Antiangiogenic Protein Research Articles

Comorbidities and Angiogenic Regulators Affect Endothelial Progenitor Cell Subtype Numbers in a Healthy Volunteer Control Group.

Endothelial progenitor cells (EPCs) are stem cells that can repair injured blood vessels through neovascularisation. This is achieved through secretion of growth factors and endothelial maturation. EPC numbers and function have been studied to determine their diagnostic, prognostic and therapeutic potential in many ischaemic diseases such as stroke. However their activation homing and migration is not definitively understood in stroke patients. In this study, we profiled the non-stroke control group recruited into the Dunhill Medical Trust Endothelial Progenitor Cell Study. Demographic, clinical and plasma levels of angiogenic regulators of participants were analysed to determine if there was any correlation with EPC numbers, subtypes and function. Participants with diabetes had significantly supressed EPC numbers (CD45-CD34 + CD133 + KDR+) and CD34 + KDR + and KDR + EPC subtypes. Male participants had significantly lower EPC numbers compared to female participants and the proliferative capacity of endothelial colony forming cells significantly decreased with increasing participant age. Pro-angiogenic proteins such as granulocyte colony-stimulating factor and stromal cell-derived factor were positively correlated with both undifferentiated and endothelial-committed EPC subtype numbers (CD133+, KDR+, CD34 + CD133+, CD34 + KDR+), whereas anti-angiogenic proteins such as thrombospondin-1 showed a negative correlation with undifferentiated EPC subtypes (CD133+, CD34 + CD133+) but a positive correlation with endothelial-committed EPC subtype numbers (KDR+, CD34 + KDR+). These results show that EPC numbers and subtypes are affected by many factors and larger studies which can analyse and deconvolute the interactions between comorbidities, plasma biomarker levels and EPC are needed.

Soluble Fms-like tyrosine kinase-1 as an endothelial dysfunction biomarker associated with pulmonary hypertension in adult patients with beta-thalassemia major.

The etiology of vascular problems in beta-thalassemia has been linked to endothelial damage. Antiangiogenic proteins such as soluble Fms-like tyrosine kinase-1 (sFLT-1) inhibit the signaling of vascular endothelial growth factor and placental growth factor, resulting in a decrease in the development of new blood vessels. Additionally, they promote the maturation of existing blood vessels and lead to endothelial dysfunction. This study aimed to assess the role of sFLT-1 in adult patients with beta-thalassemia major (TM) as a biomarker of endothelial dysfunction and its association with pulmonary hypertension (PHT). A total of 90 subjects were recruited and categorized into two groups: 45 patients with beta-TM, who were further divided based on the presence or absence of PHT, and 45 healthy individuals served as a control group. Serum sFLT-1 was determined using the enzyme-linked immunosorbent assay technique. The results revealed that Beta-TM patients had higher sFLT-1 levels than the control group. In addition, patients with PHT had significantly higher sFLT-1 levels compared to those without PHT. The levels of sFLT-1 were positively correlated with von Willebrand factor, serum ferritin, and high-sensitivity C-reactive protein. Regression analyses demonstrated a significant association between high sFLT-1 levels and the occurrence of PHT. Additionally, sFLT-1 (at a cutoff value of 8.84 pg/mL) demonstrated a sensitivity of 83.30% and a specificity of 80.0% in diagnosing thalassemic patients with PHT. In conclusion, beta-TM patients with elevated serum levels of sFLT-1 are at risk of developing endothelial dysfunction and subsequent development of PHT.

