Angiogenic Stimulation Research Articles

Therapeutic Potential of Secretome Hypoxia Mesenchymal Stem Cells: Downregulation of TNF-α and HIF-2α in Metabolic Syndrome-Induced Inflammation in Wistar Rats

Background: Metabolic syndrome (MetS) has become a global health challenge with several associated issues, such as obesity, insulin resistance, dyslipidemia, and hypertension. Important proteins such as Tumor Necrosis Factor-alpha (TNF-α) and Hypoxia Inducible Factor-2 alpha (HIF-2α) regulate the inflammatory process by inducing the expression of pro-inflammatory proteins. Secretome Hypoxia Mesenchymal Stem Cells (SH-MSCs) are immunomodulatory, anti-inflammatory, and angiogenic stimulators, which can regulate various inflammatory diseases, including MetS. Objective: This study aims to determine the effect of administering SH-MSCSs on the expression of the TNF-α and Hypoxia Inducible Factor (HIF)-2α genes in the male Wistar rat model with Metabolic Syndrome. Method: This research is an experimental study with a Post-test Only Control Group Design, using a total of 24 male Wistar rats divided into four groups: T1 (Healthy control), T2 (MetS + NaCl), T3 (MetS + administration of SH-MSCs dose 150 uL), and T4 (MetS + administration of SH-MSCs dose 300 uL). SH-MSCSs were administered intraperitoneally four times over 14 days. Adipose tissue TNF-α and HIF-2α gene expression were measured on day 15 using qRT-PCR. Results: TNF-α and HIF-2α gene expression was significantly lower in T3 and T4, compared with the MetS control group (T2). Conclusion: Administration of SH-MSCs was able to reduce the expression of the Tumor Necrosis Factor (TNF-α) and Hypoxia Inducible Factor (HIF)-2α genes in fatty tissue in the male Wistar rat model with Metabolic Syndrome.

A Nanocapsule System Combats Aging by Inhibiting Age-Related Angiogenesis Deficiency and Glucolipid Metabolism Disorders.

Insufficient angiogenic stimulation and dysregulated glycolipid metabolism in senescent vascular endothelial cells (VECs) constitute crucial features of vascular aging. Concomitantly, the generation of excess senescence-associated secretory phenotype (SASP) and active immune-inflammatory responses propagates within injured vessels, tissues, and organs. Until now, targeted therapies that efficiently rectify phenotypic abnormalities in senescent VECs have still been lacking. Here, we constructed a Pd/hCeO2-BMS309403@platelet membrane (PCBP) nanoheterostructured capsule system loaded with fatty acid-binding protein 4 (FABP4) inhibitors and modified with platelet membranes and investigated its therapeutic role in aged mice. PCBP showed significant maintenance in aged organs and demonstrated excellent biocompatibility. Through cyclic tail vein administration, PCBP extended the lifespan and steadily ameliorated abnormal phenotypes in aged mice, including SASP production, immune and inflammatory status, and age-related metabolic disorders. In senescent ECs, PCBP mediated the activation of vascular endothelial growth factor (VEGF) signaling and glycolysis and inhibition of FABP4 by inducing the synthesis of hypoxia-inducible factor-1α, thereby reawakening neovascularization and restoring glycolipid metabolic homeostasis. In conclusion, the PCBP nanocapsule system provides a promising avenue for interventions against aging-induced dysfunction.

Injectable hydrogel scaffold incorporating microspheres containing cobalt-doped bioactive glass for bone healing.

