Secretion Of Angiogenic Growth Factors Research Articles

Polymer-derived boron doped akermanite-octacalcium phosphate glass-ceramic scaffolds stimulate angiogenesis

Angiogenesis is crucial in bone tissue engineering due to expediting the healing rate and remarkably enhancing the regeneration process. Further, vascular sprouting progression is controlled by cellular autocrine and paracrine secretion of growth factors. Boron ions significantly stimulate cells in terms of excessive angiogenic growth factors secretion, therefore, could lead to excessive angiogenesis, contingent upon receiving an appropriate dose of the ion. In the current work, akermanite-octacalcium phosphate glass-ceramics were elicited from polymeric precursors, the method of synthesis that is so-called polymer-derived ceramics (PDC), and boron-containing moieties were employed to dope this element in the structure. Synthesized glass-ceramics were subjected to in vitro studies, including osteoconduction via monitoring the precipitation of hydroxycarbonate apatite (HCA), cytocompatibility, angiogenic growth factor secretion, and alkaline phosphatase (ALP) activity. The optimized sample was implanted in mice models and monitored in an in vivo study. The samples containing 6 wt% of B2O3 showed less bioactivity and cell viability. In contrast, 3 wt% of B2O3 led to more controlled biodegradation of octacalcium phosphate and through moderating the rate of release, the risk of boron overdosing was restrained.

3D micropattern force triggers YAP nuclear entry by transport across nuclear pores and modulates stem cells paracrine.

Biophysical cues of the cellular microenvironment tremendously influence cell behavior by mechanotransduction. However, it is still unclear how cells sense and transduce the mechanical signals from 3D geometry to regulate cell function. Here, the mechanotransduction of human mesenchymal stem cells (MSCs) triggered by 3D micropatterns and its effect on the paracrine of MSCs are systematically investigated. Our findings show that 3D micropattern force could influence the spatial reorganization of the cytoskeleton, leading to different local forces which mediate nucleus alteration such as orientation, morphology, expression of Lamin A/C and chromatin condensation. Specifically, in the triangular prism and cuboid micropatterns, the ordered F-actin fibers are distributed over and fully transmit compressive forces to the nucleus, which results in nuclear flattening and stretching of nuclear pores, thus enhancing the nuclear import of YES-associated protein (YAP). Furthermore, the activation of YAP significantly enhances the paracrine of MSCs and upregulates the secretion of angiogenic growth factors. In contrast, the fewer compressive forces on the nucleus in cylinder and cube micropatterns cause less YAP entering the nucleus. The skin repair experiment provides the first in vivo evidence that enhanced MSCs paracrine by 3D geometry significantly promotes tissue regeneration. The current study contributes to understanding the in-depth mechanisms of mechanical signals affecting cell function and provides inspiration for innovative design of biomaterials.

Angiogenic Potential of Co-Cultured Human Umbilical Vein Endothelial Cells and Adipose Stromal Cells in Customizable 3D Engineered Collagen Sheets.

The wound healing process is much more complex than just the four phases of hemostasis, inflammation, proliferation, and maturation. Three-dimensional (3D) scaffolds made of biopolymers or ECM molecules using bioprinting can be used to promote the wound healing process, especially for complex 3D tissue lesions like chronic wounds. Here, a 3D-printed mold has been designed to produce customizable collagen type-I sheets containing human umbilical vein endothelial cells (HUVECs) and adipose stromal cells (ASCs) for the first time. In these 3D collagen sheets, the cellular activity leads to a restructuring of the collagen matrix. The upregulation of the growth factors Serpin E1 and TIMP-1 could be demonstrated in the 3D scaffolds with ACSs and HUVECs in co-culture. Both growth factors play a key role in the wound healing process. The capillary-like tube formation of HUVECs treated with supernatant from the collagen sheets revealed the secretion of angiogenic growth factors. Altogether, this demonstrates that collagen type I combined with the co-cultivation of HUVECs and ACSs has the potential to accelerate the process of angiogenesis and, thereby, might promote wound healing.

