Endothelial cells and the IGF system

An endothelial cell is not simply an endothelial cell

Endothelial cells (ECs) are a multifaceted component of the vascular system with roles in immunity, maintaining tissue-fluid balance, and vascular tone. Dysregulation or dysfunction of ECs can have far-reaching implications, leading pathologies ranging from cardiovascular diseases, like hypertension and atherosclerosis, ischemia, chronic kidney disease, blood-brain barrier integrity, dementia, and tumor metastasis. Recent advancements in regenerative medicine have highlighted the potential of stem cell-derived ECs, particularly from induced-pluripotent stem cells (iPSCs), to treat ischemic tissues, as well as models of vascular integrity. This review will summarize what is known in the generation of ECs with an emphasis on tissue-specific ECs and EC subphenotypes important in development of targeted cell-based therapies for patient treatment.

The Association Between Oxidative Stress and Sperm Parameters in Patients with Acromegaly

OBJECTIVE

Spermatozoa are susceptible to oxidative radicals when antioxidant defenses are inadequate. The extent to which oxidative radicals contribute to sperm damage in patients with acromegaly remains unclear. This study aimed to investigate and elucidate this relationship.

METHODS

The overall status of oxidants and antioxidants in both seminal plasma and serum of patients with acromegaly compared to a control group of healthy individuals was investigated. In addition, sperm parameters, including important measures such as growth hormone and insulin-like growth factor-1 concentrations.

RESULTS

Twenty-two patients with acromegaly with controlled disease and 14 healthy controls were included. The total oxidant status was significantly higher in the semen samples of the patients with acromegaly. A negative correlation was found between sperm total oxidant status and total sperm count and sperm concentration. Similarly, a negative correlation was found between the total sperm count and the sperm oxidative stress index. In individuals diagnosed with acromegaly, there was a statistically significant increase in sperm growth hormone levels. Conversely, the level of insulin-like growth factor 1 was significantly increased in the sperm of the control group, which consisted of healthy individuals. The correlation analysis revealed a significant relationship between venous total oxidant status and growth hormone levels in semen.

CONCLUSION

The elevated levels of reactive oxygen radicals in individuals with acromegaly suggest a possible link between oxidative stress and its effects on semen quality.

Havoc in harmony: Unravelling the intricacies of angiogenesis orchestrated by the tumor microenvironment

Cancer cells merely exist in isolation; rather, they exist in an intricate microenvironment composed of blood vessels, signalling molecules, immune cells, stroma, fibroblasts, and the ECM. The TME provides a setting that is favourable for the successful growth and survivance of tumors. Angiogenesis is a multifaceted process that is essential for the growth, invasion, and metastasis of tumors. TME can be visualized as a "concert hall," where various cellular and non-cellular factors perform in a "symphony" to orchestrate tumor angiogenesis and create "Havoc" instead of "Harmony". In this review, we comprehensively summarized the involvement of TME in regulating tumor angiogenesis. Especially, we have focused on immune cells and their secreted factors, inflammatory cytokines and chemokines, and their role in altering the TME. We have also deciphered the crosstalk among various cell types that further aids the process of tumor angiogenesis. Additionally, we have highlighted the limitations of existing anti-angiogenic therapy and discussed various potential strategies that could be used to overcome these challenges and improve the efficacy of anti-angiogenic therapy.

Soluble vascular endothelial glycocalyx proteoglycans as potential therapeutic targets in inflammatory diseases

Reducing the activity of cytokines and leukocyte extravasation is an emerging therapeutic strategy to limit tissue-damaging inflammatory responses and restore immune homeostasis in inflammatory diseases. Proteoglycans embedded in the vascular endothelial glycocalyx, which regulate the activity of cytokines to restrict the inflammatory response in physiological conditions, are proteolytically cleaved in inflammatory diseases. Here we critically review the potential of proteolytically shed, soluble vascular endothelial glycocalyx proteoglycans to modulate pathological inflammatory responses. Soluble forms of the proteoglycans syndecan-1, syndecan-3 and biglycan exert beneficial anti-inflammatory effects by the removal of chemokines, suppression of proinflammatory cytokine expression and leukocyte migration, and induction of autophagy of proinflammatory M1 macrophages. By contrast, soluble versikine and decorin enhance proinflammatory responses by increasing inflammatory cytokine synthesis and leukocyte migration. Endogenous syndecan-2 and mimecan exert proinflammatory effects, syndecan-4 and perlecan mediate beneficial anti-inflammatory effects and glypican regulates Hh and Wnt signaling pathways involved in systemic inflammatory responses. Taken together, targeting the vascular endothelial glycocalyx-derived, soluble syndecan-1, syndecan-2, syndecan-3, syndecan-4, biglycan, versikine, mimecan, perlecan, glypican and decorin might be a potential therapeutic strategy to suppress overstimulated cytokine and leukocyte responses in inflammatory diseases.

Combination of Atractylenolide I, Atractylenolide III, and Paeoniflorin promotes angiogenesis and improves neurological recovery in a mouse model of ischemic Stroke

BACKGROUND

Prognosis is critically important in stroke cases, with angiogenesis playing a key role in determining outcomes. This study aimed to investigate the potential protective effects of Atractylenolide I (Atr I), Atractylenolide III (Atr III), and Paeoniflorin (Pae) in promoting angiogenesis following cerebral ischemia.

METHODS

The bEnd.3 cell line was used to evaluate the effects of these three compounds on vascular endothelial cell proliferation, migration, and tube formation. Male C57BL/6 mice underwent transient middle cerebral artery occlusion (MCAO), followed by daily intragastric administration of the Chinese medicine compounds to assess their impact on brain protection and angiogenesis. In vivo experiments included measuring infarct size and assessing neurological function. Immunofluorescence staining and an angiogenesis antibody array were used to evaluate angiogenesis in ischemic brain tissue. Functional enrichment analysis was performed to further investigate the pathways involved in the protective effects of the compounds. Molecular docking analysis explored the potential binding affinity of the compounds to insulin-like growth factor 2 (IGF-2), and Western blotting was used to measure levels of angiogenesis-related proteins.

RESULTS

In vitro, the combination of Atr I, Atr III, and Pae enhanced cell proliferation, promoted migration, and stimulated tube formation. In vivo, the combined treatment significantly facilitated neurological function recovery and angiogenesis by day 14. The treatment also increased levels of angiogenesis-related proteins, including IGF-2. Pearson correlation analysis revealed a strong positive association between IGF-2 levels in ischemic brain tissue and angiogenesis, suggesting a good affinity of the compounds for the IGF-2 binding site, as supported by molecular docking analysis.

CONCLUSION

The administration of Atr I, Atr III, and Pae has shown significant enhancements in long-term stroke recovery in mice, likely due to the promotion of angiogenesis via increased activation of the IGF-2 pathway in ischemic brain tissue.

Single cell RNA sequencing reveals endothelial cell killing and resolution pathways in experimental malaria-associated acute respiratory distress syndrome

Plasmodium parasites cause malaria, a global health disease that is responsible for more than 200 million clinical cases and 600 000 deaths each year. Most deaths are caused by various complications, including malaria-associated acute respiratory distress syndrome (MA-ARDS). Despite the very rapid and efficient killing of parasites with antimalarial drugs, 15% of patients with complicated malaria succumb. This stresses the importance of investigating resolution mechanisms that are involved in the recovery from these complications once the parasite is killed. To study the resolution of MA-ARDS, P. berghei NK65-infected C57BL/6 mice were treated with antimalarial drugs after onset of symptoms, resulting in 80% survival. Micro-computed tomography revealed alterations of the lungs upon infection, with an increase in total and non-aerated lung volume due to edema. Whole body plethysmography confirmed a drastically altered lung ventilation, which was restored during resolution. Single-cell RNA sequencing indicated an increased inflammatory state in the lungs upon infection, which was accompanied by a drastic decrease in endothelial cells, consistent with CD8+ T cell-mediated killing. During resolution, anti-inflammatory pathways were upregulated and proliferation of endothelial cells was observed. MultiNicheNet interactome analysis identified important changes in the ligand-receptor interactions during disease resolution that warrant further exploration in order to develop new therapeutic strategies. In conclusion, our study provides insights in pro-resolving pathways that limit inflammation and promote endothelial cell proliferation in experimental MA-ARDS. This information may be useful for the design of adjunctive treatments to enhance resolution after Plasmodium parasite killing by antimalarial drugs.

