Transition metals in angiogenesis - A narrative review.

The aim of this paper is to offer a narrative review of the literature regarding the influence of transition metals on angiogenesis, excluding lanthanides and actinides. To our knowledge there are not any reviews up to date offering such a summary, which inclined us to write this paper. Angiogenesis describes the process of blood vessel formation, which is an essential requirement for human growth and development. When the complex interplay between pro- and antiangiogenic mediators falls out of balance, angiogenesis can quickly become harmful. As it is so fundamental, both its inhibition and enhancement take part in various diseases, making it a target for therapeutic treatments. Current methods come with limitations, therefore, novel agents are constantly being researched, with metal agents offering promising results. Various transition metals have already been investigated in-depth, with studies indicating both pro- and antiangiogenic properties, respectively. The transition metals are being applied in various formulations, such as nanoparticles, complexes, or scaffold materials. Albeit the increasing attention this field is receiving, there remain many unanswered questions, mostly regarding the molecular mechanisms behind the observed effects. Notably, approximately half of all the transition metals have not yet been investigated regarding potential angiogenic effects. Considering the promising results which have already been established, it should be of great interest to begin investigating the remaining elements whilst also further analyzing the established effects.

Lipopolysaccharides from Porphyromonas endodontalis and Porphyromonas gingivalis promote angiogenesis via Toll-like-receptors 2 and 4 pathways in vitro.

AIM: Angiogenesis contributes to the development of apical periodontitis, periodontitis, and other oral pathologies; however, it remains unclear how this process is triggered. The aim was to evaluate whether lipopolysaccharide (LPS) from Porphyromonas endodontalis and Porphyromonas gingivalis induced angiogenesis-related effects in vitro via TLR2 and TLR4. METHODOLOGY: Porphyromonas endodontalis LPS (ATCC 35406 and clinical isolate) was purified with TRIzol, whereas P. gingivalis LPS was obtained commercially. The effects of the different LPS (24 h) in endothelial cell migration were analysed by Transwell assays, following quantification in an optical microscope (40×). The effects of LPS on FAK Y397 phosphorylation were assessed by Western blotting. Angiogenesis in vitro was determined in an endothelial tube formation assay (14 h) in Matrigel in the absence or presence of either LPS. IL-6 and VEGF-A levels were determined in cell supernatants, following 24 h treatment with LPS, and measured in multiplex bead immunoassay. The involvement of TLR2 and TLR4 was assessed with blocking antibodies. The statistical analysis was performed using STATA 12® (StataCorp LP). RESULTS: The results revealed that P. endodontalis LPS, but not P. gingivalis LPS, stimulated endothelial cell migration. Pre-treatment with anti-TLR2 and anti-TLR4 antibodies prevented P. endodontalis LPS-induced cell migration. P. endodontalis LPS promoted FAK phosphorylation on Y397, as observed by an increased p-FAK/FAK ratio. Both P. gingivalis and P. endodontalis LPS (ATCC 35406) induced endothelial tube formation in a TLR-2 and -4-dependent manner, as shown by using blocking antibodies, however, only TLR2 blocking decreased tube formation induced by P. endodontalis (clinical isolate). Moreover, all LPS induced IL-6 and VEGF-A synthesis in endothelial cells. TLR2 and TLR4 were required for IL-6 induction by P. endodontalis LPS (ATCC 35406), while only TLR4 was involved in IL-6 secretion by the other LPS. Finally, VEGF-A synthesis did not require TLR signalling. CONCLUSION: Porphyromonas endodontalis and P. gingivalis LPS induced angiogenesis via TLR2 and TLR4. Collectively, these data contribute to understanding the role of LPS from Porphyromonas spp. in angiogenesis and TLR involvement.

Adenosine-ADORA2A Promotes Ang-Induced Angiogenesis in Intrauterine Growth Restriction Placenta via the Stat3/Akt Pathway.