Risk assessment of preeclampsia

Introduction and purpose: Preeclampsia (PE) is a complication during pregnancy characterized by high blood pressure (≥140/90 mmHg) and signs of organ involvement appearing after 20 weeks’ of gestation. Various factors are known to increase the risk of this condition as well as clinical factors. The pathogenesis of the disease is complex and not fully understood. State of Knowledge: The main roles play two angiogenic factors: soluble fms-like tyrosine kinase 1 (sFlt-1), which is an antiangiogenic protein, and placental growth factor (PlGF), which is a pro-angiogenic protein. Elevated sFlt-1 and reduced PlGF levels in the mother’s blood can predict the future development of preeclampsia during pregnancy. The imbalance between these two angiogenic biomarkers indicates de new-onset preeclampsia, distinct from chronic hypertension. Both MAP and UTA-PI are essential components of first-trimester screening protocols, which, combined with maternal history and other biochemical markers, allow for accurate preeclampsia risk assessment and early intervention to improve maternal and fetal outcomes. Conclusions: Preeclampsia is a major cause of maternal and perinatal morbidity and mortality. The integration of multiple biomarkers, such as PlGF and sFlt-1, along with advanced analytical techniques, enhances early detection and accurate risk stratification, improving maternal and fetal outcomes. Aspirin prophylaxis before 16 weeks’ gestation has been shown to reduce the risk of preeclampsia.

Incidence of hand-foot syndrome with protein kinase inhibitors in advanced hepatocellular carcinoma patients who received atezolizumab-bevacizumab combination.

Treatment of advanced HepatoCellular Carcinoma (HCC) is based on first-line (L1) combination of atezolizumab and high-dose (HD) bevacizumab while second-line (L2) refers one antiangiogenic protein kinase inhibitors (aaPKI). This prolonged antiangiogenic pressure let us to observe an increasing occurrence of Hand-Foot Syndromes (HFS) in patients receiving aaPKI after HD bevacizumab combination. This study reports observations and discussions about the evidence and hypothesis that could be made. Patients who received the L1 combination from September 1st 2020 to December 31st 2022 to identify L2 aaPKI. Demographic, biological, oncological data and occurrence of HFS were collected. In addition were collected the number of L1 combination cycles, type of aaPKI, and delay between last L1 cycle and L2 initiation. This study had a purely exploratory purpose, so no statistical analysis was planned. 17 patients received an aaPKI after the L1 HD bevacizumab combination with a median time of 26 days from last L1 cycle to L2 start. Five patients experienced HFS including grade 3 (n = 2) with sorafenib and cabozantinib. The HFS occurred with a median delay of 23 days (IQR: 21-28) from aaPKI start. Three patients experienced aaPKI-related dose-limiting toxicity. Proportion of patients experienced HFS in our cohort did not differ from pivotal trials data and the sample size do not allow to conclude. Hypotheses include timing of aaPKI start in HCC treatment, vascular toxicity at aaPKI start after HD bevacizumab discontinuation instead combination, patient-related outcome for a better understanding of these aaPKI-related HFS post HD bevacizumab.

Short-term S100A8/A9 Blockade Promotes Cardiac Neovascularization after Myocardial Infarction.

Acute-phase inhibition of the pro-inflammatory alarmin S100A8/A9 improves cardiac function post-myocardial infarction (MI), but the mechanisms underlying the long-term benefits of this short-term treatment remain to be elucidated. Here, we assessed the effects of S100A8/A9 blockade with the small-molecule inhibitor ABR-238901 on myocardial neovascularization in mice with induced MI. The treatment significantly reduced S100A9 and increased neovascularization in the myocardium, assessed by CD31 staining. Proteomic analysis by mass-spectrometry showed strong myocardial upregulation of the pro-angiogenic proteins filamin A (~ 10-fold) and reticulon 4 (~ 5-fold), and downregulation of the anti-angiogenic proteins Ras homolog gene family member A (RhoA, ~ 4.7-fold), neutrophilic granule protein (Ngp, ~ 4.0-fold), and cathelicidin antimicrobial peptide (Camp, ~ 4.4-fold) versus controls. In-vitro, ABR-238901 protected against apoptosis induced by recombinant human S100A8/A9 in human umbilical vein endothelial cells (HUVECs). In conclusion, S100A8/A9 blockade promotes post-MI myocardial neovascularization by favorably modulating pro-angiogenic proteins in the myocardium and by inhibiting endothelial cell apoptosis.

