VEGF non-angiogenic functions in adult organ homeostasis: therapeutic implications

Platelet rich plasma versus Carboxytherapy in the treatment of Periorbital dark circles: A split-face study

BACKGROUND

Periorbital hyperpigmentation is a recurrent problem in dermatologic clinics that affect the patients' quality of life and their psychological status. Platelet-rich plasma (PRP) may serve as a source of different growth factors which may reduce the pigmentation in this problem. Carboxytherapy is carbon dioxide infusion into human tissue for therapeutic purposes.

OBJECTIVE

to evaluate and compare the clinical efficacy of PRP and carboxytherapy in the treatment of periorbital dark circles (PODC). Histopathological evaluation was also done.

PATIENTS AND METHODS

Split-face study of 23 patients with PODC treated with PRP at the right side and carboxytherapy at the left side. Patients received four sessions; one session/week. Final follow-up evaluation was done 3 months after the last session by clinical and histopathological assessment.

RESULTS

PRP showed significant better response (p=0.002), shorter downtime and tolerable side effects than caboxytherapy. Reduction in area percent of melanin after PRP injections showed 46.6% improvement, while after carboxytherapy, it showed only 14.3% improvement.

CONCLUSION

The present study had showed that PRP is more effective and tolerable than caboxytherapy in the treatment of PODC.

Photobiomodulation therapy does not depend on the differentiation of dental pulp cells to enhance functional activity associated with angiogenesis and mineralization

The purpose of this study is to analyze the influence of InGaAlP diode laser (660 nm) with or without an odontogenic medium (OM) in the functional activity of OD-21 cells. Undifferentiated OD-21 pulp cells were cultivated with or without OM and divided into four groups (n = 5): nonirradiated control (C -), nonirradiated + OM (C +), irradiated (L -), and irradiated + OM (L +). Laser application was performed in two sessions of a 24-h interval with an irradiance of 11.3 mW/cm2, energy density of 1 J/cm², and total cumulative energy/well of 4.6 J. Cell proliferation, VEGF-164 expression, mineralization, and expression of Alp, Runx2, and Dmp1 genes, as well as immunolocalization of RUNX2 and MEPE proteins, were evaluated. Data were analyzed by statistical tests (α = 0.05). All studied groups showed a similar increase in cell proliferation with or without OM. After 7 and 10 days, a significatively higher concentration of VEGF-164 in L - group when compared to C - group was observed. A significant increase in mineralized nodules in the L + was noted when compared to C + in the same conditions. Photobiomodulation upregulated significantly Runx2 and Dmp1 expression after 10 days in L - and after 7 days in L + , with downregulation of Dmp1 after 10 days in L + group. Immunolocalization of RUNX2 and MEPE was expressive after 7 days of culture in the cytoplasm adjacent to the nucleus with a decrease after 10 days, regardless of the presence of OM. Photobiomodulation enhances metabolism associated with angiogenesis, gene expression, and mineralization regardless of the odontogenic medium in OD-21 cells.

Autologous microfragmented adipose tissue reduces inflammatory and catabolic markers in supraspinatus tendon cells derived from patients affected by rotator cuff tears

PURPOSE

Rotator cuff tears are common musculoskeletal disorders, and surgical repair is characterized by a high rate of re-tear. Regenerative medicine strategies, in particular mesenchymal stem cell-based therapies, have been proposed to enhance tendon healing and reduce the re-tear rate. Autologous microfragmented adipose tissue (μFAT) allows for the clinical application of cell therapies and showed the ability to improve tenocyte proliferation and viability in previous in vitro assessments. The hypothesis of this study is that μFAT paracrine action would reduce the catabolic and inflammatory marker expression in tendon cells (TCs) derived from injured supraspinatus tendon (SST).

METHODS

TCs derived from injured SST were co-cultured with autologous μFAT in transwell for 48 h. Metabolic activity, DNA content, the content of soluble mediators in the media, and the gene expression of tendon-specific, inflammatory, and catabolic markers were analyzed.

RESULTS

μFAT-treated TCs showed a reduced expression of PTGS2 and MMP-3 with respect to untreated controls. Increased IL-1Ra, VEGF, and IL-6 content were observed in the media of μFAT-treated samples, in comparison with untreated TCs.

CONCLUSION

μFAT exerted an anti-inflammatory action on supraspinatus tendon cells in vitro through paracrine action, resulting in the reduction of catabolic and inflammatory marker expression. These observations potentially support the use of μFAT as adjuvant therapy in the treatment of rotator cuff disease.