Platelet-derived growth factor BB is reduced in endometrial endothelial cells of women with abnormal uterine bleeding–endometrial disorder

Research questionWhat is the expression pattern of platelet-derived growth factor BB (PDGF-BB), and its receptors, across the menstrual cycle in healthy control women and those with abnormal uterine bleeding–endometrial disorder (AUB-E)? DesignImmunohistochemical staining for PDGF-BB, platelet-derived growth factor receptor alpha (PDGFRα) and platelet-derived growth factor beta (PDGFRβ) was performed in control and AUB-E endometrium from the proliferative, early, mid- and late secretory phases of the menstrual cycle (n = 5 each group). Control proliferative phase endometrium was cultured in PDGF-BB (0, 10 ng/ml) and vascular maturation assessed (n = 3). Endothelial cell to vascular smooth muscle cell (VSMC) association was assessed after treatment with PDGF-BB (0, 1, 10 ng/ml). Secretion of angiogenic growth factors by endothelial cells or VSMC was determined. ResultsEndothelial cell immunoreactivity for PDGF-BB was reduced in the mid and late secretory phases in AUB-E (P = 0.008). PDGFRα was also reduced in mid secretory phase endothelial cells, proliferative and early secretory phase glandular epithelium in AUB-E (P = 0.008). PDGFRβ expression was not altered. Treatment of proliferative phase endometrium with PDGF-BB (10 ng/ml) reduced the percentage of vessels expressing contractile VSMC markers. PDGF-BB had no effect on angiogenic growth factor secretion by endothelial cells or VSMC in vitro and did not affect their association in an in-vitro endothelial cell–VSMC association assay. ConclusionsReduced endothelial cell expression of PDGF-BB in the AUB-E endometrium may contribute to the reduced vascular maturation previously observed in these women.

Cannabinoids orchestrate cross-talk between cancer cells and endothelial cells in colorectal cancer.

Medical marijuana has been approved by the FDA for treating chemotherapy-induced nausea and vomiting. However, less is known about its direct effects on tumor cells and the tumor microenvironment. In this study, RNA-sequencing datasets in the NCBI GEO repository were first analyzed; upregulation of cannabinoid receptors was observed in both primary and metastatic colorectal cancer (CRC) tumor tissues. An increase of cannabinoid receptors was also found in patients with CRC, azoxymethane/dextran sulfate sodium-induced CRC and CRC metastatic mouse models. Δ9-Tetrahydrocannabinol (Δ9-THC)-induced tumor progression in both primary and metastatic mouse models and also increased angiogenesis. A human growth factor antibody array indicated that Δ9-THC promoted the secretion of angiogenic growth factors in CRC, leading to the induction of tube formation and migration in human-induced pluripotent stem cell-derived vascular endothelial cells. The nuclear translocation of STAT1 played important roles in Δ9-THC-induced angiogenesis and tumor progression. Pharmacological treatment with STAT1 antagonist or abrogation of STAT1 with CRISPR/Cas9-based strategy rescued those effects of Δ9-THC in CRC. This study demonstrates that marijuana might increase the risk of CRC progression and that inhibition of STAT1 is a potential strategy for attenuating these side effects.

Porcine placenta extract improves high-glucose-induced angiogenesis impairment

BackgroundHigh glucose (HG)-induced reactive oxygen species (ROS) overproduction impairs angiogenesis that is one pivotal factor of wound healing process. Angiogenesis impairment induces delayed wound healing, whereby it eventually leads to amputation in cases of poorly controlled diabetes with diabetic ulceration. Porcine placenta extract (PPE) is a natural waste product that comprises plenty of bioactive agents including growth factors and antioxidants. It was reported as an effective compound that prevents ROS generation. The goal of this study was to investigate the in vitro effect of PPE on HG-induced ROS-mediated angiogenesis impairment.MethodsPrimary endothelial cells (HUVECs) and endothelial cell line (EA.hy926) were treated with HG in the presence of PPE. The endothelial cells (ECs) viability, intracellular ROS generation, migration, and angiogenesis were determined by MTT assay, DCFDA reagent, wound healing assay, and tube formation assay, respectively. Additionally, the molecular mechanism of PPE on HG-induced angiogenesis impairment was investigated by Western blot. The angiogenic growth factor secretion was also investigated by the sandwich ELISA technique.ResultsHG in the presence of PPE significantly decreased intracellular ROS overproduction compared to HG alone. HG in the presence of PPE significantly increased ECs viability, migration, and angiogenesis compared to HG alone by showing recovery of PI3K/Akt/ERK1/2 activation. HG in the presence of PPE also decreased ECs apoptosis compared to HG alone by decreasing p53/Bax/cleaved caspase 9/cleaved caspase 3 levels and increasing Bcl 2 level.ConclusionPPE attenuated HG-induced intracellular ROS overproduction that improved ECs viability, proliferation, migration, and angiogenesis by showing recovery of PI3K/Akt/ERK1/2 activation and inhibition of ECs apoptosis. This study suggests PPE ameliorated HG-induced ROS-mediated angiogenesis impairment, whereby it potentially provides an alternative treatment for diabetic wounds.