BENEFICIAL EFFECTS OF ANGIOSTATIN K1-3 AND LACTOFERRIN IN ALKALI-BURNED RABBIT CORNEA: A COMPARATIVE STUDY

Corneal injury is associated with hypoxia-induced neovascularization, which interferes optical transparency of the cornea, resulting in vision loss and blindness. The treatment of corneal damage remains a ignificant unmet medical need. Lactoferrin (Lf) and angiostatins (AS) are naturally occurring antiinflammatory and antiangiogenic proteins, which play important roles in eye physiology and can be used as protectors against corneal diseases. The aim of the study was to evaluate and compare the effects of plasminogen fragment AS K1-3 and Lf (as a referent preparation) on the levels of the principal markers of angiogenesis, apoptosis, and autophagy in the burn-injured cornea. Additionally, effects of AS on the metabolic activity of macrophages have been studied. Materials and methods. Experimental model of corneal burn was induced by NaOH application to rabbit’s eye surface. One of the group of animals with injured cornea topically received AS, which were applied as eye drops (1 μM solution) daily for 14 days after injury, another one was treated by the equimolar solution of Lf. The levels of protein markers of angiogenesis (VEGF), apoptosis (caspase-3), and autophagy (beclin-1) were evaluated in corneal lysates by western blot. Histological analysis was performed by hematoxylin/eosin staining of corneal slices followed by light microscopy. Effects of AS in the range of concentrations 10-200 nM on the activity of phagocytic cells were assessed in murine macrophage cell line J744.2 by the test with nitroblue tetrazolium (NBT). The quantitative results were analysed with the use of Mann-Whitney U-test. The difference between group mean values was considered significant at P < 0.05. Results. Dramatically increased levels of protein markers related to angiogenesis, apoptosis, and utophagy were found in the corneas with burn-induced injury. AS or Lf-based treatment reduced burninduced overexpression of VEGF, caspase-3, and beclin-1. It is important to note that AS, along with anti-VEGF activity, appeared to more effectively suppress apoptosis and autophagy by decreasing tested markers near the control level, as compared with Lf. Histochemical examination revealed typical signs of fibrotic and necrotic changes in the injured corneas, which were associated with excessive inflammatory infiltration and intense neovascularization. Treatment of burn-induced injury with AS alleviated histopathological changes in cornea, which is evidenced by improving epithelial regeneration, reducing neovascularization, nd moderating leucocyte infiltration. These observations are in agreement with the ata of NBT test suggesting that AS in the concentrations >50 nM is able to moderately inhibit metabolic activity of macrophages up to 30% as compared with intact cells (P<0.05). Conclusions. Obtained results indicate that AS may serve as an effective treatment option to relief alkali-induced corneal injury with the efficacy comparable or even higher than that of firmly established eye protective protein Lf.

Intramyocardial injection of hypoxia-conditioned extracellular vesicles increases myocardial perfusion in a swine model of chronic coronary disease

ObjectiveCoronary artery disease remains a leading cause of morbidity and mortality worldwide. Patients with advanced coronary artery disease who are not eligible for endovascular or surgical revascularization have limited options. Extracellular vesicles have shown potential to improve myocardial function in preclinical models. Extracellular vesicles can be conditioned to modify their components. Hypoxia-conditioned extracellular vesicles have demonstrated the ability to reduce infarct size and apoptosis in small animals. Our objective is to assess the potential benefits of hypoxia-conditioned extracellular vesicles in a large animal model of coronary artery disease. MethodsCoronary artery disease was induced in 14 Yorkshire swine by ameroid constriction of the left circumflex coronary artery. Two weeks postsurgery, swine underwent a repeat left thoracotomy for injections of hypoxia-conditioned extracellular vesicles (n = 7) or saline (control, n = 7). Five weeks later, all animals underwent terminal harvest for perfusion measurements and myocardial sectioning. ResultsMyocardial perfusion analysis demonstrated a trend toward increase at rest and a significant increase during rapid pacing (P = .09, P < .001). There were significant increases in activated phosphorylated endothelial nitric oxide synthase, endothelial nitric oxide synthase, phosphatidylinositol 3-kinase, phosphorylated protein kinase B, and the phosphorylated protein kinase B/protein kinase B ratio in the hypoxia-conditioned extracellular vesicles group compared with the control group (all P < .05). Additionally, there was a significant decrease in the antiangiogenic proteins collagen 18 and angiostatin (P = .01, P = .01) in the hypoxia-conditioned extracellular vesicles group. ConclusionsIntramyocardial injection of hypoxia-conditioned extracellular vesicles results in increased myocardial perfusion without a corresponding change in vessel density. Therefore, this improvement in perfusion is possibly due to changes in nitric oxide signaling. Hypoxia-conditioned extracellular vesicles represent a potential therapeutic strategy to increase myocardial perfusion in patients with advanced coronary artery disease.