Injectable in situ-forming scaffolds that induce both angiogenesis and osteogenesis have been proven to be promising for bone healing applications. Here, we report the synthesis of an injectable hydrogel containing cobalt-doped bioactive glass (BG)-loaded microspheres. Silk fibroin (SF)/gelatin microspheres containing BG particles were fabricated through microfluidics. The microspheres were mixed in an injectable alginate solution, which formed an in situ hydrogel by adding CaCl2. The hydrogel was evaluated for its physicochemical properties, in vitro interactions with osteoblast-like and endothelial cells, and bone healing potential in a rat model of calvarial defect. The microspheres were well-dispersed in the hydrogel and formed pores of >100 μm. The hydrogel displayed shear-thinning behavior and modulated the cobalt release so that the optimal cobalt concentration for angiogenic stimulation, cell proliferation, and deposition of mineralized matrix was only achieved by the scaffold that contained BG doped with 5% wt/wt cobalt (A-S-G5Co). In the scaffold containing higher cobalt content, a reduced biomimetic mineralization on the surface was observed. The gene expression study indicated an upregulation of the osteogenic genes of COL1A1, ALPL, OCN, and RUNX2 and angiogenic genes of HIF1A and VEGF at different time points in the cells cultured with the A-S-G5Co. Finally, the in vivo study demonstrated that A-S-G5Co significantly promoted both angiogenesis and osteogenesis and improved bone healing after 12 weeks of follow-up. These results show that incorporation of SF/gelatin microspheres containing cobalt-doped BG in an injectable in situ-forming scaffold can effectively enhance its bone healing potential through promotion of angiogenesis and osteogenesis.

A comparative in vitro and in vivo analysis of the impact of copper substitution on the cytocompatibility, osteogenic, and angiogenic properties of a borosilicate bioactive glass.

The 0106-B1-bioactive glass (BG) composition (in wt %: 37.5 SiO2, 22.6 CaO, 5.9 Na2O, 4.0 P2O5, 12.0 K2O, 5.5 MgO, and 12.5 B2O3) has demonstrated favorable processing properties and promising bone regeneration potential. The present study aimed to evaluate the biological effects of the incorporation of highly pro-angiogenic copper (Cu) in 0106-B1-BG in vitro using human bone marrow-derived mesenchymal stromal cells (BMSCs) as well as its in vivo potential for bone regeneration. CuO was added to 0106-B1-BG in exchange for CaO, resulting in Cu-doped BG compositions containing 1.0, 2.5 and 5.0 wt % CuO (composition in wt %: 37.5 SiO2, 21.6/ 20.1/17.6 CaO, 5.9 Na2O, 4.0 P2O5, 12.0 K2O, 5.5 MgO, 12.5 B2O3, and 1.0/ 2.5/ 5.0 CuO). In vitro, the BGs' impact on the viability, proliferation, and growth patterns of BMSCs was evaluated. Analyses of protein secretion, matrix formation, and gene expression were used for the assessment of the BGs' influence on BMSCs regarding osteogenic differentiation and angiogenic stimulation. The presence of Cu improved cytocompatibility, osteogenic differentiation, and angiogenic response when compared with unmodified 0106-B1-BG in vitro. In vivo, a critical-size femoral defect in rats was filled with scaffolds made from BGs. Bone regeneration was evaluated by micro-computed tomography. Histological analysis was performed to assess bone maturation and angiogenesis. In vivo effects regarding defect closure, presence of osteoclastic cells or vascular structures in the defect were not significantly changed by the addition of Cu compared with undoped 0106-B1-BG scaffolds. Hence, while the in vitro properties of the 0106-B1-BG were significantly improved by the incorporation of Cu, further evaluation of the BG composition is necessary to transfer these effects to an in vivo setting.

A Molecular Perspective on HIF-1α and Angiogenic Stimulator Networks and Their Role in Solid Tumors: An Update.

Hypoxia-inducible factor-1α (HIF-1α) is a major transcriptional factor, which plays an important role in cellular reprogramming processes under hypoxic conditions, which facilitate solid tumors' progression. HIF-1α is directly involved in the regulation of the angiogenesis, metabolic reprogramming, and extracellular matrix remodeling of the tumor microenvironment. Therefore, an in-depth study on the role of HIF-1α in solid tumor malignancies is required to develop novel anti-cancer therapeutics. HIF-1α also plays a critical role in regulating growth factors, such as the vascular endothelial growth factor, fibroblast growth factor, and platelet-derived growth factor, in a network manner. Additionally, it plays a significant role in tumor progression and chemotherapy resistance by regulating a variety of angiogenic factors, including angiopoietin 1 and angiopoietin 2, matrix metalloproteinase, and erythropoietin, along with energy pathways. Therefore, this review attempts to provide comprehensive insight into the role of HIF-1α in the energy and angiogenesis pathways of solid tumors.