Insights into the dual role of angiogenesis following stroke

Stroke remains a major cause of serious disability due to the brain's limited capacity to regenerate. Current treatments focus on acute recanalization of the occluded blood vessels; however, currently there are no approved therapy options to regenerate neural circuits and reduce stroke-related disability. To promote recovery, therapeutic angiogenesis has been proposed as a promising target. Although restoration of blood vessels providing oxygen and nutrients to the peri-infarct regions may be beneficial, newly generated capillaries may also carry pathophysiological risk factors that need to be considered. One major concern are adverse effects including edema formation and haemorrhagic transformation due to the comprised endothelial barrier function during vascular remodelling. This brief opinion article will discuss the challenges and the newest advancements of angiogenesis as a therapeutic strategy for ischemic stroke.

Apratoxin S4 Inspired by a Marine Natural Product, a New Treatment Option for Ocular Angiogenic Diseases

Purpose

Abnormal blood vessel formation is a defining feature of many blinding eye diseases. Targeting abnormal angiogenesis by inhibiting VEGF has revolutionized the treatment of many ocular angiogenic diseases over the last decade. However, a substantial number of patients are refractory to anti-VEGF treatment or may develop resistance over time. The objective of this study was to determine the efficacy and the mechanism of action of Apratoxin S4 in ocular angiogenesis.

Methods

Retinal vascular cell proliferation, migration, and the ability to form tube-like structure were studied in vitro. Ex vivo aortic ring, choroid, and metatarsal assays were used to study Apratoxin S4's impact on vessel outgrowth in a multicellular environment. Apratoxin S4 was also tested in mouse models of oxygen-induced retinopathy (OIR) and laser-induced choroidal neovascularization (CNV), and in a rabbit model of persistent retinal neovascularization (PRNV). Western blot and ELISA were used to determine the expression of key angiogenic regulators after Apratoxin S4 treatment.

Results

Apratoxin S4 strongly inhibits retinal vascular cell activation by suppressing multiple angiogenic pathways. VEGF-activated vascular cells and angiogenic vessels are more susceptible to Apratoxin S4 treatment than quiescent vascular cells and vessels. Both intraperitoneal and intravitreal delivery of Apratoxin S4 are able to impede ocular neovascularization in vivo. Apratoxin S4 specifically attenuates pathological ocular angiogenesis and exhibits a combinatorial inhibitory effect with standard-of-care VEGF inhibitor drug (aflibercept).

Conclusions

Apratoxin S4 is a potent antiangiogenic drug that inhibits the activation of retinal endothelial cells and pericytes through mediating multiple angiogenic pathways.

Autologous Microfragmented Adipose Tissue Reduces the Catabolic and Fibrosis Response in an In Vitro Model of Tendon Cell Inflammation

Background

Mesenchymal stem cells (MSCs) emerged as a promising therapy for tendon pathologies. Microfragmented adipose tissue (μFAT) represents a convenient autologous product for the application of MSC-based therapies in the clinical setting. In the present study, the ability of μFAT to counteract inflammatory processes induced by IL-1β on human tendon cells (TCs) was evaluated.

Methods

Cell viability and proliferation were evaluated after 48 hours of transwell coculture of TCs and autologous μFAT in the presence or absence of IL-1β. Gene expression of scleraxis, collagen type I and type III, metalloproteinases-1 and -3, and cyclooxygenase-2 was evaluated by real-time RT-PCR. The content of VEGF, IL-1Ra, TNFα, and IL-6 was evaluated by ELISA.

Results

IL-1β-treated TCs showed augmented collagen type III, metalloproteases, and cyclooxygenase-2 expression. μFAT was able to reduce the expression of collagen type III and metalloproteases-1 in a significant manner, and at the same time, it enhanced the production of VEGF, IL-1Ra, and IL-6.

Conclusions

In this in vitro model of tendon cell inflammation, the paracrine action of μFAT, exerted by anti-inflammatory molecules and growth factors, was able to inhibit the expression of fibrosis and catabolic markers. Then, these results suggest that the application of μFAT may represent an effective conservative or adjuvant therapy for the treatment of tendon disorders.

VEGF-like protein from Apostichopus japonicus promotes cell proliferation and migration

Vascular endothelial growth factor (VEGF) is a key conservative regulator of inflammation response by promoting cell proliferation, migration, and vascular permeability. It also induces the release of inflammatory factors in vertebrates. We previously characterized NLR family pyrin domain containing 3 and HMGB3 homology in Apostichopus japonicus, providing the occurrence of inflammation in this species. However, to our knowledge, other inflammation-related molecules, such as VEGF, have rarely been investigated. In the present study, a novel VEGF homolog was identified from A. japonicus (designated as AjVEGF) by rapid amplification of cDNA ends. Full-length cDNA of AjVEGF was 3181 bp with a putative open reading frame of 1752 bp encoding 583 amino acid (aa) residue protein. Structural analysis revealed that AjVEGF processed characteristic VEGF domains of platelet-derived growth factor domain (132-232 aa) and CXC domain (223-270 aa). Multiple sequence alignment and phylogenetic analysis both supported that AjVEGF belongs to a new member of VEGF protein subfamily. Both Vibrio splendidus challenge in vivo and lipopolysaccharide stimulation in vitro could significantly upregulate mRNA expression of AjVEGF compared with the control group. Functional analysis indicated that recombinant AjVEGF promoted coelomocyte proliferation and migration not only in sea cucumber but also in human colorectal adenocarcinoma cells (HT29). This consistent function was also detected for human VEGFs. Taken together, these findings suggest that AjVEGF has a similar function of VEGF in higher animals and might serve as a candidate cytokine in sea cucumber inflammation.