Angiogenic signaling pathways and anti-angiogenic therapy for cancer

Angiogenesis, the formation of new blood vessels, is a complex and dynamic process regulated by various pro- and anti-angiogenic molecules, which plays a crucial role in tumor growth, invasion, and metastasis. With the advances in molecular and cellular biology, various biomolecules such as growth factors, chemokines, and adhesion factors involved in tumor angiogenesis has gradually been elucidated. Targeted therapeutic research based on these molecules has driven anti-angiogenic treatment to become a promising strategy in anti-tumor therapy. The most widely used anti-angiogenic agents include monoclonal antibodies and tyrosine kinase inhibitors (TKIs) targeting vascular endothelial growth factor (VEGF) pathway. However, the clinical benefit of this modality has still been limited due to several defects such as adverse events, acquired drug resistance, tumor recurrence, and lack of validated biomarkers, which impel further research on mechanisms of tumor angiogenesis, the development of multiple drugs and the combination therapy to figure out how to improve the therapeutic efficacy. Here, we broadly summarize various signaling pathways in tumor angiogenesis and discuss the development and current challenges of anti-angiogenic therapy. We also propose several new promising approaches to improve anti-angiogenic efficacy and provide a perspective for the development and research of anti-angiogenic therapy.

Isorhynchophylline inhibits inflammatory responses in endothelial cells and macrophages through the NF-κB/NLRP3 signaling pathway

BACKGROUND

Atherosclerosis is a chronic inflammatory disease of arterial wall, which is closely related to inflammatory reaction. In this study, the anti-inflammatory effect of isorhynchophylline was studied by NF- κB / NLRP3 pathway.

METHODS

(1) ApoE^-/- mice were fed with high-fat diet to establish atherosclerotic model, while C57 with the same genetic background was fed with common diet as control group. Body weight was recorded and blood lipids were detected. The expression of NLRP3, NF-κB, IL-18 and Caspase-1 in aorta was detected by Western-Blot and PCR, and plaque formation was detected by HE and oil red O staining. (2) Lipopolysaccharide interfered with Human Umbilical Vein Endothelial Cells (HUVECs) and RAW264.7 to form inflammatory model, and was treated with isorhynchophylline. The expression of NLRP3, NF-κB, IL-18 and Caspase-1 in aorta was detected by Western-Blot and PCR, and the ability of cell migration was detected by Transwell and scratch test.

RESULTS

(1) the expression of NLRP3, NF- κB, IL-18 and Caspase-1 in aorta of model group was higher than that of control group, and plaque formation was obvious. (2) the expressions of NLRP3, NF- κB, IL-18 and Caspase-1 in HUVECs and RAW264.7 model groups were higher than those in control group, while isorhynchophylline decreased their expression and enhanced cell migration ability.

CONCLUSION

Isorhynchophylline can reduce the inflammatory reaction induced by lipopolysaccharide and promote the ability of cell migration.

Therapeutic Approach of Whole-Body Vibration Exercise on Wound Healing in Animal Models: A Systematic Review

Human skin wounds pose a gathering threat to the public health, carrying an immense epidemiologic and financial burden. Pharmacological and non-pharmacological (NP) treatments have been proposed to the management of wound healing. Physical exercise is a strong NP intervention considered for patients in wound healing. Particularly, a type of exercise intervention known as whole-body vibration (WBV) exercise has gained increasing interest. WBV exercise is generated due to the transmission of mechanical vibrations, produced by a vibrating platform, to the body. The aim of this review was to summarize studies in experimental animal models using WBV exercise in wound healing. Searches were performed in EMBASE, PubMed, Scopus and Web of Science including publications on 21 November 2022 using the string "whole body vibration" AND "wound healing" (animal or mice or mouse or rat or rodent). The SYRCLE tool was used to assess the risk of bias (RoB). From 48 studies, five studies met the inclusion criteria. RoB indicated that none of the studies fulfilled all methodological analyzed criteria, resulting in possible biases. The studies were homogeneous, and results suggest beneficial effects of WBV exercise in wound healing, mainly related to enhancing angiogenesis, granulation tissue formation, reducing the blood glucose level and enhancing blood microcirculation, by increasing myofiber growth and rapid re-epithelialization. In conclusion, the various biological effects of the response to the WBV exercise indicate the relevance of this intervention in wound healing in animals. Moreover, considering the translation approach, it is possible to speculate that the beneficial effects of this non-pharmacological therapy might justify clinical trials for wound healing also in humans, after criterion evaluation.

miR-216b-5p regulates proliferation and apoptosis of ox-LDL-stimulated VSMCs and HUVECs via IGF2

Atherosclerosis (AS) is one of the principal causes of cardiovascular disorder. Reportedly, vascular smooth muscle cells (VSMCs) and human umbilical vein endothelial cells (HUVECs) play key roles in AS development, and microRNAs (miRNAs) regulate their functions. The function of miR-216b-5p in AS remains unknown. Human VSMCs and human HUVECs were treated with ox-LDL to establish the in vitro model of AS. MiR-216b-5p and IGF2 expressions in VSMCs and HUVECs were probed by qRT-PCR and western blot. The viability, cell cycle progression, and apoptosis of VSMCs and HUVECs were evaluated by Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine, and flow cytometry assays, respectively. The binding sites between IGF2 3'UTR and miR-216b-5p were validated by dual-luciferase reporter assay. miR-216b-5p expression was declined in ox-LDL-induced VSMCs and HUVECs. In VSMCs, miR-216b-5p overexpression inhibited excessive proliferation and induced apoptosis. MiR-216b-5p could markedly restrain the viabiblity of VSMCs induced by ox-LDL and enhanced the viability of HUVECs. Additionally, IGF2 was confirmed as the direct target of miR-216b-5p and transfection of IGF2 overexpression plasmids rescued the effects of miR-216b-5p on VSMCs and HUVECs. miR-216b-5p alleviates the dysfunction of VSMCs and HUVECs caused by ox-LDL via repressing IGF2, and exerts protective functions to block the development of AS.

Insulin-like growth factor 1 reduces coronary atherosclerosis in pigs with familial hypercholesterolemia

Although murine models of coronary atherosclerotic disease have been used extensively to determine mechanisms, limited new therapeutic options have emerged. Pigs with familial hypercholesterolemia (FH pigs) develop complex coronary atheromas that are almost identical to human lesions. We reported previously that insulin-like growth factor 1 (IGF-1) reduced aortic atherosclerosis and promoted features of stable plaque in a murine model. We administered human recombinant IGF-1 or saline (control) in atherosclerotic FH pigs for 6 months. IGF-1 decreased relative coronary atheroma in vivo (intravascular ultrasound) and reduced lesion cross-sectional area (postmortem histology). IGF-1 increased plaque's fibrous cap thickness, and reduced necrotic core, macrophage content, and cell apoptosis, consistent with promotion of a stable plaque phenotype. IGF-1 reduced circulating triglycerides, markers of systemic oxidative stress, and CXCL12 chemokine levels. We used spatial transcriptomics (ST) to identify global transcriptome changes in advanced plaque compartments and to obtain mechanistic insights into IGF-1 effects. ST analysis showed that IGF-1 suppressed FOS/FOSB factors and gene expression of MMP9 and CXCL14 in plaque macrophages, suggesting possible involvement of these molecules in IGF-1's effect on atherosclerosis. Thus, IGF-1 reduced coronary plaque burden and promoted features of stable plaque in a pig model, providing support for consideration of clinical trials.

Systemic Cytokines in Retinopathy of Prematurity

Retinopathy of prematurity (ROP), a vasoproliferative vitreoretinal disorder, is the leading cause of childhood blindness worldwide. Although angiogenic pathways have been the main focus, cytokine-mediated inflammation is also involved in ROP etiology. Herein, we illustrate the characteristics and actions of all cytokines involved in ROP pathogenesis. The two-phase (vaso-obliteration followed by vasoproliferation) theory outlines the evaluation of cytokines in a time-dependent manner. Levels of cytokines may even differ between the blood and the vitreous. Data from animal models of oxygen-induced retinopathy are also valuable. Although conventional cryotherapy and laser photocoagulation are well established and anti-vascular endothelial growth factor agents are available, less destructive novel therapeutics that can precisely target the signaling pathways are required. Linking the cytokines involved in ROP to other maternal and neonatal diseases and conditions provides insights into the management of ROP. Suppressing disordered retinal angiogenesis via the modulation of hypoxia-inducible factor, supplementation of insulin-like growth factor (IGF)-1/IGF-binding protein 3 complex, erythropoietin, and its derivatives, polyunsaturated fatty acids, and inhibition of secretogranin III have attracted the attention of researchers. Recently, gut microbiota modulation, non-coding RNAs, and gene therapies have shown promise in regulating ROP. These emerging therapeutics can be used to treat preterm infants with ROP.