Immunometric and functional measurement of endogenous vasoinhibin in human sera.

Circulating levels of the antiangiogenic protein vasoinhibin, a fragment of prolactin, are of interest in vasoproliferative retinopathies, preeclampsia, and peripartum cardiomyopathy; however, it is difficult to determine the circulating levels of vasoinhibin due to the lack of quantitative assays. This study used human serum samples to assess the concentration and bioactivity of vasoinhibin using a novel enzyme-linked immunosorbent assay (ELISA) for human vasoinhibin, which employs an anti-vasoinhibin monoclonal antibody, a human umbilical vein endothelial cell (HUVEC) proliferation assay, and a chick chorioallantoic membrane (CAM) angiogenesis assay. Serum samples from 17 pregnant women without (one group) and with preeclampsia and pregnancy induced hypertension (another group) demonstrated endogenous vasoinhibin concentrations in the range of 5-340 ng/ml. Immunoactive vasoinhibin levels were significantly higher in preeclampsia serum compared to healthy pregnancy serum (mean 63.09 ± 22.15 SD vs. 19.67 ± 13.34 ng/ml, p = 0.0003), as was the bioactive vasoinhibin level as determined by the HUVEC proliferation assay (56.12 ± 19.83 vs. 13.38 ± 4.88 ng/ml, p < 0.0001). There was a correlation between the concentration of vasoinhibin measured by ELISA and the HUVEC proliferation assay (Pearson r = 0.95, p < 0.0001). Healthy serum demonstrated a proangiogenic effect in the CAM assay (p < 0.05, compared to control), while serum from preeclamptic patients demonstrated an antiangiogenic effect (p < 0.05 vs. control), as did recombinant human vasoinhibin and a synthetic circular retro-inverse vasoinhibin analogue (CRIVi45-51). The antiangiogenic effects in the CAM assay and the inhibition of HUVEC proliferation were abolished by addition of the ELISA anti-vasoinhibin monoclonal antibody, but not by mouse IgG. These results demonstrate the first quantitation of endogenous vasoinhibin in human sera and the elevation of it levels and antiangiogenic activity in sera from women with preeclampsia. The development and implementation of a quantitative assay for vasoinhibin overcomes a long-standing barrier and suggests the thorough clinical verification of vasoinhibin as a relevant biomarker.

Overexpression of Human sFLT1 in the Spongiotrophoblast Is Sufficient to Induce Placental Dysfunction and Fetal Growth Restriction in Transgenic Mice.

Preeclampsia (PE) is characterized by maternal hypertension and placental dysfunction, often leading to fetal growth restriction (FGR). It is associated with an overexpression of the anti-angiogenic sFLT1 protein, which originates from the placenta and serves as a clinical biomarker to predict PE. To analyze the impact of sFLT1 on placental function and fetal growth, we generated transgenic mice with placenta-specific human sFLT1 (hsFLT1) overexpression. Immunohistochemical, morphometrical, and molecular analyses of the placentas on 14.5 dpc and 18.5 dpc were performed with a focus on angiogenesis, nutrient transport, and inflammation. Additionally, fetal development upon placental hsFLT1 overexpression was investigated. Dams exhibited a mild increase in serum hsFLT1 levels upon placental hsFLT1 expression and revealed growth restriction of the fetuses in a sex-specific manner. Male FGR fetuses expressed higher amounts of placental hsFLT1 mRNA compared to females. FGR placentas displayed an altered morphology, hallmarked by an increase in the spongiotrophoblast layer and changes in labyrinthine vascularization. Further, FGR placentas showed a significant reduction in placental glycogen storage and nutrient transporter expression. Moreover, signs of hypoxia and inflammation were observed in FGR placentas. The transgenic spongiotrophoblast-specific hsFLT1 mouse line demonstrates that low hsFLT1 serum levels are sufficient to induce significant alterations in fetal and placental development in a sex-specific manner.