Accelerated wound healing with an ionic patch assisted by a triboelectric nanogenerator

Abstract Electrical stimulation therapy has recently been suggested as a therapeutic modality to accelerate wound healing. Despite advancements in the development of flexible electronic devices for rapid wound recovery, current systems, which are fabricated from various metals, have mechanical discontinuities that have not been fully resolved, making them unsuitable for wearable applications. Here, we introduce a wearable ionic triboelectric nanogenerator (iTENG) patch, composed of a fully stretchable gel-based platform comprising a TENG, wire, and patch that harvests biophysical energy and delivers electric potential to an impaired tissue. Ionically conductive and stretchable organogel fibers in an elastomeric microtubular structure act as both a stretchable wire and a wearable generator as they are woven like fabric. The elastomeric film-encapsulated ionic patch is multifunctional, serving as both a wound dressing and an electrode. It provides a uniform and symmetrical electric field directly to a wound bed. The electric field generated by an iTENG was shown to accelerate in vitro cell migration, proliferation, and secretion of angiogenic growth factors in studies on both normal human dermal fibroblasts and dermal fibroblasts from diabetes mellitus patients. Rapid wound closure by electrical stimulation using iTENG patches in in vivo animal models has also been verified.

Endosome-triggered ion-releasing nanoparticles as therapeutics to enhance the angiogenic efficacy of human mesenchymal stem cells

Here, we report that Fe ions delivered into human mesenchymal stem cells (hMSCs) by bioreducible metal nanoparticles (NPs) enhance their angiogenic and cell-homing efficacy by controlling ion-triggered intracellular reactive oxygen species (ROS) and improve cell migration, while reducing cytotoxicity. Endosome-triggered iron-ion-releasing nanoparticles (ETIN) were designed to be low-pH responsive to take advantage of the low-pH conditions (4–5) of endosomes for in situ iron-ion release. Due to the different redox potentials of Fe and Au, only Fe could be ionized and released from our novel ETIN, while Au remained intact after ETIN endocytosis. Treatment with an optimal amount of ETIN led to a mild increase in intracellular ROS levels in hMSCs, which enhanced the expression of HIF-1α, a key trigger for angiogenic growth factor secretion from hMSCs. Treatmetn of hMSCs with ETIN significantly enhanced the expression of angiogenesis- and lesion-targeting-related genes and proteins. Transplantation of ETIN-treated hMSCs significantly enhanced angiogenesis and tissue regeneration in a wound-closing mouse model compared with those in untreated mice and mice that underwent conventional hMSC transplantation.

Fine-tuning pro-angiogenic effects of cobalt for simultaneous enhancement of vascular endothelial growth factor secretion and implant neovascularization

Rapid neovascularization of a tissue-engineered (TE) construct by the host vasculature is quintessential to warrant effective bone regeneration. This process can be promoted through active induction of angiogenic growth factor secretion or by implementation of in vitro pre-vascularization strategies. In this study, we aimed at optimizing the pro-angiogenic effect of Cobalt (Co2+) to enhance vascular endothelial growth factor (VEGF) expression by human periosteum-derived mesenchymal stem cells (hPDCs). Simultaneously we set out to promote microvascular network formation by co-culturing with human umbilical vein endothelial cells (HUVECs). The results showed that Co2+ treatments (at 50, 100 or 150 µM) significantly upregulated in vitro VEGF expression, but inhibited hPDCs growth and HUVECs network formation in co-cultures. These inhibitory effects were mitigated at lower Co2+ concentrations (at 5, 10 or 25 µM) while VEGF expression remained significantly upregulated and further augmented in the presence of Ascorbic Acid and Dexamethasone possibly through Runx2 upregulation. The supplements also facilitated HUVECs network formation, which was dependent on the quantity and spatial distribution of collagen type-1 matrix deposited by the hPDCs. When applied to hPDCs seeded onto calcium phosphate scaffolds, the supplements significantly induced VEGF secretion in vitro, and promoted higher vascularization upon ectopic implantation in nude mice shown by an increase of CD31 positive blood vessels within the scaffolds. Our findings provided novel insights into the pleotropic effects of Co2+ on angiogenesis (i.e. promoted VEGF secretion and inhibited endothelial network formation), and showed potential to pre-condition TE constructs under one culture regime for improved implant neovascularization in vivo. Statement of SignificantCobalt (Co2+) is known to upregulate vascular endothelial growth factor (VEGF) secretion, however it also inhibits in vitro angiogenesis through unknown Co2+-induced events. This limits the potential of Co2+ for pro-angiogenesis of tissue engineered (TE) implants. We showed that Co2+ upregulated VEGF expression by human periosteum-derived cells (hPDCs) but reduced the cell growth, and endothelial network formation due to reduction of col-1 matrix deposition. Supplementation with Ascorbic acid and Dexamethasone concurrently improved hPDCs growth, endothelial network formation, and upregulated VEGF secretion. In vitro pre-conditioning of hPDC-seeded TE constructs with this fine-tuned medium enhanced VEGF secretion and implant neovascularization. Our study provided novel insights into the pleotropic effects of Co2+ on angiogenesis and formed the basis for improving implant neovascularization.