BACKGROUND: Abnormal placental angiogenesis is an important cause of fetal intrauterine growth restriction (IUGR), but its underlying mechanisms and therapies remain unclear. Adenosine and its mediated signaling has been reported to be associated with the development of angiogenesis. However, whether the adenosine-related signaling plays a role in modulating angiogenesis in placenta and the IUGR pregnancy outcomes remains unclear. METHODS: The angiogenesis and adenosine signaling expressions in normal and IUGR placentas were detected in different species. And the role of adenosine in regulating IUGR pregnancy outcomes was evaluated using diet-induced IUGR mouse model. Molecular mechanisms underlying adenosine-induced angiogenesis were investigated by in vitro angiogenesis assays and in vivo Matrigel plug assays. RESULTS: Here, we demonstrated poor angiogenesis and low adenosine concentration and downregulated expression of its receptor A2a (ADORA2A [adenosine A2a receptor]) in IUGR placenta. Additionally, the beneficial effects of adenosine in improving IUGR pregnancy outcomes were revealed in a diet-induced IUGR mouse model. Moreover, adenosine was found to effectively improve adenosine signaling and angiogenesis in IUGR mice placenta. Mechanistically, by using angiogenesis assays in vitro and in vivo, adenosine was shown to activate ADORA2A to promote the phosphorylation of Stat3 (signal transducer and activator of transcription 3) and Akt (protein kinase B), resulting in increased Ang (angiogenin)-dependent angiogenesis. CONCLUSIONS: Collectively, this study uncovers an unexpected mechanism of promoting placental angiogenesis by adenosine-ADORA2A signaling and advances the translation of this signaling as a prognostic indicator and therapeutic target in IUGR treatment.

The VEGFR2/mTOR/S6K1 pathway involved in the angiogenic effects of roxarsone in vitro and in vivo.

Roxarsone, an organoarsenic compound used in poultry industry to increase weight gain, is widely used as a feed additive in some developing countries. Roxarsone has a low absorption rate and is mostly excreted with feces, which could pose a risk to human health through environmental and animal food routes. Roxarsone has been demonstrated to have tumor-promoting and proangiogenic effects. Herein, we report the role of VEGFR2/mTOR/S6K1 signaling in roxarsone-promoted vessel endothelial cell growth and angiogenesis in the Matrigel plug model and the mouse B16 cell tumor transplantation model. In angiogenesis-related experiments in vitro, 1.0 µM roxarsone significantly increased the activity, proliferation, migration, and tube formation of rat vascular endothelial cells. In addition, 1.0 µM roxarsone upregulated the protein levels of mTOR, phosphorylated mTOR, S6K1, and phosphorylated S6K1 and significantly increase the expression of Mtor and S6k1 mRNA. Rapamycin and SU5416 significantly inhibited the effects of 1.0 µM roxarsone on cell growth. Furthermore, the weight, volume, and CD31 expression of B16-F10 xenografts and Matrigel plugs in mice were upregulated by 25 mg/kg roxarsone. The protein and mRNA levels of mTOR, S6K1 and its phosphorylated protein were significantly increased in the roxarsone treatment group in xenografts. SU5416 and a short hairpin RNA targeting Vegfr2 significantly reduced roxarsone-promoted xenograft and Matrigel plug growth. In summary, this study indicated that the VEGFR2/mTOR/S6K1 signaling plays a regulatory role in roxarsone-mediated promotion angiogenesis and enhanced tumor growth.

Effect of Lysophosphatidic Acid on the Vascular Endothelial Growth Factor Expression in Autotransplanted Mouse Ovaries Encapsulated in Sodium Alginate.

Objective: The aim of this study was to evaluate the effect of lysophosphatidic acid (LPA) supplementation during in vitro culture and transplantation of mouse ovaries on the follicular development and expression of vascular endothelial growth factor (VEGF) as an angiogenesis factor at the mRNA and protein levels. Materials and methods: Three weeks old mice ovaries were cultured in the presence and absence of LPA for 24 hours, then they were capsulated in sodium alginate in the presence and absence of LPA as four experimental groups. After transplantation the vaginal smears were performed daily to evaluate the initiation of the estrous cycle. The morphology and follicular distribution were analyzed at the first and fourth estrous cycles using hematoxylin and eosin staining. Then in the groups that showed higher and lower follicular development the immunohistochemistry assay was conducted to identify VEGF protein expression, and the real time RT-PCR was done to analyze the expression of Vegf gene at the first estrus cycle. Results: The large size follicles and also the corpus luteum were prominent in all transplanted groups at fourth estrus cycle in comparison with intact control groups. The statistically lowest percentage of small size follicles and the highest percentages of large size follicles were seen in LPA+/LPA- group (p<0.05). The expression ratio of Vegf to ß-actin was significantly higher in this group in comparison with non-LPA treated and intact control groups (p <0.05). Conclusion: LPA as an angiogenesis factor increases the follicular development in transplanted ovaries but it causes early discharge of ovarian reserve.