Angiogenic and immunomodulation role of ions for initial stages of bone tissue regeneration.

It is widely known that bone has intrinsic capacity to self-regenerate after injury. However, the physiological regeneration process can be impaired when there is an extensive damage. One of the main reasons is due to the inability to establish a new vascular network that ensures oxygen and nutrient diffusion, leading to a necrotic core and non-junction of bone. Initially, bone tissue engineering (BTE) emerged to use inert biomaterials to just fill bone defects, but it eventually evolved to mimic bone extracellular matrix and even stimulate bone physiological regeneration process. In this regard, the stimulation of osteogenesis has gained a lot of attention especially in the proper stimulation of angiogenesis, being critical to achieve a successful osteogenesis for bone regeneration. Besides, the immunomodulation of a pro-inflammatory environment towards an anti-inflammatory one upon scaffold implantation has been considered another key process for a proper tissue restoration. To stimulate these phases, growth factors and cytokines have been extensively used. Nonetheless, they present some drawbacks such as low stability and safety concerns. Alternatively, the use of inorganic ions has attracted higher attention due to their higher stability and therapeutic effects with low side effects. This review will first focus in giving fundamental aspects of initial bone regeneration phases, focusing mainly on inflammatory and angiogenic ones. Then, it will describe the role of different inorganic ions in modulating the immune response upon biomaterial implantation towards a restorative environment and their ability to stimulate angiogenic response for a proper scaffold vascularization and successful bone tissue restoration. STATEMENT OF SIGNIFICANCE: The impairment of bone tissue regeneration when there is excessive damage has led to different tissue engineered strategies to promote bone healing. Significant importance has been given in the immunomodulation towards an anti-inflammatory environment together with proper angiogenesis stimulation in order to achieve successful bone regeneration rather than stimulating only the osteogenic differentiation. Ions have been considered potential candidates to stimulate these events due to their high stability and therapeutic effects with low side effects compared to growth factors. However, up to now, no review has been published assembling all this information together, describing individual effects of ions on immunomodulation and angiogenic stimulation, as well as their multifunctionality or synergistic effects when combined together.

Fatter Is Better: Boosting the Vascularization of Adipose Tissue Grafts.

Adipose tissue resorption after fat grafting is a major drawback in plastic and reconstructive surgery, which is primarily caused by the insufficient blood perfusion of the grafts in the initial phase after transplantation. To overcome this problem, several promising strategies to boost the vascularization and, thus, increase survival rates of fat grafts have been developed in preclinical studies in recent years. These include the angiogenic stimulation of the grafts by growth factors and botulinum neurotoxin A, biologically active gels, and cellular enrichment, as well as the physical and pharmacological stimulation of the transplantation site. To transfer these approaches into future clinical practice, it will be necessary to establish standardized procedures for their safe application in humans. If this succeeds, the surgical outcomes of fat grafting may be markedly improved, resulting in a significant reduction of the physical and psychological stress for the patients.

Age-associated reduction in angiogenic capacity associates with impaired functions of neuropeptide Y