Effect of β-nerve growth factor on differentiation of endothelial progenitor cells in rats

Purpose: To investigate the effect of recombinant adenovirus-mediated human β-nerve growth factor (Ad-EGFP-hβ-NGF) on the differentiation of endothelial progenitor cells (EPCs) in rats.Methods: The successfully constructed Ad-EGFP-hβ-NGF and its negative control Ad-EGFP were infected into the isolated and purified rat EPCs to observe their morphological changes. Enzyme-linked immunosorbent assay (ELISA) was conducted to detect the levels of vascular endothelial growth factor (VEGF), von Willebrand factor (vWF) and basic fibroblast growth factor (bFGF) in different rat EPC culture solutions. Western blot was performed to determine the expression of tyrosine kinase receptor A (TrKA) protein in different groups of EPCs.Results: Primary fibrous EPCs were converted into epithelium-like cells. After infection with Ad-EGFPhβ- NGF for 1 week, some EPCs became round and exhibited neural stem cell-like changes. The expression levels of VEGF, vWF and bFGF in the Ad-EGFP-hβ-NGF infection group were significantly higher than those in the control group (p < 0.01). TrKA protein in Ad-EGFP-hβ-NGF infection was also significantly up-regulated compared with that in the negative control and blank control groups (p <0.01).Conclusion: β-NGF up-regulates the expression of TrKA receptor protein and secretion of angiogenic growth factors (i.e., VEGF, vWF and bFGF), thereby promoting the differentiation of rat EPCs, which may contribute to angiopoiesis or vascular repair.Keywords: β-Nerve growth factor, Endothelial progenitor cells, Angiogenic growth factors, Tyrosine kinase receptor A, Cell differentiation

Therapeutic Angiogenesis via Solar Cell-Facilitated Electrical Stimulation.

Cell therapy has been suggested as a treatment modality for ischemic diseases, but the poor survival and engraftment of implanted cells limit its therapeutic efficacy. To overcome such limitation, we used electrical stimulation (ES) derived from a wearable solar cell for inducing angiogenesis in ischemic tissue. ES enhanced the secretion of angiogenic growth factors and the migration of mesenchymal stem cells (MSCs), myoblasts, endothelial progenitor cells, and endothelial cells in vitro. In a mouse ischemic hindlimb model, ES generated by a solar cell and applied to the ischemic region promoted migration of MSCs toward the ischemic site and upregulated expression of angiogenic paracrine factors (vascular endothelial, basic fibroblast, and hepatocyte growth factors; and stromal cell-derived factor-1α). Importantly, solar cell-generated ES promoted the formation of capillaries and arterioles at the ischemic region, attenuated muscle necrosis and fibrosis, and eventually prevented loss of the ischemic limb. Solar cell ES therapy showed higher angiogenic efficacy than conventional MSC therapy. This study shows the feasibility of using solar cell ES as a novel treatment for therapeutic angiogenesis.