Skin graft associated with platelet-rich plasma in correcting extensive injuries resulting from the resection of skin cancer chemically induced in rats

ABSTRACT Purpose: To evaluate whether using platelet-rich plasma (PRP) in the graft recipient bed after the resection of a neoplasia can influence its recurrence because this product stimulates angiogenesis, mitogenesis and chemotaxis. Methods: A study with 30 rats Wistar (Rattus norvegicus albinus), which were separated into group A (induction of carcinogenesis, PRP in the postoperative period) and group B (induction of carcinogenesis, absence of PRP in the postoperative period), with 15 animals in each. Carcinogenesis was induced on the skin of the animals' chest by the topical application of 0.5% dimethylbenzantracene (DMBA) diluted in acetone. After surgical resection of the induced neoplasia, PRP was used to stimulate angiogenesis before surgical wound synthesis. Data on the control and experimental groups and macroscopic and microscopic variables were evaluated using analysis of variance and the Tukey's test (5%). Results: It was possible to determine that the use of PRP is good in reconstructive surgeries, but it is contraindicated in patients during tumor resection, as it can cause changes in the surgical bed, in addition to stimulating recurrences and metastases. Conclusions: PRP may interact with tumour cells that were in the recipient site of the surgical wound during the resection of a neoplasia, and a local recurrence process can be triggered by applying this product.

Effect of a novel bioceramic root canal sealer on the angiogenesis-enhancing potential of assorted human odontogenic stem cells compared with principal tricalcium silicate-based cements

Abstract Objective: This study evaluated the angiogenesis-enhancing potential of a tricalcium silicate-based mineral trioxide aggregate (ProRoot MTA), Biodentine, and a novel bioceramic root canal sealer (Well-Root ST) in human dental pulp stem cells (hDPSCs), human periodontal ligament stem cells (hPLSCs), and human tooth germ stem cells (hTGSCs). Methodology: Dulbecco's modified Eagle's medium was conditioned for 24 h by exposure to ProRoot MTA, Biodentine, or Well-Root ST specimens (prepared according to the manufacturers' instructions). The cells were cultured in these conditioned media and their viability was assessed with 3-(4,5-dimethyl-thiazol-2-yl)-5-(3-carboxy-methoxy-phenyl)-2-(4-sulfo-phenyl)-2H tetrazolium (MTS) on days 1, 3, 7, 10, and 14. Angiogenic growth factors [platelet-derived growth factor (PDGF), basic fibroblast growth factor (FGF-2), and vascular endothelial growth factor (VEGF)] were assayed by sandwich enzyme-linked immunosorbent assay (ELISA) on days 1, 7, and 14. Human umbilical vein endothelial cell (HUVEC) migration assays were used to evaluate the vascular effects of the tested materials at 6-8 h. Statistical analyses included Kruskal-Wallis, Mann-Whitney U, and Friedman and Wilcoxon signed rank tests. Results: None of tricalcium silicate-based materials were cytotoxic and all induced a similar release of angiogenic growth factors (PDGF, FGF-2, and VEGF) (p>0.05). The best cell viability was observed for hDPSCs (p<0.05) with all tricalcium silicate-based materials at day 14. Tube formation by HUVECs showed a significant increase with all tested materials (p<0.05). Conclusion: The tricalcium silicate-based materials showed potential for angiogenic stimulation of all stem cell types and significantly enhanced tube formation by HUVECs.

Angiogenesis of Extracted Tooth Wound on Wistar Rats After Application of Okra (Abelmoschus esculentus) Gel Extract

Abstract Objective: To analyze angiogenesis in the post-extracted tooth of Wistar rats after application of okra (Abelmoschus esculentus) extract. Material and Methods: A total of 18 rats were divided into two groups (control and treatment). Okra extract with a concentration of 30% in gel form was applied on the post-extraction socket of the treatment group. The rats were sacrificed on day-3, day-5, and day-7 after tooth extraction. The newly-formed blood vessels were counted and statistically analyzed by means of One Way ANOVA and Tukey HSD with a significance level set at 5%. Results: The newly-formed capillaries of the control group (4.67 ± 1.53) on day-3 were lower than the treatment group (9.00 ± 1.00). The newly-formed capillaries recorded from the control group, both in day-5 (9.33 ± 1.53) and day-7 (8.67 ± 1.53) were lower than the treatment group, which started to decreased from day-5 (13.67 ± 1.53) to day-7 (12.33 ± 0.58). Significant differences were found in treatment group, on day-3 compared to day-5 (p=0.005), and on day-3 to day-7 (p=0.024). Conclusion: Okra extract in gel form at 30% concentration can increase the angiogenesis during the wound healing process of the extracted tooth on Wistar rats.