Myosin VI and cardiomyopathy: Left ventricular hypertrophy, fibrosis, and both cardiac and pulmonary vascular endothelial cell defects in the Snell's waltzer mouse

In mice and humans, loss of myosin VI (Myo6) function results in deafness, and certain Myo6 mutations also result in cardiomyopathies in humans. The current studies have utilized the Snell's waltzer (sv) mouse (a functional null mutation for Myo6) to determine if this mouse also exhibits cardiac defects and thus used to determine the cellular and molecular basis for Myo6-associated heart disease. Myo6 is expressed in mouse heart where it is predominantly expressed in vascular endothelial cells (VECs) based on co-localization with the VEC cell marker CD31. Sv/sv heart mass is significantly greater than that of sv/+ littermates, a result of left ventricle hypertrophy. The left ventricle of the sv/sv exhibits extensive fibrosis, both interstitial and perivascular, based on histologic staining, and immunolocalization of several markers for fibrosis including fibronectin, collagen IV, and the fibroblast marker vimentin. Myo6 is also expressed in lung VECs but not in VECs of intestine, kidney, or liver. Sv/sv lungs exhibit increased periaveolar fibrosis and enlarged air sacs. Electron microscopy of sv/sv cardiac and lung VECs revealed abnormal ultrastructure, including luminal protrusions and increased numbers of cytoplasmic vesicles. Previous studies have shown that loss of function of either Myo6 or its adaptor binding partner synectin/GIPC results in impaired arterial development due to defects in VEGF signaling. However, examination of synectin/GIPC-/- heart revealed no fibrosis or significantly altered VEC ultrastructure, suggesting that the cardiac and lung defects observed in the sv/sv mouse are not due to Myo6 function in arterial development.

Anti-angiogenic alternatives to VEGF blockade

Angiogenesis is a major requirement for tumour formation and development. Anti-angiogenic treatments aim to starve the tumour of nutrients and oxygen and also guard against metastasis. The main anti-angiogenic agents to date have focused on blocking the pro-angiogenic vascular endothelial growth factors (VEGFs). While this approach has seen some success and has provided a proof of principle that such anti-angiogenic agents can be used as treatment, the overall outcome of VEGF blockade has been somewhat disappointing. There is a current need for new strategies in inhibiting tumour angiogenesis; this article will review current and historical examples in blocking various membrane receptors and components of the extracellular matrix important in angiogenesis. Targeting these newly discovered pro-angiogenic proteins could provide novel strategies for cancer therapy.

The role IL-1 in tumor-mediated angiogenesis

Tumor angiogenesis is one of the hallmarks of tumor progression and is essential for invasiveness and metastasis. Myeloid inflammatory cells, such as immature myeloid precursor cells, also termed myeloid-derived suppressor cells (MDSCs), neutrophils, and monocytes/macrophages, are recruited to the tumor microenvironment by factors released by the malignant cells that are subsequently “educated” in situ to acquire a pro-invasive, pro-angiogenic, and immunosuppressive phenotype. The proximity of myeloid cells to endothelial cells (ECs) lining blood vessels suggests that they play an important role in the angiogenic response, possibly by secreting a network of cytokines/chemokines and inflammatory mediators, as well as via activation of ECs for proliferation and secretion of pro-angiogenic factors. Interleukin-1 (IL-1) is an “alarm,” upstream, pro-inflammatory cytokine that is generated primarily by myeloid cells. IL-1 initiates and propagates inflammation, mainly by inducing a local cytokine network and enhancing inflammatory cell infiltration to affected sites and by augmenting adhesion molecule expression on ECs and leukocytes. Pro-inflammatory mediators were recently shown to play an important role in tumor-mediated angiogenesis and blocking their function may suppress tumor progression. In this review, we summarize the interactions between IL-1 and other pro-angiogenic factors during normal and pathological conditions. In addition, the feasibility of IL-1 neutralization approaches for anti-cancer therapy is discussed.