Omentin-1 effects on mesenchymal stem cells: proliferation, apoptosis, and angiogenesis in vitro

BackgroundMesenchymal stem cells (MSCs) are emerging as an extremely promising therapeutic agent for tissue repair. However, limitations exist such as the low numbers of MSCs obtained from donors, and the poor survival and function of donor cells. Omentin-1, a new fat depot-specific secretory adipokine, exerts proproliferation, prosurvival, and proangiogenic functions in certain cells via an Akt-dependent mechanism; however, little is known about the influence of omentin-1 on MSCs.MethodsMSCs were isolated from 60–80 g donor rats. Cell proliferation was assessed with CCK-8 and EdU assay. Cell cycle, apoptosis ratio, reactive oxygen species concentration, and mitochondrial membrane potential were detected by flow cytometry. Hoechst 33342 dye was used to assess morphological changes of apoptosis. Expression levels of Akt, FoxO3a, GSK-3β, and apoptosis- and cell cycle-associated proteins were detected by Western blotting. Tube formation assay was used to test the angiogenesis role of conditioned medium from MSCs in vitro. The cytokine secretion was assessed by ELISA.ResultsAfter treatment with omentin-1 (100–800 ng/ml), MSCs displayed a higher proliferative capacity with an increasing number of cells in the S and G2 phase of the cell cycle. Moreover, omentin-1 preconditioning for 1 h could protect MSCs against H2O2-induced apoptosis in a concentration-dependent manner. Furthermore, omentin-1 pretreatment reduced the excessive reactive oxygen species. Western blots revealed that increased Bcl-2 and decreased Bax appeared in MSCs after omentin-1 incubation, which inhibited the mitochondrial apoptosis pathways with evidence showing inhibition of caspase-3 cleavage and preservation of mitochondrial membrane potential. Omentin-1 could enhance angiogenic growth factor secretion and elevate the ability of MSCs to stimulate tube formation by human umbilical vein endothelial cells (HUVECs). Furthermore, omentin-1 enhanced Akt phosphorylation; however, blockade of the PI3K/Akt pathway with an inhibitor, LY294002 (20 μM), suppressed the above beneficial effects of omentin-1.ConclusionOmentin-1 can exert beneficial effects on MSCs by promoting proliferation, inhibiting apoptosis, increasing secretion of angiogenic cytokines, and enhancing the ability for stimulating tube formation by HUVECs via the PI3K/Akt signaling pathway. Thus, omentin-1 may be considered a candidate for optimizing MSC-based cell therapy.

Research Advance on Promoting Angiogenesis of Mesenchymal Stem Cells-Review

Mesenchymal stem cells (MSC) possess important biological characteristics of tissue repair and regeneration. MSC exert the properties promoting endogenous angiogenesis and have been widely applied in treatment of ischemia diseases. The therapeutic potency of MSC for ischemia diseases is owing to their secretion of angiogenic growth factors and release of exosomes. MSC promote angiogenesis stronger in hypoxia environment, and their miRNA played an important role in mediating regulation. This review summarizes recent advances in treatment of angiogenesis using MSC and their mechanisms. The angiogenic activities of MSC under hypoxia condition and their regulation by a miRNA network were discussed.

Lung Adenocarcinoma Cell Responses in a 3D in Vitro Tumor Angiogenesis Model Correlate with Metastatic Capacity.

Many tools from the field of tissue engineering can be used to develop novel model systems to study cancer. We have utilized biomimetic synthetic hydrogels, based on poly(ethylene glycol) (PEG) modified with cell adhesive peptides (RGDS) and peptides sensitive to degradation by matrix metalloproteinases 2 and 9 (GGGPQGIWGQGK), as highly controlled 3D substrates for cell culture. We have previously shown that this hydrogel can support growth of tumor cells and also growth and assembly of microvascular networks. Based on this technology, a 3D in vitro tumor angiogenesis model was developed using a dual layer PEG-based hydrogel comprised of vascular cells (endothelial cells, pericytes) and lung adenocarcinoma cells in separate layers to support recapitulation of the vessel recruitment process as it occurs in vivo. This model was previously used to study highly metastatic murine 344SQ cells and in this paper was used to investigate 2 additional types of lung adenocarcinoma cells: nonmetastatic murine 393P cells and somewhat metastatic human A549 cells. All three cell types readily formed spheroid structures in the 3D hydrogels. When cultured in the dual layer format, where tumor cell spheroids were adjacent to a hydrogel layer with microvascular tubule networks, all three tumor cell types recruited vascular cells into the cancer cell layer. Interactions between vessels invading the cancer layer and the cancer cell structures was nearly twice as high for the highly metastatic 344SQ cells as for the other two cell types. Secretion of angiogenic growth factors by the tumor cells was evaluated. 344SQ cells produced the greatest amount of VEGF and FGFb, which probably accounts for the greater degree of vessel recruitment observed. Upon interaction with vessel structures, the 344SQ spheroids underwent a dramatic change in morphology, increasing in size and adopting highly irregular shapes, suggestive of invasive phenotype. This behavior was observed to a much lesser degree for A549 cells and 393P cells.