Maternal plasma proteome profiling of biomarkers and pathogenic mechanisms of early-onset and late-onset preeclampsia

Preeclampsia is still the leading cause of morbidity and mortality in pregnancy without a cure. There are two phenotypes of preeclampsia, early-onset (EOPE) and late-onset (LOPE) with poorly defined pathogenic differences. This study aimed to facilitate better understanding of the mechanisms of pathophysiology of EOPE and LOPE, and identify specific biomarkers or therapeutic targets. In this study, we conducted an untargeted, label-free quantitative proteomic analyses of plasma samples from pregnant women with EOPE (n = 17) and LOPE (n = 11), and age, BMI-matched normotensive controls (n = 18). Targeted proteomics approach was also employed to validate a subset of proteins (n = 17). In total, there were 26 and 20 differentially abundant proteins between EOPE or LOPE, and normotensive controls, respectively. A series of angiogenic and inflammatory proteins, including insulin-like growth factor-binding protein 4 (IGFBP4; EOPE: FDR = 0.0030 and LOPE: FDR = 0.00396) and inter-alpha-trypsin inhibitor heavy chain H2-4 (ITIH2-4), were significantly altered in abundance in both phenotypes. Through validation we confirmed that ITIH2 was perturbed only in LOPE (p = 0.005) whereas ITIH3 and ITIH4 were perturbed in both phenotypes (p < 0.05). Overall, lipid metabolism/transport proteins associated with atherosclerosis were highly abundant in LOPE, however, ECM proteins had a more pronounced role in EOPE. The complement cascade and binding and uptake of ligands by scavenger receptors, pathways, were associated with both EOPE and LOPE.

Close-to-native bone repair via tissue-engineered endochondral ossification approaches

In order to solve the clinical challenges related to bone grafting, several tissue engineering (TE) strategies have been proposed to repair critical-sized defects. Generally, the classical TE approaches are designed to promote bone repair via intramembranous ossification. Although promising, strategies that direct the osteogenic differentiation of mesenchymal stem/stromal cells are usually characterized by a lack of functional vascular supply, often resulting in necrotic cores. A less explored alternative is engineering bone constructs through a cartilage-mediated approach, resembling the embryological process of endochondral ossification. The remodeling of an intermediary hypertrophic cartilaginous template triggers vascular invasion and bone tissue deposition. Thus, employing this knowledge can be a promising direction for the next generation of bone TE constructs. This review highlights the most recent biomimetic strategies for applying endochondral ossification in bone TE while discussing the plethora of cell types, culture conditions, and biomaterials essential to promote a successful bone regeneration process.

miR-31-5p-Modified RAW 264.7 Macrophages Affect Profibrotic Phenotype of Lymphatic Endothelial Cells In Vitro

Cardiac lymphatic vessel (LyV) remodeling as a contributor to heart failure has not been extensively evaluated in metabolic syndrome (MetS). Our studies have shown structural changes in cardiac LyV in MetS that contribute to the development of edema and lead to myocardial fibrosis. Tissue macrophages may affect LyV via secretion of various substances, including noncoding RNAs. The aim of the study was to evaluate the influence of macrophages modified by miR-31-5p, a molecule that regulates fibrosis and lymphangiogenesis, on lymphatic endothelial cells (LECs) in vitro. The experiments were carried out on the RAW 264.7 macrophage cell line and primary dermal lymphatic endothelial cells. RAW 264.7 macrophages were transfected with miR-31-5p and supernatant from this culture was used for LEC stimulation. mRNA expression levels for genes associated with lymphangiogenesis and fibrosis were measured with qRT-PCR. Selected results were confirmed with ELISA or Western blotting. miR-31-5p-modified RAW 264.7 macrophages secreted increased amounts of VEGF-C and TGF-β and a decreased amount of IGF-1. The supernatant from miR-31-5p-modified RAW 264.7 downregulated the mRNA expression for genes regulating endothelial-to-mesenchymal transition (EndoMT) and fibrosis in LECs. Our results suggest that macrophages under the influence of miR-31-5p show the potential to inhibit LEC-dependent fibrosis. However, more studies are needed to confirm this effect in vivo.

Systemic Biomarkers and Unique Pathways in Different Phenotypes of Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) accounts for around 50% of all heart failure cases. It is a heterogeneous condition with poorly understood pathogenesis. Here, we aimed to identify unique pathogenic mechanisms in acute and chronic HFpEF and hypertrophic cardiomyopathy (HCM). We performed unbiased, comprehensive proteomic analyses of plasma samples from gender- and BMI-matched patients with acute HFpEF (n = 8), chronic HFpEF (n = 9) and HCM (n = 14) using liquid chromatography–mass spectrometry. Distinct molecular signatures were observed in different HFpEF forms. Clusters of biomarkers differentially abundant between HFpEF forms were predominantly associated with microvascular inflammation. New candidate protein markers were also identified, including leucine-rich alpha-2-glycoprotein 1 (LRG1), serum amyloid A1 (SAA1) and inter-alpha-trypsin inhibitor heavy chain 3 (ITIH3). Our study is the first to apply systematic, quantitative proteomic screening of plasma samples from patients with different subtypes of HFpEF and identify candidate biomarkers for improved management of acute and chronic HFpEF and HCM.

Non-pharmacological interventions for vascular health and the role of the endothelium

The most common non-pharmacological intervention for both peripheral and cerebral vascular health is regular physical activity (e.g., exercise training), which improves function across a range of exercise intensities and modalities. Numerous non-exercising approaches have also been suggested to improved vascular function, including repeated ischemic preconditioning (IPC); heat therapy such as hot water bathing and sauna; and pneumatic compression. Chronic adaptive responses have been observed across a number of these approaches, yet the precise mechanisms that underlie these effects in humans are not fully understood. Acute increases in blood flow and circulating signalling factors that induce responses in endothelial function are likely to be key moderators driving these adaptations. While the impact on circulating factors and environmental mechanisms for adaptation may vary between approaches, in essence, they all centre around acutely elevating blood flow throughout the circulation and stimulating improved endothelium-dependent vascular function and ultimately vascular health. Here, we review our current understanding of the mechanisms driving endothelial adaptation to repeated exposure to elevated blood flow, and the interplay between this response and changes in circulating factors. In addition, we will consider the limitations in our current knowledge base and how these may be best addressed through the selection of more physiologically relevant experimental models and research. Ultimately, improving our understanding of the unique impact that non-pharmacological interventions have on the vasculature will allow us to develop superior strategies to tackle declining vascular function across the lifespan, prevent avoidable vascular-related disease, and alleviate dependency on drug-based interventions.

Research progress in endothelial cell injury and repair

Endothelial cells, which are important metabolic and endocrine cells, play an important role in regulating vascular function. The occurrence and development of various cardiovascular and cerebrovascular diseases are associated with endothelial dysfunction. However, the underlying mechanism of vascular endothelial injury is not fully understood. It has been reported that the mechanism of endothelial injury mainly involves inflammation and oxidative stress. Moreover, endothelial progenitor cells are regarded as important contributors in repairing damaged endothelium. Multiple interventions (including chemical drugs and traditional Chinese medicines) exert endothelial protection by decreasing the release of inducing factors, suppressing inflammation and oxidative stress, and preventing endothelial cell senescence.

Pilot dose-ranging of rhIGF-1/rhIGFBP-3 in a preterm lamb model of evolving bronchopulmonary dysplasia

BACKGROUND

Low levels of insulin-like growth factor-1 (IGF-1) protein in preterm human infants are associated with bronchopulmonary dysplasia (BPD). We used our preterm lamb model of BPD to determine (1) dosage of recombinant human (rh) IGF-1 bound to binding protein-3 (IGFBP-3) to reach infant physiologic plasma levels; and (2) whether repletion of plasma IGF-1 improves pulmonary and cardiovascular outcomes.

METHODS

Group 1: normal, unventilated lambs from 128 days gestation through postnatal age 5 months defined normal plasma levels of IGF-1. Group 2: continuous infusion of rhIGF-1/rhIGFBP-3 (0.5, 1.5, or 4.5 mg/kg/day; n = 2) for 3 days in mechanically ventilated (MV) preterm lambs determined that 1.5 mg/kg/day dosage attained physiologic plasma IGF-1 concentration of ~125 ng/mL, which was infused in four more MV preterm lambs.

RESULTS

Group 1: plasma IGF-1 protein increased from ~75 ng/mL at 128 days gestation to ~220 ng/L at 5 months. Group 2: pilot study of the optimal dosage (1.5 mg/kg/day rhIGF-1/rhIGFBP-3) in six MV preterm lambs significantly improved some pulmonary and cardiovascular outcomes (p < 0.1) compared to six MV preterm controls. RhIGF-1/rhIGFBP-3 was not toxic to the liver, kidneys, or lungs.

CONCLUSIONS

Three days of continuous iv infusion of rhIGF-1/rhIGFBP-3 at 1.5 mg/kg/day improved some pulmonary and cardiovascular outcomes without toxicity.

IMPACT

Preterm birth is associated with rapid decreases in serum or plasma IGF-1 protein level. This decline adversely impacts the growth and development of the lung and cardiovascular system. For this pilot study, continuous infusion of optimal dosage of rhIGF-1/rhIGFBP-3 (1.5 mg/kg/day) to maintain physiologic plasma IGF-1 level of ~125 ng/mL during mechanical ventilation for 3 days statistically improved some structural and biochemical outcomes related to the alveolar formation that would favor improved gas exchange compared to vehicle-control. We conclude that 3 days of continuous iv infusion of rhIGF-1/rhIGFBP-3 improved some physiological, morphological, and biochemical outcomes, without toxicity, in mechanically ventilated preterm lambs.