Platelet rich plasma extract promotes angiogenesis through the angiopoietin1-Tie2 pathway

Development and regeneration of tissues and organs require precise coordination among endothelial, epithelial and mesenchymal morphogenesis. Angiogenesis plays key roles in normal development, wound healing, recovery from ischemic disease, and organ regeneration. It has been recognized that the combination of various angiogenic factors in an appropriate physiological ratio is critical for long-term functional blood vessel formation. Here we show that mouse soluble platelet-rich-plasma (PRP) extract, which includes abundant angiopoetin-1 (Ang1) and other angiogenic factors, stimulates endothelial cell growth, migration and differentiation in cultured human dermal microvascular endothelial cells in vitro and neonatal mouse retinal angiogenesis in vivo. Mouse platelet rich fibrin (PRF) matrix, the three-dimensional fibrin matrix that releases angiogenic factors with similar concentrations and proportions to the PRP extract, also recapitulates robust angiogenesis inside the matrix when implanted subcutaneously on the living mouse. Inhibition of Ang1-Tie2 signaling suppresses PRP extract-induced angiogenesis in vitro and angiogenic ability of the PRF matrix in vivo. Since human PRP extract and PRF matrix can be prepared from autologous peripheral blood, our findings may lead to the development of novel therapeutic interventions for various angiogenesis-related diseases as well as to the improvement of strategies for tissue engineering and organ regeneration.

Recombinant sea urchin vascular endothelial growth factor directs single-crystal growth and branching in vitro

Biomineralization in sea urchin embryos is a crystal growth process that results in oriented single-crystalline spicules with a complex branching shape and smoothly curving surfaces. Uniquely, the primary mesenchyme cells (PMCs) that construct the endoskeleton can be cultured in vitro. However, in the absence of morphogenetic cues secreted by other cells in the embryo, spicules deposited in PMC culture lack the complex branching behavior observed in the embryo. Herein we demonstrate that recombinant sea urchin vascular endothelial growth factor (rVEGF), a signaling molecule that interacts with a cell-surface receptor, induces spiculogenesis and controls the spicule shape in PMC culture. Depending on the rVEGF concentration, PMCs deposit linear, "h"- and "H"-shaped, or triradiate spicules. Remarkably, the change from linear to triradiate occurs with a switch from bidirectional crystal growth parallel to the calcite c axis to growth along the three a axes. This finding has implications for our understanding of how cells integrate morphogenesis on the multi-micrometer scale with control over lattice orientation on the atomic scale. The PMC model system is uniquely suited to investigate this mechanism and develop biotechnological approaches to single-crystal growth.

Signaling required for blood vessel maintenance: molecular basis and pathological manifestations

As our understanding of molecular mechanisms leading to vascular formation increases, vessel maintenance including stabilization of new vessels and prevention of vessel regression began to be considered as an active process that requires specific cellular signaling. While signaling pathways such as VEGF, FGF, and angiopoietin-Tie2 are important for endothelial cell survival and junction stabilization, PDGF and TGF-β signaling modify mural cell (vascular smooth muscle cells and pericytes) functions, thus they fortify vessel integrity. Breakdown of these signaling systems results in pathological hyperpermeability and/or genetic vascular abnormalities such as vascular malformations, ultimately progressing to hemorrhage and edema. Hence, blood vessel maintenance is fundamental to controlling vascular homeostasis and tissue functions. This paper discusses signaling pathways essential for vascular maintenance and clinical conditions caused by deterioration of vessel integrity.

Relationships among the concentrations of 25 inflammation-associated proteins during the first postnatal weeks in the blood of infants born before the 28th week of gestation

BACKGROUND

Inflammation appears to be involved in processes leading to organ damage in preterm newborns, yet little is known about the relationships among elevated concentrations of inflammation-associated proteins in the blood of preterm newborns.

METHODS

In this exploratory study, we used an electrochemiluminescence method to measure 25 proteins in blood obtained on postnatal day 1 (range 1-3), day 7 (range 5-8), and day 14 (range 12-15) from 939 children born before the 28th week of gestation and evaluated to what extent those whose concentration of each protein was elevated (defined as in the highest quartile for gestational age and day the specimen was obtained) also had an elevated concentration of every other protein the same day or on a day 1 or 2 weeks later (p<.0001).

RESULTS

On each of the 3 days assessed, elevated concentrations of 17 proteins were associated with elevated concentrations of 15 or more of the other 24 proteins. VEGF, VEGF-R1, VEGF-R2 were among these proteins, while IGFBP-1 was associated with 13 other proteins on day 7. An elevated concentration of eight proteins on day 1 predicted an elevated concentration of 10 or more proteins on day 7, while an elevated concentration of only two proteins on day 7 were associated with elevated concentrations of 10 or more proteins on day-14. Few associations were seen between days 1 and 14. CONCLUSIONS/INFERENCES: Inflammation is a diffuse process in ELGANs, with elevated concentrations of cytokines, chemokines, adhesion molecules, matrix metalloproteinases, a growth factor and its receptors, as well as a growth factor binding protein associated with each other the same day, as well as on subsequent days.