Mesenchymal–endothelial transition in juvenile angiofibroma?

Conclusion: Mesenchymal–endothelial transition is proposed for juvenile angiofibromas (JAs). Propranolol might be an interesting new medical option in JA treatment, as it reduces mesenchymal cell growth and decreases the number of CD31-positive cells in vitro. Objective: Juvenile angiofibromas (JAs) are rare fibro-vascular tumors affecting almost exclusively adolescent males. Based on morphological aspects of irregularly configured vascular spaces and clinical features, JAs have been proposed to represent a vascular malformation. In general, mesenchymal–endothelial transition has been noted as an important process in tumorigenesis as well as in embryonal development. Methods: The study analyzed effects of vascular endothelial growth factor (VEGF)/basic fibroblast growth factor (bFGF) and propranolol on endothelial differentiation (CD31+) of cultured JA cells and their expression of angiogenic growth factors using aortic ring assay and enzyme-linked immunosorbent assay. Results: Following VEGF/bFGF supplement to cultured mesenchymal cells, an average of 4.47% (±2.35%) CD31-positive cells were found (p < 0.001). Propranolol addition reduced the number of CD31-positive cells and inhibited mesenchymal cell growth. The aortic ring assay and ELISA investigation indicated no increased angiogenic growth factor secretion from cultured JA mesenchymal cells.

Prevention of skin flap necrosis by use of adipose-derived stromal cells with light-emitting diode phototherapy

Background aimsThe aim of this study was to investigate the effects of low-level light therapy (LLLT) on transplanted human adipose-derived mesenchymal stromal cells (ASCs) in the skin flap of mice. MethodsLLLT, ASC transplantation and ASC transplantation with LLLT (ASC + LLLT) were applied to the skin flap. Immunostaining and Western blot analysis were performed to evaluate cell survival and differentiation and secretion of vascular endothelial growth factor and basic fibroblast growth factor by the ASCs. Vascular regeneration was assessed by means of immunostaining in addition to hematoxylin and eosin staining. In the ASC + LLLT group, the survival of ASCs was increased as the result of the decreased apoptosis of ASCs. ResultsThe secretion of growth factors was higher in this group as compared with ASCs alone. ASCs contributed to tissue regeneration through vascular cell differentiation and secretion of angiogenic growth factors. The ASC + LLLT group displayed improved treatment efficacy including neovascularization and tissue regeneration compared with ASCs alone. Transplanting ASCs to ischemic skin flaps improved therapeutic efficacy for ischemia treatment as the result of enhanced cell survival and paracrine effects. ConclusionsThese data suggest that LLLT is an effective biostimulator of ASCs in vascular regeneration, which enhances the survival of ASCs and stimulates the secretion of growth factors in skin flaps.

Upregulation of Bcl-2 enhances secretion of growth factors by adipose-derived stem cells deprived of oxygen and glucose

There is an increasing recognition that beneficial effects of adipose-derived stem cell (ADSC) therapy may depend largely on the secretion of multiple growth factors. This study modified ADSCs with the Bcl-2 gene in order to increase the secretion of growth factors during oxygen-glucose deprivation (OGD). The phenotypes of human ADSCs that were passaged 4 times were analyzed using flow cytometry. Then, ADSCs were genetically modified with Bcl-2 and Bcl-2 gene transduction was verified with Western blotting. Proliferative capacity and multipotent differentiation properties were evaluated in Bcl-2-modified ADSCs. Secretion of vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), and basic fibroblast growth factor (bFGF) was evaluated using an enzyme-linked immunosorbent assay (ELISA) during OGD. Human ADSCs that were passaged 4 times expressed stem cell-associated markers but not a fibroblast marker or a hematopoietic stem cell marker. The Bcl-2 gene was efficiently transfected into ADSCs; Bcl-2 modification did not affect the proliferative and multilineage differentiation capacity of ADSCs. In addition, Bcl-2 overexpression enhanced the secretion of VEGF, bFGF, and HGF by 14.47%, 16.9%, and 91%, respectively, compared to ADSCs alone that were deprived of oxygen and glucose. These data suggest that Bcl-2 overexpression enhances secretion of angiogenic growth factors by ADSCs deprived of oxygen and glucose.