The Effect of Garlic and Voluntary Exercise on Cardiac Angiogenesis in Diabetes: The Role of MiR-126 and MiR-210 / O Efeito do Alho e de Exercícios Físicos Voluntários na Angiogênese Cardíaca no Diabetes: O Papel do miRNA-126 e do miRNA-210

Abstract Background: Diabetes mellitus (DM) is one of the major risk factors for cardiovascular disease, leading to endothelial dysfunction and angiogenesis impairment . MiR-126 and miR-210 support angiogenic response in endothelial cells. Objective: The present study sought to explore the effect of garlic and voluntary exercise, alone or together, on miR-126 and miR-210 expressions and cardiac angiogenesis in rats with type 1 diabetes. Methods: Male Wistar rats were divided into five groups (n = 7): Control, Diabetes, Diabetes+Garlic, Diabetes+Exercise, and Diabetes+Garlic+Exercise. Diabetes was induced in the animals by streptozotocin (ip, 50 mg/kg). The rats were then fed raw fresh garlic homogenate (250 mg/kg) or were subjected to voluntary exercise, or to combined garlic and voluntary exercise for 6 weeks. MiR-126 and miR-210 expressions in the myocardium were determined by real time PCR, and the serum lipid profile was measured by enzymatic kits. Angiogenesis was evaluated by immunostaining for PECAM-1/ CD31 in the myocardium. Results: Diabetes reduced both cardiac miR-126 expression and angiogenesis (p < 0.05). On the other hand, there was a miR-210 expression increase in the myocardium of diabetic animals (p < 0.001). However, those effects reversed either with garlic or voluntary exercise (p < 0.01). Moreover, treating diabetic rats with garlic and voluntary exercise combined had an additional effect on the expressions of miR-126 and miR-210 (p < 0.001). Furthermore, both voluntary exercise and garlic significantly improved serum lipid profiles (p < 0.001). Conclusion: The induction of diabetes decreased angiogenesis in the myocardium, whereas our treatment using long-term voluntary exercise and garlic improved myocardial angiogenesis. These changes were possibly owing to the enhancement of myocardial miR-126 and miR-210 expressions.

Resumo Fundamento: O diabetes mellitus (DM) é um dos principais fatores de risco para doenças cardiovasculares, levando à disfunção endotelial e inibição da angiogênese. O miRNA-126 e o miRNA-210 promovem a resposta angiogênica em células endoteliais. Objetivo: O presente estudo buscou explorar o efeito do alho e de exercícios físicos voluntários, isoladamente ou em conjunto, nas expressões do miRNA-126 e do miR-210 e na angiogênese cardíaca em ratos com diabetes tipo 1. Métodos: Ratos Wistar machos foram divididos em cinco grupos (n = 7): Controle, Diabetes, Diabetes+Alho, Diabetes+Exercícios e Diabetes+Alho+Exercícios. Introduziu-se diabetes nos animais por estreptozotocina (ip, 50 mg/kg). Os ratos foram então alimentados com homogenato de alho fresco cru (250 mg/kg), ou foram submetidos a exercícios voluntários, ou a uma combinação de alho e exercícios voluntários, durante 6 semanas. As expressões do miRNA-126 e do miRNA-210 no miocárdio foram determinadas por PCR em tempo real, e o perfil lipídico sérico foi medido por kits enzimáticos. A angiogênese foi avaliada por imunocoloração por PECAM-1/CD31 no miocárdio Resultados: O diabetes reduziu a expressão do miRNA-126 cardíaco e da angiogênese (p < 0,05). Por outro lado, houve um aumento da expressão do miRNA-210 no miocárdio dos animais diabéticos (p < 0,001). No entanto, tais efeitos foram revertidos com alho ou exercícios voluntários (p < 0,01). Além disso, o tratamento de ratos diabéticos conjuntamente com alho e exercícios voluntários teve um efeito adicional sobre as expressões do miRNA-126 e do miRNA-210 (p < 0,001). Além disso, tanto os exercícios voluntários quanto o alho melhoraram significativamente os perfis lipídicos séricos (p < 0,001). Conclusões: A indução de diabetes diminuiu a angiogênese no miocárdio, enquanto nosso tratamento com exercícios voluntários de longa duração e alho melhorou a angiogênese miocárdica. Estas alterações devem-se, possivelmente, ao aumento das expressões do miRNA-126 e do miRNA no miocárdio.

