided into four groups: BYHWD group (LB), Yi­qi decoction group (LY), Huo­xue decoction group (LH) and model group (LM). Each of these groups was divided into three subgroups (n=8), which were observed on days 21, 25, 38 following treatment, respectively. The tumor weights, volumes and pulmonary metastases were recorded. The expression of CD105 and the microvessel density (MVD) were assessed, and the expression levels of vascular endothelial growth factor (VEGF), hypoxia­inducible factor 1α (HIF­1α), and regulator of G protein signaling 5 (RGS­5) were analyzed using immunohistochemical staining. Compared with the LM group, no significant decrease in tumor weight or volume were observed in the herbal medicine treatment groups, the number of the metastases in the lungs decreased, whereas the expression levels of RGS­5 and HIF­1α decreased in the LB group on day 35. However, the expression levels of VEGF increased in the LB group on days 28 and 35 post­treatment. The results of the present study suggested that BYHWD may inhibit angiogenesis and metastasis by affecting the expression levels of VEGF, RGS­5 and HIF­1α, and suggested that BYHWD may contribute to the tumor microenvironment and vasculature normalization in HCC.

The effect of fibroblast growth factor on distinct differentiation potential of cord blood-derived unrestricted somatic stem cells and Wharton's jelly-derived mesenchymal stem/stromal cells.

BACKGROUND AIMS: Perinatal tissues are considered an attractive source of mesenchymal stem/stromal cells (MSCs) and have unique characteristics depending on their origin. In this study, we compared the basic characteristics of unrestricted somatic stem cells isolated from cord blood (CB-USSCs) and MSCs isolated from Wharton's jelly of umbilical cords (WJ-MSCs). We also evaluated the effect of basic fibroblast growth factor (bFGF) supplementation on the growth and differentiation of these cells. METHODS: CB-USSCs and WJ-MSCs were isolated from the same individual (n = 6), and their morphology, cell surface antigens, proliferation, expression of stemness markers and adipogenic, osteogenic and chondrogenic differentiation potentials were evaluated. Their morphology, proliferation and differentiation potentials were then also compared in the presence of bFGF supplementation (10 ng/mL). RESULTS: Overall, CB-USSCs expressed DLK-1 and negative for all the HOX gene markers. The expression of cell surface antigen CD90, growth capacity and adipogenic differential potential of CB-USSCs were lower than those of WJ-MSCs. WJ-MSCs showed higher growth capacity, but the expression of CD73 and CD105 and their osteogenic differentiation potential were lower than those of CB-USSCs. The spindle morphology of both CB-USSCs and WJ-MSCs and the growth and adipogenic differentiation of CB-USSCs were improved by bFGF supplementation. However, the bFGF supplement did not have any positive effect on the tri-lineage differentiation potentials of WJ-MSCs. CONCLUSIONS: CB-USSCs and WJ-MSCs each had distinct characteristics including different growth capacity, distinguishable cell surface markers and distinct adipogenic and osteogenic potentials. bFGF supplementation improved the growth capacity and adipogenic differentiation of CB-USSCs.

Vitamin D Supplementation Decreases TGF-ß1 Bioavailability in PCOS: A Randomized Placebo-Controlled Trial.

CONTEXT: There is an abnormal increase in TGF-ß1 bioavailability in women with polycystic ovary syndrome (PCOS), which might play a role in the pathophysiology of this syndrome. Vitamin D (VD) supplementation improves various clinical manifestations of PCOS and decreases TGF-ß1 levels in several diseases including myelofibrosis. OBJECTIVE: The objective of the study was to determine the effect of VD supplementation on TGF-ß1 bioavailability in VD-deficient women with PCOS and assess whether changes in TGF-ß1/soluble endoglin (sENG) levels correlate with an improvement in PCOS clinical manifestations. DESIGN: This was a prospective, randomized, placebo-controlled trial. SETTING: The study was conducted at an academic-affiliated medical center. PARTICIPANTS: Sixty-eight VD-deficient women with PCOS who were not pregnant or taking any exogenous hormones were recruited between October 2013 and January 2015. INTERVENTIONS: Forty-five women received 50 000 IU of oral vitamin D3 and 23 women received oral placebo once weekly for 8 weeks. MAIN OUTCOMES MEASURES: Serum TGF-ß1, sENG, lipid profile, testosterone, dehydroepiandrosterone sulfate, and insulin resistance were measured. The clinical parameters were evaluated before and 2 months after treatment. RESULTS: The VD level significantly increased and normalized after VD supplementation (16.3 ± 0.9 [SEM] to 43.2 ± 2.4 ng/mL; P < .01), whereas it did not significantly change after placebo. After the VD supplementation, there was a significant decrease in the following: the interval between menstrual periods (80 ± 9 to 60 ± 6 d; P = .04), Ferriman-Gallwey score (9.8 ± 1.5 to 8.1 ± 1.5; P < .01), triglycerides (138 ± 22 to 117 ± 20 mg/dL; P = .03), and TGF-ß1 to sENG ratio (6.7 ± 0.4 to 5.9 ± 0.4; P = .04). In addition, the ΔTGF-ß1 to sENG ratio was positively correlated with Δtriglycerides (r = 0.59; P = .03). CONCLUSIONS: VD supplementation in VD-deficient women with PCOS significantly decreases the bioavailability of TGF-ß1, which correlates with an improvement in some abnormal clinical parameters associated with PCOS. This is a novel mechanism that could explain the beneficial effects of VD supplementation in women with PCOS. These findings may support new treatment modalities for PCOS, such as the development of anti-TGF-ß drugs.

Molecular ultrasound imaging using contrast agents targeting endoglin, vascular endothelial growth factor receptor 2 and integrin.