Triiodothyronine regulates angiogenic growth factor and cytokine secretion by isolated human decidual cells in a cell-type specific and gestational age-dependent manner

STUDY QUESTIONDoes triiodothyronine (T3) regulate the secretion of angiogenic growth factors and cytokines by human decidual cells isolated from early pregnancy?SUMMARY ANSWERT3 modulates the secretion of specific angiogenic growth factors and cytokines, with different regulatory patterns observed amongst various isolated subpopulations of human decidual cells and with a distinct change between the first and second trimesters of pregnancy.WHAT IS KNOWN ALREADYMaternal thyroid dysfunction during early pregnancy is associated with complications of malplacentation including miscarriage and pre-eclampsia. T3 regulates the proliferation and apoptosis of fetal-derived trophoblasts, as well as promotes the invasive capability of extravillous trophoblasts (EVT). We hypothesize that T3 may also have a direct impact on human maternal-derived decidual cells, which are known to exert paracrine regulation upon trophoblast behaviour and vascular development at the uteroplacental interface.STUDY DESIGN, SIZE, DURATIONThis laboratory-based study used human decidua from first (8–11 weeks; n = 18) and second (12–16 weeks; n = 12) trimester surgical terminations of apparently uncomplicated pregnancies.PARTICIPANTS/MATERIALS, SETTING, METHODSPrimary cultures of total decidual cells, and immunomagnetic bead-isolated populations of stromal-enriched (CD10+) and stromal-depleted (CD10−) cells, uterine natural killer cells (uNK cells; CD56+) and macrophages (CD14+) were assessed for thyroid hormone receptors and transporters by immunocytochemistry. Each cell population was treated with T3 (0, 1, 10, 100 nM) and assessments were made of cell viability (MTT assay) and angiogenic growth factor and cytokine secretion (immunomediated assay). The effect of decidual cell-conditioned media on EVT invasion through Matrigel® was evaluated.MAIN RESULTS AND THE ROLE OF CHANCEImmunocytochemistry showed the expression of thyroid hormone transporters (MCT8, MCT10) and receptors (TRα1, TRβ1) required for thyroid hormone-responsiveness in uNK cells and macrophages from the first trimester. The viability of total decidual cells and the different cell isolates were unaffected by T3 so changes in cell numbers could not account for any observed effects. In the first trimester, T3 decreased VEGF-A secretion by total decidual cells (P < 0.05) and increased angiopoietin-2 secretion by stromal-depleted cells (P < 0.05) but in the second trimester total decidual cells showed only increased angiogenin secretion (P < 0.05). In the first trimester, T3 reduced IL-10 secretion by total decidual cells (P < 0.05), and reduced granulocyte macrophage colony stimulating factor (P < 0.01), IL-8 (P < 0.05), IL-10 (P < 0.01), IL-1β (P < 0.05) and monocyte chemotactic protein -1 (P < 0.001) secretion by macrophages, but increased tumour necrosis factor-α secretion by stromal-depleted cells (P < 0.05) and increased IL-6 by uNK cells (P < 0.05). In contrast, in the second trimester T3 increased IL-10 secretion by total decidual cells (P < 0.01) but did not affect cytokine secretion by uNK cells and macrophages. Conditioned media from first trimester T3-treated total decidual cells and macrophages did not alter EVT invasion compared with untreated controls. Thus, treatment of decidual cells with T3 resulted in changes in both angiogenic growth factor and cytokine secretion in a cell type-specific and gestational age-dependent manner, with first trimester decidual macrophages being the most responsive to T3 treatment, but these changes in decidual cell secretome did not affect EVT invasion in vitro.LIMITATIONS, REASONS FOR CAUTIONOur results are based on in vitro findings and we cannot be certain if a similar response occurs in human pregnancy in vivo.WIDER IMPLICATIONS OF THE FINDINGSOptimal maternal thyroid hormone concentrations could play a critical role in maintaining a balanced inflammatory response in early pregnancy to prevent fetal immune rejection and promote normal placental development through the regulation of the secretion of critical cytokines and angiogenic growth factors by human decidual cells. Our data suggest that there is an ontogenically determined regulatory ‘switch’ in T3 responsiveness between the first and second trimesters, and support the notion that the timely and early correction of maternal thyroid dysfunction is critical in influencing pregnancy outcomes.STUDY FUNDING/COMPETING INTEREST(S)This study is funded by Wellbeing of Women (RG/1082/09 to S.Y.C., M.D.K., J.A.F., L.S.L., G.E.L.) and Action Medical Research – Henry Smith Charity (SP4335 to M.D.K., S.Y.C., L.S.L., J.A.F.). The authors have no conflicts of interest to disclose.