Antiangiogenic VEGF165b Regulates Macrophage Polarization via S100A8/S100A9 in Peripheral Artery Disease.

BACKGROUND: Atherosclerotic occlusions decrease blood flow to the lower limbs, causing ischemia and tissue loss in patients with peripheral artery disease (PAD). No effective medical therapies are currently available to induce angiogenesis and promote perfusion recovery in patients with severe PAD. Clinical trials aimed at inducing vascular endothelial growth factor (VEGF)-A levels, a potent proangiogenic growth factor to induce angiogenesis, and perfusion recovery were not successful. Alternate splicing in the exon-8 of VEGF-A results in the formation of VEGFxxxa (VEGF165a) and VEGFxxxb (VEGF165b) isoforms with existing literature focusing on VEGF165b's role in inhibiting vascular endothelial growth factor receptor 2-dependent angiogenesis. However, we have recently shown that VEGF165b blocks VEGF-A-induced endothelial vascular endothelial growth factor receptor 1 (VEGFR1) activation in ischemic muscle to impair perfusion recovery. Because macrophage-secreted VEGF165b has been shown to decrease angiogenesis in peripheral artery disease, and macrophages were well known to play important roles in regulating ischemic muscle vascular remodeling, we examined the role of VEGF165b in regulating macrophage function in PAD. METHODS: Femoral artery ligation and resection were used as an in vivo preclinical PAD model, and hypoxia serum starvation was used as an in vitro model for PAD. Experiments including laser-Doppler perfusion imaging, adoptive cell transfer to ischemic muscle, immunoblot analysis, ELISAs, immunostainings, flow cytometry, quantitative polymerase chain reaction analysis, and RNA sequencing were performed to determine a role of VEGF165b in regulating macrophage phenotype and function in PAD. RESULTS: First, we found increased VEGF165b expression with increased M1-like macrophages in PAD versus non-PAD (controls) muscle biopsies. Next, using in vitro hypoxia serum starvation, in vivo pre clinical PAD models, and adoptive transfer of VEGF165b-expressing bone marrow-derived macrophages or VEGFR1+/- bone marrow-derived macrophages (M1-like phenotype), we demonstrate that VEGF165b inhibits VEGFR1 activation to induce an M1-like phenotype that impairs ischemic muscle neovascularization. Subsequently, we found S100A8/S100A9 as VEGFR1 downstream regulators of macrophage polarization by RNA-Seq analysis of hypoxia serum starvation-VEGFR1+/+ versus hypoxia serum starvation-VEGFR1+/- bone marrow-derived macrophages. CONCLUSIONS: In our current study, we demonstrate that increased VEGF165b expression in macrophages induces an antiangiogenic M1-like phenotype that directly impairs angiogenesis. VEGFR1 inhibition by VEGF165b results in S100A8/S100A9-mediated calcium influx to induce an M1-like phenotype that impairs ischemic muscle revascularization and perfusion recovery.

Vaccarin hastens wound healing by promoting angiogenesis via activation of MAPK/ERK and PI3K/AKT signaling pathways in vivo

Abstract Purpose To explore the potential role and unclear molecular mechanisms of vaccarin in wound healing. Methods Rats' skin excision model to study the effects of vaccarin on wound healing in vivo . Hematoxylin and eosin staining was performed to evaluate Histopathologic characteristics. Immunohistochemistry was employed to assess the effects of vaccarin in accelerating angiogenesis. Western blot was used to evaluate relative protein expressed levels. Results Vaccarin could significantly promote wound healing and endothelial cells and fibroblasts proliferation in the wound site. Immunohistochemistry and Western blot studies showed that the nodal proteins and receptor (bFGFR) related to angiogenesis signaling pathway were activated, and the microvascular density in the wound site was markedly higher than that in the control group. Conclusions The present study was the first to demonstrate that vaccarin is able to induce angiogenesis and accelerate wound healing in vivo by increasing expressions of p-Akt, p-Erk and p-bFGFR. This process is mediated by MAPK/ERK and PI3K/AKT signaling pathways.