Impaired angiogenesis is associated with aging and several age-related pathologies, including ischemic vascular disease and delayed wound healing. However, such a reduction in angiogenic capacity could also inform therapeutic applications aiming at inhibiting tumor vascularization. Neuropeptide Y (NPY) and its Y receptors (Rs) - Y2R and Y5R - have been implicated in angiogenic responses associated with cardiovascular disease and cancer. Yet, changes in the NPY system associated with aging are not clear. Therefore, we sought to determine whether alterations in the NPY system are involved in age-associated impairment of angiogenesis. We hypothesized that NPY-mediated angiogenesis is diminished with age due to downregulation of the peptide, its receptors, and converting enzyme - cleaving full-length NPY to a Y2R agonist, as well as downstream signaling pathways. To test our hypothesis, the angiogenic profiles of human microvascular endothelial cells (HMVECs) from 24- and 90-year-old subjects were assessed via proliferation and mRNA expression. This analysis included dose-response and cross-inhibition assays with NPY, fibroblast growth factor 2 (FGF2), and vascular endothelial growth factor (VEGF) systems. Also, basal plasma levels of NPY were compared in old (24 months) and young (3 months) Balb/c mice. Further, NPY-mediated aortic sprouting was assessed in Y2R knockout (KO) mice. Angiogenic stimulation via NPY, FGF, and VEGF was observed in HMVECs from both age groups, with lower basal proliferation levels and less responsiveness to all three factors in aged HMVECs (p<0.05). While qRT-PCR analysis revealed no differences in basal expression of the NPY system, Y2R and DPPIV were induced by NPY in young HMVECs only. These results suggest that the decreased responsiveness of aged HMVECs to NPY stimulation is caused by impairment of NPY receptor function and/or signaling pathways. NPY stimulation increased mRNA expression of FGF2, FGFR1 and 2, and VEGFR2 in young HMVECs only. Further, anti-FGF2 neutralizing antibody and VEGFR2/Fc chimera, which is a potent VEGF antagonist, blocked the mitogenic effect of NPY in HMVECs from both age groups; while NPY receptor antagonists had no effect on HMVEC proliferation stimulated by FGF2 and VEGF (p<0.05). Moreover, despite completely impaired NPY-induced sprouting of Y2KO aortic rings, the response to FGF2 and VEGF remained intact. These data indicate that the FGF2 and VEGF pathways mediate angiogenic activities of NPY. In summary, our results show age-associated impairment of NPY-induced angiogenesis is due to a diminished mitogenic response of endothelium to the peptide via loss of induction of its angiogenic Y2R and DPPIV. This is also associated with reduced stimulation of downstream FGF2 and VEGF signaling. Future studies will determine if impaired angiogenesis in aging can be rescued with stimulation of the NPY angiogenic system and how these manipulations can improve revascularization of ischemic tissue. NIH R03 AG-20795 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Elabela and Apelin regulate coronary angiogenesis in a competitive manner.

APJ, a G-protein coupled receptor, regulates coronary angiogenesis in the developing mouse heart. However, the exact mechanism by which APJ regulates coronary angiogenesis from its dual ligands, ELABELA and APELIN, is unclear. Our study show that ELABELA and APELIN both stimulate angiogenic activities such as proliferation and sprouting outgrowth in explant cultures. We found APELIN to be a more robust angiogenic stimulant compared to ELABELA. When explant cultures were stimulated by both ligands together, we found that ELABELA repress the angiogenic activity of APELIN. Collectively, we show that ELABELA and APELIN regulate coronary angiogenesis in a competitive manner.

Molecular machineries of ciliogenesis, cell survival, and vasculogenesis are differentially expressed during regeneration in explants of the demosponge Halichondria panicea

Sponges are interesting animal models for regeneration studies, since even from dissociated cells, they are able to regenerate completely. In particular, explants are model systems that can be applied to many sponge species, since small fragments of sponges can regenerate all elements of the adult, including the oscula and the ability to pump water. The morphological aspects of regeneration in sponges are relatively well known, but the molecular machinery is only now starting to be elucidated for some sponge species. Here, we have used an explant system of the demosponge Halichondria panicea to understand the molecular machinery deployed during regeneration of the aquiferous system. We sequenced the transcriptomes of four replicates of the 5–day explant without an osculum (NOE), four replicates of the 17–18–day explant with a single osculum and pumping activity (PE) and also four replicates of field–collected individuals with regular pumping activity (PA), and performed differential gene expression analysis. We also described the morphology of NOE and PE samples using light and electron microscopy. Our results showed a highly disorganised mesohyl and disarranged aquiferous system in NOE that is coupled with upregulated pathways of ciliogenesis, organisation of the ECM, and cell proliferation and survival. Once the osculum is formed, genes involved in “response to stimulus in other organisms” were upregulated. Interestingly, the main molecular machinery of vasculogenesis described in vertebrates was activated during the regeneration of the aquiferous system. Notably, vasculogenesis markers were upregulated when the tissue was disorganised and about to start forming canals (NOE) and angiogenic stimulators and ECM remodelling machineries were differentially expressed once the aquiferous system was in place (PE and PA). Our results are fundamental to better understanding the molecular mechanisms involved in the formation of the aquiferous system in sponges, and its similarities with the early onset of blood-vessel formation in animal evolution.