Hypoxia‐induced ELF3 promotes tumor angiogenesis through IGF1/IGF1R

Epithelial ovarian cancer (EOC) is one of the most lethal gynecological cancers despite a relatively low incidence. Angiogenesis, one of the hallmarks of cancer, is essential for the pathogenesis of EOC, which is related to the induction of angiogenic factors. We found that ELF3 was highly expressed in EOCs under hypoxia and functioned as a transcription factor for IGF1. The ELF3‐mediated increase in the secretion of IGF1 and VEGF promoted endothelial cell proliferation, migration, and EOC angiogenesis. Although this situation was much exaggerated under hypoxia, ELF3 silencing under hypoxia significantly attenuated angiogenic activity in endothelial cells by reducing the expression and secretion of IGF1 and VEGF. ELF3 silencing attenuated angiogenesis and tumorigenesis in ex vivo and xenograft mouse models. Consequently, ELF3 plays an important role in the induction of angiogenesis and tumorigenesis in EOC as a transcription factor of IGF1. A detailed understanding of the biological mechanism of ELF3 may both improve current antiangiogenic therapies and have anticancer effects for EOC.

UC-MSCs promote frozen-thawed ovaries angiogenesis via activation of the Wnt/β-catenin pathway in vitro ovarian culture system

Background

Ovarian tissue cryopreservation and transplantation are novel therapeutic approaches for fertility preservation. However, follicle loss caused by ischemic and hypoxic damage is one of the issues after frozen-thawed ovarian tissue transplantation. Promoting angiogenesis in grafts is the key to restore cryopreserved ovarian function. Mesenchymal stem cells (MSCs) have been reported to facilitate angiogenesis in the cryopreserved ovarian tissue transplantation. However, the risk of embolization, immunogenic effect and tumorigenesis hinders the clinical application of MSCs to human organ transplantation. In this study, we established an in vitro ovarian culture system to restore frozen-thawed ovarian function before transplantation with the application of umbilical cord mesenchymal stem cells (UC-MSCs), and explored the effects of UC-MSCs on frozen-thawed ovaries in vitro ovarian culture system and the mechanisms of UC-MSCs on the angiogenesis of frozen-thawed ovaries.

Methods

A simple in vitro three dimensional (3D) ovarian culture system using Matrigel was established to support to an ideal niche, and ovary was alone cultured in the 24-well plate as a control. We also evaluated the effects of UC-MSCs treatment on ovarian function with or without Matrigel support. All thawed ovaries were randomly divided into control group (Matrigel−/UC-MSCs−), Matrigel group (Matrigel+/UC-MSCs−), UC-MSCs group (Matrigel−/UC-MSCs+) and UC-MSCs + Matrigel group (Matrigel+/UC-MSCs+). HE staining was used to detect the histological structure of follicles and TUNEL staining was used to detect cell apoptosis. The number of microvessels was counted to evaluate neovascularization. The mRNA expression of VEGFA, IGF1 and ANGPT2 were detected by RT-PCR. Western blotting was used to measure the expression of GSK-3β, β-catenin and p-β-catenin.

Results

In the absence of UC-MSCs, 3D culture system supported by Matrigel showed significantly improved follicular development and microvascular number. Additionally, UC-MSCs were also found to effectively improve follicular development and microvascular number regardless of the culture condition used. However, alleviated follicular apoptosis, increased mRNA expression of angiogenesis-related gene and activated Wnt/β-catenin pathway occurred only in the UC-MSCs + Matrigel group. Besides, with the application of IWP-2 in UC-MSCs + Matrigel group, Wnt//β-catenin pathway could be blocked by IWP-2 serving as one of Wnt/β-catenin pathway inhibitors.

Conclusions

This in vitro study showed the beneficial effects of UC-MSCs on thawed ovaries and explored a potential mechanism inducing angiogenesis. In particular, 3D ovarian culture system supported by Matrigel further improved UC-MSCs treatment. The in vitro culture system using Matrigel and UC-MSCs may provide a potential treatment strategy for improving the success rate of thawed ovaries transplantation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02989-8.

Role of platelet-derived growth factor c on endothelial dysfunction in cardiovascular diseases

Loss of endothelial function is a common feature to all cardiovascular diseases (CVDs). One of the risk factors associated with the development of CVDs is the hyperglycaemia that occurs in patients with metabolic disorders such as Type 1 and Type 2 diabetes mellitus. Hyperglycaemia causes endothelial dysfunction through increased production of reactive oxygen species (ROS) from different cellular sources leading to oxidative stress. Vascular endothelial growth factor (VEGF) is essential in the stimulation and maintenance of endothelial functional aspects and, although it can mitigate the impact of ROS, VEGF-mediated signalling is partially inhibited in diabetes mellitus. The search for therapeutic strategies that preserve, protect and improve the functions of the endothelium is of great relevance in the investigation of CVDs associated with hyperglycaemia. Platelet-derived growth factor C (PDGF-C) is a peptide with angiogenic properties, independent of VEGF, that stimulates angiogenesis and revascularization of ischemic tissue. In a diabetic mouse model, PDGF-C stimulates mature endothelial cell migration, angiogenesis, endothelial progenitor cell mobilization, and increased neovascularization, and protects blood vessels in a retinal degeneration model activating anti-apoptosis and proliferation signalling pathways in endothelial cells. This review summarizes the information on the damage that high d-glucose causes on endothelial function and the beneficial effects that PDGF-CC could exert in this condition.

microRNA-301a-3p is a potential biomarker in venous ulcers vein and gets involved in endothelial cell dysfunction

Venous ulcer is a common contributor to chronic venous insufficiency (CVI) of lower limbs, which seriously affects the life quality of patients. In this study, we researched the expression characteristics of microRNA-301a-3p (miR-301a-3p) in patients with CVI and investigated the impact of miR-301a-3p on the dysfunction of human umbilical vein endothelial cells (HUVECs). The plasma level of miR-301a-3p in normal controls, patients with varicose great saphenous vein, and patients with the venous ulcer of lower limbs were measured. We adopted Interleukin-1β (IL-1β), H2O2, and oxygen and glucose deprivation (OGD) to induce endothelial cell injury in vitro. In this way, we evaluated the influence of miR-301a-3p on HUVEC viability, apoptosis, inflammatory response, and oxidative stress. Our data showed that miR-301a-3p was substantially overexpressed in patients with lower limb venous ulcers. The viability of HUVECs decreased, and miR-301a-3p was up-regulated after IL-1β, H2O2, and OGD treatment. miR-301a-3p inhibition greatly ameliorated the dysfunction and cell damage of HUVECs, promoted IGF1/PI3K/Akt/PPARγ, and down-regulated NF-κB/MMPs. The phosphatidylinositol 3-kinase (PI3K) inhibitor (LY294002) or the peroxisome proliferator-activated receptor-γ (PPARγ) inhibitor (GW9661) reversed the anti-inflammatory, antioxidant, and anti-apoptotic effects mediated by miR-301a-3p down-regulation. The nuclear factor-κB (NF-κB) inhibitor lessened cell injury mediated by miR-301a-3p overexpression. In terms of the mechanism, miR-301a-3p targeted the 3'UTR of Insulin-like growth factor-1 (IGF1) and repressed the profile of IGF1. Thus, miR-301a-3p mediates venous endothelial cell damage by targeting IGF1 and regulating the IGF1/PI3K/Akt/PPARγ/NF-κB/MMPs pathway.

ALX1-transcribed LncRNA AC132217.4 promotes osteogenesis and bone healing via IGF-AKT signaling in mesenchymal stem cells

The osteogenic potential of bone marrow mesenchymal stem cells (BMSCs) is critical for bone formation and regeneration. A high non-/delayed-union rate of fracture healing still occurs in specific populations, implying an urgent need to discover novel targets for promoting osteogenesis and bone regeneration. Long non-coding (lnc)RNAs are emerging regulators of multiple physiological processes, including osteogenesis. Based on differential expression analysis of RNA sequencing data, we found that lncRNA AC132217.4, a 3'UTR-overlapping lncRNA of insulin growth factor 2 (IGF2), was highly induced during osteogenic differentiation of BMSCs. Afterward, both gain-of-function and loss-of-function experiments proved that AC132217.4 promotes osteoblast development from BMSCs. As for its molecular mechanism, we found that AC132217.4 binds with IGF2 mRNA to regulate its expression and downstream AKT activation to control osteoblast maturation and function. Furthermore, we identified two splicing factors, splicing component 35 KDa (SC35) and heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1), which regulate the biogenesis of AC132217.4 at the post-transcriptional level. We also identified a transcription factor, ALX1, which regulates AC132217.7 expression at the transcriptional level to promote osteogenesis. Importantly, in-vivo over-expression of AC132217.4 essentially promotes the bone healing process in a murine tibial drill-hole model. Our study demonstrates that lncRNA AC132217.4 is a novel anabolic regulator of BMSC osteogenesis and could be a plausible therapeutic target for improving bone regeneration.