Colony-stimulating factor-1 of osteosarcoma cells promotes tumor angiogenesis / 肿瘤

Objective: To investigate the effect of macrophage colony-stimulating factor-1 (CSF-1) expression in osteosarcoma cells on tumor angiogenesis, and to explore its possible mechanism. Methods: The expressions of CSF-1 and allograft inflammatory factor-1 (AIF-1) in human osteoblasts hFOB1.19, osteosarcoma SAOS-2, MG-63 and U2OS cells were detected by Western blotting. The expressions of AIF-1 and Ras-related C3 botulinum toxin substrate-1 (Rac-1) in osteosarcoma SAOS-2 cells after transfection with siRNA-CSF-1 or siRNAnegative control (siRNA-NC) were detected by Western blotting. The culture supernatant was collected after siRNA-CSF-1 or siRNA-NC was transfected into osteosarcoma SAOS-2 cells, the untransfected SAOS-2 cells were used as the blank control (BC). Then the collected culture supernatant was mixed with the complete medium at a volume ratio of 1∶1 to make the conditioned medium for the culture of human umbilical vein endothelial cells (HUVECs). After treatment with the siRNA-CSF-1 or siRNA-NC conditional medium, the proliferation, migration and tube formation of HUVECs were detected by MTT assay, Transwell chamber assay and tube formation experiment, respectively; The expressions of vascular endothelial growth factor (VEGF) and Rac-1 in HUVECs were detected by Western blotting. After HUVECs were treated with siRNA-CSF-1 conditional medium combined with 0.1% DMSO or Rac-1 activator phorbol 12-myristate 13-acetate (PMA) for 24 h, the cell proliferation, migration and the tube formation were detected by MTT assay, Transwell chamber assay and tube formation experiment, respectively; The expressions of VEGF and Rac-1 in HUVECs were detected again by Western blotting. Results: The expression levels of CSF-1 and AIF-1 proteins in osteosarcoma SAOS-2, MG-63 and U2OS cells were higher than those in osteoblasts hFOB1.19 (all P < 0.05). The expressions of CSF-1 and AIF-1 were positively correlated (R2 = 0.492 2, P = 0.001 2). The expression levels of AIF-1 and Rac-1 in osteosarcoma SAOS-2 cells of siRNA-CSF-1 transfection group were down-regulated (both P < 0.05). After treatment with siRNA-CSF-1 conditional medium, the proliferation, migration and tube formation abilities of HUVECs were decreased (all P < 0.05), and the expression levels of VEGF and Rac-1 were down-regulated (both P < 0.05). Whereas Rac-1 activator reversed the effects of siRNA-CSF-1 conditional medium on the proliferation, migration, tube formation as well as VEGF and Rac-1 expressions of HUVECs (all P < 0.05). Conclusion: CSF-1 in osteosarcoma cells may promote the tumor angiogenesis by AIF-1/ Rac-1 pathway.

Vascular endothelial growth factor gene transfer therapy for coronary artery disease: A systematic review and meta-analysis.

AIM: It is not clear whether treatment by vascular endothelial growth factor (VEGF) gene transfer can improve myocardial ischemia through a proangiogenesis mechanism and is effective against coronary artery disease (CAD). We aimed to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) that compared VEGF gene therapy and standard treatments in CAD. METHODS: We systematically searched the PubMed, Embase, and Cochrane databases and relevant references for RCTs (published up to May 2018; no language restrictions) and performed meta-analysis using both fixed and random effects models. Our primary outcome measures were mortality and serious cardiac events. The secondary outcome measures were follow-up left ventricular ejection fraction (LVEF), change in LVEF (ΔLVEF), and angina outcomes. The registration number is CRD42017058430. RESULTS: Of 524 identified studies, 14 were eligible and were included in our analysis. At a mean follow-up of 6 months, VEGF gene therapy demonstrated a decreased risk of serious cardiac events (11.7% vs 21.2%, relative risk: 0.56; 95% confidence interval (CI): 0.37, 0.84; P = 0.005) and a slight improvement in follow-up LVEF (weighted mean difference: 1.95; 95%CI: 1.28, 2.62). Furthermore, VEGF gene therapy using adenoviral vectors showed more potential benefit in terms of the risk of serious cardiac events, ΔLVEF, and Canadian Cardiovascular Society angina class. Nevertheless, mortality and angina frequency scores were not different. CONCLUSIONS: Vascular endothelial growth factor gene therapy appears to be safe and effective regarding serious cardiac events, with greater benefit when using adenoviral vectors. This meta-analysis highlights the need for further exploration in these areas.