ZIF@VO2 as an Intelligent Nano-Reactor for On-Demand Angiogenesis and Disinfection.

Absent angiogenesis and bacterial infection are two major challenges that simultaneously delay the repair of injured tissues and organs. However, most current therapeutic systems deliver therapeutic cues in a separate and inaccurate manner which stimulates angiogenesis or inhibits infection leading to limited repair and side effects. Advanced therapeutic systems capable of providing accurate angiogenic stimulation and anti-infection signals in response to the changing microenvironment are urgently needed. Herein, a nano-reactor (ZFVO) involving zeolitic imidazolate framework-67 (ZIF-67)-deposited hollow vanadium oxide (VO2 ) is developed to intelligently execute pro-angiogenesis and/or disinfection via the responsive release of cobalt ions and hydroxyl radicals to the injury and infection sites, respectively. ZFVO nano-reactor demonstrates a novel strategy for constructing drug-free nano-platforms with a hierarchical structure which has potential for the accurate treatment of trauma and orthopedic diseases.

Cellular loci involved in the development of brain arteriovenous malformations.

Brain arteriovenous malformations (bAVMs) are abnormal vessels that are prone to rupture, causing life-threatening intracranial bleeding. The mechanism of bAVM formation is poorly understood. Nevertheless, animal studies revealed that gene mutation in endothelial cells (ECs) and angiogenic stimulation are necessary for bAVM initiation. Evidence collected through analyzing bAVM specimens of human and mouse models indicate that cells other than ECs also are involved in bAVM pathogenesis. Both human and mouse bAVMs vessels showed lower mural cell-coverage, suggesting a role of pericytes and vascular smooth muscle cells (vSMCs) in bAVM pathogenesis. Perivascular astrocytes also are important in maintaining cerebral vascular function and take part in bAVM development. Furthermore, higher inflammatory cytokines in bAVM tissue and blood demonstrate the contribution of inflammatory cells in bAVM progression, and rupture. The goal of this paper is to provide our current understanding of the roles of different cellular loci in bAVM pathogenesis.

Medical Grade Honey as a Promising Treatment to Improve Ovarian Tissue Transplantation.

Ovarian tissue cryopreservation is a female fertility preservation technique that presents major challenges for the maintenance of follicular viability after transplantation. The aim of this study was to evaluate and compare the application of L-Mesitran Soft®, a product containing 40% medical grade honey (MGH), with other strategies to improve ovarian grafts’ viability. For this purpose, bovine ovarian tissue was vitrified, warmed and randomly assigned to culture groups: (1) control, (2) MGH 0.2% in vitro, (3) MGH in vivo (direct application in the xenotransplantation), (4) vascular endothelial growth factor (VEGF 50 ng/mL) and (5) vitamin D (100 Nm), during a 48 h period. A sixth group (6) of fragments was thawed on transplantation day and was not cultured. The tissue was xenotransplanted into immunodeficient (Rowett nude homozygous) ovariectomized rats. Grafts were analyzed 48 h after culture, and 7 and 28 days after transplantation. The tissue was subjected to histological and immunohistochemical analysis. Treatments using MGH showed the highest angiogenic and cell proliferation stimulation, with cellular apoptosis, within a healthy cellular turnover pathway. In conclusion, MGH should be considered as a potentially effective and less expensive strategy to improve ovarian tissue transplantation.

VEGF-A and FGF4 Engineered C2C12 Myoblasts and Angiogenesis in the Chick Chorioallantoic Membrane.