AT2R activation increases in vitro angiogenesis in pregnant human uterine artery endothelial cells

Angiogenesis is vital during pregnancy for remodeling and enhancing vasodilation of maternal uterine arteries, and increasing uterine blood flow. Abnormal angiogenesis is associated with decreased uteroplacental blood flow and development of pregnancy disorders such as gestational hypertension, preeclampsia, fetal growth restriction, preterm delivery, stillbirth, and miscarriage. The mechanisms that contribute to normal angiogenesis remain obscure. Our previous studies demonstrated that expression of the angiotensin type 2 receptor (AT2R) is increased while the angiotensin type 1 receptor (AT1R) is unchanged in the endothelium of uterine arteries, and that AT2R-mediated pregnancy adaptation facilitates enhanced vasodilation and uterine arterial blood flow. However, the role of AT2R in regulating angiogenesis during pregnancy has never been studied. This study examines whether or not AT2R activation induces angiogenesis and, if so, what mechanisms are involved. To this end, we used primary human uterine artery endothelial cells (hUAECs) isolated from pregnant and nonpregnant women undergoing hysterectomy. The present study shows that Compound 21, a selective AT2R agonist, induced proliferation of pregnant-hUAECs, but not nonpregnant-hUAECs, in a concentration-dependent manner, and that this C21-induced mitogenic effect was blocked by PD123319, a selective AT2R antagonist. The mitogenic effects induced by C21 were inhibited by blocking JNK—but not ERK, PI3K, and p38—signaling pathways. In addition, C21 concentration dependently increased cell migration and capillary-like tube formation in pregnant-hUAECs. The membrane-based antibody array showed that C21 increased expression of multiple angiogenic proteins, including EGF, bFGF, leptin, PLGF, IGF-1, and angiopoietins. Our qPCR analysis demonstrates that C21-induced increase in expression of these angiogenic proteins correlates with a proportional increase in mRNA expression, indicating that AT2R activates angiogenic proteins at the transcriptional level. In summary, the present study shows that AT2R activation induces angiogenesis of hUAECs in a pregnancy-specific manner through JNK-mediated pathways with associated transcriptional upregulation of multiple proangiogenic proteins.

Impact of serum insulin-like growth factor-1 on HSCT outcome in pediatric cancer patients

BACKGROUND

Hematopoietic stem cell transplantation (HSCT) is associated with severe medical complications and variable outcome depending on the recipient's disease stage and health condition. Biomarkers predicting outcome may have therapeutic relevance in pediatric cancer care. Insulin like growth factor 1 (IGF 1) is a mitogenic and anabolic peptide hormone that is expressed in almost all tissues. This hormone is the major growth factor in childhood. As IGF 1 is decreased in conditions that cause catabolic metabolism, it may reflect the degree of physical robustness of the patient and serve as predictive biomarker for transplant outcome.

OBJECTIVES AND STUDY DESIGN

We evaluated the impact of pre-transplant serum-IGF 1 on both survival and adverse events in 587 pediatric cancer patients, who underwent autologous or allogeneic HSCT between 1987 and 2014 at the University Children's Hospital Tübingen, Germany. Survival probabilities of the entire cohort and of defined subgroups according to pre-transplant serum-IGF-1 were estimated using the Kaplan-Meier method.

RESULTS

Mean pre-transplant IGF 1 (n = 498) was low: -1.67 SDS (SD, 1.54). Completeness of follow-up three and ten years post HSCT was 96 % and 83 %, respectively. The ten-year overall survival was 44.8 % (95 % confidence interval [CI], 40.6-48.9). With decreasing IGF-1 SDS, there was a significant increase of transplant-related mortality (p = 0.027), sinusoidal obstruction syndrome (quartiles 4 to 1: 3; 1; 12; 12%; p < 0.001) and thrombotic microangiopathy (quartiles 4 to 1: 0: 0: 2; 5%; p = 0.004). IGF 1 decile 1 showed a significantly poorer outcome (p=0.042) with lower median (12 versus 68 months) and ten-year overall survival (37 % versus 52 %) when compared to decile 2-10.

CONCLUSIONS

This retrospective study suggests pre-transplant serum-IGF 1 as a predictor of survival and selected vascular adverse events that may have diagnostic and therapeutic relevance in pediatric cancer care.

Circular RNA circ_0001445 alleviates the ox-LDL-induced endothelial injury in human primary aortic endothelial cells through regulating ABCG1 via acting as a sponge of miR-208b-5p

BACKGROUND

Coronary artery disease (CAD) originates from the blockage of the inner walls of the coronary arteries due to a plaque buildup. Circular RNA (circRNA) circ_0001445 has been reported to be downregulated in patients with a higher coronary atherosclerotic burden. This study is designed to explore the role and mechanism of circ_0001445 on the oxidized low-density lipoprotein (ox-LDL)-induced endothelial cell damage.

METHODS

Circ_0001445, microRNA-208b-5p (miR-208b-5p), and ATP-binding cassette sub-family G member 1 (ABCG1) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Inflammatory cytokines levels, cell viability, proliferation, migration were detected by Enzyme-linked immunosorbent assay (ELISA) kits, Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), and transwell assays, respectively. Protein levels were determined by western blot assay. The binding between miR-208b-5p and circ_0001445 or ABCG1 was predicted by circBank or TargetScan, and then verified by a dual-luciferase reporter, RNA Immunoprecipitation (RIP), and RNA pull-down assays.

RESULTS

Circ_0001445 and ABCG1 were decreased, and miR-208b-5p was increased in CAD patients and ox-LDL-treated HAECs. Also, circ_0001445 overexpression could weaken ox-LDL-triggered HAEC injury by boosting proliferation, migration, and repressing inflammation and extracellular matrix (ECM). Mechanically, circ_0001445 directly targeted miR-208b-5p. Furthermore, miR-208b-5p mediated the modulation of circ_0001445 in ox-LDL-induced HAEC injury. ABCG1 acted as a direct target of miR-208b-5p, and the downregulation of miR-208b-5p relieved ox-LDL-induced HAEC damage by interacting with ABCG1. Additionally, circ_0001445 regulated ABCG1 expression by sponging miR-208b-5p.

CONCLUSION

Circ_0001445 could abate ox-LDL-mediated HAEC damage by the miR-208b-5p/ABCG1 axis, providing a novel insight into the pathogenesis and treatment of CAD.

Proteomics discovery of pulmonary hypertension biomarkers: Insulin-like growth factor binding proteins are associated with disease severity

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by sustained elevations of pulmonary artery pressure. To date, we lack circulating, diagnostic, and prognostic markers that correlate to clinical and functional parameters. In this study, we performed mass spectrometry-based proteomics analysis to identify circulating biomarkers of PAH. Plasma samples from patients with idiopathic pulmonary arterial hypertension (IPAH, N = 9) and matched normal controls (N = 9) were digested with trypsin and analyzed using data-dependent acquisition on an Orbitrap mass spectrometer. A total of 826 (false discovery rate [FDR] 0.047) and 461 (FDR 0.087) proteins were identified across all plasma samples obtained from IPAH and control subjects, respectively. Of these, 153 proteins showed >2 folds change (p < 0.05) between groups. Circulating levels of carbonic anhydrase 2 (CA2), plasma kallikrein (KLKB1), and the insulin-like growth factor binding proteins (IGFBP1-7) were quantified by immunoassay in an independent verification cohort (N = 36 PAH and N = 35 controls). CA2 and KLKB1 were significantly different in PAH versus control but were not associated with any functional or hemodynamic measurements. Whereas, IGFBP1 and 2 were associated with higher pulmonary vascular resistance, IGFBP2, 4, and 7 with decreased 6-min walk distance (6MWD), and IGFBP1, 2, 4, and 7 with worse survival. This plasma proteomic discovery analysis suggests the IGF axis may serve as important new biomarkers for PAH and play an important role in PAH pathogenesis.

Uterine Fibroids (Leiomyomata) and Heavy Menstrual Bleeding

Uterine Fibroids, or leiomyomata, affect millions of women world-wide, with a high incidence of 75% within women of reproductive age. In ~30% of patients, uterine fibroids cause menorrhagia, or heavy menstrual bleeding, and more than half of the patients experience symptoms such as heavy menstrual bleeding, pelvic pain, or infertility. Treatment is symptomatic with limited options including hysterectomy as the most radical solution. The genetic foundations of uterine fibroid growth have been traced to somatic driver mutations (MED12, HMGA2, FH^−/−, and COL4A5-A6). These also lead to downstream expression of angiogenic factors including IGF-1 and IGF-2, as opposed to the VEGF-driven mechanism found in the angiogenesis of hypoxic tumors. The resulting vasculature supplying the fibroid with nutrients and oxygen is highly irregular. Of particular interest is the formation of a pseudocapsule around intramural fibroids, a unique structure within tumor angiogenesis. These aberrations in vascular architecture and network could explain the heavy menstrual bleeding observed. However, other theories have been proposed such as venous trunks, or venous lakes caused by the blocking of normal blood flow by uterine fibroids, or the increased local action of vasoactive growth factors. Here, we review and discuss the evidence for the various hypotheses proposed.