Expression levels of endoglin, αv integrin and vascular endothelial growth factor receptor 2 (VEGFR2) were investigated using targeted, contrast-enhanced ultrasonography in murine melanoma tumor models. Microvasculature and expression levels of biomarkers were investigated using specific contrast agents conjugated with biotinylated monoclonal antibodies. Ultrasound signal intensity from bound contrast agents was evaluated in two groups of mice: control mice and mice treated with sorafenib. Expression levels were analyzed by immunohistochemistry. Endoglin biomarkers were more highly expressed than αv integrin and VEGFR2. Endoglin decreased in the sorafenib group, whereas it tended to increase with time in the control group. Targeted ultrasound contrast agents may be used for non-invasive longitudinal evaluation of tumor angiogenesis during tumor growth or therapeutic treatment in preclinical studies. Endoglin protein, which plays an important role in angiogenesis, seems to be a target of interest for detection of cancer and for prediction of therapeutic efficacy.

Soluble endoglin production is upregulated by oxysterols but not quenched by pravastatin in primary placental and endothelial cells.

INTRODUCTION: Preeclampsia is a serious pregnancy complication. Soluble endoglin (sEng) is released from the placenta and contributes to the maternal endothelial dysfunction seen in preeclampsia. Recently oxysterols, which activate the Liver X Receptor (LXR), have been implicated in producing sEng, by upregulating matrix metalloproteinase-14 (MMP14; cleaves endoglin to produce sEng) and down-regulating tissue inhibitor of metalloproteinase-3 (TIMP-3; inhibitor of MMP14). The functional experiments in that study were performed on JAR cells (human choriocarcinoma cell line) and placental explants. METHODS: We characterized LXR in severe preeclamptic placentas, and assessed whether oxysterols increase release of sEng from primary human umbilical vein endothelial cells (HUVECs), primary trophoblasts and placental explants. Given pravastatin is thought to block oxysterol production and inhibit the LXR, we examined whether pravastatin reduces sEng release. RESULTS: LXRα and ß were localized to the syncytiotrophoblast and villous tips and were significantly up-regulated in preeclamptic placenta. Oxysterols upregulated sEng production in HUVECs and placental explants although the increases were far more modest than that recently reported. Oxysterols did not upregulate sEng in primary trophoblasts. Furthermore, mRNA expression of MMP14 and TIMP-3 were not altered by oxysterols in any tissue. Surprisingly, pravastatin did not decrease oxysterol-induced upregulation of sEng. DISCUSSION: LXR is up-regulated in preeclamptic placenta. Oxysterols upregulate sEng production from human tissues, but the increase is modest, suggesting this may not be the main mechanism for the very significant elevations in sEng seen in preeclampsia. Pravastatin does not decrease sEng production. CONCLUSION: Oxysterols modestly up-regulate sEng production which is not quenched by pravastatin.

Repeated supra-maximal sprint cycling with and without sodium bicarbonate supplementation induces endothelial microparticle release.

Under normal homeostatic conditions, the endothelium releases microparticles (MPs), which are known to increase under stressful conditions and in disease states. CD105 (endoglin) and CD106 (vascular cell adhesion molecule-1) are expressed on the surface of endothelial cells and increased expression in response to stress may be observed. A randomised-controlled double-blinded study aimed to examine the use of endothelial MPs as a marker for the state of one's endothelium, as well as whether maintaining acid-base homeostasis affects the release of these MPs. This study tested seven healthy male volunteers, who completed a strenuous cycling protocol, with venous blood analysed for CD105+ and CD106+ MPs by flow cytometry at regular intervals. Prior to each trial participants consumed either 0.3 g·kg(-1) body mass of sodium bicarbonate (NaHCO3), or 0.045 g·kg(-1) body mass of sodium chloride (NaCl). A significant rise in endothelial CD105+ MPs and CD106+ MPs (p<0.05) was observed at 90 min post-exercise. A significant trend was shown for these MPs to return to resting levels 180 min post-exercise in both groups. No significance was found between experimental groups, suggesting that maintaining acid-base variables closer to basal levels has little effect upon the endothelial stress response for this particular exercise mode. In conclusion, strenuous exercise is accompanied by MP release and the endothelium is able to rapidly recover in healthy individuals, whilst maintaining acid-base homeostasis does not attenuate the MP release from the endothelium after exercise.

Involvement of KLF14 and egr-1 in the TGF-beta1 action on Leydig cell proliferation.

Transforming growth factor ß1 (TGF-ß1) is a pleiotropic cytokine that modulates cell homeostasis. In Leydig cells, TGF-ß1 exerts stimulatory and inhibitory effect depending on the type I receptor involved in the signaling pathway. The aim of the present work was to study the signaling mechanisms and the intermediates involved in the action of TGF-ß1 on TM3 Leydig cell proliferation in the presence or absence of progesterone. The MTT assay showed that the presence of progesterone in the culture media lead to a proliferative effect that was blocked by Ru 486, an inhibitor of progesterone receptor; and ALK-5 did not participate in this effect. TGF-ß1 (1 ng/ml) increased the expression of p15 (an inhibitor of cell cycle) in TM3 Leydig cells, and this effect was blocked by progesterone (1µM). The expression of PCNA presented a higher increase in the cell cultured with TGF-ß1 plus progesterone than in cells cultured only with TGF-ß1. Progesterone induced the gene expression of endoglin, a cofactor of TGF-ß1 receptor that leads to a stimulatory signaling pathway, despite of the absence of progesterone response element in endoglin gene. In addition, the presence of progesterone induced the gene expression of egr-1 and also KLF14, indicating that this steroid channels the signaling pathway into a non-canonical mechanism. In conclusion, these findings suggest that the proliferative action of TGF-ß1 involves endoglin. This co-receptor might be induced by KLF14 which is probably activated by progesterone.