Stimulations of strontium-doped calcium polyphosphate for bone tissue engineering to protein secretion and mRNA expression of the angiogenic growth factors from endothelial cells in vitro

The vascularization of tissue-engineered bone is the key problem needed solving before application of tissue-engineered bone in clinical practice. Meanwhile, endothelial cells are the major and important source of seed cells in bone tissue engineering, and significant on promoting vascularization in tissue-engineered bone. Vascularization (namely angiogenesis) is a process mainly controlled by several angiogenic growth factors (VEGF, bFGF and MMP-2) which can be secreted by endothelial cells. Therefore, the research on the stimulations of SCPP to the secretion of the angiogenic growth factors from endothelial cells is very important. This study was performed to determine the ability of strontium-doped calcium polyphosphate (SCPP) to induce angiogenesis by detecting the protein secretion levels and mRNA expression of VEGF, bFGF and MMP-2 from cultured endothelial cells. As a control, we also researched the effect of HA on the mRNA expressions and protein secretion of angiogenic growth factors from cultured endothelial cells. We cultured endothelial cells with SCPP scaffolds containing various concentration of strontium and HA. The results obtained in the MTT and SEM tests indicated that endothelial cells on SCPP scaffold exhibited higher proliferation rate and were easy to get a good spread than them on CPP, the best state of growth and proliferation of cells could be observed on 8%SCPP. The results of ELISA demonstrated that the protein levels of VEGF, bFGF and MMP-2 from cultured endothelial cells increased with the increasing Sr doped in calcium polyphosphate in SCPP groups, the peaks appeared on 8%SCPP. All SCPP groups showed a better ability to stimulate the protein secretion of VEGF, bFGF and MMP-2 from endothelial cells relative to CPP group and HA group. The results of RT-PCR suggested that the 8%SCPP group exhibited a significantly higher mRNA expression of VEGF, bFGF and MMP-2 relative to CPP group and HA group. In conclusion, the results of this study demonstrated that 8%SCPP had obvious promotion for secretion and mRNA expression of angiogenic growth factors from cultured endothelial cells.

Fish oil-enriched diet protects against ischemia by improving angiogenesis, endothelial progenitor cell function and postnatal neovascularization

BackgroundFish oil consumption has been associated with a reduced incidence of cardiovascular diseases. However, the precise mechanisms involved are not completely understood. Here we tested the hypothesis that a fish oil-enriched diet improves neovascularization in response to ischemia. Methods and resultsC57Bl/6 mice were fed a diet containing either 20% fish oil, rich in long-chain n-3 polyunsaturated fatty acids (PUFAs), or 20% corn oil, rich in n-6 PUFAs. After 4 weeks, hindlimb ischemia was surgically induced by femoral artery removal. We found that blood flow recovery was significantly improved in mice fed a fish oil diet compared to those fed a corn oil diet (Doppler flow ratio (DFR) at day 21 after surgery 78 ± 5 vs. 56 ± 4; p < 0.01). Clinically, this was associated with a significant reduction of ambulatory impairment and ischemic damage in the fish oil group. At the microvascular level, capillary density was significantly improved in ischemic muscles of mice fed a fish oil diet. This correlated with increased expression of VEGF and eNOS in ischemic muscles, and higher NO concentration in the plasma. Endothelial progenitor cells (EPCs) have been shown to have an important role for postnatal neovascularization. We found that the number of EPCs was significantly increased in mice fed a fish oil diet. In addition, oxidative stress levels (DCF-DA, DHE) were reduced in EPCs isolated from mice exposed to fish oil, and this was associated with improved EPC functional activities (migration and integration into tubules). In vitro, treatment of EPCs with fish oil resulted in a significant increase of cellular migration. In addition, the secretion of angiogenic growth factors including IL6 and leptin was significantly increased in EPCs exposed to fish oil. ConclusionFish oil-enriched diet is associated with improved neovascularization in response to ischemia. Potential mechanisms involved include activation of VEGF/NO pathway in ischemic tissues together with an increase in the number and the functional activities of EPCs.