Long Non-Coding RNA LINC02802 Regulates In Vitro Sprouting Angiogenesis by Sponging microRNA-486-5p

In the last several years, accumulating evidence indicates that noncoding RNAs, especially long-noncoding RNAs (lncRNAs) and microRNAs, play essential roles in regulating angiogenesis. However, the contribution of lncRNA-mediated competing-endogenous RNA (ceRNA) activity in the control of capillary sprouting from the pre-existing ones has not been described so far. Here, by exploiting the transcriptomic profile of VEGF-A-activated endothelial cells in a consolidate three-dimensional culture system, we identified a list of lncRNAs whose expression was modified during the sprouting process. By crossing the lncRNAs with a higher expression level and the highest fold change value between unstimulated and VEGF-A-stimulated endothelial cells, we identified the unknown LINC02802 as the best candidate to take part in sprouting regulation. LINC02802 was upregulated after VEGF-A stimulation and its knockdown resulted in a significant reduction in sprouting activity. Mechanistically, we demonstrated that LINC02802 acts as a ceRNA in the post-transcriptional regulation of Mastermind-like-3 (MAML3) gene expression through a competitive binding with miR-486-5p. Taken together, these results suggest that LINC02802 plays a critical role in preventing the miR-486-5p anti-angiogenic effect and that this inhibitory effect results from the reduction in MAML3 expression.

The imprinted Igf2-Igf2r axis is critical for matching placental microvasculature expansion to fetal growth

In all eutherian mammals, growth of the fetus is dependent upon a functional placenta, but whether and how the latter adapts to putative fetal signals is currently unknown. Here, we demonstrate, through fetal, endothelial, hematopoietic, and trophoblast-specific genetic manipulations in the mouse, that endothelial and fetus-derived IGF2 is required for the continuous expansion of the feto-placental microvasculature in late pregnancy. The angiocrine effects of IGF2 on placental microvasculature expansion are mediated, in part, through IGF2R and angiopoietin-Tie2/TEK signaling. Additionally, IGF2 exerts IGF2R-ERK1/2-dependent pro-proliferative and angiogenic effects on primary feto-placental endothelial cells ex vivo. Endothelial and fetus-derived IGF2 also plays an important role in trophoblast morphogenesis, acting through Gcm1 and Synb. Thus, our study reveals a direct role for the imprinted Igf2-Igf2r axis on matching placental development to fetal growth and establishes the principle that hormone-like signals from the fetus play important roles in controlling placental microvasculature and trophoblast morphogenesis.

Immunophenotyping and Transcriptional Profiling of Human Plasmablasts in Dengue

Plasmablasts represent a specialized class of antibody-secreting effector B cells that transiently appear in blood circulation following infection or vaccination. The expansion of these cells generally tends to be massive in patients with systemic infections such as dengue or Ebola that cause hemorrhagic fever. To gain a detailed understanding of human plasmablast responses beyond antibody expression, here, we performed immunophenotyping and RNA sequencing (RNA-seq) analysis of the plasmablasts from dengue febrile children in India. We found that plasmablasts expressed several adhesion molecules and chemokines or chemokine receptors that are involved in endothelial interactions or homing to inflamed tissues, including skin, mucosa, and intestine, and upregulated the expression of several cytokine genes that are involved in leukocyte extravasation and angiogenesis. These plasmablasts also upregulated the expression of receptors for several B-cell prosurvival cytokines that are known to be induced robustly in systemic viral infections such as dengue, some of which generally tend to be relatively higher in patients manifesting hemorrhage and/or shock than in patients with mild febrile infection. These findings improve our understanding of human plasmablast responses during the acute febrile phase of systemic dengue infection. IMPORTANCE Dengue is globally spreading, with over 100 million clinical cases annually, with symptoms ranging from mild self-limiting febrile illness to more severe and sometimes life-threatening dengue hemorrhagic fever or shock, especially among children. The pathophysiology of dengue is complex and remains poorly understood despite many advances indicating a key role for antibody-dependent enhancement of infection. While serum antibodies have been extensively studied, the characteristics of the early cellular factories responsible for antibody production, i.e., plasmablasts, are only beginning to emerge. This study provides a comprehensive understanding of the transcriptional profiles of human plasmablasts from dengue patients.

Investigation of miR-126-3p loaded on adipose stem cell-derived exosomes for wound healing of full-thickness skin defects

OBJECTIVE

To investigate the function of miR-126-3p loaded on adipose stem cell (ADSC)-derived exosomes (ADSC-Exos) in wound healing of full-thickness skin defects.

METHODS

ADSCs transfected with miR-126-3p mimic, miR-126-3p inhibitor or pcDNA3.1-PIK3R2, or PKH26-marked ADSC-Exos were cultured with fibroblasts or human umbilical vein endothelial cells (HUVECs). The proliferation and migration rates of fibroblasts and angiogenesis of HUVECs were measured. Rats with full-thickness skin defects were injected with ADSC-Exos or exosomes extracted from ADSCs transfected with miR-126-3p inhibitor and the wound healing rates were measured. The wound bed, collagen deposition and angiogenesis in injured rats were assessed.

RESULTS

ADSC-Exos could be ingested by fibroblasts and HUVECs. Co-incubation with ADSCs or ADSC-Exos promoted the proliferation and migration of fibroblasts and angiogenesis of HUVECs, which was further enhanced by miR-126-3p overexpression. Inhibition of ADSC-Exos or miR-126-3p or PIK3R2 overexpression suppressed the proliferation and migration of fibroblasts and angiogenesis of HUVECs. ADSC-derived exosomal miR-126-3p increased wound healing rate, collagen deposition and newly formed vessels in injured rats.

CONCLUSION

ADSC-derived exosomal miR-126-3p promotes wound healing of full-thickness skin defects by targeting PIK3R2.

Mechanisms underlying unidirectional laminar shear stress-mediated Nrf2 activation in endothelial cells: Amplification of low shear stress signaling by primary cilia

Endothelial cells are sensitive to mechanical stress and respond differently to oscillatory flow versus unidirectional flow. This review highlights the mechanisms by which a wide range of unidirectional laminar shear stress induces activation of the redox sensitive antioxidant transcription factor nuclear factor-E2-related factor 2 (Nrf2) in cultured endothelial cells. We propose that fibroblast growth factor-2 (FGF-2), brain-derived neurotrophic factor (BDNF) and 15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) are potential Nrf2 activators induced by laminar shear stress. Shear stress-dependent secretion of FGF-2 and its receptor-mediated signaling is tightly controlled, requiring neutrophil elastase released by shear stress, αvβ3 integrin and the cell surface glycocalyx. We speculate that primary cilia respond to low laminar shear stress (<10 dyn/cm2), resulting in secretion of insulin-like growth factor 1 (IGF-1), which facilitates αvβ3 integrin-dependent FGF-2 secretion. Shear stress induces generation of heparan-binding epidermal growth factor-like growth factor (HB-EGF), which contributes to FGF-2 secretion and gene expression. Furthermore, HB-EGF signaling modulates FGF-2-mediated NADPH oxidase 1 activation that favors casein kinase 2 (CK2)-mediated phosphorylation/activation of Nrf2 associated with caveolin 1 in caveolae. Higher shear stress (>15 dyn/cm2) induces vesicular exocytosis of BDNF from endothelial cells, and we propose that BDNF via the p75NTR receptor could induce CK2-mediated Nrf2 activation. Unidirectional laminar shear stress upregulates gene expression of FGF-2 and BDNF and generation of 15d-PGJ2, which cooperate in sustaining Nrf2 activation to protect endothelial cells against oxidative damage.

Cerebrovascular alterations in NAFLD: Is it increasing our risk of Alzheimer's disease?

Non-alcoholic fatty liver disease (NAFLD) is a multisystem disease, which has been classified as an emerging epidemic not only confined to liver-related morbidity and mortality. It is also becoming apparent that NAFLD is associated with moderate cerebral dysfunction and cognitive decline. A possible link between NAFLD and Alzheimer's disease (AD) has only recently been proposed due to the multiple shared genes and pathological mechanisms contributing to the development of these conditions. Although AD is a progressive neurodegenerative disease, the exact pathophysiological mechanism remains ambiguous and similarly to NAFLD, currently available pharmacological therapies have mostly failed in clinical trials. In addition to the usual suspects (inflammation, oxidative stress, blood-brain barrier alterations and ageing) that could contribute to the NAFLD-induced development and progression of AD, changes in the vasculature, cerebral perfusion and waste clearance could be the missing link between these two diseases. Here, we review the most recent literature linking NAFLD and AD, focusing on cerebrovascular alterations and the brain's clearance system as risk factors involved in the development and progression of AD, with the aim of promoting further research using neuroimaging techniques and new mechanism-based therapeutic interventions.