The effects of proteins released from silk mat layers on macrophages.

BACKGROUND: The objective of this study was to evaluate the changes in gene expression after incubation of cells with proteins released from different silk mat layers. METHODS: A silk cocoon from Bombyx mori was separated into four layers of equal thickness. The layers were numbered from 1 to 4 (from the inner to the outer layer). The proteins were released by sonication of a silk mat layer in normal saline. The concentration of proteins was determined by spectrophotometry. They were incubated with RAW264.7 cells, and changes in the expression of genes were evaluated by cDNA microarray analysis and quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). RESULTS: Layer 1 and 4 groups had higher protein concentrations compared to those in layer 2 and 3 groups. The genes associated with inflammation and angiogenesis showed significantly higher expression in layer 1 and 4 groups. The results of qRT-PCR were in agreement with those of the cDNA microarray analysis. CONCLUSIONS: The silk mat from the middle portion of the silkworm cocoon yielded a lower protein release and caused an insignificant change in the expression of genes that are associated with inflammation and angiogenesis.

Vascularization in Craniofacial Bone Tissue Engineering.

Craniofacial bones, separate from the appendicular skeleton, bear a significant amount of strain and stress generated from mastication-related muscles. Current research on the regeneration of craniofacial bone focuses on the reestablishment of an elaborate vascular network. In this review, current challenges and efforts particularly in advances of scaffold properties and techniques for vascularization remodeling in craniofacial bone tissue engineering will be discussed. A microenvironment of ischemia and hypoxia in the biomaterial core drives propagation and reorganization of endothelial progenitor cells (EPCs) to assemble into a primitive microvascular framework. Co-culture strategies and delivery of vasculogenic molecules enhance EPCs' differentiation and stimulate the host regenerative response to promote vessel sprouting and strength. To optimize structural and vascular integration, well-designed microstructures of scaffolds are biologically considered. Proper porous structures, matrix stiffness, and surface morphology of scaffolds have a profound influence on cell behaviors and thus affect revascularization. In addition, advanced techniques facilitating angiogenesis and vaculogenesis have also been discussed. Oxygen delivery biomaterials, scaffold-free cell sheet techniques, and arteriovenous loop-induced axial vascularization strategies bring us new understanding and powerful strategies to manage revascularization of large craniofacial bone defects. Although promising histological results have been achieved, the efficient perfusion and functionalization of newly formed vessels are still challenging.

Effect of 670 nm laser photobiomodulation on vascular density and fibroplasia in late stages of tissue repair.

This study aimed to investigate the effects of gallium-aluminum-arsenium (GaAlAs) (670 nm) laser therapy on neoangiogenesis and fibroplasia during tissue remodelling. Forty male Wistar rats underwent cutaneous surgery and were divided into 2 experimental groups: the Control and Laser group (9 mW, 670 nm, 0.031 W/cm2 , 4 J/cm2 ). After 14, 21, 28, and 35 days, the animals were euthanised. Descriptive and quantitative analyses were performed in sections stained with haematoxylin-eosin and Sirius Red, respectively. The amounts of VEGF+ and CD31+ cells were evaluated by immunohistochemistry and histomorphometric analysis, respectively. Statistical analysis was performed using the Mann-Whitney, Friedman, and Spearman correlation test, P < 0.05. The collagen expression was significantly higher in the laser group compared with the control group on days 14 and 21 after the creation of the skin wound (P = 0.008; P = 0.016) and in the control group between 14 and 28 and 14 and 35 days (P = 0.001; P = 0.007). There were more blood vessels in three periods of the study only in the (Laser) treated group, with statistical significance at day 14 (P = 0.016). There was no statistically significant difference in VEGF+ cell count in the different experimental groups throughout the study, although a positive correlation was shown with the area of collagen on days 14 and 28 (P = 0.037). Laser treatment had a positive effect in the late course of healing, particularly with regards to collagen expression and the number of newly formed vessels. VEGF+ cells were present in both experimental groups, and VEGF appeared to influence fibroplasia in the treated group.