Translation of mechanistic advances in preeclampsia to the clinic: Long and winding road.

As one of the leading causes of premature birth and maternal and infant mortality worldwide, preeclampsia remains a major unmet public health challenge. Preeclampsia and related hypertensive disorders of pregnancy are estimated to cause >75 000 maternal and 500 000 infant deaths globally each year. Because of rising rates of risk factors such as obesity, invitro fertilization and advanced maternal age, the incidence of preeclampsia is going up with rates ranging from 5% to 10% of all pregnancies worldwide. A major discovery in the field was the realization that the clinical phenotypes related to preeclampsia, such as hypertension, proteinuria, and other adverse maternal/fetal events, are due to excess circulating soluble fms-like tyrosine kinase-1 (sFlt-1, also referred to as sVEGFR-1). sFlt-1 is an endogenous anti-angiogenic protein that is made by the placenta and acts by neutralizing the pro-angiogenic proteins vascular endothelial growth factor (VEGF) and placental growth factor (PlGF). During the last decade, this work has spawned a new era of molecular diagnostics for early detection of this condition. Antagonizing sFlt-1 either by reducing production or blocking its actions has shown salutary effects in animal models. Further, in early-stage human studies, the therapeutic removal of sFlt-1 from maternal circulation has shown promise in delaying disease progression and improving outcomes. Recently, the FDA approved the first molecular test for preterm preeclampsia (sFlt-1/PlGF ratio) for clinical use in the United States. Measuring serum sFlt-1/PlGF ratio in the acute hospital setting may aid short-term management, particularly regarding step-up or step-down of care, decision to transfer to settings better equipped to manage both the mother and the preterm neonate, appropriate timing of administration of steroids and magnesium sulfate, and in expectant management decisions. The test itself has the potential to save lives. Furthermore, the availability of a molecular test that correlates with adverse outcomes has set the stage for interventional clinical trials testing treatments for this disorder. In this review, we will discuss the role of circulating sFlt-1 and related factors in the pathogenesis of preeclampsia and specifically how this discovery is leading to concrete advances in the care of women with preeclampsia.

Genetically Engineered Mesenchymal Stem Cells Using Viral Vectors: A New Frontier in Anti-Angiogenic Therapy

Mesenchymal stem cells (MSCs) are adult stem cells that possess the remarkable ability to self-renew and differentiate into various cell lineages. Due to their regenerative potential, MSCs have emerged as the most commonly used stem cell type in clinical applications. Angiogenesis, the formation of new blood vessels, plays a critical role in several pathological conditions, including ocular neovascular diseases, cancer, and inflammatory disorders. Conventional anti-angiogenic therapies face limitations such as frequent visits for repeated doses, off-target effects and resistance development. Recent advances in genetic engineering techniques have opened up novel avenues in regenerative medicine. Genetically engineering MSCs using viral vectors presents a promising strategy to specifically target angiogenesis and enhance anti-angiogenic therapies' efficacy. Viral vectors, including lentiviruses, adeno-associated viruses and adenoviruses, provide an effective means of delivering therapeutic genes into MSCs, allowing the expression of a wide range of therapeutic agents, including anti-angiogenic proteins. This review explores the frontier of using genetically engineered MSCs delivered through viral vectors as a potent anti-angiogenic therapeutic approach. By leveraging the unique properties of MSCs and the targeted delivery capabilities of viral vectors, this approach initiates the potential to revolutionize anti-angiogenic therapy, offering new possibilities for the treatment of angiogenesis-related diseases.

Cardiac and Nephrological Complications Related to the Use of Antiangiogenic and Anti-Programmed Cell Death Protein 1 Receptor/Programmed Cell Death Protein 1 Ligand Therapy.