Angiogenesis is the formation of new blood vessels from pre-existing vessels. Adequate oxygen transport and waste removal are necessary for tissue homeostasis. Restrictions in blood supply can lead to ischaemia which can contribute to disease pathology. Vascular endothelial growth factor (VEGF) is essential in angiogenesis and myogenesis, making it an ideal candidate for angiogenic and myogenic stimulation in muscle. We established C2C12 mouse myoblast cell lines which stably express elevated levels of (i) human VEGF-A and (ii) dual human FGF4-VEGF-A. Both stably transfected cells secreted increased amounts of human VEGF-A compared to non-transfected cells, with the latter greater than the former. In vitro, conditioned media from engineered cells resulted in a significant increase in endothelial cell proliferation, migration, and tube formation. In vivo, this conditioned media produced a 1.5-fold increase in angiogenesis in the chick chorioallantoic membrane (CAM) assay. Delivery of the engineered myoblasts on Matrigel demonstrated continued biological activity by eliciting an almost 2-fold increase in angiogenic response when applied directly to the CAM assay. These studies qualify the use of genetically modified myoblasts in therapeutic angiogenesis for the treatment of muscle diseases associated with vascular defects.

P-383 Endometrial scratching: A strategy to stimulate the angiogenesis aspect of implantation in unexplained, repeated implantation failure

Abstract Study question Does endometrial scratching serve as an angiogenic stimulator during implantation in unexplained, repeated implantation failure (uRIF) patients? Summary answer Endometrial scratching can reimburse and regulate genes involved in both endometrial angiogenesis and receptivity. What is known already The vascular endothelial growth factor (VEGF), as an angiogenic factor, is well-known for its function in a variety of physiological and pathological aspects of female reproduction. Following the embryo transfer in the In-Vitro Fertilization cycles, the most challenging clinical obstacle to overcome is RIF. Endometrial scratching is a technique considered as an option for enhancing the embryo implantation of uRIF patients by modulating the different cellular and molecular components regulating endometrial receptivity before and during implantation. Study design, size, duration Twenty uRIF patients were enrolled based on a randomized controlled trial (RCT) to study the expression of genes involved in endometrial angiogenesis and receptivity functions (VEGFR1, VEGFR2, COL18A1, E-cadherin, FGF1) following ES. Ten uRIF patients were randomly assigned to the intervention group (twice endometrial sampling in the follicular and luteal phases) and ten in the control group (only luteal phase sampling) prior to the ovarian stimulation cycle. Participants/materials, setting, methods Women who failed to conceive following three or more IVF/ICSI cycles, high-quality embryo transfer, and at least one blastocyst embryo transfer cycle met the inclusion criteria. Post-biopsy endometrial samples were divided evenly. One component was placed in 10% formalin for histology dating and another in RNALater for genomic analysis and preserved at -80 °C for RNA extraction. Main results and the role of chance The expression levels of VEGFR1 and VEGFR2 (both as the receptors of VEGF) were significantly increased after ES (P <0.05). The mRNA expression level of COL18A1 was significantly decreased after ES. COL18A1 is an inhibitor of VEGF which can impede VEGF-mediated signaling and endothelial cell proliferation, via blocking of its receptor specifically VEGFR2. The E-cadherin expression level was significantly decreased (P <0.05) in the endometrium of the intervention group after scratching. E-cadherin is a cell-cell adhesion molecule that has a pivotal role in maintaining normal epithelial architecture, establishing cell polarity, glandular differentiation, and morphogenesis. Data showed that Fibroblast Growth Factor1 (FGF1) expression level was significantly increased in the intervention group (P <0.05). FGF1 promotes the formation of blood vessels which improves endometrial trophoblastic interaction and affects embryo implantation. Limitations, reasons for caution To further understand the function of these changes, it is preferable to compare the data with endometrium from a fertile group, which is ongoing. Wider implications of the findings On the timeline of embryo implantation, angiogenic factors (e.g., VEGFR1 and VEGFR2), their inhibitors (e.g., E-cadherin and COL18A1), and activators (e.g., FGF1) work together to establish a dynamic environment responsible for endometrial receptivity, which has been compromised in the endometrium of RIF patients.ES can reimburse and regulate these angiogenesis processes. Trial registration number IRCT20210316050723N1

Targeting SMYD2 inhibits angiogenesis and increases the efficiency of apatinib by suppressing EGFL7 in colorectal cancer.