Inhibition of TGF-ß Signaling in SHED Enhances Endothelial Differentiation.

Low efficiency of deriving endothelial cells (ECs) from adult stem cells hampers their utilization in tissue engineering studies. The purpose of this study was to investigate whether suppression of transforming growth factor beta (TGF-ß) signaling could enhance the differentiation efficiency of dental pulp-derived stem cells into ECs. We initially used vascular endothelial growth factor A (VEGF-A) to stimulate 2 dental pulp-derived stem cells (dental pulp stem cells and stem cells from human exfoliated deciduous teeth [SHED]) and compared their differentiation capacity into ECs. We further evaluated whether the vascular endothelial growth factor receptor I (VEGF-RI)-specific ligand placental growth factor-1 (PlGF-1) could mediate endothelial differentiation. Finally, we investigated whether the TGF-ß signaling inhibitor SB-431542 could enhance the inductive effect of VEGF-A on endothelial differentiation, as well as the underlying mechanisms involved. ECs differentiated from dental pulp-derived stem cells exhibited the typical phenotypes of primary ECs, with SHED possessing a higher endothelial differentiation potential than dental pulp stem cells. VEGFR1-specific ligand-PLGF exerted a negligible effect on SHED-ECs differentiation. Compared with VEGF-A alone, the combination of VEGF-A and SB-431542 significantly enhanced the endothelial differentiation of SHED. The presence of SB-431542 inhibited the phosphorylation of Suppressor of Mothers Against Decapentaplegic 2/3 (SMAD2/3), allowing for VEGF-A-dependent phosphorylation and upregulation of VEGFR2. Our results indicate that the combination of VEGF-A and SB-431542 could enhance the differentiation of dental pulp-derived stem cells into endothelial cells, and this process is mediated through enhancement of VEGF-A-VEGFR2 signaling and concomitant inhibition of TGF-ß-SMAD2/3 signaling.

The effects of proteins released from silk mat layers on macrophages / 대한악안면성형재건외과학회지

BACKGROUND: The objective of this study was to evaluate the changes in gene expression after incubation of cells with proteins released from different silk mat layers. METHODS: A silk cocoon from Bombyx mori was separated into four layers of equal thickness. The layers were numbered from 1 to 4 (from the inner to the outer layer). The proteins were released by sonication of a silk mat layer in normal saline. The concentration of proteins was determined by spectrophotometry. They were incubated with RAW264.7 cells, and changes in the expression of genes were evaluated by cDNA microarray analysis and quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). RESULTS: Layer 1 and 4 groups had higher protein concentrations compared to those in layer 2 and 3 groups. The genes associated with inflammation and angiogenesis showed significantly higher expression in layer 1 and 4 groups. The results of qRT-PCR were in agreement with those of the cDNA microarray analysis. CONCLUSIONS: The silk mat from the middle portion of the silkworm cocoon yielded a lower protein release and caused an insignificant change in the expression of genes that are associated with inflammation and angiogenesis.

The Relationship Between Regional Anesthesia and Cancer: A Metaanalysis.

BACKGROUND: Some studies have suggested using epidural analgesia after cancer surgery to reduce metastasis. This article examines the relationship between regional anesthesia (RA) and cancer metastasis in an array of cancers. METHODS: We conducted a review of the literature using PubMed and included 67,577 patients across 28 studies in a metaanalysis, evaluating the hazard ratios (HRs) of overall survival, recurrence-free survival, and biochemical recurrence-free survival. RESULTS: We found no benefit to RA as it relates to cancer. The HR was 0.92 for overall survival, 1.06 for recurrence-free survival, and 1.05 for biochemical recurrence-free survival. Despite the overall analysis showing no benefit, we found some benefit when we evaluated only the randomized trials. However, we found no significant benefit of RA when we evaluated the cancers (gastrointestinal, prostate, breast, and ovarian) individually. CONCLUSION: This metaanalysis shows that RA has no overall survival, recurrence-free survival, or biochemical recurrence-free survival benefit. However, some individual studies have shown significant benefit in terms of cancer recurrence. Further, RA reduces the use of opioids, which has led to some secondary benefits. Further studies are needed to establish the benefits of RA as it relates to cancer.