The ability to undergo neoangiogenesis is a common feature with all cancers. Signaling related to vascular endothelial growth factors (VEGF) and their receptors (VEGFR) plays a key role in the process of tumor neoangiogenesis. A close relationship has been demonstrated between excessive VEGF levels and the induction of immunosuppression in the tumor microenvironment. The use of drugs blocking the VEGF function, apart from the anticancer effect, also result in adverse effects, in particular related to the circulatory system and kidneys. Cardiac toxicity associated with the use of such therapy manifests itself mainly in the form of hypertension, thromboembolic episodes and ischemic heart disease. In the case of renal complications, the most common symptoms include renal arterial hypertension, proteinuria and microangiopathy. Although these complications are reversible in 60-80% of cases after cessation of VSP (VEGF pathway inhibitor) therapy, in some cases they can lead to irreversible changes in renal function, whereas cardiac complications may be fatal. Also, the use of PD-1/PD-L1 inhibitors may result in kidney and heart damage. In the case of cardiac complications, the most common symptoms include myocarditis, pericarditis, arrhythmia, acute coronary syndrome and vasculitis, while kidney damage most often manifests as acute kidney injury (AKI), nephrotic syndrome, pyuria or hematuria. The decision whether to resume treatment after the occurrence of cardiovascular and renal complications remains a problem.

EVALUATING THE PRE-CLINICAL EFFICACY OF VT1021 (A CLINICAL STAGE DRUG CANDIDATE) IN MULTIPLE EXPERIMENTAL MODELS OF INFLAMMATORY BOWEL DISEASE

Abstract Inflammatory bowel disease (IBD) is characterized symptomatically by chronic inflammation in the colonic tract. Despite the increased understanding of the physiological symptoms of Crohn’s Disease, and IBD in general, there have been no significant breakthroughs in understanding its etiology or improving treatment. As such, there is an urgent need for efficacious therapies that are aimed specifically at preventing or curing IBD. Bolstering the need for better therapies is the fact that patients with IBD have increased risk of developing intestinal cancers. One of the pathological traits of IBD that heightens the risk of cancer is the increased level of angiogenesis that accompanies the inflammation. As the biological processes of angiogenesis and inflammation are intricately linked, we believe increasing the levels of thrombospondin-1 (TSP-1), an anti-angiogenic and anti-inflammatory protein, can reprogram immune and inflammatory cells to inhibit angiogenesis and induce the resolution of inflammation. Vigeo has developed VT1021 which stimulates the expression of TSP-1 in inflammatory myeloid derived suppressor cells (MDSCs) systemically. VT1021 achieved proof of concept in a Phase 1/2 clinical trial with multiple cohorts and is currently in Phase 2/3 trials for oncology indications. IBD patients have increased MDSCs in both lesions and peripheral blood. MDSCs are genomically stable and not mutated in IBD patients and thus represent ideal therapeutic targets. Two dextran sulfate sodium (DSS)-induced colitis models were used to evaluate the pre-clinical efficacy of VT1021. In the preventative model, mice were treated with 4% DSS from Day 0 to Day 6 and either saline or VT1021 from Day 0 to Day 8, then sacrificed on Day 8 to collect colon tissue and plasma samples. In the rescue model, mice were treated with 4% DSS from Day 0 to Day 4, then treated with either saline, VT1021 (25, 50, 100 mg/kg) or anti-TNFa from Day 5 to Day 10. Mice were sacrificed on Day 11; colon tissue and plasma samples were collected. In both models, VT1021 treatment significantly prevented the mouse weight loss and bloody stool compared to the saline treatment. VT1021 treatment also decreased the colon inflammation by the measurement of both plasma myeloperoxidase (MPO) level and colon tissue histopathology score. Immunohistochemistry staining of colon tissue samples confirmed that VT1021 treatment stimulated TSP-1 expression in the MDSCs. Altogether, these findings show that VT1021 treatment has equivalent efficacy to anti-TNFa treatment, while significantly reducing damage to colon tissue. We believe VT1021 will show significantly greater efficacy in patients with longer term use, while avoiding the systemic deleterious side effects common to current approved therapies.