Angiogenesis is an essential factor affecting the occurrence and development of solid tumors. SET And MYND Domain Containing 2 (SMYD2) serves as an oncogene in various cancers. However, whether SMYD2 is involved in tumor angiogenesis remains unclear. Here, we report that SMYD2 expression is associated with microvessel density in colorectal cancer (CRC) tissues. SMYD2 promotes CRC angiogenesis in vitro and in vivo. Mechanistically, SMYD2 physically interacts with HNRNPK and mediates lysine monomethylation at K422 of HNRNPK, which substantially increases RNA binding activity. HNRNPK acts by binding and stabilizing EGFL7 mRNA. As an angiogenic stimulant, EGFL7 enhances CRC angiogenesis. H3K4me3 maintained by PHF8 mediates the abnormal overexpression of SMYD2 in CRC. Moreover, targeting SMYD2 blocks CRC angiogenesis in tumor xenografts. Treatment with BAY-598, a functional inhibitor of SMYD2, can also synergize with apatinib in patient-derived xenografts. Overall, our findings reveal a new regulatory axis of CRC angiogenesis and provide a potential strategy for antiangiogenic therapy.

Expression of vimentin, TPI and MAT2A in human dermal microvascular endothelial cells during angiogenesis in vitro.

IntroductionIn vitro assays of angiogenesis face immense problems considering their reproducibility based on the inhomogeneous characters of endothelial cells (ECs). It is necessary to detect influencing factors, which affect the angiogenic potency of ECs.ObjectiveThis study aimed to analyse expression profiles of vimentin (VIM), triosephosphate isomerase (TPI) and adenosylmethionine synthetase isoform type–2 (MAT2A) during the whole angiogenic cascade in vitro. Furthermore, the impact of knocking down vimentin (VIM) on angiogenesis in vitro was evaluated, while monitoring TPI and MAT2A expression.MethodsA long–term cultivation and angiogenic stimulation of human dermal microvascular ECs was performed. Cells were characterized via VEGFR–1 and VEGFR–2 expression and a shRNA–mediated knockdown of VIM was performed. The process of angiogenesis in vitro was quantified via morphological staging and mRNA–and protein–levels of all proteins were analysed.ResultsWhile native cells ran through the angiogenic cascade chronologically, knockdown cells only entered beginning stages of angiogenesis and died eventually. Cell cultures showing a higher VEGFR–1 expression survived exclusively and displayed an upregulation of MAT2A and TPI expression. Native cells highly expressed VIM in early stages, MAT2A mainly in the beginning and TPI during the course of angiogenesis in vitro.ConclusionVIM knockdown led to a deceleration of angiogenesis in vitro and knockdown cells displayed expressional changes in TPI and MAT2A. Cell populations with a higher number of stalk cells emerged as being more stable against manipulations and native expression profiles provided an indication of VIM and MAT2A being relevant predominantly in beginning stages and TPI during the whole angiogenic cascade in vitro.

Cuscuta Chinensis potentiate the effect of methotrexate in Rheumatoid Arthritis Induced Rats.

Background Rheumatoid arthritis (RA) is a chronic destructive inflammatory disease related to a breakdown in immune tolerance. This disease is characterized by joint inflammation, swelling, and in severe cases deformation may occur. Cuscuta Chinensis (C. Chinensis) is a parasitic plant, grow around other plants to absorb nutrient and water from them. C. Chinensis has a wide range of chemicals that produce a wide range of pharmacological activates. Because of its anti-oxidant and anti-inflammatory effect, it was considered as a good candidate to assess its role in RA. Methods: Rheumatoid arthritis was induced by injection of Complete Freund’s Adjuvant inside the foot-pad of male albino rats. The animals were grouped in four groups as follows group 1 considered as a normal control group, group 2 consider as positive control arthritis, group 3 treated with methotrexate (MTX), group 4 treated with MTX and C. Chinensis extract. On day 14 of immunization, treatments began and last for 21 days, at the end of the experiment all animals were sacrificed and serum was collected. The serum markers that had been evaluated were MMP3, VEGF, and SOD. Throughout the experiment time the body weight was evaluated. Results The combination significantly (P-value ≤ 0.05) improves objective parameter of RA which was the body weight. Also significantly decrease (P-value ≤ 0.05) the serum level of MMP3, VEGF, and considerably increase serum SOD. Conclusion: The combination has a significant beneficial role in suppression of destructive enzyme (MMP3), angiogenic stimulators (VEGF), and increase serum SOD enzyme.