The evolution of acquired resistance to BRAF inhibitor is sustained by IGF1-driven tumor vascular remodeling

As hallmark of cancer, angiogenesis plays a pivotal role in carcinogenesis. The correlation between angiogenesis and evolution of BRAF inhibitor acquired resistance is, however, still poorly understood. Here, we reported that the molecular signatures of angiogenesis were enriched in early on-treated biopsies but not in disease progressed biopsies. The process of drug resistance development was accompanied by remodeling of vascular morphology, which was potentially manipulated by tumor-secreted pro-angiogenic factors. Further transcriptomic dissection indicated that tumor-secreted IGF1 drove the vascular remodeling through activating IGF1/IGF1R axis on endothelial cells, and sustained the prompt re-growth of resistant tumor. Blockade of IGF1R with small molecules at early stage of response disrupted vascular reconstruction, and subsequently delayed tumor relapse. Our findings not only demonstrated the correlation between IGF1-mediated tumor vascular remodeling and the development of acquired resistance to BRAFi but also provided a potential therapeutic strategy for the prevention of tumor relapse in clinical application.

Immunoendocrine Dysregulation during Gestational Diabetes Mellitus: The Central Role of the Placenta

Gestational Diabetes Mellitus (GDM) is a transitory metabolic condition caused by dysregulation triggered by intolerance to carbohydrates, dysfunction of beta-pancreatic and endothelial cells, and insulin resistance during pregnancy. However, this disease includes not only changes related to metabolic distress but also placental immunoendocrine adaptations, resulting in harmful effects to the mother and fetus. In this review, we focus on the placenta as an immuno-endocrine organ that can recognize and respond to the hyperglycemic environment. It synthesizes diverse chemicals that play a role in inflammation, innate defense, endocrine response, oxidative stress, and angiogenesis, all associated with different perinatal outcomes.

Macrophage Polarization in Response to Biomaterials for Vascularization

Vascularization of tissue engineering constructs is an urgent need for delivering oxygen and nutrients and promoting tissue remodeling. As we all know, almost all implanted biomaterials elicit immune responses. Interestingly, the immunomodulatory biomaterials can utilize the inherent regenerative capability of endogenous cells and stem cells recruited by the activated immune cells to facilitate anagenesis and tissue remodeling. Macrophages, as almost ones of the first responses upon the implantation of biomaterials, play a vital role in guiding vascular formation and tissue remodeling. The polarization of macrophages can be influenced by the physical and chemical properties of biomaterials and thus they display diverse function states. Here, this review focus on the macrophage polarization in response to biomaterials and the interactions between them. It also summarizes the current strategies to promote vascularization of tissue engineering constructs through macrophage responses.

Insulin-like growth factors: Ligands, binding proteins, and receptors

BACKGROUND

The insulin-like growth factor family of ligands (IGF-I, IGF-II, and insulin), receptors (IGF-IR, M6P/IGF-IIR, and insulin receptor [IR]), and IGF-binding proteins (IGFBP-1-6) play critical roles in normal human physiology and disease states.

SCOPE OF REVIEW

Insulin and insulin receptors are the focus of other chapters in this series and will therefore not be discussed further. Here we review the basic components of the IGF system, their role in normal physiology and in critical pathology's. While this review concentrates on the role of IGFs in human physiology, animal models have been essential in providing understanding of the IGF system, and its regulation, and are briefly described.

MAJOR CONCLUSIONS

IGF-I has effects via the circulation and locally within tissues to regulate cellular growth, differentiation, and survival, thereby controlling overall body growth. IGF-II levels are highest prenatally when it has important effects on growth. In adults, IGF-II plays important tissue-specific roles, including the maintenance of stem cell populations. Although the IGF-IR is closely related to the IR it has distinct physiological roles both on the cell surface and in the nucleus. The M6P/IGF-IIR, in contrast, is distinct and acts as a scavenger by mediating internalization and degradation of IGF-II. The IGFBPs bind IGF-I and IGF-II in the circulation to prolong their half-lives and modulate tissue access, thereby controlling IGF function. IGFBPs also have IGF ligand-independent cell effects.

Suppression of apoptosis in vascular endothelial cell, the promising way for natural medicines to treat atherosclerosis

Atherosclerosis, a chronic multifactorial disease, is closely related to the development of cardiovascular diseases and is one of the predominant causes of death worldwide. Normal vascular endothelial cells play an important role in maintaining vascular homeostasis and inhibiting atherosclerosis by regulating vascular tension, preventing thrombosis and regulating inflammation. Currently, accumulating evidence has revealed that endothelial cell apoptosis is the first step of atherosclerosis. Excess apoptosis of endothelial cells induced by risk factors for atherosclerosis is a preliminary event in atherosclerosis development and might be a target for preventing and treating atherosclerosis. Interestingly, accumulating evidence shows that natural medicines have great potential to treat atherosclerosis by inhibiting endothelial cell apoptosis. Therefore, this paper reviewed current studies on the inhibitory effect of natural medicines on endothelial cell apoptosis and summarized the risk factors that may induce endothelial cell apoptosis, including oxidized low-density lipoprotein (ox-LDL), reactive oxygen species (ROS), angiotensin II (Ang II), tumor necrosis factor-α (TNF-α), homocysteine (Hcy) and lipopolysaccharide (LPS). We expect this review to highlight the importance of natural medicines, including extracts and monomers, in the treatment of atherosclerosis by inhibiting endothelial cell apoptosis and provide a foundation for the development of potential antiatherosclerotic drugs from natural medicines.

Expression and functional role of IGFs during early pregnancy in placenta of water buffalo

Adequate vascularisation is a key factor for successful fetal development. We hypothesized that Insulin-Like Growth Factor (IGF) family members regulate angiogenesis along with promoting fetal development and growth. In this experiment, we determined the expression and functional role of IGF family in placental compartments (caruncle; CAR, cotyledon; COT) during different stages of early pregnancy in the water buffalo (Bubalus bubalis). Samples were collected from early pregnancy 1 (EP1, 28-45 days), early pregnancy 2 (EP2, 45-90 days), and third stage of estrous cycle (11-16 days), which was taken as control. In addition, the role of IGF1 on mRNA expression of vWF, StAR, CYP11A1, 3βHSD, PCNA, and BAX were elucidated in cultured trophoblast cells (TCC) obtained from EP2. Quantitative real-time PCR (q-PCR), westernblot, and immunohistochemistry were done to investigate the gene expression, protein expression, and localization of examined factors, and RIA was also done to assess progesterone (P₄) concentration. Expression of IGFs, its receptors and binding proteins were found to be significantly higher (p < 0.05) in both CAR and COT as compared to control during early pregnancy, except binding proteins IGFBP1, 3 and 4 which were significantly (p < 0.05) downregulated in COT with advancement of pregnancy. mRNA expression was consistent with the findings of immunoblotting and immunolocalization experiments. Trophoblasts cell culture (TCC) study showed a significant time and dose-dependent effect of IGF1 onsteroidogenic transcript, which was found to be maximum at 100 ng/ml that paralleled with P₄ accretion in the media (p < 0.05). Further, IGF1 upregulated the transcripts of vWF, PCNA, and downregulated BAX at the same concentration (p < 0.05). Overall, our results demonstrated that the expression of IGFs is a site-specific phenomenon in placentome, which indicates autocrine/paracrine and endocrine function. Our in-vitro finding support that IGF1 plays a critical role in placental development by promoting angiogenesis, steroid synthesis, and cell proliferation during early pregnancy.

Acromegaly, inflammation and cardiovascular disease: a review

Acromegaly is characterized by Growth Hormone (GH) and Insulin-like Growth Factor 1 (IGF-1) excess. Uncontrolled acromegaly is associated with a strongly increased risk of cardiovascular disease (CVD), and numerous cardiovascular risk factors remain present after remission. GH and IGF-1 have numerous effects on the immune and cardiovascular system. Since endothelial damage and systemic inflammation are strongly linked to the development of CVD, and have been suggested to be present in both controlled as uncontrolled acromegaly, they may explain the presence of both micro- and macrovascular dysfunction in these patients. In addition, these changes seem to be only partially reversible after remission, as illustrated by the often reported presence of endothelial dysfunction and microvascular damage in controlled acromegaly. Previous studies suggest that insulin resistance, oxidative stress, and endothelial dysfunction are involved in the development of CVD in acromegaly. Not surprisingly, these processes are associated with systemic inflammation and respond to GH/IGF-1 normalizing treatment.