1024 Pigment epithelium derived-factor (PEDF), a potent anti-angiogenic protein, is elevated in fetal growth restriction

1024 Pigment epithelium derived-factor (PEDF), a potent anti-angiogenic protein, is elevated in fetal growth restriction

Mass Spectrometric and Immunologic Detection of Prolactin-Derived Vasoinhibin in Human Serum.

Circulating levels of the antiangiogenic protein, vasoinhibin, derived from the proteolytic cleavage of prolactin (PRL), in prolactinoma are unknown, as is the molecular nature of its isoforms. Dimerization of recombinant vasoinhibin has been reported. Vasoinhibin in a human serum sample was identified by using preparative electrophoresis with subsequent SDS-PAGE and Western blot analysis, as well as mass spectrometry (MS) and ELISA. MS identified a partial vasoinhibin sequence in a 14-kDa protein band from human serum, which eluted in the 28-kDa fraction from the preparative electrophoresis. Measurement of vasoinhibin levels by ELISA identified a concentration of 284 ng/mL at a PRL level of 9,850 ng/mL. Recombinant human vasoinhibin demonstrated dimerization and multimerization when analyzed directly by SDS-PAGE and Western blot analysis under reducing and non-reducing conditions, as well as after immunoprecipitation. The vasoinhibin sequence was identified in a higher molecular weight fraction, corroborating experi-mental evidence showing the dimerization and aggregation of recombinant human vasoinhibin. This report is sig-nificant, regarding the higher risk of cardiovascular disease and mortality in male patients with hyperprolactin-emia as well as emerging reports of linking PRL and vasoinhibin levels in patients with prolactinoma with left ventricular dysfunction and Takotsubo syndrome.

PEDF-Enriched Extracellular Vesicle for Vessel Normalization to Potentiate Immune Checkpoint Blockade Therapy

The abnormal tumor vasculature acts as the physical and functional barrier to the infiltration and activity of effector T cells, leading to the low response rate of immune checkpoint inhibitors (ICIs). Herein, antiangiogenic extracellular vesicles that enable normalization of the tumor-associated vasculature were prepared to potentiate the efficacy of ICIs. Small extracellular vesicles were exploited as the delivery platform to protect the antiangiogenic protein, pigment epithelium-derived factor (PEDF), from proteolytic degradation. Along with the physicochemical characteristics of the PEDF-enriched extracellular vesicles (P-EVs), their inhibitory effects on migration, proliferation, and tube formation of endothelial cells were investigated in vitro. In tumor-bearing mice, it was confirmed that, compared to bare PEDFs, P-EVs efficiently reduced vessel leakiness, improved blood perfusion, and attenuated hypoxia. Consequently, when combined with anti-PD-1 antibodies, P-EVs remarkably augmented the antitumor immunity, as evidenced by increased infiltration of CD8 + T cells and reduced regulatory T cells. These results suggest that P-EVs are promising therapeutics for tumors refractory to ICIs.

1025 Pigment epithelium derived-factor (PEDF), a potent anti-angiogenic protein, is upregulated in women with preeclampsia

1025 Pigment epithelium derived-factor (PEDF), a potent anti-angiogenic protein, is upregulated in women with preeclampsia

Homeostatic Regulation of Pro-Angiogenic and Anti-Angiogenic Proteins via Hedgehog, Notch Grid, and Ephrin Signaling in Tibial Dyschondroplasia.

Precise coupling of two fundamental mechanisms, chondrogenesis and osteogenesis via angiogenesis, plays a crucial role during rapid proliferation of growth plates, and alteration in their balance might lead to pathogenic conditions. Tibial dyschondroplasia (TD) is characterized by an avascular, non-mineralized, jade-white "cartilaginous wedge" with impaired endochondral ossification and chondrocyte proliferation at the proximal end of a tibial bone in rapidly growing poultry birds. Developing vascular structures are dynamic with cartilage growth and are regulated through homeostatic balance among pro and anti-angiogenic proteins and cytokines. Pro-angiogenic factors involves a wide spectrum of multifactorial mitogens, such as vascular endothelial growth factors (VEGF), platelet-derived growth factors (PDGF), basic fibroblast growth factor (bFGF), placental growth factors, transforming growth factor-β (TGF-β), and TNF-α. Considering their regulatory role via the sonic hedgehog, notch-gridlock, and ephrin-B2/EphB4 pathways and inhibition through anti-angiogenic proteins like angiostatin, endostatin, decoy receptors, vasoinhibin, thrombospondin, PEX, and troponin, their possible role in persisting inflammatory conditions like TD was studied in the current literature review. Balanced apoptosis and angiogenesis are vital for physiological bone growth. Any homeostatic imbalance among apoptotic, angiogenetic, pro-angiogenic, or anti-angiogenic proteins ultimately leads to pathological bone conditions like TD and osteoarthritis. The current review might substantiate solid grounds for developing innovative therapeutics for diseases governed by the disproportion of angiogenesis and anti-angiogenesis proteins.