Elucidating the role of hypoxia-inducible factor in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic multifactorial disease, provocative, and degenerative autoimmune condition that impacts millions of individuals around the globe. As a result of this understanding, anti-inflammatory drugs have been created, perhaps widely effective (like steroids) and highly specialized methods (including anti-TNF antibody) using biological therapies (including TNF inhibitors). Despite this, the connections between inflammatory response, articular development, and intracellular responsiveness to changes in oxygen concentration are undervalued in rheumatoid arthritis. Hypoxia, or a lack of oxygen, is thought to cause enhanced synovial angiogenesis in RA, which is mediated by some of the hypoxia-inducible factors like vascular endothelial growth factor (VEGF). Substantial genetic alterations occur when the HIF regulatory factors signaling cycle is activated, allowing organelles, tissues, and species to acclimatize to decreasing oxygen saturation. The most well-characterized hypoxia-responsive transcripts are the angiogenic stimulant VEGF, whose production is greatly elevated by hypoxia in several types of cells, especially RA synovium fibroblasts. Blocking vascular endothelial growth factors has been demonstrated to be helpful in murine models of rheumatism, indicating how hypoxia could trigger the angiogenesis process, resulting in the progression of RA. These mechanisms highlight the intimate affiliation amongst hypoxia, angiogenesis, and inflammation in rheumatoid arthritis. This review will look at how hypoxia activates molecular pathways and how other pathways involving inflammatory signals develop and sustain synovitis in rheumatoid arthritis.

Placental vascularization in middle and late gestation in the pig.

The aims of this study were to determine the changes in the capillary area density in relation to fetal development, to determine immunoexpression of angiogenic factors and to compare their mRNA expression throughout pig gestation. Samples were collected from the maternal-chorioallantoic interface at days 40, 77, 85 and 114 of pregnancy for immunohistochemistry analysis and the measurement of mRNA expression of VEGFA, ANGPT1, ANGPT2, FGF2 and its receptors KDR, TEK, FGFR1, FGFR2respectively. Morphometric measurement of blood vessels was performed. We found a significant increase in capillary area density throughout gestation (P< 0.05). On the maternal side, at day 77, we observed a significant increase in the number of vessels from small vascular areas (P < 0.05) and the vascular area was significantly higher on day 85 (P < 0.05). On the fetal side, the number of vessels and the vascular area increased between days 40 and 77 (P < 0.05) and between days 77 and 114 (P < 0.05), respectively. Immunohistochemical findings revealed intense VEGFA staining and a trend for increased expression towards the end of gestation (P < 0.05). We also demonstrated a high VEGFA, FGF2, FGFR1, ANGPT1 and ANGPT2mRNA expression at day 77 (P < 0.05). In conclusion, our findings suggest that an active angiogenesis would be present even until late-middle gestation at day 77 of pregnancy with the predominance of angiogenic stimulation by VEGFA/KDR, FGF2/FGFR1 and a balance between ANGPT1 and ANGPT2/TEK.Lay summaryCritical moments occur at different stages of placental formation in pigs, where the expression of angiogenic factors, that is, molecules that stimulate the formation of blood vessels must be adequate to promote their development. This exchange is necessary to cover the increasing nutritional demands of fetuses in continuous development. Determining the changes in the area of capillary density in relation to fetal development and the expression of angiogenic factors throughout pregnancy in pigs could contribute to understanding the causes of fetal loss. Placental samples were obtained at gestational days 40, 77, 85 and 114 (n = 7, 10, 7 and 5, respectively). We found that the capillary area density increases accompanying fetal growth with advancing gestation and an increase in capillary area density in late-middle gestation, around day 77, is due to the expansion in the number of small blood vessels on the maternal side. The present findings suggest that an intense angiogenesis would be present even until late-middle gestation at day 77 of pregnancy, with the predominance of angiogenic stimulation by specific molecules that promote this process.