Insulin and IGF-2 support rat corneal endothelial cell growth and wound repair in the organ cultured tissue

The ability of insulin and IGF-2 to support wound repair in the organ-cultured rat corneal endothelium was investigated. Corneas given a circular transcorneal freeze injury, were explanted into organ cultures containing either insulin or IGF-2 and cultured up to72 h. Both factors increased [³H]-thymidine incorporation and mitotic levels compared to controls. Insulin's ability to mediate wound closure without serum was dependent on its continuous presence in the medium. PKC was also investigated in endothelial repair using the PKC promoter phorbol 12-myristate 13-acetate (PMA). Concentrations between 10^-6 and 10^-8 M, PMA failed to accelerate wound closure. When injured endothelia were cultured in the presence of insulin and the PKC inhibitor H-7, wound closure was also unaffected. These results indicate that insulin and IGF-2 stimulate cell growth in injured rat corneal endothelium and that insulin without the benefit of serum promotes wound closure in situ independent of the PKC pathway.

Protective role of ErbB3 signaling in myeloid cells during adaptation to cardiac pressure overload

BACKGROUND

Myeloid cells play an important role in a wide variety of cardiovascular disorders, including both ischemic and non-ischemic cardiomyopathies. Neuregulin-1 (NRG-1)/ErbB signaling has recently emerged as an important factor contributing to the control of inflammatory activation of myeloid cells after an ischemic injury. However, the role of ErbB signaling in myeloid cells in non-ischemic cardiomyopathy is not fully understood. This study investigated the role of ErbB3 receptors in the regulation of early adaptive response using a mouse model of transverse aortic constriction (TAC) for non-ischemic cardiomyopathy.

METHODS AND RESULTS

TAC surgery was performed in groups of age- and sex-matched myeloid cell-specific ErbB3-deficient mice (ErbB3^MyeKO) and control animals (ErbB3^MyeWT). The number of cardiac CD45 immune cells, CD11b myeloid cells, Ly6G neutrophils, and Ly6C monocytes was determined using flow cytometric analysis. Five days after TAC, survival was dramatically reduced in male but not female ErbB3^MyeKO mice or control animals. The examination of lung weight to body weight ratio suggested that acute pulmonary edema was present in ErbB3^MyeKO male mice after TAC. To determine the cellular and molecular mechanisms involved in the increased mortality in ErbB3^MyeKO male mice, cardiac cell populations were examined at day 3 post-TAC using flow cytometry. Myeloid cells accumulated in control but not in ErbB3^MyeKO male mouse hearts. This was accompanied by increased proliferation of Sca-1 positive non-immune cells (endothelial cells and fibroblasts) in control but not ErbB3^MyeKO male mice. No significant differences in intramyocardial accumulation of myeloid cells or proliferation of Sca-1 cells were found between the groups of ErbB3^MyeKO and ErbB3^MyeWT female mice. An antibody-based protein array analysis revealed that IGF-1 expression was significantly downregulated only in ErbB3^MyeKO mice hearts compared to control animals after TAC.

CONCLUSION

Our data demonstrate the crucial role of myeloid cell-specific ErbB3 signaling in the cardiac accumulation of myeloid cells, which contributes to the activation of cardiac endothelial cells and fibroblasts and development of an early adaptive response to cardiac pressure overload in male mice.

IGFBP‑rP1‑silencing promotes hypoxia‑induced angiogenic potential of choroidal endothelial cells via the RAF/MEK/ERK signaling pathway

Insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1) has been reported to have various functions in different cellular contexts. Our previous investigation discovered that IGFBP-rP1 inhibited retinal angiogenesis in vitro and in vivo by inhibiting the pro-angiogenic effect of VEGF and downregulating VEGF expression. Recently, IGFBP-rP1 was confirmed to be downregulated in the aqueous humor of patients with neovascular age-related macular degeneration compared with controls; however, its specific role remains unknown. The present study applied the technique of gene silencing, reverse transcription-quantitative PCR, western blotting, cell viability assays, cell motility assays and tube formation assays. Chemical hypoxic conditions and choroidal endothelial (RF/6A) cells were used to explore the effect of IGFBP-rP1-silencing on the phenotype activation of RF/6A cells under hypoxic conditions and to elucidate the underlying mechanisms. siRNA achieved IGFBP-rP1-silencing in RF/6A cells without cytotoxicity. IGFBP-rP1-silencing significantly restored the viability of RF/6A cells in hypoxia and enhanced hypoxia-induced migration and capillary-like tube formation of RF/6A cells. Furthermore, IGFBP-rP1-silencing significantly upregulated the expression of B-RAF, phosphorylated (p)-MEK, p-ERK and VEGF in RF/6A cells under hypoxic conditions; however, these upregulations were inhibited by exogenous IGFBP-rP1. These data indicated that silencing IGFBP-rP1 expression in RF/6A cells effectively promoted the hypoxia-induced angiogenic potential of choroidal endothelial cells by upregulating RAF/MEK/ERK signaling pathway activation and VEGF expression.

Potential functions of embryonic cardiac macrophages in angiogenesis, lymphangiogenesis and extracellular matrix remodeling

The role of cardiac tissue macrophages (cTMs) during pre- and postnatal developmental stages remains in many aspects unknown. We aimed to characterize cTM populations and their potential functions based on surface markers. Our in situ studies of immunostained cardiac tissue specimens of murine fetuses (from E11to E17) revealed that a significant number of embryonic cTMs (phenotyped by CD45, CD68, CD64, F4/80, CD11b, CD206, Lyve-1) resided mostly in the subepicardial space, not in the entire myocardial wall, as observed in adult individuals. cTMs accompanied newly developed blood and lymphatic vessels adhering to vessel walls by cellular processes. A subpopulation of CD68-positive cells was found to form accumulations in areas of massive apoptosis during the outflow tract remodeling and shortening. Flow cytometry analysis at E14 and E17 stages revealed newly defined three subpopulations:CD64^low, CD64^highCD206-and CD64^highCD206+. The levels of mRNA expression for genes related to regulation of angiogenesis (VEGFa, VEGFb, VEGFc, bFGF), lymphangiogenesis (VEGFc) and extracellular matrix (ECM) remodeling (MMP13, Arg1, Ym1/Chil3, Retlna/FIZZ1) differed among the selected populations and/or embryonic stages. Our results demonstrate a diversity of embryonic cTMs and their tissue-specific locations, suggesting their various potential roles in regulating angiogenesis, lymphangiogenesis and ECM remodeling.

Bone Microvasculature: Stimulus for Tissue Function and Regeneration

Bone is a highly vascularized organ, providing structural support to the body, and its development, regeneration, and remodeling depend on the microvascular homeostasis. Loss or impairment of vascular function can develop diseases, such as large bone defects, avascular necrosis, osteoporosis, osteoarthritis, and osteopetrosis. In this review, we summarize how vasculature controls bone development and homeostasis in normal and disease cases. A better understanding of this process will facilitate the development of novel disease treatments that promote bone regeneration and remodeling. Specifically, approaches based on tissue engineering components, such as stem cells and growth factors, have demonstrated the capacity to induce bone microvasculature regeneration and mineralization. This knowledge will have relevant clinical implications for the treatment of bone disorders by developing novel pharmaceutical approaches and bone grafts. Finally, the tissue engineering approaches incorporating vascular components may widely be applied to treat other organ diseases by enhancing their regeneration capacity. Impact statement Bone vasculature is imperative in the process of bone development, regeneration, and remodeling. Alterations or disruption of the bone vasculature leads to loss of bone homeostasis and the development of bone diseases. In this study, we review the role of vasculature on bone diseases and how vascular tissue engineering strategies, with a detailed emphasis on the role of stem cells and growth factors, will contribute to bone therapeutics.

Novel peptide derived from IGF-2 displays anti-angiogenic activity in vitro and inhibits retinal angiogenesis in a model of oxygen-induced retinopathy

BACKGROUND

Retinopathy of prematurity (ROP), a major cause of significant visual morbidity and blindness in preterm infants, is closely related to pathological angiogenesis. The aim of the study is to evaluate the effect of a new 12-aa peptide (named peptide CW-703) from human insulin-like growth factor-2, against angiogenesis in ROP.

METHODS

In order to evaluate the inhibitory effect of CW-703 on the proliferation, migration, tube formation and apoptosis of human umbilical vein endothelial cells (ScienCell) in vitro, we used MTS assays, a modified Boyden chamber, Matrigel system and TUNEL assays. Effects in vivo were assayed using chorioallantoic membrane assays and oxygen-induced retinopathy (OIR) models in mice. We also performed eletrophysiological and histologic examinations to evaluate the possible toxicity of the peptide. Real-time PCR, ELISA and western blotting were used to elucidate the mechanism of CW-703.

RESULTS

CW-703 inhibited angiogenesis in vitro by suppressing endothelial cell proliferation, migration and tube formation. CW-703 also prevented angiogenesis in chicken chorioallantoic membrane assays and OIR assays in mice. No evident functional or morphologic abnormalities in neuroretina after CW-703 injection were revealed in electrophysiological tests and histological examinations. Moreover, we elucidated that CW-703 competed for binding to IGF-1R and inhibited angiogenesis by inhibiting IGF-1R/PI3K/AKT activation and downregulating vascular endothelial growth factor expression.

CONCLUSION

The novel peptide CW-703 may act as an effective inhibitor of ocular pathologic angiogenesis, especially in treating ROP.