The Current Role of the sFlt-1/PlGF Ratio and the Uterine-Umbilical-Cerebral Doppler Ultrasound in Predicting and Monitoring Hypertensive Disorders of Pregnancy: An Update with a Review of the Literature.

Regarding the hypertensive disorders of pregnancy, pre-eclampsia (PE) remains one of the leading causes of severe and life-threatening maternal and fetal complications. Screening of early-onset PE (<34 weeks of pregnancy), as well as late-onset PE (≥34 weeks), shows poor performance if based solely on clinical features. In recent years, biochemical markers from maternal blood-the pro-angiogenic protein placental growth factor (PlGF) and the antiangiogenic protein soluble FMS-like tyrosine kinase 1 (sFlt-1)-and Doppler velocimetry indices-primarily the mean uterine pulsatility index (PI), but also the uterine resistivity index (RI), the uterine systolic/diastolic ratio (S/D), uterine and umbilical peak systolic velocity (PSV), end-diastolic velocity (EDV), and uterine notching-have all shown improved screening performance. In this review, we summarize the current status of knowledge regarding the role of biochemical markers and Doppler velocimetry indices in early prediction of the onset and severity of PE and other placenta-related disorders, as well as their role in monitoring established PE and facilitating improved obstetrical surveillance of patients categorized as high-risk in order to prevent adverse outcomes. A sFlt-1/PlGF ratio ≤ 33 ruled out early-onset PE with 95% sensitivity and 94% specificity, whereas a sFlt-1/PlGF ≥88 predicted early-onset PE with 88.0% sensitivity and 99.5% specificity. Concerning the condition's late-onset form, sFlt-1/PlGF ≤ 33 displayed 89.6% sensitivity and 73.1% specificity in ruling out the condition, whereas sFlt-1/PlGF ≥ 110 predicted the condition with 58.2% sensitivity and 95.5% specificity. The cut-off values of the sFlt-1/PlGF ratio for the screening of PE were established in the PROGNOSIS study: a sFlt-1/PlGF ratio equal to or lower than 38 ruled out the onset of PE within one week, regardless of the pregnancy's gestational age. The negative predictive value in this study was 99.3%. In addition, sFlt-1/PlGF > 38 showed 66.2% sensitivity and 83.1% specificity in predicting the occurrence of PE within 4 weeks. Furthermore, 2018 ISUOG Practice Guidelines stated that a second-trimester mean uterine artery PI ≥ 1.44 increases the risk of later PE development. The implementation of a standard screening procedure based on the sFlt-1/PlGF ratio and uterine Doppler velocimetry may improve early detection of pre-eclampsia and other placenta-related disorders.

Nerve trunk healing and neuroma formation after nerve transection injury.

The nerve trunk healing process of a transected peripheral nerve trunk is composed of angiogenesis, nerve fiber regeneration, and scarring. Nerve trunk healing and neuroma formation probably share identical molecular mediators and similar regulations. At the nerve transection site, angiogenesis is sufficient and necessary for nerve fiber regeneration. Angiogenesis and nerve fiber regeneration reveal a positive correlation in the early time. Scarring and nerve fiber regeneration show a negative correlation in the late phase. We hypothesize that anti-angiogenesis suppresses neuromas. Subsequently, we provide potential protocols to test our hypothesis. Finally, we recommend employing anti-angiogenic small-molecule protein kinase inhibitors to investigate nerve transection injuries.